locks: turn lock_flocks into a spinlock

Nothing depends on lock_flocks using the BKL
any more, so we can do the switch over to
a private spinlock.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/fs/locks.c b/fs/locks.c
index 85fd9ce..74c3df9 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -142,6 +142,7 @@
 
 static LIST_HEAD(file_lock_list);
 static LIST_HEAD(blocked_list);
+static DEFINE_SPINLOCK(file_lock_lock);
 
 /*
  * Protects the two list heads above, plus the inode->i_flock list
@@ -149,13 +150,13 @@
  */
 void lock_flocks(void)
 {
-	lock_kernel();
+	spin_lock(&file_lock_lock);
 }
 EXPORT_SYMBOL_GPL(lock_flocks);
 
 void unlock_flocks(void)
 {
-	unlock_kernel();
+	spin_unlock(&file_lock_lock);
 }
 EXPORT_SYMBOL_GPL(unlock_flocks);