svc: Add transport hdr size for defer/revisit

Some transports have a header in front of the RPC header. The current
defer/revisit processing considers only the iov_len and arg_len to
determine how much to back up when saving the original request
to revisit. Add a field to the rqstp structure to save the size
of the transport header so svc_defer can correctly compute
the start of a request.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
Acked-by: Neil Brown <neilb@suse.de>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Greg Banks <gnb@sgi.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
This commit is contained in:
Tom Tucker 2007-12-30 21:08:29 -06:00 committed by J. Bruce Fields
parent 0f0257eaa5
commit 260c1d1298
3 changed files with 31 additions and 9 deletions

View File

@ -217,6 +217,7 @@ struct svc_rqst {
void * rq_xprt_ctxt; /* transport specific context ptr */
struct svc_deferred_req*rq_deferred; /* deferred request we are replaying */
size_t rq_xprt_hlen; /* xprt header len */
struct xdr_buf rq_arg;
struct xdr_buf rq_res;
struct page * rq_pages[RPCSVC_MAXPAGES];
@ -322,6 +323,7 @@ struct svc_deferred_req {
size_t addrlen;
union svc_addr_u daddr; /* where reply must come from */
struct cache_deferred_req handle;
size_t xprt_hlen;
int argslen;
__be32 args[0];
};

View File

@ -29,7 +29,6 @@
#include <linux/sunrpc/types.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/svcsock.h>
#include <linux/sunrpc/stats.h>
#include <linux/sunrpc/svc_xprt.h>
@ -859,10 +858,18 @@ static void svc_revisit(struct cache_deferred_req *dreq, int too_many)
svc_xprt_put(xprt);
}
/*
* Save the request off for later processing. The request buffer looks
* like this:
*
* <xprt-header><rpc-header><rpc-pagelist><rpc-tail>
*
* This code can only handle requests that consist of an xprt-header
* and rpc-header.
*/
static struct cache_deferred_req *svc_defer(struct cache_req *req)
{
struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle);
int size = sizeof(struct svc_deferred_req) + (rqstp->rq_arg.len);
struct svc_deferred_req *dr;
if (rqstp->rq_arg.page_len)
@ -871,8 +878,10 @@ static struct cache_deferred_req *svc_defer(struct cache_req *req)
dr = rqstp->rq_deferred;
rqstp->rq_deferred = NULL;
} else {
int skip = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len;
size_t skip;
size_t size;
/* FIXME maybe discard if size too large */
size = sizeof(struct svc_deferred_req) + rqstp->rq_arg.len;
dr = kmalloc(size, GFP_KERNEL);
if (dr == NULL)
return NULL;
@ -883,8 +892,12 @@ static struct cache_deferred_req *svc_defer(struct cache_req *req)
dr->addrlen = rqstp->rq_addrlen;
dr->daddr = rqstp->rq_daddr;
dr->argslen = rqstp->rq_arg.len >> 2;
memcpy(dr->args, rqstp->rq_arg.head[0].iov_base-skip,
dr->argslen<<2);
dr->xprt_hlen = rqstp->rq_xprt_hlen;
/* back up head to the start of the buffer and copy */
skip = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len;
memcpy(dr->args, rqstp->rq_arg.head[0].iov_base - skip,
dr->argslen << 2);
}
svc_xprt_get(rqstp->rq_xprt);
dr->xprt = rqstp->rq_xprt;
@ -900,16 +913,21 @@ static int svc_deferred_recv(struct svc_rqst *rqstp)
{
struct svc_deferred_req *dr = rqstp->rq_deferred;
rqstp->rq_arg.head[0].iov_base = dr->args;
rqstp->rq_arg.head[0].iov_len = dr->argslen<<2;
/* setup iov_base past transport header */
rqstp->rq_arg.head[0].iov_base = dr->args + (dr->xprt_hlen>>2);
/* The iov_len does not include the transport header bytes */
rqstp->rq_arg.head[0].iov_len = (dr->argslen<<2) - dr->xprt_hlen;
rqstp->rq_arg.page_len = 0;
rqstp->rq_arg.len = dr->argslen<<2;
/* The rq_arg.len includes the transport header bytes */
rqstp->rq_arg.len = dr->argslen<<2;
rqstp->rq_prot = dr->prot;
memcpy(&rqstp->rq_addr, &dr->addr, dr->addrlen);
rqstp->rq_addrlen = dr->addrlen;
/* Save off transport header len in case we get deferred again */
rqstp->rq_xprt_hlen = dr->xprt_hlen;
rqstp->rq_daddr = dr->daddr;
rqstp->rq_respages = rqstp->rq_pages;
return dr->argslen<<2;
return (dr->argslen<<2) - dr->xprt_hlen;
}

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@ -315,6 +315,8 @@ static int svc_recvfrom(struct svc_rqst *rqstp, struct kvec *iov, int nr,
};
int len;
rqstp->rq_xprt_hlen = 0;
len = kernel_recvmsg(svsk->sk_sock, &msg, iov, nr, buflen,
msg.msg_flags);