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authorShaohua Li <shaohua.li@intel.com>2011-06-27 09:03:47 +0200
committerJens Axboe <jaxboe@fusionio.com>2011-06-27 09:36:06 +0200
commit3181faa85bda3dc3f5e630a1846526c9caaa38e3 (patch)
tree1017c61ebf8a7711ac400e2a728e188ec5770001
parent258e43fdb00c73d424b114ae3850accd55b27cbb (diff)
cfq-iosched: fix a rcu warning
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.li@intel.com> Cc: stable@kernel.org # after ab4bd22d Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
-rw-r--r--block/cfq-iosched.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index f3799432676..fd566c1e261 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -2773,11 +2773,14 @@ static void __cfq_exit_single_io_context(struct cfq_data *cfqd,
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]);