diff options
| -rw-r--r-- | net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | 586 |
1 files changed, 586 insertions, 0 deletions
diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c new file mode 100644 index 00000000000..ab54a736486 --- /dev/null +++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c @@ -0,0 +1,586 @@ +/* + * 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> + */ + +#include <linux/sunrpc/debug.h> +#include <linux/sunrpc/rpc_rdma.h> +#include <linux/spinlock.h> +#include <asm/unaligned.h> +#include <rdma/ib_verbs.h> +#include <rdma/rdma_cm.h> +#include <linux/sunrpc/svc_rdma.h> + +#define RPCDBG_FACILITY RPCDBG_SVCXPRT + +/* + * Replace the pages in the rq_argpages array with the pages from the SGE in + * the RDMA_RECV completion. The SGL should contain full pages up until the + * last one. + */ +static void rdma_build_arg_xdr(struct svc_rqst *rqstp, + struct svc_rdma_op_ctxt *ctxt, + u32 byte_count) +{ + struct page *page; + u32 bc; + int sge_no; + + /* Swap the page in the SGE with the page in argpages */ + page = ctxt->pages[0]; + put_page(rqstp->rq_pages[0]); + rqstp->rq_pages[0] = page; + + /* Set up the XDR head */ + rqstp->rq_arg.head[0].iov_base = page_address(page); + rqstp->rq_arg.head[0].iov_len = min(byte_count, ctxt->sge[0].length); + rqstp->rq_arg.len = byte_count; + rqstp->rq_arg.buflen = byte_count; + + /* Compute bytes past head in the SGL */ + bc = byte_count - rqstp->rq_arg.head[0].iov_len; + + /* If data remains, store it in the pagelist */ + rqstp->rq_arg.page_len = bc; + rqstp->rq_arg.page_base = 0; + rqstp->rq_arg.pages = &rqstp->rq_pages[1]; + sge_no = 1; + while (bc && sge_no < ctxt->count) { + page = ctxt->pages[sge_no]; + put_page(rqstp->rq_pages[sge_no]); + rqstp->rq_pages[sge_no] = page; + bc -= min(bc, ctxt->sge[sge_no].length); + rqstp->rq_arg.buflen += ctxt->sge[sge_no].length; + sge_no++; + } + rqstp->rq_respages = &rqstp->rq_pages[sge_no]; + + /* We should never run out of SGE because the limit is defined to + * support the max allowed RPC data length + */ + BUG_ON(bc && (sge_no == ctxt->count)); + BUG_ON((rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len) + != byte_count); + BUG_ON(rqstp->rq_arg.len != byte_count); + + /* If not all pages were used from the SGL, free the remaining ones */ + bc = sge_no; + while (sge_no < ctxt->count) { + page = ctxt->pages[sge_no++]; + put_page(page); + } + ctxt->count = bc; + + /* Set up tail */ + rqstp->rq_arg.tail[0].iov_base = NULL; + rqstp->rq_arg.tail[0].iov_len = 0; +} + +struct chunk_sge { + int start; /* sge no for this chunk */ + int count; /* sge count for this chunk */ +}; + +/* Encode a read-chunk-list as an array of IB SGE + * + * Assumptions: + * - chunk[0]->position points to pages[0] at an offset of 0 + * - pages[] is not physically or virtually contigous and consists of + * PAGE_SIZE elements. + * + * Output: + * - sge array pointing into pages[] array. + * - chunk_sge array specifying sge index and count for each + * chunk in the read list + * + */ +static int rdma_rcl_to_sge(struct svcxprt_rdma *xprt, + struct svc_rqst *rqstp, + struct svc_rdma_op_ctxt *head, + struct