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authorEric Wheeler <git@linux.ewheeler.net>2016-06-17 15:01:54 -0700
committerEric Wheeler <git@linux.ewheeler.net>2016-08-18 20:28:23 -0700
commitd9dc1702b297ec4a6bb9c0326a70641b322ba886 (patch)
tree02965bf0fab5b546fe3d4f822bb3ce240ff36884
parent694d0d0bb2030d2e36df73e2d23d5770511dbc8d (diff)
bcache: register_bcache(): call blkdev_put() when cache_alloc() fails
register_cache() is supposed to return an error string on error so that register_bcache() will will blkdev_put and cleanup other user counters, but it does not set 'char *err' when cache_alloc() fails (eg, due to memory pressure) and thus register_bcache() performs no cleanup. register_bcache() <----------\ <- no jump to err_close, no blkdev_put() | | +->register_cache() | <- fails to set char *err | | +->cache_alloc() ---/ <- returns error This patch sets `char *err` for this failure case so that register_cache() will cause register_bcache() to correctly jump to err_close and do cleanup. This was tested under OOM conditions that triggered the bug. Signed-off-by: Eric Wheeler <bcache@linux.ewheeler.net> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: stable@vger.kernel.org
-rw-r--r--drivers/md/bcache/super.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 95a4ca6ce6ff..6ada14b9a157 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -1844,7 +1844,7 @@ static int register_cache(struct cache_sb *sb, struct page *sb_page,
struct block_device *bdev, struct cache *ca)
{
char name[BDEVNAME_SIZE];
- const char *err = NULL;
+ const char *err = NULL; /* must be set for any error case */
int ret = 0;
memcpy(&ca->sb, sb, sizeof(struct cache_sb));
@@ -1861,8 +1861,13 @@ static int register_cache(struct cache_sb *sb, struct page *sb_page,
ca->discard = CACHE_DISCARD(&ca->sb);
ret = cache_alloc(ca);
- if (ret != 0)
+ if (ret != 0) {
+ if (ret == -ENOMEM)
+ err = "cache_alloc(): -ENOMEM";
+ else
+ err = "cache_alloc(): unknown error";
goto err;
+ }
if (kobject_add(&ca->kobj, &part_to_dev(bdev->bd_part)->kobj, "bcache")) {
err = "error calling kobject_add";