On Jun. 12, 2009, 1:54 -0400, Ricardo Labiaga <Ricardo.Labiaga@xxxxxxxxxx> wrote:
> [squash with: nfs41: Skip past the RPC call direction]
>
> An earlier nfs41/sunrpc patch incorrectly assumed that all transports will
> read the RPC direction and route callbacks or replies to the processing
> routines. This is only currently implemented for TCP, so rpc_verify_header()
> needs to continue verifying that it is processing an RPC_REPLY.
>
> Reading and storing the RPC direction is a three step process.
>
> 1. xs_tcp_read_calldir() reads the RPC direction, but it will not store it
> in the XDR buffer since the 'struct rpc_rqst' is not yet available.
>
> 2. The 'struct rpc_rqst' is obtained during the TCP_RCV_COPY_DATA state.
> This state need not necessarily be preceeded by the TCP_RCV_READ_CALLDIR.
> For example, we may be reading a continuation packet to a large reply.
> Therefore, we can't simply obtain the 'struct rpc_rqst' during the
> TCP_RCV_READ_CALLDIR state and assume it's available during TCP_RCV_COPY_DATA.
>
> This patch adds a new TCP_RCV_READ_CALLDIR flag to indicate the need to
> read the RPC direction. It then uses TCP_RCV_COPY_CALLDIR to indicate the
> RPC direction needs to be saved after the 'struct rpc_rqst' has been allocated.
>
> 3. The 'struct rpc_rqst' is obtained by the xs_tcp_read_data() helper
> functions. xs_tcp_read_common() then saves the RPC direction in the XDR
> buffer if TCP_RCV_COPY_CALLDIR is set. This will happen when we're reading
> the data immediately after the direction was read. xs_tcp_read_common()
> then clears this flag.
>
> Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@xxxxxxxxxx>
> ---
> net/sunrpc/xprtsock.c | 31 +++++++++++++++++++++++++------
> 1 files changed, 25 insertions(+), 6 deletions(-)
>
> diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
> index 8ec2600..fe57ebd 100644
> --- a/net/sunrpc/xprtsock.c
> +++ b/net/sunrpc/xprtsock.c
> @@ -275,12 +275,13 @@ struct sock_xprt {
> #define TCP_RCV_COPY_FRAGHDR (1UL << 1)
> #define TCP_RCV_COPY_XID (1UL << 2)
> #define TCP_RCV_COPY_DATA (1UL << 3)
> -#define TCP_RCV_COPY_CALLDIR (1UL << 4)
> +#define TCP_RCV_READ_CALLDIR (1UL << 4)
> +#define TCP_RCV_COPY_CALLDIR (1UL << 5)
>
> /*
> * TCP RPC flags
> */
> -#define TCP_RPC_REPLY (1UL << 5)
> +#define TCP_RPC_REPLY (1UL << 6)
>
> static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
> {
> @@ -1002,7 +1003,7 @@ static inline void xs_tcp_read_xid(struct sock_xprt *transport, struct xdr_skb_r
> if (used != len)
> return;
> transport->tcp_flags &= ~TCP_RCV_COPY_XID;
> - transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
> + transport->tcp_flags |= TCP_RCV_READ_CALLDIR;
> transport->tcp_copied = 4;
> dprintk("RPC: reading %s XID %08x\n",
> (transport->tcp_flags & TCP_RPC_REPLY) ? "reply for"
> @@ -1031,9 +1032,13 @@ static inline void xs_tcp_read_calldir(struct sock_xprt *transport,
> transport->tcp_offset += used;
> if (used != len)
> return;
> - transport->tcp_flags &= ~TCP_RCV_COPY_CALLDIR;
> + transport->tcp_flags &= ~TCP_RCV_READ_CALLDIR;
> + transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
> transport->tcp_flags |= TCP_RCV_COPY_DATA;
> - transport->tcp_copied += 4;
> + /*
> + * We don't yet have the XDR buffer, so we will write the calldir
> + * out after we get the buffer from the 'struct rpc_rqst'
> + */
> if (ntohl(calldir) == RPC_REPLY)
> transport->tcp_flags |= TCP_RPC_REPLY;
> else
> @@ -1055,6 +1060,20 @@ static inline void xs_tcp_read_common(struct rpc_xprt *xprt,
> ssize_t r;
>
> rcvbuf = &req->rq_private_buf;
> +
> + if (transport->tcp_flags & TCP_RCV_COPY_CALLDIR) {
> + /*
> + * Save the RPC direction in the XDR buffer
> + */
> + __be32 calldir = transport->tcp_flags & TCP_RPC_REPLY ?
> + htonl(RPC_REPLY) : 0;
> +
> + memcpy(rcvbuf->head[0].iov_base + transport->tcp_copied,
> + &calldir, sizeof(calldir));
> + transport->tcp_copied += sizeof(calldir);
> + transport->tcp_flags &= ~TCP_RCV_COPY_CALLDIR;
Can this be done in xs_tcp_read_calldir()?
Benny
> + }
> +
> len = desc->count;
> if (len > transport->tcp_reclen - transport->tcp_offset) {
> struct xdr_skb_reader my_desc;
> @@ -1258,7 +1277,7 @@ static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, uns
> continue;
> }
> /* Read in the call/reply flag */
> - if (transport->tcp_flags & TCP_RCV_COPY_CALLDIR) {
> + if (transport->tcp_flags & TCP_RCV_READ_CALLDIR) {
> xs_tcp_read_calldir(transport, &desc);
> continue;
> }
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
