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: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfs41: sunrpc: Add RPC direction back into the XDR buffer]
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfs41: sunrpc: Don't skip past the RPC call direction]
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index d00e813..aca3ab6 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -1390,13 +1390,14 @@
}
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);
+ task->tk_pid, __func__, n);
goto out_garbage;
}
+
if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
if (--len < 0)
goto out_overflow;
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 8975c10..a48df144 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -270,12 +270,13 @@
#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 @@
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 @@
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 @@
}
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 @@
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;
}
