Commit 260c1d12 authored by Tom Tucker's avatar Tom Tucker Committed by J. Bruce Fields
Browse files

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: default avatarTom Tucker <tom@opengridcomputing.com>
Acked-by: default avatarNeil Brown <neilb@suse.de>
Reviewed-by: default avatarChuck Lever <chuck.lever@oracle.com>
Reviewed-by: default avatarGreg Banks <gnb@sgi.com>
Signed-off-by: default avatarJ. Bruce Fields <bfields@citi.umich.edu>
parent 0f0257ea

include/linux/sunrpc/svc.h

+2 −0
Original line number Diff line number Diff line
@@ -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];

};

net/sunrpc/svc_xprt.c

+27 −9
Original line number Diff line number Diff line
@@ -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;
@@ -883,6 +892,10 @@ 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;

		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);

	}
@@ -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;

	/* 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;

}

net/sunrpc/svcsock.c

+2 −0
Original line number Diff line number Diff line
@@ -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);

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