sysfs.c

		       !cached[n - 1])
			--n;

		while (cached < p + n &&
		       *cached == BTREE_PRIO)
			cached++, n--;

		for (i = 0; i < n; i++)
			sum += INITIAL_PRIO - cached[i];

		if (n)
			do_div(sum, n);

		for (i = 0; i < ARRAY_SIZE(q); i++)
			q[i] = INITIAL_PRIO - cached[n * (i + 1) /
				(ARRAY_SIZE(q) + 1)];

		vfree(p);

		ret = scnprintf(buf, PAGE_SIZE,
				"Unused:		%zu%%\n"
				"Clean:		%zu%%\n"
				"Dirty:		%zu%%\n"
				"Metadata:	%zu%%\n"
				"Average:	%llu\n"
				"Sectors per Q:	%zu\n"
				"Quantiles:	[",
				unused * 100 / (size_t) ca->sb.nbuckets,
				available * 100 / (size_t) ca->sb.nbuckets,
				dirty * 100 / (size_t) ca->sb.nbuckets,
				meta * 100 / (size_t) ca->sb.nbuckets, sum,
				n * ca->sb.bucket_size / (ARRAY_SIZE(q) + 1));

		for (i = 0; i < ARRAY_SIZE(q); i++)
			ret += scnprintf(buf + ret, PAGE_SIZE - ret,
					 "%u ", q[i]);
		ret--;

		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "]\n");

		return ret;
	}

	return 0;
}
SHOW_LOCKED(bch_cache)

STORE(__bch_cache)
{
	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);