Re: [PATCH] Update the exportfs documentation and comments and fix some exportfs issues

[David Howells <dhowells@redhat.com>]

Phillip Lougher <phillip@lougher.demon.co.uk> wrote:

> You define these in the filesystem c files themselves as #defines.  UDF and
> BTRFS place theirs in the enum fid_type definition itself (in
> linux/exportfs.h).  Is there any reason why you didn't do this?

I don't know that we want to stick loads of filesystem-specific stuff into a
general header file.  I believe we used to do that for struct inode (IIRC
there used to be a large union with filesystem-specific members).

> >  	int type = FILEID_INO32_GEN;
> 
>         ^^^^
> 
>         this should be changed to enum fid_type

I missed that.  Updated.

> > +#define FUSE_FILEID		((enum fid_type) 0x81)
> > +#define FUSE_FILEID_PARENT	((enum fid_type) 0x82)
> 
> Move to enum fid_type in linux/exportfs.h?

As mentioned above, do we really want to do that?

> > +#define ISOFS_FILEID		((enum fid_type) 1)
> > +#define ISOFS_FILEID_PARENT	((enum fid_type) 2)
> > +
> 
> Move to enum fid_type in linux/exportfs.h?
> 
> Type  1 and 2 are also used by the generic fid_types FILEID_INO32_GEN and
> FILEID_INO32_GEN_PARENT, but (obviously) their formats are different.

I know.  As far as I know, there's no restriction on them reusing types 1 and
2, just an advisory note where these collide with other export types.  Perhaps
Al or Christoph would care to comment on this.

Also, I don't know that changing these types would necessarily be a good
idea.  wireshark, for example, could multiplex the types by the length as the
standard types are lengths 2 and 4, and ISOFS types are 3 and 5.

David