rpcrdma_msg *rmsgp, + struct ib_sge *sge, + struct chunk_sge *ch_sge_ary, + int ch_count, + int byte_count) +{ + int sge_no; + int sge_bytes; + int page_off; + int page_no; + int ch_bytes; + int ch_no; + struct rpcrdma_read_chunk *ch; + + sge_no = 0; + page_no = 0; + page_off = 0; + ch = (struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0]; + ch_no = 0; + ch_bytes = ch->rc_target.rs_length; + head->arg.head[0] = rqstp->rq_arg.head[0]; + head->arg.tail[0] = rqstp->rq_arg.tail[0]; + head->arg.pages = &head->pages[head->count]; + head->sge[0].length = head->count; /* save count of hdr pages */ + head->arg.page_base = 0; + head->arg.page_len = ch_bytes; + head->arg.len = rqstp->rq_arg.len + ch_bytes; + head->arg.buflen = rqstp->rq_arg.buflen + ch_bytes; + head->count++; + ch_sge_ary[0].start = 0; + while (byte_count) { + sge_bytes = min_t(int, PAGE_SIZE-page_off, ch_bytes); + sge[sge_no].addr = + ib_dma_map_page(xprt->sc_cm_id->device, + rqstp->rq_arg.pages[page_no], + page_off, sge_bytes, + DMA_FROM_DEVICE); + sge[sge_no].length = sge_bytes; + sge[sge_no].lkey = xprt->sc_phys_mr->lkey; + /* + * Don't bump head->count here because the same page + * may be used by multiple SGE. + */ + head->arg.pages[page_no] = rqstp->rq_arg.pages[page_no]; + rqstp->rq_respages = &rqstp->rq_arg.pages[page_no+1]; + + byte_count -= sge_bytes; + ch_bytes -= sge_bytes; + sge_no++; + /* + * If all bytes for this chunk have been mapped to an + * SGE, move to the next SGE + */ + if (ch_bytes == 0) { + ch_sge_ary[ch_no].count = + sge_no - ch_sge_ary[ch_no].start; + ch_no++; + ch++; + ch_sge_ary[ch_no].start = sge_no; + ch_bytes = ch->rc_target.rs_length; + /* If bytes remaining account for next chunk */ + if (byte_count) { + head->arg.page_len += ch_bytes; + head->arg.len += ch_bytes; + head->arg.buflen += ch_bytes; + } + } + /* + * If this SGE consumed all of the page, move to the + * next page + */ + if ((sge_bytes + page_off) == PAGE_SIZE) { + page_no++; + page_off = 0; + /* + * If there are still bytes left to map, bump + * the page count + */ + if (byte_count) + head->count++; + } else + page_off += sge_bytes; + } + BUG_ON(byte_count != 0); + return sge_no; +} + +static void rdma_set_ctxt_sge(struct svc_rdma_op_ctxt *ctxt, + struct ib_sge *sge, + u64 *sgl_offset, + int count) +{ + int i; + + ctxt->count = count; + for (i = 0; i < count; i++) { + ctxt->sge[i].addr = sge[i].addr; + ctxt->sge[i].length = sge[i].length; + *sgl_offset = *sgl_offset + sge[i].length; + } +} + +static int rdma_read_max_sge(struct svcxprt_rdma *xprt, int sge_count) +{ +#ifdef RDMA_TRANSPORT_IWARP + if ((RDMA_TRANSPORT_IWARP == + rdma_node_get_transport(xprt->sc_cm_id-> + device->node_type)) + && sge_count > 1) + return 1; + else +#endif + return min_t(int, sge_count, xprt->sc_max_sge); +} + +/* + * Use RDMA_READ to read data from the advertised client buffer into the + * XDR stream starting at rq_arg.head[0].iov_base. + * Each chunk in the array + * contains the following fields: + * discrim - '1', This isn't used for data placement + * position - The xdr stream offset (the same for every chunk) + * handle - RMR for client memory