fs: make remaining filesystems use .rename2

This is trivial to do:

 - add flags argument to foo_rename()
 - check if flags is zero
 - assign foo_rename() to .rename2 instead of .rename

This doesn't mean it's impossible to support RENAME_NOREPLACE for these
filesystems, but it is not trivial, like for local filesystems.
RENAME_NOREPLACE must guarantee atomicity (i.e. it shouldn't be possible
for a file to be created on one host while it is overwritten by rename on
another host).

Filesystems converted:

9p, afs, ceph, coda, ecryptfs, kernfs, lustre, ncpfs, nfs, ocfs2, orangefs.

After this, we can get rid of the duplicate interfaces for rename.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: David Howells <dhowells@redhat.com> [AFS]
Acked-by: Mike Marshall <hubcap@omnibond.com>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jan Harkes <jaharkes@cs.cmu.edu>
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: Oleg Drokin <oleg.drokin@intel.com>
Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: Mark Fasheh <mfasheh@suse.com>
diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c
index a8f1225..1040c10 100644
--- a/fs/ocfs2/namei.c
+++ b/fs/ocfs2/namei.c
@@ -1203,7 +1203,8 @@
 static int ocfs2_rename(struct inode *old_dir,
 			struct dentry *old_dentry,
 			struct inode *new_dir,
-			struct dentry *new_dentry)
+			struct dentry *new_dentry,
+			unsigned int flags)
 {
 	int status = 0, rename_lock = 0, parents_locked = 0, target_exists = 0;
 	int old_child_locked = 0, new_child_locked = 0, update_dot_dot = 0;
@@ -1228,6 +1229,9 @@
 	struct ocfs2_dir_lookup_result target_insert = { NULL, };
 	bool should_add_orphan = false;
 
+	if (flags)
+		return -EINVAL;
+
 	/* At some point it might be nice to break this function up a
 	 * bit. */
 
@@ -2909,7 +2913,7 @@
 	.symlink	= ocfs2_symlink,
 	.mkdir		= ocfs2_mkdir,
 	.mknod		= ocfs2_mknod,
-	.rename		= ocfs2_rename,
+	.rename2	= ocfs2_rename,
 	.setattr	= ocfs2_setattr,
 	.getattr	= ocfs2_getattr,
 	.permission	= ocfs2_permission,