| // 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 <tom@opengridcomputing.com> |
| */ |
| |
| /* 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 <linux/slab.h> |
| #include <linux/spinlock.h> |
| #include <asm/unaligned.h> |
| #include <rdma/ib_verbs.h> |
| #include <rdma/rdma_cm.h> |
| |
| #include <linux/sunrpc/xdr.h> |
| #include <linux/sunrpc/debug.h> |
| #include <linux/sunrpc/rpc_rdma.h> |
| #include <linux/sunrpc/svc_rdma.h> |
| |
| #include "xprt_rdma.h" |
| #include <trace/events/rpcrdma.h> |
| |
| #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 void svc_rdma_recv_cid_init(struct svcxprt_rdma *rdma, |
| struct rpc_rdma_cid *cid) |
| { |
| cid->ci_queue_id = rdma->sc_rq_cq->res.id; |
| cid->ci_completion_id = atomic_inc_return(&rdma->sc_completion_ids); |
| } |
| |
| 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; |
| |
| svc_rdma_recv_cid_init(rdma, &ctxt->rc_cid); |
| pcl_init(&ctxt->rc_call_pcl); |
| pcl_init(&ctxt->rc_read_pcl); |
| pcl_init(&ctxt->rc_write_pcl); |
| pcl_init(&ctxt->rc_reply_pcl); |
| |
| 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; |
| struct llist_node *node; |
| |
| while ((node = llist_del_first(&rdma->sc_recv_ctxts))) { |
| ctxt = llist_entry(node, struct svc_rdma_recv_ctxt, rc_node); |
| svc_rdma_recv_ctxt_destroy(rdma, ctxt); |
| } |
| } |
| |
| /** |
| * svc_rdma_recv_ctxt_get - Allocate a recv_ctxt |
| * @rdma: controlling svcxprt_rdma |
| * |
| * Returns a recv_ctxt or (rarely) NULL if none are available. |
| */ |
| struct svc_rdma_recv_ctxt *svc_rdma_recv_ctxt_get(struct svcxprt_rdma *rdma) |
| { |
| struct svc_rdma_recv_ctxt *ctxt; |
| struct llist_node *node; |
| |
| node = llist_del_first(&rdma->sc_recv_ctxts); |
| if (!node) |
| goto out_empty; |
| ctxt = llist_entry(node, struct svc_rdma_recv_ctxt, rc_node); |
| |
| out: |
| ctxt->rc_page_count = 0; |
| return ctxt; |
| |
| out_empty: |
| 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]); |
| |
| pcl_free(&ctxt->rc_call_pcl); |
| pcl_free(&ctxt->rc_read_pcl); |
| pcl_free(&ctxt->rc_write_pcl); |
| pcl_free(&ctxt->rc_reply_pcl); |
| |
| if (!ctxt->rc_temp) |
| llist_add(&ctxt->rc_node, &rdma->sc_recv_ctxts); |
| else |
| svc_rdma_recv_ctxt_destroy(rdma, ctxt); |
| } |
| |
| /** |
| * svc_rdma_release_rqst - Release transport-specific per-rqst resources |
| * @rqstp: svc_rqst being released |
| * |
| * Ensure that the recv_ctxt is released whether or not a Reply |
| * was sent. For example, the client could close the connection, |
| * or svc_process could drop an RPC, before the Reply is sent. |
| */ |
| void svc_rdma_release_rqst(struct svc_rqst *rqstp) |
| { |
| struct svc_rdma_recv_ctxt *ctxt = rqstp->rq_xprt_ctxt; |
| struct svc_xprt *xprt = rqstp->rq_xprt; |
| struct svcxprt_rdma *rdma = |
| container_of(xprt, struct svcxprt_rdma, sc_xprt); |
| |
| rqstp->rq_xprt_ctxt = NULL; |
| if (ctxt) |
| svc_rdma_recv_ctxt_put(rdma, ctxt); |
| } |
| |
| static int __svc_rdma_post_recv(struct svcxprt_rdma *rdma, |
| struct svc_rdma_recv_ctxt *ctxt) |
| { |
| int ret; |
| |
| trace_svcrdma_post_recv(ctxt); |
