1 files changed, 278 insertions, 168 deletions

diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c
index 27702097b7fc..ca098fc2a607 100644
--- a/drivers/scsi/scsi_transport_fc.c
+++ b/drivers/scsi/scsi_transport_fc.c
@@ -210,7 +210,7 @@ fc_bitfield_name_search(remote_port_roles, fc_remote_port_role_names)
 #define FC_MGMTSRVR_PORTID              0x00000a
 
 
-static void fc_timeout_blocked_rport(void *data);
+static void fc_timeout_deleted_rport(void *data);
 static void fc_scsi_scan_rport(void *data);
 static void fc_rport_terminate(struct fc_rport  *rport);
 
@@ -384,7 +384,9 @@ show_fc_rport_##field (struct class_device *cdev, char *buf)		\
         struct fc_rport *rport = transport_class_to_rport(cdev);        \
         struct Scsi_Host *shost = rport_to_shost(rport);                \
         struct fc_internal *i = to_fc_internal(shost->transportt);      \
-        if (i->f->get_rport_##field)                                    \
+        if ((i->f->get_rport_##field) &&                                \
+            !((rport->port_state == FC_PORTSTATE_BLOCKED) ||            \
+              (rport->port_state == FC_PORTSTATE_NOTPRESENT)))          \
                 i->f->get_rport_##field(rport);                         \
         return snprintf(buf, sz, format_string, cast rport->field);     \
 }
@@ -398,6 +400,9 @@ store_fc_rport_##field(struct class_device *cdev, const char *buf,	\
         struct fc_rport *rport = transport_class_to_rport(cdev);        \
         struct Scsi_Host *shost = rport_to_shost(rport);                \
         struct fc_internal *i = to_fc_internal(shost->transportt);      \
+        if ((rport->port_state == FC_PORTSTATE_BLOCKED) ||              \
+            (rport->port_state == FC_PORTSTATE_NOTPRESENT))             \
+                return -EBUSY;                                          \
         val = simple_strtoul(buf, NULL, 0);                             \
         i->f->set_rport_##field(rport, val);                            \
         return count;                                                   \
@@ -500,7 +505,29 @@ static FC_CLASS_DEVICE_ATTR(rport, supported_classes, S_IRUGO,
 
 /* Dynamic Remote Port Attributes */
 
-fc_rport_rw_attr(dev_loss_tmo, "%d\n", 20);
+/*
+ * dev_loss_tmo attribute
+ */
+fc_rport_show_function(dev_loss_tmo, "%d\n", 20, )
+static ssize_t
+store_fc_rport_dev_loss_tmo(struct class_device *cdev, const char *buf,
+                           size_t count)
+{
+        int val;
+        struct fc_rport *rport = transport_class_to_rport(cdev);
+        struct Scsi_Host *shost = rport_to_shost(rport);
+        struct fc_internal *i = to_fc_internal(shost->transportt);
+        if ((rport->port_state == FC_PORTSTATE_BLOCKED) ||
+            (rport->port_state == FC_PORTSTATE_NOTPRESENT))
+                return -EBUSY;
+        val = simple_strtoul(buf, NULL, 0);
+        if ((val < 0) || (val > SCSI_DEVICE_BLOCK_MAX_TIMEOUT))
+                return -EINVAL;
+        i->f->set_rport_dev_loss_tmo(rport, val);
+        return count;
+}
+static FC_CLASS_DEVICE_ATTR(rport, dev_loss_tmo, S_IRUGO | S_IWUSR,
+                show_fc_rport_dev_loss_tmo, store_fc_rport_dev_loss_tmo);
 
 
 /* Private Remote Port Attributes */
@@ -1214,6 +1241,25 @@ fc_remove_host(struct Scsi_Host *shost)
 }
 EXPORT_SYMBOL(fc_remove_host);
 
