[PATCH 12/35] libfc: vport link handling and fc_vport state managment

Robert Love
2009-09-11T23:57:57Z

From: Chris Leech <christopher.leech@intel.com>

NPIV vports are managed in libfc by changing their virtual link state
when the parent N_Ports internal state changes. The vport link is only
online when the N_Port is in a ready state (logged into the fabric).

vport_state is updated as needed in this patch as well, currently the states
LINKDOWN, INITIALIZING, ACTIVE, DSIABLED, and NO_FABRIC_SUPP are used.

This also changes the fc_host port_state handling to differentiate between
LINKDOWN and OFFLINE.

Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
---

drivers/scsi/libfc/fc_lport.c | 72 +++++++++++++++++++++++++++++++--------
drivers/scsi/libfc/fc_npiv.c | 75 +++++++++++++++++++++++++++++++++++++++++
include/scsi/libfc.h | 8 ++++
3 files changed, 140 insertions(+), 15 deletions(-)

diff --git a/drivers/scsi/libfc/fc_lport.c b/drivers/scsi/libfc/fc_lport.c
index c5f50e2..2729e60 100644
--- a/drivers/scsi/libfc/fc_lport.c
+++ b/drivers/scsi/libfc/fc_lport.c
@@ -224,10 +224,18 @@ void fc_get_host_port_state(struct Scsi_Host *shost)
{
struct fc_lport *lp = shost_priv(shost);

- if (lp->link_up)
- fc_host_port_state(shost) = FC_PORTSTATE_ONLINE;
+ mutex_lock(&lp->lp_mutex);
+ if (!lp->link_up)
+ fc_host_port_state(shost) = FC_PORTSTATE_LINKDOWN;
else
- fc_host_port_state(shost) = FC_PORTSTATE_OFFLINE;
+ switch (lp->state) {
+ case LPORT_ST_READY:
+ fc_host_port_state(shost) = FC_PORTSTATE_ONLINE;
+ break;
+ default:
+ fc_host_port_state(shost) = FC_PORTSTATE_OFFLINE;
+ }
+ mutex_unlock(&lp->lp_mutex);
}
EXPORT_SYMBOL(fc_get_host_port_state);

@@ -493,40 +501,62 @@ int fc_fabric_login(struct fc_lport *lport)
EXPORT_SYMBOL(fc_fabric_login);

/**
- * fc_linkup() - Handler for transport linkup events
+ * __fc_linkup() - Handler for transport linkup events
* @lport: The lport whose link is up
+ *
+ * Locking: must be called with the lp_mutex held
*/
-void fc_linkup(struct fc_lport *lport)
+void __fc_linkup(struct fc_lport *lport)
{
- printk(KERN_INFO "libfc: Link up on port (%6x)\n",
- fc_host_port_id(lport->host));
-
- mutex_lock(&lport->lp_mutex);
if (!lport->link_up) {
lport->link_up = 1;

if (lport->state == LPORT_ST_RESET)
fc_lport_enter_flogi(lport);
}
+}
+
+/**
+ * fc_linkup() - Handler for transport linkup events
+ * @lport: The lport whose link is up
+ */
+void fc_linkup(struct fc_lport *lport)
+{
+ printk(KERN_INFO "libfc: Link up on port (%6x)\n",
+ fc_host_port_id(lport->host));
+
+ mutex_lock(&lport->lp_mutex);
+ __fc_linkup(lport);
mutex_unlock(&lport->lp_mutex);
}
EXPORT_SYMBOL(fc_linkup);

/**
- * fc_linkdown() - Handler for transport linkdown events
+ * __fc_linkdown() - Handler for transport linkdown events
* @lport: The lport whose link is down
+ *
+ * Locking: must be called with the lp_mutex held
*/
-void fc_linkdown(struct fc_lport *lport)
+void __fc_linkdown(struct fc_lport *lport)
{
- mutex_lock(&lport->lp_mutex);
- printk(KERN_INFO "libfc: Link down on port (%6x)\n",
- fc_host_port_id(lport->host));
-
if (lport->link_up) {
lport->link_up = 0;
fc_lport_enter_reset(lport);
lport->tt.fcp_cleanup(lport);
}
+}
+
+/**
+ * fc_linkdown() - Handler for transport linkdown events
+ * @lport: The lport whose link is down
+ */
+void fc_linkdown(struct fc_lport *lport)
+{
+ printk(KERN_INFO "libfc: Link down on port (%6x)\n",
+ fc_host_port_id(lport->host));
+
+ mutex_lock(&lport->lp_mutex);
+ __fc_linkdown(lport);
mutex_unlock(&lport->lp_mutex);
}
EXPORT_SYMBOL(fc_linkdown);
@@ -654,6 +684,9 @@ static void fc_lport_enter_ready(struct fc_lport *lport)
fc_lport_state(lport));

fc_lport_state_enter(lport, LPORT_ST_READY);
+ if (lport->vport)
+ fc_vport_set_state(lport->vport, FC_VPORT_ACTIVE);
+ fc_vports_linkchange(lport);

if (!lport->ptp_rp)
lport->tt.disc_start(fc_lport_disc_callback, lport);
@@ -868,7 +901,14 @@ static void fc_lport_enter_reset(struct fc_lport *lport)
FC_LPORT_DBG(lport, "Entered RESET state from %s state\n",
fc_lport_state(lport));

