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authorMing Lei <ming.lei@redhat.com>2020-12-02 18:04:19 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-08-03 11:59:41 +0200
commit0b0088e475870cfc36a0762354bf224d8a1041aa (patch)
tree562cf1af1cde3b94e5a3349638a36d3caa1f9e90
parent85fe8623f061679f332fb45c12e975e81092f973 (diff)
scsi: core: Fix race between handling STS_RESOURCE and completion
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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/scsi/scsi_lib.c3
1 files changed, 1 insertions, 2 deletions
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 @@ out_put_budget:
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: