Re: [PATCH] fs/dcache.c: re-add cond_resched() in shrink_dcache_parent()

David Rientjes
2018-04-13T21:15:34Z

On Fri, 13 Apr 2018, Khazhismel Kumykov wrote:

> shrink_dcache_parent may spin waiting for a parallel shrink_dentry_list.
> In this case we may have 0 dentries to dispose, so we will never
> schedule out while waiting for the parallel shrink_dentry_list to
> complete.
>
> Tested that this fixes syzbot reports of stalls in shrink_dcache_parent()
>
> Fixes: 32785c0539b7 ("fs/dcache.c: add cond_resched() in shrink_dentry_list()")
> Reported-by: syzbot+ae80b790eb412884ca77@syzkaller.appspotmail.com
>
> Cc: Nikolay Borisov <nborisov@suse.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: David Rientjes <rientjes@google.com>
> Cc: Alexander Viro <viro@zeniv.linux.org.uk>
> Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>
> Cc: Jeff Mahoney <jeffm@suse.com>
> Cc: Davidlohr Bueso <dave@stgolabs.net>
> Cc: Linus Torvalds <torvalds@linux-foundation.org>
> Signed-off-by: Khazhismel Kumykov <khazhy@google.com>

Acked-by: David Rientjes <rientjes@google.com>