[PATCH 4.18 32/53] scsi: lpfc: Synchronize access to remoteport via rport

Greg Kroah-Hartman
2018-10-18T17:57:49Z

From: James Smart <jsmart2021@gmail.com>

[ Upstream commit 9e210178267b80c4eeb832fade7e146a18c84915 ]

The driver currently uses the ndlp to get the local rport which is then used
to get the nvme transport remoteport pointer. There can be cases where a stale
remoteport pointer is obtained as synchronization isn't done through the
different dereferences.

Correct by using locks to synchronize the dereferences.

Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/scsi/lpfc/lpfc_attr.c | 15 ++++++++++-----
drivers/scsi/lpfc/lpfc_debugfs.c | 10 +++++-----
drivers/scsi/lpfc/lpfc_nvme.c | 11 ++++++++---
3 files changed, 23 insertions(+), 13 deletions(-)

--- a/drivers/scsi/lpfc/lpfc_attr.c
+++ b/drivers/scsi/lpfc/lpfc_attr.c
@@ -320,12 +320,12 @@ lpfc_nvme_info_show(struct device *dev,
localport->port_id, statep);

list_for_each_entry(ndlp, &vport->fc_nodes, nlp_listp) {
+ nrport = NULL;
+ spin_lock(&vport->phba->hbalock);
rport = lpfc_ndlp_get_nrport(ndlp);
- if (!rport)
- continue;
-
- /* local short-hand pointer. */
- nrport = rport->remoteport;
+ if (rport)
+ nrport = rport->remoteport;
+ spin_unlock(&vport->phba->hbalock);
if (!nrport)
continue;

@@ -3304,6 +3304,7 @@ lpfc_update_rport_devloss_tmo(struct lpf
struct lpfc_nodelist *ndlp;
#if (IS_ENABLED(CONFIG_NVME_FC))
struct lpfc_nvme_rport *rport;
+ struct nvme_fc_remote_port *remoteport = NULL;
#endif

shost = lpfc_shost_from_vport(vport);
@@ -3314,8 +3315,12 @@ lpfc_update_rport_devloss_tmo(struct lpf
if (ndlp->rport)
ndlp->rport->dev_loss_tmo = vport->cfg_devloss_tmo;
#if (IS_ENABLED(CONFIG_NVME_FC))
+ spin_lock(&vport->phba->hbalock);
rport = lpfc_ndlp_get_nrport(ndlp);
if (rport)
+ remoteport = rport->remoteport;
+ spin_unlock(&vport->phba->hbalock);
+ if (remoteport)
nvme_fc_set_remoteport_devloss(rport->remoteport,
vport->cfg_devloss_tmo);
#endif
--- a/drivers/scsi/lpfc/lpfc_debugfs.c
+++ b/drivers/scsi/lpfc/lpfc_debugfs.c
@@ -551,7 +551,7 @@ lpfc_debugfs_nodelist_data(struct lpfc_v
unsigned char *statep;
struct nvme_fc_local_port *localport;
struct lpfc_nvmet_tgtport *tgtp;
- struct nvme_fc_remote_port *nrport;
+ struct nvme_fc_remote_port *nrport = NULL;
struct lpfc_nvme_rport *rport;

cnt = (LPFC_NODELIST_SIZE / LPFC_NODELIST_ENTRY_SIZE);
@@ -696,11 +696,11 @@ lpfc_debugfs_nodelist_data(struct lpfc_v
len += snprintf(buf + len, size - len, "\tRport List:\n");
list_for_each_entry(ndlp, &vport->fc_nodes, nlp_listp) {
/* local short-hand pointer. */
+ spin_lock(&phba->hbalock);
rport = lpfc_ndlp_get_nrport(ndlp);
- if (!rport)
- continue;
-
- nrport = rport->remoteport;
+ if (rport)
+ nrport = rport->remoteport;
+ spin_unlock(&phba->hbalock);
if (!nrport)
continue;

--- a/drivers/scsi/lpfc/lpfc_nvme.c
+++ b/drivers/scsi/lpfc/lpfc_nvme.c
@@ -2718,7 +2718,9 @@ lpfc_nvme_register_port(struct lpfc_vpor
rpinfo.port_name = wwn_to_u64(ndlp->nlp_portname.u.wwn);
rpinfo.node_name = wwn_to_u64(ndlp->nlp_nodename.u.wwn);

+ spin_lock_irq(&vport->phba->hbalock);
oldrport = lpfc_ndlp_get_nrport(ndlp);
+ spin_unlock_irq(&vport->phba->hbalock);
if (!oldrport)
lpfc_nlp_get(ndlp);

@@ -2833,7 +2835,7 @@ lpfc_nvme_unregister_port(struct lpfc_vp
struct nvme_fc_local_port *localport;
struct lpfc_nvme_lport *lport;
struct lpfc_nvme_rport *rport;
- struct nvme_fc_remote_port *remoteport;
+ struct nvme_fc_remote_port *remoteport = NULL;

localport = vport->localport;

@@ -2847,11 +2849,14 @@ lpfc_nvme_unregister_port(struct lpfc_vp
if (!lport)
goto input_err;

+ spin_lock_irq(&vport->phba->hbalock);
rport = lpfc_ndlp_get_nrport(ndlp);
- if (!rport)
+ if (rport)
+ remoteport = rport->remoteport;
+ spin_unlock_irq(&vport->phba->hbalock);
+ if (!remoteport)
goto input_err;

- remoteport = rport->remoteport;
lpfc_printf_vlog(vport, KERN_INFO, LOG_NVME_DISC,
"6033 Unreg nvme remoteport %p, portname x%llx, "
"port_id x%06x, portstate x%x port type x%x\n",