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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>,
        Ming Lei <ming.lei@redhat.com>, <linux-scsi@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
CC:     <linfeilong@huawei.com>, <louhongxiang@huawei.com>,
        Wenchao Hao <haowenchao2@huawei.com>
Subject: [PATCH 1/2] Revert "scsi: core: Do not increase scsi_device's iorequest_cnt if dispatch failed"
Date:   Mon, 15 May 2023 15:01:55 +0800
Message-ID: <20230515070156.1790181-2-haowenchao2@huawei.com>
In-Reply-To: <20230515070156.1790181-1-haowenchao2@huawei.com>
References: <20230515070156.1790181-1-haowenchao2@huawei.com>
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Precedence: bulk

the "atomic_inc(&cmd->device->iorequest_cnt)" in scsi_queue_rq() would
causes kernel panic, because cmd->device may be freed after returning
from scsi_dispatch_cmd().

This reverts commit cfee29ffb45b1c9798011b19d454637d1b0fe87d.

Signed-off-by: Wenchao Hao <haowenchao2@huawei.com>
Reported-by: Ming Lei <ming.lei@redhat.com>
Closes:https://lore.kernel.org/linux-scsi/8e0f2d31-e6ff-ec4a-3974-450560ad49c5@huawei.com/T/#t
---
 drivers/scsi/scsi_lib.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index b7c569a42aa4..03964b26f3f2 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1463,6 +1463,8 @@ static int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
 	struct Scsi_Host *host = cmd->device->host;
 	int rtn = 0;
 
+	atomic_inc(&cmd->device->iorequest_cnt);
+
 	/* check if the device is still usable */
 	if (unlikely(cmd->device->sdev_state == SDEV_DEL)) {
 		/* in SDEV_DEL we error all commands. DID_NO_CONNECT
@@ -1761,7 +1763,6 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx,
 		goto out_dec_host_busy;
 	}
 
-	atomic_inc(&cmd->device->iorequest_cnt);
 	return BLK_STS_OK;
 
 out_dec_host_busy:
-- 
2.32.0