Commit 808012fb authored by Chuck Lever's avatar Chuck Lever Committed by Trond Myklebust

[PATCH] RPC: skip over transport-specific heads automatically

 Add a generic mechanism for skipping over transport-specific headers
 when constructing an RPC request.  This removes another "xprt->stream"
 dependency.

 Test-plan:
 Write-intensive workload on a single mount point (try both UDP and
 TCP).
Signed-off-by: default avatarChuck Lever <cel@netapp.com>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 262965f5
......@@ -76,5 +76,30 @@ enum rpc_auth_stat {
#define RPC_MAXNETNAMELEN 256
/*
* From RFC 1831:
*
* "A record is composed of one or more record fragments. A record
* fragment is a four-byte header followed by 0 to (2**31) - 1 bytes of
* fragment data. The bytes encode an unsigned binary number; as with
* XDR integers, the byte order is from highest to lowest. The number
* encodes two values -- a boolean which indicates whether the fragment
* is the last fragment of the record (bit value 1 implies the fragment
* is the last fragment) and a 31-bit unsigned binary value which is the
* length in bytes of the fragment's data. The boolean value is the
* highest-order bit of the header; the length is the 31 low-order bits.
* (Note that this record specification is NOT in XDR standard form!)"
*
* The Linux RPC client always sends its requests in a single record
* fragment, limiting the maximum payload size for stream transports to
* 2GB.
*/
typedef u32 rpc_fraghdr;
#define RPC_LAST_STREAM_FRAGMENT (1U << 31)
#define RPC_FRAGMENT_SIZE_MASK (~RPC_LAST_STREAM_FRAGMENT)
#define RPC_MAX_FRAGMENT_SIZE ((1U << 31) - 1)
#endif /* __KERNEL__ */
#endif /* _LINUX_SUNRPC_MSGPROT_H_ */
......@@ -155,6 +155,8 @@ struct rpc_xprt {
size_t max_payload; /* largest RPC payload size,
in bytes */
unsigned int tsh_size; /* size of transport specific
header */
struct rpc_wait_queue sending; /* requests waiting to send */
struct rpc_wait_queue resend; /* requests waiting to resend */
......@@ -236,6 +238,11 @@ int xprt_adjust_timeout(struct rpc_rqst *req);
void xprt_release(struct rpc_task *task);
int xprt_destroy(struct rpc_xprt *xprt);
static inline u32 *xprt_skip_transport_header(struct rpc_xprt *xprt, u32 *p)
{
return p + xprt->tsh_size;
}
/*
* Transport switch helper functions
*/
......
......@@ -844,10 +844,8 @@ gss_marshal(struct rpc_task *task, u32 *p)
/* We compute the checksum for the verifier over the xdr-encoded bytes
* starting with the xid and ending at the end of the credential: */
iov.iov_base = req->rq_snd_buf.head[0].iov_base;
if (task->tk_client->cl_xprt->stream)
/* See clnt.c:call_header() */
iov.iov_base += 4;
iov.iov_base = xprt_skip_transport_header(task->tk_xprt,
req->rq_snd_buf.head[0].iov_base);
iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
xdr_buf_from_iov(&iov, &verf_buf);
......
......@@ -1075,13 +1075,12 @@ static u32 *
call_header(struct rpc_task *task)
{
struct rpc_clnt *clnt = task->tk_client;
struct rpc_xprt *xprt = clnt->cl_xprt;
struct rpc_rqst *req = task->tk_rqstp;
u32 *p = req->rq_svec[0].iov_base;
/* FIXME: check buffer size? */
if (xprt->stream)
*p++ = 0; /* fill in later */
p = xprt_skip_transport_header(task->tk_xprt, p);
*p++ = req->rq_xid; /* XID */
*p++ = htonl(RPC_CALL); /* CALL */
*p++ = htonl(RPC_VERSION); /* RPC version */
......
......@@ -282,6 +282,13 @@ static int xs_udp_send_request(struct rpc_task *task)
return status;
}
static inline void xs_encode_tcp_record_marker(struct xdr_buf *buf)
{
u32 reclen = buf->len - sizeof(rpc_fraghdr);
rpc_fraghdr *base = buf->head[0].iov_base;
*base = htonl(RPC_LAST_STREAM_FRAGMENT | reclen);
}
/**
* xs_tcp_send_request - write an RPC request to a TCP socket
* @task: address of RPC task that manages the state of an RPC request
......@@ -301,11 +308,9 @@ static int xs_tcp_send_request(struct rpc_task *task)
struct rpc_rqst *req = task->tk_rqstp;
struct rpc_xprt *xprt = req->rq_xprt;
struct xdr_buf *xdr = &req->rq_snd_buf;
u32 *marker = req->rq_svec[0].iov_base;
int status, retry = 0;
/* Write the record marker */
*marker = htonl(0x80000000|(req->rq_slen-sizeof(*marker)));
xs_encode_tcp_record_marker(&req->rq_snd_buf);
xs_pktdump("packet data:",
req->rq_svec->iov_base,
......@@ -503,16 +508,19 @@ static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, skb_reader_t *desc
xprt->tcp_offset += used;
if (used != len)
return;
xprt->tcp_reclen = ntohl(xprt->tcp_recm);
if (xprt->tcp_reclen & 0x80000000)
if (xprt->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
xprt->tcp_flags |= XPRT_LAST_FRAG;
else
xprt->tcp_flags &= ~XPRT_LAST_FRAG;
xprt->tcp_reclen &= 0x7fffffff;
xprt->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
xprt->tcp_flags &= ~XPRT_COPY_RECM;
xprt->tcp_offset = 0;
/* Sanity check of the record length */
if (xprt->tcp_reclen < 4) {
if (unlikely(xprt->tcp_reclen < 4)) {
dprintk("RPC: invalid TCP record fragment length\n");
xprt_disconnect(xprt);
return;
......@@ -1065,6 +1073,7 @@ int xs_setup_udp(struct rpc_xprt *xprt, struct rpc_timeout *to)
xprt->prot = IPPROTO_UDP;
xprt->port = XS_MAX_RESVPORT;
xprt->tsh_size = 0;
xprt->stream = 0;
xprt->nocong = 0;
xprt->cwnd = RPC_INITCWND;
......@@ -1105,11 +1114,12 @@ int xs_setup_tcp(struct rpc_xprt *xprt, struct rpc_timeout *to)
xprt->prot = IPPROTO_TCP;
xprt->port = XS_MAX_RESVPORT;
xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
xprt->stream = 1;
xprt->nocong = 1;
xprt->cwnd = RPC_MAXCWND(xprt);
xprt->resvport = capable(CAP_NET_BIND_SERVICE) ? 1 : 0;
xprt->max_payload = (1U << 31) - 1;
xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
INIT_WORK(&xprt->connect_worker, xs_tcp_connect_worker, xprt);
......
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