/* * Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved. * * This software is available to you under a choice of one of two * licenses. You may choose to be licensed under the terms of the GNU * General Public License (GPL) Version 2, available from the file * COPYING in the main directory of this source tree, or the BSD-type * license below: * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above * copyright notice, this list of conditions and the following * disclaimer in the documentation and/or other materials provided * with the distribution. * * Neither the name of the Network Appliance, Inc. nor the names of * its contributors may be used to endorse or promote products * derived from this software without specific prior written * permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /* * rpc_rdma.c * * This file contains the guts of the RPC RDMA protocol, and * does marshaling/unmarshaling, etc. It is also where interfacing * to the Linux RPC framework lives. */ #include "xprt_rdma.h" #include #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) # define RPCDBG_FACILITY RPCDBG_TRANS #endif enum rpcrdma_chunktype { rpcrdma_noch = 0, rpcrdma_readch, rpcrdma_areadch, rpcrdma_writech, rpcrdma_replych }; static const char transfertypes[][12] = { "inline", /* no chunks */ "read list", /* some argument via rdma read */ "*read list", /* entire request via rdma read */ "write list", /* some result via rdma write */ "reply chunk" /* entire reply via rdma write */ }; /* Returns size of largest RPC-over-RDMA header in a Call message * * The largest Call header contains a full-size Read list and a * minimal Reply chunk. */ static unsigned int rpcrdma_max_call_header_size(unsigned int maxsegs) { unsigned int size; /* Fixed header fields and list discriminators */ size = RPCRDMA_HDRLEN_MIN; /* Maximum Read list size */ maxsegs += 2; /* segment for head and tail buffers */ size = maxsegs * sizeof(struct rpcrdma_read_chunk); /* Minimal Read chunk size */ size += sizeof(__be32); /* segment count */ size += sizeof(struct rpcrdma_segment); size += sizeof(__be32); /* list discriminator */ dprintk("RPC: %s: max call header size = %u\n", __func__, size); return size; } /* Returns size of largest RPC-over-RDMA header in a Reply message * * There is only one Write list or one Reply chunk per Reply * message. The larger list is the Write list. */ static unsigned int rpcrdma_max_reply_header_size(unsigned int maxsegs) { unsigned int size; /* Fixed header fields and list discriminators */ size = RPCRDMA_HDRLEN_MIN; /* Maximum Write list size */ maxsegs += 2; /* segment for head and tail buffers */ size = sizeof(__be32); /* segment count */ size += maxsegs * sizeof(struct rpcrdma_segment); size += sizeof(__be32); /* list discriminator */ dprintk("RPC: %s: max reply header size = %u\n", __func__, size); return size; } void rpcrdma_set_max_header_sizes(struct rpcrdma_ia *ia, struct rpcrdma_create_data_internal *cdata, unsigned int maxsegs) { ia->ri_max_inline_write = cdata->inline_wsize - rpcrdma_max_call_header_size(maxsegs); ia->ri_max_inline_read = cdata->inline_rsize - rpcrdma_max_reply_header_size(maxsegs); } /* The client can send a request inline as long as the RPCRDMA header * plus the RPC call fit under the transport's inline limit. If the * combined call message size exceeds that limit, the client must use * the read chunk list for this operation. */ static bool rpcrdma_args_inline(struct rpcrdma_xprt *r_xprt, struct rpc_rqst *rqst) { struct rpcrdma_ia *ia = &r_xprt->rx_ia; return rqst->rq_snd_buf.len <= ia->ri_max_inline_write; } /* The client can't know how large the actual reply will be. Thus it * plans for the largest possible reply for that particular ULP * operation. If the maximum combined reply message size exceeds that * limit, the client must provide a write list or a reply chunk for * this request. */ static bool rpcrdma_results_inline(struct rpcrdma_xprt *r_xprt, struct rpc_rqst *rqst) { struct rpcrdma_ia *ia = &r_xprt->rx_ia; return rqst->rq_rcv_buf.buflen <= ia->ri_max_inline_read; } static int rpcrdma_tail_pullup(struct xdr_buf *buf) { size_t tlen = buf->tail[0].iov_len; size_t skip = tlen & 3; /* Do not include the tail if it is only an XDR pad */ if (tlen < 4) return 0; /* xdr_write_pages() adds