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949317464b
linux/net/sunrpc/xprtrdma/verbs.c
Chuck Lever 949317464b xprtrdma: Limit number of RDMA segments in RPC-over-RDMA headers 
Send buffer space is shared between the RPC-over-RDMA header and
an RPC message. A large RPC-over-RDMA header means less space is
available for the associated RPC message, which then has to be
moved via an RDMA Read or Write.

As more segments are added to the chunk lists, the header increases
in size.  Typical modern hardware needs only a few segments to
convey the maximum payload size, but some devices and registration
modes may need a lot of segments to convey data payload. Sometimes
so many are needed that the remaining space in the Send buffer is
not enough for the RPC message. Sending such a message usually
fails.

To ensure a transport can always make forward progress, cap the
number of RDMA segments that are allowed in chunk lists. This
prevents less-capable devices and memory registrations from
consuming a large portion of the Send buffer by reducing the
maximum data payload that can be conveyed with such devices.

For now I choose an arbitrary maximum of 8 RDMA segments. This
allows a maximum size RPC-over-RDMA header to fit nicely in the
current 1024 byte inline threshold with over 700 bytes remaining
for an inline RPC message.

The current maximum data payload of NFS READ or WRITE requests is
one megabyte. To convey that payload on a client with 4KB pages,
each chunk segment would need to handle 32 or more data pages. This
is well within the capabilities of FMR. For physical registration,
the maximum payload size on platforms with 4KB pages is reduced to
32KB.

For FRWR, a device's maximum page list depth would need to be at
least 34 to support the maximum 1MB payload. A device with a smaller
maximum page list depth means the maximum data payload is reduced
when using that device.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-05-17 15:47:58 -04:00

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/*
* 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/prefetch.h>
#include <linux/sunrpc/addr.h>
#include <asm/bitops.h>
#include <linux/module.h> /* try_module_get()/module_put() */
#include "xprt_rdma.h"
/*
* Globals/Macros
*/
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
# define RPCDBG_FACILITY RPCDBG_TRANS
#endif
/*
* internal functions
*/
static struct workqueue_struct *rpcrdma_receive_wq;
int
rpcrdma_alloc_wq(void)
{
struct workqueue_struct *recv_wq;
recv_wq = alloc_workqueue("xprtrdma_receive",
WQ_MEM_RECLAIM | WQ_UNBOUND | WQ_HIGHPRI,
0);
if (!recv_wq)
return -ENOMEM;
rpcrdma_receive_wq = recv_wq;
return 0;
}
void
rpcrdma_destroy_wq(void)
{
struct workqueue_struct *wq;
if (rpcrdma_receive_wq) {
wq = rpcrdma_receive_wq;
rpcrdma_receive_wq = NULL;
destroy_workqueue(wq);
}
}
static void
rpcrdma_qp_async_error_upcall(struct ib_event *event, void *context)
{
struct rpcrdma_ep *ep = context;
pr_err("RPC: %s: %s on device %s ep %p\n",
__func__, ib_event_msg(event->event),
event->device->name, context);
if (ep->rep_connected == 1) {
ep->rep_connected = -EIO;
rpcrdma_conn_func(ep);
wake_up_all(&ep->rep_connect_wait);
}
}
/**
* 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)
{
/* WARNING: Only wr_cqe and status are reliable at this point */
if (wc->status != IB_WC_SUCCESS && wc->status != IB_WC_WR_FLUSH_ERR)
pr_err("rpcrdma: Send: %s (%u/0x%x)\n",
ib_wc_status_msg(wc->status),
wc->status, wc->vendor_err);
}
static void
rpcrdma_receive_worker(struct work_struct *work)
{
struct rpcrdma_rep *rep =
container_of(work, struct rpcrdma_rep, rr_work);
rpcrdma_reply_handler(rep);
}
/* Perform basic sanity checking to avoid using garbage
* to update the credit grant value.
