Re: [PATCH 1/2] nfs: Only update callback sequnce id when CB_SEQUENCE success

[Kinglong Mee <kinglongmee@gmail.com>]

ping .... 

On 6/2/2015 6:58 PM, Kinglong Mee wrote:
> When testing pnfs layout, nfsd got error NFS4ERR_SEQ_MISORDERED.
> It is caused by nfs return NFS4ERR_DELAY before validate_seqid(),
> don't update the sequnce id, but nfsd updates the sequnce id !!!
> 
> According to RFC5661 20.9.3,
> " If CB_SEQUENCE returns an error, then the state of the slot
>   (sequence ID, cached reply) MUST NOT change. "
> 
> Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
> ---
>  fs/nfs/callback_proc.c | 16 ++++++++++++----
>  1 file changed, 12 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
> index 197806f..7e9653a 100644
> --- a/fs/nfs/callback_proc.c
> +++ b/fs/nfs/callback_proc.c
> @@ -327,10 +327,8 @@ validate_seqid(struct nfs4_slot_table *tbl, struct cb_sequenceargs * args)
>  	dprintk("%s slot table seqid: %u\n", __func__, slot->seq_nr);
>  
>  	/* Normal */
> -	if (likely(args->csa_sequenceid == slot->seq_nr + 1)) {
> -		slot->seq_nr++;
> +	if (likely(args->csa_sequenceid == slot->seq_nr + 1))
>  		goto out_ok;
> -	}
>  
>  	/* Replay */
>  	if (args->csa_sequenceid == slot->seq_nr) {
> @@ -418,6 +416,7 @@ __be32 nfs4_callback_sequence(struct cb_sequenceargs *args,
>  			      struct cb_process_state *cps)
>  {
>  	struct nfs4_slot_table *tbl;
> +	struct nfs4_slot *slot;
>  	struct nfs_client *clp;
>  	int i;
>  	__be32 status = htonl(NFS4ERR_BADSESSION);
> @@ -429,7 +428,9 @@ __be32 nfs4_callback_sequence(struct cb_sequenceargs *args,
>  
>  	if (!(clp->cl_session->flags & SESSION4_BACK_CHAN))
>  		goto out;
> +
>  	tbl = &clp->cl_session->bc_slot_table;
> +	slot = tbl->slots + args->csa_slotid;
>  
>  	spin_lock(&tbl->slot_tbl_lock);
>  	/* state manager is resetting the session */
> @@ -444,7 +445,7 @@ __be32 nfs4_callback_sequence(struct cb_sequenceargs *args,
>  		goto out;
>  	}
>  
> -	status = validate_seqid(&clp->cl_session->bc_slot_table, args);
> +	status = validate_seqid(tbl, args);
>  	spin_unlock(&tbl->slot_tbl_lock);
>  	if (status)
>  		goto out;
> @@ -468,6 +469,13 @@ __be32 nfs4_callback_sequence(struct cb_sequenceargs *args,
>  	res->csr_highestslotid = NFS41_BC_MAX_CALLBACKS - 1;
>  	res->csr_target_highestslotid = NFS41_BC_MAX_CALLBACKS - 1;
>  
> +	/*
> +	 * RFC5661 20.9.3
> +	 * If CB_SEQUENCE returns an error, then the state of the slot
> +	 * (sequence ID, cached reply) MUST NOT change.
> +	 */
> +	slot->seq_nr++;
> +
>  out:
>  	cps->clp = clp; /* put in nfs4_callback_compound */
>  	for (i = 0; i < args->csa_nrclists; i++)
>