block: queue lock must be acquired when iterating over rls

blk_set_queue_dying() does not acquire queue lock before it calls
blk_queue_for_each_rl(). This allows a racing blkg_destroy() to
remove blkg->q_node from the linked list and have
blk_queue_for_each_rl() loop infitely over the removed blkg->q_node
list node.

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Tahsin Erdogan 2017-01-31 22:36:50 -08:00 коммит произвёл Jens Axboe
Родитель 5fad1b64ae
Коммит bbfc3c5d6c
1 изменённых файлов: 2 добавлений и 0 удалений

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@ -527,12 +527,14 @@ void blk_set_queue_dying(struct request_queue *q)
else {
struct request_list *rl;
spin_lock_irq(q->queue_lock);
blk_queue_for_each_rl(rl, q) {
if (rl->rq_pool) {
wake_up(&rl->wait[BLK_RW_SYNC]);
wake_up(&rl->wait[BLK_RW_ASYNC]);
}
}
spin_unlock_irq(q->queue_lock);
}
}
EXPORT_SYMBOL_GPL(blk_set_queue_dying);