[PATCH AUTOSEL 5.4 22/27] scsi: core: Decrease scsi_device's iorequest_cnt if dispatch failed

Sasha Levin
2023-05-25T18:56:35Z

From: Wenchao Hao <haowenchao2@huawei.com>

[ Upstream commit 09e797c8641f6ad435c33ae24c223351197ea29a ]

If scsi_dispatch_cmd() failed, the SCSI command was not sent to the target,
scsi_queue_rq() would return BLK_STS_RESOURCE and the related request would
be requeued. The timeout of this request would not fire, no one would
increase iodone_cnt.

The above flow would result the iodone_cnt smaller than iorequest_cnt. So
decrease the iorequest_cnt if dispatch failed to workaround the issue.

Signed-off-by: Wenchao Hao <haowenchao2@huawei.com>
Reported-by: Ming Lei <ming.lei@redhat.com>
Closes: https://lore.kernel.org/r/ZF+zB+bB7iqe0wGd@ovpn-8-17.pek2.redhat.com
Link: https://lore.kernel.org/r/20230515070156.1790181-3-haowenchao2@huawei.com
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/scsi/scsi_lib.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 490d6c72d8bd6..8d05faf95ac3b 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1534,6 +1534,7 @@ static int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
*/
SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
"queuecommand : device blocked\n"));
+ atomic_dec(&cmd->device->iorequest_cnt);
return SCSI_MLQUEUE_DEVICE_BUSY;
}

@@ -1566,6 +1567,7 @@ static int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
trace_scsi_dispatch_cmd_start(cmd);
rtn = host->hostt->queuecommand(host, cmd);
if (rtn) {
+ atomic_dec(&cmd->device->iorequest_cnt);
trace_scsi_dispatch_cmd_error(cmd, rtn);
if (rtn != SCSI_MLQUEUE_DEVICE_BUSY &&
rtn != SCSI_MLQUEUE_TARGET_BUSY)
--
2.39.2