[PATCH] USB:UAS:return ENODEV when submit urbs fail with device not attached.

[Weitao Wang <WeitaoWang-oc@xxxxxxxxxxx>]

In the scenario of entering hibernation with udisk in the system, if the
udisk was gone or resume fail in the thaw phase of hibernation. Its state
will be set to NOTATTACHED. However, usb_hub_wq was already freezed and
can't not handle disconnect event. Then, sync cache SCSI command will be
sent to this udisk on the poweroff phase of hibernation, that will cause
uas_submit_urbs to be called to submit URB to sense/data/cmd pipe. Then,
usb_submit_urb return value -ENODEV when device was set to NOTATTACHED
state. However, uas_submit_urbs always return "SCSI_MLQUEUE_DEVICE_BUSY"
regardless of the reason for submission failure.That will lead the SCSI
layer go into an ugly loop and system fail to go into hibernation.

To fix this issue, let uas_submit_urbs function to return real error
-ENODEV when submit URB with device in the NOTATTACHED state. In the error
checking inside of function uas_queuecommand_lck, reporting DID_ERROR will
cause device poweroff fail and system shutdown instead of entering
hibernation. So,replace DID_ERROR with DID_NO_CONNECT to report to SCSI
upper layer.

Signed-off-by: Weitao Wang <WeitaoWang-oc@xxxxxxxxxxx>
---
 drivers/usb/storage/uas.c | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/drivers/usb/storage/uas.c b/drivers/usb/storage/uas.c
index 9707f53cfda9..967f18db525a 100644
--- a/drivers/usb/storage/uas.c
+++ b/drivers/usb/storage/uas.c
@@ -533,7 +533,7 @@ static struct urb *uas_alloc_cmd_urb(struct uas_dev_info *devinfo, gfp_t gfp,
  * daft to me.
  */
 
-static struct urb *uas_submit_sense_urb(struct scsi_cmnd *cmnd, gfp_t gfp)
+static int uas_submit_sense_urb(struct scsi_cmnd *cmnd, gfp_t gfp)
 {
 	struct uas_dev_info *devinfo = cmnd->device->hostdata;
 	struct urb *urb;
@@ -541,16 +541,15 @@ static struct urb *uas_submit_sense_urb(struct scsi_cmnd *cmnd, gfp_t gfp)
 
 	urb = uas_alloc_sense_urb(devinfo, gfp, cmnd);
 	if (!urb)
-		return NULL;
+		return -ENOMEM;
 	usb_anchor_urb(urb, &devinfo->sense_urbs);
 	err = usb_submit_urb(urb, gfp);
 	if (err) {
 		usb_unanchor_urb(urb);
 		uas_log_cmd_state(cmnd, "sense submit err", err);
 		usb_free_urb(urb);
-		return NULL;
 	}
-	return urb;
+	return err;
 }
 
 static int uas_submit_urbs(struct scsi_cmnd *cmnd,
@@ -562,9 +561,9 @@ static int uas_submit_urbs(struct scsi_cmnd *cmnd,
 
 	lockdep_assert_held(&devinfo->lock);
 	if (cmdinfo->state & SUBMIT_STATUS_URB) {
-		urb = uas_submit_sense_urb(cmnd, GFP_ATOMIC);
-		if (!urb)
-			return SCSI_MLQUEUE_DEVICE_BUSY;
+		err = uas_submit_sense_urb(cmnd, GFP_ATOMIC);
+		if (err)
+			return (err == -ENODEV) ? -ENODEV : SCSI_MLQUEUE_DEVICE_BUSY;
 		cmdinfo->state &= ~SUBMIT_STATUS_URB;
 	}
 
@@ -582,7 +581,7 @@ static int uas_submit_urbs(struct scsi_cmnd *cmnd,
 		if (err) {
 			usb_unanchor_urb(cmdinfo->data_in_urb);
 			uas_log_cmd_state(cmnd, "data in submit err", err);
-			return SCSI_MLQUEUE_DEVICE_BUSY;
+			return (err == -ENODEV) ? -ENODEV : SCSI_MLQUEUE_DEVICE_BUSY;
 		}
 		cmdinfo->state &= ~SUBMIT_DATA_IN_URB;
 		cmdinfo->state |= DATA_IN_URB_INFLIGHT;
@@ -602,7 +601,7 @@ static int uas_submit_urbs(struct scsi_cmnd *cmnd,
 		if (err) {
 			usb_unanchor_urb(cmdinfo->data_out_urb);
 			uas_log_cmd_state(cmnd, "data out submit err", err);
-			return SCSI_MLQUEUE_DEVICE_BUSY;
+			return (err == -ENODEV) ? -ENODEV : SCSI_MLQUEUE_DEVICE_BUSY;
 		}
 		cmdinfo->state &= ~SUBMIT_DATA_OUT_URB;
 		cmdinfo->state |= DATA_OUT_URB_INFLIGHT;
@@ -621,7 +620,7 @@ static int uas_submit_urbs(struct scsi_cmnd *cmnd,
 		if (err) {
 			usb_unanchor_urb(cmdinfo->cmd_urb);
 			uas_log_cmd_state(cmnd, "cmd submit err", err);
-			return SCSI_MLQUEUE_DEVICE_BUSY;
+			return (err == -ENODEV) ? -ENODEV : SCSI_MLQUEUE_DEVICE_BUSY;
 		}
 		cmdinfo->cmd_urb = NULL;
 		cmdinfo->state &= ~SUBMIT_CMD_URB;
@@ -698,7 +697,7 @@ static int uas_queuecommand_lck(struct scsi_cmnd *cmnd)
 	 * of queueing, no matter how fatal the error
 	 */
 	if (err == -ENODEV) {
-		set_host_byte(cmnd, DID_ERROR);
+		set_host_byte(cmnd, DID_NO_CONNECT);
 		scsi_done(cmnd);
 		goto zombie;
 	}
-- 
2.32.0