[GFS2] Accept old format NFS filehandles

On Tue, 2007-07-10 at 10:06 +0100, Christoph Hellwig wrote:
> > -#define GFS2_LARGE_FH_SIZE 10
> > -
> > -struct gfs2_fh_obj {
> > -   struct gfs2_inum_host this;
> > -   u32 imode;
> > -};
> > +#define GFS2_LARGE_FH_SIZE 8
>
> Because gfs2_decode_fh only accepts file handles with GFS2_LARGE_FH_SIZE
> or GFS2_LARGE_FH_SIZE you don't accept filehandles sent out by and older
> gfs version anymore.  Stale filehandles because of a new kernel version
> are a big no-no, so please add back code to handle the old filehandles
> on the decode side.
>

This should fix that problem I think since its only relating to end of
the fh we can just ignore that field in order to accept the older
format.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Wendy Cheng <wcheng@redhat.com>

fs/gfs2/ops_export.c

@@ -28,6 +28,7 @@
 
 #define GFS2_SMALL_FH_SIZE 4
 #define GFS2_LARGE_FH_SIZE 8
+#define GFS2_OLD_FH_SIZE 10
 
 static struct dentry *gfs2_decode_fh(struct super_block *sb,
 				     __u32 *p,
@@ -44,6 +45,7 @@ static struct dentry *gfs2_decode_fh(struct super_block *sb,
 
 	switch (fh_len) {
 	case GFS2_LARGE_FH_SIZE:
+	case GFS2_OLD_FH_SIZE:
 		parent.no_formal_ino = ((u64)be32_to_cpu(fh[4])) << 32;
 		parent.no_formal_ino |= be32_to_cpu(fh[5]);
 		parent.no_addr = ((u64)be32_to_cpu(fh[6])) << 32;