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e5480701d3
kernel/fs/btrfs/inode.c
tqcq e5480701d3 init repo.
2024-07-22 17:22:30 +08:00

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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2007 Oracle. All rights reserved.
*/
#include <crypto/hash.h>
#include <linux/kernel.h>
#include <linux/bio.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/time.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/backing-dev.h>
#include <linux/writeback.h>
#include <linux/compat.h>
#include <linux/xattr.h>
#include <linux/posix_acl.h>
#include <linux/falloc.h>
#include <linux/slab.h>
#include <linux/ratelimit.h>
#include <linux/btrfs.h>
#include <linux/blkdev.h>
#include <linux/posix_acl_xattr.h>
#include <linux/uio.h>
#include <linux/magic.h>
#include <linux/iversion.h>
#include <linux/swap.h>
#include <linux/migrate.h>
#include <linux/sched/mm.h>
#include <linux/iomap.h>
#include <asm/unaligned.h>
#include <linux/fsverity.h>
#include "misc.h"
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "btrfs_inode.h"
#include "print-tree.h"
#include "ordered-data.h"
#include "xattr.h"
#include "tree-log.h"
#include "volumes.h"
#include "compression.h"
#include "locking.h"
#include "free-space-cache.h"
#include "props.h"
#include "qgroup.h"
#include "delalloc-space.h"
#include "block-group.h"
#include "space-info.h"
#include "zoned.h"
#include "subpage.h"
struct btrfs_iget_args {
u64 ino;
struct btrfs_root *root;
};
struct btrfs_dio_data {
ssize_t submitted;
struct extent_changeset *data_reserved;
};
static const struct inode_operations btrfs_dir_inode_operations;
static const struct inode_operations btrfs_symlink_inode_operations;
static const struct inode_operations btrfs_special_inode_operations;
static const struct inode_operations btrfs_file_inode_operations;
static const struct address_space_operations btrfs_aops;
static const struct file_operations btrfs_dir_file_operations;
static struct kmem_cache *btrfs_inode_cachep;
struct kmem_cache *btrfs_trans_handle_cachep;
struct kmem_cache *btrfs_path_cachep;
struct kmem_cache *btrfs_free_space_cachep;
struct kmem_cache *btrfs_free_space_bitmap_cachep;
static int btrfs_setsize(struct inode *inode, struct iattr *attr);
static int btrfs_truncate(struct inode *inode, bool skip_writeback);
static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
static noinline int cow_file_range(struct btrfs_inode *inode,
struct page *locked_page,
u64 start, u64 end, int *page_started,
unsigned long *nr_written, int unlock);
static struct extent_map *create_io_em(struct btrfs_inode *inode, u64 start,
u64 len, u64 orig_start, u64 block_start,
u64 block_len, u64 orig_block_len,
u64 ram_bytes, int compress_type,
int type);
static void __endio_write_update_ordered(struct btrfs_inode *inode,
const u64 offset, const u64 bytes,
const bool uptodate);
/*
* btrfs_inode_lock - lock inode i_rwsem based on arguments passed
*
* ilock_flags can have the following bit set:
*
* BTRFS_ILOCK_SHARED - acquire a shared lock on the inode
* BTRFS_ILOCK_TRY - try to acquire the lock, if fails on first attempt
* return -EAGAIN
* BTRFS_ILOCK_MMAP - acquire a write lock on the i_mmap_lock
*/
int btrfs_inode_lock(struct inode *inode, unsigned int ilock_flags)
{
if (ilock_flags & BTRFS_ILOCK_SHARED) {
if (ilock_flags & BTRFS_ILOCK_TRY) {
if (!inode_trylock_shared(inode))
return -EAGAIN;
else
return 0;
}
inode_lock_shared(inode);
} else {
if (ilock_flags & BTRFS_ILOCK_TRY) {
if (!inode_trylock(inode))
return -EAGAIN;
else
return 0;
}
inode_lock(inode);
}
if (ilock_flags & BTRFS_ILOCK_MMAP)
down_write(&BTRFS_I(inode)->i_mmap_lock);
return 0;
}
/*
* btrfs_inode_unlock - unock inode i_rwsem
*
* ilock_flags should contain the same bits set as passed to btrfs_inode_lock()
* to decide whether the lock acquired is shared or exclusive.
*/
void btrfs_inode_unlock(struct inode *inode, unsigned int ilock_flags)
{
if (ilock_flags & BTRFS_ILOCK_MMAP)
up_write(&BTRFS_I(inode)->i_mmap_lock);
if (ilock_flags & BTRFS_ILOCK_SHARED)
inode_unlock_shared(inode);
else
inode_unlock(inode);
}
/*
* Cleanup all submitted ordered extents in specified range to handle errors
* from the btrfs_run_delalloc_range() callback.
*
* NOTE: caller must ensure that when an error happens, it can not call
* extent_clear_unlock_delalloc() to clear both the bits EXTENT_DO_ACCOUNTING
* and EXTENT_DELALLOC simultaneously, because that causes the reserved metadata
* to be released, which we want to happen only when finishing the ordered
* extent (btrfs_finish_ordered_io()).
*/
static inline void btrfs_cleanup_ordered_extents(struct btrfs_inode *inode,
struct page *locked_page,
u64 offset, u64 bytes)
{
unsigned long index = offset >> PAGE_SHIFT;
unsigned long end_index = (offset + bytes - 1) >> PAGE_SHIFT;
u64 page_start = page_offset(locked_page);
u64 page_end = page_start + PAGE_SIZE - 1;
struct page *page;
while (index <= end_index) {
/*
* For locked page, we will call end_extent_writepage() on it
* in run_delalloc_range() for the error handling. That
* end_extent_writepage() function will call
* btrfs_mark_ordered_io_finished() to clear page Ordered and
* run the ordered extent accounting.
*
* Here we can't just clear the Ordered bit, or
* btrfs_mark_ordered_io_finished() would skip the accounting
* for the page range, and the ordered extent will never finish.
*/
if (index == (page_offset(locked_page) >> PAGE_SHIFT)) {
index++;
continue;
}
page = find_get_page(inode->vfs_inode.i_mapping, index);
index++;
if (!page)
continue;
/*
* Here we just clear all Ordered bits for every page in the
* range, then __endio_write_update_ordered() will handle
* the ordered extent accounting for the range.
*/
btrfs_page_clamp_clear_ordered(inode->root->fs_info, page,
offset, bytes);
put_page(page);
}
/* The locked page covers the full range, nothing needs to be done */
if (bytes + offset <= page_offset(locked_page) + PAGE_SIZE)
return;
/*
* In case this page belongs to the delalloc range being instantiated
* then skip it, since the first page of a range is going to be
* properly cleaned up by the caller of run_delalloc_range
*/
if (page_start >= offset && page_end <= (offset + bytes - 1)) {
bytes = offset + bytes - page_offset(locked_page) - PAGE_SIZE;
offset = page_offset(locked_page) + PAGE_SIZE;
}
return __endio_write_update_ordered(inode, offset, bytes, false);
}
static int btrfs_dirty_inode(struct inode *inode);
static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
struct inode *inode, struct inode *dir,
const struct qstr *qstr)
{
int err;
err = btrfs_init_acl(trans, inode, dir);
if (!err)
err = btrfs_xattr_security_init(trans, inode, dir, qstr);
return err;
}
/*
* this does all the hard work for inserting an inline extent into
* the btree. The caller should have done a btrfs_drop_extents so that
* no overlapping inline items exist in the btree
*/
static int insert_inline_extent(struct btrfs_trans_handle *trans,
struct btrfs_path *path, bool extent_inserted,
struct btrfs_root *root, struct inode *inode,
u64 start, size_t size, size_t compressed_size,
int compress_type,
struct page **compressed_pages)
{
struct extent_buffer *leaf;
struct page *page = NULL;
char *kaddr;
unsigned long ptr;
struct btrfs_file_extent_item *ei;
int ret;
size_t cur_size = size;
unsigned long offset;
ASSERT((compressed_size > 0 && compressed_pages) ||
(compressed_size == 0 && !compressed_pages));
if (compressed_size && compressed_pages)
cur_size = compressed_size;
if (!extent_inserted) {
struct btrfs_key key;
size_t datasize;
key.objectid = btrfs_ino(BTRFS_I(inode));
key.offset = start;
key.type = BTRFS_EXTENT_DATA_KEY;
datasize = btrfs_file_extent_calc_inline_size(cur_size);
ret = btrfs_insert_empty_item(trans, root, path, &key,
datasize);
if (ret)
goto fail;
}
leaf = path->nodes[0];
ei = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
btrfs_set_file_extent_generation(leaf, ei, trans->transid);
btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
btrfs_set_file_extent_encryption(leaf, ei, 0);
btrfs_set_file_extent_other_encoding(leaf, ei, 0);
btrfs_set_file_extent_ram_bytes(leaf, ei, size);
ptr = btrfs_file_extent_inline_start(ei);
if (compress_type != BTRFS_COMPRESS_NONE) {
struct page *cpage;
int i = 0;
while (compressed_size > 0) {
cpage = compressed_pages[i];
cur_size = min_t(unsigned long, compressed_size,
PAGE_SIZE);
kaddr = kmap_atomic(cpage);
write_extent_buffer(leaf, kaddr, ptr, cur_size);
kunmap_atomic(kaddr);
i++;
ptr += cur_size;
compressed_size -= cur_size;
}
btrfs_set_file_extent_compression(leaf, ei,
compress_type);
} else {
page = find_get_page(inode->i_mapping,
start >> PAGE_SHIFT);
btrfs_set_file_extent_compression(leaf, ei, 0);
kaddr = kmap_atomic(page);
offset = offset_in_page(start);
write_extent_buffer(leaf, kaddr + offset, ptr, size);
kunmap_atomic(kaddr);
put_page(page);
}
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(path);
/*
* We align size to sectorsize for inline extents just for simplicity
* sake.
*/
size = ALIGN(size, root->fs_info->sectorsize);
ret = btrfs_inode_set_file_extent_range(BTRFS_I(inode), start, size);
if (ret)
goto fail;
/*
* we're an inline extent, so nobody can
* extend the file past i_size without locking
* a page we already have locked.
*
* We must do any isize and inode updates
* before we unlock the pages. Otherwise we
* could end up racing with unlink.
*/
BTRFS_I(inode)->disk_i_size = inode->i_size;
fail:
return ret;
}
/*
* conditionally insert an inline extent into the file. This
* does the checks required to make sure the data is small enough
* to fit as an inline extent.
*/
static noinline int cow_file_range_inline(struct btrfs_inode *inode, u64 start,
u64 end, size_t compressed_size,
int compress_type,
struct page **compressed_pages)
{
struct btrfs_drop_extents_args drop_args = { 0 };
struct btrfs_root *root = inode->root;
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_trans_handle *trans;
u64 isize = i_size_read(&inode->vfs_inode);
u64 actual_end = min(end + 1, isize);
u64 inline_len = actual_end - start;
u64 aligned_end = ALIGN(end, fs_info->sectorsize);
u64 data_len = inline_len;
int ret;
struct btrfs_path *path;
if (compressed_size)
data_len = compressed_size;
if (start > 0 ||
actual_end > fs_info->sectorsize ||
data_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info) ||
(!compressed_size &&
(actual_end & (fs_info->sectorsize - 1)) == 0) ||
end + 1 < isize ||
data_len > fs_info->max_inline) {
return 1;
}
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
btrfs_free_path(path);
return PTR_ERR(trans);
}
trans->block_rsv = &inode->block_rsv;
drop_args.path = path;
drop_args.start = start;
drop_args.end = aligned_end;
drop_args.drop_cache = true;
drop_args.replace_extent = true;
if (compressed_size && compressed_pages)
drop_args.extent_item_size = btrfs_file_extent_calc_inline_size(
compressed_size);
else
drop_args.extent_item_size = btrfs_file_extent_calc_inline_size(
inline_len);
ret = btrfs_drop_extents(trans, root, inode, &drop_args);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out;
}
if (isize > actual_end)
inline_len = min_t(u64, isize, actual_end);
ret = insert_inline_extent(trans, path, drop_args.extent_inserted,
root, &inode->vfs_inode, start,
inline_len, compressed_size,
compress_type, compressed_pages);
if (ret && ret != -ENOSPC) {
btrfs_abort_transaction(trans, ret);
goto out;
} else if (ret == -ENOSPC) {
ret = 1;
goto out;
}
btrfs_update_inode_bytes(inode, inline_len, drop_args.bytes_found);
ret = btrfs_update_inode(trans, root, inode);
if (ret && ret != -ENOSPC) {
btrfs_abort_transaction(trans, ret);
goto out;
} else if (ret == -ENOSPC) {
ret = 1;
goto out;
}
set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
out:
/*
* Don't forget to free the reserved space, as for inlined extent
* it won't count as data extent, free them directly here.
* And at reserve time, it's always aligned to page size, so
* just free one page here.
*/
btrfs_qgroup_free_data(inode, NULL, 0, PAGE_SIZE);
btrfs_free_path(path);
btrfs_end_transaction(trans);
return ret;
}
struct async_extent {
u64 start;
u64 ram_size;
u64 compressed_size;
struct page **pages;
unsigned long nr_pages;
int compress_type;
struct list_head list;
};
struct async_chunk {
struct inode *inode;
struct page *locked_page;
u64 start;
u64 end;
unsigned int write_flags;
struct list_head extents;
struct cgroup_subsys_state *blkcg_css;
struct btrfs_work work;
atomic_t *pending;
};
struct async_cow {
/* Number of chunks in flight; must be first in the structure */
atomic_t num_chunks;
struct async_chunk chunks[];
};
static noinline int add_async_extent(struct async_chunk *cow,
u64 start, u64 ram_size,
u64 compressed_size,
struct page **pages,
unsigned long nr_pages,
int compress_type)
{
struct async_extent *async_extent;
async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
BUG_ON(!async_extent); /* -ENOMEM */
async_extent->start = start;
async_extent->ram_size = ram_size;
async_extent->compressed_size = compressed_size;
async_extent->pages = pages;
async_extent->nr_pages = nr_pages;
async_extent->compress_type = compress_type;
list_add_tail(&async_extent->list, &cow->extents);
return 0;
}
/*
* Check if the inode has flags compatible with compression
*/
static inline bool inode_can_compress(struct btrfs_inode *inode)
{
/* Subpage doesn't support compression yet */
if (inode->root->fs_info->sectorsize < PAGE_SIZE)
return false;
if (inode->flags & BTRFS_INODE_NODATACOW ||
inode->flags & BTRFS_INODE_NODATASUM)
return false;
return true;
}
/*
* Check if the inode needs to be submitted to compression, based on mount
* options, defragmentation, properties or heuristics.
*/
static inline int inode_need_compress(struct btrfs_inode *inode, u64 start,
u64 end)
{
struct btrfs_fs_info *fs_info = inode->root->fs_info;
if (!inode_can_compress(inode)) {
WARN(IS_ENABLED(CONFIG_BTRFS_DEBUG),
KERN_ERR "BTRFS: unexpected compression for ino %llu\n",
btrfs_ino(inode));
return 0;
}
/* force compress */
if (btrfs_test_opt(fs_info, FORCE_COMPRESS))
return 1;
/* defrag ioctl */
if (inode->defrag_compress)
return 1;
/* bad compression ratios */
if (inode->flags & BTRFS_INODE_NOCOMPRESS)
return 0;
if (btrfs_test_opt(fs_info, COMPRESS) ||
inode->flags & BTRFS_INODE_COMPRESS ||
inode->prop_compress)
return btrfs_compress_heuristic(&inode->vfs_inode, start, end);
return 0;
}
static inline void inode_should_defrag(struct btrfs_inode *inode,
u64 start, u64 end, u64 num_bytes, u64 small_write)
{
/* If this is a small write inside eof, kick off a defrag */
if (num_bytes < small_write &&
(start > 0 || end + 1 < inode->disk_i_size))
btrfs_add_inode_defrag(NULL, inode);
}
/*
* we create compressed extents in two phases. The first
* phase compresses a range of pages that have already been
* locked (both pages and state bits are locked).
*
* This is done inside an ordered work queue, and the compression
* is spread across many cpus. The actual IO submission is step
* two, and the ordered work queue takes care of making sure that
* happens in the same order things were put onto the queue by
* writepages and friends.
*
* If this code finds it can't get good compression, it puts an
* entry onto the work queue to write the uncompressed bytes. This
* makes sure that both compressed inodes and uncompressed inodes
* are written in the same order that the flusher thread sent them
* down.
*/
static noinline int compress_file_range(struct async_chunk *async_chunk)
{
struct inode *inode = async_chunk->inode;
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
u64 blocksize = fs_info->sectorsize;
u64 start = async_chunk->start;
u64 end = async_chunk->end;
u64 actual_end;
u64 i_size;
int ret = 0;
struct page **pages = NULL;
unsigned long nr_pages;
unsigned long total_compressed = 0;
unsigned long total_in = 0;
int i;
int will_compress;
int compress_type = fs_info->compress_type;
int compressed_extents = 0;
int redirty = 0;
inode_should_defrag(BTRFS_I(inode), start, end, end - start + 1,
SZ_16K);
/*
* We need to save i_size before now because it could change in between
* us evaluating the size and assigning it. This is because we lock and
* unlock the page in truncate and fallocate, and then modify the i_size
* later on.
*
* The barriers are to emulate READ_ONCE, remove that once i_size_read
* does that for us.
*/
barrier();
i_size = i_size_read(inode);
barrier();
actual_end = min_t(u64, i_size, end + 1);
again:
will_compress = 0;
nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
BUILD_BUG_ON((BTRFS_MAX_COMPRESSED % PAGE_SIZE) != 0);
nr_pages = min_t(unsigned long, nr_pages,
BTRFS_MAX_COMPRESSED / PAGE_SIZE);
/*
* we don't want to send crud past the end of i_size through
* compression, that's just a waste of CPU time. So, if the
* end of the file is before the start of our current
* requested range of bytes, we bail out to the uncompressed
* cleanup code that can deal with all of this.
*
* It isn't really the fastest way to fix things, but this is a
* very uncommon corner.
*/
if (actual_end <= start)
goto cleanup_and_bail_uncompressed;
total_compressed = actual_end - start;
/*
* skip compression for a small file range(<=blocksize) that
* isn't an inline extent, since it doesn't save disk space at all.
*/
if (total_compressed <= blocksize &&
(start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
goto cleanup_and_bail_uncompressed;
total_compressed = min_t(unsigned long, total_compressed,
BTRFS_MAX_UNCOMPRESSED);
total_in = 0;
ret = 0;
/*
* we do compression for mount -o compress and when the
* inode has not been flagged as nocompress. This flag can
* change at any time if we discover bad compression ratios.
*/
if (inode_need_compress(BTRFS_I(inode), start, end)) {
WARN_ON(pages);
pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
if (!pages) {
/* just bail out to the uncompressed code */
nr_pages = 0;
goto cont;
}
if (BTRFS_I(inode)->defrag_compress)
compress_type = BTRFS_I(inode)->defrag_compress;
else if (BTRFS_I(inode)->prop_compress)
compress_type = BTRFS_I(inode)->prop_compress;
/*
* we need to call clear_page_dirty_for_io on each
* page in the range. Otherwise applications with the file
* mmap'd can wander in and change the page contents while
* we are compressing them.
*
* If the compression fails for any reason, we set the pages
* dirty again later on.
*
* Note that the remaining part is redirtied, the start pointer
* has moved, the end is the original one.
*/
if (!redirty) {
extent_range_clear_dirty_for_io(inode, start, end);
redirty = 1;
}
/* Compression level is applied here and only here */
ret = btrfs_compress_pages(
compress_type | (fs_info->compress_level << 4),
inode->i_mapping, start,
pages,
&nr_pages,
&total_in,
&total_compressed);
if (!ret) {
unsigned long offset = offset_in_page(total_compressed);
struct page *page = pages[nr_pages - 1];
/* zero the tail end of the last page, we might be
* sending it down to disk
*/
if (offset)
memzero_page(page, offset, PAGE_SIZE - offset);
will_compress = 1;
}
}
cont:
/*
* Check cow_file_range() for why we don't even try to create inline
* extent for subpage case.
*/
if (start == 0 && fs_info->sectorsize == PAGE_SIZE) {
/* lets try to make an inline extent */
if (ret || total_in < actual_end) {
/* we didn't compress the entire range, try
* to make an uncompressed inline extent.
*/
ret = cow_file_range_inline(BTRFS_I(inode), start, end,
0, BTRFS_COMPRESS_NONE,
NULL);
} else {
/* try making a compressed inline extent */
ret = cow_file_range_inline(BTRFS_I(inode), start, end,
total_compressed,
compress_type, pages);
}
if (ret <= 0) {
unsigned long clear_flags = EXTENT_DELALLOC |
EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
EXTENT_DO_ACCOUNTING;
unsigned long page_error_op;
page_error_op = ret < 0 ? PAGE_SET_ERROR : 0;
/*
* inline extent creation worked or returned error,
* we don't need to create any more async work items.
* Unlock and free up our temp pages.
*
* We use DO_ACCOUNTING here because we need the
* delalloc_release_metadata to be done _after_ we drop
* our outstanding extent for clearing delalloc for this
* range.
*/
extent_clear_unlock_delalloc(BTRFS_I(inode), start, end,
NULL,
clear_flags,
PAGE_UNLOCK |
PAGE_START_WRITEBACK |
page_error_op |
PAGE_END_WRITEBACK);
/*
* Ensure we only free the compressed pages if we have
* them allocated, as we can still reach here with
* inode_need_compress() == false.
*/
if (pages) {
for (i = 0; i < nr_pages; i++) {
WARN_ON(pages[i]->mapping);
put_page(pages[i]);
}
kfree(pages);
}
return 0;
}
}
if (will_compress) {
/*
* we aren't doing an inline extent round the compressed size
* up to a block size boundary so the allocator does sane
* things
*/
total_compressed = ALIGN(total_compressed, blocksize);
/*
* one last check to make sure the compression is really a
* win, compare the page count read with the blocks on disk,
* compression must free at least one sector size
*/
total_in = ALIGN(total_in, PAGE_SIZE);
if (total_compressed + blocksize <= total_in) {
compressed_extents++;
/*
* The async work queues will take care of doing actual
* allocation on disk for these compressed pages, and
* will submit them to the elevator.
*/
add_async_extent(async_chunk, start, total_in,
total_compressed, pages, nr_pages,
compress_type);
if (start + total_in < end) {
start += total_in;
pages = NULL;
cond_resched();
goto again;
}
return compressed_extents;
}
}
if (pages) {
/*
* the compression code ran but failed to make things smaller,
* free any pages it allocated and our page pointer array
*/
for (i = 0; i < nr_pages; i++) {
WARN_ON(pages[i]->mapping);
put_page(pages[i]);
}
kfree(pages);
pages = NULL;
total_compressed = 0;
nr_pages = 0;
/* flag the file so we don't compress in the future */
if (!btrfs_test_opt(fs_info, FORCE_COMPRESS) &&
!(BTRFS_I(inode)->prop_compress)) {
BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
}
}
cleanup_and_bail_uncompressed:
/*
* No compression, but we still need to write the pages in the file
* we've been given so far. redirty the locked page if it corresponds
* to our extent and set things up for the async work queue to run
* cow_file_range to do the normal delalloc dance.
*/
if (async_chunk->locked_page &&
(page_offset(async_chunk->locked_page) >= start &&
page_offset(async_chunk->locked_page)) <= end) {
__set_page_dirty_nobuffers(async_chunk->locked_page);
/* unlocked later on in the async handlers */
}
if (redirty)
extent_range_redirty_for_io(inode, start, end);
add_async_extent(async_chunk, start, end - start + 1, 0, NULL, 0,
BTRFS_COMPRESS_NONE);
compressed_extents++;
return compressed_extents;
}
static void free_async_extent_pages(struct async_extent *async_extent)
{
int i;
if (!async_extent->pages)
return;
for (i = 0; i < async_extent->nr_pages; i++) {
WARN_ON(async_extent->pages[i]->mapping);
put_page(async_extent->pages[i]);
}
kfree(async_extent->pages);
async_extent->nr_pages = 0;
async_extent->pages = NULL;
}
/*
* phase two of compressed writeback. This is the ordered portion
* of the code, which only gets called in the order the work was
* queued. We walk all the async extents created by compress_file_range
* and send them down to the disk.
*/
static noinline void submit_compressed_extents(struct async_chunk *async_chunk)
{
struct btrfs_inode *inode = BTRFS_I(async_chunk->inode);
struct btrfs_fs_info *fs_info = inode->root->fs_info;
struct async_extent *async_extent;
u64 alloc_hint = 0;
struct btrfs_key ins;
struct extent_map *em;
struct btrfs_root *root = inode->root;
struct extent_io_tree *io_tree = &inode->io_tree;
int ret = 0;
again:
while (!list_empty(&async_chunk->extents)) {
async_extent = list_entry(async_chunk->extents.next,
struct async_extent, list);
list_del(&async_extent->list);
retry:
lock_extent(io_tree, async_extent->start,
async_extent->start + async_extent->ram_size - 1);
/* did the compression code fall back to uncompressed IO? */
if (!async_extent->pages) {
int page_started = 0;
unsigned long nr_written = 0;
/* allocate blocks */
ret = cow_file_range(inode, async_chunk->locked_page,
async_extent->start,
async_extent->start +
async_extent->ram_size - 1,
&page_started, &nr_written, 0);
/* JDM XXX */
/*
* if page_started, cow_file_range inserted an
* inline extent and took care of all the unlocking
* and IO for us. Otherwise, we need to submit
* all those pages down to the drive.
*/
if (!page_started && !ret)
extent_write_locked_range(&inode->vfs_inode,
async_extent->start,
async_extent->start +
async_extent->ram_size - 1,
WB_SYNC_ALL);
else if (ret && async_chunk->locked_page)
unlock_page(async_chunk->locked_page);
kfree(async_extent);
cond_resched();
continue;
}
ret = btrfs_reserve_extent(root, async_extent->ram_size,
async_extent->compressed_size,
async_extent->compressed_size,
0, alloc_hint, &ins, 1, 1);
if (ret) {
free_async_extent_pages(async_extent);
if (ret == -ENOSPC) {
unlock_extent(io_tree, async_extent->start,
async_extent->start +
async_extent->ram_size - 1);
/*
* we need to redirty the pages if we decide to
* fallback to uncompressed IO, otherwise we
* will not submit these pages down to lower
* layers.
*/
extent_range_redirty_for_io(&inode->vfs_inode,
async_extent->start,
async_extent->start +
async_extent->ram_size - 1);
goto retry;
}
goto out_free;
}
/*
* here we're doing allocation and writeback of the
* compressed pages
*/
em = create_io_em(inode, async_extent->start,
async_extent->ram_size, /* len */
async_extent->start, /* orig_start */
ins.objectid, /* block_start */
ins.offset, /* block_len */
ins.offset, /* orig_block_len */
async_extent->ram_size, /* ram_bytes */
async_extent->compress_type,
BTRFS_ORDERED_COMPRESSED);
if (IS_ERR(em))
/* ret value is not necessary due to void function */
goto out_free_reserve;
free_extent_map(em);
ret = btrfs_add_ordered_extent_compress(inode,
async_extent->start,
ins.objectid,
async_extent->ram_size,
ins.offset,
async_extent->compress_type);
if (ret) {
btrfs_drop_extent_cache(inode, async_extent->start,
async_extent->start +
async_extent->ram_size - 1, 0);
goto out_free_reserve;
}
btrfs_dec_block_group_reservations(fs_info, ins.objectid);
/*
* clear dirty, set writeback and unlock the pages.
*/
extent_clear_unlock_delalloc(inode, async_extent->start,
async_extent->start +
async_extent->ram_size - 1,
NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
PAGE_UNLOCK | PAGE_START_WRITEBACK);
if (btrfs_submit_compressed_write(inode, async_extent->start,
async_extent->ram_size,
ins.objectid,
ins.offset, async_extent->pages,
async_extent->nr_pages,
async_chunk->write_flags,
async_chunk->blkcg_css)) {
struct page *p = async_extent->pages[0];
const u64 start = async_extent->start;
const u64 end = start + async_extent->ram_size - 1;
p->mapping = inode->vfs_inode.i_mapping;
btrfs_writepage_endio_finish_ordered(inode, p, start,
end, false);
p->mapping = NULL;
extent_clear_unlock_delalloc(inode, start, end, NULL, 0,
PAGE_END_WRITEBACK |
PAGE_SET_ERROR);
free_async_extent_pages(async_extent);
}
alloc_hint = ins.objectid + ins.offset;
kfree(async_extent);
cond_resched();
}
return;
out_free_reserve:
btrfs_dec_block_group_reservations(fs_info, ins.objectid);
btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
out_free:
extent_clear_unlock_delalloc(inode, async_extent->start,
async_extent->start +
async_extent->ram_size - 1,
NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
EXTENT_DELALLOC_NEW |
EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
PAGE_UNLOCK | PAGE_START_WRITEBACK |
PAGE_END_WRITEBACK | PAGE_SET_ERROR);
free_async_extent_pages(async_extent);
kfree(async_extent);
goto again;
}
static u64 get_extent_allocation_hint(struct btrfs_inode *inode, u64 start,
u64 num_bytes)
{
struct extent_map_tree *em_tree = &inode->extent_tree;
struct extent_map *em;
u64 alloc_hint = 0;
read_lock(&em_tree->lock);
em = search_extent_mapping(em_tree, start, num_bytes);
if (em) {
/*
* if block start isn't an actual block number then find the
* first block in this inode and use that as a hint. If that
* block is also bogus then just don't worry about it.
*/
if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
free_extent_map(em);
em = search_extent_mapping(em_tree, 0, 0);
if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
alloc_hint = em->block_start;
if (em)
free_extent_map(em);
} else {
alloc_hint = em->block_start;
free_extent_map(em);
}
}
read_unlock(&em_tree->lock);
return alloc_hint;
}
/*
* when extent_io.c finds a delayed allocation range in the file,
* the call backs end up in this code. The basic idea is to
* allocate extents on disk for the range, and create ordered data structs
* in ram to track those extents.
*
* locked_page is the page that writepage had locked already. We use
* it to make sure we don't do extra locks or unlocks.
*
* *page_started is set to one if we unlock locked_page and do everything
* required to start IO on it. It may be clean and already done with
* IO when we return.
*
* When unlock == 1, we unlock the pages in successfully allocated regions.
* When unlock == 0, we leave them locked for writing them out.
*
* However, we unlock all the pages except @locked_page in case of failure.
*
* In summary, page locking state will be as follow:
*
* - page_started == 1 (return value)
* - All the pages are unlocked. IO is started.
* - Note that this can happen only on success
* - unlock == 1
* - All the pages except @locked_page are unlocked in any case
* - unlock == 0
* - On success, all the pages are locked for writing out them
* - On failure, all the pages except @locked_page are unlocked
*
* When a failure happens in the second or later iteration of the
* while-loop, the ordered extents created in previous iterations are kept
* intact. So, the caller must clean them up by calling
* btrfs_cleanup_ordered_extents(). See btrfs_run_delalloc_range() for
* example.
*/
static noinline int cow_file_range(struct btrfs_inode *inode,
struct page *locked_page,
u64 start, u64 end, int *page_started,
unsigned long *nr_written, int unlock)
{
struct btrfs_root *root = inode->root;
struct btrfs_fs_info *fs_info = root->fs_info;
u64 alloc_hint = 0;
u64 orig_start = start;
u64 num_bytes;
unsigned long ram_size;
u64 cur_alloc_size = 0;
u64 min_alloc_size;
u64 blocksize = fs_info->sectorsize;
struct btrfs_key ins;
struct extent_map *em;
unsigned clear_bits;
unsigned long page_ops;
bool extent_reserved = false;
int ret = 0;
if (btrfs_is_free_space_inode(inode)) {
ret = -EINVAL;
goto out_unlock;
}
num_bytes = ALIGN(end - start + 1, blocksize);
num_bytes = max(blocksize, num_bytes);
ASSERT(num_bytes <= btrfs_super_total_bytes(fs_info->super_copy));
inode_should_defrag(inode, start, end, num_bytes, SZ_64K);
/*
* Due to the page size limit, for subpage we can only trigger the
* writeback for the dirty sectors of page, that means data writeback
* is doing more writeback than what we want.
*
* This is especially unexpected for some call sites like fallocate,
* where we only increase i_size after everything is done.
* This means we can trigger inline extent even if we didn't want to.
* So here we skip inline extent creation completely.
*/
if (start == 0 && fs_info->sectorsize == PAGE_SIZE) {
/* lets try to make an inline extent */
ret = cow_file_range_inline(inode, start, end, 0,
BTRFS_COMPRESS_NONE, NULL);
if (ret == 0) {
/*
* We use DO_ACCOUNTING here because we need the
* delalloc_release_metadata to be run _after_ we drop
* our outstanding extent for clearing delalloc for this
* range.
*/
extent_clear_unlock_delalloc(inode, start, end,
locked_page,
EXTENT_LOCKED | EXTENT_DELALLOC |
EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
PAGE_START_WRITEBACK | PAGE_END_WRITEBACK);
*nr_written = *nr_written +
(end - start + PAGE_SIZE) / PAGE_SIZE;
*page_started = 1;
/*
* locked_page is locked by the caller of
* writepage_delalloc(), not locked by
* __process_pages_contig().
*
* We can't let __process_pages_contig() to unlock it,
* as it doesn't have any subpage::writers recorded.
*
* Here we manually unlock the page, since the caller
* can't use page_started to determine if it's an
* inline extent or a compressed extent.
*/
unlock_page(locked_page);
goto out;
} else if (ret < 0) {
goto out_unlock;
}
}
alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
/*
* Relocation relies on the relocated extents to have exactly the same
* size as the original extents. Normally writeback for relocation data
* extents follows a NOCOW path because relocation preallocates the
* extents. However, due to an operation such as scrub turning a block
* group to RO mode, it may fallback to COW mode, so we must make sure
* an extent allocated during COW has exactly the requested size and can
* not be split into smaller extents, otherwise relocation breaks and
* fails during the stage where it updates the bytenr of file extent
* items.
*/
if (btrfs_is_data_reloc_root(root))
min_alloc_size = num_bytes;
else
min_alloc_size = fs_info->sectorsize;
while (num_bytes > 0) {
cur_alloc_size = num_bytes;
ret = btrfs_reserve_extent(root, cur_alloc_size, cur_alloc_size,
min_alloc_size, 0, alloc_hint,
&ins, 1, 1);
if (ret < 0)
goto out_unlock;
cur_alloc_size = ins.offset;
extent_reserved = true;
ram_size = ins.offset;
em = create_io_em(inode, start, ins.offset, /* len */
start, /* orig_start */
ins.objectid, /* block_start */
ins.offset, /* block_len */
ins.offset, /* orig_block_len */
ram_size, /* ram_bytes */
BTRFS_COMPRESS_NONE, /* compress_type */
BTRFS_ORDERED_REGULAR /* type */);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
goto out_reserve;
}
free_extent_map(em);
ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
ram_size, cur_alloc_size,
BTRFS_ORDERED_REGULAR);
if (ret)
goto out_drop_extent_cache;
if (btrfs_is_data_reloc_root(root)) {
ret = btrfs_reloc_clone_csums(inode, start,
cur_alloc_size);
/*
* Only drop cache here, and process as normal.
*
* We must not allow extent_clear_unlock_delalloc()
* at out_unlock label to free meta of this ordered
* extent, as its meta should be freed by
* btrfs_finish_ordered_io().
*
* So we must continue until @start is increased to
* skip current ordered extent.
*/
if (ret)
btrfs_drop_extent_cache(inode, start,
start + ram_size - 1, 0);
}
btrfs_dec_block_group_reservations(fs_info, ins.objectid);
/*
* We're not doing compressed IO, don't unlock the first page
* (which the caller expects to stay locked), don't clear any
* dirty bits and don't set any writeback bits
*
* Do set the Ordered (Private2) bit so we know this page was
* properly setup for writepage.
*/
page_ops = unlock ? PAGE_UNLOCK : 0;
page_ops |= PAGE_SET_ORDERED;
extent_clear_unlock_delalloc(inode, start, start + ram_size - 1,
locked_page,
EXTENT_LOCKED | EXTENT_DELALLOC,
page_ops);
if (num_bytes < cur_alloc_size)
num_bytes = 0;
else
num_bytes -= cur_alloc_size;
alloc_hint = ins.objectid + ins.offset;
start += cur_alloc_size;
extent_reserved = false;
/*
* btrfs_reloc_clone_csums() error, since start is increased
* extent_clear_unlock_delalloc() at out_unlock label won't
* free metadata of current ordered extent, we're OK to exit.
*/
if (ret)
goto out_unlock;
}
out:
return ret;
out_drop_extent_cache:
btrfs_drop_extent_cache(inode, start, start + ram_size - 1, 0);
out_reserve:
btrfs_dec_block_group_reservations(fs_info, ins.objectid);
btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
out_unlock:
/*
* Now, we have three regions to clean up:
*
* |-------(1)----|---(2)---|-------------(3)----------|
* `- orig_start `- start `- start + cur_alloc_size `- end
*
* We process each region below.
*/
clear_bits = EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
EXTENT_DEFRAG | EXTENT_CLEAR_META_RESV;
page_ops = PAGE_UNLOCK | PAGE_START_WRITEBACK | PAGE_END_WRITEBACK;
/*
* For the range (1). We have already instantiated the ordered extents
* for this region. They are cleaned up by
* btrfs_cleanup_ordered_extents() in e.g,
* btrfs_run_delalloc_range(). EXTENT_LOCKED | EXTENT_DELALLOC are
* already cleared in the above loop. And, EXTENT_DELALLOC_NEW |
* EXTENT_DEFRAG | EXTENT_CLEAR_META_RESV are handled by the cleanup
* function.
*
* However, in case of unlock == 0, we still need to unlock the pages
* (except @locked_page) to ensure all the pages are unlocked.
*/
if (!unlock && orig_start < start)
extent_clear_unlock_delalloc(inode, orig_start, start - 1,
locked_page, 0, page_ops);
/*
* For the range (2). If we reserved an extent for our delalloc range
* (or a subrange) and failed to create the respective ordered extent,
* then it means that when we reserved the extent we decremented the
* extent's size from the data space_info's bytes_may_use counter and
* incremented the space_info's bytes_reserved counter by the same
* amount. We must make sure extent_clear_unlock_delalloc() does not try
* to decrement again the data space_info's bytes_may_use counter,
* therefore we do not pass it the flag EXTENT_CLEAR_DATA_RESV.
*/
if (extent_reserved) {
extent_clear_unlock_delalloc(inode, start,
start + cur_alloc_size - 1,
locked_page,
clear_bits,
page_ops);
start += cur_alloc_size;
if (start >= end)
goto out;
}
/*
* For the range (3). We never touched the region. In addition to the
* clear_bits above, we add EXTENT_CLEAR_DATA_RESV to release the data
* space_info's bytes_may_use counter, reserved in
* btrfs_check_data_free_space().
