diff options
| -rw-r--r-- | include/linux/sunrpc/xdr.h | 13 | ||||
| -rw-r--r-- | net/sunrpc/xprtrdma/backchannel.c | 40 | ||||
| -rw-r--r-- | net/sunrpc/xprtrdma/rpc_rdma.c | 58 |
3 files changed, 59 insertions, 52 deletions
diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h index 261b48a2701d..86b59e3525a5 100644 --- a/include/linux/sunrpc/xdr.h +++ b/include/linux/sunrpc/xdr.h @@ -239,6 +239,19 @@ extern unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len); extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len); extern int xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data); +/** + * xdr_stream_remaining - Return the number of bytes remaining in the stream + * @xdr: pointer to struct xdr_stream + * + * Return value: + * Number of bytes remaining in @xdr before xdr->end + */ +static inline size_t +xdr_stream_remaining(const struct xdr_stream *xdr) +{ + return xdr->nwords << 2; +} + ssize_t xdr_stream_decode_string_dup(struct xdr_stream *xdr, char **str, size_t maxlen, gfp_t gfp_flags); /** diff --git a/net/sunrpc/xprtrdma/backchannel.c b/net/sunrpc/xprtrdma/backchannel.c index 03f6b5840764..183a103e08a8 100644 --- a/net/sunrpc/xprtrdma/backchannel.c +++ b/net/sunrpc/xprtrdma/backchannel.c @@ -271,9 +271,6 @@ void xprt_rdma_bc_free_rqst(struct rpc_rqst *rqst) * @xprt: transport receiving the call * @rep: receive buffer containing the call * - * Called in the RPC reply handler, which runs in a tasklet. - * Be quick about it. - * * Operational assumptions: * o Backchannel credits are ignored, just as the NFS server * forechannel currently does @@ -284,7 +281,6 @@ void rpcrdma_bc_receive_call(struct rpcrdma_xprt *r_xprt, struct rpcrdma_rep *rep) { struct rpc_xprt *xprt = &r_xprt->rx_xprt; - struct rpcrdma_msg *headerp; struct svc_serv *bc_serv; struct rpcrdma_req *req; struct rpc_rqst *rqst; @@ -292,24 +288,15 @@ void rpcrdma_bc_receive_call(struct rpcrdma_xprt *r_xprt, size_t size; __be32 *p; - headerp = rdmab_to_msg(rep->rr_rdmabuf); + p = xdr_inline_decode(&rep->rr_stream, 0); + size = xdr_stream_remaining(&rep->rr_stream); + #ifdef RPCRDMA_BACKCHANNEL_DEBUG pr_info("RPC: %s: callback XID %08x, length=%u\n", - __func__, be32_to_cpu(headerp->rm_xid), rep->rr_len); - pr_info("RPC: %s: %*ph\n", __func__, rep->rr_len, headerp); + __func__, be32_to_cpup(p), size); + pr_info("RPC: %s: %*ph\n", __func__, size, p); #endif - /* Sanity check: - * Need at least enough bytes for RPC/RDMA header, as code - * here references the header fields by array offset. Also, - * backward calls are always inline, so ensure there - * are some bytes beyond the RPC/RDMA header. - */ - if (rep->rr_len < RPCRDMA_HDRLEN_MIN + 24) - goto out_short; - p = (__be32 *)((unsigned char *)headerp + RPCRDMA_HDRLEN_MIN); - size = rep->rr_len - RPCRDMA_HDRLEN_MIN; - /* Grab a free bc rqst */ spin_lock(&xprt->bc_pa_lock); if (list_empty(&xprt->bc_pa_list)) { @@ -325,7 +312,7 @@ void rpcrdma_bc_receive_call(struct rpcrdma_xprt *r_xprt, /* Prepare rqst */ rqst->rq_reply_bytes_recvd = 0; rqst->rq_bytes_sent = 0; - rqst->rq_xid = headerp->rm_xid; + rqst->rq_xid = *p; rqst->rq_private_buf.len = size; set_bit(RPC_BC_PA_IN_USE, &rqst->rq_bc_pa_state); @@ -337,9 +324,9 @@ void rpcrdma_bc_receive_call(struct rpcrdma_xprt *r_xprt, buf->len = size; /* The receive buffer has to be hooked to the rpcrdma_req - * so that