From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- net/sunrpc/xprtrdma/svc_rdma_backchannel.c | 293 +++++++++++++++++++++++++++++ 1 file changed, 293 insertions(+) create mode 100644 net/sunrpc/xprtrdma/svc_rdma_backchannel.c (limited to 'net/sunrpc/xprtrdma/svc_rdma_backchannel.c') diff --git a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c new file mode 100644 index 000000000..aa2227a7e --- /dev/null +++ b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c @@ -0,0 +1,293 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2015-2018 Oracle. All rights reserved. + * + * Support for reverse-direction RPCs on RPC/RDMA (server-side). + */ + +#include + +#include "xprt_rdma.h" +#include + +/** + * svc_rdma_handle_bc_reply - Process incoming backchannel Reply + * @rqstp: resources for handling the Reply + * @rctxt: Received message + * + */ +void svc_rdma_handle_bc_reply(struct svc_rqst *rqstp, + struct svc_rdma_recv_ctxt *rctxt) +{ + struct svc_xprt *sxprt = rqstp->rq_xprt; + struct rpc_xprt *xprt = sxprt->xpt_bc_xprt; + struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt); + struct xdr_buf *rcvbuf = &rqstp->rq_arg; + struct kvec *dst, *src = &rcvbuf->head[0]; + __be32 *rdma_resp = rctxt->rc_recv_buf; + struct rpc_rqst *req; + u32 credits; + + spin_lock(&xprt->queue_lock); + req = xprt_lookup_rqst(xprt, *rdma_resp); + if (!req) + goto out_unlock; + + dst = &req->rq_private_buf.head[0]; + memcpy(&req->rq_private_buf, &req->rq_rcv_buf, sizeof(struct xdr_buf)); + if (dst->iov_len < src->iov_len) + goto out_unlock; + memcpy(dst->iov_base, src->iov_base, src->iov_len); + xprt_pin_rqst(req); + spin_unlock(&xprt->queue_lock); + + credits = be32_to_cpup(rdma_resp + 2); + if (credits == 0) + credits = 1; /* don't deadlock */ + else if (credits > r_xprt->rx_buf.rb_bc_max_requests) + credits = r_xprt->rx_buf.rb_bc_max_requests; + spin_lock(&xprt->transport_lock); + xprt->cwnd = credits << RPC_CWNDSHIFT; + spin_unlock(&xprt->transport_lock); + + spin_lock(&xprt->queue_lock); + xprt_complete_rqst(req->rq_task, rcvbuf->len); + xprt_unpin_rqst(req); + rcvbuf->len = 0; + +out_unlock: + spin_unlock(&xprt->queue_lock); +} + +/* Send a reverse-direction RPC Call. + * + * Caller holds the connection's mutex and has already marshaled + * the RPC/RDMA request. + * + * This is similar to svc_rdma_send_reply_msg, but takes a struct + * rpc_rqst instead, does not support chunks, and avoids blocking + * memory allocation. + * + * XXX: There is still an opportunity to block in svc_rdma_send() + * if there are no SQ entries to post the Send. This may occur if + * the adapter has a small maximum SQ depth. + */ +static int svc_rdma_bc_sendto(struct svcxprt_rdma *rdma, + struct rpc_rqst *rqst, + struct svc_rdma_send_ctxt *sctxt) +{ + struct svc_rdma_recv_ctxt *rctxt; + int ret; + + rctxt = svc_rdma_recv_ctxt_get(rdma); + if (!rctxt) + return -EIO; + + ret = svc_rdma_map_reply_msg(rdma, sctxt, rctxt, &rqst->rq_snd_buf); + svc_rdma_recv_ctxt_put(rdma, rctxt); + if (ret < 0) + return -EIO; + + /* Bump page refcnt so Send completion doesn't release + * the rq_buffer before all retransmits are complete. + */ + get_page(virt_to_page(rqst->rq_buffer)); + sctxt->sc_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; +} + +/* Server-side transport endpoint wants a whole page for its send + * buffer. The client RPC code constructs the RPC header in this + * buffer before it invokes ->send_request. + */ +static int +xprt_rdma_bc_allocate(struct rpc_task *task) +{ + struct rpc_rqst *rqst = task->tk_rqstp; + size_t size = rqst->rq_callsize; + struct page *page; + + if (size > PAGE_SIZE) { + WARN_ONCE(1, "svcrdma: large bc buffer request (size %zu)\n", + size); + return -EINVAL; + } + + page = alloc_page(GFP_NOIO | __GFP_NOWARN); + if (!page) + return -ENOMEM; + rqst->rq_buffer = page_address(page); + + rqst->rq_rbuffer = kmalloc(rqst->rq_rcvsize, GFP_NOIO | __GFP_NOWARN); + if (!rqst->rq_rbuffer) { + put_page(page); + return -ENOMEM; + } + return 0; +} + +static void +xprt_rdma_bc_free(struct rpc_task *task) +{ + struct rpc_rqst *rqst = task->tk_rqstp; + + put_page(virt_to_page(rqst->rq_buffer)); + kfree(rqst->rq_rbuffer); +} + +static int +rpcrdma_bc_send_request(struct svcxprt_rdma *rdma, struct rpc_rqst *rqst) +{ + struct rpc_xprt *xprt = rqst->rq_xprt; + struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt); + struct svc_rdma_send_ctxt *ctxt; + __be32 *p; + int rc; + + ctxt = svc_rdma_send_ctxt_get(rdma); + if (!ctxt) + goto drop_connection; + + p = xdr_reserve_space(&ctxt->sc_stream, RPCRDMA_HDRLEN_MIN); + if (!p) + goto put_ctxt; + *p++ = rqst->rq_xid; + *p++ = rpcrdma_version; + *p++ = cpu_to_be32(r_xprt->rx_buf.rb_bc_max_requests); + *p++ = rdma_msg; + *p++ = xdr_zero; + *p++ = xdr_zero; + *p = xdr_zero; + + rqst->rq_xtime = ktime_get(); + rc = svc_rdma_bc_sendto(rdma, rqst, ctxt); + if (rc) + goto put_ctxt; + return 0; + +put_ctxt: + svc_rdma_send_ctxt_put(rdma, ctxt); + +drop_connection: + return -ENOTCONN; +} + +/** + * xprt_rdma_bc_send_request - Send a reverse-direction Call + * @rqst: rpc_rqst containing Call message to be sent + * + * Return values: + * %0 if the message was sent successfully + * %ENOTCONN if the message was not sent + */ +static int xprt_rdma_bc_send_request(struct rpc_rqst *rqst) +{ + struct svc_xprt *sxprt = rqst->rq_xprt->bc_xprt; + struct svcxprt_rdma *rdma = + container_of(sxprt, struct svcxprt_rdma, sc_xprt); + int ret; + + if (test_bit(XPT_DEAD, &sxprt->xpt_flags)) + return -ENOTCONN; + + ret = rpcrdma_bc_send_request(rdma, rqst); + if (ret == -ENOTCONN) + svc_xprt_close(sxprt); + return ret; +} + +static void +xprt_rdma_bc_close(struct rpc_xprt *xprt) +{ + xprt_disconnect_done(xprt); + xprt->cwnd = RPC_CWNDSHIFT; +} + +static void +xprt_rdma_bc_put(struct rpc_xprt *xprt) +{ + xprt_rdma_free_addresses(xprt); + xprt_free(xprt); +} + +static const struct rpc_xprt_ops xprt_rdma_bc_procs = { + .reserve_xprt = xprt_reserve_xprt_cong, + .release_xprt = xprt_release_xprt_cong, + .alloc_slot = xprt_alloc_slot, + .free_slot = xprt_free_slot, + .release_request = xprt_release_rqst_cong, + .buf_alloc = xprt_rdma_bc_allocate, + .buf_free = xprt_rdma_bc_free, + .send_request = xprt_rdma_bc_send_request, + .wait_for_reply_request = xprt_wait_for_reply_request_def, + .close = xprt_rdma_bc_close, + .destroy = xprt_rdma_bc_put, + .print_stats = xprt_rdma_print_stats +}; + +static const struct rpc_timeout xprt_rdma_bc_timeout = { + .to_initval = 60 * HZ, + .to_maxval = 60 * HZ, +}; + +/* It shouldn't matter if the number of backchannel session slots + * doesn't match the number of RPC/RDMA credits. That just means + * one or the other will have extra slots that aren't used. + */ +static struct rpc_xprt * +xprt_setup_rdma_bc(struct xprt_create *args) +{ + struct rpc_xprt *xprt; + struct rpcrdma_xprt *new_xprt; + + if (args->addrlen > sizeof(xprt->addr)) + return ERR_PTR(-EBADF); + + xprt = xprt_alloc(args->net, sizeof(*new_xprt), + RPCRDMA_MAX_BC_REQUESTS, + RPCRDMA_MAX_BC_REQUESTS); + if (!xprt) + return ERR_PTR(-ENOMEM); + + xprt->timeout = &xprt_rdma_bc_timeout; + xprt_set_bound(xprt); + xprt_set_connected(xprt); + xprt->bind_timeout = 0; + xprt->reestablish_timeout = 0; + xprt->idle_timeout = 0; + + xprt->prot = XPRT_TRANSPORT_BC_RDMA; + xprt->ops = &xprt_rdma_bc_procs; + + memcpy(&xprt->addr, args->dstaddr, args->addrlen); + xprt->addrlen = args->addrlen; + xprt_rdma_format_addresses(xprt, (struct sockaddr *)&xprt->addr); + xprt->resvport = 0; + + xprt->max_payload = xprt_rdma_max_inline_read; + + new_xprt = rpcx_to_rdmax(xprt); + new_xprt->rx_buf.rb_bc_max_requests = xprt->max_reqs; + + xprt_get(xprt); + args->bc_xprt->xpt_bc_xprt = xprt; + xprt->bc_xprt = args->bc_xprt; + + /* Final put for backchannel xprt is in __svc_rdma_free */ + xprt_get(xprt); + return xprt; +} + +struct xprt_class xprt_rdma_bc = { + .list = LIST_HEAD_INIT(xprt_rdma_bc.list), + .name = "rdma backchannel", + .owner = THIS_MODULE, + .ident = XPRT_TRANSPORT_BC_RDMA, + .setup = xprt_setup_rdma_bc, +}; -- cgit v1.2.3