*/
static void
rpcrdma_update_granted_credits(struct rpcrdma_rep *rep)
{
struct rpcrdma_msg *rmsgp = rdmab_to_msg(rep->rr_rdmabuf);
struct rpcrdma_buffer *buffer = &rep->rr_rxprt->rx_buf;
u32 credits;
if (rep->rr_len < RPCRDMA_HDRLEN_ERR)
return;
credits = be32_to_cpu(rmsgp->rm_credit);
if (credits == 0)
credits = 1; /* don't deadlock */
else if (credits > buffer->rb_max_requests)
credits = buffer->rb_max_requests;
atomic_set(&buffer->rb_credits, credits);
}
/**
* rpcrdma_receive_wc - Invoked by RDMA provider for each polled Receive WC
* @cq: completion queue (ignored)
* @wc: completed WR
*
*/
static void
rpcrdma_receive_wc(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);
/* WARNING: Only wr_id and status are reliable at this point */
if (wc->status != IB_WC_SUCCESS)
goto out_fail;
/* status == SUCCESS means all fields in wc are trustworthy */
if (wc->opcode != IB_WC_RECV)
return;
dprintk("RPC: %s: rep %p opcode 'recv', length %u: success\n",
__func__, rep, wc->byte_len);
rep->rr_len = wc->byte_len;
ib_dma_sync_single_for_cpu(rep->rr_device,
rdmab_addr(rep->rr_rdmabuf),
rep->rr_len, DMA_FROM_DEVICE);
rpcrdma_update_granted_credits(rep);
out_schedule:
queue_work(rpcrdma_receive_wq, &rep->rr_work);
return;
out_fail:
if (wc->status != IB_WC_WR_FLUSH_ERR)
pr_err("rpcrdma: Recv: %s (%u/0x%x)\n",
ib_wc_status_msg(wc->status),
wc->status, wc->vendor_err);
rep->rr_len = RPCRDMA_BAD_LEN;
goto out_schedule;
}
static void
rpcrdma_flush_cqs(struct rpcrdma_ep *ep)
{
struct ib_wc wc;
while (ib_poll_cq(ep->rep_attr.recv_cq, 1, &wc) > 0)
rpcrdma_receive_wc(NULL, &wc);
}
static int
rpcrdma_conn_upcall(struct rdma_cm_id *id, struct rdma_cm_event *event)
{
struct rpcrdma_xprt *xprt = id->context;
struct rpcrdma_ia *ia = &xprt->rx_ia;
struct rpcrdma_ep *ep = &xprt->rx_ep;
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
struct sockaddr *sap = (struct sockaddr *)&ep->rep_remote_addr;
#endif
struct ib_qp_attr *attr = &ia->ri_qp_attr;
struct ib_qp_init_attr *iattr = &ia->ri_qp_init_attr;
int connstate = 0;
switch (event->event) {
case RDMA_CM_EVENT_ADDR_RESOLVED:
case RDMA_CM_EVENT_ROUTE_RESOLVED:
ia->ri_async_rc = 0;
complete(&ia->ri_done);
break;
case RDMA_CM_EVENT_ADDR_ERROR:
ia->ri_async_rc = -EHOSTUNREACH;
dprintk("RPC: %s: CM address resolution error, ep 0x%p\n",
__func__, ep);
complete(&ia->ri_done);
break;
case RDMA_CM_EVENT_ROUTE_ERROR:
ia->ri_async_rc = -ENETUNREACH;
dprintk("RPC: %s: CM route resolution error, ep 0x%p\n",
__func__, ep);
complete(&ia->ri_done);
break;
case RDMA_CM_EVENT_ESTABLISHED:
connstate = 1;
ib_query_qp(ia->ri_id->qp, attr,
IB_QP_MAX_QP_RD_ATOMIC | IB_QP_MAX_DEST_RD_ATOMIC,
iattr);
dprintk("RPC: %s: %d responder resources"
" (%d initiator)\n",
__func__, attr->max_dest_rd_atomic,
attr->max_rd_atomic);
goto connected;
case RDMA_CM_EVENT_CONNECT_ERROR:
connstate = -ENOTCONN;
goto connected;
case RDMA_CM_EVENT_UNREACHABLE:
connstate = -ENETDOWN;
goto connected;
case RDMA_CM_EVENT_REJECTED:
connstate = -ECONNREFUSED;
goto connected;
case RDMA_CM_EVENT_DISCONNECTED:
connstate = -ECONNABORTED;
goto connected;
case RDMA_CM_EVENT_DEVICE_REMOVAL:
connstate = -ENODEV;
connected:
dprintk("RPC: %s: %sconnected\n",
__func__, connstate > 0 ? "" : "dis");
atomic_set(&xprt->rx_buf.rb_credits, 1);
ep->rep_connected = connstate;
rpcrdma_conn_func(ep);
wake_up_all(&ep->rep_connect_wait);
/*FALLTHROUGH*/
default:
dprintk("RPC: %s: %pIS:%u (ep 0x%p): %s\n",
__func__, sap, rpc_get_port(sap), ep,
rdma_event_msg(event->event));
break;
}
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
if (connstate == 1) {
int ird = attr->max_dest_rd_atomic;
int tird = ep->rep_remote_cma.responder_resources;
pr_info("rpcrdma: connection to %pIS:%u on %s, memreg '%s', %d credits, %d responders%s\n",
sap, rpc_get_port(sap),
ia->ri_device->name,
ia->ri_ops->ro_displayname,
xprt->rx_buf.rb_max_requests,
ird, ird < 4 && ird < tird / 2 ? " (low!)" : "");
} else if (connstate < 0) {
pr_info("rpcrdma: connection to %pIS:%u closed (%d)\n",
sap, rpc_get_port(sap), connstate);
}
#endif
return 0;
}
static void rpcrdma_destroy_id(struct rdma_cm_id *id)
{
if (id) {
module_put(id->device->owner);
rdma_destroy_id(id);
}
}
static struct rdma_cm_id *
rpcrdma_create_id(struct rpcrdma_xprt *xprt,
struct rpcrdma_ia *ia, struct sockaddr *addr)
{
struct rdma_cm_id *id;
int rc;
init_completion(&ia->ri_done);
id = rdma_create_id(&init_net, rpcrdma_conn_upcall, xprt, RDMA_PS_TCP,
IB_QPT_RC);
if (IS_ERR(id)) {
rc = PTR_ERR(id);
dprintk("RPC: %s: rdma_create_id() failed %i\n",
__func__, rc);
return id;
}
ia->ri_async_rc = -ETIMEDOUT;
rc = rdma_resolve_addr(id, NULL, addr, RDMA_RESOLVE_TIMEOUT);
if (rc) {
dprintk("RPC: %s: rdma_resolve_addr() failed %i\n",
__func__, rc);
goto out;
}
wait_for_completion_interruptible_timeout(&ia->ri_done,
msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT) + 1);
/* FIXME:
* Until xprtrdma supports DEVICE_REMOVAL, the provider must
* be pinned while there are active NFS/RDMA mounts to prevent
* hangs and crashes at umount time.
