Re: [pnfs] [PATCH 28/46] NFS: use dynamically computed compound_hdr.replen for xdr_inline_pages offset

[Benny Halevy <bhalevy@panasas.com>]

On Mar. 04, 2009, 1:58 +0200, Benny Halevy <bhalevy@panasas.com> wrote:
> As Trond suggested, rather than passing a constant to xdr_inline_pages,
> keep a running count of the expected reply bytes.  In preparation for
> nfs41, where additional op sequence are expteced when talking to nfs41
> servers.
> 
> [NFS: cb_compoundhdr.replen is in words not bytes]
> Signed-off-by: Benny Halevy <bhalevy@panasas.com>
> ---
>  fs/nfs/nfs4xdr.c |   44 ++++++--------------------------------------
>  1 files changed, 6 insertions(+), 38 deletions(-)
> 
> diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
> index e6f2d84..9cec237 100644
> --- a/fs/nfs/nfs4xdr.c
> +++ b/fs/nfs/nfs4xdr.c
> @@ -1757,20 +1757,13 @@ static int nfs4_xdr_enc_readlink(struct rpc_rqst *req, __be32 *p, const struct n
>  	struct compound_hdr hdr = {
>  		.minorversion = clp->cl_minorversion,
>  	};
> -	struct rpc_auth *auth = req->rq_task->tk_msg.rpc_cred->cr_auth;
> -	unsigned int replen;
>  
>  	xdr_init_encode(&xdr, &req->rq_snd_buf, p);
>  	encode_compound_hdr(&xdr, req, &hdr);
>  	encode_putfh(&xdr, args->fh, &hdr);
>  	encode_readlink(&xdr, args, req, &hdr);
>  
> -	/* set up reply kvec
> -	 *    toplevel_status + taglen + rescount + OP_PUTFH + status
> -	 *      + OP_READLINK + status + string length = 8
> -	 */
> -	replen = (RPC_REPHDRSIZE + auth->au_rslack + NFS4_dec_readlink_sz) << 2;
> -	xdr_inline_pages(&req->rq_rcv_buf, replen, args->pages,
> +	xdr_inline_pages(&req->rq_rcv_buf, hdr.replen << 2, args->pages,
>  			args->pgbase, args->pglen);
>  	encode_nops(&hdr);
>  	return 0;
> @@ -1787,23 +1780,16 @@ static int nfs4_xdr_enc_readdir(struct rpc_rqst *req, __be32 *p, const struct nf
>  	struct compound_hdr hdr = {
>  		.minorversion = clp->cl_minorversion,
>  	};
> -	struct rpc_auth *auth = req->rq_task->tk_msg.rpc_cred->cr_auth;
> -	int replen;
>  
>  	xdr_init_encode(&xdr, &req->rq_snd_buf, p);
>  	encode_compound_hdr(&xdr, req, &hdr);
>  	encode_putfh(&xdr, args->fh, &hdr);
>  	encode_readdir(&xdr, args, req, &hdr);
>  
> -	/* set up reply kvec
> -	 *    toplevel_status + taglen + rescount + OP_PUTFH + status
> -	 *      + OP_READDIR + status + verifer(2)  = 9
> -	 */
> -	replen = (RPC_REPHDRSIZE + auth->au_rslack + NFS4_dec_readdir_sz) << 2;
> -	xdr_inline_pages(&req->rq_rcv_buf, replen, args->pages,
> +	xdr_inline_pages(&req->rq_rcv_buf, hdr.replen << 2, args->pages,
>  			 args->pgbase, args->count);
>  	dprintk("%s: inlined page args = (%u, %p, %u, %u)\n",
> -			__func__, replen, args->pages,
> +			__func__, hdr.replen << 2, args->pages,
>  			args->pgbase, args->count);
>  	encode_nops(&hdr);
>  	return 0;
> @@ -1814,26 +1800,19 @@ static int nfs4_xdr_enc_readdir(struct rpc_rqst *req, __be32 *p, const struct nf
>   */
