// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause /* * Copyright (c) 2016-2018 Oracle. All rights reserved. * Copyright (c) 2014 Open Grid Computing, Inc. All rights reserved. * Copyright (c) 2005-2006 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. * * Author: Tom Tucker */ /* Operation * * The main entry point is svc_rdma_recvfrom. This is called from * svc_recv when the transport indicates there is incoming data to * be read. "Data Ready" is signaled when an RDMA Receive completes, * or when a set of RDMA Reads complete. * * An svc_rqst is passed in. This structure contains an array of * free pages (rq_pages) that will contain the incoming RPC message. * * Short messages are moved directly into svc_rqst::rq_arg, and * the RPC Call is ready to be processed by the Upper Layer. * svc_rdma_recvfrom returns the length of the RPC Call message, * completing the reception of the RPC Call. * * However, when an incoming message has Read chunks, * svc_rdma_recvfrom must post RDMA Reads to pull the RPC Call's * data payload from the client. svc_rdma_recvfrom sets up the * RDMA Reads using pages in svc_rqst::rq_pages, which are * transferred to an svc_rdma_recv_ctxt for the duration of the * I/O. svc_rdma_recvfrom then returns zero, since the RPC message * is still not yet ready. * * When the Read chunk payloads have become available on the * server, "Data Ready" is raised again, and svc_recv calls * svc_rdma_recvfrom again. This second call may use a different * svc_rqst than the first one, thus any information that needs * to be preserved across these two calls is kept in an * svc_rdma_recv_ctxt. * * The second call to svc_rdma_recvfrom performs final assembly * of the RPC Call message, using the RDMA Read sink pages kept in * the svc_rdma_recv_ctxt. The xdr_buf is copied from the * svc_rdma_recv_ctxt to the second svc_rqst. The second call returns * the length of the completed RPC Call message. * * Page Management * * Pages under I/O must be transferred from the first svc_rqst to an * svc_rdma_recv_ctxt before the first svc_rdma_recvfrom call returns. * * The first svc_rqst supplies pages for RDMA Reads. These are moved * from rqstp::rq_pages into ctxt::pages. The consumed elements of * the rq_pages array are set to NULL and refilled with the first * svc_rdma_recvfrom call returns. * * During the second svc_rdma_recvfrom call, RDMA Read sink pages * are transferred from the svc_rdma_recv_ctxt to the second svc_rqst * (see rdma_read_complete() below). */ #include #include #include #include #include #include #include #include #include "xprt_rdma.h" #include #define RPCDBG_FACILITY RPCDBG_SVCXPRT static void svc_rdma_wc_receive(struct ib_cq *cq, struct ib_wc *wc); static inline struct svc_rdma_recv_ctxt * svc_rdma_next_recv_ctxt(struct list_head *list) { return list_first_entry_or_null(list, struct svc_rdma_recv_ctxt, rc_list); } static struct svc_rdma_recv_ctxt * svc_rdma_recv_ctxt_alloc(struct svcxprt_rdma *rdma) { struct svc_rdma_recv_ctxt *ctxt; dma_addr_t addr; void *buffer; ctxt = kmalloc(sizeof(*ctxt), GFP_KERNEL); if (!ctxt) goto fail0; buffer = kmalloc(rdma->sc_max_req_size, GFP_KERNEL); if (!buffer) goto fail1; addr = ib_dma_map_single(rdma->sc_pd->device, buffer, rdma->sc_max_req_size, DMA_FROM_DEVICE); if (ib_dma_mapping_error(rdma->sc_pd->device, addr)) goto fail2; ctxt->rc_recv_wr.next = NULL; ctxt->rc_recv_wr.wr_cqe = &ctxt->rc_cqe; ctxt->rc_recv_wr.sg_list = &ctxt->rc_recv_sge; ctxt->rc_recv_wr.num_sge = 1; ctxt->rc_cqe.done = svc_rdma_wc_receive; ctxt->rc_recv_sge.addr = addr; ctxt->rc_recv_sge.length = rdma->sc_max_req_size; ctxt->rc_recv_sge.lkey = rdma->sc_pd->local_dma_lkey; ctxt->rc_recv_buf = buffer; ctxt->rc_temp = false; return ctxt; fail2: kfree(buffer); fail1: kfree(ctxt); fail0: return NULL; } static void svc_rdma_recv_ctxt_destroy(struct svcxprt_rdma *rdma, struct svc_rdma_recv_ctxt *ctxt) { ib_dma_unmap_single(rdma->sc_pd->device, ctxt->rc_recv_sge.addr, ctxt->rc_recv_sge.length, DMA_FROM_DEVICE); kfree(ctxt->rc_recv_buf); kfree(ctxt); } /** * svc_rdma_recv_ctxts_destroy - Release all recv_ctxt's for an xprt * @rdma: svcxprt_rdma being torn down * */ void svc_rdma_recv_ctxts_destroy(struct svcxprt_rdma *rdma) { struct svc_rdma_recv_ctxt *ctxt; while ((ctxt = svc_rdma_next_recv_ctxt(&rdma->sc_recv_ctxts))) { list_del(&ctxt->rc_list); svc_rdma_recv_ctxt_destroy(rdma, ctxt); } } static struct svc_rdma_recv_ctxt * svc_rdma_recv_ctxt_get(struct svcxprt_rdma *rdma) { struct svc_rdma_recv_ctxt *ctxt; spin_lock(&rdma->sc_recv_lock); ctxt = svc_rdma_next_recv_ctxt(&rdma->sc_recv_ctxts); if (!ctxt) goto out_empty; list_del(&ctxt->rc_list); spin_unlock(&rdma->sc_recv_lock); out: ctxt->rc_page_count = 0; return ctxt; out_empty: spin_unlock(&rdma->sc_recv_lock); ctxt = svc_rdma_recv_ctxt_alloc(rdma); if (!ctxt) return NULL; goto out; } /** * svc_rdma_recv_ctxt_put - Return recv_ctxt to free list * @rdma: controlling svcxprt_rdma * @ctxt: object to return to the free list * */ void svc_rdma_recv_ctxt_put(struct svcxprt_rdma *rdma, struct svc_rdma_recv_ctxt *ctxt) { unsigned int i; for (i = 0; i < ctxt->rc_page_count; i++) put_page(ctxt->rc_pages[i]); if (!ctxt->rc_temp) { spin_lock(&rdma->sc_recv_lock); list_add(&ctxt->rc_list, &rdma->sc_recv_ctxts); spin_unlock(&rdma->sc_recv_lock); } else svc_rdma_recv_ctxt_destroy(rdma, ctxt); } static int __svc_rdma_post_recv(struct svcxprt_rdma *rdma, struct svc_rdma_recv_ctxt *ctxt) { struct ib_recv_wr *bad_recv_wr; int ret; svc_xprt_get(&rdma->sc_xprt); ret = ib_post_recv(rdma->sc_qp, &ctxt->rc_recv_wr, &bad_recv_wr); trace_svcrdma_post_recv(&ctxt->rc_recv_wr, ret); if (ret) goto err_post; return 0; err_post: svc_rdma_recv_ctxt_put(rdma, ctxt); svc_xprt_put(&rdma->sc_xprt); return ret; } static int svc_rdma_post_recv(struct svcxprt_rdma *rdma) { struct svc_rdma_recv_ctxt *ctxt; ctxt = svc_rdma_recv_ctxt_get(rdma); if (!ctxt) return -ENOMEM; return __svc_rdma_post_recv(rdma, ctxt); } /** * svc_rdma_post_recvs - Post initial set of Recv WRs * @rdma: fresh svcxprt_rdma * * Returns true if successful, otherwise false. */ bool svc_rdma_post_recvs(struct svcxprt_rdma *rdma) { struct svc_rdma_recv_ctxt *ctxt; unsigned int i; int ret; for (i = 0; i < rdma->sc_max_requests; i++) { ctxt = svc_rdma_recv_ctxt_get(rdma); if (!ctxt) return -ENOMEM; ctxt->rc_temp = true; ret = __svc_rdma_post_recv(rdma, ctxt); if (ret) { pr_err("svcrdma: failure posting recv buffers: %d\n", ret); return false; } } return true; } /** * svc_rdma_wc_receive - Invoked by RDMA provider for each polled Receive WC * @cq: Completion Queue context * @wc: Work Completion object * * NB: The svc_xprt/svcxprt_rdma is pinned whenever it's possible that * the Receive completion handler could be running. */ static void svc_rdma_wc_receive(struct ib_cq *cq, struct ib_wc *wc) { struct svcxprt_rdma *rdma = cq->cq_context; struct ib_cqe *cqe = wc->wr_cqe; struct svc_rdma_recv_ctxt *ctxt; trace_svcrdma_wc_receive(wc); /* WARNING: Only wc->wr_cqe and wc->status are reliable */ ctxt = container_of(cqe, struct svc_rdma_recv_ctxt, rc_cqe); if (wc->status != IB_WC_SUCCESS) goto flushed; if (svc_rdma_post_recv(rdma)) goto post_err; /* All wc fields are now known to be valid */ ctxt->rc_byte_len = wc->byte_len; ib_dma_sync_single_for_cpu(rdma->sc_pd->device, ctxt->rc_recv_sge.addr, wc->byte_len, DMA_FROM_DEVICE); spin_lock(&rdma->sc_rq_dto_lock); list_add_tail(&ctxt->rc_list, &rdma->sc_rq_dto_q); spin_unlock(&rdma->sc_rq_dto_lock); set_bit(XPT_DATA, &rdma->sc_xprt.xpt_flags); if (!test_bit(RDMAXPRT_CONN_PENDING, &rdma->sc_flags)) svc_xprt_enqueue(&rdma->sc_xprt); goto out; flushed: if (wc->status != IB_WC_WR_FLUSH_ERR) pr_err("svcrdma: Recv: %s (%u/0x%x)\n", ib_wc_status_msg(wc->status), wc->status, wc->vendor_err); post_err: svc_rdma_recv_ctxt_put(rdma, ctxt); set_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags); svc_xprt_enqueue(&rdma->sc_xprt); out: svc_xprt_put(&rdma->sc_xprt); } /** * svc_rdma_flush_recv_queues - Drain pending Receive work * @rdma: svcxprt_rdma being shut down * */ void svc_rdma_flush_recv_queues(struct svcxprt_rdma *rdma) { struct svc_rdma_recv_ctxt *ctxt; while ((ctxt = svc_rdma_next_recv_ctxt(&rdma->sc_read_complete_q))) { list_del(&ctxt->rc_list); svc_rdma_recv_ctxt_put(rdma, ctxt); } while ((ctxt = svc_rdma_next_recv_ctxt(&rdma->sc_rq_dto_q))) { list_del(&ctxt->rc_list); svc_rdma_recv_ctxt_put(rdma, ctxt); } } static void svc_rdma_build_arg_xdr(struct svc_rqst *rqstp, struct svc_rdma_recv_ctxt *ctxt) { struct xdr_buf *arg = &rqstp->rq_arg; arg->head[0].iov_base = ctxt->rc_recv_buf; arg->head[0].iov_len = ctxt->rc_byte_len; arg->tail[0].iov_base = NULL; arg->tail[0].iov_len = 0; arg->page_len = 0; arg->page_base = 0; arg->buflen = ctxt->rc_byte_len; arg->len = ctxt->rc_byte_len; rqstp->rq_respages = &rqstp->rq_pages[0]; rqstp->rq_next_page = rqstp->rq_respages + 1; } /* This accommodates the largest possible Write chunk, * in one segment. */ #define MAX_BYTES_WRITE_SEG ((u32)(RPCSVC_MAXPAGES << PAGE_SHIFT)) /* This accommodates the largest possible Position-Zero * Read chunk or Reply chunk, in one segment. */ #define MAX_BYTES_SPECIAL_SEG ((u32)((RPCSVC_MAXPAGES + 2) << PAGE_SHIFT)) /* Sanity check the Read list. * * Implementation limits: * - This implementation supports only one Read chunk. * * Sanity checks: * - Read list does not overflow buffer. * - Segment size limited by largest NFS data payload. * * The segment count is limited to how many segments can * fit in the transport header without overflowing the * buffer. That's about 40 Read segments for a 1KB inline * threshold. * * Returns pointer to the following Write list. */ static __be32 *xdr_check_read_list(__be32 *p, const __be32 *end) { u32 position; bool first; first = true; while (*p++ != xdr_zero) { if (first) { position = be32_to_cpup(p++); first = false; } else if (be32_to_cpup(p++) != position) { return NULL; } p++; /* handle */ if (be32_to_cpup(p++) > MAX_BYTES_SPECIAL_SEG) return NULL; p += 2; /* offset */ if (p > end) return NULL; } return p; } /* The segment count is limited to how many segments can * fit in the transport header without overflowing the * buffer. That's about 60 Write segments for a 1KB inline * threshold. */ static __be32 *xdr_check_write_chunk(__be32 *p, const __be32 *end, u32 maxlen) { u32 i, segcount; segcount = be32_to_cpup(p++); for (i = 0; i < segcount; i++) { p++; /* handle */ if (be32_to_cpup(p++) > maxlen) return NULL; p += 2; /* offset */ if (p > end) return NULL; } return p; } /* Sanity check the Write list. * * Implementation limits: * - This implementation supports only one Write chunk. * * Sanity checks: * - Write list does not overflow buffer. * - Segment size limited by largest NFS data payload. * * Returns pointer to the following Reply chunk. */ static __be32 *xdr_check_write_list(__be32 *p, const __be32 *end) { u32 chcount; chcount = 0; while (*p++ != xdr_zero) { p = xdr_check_write_chunk(p, end, MAX_BYTES_WRITE_SEG); if (!p) return NULL; if (chcount++ > 1) return NULL; } return p; } /* Sanity check the Reply chunk. * * Sanity checks: * - Reply chunk does not overflow buffer. * - Segment size limited by largest NFS data payload. * * Returns pointer to the following RPC header. */ static __be32 *xdr_check_reply_chunk(__be32 *p, const __be32 *end) { if (*p++ != xdr_zero) { p = xdr_check_write_chunk(p, end, MAX_BYTES_SPECIAL_SEG); if (!p) return NULL; } return p; } /* On entry, xdr->head[0].iov_base points to first byte in the * RPC-over-RDMA header. * * On successful exit, head[0] points to first byte past the * RPC-over-RDMA header. For RDMA_MSG, this is the RPC message. * The length of the RPC-over-RDMA header is returned. * * Assumptions: * - The transport header is entirely contained in the head iovec. */ static int svc_rdma_xdr_decode_req(struct xdr_buf *rq_arg) { __be32 *p, *end, *rdma_argp; unsigned int hdr_len; /* Verify that there's enough bytes for header + something */ if (rq_arg->len <= RPCRDMA_HDRLEN_ERR) goto out_short; rdma_argp = rq_arg->head[0].iov_base; if (*(rdma_argp + 1) != rpcrdma_version) goto out_version; switch (*(rdma_argp + 3)) { case rdma_msg: break; case rdma_nomsg: break; case rdma_done: