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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>,
        <open-iscsi@googlegroups.com>, <linux-scsi@vger.kernel.org>
CC:     <linux-kernel@vger.kernel.org>, <louhongxiang@huawei.com>,
        Wenchao Hao <haowenchao2@huawei.com>
Subject: [PATCH 1/2] scsi: core: scsi_device_online() return false if state is SDEV_CANCEL
Date:   Fri, 22 Sep 2023 17:36:35 +0800
Message-ID: <20230922093636.2645961-2-haowenchao2@huawei.com>
In-Reply-To: <20230922093636.2645961-1-haowenchao2@huawei.com>
References: <20230922093636.2645961-1-haowenchao2@huawei.com>
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SDEV_CANCEL is set when removing device and scsi_device_online() should
return false if sdev_state is SDEV_CANCEL.

IO hang would be caused if return true when state is SDEV_CANCEL with
following order:

T1:					    T2:scsi_error_handler
__scsi_remove_device()
  scsi_device_set_state(sdev, SDEV_CANCEL)
  					    scsi_eh_flush_done_q()
					    if (scsi_device_online(sdev))
					      scsi_queue_insert(scmd,...)

The command added by scsi_queue_insert() would never be handled any
more.

Signed-off-by: Wenchao Hao <haowenchao2@huawei.com>
---
 include/scsi/scsi_device.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 75b2235b99e2..c498a12f7715 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -517,7 +517,8 @@ static inline int scsi_device_online(struct scsi_device *sdev)
 {
 	return (sdev->sdev_state != SDEV_OFFLINE &&
 		sdev->sdev_state != SDEV_TRANSPORT_OFFLINE &&
-		sdev->sdev_state != SDEV_DEL);
+		sdev->sdev_state != SDEV_DEL &&
+		sdev->sdev_state != SDEV_CANCEL);
 }
 static inline int scsi_device_blocked(struct scsi_device *sdev)
 {
-- 
2.32.0