| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Copyright (c) 2016-2018 Oracle. All rights reserved. |
| * |
| * Use the core R/W API to move RPC-over-RDMA Read and Write chunks. |
| */ |
| |
| #include <rdma/rw.h> |
| |
| #include <linux/sunrpc/xdr.h> |
| #include <linux/sunrpc/rpc_rdma.h> |
| #include <linux/sunrpc/svc_rdma.h> |
| |
| #include "xprt_rdma.h" |
| #include <trace/events/rpcrdma.h> |
| |
| static void svc_rdma_write_done(struct ib_cq *cq, struct ib_wc *wc); |
| static void svc_rdma_wc_read_done(struct ib_cq *cq, struct ib_wc *wc); |
| |
| /* Each R/W context contains state for one chain of RDMA Read or |
| * Write Work Requests. |
| * |
| * Each WR chain handles a single contiguous server-side buffer, |
| * because scatterlist entries after the first have to start on |
| * page alignment. xdr_buf iovecs cannot guarantee alignment. |
| * |
| * Each WR chain handles only one R_key. Each RPC-over-RDMA segment |
| * from a client may contain a unique R_key, so each WR chain moves |
| * up to one segment at a time. |
| * |
| * The scatterlist makes this data structure over 4KB in size. To |
| * make it less likely to fail, and to handle the allocation for |
| * smaller I/O requests without disabling bottom-halves, these |
| * contexts are created on demand, but cached and reused until the |
| * controlling svcxprt_rdma is destroyed. |
| */ |
| struct svc_rdma_rw_ctxt { |
| struct list_head rw_list; |
| struct rdma_rw_ctx rw_ctx; |
| unsigned int rw_nents; |
| struct sg_table rw_sg_table; |
| struct scatterlist rw_first_sgl[]; |
| }; |
| |
| static inline struct svc_rdma_rw_ctxt * |
| svc_rdma_next_ctxt(struct list_head *list) |
| { |
| return list_first_entry_or_null(list, struct svc_rdma_rw_ctxt, |
| rw_list); |
| } |
| |
| static struct svc_rdma_rw_ctxt * |
| svc_rdma_get_rw_ctxt(struct svcxprt_rdma *rdma, unsigned int sges) |
| { |
| struct svc_rdma_rw_ctxt *ctxt; |
| |
| spin_lock(&rdma->sc_rw_ctxt_lock); |
| |
| ctxt = svc_rdma_next_ctxt(&rdma->sc_rw_ctxts); |
| if (ctxt) { |
| list_del(&ctxt->rw_list); |
| spin_unlock(&rdma->sc_rw_ctxt_lock); |
| } else { |
| spin_unlock(&rdma->sc_rw_ctxt_lock); |
| ctxt = kmalloc(struct_size(ctxt, rw_first_sgl, SG_CHUNK_SIZE), |
| GFP_KERNEL); |
| if (!ctxt) |
| goto out_noctx; |
| INIT_LIST_HEAD(&ctxt->rw_list); |
| } |
| |
| ctxt->rw_sg_table.sgl = ctxt->rw_first_sgl; |
| if (sg_alloc_table_chained(&ctxt->rw_sg_table, sges, |
| ctxt->rw_sg_table.sgl, |
| SG_CHUNK_SIZE)) |
| goto out_free; |
| return ctxt; |
| |
| out_free: |
| kfree(ctxt); |
| out_noctx: |
| trace_svcrdma_no_rwctx_err(rdma, sges); |
| return NULL; |
| } |
| |
| static void svc_rdma_put_rw_ctxt(struct svcxprt_rdma *rdma, |
| struct svc_rdma_rw_ctxt *ctxt) |
| { |
| sg_free_table_chained(&ctxt->rw_sg_table, SG_CHUNK_SIZE); |
| |
| spin_lock(&rdma->sc_rw_ctxt_lock); |
| list_add(&ctxt->rw_list, &rdma->sc_rw_ctxts); |
| spin_unlock(&rdma->sc_rw_ctxt_lock); |
| } |
| |
| /** |
| * svc_rdma_destroy_rw_ctxts - Free accumulated R/W contexts |
| * @rdma: transport about to be destroyed |
| * |
| */ |
| void svc_rdma_destroy_rw_ctxts(struct svcxprt_rdma *rdma) |
| { |
| struct svc_rdma_rw_ctxt *ctxt; |
| |
| while ((ctxt = svc_rdma_next_ctxt(&rdma->sc_rw_ctxts)) != NULL) { |
| list_del(&ctxt->rw_list); |
| kfree(ctxt); |
| } |
| } |
| |
| /** |
| * svc_rdma_rw_ctx_init - Prepare a R/W context for I/O |
| * @rdma: controlling transport instance |
| * @ctxt: R/W context to prepare |
| * @offset: RDMA offset |
| * @handle: RDMA tag/handle |
| * @direction: I/O direction |
| * |
| * Returns on success, the number of WQEs that will be needed |
| * on the workqueue, or a negative errno. |
| */ |
| static int svc_rdma_rw_ctx_init(struct svcxprt_rdma *rdma, |
| struct svc_rdma_rw_ctxt *ctxt, |
| u64 offset, u32 handle, |
| enum dma_data_direction direction) |
| { |
| int ret; |
| |
| ret = rdma_rw_ctx_init(&ctxt->rw_ctx, rdma->sc_qp, rdma->sc_port_num, |
| ctxt->rw_sg_table.sgl, ctxt->rw_nents, |
| 0, offset, handle, direction); |
| if (unlikely(ret < 0)) { |
| svc_rdma_put_rw_ctxt(rdma, ctxt); |
| trace_svcrdma_dma_map_rw_err(rdma, ctxt->rw_nents, ret); |
| } |
| return ret; |
| } |
| |
| /* A chunk context tracks all I/O for moving one Read or Write |
| * chunk. This is a set of rdma_rw's that handle data movement |
| * for all segments of one chunk. |
| * |
| * These are small, acquired with a single allocator call, and |