| ret = ib_post_recv(rdma->sc_qp, &ctxt->rc_recv_wr, NULL); |
| if (ret) |
| goto err_post; |
| return 0; |
| |
| err_post: |
| trace_svcrdma_rq_post_err(rdma, ret); |
| svc_rdma_recv_ctxt_put(rdma, ctxt); |
| return ret; |
| } |
| |
| static int svc_rdma_post_recv(struct svcxprt_rdma *rdma) |
| { |
| struct svc_rdma_recv_ctxt *ctxt; |
| |
| if (test_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags)) |
| return 0; |
| 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 false; |
| ctxt->rc_temp = true; |
| ret = __svc_rdma_post_recv(rdma, ctxt); |
| if (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; |
| |
| /* WARNING: Only wc->wr_cqe and wc->status are reliable */ |
| ctxt = container_of(cqe, struct svc_rdma_recv_ctxt, rc_cqe); |
| |
| trace_svcrdma_wc_receive(wc, &ctxt->rc_cid); |
| 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); |
| /* Note the unlock pairs with the smp_rmb in svc_xprt_ready: */ |
| set_bit(XPT_DATA, &rdma->sc_xprt.xpt_flags); |
| spin_unlock(&rdma->sc_rq_dto_lock); |
| if (!test_bit(RDMAXPRT_CONN_PENDING, &rdma->sc_flags)) |
| svc_xprt_enqueue(&rdma->sc_xprt); |
| return; |
| |
| flushed: |
| post_err: |
| svc_rdma_recv_ctxt_put(rdma, ctxt); |
| set_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags); |
| svc_xprt_enqueue(&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; |
| } |
| |
| /** |
| * xdr_count_read_segments - Count number of Read segments in Read list |
| * @rctxt: Ingress receive context |
| * @p: Start of an un-decoded Read list |
| * |
| * Before allocating anything, ensure the ingress Read list is safe |
| * to use. |
| * |
| * 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. |
| * |
| * Return values: |
| * %true: Read list is valid. @rctxt's xdr_stream is updated to point |
| * to the first byte past the Read list. rc_read_pcl and |
| * rc_call_pcl cl_count fields are set to the number of |
| * Read segments in the list. |
| * %false: Read list is corrupt. @rctxt's xdr_stream is left in an |
| * unknown state. |
| */ |
| static bool xdr_count_read_segments(struct svc_rdma_recv_ctxt *rctxt, __be32 *p) |
| { |
| rctxt->rc_call_pcl.cl_count = 0; |
| rctxt->rc_read_pcl.cl_count = 0; |
| while (xdr_item_is_present(p)) { |
| u32 position, handle, length; |
| u64 offset; |
| |
| p = xdr_inline_decode(&rctxt->rc_stream, |
| rpcrdma_readseg_maxsz * sizeof(*p)); |
| if (!p) |
| return false; |
| |
| xdr_decode_read_segment(p, &position, &handle, |
| &length, &offset); |
| if (position) { |
| if (position & 3) |
| return false; |
| ++rctxt->rc_read_pcl.cl_count; |
| } else { |
| ++rctxt->rc_call_pcl.cl_count; |
| } |
| |
| p = xdr_inline_decode(&rctxt->rc_stream, sizeof(*p)); |
| if (!p) |
| return false; |
| } |
| return true; |
| } |
| |
| /* Sanity check the Read list. |
| * |
| * Sanity checks: |
| * - Read list does not overflow Receive buffer. |
| * - Chunk size limited by largest NFS data payload. |
| * |
| * Return values: |
| * %true: Read list is valid. @rctxt's xdr_stream is updated |
| * to point to the first byte past the Read list. |
| * %false: Read list is corrupt. @rctxt's xdr_stream is left |
