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linux/net/sunrpc/xprtrdma/verbs.c

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// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
/*
* Copyright (c) 2014-2017 Oracle. All rights reserved.
* Copyright (c) 2003-2007 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.
*/
/*
* verbs.c
*
* Encapsulates the major functions managing:
* o adapters
* o endpoints
* o connections
* o buffer memory
*/
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/sunrpc/addr.h>
#include <linux/sunrpc/svc_rdma.h>
#include <asm-generic/barrier.h>
#include <asm/bitops.h>
#include <rdma/ib_cm.h>
#include "xprt_rdma.h"
#include <trace/events/rpcrdma.h>
/*
* Globals/Macros
*/
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
# define RPCDBG_FACILITY RPCDBG_TRANS
#endif
/*
* internal functions
*/
static void rpcrdma_sendctx_put_locked(struct rpcrdma_sendctx *sc);
static void rpcrdma_mrs_create(struct rpcrdma_xprt *r_xprt);
static void rpcrdma_mrs_destroy(struct rpcrdma_buffer *buf);
static struct rpcrdma_regbuf *
rpcrdma_regbuf_alloc(size_t size, enum dma_data_direction direction,
gfp_t flags);
static void rpcrdma_regbuf_dma_unmap(struct rpcrdma_regbuf *rb);
static void rpcrdma_regbuf_free(struct rpcrdma_regbuf *rb);
static void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp);
/* Wait for outstanding transport work to finish. ib_drain_qp
* handles the drains in the wrong order for us, so open code
* them here.
*/
static void rpcrdma_xprt_drain(struct rpcrdma_xprt *r_xprt)
{
struct rpcrdma_ia *ia = &r_xprt->rx_ia;
/* Flush Receives, then wait for deferred Reply work
* to complete.
*/
ib_drain_rq(ia->ri_id->qp);
/* Deferred Reply processing might have scheduled
* local invalidations.
*/
ib_drain_sq(ia->ri_id->qp);
}
/**
* rpcrdma_qp_event_handler - Handle one QP event (error notification)
* @event: details of the event
* @context: ep that owns QP where event occurred
*
* Called from the RDMA provider (device driver) possibly in an interrupt
* context.
*/
static void
rpcrdma_qp_event_handler(struct ib_event *event, void *context)
{
struct rpcrdma_ep *ep = context;
struct rpcrdma_xprt *r_xprt = container_of(ep, struct rpcrdma_xprt,
rx_ep);
trace_xprtrdma_qp_event(r_xprt, event);
}
/**
* rpcrdma_wc_send - Invoked by RDMA provider for each polled Send WC
* @cq: completion queue (ignored)
* @wc: completed WR
*
*/
static void
rpcrdma_wc_send(struct ib_cq *cq, struct ib_wc *wc)
{
struct ib_cqe *cqe = wc->wr_cqe;
struct rpcrdma_sendctx *sc =
container_of(cqe, struct rpcrdma_sendctx, sc_cqe);
/* WARNING: Only wr_cqe and status are reliable at this point */
trace_xprtrdma_wc_send(sc, wc);
rpcrdma_sendctx_put_locked(sc);
}
/**
* rpcrdma_wc_receive - Invoked by RDMA provider for each polled Receive WC
* @cq: completion queue (ignored)
* @wc: completed WR
*
*/
static void
rpcrdma_wc_receive(struct ib_cq *cq, struct ib_wc *wc)
{
struct ib_cqe *cqe = wc->wr_cqe;
struct rpcrdma_rep *rep = container_of(cqe, struct rpcrdma_rep,
rr_cqe);
struct rpcrdma_xprt *r_xprt = rep->rr_rxprt;
/* WARNING: Only wr_cqe and status are reliable at this point */
trace_xprtrdma_wc_receive(wc);
--r_xprt->rx_ep.rep_receive_count;
if (wc->status != IB_WC_SUCCESS)
goto out_flushed;
/* status == SUCCESS means all fields in wc are trustworthy */
rpcrdma_set_xdrlen(&rep->rr_hdrbuf, wc->byte_len);
rep->rr_wc_flags = wc->wc_flags;
rep->rr_inv_rkey = wc->ex.invalidate_rkey;
ib_dma_sync_single_for_cpu(rdmab_device(rep->rr_rdmabuf),
rdmab_addr(rep->rr_rdmabuf),
wc->byte_len, DMA_FROM_DEVICE);
rpcrdma_post_recvs(r_xprt, false);
rpcrdma_reply_handler(rep);
return;
out_flushed:
rpcrdma_recv_buffer_put(rep);
}
static void
rpcrdma_update_connect_private(struct rpcrdma_xprt *r_xprt,
struct rdma_conn_param *param)
{
const struct rpcrdma_connect_private *pmsg = param->private_data;
unsigned int rsize, wsize;
/* Default settings for RPC-over-RDMA Version One */
r_xprt->rx_ia.ri_implicit_roundup = xprt_rdma_pad_optimize;
rsize = RPCRDMA_V1_DEF_INLINE_SIZE;
wsize = RPCRDMA_V1_DEF_INLINE_SIZE;
if (pmsg &&
pmsg->cp_magic == rpcrdma_cmp_magic &&
pmsg->cp_version == RPCRDMA_CMP_VERSION) {
r_xprt->rx_ia.ri_implicit_roundup = true;
rsize = rpcrdma_decode_buffer_size(pmsg->cp_send_size);
wsize = rpcrdma_decode_buffer_size(pmsg->cp_recv_size);
}
if (rsize < r_xprt->rx_ep.rep_inline_recv)
r_xprt->rx_ep.rep_inline_recv = rsize;
if (wsize < r_xprt->rx_ep.rep_inline_send)
r_xprt->rx_ep.rep_inline_send = wsize;
dprintk("RPC: %s: max send %u, max recv %u\n", __func__,
r_xprt->rx_ep.rep_inline_send,
r_xprt->rx_ep.rep_inline_recv);
rpcrdma_set_max_header_sizes(r_xprt);
}
/**
* rpcrdma_cm_event_handler - Handle RDMA CM events
* @id: rdma_cm_id on which an event has occurred
* @event: details of the event
*
* Called with @id's mutex held. Returns 1 if caller should
* destroy @id, otherwise 0.