| * no more than one is needed per chunk. They are allocated on |
| * demand, and not cached. |
| */ |
| struct svc_rdma_chunk_ctxt { |
| struct rpc_rdma_cid cc_cid; |
| struct ib_cqe cc_cqe; |
| struct svcxprt_rdma *cc_rdma; |
| struct list_head cc_rwctxts; |
| int cc_sqecount; |
| }; |
| |
| static void svc_rdma_cc_cid_init(struct svcxprt_rdma *rdma, |
| struct rpc_rdma_cid *cid) |
| { |
| cid->ci_queue_id = rdma->sc_sq_cq->res.id; |
| cid->ci_completion_id = atomic_inc_return(&rdma->sc_completion_ids); |
| } |
| |
| static void svc_rdma_cc_init(struct svcxprt_rdma *rdma, |
| struct svc_rdma_chunk_ctxt *cc) |
| { |
| svc_rdma_cc_cid_init(rdma, &cc->cc_cid); |
| cc->cc_rdma = rdma; |
| |
| INIT_LIST_HEAD(&cc->cc_rwctxts); |
| cc->cc_sqecount = 0; |
| } |
| |
| static void svc_rdma_cc_release(struct svc_rdma_chunk_ctxt *cc, |
| enum dma_data_direction dir) |
| { |
| struct svcxprt_rdma *rdma = cc->cc_rdma; |
| struct svc_rdma_rw_ctxt *ctxt; |
| |
| while ((ctxt = svc_rdma_next_ctxt(&cc->cc_rwctxts)) != NULL) { |
| list_del(&ctxt->rw_list); |
| |
| rdma_rw_ctx_destroy(&ctxt->rw_ctx, rdma->sc_qp, |
| rdma->sc_port_num, ctxt->rw_sg_table.sgl, |
| ctxt->rw_nents, dir); |
| svc_rdma_put_rw_ctxt(rdma, ctxt); |
| } |
| } |
| |
| /* State for sending a Write or Reply chunk. |
| * - Tracks progress of writing one chunk over all its segments |
| * - Stores arguments for the SGL constructor functions |
| */ |
| struct svc_rdma_write_info { |
| const struct svc_rdma_chunk *wi_chunk; |
| |
| /* write state of this chunk */ |
| unsigned int wi_seg_off; |
| unsigned int wi_seg_no; |
| |
| /* SGL constructor arguments */ |
| const struct xdr_buf *wi_xdr; |
| unsigned char *wi_base; |
| unsigned int wi_next_off; |
| |
| struct svc_rdma_chunk_ctxt wi_cc; |
| }; |
| |
| static struct svc_rdma_write_info * |
| svc_rdma_write_info_alloc(struct svcxprt_rdma *rdma, |
| const struct svc_rdma_chunk *chunk) |
| { |
| struct svc_rdma_write_info *info; |
| |
| info = kmalloc(sizeof(*info), GFP_KERNEL); |
| if (!info) |
| return info; |
| |
| info->wi_chunk = chunk; |
| info->wi_seg_off = 0; |
| info->wi_seg_no = 0; |
| svc_rdma_cc_init(rdma, &info->wi_cc); |
| info->wi_cc.cc_cqe.done = svc_rdma_write_done; |
| return info; |
| } |
| |
| static void svc_rdma_write_info_free(struct svc_rdma_write_info *info) |
| { |
| svc_rdma_cc_release(&info->wi_cc, DMA_TO_DEVICE); |
| kfree(info); |
| } |
| |
| /** |
| * svc_rdma_write_done - Write chunk completion |
| * @cq: controlling Completion Queue |
| * @wc: Work Completion |
| * |
| * Pages under I/O are freed by a subsequent Send completion. |
| */ |
| static void svc_rdma_write_done(struct ib_cq *cq, struct ib_wc *wc) |
| { |
| struct ib_cqe *cqe = wc->wr_cqe; |
| struct svc_rdma_chunk_ctxt *cc = |
| container_of(cqe, struct svc_rdma_chunk_ctxt, cc_cqe); |
| struct svcxprt_rdma *rdma = cc->cc_rdma; |
| struct svc_rdma_write_info *info = |
| container_of(cc, struct svc_rdma_write_info, wi_cc); |
| |
| trace_svcrdma_wc_write(wc, &cc->cc_cid); |
| |
| atomic_add(cc->cc_sqecount, &rdma->sc_sq_avail); |
| wake_up(&rdma->sc_send_wait); |
| |
| if (unlikely(wc->status != IB_WC_SUCCESS)) |
| set_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags); |
| |
| svc_rdma_write_info_free(info); |
| } |
| |
| /* State for pulling a Read chunk. |
| */ |
| struct svc_rdma_read_info { |
| struct svc_rqst *ri_rqst; |
| struct svc_rdma_recv_ctxt *ri_readctxt; |
| unsigned int ri_pageno; |
| unsigned int ri_pageoff; |
| unsigned int ri_totalbytes; |
| |
| struct svc_rdma_chunk_ctxt ri_cc; |
| }; |
| |
| static struct svc_rdma_read_info * |
| svc_rdma_read_info_alloc(struct svcxprt_rdma *rdma) |
| { |
| struct svc_rdma_read_info *info; |
| |
| info = kmalloc(sizeof(*info), GFP_KERNEL); |
| if (!info) |
| return info; |
| |
| svc_rdma_cc_init(rdma, &info->ri_cc); |
| info->ri_cc.cc_cqe.done = svc_rdma_wc_read_done; |
| return info; |
| } |
| |
| static void svc_rdma_read_info_free(struct svc_rdma_read_info *info) |
| { |
| svc_rdma_cc_release(&info->ri_cc, DMA_FROM_DEVICE); |
| kfree(info); |
| } |
| |
| /** |
| * svc_rdma_wc_read_done - Handle completion of an RDMA Read ctx |
| * @cq: controlling Completion Queue |
| * @wc: Work Completion |
| * |
| */ |
| static void svc_rdma_wc_read_done(struct ib_cq *cq, struct ib_wc *wc) |
| { |
| struct ib_cqe *cqe = wc->wr_cqe; |
| struct svc_rdma_chunk_ctxt *cc = |
| container_of(cqe, struct svc_rdma_chunk_ctxt, cc_cqe); |
