diff options
Diffstat (limited to 'net/sunrpc/xprtrdma/svc_rdma_sendto.c')
| -rw-r--r-- | net/sunrpc/xprtrdma/svc_rdma_sendto.c | 310 |
1 files changed, 188 insertions, 122 deletions
diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c index 22a871e6fe4d..914cd263c2f1 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c +++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c @@ -100,7 +100,7 @@ */ #include <linux/spinlock.h> -#include <asm/unaligned.h> +#include <linux/unaligned.h> #include <rdma/ib_verbs.h> #include <rdma/rdma_cm.h> @@ -113,42 +113,41 @@ static void svc_rdma_wc_send(struct ib_cq *cq, struct ib_wc *wc); -static void svc_rdma_send_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 struct svc_rdma_send_ctxt * svc_rdma_send_ctxt_alloc(struct svcxprt_rdma *rdma) { + int node = ibdev_to_node(rdma->sc_cm_id->device); struct svc_rdma_send_ctxt *ctxt; + unsigned long pages; dma_addr_t addr; void *buffer; - size_t size; int i; - size = sizeof(*ctxt); - size += rdma->sc_max_send_sges * sizeof(struct ib_sge); - ctxt = kmalloc(size, GFP_KERNEL); + ctxt = kzalloc_node(struct_size(ctxt, sc_sges, rdma->sc_max_send_sges), + GFP_KERNEL, node); if (!ctxt) goto fail0; - buffer = kmalloc(rdma->sc_max_req_size, GFP_KERNEL); - if (!buffer) + pages = svc_serv_maxpages(rdma->sc_xprt.xpt_server); + ctxt->sc_pages = kcalloc_node(pages, sizeof(struct page *), + GFP_KERNEL, node); + if (!ctxt->sc_pages) goto fail1; + ctxt->sc_maxpages = pages; + buffer = kmalloc_node(rdma->sc_max_req_size, GFP_KERNEL, node); + if (!buffer) + goto fail2; addr = ib_dma_map_single(rdma->sc_pd->device, buffer, rdma->sc_max_req_size, DMA_TO_DEVICE); if (ib_dma_mapping_error(rdma->sc_pd->device, addr)) - goto fail2; + goto fail3; svc_rdma_send_cid_init(rdma, &ctxt->sc_cid); + ctxt->sc_rdma = rdma; ctxt->sc_send_wr.next = NULL; ctxt->sc_send_wr.wr_cqe = &ctxt->sc_cqe; ctxt->sc_send_wr.sg_list = ctxt->sc_sges; ctxt->sc_send_wr.send_flags = IB_SEND_SIGNALED; - init_completion(&ctxt->sc_done); ctxt->sc_cqe.done = svc_rdma_wc_send; ctxt->sc_xprt_buf = buffer; xdr_buf_init(&ctxt->sc_hdrbuf, ctxt->sc_xprt_buf, @@ -159,8 +158,10 @@ svc_rdma_send_ctxt_alloc(struct svcxprt_rdma *rdma) ctxt->sc_sges[i].lkey = rdma->sc_pd->local_dma_lkey; return ctxt; -fail2: +fail3: kfree(buffer); +fail2: + kfree(ctxt->sc_pages); fail1: kfree(ctxt); fail0: @@ -184,6 +185,7 @@ void svc_rdma_send_ctxts_destroy(struct svcxprt_rdma *rdma) rdma->sc_max_req_size, DMA_TO_DEVICE); kfree(ctxt->sc_xprt_buf); + kfree(ctxt->sc_pages); kfree(ctxt); } } @@ -202,55 +204,82 @@ struct svc_rdma_send_ctxt *svc_rdma_send_ctxt_get(struct svcxprt_rdma *rdma) spin_lock(&rdma->sc_send_lock); node = llist_del_first(&rdma->sc_send_ctxts); + spin_unlock(&rdma->sc_send_lock); if (!node) goto out_empty; + ctxt = llist_entry(node, struct svc_rdma_send_ctxt, sc_node); - spin_unlock(&rdma->sc_send_lock); out: rpcrdma_set_xdrlen(&ctxt->sc_hdrbuf, 0); xdr_init_encode(&ctxt->sc_stream, &ctxt->sc_hdrbuf, ctxt->sc_xprt_buf, NULL); + svc_rdma_cc_init(rdma, &ctxt->sc_reply_info.wi_cc); ctxt->sc_send_wr.num_sge = 0; ctxt->sc_cur_sge_no = 0; + ctxt->sc_page_count = 