*/
if (!ia->ri_async_rc && !try_module_get(id->device->owner)) {
dprintk("RPC: %s: Failed to get device module\n",
__func__);
ia->ri_async_rc = -ENODEV;
}
rc = ia->ri_async_rc;
if (rc)
goto out;
ia->ri_async_rc = -ETIMEDOUT;
rc = rdma_resolve_route(id, RDMA_RESOLVE_TIMEOUT);
if (rc) {
dprintk("RPC: %s: rdma_resolve_route() failed %i\n",
__func__, rc);
goto put;
}
wait_for_completion_interruptible_timeout(&ia->ri_done,
msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT) + 1);
rc = ia->ri_async_rc;
if (rc)
goto put;
return id;
put:
module_put(id->device->owner);
out:
rdma_destroy_id(id);
return ERR_PTR(rc);
}
/*
* Drain any cq, prior to teardown.
*/
static void
rpcrdma_clean_cq(struct ib_cq *cq)
{
struct ib_wc wc;
int count = 0;
while (1 == ib_poll_cq(cq, 1, &wc))
++count;
if (count)
dprintk("RPC: %s: flushed %d events (last 0x%x)\n",
__func__, count, wc.opcode);
}
/*
* Exported functions.
*/
/*
* Open and initialize an Interface Adapter.
* o initializes fields of struct rpcrdma_ia, including
* interface and provider attributes and protection zone.
*/
int
rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr, int memreg)
{
struct rpcrdma_ia *ia = &xprt->rx_ia;
int rc;
ia->ri_dma_mr = NULL;
ia->ri_id = rpcrdma_create_id(xprt, ia, addr);
if (IS_ERR(ia->ri_id)) {
rc = PTR_ERR(ia->ri_id);
goto out1;
}
ia->ri_device = ia->ri_id->device;
ia->ri_pd = ib_alloc_pd(ia->ri_device);
if (IS_ERR(ia->ri_pd)) {
rc = PTR_ERR(ia->ri_pd);
dprintk("RPC: %s: ib_alloc_pd() failed %i\n",
__func__, rc);
goto out2;
}
if (memreg == RPCRDMA_FRMR) {
if (!(ia->ri_device->attrs.device_cap_flags &
IB_DEVICE_MEM_MGT_EXTENSIONS) ||
(ia->ri_device->attrs.max_fast_reg_page_list_len == 0)) {
dprintk("RPC: %s: FRMR registration "
"not supported by HCA\n", __func__);
memreg = RPCRDMA_MTHCAFMR;
}
}
if (memreg == RPCRDMA_MTHCAFMR) {
if (!ia->ri_device->alloc_fmr) {
dprintk("RPC: %s: MTHCAFMR registration "
"not supported by HCA\n", __func__);
rc = -EINVAL;
goto out3;
}
}
switch (memreg) {
case RPCRDMA_FRMR:
ia->ri_ops = &rpcrdma_frwr_memreg_ops;
break;
case RPCRDMA_ALLPHYSICAL:
ia->ri_ops = &rpcrdma_physical_memreg_ops;
break;
case RPCRDMA_MTHCAFMR:
ia->ri_ops = &rpcrdma_fmr_memreg_ops;
break;
default:
printk(KERN_ERR "RPC: Unsupported memory "
"registration mode: %d\n", memreg);
rc = -ENOMEM;
goto out3;
}
dprintk("RPC: %s: memory registration strategy is '%s'\n",
__func__, ia->ri_ops->ro_displayname);
rwlock_init(&ia->ri_qplock);
return 0;
out3:
ib_dealloc_pd(ia->ri_pd);
ia->ri_pd = NULL;
out2:
rpcrdma_destroy_id(ia->ri_id);
ia->ri_id = NULL;
out1:
return rc;
}
/*
* Clean up/close an IA.
* o if event handles and PD have been initialized, free them.