a pad at the beginning of the tail * if the content in "buf->pages" is unaligned. Force the * tail's actual content to land at the next XDR position * after the head instead. */ if (skip) { unsigned char *src, *dst; unsigned int count; src = buf->tail[0].iov_base; dst = buf->head[0].iov_base; dst += buf->head[0].iov_len; src += skip; tlen -= skip; dprintk("RPC: %s: skip=%zu, memmove(%p, %p, %zu)\n", __func__, skip, dst, src, tlen); for (count = tlen; count; count--) *dst++ = *src++; } return tlen; } /* Split "vec" on page boundaries into segments. FMR registers pages, * not a byte range. Other modes coalesce these segments into a single * MR when they can. */ static int rpcrdma_convert_kvec(struct kvec *vec, struct rpcrdma_mr_seg *seg, int n, int nsegs) { size_t page_offset; u32 remaining; char *base; base = vec->iov_base; page_offset = offset_in_page(base); remaining = vec->iov_len; while (remaining && n < nsegs) { seg[n].mr_page = NULL; seg[n].mr_offset = base; seg[n].mr_len = min_t(u32, PAGE_SIZE - page_offset, remaining); remaining -= seg[n].mr_len; base += seg[n].mr_len; ++n; page_offset = 0; } return n; } /* * Chunk assembly from upper layer xdr_buf. * * Prepare the passed-in xdr_buf into representation as RPC/RDMA chunk * elements. Segments are then coalesced when registered, if possible * within the selected memreg mode. * * Returns positive number of segments converted, or a negative errno. */ static int rpcrdma_convert_iovs(struct xdr_buf *xdrbuf, unsigned int pos, enum rpcrdma_chunktype type, struct rpcrdma_mr_seg *seg, int nsegs) { int len, n = 0, p; int page_base; struct page **ppages; if (pos == 0) { n = rpcrdma_convert_kvec(&xdrbuf->head[0], seg, n, nsegs); if (n == nsegs) return -EIO; } len = xdrbuf->page_len; ppages = xdrbuf->pages + (xdrbuf->page_base >> PAGE_SHIFT); page_base = xdrbuf->page_base & ~PAGE_MASK; p = 0; while (len && n < nsegs) { if (!ppages[p]) { /* alloc the pagelist for receiving buffer */ ppages[p] = alloc_page(GFP_ATOMIC); if (!ppages[p]) return -ENOMEM; } seg[n].mr_page = ppages[p]; seg[n].mr_offset = (void *)(unsigned long) page_base; seg[n].mr_len = min_t(u32, PAGE_SIZE - page_base, len); if (seg[n].mr_len > PAGE_SIZE) return -EIO; len -= seg[n].mr_len; ++n; ++p; page_base = 0; /* page offset only applies to first page */ } /* Message overflows the seg array */ if (len && n == nsegs) return -EIO; /* When encoding the read list, the tail is always sent inline */ if (type == rpcrdma_readch) return n; if (xdrbuf->tail[0].iov_len) { /* the rpcrdma protocol allows us to omit any trailing * xdr pad bytes, saving the server an RDMA operation. */ if (xdrbuf->tail[0].iov_len < 4 && xprt_rdma_pad_optimize) return n; n = rpcrdma_convert_kvec(&xdrbuf->tail[0], seg, n, nsegs); if (n == nsegs) return -EIO; } return n; } /* * Create read/write chunk lists, and reply chunks, for RDMA * * Assume check against THRESHOLD has been done, and chunks are required. * Assume only encoding one list entry for read|write chunks. The NFSv3 * protocol is simple enough to allow this as it only has a single "bulk * result" in each procedure - complicated NFSv4 COMPOUNDs are not. (The * RDMA/Sessions NFSv4 proposal addresses this for future v4 revs.) * * When used for a single reply chunk (which is a special write * chunk used for the entire reply, rather than just the data), it * is used primarily for READDIR and READLINK which would otherwise * be severely size-limited by a small rdma inline read max. The server * response will come back as an RDMA Write, followed by a message * of type RDMA_NOMSG carrying the xid and length. As a result, reply * chunks do not provide data alignment, however they do not require * "fixup" (moving the response to the upper layer buffer) either. * * Encoding key for single-list chunks (HLOO = Handle32 Length32 Offset64): * * Read chunklist (a linked list): * N elements, position P (same P for all chunks of same arg!): * 1 - PHLOO - 1 - PHLOO - ... - 1 - PHLOO - 0 * * Write chunklist (a list of (one) counted array): * N elements: * 1 - N - HLOO - HLOO - ... - HLOO - 0 * * Reply chunk (a counted array): * N elements: * 1 - N - HLOO - HLOO - ... - HLOO * * Returns positive RPC/RDMA header size, or negative errno. */ static ssize_t rpcrdma_create_chunks(struct