On Wed, Jan 24, 2018 at 04:15:49AM +0000, Sasha Levin wrote:
From: Jiang Biao jiang.biao2@zte.com.cn
[ Upstream commit d5dabd633922ac5ee5bcc67748f7defb8b211469 ]
When running ltp stress test for 7*24 hours, vmscan occasionally emits the following warning continuously:
mb_cache_scan+0x0/0x3f0 negative objects to delete nr=-9232265467809300450 ...
Tracing shows the freeable(mb_cache_count returns) is -1, which causes the continuous accumulation and overflow of total_scan.
This patch makes sure that mb_cache_count() cannot return a negative value, which makes the mbcache shrinker more robust.
Link: http://lkml.kernel.org/r/1511753419-52328-1-git-send-email-jiang.biao2@zte.c... Signed-off-by: Jiang Biao jiang.biao2@zte.com.cn Cc: Al Viro viro@zeniv.linux.org.uk Cc: Minchan Kim minchan@kernel.org Cc: Michal Hocko mhocko@kernel.org Cc: zhong.weidong@zte.com.cn Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin alexander.levin@microsoft.com
fs/mbcache.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/fs/mbcache.c b/fs/mbcache.c index c5bd19ffa326..35ab4187bfe1 100644 --- a/fs/mbcache.c +++ b/fs/mbcache.c @@ -269,6 +269,9 @@ static unsigned long mb_cache_count(struct shrinker *shrink, struct mb_cache *cache = container_of(shrink, struct mb_cache, c_shrink);
- /* Unlikely, but not impossible */
- if (unlikely(cache->c_entry_count < 0))
return 0;}
This patch is broken and is reverted in linux-next, via ext4/dev:
bbe45d2460da ("mbcache: revert "fs/mbcache.c: make count_objects() more robust"")
Can you please update your "autosel" script/process/whatever to not select commits that are reverted?