locks: plumb a "priv" pointer into the setlease routines

In later patches, we're going to add a new lock_manager_operation to
finish setting up the lease while still holding the i_lock.  To do
this, we'll need to pass a little bit of info in the fcntl setlease
case (primarily an fasync structure). Plumb the extra pointer into
there in advance of that.

We declare this pointer as a void ** to make it clear that this is
private info, and that the caller isn't required to set this unless
the lm_setup specifically requires it.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index ac4f260..85c70d5 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -800,7 +800,8 @@
 	return generic_file_llseek(file, offset, whence);
 }
 
-static int cifs_setlease(struct file *file, long arg, struct file_lock **lease)
+static int
+cifs_setlease(struct file *file, long arg, struct file_lock **lease, void **priv)
 {
 	/*
 	 * Note that this is called by vfs setlease with i_lock held to
@@ -815,7 +816,7 @@
 	/* check if file is oplocked */
 	if (((arg == F_RDLCK) && CIFS_CACHE_READ(CIFS_I(inode))) ||
 	    ((arg == F_WRLCK) && CIFS_CACHE_WRITE(CIFS_I(inode))))
-		return generic_setlease(file, arg, lease);
+		return generic_setlease(file, arg, lease, priv);
 	else if (tlink_tcon(cfile->tlink)->local_lease &&
 		 !CIFS_CACHE_READ(CIFS_I(inode)))
 		/*
@@ -826,7 +827,7 @@
 		 * knows that the file won't be changed on the server by anyone
 		 * else.
 		 */
-		return generic_setlease(file, arg, lease);
+		return generic_setlease(file, arg, lease, priv);
 	else
 		return -EAGAIN;
 }