[PATCH 3/7 v3] vfs: add flag to allow rename to same inode

[Miklos Szeredi <miklos@szeredi.hu>]

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From: Miklos Szeredi <mszeredi@suse.cz>

The overlay filesystem uses dummy inodes for non-directories.  Allow
rename to work in this case despite the inode being the same.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
 fs/namei.c         |    4 +++-
 include/linux/fs.h |    1 +
 2 files changed, 4 insertions(+), 1 deletion(-)

Index: linux-2.6/include/linux/fs.h
===================================================================
--- linux-2.6.orig/include/linux/fs.h	2010-08-25 14:19:34.000000000 +0200
+++ linux-2.6/include/linux/fs.h	2010-08-25 14:19:53.000000000 +0200
@@ -179,6 +179,7 @@ struct inodes_stat_t {
 #define FS_RENAME_DOES_D_MOVE	32768	/* FS will handle d_move()
 					 * during rename() internally.
 					 */
+#define FS_RENAME_SELF_ALLOW	65536	/* Allow rename to same inode */
 
 /*
  * These are the fs-independent mount-flags: up to 32 flags are supported
Index: linux-2.6/fs/namei.c
===================================================================
--- linux-2.6.orig/fs/namei.c	2010-08-25 10:19:53.000000000 +0200
+++ linux-2.6/fs/namei.c	2010-08-25 14:22:56.000000000 +0200
@@ -2620,8 +2620,10 @@ int vfs_rename(struct inode *old_dir, st
 	int is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
 	const unsigned char *old_name;
 
-	if (old_dentry->d_inode == new_dentry->d_inode)
+	if (old_dentry->d_inode == new_dentry->d_inode &&
+	    !(old_dir->i_sb->s_type->fs_flags & FS_RENAME_SELF_ALLOW)) {
  		return 0;
+	}
  
 	error = may_delete(old_dir, old_dentry, is_dir);
 	if (error)

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