From: Saurav Kashyap <skashyap@marvell.com>
Date: Fri, 23 Aug 2019 02:52:43 -0700
Subject: scsi: qedf: Fix race betwen fipvlan request and response path
Patch-mainline: v5.4-rc1
Git-commit: 3480e7a8c8e47a6ee101ab722c58d61761b67e4a
References: bsc#1149976

There is a race b/w fipvlan request and response path:

=====
qedf_fcoe_process_vlan_resp:113]:2: VLAN response, vid=0xffd.
qedf_initiate_fipvlan_req:165]:2: vlan = 0x6ffd already set.
qedf_set_vlan_id:139]:2: Setting vlan_id=0ffd prio=3.
======

The request thread sees that vlan is already set and fails to call
ctrl_link_up.

Fix:

 - While setting vlan_id use local variable and before setting vlan_id.

 - Call fcoe_ctlr_link_up in next iteration of fipvlan request.

Signed-off-by: Saurav Kashyap <skashyap@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Lee Duncan <lduncan@suse.com>
---
 drivers/scsi/qedf/qedf_main.c | 25 ++++++++++++-------------
 1 file changed, 12 insertions(+), 13 deletions(-)

diff --git a/drivers/scsi/qedf/qedf_main.c b/drivers/scsi/qedf/qedf_main.c
index 0856d136bab6..9c24f3834d70 100644
--- a/drivers/scsi/qedf/qedf_main.c
+++ b/drivers/scsi/qedf/qedf_main.c
@@ -111,16 +111,18 @@ static struct kmem_cache *qedf_io_work_cache;
 
 void qedf_set_vlan_id(struct qedf_ctx *qedf, int vlan_id)
 {
-	qedf->vlan_id = vlan_id;
-	qedf->vlan_id |= qedf->prio << VLAN_PRIO_SHIFT;
-	QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_DISC, "Setting vlan_id=%04x "
-		   "prio=%d.\n", vlan_id, qedf->prio);
+	int vlan_id_tmp = 0;
+
+	vlan_id_tmp = vlan_id  | (qedf->prio << VLAN_PRIO_SHIFT);
+	qedf->vlan_id = vlan_id_tmp;
+	QEDF_INFO(&qedf->dbg_ctx, QEDF_LOG_DISC,
+		  "Setting vlan_id=0x%04x prio=%d.\n",
+		  vlan_id_tmp, qedf->prio);
 }
 
 /* Returns true if we have a valid vlan, false otherwise */
 static bool qedf_initiate_fipvlan_req(struct qedf_ctx *qedf)
 {
-	int rc;
 
 	while (qedf->fipvlan_retries--) {
 		/* This is to catch if link goes down during fipvlan retries */
@@ -136,7 +138,10 @@ static bool qedf_initiate_fipvlan_req(struct qedf_ctx *qedf)
 
 		if (qedf->vlan_id > 0) {
 			QEDF_INFO(&qedf->dbg_ctx, QEDF_LOG_DISC,
-				  "vlan = 0x%x already set.\n", qedf->vlan_id);
+				  "vlan = 0x%x already set, calling ctlr_link_up.\n",
+				  qedf->vlan_id);
+			if (atomic_read(&qedf->link_state) == QEDF_LINK_UP)
+				fcoe_ctlr_link_up(&qedf->ctlr);
 			return true;
 		}
 
@@ -144,13 +149,7 @@ static bool qedf_initiate_fipvlan_req(struct qedf_ctx *qedf)
 			   "Retry %d.\n", qedf->fipvlan_retries);
 		init_completion(&qedf->fipvlan_compl);
 		qedf_fcoe_send_vlan_req(qedf);
-		rc = wait_for_completion_timeout(&qedf->fipvlan_compl,
-		    1 * HZ);
-		if (rc > 0 &&
-		    (atomic_read(&qedf->link_state) == QEDF_LINK_UP)) {
-			fcoe_ctlr_link_up(&qedf->ctlr);
-			return true;
-		}
+		wait_for_completion_timeout(&qedf->fipvlan_compl, 1 * HZ);
 	}
 
 	return false;