Re: [PATCH] nfsd: fix change_info in NFSv4 RENAME replies

[Jeff Layton <jlayton@kernel.org>]

On Sat, 2023-09-09 at 11:18 -0400, Chuck Lever wrote:
> On Sat, Sep 09, 2023 at 07:12:30AM -0400, Jeff Layton wrote:
> > nfsd sends the transposed directory change info in the RENAME reply. The
> > source directory is in save_fh and the target is in current_fh.
> > 
> > Reported-by: Zhi Li <yieli@redhat.com>
> > Reported-by: Benjamin Coddington <bcodding@redhat.com>
> > Signed-off-by: Jeff Layton <jlayton@kernel.org>
> > ---
> > This bug predates git, so I can't add a proper Fixes tag. I think this
> > is probably appropriate for stable series kernels though.
> > 
> > This bug was largely papered over by the fact that we factored in the
> > ctime when generating a change attribute. Since this commit, however:
> > 
> >     638e3e7d9493 nfsd: use the getattr operation to fetch i_version
> > 
> > We stopped doing that for directory inodes and that caused this bug to
> > pop up.
> 
> Applied to nfsd-fixes with a "Cc: stable" tag added.
> 
> Is there a publicly-accessible bug report link that can be included?
> 
> 

Yes. I just made this one public:

    https://bugzilla.redhat.com/show_bug.cgi?id=2218844

It has Ben's reproducer script for this in it too.

> > ---
> >  fs/nfsd/nfs4proc.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
> > index 5ca748309c26..4199ede0583c 100644
> > --- a/fs/nfsd/nfs4proc.c
> > +++ b/fs/nfsd/nfs4proc.c
> > @@ -1058,8 +1058,8 @@ nfsd4_rename(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
> >  			     rename->rn_tname, rename->rn_tnamelen);
> >  	if (status)
> >  		return status;
> > -	set_change_info(&rename->rn_sinfo, &cstate->current_fh);
> > -	set_change_info(&rename->rn_tinfo, &cstate->save_fh);
> > +	set_change_info(&rename->rn_sinfo, &cstate->save_fh);
> > +	set_change_info(&rename->rn_tinfo, &cstate->current_fh);
> >  	return nfs_ok;
> >  }
> >  
> > 
> > ---
> > base-commit: dd1386dd3c4f4bc55456c88180f9f39697bb95c0
> > change-id: 20230908-nfsd-fixes-f5bdb87e6035
> > 
> > Best regards,
> > -- 
> > Jeff Layton <jlayton@kernel.org>
> > 
> 

-- 
Jeff Layton <jlayton@kernel.org>