+/*
+ * fc_rport_tgt_remove - Removes the scsi target on the remote port
+ * @rport:      The remote port to be operated on
+ */
+static void
+fc_rport_tgt_remove(struct fc_rport *rport)
+{
+        struct Scsi_Host *shost = rport_to_shost(rport);
+
+        scsi_target_unblock(&rport->dev);
+
+        /* Stop anything on the workq */
+        if (!cancel_delayed_work(&rport->dev_loss_work))
+                flush_scheduled_work();
+        scsi_flush_work(shost);
+
+        scsi_remove_target(&rport->dev);
+}
+
 /**
  * fc_rport_create - allocates and creates a remote FC port.
  * @shost:      scsi host the remote port is connected to.
@@ -1260,7 +1306,7 @@ fc_rport_create(struct Scsi_Host *shost, int channel,
                 rport->dd_data = &rport[1];
         rport->channel = channel;
 
-        INIT_WORK(&rport->dev_loss_work, fc_timeout_blocked_rport, rport);
+        INIT_WORK(&rport->dev_loss_work, fc_timeout_deleted_rport, rport);
         INIT_WORK(&rport->scan_work, fc_scsi_scan_rport, rport);
 
         spin_lock_irqsave(shost->host_lock, flags);
@@ -1352,17 +1398,93 @@ struct fc_rport *
 fc_remote_port_add(struct Scsi_Host *shost, int channel,
         struct fc_rport_identifiers  *ids)
 {
+        struct fc_internal *fci = to_fc_internal(shost->transportt);
         struct fc_rport *rport;
         unsigned long flags;
         int match = 0;
 
+        /*
+         * Search the list of "active" rports, for an rport that has been
+         * deleted, but we've held off the real delete while the target
+         * is in a "blocked" state.
+         */
+        spin_lock_irqsave(shost->host_lock, flags);
+
+        list_for_each_entry(rport, &fc_host_rports(shost), peers) {
+
+                if ((rport->port_state == FC_PORTSTATE_BLOCKED) &&
+                        (rport->channel == channel)) {
+
+                        switch (fc_host_tgtid_bind_type(shost)) {
+                        case FC_TGTID_BIND_BY_WWPN:
+                        case FC_TGTID_BIND_NONE:
+                                if (rport->port_name == ids->port_name)
+                                        match = 1;
+                                break;
+                        case FC_TGTID_BIND_BY_WWNN:
+                                if (rport->node_name == ids->node_name)
+                                        match = 1;
+                                break;
+                        case FC_TGTID_BIND_BY_ID:
+                                if (rport->port_id == ids->port_id)
+                                        match = 1;
+                                break;
+                        }
+
+                        if (match) {
+                                struct work_struct *work = 
+                                                        &rport->dev_loss_work;
+
+                                memcpy(&rport->node_name, &ids->node_name,
+                                        sizeof(rport->node_name));
+                                memcpy(&rport->port_name, &ids->port_name,
+                                        sizeof(rport->port_name));
+                                rport->port_id = ids->port_id;
+
+                                rport->port_state = FC_PORTSTATE_ONLINE;
+                                rport->roles = ids->roles;
+
+                                spin_unlock_irqrestore(shost->host_lock, flags);
+
+                                if (fci->f->dd_fcrport_size)
+                                        memset(rport->dd_data, 0,
+                                                fci->f->dd_fcrport_size);
+
+                                /*
+                                 * If we were blocked, we were a target.
+                                 * If no longer a target, we leave the timer
+                                 * running in case the port changes roles
+                                 * prior to the timer expiring. If the timer
+                                 * fires, the target will be torn down.
+                                 */
+                                if (!(ids->roles & FC_RPORT_ROLE_FCP_TARGET))
+                                        return rport;
+
+                                /* restart the target */
+
+                                /*
+                                 * Stop the target timer first. Take no action
+                                 * on the del_timer failure as the state
+                                 * machine state change will validate the
+                                 * transaction.
+                                 */
+                                if (!cancel_delayed_work(work))
+                                        flush_scheduled_work();
+
+                                /* initiate a scan of the target */
+                                scsi_queue_work(shost, &rport->scan_work);
+
+                                return rport;
+                        }
+                }
+        }
+
+        /* Search the bindings array */
         if (likely((ids->roles & FC_RPORT_ROLE_FCP_TARGET) &&
                 (fc_host_tgtid_bind_type(shost) != FC_TGTID_BIND_NONE))) {
 
                 /* search for a matching consistent binding */
 
-                spin_lock_irqsave(shost->host_lock, flags);
-
                 list_for_each_entry(rport, &fc_host_rport_bindings(shost),
                                         peers) {
                         if (rport->channel != channel)
@@ -1392,8 +1514,6 @@ fc_remote_port_add(struct Scsi_Host *shost, int channel,
                         }
                 }
 
