bonding: remove bonding read/write semaphore

The whole read/write semaphore locking can be removed. It doesn't add any
protection that isn't already done by using the RTNL mutex properly.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 20 deletions

diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
index 1172fe649352..8041b6793532 100644
--- a/drivers/net/bonding/bond_sysfs.c
+++ b/drivers/net/bonding/bond_sysfs.c
@@ -44,20 +44,6 @@
 /*---------------------------- Declarations -------------------------------*/
 
 static int expected_refcount = -1;
-/*--------------------------- Data Structures -----------------------------*/
-
-/* Bonding sysfs lock.  Why can't we just use the subsystem lock?
- * Because kobject_register tries to acquire the subsystem lock.  If
- * we already hold the lock (which we would if the user was creating
- * a new bond through the sysfs interface), we deadlock.
- * This lock is only needed when deleting a bond - we need to make sure
- * that we don't collide with an ongoing ioctl.
- */
-
-struct rw_semaphore bonding_rwsem;
-
-
-
 
 /*------------------------------ Functions --------------------------------*/
 
@@ -70,7 +56,7 @@ static ssize_t bonding_show_bonds(struct class *cls, char *buf)
         int res = 0;
         struct bonding *bond;
 
-        down_read(&(bonding_rwsem));
+        rtnl_lock();
 
         list_for_each_entry(bond, &bond_dev_list, bond_list) {
                 if (res > (PAGE_SIZE - IFNAMSIZ)) {
@@ -84,7 +70,8 @@ static ssize_t bonding_show_bonds(struct class *cls, char *buf)
         }
         if (res)
                 buf[res-1] = '\n'; /* eat the leftover space */
-        up_read(&(bonding_rwsem));
+
+        rtnl_unlock();
         return res;
 }
 
@@ -122,7 +109,6 @@ static ssize_t bonding_store_bonds(struct class *cls, const char *buffer, size_t
 
         if (command[0] == '-') {
                 rtnl_lock();
-                down_write(&bonding_rwsem);
 
                 list_for_each_entry(bond, &bond_dev_list, bond_list)
                         if (strnicmp(bond->dev->name, ifname, IFNAMSIZ) == 0) {
@@ -157,7 +143,6 @@ err_no_cmd:
         return -EPERM;
 
 out_unlock:
-        up_write(&bonding_rwsem);
         rtnl_unlock();
 
         /* Always return either count or an error.  If you return 0, you'll
@@ -253,7 +238,6 @@ static ssize_t bonding_store_slaves(struct device *d,
 
         if (!rtnl_trylock())
                 return restart_syscall();
-        down_write(&(bonding_rwsem));
 
         sscanf(buffer, "%16s", command); /* IFNAMSIZ*/
         ifname = command + 1;
@@ -357,7 +341,6 @@ err_no_cmd:
         ret = -EPERM;
 
 out:
-        up_write(&(bonding_rwsem));
         rtnl_unlock();
         return ret;
 }