[pnfs] [PATCH] wrong hold count on clr_ref

[Marc Eshel]

Benny Halevy <bhalevy at panasas.com> wrote on 06/04/2007 05:28:47 PM:

> Marc Eshel wrote:
> > The first change is needed since know we have a compound rpc with 2 
ops.
> > Problem 6 still needs be fixed and until we do comment the BUG_ON so 
we 
> > can see the layout return working. 
> > 
> > 6. The serve is not waiting for the client to return the layout before 

> > calling destroy_layoutrecall() it because the hold count clr_ref is 
not 
> > set correctly. This problem is not fixed except for removing the BUG 
that 
> > causes the crash. 
> 
> The BUG_ON causes the crash on purpose and it's right,
> removing it just invites trouble down the road.
> Can you please try adding a kref_get(&clr->clr_ref)
> in hash_layoutrecall instead? This was the original intent...

Yes, I know, this was a quick fix to see how far we go. I will try to see 
where is the missing hold count.
Marc.

> 
> > 
> >> From: Marc Eshel <eshel at almaden.ibm.com>
> >>
> >>
> >> ---
> >>
> >>  fs/nfsd/nfs4callback.c |    2 +-
> >>  fs/nfsd/nfs4state.c    |    2 +-
> >>  2 files changed, 2 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
> >> index b7bc5c3..da20278 100644
> >> --- a/fs/nfsd/nfs4callback.c
> >> +++ b/fs/nfsd/nfs4callback.c
> >> @@ -413,7 +413,7 @@ nfs41_xdr_enc_cb_layout(struct rpc_rqst 
> >>     struct nfs4_layoutrecall *args = rpc_args->args_op;
> >>     struct nfs4_cb_compound_hdr hdr = {
> >>        .ident = 0,
> >> -      .nops   = 1,
> >> +      .nops   = 2,
> >>     };
> >>
> >>     xdr_init_encode(&xdr, &req->rq_snd_buf, p);
> >> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> >> index 2fe5414..e48f08d 100644
> >> --- a/fs/nfsd/nfs4state.c
> >> +++ b/fs/nfsd/nfs4state.c
> >> @@ -4029,7 +4029,7 @@ destroy_layoutrecall(struct kref *kref)
> >>        container_of(kref, struct nfs4_layoutrecall, clr_ref);
> >>     dprintk("pNFS %s: clr %p fp %p clp %p\n", __FUNCTION__, clr,
> >>             clr->clr_file, clr->clr_client);
> >> -   BUG_ON(!list_empty(&clr->clr_perclnt));
> >> +//???   BUG_ON(!list_empty(&clr->clr_perclnt));
> >>     if (clr->clr_file)
> >>        put_nfs4_file(clr->clr_file);
> >>     kmem_cache_free(pnfs_layoutrecall_slab, clr);
> >> _______________________________________________
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> >> pNFS at linux-nfs.org
> >> http://linux-nfs.org/cgi-bin/mailman/listinfo/pnfs
> > 
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