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Commit a6081b82 authored by Chuck Lever's avatar Chuck Lever Committed by J. Bruce Fields
Browse files

svcrdma: Make RDMA_ERROR messages work 



Fix several issues with svc_rdma_send_error():

 - Post a receive buffer to replace the one that was consumed by
   the incoming request
 - Posting a send should use DMA_TO_DEVICE, not DMA_FROM_DEVICE
 - No need to put_page _and_ free pages in svc_rdma_put_context
 - Make sure the sge is set up completely in case the error
   path goes through svc_rdma_unmap_dma()
 - Replace the use of ENOSYS, which has a reserved meaning

Related fixes in svc_rdma_recvfrom():

 - Don't leak the ctxt associated with the incoming request
 - Don't close the connection after sending an error reply
 - Let svc_rdma_send_error() figure out the right header error code

As a last clean up, move svc_rdma_send_error() to svc_rdma_sendto.c
with other similar functions. There is some common logic in these
functions that could someday be combined to reduce code duplication.

Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Reviewed-by: default avatarDevesh Sharma <devesh.sharma@broadcom.com>
Tested-by: default avatarDevesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
parent c6db03ea

include/linux/sunrpc/svc_rdma.h

+2 −2
Original line number Diff line number Diff line
@@ -228,11 +228,11 @@ extern int svc_rdma_map_xdr(struct svcxprt_rdma *, struct xdr_buf *, 
extern int svc_rdma_sendto(struct svc_rqst *);

extern struct rpcrdma_read_chunk *

	svc_rdma_get_read_chunk(struct rpcrdma_msg *);

extern void svc_rdma_send_error(struct svcxprt_rdma *, struct rpcrdma_msg *,

				int);



/* svc_rdma_transport.c */

extern int svc_rdma_send(struct svcxprt_rdma *, struct ib_send_wr *);

extern void svc_rdma_send_error(struct svcxprt_rdma *, struct rpcrdma_msg *,

				enum rpcrdma_errcode);

extern int svc_rdma_post_recv(struct svcxprt_rdma *, gfp_t);

extern int svc_rdma_repost_recv(struct svcxprt_rdma *, gfp_t);

extern int svc_rdma_create_listen(struct svc_serv *, int, struct sockaddr *);

net/sunrpc/xprtrdma/svc_rdma_marshal.c

+1 −1
Original line number Diff line number Diff line
@@ -162,7 +162,7 @@ int svc_rdma_xdr_decode_req(struct rpcrdma_msg **rdma_req, 
	}



	if (rmsgp->rm_vers != rpcrdma_version)

		return -ENOSYS;

		return -EPROTONOSUPPORT;



	/* Pull in the extra for the padded case and bump our pointer */

	if (rmsgp->rm_type == rdma_msgp) {

net/sunrpc/xprtrdma/svc_rdma_recvfrom.c

+9 −10
Original line number Diff line number Diff line
@@ -612,7 +612,6 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp) 
	struct svc_rdma_op_ctxt *ctxt = NULL;

	struct rpcrdma_msg *rmsgp;

	int ret = 0;

	int len;



	dprintk("svcrdma: rqstp=%p\n", rqstp);
@@ -654,15 +653,10 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp) 
	rdma_build_arg_xdr(rqstp, ctxt, ctxt->byte_len);



	/* Decode the RDMA header. */

	len = svc_rdma_xdr_decode_req(&rmsgp, rqstp);

	rqstp->rq_xprt_hlen = len;



	/* If the request is invalid, reply with an error */

	if (len < 0) {

		if (len == -ENOSYS)

			svc_rdma_send_error(rdma_xprt, rmsgp, ERR_VERS);

		goto close_out;

	}

	ret = svc_rdma_xdr_decode_req(&rmsgp, rqstp);

	if (ret < 0)

		goto out_err;

	rqstp->rq_xprt_hlen = ret;



	if (svc_rdma_is_backchannel_reply(xprt, rmsgp)) {

		ret = svc_rdma_handle_bc_reply(xprt->xpt_bc_xprt, rmsgp,
@@ -698,6 +692,11 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp) 
	svc_xprt_copy_addrs(rqstp, xprt);

	return ret;



out_err:

	svc_rdma_send_error(rdma_xprt, rmsgp, ret);

	svc_rdma_put_context(ctxt, 0);

	return 0;



 close_out:

	if (ctxt)

		svc_rdma_put_context(ctxt, 1);

net/sunrpc/xprtrdma/svc_rdma_sendto.c

+62 −0
Original line number Diff line number Diff line
@@ -652,3 +652,65 @@ int svc_rdma_sendto(struct svc_rqst *rqstp) 
	set_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags);

	return -ENOTCONN;