rpc_rqst *rqst, struct xdr_buf *target, struct rpcrdma_msg *headerp, enum rpcrdma_chunktype type) { struct rpcrdma_req *req = rpcr_to_rdmar(rqst); struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt); int n, nsegs, nchunks = 0; unsigned int pos; struct rpcrdma_mr_seg *seg = req->rl_segments; struct rpcrdma_read_chunk *cur_rchunk = NULL; struct rpcrdma_write_array *warray = NULL; struct rpcrdma_write_chunk *cur_wchunk = NULL; __be32 *iptr = headerp->rm_body.rm_chunks; int (*map)(struct rpcrdma_xprt *, struct rpcrdma_mr_seg *, int, bool); if (type == rpcrdma_readch || type == rpcrdma_areadch) { /* a read chunk - server will RDMA Read our memory */ cur_rchunk = (struct rpcrdma_read_chunk *) iptr; } else { /* a write or reply chunk - server will RDMA Write our memory */ *iptr++ = xdr_zero; /* encode a NULL read chunk list */ if (type == rpcrdma_replych) *iptr++ = xdr_zero; /* a NULL write chunk list */ warray = (struct rpcrdma_write_array *) iptr; cur_wchunk = (struct rpcrdma_write_chunk *) (warray + 1); } if (type == rpcrdma_replych || type == rpcrdma_areadch) pos = 0; else pos = target->head[0].iov_len; nsegs = rpcrdma_convert_iovs(target, pos, type, seg, RPCRDMA_MAX_SEGS); if (nsegs < 0) return nsegs; map = r_xprt->rx_ia.ri_ops->ro_map; do { n = map(r_xprt, seg, nsegs, cur_wchunk != NULL); if (n <= 0) goto out; if (cur_rchunk) { /* read */ cur_rchunk->rc_discrim = xdr_one; /* all read chunks have the same "position" */ cur_rchunk->rc_position = cpu_to_be32(pos); cur_rchunk->rc_target.rs_handle = cpu_to_be32(seg->mr_rkey); cur_rchunk->rc_target.rs_length = cpu_to_be32(seg->mr_len); xdr_encode_hyper( (__be32 *)&cur_rchunk->rc_target.rs_offset, seg->mr_base); dprintk("RPC: %s: read chunk " "elem %d@0x%llx:0x%x pos %u (%s)\n", __func__, seg->mr_len, (unsigned long long)seg->mr_base, seg->mr_rkey, pos, n < nsegs ? "more" : "last"); cur_rchunk++; r_xprt->rx_stats.read_chunk_count++; } else { /* write/reply */ cur_wchunk->wc_target.rs_handle = cpu_to_be32(seg->mr_rkey); cur_wchunk->wc_target.rs_length = cpu_to_be32(seg->mr_len); xdr_encode_hyper( (__be32 *)&cur_wchunk->wc_target.rs_offset, seg->mr_base); dprintk("RPC: %s: %s chunk " "elem %d@0x%llx:0x%x (%s)\n", __func__, (type == rpcrdma_replych) ? "reply" : "write", seg->mr_len, (unsigned long long)seg->mr_base, seg->mr_rkey, n < nsegs ? "more" : "last"); cur_wchunk++; if (type == rpcrdma_replych) r_xprt->rx_stats.reply_chunk_count++; else r_xprt->rx_stats.write_chunk_count++; r_xprt->rx_stats.total_rdma_request += seg->mr_len; } nchunks++; seg += n; nsegs -= n; } while (nsegs); /* success. all failures return above */ req->rl_nchunks = nchunks; /* * finish off header. If write, marshal discrim and nchunks. */ if (cur_rchunk) { iptr = (__be32 *) cur_rchunk; *iptr++ = xdr_zero; /* finish the read chunk list */ *iptr++ = xdr_zero; /* encode a NULL write chunk list */ *iptr++ = xdr_zero; /* encode a NULL reply chunk */ } else { warray->wc_discrim = xdr_one; warray->wc_nchunks = cpu_to_be32(nchunks); iptr = (__be32 *) cur_wchunk; if (type == rpcrdma_writech) { *iptr++ = xdr_zero; /* finish the write chunk list */ *iptr++ = xdr_zero; /* encode a NULL reply chunk */ } } /* * Return header size. */ return (unsigned char *)iptr - (unsigned char *)headerp; out: for (pos = 0; nchunks--;) pos += r_xprt->rx_ia.ri_ops->ro_unmap(r_xprt, &req->rl_segments[pos]); return n; } static inline __be32 * xdr_encode_rdma_segment(__be32 *iptr, struct rpcrdma_mr_seg *seg) { *iptr++ = cpu_to_be32(seg->mr_rkey); *iptr++ = cpu_to_be32(seg->mr_len); return xdr_encode_hyper(iptr, seg->mr_base); } /* XDR-encode the Read list. Supports encoding a list of read * segments that belong to a single read chunk. * * Encoding key for single-list chunks (HLOO = Handle32 Length32 Offset64): * * Read chunklist (a linked list): * N elements, position P (same P for all chunks of same arg!): * 1 - PHLOO - 1 - PHLOO - ... - 1 - PHLOO - 0 * * Returns a pointer to the XDR word in the RDMA header following * the end of the Read list, or an error pointer. */ static __be32 * rpcrdma_encode_read_list(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req, struct rpc_rqst *rqst, __be32 *iptr, enum rpcrdma_chunktype rtype) { struct rpcrdma_mr_seg *seg = req->rl_nextseg; unsigned int pos; int n, nsegs; if (rtype == rpcrdma_noch) { *iptr++ = xdr_zero; /* item not present */ return iptr; } pos = rqst->rq_snd_buf.head[0].iov_len; if (rtype == rpcrdma_areadch) pos = 0; nsegs = rpcrdma_convert_iovs(&rqst->rq_snd_buf, pos, rtype, seg, RPCRDMA_MAX_SEGS - req->rl_nchunks); if (nsegs < 0) return ERR_PTR(nsegs); do { n = r_xprt->rx_ia.ri_ops->ro_map(r_xprt, seg, nsegs, false); if (n <= 0) return ERR_PTR(n); *iptr++ = xdr_one; /* item present */ /* All read segments in this chunk * have the same "position". */ *iptr++ = cpu_to_be32(pos); iptr = xdr_encode_rdma_segment(iptr, seg); dprintk("RPC: %5u %s: read segment pos %u " "%d@0x%016llx:0x%08x (%s)\n", rqst->rq_task->tk_pid, __func__, pos, seg->mr_len, (unsigned long long)seg->mr_base, seg->mr_rkey, n < nsegs ? "more" : "last"); r_xprt->rx_stats.read_chunk_count++; req->rl_nchunks++; seg += n; nsegs -= n; } while (nsegs); req->rl_nextseg = seg; /* Finish Read list */ *iptr++ = xdr_zero; /* Next item not present */ return iptr; } /* XDR-encode the Write list. Supports encoding a list containing * one array of plain segments that belong to a single write chunk. * * Encoding key for single-list chunks (HLOO = Handle32 Length32 Offset64): * * Write chunklist (a list of (one) counted array): * N elements: * 1 - N - HLOO - HLOO - ... - HLOO - 0 * * Returns a pointer to the XDR word in the RDMA header following * the end of the Write list, or an error pointer. */ static __be32 * rpcrdma_encode_write_list(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req, struct rpc_rqst *rqst, __be32 *iptr, enum rpcrdma_chunktype wtype) { struct rpcrdma_mr_seg *seg = req->rl_nextseg; int n, nsegs, nchunks; __be32 *segcount; if (wtype != rpcrdma_writech) { *iptr++ = xdr_zero; /* no Write list present */ return iptr; } nsegs = rpcrdma_convert_iovs(&rqst->rq_rcv_buf, rqst->rq_rcv_buf.head[0].iov_len, wtype, seg, RPCRDMA_MAX_SEGS - req->rl_nchunks); if (nsegs < 0) return ERR_PTR(nsegs); *iptr++ = xdr_one; /* Write list present */ segcount = iptr++; /* save location of segment count */ nchunks = 0; do { n = r_xprt->rx_ia.ri_ops->ro_map(r_xprt, seg, nsegs, true); if (n <= 0) return ERR_PTR(n); iptr = xdr_encode_rdma_segment(iptr, seg); dprintk("RPC: %5u %s: write segment " "%d@0x016%llx:0x%08x (%s)\n", rqst->rq_task->tk_pid, __func__, seg->mr_len, (unsigned long long)seg->mr_base, seg->mr_rkey, n < nsegs ? "more" : "last"); r_xprt->rx_stats.write_chunk_count++; r_xprt->rx_stats.total_rdma_request += seg->mr_len; req->rl_nchunks++; nchunks++; seg += n; nsegs -= n; } while (nsegs); req->rl_nextseg = seg; /* Update count of segments in this Write chunk */ *segcount = cpu_to_be32(nchunks); /* Finish Write list */ *iptr++ = xdr_zero; /* Next item not present */ return iptr; } /* XDR-encode the Reply chunk. Supports encoding an array of plain * segments that belong to a single write (reply) chunk. * * Encoding key for single-list chunks (HLOO = Handle32 Length32 Offset64): * * Reply chunk (a counted array): * N elements: * 1 - N - HLOO - HLOO - ... - HLOO * * Returns a pointer to the XDR word in the RDMA header following * the end of the Reply chunk, or an error pointer. */ static __be32 * rpcrdma_encode_reply_chunk(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req, struct rpc_rqst *rqst, __be32 *iptr, enum rpcrdma_chunktype wtype) { struct rpcrdma_mr_seg *seg = req->rl_nextseg; int n, nsegs, nchunks; __be32 *segcount; if (wtype != rpcrdma_replych) { *iptr++ = xdr_zero; /* no Reply chunk present */ return iptr; } nsegs = rpcrdma_convert_iovs(&rqst->rq_rcv_buf, 0, wtype, seg, RPCRDMA_MAX_SEGS - req->rl_nchunks); if (nsegs < 0) return ERR_PTR(nsegs); *iptr++ = xdr_one; /* Reply chunk present */ segcount = iptr++; /* save location of segment count */ nchunks = 0; do { n = r_xprt->rx_ia.ri_ops->ro_map(r_xprt, seg, nsegs, true); if (n <= 0) return ERR_PTR(n); iptr = xdr_encode_rdma_segment(iptr, seg); dprintk("RPC: %5u %s: reply segment " "%d@0x%016llx:0x%08x (%s)\n", rqst->rq_task->tk_pid, __func__, seg->mr_len, (unsigned long long)seg->mr_base, seg->mr_rkey, n < nsegs ? "more" : "last"); r_xprt->rx_stats.reply_chunk_count++; r_xprt->rx_stats.total_rdma_request += seg->mr_len; req->rl_nchunks++; nchunks++; seg += n; nsegs -= n; } while (nsegs); req->rl_nextseg = seg; /* Update count of segments