| struct svcxprt_rdma *rdma = cc->cc_rdma; |
| struct svc_rdma_read_info *info = |
| container_of(cc, struct svc_rdma_read_info, ri_cc); |
| |
| trace_svcrdma_wc_read(wc, &cc->cc_cid); |
| |
| atomic_add(cc->cc_sqecount, &rdma->sc_sq_avail); |
| wake_up(&rdma->sc_send_wait); |
| |
| if (unlikely(wc->status != IB_WC_SUCCESS)) { |
| set_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags); |
| svc_rdma_recv_ctxt_put(rdma, info->ri_readctxt); |
| } else { |
| spin_lock(&rdma->sc_rq_dto_lock); |
| list_add_tail(&info->ri_readctxt->rc_list, |
| &rdma->sc_read_complete_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); |
| |
| svc_xprt_enqueue(&rdma->sc_xprt); |
| } |
| |
| svc_rdma_read_info_free(info); |
| } |
| |
| /* This function sleeps when the transport's Send Queue is congested. |
| * |
| * Assumptions: |
| * - If ib_post_send() succeeds, only one completion is expected, |
| * even if one or more WRs are flushed. This is true when posting |
| * an rdma_rw_ctx or when posting a single signaled WR. |
| */ |
| static int svc_rdma_post_chunk_ctxt(struct svc_rdma_chunk_ctxt *cc) |
| { |
| struct svcxprt_rdma *rdma = cc->cc_rdma; |
| struct svc_xprt *xprt = &rdma->sc_xprt; |
| struct ib_send_wr *first_wr; |
| const struct ib_send_wr *bad_wr; |
| struct list_head *tmp; |
| struct ib_cqe *cqe; |
| int ret; |
| |
| if (cc->cc_sqecount > rdma->sc_sq_depth) |
| return -EINVAL; |
| |
| first_wr = NULL; |
| cqe = &cc->cc_cqe; |
| list_for_each(tmp, &cc->cc_rwctxts) { |
| struct svc_rdma_rw_ctxt *ctxt; |
| |
| ctxt = list_entry(tmp, struct svc_rdma_rw_ctxt, rw_list); |
| first_wr = rdma_rw_ctx_wrs(&ctxt->rw_ctx, rdma->sc_qp, |
| rdma->sc_port_num, cqe, first_wr); |
| cqe = NULL; |
| } |
| |
| do { |
| if (atomic_sub_return(cc->cc_sqecount, |
| &rdma->sc_sq_avail) > 0) { |
| ret = ib_post_send(rdma->sc_qp, first_wr, &bad_wr); |
| if (ret) |
| break; |
| return 0; |
| } |
| |
| trace_svcrdma_sq_full(rdma); |
| atomic_add(cc->cc_sqecount, &rdma->sc_sq_avail); |
| wait_event(rdma->sc_send_wait, |
| atomic_read(&rdma->sc_sq_avail) > cc->cc_sqecount); |
| trace_svcrdma_sq_retry(rdma); |
| } while (1); |
| |
| trace_svcrdma_sq_post_err(rdma, ret); |
| set_bit(XPT_CLOSE, &xprt->xpt_flags); |
| |
| /* If even one was posted, there will be a completion. */ |
| if (bad_wr != first_wr) |
| return 0; |
| |
| atomic_add(cc->cc_sqecount, &rdma->sc_sq_avail); |
| wake_up(&rdma->sc_send_wait); |
| return -ENOTCONN; |
| } |
| |
| /* Build and DMA-map an SGL that covers one kvec in an xdr_buf |
| */ |
| static void svc_rdma_vec_to_sg(struct svc_rdma_write_info *info, |
| unsigned int len, |
| struct svc_rdma_rw_ctxt *ctxt) |
| { |
| struct scatterlist *sg = ctxt->rw_sg_table.sgl; |
| |
| sg_set_buf(&sg[0], info->wi_base, len); |
| info->wi_base += len; |
| |
| ctxt->rw_nents = 1; |
| } |
| |
| /* Build and DMA-map an SGL that covers part of an xdr_buf's pagelist. |
| */ |
| static void svc_rdma_pagelist_to_sg(struct svc_rdma_write_info *info, |
| unsigned int remaining, |
| struct svc_rdma_rw_ctxt *ctxt) |
| { |
| unsigned int sge_no, sge_bytes, page_off, page_no; |
| const struct xdr_buf *xdr = info->wi_xdr; |
| struct scatterlist *sg; |
| struct page **page; |
| |
| page_off = info->wi_next_off + xdr->page_base; |
| page_no = page_off >> PAGE_SHIFT; |
| page_off = offset_in_page(page_off); |
| page = xdr->pages + page_no; |
| info->wi_next_off += remaining; |
| sg = ctxt->rw_sg_table.sgl; |
| sge_no = 0; |
| do { |
| sge_bytes = min_t(unsigned int, remaining, |
| PAGE_SIZE - page_off); |
| sg_set_page(sg, *page, sge_bytes, page_off); |
| |
| remaining -= sge_bytes; |
| sg = sg_next(sg); |
| page_off = 0; |
| sge_no++; |
| page++; |
| } while (remaining); |
| |
| ctxt->rw_nents = sge_no; |
| } |
| |
| /* Construct RDMA Write WRs to send a portion of an xdr_buf containing |
| * an RPC Reply. |
| */ |
| static int |
| svc_rdma_build_writes(struct svc_rdma_write_info *info, |
| void (*constructor)(struct svc_rdma_write_info *info, |
| unsigned int len, |
| struct svc_rdma_rw_ctxt *ctxt), |
| unsigned int remaining) |
| { |
| struct svc_rdma_chunk_ctxt *cc = &info->wi_cc; |
| struct svcxprt_rdma *rdma = cc->cc_rdma; |
| const struct svc_rdma_segment *seg; |
| struct svc_rdma_rw_ctxt *ctxt; |
| int ret; |
| |
| do { |
| unsigned int write_len; |
| u64 offset; |
| |
| seg = &info->wi_chunk->ch_segments[info->wi_seg_no]; |
| if (!seg) |
