[SCSI] zfcp: Fix oops when port disappears

The zfcp_port might have been removed, while the FC fast_io_fail timer
is still running and could trigger the terminate_rport_io callback.
Set the pointer to the zfcp_port to NULL and check accordingly
before using it.

Reviewed-by: Martin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

diff --git a/drivers/s390/scsi/zfcp_aux.c b/drivers/s390/scsi/zfcp_aux.c
index a00d2bb..3ac27ee 100644 (file)
--- a/drivers/s390/scsi/zfcp_aux.c
+++ b/drivers/s390/scsi/zfcp_aux.c
@@ -671,8 +671,7 @@ void zfcp_port_dequeue(struct zfcp_port *port)
        list_del(&port->list);
        write_unlock_irq(&zfcp_data.config_lock);
        if (port->rport)
-               fc_remote_port_delete(port->rport);
-       port->rport = NULL;
+               port->rport->dd_data = NULL;
        zfcp_adapter_put(port->adapter);
        sysfs_remove_group(&port->sysfs_device.kobj, &zfcp_sysfs_port_attrs);
        device_unregister(&port->sysfs_device);

diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index 3f365ac..74dee32 100644 (file)
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -172,12 +172,16 @@ static void zfcp_fsf_link_down_info_eval(struct zfcp_fsf_req *req, char *id,
                                         struct fsf_link_down_info *link_down)
 {
        struct zfcp_adapter *adapter = req->adapter;
+       unsigned long flags;
 
        if (atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED)
                return;
 
        atomic_set_mask(ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED, &adapter->status);
+
+       read_lock_irqsave(&zfcp_data.config_lock, flags);
        zfcp_scsi_schedule_rports_block(adapter);
+       read_unlock_irqrestore(&zfcp_data.config_lock, flags);
 
        if (!link_down)
                goto out;

diff --git a/drivers/s390/scsi/zfcp_scsi.c b/drivers/s390/scsi/zfcp_scsi.c
index e7d0652..e8fbeae 100644 (file)
--- a/drivers/s390/scsi/zfcp_scsi.c
+++ b/drivers/s390/scsi/zfcp_scsi.c
@@ -486,10 +486,12 @@ static void zfcp_set_rport_dev_loss_tmo(struct fc_rport *rport, u32 timeout)
  */
 static void zfcp_scsi_dev_loss_tmo_callbk(struct fc_rport *rport)
 {
-       struct zfcp_port *port = rport->dd_data;
+       struct zfcp_port *port;
 
        write_lock_irq(&zfcp_data.config_lock);
-       port->rport = NULL;
+       port = rport->dd_data;
+       if (port)
+               port->rport = NULL;
        write_unlock_irq(&zfcp_data.config_lock);
 }
 
@@ -503,9 +505,18 @@ static void zfcp_scsi_dev_loss_tmo_callbk(struct fc_rport *rport)
  */
 static void zfcp_scsi_terminate_rport_io(struct fc_rport *rport)
 {
-       struct zfcp_port *port = rport->dd_data;
+       struct zfcp_port *port;
+
+       write_lock_irq(&zfcp_data.config_lock);
+       port = rport->dd_data;
+       if (port)
+               zfcp_port_get(port);
+       write_unlock_irq(&zfcp_data.config_lock);
 
-       zfcp_erp_port_reopen(port, 0, "sctrpi1", NULL);
+       if (port) {
+               zfcp_erp_port_reopen(port, 0, "sctrpi1", NULL);
+               zfcp_port_put(port);
+       }
 }
 
 static void zfcp_scsi_rport_register(struct zfcp_port *port)
@@ -534,8 +545,10 @@ static void zfcp_scsi_rport_register(struct zfcp_port *port)
 
 static void zfcp_scsi_rport_block(struct zfcp_port *port)
 {
-       if (port->rport)
-               fc_remote_port_delete(port->rport);
+       struct fc_rport *rport = port->rport;
+
+       if (rport)
+               fc_remote_port_delete(rport);
 }
 
 void zfcp_scsi_schedule_rport_register(struct zfcp_port *port)