FAILED: patch "[PATCH] scsi: qla2xxx: Fix loss of NVMe namespaces after driver" failed to apply to 5.15-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From db212f2eb3fb7f546366777e93c8f54614d39269 Mon Sep 17 00:00:00 2001
From: Arun Easi <aeasi@marvell.com>
Date: Thu, 10 Mar 2022 01:25:54 -0800
Subject: [PATCH] scsi: qla2xxx: Fix loss of NVMe namespaces after driver
 reload test

Driver registration of localport can race when it happens at the remote
port discovery time. Fix this by calling the registration under a mutex.

Link: https://lore.kernel.org/r/20220310092604.22950-4-njavali@marvell.com
Fixes: e84067d74301 ("scsi: qla2xxx: Add FC-NVMe F/W initialization and transport registration")
Cc: stable@vger.kernel.org
Reported-by: Marco Patalano <mpatalan@redhat.com>
Tested-by: Marco Patalano <mpatalan@redhat.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Arun Easi <aeasi@marvell.com>
Signed-off-by: Nilesh Javali <njavali@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/qla2xxx/qla_nvme.c b/drivers/scsi/qla2xxx/qla_nvme.c
index 5723082d94d6..3bf5cbd754a7 100644
--- a/drivers/scsi/qla2xxx/qla_nvme.c
+++ b/drivers/scsi/qla2xxx/qla_nvme.c
@@ -782,8 +782,6 @@ int qla_nvme_register_hba(struct scsi_qla_host *vha)
 	ha = vha->hw;
 	tmpl = &qla_nvme_fc_transport;
 
-	WARN_ON(vha->nvme_local_port);
-
 	if (ql2xnvme_queues < MIN_NVME_HW_QUEUES || ql2xnvme_queues > MAX_NVME_HW_QUEUES) {
 		ql_log(ql_log_warn, vha, 0xfffd,
 		    "ql2xnvme_queues=%d is out of range(MIN:%d - MAX:%d). Resetting ql2xnvme_queues to:%d\n",
@@ -797,7 +795,7 @@ int qla_nvme_register_hba(struct scsi_qla_host *vha)
 		(uint8_t)(ha->max_qpairs ? ha->max_qpairs : 1));
 
 	ql_log(ql_log_info, vha, 0xfffb,
-	    "Number of NVME queues used for this port: %d\n",
+	       "Number of NVME queues used for this port: %d\n",
 	    qla_nvme_fc_transport.max_hw_queues);
 
 	pinfo.node_name = wwn_to_u64(vha->node_name);
@@ -805,13 +803,25 @@ int qla_nvme_register_hba(struct scsi_qla_host *vha)
 	pinfo.port_role = FC_PORT_ROLE_NVME_INITIATOR;
 	pinfo.port_id = vha->d_id.b24;
 
-	ql_log(ql_log_info, vha, 0xffff,
-	    "register_localport: host-traddr=nn-0x%llx:pn-0x%llx on portID:%x\n",
-	    pinfo.node_name, pinfo.port_name, pinfo.port_id);
-	qla_nvme_fc_transport.dma_boundary = vha->host->dma_boundary;
-
-	ret = nvme_fc_register_localport(&pinfo, tmpl,
-	    get_device(&ha->pdev->dev), &vha->nvme_local_port);
+	mutex_lock(&ha->vport_lock);
+	/*
+	 * Check again for nvme_local_port to see if any other thread raced
+	 * with this one and finished registration.
+	 */
+	if (!vha->nvme_local_port) {
+		ql_log(ql_log_info, vha, 0xffff,
+		    "register_localport: host-traddr=nn-0x%llx:pn-0x%llx on portID:%x\n",
+		    pinfo.node_name, pinfo.port_name, pinfo.port_id);
+		qla_nvme_fc_transport.dma_boundary = vha->host->dma_boundary;
+
+		ret = nvme_fc_register_localport(&pinfo, tmpl,
+						 get_device(&ha->pdev->dev),
+						 &vha->nvme_local_port);
+		mutex_unlock(&ha->vport_lock);
+	} else {
+		mutex_unlock(&ha->vport_lock);
+		return 0;
+	}
 	if (ret) {
 		ql_log(ql_log_warn, vha, 0xffff,
 		    "register_localport failed: ret=%x\n", ret);