[PATCH 3.10 28/70] scsi: only re-lock door after EH on devices that were reset

Greg Kroah-Hartman
2014-11-19T21:31:42Z

From: Christoph Hellwig <hch@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@lst.de>
Reported-by: Meelis Roos <meelis.roos@ut.ee>
Tested-by: Meelis Roos <meelis.roos@ut.ee>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/scsi/scsi_error.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -1689,8 +1689,10 @@ static void scsi_restart_operations(stru
* 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;
+ }
}

/*