*/
static int
rpcrdma_cm_event_handler(struct rdma_cm_id *id, struct rdma_cm_event *event)
{
struct rpcrdma_xprt *r_xprt = id->context;
struct rpcrdma_ia *ia = &r_xprt->rx_ia;
struct rpcrdma_ep *ep = &r_xprt->rx_ep;
struct rpc_xprt *xprt = &r_xprt->rx_xprt;
might_sleep();
trace_xprtrdma_cm_event(r_xprt, event);
switch (event->event) {
case RDMA_CM_EVENT_ADDR_RESOLVED:
case RDMA_CM_EVENT_ROUTE_RESOLVED:
ia->ri_async_rc = 0;
complete(&ia->ri_done);
return 0;
case RDMA_CM_EVENT_ADDR_ERROR:
ia->ri_async_rc = -EPROTO;
complete(&ia->ri_done);
return 0;
case RDMA_CM_EVENT_ROUTE_ERROR:
ia->ri_async_rc = -ENETUNREACH;
complete(&ia->ri_done);
return 0;
case RDMA_CM_EVENT_DEVICE_REMOVAL:
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
pr_info("rpcrdma: removing device %s for %s:%s\n",
ia->ri_id->device->name,
rpcrdma_addrstr(r_xprt), rpcrdma_portstr(r_xprt));
#endif
set_bit(RPCRDMA_IAF_REMOVING, &ia->ri_flags);
ep->rep_connected = -ENODEV;
xprt_force_disconnect(xprt);
wait_for_completion(&ia->ri_remove_done);
ia->ri_id = NULL;
/* Return 1 to ensure the core destroys the id. */
return 1;
case RDMA_CM_EVENT_ESTABLISHED:
++xprt->connect_cookie;
ep->rep_connected = 1;
rpcrdma_update_connect_private(r_xprt, &event->param.conn);
wake_up_all(&ep->rep_connect_wait);
break;
case RDMA_CM_EVENT_CONNECT_ERROR:
ep->rep_connected = -ENOTCONN;
goto disconnected;
case RDMA_CM_EVENT_UNREACHABLE:
ep->rep_connected = -ENETUNREACH;
goto disconnected;
case RDMA_CM_EVENT_REJECTED:
dprintk("rpcrdma: connection to %s:%s rejected: %s\n",
rpcrdma_addrstr(r_xprt), rpcrdma_portstr(r_xprt),
rdma_reject_msg(id, event->status));
ep->rep_connected = -ECONNREFUSED;
if (event->status == IB_CM_REJ_STALE_CONN)
ep->rep_connected = -EAGAIN;
goto disconnected;
case RDMA_CM_EVENT_DISCONNECTED:
ep->rep_connected = -ECONNABORTED;
disconnected:
xprt_force_disconnect(xprt);
wake_up_all(&ep->rep_connect_wait);
break;
default:
break;
}
dprintk("RPC: %s: %s:%s on %s/frwr: %s\n", __func__,
rpcrdma_addrstr(r_xprt), rpcrdma_portstr(r_xprt),
ia->ri_id->device->name, rdma_event_msg(event->event));
return 0;
}
static struct rdma_cm_id *
rpcrdma_create_id(struct rpcrdma_xprt *xprt, struct rpcrdma_ia *ia)
{
unsigned long wtimeout = msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT) + 1;
struct rdma_cm_id *id;
int rc;
trace_xprtrdma_conn_start(xprt);
init_completion(&ia->ri_done);
init_completion(&ia->ri_remove_done);
id = rdma_create_id(xprt->rx_xprt.xprt_net, rpcrdma_cm_event_handler,
xprt, RDMA_PS_TCP, IB_QPT_RC);
if (IS_ERR(id))
return id;
ia->ri_async_rc = -ETIMEDOUT;
rc = rdma_resolve_addr(id, NULL,
(struct sockaddr *)&xprt->rx_xprt.addr,
RDMA_RESOLVE_TIMEOUT);
if (rc)
goto out;
rc = wait_for_completion_interruptible_timeout(&ia->ri_done, wtimeout);
if (rc < 0) {
trace_xprtrdma_conn_tout(xprt);
goto out;
}
rc = ia->ri_async_rc;
if (rc)
goto out;
ia->ri_async_rc = -ETIMEDOUT;
rc = rdma_resolve_route(id, RDMA_RESOLVE_TIMEOUT);
if (rc)
goto out;
rc = wait_for_completion_interruptible_timeout(&ia->ri_done, wtimeout);
if (rc < 0) {
trace_xprtrdma_conn_tout(xprt);
goto out;
}
rc = ia->ri_async_rc;
if (rc)
goto out;
return id;
out:
rdma_destroy_id(id);
return ERR_PTR(rc);
}
/*
* Exported functions.
*/
/**
* rpcrdma_ia_open - Open and initialize an Interface Adapter.
* @xprt: transport with IA to (re)initialize
*
* Returns 0 on success, negative errno if an appropriate
* Interface Adapter could not be found and opened.
*/
int
rpcrdma_ia_open(struct rpcrdma_xprt *xprt)
{
struct rpcrdma_ia *ia = &xprt->rx_ia;
int rc;
ia->ri_id = rpcrdma_create_id(xprt, ia);
if (IS_ERR(ia->ri_id)) {
rc = PTR_ERR(ia->ri_id);
goto out_err;
}
ia->ri_pd = ib_alloc_pd(ia->ri_id->device, 0);
if (IS_ERR(ia->ri_pd)) {
rc = PTR_ERR(ia->ri_pd);
pr_err("rpcrdma: ib_alloc_pd() returned %d\n", rc);
goto out_err;
}
switch (xprt_rdma_memreg_strategy) {
case RPCRDMA_FRWR:
if (frwr_is_supported(ia->ri_id->device))
break;
/*FALLTHROUGH*/
default:
pr_err("rpcrdma: Device %s does not support memreg mode %d\n",
ia->ri_id->device->name, xprt_rdma_memreg_strategy);
rc = -EINVAL;
goto out_err;
}
return 0;
out_err:
rpcrdma_ia_close(ia);
return rc;
}
/**
* rpcrdma_ia_remove - Handle device driver unload
* @ia: interface adapter being removed
*
* Divest transport H/W resources associated with this adapter,
* but allow it to be restored later.