| goto out_overflow; |
| |
| write_len = min(remaining, seg->rs_length - info->wi_seg_off); |
| if (!write_len) |
| goto out_overflow; |
| ctxt = svc_rdma_get_rw_ctxt(rdma, |
| (write_len >> PAGE_SHIFT) + 2); |
| if (!ctxt) |
| return -ENOMEM; |
| |
| constructor(info, write_len, ctxt); |
| offset = seg->rs_offset + info->wi_seg_off; |
| ret = svc_rdma_rw_ctx_init(rdma, ctxt, offset, seg->rs_handle, |
| DMA_TO_DEVICE); |
| if (ret < 0) |
| return -EIO; |
| |
| list_add(&ctxt->rw_list, &cc->cc_rwctxts); |
| cc->cc_sqecount += ret; |
| if (write_len == seg->rs_length - info->wi_seg_off) { |
| info->wi_seg_no++; |
| info->wi_seg_off = 0; |
| } else { |
| info->wi_seg_off += write_len; |
| } |
| remaining -= write_len; |
| } while (remaining); |
| |
| return 0; |
| |
| out_overflow: |
| trace_svcrdma_small_wrch_err(rdma, remaining, info->wi_seg_no, |
| info->wi_chunk->ch_segcount); |
| return -E2BIG; |
| } |
| |
| /** |
| * svc_rdma_iov_write - Construct RDMA Writes from an iov |
| * @info: pointer to write arguments |
| * @iov: kvec to write |
| * |
| * Returns: |
| * On succes, returns zero |
| * %-E2BIG if the client-provided Write chunk is too small |
| * %-ENOMEM if a resource has been exhausted |
| * %-EIO if an rdma-rw error occurred |
| */ |
| static int svc_rdma_iov_write(struct svc_rdma_write_info *info, |
| const struct kvec *iov) |
| { |
| info->wi_base = iov->iov_base; |
| return svc_rdma_build_writes(info, svc_rdma_vec_to_sg, |
| iov->iov_len); |
| } |
| |
| /** |
| * svc_rdma_pages_write - Construct RDMA Writes from pages |
| * @info: pointer to write arguments |
| * @xdr: xdr_buf with pages to write |
| * @offset: offset into the content of @xdr |
| * @length: number of bytes to write |
| * |
| * Returns: |
| * On succes, returns zero |
| * %-E2BIG if the client-provided Write chunk is too small |
| * %-ENOMEM if a resource has been exhausted |
| * %-EIO if an rdma-rw error occurred |
| */ |
| static int svc_rdma_pages_write(struct svc_rdma_write_info *info, |
| const struct xdr_buf *xdr, |
| unsigned int offset, |
| unsigned long length) |
| { |
| info->wi_xdr = xdr; |
| info->wi_next_off = offset - xdr->head[0].iov_len; |
| return svc_rdma_build_writes(info, svc_rdma_pagelist_to_sg, |
| length); |
| } |
| |
| /** |
| * svc_rdma_xb_write - Construct RDMA Writes to write an xdr_buf |
| * @xdr: xdr_buf to write |
| * @data: pointer to write arguments |
| * |
| * Returns: |
| * On succes, returns zero |
| * %-E2BIG if the client-provided Write chunk is too small |
| * %-ENOMEM if a resource has been exhausted |
| * %-EIO if an rdma-rw error occurred |
| */ |
| static int svc_rdma_xb_write(const struct xdr_buf *xdr, void *data) |
| { |
| struct svc_rdma_write_info *info = data; |
| int ret; |
| |
| if (xdr->head[0].iov_len) { |
| ret = svc_rdma_iov_write(info, &xdr->head[0]); |
| if (ret < 0) |
| return ret; |
| } |
| |
| if (xdr->page_len) { |
| ret = svc_rdma_pages_write(info, xdr, xdr->head[0].iov_len, |
| xdr->page_len); |
| if (ret < 0) |
| return ret; |
| } |
| |
| if (xdr->tail[0].iov_len) { |
| ret = svc_rdma_iov_write(info, &xdr->tail[0]); |
| if (ret < 0) |
| return ret; |
| } |
| |
| return xdr->len; |
| } |
| |
| /** |
| * svc_rdma_send_write_chunk - Write all segments in a Write chunk |
| * @rdma: controlling RDMA transport |
| * @chunk: Write chunk provided by the client |
| * @xdr: xdr_buf containing the data payload |
| * |
| * Returns a non-negative number of bytes the chunk consumed, or |
| * %-E2BIG if the payload was larger than the Write chunk, |
| * %-EINVAL if client provided too many segments, |
| * %-ENOMEM if rdma_rw context pool was exhausted, |
| * %-ENOTCONN if posting failed (connection is lost), |
| * %-EIO if rdma_rw initialization failed (DMA mapping, etc). |
| */ |
| int svc_rdma_send_write_chunk(struct svcxprt_rdma *rdma, |
| const struct svc_rdma_chunk *chunk, |
| const struct xdr_buf *xdr) |
| { |
| struct svc_rdma_write_info *info; |
| struct svc_rdma_chunk_ctxt *cc; |
| int ret; |
| |
| info = svc_rdma_write_info_alloc(rdma, chunk); |
| if (!info) |
| return -ENOMEM; |
| cc = &info->wi_cc; |
| |
| ret = svc_rdma_xb_write(xdr, info); |
| if (ret != xdr->len) |
| goto out_err; |
| |
| trace_svcrdma_post_write_chunk(&cc->cc_cid, cc->cc_sqecount); |
| ret = svc_rdma_post_chunk_ctxt(cc); |
| if (ret < 0) |
| goto out_err; |
| return xdr->len; |
| |
| out_err: |
| svc_rdma_write_info_free(info); |
