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From:   Wenchao Hao <haowenchao2@huawei.com>
To:     "James E . J . Bottomley" <jejb@linux.ibm.com>,
        "Martin K . Petersen" <martin.petersen@oracle.com>,
        <linux-scsi@vger.kernel.org>
CC:     Hannes Reinecke <hare@suse.de>, <linux-kernel@vger.kernel.org>,
        <louhongxiang@huawei.com>, <lixiaokeng@huawei.com>,
        Wenchao Hao <haowenchao2@huawei.com>
Subject: [RFC PATCH v2 09/19] scsi: core: increase/decrease target_busy without check can_queue
Date:   Fri, 1 Sep 2023 17:41:17 +0800
Message-ID: <20230901094127.2010873-10-haowenchao2@huawei.com>
In-Reply-To: <20230901094127.2010873-1-haowenchao2@huawei.com>
References: <20230901094127.2010873-1-haowenchao2@huawei.com>
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Precedence: bulk

This is preparation for a genernal target based error handle strategy
to check if to wake up actual error handler.

Signed-off-by: Wenchao Hao <haowenchao2@huawei.com>
---
 drivers/scsi/scsi_lib.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index db0a42fe49c0..4a7fb48aa60f 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -293,8 +293,7 @@ void scsi_device_unbusy(struct scsi_device *sdev, struct scsi_cmnd *cmd)
 
 	scsi_dec_host_busy(shost, cmd);
 
-	if (starget->can_queue > 0)
-		atomic_dec(&starget->target_busy);
+	atomic_dec(&starget->target_busy);
 
 	sbitmap_put(&sdev->budget_map, cmd->budget_token);
 	cmd->budget_token = -1;
@@ -1311,10 +1310,10 @@ static inline int scsi_target_queue_ready(struct Scsi_Host *shost,
 		spin_unlock_irq(shost->host_lock);
 	}
 
+	busy = atomic_inc_return(&starget->target_busy) - 1;
 	if (starget->can_queue <= 0)
 		return 1;
 
-	busy = atomic_inc_return(&starget->target_busy) - 1;
 	if (atomic_read(&starget->target_blocked) > 0) {
 		if (busy)
 			goto starved;
@@ -1339,8 +1338,7 @@ static inline int scsi_target_queue_ready(struct Scsi_Host *shost,
 	list_move_tail(&sdev->starved_entry, &shost->starved_list);
 	spin_unlock_irq(shost->host_lock);
 out_dec:
-	if (starget->can_queue > 0)
-		atomic_dec(&starget->target_busy);
+	atomic_dec(&starget->target_busy);
 	return 0;
 }
 
@@ -1784,8 +1782,7 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx,
 out_dec_host_busy:
 	scsi_dec_host_busy(shost, cmd);
 out_dec_target_busy:
-	if (scsi_target(sdev)->can_queue > 0)
-		atomic_dec(&scsi_target(sdev)->target_busy);
+	atomic_dec(&scsi_target(sdev)->target_busy);
 out_put_budget:
 	scsi_mq_put_budget(q, cmd->budget_token);
 	cmd->budget_token = -1;
-- 
2.35.3