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Commit f4a2e418 authored by Ricardo Labiaga's avatar Ricardo Labiaga Committed by Benny Halevy
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nfs41: Process the RPC call direction 



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.

[was nfs41: Skip past the RPC call direction]
Signed-off-by: default avatarRicardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: default avatarBenny Halevy <bhalevy@panasas.com>
[nfs41: sunrpc: Add RPC direction back into the XDR buffer]
Signed-off-by: default avatarRicardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: default avatarBenny Halevy <bhalevy@panasas.com>
[nfs41: sunrpc: Don't skip past the RPC call direction]
Signed-off-by: default avatarRicardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: default avatarBenny Halevy <bhalevy@panasas.com>
parent 18dca02a

net/sunrpc/clnt.c

+3 −2
Original line number Diff line number Diff line
@@ -1390,13 +1390,14 @@ rpc_verify_header(struct rpc_task *task) 
	}

	if ((len -= 3) < 0)

		goto out_overflow;

	p += 1;	/* skip XID */



	p += 1; /* skip XID */

	if ((n = ntohl(*p++)) != RPC_REPLY) {

		dprintk("RPC: %5u %s: not an RPC reply: %x\n",

			task->tk_pid, __func__, n);

		goto out_garbage;

	}



	if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {

		if (--len < 0)

			goto out_overflow;

net/sunrpc/xprtsock.c

+25 −6
Original line number Diff line number Diff line
@@ -270,12 +270,13 @@ 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)

{
@@ -997,7 +998,7 @@ 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"
@@ -1026,9 +1027,13 @@ 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
@@ -1059,6 +1064,20 @@ static inline void xs_tcp_read_request(struct rpc_xprt *xprt, struct xdr_skb_rea 
	}



	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;

	}



	len = desc->count;

	if (len > transport->tcp_reclen - transport->tcp_offset) {

		struct xdr_skb_reader my_desc;
@@ -1156,7 +1175,7 @@ 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;

		}