* o close the IA
*/
void
rpcrdma_ia_close(struct rpcrdma_ia *ia)
{
dprintk("RPC: %s: entering\n", __func__);
if (ia->ri_id != NULL && !IS_ERR(ia->ri_id)) {
if (ia->ri_id->qp)
rdma_destroy_qp(ia->ri_id);
rpcrdma_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);
}
/*
* Create unconnected endpoint.
*/
int
rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
struct rpcrdma_create_data_internal *cdata)
{
struct ib_cq *sendcq, *recvcq;
unsigned int max_qp_wr;
int rc;
if (ia->ri_device->attrs.max_sge < RPCRDMA_MAX_IOVS) {
dprintk("RPC: %s: insufficient sge's available\n",
__func__);
return -ENOMEM;
}
if (ia->ri_device->attrs.max_qp_wr <= RPCRDMA_BACKWARD_WRS) {
dprintk("RPC: %s: insufficient wqe's available\n",
__func__);
return -ENOMEM;
}
max_qp_wr = ia->ri_device->attrs.max_qp_wr - RPCRDMA_BACKWARD_WRS;
/* check provider's send/recv wr limits */
if (cdata->max_requests > max_qp_wr)
cdata->max_requests = max_qp_wr;
ep->rep_attr.event_handler = rpcrdma_qp_async_error_upcall;
ep->rep_attr.qp_context = ep;
ep->rep_attr.srq = NULL;
ep->rep_attr.cap.max_send_wr = cdata->max_requests;
ep->rep_attr.cap.max_send_wr += RPCRDMA_BACKWARD_WRS;
rc = ia->ri_ops->ro_open(ia, ep, cdata);
if (rc)
return rc;
ep->rep_attr.cap.max_recv_wr = cdata->max_requests;
ep->rep_attr.cap.max_recv_wr += RPCRDMA_BACKWARD_WRS;
ep->rep_attr.cap.max_send_sge = RPCRDMA_MAX_IOVS;
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);
/* set trigger for requesting send completion */
ep->rep_cqinit = ep->rep_attr.cap.max_send_wr/2 - 1;
if (ep->rep_cqinit <= 2)
ep->rep_cqinit = 0; /* always signal? */
INIT_CQCOUNT(ep);
init_waitqueue_head(&ep->rep_connect_wait);
INIT_DELAYED_WORK(&ep->rep_connect_worker, rpcrdma_connect_worker);
sendcq = ib_alloc_cq(ia->ri_device, NULL,
ep->rep_attr.cap.max_send_wr + 1,
0, IB_POLL_SOFTIRQ);
if (IS_ERR(sendcq)) {
rc = PTR_ERR(sendcq);
dprintk("RPC: %s: failed to create send CQ: %i\n",
__func__, rc);
goto out1;
}
recvcq = ib_alloc_cq(ia->ri_device, NULL,
ep->rep_attr.cap.max_recv_wr + 1,
0, IB_POLL_SOFTIRQ);
if (IS_ERR(recvcq)) {
rc = PTR_ERR(recvcq);
dprintk("RPC: %s: failed to create recv CQ: %i\n",
__func__, rc);
goto out2;
}
ep->rep_attr.send_cq = sendcq;
ep->rep_attr.recv_cq = recvcq;
/* Initialize cma parameters */
/* RPC/RDMA does not use private data */
ep->rep_remote_cma.private_data = NULL;
ep->rep_remote_cma.private_data_len = 0;
/* Client offers RDMA Read but does not initiate */
ep->rep_remote_cma.initiator_depth = 0;
if (ia->ri_device->attrs.max_qp_rd_atom > 32) /* arbitrary but <= 255 */
ep->rep_remote_cma.responder_resources = 32;
else
ep->rep_remote_cma.responder_resources =
ia->ri_device->attrs.max_qp_rd_atom;
ep->rep_remote_cma.retry_count = 7;
ep->rep_remote_cma.flow_control = 0;
ep->rep_remote_cma.rnr_retry_count = 0;
return 0;
out2:
ib_free_cq(sendcq);
out1:
if (ia->ri_dma_mr)
ib_dereg_mr(ia->ri_dma_mr);
return rc;
}
/*
* rpcrdma_ep_destroy
*
* Disconnect and destroy endpoint. After this, the only
* valid operations on the ep are to free it (if dynamically
* allocated) or re-create it.
*/
void
rpcrdma_ep_destroy(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
{
int rc;
dprintk("RPC: %s: entering, connected is %d\n",
__func__, ep->rep_connected);
cancel_delayed_work_sync(&ep->rep_connect_worker);
if (ia->ri_id->qp)
rpcrdma_ep_disconnect(ep, ia);
rpcrdma_clean_cq(ep->rep_attr.recv_cq);
rpcrdma_clean_cq(ep->rep_attr.send_cq);
if (ia->ri_id->qp) {
rdma_destroy_qp(ia->ri_id);
ia->ri_id->qp = NULL;
}
ib_free_cq(ep->rep_attr.recv_cq);
ib_free_cq(ep->rep_attr.send_cq);
if (ia->ri_dma_mr) {
rc = ib_dereg_mr(ia->ri_dma_mr);
dprintk("RPC: %s: ib_dereg_mr returned %i\n",
__func__, rc);
}
}
/*
* Connect unconnected endpoint.
