diff options
| -rw-r--r-- | block/cfq-iosched.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index ee8a90c7c46..e8525fa7282 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -1314,7 +1314,15 @@ static void cfq_exit_single_io_context(struct io_context *ioc, unsigned long flags; spin_lock_irqsave(q->queue_lock, flags); - __cfq_exit_single_io_context(cfqd, cic); + + /* + * Ensure we get a fresh copy of the ->key to prevent + * race between exiting task and queue + */ + smp_read_barrier_depends(); + if (cic->key) + __cfq_exit_single_io_context(cfqd, cic); + spin_unlock_irqrestore(q->queue_lock, flags); } } |