| * in an unknown state. |
| */ |
| static bool xdr_check_read_list(struct svc_rdma_recv_ctxt *rctxt) |
| { |
| __be32 *p; |
| |
| p = xdr_inline_decode(&rctxt->rc_stream, sizeof(*p)); |
| if (!p) |
| return false; |
| if (!xdr_count_read_segments(rctxt, p)) |
| return false; |
| if (!pcl_alloc_call(rctxt, p)) |
| return false; |
| return pcl_alloc_read(rctxt, p); |
| } |
| |
| static bool xdr_check_write_chunk(struct svc_rdma_recv_ctxt *rctxt) |
| { |
| u32 segcount; |
| __be32 *p; |
| |
| if (xdr_stream_decode_u32(&rctxt->rc_stream, &segcount)) |
| return false; |
| |
| /* A bogus segcount causes this buffer overflow check to fail. */ |
| p = xdr_inline_decode(&rctxt->rc_stream, |
| segcount * rpcrdma_segment_maxsz * sizeof(*p)); |
| return p != NULL; |
| } |
| |
| /** |
| * xdr_count_write_chunks - Count number of Write chunks in Write list |
| * @rctxt: Received header and decoding state |
| * @p: start of an un-decoded Write list |
| * |
| * Before allocating anything, ensure the ingress Write list is |
| * safe to use. |
| * |
| * Return values: |
| * %true: Write list is valid. @rctxt's xdr_stream is updated |
| * to point to the first byte past the Write list, and |
| * the number of Write chunks is in rc_write_pcl.cl_count. |
| * %false: Write list is corrupt. @rctxt's xdr_stream is left |
| * in an indeterminate state. |
| */ |
| static bool xdr_count_write_chunks(struct svc_rdma_recv_ctxt *rctxt, __be32 *p) |
| { |
| rctxt->rc_write_pcl.cl_count = 0; |
| while (xdr_item_is_present(p)) { |
| if (!xdr_check_write_chunk(rctxt)) |
| return false; |
| ++rctxt->rc_write_pcl.cl_count; |
| p = xdr_inline_decode(&rctxt->rc_stream, sizeof(*p)); |
| if (!p) |
| return false; |
| } |
| return true; |
| } |
| |
| /* Sanity check the Write list. |
| * |
| * Implementation limits: |
| * - This implementation currently supports only one Write chunk. |
| * |
| * Sanity checks: |
| * - Write list does not overflow Receive buffer. |
| * - Chunk size limited by largest NFS data payload. |
| * |
| * Return values: |
| * %true: Write list is valid. @rctxt's xdr_stream is updated |
| * to point to the first byte past the Write list. |
| * %false: Write list is corrupt. @rctxt's xdr_stream is left |
| * in an unknown state. |
| */ |
| static bool xdr_check_write_list(struct svc_rdma_recv_ctxt *rctxt) |
| { |
| __be32 *p; |
| |
| p = xdr_inline_decode(&rctxt->rc_stream, sizeof(*p)); |
| if (!p) |
| return false; |
| if (!xdr_count_write_chunks(rctxt, p)) |
| return false; |
| if (!pcl_alloc_write(rctxt, &rctxt->rc_write_pcl, p)) |
| return false; |
| |
| rctxt->rc_cur_result_payload = pcl_first_chunk(&rctxt->rc_write_pcl); |
| return true; |
| } |
| |
| /* Sanity check the Reply chunk. |
| * |
| * Sanity checks: |
| * - Reply chunk does not overflow Receive buffer. |
| * - Chunk size limited by largest NFS data payload. |
| * |
| * Return values: |
| * %true: Reply chunk is valid. @rctxt's xdr_stream is updated |
| * to point to the first byte past the Reply chunk. |
| * %false: Reply chunk is corrupt. @rctxt's xdr_stream is left |
| * in an unknown state. |
| */ |
