Quelle  features.c   Sprache: C

// 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 "bcache_ondisk.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;
}