+ if (lport->vport) {
+ if (lport->link_up)
+ fc_vport_set_state(lport->vport, FC_VPORT_INITIALIZING);
+ else
+ fc_vport_set_state(lport->vport, FC_VPORT_LINKDOWN);
+ }
fc_lport_state_enter(lport, LPORT_ST_RESET);
+ fc_vports_linkchange(lport);
fc_lport_reset_locked(lport);
if (lport->link_up)
fc_lport_enter_flogi(lport);
@@ -887,6 +927,7 @@ static void fc_lport_enter_disabled(struct fc_lport *lport)
fc_lport_state(lport));

fc_lport_state_enter(lport, LPORT_ST_DISABLED);
+ fc_vports_linkchange(lport);
fc_lport_reset_locked(lport);
}

@@ -1330,6 +1371,7 @@ static void fc_lport_enter_logo(struct fc_lport *lport)
fc_lport_state(lport));

fc_lport_state_enter(lport, LPORT_ST_LOGO);
+ fc_vports_linkchange(lport);

fp = fc_frame_alloc(lport, sizeof(*logo));
if (!fp) {
diff --git a/drivers/scsi/libfc/fc_npiv.c b/drivers/scsi/libfc/fc_npiv.c
index 39f02c0..c68f6c7 100644
--- a/drivers/scsi/libfc/fc_npiv.c
+++ b/drivers/scsi/libfc/fc_npiv.c
@@ -84,3 +84,78 @@ struct fc_lport *fc_vport_id_lookup(struct fc_lport *n_port, u32 port_id)
return lport;
}

+/*
+ * When setting the link state of vports during an lport state change, it's
+ * necessary to hold the lp_mutex of both the N_Port and the VN_Port.
+ * This tells the lockdep engine to treat the nested locking of the VN_Port
+ * as a different lock class.
+ */
+enum libfc_lport_mutex_class {
+ LPORT_MUTEX_NORMAL = 0,
+ LPORT_MUTEX_VN_PORT = 1,
+};
+
+/**
+ * __fc_vport_setlink() - update link and status on a VN_Port
+ * @n_port: parent N_Port
+ * @vn_port: VN_Port to update
+ *
+ * Locking: must be called with both the N_Port and VN_Port lp_mutex held
+ */
+static void __fc_vport_setlink(struct fc_lport *n_port,
+ struct fc_lport *vn_port)
+{
+ struct fc_vport *vport = vn_port->vport;
+
+ if (vn_port->state == LPORT_ST_DISABLED)
+ return;
+
+ if (n_port->state == LPORT_ST_READY) {
+ if (n_port->npiv_enabled) {
+ fc_vport_set_state(vport, FC_VPORT_INITIALIZING);
+ __fc_linkup(vn_port);
+ } else {
+ fc_vport_set_state(vport, FC_VPORT_NO_FABRIC_SUPP);
+ __fc_linkdown(vn_port);
+ }
+ } else {
+ fc_vport_set_state(vport, FC_VPORT_LINKDOWN);
+ __fc_linkdown(vn_port);
+ }
+}
+
+/**
+ * fc_vport_setlink() - update link and status on a VN_Port
+ * @vn_port: virtual port to update
+ */
+void fc_vport_setlink(struct fc_lport *vn_port)
+{
+ struct fc_vport *vport = vn_port->vport;
+ struct Scsi_Host *shost = vport_to_shost(vport);
+ struct fc_lport *n_port = shost_priv(shost);
+
+ mutex_lock(&n_port->lp_mutex);
+ mutex_lock_nested(&vn_port->lp_mutex, LPORT_MUTEX_VN_PORT);
+ __fc_vport_setlink(n_port, vn_port);
+ mutex_unlock(&vn_port->lp_mutex);
+ mutex_unlock(&n_port->lp_mutex);
+}
+EXPORT_SYMBOL(fc_vport_setlink);
+
+/**
+ * fc_vports_linkchange() - change the link state of all vports
+ * @n_port: Parent N_Port that has changed state
+ *
+ * Locking: called with the n_port lp_mutex held
+ */
+void fc_vports_linkchange(struct fc_lport *n_port)
+{
+ struct fc_lport *vn_port;
+
+ list_for_each_entry(vn_port, &n_port->vports, list) {
+ mutex_lock_nested(&vn_port->lp_mutex, LPORT_MUTEX_VN_PORT);
+ __fc_vport_setlink(n_port, vn_port);
+ mutex_unlock(&vn_port->lp_mutex);
+ }
+}
+
diff --git a/include/scsi/libfc.h b/include/scsi/libfc.h
index e5078a0..015e520 100644
--- a/include/scsi/libfc.h
+++ b/include/scsi/libfc.h
@@ -788,11 +788,13 @@ int fc_fabric_login(struct fc_lport *lp);
/*
* The link is up for the given local port.
*/
+void __fc_linkup(struct fc_lport *);
void fc_linkup(struct fc_lport *);

/*
* Link is down for the given local port.
*/
+void __fc_linkdown(struct fc_lport *);
void fc_linkdown(struct fc_lport *);

/*
@@ -821,6 +823,12 @@ struct fc_lport *libfc_vport_create(struct fc_vport *vport, int privsize);
struct fc_lport *fc_vport_id_lookup(struct fc_lport *n_port, u32 port_id);

/*
+ * NPIV VN_Port link state management
+ */
+void fc_vport_setlink(struct fc_lport *vn_port);
+void fc_vports_linkchange(struct fc_lport *n_port);
+
+/*
* REMOTE PORT LAYER
*****************************/
int fc_rport_init(struct fc_lport *lp);