Hi, Since 45a9c9d909b2 ("blk-mq: Fix a use-after-free"), run queue isn't allowed during cleanup queue even though queue refcount is held. This change has caused lots of kernel oops triggered in run queue path, turns out it isn't easy to fix them all. So move freeing of hw queue resources into queue's release handler, then the above issue is fixed. Meantime, this way is safe given freeing hw queue resource doesn't require to use tags. Thanks, Ming Lei (5): blk-mq: re-organize blk_mq_exit_hctx() into two parts blk-mq: re-organize blk_mq_exit_hw_queues() into two parts blk-mq: free hw queues in queue's release handler block: don't drain in-progress dispatch in blk_cleanup_queue() SCSI: don't grab queue usage counter before run queue block/blk-core.c | 14 +------------- block/blk-mq.c | 32 +++++++++++++++++++++++++------- block/blk-mq.h | 3 ++- drivers/scsi/scsi_lib.c | 7 ------- 4 files changed, 28 insertions(+), 28 deletions(-) Cc: James Smart <james.smart@xxxxxxxxxxxx> Cc: Bart Van Assche <bart.vanassche@xxxxxxx> Cc: linux-scsi@xxxxxxxxxxxxxxx, Cc: Martin K . Petersen <martin.petersen@xxxxxxxxxx>, Cc: Christoph Hellwig <hch@xxxxxx>, Cc: James E . J . Bottomley <jejb@xxxxxxxxxxxxxxxxxx>, Cc: jianchao wang <jianchao.w.wang@xxxxxxxxxx> -- 2.9.5