*/
extent_clear_unlock_delalloc(inode, start, end, locked_page,
clear_bits | EXTENT_CLEAR_DATA_RESV,
page_ops);
goto out;
}
/*
* work queue call back to started compression on a file and pages
*/
static noinline void async_cow_start(struct btrfs_work *work)
{
struct async_chunk *async_chunk;
int compressed_extents;
async_chunk = container_of(work, struct async_chunk, work);
compressed_extents = compress_file_range(async_chunk);
if (compressed_extents == 0) {
btrfs_add_delayed_iput(async_chunk->inode);
async_chunk->inode = NULL;
}
}
/*
* work queue call back to submit previously compressed pages
*/
static noinline void async_cow_submit(struct btrfs_work *work)
{
struct async_chunk *async_chunk = container_of(work, struct async_chunk,
work);
struct btrfs_fs_info *fs_info = btrfs_work_owner(work);
unsigned long nr_pages;
nr_pages = (async_chunk->end - async_chunk->start + PAGE_SIZE) >>
PAGE_SHIFT;
/*
* ->inode could be NULL if async_chunk_start has failed to compress,
* in which case we don't have anything to submit, yet we need to
* always adjust ->async_delalloc_pages as its paired with the init
* happening in cow_file_range_async
*/
if (async_chunk->inode)
submit_compressed_extents(async_chunk);
/* atomic_sub_return implies a barrier */
if (atomic_sub_return(nr_pages, &fs_info->async_delalloc_pages) <
5 * SZ_1M)
cond_wake_up_nomb(&fs_info->async_submit_wait);
}
static noinline void async_cow_free(struct btrfs_work *work)
{
struct async_chunk *async_chunk;
async_chunk = container_of(work, struct async_chunk, work);
if (async_chunk->inode)
btrfs_add_delayed_iput(async_chunk->inode);
if (async_chunk->blkcg_css)
css_put(async_chunk->blkcg_css);
/*
* Since the pointer to 'pending' is at the beginning of the array of
* async_chunk's, freeing it ensures the whole array has been freed.
*/
if (atomic_dec_and_test(async_chunk->pending))
kvfree(async_chunk->pending);
}
static int cow_file_range_async(struct btrfs_inode *inode,
struct writeback_control *wbc,
struct page *locked_page,
u64 start, u64 end, int *page_started,
unsigned long *nr_written)
{
struct btrfs_fs_info *fs_info = inode->root->fs_info;
struct cgroup_subsys_state *blkcg_css = wbc_blkcg_css(wbc);
struct async_cow *ctx;
struct async_chunk *async_chunk;
unsigned long nr_pages;
u64 cur_end;
u64 num_chunks = DIV_ROUND_UP(end - start, SZ_512K);
int i;
bool should_compress;
unsigned nofs_flag;
const unsigned int write_flags = wbc_to_write_flags(wbc);
unlock_extent(&inode->io_tree, start, end);
if (inode->flags & BTRFS_INODE_NOCOMPRESS &&
!btrfs_test_opt(fs_info, FORCE_COMPRESS)) {
num_chunks = 1;
should_compress = false;
} else {
should_compress = true;
}
nofs_flag = memalloc_nofs_save();
ctx = kvmalloc(struct_size(ctx, chunks, num_chunks), GFP_KERNEL);
memalloc_nofs_restore(nofs_flag);
if (!ctx) {
unsigned clear_bits = EXTENT_LOCKED | EXTENT_DELALLOC |
EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
EXTENT_DO_ACCOUNTING;
unsigned long page_ops = PAGE_UNLOCK | PAGE_START_WRITEBACK |
PAGE_END_WRITEBACK | PAGE_SET_ERROR;
extent_clear_unlock_delalloc(inode, start, end, locked_page,
clear_bits, page_ops);
return -ENOMEM;
}
async_chunk = ctx->chunks;
atomic_set(&ctx->num_chunks, num_chunks);
for (i = 0; i < num_chunks; i++) {
if (should_compress)
cur_end = min(end, start + SZ_512K - 1);
else
cur_end = end;
/*
* igrab is called higher up in the call chain, take only the
* lightweight reference for the callback lifetime
*/
ihold(&inode->vfs_inode);
async_chunk[i].pending = &ctx->num_chunks;
async_chunk[i].inode = &inode->vfs_inode;
async_chunk[i].start = start;
async_chunk[i].end = cur_end;
async_chunk[i].write_flags = write_flags;
INIT_LIST_HEAD(&async_chunk[i].extents);
/*
* The locked_page comes all the way from writepage and its
* the original page we were actually given. As we spread
* this large delalloc region across multiple async_chunk
* structs, only the first struct needs a pointer to locked_page
*
* This way we don't need racey decisions about who is supposed
* to unlock it.
*/
if (locked_page) {
/*
* Depending on the compressibility, the pages might or
* might not go through async. We want all of them to
* be accounted against wbc once. Let's do it here
* before the paths diverge. wbc accounting is used
* only for foreign writeback detection and doesn't
* need full accuracy. Just account the whole thing
* against the first page.
*/
wbc_account_cgroup_owner(wbc, locked_page,
cur_end - start);
async_chunk[i].locked_page = locked_page;
locked_page = NULL;
} else {
async_chunk[i].locked_page = NULL;
}
if (blkcg_css != blkcg_root_css) {
css_get(blkcg_css);
async_chunk[i].blkcg_css = blkcg_css;
} else {
async_chunk[i].blkcg_css = NULL;
}
btrfs_init_work(&async_chunk[i].work, async_cow_start,
async_cow_submit, async_cow_free);
nr_pages = DIV_ROUND_UP(cur_end - start, PAGE_SIZE);
atomic_add(nr_pages, &fs_info->async_delalloc_pages);
btrfs_queue_work(fs_info->delalloc_workers, &async_chunk[i].work);
*nr_written += nr_pages;
start = cur_end + 1;
}
*page_started = 1;
return 0;
}
static noinline int run_delalloc_zoned(struct btrfs_inode *inode,
struct page *locked_page, u64 start,
u64 end, int *page_started,
unsigned long *nr_written)
{
int ret;
ret = cow_file_range(inode, locked_page, start, end, page_started,
nr_written, 0);
if (ret)
return ret;
if (*page_started)
return 0;
__set_page_dirty_nobuffers(locked_page);
account_page_redirty(locked_page);
extent_write_locked_range(&inode->vfs_inode, start, end, WB_SYNC_ALL);
*page_started = 1;
return 0;
}
static noinline int csum_exist_in_range(struct btrfs_fs_info *fs_info,
u64 bytenr, u64 num_bytes)
{
int ret;
struct btrfs_ordered_sum *sums;
LIST_HEAD(list);
ret = btrfs_lookup_csums_range(fs_info->csum_root, bytenr,
bytenr + num_bytes - 1, &list, 0);
if (ret == 0 && list_empty(&list))
return 0;
while (!list_empty(&list)) {
sums = list_entry(list.next, struct btrfs_ordered_sum, list);
list_del(&sums->list);
kfree(sums);
}
if (ret < 0)
return ret;
return 1;
}
static int fallback_to_cow(struct btrfs_inode *inode, struct page *locked_page,
const u64 start, const u64 end,
int *page_started, unsigned long *nr_written)
{
const bool is_space_ino = btrfs_is_free_space_inode(inode);
const bool is_reloc_ino = btrfs_is_data_reloc_root(inode->root);
const u64 range_bytes = end + 1 - start;
struct extent_io_tree *io_tree = &inode->io_tree;
u64 range_start = start;
u64 count;
/*
* If EXTENT_NORESERVE is set it means that when the buffered write was
* made we had not enough available data space and therefore we did not
* reserve data space for it, since we though we could do NOCOW for the
* respective file range (either there is prealloc extent or the inode
* has the NOCOW bit set).
*
* However when we need to fallback to COW mode (because for example the
* block group for the corresponding extent was turned to RO mode by a
* scrub or relocation) we need to do the following:
*
* 1) We increment the bytes_may_use counter of the data space info.
* If COW succeeds, it allocates a new data extent and after doing
* that it decrements the space info's bytes_may_use counter and
* increments its bytes_reserved counter by the same amount (we do
* this at btrfs_add_reserved_bytes()). So we need to increment the
* bytes_may_use counter to compensate (when space is reserved at
* buffered write time, the bytes_may_use counter is incremented);
*
* 2) We clear the EXTENT_NORESERVE bit from the range. We do this so
* that if the COW path fails for any reason, it decrements (through
* extent_clear_unlock_delalloc()) the bytes_may_use counter of the
* data space info, which we incremented in the step above.
*
* If we need to fallback to cow and the inode corresponds to a free
* space cache inode or an inode of the data relocation tree, we must
* also increment bytes_may_use of the data space_info for the same
* reason. Space caches and relocated data extents always get a prealloc
* extent for them, however scrub or balance may have set the block
* group that contains that extent to RO mode and therefore force COW
* when starting writeback.
*/
count = count_range_bits(io_tree, &range_start, end, range_bytes,
EXTENT_NORESERVE, 0);
if (count > 0 || is_space_ino || is_reloc_ino) {
u64 bytes = count;
struct btrfs_fs_info *fs_info = inode->root->fs_info;
struct btrfs_space_info *sinfo = fs_info->data_sinfo;
if (is_space_ino || is_reloc_ino)
bytes = range_bytes;
spin_lock(&sinfo->lock);
btrfs_space_info_update_bytes_may_use(fs_info, sinfo, bytes);
spin_unlock(&sinfo->lock);
if (count > 0)
clear_extent_bit(io_tree, start, end, EXTENT_NORESERVE,
0, 0, NULL);
}
return cow_file_range(inode, locked_page, start, end, page_started,
nr_written, 1);
}
/*
* when nowcow writeback call back. This checks for snapshots or COW copies
* of the extents that exist in the file, and COWs the file as required.
*
* If no cow copies or snapshots exist, we write directly to the existing
* blocks on disk
*/
static noinline int run_delalloc_nocow(struct btrfs_inode *inode,
struct page *locked_page,
const u64 start, const u64 end,
int *page_started,
unsigned long *nr_written)
{
struct btrfs_fs_info *fs_info = inode->root->fs_info;
struct btrfs_root *root = inode->root;
struct btrfs_path *path;
u64 cow_start = (u64)-1;
u64 cur_offset = start;
int ret;
bool check_prev = true;
const bool freespace_inode = btrfs_is_free_space_inode(inode);
u64 ino = btrfs_ino(inode);
bool nocow = false;
u64 disk_bytenr = 0;
const bool force = inode->flags & BTRFS_INODE_NODATACOW;
path = btrfs_alloc_path();
if (!path) {
extent_clear_unlock_delalloc(inode, start, end, locked_page,
EXTENT_LOCKED | EXTENT_DELALLOC |
EXTENT_DO_ACCOUNTING |
EXTENT_DEFRAG, PAGE_UNLOCK |
PAGE_START_WRITEBACK |
PAGE_END_WRITEBACK);
return -ENOMEM;
}
while (1) {
struct btrfs_key found_key;
struct btrfs_file_extent_item *fi;
struct extent_buffer *leaf;
u64 extent_end;
u64 extent_offset;
u64 num_bytes = 0;
u64 disk_num_bytes;
u64 ram_bytes;
int extent_type;
nocow = false;
ret = btrfs_lookup_file_extent(NULL, root, path, ino,
cur_offset, 0);
if (ret < 0)
goto error;
/*
* If there is no extent for our range when doing the initial
* search, then go back to the previous slot as it will be the
* one containing the search offset
*/
if (ret > 0 && path->slots[0] > 0 && check_prev) {
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key,
path->slots[0] - 1);
if (found_key.objectid == ino &&
found_key.type == BTRFS_EXTENT_DATA_KEY)
path->slots[0]--;
}
check_prev = false;
next_slot:
/* Go to next leaf if we have exhausted the current one */
leaf = path->nodes[0];
if (path->slots[0] >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0) {
if (cow_start != (u64)-1)
cur_offset = cow_start;
goto error;
}
if (ret > 0)
break;
leaf = path->nodes[0];
}
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
/* Didn't find anything for our INO */
if (found_key.objectid > ino)
break;
/*
* Keep searching until we find an EXTENT_ITEM or there are no
* more extents for this inode
*/
if (WARN_ON_ONCE(found_key.objectid < ino) ||
found_key.type < BTRFS_EXTENT_DATA_KEY) {
path->slots[0]++;
goto next_slot;
}
/* Found key is not EXTENT_DATA_KEY or starts after req range */
if (found_key.type > BTRFS_EXTENT_DATA_KEY ||
found_key.offset > end)
break;
/*
* If the found extent starts after requested offset, then
* adjust extent_end to be right before this extent begins
*/
if (found_key.offset > cur_offset) {
extent_end = found_key.offset;
extent_type = 0;
goto out_check;
}
/*
* Found extent which begins before our range and potentially
* intersect it
*/
fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
extent_type = btrfs_file_extent_type(leaf, fi);
ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
if (extent_type == BTRFS_FILE_EXTENT_REG ||
extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
extent_offset = btrfs_file_extent_offset(leaf, fi);
extent_end = found_key.offset +
btrfs_file_extent_num_bytes(leaf, fi);
disk_num_bytes =
btrfs_file_extent_disk_num_bytes(leaf, fi);
/*
* If the extent we got ends before our current offset,
* skip to the next extent.
*/
if (extent_end <= cur_offset) {
path->slots[0]++;
goto next_slot;
}
/* Skip holes */
if (disk_bytenr == 0)
goto out_check;
/* Skip compressed/encrypted/encoded extents */
if (btrfs_file_extent_compression(leaf, fi) ||
btrfs_file_extent_encryption(leaf, fi) ||
btrfs_file_extent_other_encoding(leaf, fi))
goto out_check;
/*
* If extent is created before the last volume's snapshot
* this implies the extent is shared, hence we can't do
* nocow. This is the same check as in
* btrfs_cross_ref_exist but without calling
* btrfs_search_slot.
*/
if (!freespace_inode &&
btrfs_file_extent_generation(leaf, fi) <=
btrfs_root_last_snapshot(&root->root_item))
goto out_check;
if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
goto out_check;
/*
* The following checks can be expensive, as they need to
* take other locks and do btree or rbtree searches, so
* release the path to avoid blocking other tasks for too
* long.
*/
btrfs_release_path(path);
ret = btrfs_cross_ref_exist(root, ino,
found_key.offset -
extent_offset, disk_bytenr, false);
if (ret) {
/*
* ret could be -EIO if the above fails to read
* metadata.
*/
if (ret < 0) {
if (cow_start != (u64)-1)
cur_offset = cow_start;
goto error;
}
WARN_ON_ONCE(freespace_inode);
goto out_check;
}
disk_bytenr += extent_offset;
disk_bytenr += cur_offset - found_key.offset;
num_bytes = min(end + 1, extent_end) - cur_offset;
/*
* If there are pending snapshots for this root, we
* fall into common COW way
*/
if (!freespace_inode && atomic_read(&root->snapshot_force_cow))
goto out_check;
/*
* force cow if csum exists in the range.
* this ensure that csum for a given extent are
* either valid or do not exist.
*/
ret = csum_exist_in_range(fs_info, disk_bytenr,
num_bytes);
if (ret) {
/*
* ret could be -EIO if the above fails to read
* metadata.
*/
if (ret < 0) {
if (cow_start != (u64)-1)
cur_offset = cow_start;
goto error;
}
WARN_ON_ONCE(freespace_inode);
goto out_check;
}
/* If the extent's block group is RO, we must COW */
if (!btrfs_inc_nocow_writers(fs_info, disk_bytenr))
goto out_check;
nocow = true;
} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
extent_end = found_key.offset + ram_bytes;
extent_end = ALIGN(extent_end, fs_info->sectorsize);
/* Skip extents outside of our requested range */
if (extent_end <= start) {
path->slots[0]++;
goto next_slot;
}
} else {
/* If this triggers then we have a memory corruption */
BUG();
}
out_check:
/*
* If nocow is false then record the beginning of the range
* that needs to be COWed
*/
if (!nocow) {
if (cow_start == (u64)-1)
cow_start = cur_offset;
cur_offset = extent_end;
if (cur_offset > end)
break;
if (!path->nodes[0])
continue;
path->slots[0]++;
goto next_slot;
}
/*
* COW range from cow_start to found_key.offset - 1. As the key
* will contain the beginning of the first extent that can be
* NOCOW, following one which needs to be COW'ed
*/
if (cow_start != (u64)-1) {
ret = fallback_to_cow(inode, locked_page,
cow_start, found_key.offset - 1,
page_started, nr_written);
if (ret)
goto error;
cow_start = (u64)-1;
}
if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
u64 orig_start = found_key.offset - extent_offset;
struct extent_map *em;
em = create_io_em(inode, cur_offset, num_bytes,
orig_start,
disk_bytenr, /* block_start */
num_bytes, /* block_len */
disk_num_bytes, /* orig_block_len */
ram_bytes, BTRFS_COMPRESS_NONE,
BTRFS_ORDERED_PREALLOC);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
goto error;
}
free_extent_map(em);
ret = btrfs_add_ordered_extent(inode, cur_offset,
disk_bytenr, num_bytes,
num_bytes,
BTRFS_ORDERED_PREALLOC);
if (ret) {
btrfs_drop_extent_cache(inode, cur_offset,
cur_offset + num_bytes - 1,
0);
goto error;
}
} else {
ret = btrfs_add_ordered_extent(inode, cur_offset,
disk_bytenr, num_bytes,
num_bytes,
BTRFS_ORDERED_NOCOW);
if (ret)
goto error;
}
if (nocow)
btrfs_dec_nocow_writers(fs_info, disk_bytenr);
nocow = false;
if (btrfs_is_data_reloc_root(root))
/*
* Error handled later, as we must prevent
* extent_clear_unlock_delalloc() in error handler
* from freeing metadata of created ordered extent.
*/
ret = btrfs_reloc_clone_csums(inode, cur_offset,
num_bytes);
extent_clear_unlock_delalloc(inode, cur_offset,
cur_offset + num_bytes - 1,
locked_page, EXTENT_LOCKED |
EXTENT_DELALLOC |
EXTENT_CLEAR_DATA_RESV,
PAGE_UNLOCK | PAGE_SET_ORDERED);
cur_offset = extent_end;
/*
* btrfs_reloc_clone_csums() error, now we're OK to call error
* handler, as metadata for created ordered extent will only
* be freed by btrfs_finish_ordered_io().
*/
if (ret)
goto error;
if (cur_offset > end)
break;
}
btrfs_release_path(path);
if (cur_offset <= end && cow_start == (u64)-1)
cow_start = cur_offset;
if (cow_start != (u64)-1) {
cur_offset = end;
ret = fallback_to_cow(inode, locked_page, cow_start, end,
page_started, nr_written);
if (ret)
goto error;
}
error:
if (nocow)
btrfs_dec_nocow_writers(fs_info, disk_bytenr);
if (ret && cur_offset < end)
extent_clear_unlock_delalloc(inode, cur_offset, end,
locked_page, EXTENT_LOCKED |
EXTENT_DELALLOC | EXTENT_DEFRAG |
EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
PAGE_START_WRITEBACK |
PAGE_END_WRITEBACK);
btrfs_free_path(path);
return ret;
}
static bool should_nocow(struct btrfs_inode *inode, u64 start, u64 end)
{
if (inode->flags & (BTRFS_INODE_NODATACOW | BTRFS_INODE_PREALLOC)) {
if (inode->defrag_bytes &&
test_range_bit(&inode->io_tree, start, end, EXTENT_DEFRAG,
0, NULL))
return false;
return true;
}
return false;
}
/*
* Function to process delayed allocation (create CoW) for ranges which are
* being touched for the first time.
*/
int btrfs_run_delalloc_range(struct btrfs_inode *inode, struct page *locked_page,
u64 start, u64 end, int *page_started, unsigned long *nr_written,
struct writeback_control *wbc)
{
int ret;
const bool zoned = btrfs_is_zoned(inode->root->fs_info);
if (should_nocow(inode, start, end)) {
/*
* Normally on a zoned device we're only doing COW writes, but
* in case of relocation on a zoned filesystem we have taken
* precaution, that we're only writing sequentially. It's safe
* to use run_delalloc_nocow() here, like for regular
* preallocated inodes.
*/
ASSERT(!zoned ||
(zoned && btrfs_is_data_reloc_root(inode->root)));
ret = run_delalloc_nocow(inode, locked_page, start, end,
page_started, nr_written);
} else if (!inode_can_compress(inode) ||
!inode_need_compress(inode, start, end)) {
if (zoned)
ret = run_delalloc_zoned(inode, locked_page, start, end,
page_started, nr_written);
else
ret = cow_file_range(inode, locked_page, start, end,
page_started, nr_written, 1);
} else {
set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, &inode->runtime_flags);
ret = cow_file_range_async(inode, wbc, locked_page, start, end,
page_started, nr_written);
}
ASSERT(ret <= 0);
if (ret)
btrfs_cleanup_ordered_extents(inode, locked_page, start,
end - start + 1);
return ret;
}
void btrfs_split_delalloc_extent(struct inode *inode,
struct extent_state *orig, u64 split)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
u64 size;
/* not delalloc, ignore it */
if (!(orig->state & EXTENT_DELALLOC))
return;
size = orig->end - orig->start + 1;
if (size > fs_info->max_extent_size) {
u32 num_extents;
u64 new_size;
/*
* See the explanation in btrfs_merge_delalloc_extent, the same
* applies here, just in reverse.
*/
new_size = orig->end - split + 1;
num_extents = count_max_extents(fs_info, new_size);
new_size = split - orig->start;
num_extents += count_max_extents(fs_info, new_size);
if (count_max_extents(fs_info, size) >= num_extents)
return;
}
spin_lock(&BTRFS_I(inode)->lock);
btrfs_mod_outstanding_extents(BTRFS_I(inode), 1);
spin_unlock(&BTRFS_I(inode)->lock);
}
/*
* Handle merged delayed allocation extents so we can keep track of new extents
* that are just merged onto old extents, such as when we are doing sequential
* writes, so we can properly account for the metadata space we'll need.
*/
void btrfs_merge_delalloc_extent(struct inode *inode, struct extent_state *new,
struct extent_state *other)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
u64 new_size, old_size;
u32 num_extents;
/* not delalloc, ignore it */
if (!(other->state & EXTENT_DELALLOC))
return;
if (new->start > other->start)
new_size = new->end - other->start + 1;
else
new_size = other->end - new->start + 1;
/* we're not bigger than the max, unreserve the space and go */
if (new_size <= fs_info->max_extent_size) {
spin_lock(&BTRFS_I(inode)->lock);
btrfs_mod_outstanding_extents(BTRFS_I(inode), -1);
spin_unlock(&BTRFS_I(inode)->lock);
return;
}
/*
* We have to add up either side to figure out how many extents were
* accounted for before we merged into one big extent. If the number of
* extents we accounted for is <= the amount we need for the new range
* then we can return, otherwise drop. Think of it like this
*
* [ 4k][MAX_SIZE]
*
* So we've grown the extent by a MAX_SIZE extent, this would mean we
* need 2 outstanding extents, on one side we have 1 and the other side
* we have 1 so they are == and we can return. But in this case
*
* [MAX_SIZE+4k][MAX_SIZE+4k]
*
* Each range on their own accounts for 2 extents, but merged together
* they are only 3 extents worth of accounting, so we need to drop in
* this case.
*/
old_size = other->end - other->start + 1;
num_extents = count_max_extents(fs_info, old_size);
old_size = new->end - new->start + 1;
num_extents += count_max_extents(fs_info, old_size);
if (count_max_extents(fs_info, new_size) >= num_extents)
return;
spin_lock(&BTRFS_I(inode)->lock);
btrfs_mod_outstanding_extents(BTRFS_I(inode), -1);
spin_unlock(&BTRFS_I(inode)->lock);
}
static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
struct inode *inode)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
spin_lock(&root->delalloc_lock);
if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
&root->delalloc_inodes);
set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
&BTRFS_I(inode)->runtime_flags);
root->nr_delalloc_inodes++;
if (root->nr_delalloc_inodes == 1) {
spin_lock(&fs_info->delalloc_root_lock);
BUG_ON(!list_empty(&root->delalloc_root));
list_add_tail(&root->delalloc_root,
&fs_info->delalloc_roots);
spin_unlock(&fs_info->delalloc_root_lock);
}
}
spin_unlock(&root->delalloc_lock);
}
void __btrfs_del_delalloc_inode(struct btrfs_root *root,
struct btrfs_inode *inode)
{
struct btrfs_fs_info *fs_info = root->fs_info;
if (!list_empty(&inode->delalloc_inodes)) {
list_del_init(&inode->delalloc_inodes);
clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
&inode->runtime_flags);
root->nr_delalloc_inodes--;
if (!root->nr_delalloc_inodes) {
ASSERT(list_empty(&root->delalloc_inodes));
spin_lock(&fs_info->delalloc_root_lock);
BUG_ON(list_empty(&root->delalloc_root));
list_del_init(&root->delalloc_root);
spin_unlock(&fs_info->delalloc_root_lock);
}
}
}
static void btrfs_del_delalloc_inode(struct btrfs_root *root,
struct btrfs_inode *inode)
{
spin_lock(&root->delalloc_lock);
__btrfs_del_delalloc_inode(root, inode);
spin_unlock(&root->delalloc_lock);
}
/*
* Properly track delayed allocation bytes in the inode and to maintain the
* list of inodes that have pending delalloc work to be done.
*/
void btrfs_set_delalloc_extent(struct inode *inode, struct extent_state *state,
unsigned *bits)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
WARN_ON(1);
/*
* set_bit and clear bit hooks normally require _irqsave/restore
* but in this case, we are only testing for the DELALLOC
* bit, which is only set or cleared with irqs on
*/
if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
struct btrfs_root *root = BTRFS_I(inode)->root;
u64 len = state->end + 1 - state->start;
u32 num_extents = count_max_extents(fs_info, len);
bool do_list = !btrfs_is_free_space_inode(BTRFS_I(inode));
spin_lock(&BTRFS_I(inode)->lock);
btrfs_mod_outstanding_extents(BTRFS_I(inode), num_extents);
spin_unlock(&BTRFS_I(inode)->lock);
/* For sanity tests */
if (btrfs_is_testing(fs_info))
return;
percpu_counter_add_batch(&fs_info->delalloc_bytes, len,
fs_info->delalloc_batch);
spin_lock(&BTRFS_I(inode)->lock);
BTRFS_I(inode)->delalloc_bytes += len;
if (*bits & EXTENT_DEFRAG)
BTRFS_I(inode)->defrag_bytes += len;
if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
&BTRFS_I(inode)->runtime_flags))
btrfs_add_delalloc_inodes(root, inode);
spin_unlock(&BTRFS_I(inode)->lock);
}
if (!(state->state & EXTENT_DELALLOC_NEW) &&
(*bits & EXTENT_DELALLOC_NEW)) {
spin_lock(&BTRFS_I(inode)->lock);
BTRFS_I(inode)->new_delalloc_bytes += state->end + 1 -
state->start;
spin_unlock(&BTRFS_I(inode)->lock);
}
}
/*
* Once a range is no longer delalloc this function ensures that proper
* accounting happens.
*/
void btrfs_clear_delalloc_extent(struct inode *vfs_inode,
struct extent_state *state, unsigned *bits)
{
struct btrfs_inode *inode = BTRFS_I(vfs_inode);
struct btrfs_fs_info *fs_info = btrfs_sb(vfs_inode->i_sb);
u64 len = state->end + 1 - state->start;
u32 num_extents = count_max_extents(fs_info, len);
if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG)) {
spin_lock(&inode->lock);
inode->defrag_bytes -= len;
spin_unlock(&inode->lock);
}
/*
* set_bit and clear bit hooks normally require _irqsave/restore
* but in this case, we are only testing for the DELALLOC
* bit, which is only set or cleared with irqs on
*/
if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
struct btrfs_root *root = inode->root;
bool do_list = !btrfs_is_free_space_inode(inode);
spin_lock(&inode->lock);
btrfs_mod_outstanding_extents(inode, -num_extents);
spin_unlock(&inode->lock);
/*
* We don't reserve metadata space for space cache inodes so we
* don't need to call delalloc_release_metadata if there is an
* error.
*/
if (*bits & EXTENT_CLEAR_META_RESV &&
root != fs_info->tree_root)
btrfs_delalloc_release_metadata(inode, len, true);
/* For sanity tests. */
if (btrfs_is_testing(fs_info))
return;
if (!btrfs_is_data_reloc_root(root) &&
do_list && !(state->state & EXTENT_NORESERVE) &&
(*bits & EXTENT_CLEAR_DATA_RESV))
btrfs_free_reserved_data_space_noquota(fs_info, len);
percpu_counter_add_batch(&fs_info->delalloc_bytes, -len,
fs_info->delalloc_batch);
spin_lock(&inode->lock);
inode->delalloc_bytes -= len;
if (do_list && inode->delalloc_bytes == 0 &&
test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
&inode->runtime_flags))
btrfs_del_delalloc_inode(root, inode);
spin_unlock(&inode->lock);
}
if ((state->state & EXTENT_DELALLOC_NEW) &&
(*bits & EXTENT_DELALLOC_NEW)) {
spin_lock(&inode->lock);
ASSERT(inode->new_delalloc_bytes >= len);
inode->new_delalloc_bytes -= len;
if (*bits & EXTENT_ADD_INODE_BYTES)
inode_add_bytes(&inode->vfs_inode, len);
spin_unlock(&inode->lock);
}
}
/*
* btrfs_bio_fits_in_stripe - Checks whether the size of the given bio will fit
* in a chunk's stripe. This function ensures that bios do not span a
* stripe/chunk
*
* @page - The page we are about to add to the bio
* @size - size we want to add to the bio
* @bio - bio we want to ensure is smaller than a stripe
* @bio_flags - flags of the bio
*
* return 1 if page cannot be added to the bio
* return 0 if page can be added to the bio
* return error otherwise
*/
int btrfs_bio_fits_in_stripe(struct page *page, size_t size, struct bio *bio,
unsigned long bio_flags)
{
struct inode *inode = page->mapping->host;
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
u64 logical = bio->bi_iter.bi_sector << 9;
u32 bio_len = bio->bi_iter.bi_size;
struct extent_map *em;
int ret = 0;
struct btrfs_io_geometry geom;
if (bio_flags & EXTENT_BIO_COMPRESSED)
return 0;
em = btrfs_get_chunk_map(fs_info, logical, fs_info->sectorsize);
if (IS_ERR(em))
return PTR_ERR(em);
ret = btrfs_get_io_geometry(fs_info, em, btrfs_op(bio), logical, &geom);
if (ret < 0)
goto out;
if (geom.len < bio_len + size)
ret = 1;
out:
free_extent_map(em);
return ret;
}
/*
* in order to insert checksums into the metadata in large chunks,
* we wait until bio submission time. All the pages in the bio are
* checksummed and sums are attached onto the ordered extent record.
*
* At IO completion time the cums attached on the ordered extent record
* are inserted into the btree
*/
static blk_status_t btrfs_submit_bio_start(struct inode *inode, struct bio *bio,
u64 dio_file_offset)
{
return btrfs_csum_one_bio(BTRFS_I(inode), bio, 0, 0);
}
/*
* Split an extent_map at [start, start + len]
*
* This function is intended to be used only for extract_ordered_extent().
*/
static int split_zoned_em(struct btrfs_inode *inode, u64 start, u64 len,
u64 pre, u64 post)
{
struct extent_map_tree *em_tree = &inode->extent_tree;
struct extent_map *em;
struct extent_map *split_pre = NULL;
struct extent_map *split_mid = NULL;
struct extent_map *split_post = NULL;
int ret = 0;
unsigned long flags;
/* Sanity check */
if (pre == 0 && post == 0)
return 0;
split_pre = alloc_extent_map();
if (pre)
split_mid = alloc_extent_map();
if (post)
split_post = alloc_extent_map();
if (!split_pre || (pre && !split_mid) || (post && !split_post)) {
ret = -ENOMEM;
goto out;
}
ASSERT(pre + post < len);
lock_extent(&inode->io_tree, start, start + len - 1);
write_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, start, len);
if (!em) {
ret = -EIO;
goto out_unlock;
}
ASSERT(em->len == len);
ASSERT(!test_bit(EXTENT_FLAG_COMPRESSED, &em->flags));
ASSERT(em->block_start < EXTENT_MAP_LAST_BYTE);
ASSERT(test_bit(EXTENT_FLAG_PINNED, &em->flags));
ASSERT(!test_bit(EXTENT_FLAG_LOGGING, &em->flags));
ASSERT(!list_empty(&em->list));
flags = em->flags;
clear_bit(EXTENT_FLAG_PINNED, &em->flags);
/* First, replace the em with a new extent_map starting from * em->start */
split_pre->start = em->start;
split_pre->len = (pre ? pre : em->len - post);
split_pre->orig_start = split_pre->start;
split_pre->block_start = em->block_start;
split_pre->block_len = split_pre->len;
split_pre->orig_block_len = split_pre->block_len;
split_pre->ram_bytes = split_pre->len;
split_pre->flags = flags;
split_pre->compress_type = em->compress_type;
split_pre->generation = em->generation;
replace_extent_mapping(em_tree, em, split_pre, 1);
/*
* Now we only have an extent_map at:
* [em->start, em->start + pre] if pre != 0
* [em->start, em->start + em->len - post] if pre == 0
*/
if (pre) {
/* Insert the middle extent_map */
split_mid->start = em->start + pre;
split_mid->len = em->len - pre - post;
split_mid->orig_start = split_mid->start;
split_mid->block_start = em->block_start + pre;
split_mid->block_len = split_mid->len;
split_mid->orig_block_len = split_mid->block_len;
split_mid->ram_bytes = split_mid->len;
split_mid->flags = flags;
split_mid->compress_type = em->compress_type;
split_mid->generation = em->generation;
add_extent_mapping(em_tree, split_mid, 1);
}
if (post) {
split_post->start = em->start + em->len - post;
split_post->len = post;
split_post->orig_start = split_post->start;
split_post->block_start = em->block_start + em->len - post;
split_post->block_len = split_post->len;
split_post->orig_block_len = split_post->block_len;
split_post->ram_bytes = split_post->len;
split_post->flags = flags;
split_post->compress_type = em->compress_type;
split_post->generation = em->generation;
add_extent_mapping(em_tree, split_post, 1);
}
/* Once for us */
free_extent_map(em);
/* Once for the tree */
free_extent_map(em);
out_unlock:
write_unlock(&em_tree->lock);
unlock_extent(&inode->io_tree, start, start + len - 1);
out:
free_extent_map(split_pre);
free_extent_map(split_mid);
free_extent_map(split_post);
return ret;
}
static blk_status_t extract_ordered_extent(struct btrfs_inode *inode,
struct bio *bio, loff_t file_offset)
{
struct btrfs_ordered_extent *ordered;
u64 start = (u64)bio->bi_iter.bi_sector << SECTOR_SHIFT;
u64 file_len;
u64 len = bio->bi_iter.bi_size;
u64 end = start + len;
u64 ordered_end;
u64 pre, post;
int ret = 0;
ordered = btrfs_lookup_ordered_extent(inode, file_offset);
if (WARN_ON_ONCE(!ordered))
return BLK_STS_IOERR;
/* No need to split */
if (ordered->disk_num_bytes == len)
goto out;
/* We cannot split once end_bio'd ordered extent */
if (WARN_ON_ONCE(ordered->bytes_left != ordered->disk_num_bytes)) {
ret = -EINVAL;
goto out;
}
/* We cannot split a compressed ordered extent */
if (WARN_ON_ONCE(ordered->disk_num_bytes != ordered->num_bytes)) {
ret = -EINVAL;
goto out;
}
ordered_end = ordered->disk_bytenr + ordered->disk_num_bytes;
/* bio must be in one ordered extent */
if (WARN_ON_ONCE(start < ordered->disk_bytenr || end > ordered_end)) {
ret = -EINVAL;
goto out;
}
/* Checksum list should be empty */
if (WARN_ON_ONCE(!list_empty(&ordered->list))) {
ret = -EINVAL;
goto out;
}
file_len = ordered->num_bytes;
pre = start - ordered->disk_bytenr;
post = ordered_end - end;
ret = btrfs_split_ordered_extent(ordered, pre, post);
if (ret)
goto out;
ret = split_zoned_em(inode, file_offset, file_len, pre, post);
out:
btrfs_put_ordered_extent(ordered);
return errno_to_blk_status(ret);
}
/*
* extent_io.c submission hook. This does the right thing for csum calculation
* on write, or reading the csums from the tree before a read.
*
* Rules about async/sync submit,
* a) read: sync submit
*
* b) write without checksum: sync submit
*
* c) write with checksum:
* c-1) if bio is issued by fsync: sync submit
* (sync_writers != 0)
*
* c-2) if root is reloc root: sync submit
* (only in case of buffered IO)
*
* c-3) otherwise: async submit
*/
blk_status_t btrfs_submit_data_bio(struct inode *inode, struct bio *bio,
int mirror_num, unsigned long bio_flags)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_root *root = BTRFS_I(inode)->root;
enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA;
blk_status_t ret = 0;
int skip_sum;
int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
skip_sum = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM) ||
!fs_info->csum_root;
if (btrfs_is_free_space_inode(BTRFS_I(inode)))
metadata = BTRFS_WQ_ENDIO_FREE_SPACE;
if (bio_op(bio) == REQ_OP_ZONE_APPEND) {
struct page *page = bio_first_bvec_all(bio)->bv_page;
loff_t file_offset = page_offset(page);
ret = extract_ordered_extent(BTRFS_I(inode), bio, file_offset);
if (ret)
goto out;
}
if (btrfs_op(bio) != BTRFS_MAP_WRITE) {
ret = btrfs_bio_wq_end_io(fs_info, bio, metadata);
if (ret)
goto out;
if (bio_flags & EXTENT_BIO_COMPRESSED) {
ret = btrfs_submit_compressed_read(inode, bio,
mirror_num,
bio_flags);
goto out;
} else {
/*
* Lookup bio sums does extra checks around whether we
* need to csum or not, which is why we ignore skip_sum
* here.
*/
ret = btrfs_lookup_bio_sums(inode, bio, NULL);
if (ret)
goto out;
}
goto mapit;
} else if (async && !skip_sum) {
/* csum items have already been cloned */
if (btrfs_is_data_reloc_root(root))
goto mapit;
/* we're doing a write, do the async checksumming */
ret = btrfs_wq_submit_bio(inode, bio, mirror_num, bio_flags,
0, btrfs_submit_bio_start);
goto out;
} else if (!skip_sum) {
ret = btrfs_csum_one_bio(BTRFS_I(inode), bio, 0, 0);
if (ret)
goto out;
}
mapit:
ret = btrfs_map_bio(fs_info, bio, mirror_num);
out:
if (ret) {
bio->bi_status = ret;
bio_endio(bio);
}
return ret;
}
/*
* given a list of ordered sums record them in the inode. This happens
* at IO completion time based on sums calculated at bio submission time.
*/
static int add_pending_csums(struct btrfs_trans_handle *trans,
struct list_head *list)
{
struct btrfs_ordered_sum *sum;
int ret;
list_for_each_entry(sum, list, list) {
trans->adding_csums = true;
ret = btrfs_csum_file_blocks(trans, trans->fs_info->csum_root, sum);
trans->adding_csums = false;
if (ret)
return ret;
}
return 0;
}
static int btrfs_find_new_delalloc_bytes(struct btrfs_inode *inode,
const u64 start,
const u64 len,
struct extent_state **cached_state)
{
u64 search_start = start;
const u64 end = start + len - 1;
while (search_start < end) {
const u64 search_len = end - search_start + 1;
struct extent_map *em;
u64 em_len;
int ret = 0;
em = btrfs_get_extent(inode, NULL, 0, search_start, search_len);
if (IS_ERR(em))
return PTR_ERR(em);
if (em->block_start != EXTENT_MAP_HOLE)
goto next;
em_len = em->len;
if (em->start < search_start)
em_len -= search_start - em->start;
if (em_len > search_len)
em_len = search_len;
ret = set_extent_bit(&inode->io_tree, search_start,
search_start + em_len - 1,
EXTENT_DELALLOC_NEW, 0, NULL, cached_state,
GFP_NOFS, NULL);
next:
search_start = extent_map_end(em);
free_extent_map(em);
if (ret)
return ret;
}
return 0;
}
int btrfs_set_extent_delalloc(struct btrfs_inode *inode, u64 start, u64 end,
unsigned int extra_bits,
struct extent_state **cached_state)
{
WARN_ON(PAGE_ALIGNED(end));
if (start >= i_size_read(&inode->vfs_inode) &&
!(inode->flags & BTRFS_INODE_PREALLOC)) {
/*
* There can't be any extents following eof in this case so just
* set the delalloc new bit for the range directly.