in the Reply chunk */ *segcount = cpu_to_be32(nchunks); return iptr; } /* * Copy write data inline. * This function is used for "small" requests. Data which is passed * to RPC via iovecs (or page list) is copied directly into the * pre-registered memory buffer for this request. For small amounts * of data, this is efficient. The cutoff value is tunable. */ static void rpcrdma_inline_pullup(struct rpc_rqst *rqst) { int i, npages, curlen; int copy_len; unsigned char *srcp, *destp; struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt); int page_base; struct page **ppages; destp = rqst->rq_svec[0].iov_base; curlen = rqst->rq_svec[0].iov_len; destp += curlen; dprintk("RPC: %s: destp 0x%p len %d hdrlen %d\n", __func__, destp, rqst->rq_slen, curlen); copy_len = rqst->rq_snd_buf.page_len; if (rqst->rq_snd_buf.tail[0].iov_len) { curlen = rqst->rq_snd_buf.tail[0].iov_len; if (destp + copy_len != rqst->rq_snd_buf.tail[0].iov_base) { memmove(destp + copy_len, rqst->rq_snd_buf.tail[0].iov_base, curlen); r_xprt->rx_stats.pullup_copy_count += curlen; } dprintk("RPC: %s: tail destp 0x%p len %d\n", __func__, destp + copy_len, curlen); rqst->rq_svec[0].iov_len += curlen; } r_xprt->rx_stats.pullup_copy_count += copy_len; page_base = rqst->rq_snd_buf.page_base; ppages = rqst->rq_snd_buf.pages + (page_base >> PAGE_SHIFT); page_base &= ~PAGE_MASK; npages = PAGE_ALIGN(page_base+copy_len) >> PAGE_SHIFT; for (i = 0; copy_len && i < npages; i++) { curlen = PAGE_SIZE - page_base; if (curlen > copy_len) curlen = copy_len; dprintk("RPC: %s: page %d destp 0x%p len %d curlen %d\n", __func__, i, destp, copy_len, curlen); srcp = kmap_atomic(ppages[i]); memcpy(destp, srcp+page_base, curlen); kunmap_atomic(srcp); rqst->rq_svec[0].iov_len += curlen; destp += curlen; copy_len -= curlen; page_base = 0; } /* header now contains entire send message */ } /* * Marshal a request: the primary job of this routine is to choose * the transfer modes. See comments below. * * Prepares up to two IOVs per Call message: * * [0] -- RPC RDMA header * [1] -- the RPC header/data * * Returns zero on success, otherwise a negative errno. */ int rpcrdma_marshal_req(struct rpc_rqst *rqst) { struct rpc_xprt *xprt = rqst->rq_xprt; struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt); struct rpcrdma_req *req = rpcr_to_rdmar(rqst); enum rpcrdma_chunktype rtype, wtype; struct rpcrdma_msg *headerp; unsigned int pos; ssize_t hdrlen; size_t rpclen; __be32 *iptr; #if defined(CONFIG_SUNRPC_BACKCHANNEL) if (test_bit(RPC_BC_PA_IN_USE, &rqst->rq_bc_pa_state)) return rpcrdma_bc_marshal_reply(rqst); #endif headerp = rdmab_to_msg(req->rl_rdmabuf); /* don't byte-swap XID, it's already done in request */ headerp->rm_xid = rqst->rq_xid; headerp->rm_vers = rpcrdma_version; headerp->rm_credit = cpu_to_be32(r_xprt->rx_buf.rb_max_requests); headerp->rm_type = rdma_msg; /* * Chunks needed for results? * * o If the expected result is under the inline threshold, all ops * return as inline. * o Large read ops return data as write chunk(s), header as * inline. * o Large non-read ops return as a single reply chunk. */ if (rpcrdma_results_inline(r_xprt, rqst)) wtype = rpcrdma_noch; else if (rqst->rq_rcv_buf.flags & XDRBUF_READ) wtype = rpcrdma_writech; else wtype = rpcrdma_replych; /* * Chunks needed for arguments? * * o If the total request is under the inline threshold, all ops * are sent as inline. * o Large write ops transmit data as read chunk(s), header as * inline. * o Large non-write ops are sent with the entire message as a * single read chunk (protocol 0-position special case). * * This assumes that the upper layer does not present a request * that both has a data payload, and whose non-data arguments * by themselves are larger than the inline threshold. */ if (rpcrdma_args_inline(r_xprt, rqst)) { rtype = rpcrdma_noch; rpcrdma_inline_pullup(rqst); rpclen = rqst->rq_svec[0].iov_len; } else if (rqst->rq_snd_buf.flags & XDRBUF_WRITE) { rtype = rpcrdma_readch; rpclen = rqst->rq_svec[0].iov_len; rpclen += rpcrdma_tail_pullup(&rqst->rq_snd_buf); } else { r_xprt->rx_stats.nomsg_call_count++; headerp->rm_type = htonl(RDMA_NOMSG); rtype = rpcrdma_areadch; rpclen = 0; } /* This implementation supports the following combinations * of chunk lists in one RPC-over-RDMA Call message: * * - Read list * - Write list * - Reply chunk * - Read list + Reply chunk * * It might not yet support the following combinations: * * - Read list + Write list * * It does not support the following combinations: * * - Write list + Reply chunk * - Read list + Write list + Reply chunk * * This implementation supports only a single chunk in each * Read or Write list. Thus for example the client cannot * send a Call message with a Position Zero Read chunk and a * regular Read chunk at the same time. */ req->rl_nchunks = 0; req->rl_nextseg = req->rl_segments; iptr = headerp->rm_body.rm_chunks; iptr = rpcrdma_encode_read_list(r_xprt, req, rqst, iptr, rtype); if (IS_ERR(iptr)) goto out_unmap; iptr = rpcrdma_encode_write_list(r_xprt, req, rqst, iptr, wtype); if (IS_ERR(iptr)) goto out_unmap; iptr = rpcrdma_encode_reply_chunk(r_xprt, req, rqst, iptr, wtype); if (IS_ERR(iptr)) goto out_unmap; hdrlen = (unsigned char *)iptr - (unsigned char *)headerp; if (hdrlen + rpclen > RPCRDMA_INLINE_WRITE_THRESHOLD(rqst)) goto out_overflow; dprintk("RPC: %5u %s: %s/%s: hdrlen %zd rpclen %zd\n", rqst->rq_task->tk_pid, __func__, transfertypes[rtype], transfertypes[wtype], hdrlen, rpclen); req->rl_send_iov[0].addr = rdmab_addr(req->rl_rdmabuf); req->rl_send_iov[0].length = hdrlen; req->rl_send_iov[0].lkey = rdmab_lkey(req->rl_rdmabuf); req->rl_niovs = 1; if (rtype == rpcrdma_areadch) return 0; req->rl_send_iov[1].addr = rdmab_addr(req->rl_sendbuf); req->rl_send_iov[1].length = rpclen; req->rl_send_iov[1].lkey = rdmab_lkey(req->rl_sendbuf); req->rl_niovs = 2; return 0; out_overflow: pr_err("rpcrdma: send overflow: hdrlen %zd rpclen %zu %s/%s\n", hdrlen, rpclen, transfertypes[rtype], transfertypes[wtype]); /* Terminate this RPC. Chunks registered above will be * released by xprt_release -> xprt_rmda_free . */ return -EIO; out_unmap: for (pos = 0; req->rl_nchunks--;) pos += r_xprt->rx_ia.ri_ops->ro_unmap(r_xprt, &req->rl_segments[pos]); return PTR_ERR(iptr); } /* * Chase down a received write or reply chunklist to get length * RDMA'd by server. See map at rpcrdma_create_chunks()! :-) */ static int rpcrdma_count_chunks(struct rpcrdma_rep *rep, unsigned int max, int wrchunk, __be32 **iptrp) { unsigned int i, total_len; struct rpcrdma_write_chunk *cur_wchunk; char *base = (char *)rdmab_to_msg(rep->rr_rdmabuf); i = be32_to_cpu(**iptrp); if (i > max) return -1; cur_wchunk = (struct rpcrdma_write_chunk *) (*iptrp + 1); total_len = 0; while (i--) { struct rpcrdma_segment *seg = &cur_wchunk->wc_target; ifdebug(FACILITY) { u64 off; xdr_decode_hyper((__be32 *)&seg->rs_offset, &off); dprintk("RPC: %s: chunk %d@0x%llx:0x%x\n", __func__, be32_to_cpu(seg->rs_length), (unsigned long long)off, be32_to_cpu(seg->rs_handle)); } total_len += be32_to_cpu(seg->rs_length); ++cur_wchunk; } /* check and adjust for properly terminated write chunk */ if (wrchunk) { __be32 *w = (__be32 *) cur_wchunk; if (*w++ != xdr_zero) return -1; cur_wchunk = (struct rpcrdma_write_chunk *) w; } if ((char *)cur_wchunk > base + rep->rr_len) return -1; *iptrp = (__be32 *) cur_wchunk; return total_len; } /* * Scatter inline received data back into provided iov's. */ static void rpcrdma_inline_fixup(struct rpc_rqst *rqst, char *srcp, int copy_len, int pad) { int i, npages, curlen, olen; char *destp; struct page **ppages; int page_base; curlen = rqst->rq_rcv_buf.head[0].iov_len; if (curlen > copy_len) { /* write chunk header fixup */ curlen = copy_len; rqst->rq_rcv_buf.head[0].iov_len = curlen; } dprintk("RPC: %s: srcp 0x%p len %d hdrlen %d\n", __func__, srcp, copy_len, curlen); /* Shift pointer for first receive segment only */ rqst->rq_rcv_buf.head[0].iov_base = srcp; srcp += curlen; copy_len -= curlen; olen = copy_len; i = 0; rpcx_to_rdmax(rqst->rq_xprt)->rx_stats.fixup_copy_count += olen; page_base = rqst->rq_rcv_buf.page_base; ppages = rqst->rq_rcv_buf.pages + (page_base >> PAGE_SHIFT); page_base &= ~PAGE_MASK; if (copy_len && rqst->rq_rcv_buf.page_len) { npages = PAGE_ALIGN(page_base + rqst->rq_rcv_buf.page_len) >> PAGE_SHIFT; for (; i < npages; i++) { curlen = PAGE_SIZE - page_base; if (curlen > copy_len) curlen = copy_len; dprintk("RPC: %s: page %d" " srcp 0x%p len %d curlen %d\n", __func__, i, srcp, copy_len, curlen); destp = kmap_atomic(ppages[i]); memcpy(destp + page_base, srcp, curlen); flush_dcache_page(ppages[i]); kunmap_atomic(destp); srcp += curlen; copy_len -= curlen; if (copy_len == 0) break; page_base = 0; } } if (copy_len && rqst->rq_rcv_buf.tail[0].iov_len) { curlen = copy_len; if (curlen > rqst->rq_rcv_buf.tail[0].iov_len) curlen = rqst->rq_rcv_buf.tail[0].iov_len; if (rqst->rq_rcv_buf.tail[0].iov_base != srcp) memmove(rqst->rq_rcv_buf.tail[0].iov_base, srcp, curlen); dprintk("RPC: %s: tail srcp 0x%p len %d curlen %d\n", __func__, srcp, copy_len, curlen); rqst->rq_rcv_buf.tail[0].iov_len = curlen; copy_len -= curlen; ++i; } else rqst->rq_rcv_buf.tail[0].iov_len = 0; if (pad) { /* implicit padding on terminal chunk */ unsigned char *p = rqst->rq_rcv_buf.tail[0].iov_base; while (pad--) p[rqst->rq_rcv_buf.tail[0].iov_len++] = 0; } if (copy_len) dprintk("RPC: %s: %d bytes in" " %d extra segments (%d lost)\n", __func__, olen, i, copy_len); /* TBD avoid a warning from call_decode() */ rqst->rq_private_buf = rqst->rq_rcv_buf; } void rpcrdma_connect_worker(struct work_struct *work) { struct rpcrdma_ep *ep = container_of(work, struct rpcrdma_ep, rep_connect_worker.work); struct rpcrdma_xprt *r_xprt = container_of(ep, struct rpcrdma_xprt, rx_ep); struct rpc_xprt *xprt = &r_xprt->rx_xprt; spin_lock_bh(&xprt->transport_lock); if (++xprt->connect_cookie == 0) /* maintain a reserved value */ ++xprt->connect_cookie; if (ep->rep_connected > 0) { if (!xprt_test_and_set_connected(xprt)) xprt_wake_pending_tasks(xprt, 0); } else { if (xprt_test_and_clear_connected(xprt)) xprt_wake_pending_tasks(xprt, -ENOTCONN); } spin_unlock_bh(&xprt->transport_lock); } #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) { __be32 *p = (__be32 *)headerp; if (headerp->rm_type != rdma_msg) return false; if (headerp->rm_body.rm_chunks[0] != xdr_zero) return false; if (headerp->rm_body.rm_chunks[1] != xdr_zero) return false; if (headerp->rm_body.rm_chunks[2] != xdr_zero) return false; /* sanity */ if (p[7] != headerp->rm_xid) return false; /* call direction */ if (p[8] != cpu_to_be32(RPC_CALL)) return false; return true; } #endif /* CONFIG_SUNRPC_BACKCHANNEL */ /* * This function is called when an async event is posted to * the connection which changes the connection state. All it * does at this point is mark the connection up/down, the rpc * timers do the rest. */ void rpcrdma_conn_func(struct rpcrdma_ep *ep) { schedule_delayed_work(&ep->rep_connect_worker, 0); } /* Process received RPC/RDMA messages. * * Errors must result in the RPC task either being awakened, or * allowed to timeout, to discover the errors at that time. */ void rpcrdma_reply_handler(struct rpcrdma_rep *rep) { struct rpcrdma_msg *headerp; struct rpcrdma_req *req; struct rpc_rqst *rqst; struct rpcrdma_xprt *r_xprt = rep->rr_rxprt; struct rpc_xprt *xprt = &r_xprt->rx_xprt; __be32 *iptr; int rdmalen, status, rmerr; unsigned long cwnd; dprintk("RPC: %s: incoming rep %p\n", __func__, rep); if (rep->rr_len == RPCRDMA_BAD_LEN) goto out_badstatus; if (rep->rr_len < RPCRDMA_HDRLEN_ERR) goto out_shortreply; headerp = rdmab_to_msg(rep->rr_rdmabuf); #if defined(CONFIG_SUNRPC_BACKCHANNEL) if (rpcrdma_is_bcall(headerp)) goto out_bcall; #endif /* Match incoming rpcrdma_rep to an rpcrdma_req to * get context for handling any incoming chunks. */ spin_lock_bh(&xprt->transport_lock); rqst = xprt_lookup_rqst(xprt, headerp->rm_xid); if (!rqst) goto out_nomatch; req = rpcr_to_rdmar(rqst); if (req->rl_reply) goto out_duplicate; /* Sanity checking has passed. We are now committed * to complete this transaction. */ list_del_init(&rqst->rq_list); spin_unlock_bh(&xprt->transport_lock); dprintk("RPC: %s: reply %p completes request %p (xid 0x%08x)\n", __func__, rep, req, be32_to_cpu(headerp->rm_xid)); /* from here on, the reply is no longer an orphan */ req->rl_reply = rep; xprt->reestablish_timeout = 0; if (headerp->rm_vers != rpcrdma_version) goto out_badversion; /* check for expected message types */ /* The order of some of these tests is important. */ switch (headerp->rm_type) { case rdma_msg: /* never expect read chunks */ /* never expect reply chunks (two ways to check) */ /* never expect write chunks without having offered RDMA */ if (headerp->rm_body.rm_chunks[0] != xdr_zero || (headerp->rm_body.rm_chunks[1] == xdr_zero && headerp->rm_body.rm_chunks[2] != xdr_zero) || (headerp->rm_body.rm_chunks[1] != xdr_zero && req->rl_nchunks == 0)) goto badheader; if (headerp->rm_body.rm_chunks[1] != xdr_zero) { /* count any expected write chunks in read reply */ /* start at write chunk array count */ iptr = &headerp->rm_body.rm_chunks[2]; rdmalen = rpcrdma_count_chunks(rep, req->rl_nchunks, 1, &iptr); /* check for validity, and no reply chunk after */ if (rdmalen < 0 || *iptr++ != xdr_zero) goto badheader; rep->rr_len -= ((unsigned char *)iptr - (unsigned char *)headerp); status = rep->rr_len + rdmalen; r_xprt->rx_stats.total_rdma_reply += rdmalen; /* special case - last chunk may omit padding */ if (rdmalen &= 3) { rdmalen = 4 - rdmalen; status += rdmalen; } } else { /* else ordinary inline */ rdmalen = 0; iptr = (__be32 *)((unsigned char *)headerp + RPCRDMA_HDRLEN_MIN); rep->rr_len -= RPCRDMA_HDRLEN_MIN; status = rep->rr_len; } /* Fix up the rpc results for upper layer */ rpcrdma_inline_fixup(rqst, (char *)iptr, rep->rr_len, rdmalen); break; case rdma_nomsg: /* never expect read or write chunks, always reply chunks */ if (headerp->rm_body.rm_chunks[0] != xdr_zero || headerp->rm_body.rm_chunks[1] != xdr_zero || headerp->rm_body.rm_chunks[2] != xdr_one || req->rl_nchunks == 0) goto badheader; iptr = (__be32 *)((unsigned char *)headerp + RPCRDMA_HDRLEN_MIN); rdmalen = rpcrdma_count_chunks(rep, req->rl_nchunks, 0, &iptr); if (rdmalen < 0) goto badheader; r_xprt->rx_stats.total_rdma_reply += rdmalen; /* Reply chunk buffer already is the reply vector - no fixup. */ status = rdmalen; break; case rdma_error: goto out_rdmaerr; badheader: default: dprintk("%s: invalid rpcrdma reply header (type %d):" " chunks[012] == %d %d %d" " expected chunks <= %d\n", __func__, be32_to_cpu(headerp->rm_type), headerp->rm_body.rm_chunks[0], headerp->rm_body.rm_chunks[1], headerp->rm_body.rm_chunks[2], req->rl_nchunks); status = -EIO; r_xprt->rx_stats.bad_reply_count++; break; } out: /* Invalidate and flush the data payloads before waking the * waiting application. This guarantees the memory region is * properly fenced from the server before the application * accesses the data. It also ensures proper send flow * control: waking the next RPC waits until this RPC has * relinquished all its Send Queue entries. */ if (req->rl_nchunks) r_xprt->rx_ia.ri_ops->ro_unmap_sync(r_xprt, req); spin_lock_bh(&xprt->transport_lock); cwnd = xprt->cwnd; xprt->cwnd = atomic_read(&r_xprt->rx_buf.rb_credits) << RPC_CWNDSHIFT; if (xprt->cwnd > cwnd) xprt_release_rqst_cong(rqst->rq_task); xprt_complete_rqst(rqst->rq_task, status); spin_unlock_bh(&xprt->transport_lock); dprintk("RPC: %s: xprt_complete_rqst(0x%p, 0x%p, %d)\n", __func__, xprt, rqst, status); return; out_badstatus: rpcrdma_recv_buffer_put(rep); if (r_xprt->rx_ep.rep_connected == 1) { r_xprt->rx_ep.rep_connected = -EIO; rpcrdma_conn_func(&r_xprt->rx_ep); } 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. */ out_badversion: dprintk("RPC: %s: invalid version %d\n", __func__, be32_to_cpu(headerp->rm_vers)); status = -EIO; r_xprt->rx_stats.bad_reply_count++; goto out; out_rdmaerr: rmerr = be32_to_cpu(headerp->rm_body.rm_error.rm_err); switch (rmerr) { case ERR_VERS: pr_err("%s: server reports header version error (%u-%u)\n", __func__, be32_to_cpu(headerp->rm_body.rm_error.rm_vers_low), be32_to_cpu(headerp->rm_body.rm_error.rm_vers_high)); break; case ERR_CHUNK: pr_err("%s: server reports header decoding error\n", __func__); break; default: pr_err("%s: server reports unknown error %d\n", __func__, rmerr); } status = -EREMOTEIO; r_xprt->rx_stats.bad_reply_count++; goto out; /* If no pending RPC transaction was matched, post a replacement * receive buffer before returning. */ out_shortreply: dprintk("RPC: %s: short/invalid reply\n", __func__); goto repost; out_nomatch: spin_unlock_bh(&xprt->transport_lock); dprintk("RPC: %s: no match for incoming xid 0x%08x len %d\n", __func__, be32_to_cpu(headerp->rm_xid), rep->rr_len); goto repost; out_duplicate: spin_unlock_bh(&xprt->transport_lock); dprintk("RPC: %s: " "duplicate reply %p to RPC request %p: xid 0x%08x\n", __func__, rep, req, be32_to_cpu(headerp->rm_xid)); repost: r_xprt->rx_stats.bad_reply_count++; if (rpcrdma_ep_post_recv(&r_xprt->rx_ia, &r_xprt->rx_ep, rep)) rpcrdma_recv_buffer_put(rep); }