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: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Devesh Sharma <devesh.sharma@broadcom.com>
Tested-by: Devesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This commit is contained in:
Chuck Lever 2016-03-01 13:06:38 -05:00 committed by J. Bruce Fields
parent c6db03ea57
commit a6081b82c5
5 changed files with 74 additions and 67 deletions

View File

@ -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 *);

View File

@ -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) {

View File

@ -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);

View File

@ -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);
}
}

View File

@ -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);
}
}