}



void svc_rdma_send_error(struct svcxprt_rdma *xprt, struct rpcrdma_msg *rmsgp,

			 int status)

{

	struct ib_send_wr err_wr;

	struct page *p;

	struct svc_rdma_op_ctxt *ctxt;

	enum rpcrdma_errcode err;

	__be32 *va;

	int length;

	int ret;



	ret = svc_rdma_repost_recv(xprt, GFP_KERNEL);

	if (ret)

		return;



	p = alloc_page(GFP_KERNEL);

	if (!p)

		return;

	va = page_address(p);



	/* XDR encode an error reply */

	err = ERR_CHUNK;

	if (status == -EPROTONOSUPPORT)

		err = ERR_VERS;

	length = svc_rdma_xdr_encode_error(xprt, rmsgp, err, va);



	ctxt = svc_rdma_get_context(xprt);

	ctxt->direction = DMA_TO_DEVICE;

	ctxt->count = 1;

	ctxt->pages[0] = p;



	/* Prepare SGE for local address */

	ctxt->sge[0].lkey = xprt->sc_pd->local_dma_lkey;

	ctxt->sge[0].length = length;

	ctxt->sge[0].addr = ib_dma_map_page(xprt->sc_cm_id->device,

					    p, 0, length, DMA_TO_DEVICE);

	if (ib_dma_mapping_error(xprt->sc_cm_id->device, ctxt->sge[0].addr)) {

		dprintk("svcrdma: Error mapping buffer for protocol error\n");

		svc_rdma_put_context(ctxt, 1);

		return;

	}

	atomic_inc(&xprt->sc_dma_used);



	/* Prepare SEND WR */

	memset(&err_wr, 0, sizeof(err_wr));

	ctxt->wr_op = IB_WR_SEND;

	err_wr.wr_id = (unsigned long)ctxt;

	err_wr.sg_list = ctxt->sge;

	err_wr.num_sge = 1;

	err_wr.opcode = IB_WR_SEND;

	err_wr.send_flags = IB_SEND_SIGNALED;



	/* Post It */

	ret = svc_rdma_send(xprt, &err_wr);

	if (ret) {

		dprintk("svcrdma: Error %d posting send for protocol error\n",

			ret);

		svc_rdma_unmap_dma(ctxt);

		svc_rdma_put_context(ctxt, 1);

	}

}

net/sunrpc/xprtrdma/svc_rdma_transport.c

+0 −54
Original line number Diff line number Diff line
@@ -1433,57 +1433,3 @@ int svc_rdma_send(struct svcxprt_rdma *xprt, struct ib_send_wr *wr) 
	}

	return ret;

}
 


void svc_rdma_send_error(struct svcxprt_rdma *xprt, struct rpcrdma_msg *rmsgp,

			 enum rpcrdma_errcode err)

{

	struct ib_send_wr err_wr;

	struct page *p;

	struct svc_rdma_op_ctxt *ctxt;

	__be32 *va;

	int length;

	int ret;



	p = alloc_page(GFP_KERNEL);

	if (!p)

		return;

	va = page_address(p);



	/* XDR encode error */

	length = svc_rdma_xdr_encode_error(xprt, rmsgp, err, va);



	ctxt = svc_rdma_get_context(xprt);

	ctxt->direction = DMA_FROM_DEVICE;

	ctxt->count = 1;

	ctxt->pages[0] = p;



	/* Prepare SGE for local address */

	ctxt->sge[0].addr = ib_dma_map_page(xprt->sc_cm_id->device,

					    p, 0, length, DMA_FROM_DEVICE);

	if (ib_dma_mapping_error(xprt->sc_cm_id->device, ctxt->sge[0].addr)) {

		put_page(p);

		svc_rdma_put_context(ctxt, 1);

		return;

	}

	atomic_inc(&xprt->sc_dma_used);

	ctxt->sge[0].lkey = xprt->sc_pd->local_dma_lkey;

	ctxt->sge[0].length = length;



	/* Prepare SEND WR */

	memset(&err_wr, 0, sizeof err_wr);

	ctxt->wr_op = IB_WR_SEND;

	err_wr.wr_id = (unsigned long)ctxt;

	err_wr.sg_list = ctxt->sge;

	err_wr.num_sge = 1;

	err_wr.opcode = IB_WR_SEND;

	err_wr.send_flags = IB_SEND_SIGNALED;



	/* Post It */

	ret = svc_rdma_send(xprt, &err_wr);

	if (ret) {

		dprintk("svcrdma: Error %d posting send for protocol error\n",

			ret);

		svc_rdma_unmap_dma(ctxt);

		svc_rdma_put_context(ctxt, 1);

	}

}