[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>

1 files changed, 39 insertions, 1 deletions

diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c
index 63aeeca384ba..43added0a17c 100644
--- 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);