block: add missing blk_queue_dead() checks

commit 8ba61435d73f2274e12d4d823fde06735e8f6a54 upstream.

blk_insert_cloned_request(), blk_execute_rq_nowait() and
blk_flush_plug_list() either didn't check whether the queue was dead
or did it without holding queue_lock.  Update them so that dead state
is checked while holding queue_lock.

AFAICS, this plugs all holes (requeue doesn't matter as the request is
transitioning atomically from in_flight to queued).

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
[bwh: Backported to 2.6.32:
 - Drop inapplicable changes to queue_unplugged() and
   blk_flush_plug_list()
 - We don't have blk_queue_dead() so open-code it
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Willy Tarreau <w@1wt.eu>

diff --git a/block/blk-core.c b/block/blk-core.c
index 4058f4625f1a2da66d08bb8b55e8182a7614ecda..ad566e252935cea7d1312fc4301460693ae6e327 100644 (file)
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1651,6 +1651,10 @@ int blk_insert_cloned_request(struct request_queue *q, struct request *rq)
 #endif
 
        spin_lock_irqsave(q->queue_lock, flags);
+       if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags))) {
+               spin_unlock_irqrestore(q->queue_lock, flags);
+               return -ENODEV;
+       }
 
        /*
         * Submitting request must be dequeued before calling this function

diff --git a/block/blk-exec.c b/block/blk-exec.c
index 85bd7b445d86a08bb0a6ea829081f06b52b7cb2c..ae0f2c7bcfc98d39edaecd1829d1f3fdb9095dfc 100644 (file)
--- a/block/blk-exec.c
+++ b/block/blk-exec.c
@@ -50,7 +50,11 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
 {
        int where = at_head ? ELEVATOR_INSERT_FRONT : ELEVATOR_INSERT_BACK;
 
+       WARN_ON(irqs_disabled());
+       spin_lock_irq(q->queue_lock);
+
        if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags))) {
+               spin_unlock_irq(q->queue_lock);
                rq->errors = -ENXIO;
                if (rq->end_io)
                        rq->end_io(rq, rq->errors);
@@ -59,8 +63,6 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
 
        rq->rq_disk = bd_disk;
        rq->end_io = done;
-       WARN_ON(irqs_disabled());
-       spin_lock_irq(q->queue_lock);
        __elv_add_request(q, rq, where, 1);
        __generic_unplug_device(q);
        /* the queue is stopped so it won't be plugged+unplugged */