*/
int
rpcrdma_ep_connect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
{
struct rdma_cm_id *id, *old;
int rc = 0;
int retry_count = 0;
if (ep->rep_connected != 0) {
struct rpcrdma_xprt *xprt;
retry:
dprintk("RPC: %s: reconnecting...\n", __func__);
rpcrdma_ep_disconnect(ep, ia);
rpcrdma_flush_cqs(ep);
xprt = container_of(ia, struct rpcrdma_xprt, rx_ia);
id = rpcrdma_create_id(xprt, ia,
(struct sockaddr *)&xprt->rx_data.addr);
if (IS_ERR(id)) {
rc = -EHOSTUNREACH;
goto out;
}
/* TEMP TEMP TEMP - fail if new device:
* Deregister/remarshal *all* requests!
* Close and recreate adapter, pd, etc!
* Re-determine all attributes still sane!
* More stuff I haven't thought of!
* Rrrgh!
*/
if (ia->ri_device != id->device) {
printk("RPC: %s: can't reconnect on "
"different device!\n", __func__);
rpcrdma_destroy_id(id);
rc = -ENETUNREACH;
goto out;
}
/* END TEMP */
rc = rdma_create_qp(id, ia->ri_pd, &ep->rep_attr);
if (rc) {
dprintk("RPC: %s: rdma_create_qp failed %i\n",
__func__, rc);
rpcrdma_destroy_id(id);
rc = -ENETUNREACH;
goto out;
}
write_lock(&ia->ri_qplock);
old = ia->ri_id;
ia->ri_id = id;
write_unlock(&ia->ri_qplock);
rdma_destroy_qp(old);
rpcrdma_destroy_id(old);
} else {
dprintk("RPC: %s: connecting...\n", __func__);
rc = rdma_create_qp(ia->ri_id, ia->ri_pd, &ep->rep_attr);
if (rc) {
dprintk("RPC: %s: rdma_create_qp failed %i\n",
__func__, rc);
/* do not update ep->rep_connected */
return -ENETUNREACH;
}
}
ep->rep_connected = 0;
rc = rdma_connect(ia->ri_id, &ep->rep_remote_cma);
if (rc) {
dprintk("RPC: %s: rdma_connect() failed with %i\n",
__func__, rc);
goto out;
}
wait_event_interruptible(ep->rep_connect_wait, ep->rep_connected != 0);
/*
* Check state. A non-peer reject indicates no listener
* (ECONNREFUSED), which may be a transient state. All
* others indicate a transport condition which has already
* undergone a best-effort.
*/
if (ep->rep_connected == -ECONNREFUSED &&
++retry_count <= RDMA_CONNECT_RETRY_MAX) {
dprintk("RPC: %s: non-peer_reject, retry\n", __func__);
goto retry;
}
if (ep->rep_connected <= 0) {
/* Sometimes, the only way to reliably connect to remote
* CMs is to use same nonzero values for ORD and IRD. */
if (retry_count++ <= RDMA_CONNECT_RETRY_MAX + 1 &&
(ep->rep_remote_cma.responder_resources == 0 ||
ep->rep_remote_cma.initiator_depth !=
ep->rep_remote_cma.responder_resources)) {
if (ep->rep_remote_cma.responder_resources == 0)
ep->rep_remote_cma.responder_resources = 1;
ep->rep_remote_cma.initiator_depth =
ep->rep_remote_cma.responder_resources;
goto retry;
}
rc = ep->rep_connected;
} else {
struct rpcrdma_xprt *r_xprt;
unsigned int extras;
dprintk("RPC: %s: connected\n", __func__);
r_xprt = container_of(ia, struct rpcrdma_xprt, rx_ia);
extras = r_xprt->rx_buf.rb_bc_srv_max_requests;
if (extras) {
rc = rpcrdma_ep_post_extra_recv(r_xprt, extras);
if (rc) {
pr_warn("%s: rpcrdma_ep_post_extra_recv: %i\n",
__func__, rc);
rc = 0;
}
}
}
out:
if (rc)
ep->rep_connected = rc;
return rc;
}
/*
* rpcrdma_ep_disconnect
*
* 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)
{
int rc;
rpcrdma_flush_cqs(ep);
rc = rdma_disconnect(ia->ri_id);
if (!rc) {
/* returns without wait if not connected */
wait_event_interruptible(ep->rep_connect_wait,
ep->rep_connected != 1);
dprintk("RPC: %s: after wait, %sconnected\n", __func__,
(ep->rep_connected == 1) ? "still " : "dis");
} else {
dprintk("RPC: %s: rdma_disconnect %i\n", __func__, rc);
ep->rep_connected = rc;
}
}
struct rpcrdma_req *
rpcrdma_create_req(struct rpcrdma_xprt *r_xprt)
{
struct rpcrdma_buffer *buffer = &r_xprt->rx_buf;
struct rpcrdma_req *req;
req = kzalloc(sizeof(*req), GFP_KERNEL);
if (req == NULL)
return ERR_PTR(-ENOMEM);
INIT_LIST_HEAD(&req->rl_free);
spin_lock(&buffer->rb_reqslock);
list_add(&req->rl_all, &buffer->rb_allreqs);
spin_unlock(&buffer->rb_reqslock);
req->rl_cqe.done = rpcrdma_wc_send;
req->rl_buffer = &r_xprt->rx_buf;