-                spin_unlock_irqrestore(shost->host_lock, flags);
-
                 if (match) {
                         memcpy(&rport->node_name, &ids->node_name,
                                 sizeof(rport->node_name));
@@ -1403,6 +1523,12 @@ fc_remote_port_add(struct Scsi_Host *shost, int channel,
                         rport->roles = ids->roles;
                         rport->port_state = FC_PORTSTATE_ONLINE;
 
+                        spin_unlock_irqrestore(shost->host_lock, flags);
+
+                        if (fci->f->dd_fcrport_size)
+                                memset(rport->dd_data, 0,
+                                                fci->f->dd_fcrport_size);
+
                         if (rport->roles & FC_RPORT_ROLE_FCP_TARGET)
                                 /* initiate a scan of the target */
                                 scsi_queue_work(shost, &rport->scan_work);
@@ -1411,6 +1537,8 @@ fc_remote_port_add(struct Scsi_Host *shost, int channel,
                 }
         }
 
+        spin_unlock_irqrestore(shost->host_lock, flags);
+
         /* No consistent binding found - create new remote port entry */
         rport = fc_rport_create(shost, channel, ids);
 
@@ -1419,25 +1547,6 @@ fc_remote_port_add(struct Scsi_Host *shost, int channel,
 EXPORT_SYMBOL(fc_remote_port_add);
 
 /*
- * fc_rport_tgt_remove - Removes the scsi target on the remote port
- * @rport:      The remote port to be operated on
- */
-static void
-fc_rport_tgt_remove(struct fc_rport *rport)
-{
-        struct Scsi_Host *shost = rport_to_shost(rport);
-
-        scsi_target_unblock(&rport->dev);
-
-        /* Stop anything on the workq */
-        if (!cancel_delayed_work(&rport->dev_loss_work))
-                flush_scheduled_work();
-        scsi_flush_work(shost);
-
-        scsi_remove_target(&rport->dev);
-}
-
-/*
  * fc_rport_terminate - this routine tears down and deallocates a remote port.
  * @rport:      The remote port to be terminated
  *
@@ -1470,24 +1579,44 @@ fc_rport_terminate(struct fc_rport  *rport)
  * The LLDD calls this routine to notify the transport that a remote
  * port is no longer part of the topology. Note: Although a port
  * may no longer be part of the topology, it may persist in the remote
- * ports displayed by the fc_host. This is done so that target id
- * mappings (managed via the remote port structures), are always visible
- * as long as the mapping is valid, regardless of port state,
+ * ports displayed by the fc_host. We do this under 2 conditions:
+ * - If the port was a scsi target, we delay its deletion by "blocking" it.
+ *   This allows the port to temporarily disappear, then reappear without
+ *   disrupting the SCSI device tree attached to it. During the "blocked"
+ *   period the port will still exist.
+ * - If the port was a scsi target and disappears for longer than we
+ *   expect, we'll delete the port and the tear down the SCSI device tree
+ *   attached to it. However, we want to semi-persist the target id assigned
+ *   to that port if it eventually does exist. The port structure will
+ *   remain (although with minimal information) so that the target id
+ *   bindings remails.
  *
  * If the remote port is not an FCP Target, it will be fully torn down
  * and deallocated, including the fc_remote_port class device.
  *
- * If the remote port is an FCP Target, the port structure will be
- * marked as Not Present, but will remain as long as there is a valid
- * SCSI target id mapping associated with the port structure. Validity
- * is determined by the binding type. If binding by wwpn, then the port
- * structure is always valid and will not be deallocated until the host
- * is removed.  If binding by wwnn, then the port structure is valid
- * until another port with the same node name is found in the topology.
- * If binding by port id (fc address), then the port structure is valid
- * valid until another port with the same address is identified.
+ * If the remote port is an FCP Target, the port will be placed in a
+ * temporary blocked state. From the LLDD's perspective, the rport no
+ * longer exists. From the SCSI midlayer's perspective, the SCSI target
+ * exists, but all sdevs on it are blocked from further I/O. The following
+ * is then expected:
+ *   If the remote port does not return (signaled by a LLDD call to
+ *   fc_remote_port_add()) within the dev_loss_tmo timeout, then the
+ *   scsi target is removed - killing all outstanding i/o and removing the
+ *   scsi devices attached ot it. The port structure will be marked Not
+ *   Present and be partially cleared, leaving only enough information to
+ *   recognize the remote port relative to the scsi target id binding if
+ *   it later appears.  The port will remain as long as there is a valid
+ *   binding (e.g. until the user changes the binding type or unloads the
+ *   scsi host with the binding).
  *
- * Called from interrupt or normal process context.
+ *   If the remote port returns within the dev_loss_tmo value (and matches
+ *   according to the target id binding type), the port structure will be
+ *   reused. If it is no longer a SCSI target, the target will be torn
+ *   down. If it continues to be a SCSI target, then the target will be
+ *   unblocked (allowing i/o to be resumed), and a scan will be activated
+ *   to ensure that all luns are detected.
+ *
+ * Called from normal process context only - cannot be called from interrupt.
  *
  * Notes:
  *      This routine assumes no locks are held on entry.
@@ -1495,53 +1624,20 @@ fc_rport_terminate(struct fc_rport  *rport)
 void
 fc_remote_port_delete(struct fc_rport  *rport)
 {
-        struct Scsi_Host *shost = rport_to_shost(rport);
-        unsigned long flags;
+        int timeout = rport->dev_loss_tmo;
 
