Re: NFSv3 pathname problems in 2.4 kernels

[Neil Brown]

On Monday July 23, [e-mail] wrote:
> Neil Brown wrote:
> > 
> > This shouldn't be a problem for Solaris 2.6, but definately is for
> > Irix.
> 
>    Well, there are many 2.6 systems and they all fail in the same aay
> as Irix.  So does Solaris 2.7.  (2.8 seems to be Ok).

Odd indeed.  I use 2.6 systems and they seem fine.  I have only had
the problem when using an old version of mountd.  What verion of
nfs-utils are you using?

> > Look in fs/nfsd/nfsfh.c, in fh_compose.
> > If you change:
> >         if (ref_fh &&
> >             ref_fh->fh_handle.fh_version == 0xca &&
> >             parent->d_inode->i_sb->s_op->dentry_to_fh == NULL) {
> > to
> >         if (parent->d_inode->i_sb->s_op->dentry_to_fh == NULL) {
> > you will probably get what you want, for ext2 at least.
> 
>    Thanks, but this is for xfs (I didn't fancy fsck'ing a 470GB file
> system!).  I suppose it's suck it and see....

It should work for xfs, and infact everything but reiserfs as it is
the only filesys that currently sets dentry_to_fh.
However a better, more general solution would be to add a line:

 if (fhp->fh_handle.fh_size < NFS_FHSIZE)
     fhp->fh_handle.fh_size = NFS_FHSIZE;

just before the "return 0" in fh_update, and

 if (inode && fhp->fh_handle.fh_size < NFS_FHSIZE)
     fhp->fh_handle.fh_size = NFS_FHSIZE;

before the "return 0" in fh_compose.

NeilBrown