return req;
}
struct rpcrdma_rep *
rpcrdma_create_rep(struct rpcrdma_xprt *r_xprt)
{
struct rpcrdma_create_data_internal *cdata = &r_xprt->rx_data;
struct rpcrdma_ia *ia = &r_xprt->rx_ia;
struct rpcrdma_rep *rep;
int rc;
rc = -ENOMEM;
rep = kzalloc(sizeof(*rep), GFP_KERNEL);
if (rep == NULL)
goto out;
rep->rr_rdmabuf = rpcrdma_alloc_regbuf(ia, cdata->inline_rsize,
GFP_KERNEL);
if (IS_ERR(rep->rr_rdmabuf)) {
rc = PTR_ERR(rep->rr_rdmabuf);
goto out_free;
}
rep->rr_device = ia->ri_device;
rep->rr_cqe.done = rpcrdma_receive_wc;
rep->rr_rxprt = r_xprt;
INIT_WORK(&rep->rr_work, rpcrdma_receive_worker);
return rep;
out_free:
kfree(rep);
out:
return ERR_PTR(rc);
}
int
rpcrdma_buffer_create(struct rpcrdma_xprt *r_xprt)
{
struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
struct rpcrdma_ia *ia = &r_xprt->rx_ia;
int i, rc;
buf->rb_max_requests = r_xprt->rx_data.max_requests;
buf->rb_bc_srv_max_requests = 0;
spin_lock_init(&buf->rb_lock);
atomic_set(&buf->rb_credits, 1);
rc = ia->ri_ops->ro_init(r_xprt);
if (rc)
goto out;
INIT_LIST_HEAD(&buf->rb_send_bufs);
INIT_LIST_HEAD(&buf->rb_allreqs);
spin_lock_init(&buf->rb_reqslock);
for (i = 0; i < buf->rb_max_requests; i++) {
struct rpcrdma_req *req;
req = rpcrdma_create_req(r_xprt);
if (IS_ERR(req)) {
dprintk("RPC: %s: request buffer %d alloc"
" failed\n", __func__, i);
rc = PTR_ERR(req);
goto out;
}
req->rl_backchannel = false;
list_add(&req->rl_free, &buf->rb_send_bufs);
}
INIT_LIST_HEAD(&buf->rb_recv_bufs);
for (i = 0; i < buf->rb_max_requests + 2; i++) {
struct rpcrdma_rep *rep;
rep = rpcrdma_create_rep(r_xprt);
if (IS_ERR(rep)) {
dprintk("RPC: %s: reply buffer %d alloc failed\n",
__func__, i);
rc = PTR_ERR(rep);
goto out;
}
list_add(&rep->rr_list, &buf->rb_recv_bufs);
}
return 0;
out:
rpcrdma_buffer_destroy(buf);
return rc;
}
static struct rpcrdma_req *
rpcrdma_buffer_get_req_locked(struct rpcrdma_buffer *buf)
{
struct rpcrdma_req *req;
req = list_first_entry(&buf->rb_send_bufs,
struct rpcrdma_req, rl_free);
list_del(&req->rl_free);
return req;
}
static struct rpcrdma_rep *
rpcrdma_buffer_get_rep_locked(struct rpcrdma_buffer *buf)
{
struct rpcrdma_rep *rep;
rep = list_first_entry(&buf->rb_recv_bufs,
struct rpcrdma_rep, rr_list);
list_del(&rep->rr_list);
return rep;
}
static void
rpcrdma_destroy_rep(struct rpcrdma_ia *ia, struct rpcrdma_rep *rep)
{
rpcrdma_free_regbuf(ia, rep->rr_rdmabuf);
kfree(rep);
}
void
rpcrdma_destroy_req(struct rpcrdma_ia *ia, struct rpcrdma_req *req)
{
rpcrdma_free_regbuf(ia, req->rl_sendbuf);
rpcrdma_free_regbuf(ia, req->rl_rdmabuf);
kfree(req);
}
void
rpcrdma_buffer_destroy(struct rpcrdma_buffer *buf)
{
struct rpcrdma_ia *ia = rdmab_to_ia(buf);
while (!list_empty(&buf->rb_recv_bufs)) {
struct rpcrdma_rep *rep;
rep = rpcrdma_buffer_get_rep_locked(buf);
rpcrdma_destroy_rep(ia, rep);
}
spin_lock(&buf->rb_reqslock);
while (!list_empty(&buf->rb_allreqs)) {
struct rpcrdma_req *req;
req = list_first_entry(&buf->rb_allreqs,
struct rpcrdma_req, rl_all);
list_del(&req->rl_all);
spin_unlock(&buf->rb_reqslock);
rpcrdma_destroy_req(ia, req);
spin_lock(&buf->rb_reqslock);
}
spin_unlock(&buf->rb_reqslock);
ia->ri_ops->ro_destroy(buf);
}
struct rpcrdma_mw *
rpcrdma_get_mw(struct rpcrdma_xprt *r_xprt)
{
struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
struct rpcrdma_mw *mw = NULL;
spin_lock(&buf->rb_mwlock);
if (!list_empty(&buf->rb_mws)) {
mw = list_first_entry(&buf->rb_mws,
struct rpcrdma_mw, mw_list);
list_del_init(&mw->mw_list);
}
spin_unlock(&buf->rb_mwlock);
if (!mw)
pr_err("RPC: %s: no MWs available\n", __func__);
return mw;
}
void
rpcrdma_put_mw(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mw *mw)
{
struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
spin_lock(&buf->rb_mwlock);
list_add_tail(&mw->mw_list, &buf->rb_mws);
spin_unlock(&buf->rb_mwlock);
}
/*
* Get a set of request/reply buffers.
