| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 152/192] block: Fix race triggered by blk_set_queue_dying() | Date | Mon, 12 Sep 2016 19:01:01 +0200 |
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4.4-stable review patch. If anyone has any objections, please let me know.
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From: Bart Van Assche <bart.vanassche@sandisk.com>
commit 1b856086813be9371929b6cc62045f9fd470f5a0 upstream.
blk_set_queue_dying() can be called while another thread is submitting I/O or changing queue flags, e.g. through dm_stop_queue(). Hence protect the QUEUE_FLAG_DYING flag change with locking.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- block/blk-core.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/block/blk-core.c +++ b/block/blk-core.c @@ -515,7 +515,9 @@ EXPORT_SYMBOL_GPL(blk_queue_bypass_end); void blk_set_queue_dying(struct request_queue *q) { - queue_flag_set_unlocked(QUEUE_FLAG_DYING, q); + spin_lock_irq(q->queue_lock); + queue_flag_set(QUEUE_FLAG_DYING, q); + spin_unlock_irq(q->queue_lock); if (q->mq_ops) blk_mq_wake_waiters(q);
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