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authorShaohua Li <shaohua.li@intel.com>2011-06-27 09:03:47 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2011-07-13 05:29:25 +0200
commit1e03bb2a2712d29db6f3ab5c642d007658a91dd6 (patch)
treeac9cc960b4e20e6e1bf5da597fe326f48d6c4d04 /block
parent1ff36a0e02f978e533b13ce6a86ad6a73444cec8 (diff)
cfq-iosched: fix a rcu warning
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.li@intel.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'block')
-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 da7327edaa10..847c9476c20d 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1540,11 +1540,14 @@ static void __cfq_exit_single_io_context(struct cfq_data *cfqd,
cic->dead_key = (unsigned long) cic->key;
cic->key = NULL;
+ 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]);