vfs: add cross-rename

If flags contain RENAME_EXCHANGE then exchange source and destination files.
There's no restriction on the type of the files; e.g. a directory can be
exchanged with a symlink.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h
index 9250f4dd7d96..ca1a11bb4443 100644
--- a/include/uapi/linux/fs.h
+++ b/include/uapi/linux/fs.h
@@ -36,6 +36,7 @@
 #define SEEK_MAX        SEEK_HOLE
 
 #define RENAME_NOREPLACE        (1 << 0)        /* Don't overwrite target */
+#define RENAME_EXCHANGE         (1 << 1)        /* Exchange source and dest */
 
 struct fstrim_range {
         __u64 start;