0; + ctxt->sc_wr_chain = &ctxt->sc_send_wr; + ctxt->sc_sqecount = 1; + return ctxt; out_empty: - spin_unlock(&rdma->sc_send_lock); ctxt = svc_rdma_send_ctxt_alloc(rdma); if (!ctxt) return NULL; goto out; } -/** - * svc_rdma_send_ctxt_put - Return send_ctxt to free list - * @rdma: controlling svcxprt_rdma - * @ctxt: object to return to the free list - */ -void svc_rdma_send_ctxt_put(struct svcxprt_rdma *rdma, - struct svc_rdma_send_ctxt *ctxt) +static void svc_rdma_send_ctxt_release(struct svcxprt_rdma *rdma, + struct svc_rdma_send_ctxt *ctxt) { struct ib_device *device = rdma->sc_cm_id->device; unsigned int i; + svc_rdma_reply_chunk_release(rdma, ctxt); + + if (ctxt->sc_page_count) + release_pages(ctxt->sc_pages, ctxt->sc_page_count); + /* The first SGE contains the transport header, which * remains mapped until @ctxt is destroyed. */ for (i = 1; i < ctxt->sc_send_wr.num_sge; i++) { + trace_svcrdma_dma_unmap_page(&ctxt->sc_cid, + ctxt->sc_sges[i].addr, + ctxt->sc_sges[i].length); ib_dma_unmap_page(device, ctxt->sc_sges[i].addr, ctxt->sc_sges[i].length, DMA_TO_DEVICE); - trace_svcrdma_dma_unmap_page(rdma, - ctxt->sc_sges[i].addr, - ctxt->sc_sges[i].length); } llist_add(&ctxt->sc_node, &rdma->sc_send_ctxts); } +static void svc_rdma_send_ctxt_put_async(struct work_struct *work) +{ + struct svc_rdma_send_ctxt *ctxt; + + ctxt = container_of(work, struct svc_rdma_send_ctxt, sc_work); + svc_rdma_send_ctxt_release(ctxt->sc_rdma, ctxt); +} + +/** + * svc_rdma_send_ctxt_put - Return send_ctxt to free list + * @rdma: controlling svcxprt_rdma + * @ctxt: object to return to the free list + * + * Pages left in sc_pages are DMA unmapped and released. + */ +void svc_rdma_send_ctxt_put(struct svcxprt_rdma *rdma, + struct svc_rdma_send_ctxt *ctxt) +{ + INIT_WORK(&ctxt->sc_work, svc_rdma_send_ctxt_put_async); + queue_work(svcrdma_wq, &ctxt->sc_work); +} + /** * svc_rdma_wake_send_waiters - manage Send Queue accounting * @rdma: controlling transport @@ -280,13 +309,13 @@ static void svc_rdma_wc_send(struct ib_cq *cq, struct ib_wc *wc) struct svc_rdma_send_ctxt *ctxt = container_of(cqe, struct svc_rdma_send_ctxt, sc_cqe); - svc_rdma_wake_send_waiters(rdma, 1); - complete(&ctxt->sc_done); + svc_rdma_wake_send_waiters(rdma, ctxt->sc_sqecount); if (unlikely(wc->status != IB_WC_SUCCESS)) goto flushed; - trace_svcrdma_wc_send(wc, &ctxt->sc_cid); + trace_svcrdma_wc_send(&ctxt->sc_cid); + svc_rdma_send_ctxt_put(rdma, ctxt); return; flushed: @@ -294,55 +323,81 @@ flushed: trace_svcrdma_wc_send_err(wc, &ctxt->sc_cid); else trace_svcrdma_wc_send_flush(wc, &ctxt->sc_cid); + svc_rdma_send_ctxt_put(rdma, ctxt); svc_xprt_deferred_close(&rdma->sc_xprt); } /** - * svc_rdma_send - Post a single Send WR - * @rdma: transport on which to post the WR - * @ctxt: send ctxt with a Send WR ready to post + * svc_rdma_post_send - Post a WR chain to the Send Queue + * @rdma: transport context + * @ctxt: WR chain to post + * + * Copy fields in @ctxt to stack variables in order to guarantee + * that these values remain available after the ib_post_send() call. + * In some error flow cases, svc_rdma_wc_send() releases @ctxt. + * + * Note there is potential for starvation when the Send Queue is + * full because there is no order to when waiting threads are + * awoken. The transport is typically provisioned with a deep + * enough Send Queue that SQ exhaustion should be a rare event. * - * Returns zero if the Send WR was posted successfully. Otherwise, a - * negative errno is returned. + * Return values: + * %0: @ctxt's WR chain was posted successfully + * %-ENOTCONN: The connection was lost */ -int svc_rdma_send(struct svcxprt_rdma *rdma, struct svc_rdma_send_ctxt *ctxt) +int svc_rdma_post_send(struct svcxprt_rdma *rdma, + struct svc_rdma_send_ctxt *ctxt) { - struct ib_send_wr *wr = &ctxt->sc_send_wr; - int ret; + struct ib_send_wr *first_wr = ctxt->sc_wr_chain; + struct ib_send_wr *send_wr = &ctxt->sc_send_wr; + const struct ib_send_wr *bad_wr = first_wr; + struct rpc_rdma_cid cid = ctxt->sc_cid; + int ret, sqecount = ctxt->sc_sqecount; - reinit_completion(&ctxt->sc_done); + might_sleep(); /* Sync the transport header buffer */ ib_dma_sync_single_for_device(rdma->sc_pd->device, - wr->sg_list[0].addr, - wr->sg_list[0].length, + send_wr->sg_list[0].addr, + send_wr->sg_list[0].length, DMA_TO_DEVICE); /* If the SQ is full, wait until an SQ entry is available */ - while (1) { - if ((atomic_dec_return(&rdma->sc_sq_avail) < 0)) { + while (!test_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags)) { + if (atomic_sub_return(sqecount, &rdma->sc_sq_avail) < 0) { + svc_rdma_wake_send_waiters(rdma, sqecount); + + /* When the transport is torn down, assume + * ib_drain_sq() will trigger enough Send + * completions to wake us. The XPT_CLOSE test + * above should then cause the while loop to + * exit. + */ percpu_counter_inc(&svcrdma_stat_sq_starve); - trace_svcrdma_sq_full(rdma); - atomic_inc(&rdma->sc_sq_avail); + trace_svcrdma_sq_full(rdma, &cid); wait_event(rdma->sc_send_wait, - atomic_read(&rdma->sc_sq_avail) > 1); - if (test_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags)) - return -ENOTCONN; - trace_svcrdma_sq_retry(rdma); + atomic_read(&rdma->sc_sq_avail) > 0); + trace_svcrdma_sq_retry(rdma, &cid); continue; } trace_svcrdma_post_send(ctxt); - ret = ib_post_send(rdma->sc_qp, wr, NULL); - if (ret) - break; + ret = ib_post_send(rdma->sc_qp, first_wr, &bad_wr); + if (ret) { + trace_svcrdma_sq_post_err(rdma, &cid, ret); + svc_xprt_deferred_close(&rdma->sc_xprt); + + /* If even one WR was posted, there will be a + * Send completion that bumps sc_sq_avail. + */ + if (bad_wr == first_wr) { + svc_rdma_wake_send_waiters(rdma, sqecount); + break; + } + } return 0; } - - trace_svcrdma_sq_post_err(rdma, ret); - svc_xprt_deferred_close(&rdma->sc_xprt); - wake_up(&rdma->sc_send_wait); - return ret; + return -ENOTCONN; } /** @@ -529,14 +584,14 @@ static int svc_rdma_page_dma_map(void *data, struct page *page, if (ib_dma_mapping_error(dev, dma_addr)) goto out_maperr; - trace_svcrdma_dma_map_page(rdma, dma_addr, len); + trace_svcrdma_dma_map_page(&ctxt->sc_cid, dma_addr, len); ctxt->sc_sges[ctxt->sc_cur_sge_no].addr = dma_addr; ctxt->sc_sges[ctxt->sc_cur_sge_no].length = len; ctxt->sc_send_wr.num_sge++; return 