*
* Reply buffer (if available) is attached to send buffer upon return.
*/
struct rpcrdma_req *
rpcrdma_buffer_get(struct rpcrdma_buffer *buffers)
{
struct rpcrdma_req *req;
spin_lock(&buffers->rb_lock);
if (list_empty(&buffers->rb_send_bufs))
goto out_reqbuf;
req = rpcrdma_buffer_get_req_locked(buffers);
if (list_empty(&buffers->rb_recv_bufs))
goto out_repbuf;
req->rl_reply = rpcrdma_buffer_get_rep_locked(buffers);
spin_unlock(&buffers->rb_lock);
return req;
out_reqbuf:
spin_unlock(&buffers->rb_lock);
pr_warn("RPC: %s: out of request buffers\n", __func__);
return NULL;
out_repbuf:
spin_unlock(&buffers->rb_lock);
pr_warn("RPC: %s: out of reply buffers\n", __func__);
req->rl_reply = NULL;
return req;
}
/*
* Put request/reply buffers back into pool.
* Pre-decrement counter/array index.
*/
void
rpcrdma_buffer_put(struct rpcrdma_req *req)
{
struct rpcrdma_buffer *buffers = req->rl_buffer;
struct rpcrdma_rep *rep = req->rl_reply;
req->rl_niovs = 0;
req->rl_reply = NULL;
spin_lock(&buffers->rb_lock);
list_add_tail(&req->rl_free, &buffers->rb_send_bufs);
if (rep)
list_add_tail(&rep->rr_list, &buffers->rb_recv_bufs);
spin_unlock(&buffers->rb_lock);
}
/*
* Recover reply buffers from pool.
* This happens when recovering from disconnect.
*/
void
rpcrdma_recv_buffer_get(struct rpcrdma_req *req)
{
struct rpcrdma_buffer *buffers = req->rl_buffer;
spin_lock(&buffers->rb_lock);
if (!list_empty(&buffers->rb_recv_bufs))
req->rl_reply = rpcrdma_buffer_get_rep_locked(buffers);
spin_unlock(&buffers->rb_lock);
}
/*
* 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;
spin_lock(&buffers->rb_lock);
list_add_tail(&rep->rr_list, &buffers->rb_recv_bufs);
spin_unlock(&buffers->rb_lock);
}
/*
* Wrappers for internal-use kmalloc memory registration, used by buffer code.
*/
void
rpcrdma_mapping_error(struct rpcrdma_mr_seg *seg)
{
dprintk("RPC: map_one: offset %p iova %llx len %zu\n",
seg->mr_offset,
(unsigned long long)seg->mr_dma, seg->mr_dmalen);
}
/**
* rpcrdma_alloc_regbuf - kmalloc and register memory for SEND/RECV buffers
* @ia: controlling rpcrdma_ia
* @size: size of buffer to be allocated, in bytes
* @flags: GFP flags
*
* Returns pointer to private header of an area of internally
* registered memory, or an ERR_PTR. The registered buffer follows
* the end of the private header.
*
* xprtrdma uses a regbuf for posting an outgoing RDMA SEND, or for
* receiving the payload of RDMA RECV operations. regbufs are not
* used for RDMA READ/WRITE operations, thus are registered only for
* LOCAL access.