*/
extra_bits |= EXTENT_DELALLOC_NEW;
} else {
int ret;
ret = btrfs_find_new_delalloc_bytes(inode, start,
end + 1 - start,
cached_state);
if (ret)
return ret;
}
return set_extent_delalloc(&inode->io_tree, start, end, extra_bits,
cached_state);
}
/* see btrfs_writepage_start_hook for details on why this is required */
struct btrfs_writepage_fixup {
struct page *page;
struct inode *inode;
struct btrfs_work work;
};
static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
{
struct btrfs_writepage_fixup *fixup;
struct btrfs_ordered_extent *ordered;
struct extent_state *cached_state = NULL;
struct extent_changeset *data_reserved = NULL;
struct page *page;
struct btrfs_inode *inode;
u64 page_start;
u64 page_end;
int ret = 0;
bool free_delalloc_space = true;
fixup = container_of(work, struct btrfs_writepage_fixup, work);
page = fixup->page;
inode = BTRFS_I(fixup->inode);
page_start = page_offset(page);
page_end = page_offset(page) + PAGE_SIZE - 1;
/*
* This is similar to page_mkwrite, we need to reserve the space before
* we take the page lock.
*/
ret = btrfs_delalloc_reserve_space(inode, &data_reserved, page_start,
PAGE_SIZE);
again:
lock_page(page);
/*
* Before we queued this fixup, we took a reference on the page.
* page->mapping may go NULL, but it shouldn't be moved to a different
* address space.
*/
if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
/*
* Unfortunately this is a little tricky, either
*
* 1) We got here and our page had already been dealt with and
* we reserved our space, thus ret == 0, so we need to just
* drop our space reservation and bail. This can happen the
* first time we come into the fixup worker, or could happen
* while waiting for the ordered extent.
* 2) Our page was already dealt with, but we happened to get an
* ENOSPC above from the btrfs_delalloc_reserve_space. In
* this case we obviously don't have anything to release, but
* because the page was already dealt with we don't want to
* mark the page with an error, so make sure we're resetting
* ret to 0. This is why we have this check _before_ the ret
* check, because we do not want to have a surprise ENOSPC
* when the page was already properly dealt with.
*/
if (!ret) {
btrfs_delalloc_release_extents(inode, PAGE_SIZE);
btrfs_delalloc_release_space(inode, data_reserved,
page_start, PAGE_SIZE,
true);
}
ret = 0;
goto out_page;
}
/*
* We can't mess with the page state unless it is locked, so now that
* it is locked bail if we failed to make our space reservation.
*/
if (ret)
goto out_page;
lock_extent_bits(&inode->io_tree, page_start, page_end, &cached_state);
/* already ordered? We're done */
if (PageOrdered(page))
goto out_reserved;
ordered = btrfs_lookup_ordered_range(inode, page_start, PAGE_SIZE);
if (ordered) {
unlock_extent_cached(&inode->io_tree, page_start, page_end,
&cached_state);
unlock_page(page);
btrfs_start_ordered_extent(ordered, 1);
btrfs_put_ordered_extent(ordered);
goto again;
}
ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 0,
&cached_state);
if (ret)
goto out_reserved;
/*
* Everything went as planned, we're now the owner of a dirty page with
* delayed allocation bits set and space reserved for our COW
* destination.
*
* The page was dirty when we started, nothing should have cleaned it.
*/
BUG_ON(!PageDirty(page));
free_delalloc_space = false;
out_reserved:
btrfs_delalloc_release_extents(inode, PAGE_SIZE);
if (free_delalloc_space)
btrfs_delalloc_release_space(inode, data_reserved, page_start,
PAGE_SIZE, true);
unlock_extent_cached(&inode->io_tree, page_start, page_end,
&cached_state);
out_page:
if (ret) {
/*
* We hit ENOSPC or other errors. Update the mapping and page
* to reflect the errors and clean the page.
*/
mapping_set_error(page->mapping, ret);
end_extent_writepage(page, ret, page_start, page_end);
clear_page_dirty_for_io(page);
SetPageError(page);
}
ClearPageChecked(page);
unlock_page(page);
put_page(page);
kfree(fixup);
extent_changeset_free(data_reserved);
/*
* As a precaution, do a delayed iput in case it would be the last iput
* that could need flushing space. Recursing back to fixup worker would
* deadlock.
*/
btrfs_add_delayed_iput(&inode->vfs_inode);
}
/*
* There are a few paths in the higher layers of the kernel that directly
* set the page dirty bit without asking the filesystem if it is a
* good idea. This causes problems because we want to make sure COW
* properly happens and the data=ordered rules are followed.
*
* In our case any range that doesn't have the ORDERED bit set
* hasn't been properly setup for IO. We kick off an async process
* to fix it up. The async helper will wait for ordered extents, set
* the delalloc bit and make it safe to write the page.
*/
int btrfs_writepage_cow_fixup(struct page *page)
{
struct inode *inode = page->mapping->host;
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_writepage_fixup *fixup;
/* This page has ordered extent covering it already */
if (PageOrdered(page))
return 0;
/*
* PageChecked is set below when we create a fixup worker for this page,
* don't try to create another one if we're already PageChecked()
*
* The extent_io writepage code will redirty the page if we send back
* EAGAIN.
*/
if (PageChecked(page))
return -EAGAIN;
fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
if (!fixup)
return -EAGAIN;
/*
* We are already holding a reference to this inode from
* write_cache_pages. We need to hold it because the space reservation
* takes place outside of the page lock, and we can't trust
* page->mapping outside of the page lock.
*/
ihold(inode);
SetPageChecked(page);
get_page(page);
btrfs_init_work(&fixup->work, btrfs_writepage_fixup_worker, NULL, NULL);
fixup->page = page;
fixup->inode = inode;
btrfs_queue_work(fs_info->fixup_workers, &fixup->work);
return -EAGAIN;
}
static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode, u64 file_pos,
struct btrfs_file_extent_item *stack_fi,
const bool update_inode_bytes,
u64 qgroup_reserved)
{
struct btrfs_root *root = inode->root;
const u64 sectorsize = root->fs_info->sectorsize;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_key ins;
u64 disk_num_bytes = btrfs_stack_file_extent_disk_num_bytes(stack_fi);
u64 disk_bytenr = btrfs_stack_file_extent_disk_bytenr(stack_fi);
u64 num_bytes = btrfs_stack_file_extent_num_bytes(stack_fi);
u64 ram_bytes = btrfs_stack_file_extent_ram_bytes(stack_fi);
struct btrfs_drop_extents_args drop_args = { 0 };
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
/*
* we may be replacing one extent in the tree with another.
* The new extent is pinned in the extent map, and we don't want
* to drop it from the cache until it is completely in the btree.
*
* So, tell btrfs_drop_extents to leave this extent in the cache.
* the caller is expected to unpin it and allow it to be merged
* with the others.
*/
drop_args.path = path;
drop_args.start = file_pos;
drop_args.end = file_pos + num_bytes;
drop_args.replace_extent = true;
drop_args.extent_item_size = sizeof(*stack_fi);
ret = btrfs_drop_extents(trans, root, inode, &drop_args);
if (ret)
goto out;
if (!drop_args.extent_inserted) {
ins.objectid = btrfs_ino(inode);
ins.offset = file_pos;
ins.type = BTRFS_EXTENT_DATA_KEY;
ret = btrfs_insert_empty_item(trans, root, path, &ins,
sizeof(*stack_fi));
if (ret)
goto out;
}
leaf = path->nodes[0];
btrfs_set_stack_file_extent_generation(stack_fi, trans->transid);
write_extent_buffer(leaf, stack_fi,
btrfs_item_ptr_offset(leaf, path->slots[0]),
sizeof(struct btrfs_file_extent_item));
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(path);
/*
* If we dropped an inline extent here, we know the range where it is
* was not marked with the EXTENT_DELALLOC_NEW bit, so we update the
* number of bytes only for that range containing the inline extent.
* The remaining of the range will be processed when clearning the
* EXTENT_DELALLOC_BIT bit through the ordered extent completion.
*/
if (file_pos == 0 && !IS_ALIGNED(drop_args.bytes_found, sectorsize)) {
u64 inline_size = round_down(drop_args.bytes_found, sectorsize);
inline_size = drop_args.bytes_found - inline_size;
btrfs_update_inode_bytes(inode, sectorsize, inline_size);
drop_args.bytes_found -= inline_size;
num_bytes -= sectorsize;
}
if (update_inode_bytes)
btrfs_update_inode_bytes(inode, num_bytes, drop_args.bytes_found);
ins.objectid = disk_bytenr;
ins.offset = disk_num_bytes;
ins.type = BTRFS_EXTENT_ITEM_KEY;
ret = btrfs_inode_set_file_extent_range(inode, file_pos, ram_bytes);
if (ret)
goto out;
ret = btrfs_alloc_reserved_file_extent(trans, root, btrfs_ino(inode),
file_pos, qgroup_reserved, &ins);
out:
btrfs_free_path(path);
return ret;
}
static void btrfs_release_delalloc_bytes(struct btrfs_fs_info *fs_info,
u64 start, u64 len)
{
struct btrfs_block_group *cache;
cache = btrfs_lookup_block_group(fs_info, start);
ASSERT(cache);
spin_lock(&cache->lock);
cache->delalloc_bytes -= len;
spin_unlock(&cache->lock);
btrfs_put_block_group(cache);
}
static int insert_ordered_extent_file_extent(struct btrfs_trans_handle *trans,
struct btrfs_ordered_extent *oe)
{
struct btrfs_file_extent_item stack_fi;
u64 logical_len;
bool update_inode_bytes;
memset(&stack_fi, 0, sizeof(stack_fi));
btrfs_set_stack_file_extent_type(&stack_fi, BTRFS_FILE_EXTENT_REG);
btrfs_set_stack_file_extent_disk_bytenr(&stack_fi, oe->disk_bytenr);
btrfs_set_stack_file_extent_disk_num_bytes(&stack_fi,
oe->disk_num_bytes);
if (test_bit(BTRFS_ORDERED_TRUNCATED, &oe->flags))
logical_len = oe->truncated_len;
else
logical_len = oe->num_bytes;
btrfs_set_stack_file_extent_num_bytes(&stack_fi, logical_len);
btrfs_set_stack_file_extent_ram_bytes(&stack_fi, logical_len);
btrfs_set_stack_file_extent_compression(&stack_fi, oe->compress_type);
/* Encryption and other encoding is reserved and all 0 */
/*
* For delalloc, when completing an ordered extent we update the inode's
* bytes when clearing the range in the inode's io tree, so pass false
* as the argument 'update_inode_bytes' to insert_reserved_file_extent(),
* except if the ordered extent was truncated.
*/
update_inode_bytes = test_bit(BTRFS_ORDERED_DIRECT, &oe->flags) ||
test_bit(BTRFS_ORDERED_TRUNCATED, &oe->flags);
return insert_reserved_file_extent(trans, BTRFS_I(oe->inode),
oe->file_offset, &stack_fi,
update_inode_bytes, oe->qgroup_rsv);
}
/*
* As ordered data IO finishes, this gets called so we can finish
* an ordered extent if the range of bytes in the file it covers are
* fully written.
*/
static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
{
struct btrfs_inode *inode = BTRFS_I(ordered_extent->inode);
struct btrfs_root *root = inode->root;
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_trans_handle *trans = NULL;
struct extent_io_tree *io_tree = &inode->io_tree;
struct extent_state *cached_state = NULL;
u64 start, end;
int compress_type = 0;
int ret = 0;
u64 logical_len = ordered_extent->num_bytes;
bool freespace_inode;
bool truncated = false;
bool clear_reserved_extent = true;
unsigned int clear_bits = EXTENT_DEFRAG;
start = ordered_extent->file_offset;
end = start + ordered_extent->num_bytes - 1;
if (!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
!test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags) &&
!test_bit(BTRFS_ORDERED_DIRECT, &ordered_extent->flags))
clear_bits |= EXTENT_DELALLOC_NEW;
freespace_inode = btrfs_is_free_space_inode(inode);
if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
ret = -EIO;
goto out;
}
if (ordered_extent->bdev)
btrfs_rewrite_logical_zoned(ordered_extent);
btrfs_free_io_failure_record(inode, start, end);
if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
truncated = true;
logical_len = ordered_extent->truncated_len;
/* Truncated the entire extent, don't bother adding */
if (!logical_len)
goto out;
}
if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
btrfs_inode_safe_disk_i_size_write(inode, 0);
if (freespace_inode)
trans = btrfs_join_transaction_spacecache(root);
else
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
trans = NULL;
goto out;
}
trans->block_rsv = &inode->block_rsv;
ret = btrfs_update_inode_fallback(trans, root, inode);
if (ret) /* -ENOMEM or corruption */
btrfs_abort_transaction(trans, ret);
goto out;
}
clear_bits |= EXTENT_LOCKED;
lock_extent_bits(io_tree, start, end, &cached_state);
if (freespace_inode)
trans = btrfs_join_transaction_spacecache(root);
else
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
trans = NULL;
goto out;
}
trans->block_rsv = &inode->block_rsv;
if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
compress_type = ordered_extent->compress_type;
if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
BUG_ON(compress_type);
ret = btrfs_mark_extent_written(trans, inode,
ordered_extent->file_offset,
ordered_extent->file_offset +
logical_len);
btrfs_zoned_release_data_reloc_bg(fs_info, ordered_extent->disk_bytenr,
ordered_extent->disk_num_bytes);
} else {
BUG_ON(root == fs_info->tree_root);
ret = insert_ordered_extent_file_extent(trans, ordered_extent);
if (!ret) {
clear_reserved_extent = false;
btrfs_release_delalloc_bytes(fs_info,
ordered_extent->disk_bytenr,
ordered_extent->disk_num_bytes);
}
}
unpin_extent_cache(&inode->extent_tree, ordered_extent->file_offset,
ordered_extent->num_bytes, trans->transid);
if (ret < 0) {
btrfs_abort_transaction(trans, ret);
goto out;
}
ret = add_pending_csums(trans, &ordered_extent->list);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out;
}
/*
* If this is a new delalloc range, clear its new delalloc flag to
* update the inode's number of bytes. This needs to be done first
* before updating the inode item.
*/
if ((clear_bits & EXTENT_DELALLOC_NEW) &&
!test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags))
clear_extent_bit(&inode->io_tree, start, end,
EXTENT_DELALLOC_NEW | EXTENT_ADD_INODE_BYTES,
0, 0, &cached_state);
btrfs_inode_safe_disk_i_size_write(inode, 0);
ret = btrfs_update_inode_fallback(trans, root, inode);
if (ret) { /* -ENOMEM or corruption */
btrfs_abort_transaction(trans, ret);
goto out;
}
ret = 0;
out:
clear_extent_bit(&inode->io_tree, start, end, clear_bits,
(clear_bits & EXTENT_LOCKED) ? 1 : 0, 0,
&cached_state);
if (trans)
btrfs_end_transaction(trans);
if (ret || truncated) {
u64 unwritten_start = start;
/*
* If we failed to finish this ordered extent for any reason we
* need to make sure BTRFS_ORDERED_IOERR is set on the ordered
* extent, and mark the inode with the error if it wasn't
* already set. Any error during writeback would have already
* set the mapping error, so we need to set it if we're the ones
* marking this ordered extent as failed.
*/
if (ret && !test_and_set_bit(BTRFS_ORDERED_IOERR,
&ordered_extent->flags))
mapping_set_error(ordered_extent->inode->i_mapping, -EIO);
if (truncated)
unwritten_start += logical_len;
clear_extent_uptodate(io_tree, unwritten_start, end, NULL);
/* Drop the cache for the part of the extent we didn't write. */
btrfs_drop_extent_cache(inode, unwritten_start, end, 0);
/*
* If the ordered extent had an IOERR or something else went
* wrong we need to return the space for this ordered extent
* back to the allocator. We only free the extent in the
* truncated case if we didn't write out the extent at all.
*
* If we made it past insert_reserved_file_extent before we
* errored out then we don't need to do this as the accounting
* has already been done.
*/
if ((ret || !logical_len) &&
clear_reserved_extent &&
!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
!test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
/*
* Discard the range before returning it back to the
* free space pool
*/
if (ret && btrfs_test_opt(fs_info, DISCARD_SYNC))
btrfs_discard_extent(fs_info,
ordered_extent->disk_bytenr,
ordered_extent->disk_num_bytes,
NULL);
btrfs_free_reserved_extent(fs_info,
ordered_extent->disk_bytenr,
ordered_extent->disk_num_bytes, 1);
/*
* Actually free the qgroup rsv which was released when
* the ordered extent was created.
*/
btrfs_qgroup_free_refroot(fs_info, inode->root->root_key.objectid,
ordered_extent->qgroup_rsv,
BTRFS_QGROUP_RSV_DATA);
}
}
/*
* This needs to be done to make sure anybody waiting knows we are done
* updating everything for this ordered extent.
*/
btrfs_remove_ordered_extent(inode, ordered_extent);
/* once for us */
btrfs_put_ordered_extent(ordered_extent);
/* once for the tree */
btrfs_put_ordered_extent(ordered_extent);
return ret;
}
static void finish_ordered_fn(struct btrfs_work *work)
{
struct btrfs_ordered_extent *ordered_extent;
ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
btrfs_finish_ordered_io(ordered_extent);
}
void btrfs_writepage_endio_finish_ordered(struct btrfs_inode *inode,
struct page *page, u64 start,
u64 end, bool uptodate)
{
trace_btrfs_writepage_end_io_hook(inode, start, end, uptodate);
btrfs_mark_ordered_io_finished(inode, page, start, end + 1 - start,
finish_ordered_fn, uptodate);
}
/*
* check_data_csum - verify checksum of one sector of uncompressed data
* @inode: inode
* @io_bio: btrfs_io_bio which contains the csum
* @bio_offset: offset to the beginning of the bio (in bytes)
* @page: page where is the data to be verified
* @pgoff: offset inside the page
* @start: logical offset in the file
*
* The length of such check is always one sector size.
*/
static int check_data_csum(struct inode *inode, struct btrfs_io_bio *io_bio,
u32 bio_offset, struct page *page, u32 pgoff,
u64 start)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
char *kaddr;
u32 len = fs_info->sectorsize;
const u32 csum_size = fs_info->csum_size;
unsigned int offset_sectors;
u8 *csum_expected;
u8 csum[BTRFS_CSUM_SIZE];
ASSERT(pgoff + len <= PAGE_SIZE);
offset_sectors = bio_offset >> fs_info->sectorsize_bits;
csum_expected = ((u8 *)io_bio->csum) + offset_sectors * csum_size;
kaddr = kmap_atomic(page);
shash->tfm = fs_info->csum_shash;
crypto_shash_digest(shash, kaddr + pgoff, len, csum);
if (memcmp(csum, csum_expected, csum_size))
goto zeroit;
kunmap_atomic(kaddr);
return 0;
zeroit:
btrfs_print_data_csum_error(BTRFS_I(inode), start, csum, csum_expected,
io_bio->mirror_num);
if (io_bio->device)
btrfs_dev_stat_inc_and_print(io_bio->device,
BTRFS_DEV_STAT_CORRUPTION_ERRS);
memset(kaddr + pgoff, 1, len);
flush_dcache_page(page);
kunmap_atomic(kaddr);
return -EIO;
}
/*
* When reads are done, we need to check csums to verify the data is correct.
* if there's a match, we allow the bio to finish. If not, the code in
* extent_io.c will try to find good copies for us.
*
* @bio_offset: offset to the beginning of the bio (in bytes)
* @start: file offset of the range start
* @end: file offset of the range end (inclusive)
*
* Return a bitmap where bit set means a csum mismatch, and bit not set means
* csum match.
*/
unsigned int btrfs_verify_data_csum(struct btrfs_io_bio *io_bio, u32 bio_offset,
struct page *page, u64 start, u64 end)
{
struct inode *inode = page->mapping->host;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct btrfs_root *root = BTRFS_I(inode)->root;
const u32 sectorsize = root->fs_info->sectorsize;
u32 pg_off;
unsigned int result = 0;
if (PageChecked(page)) {
ClearPageChecked(page);
return 0;
}
/*
* For subpage case, above PageChecked is not safe as it's not subpage
* compatible.
* But for now only cow fixup and compressed read utilize PageChecked
* flag, while in this context we can easily use io_bio->csum to
* determine if we really need to do csum verification.
*
* So for now, just exit if io_bio->csum is NULL, as it means it's
* compressed read, and its compressed data csum has already been
* verified.
*/
if (io_bio->csum == NULL)
return 0;
if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
return 0;
if (!root->fs_info->csum_root)
return 0;
ASSERT(page_offset(page) <= start &&
end <= page_offset(page) + PAGE_SIZE - 1);
for (pg_off = offset_in_page(start);
pg_off < offset_in_page(end);
pg_off += sectorsize, bio_offset += sectorsize) {
u64 file_offset = pg_off + page_offset(page);
int ret;
if (btrfs_is_data_reloc_root(root) &&
test_range_bit(io_tree, file_offset,
file_offset + sectorsize - 1,
EXTENT_NODATASUM, 1, NULL)) {
/* Skip the range without csum for data reloc inode */
clear_extent_bits(io_tree, file_offset,
file_offset + sectorsize - 1,
EXTENT_NODATASUM);
continue;
}
ret = check_data_csum(inode, io_bio, bio_offset, page, pg_off,
page_offset(page) + pg_off);
if (ret < 0) {
const int nr_bit = (pg_off - offset_in_page(start)) >>
root->fs_info->sectorsize_bits;
result |= (1U << nr_bit);
}
}
return result;
}
/*
* btrfs_add_delayed_iput - perform a delayed iput on @inode
*
* @inode: The inode we want to perform iput on
*
* This function uses the generic vfs_inode::i_count to track whether we should
* just decrement it (in case it's > 1) or if this is the last iput then link
* the inode to the delayed iput machinery. Delayed iputs are processed at
* transaction commit time/superblock commit/cleaner kthread.
*/
void btrfs_add_delayed_iput(struct inode *inode)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_inode *binode = BTRFS_I(inode);
if (atomic_add_unless(&inode->i_count, -1, 1))
return;
atomic_inc(&fs_info->nr_delayed_iputs);
spin_lock(&fs_info->delayed_iput_lock);
ASSERT(list_empty(&binode->delayed_iput));
list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs);
spin_unlock(&fs_info->delayed_iput_lock);
if (!test_bit(BTRFS_FS_CLEANER_RUNNING, &fs_info->flags))
wake_up_process(fs_info->cleaner_kthread);
}
static void run_delayed_iput_locked(struct btrfs_fs_info *fs_info,
struct btrfs_inode *inode)
{
list_del_init(&inode->delayed_iput);
spin_unlock(&fs_info->delayed_iput_lock);
iput(&inode->vfs_inode);
if (atomic_dec_and_test(&fs_info->nr_delayed_iputs))
wake_up(&fs_info->delayed_iputs_wait);
spin_lock(&fs_info->delayed_iput_lock);
}
static void btrfs_run_delayed_iput(struct btrfs_fs_info *fs_info,
struct btrfs_inode *inode)
{
if (!list_empty(&inode->delayed_iput)) {
spin_lock(&fs_info->delayed_iput_lock);
if (!list_empty(&inode->delayed_iput))
run_delayed_iput_locked(fs_info, inode);
spin_unlock(&fs_info->delayed_iput_lock);
}
}
void btrfs_run_delayed_iputs(struct btrfs_fs_info *fs_info)
{
spin_lock(&fs_info->delayed_iput_lock);
while (!list_empty(&fs_info->delayed_iputs)) {
struct btrfs_inode *inode;
inode = list_first_entry(&fs_info->delayed_iputs,
struct btrfs_inode, delayed_iput);
run_delayed_iput_locked(fs_info, inode);
cond_resched_lock(&fs_info->delayed_iput_lock);
}
spin_unlock(&fs_info->delayed_iput_lock);
}
/**
* Wait for flushing all delayed iputs
*
* @fs_info: the filesystem
*
* This will wait on any delayed iputs that are currently running with KILLABLE
* set. Once they are all done running we will return, unless we are killed in
* which case we return EINTR. This helps in user operations like fallocate etc
* that might get blocked on the iputs.
*
* Return EINTR if we were killed, 0 if nothing's pending
*/
int btrfs_wait_on_delayed_iputs(struct btrfs_fs_info *fs_info)
{
int ret = wait_event_killable(fs_info->delayed_iputs_wait,
atomic_read(&fs_info->nr_delayed_iputs) == 0);
if (ret)
return -EINTR;
return 0;
}
/*
* This creates an orphan entry for the given inode in case something goes wrong
* in the middle of an unlink.
*/
int btrfs_orphan_add(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode)
{
int ret;
ret = btrfs_insert_orphan_item(trans, inode->root, btrfs_ino(inode));
if (ret && ret != -EEXIST) {
btrfs_abort_transaction(trans, ret);
return ret;
}
return 0;
}
/*
* We have done the delete so we can go ahead and remove the orphan item for
* this particular inode.
*/
static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode)
{
return btrfs_del_orphan_item(trans, inode->root, btrfs_ino(inode));
}
/*
* this cleans up any orphans that may be left on the list from the last use
* of this root.
*/
int btrfs_orphan_cleanup(struct btrfs_root *root)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_key key, found_key;
struct btrfs_trans_handle *trans;
struct inode *inode;
u64 last_objectid = 0;
int ret = 0, nr_unlink = 0;
if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
return 0;
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto out;
}
path->reada = READA_BACK;
key.objectid = BTRFS_ORPHAN_OBJECTID;
key.type = BTRFS_ORPHAN_ITEM_KEY;
key.offset = (u64)-1;
while (1) {
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
/*
* if ret == 0 means we found what we were searching for, which
* is weird, but possible, so only screw with path if we didn't
* find the key and see if we have stuff that matches
*/
if (ret > 0) {
ret = 0;
if (path->slots[0] == 0)
break;
path->slots[0]--;
}
/* pull out the item */
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
/* make sure the item matches what we want */
if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
break;
if (found_key.type != BTRFS_ORPHAN_ITEM_KEY)
break;
/* release the path since we're done with it */
btrfs_release_path(path);
/*
* this is where we are basically btrfs_lookup, without the
* crossing root thing. we store the inode number in the
* offset of the orphan item.
*/
if (found_key.offset == last_objectid) {
btrfs_err(fs_info,
"Error removing orphan entry, stopping orphan cleanup");
ret = -EINVAL;
goto out;
}
last_objectid = found_key.offset;
found_key.objectid = found_key.offset;
found_key.type = BTRFS_INODE_ITEM_KEY;
found_key.offset = 0;
inode = btrfs_iget(fs_info->sb, last_objectid, root);
ret = PTR_ERR_OR_ZERO(inode);
if (ret && ret != -ENOENT)
goto out;
if (ret == -ENOENT && root == fs_info->tree_root) {
struct btrfs_root *dead_root;
int is_dead_root = 0;
/*
* This is an orphan in the tree root. Currently these
* could come from 2 sources:
* a) a root (snapshot/subvolume) deletion in progress
* b) a free space cache inode
* We need to distinguish those two, as the orphan item
* for a root must not get deleted before the deletion
* of the snapshot/subvolume's tree completes.
*
* btrfs_find_orphan_roots() ran before us, which has
* found all deleted roots and loaded them into
* fs_info->fs_roots_radix. So here we can find if an
* orphan item corresponds to a deleted root by looking
* up the root from that radix tree.
*/
spin_lock(&fs_info->fs_roots_radix_lock);
dead_root = radix_tree_lookup(&fs_info->fs_roots_radix,
(unsigned long)found_key.objectid);
if (dead_root && btrfs_root_refs(&dead_root->root_item) == 0)
is_dead_root = 1;
spin_unlock(&fs_info->fs_roots_radix_lock);
if (is_dead_root) {
/* prevent this orphan from being found again */
key.offset = found_key.objectid - 1;
continue;
}
}
/*
* If we have an inode with links, there are a couple of
* possibilities:
*
* 1. We were halfway through creating fsverity metadata for the
* file. In that case, the orphan item represents incomplete
* fsverity metadata which must be cleaned up with
* btrfs_drop_verity_items and deleting the orphan item.
* 2. Old kernels (before v3.12) used to create an
* orphan item for truncate indicating that there were possibly
* extent items past i_size that needed to be deleted. In v3.12,
* truncate was changed to update i_size in sync with the extent
* items, but the (useless) orphan item was still created. Since
* v4.18, we don't create the orphan item for truncate at all.
*
* So, this item could mean that we need to do a truncate, but
* only if this filesystem was last used on a pre-v3.12 kernel
* and was not cleanly unmounted. The odds of that are quite
* slim, and it's a pain to do the truncate now, so just delete
* the orphan item.
*
* It's also possible that this orphan item was supposed to be
* deleted but wasn't. The inode number may have been reused,
* but either way, we can delete the orphan item.
*/
if (ret == -ENOENT || inode->i_nlink) {
if (!ret) {
ret = btrfs_drop_verity_items(BTRFS_I(inode));
iput(inode);
if (ret)
goto out;
}
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out;
}
btrfs_debug(fs_info, "auto deleting %Lu",
found_key.objectid);
ret = btrfs_del_orphan_item(trans, root,
found_key.objectid);
btrfs_end_transaction(trans);
if (ret)
goto out;
continue;
}
nr_unlink++;
/* this will do delete_inode and everything for us */
iput(inode);
}
/* release the path since we're done with it */
btrfs_release_path(path);
root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
trans = btrfs_join_transaction(root);
if (!IS_ERR(trans))
btrfs_end_transaction(trans);
}
if (nr_unlink)
btrfs_debug(fs_info, "unlinked %d orphans", nr_unlink);
out:
if (ret)
btrfs_err(fs_info, "could not do orphan cleanup %d", ret);
btrfs_free_path(path);
return ret;
}
/*
* very simple check to peek ahead in the leaf looking for xattrs. If we
* don't find any xattrs, we know there can't be any acls.
*
* slot is the slot the inode is in, objectid is the objectid of the inode
*/
static noinline int acls_after_inode_item(struct extent_buffer *leaf,
int slot, u64 objectid,
int *first_xattr_slot)
{
u32 nritems = btrfs_header_nritems(leaf);
struct btrfs_key found_key;
static u64 xattr_access = 0;
static u64 xattr_default = 0;
int scanned = 0;
if (!xattr_access) {
xattr_access = btrfs_name_hash(XATTR_NAME_POSIX_ACL_ACCESS,
strlen(XATTR_NAME_POSIX_ACL_ACCESS));
xattr_default = btrfs_name_hash(XATTR_NAME_POSIX_ACL_DEFAULT,
strlen(XATTR_NAME_POSIX_ACL_DEFAULT));
}
slot++;
*first_xattr_slot = -1;
while (slot < nritems) {
btrfs_item_key_to_cpu(leaf, &found_key, slot);
/* we found a different objectid, there must not be acls */
if (found_key.objectid != objectid)
return 0;
/* we found an xattr, assume we've got an acl */
if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
if (*first_xattr_slot == -1)
*first_xattr_slot = slot;
if (found_key.offset == xattr_access ||
found_key.offset == xattr_default)
return 1;
}
/*
* we found a key greater than an xattr key, there can't
* be any acls later on
*/
if (found_key.type > BTRFS_XATTR_ITEM_KEY)
return 0;
slot++;
scanned++;
/*
* it goes inode, inode backrefs, xattrs, extents,
* so if there are a ton of hard links to an inode there can
* be a lot of backrefs. Don't waste time searching too hard,
* this is just an optimization
*/
if (scanned >= 8)
break;
}
/* we hit the end of the leaf before we found an xattr or
* something larger than an xattr. We have to assume the inode
* has acls
*/
if (*first_xattr_slot == -1)
*first_xattr_slot = slot;
return 1;
}
/*
* read an inode from the btree into the in-memory inode
*/
static int btrfs_read_locked_inode(struct inode *inode,
struct btrfs_path *in_path)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_path *path = in_path;
struct extent_buffer *leaf;
struct btrfs_inode_item *inode_item;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_key location;
unsigned long ptr;
int maybe_acls;
u32 rdev;
int ret;
bool filled = false;
int first_xattr_slot;
ret = btrfs_fill_inode(inode, &rdev);
if (!ret)
filled = true;
if (!path) {
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
}
memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
if (ret) {
if (path != in_path)
btrfs_free_path(path);
return ret;
}
leaf = path->nodes[0];
if (filled)
goto cache_index;
inode_item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_inode_item);
inode->i_mode = btrfs_inode_mode(leaf, inode_item);
set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
btrfs_i_size_write(BTRFS_I(inode), btrfs_inode_size(leaf, inode_item));
btrfs_inode_set_file_extent_range(BTRFS_I(inode), 0,
round_up(i_size_read(inode), fs_info->sectorsize));
inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime);
inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime);
inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime);
inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime);
inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime);
inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime);
BTRFS_I(inode)->i_otime.tv_sec =
btrfs_timespec_sec(leaf, &inode_item->otime);
BTRFS_I(inode)->i_otime.tv_nsec =
btrfs_timespec_nsec(leaf, &inode_item->otime);
inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
inode_set_iversion_queried(inode,
btrfs_inode_sequence(leaf, inode_item));
inode->i_generation = BTRFS_I(inode)->generation;
inode->i_rdev = 0;
rdev = btrfs_inode_rdev(leaf, inode_item);
BTRFS_I(inode)->index_cnt = (u64)-1;
btrfs_inode_split_flags(btrfs_inode_flags(leaf, inode_item),
&BTRFS_I(inode)->flags, &BTRFS_I(inode)->ro_flags);
cache_index:
/*
* If we were modified in the current generation and evicted from memory
* and then re-read we need to do a full sync since we don't have any
* idea about which extents were modified before we were evicted from
* cache.
*
* This is required for both inode re-read from disk and delayed inode
* in delayed_nodes_tree.
*/
if (BTRFS_I(inode)->last_trans == fs_info->generation)
set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
&BTRFS_I(inode)->runtime_flags);
/*
* We don't persist the id of the transaction where an unlink operation
* against the inode was last made. So here we assume the inode might
* have been evicted, and therefore the exact value of last_unlink_trans
* lost, and set it to last_trans to avoid metadata inconsistencies
* between the inode and its parent if the inode is fsync'ed and the log
* replayed. For example, in the scenario:
*
* touch mydir/foo
* ln mydir/foo mydir/bar
* sync
* unlink mydir/bar
* echo 2 > /proc/sys/vm/drop_caches # evicts inode
* xfs_io -c fsync mydir/foo
* <power failure>
* mount fs, triggers fsync log replay
*
* We must make sure that when we fsync our inode foo we also log its
* parent inode, otherwise after log replay the parent still has the
* dentry with the "bar" name but our inode foo has a link count of 1
* and doesn't have an inode ref with the name "bar" anymore.
*
* Setting last_unlink_trans to last_trans is a pessimistic approach,
* but it guarantees correctness at the expense of occasional full
* transaction commits on fsync if our inode is a directory, or if our
* inode is not a directory, logging its parent unnecessarily.
*/
BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans;
/*
* Same logic as for last_unlink_trans. We don't persist the generation
* of the last transaction where this inode was used for a reflink
* operation, so after eviction and reloading the inode we must be
* pessimistic and assume the last transaction that modified the inode.
*/
BTRFS_I(inode)->last_reflink_trans = BTRFS_I(inode)->last_trans;
path->slots[0]++;
if (inode->i_nlink != 1 ||
path->slots[0] >= btrfs_header_nritems(leaf))
goto cache_acl;
btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
if (location.objectid != btrfs_ino(BTRFS_I(inode)))
goto cache_acl;
ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
if (location.type == BTRFS_INODE_REF_KEY) {
struct btrfs_inode_ref *ref;
ref = (struct btrfs_inode_ref *)ptr;
BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
} else if (location.type == BTRFS_INODE_EXTREF_KEY) {
struct btrfs_inode_extref *extref;
extref = (struct btrfs_inode_extref *)ptr;
BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
extref);
}
cache_acl:
/*
* try to precache a NULL acl entry for files that don't have
* any xattrs or acls
*/
maybe_acls = acls_after_inode_item(leaf, path->slots[0],
btrfs_ino(BTRFS_I(inode)), &first_xattr_slot);
if (first_xattr_slot != -1) {
path->slots[0] = first_xattr_slot;
ret = btrfs_load_inode_props(inode, path);
if (ret)
btrfs_err(fs_info,
"error loading props for ino %llu (root %llu): %d",
btrfs_ino(BTRFS_I(inode)),
root->root_key.objectid, ret);
}
if (path != in_path)
btrfs_free_path(path);
if (!maybe_acls)
cache_no_acl(inode);
switch (inode->i_mode & S_IFMT) {
case S_IFREG:
inode->i_mapping->a_ops = &btrfs_aops;
inode->i_fop = &btrfs_file_operations;
inode->i_op = &btrfs_file_inode_operations;
break;
case S_IFDIR:
inode->i_fop = &btrfs_dir_file_operations;
inode->i_op = &btrfs_dir_inode_operations;
break;
case S_IFLNK:
inode->i_op = &btrfs_symlink_inode_operations;
inode_nohighmem(inode);
inode->i_mapping->a_ops = &btrfs_aops;
break;
default:
inode->i_op = &btrfs_special_inode_operations;
init_special_inode(inode, inode->i_mode, rdev);
break;
}
btrfs_sync_inode_flags_to_i_flags(inode);
return 0;
}
/*
* given a leaf and an inode, copy the inode fields into the leaf
*/
static void fill_inode_item(struct btrfs_trans_handle *trans,
struct extent_buffer *leaf,
struct btrfs_inode_item *item,
struct inode *inode)
{
struct btrfs_map_token token;
u64 flags;
btrfs_init_map_token(&token, leaf);
btrfs_set_token_inode_uid(&token, item, i_uid_read(inode));
btrfs_set_token_inode_gid(&token, item, i_gid_read(inode));
btrfs_set_token_inode_size(&token, item, BTRFS_I(inode)->disk_i_size);
btrfs_set_token_inode_mode(&token, item, inode->i_mode);
btrfs_set_token_inode_nlink(&token, item, inode->i_nlink);
btrfs_set_token_timespec_sec(&token, &item->atime,
inode->i_atime.tv_sec);
btrfs_set_token_timespec_nsec(&token, &item->atime,
inode->i_atime.tv_nsec);
btrfs_set_token_timespec_sec(&token, &item->mtime,
inode->i_mtime.tv_sec);
btrfs_set_token_timespec_nsec(&token, &item->mtime,
inode->i_mtime.tv_nsec);
btrfs_set_token_timespec_sec(&token, &item->ctime,
inode->i_ctime.tv_sec);
btrfs_set_token_timespec_nsec(&token, &item->ctime,
inode->i_ctime.tv_nsec);
btrfs_set_token_timespec_sec(&token, &item->otime,
BTRFS_I(inode)->i_otime.tv_sec);
btrfs_set_token_timespec_nsec(&token, &item->otime,
BTRFS_I(inode)->i_otime.tv_nsec);
btrfs_set_token_inode_nbytes(&token, item, inode_get_bytes(inode));
btrfs_set_token_inode_generation(&token, item,
BTRFS_I(inode)->generation);
btrfs_set_token_inode_sequence(&token, item, inode_peek_iversion(inode));
btrfs_set_token_inode_transid(&token, item, trans->transid);
btrfs_set_token_inode_rdev(&token, item, inode->i_rdev);
flags = btrfs_inode_combine_flags(BTRFS_I(inode)->flags,
BTRFS_I(inode)->ro_flags);
btrfs_set_token_inode_flags(&token, item, flags);
btrfs_set_token_inode_block_group(&token, item, 0);
}
/*
* copy everything in the in-memory inode into the btree.