0; out_maperr: - trace_svcrdma_dma_map_err(rdma, dma_addr, len); + trace_svcrdma_dma_map_err(&ctxt->sc_cid, dma_addr, len); return -EIO; } @@ -648,7 +703,7 @@ static int svc_rdma_xb_count_sges(const struct xdr_buf *xdr, * svc_rdma_pull_up_needed - Determine whether to use pull-up * @rdma: controlling transport * @sctxt: send_ctxt for the Send WR - * @rctxt: Write and Reply chunks provided by client + * @write_pcl: Write chunk list provided by client * @xdr: xdr_buf containing RPC message to transmit * * Returns: @@ -657,7 +712,7 @@ static int svc_rdma_xb_count_sges(const struct xdr_buf *xdr, */ static bool svc_rdma_pull_up_needed(const struct svcxprt_rdma *rdma, const struct svc_rdma_send_ctxt *sctxt, - const struct svc_rdma_recv_ctxt *rctxt, + const struct svc_rdma_pcl *write_pcl, const struct xdr_buf *xdr) { /* Resources needed for the transport header */ @@ -667,7 +722,7 @@ static bool svc_rdma_pull_up_needed(const struct svcxprt_rdma *rdma, }; int ret; - ret = pcl_process_nonpayloads(&rctxt->rc_write_pcl, xdr, + ret = pcl_process_nonpayloads(write_pcl, xdr, svc_rdma_xb_count_sges, &args); if (ret < 0) return false; @@ -723,7 +778,7 @@ static int svc_rdma_xb_linearize(const struct xdr_buf *xdr, * svc_rdma_pull_up_reply_msg - Copy Reply into a single buffer * @rdma: controlling transport * @sctxt: send_ctxt for the Send WR; xprt hdr is already prepared - * @rctxt: Write and Reply chunks provided by client + * @write_pcl: Write chunk list provided by client * @xdr: prepared xdr_buf containing RPC message * * The device is not capable of sending the reply directly. @@ -738,7 +793,7 @@ static int svc_rdma_xb_linearize(const struct xdr_buf *xdr, */ static int svc_rdma_pull_up_reply_msg(const struct svcxprt_rdma *rdma, struct svc_rdma_send_ctxt *sctxt, - const struct svc_rdma_recv_ctxt *rctxt, + const struct svc_rdma_pcl *write_pcl, const struct xdr_buf *xdr) { struct svc_rdma_pullup_data args = { @@ -746,7 +801,7 @@ static int svc_rdma_pull_up_reply_msg(const struct svcxprt_rdma *rdma, }; int ret; - ret = pcl_process_nonpayloads(&rctxt->rc_write_pcl, xdr, + ret = pcl_process_nonpayloads(write_pcl, xdr, svc_rdma_xb_linearize, &args); if (ret < 0) return ret; @@ -759,7 +814,8 @@ static int svc_rdma_pull_up_reply_msg(const struct svcxprt_rdma *rdma, /* svc_rdma_map_reply_msg - DMA map the buffer holding RPC message * @rdma: controlling transport * @sctxt: send_ctxt for the Send WR - * @rctxt: Write and Reply chunks provided by client + * @write_pcl: Write chunk list provided by client + * @reply_pcl: Reply chunk provided by client * @xdr: prepared xdr_buf containing RPC message * * Returns: @@ -771,7 +827,8 @@ static int svc_rdma_pull_up_reply_msg(const struct svcxprt_rdma *rdma, */ int svc_rdma_map_reply_msg(struct svcxprt_rdma *rdma, struct svc_rdma_send_ctxt *sctxt, - const struct svc_rdma_recv_ctxt *rctxt, + const struct svc_rdma_pcl *write_pcl, + const struct svc_rdma_pcl *reply_pcl, const struct xdr_buf *xdr) { struct svc_rdma_map_data args = { @@ -784,36 +841,49 @@ int svc_rdma_map_reply_msg(struct svcxprt_rdma *rdma, sctxt->sc_sges[0].length = sctxt->sc_hdrbuf.len; /* If