*/
void
rpcrdma_ia_remove(struct rpcrdma_ia *ia)
{
struct rpcrdma_xprt *r_xprt = container_of(ia, struct rpcrdma_xprt,
rx_ia);
struct rpcrdma_ep *ep = &r_xprt->rx_ep;
struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
struct rpcrdma_req *req;
struct rpcrdma_rep *rep;
cancel_delayed_work_sync(&buf->rb_refresh_worker);
/* This is similar to rpcrdma_ep_destroy, but:
* - Don't cancel the connect worker.
* - Don't call rpcrdma_ep_disconnect, which waits
* for another conn upcall, which will deadlock.
* - rdma_disconnect is unneeded, the underlying
* connection is already gone.
*/
if (ia->ri_id->qp) {
rpcrdma_xprt_drain(r_xprt);
rdma_destroy_qp(ia->ri_id);
ia->ri_id->qp = NULL;
}
ib_free_cq(ep->rep_attr.recv_cq);
ep->rep_attr.recv_cq = NULL;
ib_free_cq(ep->rep_attr.send_cq);
ep->rep_attr.send_cq = NULL;
/* The ULP is responsible for ensuring all DMA
* mappings and MRs are gone.
*/
list_for_each_entry(rep, &buf->rb_recv_bufs, rr_list)
rpcrdma_regbuf_dma_unmap(rep->rr_rdmabuf);
list_for_each_entry(req, &buf->rb_allreqs, rl_all) {
rpcrdma_regbuf_dma_unmap(req->rl_rdmabuf);
rpcrdma_regbuf_dma_unmap(req->rl_sendbuf);
rpcrdma_regbuf_dma_unmap(req->rl_recvbuf);
}
rpcrdma_mrs_destroy(buf);
ib_dealloc_pd(ia->ri_pd);
ia->ri_pd = NULL;
/* Allow waiters to continue */
complete(&ia->ri_remove_done);
trace_xprtrdma_remove(r_xprt);
}
/**
* rpcrdma_ia_close - Clean up/close an IA.
* @ia: interface adapter to close
*
*/
void
rpcrdma_ia_close(struct rpcrdma_ia *ia)
{
if (ia->ri_id != NULL && !IS_ERR(ia->ri_id)) {
if (ia->ri_id->qp)
rdma_destroy_qp(ia->ri_id);
rdma_destroy_id(ia->ri_id);
}
ia->ri_id = NULL;
/* If the pd is still busy, xprtrdma missed freeing a resource */
if (ia->ri_pd && !IS_ERR(ia->ri_pd))
ib_dealloc_pd(ia->ri_pd);
ia->ri_pd = NULL;
}
/**
* rpcrdma_ep_create - Create unconnected endpoint
* @r_xprt: transport to instantiate
*
* Returns zero on success, or a negative errno.
*/
int rpcrdma_ep_create(struct rpcrdma_xprt *r_xprt)
{
struct rpcrdma_ep *ep = &r_xprt->rx_ep;
struct rpcrdma_ia *ia = &r_xprt->rx_ia;
struct rpcrdma_connect_private *pmsg = &ep->rep_cm_private;
struct ib_cq *sendcq, *recvcq;
unsigned int max_sge;
int rc;
ep->rep_max_requests = xprt_rdma_slot_table_entries;
ep->rep_inline_send = xprt_rdma_max_inline_write;
ep->rep_inline_recv = xprt_rdma_max_inline_read;
max_sge = min_t(unsigned int, ia->ri_id->device->attrs.max_send_sge,
RPCRDMA_MAX_SEND_SGES);
if (max_sge < RPCRDMA_MIN_SEND_SGES) {
pr_warn("rpcrdma: HCA provides only %d send SGEs\n", max_sge);
return -ENOMEM;
}
ia->ri_max_send_sges = max_sge;
rc = frwr_open(ia, ep);
if (rc)
return rc;
ep->rep_attr.event_handler = rpcrdma_qp_event_handler;
ep->rep_attr.qp_context = ep;
ep->rep_attr.srq = NULL;
ep->rep_attr.cap.max_send_sge = max_sge;
ep->rep_attr.cap.max_recv_sge = 1;
ep->rep_attr.cap.max_inline_data = 0;
ep->rep_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
ep->rep_attr.qp_type = IB_QPT_RC;
ep->rep_attr.port_num = ~0;
dprintk("RPC: %s: requested max: dtos: send %d recv %d; "
"iovs: send %d recv %d\n",
__func__,
ep->rep_attr.cap.max_send_wr,
ep->rep_attr.cap.max_recv_wr,
ep->rep_attr.cap.max_send_sge,
ep->rep_attr.cap.max_recv_sge);
ep->rep_send_batch = ep->rep_max_requests >> 3;
ep->rep_send_count = ep->rep_send_batch;
init_waitqueue_head(&ep->rep_connect_wait);
ep->rep_receive_count = 0;
sendcq = ib_alloc_cq(ia->ri_id->device, NULL,
ep->rep_attr.cap.max_send_wr + 1,
ia->ri_id->device->num_comp_vectors > 1 ? 1 : 0,
IB_POLL_WORKQUEUE);
if (IS_ERR(sendcq)) {
rc = PTR_ERR(sendcq);
goto out1;
}
recvcq = ib_alloc_cq(ia->ri_id->device, NULL,
ep->rep_attr.cap.max_recv_wr + 1,
0, IB_POLL_WORKQUEUE);
if (IS_ERR(recvcq)) {
rc = PTR_ERR(recvcq);
goto out2;
}
ep->rep_attr.send_cq = sendcq;
ep->rep_attr.recv_cq = recvcq;
/* Initialize cma parameters */
memset(&ep->rep_remote_cma, 0, sizeof(ep->rep_remote_cma));
/* Prepare RDMA-CM private message */
pmsg->cp_magic = rpcrdma_cmp_magic;
pmsg->cp_version = RPCRDMA_CMP_VERSION;
pmsg->cp_flags |= RPCRDMA_CMP_F_SND_W_INV_OK;
pmsg->cp_send_size = rpcrdma_encode_buffer_size(ep->rep_inline_send);
pmsg->cp_recv_size = rpcrdma_encode_buffer_size(ep->rep_inline_recv);
ep->rep_remote_cma.private_data = pmsg;
ep->rep_remote_cma.private_data_len = sizeof(*pmsg);
/* Client offers RDMA Read but does not initiate */
ep->rep_remote_cma.initiator_depth = 0;
ep->rep_remote_cma.responder_resources =
min_t(int, U8_MAX, ia->ri_id->device->attrs.max_qp_rd_atom);
/* Limit transport retries so client can detect server
* GID changes quickly. RPC layer handles re-establishing
* transport connection and retransmission.