*/
static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_inode *inode)
{
struct btrfs_inode_item *inode_item;
struct btrfs_path *path;
struct extent_buffer *leaf;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_lookup_inode(trans, root, path, &inode->location, 1);
if (ret) {
if (ret > 0)
ret = -ENOENT;
goto failed;
}
leaf = path->nodes[0];
inode_item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_inode_item);
fill_inode_item(trans, leaf, inode_item, &inode->vfs_inode);
btrfs_mark_buffer_dirty(leaf);
btrfs_set_inode_last_trans(trans, inode);
ret = 0;
failed:
btrfs_free_path(path);
return ret;
}
/*
* copy everything in the in-memory inode into the btree.
*/
noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_inode *inode)
{
struct btrfs_fs_info *fs_info = root->fs_info;
int ret;
/*
* If the inode is a free space inode, we can deadlock during commit
* if we put it into the delayed code.
*
* The data relocation inode should also be directly updated
* without delay
*/
if (!btrfs_is_free_space_inode(inode)
&& !btrfs_is_data_reloc_root(root)
&& !test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) {
btrfs_update_root_times(trans, root);
ret = btrfs_delayed_update_inode(trans, root, inode);
if (!ret)
btrfs_set_inode_last_trans(trans, inode);
return ret;
}
return btrfs_update_inode_item(trans, root, inode);
}
int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct btrfs_inode *inode)
{
int ret;
ret = btrfs_update_inode(trans, root, inode);
if (ret == -ENOSPC)
return btrfs_update_inode_item(trans, root, inode);
return ret;
}
/*
* unlink helper that gets used here in inode.c and in the tree logging
* recovery code. It remove a link in a directory with a given name, and
* also drops the back refs in the inode to the directory
*/
static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
struct btrfs_inode *dir,
struct btrfs_inode *inode,
const char *name, int name_len)
{
struct btrfs_root *root = dir->root;
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_path *path;
int ret = 0;
struct btrfs_dir_item *di;
u64 index;
u64 ino = btrfs_ino(inode);
u64 dir_ino = btrfs_ino(dir);
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto out;
}
di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
name, name_len, -1);
if (IS_ERR_OR_NULL(di)) {
ret = di ? PTR_ERR(di) : -ENOENT;
goto err;
}
ret = btrfs_delete_one_dir_name(trans, root, path, di);
if (ret)
goto err;
btrfs_release_path(path);
/*
* If we don't have dir index, we have to get it by looking up
* the inode ref, since we get the inode ref, remove it directly,
* it is unnecessary to do delayed deletion.
*
* But if we have dir index, needn't search inode ref to get it.
* Since the inode ref is close to the inode item, it is better
* that we delay to delete it, and just do this deletion when
* we update the inode item.
*/
if (inode->dir_index) {
ret = btrfs_delayed_delete_inode_ref(inode);
if (!ret) {
index = inode->dir_index;
goto skip_backref;
}
}
ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
dir_ino, &index);
if (ret) {
btrfs_info(fs_info,
"failed to delete reference to %.*s, inode %llu parent %llu",
name_len, name, ino, dir_ino);
btrfs_abort_transaction(trans, ret);
goto err;
}
skip_backref:
ret = btrfs_delete_delayed_dir_index(trans, dir, index);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto err;
}
ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len, inode,
dir_ino);
if (ret != 0 && ret != -ENOENT) {
btrfs_abort_transaction(trans, ret);
goto err;
}
ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len, dir,
index);
if (ret == -ENOENT)
ret = 0;
else if (ret)
btrfs_abort_transaction(trans, ret);
/*
* If we have a pending delayed iput we could end up with the final iput
* being run in btrfs-cleaner context. If we have enough of these built
* up we can end up burning a lot of time in btrfs-cleaner without any
* way to throttle the unlinks. Since we're currently holding a ref on
* the inode we can run the delayed iput here without any issues as the
* final iput won't be done until after we drop the ref we're currently
* holding.
*/
btrfs_run_delayed_iput(fs_info, inode);
err:
btrfs_free_path(path);
if (ret)
goto out;
btrfs_i_size_write(dir, dir->vfs_inode.i_size - name_len * 2);
inode_inc_iversion(&inode->vfs_inode);
inode_inc_iversion(&dir->vfs_inode);
inode->vfs_inode.i_ctime = dir->vfs_inode.i_mtime =
dir->vfs_inode.i_ctime = current_time(&inode->vfs_inode);
ret = btrfs_update_inode(trans, root, dir);
out:
return ret;
}
int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
struct btrfs_inode *dir, struct btrfs_inode *inode,
const char *name, int name_len)
{
int ret;
ret = __btrfs_unlink_inode(trans, dir, inode, name, name_len);
if (!ret) {
drop_nlink(&inode->vfs_inode);
ret = btrfs_update_inode(trans, inode->root, inode);
}
return ret;
}
/*
* helper to start transaction for unlink and rmdir.
*
* unlink and rmdir are special in btrfs, they do not always free space, so
* if we cannot make our reservations the normal way try and see if there is
* plenty of slack room in the global reserve to migrate, otherwise we cannot
* allow the unlink to occur.
*/
static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
{
struct btrfs_root *root = BTRFS_I(dir)->root;
/*
* 1 for the possible orphan item
* 1 for the dir item
* 1 for the dir index
* 1 for the inode ref
* 1 for the inode
*/
return btrfs_start_transaction_fallback_global_rsv(root, 5);
}
static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
{
struct btrfs_trans_handle *trans;
struct inode *inode = d_inode(dentry);
int ret;
trans = __unlink_start_trans(dir);
if (IS_ERR(trans))
return PTR_ERR(trans);
btrfs_record_unlink_dir(trans, BTRFS_I(dir), BTRFS_I(d_inode(dentry)),
0);
ret = btrfs_unlink_inode(trans, BTRFS_I(dir),
BTRFS_I(d_inode(dentry)), dentry->d_name.name,
dentry->d_name.len);
if (ret)
goto out;
if (inode->i_nlink == 0) {
ret = btrfs_orphan_add(trans, BTRFS_I(inode));
if (ret)
goto out;
}
out:
btrfs_end_transaction(trans);
btrfs_btree_balance_dirty(BTRFS_I(dir)->root->fs_info);
return ret;
}
static int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
struct inode *dir, struct dentry *dentry)
{
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_inode *inode = BTRFS_I(d_inode(dentry));
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_dir_item *di;
struct btrfs_key key;
const char *name = dentry->d_name.name;
int name_len = dentry->d_name.len;
u64 index;
int ret;
u64 objectid;
u64 dir_ino = btrfs_ino(BTRFS_I(dir));
if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID) {
objectid = inode->root->root_key.objectid;
} else if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) {
objectid = inode->location.objectid;
} else {
WARN_ON(1);
return -EINVAL;
}
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
name, name_len, -1);
if (IS_ERR_OR_NULL(di)) {
ret = di ? PTR_ERR(di) : -ENOENT;
goto out;
}
leaf = path->nodes[0];
btrfs_dir_item_key_to_cpu(leaf, di, &key);
WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
ret = btrfs_delete_one_dir_name(trans, root, path, di);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out;
}
btrfs_release_path(path);
/*
* This is a placeholder inode for a subvolume we didn't have a
* reference to at the time of the snapshot creation. In the meantime
* we could have renamed the real subvol link into our snapshot, so
* depending on btrfs_del_root_ref to return -ENOENT here is incorrect.
* Instead simply lookup the dir_index_item for this entry so we can
* remove it. Otherwise we know we have a ref to the root and we can
* call btrfs_del_root_ref, and it _shouldn't_ fail.
*/
if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) {
di = btrfs_search_dir_index_item(root, path, dir_ino,
name, name_len);
if (IS_ERR_OR_NULL(di)) {
if (!di)
ret = -ENOENT;
else
ret = PTR_ERR(di);
btrfs_abort_transaction(trans, ret);
goto out;
}
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
index = key.offset;
btrfs_release_path(path);
} else {
ret = btrfs_del_root_ref(trans, objectid,
root->root_key.objectid, dir_ino,
&index, name, name_len);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out;
}
}
ret = btrfs_delete_delayed_dir_index(trans, BTRFS_I(dir), index);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out;
}
btrfs_i_size_write(BTRFS_I(dir), dir->i_size - name_len * 2);
inode_inc_iversion(dir);
dir->i_mtime = dir->i_ctime = current_time(dir);
ret = btrfs_update_inode_fallback(trans, root, BTRFS_I(dir));
if (ret)
btrfs_abort_transaction(trans, ret);
out:
btrfs_free_path(path);
return ret;
}
/*
* Helper to check if the subvolume references other subvolumes or if it's
* default.
*/
static noinline int may_destroy_subvol(struct btrfs_root *root)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_path *path;
struct btrfs_dir_item *di;
struct btrfs_key key;
u64 dir_id;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
/* Make sure this root isn't set as the default subvol */
dir_id = btrfs_super_root_dir(fs_info->super_copy);
di = btrfs_lookup_dir_item(NULL, fs_info->tree_root, path,
dir_id, "default", 7, 0);
if (di && !IS_ERR(di)) {
btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
if (key.objectid == root->root_key.objectid) {
ret = -EPERM;
btrfs_err(fs_info,
"deleting default subvolume %llu is not allowed",
key.objectid);
goto out;
}
btrfs_release_path(path);
}
key.objectid = root->root_key.objectid;
key.type = BTRFS_ROOT_REF_KEY;
key.offset = (u64)-1;
ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
if (ret < 0)
goto out;
BUG_ON(ret == 0);
ret = 0;
if (path->slots[0] > 0) {
path->slots[0]--;
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
if (key.objectid == root->root_key.objectid &&
key.type == BTRFS_ROOT_REF_KEY)
ret = -ENOTEMPTY;
}
out:
btrfs_free_path(path);
return ret;
}
/* Delete all dentries for inodes belonging to the root */
static void btrfs_prune_dentries(struct btrfs_root *root)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct rb_node *node;
struct rb_node *prev;
struct btrfs_inode *entry;
struct inode *inode;
u64 objectid = 0;
if (!test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
WARN_ON(btrfs_root_refs(&root->root_item) != 0);
spin_lock(&root->inode_lock);
again:
node = root->inode_tree.rb_node;
prev = NULL;
while (node) {
prev = node;
entry = rb_entry(node, struct btrfs_inode, rb_node);
if (objectid < btrfs_ino(entry))
node = node->rb_left;
else if (objectid > btrfs_ino(entry))
node = node->rb_right;
else
break;
}
if (!node) {
while (prev) {
entry = rb_entry(prev, struct btrfs_inode, rb_node);
if (objectid <= btrfs_ino(entry)) {
node = prev;
break;
}
prev = rb_next(prev);
}
}
while (node) {
entry = rb_entry(node, struct btrfs_inode, rb_node);
objectid = btrfs_ino(entry) + 1;
inode = igrab(&entry->vfs_inode);
if (inode) {
spin_unlock(&root->inode_lock);
if (atomic_read(&inode->i_count) > 1)
d_prune_aliases(inode);
/*
* btrfs_drop_inode will have it removed from the inode
* cache when its usage count hits zero.
*/
iput(inode);
cond_resched();
spin_lock(&root->inode_lock);
goto again;
}
if (cond_resched_lock(&root->inode_lock))
goto again;
node = rb_next(node);
}
spin_unlock(&root->inode_lock);
}
int btrfs_delete_subvolume(struct inode *dir, struct dentry *dentry)
{
struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
struct btrfs_root *root = BTRFS_I(dir)->root;
struct inode *inode = d_inode(dentry);
struct btrfs_root *dest = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
struct btrfs_block_rsv block_rsv;
u64 root_flags;
int ret;
down_write(&fs_info->subvol_sem);
/*
* Don't allow to delete a subvolume with send in progress. This is
* inside the inode lock so the error handling that has to drop the bit
* again is not run concurrently.
*/
spin_lock(&dest->root_item_lock);
if (dest->send_in_progress) {
spin_unlock(&dest->root_item_lock);
btrfs_warn(fs_info,
"attempt to delete subvolume %llu during send",
dest->root_key.objectid);
ret = -EPERM;
goto out_up_write;
}
if (atomic_read(&dest->nr_swapfiles)) {
spin_unlock(&dest->root_item_lock);
btrfs_warn(fs_info,
"attempt to delete subvolume %llu with active swapfile",
root->root_key.objectid);
ret = -EPERM;
goto out_up_write;
}
root_flags = btrfs_root_flags(&dest->root_item);
btrfs_set_root_flags(&dest->root_item,
root_flags | BTRFS_ROOT_SUBVOL_DEAD);
spin_unlock(&dest->root_item_lock);
ret = may_destroy_subvol(dest);
if (ret)
goto out_undead;
btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
/*
* One for dir inode,
* two for dir entries,
* two for root ref/backref.
*/
ret = btrfs_subvolume_reserve_metadata(root, &block_rsv, 5, true);
if (ret)
goto out_undead;
trans = btrfs_start_transaction(root, 0);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out_release;
}
trans->block_rsv = &block_rsv;
trans->bytes_reserved = block_rsv.size;
btrfs_record_snapshot_destroy(trans, BTRFS_I(dir));
ret = btrfs_unlink_subvol(trans, dir, dentry);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_end_trans;
}
ret = btrfs_record_root_in_trans(trans, dest);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_end_trans;
}
memset(&dest->root_item.drop_progress, 0,
sizeof(dest->root_item.drop_progress));
btrfs_set_root_drop_level(&dest->root_item, 0);
btrfs_set_root_refs(&dest->root_item, 0);
if (!test_and_set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &dest->state)) {
ret = btrfs_insert_orphan_item(trans,
fs_info->tree_root,
dest->root_key.objectid);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_end_trans;
}
}
ret = btrfs_uuid_tree_remove(trans, dest->root_item.uuid,
BTRFS_UUID_KEY_SUBVOL,
dest->root_key.objectid);
if (ret && ret != -ENOENT) {
btrfs_abort_transaction(trans, ret);
goto out_end_trans;
}
if (!btrfs_is_empty_uuid(dest->root_item.received_uuid)) {
ret = btrfs_uuid_tree_remove(trans,
dest->root_item.received_uuid,
BTRFS_UUID_KEY_RECEIVED_SUBVOL,
dest->root_key.objectid);
if (ret && ret != -ENOENT) {
btrfs_abort_transaction(trans, ret);
goto out_end_trans;
}
}
free_anon_bdev(dest->anon_dev);
dest->anon_dev = 0;
out_end_trans:
trans->block_rsv = NULL;
trans->bytes_reserved = 0;
ret = btrfs_end_transaction(trans);
inode->i_flags |= S_DEAD;
out_release:
btrfs_subvolume_release_metadata(root, &block_rsv);
out_undead:
if (ret) {
spin_lock(&dest->root_item_lock);
root_flags = btrfs_root_flags(&dest->root_item);
btrfs_set_root_flags(&dest->root_item,
root_flags & ~BTRFS_ROOT_SUBVOL_DEAD);
spin_unlock(&dest->root_item_lock);
}
out_up_write:
up_write(&fs_info->subvol_sem);
if (!ret) {
d_invalidate(dentry);
btrfs_prune_dentries(dest);
ASSERT(dest->send_in_progress == 0);
}
return ret;
}
static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
{
struct inode *inode = d_inode(dentry);
int err = 0;
struct btrfs_trans_handle *trans;
u64 last_unlink_trans;
if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
return -ENOTEMPTY;
if (btrfs_ino(BTRFS_I(inode)) == BTRFS_FIRST_FREE_OBJECTID)
return btrfs_delete_subvolume(dir, dentry);
trans = __unlink_start_trans(dir);
if (IS_ERR(trans))
return PTR_ERR(trans);
if (unlikely(btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
err = btrfs_unlink_subvol(trans, dir, dentry);
goto out;
}
err = btrfs_orphan_add(trans, BTRFS_I(inode));
if (err)
goto out;
last_unlink_trans = BTRFS_I(inode)->last_unlink_trans;
/* now the directory is empty */
err = btrfs_unlink_inode(trans, BTRFS_I(dir),
BTRFS_I(d_inode(dentry)), dentry->d_name.name,
dentry->d_name.len);
if (!err) {
btrfs_i_size_write(BTRFS_I(inode), 0);
/*
* Propagate the last_unlink_trans value of the deleted dir to
* its parent directory. This is to prevent an unrecoverable
* log tree in the case we do something like this:
* 1) create dir foo
* 2) create snapshot under dir foo
* 3) delete the snapshot
* 4) rmdir foo
* 5) mkdir foo
* 6) fsync foo or some file inside foo
*/
if (last_unlink_trans >= trans->transid)
BTRFS_I(dir)->last_unlink_trans = last_unlink_trans;
}
out:
btrfs_end_transaction(trans);
btrfs_btree_balance_dirty(BTRFS_I(dir)->root->fs_info);
return err;
}
/*
* Return this if we need to call truncate_block for the last bit of the
* truncate.
*/
#define NEED_TRUNCATE_BLOCK 1
/*
* Remove inode items from a given root.
*
* @trans: A transaction handle.
* @root: The root from which to remove items.
* @inode: The inode whose items we want to remove.
* @new_size: The new i_size for the inode. This is only applicable when
* @min_type is BTRFS_EXTENT_DATA_KEY, must be 0 otherwise.
* @min_type: The minimum key type to remove. All keys with a type
* greater than this value are removed and all keys with
* this type are removed only if their offset is >= @new_size.
* @extents_found: Output parameter that will contain the number of file
* extent items that were removed or adjusted to the new
* inode i_size. The caller is responsible for initializing
* the counter. Also, it can be NULL if the caller does not
* need this counter.
*
* Remove all keys associated with the inode from the given root that have a key
* with a type greater than or equals to @min_type. When @min_type has a value of
* BTRFS_EXTENT_DATA_KEY, only remove file extent items that have an offset value
* greater than or equals to @new_size. If a file extent item that starts before
* @new_size and ends after it is found, its length is adjusted.
*
* Returns: 0 on success, < 0 on error and NEED_TRUNCATE_BLOCK when @min_type is
* BTRFS_EXTENT_DATA_KEY and the caller must truncate the last block.
*/
int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_inode *inode,
u64 new_size, u32 min_type,
u64 *extents_found)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_file_extent_item *fi;
struct btrfs_key key;
struct btrfs_key found_key;
u64 extent_start = 0;
u64 extent_num_bytes = 0;
u64 extent_offset = 0;
u64 item_end = 0;
u64 last_size = new_size;
u32 found_type = (u8)-1;
int found_extent;
int del_item;
int pending_del_nr = 0;
int pending_del_slot = 0;
int extent_type = -1;
int ret;
u64 ino = btrfs_ino(inode);
u64 bytes_deleted = 0;
bool be_nice = false;
bool should_throttle = false;
const u64 lock_start = ALIGN_DOWN(new_size, fs_info->sectorsize);
struct extent_state *cached_state = NULL;
BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
/*
* For non-free space inodes and non-shareable roots, we want to back
* off from time to time. This means all inodes in subvolume roots,
* reloc roots, and data reloc roots.
*/
if (!btrfs_is_free_space_inode(inode) &&
test_bit(BTRFS_ROOT_SHAREABLE, &root->state))
be_nice = true;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = READA_BACK;
if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
lock_extent_bits(&inode->io_tree, lock_start, (u64)-1,
&cached_state);
/*
* We want to drop from the next block forward in case this
* new size is not block aligned since we will be keeping the
* last block of the extent just the way it is.
*/
btrfs_drop_extent_cache(inode, ALIGN(new_size,
fs_info->sectorsize),
(u64)-1, 0);
}
/*
* This function is also used to drop the items in the log tree before
* we relog the inode, so if root != BTRFS_I(inode)->root, it means
* it is used to drop the logged items. So we shouldn't kill the delayed
* items.
*/
if (min_type == 0 && root == inode->root)
btrfs_kill_delayed_inode_items(inode);
key.objectid = ino;
key.offset = (u64)-1;
key.type = (u8)-1;
search_again:
/*
* with a 16K leaf size and 128MB extents, you can actually queue
* up a huge file in a single leaf. Most of the time that
* bytes_deleted is > 0, it will be huge by the time we get here
*/
if (be_nice && bytes_deleted > SZ_32M &&
btrfs_should_end_transaction(trans)) {
ret = -EAGAIN;
goto out;
}
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0)
goto out;
if (ret > 0) {
ret = 0;
/* there are no items in the tree for us to truncate, we're
* done
*/
if (path->slots[0] == 0)
goto out;
path->slots[0]--;
}
while (1) {
u64 clear_start = 0, clear_len = 0;
fi = NULL;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
found_type = found_key.type;
if (found_key.objectid != ino)
break;
if (found_type < min_type)
break;
item_end = found_key.offset;
if (found_type == BTRFS_EXTENT_DATA_KEY) {
fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
extent_type = btrfs_file_extent_type(leaf, fi);
if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
item_end +=
btrfs_file_extent_num_bytes(leaf, fi);
trace_btrfs_truncate_show_fi_regular(
inode, leaf, fi, found_key.offset);
} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
item_end += btrfs_file_extent_ram_bytes(leaf,
fi);
trace_btrfs_truncate_show_fi_inline(
inode, leaf, fi, path->slots[0],
found_key.offset);
}
item_end--;
}
if (found_type > min_type) {
del_item = 1;
} else {
if (item_end < new_size)
break;
if (found_key.offset >= new_size)
del_item = 1;
else
del_item = 0;
}
found_extent = 0;
/* FIXME, shrink the extent if the ref count is only 1 */
if (found_type != BTRFS_EXTENT_DATA_KEY)
goto delete;
if (extents_found != NULL)
(*extents_found)++;
if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
u64 num_dec;
clear_start = found_key.offset;
extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
if (!del_item) {
u64 orig_num_bytes =
btrfs_file_extent_num_bytes(leaf, fi);
extent_num_bytes = ALIGN(new_size -
found_key.offset,
fs_info->sectorsize);
clear_start = ALIGN(new_size, fs_info->sectorsize);
btrfs_set_file_extent_num_bytes(leaf, fi,
extent_num_bytes);
num_dec = (orig_num_bytes -
extent_num_bytes);
if (test_bit(BTRFS_ROOT_SHAREABLE,
&root->state) &&
extent_start != 0)
inode_sub_bytes(&inode->vfs_inode,
num_dec);
btrfs_mark_buffer_dirty(leaf);
} else {
extent_num_bytes =
btrfs_file_extent_disk_num_bytes(leaf,
fi);
extent_offset = found_key.offset -
btrfs_file_extent_offset(leaf, fi);
/* FIXME blocksize != 4096 */
num_dec = btrfs_file_extent_num_bytes(leaf, fi);
if (extent_start != 0) {
found_extent = 1;
if (test_bit(BTRFS_ROOT_SHAREABLE,
&root->state))
inode_sub_bytes(&inode->vfs_inode,
num_dec);
}
}
clear_len = num_dec;
} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
/*
* we can't truncate inline items that have had
* special encodings
*/
if (!del_item &&
btrfs_file_extent_encryption(leaf, fi) == 0 &&
btrfs_file_extent_other_encoding(leaf, fi) == 0 &&
btrfs_file_extent_compression(leaf, fi) == 0) {
u32 size = (u32)(new_size - found_key.offset);
btrfs_set_file_extent_ram_bytes(leaf, fi, size);
size = btrfs_file_extent_calc_inline_size(size);
btrfs_truncate_item(path, size, 1);
} else if (!del_item) {
/*
* We have to bail so the last_size is set to
* just before this extent.
*/
ret = NEED_TRUNCATE_BLOCK;
break;
} else {
/*
* Inline extents are special, we just treat
* them as a full sector worth in the file
* extent tree just for simplicity sake.
*/
clear_len = fs_info->sectorsize;
}
if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state))
inode_sub_bytes(&inode->vfs_inode,
item_end + 1 - new_size);
}
delete:
/*
* We use btrfs_truncate_inode_items() to clean up log trees for
* multiple fsyncs, and in this case we don't want to clear the
* file extent range because it's just the log.
*/
if (root == inode->root) {
ret = btrfs_inode_clear_file_extent_range(inode,
clear_start, clear_len);
if (ret) {
btrfs_abort_transaction(trans, ret);
break;
}
}
if (del_item)
last_size = found_key.offset;
else
last_size = new_size;
if (del_item) {
if (!pending_del_nr) {
/* no pending yet, add ourselves */
pending_del_slot = path->slots[0];
pending_del_nr = 1;
} else if (pending_del_nr &&
path->slots[0] + 1 == pending_del_slot) {
/* hop on the pending chunk */
pending_del_nr++;
pending_del_slot = path->slots[0];
} else {
BUG();
}
} else {
break;
}
should_throttle = false;
if (found_extent &&
root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
struct btrfs_ref ref = { 0 };
bytes_deleted += extent_num_bytes;
btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF,
extent_start, extent_num_bytes, 0);
ref.real_root = root->root_key.objectid;
btrfs_init_data_ref(&ref, btrfs_header_owner(leaf),
ino, extent_offset,
root->root_key.objectid, false);
ret = btrfs_free_extent(trans, &ref);
if (ret) {
btrfs_abort_transaction(trans, ret);
break;
}
if (be_nice) {
if (btrfs_should_throttle_delayed_refs(trans))
should_throttle = true;
}
}
if (found_type == BTRFS_INODE_ITEM_KEY)
break;
if (path->slots[0] == 0 ||
path->slots[0] != pending_del_slot ||
should_throttle) {
if (pending_del_nr) {
ret = btrfs_del_items(trans, root, path,
pending_del_slot,
pending_del_nr);
if (ret) {
btrfs_abort_transaction(trans, ret);
break;
}
pending_del_nr = 0;
}
btrfs_release_path(path);
/*
* We can generate a lot of delayed refs, so we need to
* throttle every once and a while and make sure we're
* adding enough space to keep up with the work we are
* generating. Since we hold a transaction here we
* can't flush, and we don't want to FLUSH_LIMIT because
* we could have generated too many delayed refs to
* actually allocate, so just bail if we're short and
* let the normal reservation dance happen higher up.
*/
if (should_throttle) {
ret = btrfs_delayed_refs_rsv_refill(fs_info,
BTRFS_RESERVE_NO_FLUSH);
if (ret) {
ret = -EAGAIN;
break;
}
}
goto search_again;
} else {
path->slots[0]--;
}
}
out:
if (ret >= 0 && pending_del_nr) {
int err;
err = btrfs_del_items(trans, root, path, pending_del_slot,
pending_del_nr);
if (err) {
btrfs_abort_transaction(trans, err);
ret = err;
}
}
if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
ASSERT(last_size >= new_size);
if (!ret && last_size > new_size)
last_size = new_size;
btrfs_inode_safe_disk_i_size_write(inode, last_size);
unlock_extent_cached(&inode->io_tree, lock_start, (u64)-1,
&cached_state);
}
btrfs_free_path(path);
return ret;
}
/*
* btrfs_truncate_block - read, zero a chunk and write a block
* @inode - inode that we're zeroing
* @from - the offset to start zeroing
* @len - the length to zero, 0 to zero the entire range respective to the
* offset
* @front - zero up to the offset instead of from the offset on
*
* This will find the block for the "from" offset and cow the block and zero the
* part we want to zero. This is used with truncate and hole punching.
*/
int btrfs_truncate_block(struct btrfs_inode *inode, loff_t from, loff_t len,
int front)
{
struct btrfs_fs_info *fs_info = inode->root->fs_info;
struct address_space *mapping = inode->vfs_inode.i_mapping;
struct extent_io_tree *io_tree = &inode->io_tree;
struct btrfs_ordered_extent *ordered;
struct extent_state *cached_state = NULL;
struct extent_changeset *data_reserved = NULL;
bool only_release_metadata = false;
u32 blocksize = fs_info->sectorsize;
pgoff_t index = from >> PAGE_SHIFT;
unsigned offset = from & (blocksize - 1);
struct page *page;
gfp_t mask = btrfs_alloc_write_mask(mapping);
size_t write_bytes = blocksize;
int ret = 0;
u64 block_start;
u64 block_end;
if (IS_ALIGNED(offset, blocksize) &&
(!len || IS_ALIGNED(len, blocksize)))
goto out;
block_start = round_down(from, blocksize);
block_end = block_start + blocksize - 1;
ret = btrfs_check_data_free_space(inode, &data_reserved, block_start,
blocksize);
if (ret < 0) {
if (btrfs_check_nocow_lock(inode, block_start, &write_bytes) > 0) {
/* For nocow case, no need to reserve data space */
only_release_metadata = true;
} else {
goto out;
}
}
ret = btrfs_delalloc_reserve_metadata(inode, blocksize);
if (ret < 0) {
if (!only_release_metadata)
btrfs_free_reserved_data_space(inode, data_reserved,
block_start, blocksize);
goto out;
}
again:
page = find_or_create_page(mapping, index, mask);
if (!page) {
btrfs_delalloc_release_space(inode, data_reserved, block_start,
blocksize, true);
btrfs_delalloc_release_extents(inode, blocksize);
ret = -ENOMEM;
goto out;
}
ret = set_page_extent_mapped(page);
if (ret < 0)
goto out_unlock;
if (!PageUptodate(page)) {
ret = btrfs_readpage(NULL, page);
lock_page(page);
if (page->mapping != mapping) {
unlock_page(page);
put_page(page);
goto again;
}
if (!PageUptodate(page)) {
ret = -EIO;
goto out_unlock;
}
}
wait_on_page_writeback(page);
lock_extent_bits(io_tree, block_start, block_end, &cached_state);
ordered = btrfs_lookup_ordered_extent(inode, block_start);
if (ordered) {
unlock_extent_cached(io_tree, block_start, block_end,
&cached_state);
unlock_page(page);
put_page(page);
btrfs_start_ordered_extent(ordered, 1);
btrfs_put_ordered_extent(ordered);
goto again;
}
clear_extent_bit(&inode->io_tree, block_start, block_end,
EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
0, 0, &cached_state);
ret = btrfs_set_extent_delalloc(inode, block_start, block_end, 0,
&cached_state);
if (ret) {
unlock_extent_cached(io_tree, block_start, block_end,
&cached_state);
goto out_unlock;
}
if (offset != blocksize) {
if (!len)
len = blocksize - offset;
if (front)
memzero_page(page, (block_start - page_offset(page)),
offset);
else
memzero_page(page, (block_start - page_offset(page)) + offset,
len);
flush_dcache_page(page);
}
ClearPageChecked(page);
btrfs_page_set_dirty(fs_info, page, block_start, block_end + 1 - block_start);
unlock_extent_cached(io_tree, block_start, block_end, &cached_state);
if (only_release_metadata)
set_extent_bit(&inode->io_tree, block_start, block_end,
EXTENT_NORESERVE, 0, NULL, NULL, GFP_NOFS, NULL);
out_unlock:
if (ret) {
if (only_release_metadata)
btrfs_delalloc_release_metadata(inode, blocksize, true);
else
btrfs_delalloc_release_space(inode, data_reserved,
block_start, blocksize, true);
}
btrfs_delalloc_release_extents(inode, blocksize);
unlock_page(page);
put_page(page);
out:
if (only_release_metadata)
btrfs_check_nocow_unlock(inode);
extent_changeset_free(data_reserved);
return ret;
}
static int maybe_insert_hole(struct btrfs_root *root, struct btrfs_inode *inode,
u64 offset, u64 len)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_trans_handle *trans;
struct btrfs_drop_extents_args drop_args = { 0 };
int ret;
/*
* If NO_HOLES is enabled, we don't need to do anything.
* Later, up in the call chain, either btrfs_set_inode_last_sub_trans()
* or btrfs_update_inode() will be called, which guarantee that the next
* fsync will know this inode was changed and needs to be logged.
*/
if (btrfs_fs_incompat(fs_info, NO_HOLES))
return 0;
/*
* 1 - for the one we're dropping
* 1 - for the one we're adding
* 1 - for updating the inode.
*/
trans = btrfs_start_transaction(root, 3);
if (IS_ERR(trans))
return PTR_ERR(trans);
drop_args.start = offset;
drop_args.end = offset + len;
drop_args.drop_cache = true;
ret = btrfs_drop_extents(trans, root, inode, &drop_args);
if (ret) {
btrfs_abort_transaction(trans, ret);
btrfs_end_transaction(trans);
return ret;
}
ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode),
offset, 0, 0, len, 0, len, 0, 0, 0);
if (ret) {
btrfs_abort_transaction(trans, ret);
} else {
btrfs_update_inode_bytes(inode, 0, drop_args.bytes_found);
btrfs_update_inode(trans, root, inode);
}
btrfs_end_transaction(trans);
return ret;
}
/*
* This function puts in dummy file extents for the area we're creating a hole
* for. So if we are truncating this file to a larger size we need to insert
* these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
* the range between oldsize and size
*/
int btrfs_cont_expand(struct btrfs_inode *inode, loff_t oldsize, loff_t size)
{
struct btrfs_root *root = inode->root;
struct btrfs_fs_info *fs_info = root->fs_info;
struct extent_io_tree *io_tree = &inode->io_tree;
struct extent_map *em = NULL;
struct extent_state *cached_state = NULL;
struct extent_map_tree *em_tree = &inode->extent_tree;
u64 hole_start = ALIGN(oldsize, fs_info->sectorsize);
u64 block_end = ALIGN(size, fs_info->sectorsize);
u64 last_byte;
u64 cur_offset;
u64 hole_size;
int err = 0;
/*
* If our size started in the middle of a block we need to zero out the
* rest of the block before we expand the i_size, otherwise we could
* expose stale data.
*/
err = btrfs_truncate_block(inode, oldsize, 0, 0);
if (err)
return err;
if (size <= hole_start)
return 0;
btrfs_lock_and_flush_ordered_range(inode, hole_start, block_end - 1,
&cached_state);
cur_offset = hole_start;
while (1) {
em = btrfs_get_extent(inode, NULL, 0, cur_offset,
block_end - cur_offset);
if (IS_ERR(em)) {
err = PTR_ERR(em);
em = NULL;
break;
}
last_byte = min(extent_map_end(em), block_end);
last_byte = ALIGN(last_byte, fs_info->sectorsize);
hole_size = last_byte - cur_offset;
if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
struct extent_map *hole_em;
err = maybe_insert_hole(root, inode, cur_offset,
hole_size);
if (err)
break;
err = btrfs_inode_set_file_extent_range(inode,
cur_offset, hole_size);
if (err)
break;
btrfs_drop_extent_cache(inode, cur_offset,
cur_offset + hole_size - 1, 0);
hole_em = alloc_extent_map();
if (!hole_em) {
set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
&inode->runtime_flags);
goto next;
}
hole_em->start = cur_offset;
hole_em->len = hole_size;
hole_em->orig_start = cur_offset;
hole_em->block_start = EXTENT_MAP_HOLE;
hole_em->block_len = 0;
hole_em->orig_block_len = 0;
hole_em->ram_bytes = hole_size;
hole_em->compress_type = BTRFS_COMPRESS_NONE;
hole_em->generation = fs_info->generation;
while (1) {
write_lock(&em_tree->lock);
err = add_extent_mapping(em_tree, hole_em, 1);
write_unlock(&em_tree->lock);
if (err != -EEXIST)
break;
btrfs_drop_extent_cache(inode, cur_offset,
cur_offset +
hole_size - 1, 0);
}
free_extent_map(hole_em);
} else {
err = btrfs_inode_set_file_extent_range(inode,
cur_offset, hole_size);
if (err)
break;
}
next:
free_extent_map(em);
em = NULL;
cur_offset = last_byte;
if (cur_offset >= block_end)
break;
}
free_extent_map(em);
unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state);
return err;
}
static int btrfs_setsize(struct inode *inode, struct iattr *attr)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
loff_t oldsize = i_size_read(inode);
loff_t newsize = attr->ia_size;
int mask = attr->ia_valid;
int ret;
/*
* The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
* special case where we need to update the times despite not having
* these flags set. For all other operations the VFS set these flags
* explicitly if it wants a timestamp update.
*/
if (newsize != oldsize) {
inode_inc_iversion(inode);
if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
inode->i_ctime = inode->i_mtime =
current_time(inode);
}
if (newsize > oldsize) {
/*
* Don't do an expanding truncate while snapshotting is ongoing.
* This is to ensure the snapshot captures a fully consistent
* state of this file - if the snapshot captures this expanding
* truncation, it must capture all writes that happened before
* this truncation.
*/
btrfs_drew_write_lock(&root->snapshot_lock);
ret = btrfs_cont_expand(BTRFS_I(inode), oldsize, newsize);
if (ret) {
btrfs_drew_write_unlock(&root->snapshot_lock);
return ret;
}
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans)) {
btrfs_drew_write_unlock(&root->snapshot_lock);
return PTR_ERR(trans);
}
i_size_write(inode, newsize);
btrfs_inode_safe_disk_i_size_write(BTRFS_I(inode), 0);
pagecache_isize_extended(inode, oldsize, newsize);
ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
btrfs_drew_write_unlock(&root->snapshot_lock);
btrfs_end_transaction(trans);
} else {
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
if (btrfs_is_zoned(fs_info)) {
ret = btrfs_wait_ordered_range(inode,
ALIGN(newsize, fs_info->sectorsize),
(u64)-1);
if (ret)
return ret;
}
/*
* We're truncating a file that used to have good data down to
* zero. Make sure any new writes to the file get on disk
* on close.
*/
if (newsize == 0)
set_bit(BTRFS_INODE_FLUSH_ON_CLOSE,
&BTRFS_I(inode)->runtime_flags);
truncate_setsize(inode, newsize);
inode_dio_wait(inode);
ret = btrfs_truncate(inode, newsize == oldsize);
if (ret && inode->i_nlink) {
int err;
/*
* Truncate failed, so fix up the in-memory size. We
* adjusted disk_i_size down as we removed extents, so
* wait for disk_i_size to be stable and then update the
* in-memory size to match.
*/
err = btrfs_wait_ordered_range(inode, 0, (u64)-1);
if (err)
return err;
i_size_write(inode, BTRFS_I(inode)->disk_i_size);
}
}
return ret;
}
static int btrfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
struct iattr *attr)
{
struct inode *inode = d_inode(dentry);
struct btrfs_root *root = BTRFS_I(inode)->root;
int err;
if (btrfs_root_readonly(root))
return -EROFS;
err = setattr_prepare(mnt_userns, dentry, attr);
if (err)
return err;
if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
err = btrfs_setsize(inode, attr);
if (err)
return err;
}
if (attr->ia_valid) {
setattr_copy(mnt_userns, inode, attr);
inode_inc_iversion(inode);
err = btrfs_dirty_inode(inode);
if (!err && attr->ia_valid & ATTR_MODE)
err = posix_acl_chmod(mnt_userns, inode, inode->i_mode);
}
return err;
}
/*
* While truncating the inode pages during eviction, we get the VFS calling
* btrfs_invalidatepage() against each page of the inode. This is slow because
* the calls to btrfs_invalidatepage() result in a huge amount of calls to
* lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
* extent_state structures over and over, wasting lots of time.
