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| author | Hong Zhiguo <zhiguohong@tencent.com> | 2013-11-20 21:35:05 +0400 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2013-11-21 02:33:04 +0400 |
| commit | 2c575026fae6e63771bd2a4c1d407214a8096a89 (patch) | |
| tree | 4ab6ccbdf75b96229f176fc54e01580954e7a633 /block | |
| parent | 82023bb7f75b0052f40d3e74169d191c3e4e6286 (diff) | |
| download | linux-2c575026fae6e63771bd2a4c1d407214a8096a89.tar.xz | |
Update of blkg_stat and blkg_rwstat may happen in bh context.
While u64_stats_fetch_retry is only preempt_disable on 32bit
UP system. This is not enough to avoid preemption by bh and
may read strange 64 bit value.
Signed-off-by: Hong Zhiguo <zhiguohong@tencent.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-cgroup.h | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h index 1610b22edf09..86154eab9523 100644 --- a/block/blk-cgroup.h +++ b/block/blk-cgroup.h @@ -435,9 +435,9 @@ static inline uint64_t blkg_stat_read(struct blkg_stat *stat) uint64_t v; do { - start = u64_stats_fetch_begin(&stat->syncp); + start = u64_stats_fetch_begin_bh(&stat->syncp); v = stat->cnt; - } while (u64_stats_fetch_retry(&stat->syncp, start)); + } while (u64_stats_fetch_retry_bh(&stat->syncp, start)); return v; } @@ -508,9 +508,9 @@ static inline struct blkg_rwstat blkg_rwstat_read(struct blkg_rwstat *rwstat) struct blkg_rwstat tmp; do { - start = u64_stats_fetch_begin(&rwstat->syncp); + start = u64_stats_fetch_begin_bh(&rwstat->syncp); tmp = *rwstat; - } while (u64_stats_fetch_retry(&rwstat->syncp, start)); + } while (u64_stats_fetch_retry_bh(&rwstat->syncp, start)); return tmp; } |