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/coda/dir.c b/fs/coda/dir.c
index 6fb8672..5d79c26 100644
--- a/fs/coda/dir.c
+++ b/fs/coda/dir.c
@@ -291,7 +291,8 @@
 
 /* rename */
 static int coda_rename(struct inode *old_dir, struct dentry *old_dentry,
-		       struct inode *new_dir, struct dentry *new_dentry)
+		       struct inode *new_dir, struct dentry *new_dentry,
+		       unsigned int flags)
 {
 	const char *old_name = old_dentry->d_name.name;
 	const char *new_name = new_dentry->d_name.name;
@@ -299,6 +300,9 @@
 	int new_length = new_dentry->d_name.len;
 	int error;
 
+	if (flags)
+		return -EINVAL;
+
 	error = venus_rename(old_dir->i_sb, coda_i2f(old_dir),
 			     coda_i2f(new_dir), old_length, new_length,
 			     (const char *) old_name, (const char *)new_name);
@@ -569,7 +573,7 @@
 	.mkdir		= coda_mkdir,
 	.rmdir		= coda_rmdir,
 	.mknod		= CODA_EIO_ERROR,
-	.rename		= coda_rename,
+	.rename2	= coda_rename,
 	.permission	= coda_permission,
 	.getattr	= coda_getattr,
 	.setattr	= coda_setattr,