From: Ye Bin <yebin10@huawei.com>

Unlike recovery state may block other process, blocking IO only
when host is blocked.

Signed-off-by: Ye Bin <yebin10@huawei.com>
---
 drivers/scsi/scsi_lib.c  | 4 ++++
 include/scsi/scsi_host.h | 5 +++++
 2 files changed, 9 insertions(+)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index b7c569a42aa4..492487717f41 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1731,6 +1731,10 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx,
 			ret = BLK_STS_OFFLINE;
 		goto out_dec_target_busy;
 	}
+
+	if (unlikely(scsi_host_blocked(shost)))
+		goto out_dec_target_busy;
+
 	if (!scsi_host_queue_ready(q, shost, sdev, cmd))
 		goto out_dec_target_busy;
 
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 9e99317b11fa..571321bbb706 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -745,6 +745,11 @@ static inline int scsi_host_in_recovery(struct Scsi_Host *shost)
 		shost->tmf_in_progress;
 }
 
+static inline int scsi_host_blocked(struct Scsi_Host *shost)
+{
+	return shost->shost_state == SHOST_BLOCKED;
+}
+
 extern int scsi_queue_work(struct Scsi_Host *, struct work_struct *);
 extern void scsi_flush_work(struct Scsi_Host *);
 
-- 
2.31.1

On 3/24/23 18:17, Ye Bin wrote:
> +	if (unlikely(scsi_host_blocked(shost)))
> +		goto out_dec_target_busy;
I this check would be moved earlier then the atomic_inc() and 
atomic_dec() of scsi_target(sdev)->target_busy could be skipped.

Thanks,

Bart.