Commit c1b707d2 authored by Jens Axboe's avatar Jens Axboe Committed by Linus Torvalds

[PATCH] CFQ: bad locking in changed_ioprio()

When the ioprio code recently got juggled a bit, a bug was introduced.
changed_ioprio() is no longer called with interrupts disabled, so using
plain spin_lock() on the queue_lock is a bug.
Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 0261d688
......@@ -1215,11 +1215,12 @@ static inline void changed_ioprio(struct cfq_io_context *cic)
{
struct cfq_data *cfqd = cic->key;
struct cfq_queue *cfqq;
unsigned long flags;
if (unlikely(!cfqd))
return;
spin_lock(cfqd->queue->queue_lock);
spin_lock_irqsave(cfqd->queue->queue_lock, flags);
cfqq = cic->cfqq[ASYNC];
if (cfqq) {
......@@ -1236,7 +1237,7 @@ static inline void changed_ioprio(struct cfq_io_context *cic)
if (cfqq)
cfq_mark_cfqq_prio_changed(cfqq);
spin_unlock(cfqd->queue->queue_lock);
spin_unlock_irqrestore(cfqd->queue->queue_lock, flags);
}
static void cfq_ioc_set_ioprio(struct io_context *ioc)
......
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