*/
ep->rep_remote_cma.retry_count = 6;
/* RPC-over-RDMA handles its own flow control. In addition,
* make all RNR NAKs visible so we know that RPC-over-RDMA
* flow control is working correctly (no NAKs should be seen).
*/
ep->rep_remote_cma.flow_control = 0;
ep->rep_remote_cma.rnr_retry_count = 0;
return 0;
out2:
ib_free_cq(sendcq);
out1:
return rc;
}
/**
* rpcrdma_ep_destroy - Disconnect and destroy endpoint.
* @r_xprt: transport instance to shut down
*
*/
void rpcrdma_ep_destroy(struct rpcrdma_xprt *r_xprt)
{
struct rpcrdma_ep *ep = &r_xprt->rx_ep;
struct rpcrdma_ia *ia = &r_xprt->rx_ia;
if (ia->ri_id && ia->ri_id->qp) {
rpcrdma_ep_disconnect(ep, ia);
rdma_destroy_qp(ia->ri_id);
ia->ri_id->qp = NULL;
}
if (ep->rep_attr.recv_cq)
ib_free_cq(ep->rep_attr.recv_cq);
if (ep->rep_attr.send_cq)
ib_free_cq(ep->rep_attr.send_cq);
}
/* Re-establish a connection after a device removal event.
* Unlike a normal reconnection, a fresh PD and a new set
* of MRs and buffers is needed.
*/
static int
rpcrdma_ep_recreate_xprt(struct rpcrdma_xprt *r_xprt,
struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
{
int rc, err;
trace_xprtrdma_reinsert(r_xprt);
rc = -EHOSTUNREACH;
if (rpcrdma_ia_open(r_xprt))
goto out1;
rc = -ENOMEM;
err = rpcrdma_ep_create(r_xprt);
if (err) {
pr_err("rpcrdma: rpcrdma_ep_create returned %d\n", err);
goto out2;
}
rc = -ENETUNREACH;
err = rdma_create_qp(ia->ri_id, ia->ri_pd, &ep->rep_attr);
if (err) {
pr_err("rpcrdma: rdma_create_qp returned %d\n", err);
goto out3;
}
rpcrdma_mrs_create(r_xprt);
return 0;
out3:
rpcrdma_ep_destroy(r_xprt);
out2:
rpcrdma_ia_close(ia);
out1:
return rc;
}
static int
rpcrdma_ep_reconnect(struct rpcrdma_xprt *r_xprt, struct rpcrdma_ep *ep,
struct rpcrdma_ia *ia)
{
struct rdma_cm_id *id, *old;
int err, rc;
trace_xprtrdma_reconnect(r_xprt);
rpcrdma_ep_disconnect(ep, ia);
rc = -EHOSTUNREACH;
id = rpcrdma_create_id(r_xprt, ia);
if (IS_ERR(id))
goto out;
/* As long as the new ID points to the same device as the
* old ID, we can reuse the transport's existing PD and all
* previously allocated MRs. Also, the same device means
* the transport's previous DMA mappings are still valid.
*
* This is a sanity check only. There should be no way these
* point to two different devices here.
*/
old = id;
rc = -ENETUNREACH;
if (ia->ri_id->device != id->device) {
pr_err("rpcrdma: can't reconnect on different device!\n");
goto out_destroy;
}
err = rdma_create_qp(id, ia->ri_pd, &ep->rep_attr);
if (err)
goto out_destroy;
/* Atomically replace the transport's ID and QP. */
rc = 0;
old = ia->ri_id;
ia->ri_id = id;
rdma_destroy_qp(old);
out_destroy:
rdma_destroy_id(old);
out:
return rc;
}
/*
* Connect unconnected endpoint.
*/
int
rpcrdma_ep_connect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
{
struct rpcrdma_xprt *r_xprt = container_of(ia, struct rpcrdma_xprt,
rx_ia);
struct rpc_xprt *xprt = &r_xprt->rx_xprt;
int rc;
retry:
switch (ep->rep_connected) {
case 0:
dprintk("RPC: %s: connecting...\n", __func__);
rc = rdma_create_qp(ia->ri_id, ia->ri_pd, &ep->rep_attr);
if (rc) {
rc = -ENETUNREACH;
goto out_noupdate;
}
break;
case -ENODEV:
rc = rpcrdma_ep_recreate_xprt(r_xprt, ep, ia);
if (rc)
goto out_noupdate;
break;
default:
rc = rpcrdma_ep_reconnect(r_xprt, ep, ia);
if (rc)
goto out;
}
ep->rep_connected = 0;
xprt_clear_connected(xprt);
rpcrdma_post_recvs(r_xprt, true);
rc = rdma_connect(ia->ri_id, &ep->rep_remote_cma);
if (rc)
goto out;
wait_event_interruptible(ep->rep_connect_wait, ep->rep_connected != 0);
if (ep->rep_connected <= 0) {
if (ep->rep_connected == -EAGAIN)
goto retry;
rc = ep->rep_connected;
goto out;
}
dprintk("RPC: %s: connected\n", __func__);
out:
if (rc)
ep->rep_connected = rc;
out_noupdate:
return rc;
}
/**
* rpcrdma_ep_disconnect - Disconnect underlying transport
* @ep: endpoint to disconnect
* @ia: associated interface adapter
*
* This is separate from destroy to facilitate the ability
* to reconnect without recreating the endpoint.
*
* This call is not reentrant, and must not be made in parallel
* on the same endpoint.
