[3.19.y-ckt stable] Patch "qla2xxx: drop cmds/tmrs arrived while session is being deleted" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    qla2xxx: drop cmds/tmrs arrived while session is being deleted

to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue

This patch is scheduled to be released in version 3.19.8-ckt6.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.19.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 62894b6614994cbc73af1ff8ee226429b702a5e2 Mon Sep 17 00:00:00 2001
From: Alexei Potashnik <alexei at purestorage.com>
Date: Tue, 14 Jul 2015 16:00:48 -0400
Subject: qla2xxx: drop cmds/tmrs arrived while session is being deleted

commit e52a8b45b9c782937f74b701f8c656d4e5619eb5 upstream.

If a new initiator (different WWN) shows up on the same fcport, old
initiator's session is scheduled for deletion. But there is a small
window between it being marked with QLA_SESS_DELETION_IN_PROGRESS
and qlt_unret_sess getting called when new session's commands will
keep finding old session in the fcport map.

This patch drops cmds/tmrs if they find session in the progress of
being deleted.

Signed-off-by: Alexei Potashnik <alexei at purestorage.com>
Acked-by: Quinn Tran <quinn.tran at qlogic.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani at qlogic.com>
Signed-off-by: Nicholas Bellinger <nab at linux-iscsi.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/scsi/qla2xxx/qla_target.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/drivers/scsi/qla2xxx/qla_target.c b/drivers/scsi/qla2xxx/qla_target.c
index d9ae08a..6c66a31 100644
--- a/drivers/scsi/qla2xxx/qla_target.c
+++ b/drivers/scsi/qla2xxx/qla_target.c
@@ -1477,6 +1477,11 @@ static void qlt_24xx_handle_abts(struct scsi_qla_host *vha,
 		return;
 	}

+	if (sess->deleted == QLA_SESS_DELETION_IN_PROGRESS) {
+		qlt_24xx_send_abts_resp(vha, abts, FCP_TMF_REJECTED, false);
+		return;
+	}
+
 	rc = __qlt_24xx_handle_abts(vha, abts, sess);
 	if (rc != 0) {
 		ql_dbg(ql_dbg_tgt_mgt, vha, 0xf054,
@@ -3769,6 +3774,16 @@ static int qlt_handle_cmd_for_atio(struct scsi_qla_host *vha,
 		queue_work(qla_tgt_wq, &op->work);
 		return 0;
 	}
+
+	/* Another WWN used to have our s_id. Our PLOGI scheduled its
+	 * session deletion, but it's still in sess_del_work wq */
+	if (sess->deleted == QLA_SESS_DELETION_IN_PROGRESS) {
+		ql_dbg(ql_dbg_io, vha, 0x3061,
+		    "New command while old session %p is being deleted\n",
+		    sess);
+		return -EFAULT;
+	}
+
 	/*
 	 * Do kref_get() before returning + dropping qla_hw_data->hardware_lock.
 	 */
@@ -3932,6 +3947,9 @@ static int qlt_handle_task_mgmt(struct scsi_qla_host *vha, void *iocb)
 		    sizeof(struct atio_from_isp));
 	}

+	if (sess->deleted == QLA_SESS_DELETION_IN_PROGRESS)
+		return -EFAULT;
+
 	return qlt_issue_task_mgmt(sess, unpacked_lun, fn, iocb, 0);
 }

@@ -5606,6 +5624,11 @@ static void qlt_abort_work(struct qla_tgt *tgt,
 		if (!sess)
 			goto out_term;
 	} else {
+		if (sess->deleted == QLA_SESS_DELETION_IN_PROGRESS) {
+			sess = NULL;
+			goto out_term;
+		}
+
 		kref_get(&sess->se_sess->sess_kref);
 	}

@@ -5660,6 +5683,11 @@ static void qlt_tmr_work(struct qla_tgt *tgt,
 		if (!sess)
 			goto out_term;
 	} else {
+		if (sess->deleted == QLA_SESS_DELETION_IN_PROGRESS) {
+			sess = NULL;
+			goto out_term;
+		}
+
 		kref_get(&sess->se_sess->sess_kref);
 	}

--
1.9.1