*
* Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
* those expensive operations on a per page basis and do only the ordered io
* finishing, while we release here the extent_map and extent_state structures,
* without the excessive merging and splitting.
*/
static void evict_inode_truncate_pages(struct inode *inode)
{
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
struct rb_node *node;
ASSERT(inode->i_state & I_FREEING);
truncate_inode_pages_final(&inode->i_data);
write_lock(&map_tree->lock);
while (!RB_EMPTY_ROOT(&map_tree->map.rb_root)) {
struct extent_map *em;
node = rb_first_cached(&map_tree->map);
em = rb_entry(node, struct extent_map, rb_node);
clear_bit(EXTENT_FLAG_PINNED, &em->flags);
clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
remove_extent_mapping(map_tree, em);
free_extent_map(em);
if (need_resched()) {
write_unlock(&map_tree->lock);
cond_resched();
write_lock(&map_tree->lock);
}
}
write_unlock(&map_tree->lock);
/*
* Keep looping until we have no more ranges in the io tree.
* We can have ongoing bios started by readahead that have
* their endio callback (extent_io.c:end_bio_extent_readpage)
* still in progress (unlocked the pages in the bio but did not yet
* unlocked the ranges in the io tree). Therefore this means some
* ranges can still be locked and eviction started because before
* submitting those bios, which are executed by a separate task (work
* queue kthread), inode references (inode->i_count) were not taken
* (which would be dropped in the end io callback of each bio).
* Therefore here we effectively end up waiting for those bios and
* anyone else holding locked ranges without having bumped the inode's
* reference count - if we don't do it, when they access the inode's
* io_tree to unlock a range it may be too late, leading to an
* use-after-free issue.
*/
spin_lock(&io_tree->lock);
while (!RB_EMPTY_ROOT(&io_tree->state)) {
struct extent_state *state;
struct extent_state *cached_state = NULL;
u64 start;
u64 end;
unsigned state_flags;
node = rb_first(&io_tree->state);
state = rb_entry(node, struct extent_state, rb_node);
start = state->start;
end = state->end;
state_flags = state->state;
spin_unlock(&io_tree->lock);
lock_extent_bits(io_tree, start, end, &cached_state);
/*
* If still has DELALLOC flag, the extent didn't reach disk,
* and its reserved space won't be freed by delayed_ref.
* So we need to free its reserved space here.
* (Refer to comment in btrfs_invalidatepage, case 2)
*
* Note, end is the bytenr of last byte, so we need + 1 here.
*/
if (state_flags & EXTENT_DELALLOC)
btrfs_qgroup_free_data(BTRFS_I(inode), NULL, start,
end - start + 1);
clear_extent_bit(io_tree, start, end,
EXTENT_LOCKED | EXTENT_DELALLOC |
EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 1,
&cached_state);
cond_resched();
spin_lock(&io_tree->lock);
}
spin_unlock(&io_tree->lock);
}
static struct btrfs_trans_handle *evict_refill_and_join(struct btrfs_root *root,
struct btrfs_block_rsv *rsv)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
struct btrfs_trans_handle *trans;
u64 delayed_refs_extra = btrfs_calc_insert_metadata_size(fs_info, 1);
int ret;
/*
* Eviction should be taking place at some place safe because of our
* delayed iputs. However the normal flushing code will run delayed
* iputs, so we cannot use FLUSH_ALL otherwise we'll deadlock.
*
* We reserve the delayed_refs_extra here again because we can't use
* btrfs_start_transaction(root, 0) for the same deadlocky reason as
* above. We reserve our extra bit here because we generate a ton of
* delayed refs activity by truncating.
*
* If we cannot make our reservation we'll attempt to steal from the
* global reserve, because we really want to be able to free up space.
*/
ret = btrfs_block_rsv_refill(root, rsv, rsv->size + delayed_refs_extra,
BTRFS_RESERVE_FLUSH_EVICT);
if (ret) {
/*
* Try to steal from the global reserve if there is space for
* it.
*/
if (btrfs_check_space_for_delayed_refs(fs_info) ||
btrfs_block_rsv_migrate(global_rsv, rsv, rsv->size, 0)) {
btrfs_warn(fs_info,
"could not allocate space for delete; will truncate on mount");
return ERR_PTR(-ENOSPC);
}
delayed_refs_extra = 0;
}
trans = btrfs_join_transaction(root);
if (IS_ERR(trans))
return trans;
if (delayed_refs_extra) {
trans->block_rsv = &fs_info->trans_block_rsv;
trans->bytes_reserved = delayed_refs_extra;
btrfs_block_rsv_migrate(rsv, trans->block_rsv,
delayed_refs_extra, 1);
}
return trans;
}
void btrfs_evict_inode(struct inode *inode)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_block_rsv *rsv;
int ret;
trace_btrfs_inode_evict(inode);
if (!root) {
fsverity_cleanup_inode(inode);
clear_inode(inode);
return;
}
evict_inode_truncate_pages(inode);
if (inode->i_nlink &&
((btrfs_root_refs(&root->root_item) != 0 &&
root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
btrfs_is_free_space_inode(BTRFS_I(inode))))
goto no_delete;
if (is_bad_inode(inode))
goto no_delete;
btrfs_free_io_failure_record(BTRFS_I(inode), 0, (u64)-1);
if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))
goto no_delete;
if (inode->i_nlink > 0) {
BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
goto no_delete;
}
ret = btrfs_commit_inode_delayed_inode(BTRFS_I(inode));
if (ret)
goto no_delete;
rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
if (!rsv)
goto no_delete;
rsv->size = btrfs_calc_metadata_size(fs_info, 1);
rsv->failfast = 1;
btrfs_i_size_write(BTRFS_I(inode), 0);
while (1) {
trans = evict_refill_and_join(root, rsv);
if (IS_ERR(trans))
goto free_rsv;
trans->block_rsv = rsv;
ret = btrfs_truncate_inode_items(trans, root, BTRFS_I(inode),
0, 0, NULL);
trans->block_rsv = &fs_info->trans_block_rsv;
btrfs_end_transaction(trans);
btrfs_btree_balance_dirty(fs_info);
if (ret && ret != -ENOSPC && ret != -EAGAIN)
goto free_rsv;
else if (!ret)
break;
}
/*
* Errors here aren't a big deal, it just means we leave orphan items in
* the tree. They will be cleaned up on the next mount. If the inode
* number gets reused, cleanup deletes the orphan item without doing
* anything, and unlink reuses the existing orphan item.
*
* If it turns out that we are dropping too many of these, we might want
* to add a mechanism for retrying these after a commit.
*/
trans = evict_refill_and_join(root, rsv);
if (!IS_ERR(trans)) {
trans->block_rsv = rsv;
btrfs_orphan_del(trans, BTRFS_I(inode));
trans->block_rsv = &fs_info->trans_block_rsv;
btrfs_end_transaction(trans);
}
free_rsv:
btrfs_free_block_rsv(fs_info, rsv);
no_delete:
/*
* If we didn't successfully delete, the orphan item will still be in
* the tree and we'll retry on the next mount. Again, we might also want
* to retry these periodically in the future.
*/
btrfs_remove_delayed_node(BTRFS_I(inode));
fsverity_cleanup_inode(inode);
clear_inode(inode);
}
/*
* Return the key found in the dir entry in the location pointer, fill @type
* with BTRFS_FT_*, and return 0.
*
* If no dir entries were found, returns -ENOENT.
* If found a corrupted location in dir entry, returns -EUCLEAN.
*/
static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
struct btrfs_key *location, u8 *type)
{
const char *name = dentry->d_name.name;
int namelen = dentry->d_name.len;
struct btrfs_dir_item *di;
struct btrfs_path *path;
struct btrfs_root *root = BTRFS_I(dir)->root;
int ret = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(BTRFS_I(dir)),
name, namelen, 0);
if (IS_ERR_OR_NULL(di)) {
ret = di ? PTR_ERR(di) : -ENOENT;
goto out;
}
btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
if (location->type != BTRFS_INODE_ITEM_KEY &&
location->type != BTRFS_ROOT_ITEM_KEY) {
ret = -EUCLEAN;
btrfs_warn(root->fs_info,
"%s gets something invalid in DIR_ITEM (name %s, directory ino %llu, location(%llu %u %llu))",
__func__, name, btrfs_ino(BTRFS_I(dir)),
location->objectid, location->type, location->offset);
}
if (!ret)
*type = btrfs_dir_type(path->nodes[0], di);
out:
btrfs_free_path(path);
return ret;
}
/*
* when we hit a tree root in a directory, the btrfs part of the inode
* needs to be changed to reflect the root directory of the tree root. This
* is kind of like crossing a mount point.
*/
static int fixup_tree_root_location(struct btrfs_fs_info *fs_info,
struct inode *dir,
struct dentry *dentry,
struct btrfs_key *location,
struct btrfs_root **sub_root)
{
struct btrfs_path *path;
struct btrfs_root *new_root;
struct btrfs_root_ref *ref;
struct extent_buffer *leaf;
struct btrfs_key key;
int ret;
int err = 0;
path = btrfs_alloc_path();
if (!path) {
err = -ENOMEM;
goto out;
}
err = -ENOENT;
key.objectid = BTRFS_I(dir)->root->root_key.objectid;
key.type = BTRFS_ROOT_REF_KEY;
key.offset = location->objectid;
ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
if (ret) {
if (ret < 0)
err = ret;
goto out;
}
leaf = path->nodes[0];
ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(BTRFS_I(dir)) ||
btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
goto out;
ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
(unsigned long)(ref + 1),
dentry->d_name.len);
if (ret)
goto out;
btrfs_release_path(path);
new_root = btrfs_get_fs_root(fs_info, location->objectid, true);
if (IS_ERR(new_root)) {
err = PTR_ERR(new_root);
goto out;
}
*sub_root = new_root;
location->objectid = btrfs_root_dirid(&new_root->root_item);
location->type = BTRFS_INODE_ITEM_KEY;
location->offset = 0;
err = 0;
out:
btrfs_free_path(path);
return err;
}
static void inode_tree_add(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_inode *entry;
struct rb_node **p;
struct rb_node *parent;
struct rb_node *new = &BTRFS_I(inode)->rb_node;
u64 ino = btrfs_ino(BTRFS_I(inode));
if (inode_unhashed(inode))
return;
parent = NULL;
spin_lock(&root->inode_lock);
p = &root->inode_tree.rb_node;
while (*p) {
parent = *p;
entry = rb_entry(parent, struct btrfs_inode, rb_node);
if (ino < btrfs_ino(entry))
p = &parent->rb_left;
else if (ino > btrfs_ino(entry))
p = &parent->rb_right;
else {
WARN_ON(!(entry->vfs_inode.i_state &
(I_WILL_FREE | I_FREEING)));
rb_replace_node(parent, new, &root->inode_tree);
RB_CLEAR_NODE(parent);
spin_unlock(&root->inode_lock);
return;
}
}
rb_link_node(new, parent, p);
rb_insert_color(new, &root->inode_tree);
spin_unlock(&root->inode_lock);
}
static void inode_tree_del(struct btrfs_inode *inode)
{
struct btrfs_root *root = inode->root;
int empty = 0;
spin_lock(&root->inode_lock);
if (!RB_EMPTY_NODE(&inode->rb_node)) {
rb_erase(&inode->rb_node, &root->inode_tree);
RB_CLEAR_NODE(&inode->rb_node);
empty = RB_EMPTY_ROOT(&root->inode_tree);
}
spin_unlock(&root->inode_lock);
if (empty && btrfs_root_refs(&root->root_item) == 0) {
spin_lock(&root->inode_lock);
empty = RB_EMPTY_ROOT(&root->inode_tree);
spin_unlock(&root->inode_lock);
if (empty)
btrfs_add_dead_root(root);
}
}
static int btrfs_init_locked_inode(struct inode *inode, void *p)
{
struct btrfs_iget_args *args = p;
inode->i_ino = args->ino;
BTRFS_I(inode)->location.objectid = args->ino;
BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
BTRFS_I(inode)->location.offset = 0;
BTRFS_I(inode)->root = btrfs_grab_root(args->root);
BUG_ON(args->root && !BTRFS_I(inode)->root);
return 0;
}
static int btrfs_find_actor(struct inode *inode, void *opaque)
{
struct btrfs_iget_args *args = opaque;
return args->ino == BTRFS_I(inode)->location.objectid &&
args->root == BTRFS_I(inode)->root;
}
static struct inode *btrfs_iget_locked(struct super_block *s, u64 ino,
struct btrfs_root *root)
{
struct inode *inode;
struct btrfs_iget_args args;
unsigned long hashval = btrfs_inode_hash(ino, root);
args.ino = ino;
args.root = root;
inode = iget5_locked(s, hashval, btrfs_find_actor,
btrfs_init_locked_inode,
(void *)&args);
return inode;
}
/*
* Get an inode object given its inode number and corresponding root.
* Path can be preallocated to prevent recursing back to iget through
* allocator. NULL is also valid but may require an additional allocation
* later.
*/
struct inode *btrfs_iget_path(struct super_block *s, u64 ino,
struct btrfs_root *root, struct btrfs_path *path)
{
struct inode *inode;
inode = btrfs_iget_locked(s, ino, root);
if (!inode)
return ERR_PTR(-ENOMEM);
if (inode->i_state & I_NEW) {
int ret;
ret = btrfs_read_locked_inode(inode, path);
if (!ret) {
inode_tree_add(inode);
unlock_new_inode(inode);
} else {
iget_failed(inode);
/*
* ret > 0 can come from btrfs_search_slot called by
* btrfs_read_locked_inode, this means the inode item
* was not found.
*/
if (ret > 0)
ret = -ENOENT;
inode = ERR_PTR(ret);
}
}
return inode;
}
struct inode *btrfs_iget(struct super_block *s, u64 ino, struct btrfs_root *root)
{
return btrfs_iget_path(s, ino, root, NULL);
}
static struct inode *new_simple_dir(struct super_block *s,
struct btrfs_key *key,
struct btrfs_root *root)
{
struct inode *inode = new_inode(s);
if (!inode)
return ERR_PTR(-ENOMEM);
BTRFS_I(inode)->root = btrfs_grab_root(root);
memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
/*
* We only need lookup, the rest is read-only and there's no inode
* associated with the dentry
*/
inode->i_op = &simple_dir_inode_operations;
inode->i_opflags &= ~IOP_XATTR;
inode->i_fop = &simple_dir_operations;
inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
inode->i_mtime = current_time(inode);
inode->i_atime = inode->i_mtime;
inode->i_ctime = inode->i_mtime;
BTRFS_I(inode)->i_otime = inode->i_mtime;
return inode;
}
static inline u8 btrfs_inode_type(struct inode *inode)
{
/*
* Compile-time asserts that generic FT_* types still match
* BTRFS_FT_* types
*/
BUILD_BUG_ON(BTRFS_FT_UNKNOWN != FT_UNKNOWN);
BUILD_BUG_ON(BTRFS_FT_REG_FILE != FT_REG_FILE);
BUILD_BUG_ON(BTRFS_FT_DIR != FT_DIR);
BUILD_BUG_ON(BTRFS_FT_CHRDEV != FT_CHRDEV);
BUILD_BUG_ON(BTRFS_FT_BLKDEV != FT_BLKDEV);
BUILD_BUG_ON(BTRFS_FT_FIFO != FT_FIFO);
BUILD_BUG_ON(BTRFS_FT_SOCK != FT_SOCK);
BUILD_BUG_ON(BTRFS_FT_SYMLINK != FT_SYMLINK);
return fs_umode_to_ftype(inode->i_mode);
}
struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
{
struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
struct inode *inode;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_root *sub_root = root;
struct btrfs_key location;
u8 di_type = 0;
int ret = 0;
if (dentry->d_name.len > BTRFS_NAME_LEN)
return ERR_PTR(-ENAMETOOLONG);
ret = btrfs_inode_by_name(dir, dentry, &location, &di_type);
if (ret < 0)
return ERR_PTR(ret);
if (location.type == BTRFS_INODE_ITEM_KEY) {
inode = btrfs_iget(dir->i_sb, location.objectid, root);
if (IS_ERR(inode))
return inode;
/* Do extra check against inode mode with di_type */
if (btrfs_inode_type(inode) != di_type) {
btrfs_crit(fs_info,
"inode mode mismatch with dir: inode mode=0%o btrfs type=%u dir type=%u",
inode->i_mode, btrfs_inode_type(inode),
di_type);
iput(inode);
return ERR_PTR(-EUCLEAN);
}
return inode;
}
ret = fixup_tree_root_location(fs_info, dir, dentry,
&location, &sub_root);
if (ret < 0) {
if (ret != -ENOENT)
inode = ERR_PTR(ret);
else
inode = new_simple_dir(dir->i_sb, &location, sub_root);
} else {
inode = btrfs_iget(dir->i_sb, location.objectid, sub_root);
}
if (root != sub_root)
btrfs_put_root(sub_root);
if (!IS_ERR(inode) && root != sub_root) {
down_read(&fs_info->cleanup_work_sem);
if (!sb_rdonly(inode->i_sb))
ret = btrfs_orphan_cleanup(sub_root);
up_read(&fs_info->cleanup_work_sem);
if (ret) {
iput(inode);
inode = ERR_PTR(ret);
}
}
return inode;
}
static int btrfs_dentry_delete(const struct dentry *dentry)
{
struct btrfs_root *root;
struct inode *inode = d_inode(dentry);
if (!inode && !IS_ROOT(dentry))
inode = d_inode(dentry->d_parent);
if (inode) {
root = BTRFS_I(inode)->root;
if (btrfs_root_refs(&root->root_item) == 0)
return 1;
if (btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
return 1;
}
return 0;
}
static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags)
{
struct inode *inode = btrfs_lookup_dentry(dir, dentry);
if (inode == ERR_PTR(-ENOENT))
inode = NULL;
return d_splice_alias(inode, dentry);
}
/*
* Find the highest existing sequence number in a directory and then set the
* in-memory index_cnt variable to the first free sequence number.
*/
static int btrfs_set_inode_index_count(struct btrfs_inode *inode)
{
struct btrfs_root *root = inode->root;
struct btrfs_key key, found_key;
struct btrfs_path *path;
struct extent_buffer *leaf;
int ret;
key.objectid = btrfs_ino(inode);
key.type = BTRFS_DIR_INDEX_KEY;
key.offset = (u64)-1;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
/* FIXME: we should be able to handle this */
if (ret == 0)
goto out;
ret = 0;
if (path->slots[0] == 0) {
inode->index_cnt = BTRFS_DIR_START_INDEX;
goto out;
}
path->slots[0]--;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.objectid != btrfs_ino(inode) ||
found_key.type != BTRFS_DIR_INDEX_KEY) {
inode->index_cnt = BTRFS_DIR_START_INDEX;
goto out;
}
inode->index_cnt = found_key.offset + 1;
out:
btrfs_free_path(path);
return ret;
}
static int btrfs_get_dir_last_index(struct btrfs_inode *dir, u64 *index)
{
int ret = 0;
btrfs_inode_lock(&dir->vfs_inode, 0);
if (dir->index_cnt == (u64)-1) {
ret = btrfs_inode_delayed_dir_index_count(dir);
if (ret) {
ret = btrfs_set_inode_index_count(dir);
if (ret)
goto out;
}
}
/* index_cnt is the index number of next new entry, so decrement it. */
*index = dir->index_cnt - 1;
out:
btrfs_inode_unlock(&dir->vfs_inode, 0);
return ret;
}
/*
* All this infrastructure exists because dir_emit can fault, and we are holding
* the tree lock when doing readdir. For now just allocate a buffer and copy
* our information into that, and then dir_emit from the buffer. This is
* similar to what NFS does, only we don't keep the buffer around in pagecache
* because I'm afraid I'll mess that up. Long term we need to make filldir do
* copy_to_user_inatomic so we don't have to worry about page faulting under the
* tree lock.
*/
static int btrfs_opendir(struct inode *inode, struct file *file)
{
struct btrfs_file_private *private;
u64 last_index;
int ret;
ret = btrfs_get_dir_last_index(BTRFS_I(inode), &last_index);
if (ret)
return ret;
private = kzalloc(sizeof(struct btrfs_file_private), GFP_KERNEL);
if (!private)
return -ENOMEM;
private->last_index = last_index;
private->filldir_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
if (!private->filldir_buf) {
kfree(private);
return -ENOMEM;
}
file->private_data = private;
return 0;
}
static loff_t btrfs_dir_llseek(struct file *file, loff_t offset, int whence)
{
struct btrfs_file_private *private = file->private_data;
int ret;
ret = btrfs_get_dir_last_index(BTRFS_I(file_inode(file)),
&private->last_index);
if (ret)
return ret;
return generic_file_llseek(file, offset, whence);
}
struct dir_entry {
u64 ino;
u64 offset;
unsigned type;
int name_len;
};
static int btrfs_filldir(void *addr, int entries, struct dir_context *ctx)
{
while (entries--) {
struct dir_entry *entry = addr;
char *name = (char *)(entry + 1);
ctx->pos = get_unaligned(&entry->offset);
if (!dir_emit(ctx, name, get_unaligned(&entry->name_len),
get_unaligned(&entry->ino),
get_unaligned(&entry->type)))
return 1;
addr += sizeof(struct dir_entry) +
get_unaligned(&entry->name_len);
ctx->pos++;
}
return 0;
}
static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
{
struct inode *inode = file_inode(file);
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_file_private *private = file->private_data;
struct btrfs_dir_item *di;
struct btrfs_key key;
struct btrfs_key found_key;
struct btrfs_path *path;
void *addr;
struct list_head ins_list;
struct list_head del_list;
int ret;
struct extent_buffer *leaf;
int slot;
char *name_ptr;
int name_len;
int entries = 0;
int total_len = 0;
bool put = false;
struct btrfs_key location;
if (!dir_emit_dots(file, ctx))
return 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
addr = private->filldir_buf;
path->reada = READA_FORWARD;
INIT_LIST_HEAD(&ins_list);
INIT_LIST_HEAD(&del_list);
put = btrfs_readdir_get_delayed_items(inode, private->last_index,
&ins_list, &del_list);
again:
key.type = BTRFS_DIR_INDEX_KEY;
key.offset = ctx->pos;
key.objectid = btrfs_ino(BTRFS_I(inode));
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto err;
while (1) {
struct dir_entry *entry;
leaf = path->nodes[0];
slot = path->slots[0];
if (slot >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
goto err;
else if (ret > 0)
break;
continue;
}
btrfs_item_key_to_cpu(leaf, &found_key, slot);
if (found_key.objectid != key.objectid)
break;
if (found_key.type != BTRFS_DIR_INDEX_KEY)
break;
if (found_key.offset < ctx->pos)
goto next;
if (found_key.offset > private->last_index)
break;
if (btrfs_should_delete_dir_index(&del_list, found_key.offset))
goto next;
di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
name_len = btrfs_dir_name_len(leaf, di);
if ((total_len + sizeof(struct dir_entry) + name_len) >=
PAGE_SIZE) {
btrfs_release_path(path);
ret = btrfs_filldir(private->filldir_buf, entries, ctx);
if (ret)
goto nopos;
addr = private->filldir_buf;
entries = 0;
total_len = 0;
goto again;
}
entry = addr;
put_unaligned(name_len, &entry->name_len);
name_ptr = (char *)(entry + 1);
read_extent_buffer(leaf, name_ptr, (unsigned long)(di + 1),
name_len);
put_unaligned(fs_ftype_to_dtype(btrfs_dir_type(leaf, di)),
&entry->type);
btrfs_dir_item_key_to_cpu(leaf, di, &location);
put_unaligned(location.objectid, &entry->ino);
put_unaligned(found_key.offset, &entry->offset);
entries++;
addr += sizeof(struct dir_entry) + name_len;
total_len += sizeof(struct dir_entry) + name_len;
next:
path->slots[0]++;
}
btrfs_release_path(path);
ret = btrfs_filldir(private->filldir_buf, entries, ctx);
if (ret)
goto nopos;
ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list);
if (ret)
goto nopos;
/*
* Stop new entries from being returned after we return the last
* entry.
*
* New directory entries are assigned a strictly increasing
* offset. This means that new entries created during readdir
* are *guaranteed* to be seen in the future by that readdir.
* This has broken buggy programs which operate on names as
* they're returned by readdir. Until we re-use freed offsets
* we have this hack to stop new entries from being returned
* under the assumption that they'll never reach this huge
* offset.
*
* This is being careful not to overflow 32bit loff_t unless the
* last entry requires it because doing so has broken 32bit apps
* in the past.
*/
if (ctx->pos >= INT_MAX)
ctx->pos = LLONG_MAX;
else
ctx->pos = INT_MAX;
nopos:
ret = 0;
err:
if (put)
btrfs_readdir_put_delayed_items(inode, &ins_list, &del_list);
btrfs_free_path(path);
return ret;
}
/*
* This is somewhat expensive, updating the tree every time the
* inode changes. But, it is most likely to find the inode in cache.
* FIXME, needs more benchmarking...there are no reasons other than performance
* to keep or drop this code.
*/
static int btrfs_dirty_inode(struct inode *inode)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
int ret;
if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
return 0;
trans = btrfs_join_transaction(root);
if (IS_ERR(trans))
return PTR_ERR(trans);
ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
if (ret && (ret == -ENOSPC || ret == -EDQUOT)) {
/* whoops, lets try again with the full transaction */
btrfs_end_transaction(trans);
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans))
return PTR_ERR(trans);
ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
}
btrfs_end_transaction(trans);
if (BTRFS_I(inode)->delayed_node)
btrfs_balance_delayed_items(fs_info);
return ret;
}
/*
* This is a copy of file_update_time. We need this so we can return error on
* ENOSPC for updating the inode in the case of file write and mmap writes.
*/
static int btrfs_update_time(struct inode *inode, struct timespec64 *now,
int flags)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
bool dirty = flags & ~S_VERSION;
if (btrfs_root_readonly(root))
return -EROFS;
if (flags & S_VERSION)
dirty |= inode_maybe_inc_iversion(inode, dirty);
if (flags & S_CTIME)
inode->i_ctime = *now;
if (flags & S_MTIME)
inode->i_mtime = *now;
if (flags & S_ATIME)
inode->i_atime = *now;
return dirty ? btrfs_dirty_inode(inode) : 0;
}
/*
* helper to find a free sequence number in a given directory. This current
* code is very simple, later versions will do smarter things in the btree
*/
int btrfs_set_inode_index(struct btrfs_inode *dir, u64 *index)
{
int ret = 0;
if (dir->index_cnt == (u64)-1) {
ret = btrfs_inode_delayed_dir_index_count(dir);
if (ret) {
ret = btrfs_set_inode_index_count(dir);
if (ret)
return ret;
}
}
*index = dir->index_cnt;
dir->index_cnt++;
return ret;
}
static int btrfs_insert_inode_locked(struct inode *inode)
{
struct btrfs_iget_args args;
args.ino = BTRFS_I(inode)->location.objectid;
args.root = BTRFS_I(inode)->root;
return insert_inode_locked4(inode,
btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root),
btrfs_find_actor, &args);
}
/*
* Inherit flags from the parent inode.
*
* Currently only the compression flags and the cow flags are inherited.
*/
static void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
{
unsigned int flags;
if (!dir)
return;
flags = BTRFS_I(dir)->flags;
if (flags & BTRFS_INODE_NOCOMPRESS) {
BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
} else if (flags & BTRFS_INODE_COMPRESS) {
BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
}
if (flags & BTRFS_INODE_NODATACOW) {
BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
if (S_ISREG(inode->i_mode))
BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
}
btrfs_sync_inode_flags_to_i_flags(inode);
}
static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct user_namespace *mnt_userns,
struct inode *dir,
const char *name, int name_len,
u64 ref_objectid, u64 objectid,
umode_t mode, u64 *index)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct inode *inode;
struct btrfs_inode_item *inode_item;
struct btrfs_key *location;
struct btrfs_path *path;
struct btrfs_inode_ref *ref;
struct btrfs_key key[2];
u32 sizes[2];
int nitems = name ? 2 : 1;
unsigned long ptr;
unsigned int nofs_flag;
int ret;
path = btrfs_alloc_path();
if (!path)
return ERR_PTR(-ENOMEM);
nofs_flag = memalloc_nofs_save();
inode = new_inode(fs_info->sb);
memalloc_nofs_restore(nofs_flag);
if (!inode) {
btrfs_free_path(path);
return ERR_PTR(-ENOMEM);
}
/*
* O_TMPFILE, set link count to 0, so that after this point,
* we fill in an inode item with the correct link count.
*/
if (!name)
set_nlink(inode, 0);
/*
* we have to initialize this early, so we can reclaim the inode
* number if we fail afterwards in this function.
*/
inode->i_ino = objectid;
if (dir && name) {
trace_btrfs_inode_request(dir);
ret = btrfs_set_inode_index(BTRFS_I(dir), index);
if (ret) {
btrfs_free_path(path);
iput(inode);
return ERR_PTR(ret);
}
} else if (dir) {
*index = 0;
}
/*
* index_cnt is ignored for everything but a dir,
* btrfs_set_inode_index_count has an explanation for the magic
* number
*/
BTRFS_I(inode)->index_cnt = 2;
BTRFS_I(inode)->dir_index = *index;
BTRFS_I(inode)->root = btrfs_grab_root(root);
BTRFS_I(inode)->generation = trans->transid;
inode->i_generation = BTRFS_I(inode)->generation;
/*
* We could have gotten an inode number from somebody who was fsynced
* and then removed in this same transaction, so let's just set full
* sync since it will be a full sync anyway and this will blow away the
* old info in the log.
*/
set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
key[0].objectid = objectid;
key[0].type = BTRFS_INODE_ITEM_KEY;
key[0].offset = 0;
sizes[0] = sizeof(struct btrfs_inode_item);
if (name) {
/*
* Start new inodes with an inode_ref. This is slightly more
* efficient for small numbers of hard links since they will
* be packed into one item. Extended refs will kick in if we
* add more hard links than can fit in the ref item.
*/
key[1].objectid = objectid;
key[1].type = BTRFS_INODE_REF_KEY;
key[1].offset = ref_objectid;
sizes[1] = name_len + sizeof(*ref);
}
location = &BTRFS_I(inode)->location;
location->objectid = objectid;
location->offset = 0;
location->type = BTRFS_INODE_ITEM_KEY;
ret = btrfs_insert_inode_locked(inode);
if (ret < 0) {
iput(inode);
goto fail;
}
ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
if (ret != 0)
goto fail_unlock;
inode_init_owner(mnt_userns, inode, dir, mode);
inode_set_bytes(inode, 0);
inode->i_mtime = current_time(inode);
inode->i_atime = inode->i_mtime;
inode->i_ctime = inode->i_mtime;
BTRFS_I(inode)->i_otime = inode->i_mtime;
inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_item);
memzero_extent_buffer(path->nodes[0], (unsigned long)inode_item,
sizeof(*inode_item));
fill_inode_item(trans, path->nodes[0], inode_item, inode);
if (name) {
ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
struct btrfs_inode_ref);
btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
ptr = (unsigned long)(ref + 1);
write_extent_buffer(path->nodes[0], name, ptr, name_len);
}
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_free_path(path);
btrfs_inherit_iflags(inode, dir);
if (S_ISREG(mode)) {
if (btrfs_test_opt(fs_info, NODATASUM))
BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
if (btrfs_test_opt(fs_info, NODATACOW))
BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
BTRFS_INODE_NODATASUM;
}
inode_tree_add(inode);
trace_btrfs_inode_new(inode);
btrfs_set_inode_last_trans(trans, BTRFS_I(inode));
btrfs_update_root_times(trans, root);
ret = btrfs_inode_inherit_props(trans, inode, dir);
if (ret)
btrfs_err(fs_info,
"error inheriting props for ino %llu (root %llu): %d",
btrfs_ino(BTRFS_I(inode)), root->root_key.objectid, ret);
return inode;
fail_unlock:
discard_new_inode(inode);
fail:
if (dir && name)
BTRFS_I(dir)->index_cnt--;
btrfs_free_path(path);
return ERR_PTR(ret);
}
/*
* utility function to add 'inode' into 'parent_inode' with
* a give name and a given sequence number.
* if 'add_backref' is true, also insert a backref from the
* inode to the parent directory.
*/
int btrfs_add_link(struct btrfs_trans_handle *trans,
struct btrfs_inode *parent_inode, struct btrfs_inode *inode,
const char *name, int name_len, int add_backref, u64 index)
{
int ret = 0;
struct btrfs_key key;
struct btrfs_root *root = parent_inode->root;
u64 ino = btrfs_ino(inode);
u64 parent_ino = btrfs_ino(parent_inode);
if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
memcpy(&key, &inode->root->root_key, sizeof(key));
} else {
key.objectid = ino;
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
}
if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
ret = btrfs_add_root_ref(trans, key.objectid,
root->root_key.objectid, parent_ino,
index, name, name_len);
} else if (add_backref) {
ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
parent_ino, index);
}
/* Nothing to clean up yet */
if (ret)
return ret;
ret = btrfs_insert_dir_item(trans, name, name_len, parent_inode, &key,
btrfs_inode_type(&inode->vfs_inode), index);
if (ret == -EEXIST || ret == -EOVERFLOW)
goto fail_dir_item;
else if (ret) {
btrfs_abort_transaction(trans, ret);
return ret;
}
btrfs_i_size_write(parent_inode, parent_inode->vfs_inode.i_size +
name_len * 2);
inode_inc_iversion(&parent_inode->vfs_inode);
/*
* If we are replaying a log tree, we do not want to update the mtime
* and ctime of the parent directory with the current time, since the
* log replay procedure is responsible for setting them to their correct
* values (the ones it had when the fsync was done).
*/
if (!test_bit(BTRFS_FS_LOG_RECOVERING, &root->fs_info->flags)) {
struct timespec64 now = current_time(&parent_inode->vfs_inode);
parent_inode->vfs_inode.i_mtime = now;
parent_inode->vfs_inode.i_ctime = now;
}
ret = btrfs_update_inode(trans, root, parent_inode);
if (ret)
btrfs_abort_transaction(trans, ret);
return ret;
fail_dir_item:
if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
u64 local_index;
int err;
err = btrfs_del_root_ref(trans, key.objectid,
root->root_key.objectid, parent_ino,
&local_index, name, name_len);
if (err)
btrfs_abort_transaction(trans, err);
} else if (add_backref) {
u64 local_index;
int err;
err = btrfs_del_inode_ref(trans, root, name, name_len,
ino, parent_ino, &local_index);
if (err)
btrfs_abort_transaction(trans, err);
}
/* Return the original error code */
return ret;
}
static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
struct btrfs_inode *dir, struct dentry *dentry,
struct btrfs_inode *inode, int backref, u64 index)
{
int err = btrfs_add_link(trans, dir, inode,
dentry->d_name.name, dentry->d_name.len,
backref, index);
if (err > 0)
err = -EEXIST;
return err;
}
static int btrfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
struct dentry *dentry, umode_t mode, dev_t rdev)
{
struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct inode *inode = NULL;
int err;
u64 objectid;
u64 index = 0;
/*
* 2 for inode item and ref
* 2 for dir items
* 1 for xattr if selinux is on
*/
trans = btrfs_start_transaction(root, 5);
if (IS_ERR(trans))
return PTR_ERR(trans);
err = btrfs_get_free_objectid(root, &objectid);
if (err)
goto out_unlock;
inode = btrfs_new_inode(trans, root, mnt_userns, dir,
dentry->d_name.name, dentry->d_name.len,
btrfs_ino(BTRFS_I(dir)), objectid, mode, &index);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
inode = NULL;
goto out_unlock;
}
/*
* If the active LSM wants to access the inode during
* d_instantiate it needs these. Smack checks to see
* if the filesystem supports xattrs by looking at the
* ops vector.
*/
inode->i_op = &btrfs_special_inode_operations;
init_special_inode(inode, inode->i_mode, rdev);
err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
if (err)
goto out_unlock;
err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
0, index);
if (err)
goto out_unlock;
btrfs_update_inode(trans, root, BTRFS_I(inode));
d_instantiate_new(dentry, inode);
out_unlock:
btrfs_end_transaction(trans);
btrfs_btree_balance_dirty(fs_info);
if (err && inode) {
inode_dec_link_count(inode);
discard_new_inode(inode);
}
return err;
}
static int btrfs_create(struct user_namespace *mnt_userns, struct inode *dir,
struct dentry *dentry, umode_t mode, bool excl)
{
struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct inode *inode = NULL;
int err;
u64 objectid;
u64 index = 0;
/*
* 2 for inode item and ref
* 2 for dir items
* 1 for xattr if selinux is on
*/
trans = btrfs_start_transaction(root, 5);
if (IS_ERR(trans))
return PTR_ERR(trans);
err = btrfs_get_free_objectid(root, &objectid);
if (err)
goto out_unlock;
inode = btrfs_new_inode(trans, root, mnt_userns, dir,
dentry->d_name.name, dentry->d_name.len,
btrfs_ino(BTRFS_I(dir)), objectid, mode, &index);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
inode = NULL;
goto out_unlock;
}
/*
* If the active LSM wants to access the inode during
* d_instantiate it needs these. Smack checks to see
* if the filesystem supports xattrs by looking at the
* ops vector.
*/
inode->i_fop = &btrfs_file_operations;
inode->i_op = &btrfs_file_inode_operations;
inode->i_mapping->a_ops = &btrfs_aops;
err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
if (err)
goto out_unlock;
err = btrfs_update_inode(trans, root, BTRFS_I(inode));
if (err)
goto out_unlock;
err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
0, index);
if (err)
goto out_unlock;
d_instantiate_new(dentry, inode);
out_unlock:
btrfs_end_transaction(trans);
if (err && inode) {
inode_dec_link_count(inode);
discard_new_inode(inode);
}
btrfs_btree_balance_dirty(fs_info);
return err;
}
static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *dentry)
{
struct btrfs_trans_handle *trans = NULL;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct inode *inode = d_inode(old_dentry);
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
u64 index;
int err;
int drop_inode = 0;
/* do not allow sys_link's with other subvols of the same device */
if (root->root_key.objectid != BTRFS_I(inode)->root->root_key.objectid)
return -EXDEV;
if (inode->i_nlink >= BTRFS_LINK_MAX)
return -EMLINK;
err = btrfs_set_inode_index(BTRFS_I(dir), &index);
if (err)
goto fail;
/*
* 2 items for inode and inode ref
* 2 items for dir items
* 1 item for parent inode
* 1 item for orphan item deletion if O_TMPFILE
*/
trans = btrfs_start_transaction(root, inode->i_nlink ? 5 : 6);
if (IS_ERR(trans)) {
err = PTR_ERR(trans);
trans = NULL;
goto fail;
}
/* There are several dir indexes for this inode, clear the cache. */
BTRFS_I(inode)->dir_index = 0ULL;
inc_nlink(inode);
inode_inc_iversion(inode);
inode->i_ctime = current_time(inode);
ihold(inode);
set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
1, index);
if (err) {
drop_inode = 1;
} else {
struct dentry *parent = dentry->d_parent;
err = btrfs_update_inode(trans, root, BTRFS_I(inode));
if (err)
goto fail;
if (inode->i_nlink == 1) {
/*
* If new hard link count is 1, it's a file created
* with open(2) O_TMPFILE flag.
