[PATCH AUTOSEL 4.19 14/36] scsi: lpfc: correct rcu unlock issue in lpfc_nvme_info_show

[Sasha Levin]

From: James Smart <jsmart2021@xxxxxxxxx>

[ Upstream commit 79080d349f7f58a2e86c56043a3d04184d5f294a ]

Many of the exit cases were not releasing the rcu read lock.  Corrected the
exit paths.

Signed-off-by: Dick Kennedy <dick.kennedy@xxxxxxxxxxxx>
Signed-off-by: James Smart <jsmart2021@xxxxxxxxx>
Tested-by: Bart Van Assche <bvanassche@xxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/scsi/lpfc/lpfc_attr.c | 32 +++++++++++++++++++-------------
 1 file changed, 19 insertions(+), 13 deletions(-)

diff --git a/drivers/scsi/lpfc/lpfc_attr.c b/drivers/scsi/lpfc/lpfc_attr.c
index cb19b12e7211..55cd96e2469c 100644
--- a/drivers/scsi/lpfc/lpfc_attr.c
+++ b/drivers/scsi/lpfc/lpfc_attr.c
@@ -341,7 +341,7 @@ lpfc_nvme_info_show(struct device *dev, struct device_attribute *attr,
 		  phba->sli4_hba.scsi_xri_max,
 		  lpfc_sli4_get_els_iocb_cnt(phba));
 	if (strlcat(buf, tmp, PAGE_SIZE) >= PAGE_SIZE)
-		goto buffer_done;
+		goto rcu_unlock_buf_done;
 
 	/* Port state is only one of two values for now. */
 	if (localport->port_id)
@@ -357,7 +357,7 @@ lpfc_nvme_info_show(struct device *dev, struct device_attribute *attr,
 		  wwn_to_u64(vport->fc_nodename.u.wwn),
 		  localport->port_id, statep);
 	if (strlcat(buf, tmp, PAGE_SIZE) >= PAGE_SIZE)
-		goto buffer_done;
+		goto rcu_unlock_buf_done;
 
 	list_for_each_entry(ndlp, &vport->fc_nodes, nlp_listp) {
 		nrport = NULL;
@@ -384,39 +384,39 @@ lpfc_nvme_info_show(struct device *dev, struct device_attribute *attr,
 
 		/* Tab in to show lport ownership. */
 		if (strlcat(buf, "NVME RPORT       ", PAGE_SIZE) >= PAGE_SIZE)
-			goto buffer_done;
+			goto rcu_unlock_buf_done;
 		if (phba->brd_no >= 10) {
 			if (strlcat(buf, " ", PAGE_SIZE) >= PAGE_SIZE)
-				goto buffer_done;
+				goto rcu_unlock_buf_done;
 		}
 
 		scnprintf(tmp, sizeof(tmp), "WWPN x%llx ",
 			  nrport->port_name);
 		if (strlcat(buf, tmp, PAGE_SIZE) >= PAGE_SIZE)
-			goto buffer_done;
+			goto rcu_unlock_buf_done;
 
 		scnprintf(tmp, sizeof(tmp), "WWNN x%llx ",
 			  nrport->node_name);
 		if (strlcat(buf, tmp, PAGE_SIZE) >= PAGE_SIZE)
-			goto buffer_done;
+			goto rcu_unlock_buf_done;
 
 		scnprintf(tmp, sizeof(tmp), "DID x%06x ",
 			  nrport->port_id);
 		if (strlcat(buf, tmp, PAGE_SIZE) >= PAGE_SIZE)
-			goto buffer_done;
+			goto rcu_unlock_buf_done;
 
 		/* An NVME rport can have multiple roles. */
 		if (nrport->port_role & FC_PORT_ROLE_NVME_INITIATOR) {
 			if (strlcat(buf, "INITIATOR ", PAGE_SIZE) >= PAGE_SIZE)
-				goto buffer_done;
+				goto rcu_unlock_buf_done;
 		}
 		if (nrport->port_role & FC_PORT_ROLE_NVME_TARGET) {
 			if (strlcat(buf, "TARGET ", PAGE_SIZE) >= PAGE_SIZE)
-				goto buffer_done;
+				goto rcu_unlock_buf_done;
 		}
 		if (nrport->port_role & FC_PORT_ROLE_NVME_DISCOVERY) {
 			if (strlcat(buf, "DISCSRVC ", PAGE_SIZE) >= PAGE_SIZE)
-				goto buffer_done;
+				goto rcu_unlock_buf_done;
 		}
 		if (nrport->port_role & ~(FC_PORT_ROLE_NVME_INITIATOR |
 					  FC_PORT_ROLE_NVME_TARGET |
@@ -424,12 +424,12 @@ lpfc_nvme_info_show(struct device *dev, struct device_attribute *attr,
 			scnprintf(tmp, sizeof(tmp), "UNKNOWN ROLE x%x",
 				  nrport->port_role);
 			if (strlcat(buf, tmp, PAGE_SIZE) >= PAGE_SIZE)
-				goto buffer_done;
+				goto rcu_unlock_buf_done;
 		}
 
 		scnprintf(tmp, sizeof(tmp), "%s\n", statep);
 		if (strlcat(buf, tmp, PAGE_SIZE) >= PAGE_SIZE)
-			goto buffer_done;
+			goto rcu_unlock_buf_done;
 	}
 	rcu_read_unlock();
 
@@ -491,7 +491,13 @@ lpfc_nvme_info_show(struct device *dev, struct device_attribute *attr,
 		  atomic_read(&lport->cmpl_fcp_err));
 	strlcat(buf, tmp, PAGE_SIZE);
 
-buffer_done:
+	/* RCU is already unlocked. */
+	goto buffer_done;
+
+ rcu_unlock_buf_done:
+	rcu_read_unlock();
+
+ buffer_done:
 	len = strnlen(buf, PAGE_SIZE);
 
 	if (unlikely(len >= (PAGE_SIZE - 1))) {
-- 
2.20.1