locks: introduce locks_lock_inode_wait()

Users of the locks API commonly call either posix_lock_file_wait() or
flock_lock_file_wait() depending upon the lock type.  Add a new function
locks_lock_inode_wait() which will check and call the correct function for
the type of lock passed in.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>

fs/locks.c

@@ -1881,6 +1881,30 @@ int flock_lock_inode_wait(struct inode *inode, struct file_lock *fl)
 }
 EXPORT_SYMBOL(flock_lock_inode_wait);
 
+/**
+ * locks_lock_inode_wait - Apply a lock to an inode
+ * @inode: inode of the file to apply to
+ * @fl: The lock to be applied
+ *
+ * Apply a POSIX or FLOCK style lock request to an inode.
+ */
+int locks_lock_inode_wait(struct inode *inode, struct file_lock *fl)
+{
+	int res = 0;
+	switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) {
+		case FL_POSIX:
+			res = posix_lock_inode_wait(inode, fl);
+			break;
+		case FL_FLOCK:
+			res = flock_lock_inode_wait(inode, fl);
+			break;
+		default:
+			BUG();
+	}
+	return res;
+}
+EXPORT_SYMBOL(locks_lock_inode_wait);
+
 /**
  *	sys_flock: - flock() system call.
  *	@fd: the file descriptor to lock.

include/linux/fs.h

@@ -1059,6 +1059,7 @@ extern int vfs_test_lock(struct file *, struct file_lock *);
 extern int vfs_lock_file(struct file *, unsigned int, struct file_lock *, struct file_lock *);
 extern int vfs_cancel_lock(struct file *filp, struct file_lock *fl);
 extern int flock_lock_inode_wait(struct inode *inode, struct file_lock *fl);
+extern int locks_lock_inode_wait(struct inode *inode, struct file_lock *fl);
 extern int __break_lease(struct inode *inode, unsigned int flags, unsigned int type);
 extern void lease_get_mtime(struct inode *, struct timespec *time);
 extern int generic_setlease(struct file *, long, struct file_lock **, void **priv);
@@ -1177,6 +1178,11 @@ static inline int flock_lock_inode_wait(struct inode *inode,
 	return -ENOLCK;
 }
 
+static inline int locks_lock_inode_wait(struct inode *inode, struct file_lock *fl)
+{
+	return -ENOLCK;
+}
+
 static inline int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
 {
 	return 0;
@@ -1225,6 +1231,11 @@ static inline int flock_lock_file_wait(struct file *filp, struct file_lock *fl)
 	return flock_lock_inode_wait(file_inode(filp), fl);
 }
 
+static inline int locks_lock_file_wait(struct file *filp, struct file_lock *fl)
+{
+	return locks_lock_inode_wait(file_inode(filp), fl);
+}
+
 struct fasync_struct {
 	spinlock_t		fa_lock;
 	int			magic;