| static bool xdr_check_reply_chunk(struct svc_rdma_recv_ctxt *rctxt) |
| { |
| __be32 *p; |
| |
| p = xdr_inline_decode(&rctxt->rc_stream, sizeof(*p)); |
| if (!p) |
| return false; |
| |
| if (!xdr_item_is_present(p)) |
| return true; |
| if (!xdr_check_write_chunk(rctxt)) |
| return false; |
| |
| rctxt->rc_reply_pcl.cl_count = 1; |
| return pcl_alloc_write(rctxt, &rctxt->rc_reply_pcl, p); |
| } |
| |
| /* RPC-over-RDMA Version One private extension: Remote Invalidation. |
| * Responder's choice: requester signals it can handle Send With |
| * Invalidate, and responder chooses one R_key to invalidate. |
| * |
| * If there is exactly one distinct R_key in the received transport |
| * header, set rc_inv_rkey to that R_key. Otherwise, set it to zero. |
| */ |
| static void svc_rdma_get_inv_rkey(struct svcxprt_rdma *rdma, |
| struct svc_rdma_recv_ctxt *ctxt) |
| { |
| struct svc_rdma_segment *segment; |
| struct svc_rdma_chunk *chunk; |
| u32 inv_rkey; |
| |
| ctxt->rc_inv_rkey = 0; |
| |
| if (!rdma->sc_snd_w_inv) |
| return; |
| |
| inv_rkey = 0; |
| pcl_for_each_chunk(chunk, &ctxt->rc_call_pcl) { |
| pcl_for_each_segment(segment, chunk) { |
| if (inv_rkey == 0) |
| inv_rkey = segment->rs_handle; |
| else if (inv_rkey != segment->rs_handle) |
| return; |
| } |
| } |
| pcl_for_each_chunk(chunk, &ctxt->rc_read_pcl) { |
| pcl_for_each_segment(segment, chunk) { |
| if (inv_rkey == 0) |
| inv_rkey = segment->rs_handle; |
| else if (inv_rkey != segment->rs_handle) |
| return; |
| } |
| } |
| pcl_for_each_chunk(chunk, &ctxt->rc_write_pcl) { |
| pcl_for_each_segment(segment, chunk) { |
| if (inv_rkey == 0) |
| inv_rkey = segment->rs_handle; |
| else if (inv_rkey != segment->rs_handle) |
| return; |
| } |
| } |
| pcl_for_each_chunk(chunk, &ctxt->rc_reply_pcl) { |
| pcl_for_each_segment(segment, chunk) { |
| if (inv_rkey == 0) |
| inv_rkey = segment->rs_handle; |
| else if (inv_rkey != segment->rs_handle) |
| return; |
| } |
| } |
| ctxt->rc_inv_rkey = inv_rkey; |
| } |
| |
| /** |
| * svc_rdma_xdr_decode_req - Decode the transport header |
| * @rq_arg: xdr_buf containing ingress RPC/RDMA message |
| * @rctxt: state of decoding |
| * |
| * On entry, xdr->head[0].iov_base points to first byte of the |
| * RPC-over-RDMA transport 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, |
| struct svc_rdma_recv_ctxt *rctxt) |
| { |
| __be32 *p, *rdma_argp; |
| unsigned int hdr_len; |
| |
| rdma_argp = rq_arg->head[0].iov_base; |
| xdr_init_decode(&rctxt->rc_stream, rq_arg, rdma_argp, NULL); |
| |
| p = xdr_inline_decode(&rctxt->rc_stream, |
| rpcrdma_fixed_maxsz * sizeof(*p)); |
| if (unlikely(!p)) |
| goto out_short; |
| p++; |
| if (*p != rpcrdma_version) |
| goto out_version; |
| p += 2; |
| rctxt->rc_msgtype = *p; |
| switch (rctxt->rc_msgtype) { |
| case rdma_msg: |
| break; |
| case rdma_nomsg: |
| break; |
| case rdma_done: |
| goto out_drop; |
| case rdma_error: |
| goto out_drop; |
| default: |
| goto out_proc; |
| } |
| |
| if (!xdr_check_read_list(rctxt)) |
| goto out_inval; |
| if (!xdr_check_write_list(rctxt)) |
| goto out_inval; |
| if (!xdr_check_reply_chunk(rctxt)) |
