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>

fs/orangefs/namei.c

@@ -409,11 +409,15 @@ out:
 static int orangefs_rename(struct inode *old_dir,
 			struct dentry *old_dentry,
 			struct inode *new_dir,
-			struct dentry *new_dentry)
+			struct dentry *new_dentry,
+			unsigned int flags)
 {
 	struct orangefs_kernel_op_s *new_op;
 	int ret;
 
+	if (flags)
+		return -EINVAL;
+
 	gossip_debug(GOSSIP_NAME_DEBUG,
 		     "orangefs_rename: called (%pd2 => %pd2) ct=%d\n",
 		     old_dentry, new_dentry, d_count(new_dentry));
@@ -459,7 +463,7 @@ const struct inode_operations orangefs_dir_inode_operations = {
 	.symlink = orangefs_symlink,
 	.mkdir = orangefs_mkdir,
 	.rmdir = orangefs_unlink,
-	.rename = orangefs_rename,
+	.rename2 = orangefs_rename,
 	.setattr = orangefs_setattr,
 	.getattr = orangefs_getattr,
 	.setxattr = generic_setxattr,