scsi: core: Decrease scsi_device's iorequest_cnt if dispatch failed

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>

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 03964b26f3f27af1be9cf85579b7f3641b2ae595..0226c9279cef60b0daf3cebfba77c467200975c9 100644 (file)
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1485,6 +1485,7 @@ 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;
        }
 
@@ -1517,6 +1518,7 @@ 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)