Commit d4008f81 authored Feb 07, 2018 by Tang Junhui Committed by Greg Kroah-Hartman May 30, 2018

bcache: return attach error when no cache set exist



[ Upstream commit 7f4fc93d4713394ee8f1cd44c238e046e11b4f15 ]

I attach a back-end device to a cache set, and the cache set is not
registered yet, this back-end device did not attach successfully, and no
error returned:
[root]# echo 87859280-fec6-4bcc-20df7ca8f86b > /sys/block/sde/bcache/attach
[root]#

In sysfs_attach(), the return value "v" is initialized to "size" in
the beginning, and if no cache set exist in bch_cache_sets, the "v" value
would not change any more, and return to sysfs, sysfs regard it as success
since the "size" is a positive number.

This patch fixes this issue by assigning "v" with "-ENOENT" in the
initialization.

Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 0d5da312

drivers/md/bcache/sysfs.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -191,7 +191,7 @@ STORE(__cached_dev)
		{
		struct cached_dev *dc = container_of(kobj, struct cached_dev,
		disk.kobj);
		ssize_t v = size;
		ssize_t v;
		struct cache_set *c;
		struct kobj_uevent_env *env;

		@@ -268,6 +268,7 @@ STORE(__cached_dev)
		if (bch_parse_uuid(buf, set_uuid) < 16)
		return -EINVAL;

		v = -ENOENT;
		list_for_each_entry(c, &bch_cache_sets, list) {
		v = bch_cached_dev_attach(dc, c, set_uuid);
		if (!v)
		@@ -275,7 +276,7 @@ STORE(__cached_dev)
		}

		pr_err("Can't attach %s: cache set not found", buf);
		size = v;
		return v;
		}

		if (attr == &sysfs_detach && dc->disk.c)