[SCSI] Merge scsi-misc-2.6 into scsi-rc-fixes-2.6

[safe/jmp/linux-2.6] / drivers / scsi / fcoe / fcoe.c

diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c
index 4834d3c..ba75a98 100644 (file)
--- a/drivers/scsi/fcoe/fcoe.c
+++ b/drivers/scsi/fcoe/fcoe.c
@@ -801,6 +801,12 @@ skip_oem:
 /**
  * fcoe_if_destroy() - Tear down a SW FCoE instance
  * @lport: The local port to be destroyed
+ *
+ * Locking: must be called with the RTNL mutex held and RTNL mutex
+ * needed to be dropped by this function since not dropping RTNL
+ * would cause circular locking warning on synchronous fip worker
+ * cancelling thru fcoe_interface_put invoked by this function.
+ *
  */
 static void fcoe_if_destroy(struct fc_lport *lport)
 {
@@ -823,7 +829,6 @@ static void fcoe_if_destroy(struct fc_lport *lport)
        /* Free existing transmit skbs */
        fcoe_clean_pending_queue(lport);
 
-       rtnl_lock();
        if (!is_zero_ether_addr(port->data_src_addr))
                dev_unicast_delete(netdev, port->data_src_addr);
        rtnl_unlock();
@@ -846,6 +851,7 @@ static void fcoe_if_destroy(struct fc_lport *lport)
 
        /* Release the Scsi_Host */
        scsi_host_put(lport->host);
+       module_put(THIS_MODULE);
 }
 
 /**
@@ -1902,7 +1908,12 @@ static int fcoe_disable(const char *buffer, struct kernel_param *kp)
                goto out_nodev;
        }
 
-       rtnl_lock();
+       if (!rtnl_trylock()) {
+               dev_put(netdev);
+               mutex_unlock(&fcoe_config_mutex);
+               return restart_syscall();
+       }
+
        fcoe = fcoe_hostlist_lookup_port(netdev);
        rtnl_unlock();
 
@@ -1952,7 +1963,12 @@ static int fcoe_enable(const char *buffer, struct kernel_param *kp)
                goto out_nodev;
        }
 
-       rtnl_lock();
+       if (!rtnl_trylock()) {
+               dev_put(netdev);
+               mutex_unlock(&fcoe_config_mutex);
+               return restart_syscall();
+       }
+
        fcoe = fcoe_hostlist_lookup_port(netdev);
        rtnl_unlock();
 
@@ -2003,7 +2019,12 @@ static int fcoe_destroy(const char *buffer, struct kernel_param *kp)
                goto out_nodev;
        }
 
-       rtnl_lock();
+       if (!rtnl_trylock()) {
+               dev_put(netdev);
+               mutex_unlock(&fcoe_config_mutex);
+               return restart_syscall();
+       }
+
        fcoe = fcoe_hostlist_lookup_port(netdev);
        if (!fcoe) {
                rtnl_unlock();
@@ -2012,9 +2033,8 @@ static int fcoe_destroy(const char *buffer, struct kernel_param *kp)
        }
        list_del(&fcoe->list);
        fcoe_interface_cleanup(fcoe);
-       rtnl_unlock();
+       /* RTNL mutex is dropped by fcoe_if_destroy */
        fcoe_if_destroy(fcoe->ctlr.lp);
-       module_put(THIS_MODULE);
 
 out_putdev:
        dev_put(netdev);
@@ -2033,6 +2053,8 @@ static void fcoe_destroy_work(struct work_struct *work)
 
        port = container_of(work, struct fcoe_port, destroy_work);
        mutex_lock(&fcoe_config_mutex);
+       rtnl_lock();
+       /* RTNL mutex is dropped by fcoe_if_destroy */
        fcoe_if_destroy(port->lport);
        mutex_unlock(&fcoe_config_mutex);
 }
@@ -2054,6 +2076,12 @@ static int fcoe_create(const char *buffer, struct kernel_param *kp)
        struct net_device *netdev;
 
        mutex_lock(&fcoe_config_mutex);
+
+       if (!rtnl_trylock()) {
+               mutex_unlock(&fcoe_config_mutex);
+               return restart_syscall();
+       }
+
 #ifdef CONFIG_FCOE_MODULE
        /*
         * Make sure the module has been initialized, and is not about to be
@@ -2071,7 +2099,6 @@ static int fcoe_create(const char *buffer, struct kernel_param *kp)
                goto out_nomod;
        }
 
-       rtnl_lock();
        netdev = fcoe_if_to_netdev(buffer);
        if (!netdev) {
                rc = -ENODEV;
@@ -2126,9 +2153,9 @@ out_free:
 out_putdev:
        dev_put(netdev);
 out_nodev:
-       rtnl_unlock();
        module_put(THIS_MODULE);
 out_nomod:
+       rtnl_unlock();
        mutex_unlock(&fcoe_config_mutex);
        return rc;
 }