-        /* If no scsi target id mapping or consistent binding type, delete it */
-        if ((rport->scsi_target_id == -1) ||
-            (fc_host_tgtid_bind_type(shost) == FC_TGTID_BIND_NONE)) {
+        /* If no scsi target id mapping, delete it */
+        if (rport->scsi_target_id == -1) {
                 fc_rport_terminate(rport);
                 return;
         }
 
-        fc_rport_tgt_remove(rport);
-
-        spin_lock_irqsave(shost->host_lock, flags);
-        list_move_tail(&rport->peers, &fc_host_rport_bindings(shost));
-        spin_unlock_irqrestore(shost->host_lock, flags);
-
-        /*
-         * Note: We do not remove or clear the hostdata area. This allows
-         *   host-specific target data to persist along with the
-         *   scsi_target_id. It's up to the host to manage it's hostdata area.
-         */
+        scsi_target_block(&rport->dev);
 
-        /*
-         * Reinitialize port attributes that may change if the port comes back.
-         */
-        rport->maxframe_size = -1;
-        rport->supported_classes = FC_COS_UNSPECIFIED;
-        rport->roles = FC_RPORT_ROLE_UNKNOWN;
-        rport->port_state = FC_PORTSTATE_NOTPRESENT;
+        /* cap the length the devices can be blocked until they are deleted */
+        schedule_delayed_work(&rport->dev_loss_work, timeout * HZ);
 
-        /* remove the identifiers that aren't used in the consisting binding */
-        switch (fc_host_tgtid_bind_type(shost)) {
-        case FC_TGTID_BIND_BY_WWPN:
-                rport->node_name = -1;
-                rport->port_id = -1;
-                break;
-        case FC_TGTID_BIND_BY_WWNN:
-                rport->port_name = -1;
-                rport->port_id = -1;
-                break;
-        case FC_TGTID_BIND_BY_ID:
-                rport->node_name = -1;
-                rport->port_name = -1;
-                break;
-        case FC_TGTID_BIND_NONE:        /* to keep compiler happy */
-                break;
-        }
+        rport->port_state = FC_PORTSTATE_BLOCKED;
 }
 EXPORT_SYMBOL(fc_remote_port_delete);
 
@@ -1574,127 +1670,140 @@ fc_remote_port_rolechg(struct fc_rport  *rport, u32 roles)
         unsigned long flags;
         int create = 0;
 
-        rport->roles = roles;
-
         spin_lock_irqsave(shost->host_lock, flags);
-        if ((rport->scsi_target_id == -1) &&
-            (rport->roles & FC_RPORT_ROLE_FCP_TARGET)) {
-                rport->scsi_target_id = fc_host->next_target_id++;
-                create = 1;
+        if (roles & FC_RPORT_ROLE_FCP_TARGET) {
+                if (rport->scsi_target_id == -1) {
+                        rport->scsi_target_id = fc_host->next_target_id++;
+                        create = 1;
+                } else if (!(rport->roles & FC_RPORT_ROLE_FCP_TARGET))
+                        create = 1;
         }
         spin_unlock_irqrestore(shost->host_lock, flags);
 
