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| author | Ming Lei <ming.lei@redhat.com> | 2020-12-02 18:04:19 +0800 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2020-12-07 21:21:20 -0500 |
| commit | 673235f915318ced5d7ec4b2bfd8cb909e6a4a55 (patch) | |
| tree | 940da5b1c170a193015610961e2b881bf4a34d1f | |
| parent | eeaf06af6f87e1dba371fbe42674e6f963220b9c (diff) | |
| download | linux-673235f915318ced5d7ec4b2bfd8cb909e6a4a55.tar.gz linux-673235f915318ced5d7ec4b2bfd8cb909e6a4a55.tar.bz2 linux-673235f915318ced5d7ec4b2bfd8cb909e6a4a55.zip | |
scsi: core: Fix race between handling STS_RESOURCE and completion
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>
| -rw-r--r-- | drivers/scsi/scsi_lib.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 60c7a7d74852..03c6d0620bfd 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1703,8 +1703,7 @@ out_put_budget: break; case BLK_STS_RESOURCE: case BLK_STS_ZONE_RESOURCE: - if (atomic_read(&sdev->device_busy) || - scsi_device_blocked(sdev)) + if (scsi_device_blocked(sdev)) ret = BLK_STS_DEV_RESOURCE; break; default: |