there is a Reply chunk, nothing follows the transport - * header, and we're done here. + * header, so there is nothing to map. */ - if (!pcl_is_empty(&rctxt->rc_reply_pcl)) + if (!pcl_is_empty(reply_pcl)) return 0; /* For pull-up, svc_rdma_send() will sync the transport header. * No additional DMA mapping is necessary. */ - if (svc_rdma_pull_up_needed(rdma, sctxt, rctxt, xdr)) - return svc_rdma_pull_up_reply_msg(rdma, sctxt, rctxt, xdr); + if (svc_rdma_pull_up_needed(rdma, sctxt, write_pcl, xdr)) + return svc_rdma_pull_up_reply_msg(rdma, sctxt, write_pcl, xdr); - return pcl_process_nonpayloads(&rctxt->rc_write_pcl, xdr, + return pcl_process_nonpayloads(write_pcl, xdr, svc_rdma_xb_dma_map, &args); } +/* The svc_rqst and all resources it owns are released as soon as + * svc_rdma_sendto returns. Transfer pages under I/O to the ctxt + * so they are released by the Send completion handler. + */ +static void svc_rdma_save_io_pages(struct svc_rqst *rqstp, + struct svc_rdma_send_ctxt *ctxt) +{ + int i, pages = rqstp->rq_next_page - rqstp->rq_respages; + + ctxt->sc_page_count += pages; + for (i = 0; i < pages; i++) { + ctxt->sc_pages[i] = rqstp->rq_respages[i]; + rqstp->rq_respages[i] = NULL; + } + + /* Prevent svc_xprt_release from releasing pages in rq_pages */ + rqstp->rq_next_page = rqstp->rq_respages; +} + /* Prepare the portion of the RPC Reply that will be transmitted * via RDMA Send. The RPC-over-RDMA transport header is prepared * in sc_sges[0], and the RPC xdr_buf is prepared in following sges. * * Depending on whether a Write list or Reply chunk is present, - * the server may send all, a portion of, or none of the xdr_buf. + * the server may Send all, a portion of, or none of the xdr_buf. * In the latter case, only the transport header (sc_sges[0]) is * transmitted. * - * RDMA Send is the last step of transmitting an RPC reply. Pages - * involved in the earlier RDMA Writes are here transferred out - * of the rqstp and into the sctxt's page array. These pages are - * DMA unmapped by each Write completion, but the subsequent Send - * completion finally releases these pages. - * * Assumptions: * - The Reply's transport header will never be larger than a page. */ @@ -822,26 +892,27 @@ static int svc_rdma_send_reply_msg(struct svcxprt_rdma *rdma, const struct svc_rdma_recv_ctxt *rctxt, struct svc_rqst *rqstp) { + struct ib_send_wr *send_wr = &sctxt->sc_send_wr; int ret; - ret = svc_rdma_map_reply_msg(rdma, sctxt, rctxt, &rqstp->rq_res); + ret = svc_rdma_map_reply_msg(rdma, sctxt, &rctxt->rc_write_pcl, + &rctxt->rc_reply_pcl, &rqstp->rq_res); if (ret < 0) return ret; + /* Transfer pages involved in RDMA Writes to the sctxt's + * page array. Completion handling releases these pages. + */ + svc_rdma_save_io_pages(rqstp, sctxt); + if (rctxt->rc_inv_rkey) { - sctxt->sc_send_wr.opcode = IB_WR_SEND_WITH_INV; - sctxt->sc_send_wr.ex.invalidate_rkey = rctxt->rc_inv_rkey; + send_wr->opcode = IB_WR_SEND_WITH_INV; + send_wr->ex.invalidate_rkey = rctxt->rc_inv_rkey; } else { - sctxt->sc_send_wr.opcode = IB_WR_SEND; + send_wr->opcode = IB_WR_SEND; } - ret = svc_rdma_send(rdma, sctxt); - if (ret < 0) - return ret; - - ret = wait_for_completion_killable(&sctxt->sc_done); - svc_rdma_send_ctxt_put(rdma, sctxt); - return ret; + return svc_rdma_post_send(rdma, sctxt); } /** @@ -905,10 +976,9 @@ void svc_rdma_send_error_msg(struct svcxprt_rdma *rdma, sctxt->sc_send_wr.num_sge = 1; sctxt->sc_send_wr.opcode = IB_WR_SEND; sctxt->sc_sges[0].length = sctxt->sc_hdrbuf.len; - if (svc_rdma_send(rdma, sctxt)) + if (svc_rdma_post_send(rdma, sctxt)) goto put_ctxt; - - wait_for_completion_killable(&sctxt->sc_done); + return; put_ctxt: svc_rdma_send_ctxt_put(rdma, sctxt); @@ -953,10 +1023,19 @@ int svc_rdma_sendto(struct svc_rqst *rqstp) if (!p) goto put_ctxt; - ret = svc_rdma_send_reply_chunk(rdma, rctxt, &rqstp->rq_res); + ret = svc_rdma_send_write_list(rdma, rctxt, &rqstp->rq_res); if (ret < 0) - goto reply_chunk; - rc_size = ret; + goto put_ctxt; + + rc_size = 0; + if (!pcl_is_empty(&rctxt->rc_reply_pcl)) { + ret = svc_rdma_prepare_reply_chunk(rdma, &rctxt->rc_write_pcl, + &rctxt->rc_reply_pcl, sctxt, + &rqstp->rq_res); + if (ret < 0) + goto reply_chunk; + rc_size = ret; + } *p++ = *rdma_argp; *p++ = *(rdma_argp + 1); @@ -976,17 +1055,16 @@ int svc_rdma_sendto(struct svc_rqst *rqstp) ret = svc_rdma_send_reply_msg(rdma, sctxt, rctxt, rqstp); if (ret < 0) goto put_ctxt; - - /* Prevent svc_xprt_release() from releasing the page backing - * rq_res.head[0].iov_base. It's no longer being accessed by - * the I/O device. */ - rqstp->rq_respages++; return 0; reply_chunk: if (ret != -E2BIG && ret != -EINVAL) goto put_ctxt; + /* Send completion releases payload pages that were part + * of previously posted RDMA Writes. + */ + svc_rdma_save_io_pages(rqstp, sctxt); svc_rdma_send_error_msg(rdma, sctxt, rctxt, ret); return 0; @@ -1000,45 +1078,33 @@ drop_connection: /** * svc_rdma_result_payload - special processing for a result payload - * @rqstp: svc_rqst to operate on - * @offset: payload's byte offset in @xdr + * @rqstp: RPC transaction context + * @offset: payload's byte offset in @rqstp->rq_res * @length: size of payload, in bytes * + * Assign the passed-in result payload to the current Write chunk, + * and advance to cur_result_payload to the next Write chunk, if + * there is one. + * * Return values: * %0 if successful or nothing needed to be done - * %-EMSGSIZE on XDR buffer overflow * %-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_result_payload(struct svc_rqst *rqstp, unsigned int offset, unsigned int length) { struct svc_rdma_recv_ctxt *rctxt = rqstp->rq_xprt_ctxt; struct svc_rdma_chunk *chunk; - struct svcxprt_rdma *rdma; - struct xdr_buf subbuf; - int ret; chunk = rctxt->rc_cur_result_payload; if (!length || !chunk) return 0; rctxt->rc_cur_result_payload = pcl_next_chunk(&rctxt->rc_write_pcl, chunk); + if (length > chunk->ch_length) return -E2BIG; - chunk->ch_position = offset; chunk->ch_payload_length = length; - - if (xdr_buf_subsegment(&rqstp->rq_res, &subbuf, offset, length)) - return -EMSGSIZE; - - rdma = container_of(rqstp->rq_xprt, struct svcxprt_rdma, sc_xprt); - ret = svc_rdma_send_write_chunk(rdma, chunk, &subbuf); - if (ret < 0) - return ret; return 0; } |