*/
void
rpcrdma_ep_disconnect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
{
struct rpcrdma_xprt *r_xprt = container_of(ep, struct rpcrdma_xprt,
rx_ep);
int rc;
/* returns without wait if ID is not connected */
rc = rdma_disconnect(ia->ri_id);
if (!rc)
wait_event_interruptible(ep->rep_connect_wait,
ep->rep_connected != 1);
else
ep->rep_connected = rc;
trace_xprtrdma_disconnect(r_xprt, rc);
rpcrdma_xprt_drain(r_xprt);
}
/* Fixed-size circular FIFO queue. This implementation is wait-free and
* lock-free.
*
* Consumer is the code path that posts Sends. This path dequeues a
* sendctx for use by a Send operation. Multiple consumer threads
* are serialized by the RPC transport lock, which allows only one
* ->send_request call at a time.
*
* Producer is the code path that handles Send completions. This path
* enqueues a sendctx that has been completed. Multiple producer
* threads are serialized by the ib_poll_cq() function.
*/
/* rpcrdma_sendctxs_destroy() assumes caller has already quiesced
* queue activity, and rpcrdma_xprt_drain has flushed all remaining
* Send requests.
*/
static void rpcrdma_sendctxs_destroy(struct rpcrdma_buffer *buf)
{
unsigned long i;
for (i = 0; i <= buf->rb_sc_last; i++)
kfree(buf->rb_sc_ctxs[i]);
kfree(buf->rb_sc_ctxs);
}
static struct rpcrdma_sendctx *rpcrdma_sendctx_create(struct rpcrdma_ia *ia)
{
struct rpcrdma_sendctx *sc;
sc = kzalloc(struct_size(sc, sc_sges, ia->ri_max_send_sges),
GFP_KERNEL);
if (!sc)
return NULL;
sc->sc_wr.wr_cqe = &sc->sc_cqe;
sc->sc_wr.sg_list = sc->sc_sges;
sc->sc_wr.opcode = IB_WR_SEND;
sc->sc_cqe.done = rpcrdma_wc_send;
return sc;
}
static int rpcrdma_sendctxs_create(struct rpcrdma_xprt *r_xprt)
{
struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
struct rpcrdma_sendctx *sc;
unsigned long i;
/* Maximum number of concurrent outstanding Send WRs. Capping
* the circular queue size stops Send Queue overflow by causing
* the ->send_request call to fail temporarily before too many
* Sends are posted.
*/
i = buf->rb_max_requests + RPCRDMA_MAX_BC_REQUESTS;
dprintk("RPC: %s: allocating %lu send_ctxs\n", __func__, i);
buf->rb_sc_ctxs = kcalloc(i, sizeof(sc), GFP_KERNEL);
if (!buf->rb_sc_ctxs)
return -ENOMEM;
buf->rb_sc_last = i - 1;
for (i = 0; i <= buf->rb_sc_last; i++) {
sc = rpcrdma_sendctx_create(&r_xprt->rx_ia);
if (!sc)
return -ENOMEM;
sc->sc_xprt = r_xprt;
buf->rb_sc_ctxs[i] = sc;
}
return 0;
}
/* The sendctx queue is not guaranteed to have a size that is a
* power of two, thus the helpers in circ_buf.h cannot be used.
* The other option is to use modulus (%), which can be expensive.
*/
static unsigned long rpcrdma_sendctx_next(struct rpcrdma_buffer *buf,
unsigned long item)
{
return likely(item < buf->rb_sc_last) ? item + 1 : 0;
}
/**
* rpcrdma_sendctx_get_locked - Acquire a send context
* @r_xprt: controlling transport instance
*
* Returns pointer to a free send completion context; or NULL if
* the queue is empty.
*
* Usage: Called to acquire an SGE array before preparing a Send WR.
*
* The caller serializes calls to this function (per transport), and
* provides an effective memory barrier that flushes the new value
* of rb_sc_head.
*/
struct rpcrdma_sendctx *rpcrdma_sendctx_get_locked(struct rpcrdma_xprt *r_xprt)
{
struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
struct rpcrdma_sendctx *sc;
unsigned long next_head;
next_head = rpcrdma_sendctx_next(buf, buf->rb_sc_head);
if (next_head == READ_ONCE(buf->rb_sc_tail))
goto out_emptyq;
/* ORDER: item must be accessed _before_ head is updated */
sc = buf->rb_sc_ctxs[next_head];
/* Releasing the lock in the caller acts as a memory
* barrier that flushes rb_sc_head.
*/
buf->rb_sc_head = next_head;
return sc;
out_emptyq:
/* The queue is "empty" if there have not been enough Send
* completions recently. This is a sign the Send Queue is
* backing up. Cause the caller to pause and try again.
*/
xprt_wait_for_buffer_space(&r_xprt->rx_xprt);
r_xprt->rx_stats.empty_sendctx_q++;
return NULL;
}
/**
* rpcrdma_sendctx_put_locked - Release a send context
* @sc: send context to release
*
* Usage: Called from Send completion to return a sendctxt
* to the queue.
*
* The caller serializes calls to this function (per transport).
*/
static void
rpcrdma_sendctx_put_locked(struct rpcrdma_sendctx *sc)
{
struct rpcrdma_buffer *buf = &sc->sc_xprt->rx_buf;
unsigned long next_tail;
/* Unmap SGEs of previously completed but unsignaled
* Sends by walking up the queue until @sc is found.