| return ret; |
| } |
| |
| /** |
| * svc_rdma_send_reply_chunk - Write all segments in the Reply chunk |
| * @rdma: controlling RDMA transport |
| * @rctxt: Write and Reply chunks from client |
| * @xdr: xdr_buf containing an RPC Reply |
| * |
| * Returns a non-negative number of bytes the chunk consumed, or |
| * %-E2BIG if the payload was larger than the Reply chunk, |
| * %-EINVAL if client provided too many segments, |
| * %-ENOMEM if rdma_rw context pool was exhausted, |
| * %-ENOTCONN if posting failed (connection is lost), |
| * %-EIO if rdma_rw initialization failed (DMA mapping, etc). |
| */ |
| int svc_rdma_send_reply_chunk(struct svcxprt_rdma *rdma, |
| const struct svc_rdma_recv_ctxt *rctxt, |
| const struct xdr_buf *xdr) |
| { |
| struct svc_rdma_write_info *info; |
| struct svc_rdma_chunk_ctxt *cc; |
| struct svc_rdma_chunk *chunk; |
| int ret; |
| |
| if (pcl_is_empty(&rctxt->rc_reply_pcl)) |
| return 0; |
| |
| chunk = pcl_first_chunk(&rctxt->rc_reply_pcl); |
| info = svc_rdma_write_info_alloc(rdma, chunk); |
| if (!info) |
| return -ENOMEM; |
| cc = &info->wi_cc; |
| |
| ret = pcl_process_nonpayloads(&rctxt->rc_write_pcl, xdr, |
| svc_rdma_xb_write, info); |
| if (ret < 0) |
| goto out_err; |
| |
| trace_svcrdma_post_reply_chunk(&cc->cc_cid, cc->cc_sqecount); |
| ret = svc_rdma_post_chunk_ctxt(cc); |
| if (ret < 0) |
| goto out_err; |
| |
| return xdr->len; |
| |
| out_err: |
| svc_rdma_write_info_free(info); |
| return ret; |
| } |
| |
| /** |
| * svc_rdma_build_read_segment - Build RDMA Read WQEs to pull one RDMA segment |
| * @info: context for ongoing I/O |
| * @segment: co-ordinates of remote memory to be read |
| * |
| * Returns: |
| * %0: the Read WR chain was constructed successfully |
| * %-EINVAL: there were not enough rq_pages to finish |
| * %-ENOMEM: allocating a local resources failed |
| * %-EIO: a DMA mapping error occurred |
| */ |
| static int svc_rdma_build_read_segment(struct svc_rdma_read_info *info, |
| const struct svc_rdma_segment *segment) |
| { |
| struct svc_rdma_recv_ctxt *head = info->ri_readctxt; |
| struct svc_rdma_chunk_ctxt *cc = &info->ri_cc; |
| struct svc_rqst *rqstp = info->ri_rqst; |
| struct svc_rdma_rw_ctxt *ctxt; |
| unsigned int sge_no, seg_len, len; |
| struct scatterlist *sg; |
| int ret; |
| |
| len = segment->rs_length; |
| sge_no = PAGE_ALIGN(info->ri_pageoff + len) >> PAGE_SHIFT; |
| ctxt = svc_rdma_get_rw_ctxt(cc->cc_rdma, sge_no); |
| if (!ctxt) |
| return -ENOMEM; |
| ctxt->rw_nents = sge_no; |
| |
| sg = ctxt->rw_sg_table.sgl; |
| for (sge_no = 0; sge_no < ctxt->rw_nents; sge_no++) { |
| seg_len = min_t(unsigned int, len, |
| PAGE_SIZE - info->ri_pageoff); |
| |
| head->rc_arg.pages[info->ri_pageno] = |
| rqstp->rq_pages[info->ri_pageno]; |
| if (!info->ri_pageoff) |
| head->rc_page_count++; |
| |
| sg_set_page(sg, rqstp->rq_pages[info->ri_pageno], |
| seg_len, info->ri_pageoff); |
| sg = sg_next(sg); |
| |
| info->ri_pageoff += seg_len; |
| if (info->ri_pageoff == PAGE_SIZE) { |
| info->ri_pageno++; |
| info->ri_pageoff = 0; |
| } |
| len -= seg_len; |
| |
| /* Safety check */ |
| if (len && |
| &rqstp->rq_pages[info->ri_pageno + 1] > rqstp->rq_page_end) |
| goto out_overrun; |
| } |
| |
| ret = svc_rdma_rw_ctx_init(cc->cc_rdma, ctxt, segment->rs_offset, |
| segment->rs_handle, DMA_FROM_DEVICE); |
| if (ret < 0) |
| return -EIO; |
| |
| list_add(&ctxt->rw_list, &cc->cc_rwctxts); |
| cc->cc_sqecount += ret; |
| return 0; |
| |
| out_overrun: |
| trace_svcrdma_page_overrun_err(cc->cc_rdma, rqstp, info->ri_pageno); |
| return -EINVAL; |
| } |
| |
| /** |
| * svc_rdma_build_read_chunk - Build RDMA Read WQEs to pull one RDMA chunk |
| * @info: context for ongoing I/O |
| * @chunk: Read chunk to pull |
| * |
| * Return values: |
| * %0: the Read WR chain was constructed successfully |
| * %-EINVAL: there were not enough resources to finish |
| * %-ENOMEM: allocating a local resources failed |
| * %-EIO: a DMA mapping error occurred |
| */ |
| static int svc_rdma_build_read_chunk(struct svc_rdma_read_info *info, |
| const struct svc_rdma_chunk *chunk) |
| { |
| const struct svc_rdma_segment *segment; |
| int ret; |
| |
| ret = -EINVAL; |
| pcl_for_each_segment(segment, chunk) { |
| ret = svc_rdma_build_read_segment(info, segment); |
| if (ret < 0) |
| break; |
| info->ri_totalbytes += segment->rs_length; |
| } |
| return ret; |
| } |
| |
| /** |