-        if (create)
+        rport->roles = roles;
+
+        if (create) {
+                /*
+                 * There may have been a delete timer running on the
+                 * port. Ensure that it is cancelled as we now know
+                 * the port is an FCP Target.
+                 * Note: we know the rport is exists and in an online
+                 *  state as the LLDD would not have had an rport
+                 *  reference to pass us.
+                 *
+                 * Take no action on the del_timer failure as the state
+                 * machine state change will validate the
+                 * transaction.
+                 */
+                if (!cancel_delayed_work(&rport->dev_loss_work))
+                        flush_scheduled_work();
+
                 /* initiate a scan of the target */
                 scsi_queue_work(shost, &rport->scan_work);
+        }
 }
 EXPORT_SYMBOL(fc_remote_port_rolechg);
 
 /**
- * fc_timeout_blocked_rport - Timeout handler for blocked remote port
- *                       that fails to return in the alloted time.
- * @data:       scsi target that failed to reappear in the alloted time.
+ * fc_timeout_deleted_rport - Timeout handler for a deleted remote port that
+ *                       was a SCSI target (thus was blocked), and failed
+ *                       to return in the alloted time.
+ * 
+ * @data:       rport target that failed to reappear in the alloted time.
  **/
 static void
-fc_timeout_blocked_rport(void  *data)
+fc_timeout_deleted_rport(void  *data)
 {
         struct fc_rport *rport = (struct fc_rport *)data;
+        struct Scsi_Host *shost = rport_to_shost(rport);
+        unsigned long flags;
 
-        rport->port_state = FC_PORTSTATE_OFFLINE;
-
-        dev_printk(KERN_ERR, &rport->dev,
-                "blocked FC remote port time out: removing target\n");
+        spin_lock_irqsave(shost->host_lock, flags);
 
         /*
-         * As this only occurs if the remote port (scsi target)
-         * went away and didn't come back - we'll remove
-         * all attached scsi devices.
+         * If the port is ONLINE, then it came back, but was no longer an
+         * FCP target. Thus we need to tear down the scsi_target on it.
          */
-        scsi_target_unblock(&rport->dev);
-        scsi_remove_target(&rport->dev);
-}
+        if (rport->port_state == FC_PORTSTATE_ONLINE) {
+                spin_unlock_irqrestore(shost->host_lock, flags);
 
-/**
- * fc_remote_port_block - temporarily block any scsi traffic to a remote port.
- * @rport:      remote port to be blocked.
- *
- * scsi lldd's with a FC transport call this routine to temporarily stop
- * all scsi traffic to a remote port. If the port is not a SCSI target,
- * no action is taken. If the port is a SCSI target, all attached devices
- * are placed into a SDEV_BLOCK state and a timer is started. The timer is
- * represents the maximum amount of time the port may be blocked. If the
- * timer expires, the port is considered non-existent and the attached
- * scsi devices will be removed.
- *
- * Called from interrupt or normal process context.
- *
- * Returns zero if successful or error if not
- *
- * Notes:
- *      This routine assumes no locks are held on entry.
- *
- *      The timeout and timer types are extracted from the fc transport 
- *      attributes from the caller's rport pointer.
- **/
-int
-fc_remote_port_block(struct fc_rport *rport)
-{
-        int timeout = rport->dev_loss_tmo;
-        struct work_struct *work = &rport->dev_loss_work;
+                dev_printk(KERN_ERR, &rport->dev,
+                        "blocked FC remote port time out: removing target\n");
 
-        if (timeout < 0 || timeout > SCSI_DEVICE_BLOCK_MAX_TIMEOUT)
-                return -EINVAL;
+                fc_rport_tgt_remove(rport);
 
-        scsi_target_block(&rport->dev);
+                return;
+        }
 
-        /* cap the length the devices can be blocked */
-        schedule_delayed_work(work, timeout * HZ);
+        if (rport->port_state != FC_PORTSTATE_BLOCKED) {
+                spin_unlock_irqrestore(shost->host_lock, flags);
+                dev_printk(KERN_ERR, &rport->dev,
+                        "blocked FC remote port time out: leaving target alone\n");
+                return;
+        }
 
