[SCSI] fcoe: add mutex to protect create and destroy

Rather than rely on the hostlist_lock to be held while creating exchange
managers, serialize fcoe instance creation and destruction with a mutex.
This will allow the hostlist addition to be moved out of fcoe_if_create(),
which will simplify NPIV support.

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

diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c
index 63aeeca..43added 100644 (file)
--- a/drivers/scsi/fcoe/fcoe.c
+++ b/drivers/scsi/fcoe/fcoe.c
@@ -55,6 +55,8 @@ module_param_named(ddp_min, fcoe_ddp_min, uint, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(ddp_min, "Minimum I/O size in bytes for "     \
                 "Direct Data Placement (DDP).");
 
+DEFINE_MUTEX(fcoe_config_mutex);
+
 /* fcoe host list */
 LIST_HEAD(fcoe_hostlist);
 DEFINE_RWLOCK(fcoe_hostlist_lock);
@@ -811,6 +813,7 @@ static int __init fcoe_if_init(void)
 int __exit fcoe_if_exit(void)
 {
        fc_release_transport(scsi_transport_fcoe_sw);
+       scsi_transport_fcoe_sw = NULL;
        return 0;
 }
 
@@ -1686,6 +1689,19 @@ static int fcoe_destroy(const char *buffer, struct kernel_param *kp)
        struct fc_lport *lport;
        int rc;
 
+       mutex_lock(&fcoe_config_mutex);
+#ifdef CONFIG_FCOE_MODULE
+       /*
+        * Make sure the module has been initialized, and is not about to be
+        * removed.  Module paramter sysfs files are writable before the
+        * module_init function is called and after module_exit.
+        */
+       if (THIS_MODULE->state != MODULE_STATE_LIVE) {
+               rc = -ENODEV;
+               goto out_nodev;
+       }
+#endif
+
        netdev = fcoe_if_to_netdev(buffer);
        if (!netdev) {
                rc = -ENODEV;
@@ -1705,6 +1721,7 @@ static int fcoe_destroy(const char *buffer, struct kernel_param *kp)
 out_putdev:
        dev_put(netdev);
 out_nodev:
+       mutex_unlock(&fcoe_config_mutex);
        return rc;
 }
 
@@ -1722,6 +1739,19 @@ static int fcoe_create(const char *buffer, struct kernel_param *kp)
        struct fc_lport *lport;
        struct net_device *netdev;
 
+       mutex_lock(&fcoe_config_mutex);
+#ifdef CONFIG_FCOE_MODULE
+       /*
+        * Make sure the module has been initialized, and is not about to be
+        * removed.  Module paramter sysfs files are writable before the
+        * module_init function is called and after module_exit.
+        */
+       if (THIS_MODULE->state != MODULE_STATE_LIVE) {
+               rc = -ENODEV;
+               goto out_nodev;
+       }
+#endif
+
        netdev = fcoe_if_to_netdev(buffer);
        if (!netdev) {
                rc = -ENODEV;
@@ -1768,6 +1798,7 @@ out_free:
 out_putdev:
        dev_put(netdev);
 out_nodev:
+       mutex_unlock(&fcoe_config_mutex);
        return rc;
 }
 
@@ -1971,6 +2002,8 @@ static int __init fcoe_init(void)
        int rc = 0;
        struct fcoe_percpu_s *p;
 
+       mutex_lock(&fcoe_config_mutex);
+
        for_each_possible_cpu(cpu) {
                p = &per_cpu(fcoe_percpu, cpu);
                skb_queue_head_init(&p->fcoe_rx_list);
@@ -1991,13 +2024,14 @@ static int __init fcoe_init(void)
        if (rc)
                goto out_free;
 
+       mutex_unlock(&fcoe_config_mutex);
        return 0;
 
 out_free:
        for_each_online_cpu(cpu) {
                fcoe_percpu_thread_destroy(cpu);
        }
-
+       mutex_unlock(&fcoe_config_mutex);
        return rc;
 }
 module_init(fcoe_init);
@@ -2012,6 +2046,8 @@ static void __exit fcoe_exit(void)
        unsigned int cpu;
        struct fcoe_interface *fcoe, *tmp;
 
+       mutex_lock(&fcoe_config_mutex);
+
        fcoe_dev_cleanup();
 
        /* releases the associated fcoe hosts */
@@ -2025,5 +2061,7 @@ static void __exit fcoe_exit(void)
 
        /* detach from scsi transport */
        fcoe_if_exit();
+
+       mutex_unlock(&fcoe_config_mutex);
 }
 module_exit(fcoe_exit);