*/
next_tail = buf->rb_sc_tail;
do {
next_tail = rpcrdma_sendctx_next(buf, next_tail);
/* ORDER: item must be accessed _before_ tail is updated */
rpcrdma_sendctx_unmap(buf->rb_sc_ctxs[next_tail]);
} while (buf->rb_sc_ctxs[next_tail] != sc);
/* Paired with READ_ONCE */
smp_store_release(&buf->rb_sc_tail, next_tail);
xprt_write_space(&sc->sc_xprt->rx_xprt);
}
static void
rpcrdma_mrs_create(struct rpcrdma_xprt *r_xprt)
{
struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
struct rpcrdma_ia *ia = &r_xprt->rx_ia;
unsigned int count;
LIST_HEAD(free);
LIST_HEAD(all);
for (count = 0; count < ia->ri_max_segs; count++) {
struct rpcrdma_mr *mr;
int rc;
mr = kzalloc(sizeof(*mr), GFP_KERNEL);
if (!mr)
break;
rc = frwr_init_mr(ia, mr);
if (rc) {
kfree(mr);
break;
}
mr->mr_xprt = r_xprt;
list_add(&mr->mr_list, &free);
list_add(&mr->mr_all, &all);
}
spin_lock(&buf->rb_mrlock);
list_splice(&free, &buf->rb_mrs);
list_splice(&all, &buf->rb_all);
r_xprt->rx_stats.mrs_allocated += count;
spin_unlock(&buf->rb_mrlock);
trace_xprtrdma_createmrs(r_xprt, count);
}
static void
rpcrdma_mr_refresh_worker(struct work_struct *work)
{
struct rpcrdma_buffer *buf = container_of(work, struct rpcrdma_buffer,
rb_refresh_worker.work);
struct rpcrdma_xprt *r_xprt = container_of(buf, struct rpcrdma_xprt,
rx_buf);
rpcrdma_mrs_create(r_xprt);
xprt_write_space(&r_xprt->rx_xprt);
}
/**
* rpcrdma_req_create - Allocate an rpcrdma_req object
* @r_xprt: controlling r_xprt
* @size: initial size, in bytes, of send and receive buffers
* @flags: GFP flags passed to memory allocators
*
* Returns an allocated and fully initialized rpcrdma_req or NULL.
*/
struct rpcrdma_req *rpcrdma_req_create(struct rpcrdma_xprt *r_xprt, size_t size,
gfp_t flags)
{
struct rpcrdma_buffer *buffer = &r_xprt->rx_buf;
struct rpcrdma_regbuf *rb;
struct rpcrdma_req *req;
req = kzalloc(sizeof(*req), flags);
if (req == NULL)
goto out1;
rb = rpcrdma_regbuf_alloc(RPCRDMA_HDRBUF_SIZE, DMA_TO_DEVICE, flags);
if (!rb)
goto out2;
req->rl_rdmabuf = rb;
xdr_buf_init(&req->rl_hdrbuf, rdmab_data(rb), rdmab_length(rb));
req->rl_sendbuf = rpcrdma_regbuf_alloc(size, DMA_TO_DEVICE, flags);
if (!req->rl_sendbuf)
goto out3;
req->rl_recvbuf = rpcrdma_regbuf_alloc(size, DMA_NONE, flags);
if (!req->rl_recvbuf)
goto out4;
INIT_LIST_HEAD(&req->rl_registered);
spin_lock(&buffer->rb_lock);
list_add(&req->rl_all, &buffer->rb_allreqs);
spin_unlock(&buffer->rb_lock);
return req;
out4:
kfree(req->rl_sendbuf);
out3:
kfree(req->rl_rdmabuf);
out2:
kfree(req);
out1:
return NULL;
}
static struct rpcrdma_rep *rpcrdma_rep_create(struct rpcrdma_xprt *r_xprt,
bool temp)
{
struct rpcrdma_rep *rep;
rep = kzalloc(sizeof(*rep), GFP_KERNEL);
if (rep == NULL)
goto out;
rep->rr_rdmabuf = rpcrdma_regbuf_alloc(r_xprt->rx_ep.rep_inline_recv,
DMA_FROM_DEVICE, GFP_KERNEL);
if (!rep->rr_rdmabuf)
goto out_free;
xdr_buf_init(&rep->rr_hdrbuf, rdmab_data(rep->rr_rdmabuf),
rdmab_length(rep->rr_rdmabuf));
rep->rr_cqe.done = rpcrdma_wc_receive;
rep->rr_rxprt = r_xprt;
rep->rr_recv_wr.next = NULL;
rep->rr_recv_wr.wr_cqe = &rep->rr_cqe;
rep->rr_recv_wr.sg_list = &rep->rr_rdmabuf->rg_iov;
rep->rr_recv_wr.num_sge = 1;
rep->rr_temp = temp;
return rep;
out_free:
kfree(rep);
out:
return NULL;
}
/**
* rpcrdma_buffer_create - Create initial set of req/rep objects
* @r_xprt: transport instance to (re)initialize
*
* Returns zero on success, otherwise a negative errno.
*/
int rpcrdma_buffer_create(struct rpcrdma_xprt *r_xprt)
{
struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
int i, rc;
buf->rb_max_requests = r_xprt->rx_ep.rep_max_requests;
buf->rb_bc_srv_max_requests = 0;
spin_lock_init(&buf->rb_mrlock);
spin_lock_init(&buf->rb_lock);
INIT_LIST_HEAD(&buf->rb_mrs);
INIT_LIST_HEAD(&buf->rb_all);
INIT_DELAYED_WORK(&buf->rb_refresh_worker,
rpcrdma_mr_refresh_worker);
rpcrdma_mrs_create(r_xprt);
INIT_LIST_HEAD(&buf->rb_send_bufs);
INIT_LIST_HEAD(&buf->rb_allreqs);
rc = -ENOMEM;
for (i = 0; i < buf->rb_max_requests; i++) {
struct rpcrdma_req *req;
req = rpcrdma_req_create(r_xprt, RPCRDMA_V1_DEF_INLINE_SIZE,
GFP_KERNEL);
if (!req)
goto out;
list_add(&req->rl_list, &buf->rb_send_bufs);
}
buf->rb_credits = 1;
INIT_LIST_HEAD(&buf->rb_recv_bufs);
rc = rpcrdma_sendctxs_create(r_xprt);
if (rc)
goto out;
return 0;
out:
rpcrdma_buffer_destroy(buf);
return rc;
}
static void rpcrdma_rep_destroy(struct rpcrdma_rep *rep)
{
rpcrdma_regbuf_free(rep->rr_rdmabuf);
kfree(rep);
}
/**
* rpcrdma_req_destroy - Destroy an rpcrdma_req object
* @req: unused object to be destroyed
*
* This function assumes that the caller prevents concurrent device
* unload and transport tear-down.
