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>

1 files changed, 6 insertions, 2 deletions

diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index e57174d43683..c7e23ca945ab 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -1096,13 +1096,17 @@ static int kernfs_iop_rmdir(struct inode *dir, struct dentry *dentry)
 }
 
 static int kernfs_iop_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)
 {
 	struct kernfs_node *kn  = old_dentry->d_fsdata;
 	struct kernfs_node *new_parent = new_dir->i_private;
 	struct kernfs_syscall_ops *scops = kernfs_root(kn)->syscall_ops;
 	int ret;
 
+	if (flags)
+		return -EINVAL;
+
 	if (!scops || !scops->rename)
 		return -EPERM;
 
@@ -1133,7 +1137,7 @@ const struct inode_operations kernfs_dir_iops = {
 
 	.mkdir		= kernfs_iop_mkdir,
 	.rmdir		= kernfs_iop_rmdir,
-	.rename		= kernfs_iop_rename,
+	.rename2	= kernfs_iop_rename,
 };
 
 static struct kernfs_node *kernfs_leftmost_descendant(struct kernfs_node *pos)