*/
err = btrfs_orphan_del(trans, BTRFS_I(inode));
if (err)
goto fail;
}
d_instantiate(dentry, inode);
btrfs_log_new_name(trans, old_dentry, NULL, parent);
}
fail:
if (trans)
btrfs_end_transaction(trans);
if (drop_inode) {
inode_dec_link_count(inode);
iput(inode);
}
btrfs_btree_balance_dirty(fs_info);
return err;
}
static int btrfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
struct dentry *dentry, umode_t mode)
{
struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
struct inode *inode = NULL;
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
int err = 0;
u64 objectid = 0;
u64 index = 0;
/*
* 2 items for inode and ref
* 2 items for dir items
* 1 for xattr if selinux is on
*/
trans = btrfs_start_transaction(root, 5);
if (IS_ERR(trans))
return PTR_ERR(trans);
err = btrfs_get_free_objectid(root, &objectid);
if (err)
goto out_fail;
inode = btrfs_new_inode(trans, root, mnt_userns, dir,
dentry->d_name.name, dentry->d_name.len,
btrfs_ino(BTRFS_I(dir)), objectid,
S_IFDIR | mode, &index);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
inode = NULL;
goto out_fail;
}
/* these must be set before we unlock the inode */
inode->i_op = &btrfs_dir_inode_operations;
inode->i_fop = &btrfs_dir_file_operations;
err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
if (err)
goto out_fail;
btrfs_i_size_write(BTRFS_I(inode), 0);
err = btrfs_update_inode(trans, root, BTRFS_I(inode));
if (err)
goto out_fail;
err = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode),
dentry->d_name.name,
dentry->d_name.len, 0, index);
if (err)
goto out_fail;
d_instantiate_new(dentry, inode);
out_fail:
btrfs_end_transaction(trans);
if (err && inode) {
inode_dec_link_count(inode);
discard_new_inode(inode);
}
btrfs_btree_balance_dirty(fs_info);
return err;
}
static noinline int uncompress_inline(struct btrfs_path *path,
struct page *page,
size_t pg_offset, u64 extent_offset,
struct btrfs_file_extent_item *item)
{
int ret;
struct extent_buffer *leaf = path->nodes[0];
char *tmp;
size_t max_size;
unsigned long inline_size;
unsigned long ptr;
int compress_type;
WARN_ON(pg_offset != 0);
compress_type = btrfs_file_extent_compression(leaf, item);
max_size = btrfs_file_extent_ram_bytes(leaf, item);
inline_size = btrfs_file_extent_inline_item_len(leaf,
btrfs_item_nr(path->slots[0]));
tmp = kmalloc(inline_size, GFP_NOFS);
if (!tmp)
return -ENOMEM;
ptr = btrfs_file_extent_inline_start(item);
read_extent_buffer(leaf, tmp, ptr, inline_size);
max_size = min_t(unsigned long, PAGE_SIZE, max_size);
ret = btrfs_decompress(compress_type, tmp, page,
extent_offset, inline_size, max_size);
/*
* decompression code contains a memset to fill in any space between the end
* of the uncompressed data and the end of max_size in case the decompressed
* data ends up shorter than ram_bytes. That doesn't cover the hole between
* the end of an inline extent and the beginning of the next block, so we
* cover that region here.
*/
if (max_size + pg_offset < PAGE_SIZE)
memzero_page(page, pg_offset + max_size,
PAGE_SIZE - max_size - pg_offset);
kfree(tmp);
return ret;
}
/**
* btrfs_get_extent - Lookup the first extent overlapping a range in a file.
* @inode: file to search in
* @page: page to read extent data into if the extent is inline
* @pg_offset: offset into @page to copy to
* @start: file offset
* @len: length of range starting at @start
*
* This returns the first &struct extent_map which overlaps with the given
* range, reading it from the B-tree and caching it if necessary. Note that
* there may be more extents which overlap the given range after the returned
* extent_map.
*
* If @page is not NULL and the extent is inline, this also reads the extent
* data directly into the page and marks the extent up to date in the io_tree.
*
* Return: ERR_PTR on error, non-NULL extent_map on success.
*/
struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
struct page *page, size_t pg_offset,
u64 start, u64 len)
{
struct btrfs_fs_info *fs_info = inode->root->fs_info;
int ret = 0;
u64 extent_start = 0;
u64 extent_end = 0;
u64 objectid = btrfs_ino(inode);
int extent_type = -1;
struct btrfs_path *path = NULL;
struct btrfs_root *root = inode->root;
struct btrfs_file_extent_item *item;
struct extent_buffer *leaf;
struct btrfs_key found_key;
struct extent_map *em = NULL;
struct extent_map_tree *em_tree = &inode->extent_tree;
struct extent_io_tree *io_tree = &inode->io_tree;
read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, start, len);
read_unlock(&em_tree->lock);
if (em) {
if (em->start > start || em->start + em->len <= start)
free_extent_map(em);
else if (em->block_start == EXTENT_MAP_INLINE && page)
free_extent_map(em);
else
goto out;
}
em = alloc_extent_map();
if (!em) {
ret = -ENOMEM;
goto out;
}
em->start = EXTENT_MAP_HOLE;
em->orig_start = EXTENT_MAP_HOLE;
em->len = (u64)-1;
em->block_len = (u64)-1;
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto out;
}
/* Chances are we'll be called again, so go ahead and do readahead */
path->reada = READA_FORWARD;
/*
* The same explanation in load_free_space_cache applies here as well,
* we only read when we're loading the free space cache, and at that
* point the commit_root has everything we need.
*/
if (btrfs_is_free_space_inode(inode)) {
path->search_commit_root = 1;
path->skip_locking = 1;
}
ret = btrfs_lookup_file_extent(NULL, root, path, objectid, start, 0);
if (ret < 0) {
goto out;
} else if (ret > 0) {
if (path->slots[0] == 0)
goto not_found;
path->slots[0]--;
ret = 0;
}
leaf = path->nodes[0];
item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.objectid != objectid ||
found_key.type != BTRFS_EXTENT_DATA_KEY) {
/*
* If we backup past the first extent we want to move forward
* and see if there is an extent in front of us, otherwise we'll
* say there is a hole for our whole search range which can
* cause problems.
*/
extent_end = start;
goto next;
}
extent_type = btrfs_file_extent_type(leaf, item);
extent_start = found_key.offset;
extent_end = btrfs_file_extent_end(path);
if (extent_type == BTRFS_FILE_EXTENT_REG ||
extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
/* Only regular file could have regular/prealloc extent */
if (!S_ISREG(inode->vfs_inode.i_mode)) {
ret = -EUCLEAN;
btrfs_crit(fs_info,
"regular/prealloc extent found for non-regular inode %llu",
btrfs_ino(inode));
goto out;
}
trace_btrfs_get_extent_show_fi_regular(inode, leaf, item,
extent_start);
} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
trace_btrfs_get_extent_show_fi_inline(inode, leaf, item,
path->slots[0],
extent_start);
}
next:
if (start >= extent_end) {
path->slots[0]++;
if (path->slots[0] >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
goto out;
else if (ret > 0)
goto not_found;
leaf = path->nodes[0];
}
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.objectid != objectid ||
found_key.type != BTRFS_EXTENT_DATA_KEY)
goto not_found;
if (start + len <= found_key.offset)
goto not_found;
if (start > found_key.offset)
goto next;
/* New extent overlaps with existing one */
em->start = start;
em->orig_start = start;
em->len = found_key.offset - start;
em->block_start = EXTENT_MAP_HOLE;
goto insert;
}
btrfs_extent_item_to_extent_map(inode, path, item, !page, em);
if (extent_type == BTRFS_FILE_EXTENT_REG ||
extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
goto insert;
} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
unsigned long ptr;
char *map;
size_t size;
size_t extent_offset;
size_t copy_size;
if (!page)
goto out;
size = btrfs_file_extent_ram_bytes(leaf, item);
extent_offset = page_offset(page) + pg_offset - extent_start;
copy_size = min_t(u64, PAGE_SIZE - pg_offset,
size - extent_offset);
em->start = extent_start + extent_offset;
em->len = ALIGN(copy_size, fs_info->sectorsize);
em->orig_block_len = em->len;
em->orig_start = em->start;
ptr = btrfs_file_extent_inline_start(item) + extent_offset;
if (!PageUptodate(page)) {
if (btrfs_file_extent_compression(leaf, item) !=
BTRFS_COMPRESS_NONE) {
ret = uncompress_inline(path, page, pg_offset,
extent_offset, item);
if (ret)
goto out;
} else {
map = kmap_local_page(page);
read_extent_buffer(leaf, map + pg_offset, ptr,
copy_size);
if (pg_offset + copy_size < PAGE_SIZE) {
memset(map + pg_offset + copy_size, 0,
PAGE_SIZE - pg_offset -
copy_size);
}
kunmap_local(map);
}
flush_dcache_page(page);
}
set_extent_uptodate(io_tree, em->start,
extent_map_end(em) - 1, NULL, GFP_NOFS);
goto insert;
}
not_found:
em->start = start;
em->orig_start = start;
em->len = len;
em->block_start = EXTENT_MAP_HOLE;
insert:
ret = 0;
btrfs_release_path(path);
if (em->start > start || extent_map_end(em) <= start) {
btrfs_err(fs_info,
"bad extent! em: [%llu %llu] passed [%llu %llu]",
em->start, em->len, start, len);
ret = -EIO;
goto out;
}
write_lock(&em_tree->lock);
ret = btrfs_add_extent_mapping(fs_info, em_tree, &em, start, len);
write_unlock(&em_tree->lock);
out:
btrfs_free_path(path);
trace_btrfs_get_extent(root, inode, em);
if (ret) {
free_extent_map(em);
return ERR_PTR(ret);
}
return em;
}
struct extent_map *btrfs_get_extent_fiemap(struct btrfs_inode *inode,
u64 start, u64 len)
{
struct extent_map *em;
struct extent_map *hole_em = NULL;
u64 delalloc_start = start;
u64 end;
u64 delalloc_len;
u64 delalloc_end;
int err = 0;
em = btrfs_get_extent(inode, NULL, 0, start, len);
if (IS_ERR(em))
return em;
/*
* If our em maps to:
* - a hole or
* - a pre-alloc extent,
* there might actually be delalloc bytes behind it.
*/
if (em->block_start != EXTENT_MAP_HOLE &&
!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
return em;
else
hole_em = em;
/* check to see if we've wrapped (len == -1 or similar) */
end = start + len;
if (end < start)
end = (u64)-1;
else
end -= 1;
em = NULL;
/* ok, we didn't find anything, lets look for delalloc */
delalloc_len = count_range_bits(&inode->io_tree, &delalloc_start,
end, len, EXTENT_DELALLOC, 1);
delalloc_end = delalloc_start + delalloc_len;
if (delalloc_end < delalloc_start)
delalloc_end = (u64)-1;
/*
* We didn't find anything useful, return the original results from
* get_extent()
*/
if (delalloc_start > end || delalloc_end <= start) {
em = hole_em;
hole_em = NULL;
goto out;
}
/*
* Adjust the delalloc_start to make sure it doesn't go backwards from
* the start they passed in
*/
delalloc_start = max(start, delalloc_start);
delalloc_len = delalloc_end - delalloc_start;
if (delalloc_len > 0) {
u64 hole_start;
u64 hole_len;
const u64 hole_end = extent_map_end(hole_em);
em = alloc_extent_map();
if (!em) {
err = -ENOMEM;
goto out;
}
ASSERT(hole_em);
/*
* When btrfs_get_extent can't find anything it returns one
* huge hole
*
* Make sure what it found really fits our range, and adjust to
* make sure it is based on the start from the caller
*/
if (hole_end <= start || hole_em->start > end) {
free_extent_map(hole_em);
hole_em = NULL;
} else {
hole_start = max(hole_em->start, start);
hole_len = hole_end - hole_start;
}
if (hole_em && delalloc_start > hole_start) {
/*
* Our hole starts before our delalloc, so we have to
* return just the parts of the hole that go until the
* delalloc starts
*/
em->len = min(hole_len, delalloc_start - hole_start);
em->start = hole_start;
em->orig_start = hole_start;
/*
* Don't adjust block start at all, it is fixed at
* EXTENT_MAP_HOLE
*/
em->block_start = hole_em->block_start;
em->block_len = hole_len;
if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
} else {
/*
* Hole is out of passed range or it starts after
* delalloc range
*/
em->start = delalloc_start;
em->len = delalloc_len;
em->orig_start = delalloc_start;
em->block_start = EXTENT_MAP_DELALLOC;
em->block_len = delalloc_len;
}
} else {
return hole_em;
}
out:
free_extent_map(hole_em);
if (err) {
free_extent_map(em);
return ERR_PTR(err);
}
return em;
}
static struct extent_map *btrfs_create_dio_extent(struct btrfs_inode *inode,
const u64 start,
const u64 len,
const u64 orig_start,
const u64 block_start,
const u64 block_len,
const u64 orig_block_len,
const u64 ram_bytes,
const int type)
{
struct extent_map *em = NULL;
int ret;
if (type != BTRFS_ORDERED_NOCOW) {
em = create_io_em(inode, start, len, orig_start, block_start,
block_len, orig_block_len, ram_bytes,
BTRFS_COMPRESS_NONE, /* compress_type */
type);
if (IS_ERR(em))
goto out;
}
ret = btrfs_add_ordered_extent_dio(inode, start, block_start, len,
block_len, type);
if (ret) {
if (em) {
free_extent_map(em);
btrfs_drop_extent_cache(inode, start, start + len - 1, 0);
}
em = ERR_PTR(ret);
}
out:
return em;
}
static struct extent_map *btrfs_new_extent_direct(struct btrfs_inode *inode,
u64 start, u64 len)
{
struct btrfs_root *root = inode->root;
struct btrfs_fs_info *fs_info = root->fs_info;
struct extent_map *em;
struct btrfs_key ins;
u64 alloc_hint;
int ret;
alloc_hint = get_extent_allocation_hint(inode, start, len);
ret = btrfs_reserve_extent(root, len, len, fs_info->sectorsize,
0, alloc_hint, &ins, 1, 1);
if (ret)
return ERR_PTR(ret);
em = btrfs_create_dio_extent(inode, start, ins.offset, start,
ins.objectid, ins.offset, ins.offset,
ins.offset, BTRFS_ORDERED_REGULAR);
btrfs_dec_block_group_reservations(fs_info, ins.objectid);
if (IS_ERR(em))
btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset,
1);
return em;
}
static bool btrfs_extent_readonly(struct btrfs_fs_info *fs_info, u64 bytenr)
{
struct btrfs_block_group *block_group;
bool readonly = false;
block_group = btrfs_lookup_block_group(fs_info, bytenr);
if (!block_group || block_group->ro)
readonly = true;
if (block_group)
btrfs_put_block_group(block_group);
return readonly;
}
/*
* Check if we can do nocow write into the range [@offset, @offset + @len)
*
* @offset: File offset
* @len: The length to write, will be updated to the nocow writeable
* range
* @orig_start: (optional) Return the original file offset of the file extent
* @orig_len: (optional) Return the original on-disk length of the file extent
* @ram_bytes: (optional) Return the ram_bytes of the file extent
* @strict: if true, omit optimizations that might force us into unnecessary
* cow. e.g., don't trust generation number.
*
* Return:
* >0 and update @len if we can do nocow write
* 0 if we can't do nocow write
* <0 if error happened
*
* NOTE: This only checks the file extents, caller is responsible to wait for
* any ordered extents.
*/
noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
u64 *orig_start, u64 *orig_block_len,
u64 *ram_bytes, bool strict)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_path *path;
int ret;
struct extent_buffer *leaf;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct btrfs_file_extent_item *fi;
struct btrfs_key key;
u64 disk_bytenr;
u64 backref_offset;
u64 extent_end;
u64 num_bytes;
int slot;
int found_type;
bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_lookup_file_extent(NULL, root, path,
btrfs_ino(BTRFS_I(inode)), offset, 0);
if (ret < 0)
goto out;
slot = path->slots[0];
if (ret == 1) {
if (slot == 0) {
/* can't find the item, must cow */
ret = 0;
goto out;
}
slot--;
}
ret = 0;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, slot);
if (key.objectid != btrfs_ino(BTRFS_I(inode)) ||
key.type != BTRFS_EXTENT_DATA_KEY) {
/* not our file or wrong item type, must cow */
goto out;
}
if (key.offset > offset) {
/* Wrong offset, must cow */
goto out;
}
fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
found_type = btrfs_file_extent_type(leaf, fi);
if (found_type != BTRFS_FILE_EXTENT_REG &&
found_type != BTRFS_FILE_EXTENT_PREALLOC) {
/* not a regular extent, must cow */
goto out;
}
if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
goto out;
extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
if (extent_end <= offset)
goto out;
disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
if (disk_bytenr == 0)
goto out;
if (btrfs_file_extent_compression(leaf, fi) ||
btrfs_file_extent_encryption(leaf, fi) ||
btrfs_file_extent_other_encoding(leaf, fi))
goto out;
/*
* Do the same check as in btrfs_cross_ref_exist but without the
* unnecessary search.
*/
if (!strict &&
(btrfs_file_extent_generation(leaf, fi) <=
btrfs_root_last_snapshot(&root->root_item)))
goto out;
backref_offset = btrfs_file_extent_offset(leaf, fi);
if (orig_start) {
*orig_start = key.offset - backref_offset;
*orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
*ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
}
if (btrfs_extent_readonly(fs_info, disk_bytenr))
goto out;
num_bytes = min(offset + *len, extent_end) - offset;
if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) {
u64 range_end;
range_end = round_up(offset + num_bytes,
root->fs_info->sectorsize) - 1;
ret = test_range_bit(io_tree, offset, range_end,
EXTENT_DELALLOC, 0, NULL);
if (ret) {
ret = -EAGAIN;
goto out;
}
}
btrfs_release_path(path);
/*
* look for other files referencing this extent, if we
* find any we must cow
*/
ret = btrfs_cross_ref_exist(root, btrfs_ino(BTRFS_I(inode)),
key.offset - backref_offset, disk_bytenr,
strict);
if (ret) {
ret = 0;
goto out;
}
/*
* adjust disk_bytenr and num_bytes to cover just the bytes
* in this extent we are about to write. If there
* are any csums in that range we have to cow in order
* to keep the csums correct
*/
disk_bytenr += backref_offset;
disk_bytenr += offset - key.offset;
if (csum_exist_in_range(fs_info, disk_bytenr, num_bytes))
goto out;
/*
* all of the above have passed, it is safe to overwrite this extent
* without cow
*/
*len = num_bytes;
ret = 1;
out:
btrfs_free_path(path);
return ret;
}
static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
struct extent_state **cached_state, bool writing)
{
struct btrfs_ordered_extent *ordered;
int ret = 0;
while (1) {
lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
cached_state);
/*
* We're concerned with the entire range that we're going to be
* doing DIO to, so we need to make sure there's no ordered
* extents in this range.
*/
ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), lockstart,
lockend - lockstart + 1);
/*
* We need to make sure there are no buffered pages in this
* range either, we could have raced between the invalidate in
* generic_file_direct_write and locking the extent. The
* invalidate needs to happen so that reads after a write do not
* get stale data.
*/
if (!ordered &&
(!writing || !filemap_range_has_page(inode->i_mapping,
lockstart, lockend)))
break;
unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
cached_state);
if (ordered) {
/*
* If we are doing a DIO read and the ordered extent we
* found is for a buffered write, we can not wait for it
* to complete and retry, because if we do so we can
* deadlock with concurrent buffered writes on page
* locks. This happens only if our DIO read covers more
* than one extent map, if at this point has already
* created an ordered extent for a previous extent map
* and locked its range in the inode's io tree, and a
* concurrent write against that previous extent map's
* range and this range started (we unlock the ranges
* in the io tree only when the bios complete and
* buffered writes always lock pages before attempting
* to lock range in the io tree).
*/
if (writing ||
test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags))
btrfs_start_ordered_extent(ordered, 1);
else
ret = -ENOTBLK;
btrfs_put_ordered_extent(ordered);
} else {
/*
* We could trigger writeback for this range (and wait
* for it to complete) and then invalidate the pages for
* this range (through invalidate_inode_pages2_range()),
* but that can lead us to a deadlock with a concurrent
* call to readahead (a buffered read or a defrag call
* triggered a readahead) on a page lock due to an
* ordered dio extent we created before but did not have
* yet a corresponding bio submitted (whence it can not
* complete), which makes readahead wait for that
* ordered extent to complete while holding a lock on
* that page.
*/
ret = -ENOTBLK;
}
if (ret)
break;
cond_resched();
}
return ret;
}
/* The callers of this must take lock_extent() */
static struct extent_map *create_io_em(struct btrfs_inode *inode, u64 start,
u64 len, u64 orig_start, u64 block_start,
u64 block_len, u64 orig_block_len,
u64 ram_bytes, int compress_type,
int type)
{
struct extent_map_tree *em_tree;
struct extent_map *em;
int ret;
ASSERT(type == BTRFS_ORDERED_PREALLOC ||
type == BTRFS_ORDERED_COMPRESSED ||
type == BTRFS_ORDERED_NOCOW ||
type == BTRFS_ORDERED_REGULAR);
em_tree = &inode->extent_tree;
em = alloc_extent_map();
if (!em)
return ERR_PTR(-ENOMEM);
em->start = start;
em->orig_start = orig_start;
em->len = len;
em->block_len = block_len;
em->block_start = block_start;
em->orig_block_len = orig_block_len;
em->ram_bytes = ram_bytes;
em->generation = -1;
set_bit(EXTENT_FLAG_PINNED, &em->flags);
if (type == BTRFS_ORDERED_PREALLOC) {
set_bit(EXTENT_FLAG_FILLING, &em->flags);
} else if (type == BTRFS_ORDERED_COMPRESSED) {
set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
em->compress_type = compress_type;
}
do {
btrfs_drop_extent_cache(inode, em->start,
em->start + em->len - 1, 0);
write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em, 1);
write_unlock(&em_tree->lock);
/*
* The caller has taken lock_extent(), who could race with us
* to add em?
*/
} while (ret == -EEXIST);
if (ret) {
free_extent_map(em);
return ERR_PTR(ret);
}
/* em got 2 refs now, callers needs to do free_extent_map once. */
return em;
}
static int btrfs_get_blocks_direct_write(struct extent_map **map,
struct inode *inode,
struct btrfs_dio_data *dio_data,
u64 start, u64 len)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct extent_map *em = *map;
int type;
u64 block_start, orig_start, orig_block_len, ram_bytes;
bool can_nocow = false;
bool space_reserved = false;
u64 prev_len;
int ret = 0;
/*
* We don't allocate a new extent in the following cases
*
* 1) The inode is marked as NODATACOW. In this case we'll just use the
* existing extent.
* 2) The extent is marked as PREALLOC. We're good to go here and can
* just use the extent.
*
*/
if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
em->block_start != EXTENT_MAP_HOLE)) {
if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
type = BTRFS_ORDERED_PREALLOC;
else
type = BTRFS_ORDERED_NOCOW;
len = min(len, em->len - (start - em->start));
block_start = em->block_start + (start - em->start);
if (can_nocow_extent(inode, start, &len, &orig_start,
&orig_block_len, &ram_bytes, false) == 1 &&
btrfs_inc_nocow_writers(fs_info, block_start))
can_nocow = true;
}
prev_len = len;
if (can_nocow) {
struct extent_map *em2;
/* We can NOCOW, so only need to reserve metadata space. */
ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode), len);
if (ret < 0) {
/* Our caller expects us to free the input extent map. */
free_extent_map(em);
*map = NULL;
btrfs_dec_nocow_writers(fs_info, block_start);
goto out;
}
space_reserved = true;
em2 = btrfs_create_dio_extent(BTRFS_I(inode), start, len,
orig_start, block_start,
len, orig_block_len,
ram_bytes, type);
btrfs_dec_nocow_writers(fs_info, block_start);
if (type == BTRFS_ORDERED_PREALLOC) {
free_extent_map(em);
*map = em = em2;
}
if (IS_ERR(em2)) {
ret = PTR_ERR(em2);
goto out;
}
} else {
/* Our caller expects us to free the input extent map. */
free_extent_map(em);
*map = NULL;
/* We have to COW, so need to reserve metadata and data space. */
ret = btrfs_delalloc_reserve_space(BTRFS_I(inode),
&dio_data->data_reserved,
start, len);
if (ret < 0)
goto out;
space_reserved = true;
em = btrfs_new_extent_direct(BTRFS_I(inode), start, len);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
goto out;
}
*map = em;
len = min(len, em->len - (start - em->start));
if (len < prev_len)
btrfs_delalloc_release_space(BTRFS_I(inode),
dio_data->data_reserved,
start + len, prev_len - len,
true);
}
/*
* We have created our ordered extent, so we can now release our reservation
* for an outstanding extent.
*/
btrfs_delalloc_release_extents(BTRFS_I(inode), prev_len);
/*
* Need to update the i_size under the extent lock so buffered
* readers will get the updated i_size when we unlock.
*/
if (start + len > i_size_read(inode))
i_size_write(inode, start + len);
out:
if (ret && space_reserved) {
btrfs_delalloc_release_extents(BTRFS_I(inode), len);
if (can_nocow) {
btrfs_delalloc_release_metadata(BTRFS_I(inode), len, true);
} else {
btrfs_delalloc_release_space(BTRFS_I(inode),
dio_data->data_reserved,
start, len, true);
extent_changeset_free(dio_data->data_reserved);
dio_data->data_reserved = NULL;
}
}
return ret;
}
static int btrfs_dio_iomap_begin(struct inode *inode, loff_t start,
loff_t length, unsigned int flags, struct iomap *iomap,
struct iomap *srcmap)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct extent_map *em;
struct extent_state *cached_state = NULL;
struct btrfs_dio_data *dio_data = NULL;
u64 lockstart, lockend;
const bool write = !!(flags & IOMAP_WRITE);
int ret = 0;
u64 len = length;
bool unlock_extents = false;
if (!write)
len = min_t(u64, len, fs_info->sectorsize);
lockstart = start;
lockend = start + len - 1;
/*
* The generic stuff only does filemap_write_and_wait_range, which
* isn't enough if we've written compressed pages to this area, so we
* need to flush the dirty pages again to make absolutely sure that any
* outstanding dirty pages are on disk.
*/
if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
&BTRFS_I(inode)->runtime_flags)) {
ret = filemap_fdatawrite_range(inode->i_mapping, start,
start + length - 1);
if (ret)
return ret;
}
dio_data = kzalloc(sizeof(*dio_data), GFP_NOFS);
if (!dio_data)
return -ENOMEM;
iomap->private = dio_data;
/*
* If this errors out it's because we couldn't invalidate pagecache for
* this range and we need to fallback to buffered.
*/
if (lock_extent_direct(inode, lockstart, lockend, &cached_state, write)) {
ret = -ENOTBLK;
goto err;
}
em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
goto unlock_err;
}
/*
* Ok for INLINE and COMPRESSED extents we need to fallback on buffered
* io. INLINE is special, and we could probably kludge it in here, but
* it's still buffered so for safety lets just fall back to the generic
* buffered path.
*
* For COMPRESSED we _have_ to read the entire extent in so we can
* decompress it, so there will be buffering required no matter what we
* do, so go ahead and fallback to buffered.
*
* We return -ENOTBLK because that's what makes DIO go ahead and go back
* to buffered IO. Don't blame me, this is the price we pay for using
* the generic code.
*/
if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
em->block_start == EXTENT_MAP_INLINE) {
free_extent_map(em);
/*
* If we are in a NOWAIT context, return -EAGAIN in order to
* fallback to buffered IO. This is not only because we can
* block with buffered IO (no support for NOWAIT semantics at
* the moment) but also to avoid returning short reads to user
* space - this happens if we were able to read some data from
* previous non-compressed extents and then when we fallback to
* buffered IO, at btrfs_file_read_iter() by calling
* filemap_read(), we fail to fault in pages for the read buffer,
* in which case filemap_read() returns a short read (the number
* of bytes previously read is > 0, so it does not return -EFAULT).
*/
ret = (flags & IOMAP_NOWAIT) ? -EAGAIN : -ENOTBLK;
goto unlock_err;
}
len = min(len, em->len - (start - em->start));
/*
* If we have a NOWAIT request and the range contains multiple extents
* (or a mix of extents and holes), then we return -EAGAIN to make the
* caller fallback to a context where it can do a blocking (without
* NOWAIT) request. This way we avoid doing partial IO and returning
* success to the caller, which is not optimal for writes and for reads
* it can result in unexpected behaviour for an application.
*
* When doing a read, because we use IOMAP_DIO_PARTIAL when calling
* iomap_dio_rw(), we can end up returning less data then what the caller
* asked for, resulting in an unexpected, and incorrect, short read.
* That is, the caller asked to read N bytes and we return less than that,
* which is wrong unless we are crossing EOF. This happens if we get a
* page fault error when trying to fault in pages for the buffer that is
* associated to the struct iov_iter passed to iomap_dio_rw(), and we
* have previously submitted bios for other extents in the range, in
* which case iomap_dio_rw() may return us EIOCBQUEUED if not all of
* those bios have completed by the time we get the page fault error,
* which we return back to our caller - we should only return EIOCBQUEUED
* after we have submitted bios for all the extents in the range.
*/
if ((flags & IOMAP_NOWAIT) && len < length) {
free_extent_map(em);
ret = -EAGAIN;
goto unlock_err;
}
if (write) {
ret = btrfs_get_blocks_direct_write(&em, inode, dio_data,
start, len);
if (ret < 0)
goto unlock_err;
unlock_extents = true;
/* Recalc len in case the new em is smaller than requested */
len = min(len, em->len - (start - em->start));
} else {
/*
* We need to unlock only the end area that we aren't using.
* The rest is going to be unlocked by the endio routine.
*/
lockstart = start + len;
if (lockstart < lockend)
unlock_extents = true;
}
if (unlock_extents)
unlock_extent_cached(&BTRFS_I(inode)->io_tree,
lockstart, lockend, &cached_state);
else
free_extent_state(cached_state);
/*
* Translate extent map information to iomap.
* We trim the extents (and move the addr) even though iomap code does
* that, since we have locked only the parts we are performing I/O in.
*/
if ((em->block_start == EXTENT_MAP_HOLE) ||
(test_bit(EXTENT_FLAG_PREALLOC, &em->flags) && !write)) {
iomap->addr = IOMAP_NULL_ADDR;
iomap->type = IOMAP_HOLE;
} else {
iomap->addr = em->block_start + (start - em->start);
iomap->type = IOMAP_MAPPED;
}
iomap->offset = start;
iomap->bdev = fs_info->fs_devices->latest_dev->bdev;
iomap->length = len;
if (write && btrfs_use_zone_append(BTRFS_I(inode), em->block_start))
iomap->flags |= IOMAP_F_ZONE_APPEND;
free_extent_map(em);
return 0;
unlock_err:
unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
&cached_state);
err:
kfree(dio_data);
return ret;
}
static int btrfs_dio_iomap_end(struct inode *inode, loff_t pos, loff_t length,
ssize_t written, unsigned int flags, struct iomap *iomap)
{
int ret = 0;
struct btrfs_dio_data *dio_data = iomap->private;
size_t submitted = dio_data->submitted;
const bool write = !!(flags & IOMAP_WRITE);
if (!write && (iomap->type == IOMAP_HOLE)) {
/* If reading from a hole, unlock and return */
unlock_extent(&BTRFS_I(inode)->io_tree, pos, pos + length - 1);
goto out;
}
if (submitted < length) {
pos += submitted;
length -= submitted;
if (write)
__endio_write_update_ordered(BTRFS_I(inode), pos,
length, false);
else
unlock_extent(&BTRFS_I(inode)->io_tree, pos,
pos + length - 1);
ret = -ENOTBLK;
}
if (write)
extent_changeset_free(dio_data->data_reserved);
out:
kfree(dio_data);
iomap->private = NULL;
return ret;
}
static void btrfs_dio_private_put(struct btrfs_dio_private *dip)
{
/*
* This implies a barrier so that stores to dio_bio->bi_status before
* this and loads of dio_bio->bi_status after this are fully ordered.
*/
if (!refcount_dec_and_test(&dip->refs))
return;
if (btrfs_op(dip->dio_bio) == BTRFS_MAP_WRITE) {
__endio_write_update_ordered(BTRFS_I(dip->inode),
dip->logical_offset,
dip->bytes,
!dip->dio_bio->bi_status);
} else {
unlock_extent(&BTRFS_I(dip->inode)->io_tree,
dip->logical_offset,
dip->logical_offset + dip->bytes - 1);
}
bio_endio(dip->dio_bio);
kfree(dip);
}
static blk_status_t submit_dio_repair_bio(struct inode *inode, struct bio *bio,
int mirror_num,
unsigned long bio_flags)
{
struct btrfs_dio_private *dip = bio->bi_private;
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
blk_status_t ret;
BUG_ON(bio_op(bio) == REQ_OP_WRITE);
ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DATA);
if (ret)
return ret;
refcount_inc(&dip->refs);
ret = btrfs_map_bio(fs_info, bio, mirror_num);
if (ret)
refcount_dec(&dip->refs);
return ret;
}
static blk_status_t btrfs_check_read_dio_bio(struct inode *inode,
struct btrfs_io_bio *io_bio,
const bool uptodate)
{
struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
const u32 sectorsize = fs_info->sectorsize;
struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
const bool csum = !(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM);
struct bio_vec bvec;
struct bvec_iter iter;
u64 start = io_bio->logical;
u32 bio_offset = 0;
blk_status_t err = BLK_STS_OK;
__bio_for_each_segment(bvec, &io_bio->bio, iter, io_bio->iter) {
unsigned int i, nr_sectors, pgoff;
nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec.bv_len);
pgoff = bvec.bv_offset;
for (i = 0; i < nr_sectors; i++) {
ASSERT(pgoff < PAGE_SIZE);
if (uptodate &&
(!csum || !check_data_csum(inode, io_bio,
bio_offset, bvec.bv_page,
pgoff, start))) {
clean_io_failure(fs_info, failure_tree, io_tree,
start, bvec.bv_page,
btrfs_ino(BTRFS_I(inode)),
pgoff);
} else {
int ret;
ASSERT((start - io_bio->logical) < UINT_MAX);
ret = btrfs_repair_one_sector(inode,
&io_bio->bio,
start - io_bio->logical,
bvec.bv_page, pgoff,
start, io_bio->mirror_num,
submit_dio_repair_bio);
if (ret)
err = errno_to_blk_status(ret);
}
start += sectorsize;
ASSERT(bio_offset + sectorsize > bio_offset);
bio_offset += sectorsize;
pgoff += sectorsize;
}
}
return err;
}
static void __endio_write_update_ordered(struct btrfs_inode *inode,
const u64 offset, const u64 bytes,
const bool uptodate)
{
btrfs_mark_ordered_io_finished(inode, NULL, offset, bytes,
finish_ordered_fn, uptodate);
}
static blk_status_t btrfs_submit_bio_start_direct_io(struct inode *inode,
struct bio *bio,
u64 dio_file_offset)
{
return btrfs_csum_one_bio(BTRFS_I(inode), bio, dio_file_offset, 1);
}
static void btrfs_end_dio_bio(struct bio *bio)
{
struct btrfs_dio_private *dip = bio->bi_private;
blk_status_t err = bio->bi_status;
if (err)
btrfs_warn(BTRFS_I(dip->inode)->root->fs_info,
"direct IO failed ino %llu rw %d,%u sector %#Lx len %u err no %d",
btrfs_ino(BTRFS_I(dip->inode)), bio_op(bio),
bio->bi_opf, bio->bi_iter.bi_sector,
bio->bi_iter.bi_size, err);
if (bio_op(bio) == REQ_OP_READ) {
err = btrfs_check_read_dio_bio(dip->inode, btrfs_io_bio(bio),
!err);
}
if (err)
dip->dio_bio->bi_status = err;
btrfs_record_physical_zoned(dip->inode, dip->logical_offset, bio);
bio_put(bio);
btrfs_dio_private_put(dip);
}
static inline blk_status_t btrfs_submit_dio_bio(struct bio *bio,
struct inode *inode, u64 file_offset, int async_submit)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_dio_private *dip = bio->bi_private;
bool write = btrfs_op(bio) == BTRFS_MAP_WRITE;
blk_status_t ret;
/* Check btrfs_submit_bio_hook() for rules about async submit. */
if (async_submit)
async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
if (!write) {
ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DATA);
if (ret)
goto err;
}
if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
goto map;
if (write && async_submit) {
ret = btrfs_wq_submit_bio(inode, bio, 0, 0, file_offset,
btrfs_submit_bio_start_direct_io);
goto err;
} else if (write) {
/*
* If we aren't doing async submit, calculate the csum of the
* bio now.
*/
ret = btrfs_csum_one_bio(BTRFS_I(inode), bio, file_offset, 1);
if (ret)
goto err;
} else {
u64 csum_offset;
csum_offset = file_offset - dip->logical_offset;
csum_offset >>= fs_info->sectorsize_bits;
csum_offset *= fs_info->csum_size;
btrfs_io_bio(bio)->csum = dip->csums + csum_offset;
}
map:
ret = btrfs_map_bio(fs_info, bio, 0);
err:
return ret;
}
/*
* If this succeeds, the btrfs_dio_private is responsible for cleaning up locked
* or ordered extents whether or not we submit any bios.
*/
static struct btrfs_dio_private *btrfs_create_dio_private(struct bio *dio_bio,
struct inode *inode,
loff_t file_offset)
{
const bool write = (btrfs_op(dio_bio) == BTRFS_MAP_WRITE);
const bool csum = !(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM);
size_t dip_size;
struct btrfs_dio_private *dip;
dip_size = sizeof(*dip);
if (!write && csum) {
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
size_t nblocks;
nblocks = dio_bio->bi_iter.bi_size >> fs_info->sectorsize_bits;
dip_size += fs_info->csum_size * nblocks;
}
dip = kzalloc(dip_size, GFP_NOFS);
if (!dip)
return NULL;
dip->inode = inode;
dip->logical_offset = file_offset;
dip->bytes = dio_bio->bi_iter.bi_size;
dip->disk_bytenr = dio_bio->bi_iter.bi_sector << 9;
dip->dio_bio = dio_bio;
refcount_set(&dip->refs, 1);
return dip;
}
static blk_qc_t btrfs_submit_direct(const struct iomap_iter *iter,
struct bio *dio_bio, loff_t file_offset)
{
struct inode *inode = iter->inode;
const bool write = (btrfs_op(dio_bio) == BTRFS_MAP_WRITE);
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
const bool raid56 = (btrfs_data_alloc_profile(fs_info) &
BTRFS_BLOCK_GROUP_RAID56_MASK);
struct btrfs_dio_private *dip;
struct bio *bio;
u64 start_sector;
int async_submit = 0;
u64 submit_len;
u64 clone_offset = 0;
u64 clone_len;
u64 logical;
int ret;
blk_status_t status;
struct btrfs_io_geometry geom;
struct btrfs_dio_data *dio_data = iter->iomap.private;
struct extent_map *em = NULL;
dip = btrfs_create_dio_private(dio_bio, inode, file_offset);
if (!dip) {
if (!write) {
unlock_extent(&BTRFS_I(inode)->io_tree, file_offset,
file_offset + dio_bio->bi_iter.bi_size - 1);
}
dio_bio->bi_status = BLK_STS_RESOURCE;
bio_endio(dio_bio);
return BLK_QC_T_NONE;
}
if (!write) {
/*
* Load the csums up front to reduce csum tree searches and
* contention when submitting bios.
*
* If we have csums disabled this will do nothing.
