block: add a read barrier in blk_queue_enter()

Without the barrier, reading DEAD flag of .q_usage_counter
and reading .mq_freeze_depth may be reordered, then the
following wait_event_interruptible() may never return.

Reviewed-by: Hannes Reinecke <[email protected]>
Signed-off-by: Ming Lei <[email protected]>
Reviewed-by: Johannes Thumshirn <[email protected]>
Reviewed-by: Bart Van Assche <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>

0 files changed, 0 insertions, 0 deletions