| Submitter | Artem Bityutskiy |
|---|---|
| Date | June 3, 2011, 1:49 p.m. |
| Message ID | <1307109001-19761-6-git-send-email-dedekind1@gmail.com> |
| Download | mbox | patch |
| Permalink | /patch/98573/ |
| State | New |
| Headers | show |
Comments
From: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Sometimes VM asks the shrinker to return amount of objects it can shrink, and we return the ubifs_clean_zn_cnt in that case. However, it is possible that this counter is negative for a short period of time, due to the way UBIFS TNC code updates it. And I can observe the following warnings sometimes: shrink_slab: ubifs_shrinker+0x0/0x2b7 [ubifs] negative objects to delete nr=-8541616642706119788 This patch makes sure UBIFS never returns negative count of objects. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Cc: stable@kernel.org --- fs/ubifs/shrinker.c | 6 +++++- 1 files changed, 5 insertions(+), 1 deletions(-)
On Fri, 2011-06-03 at 16:48 +0300, Artem Bityutskiy wrote: > On Fri, 2011-06-03 at 16:49 +0300, Artem Bityutskiy wrote: > > + /* > > + * Due to the way UBIFS updates the clean znode counter it may > > + * temporarily be negative. > > + */ > > + return clean_zn_cnt > 0 ?: 1; > > Oh, this should be clean_zn_cnt >= 0 ?: 1; Crap, sorry, stupid me :-) return clean_zn_cnt < 0 ?: clean_zn_cnt; But yeah, it is saner to not use "?:" at all: return clean_zn_cnt >= 0 ? clean_zn_cnt: 1;
Patch
diff --git a/fs/ubifs/shrinker.c b/fs/ubifs/shrinker.c index ca953a9..dfc105a 100644 --- a/fs/ubifs/shrinker.c +++ b/fs/ubifs/shrinker.c @@ -284,7 +284,11 @@ int ubifs_shrinker(struct shrinker *shrink, struct shrink_control *sc) long clean_zn_cnt = atomic_long_read(&ubifs_clean_zn_cnt); if (nr == 0) - return clean_zn_cnt; + /* + * Due to the way UBIFS updates the clean znode counter it may + * temporarily be negative. + */ + return clean_zn_cnt > 0 ?: 1; if (!clean_zn_cnt) { /*