*/
status = btrfs_lookup_bio_sums(inode, dio_bio, dip->csums);
if (status != BLK_STS_OK)
goto out_err;
}
start_sector = dio_bio->bi_iter.bi_sector;
submit_len = dio_bio->bi_iter.bi_size;
do {
logical = start_sector << 9;
em = btrfs_get_chunk_map(fs_info, logical, submit_len);
if (IS_ERR(em)) {
status = errno_to_blk_status(PTR_ERR(em));
em = NULL;
goto out_err_em;
}
ret = btrfs_get_io_geometry(fs_info, em, btrfs_op(dio_bio),
logical, &geom);
if (ret) {
status = errno_to_blk_status(ret);
goto out_err_em;
}
clone_len = min(submit_len, geom.len);
ASSERT(clone_len <= UINT_MAX);
/*
* This will never fail as it's passing GPF_NOFS and
* the allocation is backed by btrfs_bioset.
*/
bio = btrfs_bio_clone_partial(dio_bio, clone_offset, clone_len);
bio->bi_private = dip;
bio->bi_end_io = btrfs_end_dio_bio;
btrfs_io_bio(bio)->logical = file_offset;
if (bio_op(bio) == REQ_OP_ZONE_APPEND) {
status = extract_ordered_extent(BTRFS_I(inode), bio,
file_offset);
if (status) {
bio_put(bio);
goto out_err;
}
}
ASSERT(submit_len >= clone_len);
submit_len -= clone_len;
/*
* Increase the count before we submit the bio so we know
* the end IO handler won't happen before we increase the
* count. Otherwise, the dip might get freed before we're
* done setting it up.
*
* We transfer the initial reference to the last bio, so we
* don't need to increment the reference count for the last one.
*/
if (submit_len > 0) {
refcount_inc(&dip->refs);
/*
* If we are submitting more than one bio, submit them
* all asynchronously. The exception is RAID 5 or 6, as
* asynchronous checksums make it difficult to collect
* full stripe writes.
*/
if (!raid56)
async_submit = 1;
}
status = btrfs_submit_dio_bio(bio, inode, file_offset,
async_submit);
if (status) {
bio_put(bio);
if (submit_len > 0)
refcount_dec(&dip->refs);
goto out_err_em;
}
dio_data->submitted += clone_len;
clone_offset += clone_len;
start_sector += clone_len >> 9;
file_offset += clone_len;
free_extent_map(em);
} while (submit_len > 0);
return BLK_QC_T_NONE;
out_err_em:
free_extent_map(em);
out_err:
dip->dio_bio->bi_status = status;
btrfs_dio_private_put(dip);
return BLK_QC_T_NONE;
}
const struct iomap_ops btrfs_dio_iomap_ops = {
.iomap_begin = btrfs_dio_iomap_begin,
.iomap_end = btrfs_dio_iomap_end,
};
const struct iomap_dio_ops btrfs_dio_ops = {
.submit_io = btrfs_submit_direct,
};
static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
u64 start, u64 len)
{
int ret;
ret = fiemap_prep(inode, fieinfo, start, &len, 0);
if (ret)
return ret;
return extent_fiemap(BTRFS_I(inode), fieinfo, start, len);
}
int btrfs_readpage(struct file *file, struct page *page)
{
struct btrfs_inode *inode = BTRFS_I(page->mapping->host);
u64 start = page_offset(page);
u64 end = start + PAGE_SIZE - 1;
struct btrfs_bio_ctrl bio_ctrl = { 0 };
int ret;
btrfs_lock_and_flush_ordered_range(inode, start, end, NULL);
ret = btrfs_do_readpage(page, NULL, &bio_ctrl, 0, NULL);
if (bio_ctrl.bio)
ret = submit_one_bio(bio_ctrl.bio, 0, bio_ctrl.bio_flags);
return ret;
}
static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
{
struct inode *inode = page->mapping->host;
int ret;
if (current->flags & PF_MEMALLOC) {
redirty_page_for_writepage(wbc, page);
unlock_page(page);
return 0;
}
/*
* If we are under memory pressure we will call this directly from the
* VM, we need to make sure we have the inode referenced for the ordered
* extent. If not just return like we didn't do anything.
*/
if (!igrab(inode)) {
redirty_page_for_writepage(wbc, page);
return AOP_WRITEPAGE_ACTIVATE;
}
ret = extent_write_full_page(page, wbc);
btrfs_add_delayed_iput(inode);
return ret;
}
static int btrfs_writepages(struct address_space *mapping,
struct writeback_control *wbc)
{
return extent_writepages(mapping, wbc);
}
static void btrfs_readahead(struct readahead_control *rac)
{
extent_readahead(rac);
}
/*
* For releasepage() and invalidatepage() we have a race window where
* end_page_writeback() is called but the subpage spinlock is not yet released.
* If we continue to release/invalidate the page, we could cause use-after-free
* for subpage spinlock. So this function is to spin and wait for subpage
* spinlock.
*/
static void wait_subpage_spinlock(struct page *page)
{
struct btrfs_fs_info *fs_info = btrfs_sb(page->mapping->host->i_sb);
struct btrfs_subpage *subpage;
if (fs_info->sectorsize == PAGE_SIZE)
return;
ASSERT(PagePrivate(page) && page->private);
subpage = (struct btrfs_subpage *)page->private;
/*
* This may look insane as we just acquire the spinlock and release it,
* without doing anything. But we just want to make sure no one is
* still holding the subpage spinlock.
* And since the page is not dirty nor writeback, and we have page
* locked, the only possible way to hold a spinlock is from the endio
* function to clear page writeback.
*
* Here we just acquire the spinlock so that all existing callers
* should exit and we're safe to release/invalidate the page.
*/
spin_lock_irq(&subpage->lock);
spin_unlock_irq(&subpage->lock);
}
static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
{
int ret = try_release_extent_mapping(page, gfp_flags);
if (ret == 1) {
wait_subpage_spinlock(page);
clear_page_extent_mapped(page);
}
return ret;
}
static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
{
if (PageWriteback(page) || PageDirty(page))
return 0;
return __btrfs_releasepage(page, gfp_flags);
}
#ifdef CONFIG_MIGRATION
static int btrfs_migratepage(struct address_space *mapping,
struct page *newpage, struct page *page,
enum migrate_mode mode)
{
int ret;
ret = migrate_page_move_mapping(mapping, newpage, page, 0);
if (ret != MIGRATEPAGE_SUCCESS)
return ret;
if (page_has_private(page))
attach_page_private(newpage, detach_page_private(page));
if (PageOrdered(page)) {
ClearPageOrdered(page);
SetPageOrdered(newpage);
}
if (mode != MIGRATE_SYNC_NO_COPY)
migrate_page_copy(newpage, page);
else
migrate_page_states(newpage, page);
return MIGRATEPAGE_SUCCESS;
}
#endif
static void btrfs_invalidatepage(struct page *page, unsigned int offset,
unsigned int length)
{
struct btrfs_inode *inode = BTRFS_I(page->mapping->host);
struct btrfs_fs_info *fs_info = inode->root->fs_info;
struct extent_io_tree *tree = &inode->io_tree;
struct extent_state *cached_state = NULL;
u64 page_start = page_offset(page);
u64 page_end = page_start + PAGE_SIZE - 1;
u64 cur;
int inode_evicting = inode->vfs_inode.i_state & I_FREEING;
/*
* We have page locked so no new ordered extent can be created on this
* page, nor bio can be submitted for this page.
*
* But already submitted bio can still be finished on this page.
* Furthermore, endio function won't skip page which has Ordered
* (Private2) already cleared, so it's possible for endio and
* invalidatepage to do the same ordered extent accounting twice
* on one page.
*
* So here we wait for any submitted bios to finish, so that we won't
* do double ordered extent accounting on the same page.
*/
wait_on_page_writeback(page);
wait_subpage_spinlock(page);
/*
* For subpage case, we have call sites like
* btrfs_punch_hole_lock_range() which passes range not aligned to
* sectorsize.
* If the range doesn't cover the full page, we don't need to and
* shouldn't clear page extent mapped, as page->private can still
* record subpage dirty bits for other part of the range.
*
* For cases that can invalidate the full even the range doesn't
* cover the full page, like invalidating the last page, we're
* still safe to wait for ordered extent to finish.
*/
if (!(offset == 0 && length == PAGE_SIZE)) {
btrfs_releasepage(page, GFP_NOFS);
return;
}
if (!inode_evicting)
lock_extent_bits(tree, page_start, page_end, &cached_state);
cur = page_start;
while (cur < page_end) {
struct btrfs_ordered_extent *ordered;
bool delete_states;
u64 range_end;
u32 range_len;
ordered = btrfs_lookup_first_ordered_range(inode, cur,
page_end + 1 - cur);
if (!ordered) {
range_end = page_end;
/*
* No ordered extent covering this range, we are safe
* to delete all extent states in the range.
*/
delete_states = true;
goto next;
}
if (ordered->file_offset > cur) {
/*
* There is a range between [cur, oe->file_offset) not
* covered by any ordered extent.
* We are safe to delete all extent states, and handle
* the ordered extent in the next iteration.
*/
range_end = ordered->file_offset - 1;
delete_states = true;
goto next;
}
range_end = min(ordered->file_offset + ordered->num_bytes - 1,
page_end);
ASSERT(range_end + 1 - cur < U32_MAX);
range_len = range_end + 1 - cur;
if (!btrfs_page_test_ordered(fs_info, page, cur, range_len)) {
/*
* If Ordered (Private2) is cleared, it means endio has
* already been executed for the range.
* We can't delete the extent states as
* btrfs_finish_ordered_io() may still use some of them.
*/
delete_states = false;
goto next;
}
btrfs_page_clear_ordered(fs_info, page, cur, range_len);
/*
* IO on this page will never be started, so we need to account
* for any ordered extents now. Don't clear EXTENT_DELALLOC_NEW
* here, must leave that up for the ordered extent completion.
*
* This will also unlock the range for incoming
* btrfs_finish_ordered_io().
*/
if (!inode_evicting)
clear_extent_bit(tree, cur, range_end,
EXTENT_DELALLOC |
EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
EXTENT_DEFRAG, 1, 0, &cached_state);
spin_lock_irq(&inode->ordered_tree.lock);
set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
ordered->truncated_len = min(ordered->truncated_len,
cur - ordered->file_offset);
spin_unlock_irq(&inode->ordered_tree.lock);
if (btrfs_dec_test_ordered_pending(inode, &ordered,
cur, range_end + 1 - cur)) {
btrfs_finish_ordered_io(ordered);
/*
* The ordered extent has finished, now we're again
* safe to delete all extent states of the range.
*/
delete_states = true;
} else {
/*
* btrfs_finish_ordered_io() will get executed by endio
* of other pages, thus we can't delete extent states
* anymore
*/
delete_states = false;
}
next:
if (ordered)
btrfs_put_ordered_extent(ordered);
/*
* Qgroup reserved space handler
* Sector(s) here will be either:
*
* 1) Already written to disk or bio already finished
* Then its QGROUP_RESERVED bit in io_tree is already cleared.
* Qgroup will be handled by its qgroup_record then.
* btrfs_qgroup_free_data() call will do nothing here.
*
* 2) Not written to disk yet
* Then btrfs_qgroup_free_data() call will clear the
* QGROUP_RESERVED bit of its io_tree, and free the qgroup
* reserved data space.
* Since the IO will never happen for this page.
*/
btrfs_qgroup_free_data(inode, NULL, cur, range_end + 1 - cur);
if (!inode_evicting) {
clear_extent_bit(tree, cur, range_end, EXTENT_LOCKED |
EXTENT_DELALLOC | EXTENT_UPTODATE |
EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1,
delete_states, &cached_state);
}
cur = range_end + 1;
}
/*
* We have iterated through all ordered extents of the page, the page
* should not have Ordered (Private2) anymore, or the above iteration
* did something wrong.
*/
ASSERT(!PageOrdered(page));
if (!inode_evicting)
__btrfs_releasepage(page, GFP_NOFS);
ClearPageChecked(page);
clear_page_extent_mapped(page);
}
/*
* btrfs_page_mkwrite() is not allowed to change the file size as it gets
* called from a page fault handler when a page is first dirtied. Hence we must
* be careful to check for EOF conditions here. We set the page up correctly
* for a written page which means we get ENOSPC checking when writing into
* holes and correct delalloc and unwritten extent mapping on filesystems that
* support these features.
*
* We are not allowed to take the i_mutex here so we have to play games to
* protect against truncate races as the page could now be beyond EOF. Because
* truncate_setsize() writes the inode size before removing pages, once we have
* the page lock we can determine safely if the page is beyond EOF. If it is not
* beyond EOF, then the page is guaranteed safe against truncation until we
* unlock the page.
*/
vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf)
{
struct page *page = vmf->page;
struct inode *inode = file_inode(vmf->vma->vm_file);
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct btrfs_ordered_extent *ordered;
struct extent_state *cached_state = NULL;
struct extent_changeset *data_reserved = NULL;
unsigned long zero_start;
loff_t size;
vm_fault_t ret;
int ret2;
int reserved = 0;
u64 reserved_space;
u64 page_start;
u64 page_end;
u64 end;
reserved_space = PAGE_SIZE;
sb_start_pagefault(inode->i_sb);
page_start = page_offset(page);
page_end = page_start + PAGE_SIZE - 1;
end = page_end;
/*
* Reserving delalloc space after obtaining the page lock can lead to
* deadlock. For example, if a dirty page is locked by this function
* and the call to btrfs_delalloc_reserve_space() ends up triggering
* dirty page write out, then the btrfs_writepage() function could
* end up waiting indefinitely to get a lock on the page currently
* being processed by btrfs_page_mkwrite() function.
*/
ret2 = btrfs_delalloc_reserve_space(BTRFS_I(inode), &data_reserved,
page_start, reserved_space);
if (!ret2) {
ret2 = file_update_time(vmf->vma->vm_file);
reserved = 1;
}
if (ret2) {
ret = vmf_error(ret2);
if (reserved)
goto out;
goto out_noreserve;
}
ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
again:
down_read(&BTRFS_I(inode)->i_mmap_lock);
lock_page(page);
size = i_size_read(inode);
if ((page->mapping != inode->i_mapping) ||
(page_start >= size)) {
/* page got truncated out from underneath us */
goto out_unlock;
}
wait_on_page_writeback(page);
lock_extent_bits(io_tree, page_start, page_end, &cached_state);
ret2 = set_page_extent_mapped(page);
if (ret2 < 0) {
ret = vmf_error(ret2);
unlock_extent_cached(io_tree, page_start, page_end, &cached_state);
goto out_unlock;
}
/*
* we can't set the delalloc bits if there are pending ordered
* extents. Drop our locks and wait for them to finish
*/
ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), page_start,
PAGE_SIZE);
if (ordered) {
unlock_extent_cached(io_tree, page_start, page_end,
&cached_state);
unlock_page(page);
up_read(&BTRFS_I(inode)->i_mmap_lock);
btrfs_start_ordered_extent(ordered, 1);
btrfs_put_ordered_extent(ordered);
goto again;
}
if (page->index == ((size - 1) >> PAGE_SHIFT)) {
reserved_space = round_up(size - page_start,
fs_info->sectorsize);
if (reserved_space < PAGE_SIZE) {
end = page_start + reserved_space - 1;
btrfs_delalloc_release_space(BTRFS_I(inode),
data_reserved, page_start,
PAGE_SIZE - reserved_space, true);
}
}
/*
* page_mkwrite gets called when the page is firstly dirtied after it's
* faulted in, but write(2) could also dirty a page and set delalloc
* bits, thus in this case for space account reason, we still need to
* clear any delalloc bits within this page range since we have to
* reserve data&meta space before lock_page() (see above comments).
*/
clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, end,
EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
EXTENT_DEFRAG, 0, 0, &cached_state);
ret2 = btrfs_set_extent_delalloc(BTRFS_I(inode), page_start, end, 0,
&cached_state);
if (ret2) {
unlock_extent_cached(io_tree, page_start, page_end,
&cached_state);
ret = VM_FAULT_SIGBUS;
goto out_unlock;
}
/* page is wholly or partially inside EOF */
if (page_start + PAGE_SIZE > size)
zero_start = offset_in_page(size);
else
zero_start = PAGE_SIZE;
if (zero_start != PAGE_SIZE) {
memzero_page(page, zero_start, PAGE_SIZE - zero_start);
flush_dcache_page(page);
}
ClearPageChecked(page);
btrfs_page_set_dirty(fs_info, page, page_start, end + 1 - page_start);
btrfs_page_set_uptodate(fs_info, page, page_start, end + 1 - page_start);
btrfs_set_inode_last_sub_trans(BTRFS_I(inode));
unlock_extent_cached(io_tree, page_start, page_end, &cached_state);
up_read(&BTRFS_I(inode)->i_mmap_lock);
btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
sb_end_pagefault(inode->i_sb);
extent_changeset_free(data_reserved);
return VM_FAULT_LOCKED;
out_unlock:
unlock_page(page);
up_read(&BTRFS_I(inode)->i_mmap_lock);
out:
btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
btrfs_delalloc_release_space(BTRFS_I(inode), data_reserved, page_start,
reserved_space, (ret != 0));
out_noreserve:
sb_end_pagefault(inode->i_sb);
extent_changeset_free(data_reserved);
return ret;
}
static int btrfs_truncate(struct inode *inode, bool skip_writeback)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_block_rsv *rsv;
int ret;
struct btrfs_trans_handle *trans;
u64 mask = fs_info->sectorsize - 1;
u64 min_size = btrfs_calc_metadata_size(fs_info, 1);
u64 extents_found = 0;
if (!skip_writeback) {
ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
(u64)-1);
if (ret)
return ret;
}
/*
* Yes ladies and gentlemen, this is indeed ugly. We have a couple of
* things going on here:
*
* 1) We need to reserve space to update our inode.
*
* 2) We need to have something to cache all the space that is going to
* be free'd up by the truncate operation, but also have some slack
* space reserved in case it uses space during the truncate (thank you
* very much snapshotting).
*
* And we need these to be separate. The fact is we can use a lot of
* space doing the truncate, and we have no earthly idea how much space
* we will use, so we need the truncate reservation to be separate so it
* doesn't end up using space reserved for updating the inode. We also
* need to be able to stop the transaction and start a new one, which
* means we need to be able to update the inode several times, and we
* have no idea of knowing how many times that will be, so we can't just
* reserve 1 item for the entirety of the operation, so that has to be
* done separately as well.
*
* So that leaves us with
*
* 1) rsv - for the truncate reservation, which we will steal from the
* transaction reservation.
* 2) fs_info->trans_block_rsv - this will have 1 items worth left for
* updating the inode.
*/
rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
if (!rsv)
return -ENOMEM;
rsv->size = min_size;
rsv->failfast = 1;
/*
* 1 for the truncate slack space
* 1 for updating the inode.
*/
trans = btrfs_start_transaction(root, 2);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out;
}
/* Migrate the slack space for the truncate to our reserve */
ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv,
min_size, false);
BUG_ON(ret);
trans->block_rsv = rsv;
while (1) {
ret = btrfs_truncate_inode_items(trans, root, BTRFS_I(inode),
inode->i_size,
BTRFS_EXTENT_DATA_KEY,
&extents_found);
trans->block_rsv = &fs_info->trans_block_rsv;
if (ret != -ENOSPC && ret != -EAGAIN)
break;
ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
if (ret)
break;
btrfs_end_transaction(trans);
btrfs_btree_balance_dirty(fs_info);
trans = btrfs_start_transaction(root, 2);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
trans = NULL;
break;
}
btrfs_block_rsv_release(fs_info, rsv, -1, NULL);
ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv,
rsv, min_size, false);
BUG_ON(ret); /* shouldn't happen */
trans->block_rsv = rsv;
}
/*
* We can't call btrfs_truncate_block inside a trans handle as we could
* deadlock with freeze, if we got NEED_TRUNCATE_BLOCK then we know
* we've truncated everything except the last little bit, and can do
* btrfs_truncate_block and then update the disk_i_size.
*/
if (ret == NEED_TRUNCATE_BLOCK) {
btrfs_end_transaction(trans);
btrfs_btree_balance_dirty(fs_info);
ret = btrfs_truncate_block(BTRFS_I(inode), inode->i_size, 0, 0);
if (ret)
goto out;
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out;
}
btrfs_inode_safe_disk_i_size_write(BTRFS_I(inode), 0);
}
if (trans) {
int ret2;
trans->block_rsv = &fs_info->trans_block_rsv;
ret2 = btrfs_update_inode(trans, root, BTRFS_I(inode));
if (ret2 && !ret)
ret = ret2;
ret2 = btrfs_end_transaction(trans);
if (ret2 && !ret)
ret = ret2;
btrfs_btree_balance_dirty(fs_info);
}
out:
btrfs_free_block_rsv(fs_info, rsv);
/*
* So if we truncate and then write and fsync we normally would just
* write the extents that changed, which is a problem if we need to
* first truncate that entire inode. So set this flag so we write out
* all of the extents in the inode to the sync log so we're completely
* safe.
*
* If no extents were dropped or trimmed we don't need to force the next
* fsync to truncate all the inode's items from the log and re-log them
* all. This means the truncate operation did not change the file size,
* or changed it to a smaller size but there was only an implicit hole
* between the old i_size and the new i_size, and there were no prealloc
* extents beyond i_size to drop.
*/
if (extents_found > 0)
set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
return ret;
}
/*
* create a new subvolume directory/inode (helper for the ioctl).
*/
int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
struct btrfs_root *new_root,
struct btrfs_root *parent_root,
struct user_namespace *mnt_userns)
{
struct inode *inode;
int err;
u64 index = 0;
u64 ino;
err = btrfs_get_free_objectid(new_root, &ino);
if (err < 0)
return err;
inode = btrfs_new_inode(trans, new_root, mnt_userns, NULL, "..", 2,
ino, ino,
S_IFDIR | (~current_umask() & S_IRWXUGO),
&index);
if (IS_ERR(inode))
return PTR_ERR(inode);
inode->i_op = &btrfs_dir_inode_operations;
inode->i_fop = &btrfs_dir_file_operations;
set_nlink(inode, 1);
btrfs_i_size_write(BTRFS_I(inode), 0);
unlock_new_inode(inode);
err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
if (err)
btrfs_err(new_root->fs_info,
"error inheriting subvolume %llu properties: %d",
new_root->root_key.objectid, err);
err = btrfs_update_inode(trans, new_root, BTRFS_I(inode));
iput(inode);
return err;
}
struct inode *btrfs_alloc_inode(struct super_block *sb)
{
struct btrfs_fs_info *fs_info = btrfs_sb(sb);
struct btrfs_inode *ei;
struct inode *inode;
ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_KERNEL);
if (!ei)
return NULL;
ei->root = NULL;
ei->generation = 0;
ei->last_trans = 0;
ei->last_sub_trans = 0;
ei->logged_trans = 0;
ei->delalloc_bytes = 0;
ei->new_delalloc_bytes = 0;
ei->defrag_bytes = 0;
ei->disk_i_size = 0;
ei->flags = 0;
ei->ro_flags = 0;
ei->csum_bytes = 0;
ei->index_cnt = (u64)-1;
ei->dir_index = 0;
ei->last_unlink_trans = 0;
ei->last_reflink_trans = 0;
ei->last_log_commit = 0;
spin_lock_init(&ei->lock);
ei->outstanding_extents = 0;
if (sb->s_magic != BTRFS_TEST_MAGIC)
btrfs_init_metadata_block_rsv(fs_info, &ei->block_rsv,
BTRFS_BLOCK_RSV_DELALLOC);
ei->runtime_flags = 0;
ei->prop_compress = BTRFS_COMPRESS_NONE;
ei->defrag_compress = BTRFS_COMPRESS_NONE;
ei->delayed_node = NULL;
ei->i_otime.tv_sec = 0;
ei->i_otime.tv_nsec = 0;
inode = &ei->vfs_inode;
extent_map_tree_init(&ei->extent_tree);
extent_io_tree_init(fs_info, &ei->io_tree, IO_TREE_INODE_IO, inode);
extent_io_tree_init(fs_info, &ei->io_failure_tree,
IO_TREE_INODE_IO_FAILURE, inode);
extent_io_tree_init(fs_info, &ei->file_extent_tree,
IO_TREE_INODE_FILE_EXTENT, inode);
ei->io_tree.track_uptodate = true;
ei->io_failure_tree.track_uptodate = true;
atomic_set(&ei->sync_writers, 0);
mutex_init(&ei->log_mutex);
btrfs_ordered_inode_tree_init(&ei->ordered_tree);
INIT_LIST_HEAD(&ei->delalloc_inodes);
INIT_LIST_HEAD(&ei->delayed_iput);
RB_CLEAR_NODE(&ei->rb_node);
init_rwsem(&ei->i_mmap_lock);
return inode;
}
#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
void btrfs_test_destroy_inode(struct inode *inode)
{
btrfs_drop_extent_cache(BTRFS_I(inode), 0, (u64)-1, 0);
kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
}
#endif
void btrfs_free_inode(struct inode *inode)
{
kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
}
void btrfs_destroy_inode(struct inode *vfs_inode)
{
struct btrfs_ordered_extent *ordered;
struct btrfs_inode *inode = BTRFS_I(vfs_inode);
struct btrfs_root *root = inode->root;
WARN_ON(!hlist_empty(&vfs_inode->i_dentry));
WARN_ON(vfs_inode->i_data.nrpages);
WARN_ON(inode->block_rsv.reserved);
WARN_ON(inode->block_rsv.size);
WARN_ON(inode->outstanding_extents);
WARN_ON(inode->delalloc_bytes);
WARN_ON(inode->new_delalloc_bytes);
WARN_ON(inode->csum_bytes);
WARN_ON(inode->defrag_bytes);
/*
* This can happen where we create an inode, but somebody else also
* created the same inode and we need to destroy the one we already
* created.
*/
if (!root)
return;
while (1) {
ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
if (!ordered)
break;
else {
btrfs_err(root->fs_info,
"found ordered extent %llu %llu on inode cleanup",
ordered->file_offset, ordered->num_bytes);
btrfs_remove_ordered_extent(inode, ordered);
btrfs_put_ordered_extent(ordered);
btrfs_put_ordered_extent(ordered);
}
}
btrfs_qgroup_check_reserved_leak(inode);
inode_tree_del(inode);
btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
btrfs_inode_clear_file_extent_range(inode, 0, (u64)-1);
btrfs_put_root(inode->root);
}
int btrfs_drop_inode(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
if (root == NULL)
return 1;
/* the snap/subvol tree is on deleting */
if (btrfs_root_refs(&root->root_item) == 0)
return 1;
else
return generic_drop_inode(inode);
}
static void init_once(void *foo)
{
struct btrfs_inode *ei = (struct btrfs_inode *) foo;
inode_init_once(&ei->vfs_inode);
}
void __cold btrfs_destroy_cachep(void)
{
/*
* Make sure all delayed rcu free inodes are flushed before we
* destroy cache.
*/
rcu_barrier();
kmem_cache_destroy(btrfs_inode_cachep);
kmem_cache_destroy(btrfs_trans_handle_cachep);
kmem_cache_destroy(btrfs_path_cachep);
kmem_cache_destroy(btrfs_free_space_cachep);
kmem_cache_destroy(btrfs_free_space_bitmap_cachep);
}
int __init btrfs_init_cachep(void)
{
btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
sizeof(struct btrfs_inode), 0,
SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT,
init_once);
if (!btrfs_inode_cachep)
goto fail;
btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
sizeof(struct btrfs_trans_handle), 0,
SLAB_TEMPORARY | SLAB_MEM_SPREAD, NULL);
if (!btrfs_trans_handle_cachep)
goto fail;
btrfs_path_cachep = kmem_cache_create("btrfs_path",
sizeof(struct btrfs_path), 0,
SLAB_MEM_SPREAD, NULL);
if (!btrfs_path_cachep)
goto fail;
btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
sizeof(struct btrfs_free_space), 0,
SLAB_MEM_SPREAD, NULL);
if (!btrfs_free_space_cachep)
goto fail;
btrfs_free_space_bitmap_cachep = kmem_cache_create("btrfs_free_space_bitmap",
PAGE_SIZE, PAGE_SIZE,
SLAB_MEM_SPREAD, NULL);
if (!btrfs_free_space_bitmap_cachep)
goto fail;
return 0;
fail:
btrfs_destroy_cachep();
return -ENOMEM;
}
static int btrfs_getattr(struct user_namespace *mnt_userns,
const struct path *path, struct kstat *stat,
u32 request_mask, unsigned int flags)
{
u64 delalloc_bytes;
u64 inode_bytes;
struct inode *inode = d_inode(path->dentry);
u32 blocksize = inode->i_sb->s_blocksize;
u32 bi_flags = BTRFS_I(inode)->flags;
u32 bi_ro_flags = BTRFS_I(inode)->ro_flags;
stat->result_mask |= STATX_BTIME;
stat->btime.tv_sec = BTRFS_I(inode)->i_otime.tv_sec;
stat->btime.tv_nsec = BTRFS_I(inode)->i_otime.tv_nsec;
if (bi_flags & BTRFS_INODE_APPEND)
stat->attributes |= STATX_ATTR_APPEND;
if (bi_flags & BTRFS_INODE_COMPRESS)
stat->attributes |= STATX_ATTR_COMPRESSED;
if (bi_flags & BTRFS_INODE_IMMUTABLE)
stat->attributes |= STATX_ATTR_IMMUTABLE;
if (bi_flags & BTRFS_INODE_NODUMP)
stat->attributes |= STATX_ATTR_NODUMP;
if (bi_ro_flags & BTRFS_INODE_RO_VERITY)
stat->attributes |= STATX_ATTR_VERITY;
stat->attributes_mask |= (STATX_ATTR_APPEND |
STATX_ATTR_COMPRESSED |
STATX_ATTR_IMMUTABLE |
STATX_ATTR_NODUMP);
generic_fillattr(mnt_userns, inode, stat);
stat->dev = BTRFS_I(inode)->root->anon_dev;
spin_lock(&BTRFS_I(inode)->lock);
delalloc_bytes = BTRFS_I(inode)->new_delalloc_bytes;
inode_bytes = inode_get_bytes(inode);
spin_unlock(&BTRFS_I(inode)->lock);
stat->blocks = (ALIGN(inode_bytes, blocksize) +
ALIGN(delalloc_bytes, blocksize)) >> 9;
return 0;
}
static int btrfs_rename_exchange(struct inode *old_dir,
struct dentry *old_dentry,
struct inode *new_dir,
struct dentry *new_dentry)
{
struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb);
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(old_dir)->root;
struct btrfs_root *dest = BTRFS_I(new_dir)->root;
struct inode *new_inode = new_dentry->d_inode;
struct inode *old_inode = old_dentry->d_inode;
struct timespec64 ctime = current_time(old_inode);
u64 old_ino = btrfs_ino(BTRFS_I(old_inode));
u64 new_ino = btrfs_ino(BTRFS_I(new_inode));
u64 old_idx = 0;
u64 new_idx = 0;
int ret;
int ret2;
bool root_log_pinned = false;
bool dest_log_pinned = false;
bool need_abort = false;
/*
* For non-subvolumes allow exchange only within one subvolume, in the
* same inode namespace. Two subvolumes (represented as directory) can
* be exchanged as they're a logical link and have a fixed inode number.
*/
if (root != dest &&
(old_ino != BTRFS_FIRST_FREE_OBJECTID ||
new_ino != BTRFS_FIRST_FREE_OBJECTID))
return -EXDEV;
/* close the race window with snapshot create/destroy ioctl */
if (old_ino == BTRFS_FIRST_FREE_OBJECTID ||
new_ino == BTRFS_FIRST_FREE_OBJECTID)
down_read(&fs_info->subvol_sem);
/*
* We want to reserve the absolute worst case amount of items. So if
* both inodes are subvols and we need to unlink them then that would
* require 4 item modifications, but if they are both normal inodes it
* would require 5 item modifications, so we'll assume their normal
* inodes. So 5 * 2 is 10, plus 2 for the new links, so 12 total items
* should cover the worst case number of items we'll modify.
*/
trans = btrfs_start_transaction(root, 12);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out_notrans;
}
if (dest != root) {
ret = btrfs_record_root_in_trans(trans, dest);
if (ret)
goto out_fail;
}
/*
* We need to find a free sequence number both in the source and
* in the destination directory for the exchange.
*/
ret = btrfs_set_inode_index(BTRFS_I(new_dir), &old_idx);
if (ret)
goto out_fail;
ret = btrfs_set_inode_index(BTRFS_I(old_dir), &new_idx);
if (ret)
goto out_fail;
BTRFS_I(old_inode)->dir_index = 0ULL;
BTRFS_I(new_inode)->dir_index = 0ULL;
/* Reference for the source. */
if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
/* force full log commit if subvolume involved. */
btrfs_set_log_full_commit(trans);
} else {
ret = btrfs_insert_inode_ref(trans, dest,
new_dentry->d_name.name,
new_dentry->d_name.len,
old_ino,
btrfs_ino(BTRFS_I(new_dir)),
old_idx);
if (ret)
goto out_fail;
need_abort = true;
}
/* And now for the dest. */
if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
/* force full log commit if subvolume involved. */
btrfs_set_log_full_commit(trans);
} else {
ret = btrfs_insert_inode_ref(trans, root,
old_dentry->d_name.name,
old_dentry->d_name.len,
new_ino,
btrfs_ino(BTRFS_I(old_dir)),
new_idx);
if (ret) {
if (need_abort)
btrfs_abort_transaction(trans, ret);
goto out_fail;
}
}
/* Update inode version and ctime/mtime. */
inode_inc_iversion(old_dir);
inode_inc_iversion(new_dir);
inode_inc_iversion(old_inode);
inode_inc_iversion(new_inode);
old_dir->i_ctime = old_dir->i_mtime = ctime;
new_dir->i_ctime = new_dir->i_mtime = ctime;
old_inode->i_ctime = ctime;
new_inode->i_ctime = ctime;
if (old_dentry->d_parent != new_dentry->d_parent) {
btrfs_record_unlink_dir(trans, BTRFS_I(old_dir),
BTRFS_I(old_inode), 1);
btrfs_record_unlink_dir(trans, BTRFS_I(new_dir),
BTRFS_I(new_inode), 1);
}
/*
* Now pin the logs of the roots. We do it to ensure that no other task
* can sync the logs while we are in progress with the rename, because
* that could result in an inconsistency in case any of the inodes that
* are part of this rename operation were logged before.
*
* We pin the logs even if at this precise moment none of the inodes was
* logged before. This is because right after we checked for that, some
* other task fsyncing some other inode not involved with this rename
* operation could log that one of our inodes exists.
*
* We don't need to pin the logs before the above calls to
* btrfs_insert_inode_ref(), since those don't ever need to change a log.
*/
if (old_ino != BTRFS_FIRST_FREE_OBJECTID) {
btrfs_pin_log_trans(root);
root_log_pinned = true;
}
if (new_ino != BTRFS_FIRST_FREE_OBJECTID) {
btrfs_pin_log_trans(dest);
dest_log_pinned = true;
}
/* src is a subvolume */
if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
ret = btrfs_unlink_subvol(trans, old_dir, old_dentry);
} else { /* src is an inode */
ret = __btrfs_unlink_inode(trans, BTRFS_I(old_dir),
BTRFS_I(old_dentry->d_inode),
old_dentry->d_name.name,
old_dentry->d_name.len);
if (!ret)
ret = btrfs_update_inode(trans, root, BTRFS_I(old_inode));
}
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_fail;
}
/* dest is a subvolume */
if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
ret = btrfs_unlink_subvol(trans, new_dir, new_dentry);
} else { /* dest is an inode */
ret = __btrfs_unlink_inode(trans, BTRFS_I(new_dir),
BTRFS_I(new_dentry->d_inode),
new_dentry->d_name.name,
new_dentry->d_name.len);
if (!ret)
ret = btrfs_update_inode(trans, dest, BTRFS_I(new_inode));
}
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_fail;
}
ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode),
new_dentry->d_name.name,
new_dentry->d_name.len, 0, old_idx);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_fail;
}
ret = btrfs_add_link(trans, BTRFS_I(old_dir), BTRFS_I(new_inode),
old_dentry->d_name.name,
old_dentry->d_name.len, 0, new_idx);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_fail;
}
if (old_inode->i_nlink == 1)
BTRFS_I(old_inode)->dir_index = old_idx;
if (new_inode->i_nlink == 1)
BTRFS_I(new_inode)->dir_index = new_idx;
if (root_log_pinned) {
btrfs_log_new_name(trans, old_dentry, BTRFS_I(old_dir),
new_dentry->d_parent);
btrfs_end_log_trans(root);
root_log_pinned = false;
}
if (dest_log_pinned) {
btrfs_log_new_name(trans, new_dentry, BTRFS_I(new_dir),
old_dentry->d_parent);
btrfs_end_log_trans(dest);
dest_log_pinned = false;
}
out_fail:
/*
* If we have pinned a log and an error happened, we unpin tasks
* trying to sync the log and force them to fallback to a transaction
* commit if the log currently contains any of the inodes involved in
* this rename operation (to ensure we do not persist a log with an
* inconsistent state for any of these inodes or leading to any
* inconsistencies when replayed). If the transaction was aborted, the
* abortion reason is propagated to userspace when attempting to commit
* the transaction. If the log does not contain any of these inodes, we
* allow the tasks to sync it.
*/
if (ret && (root_log_pinned || dest_log_pinned)) {
if (btrfs_inode_in_log(BTRFS_I(old_dir), fs_info->generation) ||
btrfs_inode_in_log(BTRFS_I(new_dir), fs_info->generation) ||
btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) ||
btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation))
btrfs_set_log_full_commit(trans);
if (root_log_pinned) {
btrfs_end_log_trans(root);
root_log_pinned = false;
}
if (dest_log_pinned) {
btrfs_end_log_trans(dest);
dest_log_pinned = false;
}
}
ret2 = btrfs_end_transaction(trans);
ret = ret ? ret : ret2;
out_notrans:
if (new_ino == BTRFS_FIRST_FREE_OBJECTID ||
old_ino == BTRFS_FIRST_FREE_OBJECTID)
up_read(&fs_info->subvol_sem);
return ret;
}
static int btrfs_whiteout_for_rename(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct user_namespace *mnt_userns,
struct inode *dir,
struct dentry *dentry)
{
int ret;
struct inode *inode;
u64 objectid;
u64 index;
ret = btrfs_get_free_objectid(root, &objectid);
if (ret)
return ret;
inode = btrfs_new_inode(trans, root, mnt_userns, dir,
dentry->d_name.name,
dentry->d_name.len,
btrfs_ino(BTRFS_I(dir)),
objectid,
S_IFCHR | WHITEOUT_MODE,
&index);
if (IS_ERR(inode)) {
ret = PTR_ERR(inode);
return ret;
}
inode->i_op = &btrfs_special_inode_operations;
init_special_inode(inode, inode->i_mode,
WHITEOUT_DEV);
ret = btrfs_init_inode_security(trans, inode, dir,
&dentry->d_name);
if (ret)
goto out;
ret = btrfs_add_nondir(trans, BTRFS_I(dir), dentry,
BTRFS_I(inode), 0, index);
if (ret)
goto out;
ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
out:
unlock_new_inode(inode);
if (ret)
inode_dec_link_count(inode);
iput(inode);
return ret;
}
static int btrfs_rename(struct user_namespace *mnt_userns,
struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry,
unsigned int flags)
{
struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb);
struct btrfs_trans_handle *trans;
unsigned int trans_num_items;
struct btrfs_root *root = BTRFS_I(old_dir)->root;
struct btrfs_root *dest = BTRFS_I(new_dir)->root;
struct inode *new_inode = d_inode(new_dentry);
struct inode *old_inode = d_inode(old_dentry);
u64 index = 0;
int ret;
int ret2;
u64 old_ino = btrfs_ino(BTRFS_I(old_inode));
bool log_pinned = false;
if (btrfs_ino(BTRFS_I(new_dir)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
return -EPERM;
/* we only allow rename subvolume link between subvolumes */
if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
return -EXDEV;
if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
(new_inode && btrfs_ino(BTRFS_I(new_inode)) == BTRFS_FIRST_FREE_OBJECTID))
return -ENOTEMPTY;
if (S_ISDIR(old_inode->i_mode) && new_inode &&
new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
return -ENOTEMPTY;
/* check for collisions, even if the name isn't there */
ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
new_dentry->d_name.name,
new_dentry->d_name.len);
if (ret) {
if (ret == -EEXIST) {
/* we shouldn't get
* eexist without a new_inode */
if (WARN_ON(!new_inode)) {
return ret;
}
} else {
/* maybe -EOVERFLOW */
return ret;
}
}
ret = 0;
/*
* we're using rename to replace one file with another. Start IO on it
* now so we don't add too much work to the end of the transaction
*/
if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size)
filemap_flush(old_inode->i_mapping);
/* close the racy window with snapshot create/destroy ioctl */
if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
down_read(&fs_info->subvol_sem);
/*
* We want to reserve the absolute worst case amount of items. So if
* both inodes are subvols and we need to unlink them then that would
* require 4 item modifications, but if they are both normal inodes it
* would require 5 item modifications, so we'll assume they are normal
* inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
* should cover the worst case number of items we'll modify.