region + * length - data transfer length + * offset - 64 bit tagged offset in remote memory region + * + * On our side, we need to read into a pagelist. The first page immediately + * follows the RPC header. + * + * This function returns 1 to indicate success. The data is not yet in + * the pagelist and therefore the RPC request must be deferred. The + * I/O completion will enqueue the transport again and + * svc_rdma_recvfrom will complete the request. + * + * NOTE: The ctxt must not be touched after the last WR has been posted + * because the I/O completion processing may occur on another + * processor and free / modify the context. Ne touche pas! + */ +static int rdma_read_xdr(struct svcxprt_rdma *xprt, + struct rpcrdma_msg *rmsgp, + struct svc_rqst *rqstp, + struct svc_rdma_op_ctxt *hdr_ctxt) +{ + struct ib_send_wr read_wr; + int err = 0; + int ch_no; + struct ib_sge *sge; + int ch_count; + int byte_count; + int sge_count; + u64 sgl_offset; + struct rpcrdma_read_chunk *ch; + struct svc_rdma_op_ctxt *ctxt = NULL; + struct svc_rdma_op_ctxt *head; + struct svc_rdma_op_ctxt *tmp_sge_ctxt; + struct svc_rdma_op_ctxt *tmp_ch_ctxt; + struct chunk_sge *ch_sge_ary; + + /* If no read list is present, return 0 */ + ch = svc_rdma_get_read_chunk(rmsgp); + if (!ch) + return 0; + + /* Allocate temporary contexts to keep SGE */ + BUG_ON(sizeof(struct ib_sge) < sizeof(struct chunk_sge)); + tmp_sge_ctxt = svc_rdma_get_context(xprt); + sge = tmp_sge_ctxt->sge; + tmp_ch_ctxt = svc_rdma_get_context(xprt); + ch_sge_ary = (struct chunk_sge *)tmp_ch_ctxt->sge; + + svc_rdma_rcl_chunk_counts(ch, &ch_count, &byte_count); + sge_count = rdma_rcl_to_sge(xprt, rqstp, hdr_ctxt, rmsgp, + sge, ch_sge_ary, + ch_count, byte_count); + head = svc_rdma_get_context(xprt); + sgl_offset = 0; + ch_no = 0; + + for (ch = (struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0]; + ch->rc_discrim != 0; ch++, ch_no++) { +next_sge: + if (!ctxt) + ctxt = head; + else { + ctxt->next = svc_rdma_get_context(xprt); + ctxt = ctxt->next; + } + ctxt->next = NULL; + ctxt->direction = DMA_FROM_DEVICE; + clear_bit(RDMACTXT_F_READ_DONE, &ctxt->flags); + clear_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags); + if ((ch+1)->rc_discrim == 0) { + /* + * Checked in sq_cq_reap to see if we need to + * be enqueued + */ + set_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags); + ctxt->next = hdr_ctxt; + hdr_ctxt->next = head; + } + + /* Prepare READ WR */ + memset(&read_wr, 0, sizeof read_wr); + ctxt->wr_op = IB_WR_RDMA_READ; + read_wr.wr_id = (unsigned long)ctxt; + read_wr.opcode = IB_WR_RDMA_READ; + read_wr.send_flags = IB_SEND_SIGNALED; + read_wr.wr.rdma.rkey = ch->rc_target.rs_handle; + read_wr.wr.rdma.remote_addr = + get_unaligned(&(ch->rc_target.rs_offset)) + + sgl_offset; + read_wr.sg_list = &sge[ch_sge_ary[ch_no].start]; + read_wr.num_sge = + rdma_read_max_sge(xprt, ch_sge_ary[ch_no].count); + rdma_set_ctxt_sge(ctxt, &sge[ch_sge_ary[ch_no].start], + &sgl_offset, + read_wr.num_sge); + + /* Post the read */ + err = svc_rdma_send(xprt, &read_wr); + if (err) { + printk(KERN_ERR "svcrdma: Error posting send = %d\n", + err); + /* + * Break