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| author | Shaohua Li <shaohua.li@intel.com> | 2011-06-27 09:03:47 +0200 |
|---|---|---|
| committer | Paul Gortmaker <paul.gortmaker@windriver.com> | 2012-05-17 11:21:01 -0400 |
| commit | 927b2d35f06f1c5d234a9392d0a18cee86da3790 (patch) | |
| tree | 4303464b7d66c3fb3d520f489c5c3eae5773fdc4 /block | |
| parent | 470564b1d4c27fd2bafc421acf49718bfcf5ea5a (diff) | |
| download | lwn-927b2d35f06f1c5d234a9392d0a18cee86da3790.tar.gz lwn-927b2d35f06f1c5d234a9392d0a18cee86da3790.zip | |
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: Paul Gortmaker <paul.gortmaker@windriver.com>
Diffstat (limited to 'block')
| -rw-r--r-- | block/cfq-iosched.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 510552a4bde2..d39a07a11768 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -2559,11 +2559,14 @@ 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]); |