* If our rename has the whiteout flag, we need more 5 units for the
* new inode (1 inode item, 1 inode ref, 2 dir items and 1 xattr item
* when selinux is enabled).
*/
trans_num_items = 11;
if (flags & RENAME_WHITEOUT)
trans_num_items += 5;
trans = btrfs_start_transaction(root, trans_num_items);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out_notrans;
}
if (dest != root) {
ret = btrfs_record_root_in_trans(trans, dest);
if (ret)
goto out_fail;
}
ret = btrfs_set_inode_index(BTRFS_I(new_dir), &index);
if (ret)
goto out_fail;
BTRFS_I(old_inode)->dir_index = 0ULL;
if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
/* force full log commit if subvolume involved. */
btrfs_set_log_full_commit(trans);
} else {
ret = btrfs_insert_inode_ref(trans, dest,
new_dentry->d_name.name,
new_dentry->d_name.len,
old_ino,
btrfs_ino(BTRFS_I(new_dir)), index);
if (ret)
goto out_fail;
}
inode_inc_iversion(old_dir);
inode_inc_iversion(new_dir);
inode_inc_iversion(old_inode);
old_dir->i_ctime = old_dir->i_mtime =
new_dir->i_ctime = new_dir->i_mtime =
old_inode->i_ctime = current_time(old_dir);
if (old_dentry->d_parent != new_dentry->d_parent)
btrfs_record_unlink_dir(trans, BTRFS_I(old_dir),
BTRFS_I(old_inode), 1);
if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
ret = btrfs_unlink_subvol(trans, old_dir, old_dentry);
} else {
/*
* Now pin the log. We do it to ensure that no other task can
* sync the log while we are in progress with the rename, as
* that could result in an inconsistency in case any of the
* inodes that are part of this rename operation were logged
* before.
*
* We pin the log even if at this precise moment none of the
* inodes was logged before. This is because right after we
* checked for that, some other task fsyncing some other inode
* not involved with this rename operation could log that one of
* our inodes exists.
*
* We don't need to pin the logs before the above call to
* btrfs_insert_inode_ref(), since that does not need to change
* a log.
*/
btrfs_pin_log_trans(root);
log_pinned = true;
ret = __btrfs_unlink_inode(trans, BTRFS_I(old_dir),
BTRFS_I(d_inode(old_dentry)),
old_dentry->d_name.name,
old_dentry->d_name.len);
if (!ret)
ret = btrfs_update_inode(trans, root, BTRFS_I(old_inode));
}
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_fail;
}
if (new_inode) {
inode_inc_iversion(new_inode);
new_inode->i_ctime = current_time(new_inode);
if (unlikely(btrfs_ino(BTRFS_I(new_inode)) ==
BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
ret = btrfs_unlink_subvol(trans, new_dir, new_dentry);
BUG_ON(new_inode->i_nlink == 0);
} else {
ret = btrfs_unlink_inode(trans, BTRFS_I(new_dir),
BTRFS_I(d_inode(new_dentry)),
new_dentry->d_name.name,
new_dentry->d_name.len);
}
if (!ret && new_inode->i_nlink == 0)
ret = btrfs_orphan_add(trans,
BTRFS_I(d_inode(new_dentry)));
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_fail;
}
}
ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode),
new_dentry->d_name.name,
new_dentry->d_name.len, 0, index);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_fail;
}
if (old_inode->i_nlink == 1)
BTRFS_I(old_inode)->dir_index = index;
if (log_pinned) {
btrfs_log_new_name(trans, old_dentry, BTRFS_I(old_dir),
new_dentry->d_parent);
btrfs_end_log_trans(root);
log_pinned = false;
}
if (flags & RENAME_WHITEOUT) {
ret = btrfs_whiteout_for_rename(trans, root, mnt_userns,
old_dir, old_dentry);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_fail;
}
}
out_fail:
/*
* If we have pinned the log and an error happened, we unpin tasks
* trying to sync the log and force them to fallback to a transaction
* commit if the log currently contains any of the inodes involved in
* this rename operation (to ensure we do not persist a log with an
* inconsistent state for any of these inodes or leading to any
* inconsistencies when replayed). If the transaction was aborted, the
* abortion reason is propagated to userspace when attempting to commit
* the transaction. If the log does not contain any of these inodes, we
* allow the tasks to sync it.
*/
if (ret && log_pinned) {
if (btrfs_inode_in_log(BTRFS_I(old_dir), fs_info->generation) ||
btrfs_inode_in_log(BTRFS_I(new_dir), fs_info->generation) ||
btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) ||
(new_inode &&
btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation)))
btrfs_set_log_full_commit(trans);
btrfs_end_log_trans(root);
log_pinned = false;
}
ret2 = btrfs_end_transaction(trans);
ret = ret ? ret : ret2;
out_notrans:
if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
up_read(&fs_info->subvol_sem);
return ret;
}
static int btrfs_rename2(struct user_namespace *mnt_userns, struct inode *old_dir,
struct dentry *old_dentry, struct inode *new_dir,
struct dentry *new_dentry, unsigned int flags)
{
if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
return -EINVAL;
if (flags & RENAME_EXCHANGE)
return btrfs_rename_exchange(old_dir, old_dentry, new_dir,
new_dentry);
return btrfs_rename(mnt_userns, old_dir, old_dentry, new_dir,
new_dentry, flags);
}
struct btrfs_delalloc_work {
struct inode *inode;
struct completion completion;
struct list_head list;
struct btrfs_work work;
};
static void btrfs_run_delalloc_work(struct btrfs_work *work)
{
struct btrfs_delalloc_work *delalloc_work;
struct inode *inode;
delalloc_work = container_of(work, struct btrfs_delalloc_work,
work);
inode = delalloc_work->inode;
filemap_flush(inode->i_mapping);
if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
&BTRFS_I(inode)->runtime_flags))
filemap_flush(inode->i_mapping);
iput(inode);
complete(&delalloc_work->completion);
}
static struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode)
{
struct btrfs_delalloc_work *work;
work = kmalloc(sizeof(*work), GFP_NOFS);
if (!work)
return NULL;
init_completion(&work->completion);
INIT_LIST_HEAD(&work->list);
work->inode = inode;
btrfs_init_work(&work->work, btrfs_run_delalloc_work, NULL, NULL);
return work;
}
/*
* some fairly slow code that needs optimization. This walks the list
* of all the inodes with pending delalloc and forces them to disk.
*/
static int start_delalloc_inodes(struct btrfs_root *root,
struct writeback_control *wbc, bool snapshot,
bool in_reclaim_context)
{
struct btrfs_inode *binode;
struct inode *inode;
struct btrfs_delalloc_work *work, *next;
struct list_head works;
struct list_head splice;
int ret = 0;
bool full_flush = wbc->nr_to_write == LONG_MAX;
INIT_LIST_HEAD(&works);
INIT_LIST_HEAD(&splice);
mutex_lock(&root->delalloc_mutex);
spin_lock(&root->delalloc_lock);
list_splice_init(&root->delalloc_inodes, &splice);
while (!list_empty(&splice)) {
binode = list_entry(splice.next, struct btrfs_inode,
delalloc_inodes);
list_move_tail(&binode->delalloc_inodes,
&root->delalloc_inodes);
if (in_reclaim_context &&
test_bit(BTRFS_INODE_NO_DELALLOC_FLUSH, &binode->runtime_flags))
continue;
inode = igrab(&binode->vfs_inode);
if (!inode) {
cond_resched_lock(&root->delalloc_lock);
continue;
}
spin_unlock(&root->delalloc_lock);
if (snapshot)
set_bit(BTRFS_INODE_SNAPSHOT_FLUSH,
&binode->runtime_flags);
if (full_flush) {
work = btrfs_alloc_delalloc_work(inode);
if (!work) {
iput(inode);
ret = -ENOMEM;
goto out;
}
list_add_tail(&work->list, &works);
btrfs_queue_work(root->fs_info->flush_workers,
&work->work);
} else {
ret = filemap_fdatawrite_wbc(inode->i_mapping, wbc);
btrfs_add_delayed_iput(inode);
if (ret || wbc->nr_to_write <= 0)
goto out;
}
cond_resched();
spin_lock(&root->delalloc_lock);
}
spin_unlock(&root->delalloc_lock);
out:
list_for_each_entry_safe(work, next, &works, list) {
list_del_init(&work->list);
wait_for_completion(&work->completion);
kfree(work);
}
if (!list_empty(&splice)) {
spin_lock(&root->delalloc_lock);
list_splice_tail(&splice, &root->delalloc_inodes);
spin_unlock(&root->delalloc_lock);
}
mutex_unlock(&root->delalloc_mutex);
return ret;
}
int btrfs_start_delalloc_snapshot(struct btrfs_root *root, bool in_reclaim_context)
{
struct writeback_control wbc = {
.nr_to_write = LONG_MAX,
.sync_mode = WB_SYNC_NONE,
.range_start = 0,
.range_end = LLONG_MAX,
};
struct btrfs_fs_info *fs_info = root->fs_info;
if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
return -EROFS;
return start_delalloc_inodes(root, &wbc, true, in_reclaim_context);
}
int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, long nr,
bool in_reclaim_context)
{
struct writeback_control wbc = {
.nr_to_write = nr,
.sync_mode = WB_SYNC_NONE,
.range_start = 0,
.range_end = LLONG_MAX,
};
struct btrfs_root *root;
struct list_head splice;
int ret;
if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
return -EROFS;
INIT_LIST_HEAD(&splice);
mutex_lock(&fs_info->delalloc_root_mutex);
spin_lock(&fs_info->delalloc_root_lock);
list_splice_init(&fs_info->delalloc_roots, &splice);
while (!list_empty(&splice)) {
/*
* Reset nr_to_write here so we know that we're doing a full
* flush.
*/
if (nr == LONG_MAX)
wbc.nr_to_write = LONG_MAX;
root = list_first_entry(&splice, struct btrfs_root,
delalloc_root);
root = btrfs_grab_root(root);
BUG_ON(!root);
list_move_tail(&root->delalloc_root,
&fs_info->delalloc_roots);
spin_unlock(&fs_info->delalloc_root_lock);
ret = start_delalloc_inodes(root, &wbc, false, in_reclaim_context);
btrfs_put_root(root);
if (ret < 0 || wbc.nr_to_write <= 0)
goto out;
spin_lock(&fs_info->delalloc_root_lock);
}
spin_unlock(&fs_info->delalloc_root_lock);
ret = 0;
out:
if (!list_empty(&splice)) {
spin_lock(&fs_info->delalloc_root_lock);
list_splice_tail(&splice, &fs_info->delalloc_roots);
spin_unlock(&fs_info->delalloc_root_lock);
}
mutex_unlock(&fs_info->delalloc_root_mutex);
return ret;
}
static int btrfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
struct dentry *dentry, const char *symname)
{
struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_path *path;
struct btrfs_key key;
struct inode *inode = NULL;
int err;
u64 objectid;
u64 index = 0;
int name_len;
int datasize;
unsigned long ptr;
struct btrfs_file_extent_item *ei;
struct extent_buffer *leaf;
name_len = strlen(symname);
if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info))
return -ENAMETOOLONG;
/*
* 2 items for inode item and ref
* 2 items for dir items
* 1 item for updating parent inode item
* 1 item for the inline extent item
* 1 item for xattr if selinux is on
*/
trans = btrfs_start_transaction(root, 7);
if (IS_ERR(trans))
return PTR_ERR(trans);
err = btrfs_get_free_objectid(root, &objectid);
if (err)
goto out_unlock;
inode = btrfs_new_inode(trans, root, mnt_userns, dir,
dentry->d_name.name, dentry->d_name.len,
btrfs_ino(BTRFS_I(dir)), objectid,
S_IFLNK | S_IRWXUGO, &index);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
inode = NULL;
goto out_unlock;
}
/*
* If the active LSM wants to access the inode during
* d_instantiate it needs these. Smack checks to see
* if the filesystem supports xattrs by looking at the
* ops vector.
*/
inode->i_fop = &btrfs_file_operations;
inode->i_op = &btrfs_file_inode_operations;
inode->i_mapping->a_ops = &btrfs_aops;
err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
if (err)
goto out_unlock;
path = btrfs_alloc_path();
if (!path) {
err = -ENOMEM;
goto out_unlock;
}
key.objectid = btrfs_ino(BTRFS_I(inode));
key.offset = 0;
key.type = BTRFS_EXTENT_DATA_KEY;
datasize = btrfs_file_extent_calc_inline_size(name_len);
err = btrfs_insert_empty_item(trans, root, path, &key,
datasize);
if (err) {
btrfs_free_path(path);
goto out_unlock;
}
leaf = path->nodes[0];
ei = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
btrfs_set_file_extent_generation(leaf, ei, trans->transid);
btrfs_set_file_extent_type(leaf, ei,
BTRFS_FILE_EXTENT_INLINE);
btrfs_set_file_extent_encryption(leaf, ei, 0);
btrfs_set_file_extent_compression(leaf, ei, 0);
btrfs_set_file_extent_other_encoding(leaf, ei, 0);
btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
ptr = btrfs_file_extent_inline_start(ei);
write_extent_buffer(leaf, symname, ptr, name_len);
btrfs_mark_buffer_dirty(leaf);
btrfs_free_path(path);
inode->i_op = &btrfs_symlink_inode_operations;
inode_nohighmem(inode);
inode_set_bytes(inode, name_len);
btrfs_i_size_write(BTRFS_I(inode), name_len);
err = btrfs_update_inode(trans, root, BTRFS_I(inode));
/*
* Last step, add directory indexes for our symlink inode. This is the
* last step to avoid extra cleanup of these indexes if an error happens
* elsewhere above.
*/
if (!err)
err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry,
BTRFS_I(inode), 0, index);
if (err)
goto out_unlock;
d_instantiate_new(dentry, inode);
out_unlock:
btrfs_end_transaction(trans);
if (err && inode) {
inode_dec_link_count(inode);
discard_new_inode(inode);
}
btrfs_btree_balance_dirty(fs_info);
return err;
}
static struct btrfs_trans_handle *insert_prealloc_file_extent(
struct btrfs_trans_handle *trans_in,
struct btrfs_inode *inode,
struct btrfs_key *ins,
u64 file_offset)
{
struct btrfs_file_extent_item stack_fi;
struct btrfs_replace_extent_info extent_info;
struct btrfs_trans_handle *trans = trans_in;
struct btrfs_path *path;
u64 start = ins->objectid;
u64 len = ins->offset;
int qgroup_released;
int ret;
memset(&stack_fi, 0, sizeof(stack_fi));
btrfs_set_stack_file_extent_type(&stack_fi, BTRFS_FILE_EXTENT_PREALLOC);
btrfs_set_stack_file_extent_disk_bytenr(&stack_fi, start);
btrfs_set_stack_file_extent_disk_num_bytes(&stack_fi, len);
btrfs_set_stack_file_extent_num_bytes(&stack_fi, len);
btrfs_set_stack_file_extent_ram_bytes(&stack_fi, len);
btrfs_set_stack_file_extent_compression(&stack_fi, BTRFS_COMPRESS_NONE);
/* Encryption and other encoding is reserved and all 0 */
qgroup_released = btrfs_qgroup_release_data(inode, file_offset, len);
if (qgroup_released < 0)
return ERR_PTR(qgroup_released);
if (trans) {
ret = insert_reserved_file_extent(trans, inode,
file_offset, &stack_fi,
true, qgroup_released);
if (ret)
goto free_qgroup;
return trans;
}
extent_info.disk_offset = start;
extent_info.disk_len = len;
extent_info.data_offset = 0;
extent_info.data_len = len;
extent_info.file_offset = file_offset;
extent_info.extent_buf = (char *)&stack_fi;
extent_info.is_new_extent = true;
extent_info.qgroup_reserved = qgroup_released;
extent_info.insertions = 0;
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto free_qgroup;
}
ret = btrfs_replace_file_extents(inode, path, file_offset,
file_offset + len - 1, &extent_info,
&trans);
btrfs_free_path(path);
if (ret)
goto free_qgroup;
return trans;
free_qgroup:
/*
* We have released qgroup data range at the beginning of the function,
* and normally qgroup_released bytes will be freed when committing
* transaction.
* But if we error out early, we have to free what we have released
* or we leak qgroup data reservation.
*/
btrfs_qgroup_free_refroot(inode->root->fs_info,
inode->root->root_key.objectid, qgroup_released,
BTRFS_QGROUP_RSV_DATA);
return ERR_PTR(ret);
}
static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
u64 start, u64 num_bytes, u64 min_size,
loff_t actual_len, u64 *alloc_hint,
struct btrfs_trans_handle *trans)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
struct extent_map *em;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_key ins;
u64 cur_offset = start;
u64 clear_offset = start;
u64 i_size;
u64 cur_bytes;
u64 last_alloc = (u64)-1;
int ret = 0;
bool own_trans = true;
u64 end = start + num_bytes - 1;
if (trans)
own_trans = false;
while (num_bytes > 0) {
cur_bytes = min_t(u64, num_bytes, SZ_256M);
cur_bytes = max(cur_bytes, min_size);
/*
* If we are severely fragmented we could end up with really
* small allocations, so if the allocator is returning small
* chunks lets make its job easier by only searching for those
* sized chunks.
*/
cur_bytes = min(cur_bytes, last_alloc);
ret = btrfs_reserve_extent(root, cur_bytes, cur_bytes,
min_size, 0, *alloc_hint, &ins, 1, 0);
if (ret)
break;
/*
* We've reserved this space, and thus converted it from
* ->bytes_may_use to ->bytes_reserved. Any error that happens
* from here on out we will only need to clear our reservation
* for the remaining unreserved area, so advance our
* clear_offset by our extent size.
*/
clear_offset += ins.offset;
last_alloc = ins.offset;
trans = insert_prealloc_file_extent(trans, BTRFS_I(inode),
&ins, cur_offset);
/*
* Now that we inserted the prealloc extent we can finally
* decrement the number of reservations in the block group.
* If we did it before, we could race with relocation and have
* relocation miss the reserved extent, making it fail later.
*/
btrfs_dec_block_group_reservations(fs_info, ins.objectid);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
btrfs_free_reserved_extent(fs_info, ins.objectid,
ins.offset, 0);
break;
}
btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
cur_offset + ins.offset -1, 0);
em = alloc_extent_map();
if (!em) {
set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
&BTRFS_I(inode)->runtime_flags);
goto next;
}
em->start = cur_offset;
em->orig_start = cur_offset;
em->len = ins.offset;
em->block_start = ins.objectid;
em->block_len = ins.offset;
em->orig_block_len = ins.offset;
em->ram_bytes = ins.offset;
set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
em->generation = trans->transid;
while (1) {
write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em, 1);
write_unlock(&em_tree->lock);
if (ret != -EEXIST)
break;
btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
cur_offset + ins.offset - 1,
0);
}
free_extent_map(em);
next:
num_bytes -= ins.offset;
cur_offset += ins.offset;
*alloc_hint = ins.objectid + ins.offset;
inode_inc_iversion(inode);
inode->i_ctime = current_time(inode);
BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
if (!(mode & FALLOC_FL_KEEP_SIZE) &&
(actual_len > inode->i_size) &&
(cur_offset > inode->i_size)) {
if (cur_offset > actual_len)
i_size = actual_len;
else
i_size = cur_offset;
i_size_write(inode, i_size);
btrfs_inode_safe_disk_i_size_write(BTRFS_I(inode), 0);
}
ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
if (ret) {
btrfs_abort_transaction(trans, ret);
if (own_trans)
btrfs_end_transaction(trans);
break;
}
if (own_trans) {
btrfs_end_transaction(trans);
trans = NULL;
}
}
if (clear_offset < end)
btrfs_free_reserved_data_space(BTRFS_I(inode), NULL, clear_offset,
end - clear_offset + 1);
return ret;
}
int btrfs_prealloc_file_range(struct inode *inode, int mode,
u64 start, u64 num_bytes, u64 min_size,
loff_t actual_len, u64 *alloc_hint)
{
return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
min_size, actual_len, alloc_hint,
NULL);
}
int btrfs_prealloc_file_range_trans(struct inode *inode,
struct btrfs_trans_handle *trans, int mode,
u64 start, u64 num_bytes, u64 min_size,
loff_t actual_len, u64 *alloc_hint)
{
return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
min_size, actual_len, alloc_hint, trans);
}
static int btrfs_set_page_dirty(struct page *page)
{
return __set_page_dirty_nobuffers(page);
}
static int btrfs_permission(struct user_namespace *mnt_userns,
struct inode *inode, int mask)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
umode_t mode = inode->i_mode;
if (mask & MAY_WRITE &&
(S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
if (btrfs_root_readonly(root))
return -EROFS;
if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
return -EACCES;
}
return generic_permission(mnt_userns, inode, mask);
}
static int btrfs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
struct dentry *dentry, umode_t mode)
{
struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct inode *inode = NULL;
u64 objectid;
u64 index;
int ret = 0;
/*
* 5 units required for adding orphan entry
*/
trans = btrfs_start_transaction(root, 5);
if (IS_ERR(trans))
return PTR_ERR(trans);
ret = btrfs_get_free_objectid(root, &objectid);
if (ret)
goto out;
inode = btrfs_new_inode(trans, root, mnt_userns, dir, NULL, 0,
btrfs_ino(BTRFS_I(dir)), objectid, mode, &index);
if (IS_ERR(inode)) {
ret = PTR_ERR(inode);
inode = NULL;
goto out;
}
inode->i_fop = &btrfs_file_operations;
inode->i_op = &btrfs_file_inode_operations;
inode->i_mapping->a_ops = &btrfs_aops;
ret = btrfs_init_inode_security(trans, inode, dir, NULL);
if (ret)
goto out;
ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
if (ret)
goto out;
ret = btrfs_orphan_add(trans, BTRFS_I(inode));
if (ret)
goto out;
/*
* We set number of links to 0 in btrfs_new_inode(), and here we set
* it to 1 because d_tmpfile() will issue a warning if the count is 0,
* through:
*
* d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
*/
set_nlink(inode, 1);
d_tmpfile(dentry, inode);
unlock_new_inode(inode);
mark_inode_dirty(inode);
out:
btrfs_end_transaction(trans);
if (ret && inode)
discard_new_inode(inode);
btrfs_btree_balance_dirty(fs_info);
return ret;
}
void btrfs_set_range_writeback(struct btrfs_inode *inode, u64 start, u64 end)
{
struct btrfs_fs_info *fs_info = inode->root->fs_info;
unsigned long index = start >> PAGE_SHIFT;
unsigned long end_index = end >> PAGE_SHIFT;
struct page *page;
u32 len;
ASSERT(end + 1 - start <= U32_MAX);
len = end + 1 - start;
while (index <= end_index) {
page = find_get_page(inode->vfs_inode.i_mapping, index);
ASSERT(page); /* Pages should be in the extent_io_tree */
btrfs_page_set_writeback(fs_info, page, start, len);
put_page(page);
index++;
}
}
#ifdef CONFIG_SWAP
/*
* Add an entry indicating a block group or device which is pinned by a
* swapfile. Returns 0 on success, 1 if there is already an entry for it, or a
* negative errno on failure.
*/
static int btrfs_add_swapfile_pin(struct inode *inode, void *ptr,
bool is_block_group)
{
struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
struct btrfs_swapfile_pin *sp, *entry;
struct rb_node **p;
struct rb_node *parent = NULL;
sp = kmalloc(sizeof(*sp), GFP_NOFS);
if (!sp)
return -ENOMEM;
sp->ptr = ptr;
sp->inode = inode;
sp->is_block_group = is_block_group;
sp->bg_extent_count = 1;
spin_lock(&fs_info->swapfile_pins_lock);
p = &fs_info->swapfile_pins.rb_node;
while (*p) {
parent = *p;
entry = rb_entry(parent, struct btrfs_swapfile_pin, node);
if (sp->ptr < entry->ptr ||
(sp->ptr == entry->ptr && sp->inode < entry->inode)) {
p = &(*p)->rb_left;
} else if (sp->ptr > entry->ptr ||
(sp->ptr == entry->ptr && sp->inode > entry->inode)) {
p = &(*p)->rb_right;
} else {
if (is_block_group)
entry->bg_extent_count++;
spin_unlock(&fs_info->swapfile_pins_lock);
kfree(sp);
return 1;
}
}
rb_link_node(&sp->node, parent, p);
rb_insert_color(&sp->node, &fs_info->swapfile_pins);
spin_unlock(&fs_info->swapfile_pins_lock);
return 0;
}
/* Free all of the entries pinned by this swapfile. */
static void btrfs_free_swapfile_pins(struct inode *inode)
{
struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
struct btrfs_swapfile_pin *sp;
struct rb_node *node, *next;
spin_lock(&fs_info->swapfile_pins_lock);
node = rb_first(&fs_info->swapfile_pins);
while (node) {
next = rb_next(node);
sp = rb_entry(node, struct btrfs_swapfile_pin, node);
if (sp->inode == inode) {
rb_erase(&sp->node, &fs_info->swapfile_pins);
if (sp->is_block_group) {
btrfs_dec_block_group_swap_extents(sp->ptr,
sp->bg_extent_count);
btrfs_put_block_group(sp->ptr);
}
kfree(sp);
}
node = next;
}
spin_unlock(&fs_info->swapfile_pins_lock);
}
struct btrfs_swap_info {
u64 start;
u64 block_start;
u64 block_len;
u64 lowest_ppage;
u64 highest_ppage;
unsigned long nr_pages;
int nr_extents;
};
static int btrfs_add_swap_extent(struct swap_info_struct *sis,
struct btrfs_swap_info *bsi)
{
unsigned long nr_pages;
unsigned long max_pages;
u64 first_ppage, first_ppage_reported, next_ppage;
int ret;
/*
* Our swapfile may have had its size extended after the swap header was
* written. In that case activating the swapfile should not go beyond
* the max size set in the swap header.
*/
if (bsi->nr_pages >= sis->max)
return 0;
max_pages = sis->max - bsi->nr_pages;
first_ppage = ALIGN(bsi->block_start, PAGE_SIZE) >> PAGE_SHIFT;
next_ppage = ALIGN_DOWN(bsi->block_start + bsi->block_len,
PAGE_SIZE) >> PAGE_SHIFT;
if (first_ppage >= next_ppage)
return 0;
nr_pages = next_ppage - first_ppage;
nr_pages = min(nr_pages, max_pages);
first_ppage_reported = first_ppage;
if (bsi->start == 0)
first_ppage_reported++;
if (bsi->lowest_ppage > first_ppage_reported)
bsi->lowest_ppage = first_ppage_reported;
if (bsi->highest_ppage < (next_ppage - 1))
bsi->highest_ppage = next_ppage - 1;
ret = add_swap_extent(sis, bsi->nr_pages, nr_pages, first_ppage);
if (ret < 0)
return ret;
bsi->nr_extents += ret;
bsi->nr_pages += nr_pages;
return 0;
}
static void btrfs_swap_deactivate(struct file *file)
{
struct inode *inode = file_inode(file);
btrfs_free_swapfile_pins(inode);
atomic_dec(&BTRFS_I(inode)->root->nr_swapfiles);
}
static int btrfs_swap_activate(struct swap_info_struct *sis, struct file *file,
sector_t *span)
{
struct inode *inode = file_inode(file);
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_fs_info *fs_info = root->fs_info;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct extent_state *cached_state = NULL;
struct extent_map *em = NULL;
struct btrfs_device *device = NULL;
struct btrfs_swap_info bsi = {
.lowest_ppage = (sector_t)-1ULL,
};
int ret = 0;
u64 isize;
u64 start;
/*
* If the swap file was just created, make sure delalloc is done. If the
* file changes again after this, the user is doing something stupid and
* we don't really care.
*/
ret = btrfs_wait_ordered_range(inode, 0, (u64)-1);
if (ret)
return ret;
/*
* The inode is locked, so these flags won't change after we check them.
*/
if (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS) {
btrfs_warn(fs_info, "swapfile must not be compressed");
return -EINVAL;
}
if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW)) {
btrfs_warn(fs_info, "swapfile must not be copy-on-write");
return -EINVAL;
}
if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
btrfs_warn(fs_info, "swapfile must not be checksummed");
return -EINVAL;
}
/*
* Balance or device remove/replace/resize can move stuff around from
* under us. The exclop protection makes sure they aren't running/won't
* run concurrently while we are mapping the swap extents, and
* fs_info->swapfile_pins prevents them from running while the swap
* file is active and moving the extents. Note that this also prevents
* a concurrent device add which isn't actually necessary, but it's not
* really worth the trouble to allow it.
*/
if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_SWAP_ACTIVATE)) {
btrfs_warn(fs_info,
"cannot activate swapfile while exclusive operation is running");
return -EBUSY;
}
/*
* Prevent snapshot creation while we are activating the swap file.
* We do not want to race with snapshot creation. If snapshot creation
* already started before we bumped nr_swapfiles from 0 to 1 and
* completes before the first write into the swap file after it is
* activated, than that write would fallback to COW.
*/
if (!btrfs_drew_try_write_lock(&root->snapshot_lock)) {
btrfs_exclop_finish(fs_info);
btrfs_warn(fs_info,
"cannot activate swapfile because snapshot creation is in progress");
return -EINVAL;
}
/*
* Snapshots can create extents which require COW even if NODATACOW is
* set. We use this counter to prevent snapshots. We must increment it
* before walking the extents because we don't want a concurrent
* snapshot to run after we've already checked the extents.
*
* It is possible that subvolume is marked for deletion but still not
* removed yet. To prevent this race, we check the root status before
* activating the swapfile.
*/
spin_lock(&root->root_item_lock);
if (btrfs_root_dead(root)) {
spin_unlock(&root->root_item_lock);
btrfs_exclop_finish(fs_info);
btrfs_warn(fs_info,
"cannot activate swapfile because subvolume %llu is being deleted",
root->root_key.objectid);
return -EPERM;
}
atomic_inc(&root->nr_swapfiles);
spin_unlock(&root->root_item_lock);
isize = ALIGN_DOWN(inode->i_size, fs_info->sectorsize);
lock_extent_bits(io_tree, 0, isize - 1, &cached_state);
start = 0;
while (start < isize) {
u64 logical_block_start, physical_block_start;
struct btrfs_block_group *bg;
u64 len = isize - start;
em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
goto out;
}
if (em->block_start == EXTENT_MAP_HOLE) {
btrfs_warn(fs_info, "swapfile must not have holes");
ret = -EINVAL;
goto out;
}
if (em->block_start == EXTENT_MAP_INLINE) {
/*
* It's unlikely we'll ever actually find ourselves
* here, as a file small enough to fit inline won't be
* big enough to store more than the swap header, but in
* case something changes in the future, let's catch it
* here rather than later.
*/
btrfs_warn(fs_info, "swapfile must not be inline");
ret = -EINVAL;
goto out;
}
if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
btrfs_warn(fs_info, "swapfile must not be compressed");
ret = -EINVAL;
goto out;
}
logical_block_start = em->block_start + (start - em->start);
len = min(len, em->len - (start - em->start));
free_extent_map(em);
em = NULL;
ret = can_nocow_extent(inode, start, &len, NULL, NULL, NULL, true);
if (ret < 0) {
goto out;
} else if (ret) {
ret = 0;
} else {
btrfs_warn(fs_info,
"swapfile must not be copy-on-write");
ret = -EINVAL;
goto out;
}
em = btrfs_get_chunk_map(fs_info, logical_block_start, len);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
goto out;
}
if (em->map_lookup->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
btrfs_warn(fs_info,
"swapfile must have single data profile");
ret = -EINVAL;
goto out;
}
if (device == NULL) {
device = em->map_lookup->stripes[0].dev;
ret = btrfs_add_swapfile_pin(inode, device, false);
if (ret == 1)
ret = 0;
else if (ret)
goto out;
} else if (device != em->map_lookup->stripes[0].dev) {
btrfs_warn(fs_info, "swapfile must be on one device");
ret = -EINVAL;
goto out;
}
physical_block_start = (em->map_lookup->stripes[0].physical +
(logical_block_start - em->start));
len = min(len, em->len - (logical_block_start - em->start));
free_extent_map(em);
em = NULL;
bg = btrfs_lookup_block_group(fs_info, logical_block_start);
if (!bg) {
btrfs_warn(fs_info,
"could not find block group containing swapfile");
ret = -EINVAL;
goto out;
}
if (!btrfs_inc_block_group_swap_extents(bg)) {
btrfs_warn(fs_info,
"block group for swapfile at %llu is read-only%s",
bg->start,
atomic_read(&fs_info->scrubs_running) ?
" (scrub running)" : "");
btrfs_put_block_group(bg);
ret = -EINVAL;
goto out;
}
ret = btrfs_add_swapfile_pin(inode, bg, true);
if (ret) {
btrfs_put_block_group(bg);
if (ret == 1)
ret = 0;
else
goto out;
}
if (bsi.block_len &&
bsi.block_start + bsi.block_len == physical_block_start) {
bsi.block_len += len;
} else {
if (bsi.block_len) {
ret = btrfs_add_swap_extent(sis, &bsi);
if (ret)
goto out;
}
bsi.start = start;
bsi.block_start = physical_block_start;
bsi.block_len = len;
}
start += len;
}
if (bsi.block_len)
ret = btrfs_add_swap_extent(sis, &bsi);
out:
if (!IS_ERR_OR_NULL(em))
free_extent_map(em);
unlock_extent_cached(io_tree, 0, isize - 1, &cached_state);
if (ret)
btrfs_swap_deactivate(file);
btrfs_drew_write_unlock(&root->snapshot_lock);
btrfs_exclop_finish(fs_info);
if (ret)
return ret;
if (device)
sis->bdev = device->bdev;
*span = bsi.highest_ppage - bsi.lowest_ppage + 1;
sis->max = bsi.nr_pages;
sis->pages = bsi.nr_pages - 1;
sis->highest_bit = bsi.nr_pages - 1;
return bsi.nr_extents;
}
#else
static void btrfs_swap_deactivate(struct file *file)
{
}
static int btrfs_swap_activate(struct swap_info_struct *sis, struct file *file,
sector_t *span)
{
return -EOPNOTSUPP;
}
#endif
/*
* Update the number of bytes used in the VFS' inode. When we replace extents in
* a range (clone, dedupe, fallocate's zero range), we must update the number of
* bytes used by the inode in an atomic manner, so that concurrent stat(2) calls
* always get a correct value.
*/
void btrfs_update_inode_bytes(struct btrfs_inode *inode,
const u64 add_bytes,
const u64 del_bytes)
{
if (add_bytes == del_bytes)
return;
spin_lock(&inode->lock);
if (del_bytes > 0)
inode_sub_bytes(&inode->vfs_inode, del_bytes);
if (add_bytes > 0)
inode_add_bytes(&inode->vfs_inode, add_bytes);
spin_unlock(&inode->lock);
}
static const struct inode_operations btrfs_dir_inode_operations = {
.getattr = btrfs_getattr,
.lookup = btrfs_lookup,
.create = btrfs_create,
.unlink = btrfs_unlink,
.link = btrfs_link,
.mkdir = btrfs_mkdir,
.rmdir = btrfs_rmdir,
.rename = btrfs_rename2,
.symlink = btrfs_symlink,
.setattr = btrfs_setattr,
.mknod = btrfs_mknod,
.listxattr = btrfs_listxattr,
.permission = btrfs_permission,
.get_acl = btrfs_get_acl,
.set_acl = btrfs_set_acl,
.update_time = btrfs_update_time,
.tmpfile = btrfs_tmpfile,
.fileattr_get = btrfs_fileattr_get,
.fileattr_set = btrfs_fileattr_set,
};
static const struct file_operations btrfs_dir_file_operations = {
.llseek = btrfs_dir_llseek,
.read = generic_read_dir,
.iterate_shared = btrfs_real_readdir,
.open = btrfs_opendir,
.unlocked_ioctl = btrfs_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = btrfs_compat_ioctl,
#endif
.release = btrfs_release_file,
.fsync = btrfs_sync_file,
};
/*
* btrfs doesn't support the bmap operation because swapfiles
* use bmap to make a mapping of extents in the file. They assume
* these extents won't change over the life of the file and they
* use the bmap result to do IO directly to the drive.
*
* the btrfs bmap call would return logical addresses that aren't
* suitable for IO and they also will change frequently as COW
* operations happen. So, swapfile + btrfs == corruption.
*
* For now we're avoiding this by dropping bmap.
*/
static const struct address_space_operations btrfs_aops = {
.readpage = btrfs_readpage,
.writepage = btrfs_writepage,
.writepages = btrfs_writepages,
.readahead = btrfs_readahead,
.direct_IO = noop_direct_IO,
.invalidatepage = btrfs_invalidatepage,
.releasepage = btrfs_releasepage,
#ifdef CONFIG_MIGRATION
.migratepage = btrfs_migratepage,
#endif
.set_page_dirty = btrfs_set_page_dirty,
.error_remove_page = generic_error_remove_page,
.swap_activate = btrfs_swap_activate,
.swap_deactivate = btrfs_swap_deactivate,
};
static const struct inode_operations btrfs_file_inode_operations = {
.getattr = btrfs_getattr,
.setattr = btrfs_setattr,
.listxattr = btrfs_listxattr,
.permission = btrfs_permission,
.fiemap = btrfs_fiemap,
.get_acl = btrfs_get_acl,
.set_acl = btrfs_set_acl,
.update_time = btrfs_update_time,
.fileattr_get = btrfs_fileattr_get,
.fileattr_set = btrfs_fileattr_set,
};
static const struct inode_operations btrfs_special_inode_operations = {
.getattr = btrfs_getattr,
.setattr = btrfs_setattr,
.permission = btrfs_permission,
.listxattr = btrfs_listxattr,
.get_acl = btrfs_get_acl,
.set_acl = btrfs_set_acl,
.update_time = btrfs_update_time,
};
static const struct inode_operations btrfs_symlink_inode_operations = {
.get_link = page_get_link,
.getattr = btrfs_getattr,
.setattr = btrfs_setattr,
.permission = btrfs_permission,
.listxattr = btrfs_listxattr,
.update_time = btrfs_update_time,
};
const struct dentry_operations btrfs_dentry_operations = {
.d_delete = btrfs_dentry_delete,
};
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