From 3b77fc36cefaacba19a48db43ab3b8dc57cbfc1b Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sun, 7 Dec 2014 19:55:49 +0000 Subject: [PATCH] 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 Signed-off-by: Jens Axboe [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 Signed-off-by: Willy Tarreau --- block/blk-core.c | 4 ++++ block/blk-exec.c | 6 ++++-- 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 4058f4625f1a2..ad566e252935c 100644 --- 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 85bd7b445d86a..ae0f2c7bcfc98 100644 --- 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 */