| Message ID | 20220801012251.1959147-1-yukuai1@huaweicloud.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | [stable,5.4] scsi: core: Fix race between handling STS_RESOURCE and completion | expand |
On Mon, Aug 01, 2022 at 09:22:51AM +0800, Yu Kuai wrote: > From: Ming Lei <ming.lei@redhat.com> > > commit 673235f915318ced5d7ec4b2bfd8cb909e6a4a55 upstream. > > When queuing I/O request to LLD, STS_RESOURCE may be returned because: > > - Host is in recovery or blocked > > - Target queue throttling or target is blocked > > - LLD rejection > > In these scenarios BLK_STS_DEV_RESOURCE is returned to the block layer to > avoid an unnecessary re-run of the queue. However, all of the requests > queued to this SCSI device may complete immediately after reading > 'sdev->device_busy' and BLK_STS_DEV_RESOURCE is returned to block layer. In > that case the current I/O won't get a chance to get queued since it is > invisible at that time for both scsi_run_queue_async() and blk-mq's > RESTART. > > Fix the issue by not returning BLK_STS_DEV_RESOURCE in this situation. > > Link: https://lore.kernel.org/r/20201202100419.525144-1-ming.lei@redhat.com > Fixes: 86ff7c2a80cd ("blk-mq: introduce BLK_STS_DEV_RESOURCE") > Cc: Hannes Reinecke <hare@suse.com> > Cc: Sumit Saxena <sumit.saxena@broadcom.com> > Cc: Kashyap Desai <kashyap.desai@broadcom.com> > Cc: Bart Van Assche <bvanassche@acm.org> > Cc: Ewan Milne <emilne@redhat.com> > Cc: Long Li <longli@microsoft.com> > Reported-by: John Garry <john.garry@huawei.com> > Tested-by: "chenxiang (M)" <chenxiang66@hisilicon.com> > Signed-off-by: Ming Lei <ming.lei@redhat.com> > Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> > Signed-off-by: Yu Kuai <yukuai3@huawei.com> > --- > drivers/scsi/scsi_lib.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) Both now queued up, thanks. greg k-h
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 8e6d7ba95df1..98e363d0025b 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1719,8 +1719,7 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx, case BLK_STS_OK: break; case BLK_STS_RESOURCE: - if (atomic_read(&sdev->device_busy) || - scsi_device_blocked(sdev)) + if (scsi_device_blocked(sdev)) ret = BLK_STS_DEV_RESOURCE; break; default: