This is a note to let you know that I've just added the patch titled
Update of blkg_stat and blkg_rwstat may happen in bh context.
to the 3.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
update-of-blkg_stat-and-blkg_rwstat-may-happen-in-bh-context.patch
and it can be found in the queue-3.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 2c575026fae6e63771bd2a4c1d407214a8096a89 Mon Sep 17 00:00:00 2001
From: Hong Zhiguo <zhiguohong@xxxxxxxxxxx>
Date: Wed, 20 Nov 2013 10:35:05 -0700
Subject: 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.
From: Hong Zhiguo <zhiguohong@xxxxxxxxxxx>
commit 2c575026fae6e63771bd2a4c1d407214a8096a89 upstream.
Signed-off-by: Hong Zhiguo <zhiguohong@xxxxxxxxxxx>
Acked-by: Tejun Heo <tj@xxxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
block/blk-cgroup.h | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -430,9 +430,9 @@ static inline uint64_t blkg_stat_read(st
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;
}
@@ -498,9 +498,9 @@ static inline struct blkg_rwstat blkg_rw
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;
}
Patches currently in stable-queue which might be from zhiguohong@xxxxxxxxxxx are
queue-3.12/update-of-blkg_stat-and-blkg_rwstat-may-happen-in-bh-context.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html