sysfs.c

{
	struct cache *ca = container_of(kobj, struct cache, kobj);
	ssize_t v;

	if (attr == &sysfs_discard) {
		bool v = strtoul_or_return(buf);

		if (blk_queue_discard(bdev_get_queue(ca->bdev)))
			ca->discard = v;

		if (v != CACHE_DISCARD(&ca->sb)) {
			SET_CACHE_DISCARD(&ca->sb, v);
			bcache_write_super(ca->set);
		}
	}

	if (attr == &sysfs_cache_replacement_policy) {
		v = __sysfs_match_string(cache_replacement_policies, -1, buf);
		if (v < 0)
			return v;

		if ((unsigned int) v != CACHE_REPLACEMENT(&ca->sb)) {
			mutex_lock(&ca->set->bucket_lock);
			SET_CACHE_REPLACEMENT(&ca->sb, v);
			mutex_unlock(&ca->set->bucket_lock);

			bcache_write_super(ca->set);
		}
	}

	if (attr == &sysfs_clear_stats) {
		atomic_long_set(&ca->sectors_written, 0);
		atomic_long_set(&ca->btree_sectors_written, 0);
		atomic_long_set(&ca->meta_sectors_written, 0);
		atomic_set(&ca->io_count, 0);
		atomic_set(&ca->io_errors, 0);
	}

	return size;
}
STORE_LOCKED(bch_cache)

static struct attribute *bch_cache_files[] = {
	&sysfs_bucket_size,
	&sysfs_block_size,
	&sysfs_nbuckets,
	&sysfs_priority_stats,
	&sysfs_discard,
	&sysfs_written,
	&sysfs_btree_written,
	&sysfs_metadata_written,
	&sysfs_io_errors,
	&sysfs_clear_stats,
	&sysfs_cache_replacement_policy,
	NULL
};
KTYPE(bch_cache);