*/
void
rpcrdma_req_destroy(struct rpcrdma_req *req)
{
list_del(&req->rl_all);
rpcrdma_regbuf_free(req->rl_recvbuf);
rpcrdma_regbuf_free(req->rl_sendbuf);
rpcrdma_regbuf_free(req->rl_rdmabuf);
kfree(req);
}
static void
rpcrdma_mrs_destroy(struct rpcrdma_buffer *buf)
{
struct rpcrdma_xprt *r_xprt = container_of(buf, struct rpcrdma_xprt,
rx_buf);
struct rpcrdma_mr *mr;
unsigned int count;
count = 0;
spin_lock(&buf->rb_mrlock);
while (!list_empty(&buf->rb_all)) {
mr = list_entry(buf->rb_all.next, struct rpcrdma_mr, mr_all);
list_del(&mr->mr_all);
spin_unlock(&buf->rb_mrlock);
/* Ensure MW is not on any rl_registered list */
if (!list_empty(&mr->mr_list))
list_del(&mr->mr_list);
frwr_release_mr(mr);
count++;
spin_lock(&buf->rb_mrlock);
}
spin_unlock(&buf->rb_mrlock);
r_xprt->rx_stats.mrs_allocated = 0;
dprintk("RPC: %s: released %u MRs\n", __func__, count);
}
/**
* rpcrdma_buffer_destroy - Release all hw resources
* @buf: root control block for resources
*
* ORDERING: relies on a prior rpcrdma_xprt_drain :
* - No more Send or Receive completions can occur
* - All MRs, reps, and reqs are returned to their free lists
*/
void
rpcrdma_buffer_destroy(struct rpcrdma_buffer *buf)
{
cancel_delayed_work_sync(&buf->rb_refresh_worker);
rpcrdma_sendctxs_destroy(buf);
while (!list_empty(&buf->rb_recv_bufs)) {
struct rpcrdma_rep *rep;
rep = list_first_entry(&buf->rb_recv_bufs,
struct rpcrdma_rep, rr_list);
list_del(&rep->rr_list);
rpcrdma_rep_destroy(rep);
}
while (!list_empty(&buf->rb_send_bufs)) {
struct rpcrdma_req *req;
req = list_first_entry(&buf->rb_send_bufs,
struct rpcrdma_req, rl_list);
list_del(&req->rl_list);
rpcrdma_req_destroy(req);
}
rpcrdma_mrs_destroy(buf);
}
/**
* rpcrdma_mr_get - Allocate an rpcrdma_mr object
* @r_xprt: controlling transport
*
* Returns an initialized rpcrdma_mr or NULL if no free
* rpcrdma_mr objects are available.
*/
struct rpcrdma_mr *
rpcrdma_mr_get(struct rpcrdma_xprt *r_xprt)
{
struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
struct rpcrdma_mr *mr = NULL;
spin_lock(&buf->rb_mrlock);
if (!list_empty(&buf->rb_mrs))
mr = rpcrdma_mr_pop(&buf->rb_mrs);
spin_unlock(&buf->rb_mrlock);
if (!mr)
goto out_nomrs;
return mr;
out_nomrs:
trace_xprtrdma_nomrs(r_xprt);
if (r_xprt->rx_ep.rep_connected != -ENODEV)
schedule_delayed_work(&buf->rb_refresh_worker, 0);
/* Allow the reply handler and refresh worker to run */
cond_resched();
return NULL;
}
static void
__rpcrdma_mr_put(struct rpcrdma_buffer *buf, struct rpcrdma_mr *mr)
{
spin_lock(&buf->rb_mrlock);
rpcrdma_mr_push(mr, &buf->rb_mrs);
spin_unlock(&buf->rb_mrlock);
}
/**
* rpcrdma_mr_put - Release an rpcrdma_mr object
* @mr: object to release
*
*/
void
rpcrdma_mr_put(struct rpcrdma_mr *mr)
{
__rpcrdma_mr_put(&mr->mr_xprt->rx_buf, mr);
}
/**
* rpcrdma_mr_unmap_and_put - DMA unmap an MR and release it
* @mr: object to release
*
*/
void
rpcrdma_mr_unmap_and_put(struct rpcrdma_mr *mr)
{
struct rpcrdma_xprt *r_xprt = mr->mr_xprt;
if (mr->mr_dir != DMA_NONE) {
trace_xprtrdma_mr_unmap(mr);
ib_dma_unmap_sg(r_xprt->rx_ia.ri_id->device,
mr->mr_sg, mr->mr_nents, mr->mr_dir);
mr->mr_dir = DMA_NONE;
}
__rpcrdma_mr_put(&r_xprt->rx_buf, mr);
}
/**
* rpcrdma_buffer_get - Get a request buffer
* @buffers: Buffer pool from which to obtain a buffer
*
* Returns a fresh rpcrdma_req, or NULL if none are available.
*/
struct rpcrdma_req *
rpcrdma_buffer_get(struct rpcrdma_buffer *buffers)
{
struct rpcrdma_req *req;
spin_lock(&buffers->rb_lock);
req = list_first_entry_or_null(&buffers->rb_send_bufs,
struct rpcrdma_req, rl_list);
if (req)
list_del_init(&req->rl_list);
spin_unlock(&buffers->rb_lock);
return req;
}
/**
* rpcrdma_buffer_put - Put request/reply buffers back into pool
* @buffers: buffer pool
* @req: object to return
*
*/
void rpcrdma_buffer_put(struct rpcrdma_buffer *buffers, struct rpcrdma_req *req)
{
struct rpcrdma_rep *rep = req->rl_reply;
req->rl_reply = NULL;
spin_lock(&buffers->rb_lock);
list_add(&req->rl_list, &buffers->rb_send_bufs);
if (rep) {
if (!rep->rr_temp) {
list_add(&rep->rr_list, &buffers->rb_recv_bufs);
rep = NULL;
}
}
spin_unlock(&buffers->rb_lock);
if (rep)
rpcrdma_rep_destroy(rep);
}
/*
* Put reply buffers back into pool when not attached to
* request. This happens in error conditions.
*/
void
rpcrdma_recv_buffer_put(struct rpcrdma_rep *rep)
{
struct rpcrdma_buffer *buffers = &rep->rr_rxprt->rx_buf;
if (!rep->rr_temp) {
spin_lock(&buffers->rb_lock);
list_add(&rep->rr_list, &buffers->rb_recv_bufs);
spin_unlock(&buffers->rb_lock);
} else {
rpcrdma_rep_destroy(rep);
}
}
/* Returns a pointer to a rpcrdma_regbuf object, or NULL.