-        rport->port_state = FC_PORTSTATE_BLOCKED;
-        return 0;
-}
-EXPORT_SYMBOL(fc_remote_port_block);
+        if (fc_host_tgtid_bind_type(shost) == FC_TGTID_BIND_NONE) {
+                spin_unlock_irqrestore(shost->host_lock, flags);
+                dev_printk(KERN_ERR, &rport->dev,
+                        "blocked FC remote port time out: removing target\n");
+                fc_rport_terminate(rport);
+                return;
+        }
 
-/**
- * fc_remote_port_unblock - restart any blocked scsi traffic to a remote port.
- * @rport:      remote port to be unblocked.
- *
- * scsi lld's with a FC transport call this routine to restart IO to all
- * devices associated with the caller's scsi target following a fc_target_block
- * request.  Called from interrupt or normal process context.
- *
- * Notes:
- *      This routine assumes no locks are held on entry.
- **/
- void
-fc_remote_port_unblock(struct fc_rport *rport)
-{
-        struct work_struct *work = &rport->dev_loss_work;
-        struct Scsi_Host *shost = rport_to_shost(rport);
+        dev_printk(KERN_ERR, &rport->dev,
+                "blocked FC remote port time out: removing target and "
+                "saving binding\n");
+
+        list_move_tail(&rport->peers, &fc_host_rport_bindings(shost));
 
         /*
-         * Stop the target timer first. Take no action on the del_timer
-         * failure as the state machine state change will validate the
-         * transaction.
+         * Note: We do not remove or clear the hostdata area. This allows
+         *   host-specific target data to persist along with the
+         *   scsi_target_id. It's up to the host to manage it's hostdata area.
          */
-        if (!cancel_delayed_work(work))
-                flush_scheduled_work();
 
-        if (rport->port_state == FC_PORTSTATE_OFFLINE)
-                /*
-                 * initiate a scan of the target as the target has
-                 * been torn down.
-                 */
-                scsi_queue_work(shost, &rport->scan_work);
-        else
-                scsi_target_unblock(&rport->dev);
+        /*
+         * Reinitialize port attributes that may change if the port comes back.
+         */
+        rport->maxframe_size = -1;
+        rport->supported_classes = FC_COS_UNSPECIFIED;
+        rport->roles = FC_RPORT_ROLE_UNKNOWN;
+        rport->port_state = FC_PORTSTATE_NOTPRESENT;
 
-        rport->port_state = FC_PORTSTATE_ONLINE;
+        /* remove the identifiers that aren't used in the consisting binding */
+        switch (fc_host_tgtid_bind_type(shost)) {
+        case FC_TGTID_BIND_BY_WWPN:
+                rport->node_name = -1;
+                rport->port_id = -1;
+                break;
+        case FC_TGTID_BIND_BY_WWNN:
+                rport->port_name = -1;
+                rport->port_id = -1;
+                break;
+        case FC_TGTID_BIND_BY_ID:
+                rport->node_name = -1;
+                rport->port_name = -1;
+                break;
+        case FC_TGTID_BIND_NONE:        /* to keep compiler happy */
+                break;
+        }
+
+        spin_unlock_irqrestore(shost->host_lock, flags);
+
+        /*
+         * As this only occurs if the remote port (scsi target)
+         * went away and didn't come back - we'll remove
+         * all attached scsi devices.
+         */
+        fc_rport_tgt_remove(rport);
 }
-EXPORT_SYMBOL(fc_remote_port_unblock);
 
 /**
  * fc_scsi_scan_rport - called to perform a scsi scan on a remote port.
+ *
+ * Will unblock the target (in case it went away and has now come back),
+ * then invoke a scan.
+ *
  * @data:       remote port to be scanned.
  **/
 static void
@@ -1702,6 +1811,7 @@ fc_scsi_scan_rport(void *data)
 {
         struct fc_rport *rport = (struct fc_rport *)data;
 
+        scsi_target_unblock(&rport->dev);
         scsi_scan_target(&rport->dev, rport->channel, rport->scsi_target_id,
                         SCAN_WILD_CARD, 1);
 }