*/
struct rpcrdma_regbuf *
rpcrdma_alloc_regbuf(struct rpcrdma_ia *ia, size_t size, gfp_t flags)
{
struct rpcrdma_regbuf *rb;
struct ib_sge *iov;
rb = kmalloc(sizeof(*rb) + size, flags);
if (rb == NULL)
goto out;
iov = &rb->rg_iov;
iov->addr = ib_dma_map_single(ia->ri_device,
(void *)rb->rg_base, size,
DMA_BIDIRECTIONAL);
if (ib_dma_mapping_error(ia->ri_device, iov->addr))
goto out_free;
iov->length = size;
iov->lkey = ia->ri_pd->local_dma_lkey;
rb->rg_size = size;
rb->rg_owner = NULL;
return rb;
out_free:
kfree(rb);
out:
return ERR_PTR(-ENOMEM);
}
/**
* rpcrdma_free_regbuf - deregister and free registered buffer
* @ia: controlling rpcrdma_ia
* @rb: regbuf to be deregistered and freed
*/
void
rpcrdma_free_regbuf(struct rpcrdma_ia *ia, struct rpcrdma_regbuf *rb)
{
struct ib_sge *iov;
if (!rb)
return;
iov = &rb->rg_iov;
ib_dma_unmap_single(ia->ri_device,
iov->addr, iov->length, DMA_BIDIRECTIONAL);
kfree(rb);
}
/*
* Prepost any receive buffer, then post send.
*
* Receive buffer is donated to hardware, reclaimed upon recv completion.
*/
int
rpcrdma_ep_post(struct rpcrdma_ia *ia,
struct rpcrdma_ep *ep,
struct rpcrdma_req *req)
{
struct ib_device *device = ia->ri_device;
struct ib_send_wr send_wr, *send_wr_fail;
struct rpcrdma_rep *rep = req->rl_reply;
struct ib_sge *iov = req->rl_send_iov;
int i, rc;
if (rep) {
rc = rpcrdma_ep_post_recv(ia, ep, rep);
if (rc)
goto out;
req->rl_reply = NULL;
}
send_wr.next = NULL;
send_wr.wr_cqe = &req->rl_cqe;
send_wr.sg_list = iov;
send_wr.num_sge = req->rl_niovs;
send_wr.opcode = IB_WR_SEND;
for (i = 0; i < send_wr.num_sge; i++)
ib_dma_sync_single_for_device(device, iov[i].addr,
iov[i].length, DMA_TO_DEVICE);
dprintk("RPC: %s: posting %d s/g entries\n",
__func__, send_wr.num_sge);
if (DECR_CQCOUNT(ep) > 0)
send_wr.send_flags = 0;
else { /* Provider must take a send completion every now and then */
INIT_CQCOUNT(ep);
send_wr.send_flags = IB_SEND_SIGNALED;
}
rc = ib_post_send(ia->ri_id->qp, &send_wr, &send_wr_fail);
if (rc)
dprintk("RPC: %s: ib_post_send returned %i\n", __func__,
rc);
out:
return rc;
}
/*
* (Re)post a receive buffer.
*/
int
rpcrdma_ep_post_recv(struct rpcrdma_ia *ia,
struct rpcrdma_ep *ep,
struct rpcrdma_rep *rep)
{
struct ib_recv_wr recv_wr, *recv_wr_fail;
int rc;
recv_wr.next = NULL;
recv_wr.wr_cqe = &rep->rr_cqe;
recv_wr.sg_list = &rep->rr_rdmabuf->rg_iov;
recv_wr.num_sge = 1;
ib_dma_sync_single_for_cpu(ia->ri_device,
rdmab_addr(rep->rr_rdmabuf),
rdmab_length(rep->rr_rdmabuf),
DMA_BIDIRECTIONAL);
rc = ib_post_recv(ia->ri_id->qp, &recv_wr, &recv_wr_fail);
if (rc)
dprintk("RPC: %s: ib_post_recv returned %i\n", __func__,
rc);
return rc;
}
/**
* rpcrdma_ep_post_extra_recv - Post buffers for incoming backchannel requests
* @r_xprt: transport associated with these backchannel resources
* @min_reqs: minimum number of incoming requests expected
*
* Returns zero if all requested buffers were posted, or a negative errno.
*/
int
rpcrdma_ep_post_extra_recv(struct rpcrdma_xprt *r_xprt, unsigned int count)
{
struct rpcrdma_buffer *buffers = &r_xprt->rx_buf;
struct rpcrdma_ia *ia = &r_xprt->rx_ia;
struct rpcrdma_ep *ep = &r_xprt->rx_ep;
struct rpcrdma_rep *rep;
int rc;
while (count--) {
spin_lock(&buffers->rb_lock);
if (list_empty(&buffers->rb_recv_bufs))
goto out_reqbuf;
rep = rpcrdma_buffer_get_rep_locked(buffers);
spin_unlock(&buffers->rb_lock);
rc = rpcrdma_ep_post_recv(ia, ep, rep);
if (rc)
goto out_rc;
}
return 0;
out_reqbuf:
spin_unlock(&buffers->rb_lock);
pr_warn("%s: no extra receive buffers\n", __func__);
return -ENOMEM;
out_rc:
rpcrdma_recv_buffer_put(rep);
return rc;
}
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