[PATCH 3.16.y-ckt 185/254] scsi: only re-lock door after EH on devices that were reset

[Luis Henriques]

3.16.7-ckt2 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Christoph Hellwig <hch at lst.de>

commit 48379270fe6808cf4612ee094adc8da2b7a83baa upstream.

Setups that use the blk-mq I/O path can lock up if a host with a single
device that has its door locked enters EH.  Make sure to only send the
command to re-lock the door to devices that actually were reset and thus
might have lost their state.  Otherwise the EH code might be get blocked
on blk_get_request as all requests for non-reset devices might be in use.

Signed-off-by: Christoph Hellwig <hch at lst.de>
Reported-by: Meelis Roos <meelis.roos at ut.ee>
Tested-by: Meelis Roos <meelis.roos at ut.ee>
Reviewed-by: Martin K. Petersen <martin.petersen at oracle.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/scsi/scsi_error.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 7e957918f33f..b350eb8ec898 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -1989,8 +1989,10 @@ static void scsi_restart_operations(struct Scsi_Host *shost)
 	 * is no point trying to lock the door of an off-line device.
 	 */
 	shost_for_each_device(sdev, shost) {
-		if (scsi_device_online(sdev) && sdev->locked)
+		if (scsi_device_online(sdev) && sdev->was_reset && sdev->locked) {
 			scsi_eh_lock_door(sdev);
+			sdev->was_reset = 0;
+		}
 	}
 
 	/*
-- 
2.1.0