Patch "scsi_transport_srp: Fix a race condition" has been added to the 3.14-stable tree

This is a note to let you know that I've just added the patch titled

scsi_transport_srp: Fix a race condition

to the 3.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
scsi_transport_srp-fix-a-race-condition.patch
and it can be found in the queue-3.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Bart Van Assche <[email protected]>
Date: Mon, 18 May 2015 13:22:44 +0200
Subject: scsi_transport_srp: Fix a race condition

From: Bart Van Assche <[email protected]>

commit 535fb906225fb7436cb658144d0c0cea14a26f3e upstream.

Avoid that srp_terminate_io() can get invoked while srp_queuecommand() is in progress. This patch avoids that an I/O timeout can trigger the following kernel warning:

WARNING: at drivers/infiniband/ulp/srp/ib_srp.c:1447 srp_terminate_io+0xef/0x100 [ib_srp]()
Call Trace:
 [<ffffffff814c65a2>] dump_stack+0x4e/0x68
 [<ffffffff81051f71>] warn_slowpath_common+0x81/0xa0
 [<ffffffff8105204a>] warn_slowpath_null+0x1a/0x20
 [<ffffffffa075f51f>] srp_terminate_io+0xef/0x100 [ib_srp]
 [<ffffffffa07495da>] __rport_fail_io_fast+0xba/0xc0 [scsi_transport_srp]
 [<ffffffffa0749a90>] rport_fast_io_fail_timedout+0xe0/0xf0 [scsi_transport_srp]
 [<ffffffff8106e09b>] process_one_work+0x1db/0x780
 [<ffffffff8106e75b>] worker_thread+0x11b/0x450
 [<ffffffff81073c64>] kthread+0xe4/0x100
 [<ffffffff814cf26c>] ret_from_fork+0x7c/0xb0

See also patch "scsi_transport_srp: Add transport layer error handling" (commit ID 29c17324803c).

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

@@ -440,8 +440,10 @@ static void __rport_fail_io_fast(struct
 
 	/* Involve the LLD if possible to terminate all I/O on the rport. */
 	i = to_srp_internal(shost->transportt);
-	if (i->f->terminate_rport_io)
+	if (i->f->terminate_rport_io) {
+		srp_wait_for_queuecommand(shost);
 		i->f->terminate_rport_io(rport);
+	}
 }
 
 /**

Patches currently in stable-queue which might be from [email protected] are

queue-3.14/scsi_transport_srp-introduce-srp_wait_for_queuecommand.patch queue-3.14/scsi_transport_srp-fix-a-race-condition.patch