sbp2: fix another deadlock after disconnection

If there were commands enqueued but not completed before an SBP-2 unit
was unplugged (or an attempt to reconnect failed), knodemgrd or any
process which tried to remove the device would sleep uninterruptibly
in blk_execute_rq().  Therefore make sure that all commands are
completed when sbp2 retreats.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Jody McIntyre <scjody@modernduck.com>
(cherry picked from 61daa34c132c5d4ed8630e2c46e9bf2f0c7b3428 commit)

1 files changed, 8 insertions, 2 deletions

diff --git a/drivers/ieee1394/sbp2.c b/drivers/ieee1394/sbp2.c
index c2c776fbda01..8963dd484eb9 100644
--- a/drivers/ieee1394/sbp2.c
+++ b/drivers/ieee1394/sbp2.c
@@ -643,9 +643,15 @@ static int sbp2_remove(struct device *dev)
         if (!scsi_id)
                 return 0;
 
-        /* Trigger shutdown functions in scsi's highlevel. */
-        if (scsi_id->scsi_host)
+        if (scsi_id->scsi_host) {
+                /* Get rid of enqueued commands if there is no chance to
+                 * send them. */
+                if (!sbp2util_node_is_available(scsi_id))
+                        sbp2scsi_complete_all_commands(scsi_id, DID_NO_CONNECT);
+                /* scsi_remove_device() will trigger shutdown functions of SCSI
+                 * highlevel drivers which would deadlock if blocked. */
                 scsi_unblock_requests(scsi_id->scsi_host);
+        }
         sdev = scsi_id->sdev;
         if (sdev) {
                 scsi_id->sdev = NULL;