On Fri, May 16, 2014 at 12:12:00AM +0200, Joerg Sonnenberger wrote: > I don't think it is a problem by itself as the file handle is opaque, > but it is certainly wasteful to not put ufid_ino first.
That is not possible, the first few bytes of the structure must match struct fid from fstypes.h. The structure is only used to construct opaque tokens for filehandles, and the encoding includes the size, so I see no problem. Indeed rebooting with an updated kernel will give active NFS clients problems, but I am not sure we should realy care nor how we could possibly avoid this one time issue. We have changed encoding of filehandles before (at least once). Martin