[PATCH 20/64] fcoe: add mutex to protect create and destroy

Robert Love
2009-08-25T21:00:11Z

From: Chris Leech <christopher.leech@intel.com>

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>
---

drivers/scsi/fcoe/fcoe.c | 40 +++++++++++++++++++++++++++++++++++++++-
1 files changed, 39 insertions(+), 1 deletions(-)

diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c
index 63aeeca..43added 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);