kernel/drivers/md/bcache/features.c

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2024-07-22 17:22:30 +08:00
// SPDX-License-Identifier: GPL-2.0
/*
* Feature set bits and string conversion.
* Inspired by ext4's features compat/incompat/ro_compat related code.
*
* Copyright 2020 Coly Li <colyli@suse.de>
*
*/
#include <linux/bcache.h>
#include "bcache.h"
#include "features.h"
struct feature {
int compat;
unsigned int mask;
const char *string;
};
static struct feature feature_list[] = {
{BCH_FEATURE_INCOMPAT, BCH_FEATURE_INCOMPAT_LOG_LARGE_BUCKET_SIZE,
"large_bucket"},
{0, 0, NULL },
};
#define compose_feature_string(type) \
({ \
struct feature *f; \
bool first = true; \
\
for (f = &feature_list[0]; f->compat != 0; f++) { \
if (f->compat != BCH_FEATURE_ ## type) \
continue; \
if (BCH_HAS_ ## type ## _FEATURE(&c->cache->sb, f->mask)) { \
if (first) { \
out += snprintf(out, buf + size - out, \
"["); \
} else { \
out += snprintf(out, buf + size - out, \
" ["); \
} \
} else if (!first) { \
out += snprintf(out, buf + size - out, " "); \
} \
\
out += snprintf(out, buf + size - out, "%s", f->string);\
\
if (BCH_HAS_ ## type ## _FEATURE(&c->cache->sb, f->mask)) \
out += snprintf(out, buf + size - out, "]"); \
\
first = false; \
} \
if (!first) \
out += snprintf(out, buf + size - out, "\n"); \
})
int bch_print_cache_set_feature_compat(struct cache_set *c, char *buf, int size)
{
char *out = buf;
compose_feature_string(COMPAT);
return out - buf;
}
int bch_print_cache_set_feature_ro_compat(struct cache_set *c, char *buf, int size)
{
char *out = buf;
compose_feature_string(RO_COMPAT);
return out - buf;
}
int bch_print_cache_set_feature_incompat(struct cache_set *c, char *buf, int size)
{
char *out = buf;
compose_feature_string(INCOMPAT);
return out - buf;
}