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authorShaohua Li <shaohua.li@intel.com>2011-06-27 09:03:47 +0200
committerWilly Tarreau <w@1wt.eu>2012-02-11 15:37:32 +0100
commit95f89dc7063f6efd2c5ce21ee165fd3df1f010e0 (patch)
tree470e8a9d3f2661650cbc658dbbb50ac9b970276d /block
parent2a3400a8f5f3a17dec349adb484ef2ac5a026ed5 (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> Signed-off-by: Willy Tarreau <w@1wt.eu>
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 ee3c6068ceb7..524608ca92b9 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1286,11 +1286,14 @@ 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[ASYNC]) {
cfq_exit_cfqq(cfqd, cic->cfqq[ASYNC]);