| * svc_rdma_copy_inline_range - Copy part of the inline content into pages |
| * @info: context for RDMA Reads |
| * @offset: offset into the Receive buffer of region to copy |
| * @remaining: length of region to copy |
| * |
| * Take a page at a time from rqstp->rq_pages and copy the inline |
| * content from the Receive buffer into that page. Update |
| * info->ri_pageno and info->ri_pageoff so that the next RDMA Read |
| * result will land contiguously with the copied content. |
| * |
| * Return values: |
| * %0: Inline content was successfully copied |
| * %-EINVAL: offset or length was incorrect |
| */ |
| static int svc_rdma_copy_inline_range(struct svc_rdma_read_info *info, |
| unsigned int offset, |
| unsigned int remaining) |
| { |
| struct svc_rdma_recv_ctxt *head = info->ri_readctxt; |
| unsigned char *dst, *src = head->rc_recv_buf; |
| struct svc_rqst *rqstp = info->ri_rqst; |
| unsigned int page_no, numpages; |
| |
| numpages = PAGE_ALIGN(info->ri_pageoff + remaining) >> PAGE_SHIFT; |
| for (page_no = 0; page_no < numpages; page_no++) { |
| unsigned int page_len; |
| |
| page_len = min_t(unsigned int, remaining, |
| PAGE_SIZE - info->ri_pageoff); |
| |
| head->rc_arg.pages[info->ri_pageno] = |
| rqstp->rq_pages[info->ri_pageno]; |
| if (!info->ri_pageoff) |
| head->rc_page_count++; |
| |
| dst = page_address(head->rc_arg.pages[info->ri_pageno]); |
| memcpy(dst + info->ri_pageno, src + offset, page_len); |
| |
| info->ri_totalbytes += page_len; |
| info->ri_pageoff += page_len; |
| if (info->ri_pageoff == PAGE_SIZE) { |
| info->ri_pageno++; |
| info->ri_pageoff = 0; |
| } |
| remaining -= page_len; |
| offset += page_len; |
| } |
| |
| return -EINVAL; |
| } |
| |
| /** |
| * svc_rdma_read_multiple_chunks - Construct RDMA Reads to pull data item Read chunks |
| * @info: context for RDMA Reads |
| * |
| * The chunk data lands in head->rc_arg as a series of contiguous pages, |
| * like an incoming TCP call. |
| * |
| * Return values: |
| * %0: RDMA Read WQEs were successfully built |
| * %-EINVAL: client provided too many chunks or segments, |
| * %-ENOMEM: rdma_rw context pool was exhausted, |
| * %-ENOTCONN: posting failed (connection is lost), |
| * %-EIO: rdma_rw initialization failed (DMA mapping, etc). |
| */ |
| static noinline int svc_rdma_read_multiple_chunks(struct svc_rdma_read_info *info) |
| { |
| struct svc_rdma_recv_ctxt *head = info->ri_readctxt; |
| const struct svc_rdma_pcl *pcl = &head->rc_read_pcl; |
| struct svc_rdma_chunk *chunk, *next; |
| struct xdr_buf *buf = &head->rc_arg; |
| unsigned int start, length; |
| int ret; |
| |
| start = 0; |
| chunk = pcl_first_chunk(pcl); |
| length = chunk->ch_position; |
| ret = svc_rdma_copy_inline_range(info, start, length); |
| if (ret < 0) |
| return ret; |
| |
| pcl_for_each_chunk(chunk, pcl) { |
| ret = svc_rdma_build_read_chunk(info, chunk); |
| if (ret < 0) |
| return ret; |
| |
| next = pcl_next_chunk(pcl, chunk); |
| if (!next) |
| break; |
| |
| start += length; |
| length = next->ch_position - info->ri_totalbytes; |
| ret = svc_rdma_copy_inline_range(info, start, length); |
| if (ret < 0) |
| return ret; |
| } |
| |
| start += length; |
| length = head->rc_byte_len - start; |
| ret = svc_rdma_copy_inline_range(info, start, length); |
| if (ret < 0) |
| return ret; |
| |
| buf->len += info->ri_totalbytes; |
| buf->buflen += info->ri_totalbytes; |
| |
| head->rc_hdr_count = 1; |
| buf->head[0].iov_base = page_address(head->rc_pages[0]); |
| buf->head[0].iov_len = min_t(size_t, PAGE_SIZE, info->ri_totalbytes); |
| buf->page_len = info->ri_totalbytes - buf->head[0].iov_len; |
| return 0; |
| } |
| |
| /** |
| * svc_rdma_read_data_item - Construct RDMA Reads to pull data item Read chunks |
| * @info: context for RDMA Reads |
| * |
| * The chunk data lands in the page list of head->rc_arg.pages. |
| * |
| * Currently NFSD does not look at the head->rc_arg.tail[0] iovec. |
| * Therefore, XDR round-up of the Read chunk and trailing |
| * inline content must both be added at the end of the pagelist. |
| * |
| * Return values: |
| * %0: RDMA Read WQEs were successfully built |
| * %-EINVAL: client provided too many chunks or segments, |
| * %-ENOMEM: rdma_rw context pool was exhausted, |
| * %-ENOTCONN: posting failed (connection is lost), |
| * %-EIO: rdma_rw initialization failed (DMA mapping, etc). |
| */ |
| static int svc_rdma_read_data_item(struct svc_rdma_read_info *info) |
| { |
