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| author | Mikulas Patocka <mpatocka@redhat.com> | 2011-10-31 17:08:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-10-31 17:30:49 -0700 |
| commit | 09f363c7363eb10cfb4b82094bd7064e5608258b (patch) | |
| tree | 4b1890150cf7f7a2339694ea97efa6c45b8705a1 | |
| parent | 20c8c62891a346e09c8d26de41ce78bd7a76c5b0 (diff) | |
| download | lwn-09f363c7363eb10cfb4b82094bd7064e5608258b.tar.gz lwn-09f363c7363eb10cfb4b82094bd7064e5608258b.zip | |
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 <mpatocka@redhat.com>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | fs/super.c | 2 | ||||
| -rw-r--r-- | include/linux/shrinker.h | 1 |
2 files changed, 2 insertions, 1 deletions
diff --git a/fs/super.c b/fs/super.c index 3f56a269a4f4..32a81f3467e0 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 790651b4e5ba..a83833a1f7a2 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. |