goto out_drop; case rdma_error: goto out_drop; default: goto out_proc; } end = (__be32 *)((unsigned long)rdma_argp + rq_arg->len); p = xdr_check_read_list(rdma_argp + 4, end); if (!p) goto out_inval; p = xdr_check_write_list(p, end); if (!p) goto out_inval; p = xdr_check_reply_chunk(p, end); if (!p) goto out_inval; if (p > end) goto out_inval; rq_arg->head[0].iov_base = p; hdr_len = (unsigned long)p - (unsigned long)rdma_argp; rq_arg->head[0].iov_len -= hdr_len; rq_arg->len -= hdr_len; trace_svcrdma_decode_rqst(rdma_argp, hdr_len); return hdr_len; out_short: trace_svcrdma_decode_short(rq_arg->len); return -EINVAL; out_version: trace_svcrdma_decode_badvers(rdma_argp); return -EPROTONOSUPPORT; out_drop: trace_svcrdma_decode_drop(rdma_argp); return 0; out_proc: trace_svcrdma_decode_badproc(rdma_argp); return -EINVAL; out_inval: trace_svcrdma_decode_parse(rdma_argp); return -EINVAL; } static void rdma_read_complete(struct svc_rqst *rqstp, struct svc_rdma_recv_ctxt *head) { int page_no; /* Move Read chunk pages to rqstp so that they will be released * when svc_process is done with them. */ for (page_no = 0; page_no < head->rc_page_count; page_no++) { put_page(rqstp->rq_pages[page_no]); rqstp->rq_pages[page_no] = head->rc_pages[page_no]; } head->rc_page_count = 0; /* Point rq_arg.pages past header */ rqstp->rq_arg.pages = &rqstp->rq_pages[head->rc_hdr_count]; rqstp->rq_arg.page_len = head->rc_arg.page_len; /* rq_respages starts after the last arg page */ rqstp->rq_respages = &rqstp->rq_pages[page_no]; rqstp->rq_next_page = rqstp->rq_respages + 1; /* Rebuild rq_arg head and tail. */ rqstp->rq_arg.head[0] = head->rc_arg.head[0]; rqstp->rq_arg.tail[0] = head->rc_arg.tail[0]; rqstp->rq_arg.len = head->rc_arg.len; rqstp->rq_arg.buflen = head->rc_arg.buflen; } static void svc_rdma_send_error(struct svcxprt_rdma *xprt, __be32 *rdma_argp, int status) { struct svc_rdma_op_ctxt *ctxt; __be32 *p, *err_msgp; unsigned int length; struct page *page; int ret; page = alloc_page(GFP_KERNEL); if (!page) return; err_msgp = page_address(page); p = err_msgp; *p++ = *rdma_argp; *p++ = *(rdma_argp + 1); *p++ = xprt->sc_fc_credits; *p++ = rdma_error; switch (status) { case -EPROTONOSUPPORT: *p++ = err_vers; *p++ = rpcrdma_version; *p++ = rpcrdma_version; trace_svcrdma_err_vers(*rdma_argp); break; default: *p++ = err_chunk; trace_svcrdma_err_chunk(*rdma_argp); } length = (unsigned long)p - (unsigned long)err_msgp; /* Map transport header; no RPC message payload */ ctxt = svc_rdma_get_context(xprt); ret = svc_rdma_map_reply_hdr(xprt, ctxt, err_msgp, length); if (ret) { dprintk("svcrdma: Error %d mapping send for protocol error\n", ret); return; } ret = svc_rdma_post_send_wr(xprt, ctxt, 0); if (ret) { svc_rdma_unmap_dma(ctxt); svc_rdma_put_context(ctxt, 1); } } /* 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 svc_rdma_is_backchannel_reply(struct svc_xprt *xprt, __be32 *rdma_resp) { __be32 *p; if (!xprt->xpt_bc_xprt) return false; p = rdma_resp + 3; if (*p++ != rdma_msg) return false; if (*p++ != xdr_zero) return false; if (*p++ != xdr_zero) return false; if (*p++ != xdr_zero) return false; /* XID sanity */ if (*p++ != *rdma_resp) return false; /* call direction */ if (*p == cpu_to_be32(RPC_CALL)) return false; return true; } /** * svc_rdma_recvfrom - Receive an RPC call * @rqstp: request structure into which to receive an RPC Call * * Returns: * The positive number of bytes in the RPC Call message, * %0 if there were no Calls ready to return, * %-EINVAL if the Read chunk data is too large, * %-ENOMEM if rdma_rw context pool was exhausted, * %-ENOTCONN if posting failed (connection is lost), * %-EIO if rdma_rw initialization failed (DMA mapping, etc). * * Called in a loop when XPT_DATA is set. XPT_DATA is cleared only * when there are no remaining ctxt's to process. * * The next ctxt is removed from the "receive" lists. * * - If the ctxt completes a Read, then finish assembling the Call * message and return the number of bytes in the message. * * - If the ctxt completes a Receive, then construct the Call * message from the contents of the Receive buffer. * * - If there are no Read chunks in this message, then finish * assembling the Call message and return the number of bytes * in the message. * * - If there are Read chunks in this message, post Read WRs to * pull that payload and return 0. */ int svc_rdma_recvfrom(struct svc_rqst *rqstp) { struct svc_xprt *xprt = rqstp->rq_xprt; struct svcxprt_rdma *rdma_xprt = container_of(xprt, struct svcxprt_rdma, sc_xprt); struct svc_rdma_recv_ctxt *ctxt; __be32 *p; int ret; spin_lock(&rdma_xprt->sc_rq_dto_lock); ctxt = svc_rdma_next_recv_ctxt(&rdma_xprt->sc_read_complete_q); if (ctxt) { list_del(&ctxt->rc_list); spin_unlock(&rdma_xprt->sc_rq_dto_lock); rdma_read_complete(rqstp, ctxt); goto complete; } ctxt = svc_rdma_next_recv_ctxt(&rdma_xprt->sc_rq_dto_q); if (!ctxt) { /* No new incoming requests, terminate the loop */ clear_bit(XPT_DATA, &xprt->xpt_flags); spin_unlock(&rdma_xprt->sc_rq_dto_lock); return 0; } list_del(&ctxt->rc_list); spin_unlock(&rdma_xprt->sc_rq_dto_lock); atomic_inc(&rdma_stat_recv); svc_rdma_build_arg_xdr(rqstp, ctxt); p = (__be32 *)rqstp->rq_arg.head[0].iov_base; ret = svc_rdma_xdr_decode_req(&rqstp->rq_arg); if (ret < 0) goto out_err; if (ret == 0) goto out_drop; rqstp->rq_xprt_hlen = ret; if (svc_rdma_is_backchannel_reply(xprt, p)) { ret = svc_rdma_handle_bc_reply(xprt->xpt_bc_xprt, p, &rqstp->rq_arg); svc_rdma_recv_ctxt_put(rdma_xprt, ctxt); return ret; } p += rpcrdma_fixed_maxsz; if (*p != xdr_zero) goto out_readchunk; complete: rqstp->rq_xprt_ctxt = ctxt; rqstp->rq_prot = IPPROTO_MAX; svc_xprt_copy_addrs(rqstp, xprt); return rqstp->rq_arg.len; out_readchunk: ret = svc_rdma_recv_read_chunk(rdma_xprt, rqstp, ctxt, p); if (ret < 0) goto out_postfail; return 0; out_err: svc_rdma_send_error(rdma_xprt, p, ret); svc_rdma_recv_ctxt_put(rdma_xprt, ctxt); return 0; out_postfail: if (ret == -EINVAL) svc_rdma_send_error(rdma_xprt, p, ret); svc_rdma_recv_ctxt_put(rdma_xprt, ctxt); return ret; out_drop: svc_rdma_recv_ctxt_put(rdma_xprt, ctxt); return 0; }