*
* xprtrdma uses a regbuf for posting an outgoing RDMA SEND, or for
* receiving the payload of RDMA RECV operations. During Long Calls
* or Replies they may be registered externally via frwr_map.
*/
static struct rpcrdma_regbuf *
rpcrdma_regbuf_alloc(size_t size, enum dma_data_direction direction,
gfp_t flags)
{
struct rpcrdma_regbuf *rb;
rb = kmalloc(sizeof(*rb), flags);
if (!rb)
return NULL;
rb->rg_data = kmalloc(size, flags);
if (!rb->rg_data) {
kfree(rb);
return NULL;
}
rb->rg_device = NULL;
rb->rg_direction = direction;
rb->rg_iov.length = size;
return rb;
}
/**
* rpcrdma_regbuf_realloc - re-allocate a SEND/RECV buffer
* @rb: regbuf to reallocate
* @size: size of buffer to be allocated, in bytes
* @flags: GFP flags
*
* Returns true if reallocation was successful. If false is
* returned, @rb is left untouched.
*/
bool rpcrdma_regbuf_realloc(struct rpcrdma_regbuf *rb, size_t size, gfp_t flags)
{
void *buf;
buf = kmalloc(size, flags);
if (!buf)
return false;
rpcrdma_regbuf_dma_unmap(rb);
kfree(rb->rg_data);
rb->rg_data = buf;
rb->rg_iov.length = size;
return true;
}
/**
* __rpcrdma_regbuf_dma_map - DMA-map a regbuf
* @r_xprt: controlling transport instance
* @rb: regbuf to be mapped
*
* Returns true if the buffer is now DMA mapped to @r_xprt's device
*/
bool __rpcrdma_regbuf_dma_map(struct rpcrdma_xprt *r_xprt,
struct rpcrdma_regbuf *rb)
{
struct ib_device *device = r_xprt->rx_ia.ri_id->device;
if (rb->rg_direction == DMA_NONE)
return false;
rb->rg_iov.addr = ib_dma_map_single(device, rdmab_data(rb),
rdmab_length(rb), rb->rg_direction);
if (ib_dma_mapping_error(device, rdmab_addr(rb))) {
trace_xprtrdma_dma_maperr(rdmab_addr(rb));
return false;
}
rb->rg_device = device;
rb->rg_iov.lkey = r_xprt->rx_ia.ri_pd->local_dma_lkey;
return true;
}
static void rpcrdma_regbuf_dma_unmap(struct rpcrdma_regbuf *rb)
{
if (!rb)
return;
if (!rpcrdma_regbuf_is_mapped(rb))
return;
ib_dma_unmap_single(rb->rg_device, rdmab_addr(rb), rdmab_length(rb),
rb->rg_direction);
rb->rg_device = NULL;
}
static void rpcrdma_regbuf_free(struct rpcrdma_regbuf *rb)
{
rpcrdma_regbuf_dma_unmap(rb);
if (rb)
kfree(rb->rg_data);
kfree(rb);
}
/**
* rpcrdma_ep_post - Post WRs to a transport's Send Queue
* @ia: transport's device information
* @ep: transport's RDMA endpoint information
* @req: rpcrdma_req containing the Send WR to post
*
* Returns 0 if the post was successful, otherwise -ENOTCONN
* is returned.
*/
int
rpcrdma_ep_post(struct rpcrdma_ia *ia,
struct rpcrdma_ep *ep,
struct rpcrdma_req *req)
{
struct ib_send_wr *send_wr = &req->rl_sendctx->sc_wr;
int rc;
if (!ep->rep_send_count || kref_read(&req->rl_kref) > 1) {
send_wr->send_flags |= IB_SEND_SIGNALED;
ep->rep_send_count = ep->rep_send_batch;
} else {
send_wr->send_flags &= ~IB_SEND_SIGNALED;
--ep->rep_send_count;
}
rc = frwr_send(ia, req);
trace_xprtrdma_post_send(req, rc);
if (rc)
return -ENOTCONN;
return 0;
}
static void
rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp)
{
struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
struct rpcrdma_ep *ep = &r_xprt->rx_ep;
struct ib_recv_wr *i, *wr, *bad_wr;
struct rpcrdma_rep *rep;
int needed, count, rc;
rc = 0;
count = 0;
needed = buf->rb_credits + (buf->rb_bc_srv_max_requests << 1);
if (ep->rep_receive_count > needed)
goto out;
needed -= ep->rep_receive_count;
if (!temp)
needed += RPCRDMA_MAX_RECV_BATCH;
/* fast path: all needed reps can be found on the free list */
wr = NULL;
spin_lock(&buf->rb_lock);
while (needed) {
rep = list_first_entry_or_null(&buf->rb_recv_bufs,
struct rpcrdma_rep, rr_list);
if (!rep)
break;
list_del(&rep->rr_list);
rep->rr_recv_wr.next = wr;
wr = &rep->rr_recv_wr;
--needed;
}
spin_unlock(&buf->rb_lock);
while (needed) {
rep = rpcrdma_rep_create(r_xprt, temp);
if (!rep)
break;
rep->rr_recv_wr.next = wr;
wr = &rep->rr_recv_wr;
--needed;
}
if (!wr)
goto out;
for (i = wr; i; i = i->next) {
rep = container_of(i, struct rpcrdma_rep, rr_recv_wr);
if (!rpcrdma_regbuf_dma_map(r_xprt, rep->rr_rdmabuf))
goto release_wrs;
trace_xprtrdma_post_recv(rep->rr_recv_wr.wr_cqe);
++count;
}
rc = ib_post_recv(r_xprt->rx_ia.ri_id->qp, wr,
(const struct ib_recv_wr **)&bad_wr);
out:
trace_xprtrdma_post_recvs(r_xprt, count, rc);
if (rc) {
for (wr = bad_wr; wr;) {
struct rpcrdma_rep *rep;
rep = container_of(wr, struct rpcrdma_rep, rr_recv_wr);
wr = wr->next;
rpcrdma_recv_buffer_put(rep);
--count;
}
}
ep->rep_receive_count += count;
return;
release_wrs:
for (i = wr; i;) {
rep = container_of(i, struct rpcrdma_rep, rr_recv_wr);
i = i->next;
rpcrdma_recv_buffer_put(rep);
}
}
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