Imported linux-2.6.27.39 suse/xen patches.

[ipfire-2.x.git] / src / patches / suse-2.6.27.39 / patches.fixes / libiscsi-fix-locking-in-eh_device_reset

From: Mike Christie <michaelc@cs.wisc.edu>
Date: Wed Sep 24 11:46:15 2008 -0500
Subject: fix locking in iscsi_eh_device_reset
X-Git: a343914831a8e29d89af3b26495ab1136a9e3153
References: bnc#498369

We must be using the bh spin locking functions in
iscsi_eh_device_reset becuase the session lock interacts with
a thread and softirq.

This patch also fixes up a bogus comment and check in fail_command,
because no one drops the lock (bnx2i did but it is not going
upstream yet and there were other refcount changes for that).

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>

---
 drivers/scsi/libiscsi.c |    9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -413,11 +413,6 @@ static void fail_command(struct iscsi_co
 		conn->session->queued_cmdsn--;
 	else
 		conn->session->tt->cleanup_task(conn, task);
-	/*
-	 * Check if cleanup_task dropped the lock and the command completed,
-	 */
-	if (!task->sc)
-		return;
 
 	sc->result = err;
 	if (!scsi_bidi_cmnd(sc))
@@ -1839,10 +1834,10 @@ int iscsi_eh_device_reset(struct scsi_cm
 
 	iscsi_suspend_tx(conn);
 
-	spin_lock(&session->lock);
+	spin_lock_bh(&session->lock);
 	fail_all_commands(conn, sc->device->lun, DID_ERROR);
 	conn->tmf_state = TMF_INITIAL;
-	spin_unlock(&session->lock);
+	spin_unlock_bh(&session->lock);
 
 	iscsi_start_tx(conn);
 	goto done;