| struct svc_rdma_recv_ctxt *head = info->ri_readctxt; |
| struct xdr_buf *buf = &head->rc_arg; |
| struct svc_rdma_chunk *chunk; |
| unsigned int length; |
| int ret; |
| |
| chunk = pcl_first_chunk(&head->rc_read_pcl); |
| ret = svc_rdma_build_read_chunk(info, chunk); |
| if (ret < 0) |
| goto out; |
| |
| head->rc_hdr_count = 0; |
| |
| /* Split the Receive buffer between the head and tail |
| * buffers at Read chunk's position. XDR roundup of the |
| * chunk is not included in either the pagelist or in |
| * the tail. |
| */ |
| buf->tail[0].iov_base = buf->head[0].iov_base + chunk->ch_position; |
| buf->tail[0].iov_len = buf->head[0].iov_len - chunk->ch_position; |
| buf->head[0].iov_len = chunk->ch_position; |
| |
| /* Read chunk may need XDR roundup (see RFC 8166, s. 3.4.5.2). |
| * |
| * If the client already rounded up the chunk length, the |
| * length does not change. Otherwise, the length of the page |
| * list is increased to include XDR round-up. |
| * |
| * Currently these chunks always start at page offset 0, |
| * thus the rounded-up length never crosses a page boundary. |
| */ |
| length = XDR_QUADLEN(info->ri_totalbytes) << 2; |
| buf->page_len = length; |
| buf->len += length; |
| buf->buflen += length; |
| |
| out: |
| return ret; |
| } |
| |
| /** |
| * svc_rdma_read_chunk_range - Build RDMA Read WQEs for portion of a chunk |
| * @info: context for RDMA Reads |
| * @chunk: parsed Call chunk to pull |
| * @offset: offset of region to pull |
| * @length: length of region to pull |
| * |
| * Return values: |
| * %0: RDMA Read WQEs were successfully built |
| * %-EINVAL: there were not enough resources to finish |
| * %-ENOMEM: rdma_rw context pool was exhausted, |
| * %-ENOTCONN: posting failed (connection is lost), |
| * %-EIO: rdma_rw initialization failed (DMA mapping, etc). |
| */ |
| static int svc_rdma_read_chunk_range(struct svc_rdma_read_info *info, |
| const struct svc_rdma_chunk *chunk, |
| unsigned int offset, unsigned int length) |
| { |
| const struct svc_rdma_segment *segment; |
| int ret; |
| |
| ret = -EINVAL; |
| pcl_for_each_segment(segment, chunk) { |
| struct svc_rdma_segment dummy; |
| |
| if (offset > segment->rs_length) { |
| offset -= segment->rs_length; |
| continue; |
| } |
| |
| dummy.rs_handle = segment->rs_handle; |
| dummy.rs_length = min_t(u32, length, segment->rs_length) - offset; |
| dummy.rs_offset = segment->rs_offset + offset; |
| |
| ret = svc_rdma_build_read_segment(info, &dummy); |
| if (ret < 0) |
| break; |
| |
| info->ri_totalbytes += dummy.rs_length; |
| length -= dummy.rs_length; |
| offset = 0; |
| } |
| return ret; |
| } |
| |
| /** |
| * svc_rdma_read_call_chunk - Build RDMA Read WQEs to pull a Long Message |
| * @info: context for RDMA Reads |
| * |
| * Return values: |
| * %0: RDMA Read WQEs were successfully built |
| * %-EINVAL: there were not enough resources to finish |
| * %-ENOMEM: rdma_rw context pool was exhausted, |
| * %-ENOTCONN: posting failed (connection is lost), |
| * %-EIO: rdma_rw initialization failed (DMA mapping, etc). |
| */ |
| static int svc_rdma_read_call_chunk(struct svc_rdma_read_info *info) |
| { |
| struct svc_rdma_recv_ctxt *head = info->ri_readctxt; |
| const struct svc_rdma_chunk *call_chunk = |
| pcl_first_chunk(&head->rc_call_pcl); |
| const struct svc_rdma_pcl *pcl = &head->rc_read_pcl; |
| struct svc_rdma_chunk *chunk, *next; |
| unsigned int start, length; |
| int ret; |
| |
| if (pcl_is_empty(pcl)) |
| return svc_rdma_build_read_chunk(info, call_chunk); |
| |
| start = 0; |
| chunk = pcl_first_chunk(pcl); |
| length = chunk->ch_position; |
| ret = svc_rdma_read_chunk_range(info, call_chunk, start, length); |
| if (ret < 0) |
| return ret; |
| |
| pcl_for_each_chunk(chunk, pcl) { |
| ret = svc_rdma_build_read_chunk(info, chunk); |
| if (ret < 0) |
| return ret; |
| |
| next = pcl_next_chunk(pcl, chunk); |
| if (!next) |
| break; |
| |
| start += length; |
| length = next->ch_position - info->ri_totalbytes; |
| ret = svc_rdma_read_chunk_range(info, call_chunk, |
| start, length); |
| if (ret < 0) |
| return ret; |
| } |
| |
| start += length; |
| length = call_chunk->ch_length - start; |
| return svc_rdma_read_chunk_range(info, call_chunk, start, length); |
| } |
| |
| /** |
| * svc_rdma_read_special - Build RDMA Read WQEs to pull a Long Message |
| * @info: context for RDMA Reads |
| * |
| * The start of the data lands in the first page just after the |
