From: Mikulas Patocka Date: Tue, 1 Nov 2011 00:08:57 +0000 (-0700) Subject: vmscan: fix shrinker callback bug in fs/super.c X-Git-Tag: upstream/snapshot3+hdmi~8868^2~78 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=09f363c7363eb10cfb4b82094bd7064e5608258b;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git vmscan: fix shrinker callback bug in fs/super.c The callback must not return -1 when nr_to_scan is zero. Fix the bug in fs/super.c and add this requirement to the callback specification. Signed-off-by: Mikulas Patocka Cc: Dave Chinner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/fs/super.c b/fs/super.c index 3f56a26..32a81f3 100644 --- a/fs/super.c +++ b/fs/super.c @@ -61,7 +61,7 @@ static int prune_super(struct shrinker *shrink, struct shrink_control *sc) return -1; if (!grab_super_passive(sb)) - return -1; + return !sc->nr_to_scan ? 0 : -1; if (sb->s_op && sb->s_op->nr_cached_objects) fs_objects = sb->s_op->nr_cached_objects(sb); diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h index 790651b..a83833a 100644 --- a/include/linux/shrinker.h +++ b/include/linux/shrinker.h @@ -20,6 +20,7 @@ struct shrink_control { * 'nr_to_scan' entries and attempt to free them up. It should return * the number of objects which remain in the cache. If it returns -1, it means * it cannot do any scanning at this time (eg. there is a risk of deadlock). + * The callback must not return -1 if nr_to_scan is zero. * * The 'gfpmask' refers to the allocation we are currently trying to * fulfil.