>  static int nfs4_xdr_enc_read(struct rpc_rqst *req, __be32 *p, struct nfs_readargs *args)
>  {
> -	struct rpc_auth *auth = req->rq_task->tk_msg.rpc_cred->cr_auth;
>  	struct xdr_stream xdr;
>  	struct nfs_client *clp =
>  		(struct nfs_client *)req->rq_task->tk_client->cl_private;
>  	struct compound_hdr hdr = {
>  		.minorversion = clp->cl_minorversion,
>  	};
> -	int replen;
>  
>  	xdr_init_encode(&xdr, &req->rq_snd_buf, p);
>  	encode_compound_hdr(&xdr, req, &hdr);
>  	encode_putfh(&xdr, args->fh, &hdr);
>  	encode_read(&xdr, args, &hdr);
>  
> -	/* set up reply kvec
> -	 *    toplevel status + taglen=0 + rescount + OP_PUTFH + status
> -	 *       + OP_READ + status + eof + datalen = 9
> -	 */
> -	replen = (RPC_REPHDRSIZE + auth->au_rslack + NFS4_dec_read_sz) << 2;
> -	xdr_inline_pages(&req->rq_rcv_buf, replen,
> +	xdr_inline_pages(&req->rq_rcv_buf, hdr.replen << 2,
>  			 args->pages, args->pgbase, args->count);
>  	req->rq_rcv_buf.flags |= XDRBUF_READ;
>  	encode_nops(&hdr);
> @@ -1869,22 +1848,18 @@ nfs4_xdr_enc_getacl(struct rpc_rqst *req, __be32 *p,
>  		struct nfs_getaclargs *args)
>  {
>  	struct xdr_stream xdr;
> -	struct rpc_auth *auth = req->rq_task->tk_msg.rpc_cred->cr_auth;
>  	struct nfs_client *clp =
>  		(struct nfs_client *)req->rq_task->tk_client->cl_private;
>  	struct compound_hdr hdr = {
>  		.minorversion = clp->cl_minorversion,
>  	};
> -	int replen;
>  
>  	xdr_init_encode(&xdr, &req->rq_snd_buf, p);
>  	encode_compound_hdr(&xdr, req, &hdr);
>  	encode_putfh(&xdr, args->fh, &hdr);
>  	encode_getattr_two(&xdr, FATTR4_WORD0_ACL, 0, &hdr);
>  
> -	/* set up reply buffer: */
> -	replen = (RPC_REPHDRSIZE + auth->au_rslack + NFS4_dec_getacl_sz) << 2;
> -	xdr_inline_pages(&req->rq_rcv_buf, replen,
> +	xdr_inline_pages(&req->rq_rcv_buf, hdr.replen << 2,
>  		args->acl_pages, args->acl_pgbase, args->acl_len);
>  	encode_nops(&hdr);
>  	return 0;
> @@ -2105,8 +2080,6 @@ static int nfs4_xdr_enc_fs_locations(struct rpc_rqst *req, __be32 *p, struct nfs
>  	struct compound_hdr hdr = {
>  		.minorversion = clp->cl_minorversion,
>  	};
> -	struct rpc_auth *auth = req->rq_task->tk_msg.rpc_cred->cr_auth;
> -	int replen;
>  
>  	xdr_init_encode(&xdr, &req->rq_snd_buf, p);
>  	encode_compound_hdr(&xdr, req, &hdr);
> @@ -2114,12 +2087,7 @@ static int nfs4_xdr_enc_fs_locations(struct rpc_rqst *req, __be32 *p, struct nfs
>  	encode_lookup(&xdr, args->name, &hdr);

To work around the fs_locations issue we can also get hdr.sample
replen here, right before calling encode_fs_locations.

Benny

>  	encode_fs_locations(&xdr, args->bitmask, &hdr);
>  
> -	/* set up reply
> -	 *   toplevel_status + OP_PUTFH + status
> -	 *   + OP_LOOKUP + status + OP_GETATTR + status = 7
> -	 */
> -	replen = (RPC_REPHDRSIZE + auth->au_rslack + 7) << 2;
> -	xdr_inline_pages(&req->rq_rcv_buf, replen, &args->page,
> +	xdr_inline_pages(&req->rq_rcv_buf, hdr.replen << 2, &args->page,
>  			0, PAGE_SIZE);
>  	encode_nops(&hdr);
>  	return 0;