| From ffd392de7eb7dfaee9019e10889025fd8234c918 Mon Sep 17 00:00:00 2001 |
| From: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> |
| Date: Tue, 31 May 2011 07:03:21 +0300 |
| Subject: [PATCH] UBIFS: fix shrinker object count reports |
| |
| commit cf610bf4199770420629d3bc273494bd27ad6c1d upstream. |
| |
| 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> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| --- |
| fs/ubifs/shrinker.c | 6 +++++- |
| 1 file changed, 5 insertions(+), 1 deletion(-) |
| |
| diff --git a/fs/ubifs/shrinker.c b/fs/ubifs/shrinker.c |
| index 02feb59..aec6689 100644 |
| --- a/fs/ubifs/shrinker.c |
| +++ b/fs/ubifs/shrinker.c |
| @@ -283,7 +283,11 @@ int ubifs_shrinker(int nr, gfp_t gfp_mask) |
| 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 ? clean_zn_cnt : 1; |
| |
| if (!clean_zn_cnt) { |
| /* |
| -- |
| 1.7.9.3 |
| |