| * Transport header, and the rest lands in the page list of |
| * head->rc_arg.pages. |
| * |
| * Assumptions: |
| * - A PZRC is never sent in an RDMA_MSG message, though it's |
| * allowed by spec. |
| * |
| * Return values: |
| * %0: RDMA Read WQEs were successfully built |
| * %-EINVAL: client provided too many chunks or segments, |
| * %-ENOMEM: rdma_rw context pool was exhausted, |
| * %-ENOTCONN: posting failed (connection is lost), |
| * %-EIO: rdma_rw initialization failed (DMA mapping, etc). |
| */ |
| static noinline int svc_rdma_read_special(struct svc_rdma_read_info *info) |
| { |
| struct svc_rdma_recv_ctxt *head = info->ri_readctxt; |
| struct xdr_buf *buf = &head->rc_arg; |
| int ret; |
| |
| ret = svc_rdma_read_call_chunk(info); |
| if (ret < 0) |
| goto out; |
| |
| buf->len += info->ri_totalbytes; |
| buf->buflen += info->ri_totalbytes; |
| |
| head->rc_hdr_count = 1; |
| buf->head[0].iov_base = page_address(head->rc_pages[0]); |
| buf->head[0].iov_len = min_t(size_t, PAGE_SIZE, info->ri_totalbytes); |
| buf->page_len = info->ri_totalbytes - buf->head[0].iov_len; |
| |
| out: |
| return ret; |
| } |
| |
| /* Pages under I/O have been copied to head->rc_pages. Ensure they |
| * are not released by svc_xprt_release() until the I/O is complete. |
| * |
| * This has to be done after all Read WRs are constructed to properly |
| * handle a page that is part of I/O on behalf of two different RDMA |
| * segments. |
| * |
| * Do this only if I/O has been posted. Otherwise, we do indeed want |
| * svc_xprt_release() to clean things up properly. |
| */ |
| static void svc_rdma_save_io_pages(struct svc_rqst *rqstp, |
| const unsigned int start, |
| const unsigned int num_pages) |
| { |
| unsigned int i; |
| |
| for (i = start; i < num_pages + start; i++) |
| rqstp->rq_pages[i] = NULL; |
| } |
| |
| /** |
| * svc_rdma_process_read_list - Pull list of Read chunks from the client |
| * @rdma: controlling RDMA transport |
| * @rqstp: set of pages to use as Read sink buffers |
| * @head: pages under I/O collect here |
| * |
| * The RPC/RDMA protocol assumes that the upper layer's XDR decoders |
| * pull each Read chunk as they decode an incoming RPC message. |
| * |
| * On Linux, however, the server needs to have a fully-constructed RPC |
| * message in rqstp->rq_arg when there is a positive return code from |
| * ->xpo_recvfrom. So the Read list is safety-checked immediately when |
| * it is received, then here the whole Read list is pulled all at once. |
| * The ingress RPC message is fully reconstructed once all associated |
| * RDMA Reads have completed. |
| * |
| * Return values: |
| * %1: all needed RDMA Reads were posted successfully, |
| * %-EINVAL: client provided too many chunks or segments, |
| * %-ENOMEM: rdma_rw context pool was exhausted, |
| * %-ENOTCONN: posting failed (connection is lost), |
| * %-EIO: rdma_rw initialization failed (DMA mapping, etc). |
| */ |
| int svc_rdma_process_read_list(struct svcxprt_rdma *rdma, |
| struct svc_rqst *rqstp, |
| struct svc_rdma_recv_ctxt *head) |
| { |
| struct svc_rdma_read_info *info; |
| struct svc_rdma_chunk_ctxt *cc; |
| int ret; |
| |
| /* The request (with page list) is constructed in |
| * head->rc_arg. Pages involved with RDMA Read I/O are |
| * transferred there. |
| */ |
| head->rc_arg.head[0] = rqstp->rq_arg.head[0]; |
| head->rc_arg.tail[0] = rqstp->rq_arg.tail[0]; |
| head->rc_arg.pages = head->rc_pages; |
| head->rc_arg.page_base = 0; |
| head->rc_arg.page_len = 0; |
| head->rc_arg.len = rqstp->rq_arg.len; |
| head->rc_arg.buflen = rqstp->rq_arg.buflen; |
| |
| info = svc_rdma_read_info_alloc(rdma); |
| if (!info) |
| return -ENOMEM; |
| cc = &info->ri_cc; |
| info->ri_rqst = rqstp; |
| info->ri_readctxt = head; |
| info->ri_pageno = 0; |
| info->ri_pageoff = 0; |
| info->ri_totalbytes = 0; |
| |
| if (pcl_is_empty(&head->rc_call_pcl)) { |
| if (head->rc_read_pcl.cl_count == 1) |
| ret = svc_rdma_read_data_item(info); |
| else |
| ret = svc_rdma_read_multiple_chunks(info); |
| } else |
| ret = svc_rdma_read_special(info); |
| if (ret < 0) |
| goto out_err; |
| |
| trace_svcrdma_post_read_chunk(&cc->cc_cid, cc->cc_sqecount); |
| ret = svc_rdma_post_chunk_ctxt(cc); |
| if (ret < 0) |
| goto out_err; |
| svc_rdma_save_io_pages(rqstp, 0, head->rc_page_count); |
| return 1; |
| |
| out_err: |
| svc_rdma_read_info_free(info); |
| return ret; |
| } |