mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-24 17:59:32 +00:00
xen-blkfront: fix mq start/stop race
When ring buf full, hw queue will be stopped. While blkif interrupt consume request and make free space in ring buf, hw queue will be started again. But since start queue is protected by spin lock while stop not, that will cause a race. interrupt: process: blkif_interrupt() blkif_queue_rq() kick_pending_request_queues_locked() blk_mq_start_stopped_hw_queues() clear_bit(BLK_MQ_S_STOPPED, &hctx->state) blk_mq_stop_hw_queue(hctx) blk_mq_run_hw_queue(hctx, async) If ring buf is made empty in this case, interrupt will never come, then the hw queue will be stopped forever, all processes waiting for the pending io in the queue will hung. Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Reviewed-by: Ankur Arora <ankur.a.arora@oracle.com> Acked-by: Roger Pau Monné <roger.pau@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This commit is contained in:
parent
76451d79bd
commit
4b422cb998
1 changed files with 1 additions and 1 deletions
|
@ -906,8 +906,8 @@ static blk_status_t blkif_queue_rq(struct blk_mq_hw_ctx *hctx,
|
|||
return BLK_STS_IOERR;
|
||||
|
||||
out_busy:
|
||||
spin_unlock_irqrestore(&rinfo->ring_lock, flags);
|
||||
blk_mq_stop_hw_queue(hctx);
|
||||
spin_unlock_irqrestore(&rinfo->ring_lock, flags);
|
||||
return BLK_STS_RESOURCE;
|
||||
}
|
||||
|
||||
|
|
Loading…
Reference in a new issue