it can be reposted after the server is done - * parsing it but just before sending the backward - * direction reply. + * so that it is not released while the req is pointing + * to its buffer, and so that it can be reposted after + * the Upper Layer is done decoding it. */ req = rpcr_to_rdmar(rqst); dprintk("RPC: %s: attaching rep %p to req %p\n", @@ -367,13 +354,4 @@ out_overflow: * when the connection is re-established. */ return; - -out_short: - pr_warn("RPC/RDMA short backward direction call\n"); - - if (rpcrdma_ep_post_recv(&r_xprt->rx_ia, rep)) - xprt_disconnect_done(xprt); - else - pr_warn("RPC: %s: reposting rep %p\n", - __func__, rep); } diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c index 24f58c7b3106..9b5ab598ab7b 100644 --- a/net/sunrpc/xprtrdma/rpc_rdma.c +++ b/net/sunrpc/xprtrdma/rpc_rdma.c @@ -949,35 +949,59 @@ rpcrdma_mark_remote_invalidation(struct list_head *mws, } } -#if defined(CONFIG_SUNRPC_BACKCHANNEL) /* By convention, backchannel calls arrive via rdma_msg type * messages, and never populate the chunk lists. This makes * the RPC/RDMA header small and fixed in size, so it is * straightforward to check the RPC header's direction field. */ static bool -rpcrdma_is_bcall(struct rpcrdma_msg *headerp) +rpcrdma_is_bcall(struct rpcrdma_xprt *r_xprt, struct rpcrdma_rep *rep, + __be32 xid, __be32 proc) +#if defined(CONFIG_SUNRPC_BACKCHANNEL) { - __be32 *p = (__be32 *)headerp; + struct xdr_stream *xdr = &rep->rr_stream; + __be32 *p; - if (headerp->rm_type != rdma_msg) + if (proc != rdma_msg) return false; - if (headerp->rm_body.rm_chunks[0] != xdr_zero) + + /* Peek at stream contents without advancing. */ + p = xdr_inline_decode(xdr, 0); + + /* Chunk lists */ + if (*p++ != xdr_zero) return false; - if (headerp->rm_body.rm_chunks[1] != xdr_zero) + if (*p++ != xdr_zero) return false; - if (headerp->rm_body.rm_chunks[2] != xdr_zero) + if (*p++ != xdr_zero) return false; - /* sanity */ - if (p[7] != headerp->rm_xid) + /* RPC header */ + if (*p++ != xid) return false; - /* call direction */ - if (p[8] != cpu_to_be32(RPC_CALL)) + if (*p != cpu_to_be32(RPC_CALL)) return false; + /* Now that we are sure this is a backchannel call, + * advance to the RPC header. + */ + p = xdr_inline_decode(xdr, 3 * sizeof(*p)); + if (unlikely(!p)) + goto out_short; + + rpcrdma_bc_receive_call(r_xprt, rep); + return true; + +out_short: + pr_warn("RPC/RDMA short backward direction call\n"); + if (rpcrdma_ep_post_recv(&r_xprt->rx_ia, rep)) + xprt_disconnect_done(&r_xprt->rx_xprt); return true; } +#else /* CONFIG_SUNRPC_BACKCHANNEL */ +{ + return false; +} #endif /* CONFIG_SUNRPC_BACKCHANNEL */ /* Process received RPC/RDMA messages. @@ -1020,10 +1044,8 @@ rpcrdma_reply_handler(struct work_struct *work) proc = *p++; headerp = rdmab_to_msg(rep->rr_rdmabuf); -#if defined(CONFIG_SUNRPC_BACKCHANNEL) - if (rpcrdma_is_bcall(headerp)) - goto out_bcall; -#endif + if (rpcrdma_is_bcall(r_xprt, rep, xid, proc)) + return; /* Match incoming rpcrdma_rep to an rpcrdma_req to * get context for handling any incoming chunks. @@ -1159,12 +1181,6 @@ out_badstatus: } return; -#if defined(CONFIG_SUNRPC_BACKCHANNEL) -out_bcall: - rpcrdma_bc_receive_call(r_xprt, rep); - return; -#endif - /* If the incoming reply terminated a pending RPC, the next * RPC call will post a replacement receive buffer as it is * being marshaled. |