This is a note to let you know that I've just added the patch titled
cfq-iosched: fix a rcu warning
to the 2.6.39-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:
cfq-iosched-fix-a-rcu-warning.patch
and it can be found in the queue-2.6.39 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <sta...@kernel.org> know about it.
>From 3181faa85bda3dc3f5e630a1846526c9caaa38e3 Mon Sep 17 00:00:00 2001
From: Shaohua Li <shaohua...@intel.com>
Date: Mon, 27 Jun 2011 09:03:47 +0200
Subject: cfq-iosched: fix a rcu warning
From: Shaohua Li <shaohua...@intel.com>
commit 3181faa85bda3dc3f5e630a1846526c9caaa38e3 upstream.
I got a rcu warnning at boot. the ioc->ioc_data is rcu_deferenced, but
doesn't hold rcu_read_lock.
Signed-off-by: Shaohua Li <shaohua...@intel.com>
Signed-off-by: Jens Axboe <jax...@fusionio.com>
Signed-off-by: Greg Kroah-Hartman <gre...@suse.de>
---
block/cfq-iosched.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -2704,11 +2704,14 @@ static void __cfq_exit_single_io_context
smp_wmb();
cic->key = cfqd_dead_key(cfqd);
+ rcu_read_lock();
if (rcu_dereference(ioc->ioc_data) == cic) {
+ rcu_read_unlock();
spin_lock(&ioc->lock);
rcu_assign_pointer(ioc->ioc_data, NULL);
spin_unlock(&ioc->lock);
- }
+ } else
+ rcu_read_unlock();
if (cic->cfqq[BLK_RW_ASYNC]) {
cfq_exit_cfqq(cfqd, cic->cfqq[BLK_RW_ASYNC]);
Patches currently in stable-queue which might be from shaohua...@intel.com are
queue-2.6.39/cfq-iosched-fix-a-rcu-warning.patch
queue-2.6.39/cfq-iosched-make-code-consistent.patch
_______________________________________________
stable mailing list
stable@linux.kernel.org
http://linux.kernel.org/mailman/listinfo/stable
