Re: [RFC][PATCH 3/14] Add the whiteout file type

Jan Blunck
2007-05-15T06:00:27Z

On 5/14/07, Jan Engelhardt <jengelh@linux01.gwdg.de> wrote:
>
> On May 14 2007 15:09, Bharata B Rao wrote:
> >
> >A white-out stops the VFS from further lookups of the white-outs name and
> >returns -ENOENT. This is the same behaviour as if the filename isn't
> >found. This can be used in combination with union mounts to virtually
> >delete (white-out) files by creating a file with this file type.
> >
> >Signed-off-by: Jan Blunck <j.blunck@tu-harburg.de>
> >Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
> >---
> > include/linux/stat.h | 2 ++
> > 1 files changed, 2 insertions(+)
> >
> >--- a/include/linux/stat.h
> >+++ b/include/linux/stat.h
> >@@ -10,6 +10,7 @@
> > #if defined(__KERNEL__) || !defined(__GLIBC__) || (__GLIBC__ < 2)
> >
> > #define S_IFMT 00170000
> >+#define S_IFWHT 0160000 /* whiteout */
> > #define S_IFSOCK 0140000
> > #define S_IFLNK 0120000
> > #define S_IFREG 0100000
>
> I wonder why 110000, 130000 or 150000 could not also be used?
>

I used the S_IFWHT definition like it is referenced in stat(2). I
guess it would be a good idea to use the same flag on BSD and Linux.

As you can see in stat(2) other OS use 011, 013 and 015.