the circular list so free knows when + * to stop if the error happened to occur on + * the last read + */ + ctxt->next = NULL; + goto out; + } + atomic_inc(&rdma_stat_read); + + if (read_wr.num_sge < ch_sge_ary[ch_no].count) { + ch_sge_ary[ch_no].count -= read_wr.num_sge; + ch_sge_ary[ch_no].start += read_wr.num_sge; + goto next_sge; + } + sgl_offset = 0; + err = 0; + } + + out: + svc_rdma_put_context(tmp_sge_ctxt, 0); + svc_rdma_put_context(tmp_ch_ctxt, 0); + + /* Detach arg pages. svc_recv will replenish them */ + for (ch_no = 0; &rqstp->rq_pages[ch_no] < rqstp->rq_respages; ch_no++) + rqstp->rq_pages[ch_no] = NULL; + + /* + * Detach res pages. svc_release must see a resused count of + * zero or it will attempt to put them. + */ + while (rqstp->rq_resused) + rqstp->rq_respages[--rqstp->rq_resused] = NULL; + + if (err) { + printk(KERN_ERR "svcrdma : RDMA_READ error = %d\n", err); + set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags); + /* Free the linked list of read contexts */ + while (head != NULL) { + ctxt = head->next; + svc_rdma_put_context(head, 1); + head = ctxt; + } + return 0; + } + + return 1; +} + +static int rdma_read_complete(struct svc_rqst *rqstp, + struct svc_rdma_op_ctxt *data) +{ + struct svc_rdma_op_ctxt *head = data->next; + int page_no; + int ret; + + BUG_ON(!head); + + /* Copy RPC pages */ + for (page_no = 0; page_no < head->count; page_no++) { + put_page(rqstp->rq_pages[page_no]); + rqstp->rq_pages[page_no] = head->pages[page_no]; + } + /* Point rq_arg.pages past header */ + rqstp->rq_arg.pages = &rqstp->rq_pages[head->sge[0].length]; + rqstp->rq_arg.page_len = head->arg.page_len; + rqstp->rq_arg.page_base = head->arg.page_base; + + /* rq_respages starts after the last arg page */ + rqstp->rq_respages = &rqstp->rq_arg.pages[page_no]; + rqstp->rq_resused = 0; + + /* Rebuild rq_arg head and tail. */ + rqstp->rq_arg.head[0] = head->arg.head[0]; + rqstp->rq_arg.tail[0] = head->arg.tail[0]; + rqstp->rq_arg.len = head->arg.len; + rqstp->rq_arg.buflen = head->arg.buflen; + + /* XXX: What should this be? */ + rqstp->rq_prot = IPPROTO_MAX; + + /* + * Free the contexts we used to build the RDMA_READ. We have + * to be careful here because the context list uses the same + * next pointer used to chain the contexts associated with the + * RDMA_READ + */ + data->next = NULL; /* terminate circular list */ + do { + data = head->next; + svc_rdma_put_context(head, 0); + head = data; + } while (head != NULL); + + ret = rqstp->rq_arg.head[0].iov_len + + rqstp->rq_arg.page_len + + rqstp->rq_arg.tail[0].iov_len; + dprintk("svcrdma: deferred read ret=%d, rq_arg.len =%d, " + "rq_arg.head[0].iov_base=%p, rq_arg.head[0].iov_len = %zd\n", + ret, rqstp->rq_arg.len, rqstp->rq_arg.head[0].iov_base, + rqstp->rq_arg.head[0].iov_len); + + /* Indicate that we've consumed an RQ credit */ + rqstp->rq_xprt_ctxt = rqstp->rq_xprt; + svc_xprt_received(rqstp->rq_xprt); + return ret; +} + +/* + * Set up the rqstp thread context to point to the RQ buffer. If + * necessary, pull additional data from the client with an RDMA_READ + * request. + */ +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_op_ctxt *ctxt = NULL; + struct rpcrdma_msg *rmsgp; + int ret = 0; + int len; + + dprintk("svcrdma: rqstp=%p\n", rqstp); + + /* + * The rq_xprt_ctxt indicates if we've consumed an RQ credit + * or not. It is used in the rdma xpo_release_rqst function to + * determine whether or not to return an RQ WQE to the RQ. + */ + rqstp->rq_xprt_ctxt = NULL; + + spin_lock_bh(&rdma_xprt->sc_read_complete_lock); + if (!list_empty(&rdma_xprt->sc_read_complete_q)) { + ctxt = list_entry(rdma_xprt->sc_read_complete_q.next, + struct svc_rdma_op_ctxt, + dto_q); + list_del_init(&ctxt->dto_q); + } + spin_unlock_bh(&rdma_xprt->sc_read_complete_lock); + if (ctxt) + return rdma_read_complete(rqstp, ctxt); + + spin_lock_bh(&rdma_xprt->sc_rq_dto_lock); + if (!list_empty(&rdma_xprt->sc_rq_dto_q)) { + ctxt = list_entry(rdma_xprt->sc_rq_dto_q.next, + struct svc_rdma_op_ctxt, + dto_q); + list_del_init(&ctxt->dto_q); + } else { + atomic_inc(&rdma_stat_rq_starve); + clear_bit(XPT_DATA, &xprt->xpt_flags); + ctxt = NULL; + } + spin_unlock_bh(&rdma_xprt->sc_rq_dto_lock); + if (!ctxt) { + /* This is the EAGAIN path. The svc_recv routine will + * return -EAGAIN, the nfsd thread will go to call into + * svc_recv again and we shouldn't be on the active + * transport list + */ + if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) + goto close_out; + + BUG_ON(ret); + goto out; + } + dprintk("svcrdma: processing ctxt=%p on xprt=%p, rqstp=%p, status=%d\n", + ctxt, rdma_xprt, rqstp, ctxt->wc_status); + BUG_ON(ctxt->wc_status != IB_WC_SUCCESS); + atomic_inc(&rdma_stat_recv); + + /* Build up the XDR from the receive buffers. */ + rdma_build_arg_xdr(rqstp, ctxt, ctxt->byte_len); + + /* Decode the RDMA header. */ + len = svc_rdma_xdr_decode_req(&rmsgp, rqstp); + rqstp->rq_xprt_hlen = len; + + /* If the request is invalid, reply with an error */ + if (len < 0) { + if (len == -ENOSYS) + (void)svc_rdma_send_error(rdma_xprt, rmsgp, ERR_VERS); + goto close_out; + } + + /* Read read-list data. If we would need to wait, defer + * it. Not that in this case, we don't return the RQ credit + * until after the read completes. + */ + if (rdma_read_xdr(rdma_xprt, rmsgp, rqstp, ctxt)) { + svc_xprt_received(xprt); + return 0; + } + + /* Indicate we've consumed an RQ credit */ + rqstp->rq_xprt_ctxt = rqstp->rq_xprt; + + ret = rqstp->rq_arg.head[0].iov_len + + rqstp->rq_arg.page_len + + rqstp->rq_arg.tail[0].iov_len; + svc_rdma_put_context(ctxt, 0); + out: + dprintk("svcrdma: ret = %d, rq_arg.len =%d, " + "rq_arg.head[0].iov_base=%p, rq_arg.head[0].iov_len = %zd\n", + ret, rqstp->rq_arg.len, + rqstp->rq_arg.head[0].iov_base, + rqstp->rq_arg.head[0].iov_len); + rqstp->rq_prot = IPPROTO_MAX; + svc_xprt_copy_addrs(rqstp, xprt); + svc_xprt_received(xprt); + return ret; + + close_out: + if (ctxt) { + svc_rdma_put_context(ctxt, 1); + /* Indicate we've consumed an RQ credit */ + rqstp->rq_xprt_ctxt = rqstp->rq_xprt; + } + dprintk("svcrdma: transport %p is closing\n", xprt); + /* + * Set the close bit and enqueue it. svc_recv will see the + * close bit and call svc_xprt_delete + */ + set_bit(XPT_CLOSE, &xprt->xpt_flags); + svc_xprt_received(xprt); + return 0; +} |