From dd167cef787e435604d9553b022a8328b8c167dc Mon Sep 17 00:00:00 2001
From: Himanshu Madhani <hmadhani@redhat.com>
Date: Thu, 1 Aug 2019 15:54:26 -0400
Subject: [PATCH 006/124] [scsi] scsi: qla2xxx: Fix session cleanup hang

Message-id: <20190801155618.12650-7-hmadhani@redhat.com>
Patchwork-id: 267790
O-Subject: [RHEL 7.8 e-stor PATCH 006/118] scsi: qla2xxx: Fix session cleanup hang
Bugzilla: 1729270
RH-Acked-by: Jarod Wilson <jarod@redhat.com>
RH-Acked-by: Tony Camuso <tcamuso@redhat.com>

From: Quinn Tran <quinn.tran@cavium.com>

Bugzilla 1729270

On session cleanup, either an implicit LOGO or an implicit PRLO is used to
flush IOs.  If the flush command hit Queue Full condition, then it is
dropped.  This patch adds retry code to prevent command drop.

Signed-off-by: Quinn Tran <quinn.tran@cavium.com>
Signed-off-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
(cherry picked from commit 80676d054e5a945f8192802b68093764fbf3c5fc)
Signed-off-by: Himanshu Madhani <hmadhani@redhat.com>
Signed-off-by: Jan Stancek <jstancek@redhat.com>
---
 drivers/scsi/qla2xxx/qla_iocb.c |  5 ++---
 drivers/scsi/qla2xxx/qla_os.c   | 17 +++++++++++++----
 2 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/drivers/scsi/qla2xxx/qla_iocb.c b/drivers/scsi/qla2xxx/qla_iocb.c
index b0ab5d362f64..348d9d3bf590 100644
--- a/drivers/scsi/qla2xxx/qla_iocb.c
+++ b/drivers/scsi/qla2xxx/qla_iocb.c
@@ -3716,23 +3716,22 @@ qla24xx_prlo_iocb(srb_t *sp, struct logio_entry_24xx *logio)
 int
 qla2x00_start_sp(srb_t *sp)
 {
-	int rval;
+	int rval = QLA_SUCCESS;
 	scsi_qla_host_t *vha = sp->vha;
 	struct qla_hw_data *ha = vha->hw;
 	struct qla_qpair *qp = sp->qpair;
 	void *pkt;
 	unsigned long flags;
 
-	rval = QLA_FUNCTION_FAILED;
 	spin_lock_irqsave(qp->qp_lock_ptr, flags);
 	pkt = __qla2x00_alloc_iocbs(sp->qpair, sp);
 	if (!pkt) {
+		rval = EAGAIN;
 		ql_log(ql_log_warn, vha, 0x700c,
 		    "qla2x00_alloc_iocbs failed.\n");
 		goto done;
 	}
 
-	rval = QLA_SUCCESS;
 	switch (sp->type) {
 	case SRB_LOGIN_CMD:
 		IS_FWI2_CAPABLE(ha) ?
diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index 399a9072ae02..ee09796b9847 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -5298,14 +5298,14 @@ qla2x00_do_work(struct scsi_qla_host *vha)
 	struct qla_work_evt *e, *tmp;
 	unsigned long flags;
 	LIST_HEAD(work);
+	int rc;
 
 	spin_lock_irqsave(&vha->work_lock, flags);
 	list_splice_init(&vha->work_list, &work);
 	spin_unlock_irqrestore(&vha->work_lock, flags);
 
 	list_for_each_entry_safe(e, tmp, &work, list) {
-		list_del_init(&e->list);
-
+		rc = QLA_SUCCESS;
 		switch (e->type) {
 		case QLA_EVT_AEN:
 			fc_host_post_event(vha->host, fc_get_event_number(),
@@ -5319,7 +5319,7 @@ qla2x00_do_work(struct scsi_qla_host *vha)
 			    e->u.logio.data);
 			break;
 		case QLA_EVT_ASYNC_LOGOUT:
-			qla2x00_async_logout(vha, e->u.logio.fcport);
+			rc = qla2x00_async_logout(vha, e->u.logio.fcport);
 			break;
 		case QLA_EVT_ASYNC_LOGOUT_DONE:
 			qla2x00_async_logout_done(vha, e->u.logio.fcport,
@@ -5364,7 +5364,7 @@ qla2x00_do_work(struct scsi_qla_host *vha)
 			qla24xx_do_nack_work(vha, e);
 			break;
 		case QLA_EVT_ASYNC_PRLO:
-			qla2x00_async_prlo(vha, e->u.logio.fcport);
+			rc = qla2x00_async_prlo(vha, e->u.logio.fcport);
 			break;
 		case QLA_EVT_ASYNC_PRLO_DONE:
 			qla2x00_async_prlo_done(vha, e->u.logio.fcport,
@@ -5397,6 +5397,15 @@ qla2x00_do_work(struct scsi_qla_host *vha)
 			    e->u.fcport.fcport, false);
 			break;
 		}
+
+		if (rc == EAGAIN) {
+			/* put 'work' at head of 'vha->work_list' */
+			spin_lock_irqsave(&vha->work_lock, flags);
+			list_splice(&work, &vha->work_list);
+			spin_unlock_irqrestore(&vha->work_lock, flags);
+			break;
+		}
+		list_del_init(&e->list);
 		if (e->flags & QLA_EVT_FLAG_FREE)
 			kfree(e);
 
-- 
2.13.6