| goto out_inval; |
| |
| rq_arg->head[0].iov_base = rctxt->rc_stream.p; |
| hdr_len = xdr_stream_pos(&rctxt->rc_stream); |
| rq_arg->head[0].iov_len -= hdr_len; |
| rq_arg->len -= hdr_len; |
| trace_svcrdma_decode_rqst(rctxt, rdma_argp, hdr_len); |
| return hdr_len; |
| |
| out_short: |
| trace_svcrdma_decode_short_err(rctxt, rq_arg->len); |
| return -EINVAL; |
| |
| out_version: |
| trace_svcrdma_decode_badvers_err(rctxt, rdma_argp); |
| return -EPROTONOSUPPORT; |
| |
| out_drop: |
| trace_svcrdma_decode_drop_err(rctxt, rdma_argp); |
| return 0; |
| |
| out_proc: |
| trace_svcrdma_decode_badproc_err(rctxt, rdma_argp); |
| return -EINVAL; |
| |
| out_inval: |
| trace_svcrdma_decode_parse_err(rctxt, 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 *rdma, |
| struct svc_rdma_recv_ctxt *rctxt, |
| int status) |
| { |
| struct svc_rdma_send_ctxt *sctxt; |
| |
| sctxt = svc_rdma_send_ctxt_get(rdma); |
| if (!sctxt) |
| return; |
| svc_rdma_send_error_msg(rdma, sctxt, rctxt, status); |
| } |
| |
| /* 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_reverse_direction_reply(struct svc_xprt *xprt, |
| struct svc_rdma_recv_ctxt *rctxt) |
| { |
| __be32 *p = rctxt->rc_recv_buf; |
| |
| if (!xprt->xpt_bc_xprt) |
| return false; |
| |
| if (rctxt->rc_msgtype != rdma_msg) |
| return false; |
| |
| if (!pcl_is_empty(&rctxt->rc_call_pcl)) |
| return false; |
| if (!pcl_is_empty(&rctxt->rc_read_pcl)) |
| return false; |
| if (!pcl_is_empty(&rctxt->rc_write_pcl)) |
| return false; |
| if (!pcl_is_empty(&rctxt->rc_reply_pcl)) |
| return false; |
| |
| /* RPC call direction */ |
| if (*(p + 8) == 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; |
| int ret; |
| |
| rqstp->rq_xprt_ctxt = NULL; |
| |
| 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); |
| |
| /* Prevent svc_xprt_release from releasing pages in rq_pages |
| * if we return 0 or an error. |
| */ |
| rqstp->rq_respages = rqstp->rq_pages; |
| rqstp->rq_next_page = rqstp->rq_respages; |
| |
| ret = svc_rdma_xdr_decode_req(&rqstp->rq_arg, ctxt); |
| if (ret < 0) |
| goto out_err; |
| if (ret == 0) |
| goto out_drop; |
| rqstp->rq_xprt_hlen = ret; |
| |
| if (svc_rdma_is_reverse_direction_reply(xprt, ctxt)) |
| goto out_backchannel; |
| |
| svc_rdma_get_inv_rkey(rdma_xprt, ctxt); |
| |
| if (!pcl_is_empty(&ctxt->rc_read_pcl) || |
| !pcl_is_empty(&ctxt->rc_call_pcl)) |
| goto out_readlist; |
| |
| complete: |
| rqstp->rq_xprt_ctxt = ctxt; |
| rqstp->rq_prot = IPPROTO_MAX; |
| svc_xprt_copy_addrs(rqstp, xprt); |
| return rqstp->rq_arg.len; |
| |
| out_readlist: |
| ret = svc_rdma_process_read_list(rdma_xprt, rqstp, ctxt); |
| if (ret < 0) |
| goto out_readfail; |
| return 0; |
| |
| out_err: |
| svc_rdma_send_error(rdma_xprt, ctxt, ret); |
| svc_rdma_recv_ctxt_put(rdma_xprt, ctxt); |
| return 0; |
| |
| out_readfail: |
| if (ret == -EINVAL) |
| svc_rdma_send_error(rdma_xprt, ctxt, ret); |
| svc_rdma_recv_ctxt_put(rdma_xprt, ctxt); |
| return ret; |
| |
| out_backchannel: |
| svc_rdma_handle_bc_reply(rqstp, ctxt); |
| out_drop: |
| svc_rdma_recv_ctxt_put(rdma_xprt, ctxt); |
| return 0; |
| } |