Messages in this thread Patch in this message | | | From | Tejun Heo <> | Subject | [PATCH 6/6] block: add missing blk_queue_dead() checks | Date | Tue, 25 Oct 2011 18:02:07 -0700 |
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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> Cc: Jens Axboe <axboe@kernel.dk> --- block/blk-core.c | 21 +++++++++++++++++++++ block/blk-exec.c | 5 +++-- 2 files changed, 24 insertions(+), 2 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c index 4224e0a..8267409 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1722,6 +1722,10 @@ int blk_insert_cloned_request(struct request_queue *q, struct request *rq) return -EIO; spin_lock_irqsave(q->queue_lock, flags); + if (unlikely(blk_queue_dead(q))) { + spin_unlock_irqrestore(q->queue_lock, flags); + return -ENODEV; + } /* * Submitting request must be dequeued before calling this function @@ -2696,6 +2700,14 @@ static void queue_unplugged(struct request_queue *q, unsigned int depth, trace_block_unplug(q, depth, !from_schedule); /* + * Don't mess with dead queue. + */ + if (unlikely(blk_queue_dead(q))) { + spin_unlock(q->queue_lock); + return; + } + + /* * If we are punting this to kblockd, then we can safely drop * the queue_lock before waking kblockd (which needs to take * this lock). @@ -2771,6 +2783,15 @@ void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule) depth = 0; spin_lock(q->queue_lock); } + + /* + * Short-circuit if @q is dead + */ + if (unlikely(blk_queue_dead(q))) { + __blk_end_request_all(rq, -ENODEV); + continue; + } + /* * rq is already accounted, so use raw insert */ diff --git a/block/blk-exec.c b/block/blk-exec.c index 8716557..660a722 100644 --- a/block/blk-exec.c +++ b/block/blk-exec.c @@ -52,7 +52,10 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk, bool may_sleep = !preempt_count() && !irqs_disabled(); unsigned long flags; + spin_lock_irqsave(q->queue_lock, flags); + if (unlikely(blk_queue_dead(q))) { + spin_unlock_irqrestore(q->queue_lock, flags); rq->errors = -ENXIO; if (rq->end_io) rq->end_io(rq, rq->errors); @@ -61,8 +64,6 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk, rq->rq_disk = bd_disk; rq->end_io = done; - - spin_lock_irqsave(q->queue_lock, flags); elv_add_request(q, rq, where); /* -- 1.7.3.1
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