forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
284 lines
7.2 KiB
284 lines
7.2 KiB
// SPDX-License-Identifier: GPL-2.0 |
|
/* |
|
* Copyright (c) 2015-2020, Oracle and/or its affiliates. |
|
* |
|
* Support for reverse-direction RPCs on RPC/RDMA. |
|
*/ |
|
|
|
#include <linux/sunrpc/xprt.h> |
|
#include <linux/sunrpc/svc.h> |
|
#include <linux/sunrpc/svc_xprt.h> |
|
#include <linux/sunrpc/svc_rdma.h> |
|
|
|
#include "xprt_rdma.h" |
|
#include <trace/events/rpcrdma.h> |
|
|
|
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) |
|
# define RPCDBG_FACILITY RPCDBG_TRANS |
|
#endif |
|
|
|
#undef RPCRDMA_BACKCHANNEL_DEBUG |
|
|
|
/** |
|
* xprt_rdma_bc_setup - Pre-allocate resources for handling backchannel requests |
|
* @xprt: transport associated with these backchannel resources |
|
* @reqs: number of concurrent incoming requests to expect |
|
* |
|
* Returns 0 on success; otherwise a negative errno |
|
*/ |
|
int xprt_rdma_bc_setup(struct rpc_xprt *xprt, unsigned int reqs) |
|
{ |
|
struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt); |
|
|
|
r_xprt->rx_buf.rb_bc_srv_max_requests = RPCRDMA_BACKWARD_WRS >> 1; |
|
trace_xprtrdma_cb_setup(r_xprt, reqs); |
|
return 0; |
|
} |
|
|
|
/** |
|
* xprt_rdma_bc_maxpayload - Return maximum backchannel message size |
|
* @xprt: transport |
|
* |
|
* Returns maximum size, in bytes, of a backchannel message |
|
*/ |
|
size_t xprt_rdma_bc_maxpayload(struct rpc_xprt *xprt) |
|
{ |
|
struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt); |
|
struct rpcrdma_ep *ep = r_xprt->rx_ep; |
|
size_t maxmsg; |
|
|
|
maxmsg = min_t(unsigned int, ep->re_inline_send, ep->re_inline_recv); |
|
maxmsg = min_t(unsigned int, maxmsg, PAGE_SIZE); |
|
return maxmsg - RPCRDMA_HDRLEN_MIN; |
|
} |
|
|
|
unsigned int xprt_rdma_bc_max_slots(struct rpc_xprt *xprt) |
|
{ |
|
return RPCRDMA_BACKWARD_WRS >> 1; |
|
} |
|
|
|
static int rpcrdma_bc_marshal_reply(struct rpc_rqst *rqst) |
|
{ |
|
struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt); |
|
struct rpcrdma_req *req = rpcr_to_rdmar(rqst); |
|
__be32 *p; |
|
|
|
rpcrdma_set_xdrlen(&req->rl_hdrbuf, 0); |
|
xdr_init_encode(&req->rl_stream, &req->rl_hdrbuf, |
|
rdmab_data(req->rl_rdmabuf), rqst); |
|
|
|
p = xdr_reserve_space(&req->rl_stream, 28); |
|
if (unlikely(!p)) |
|
return -EIO; |
|
*p++ = rqst->rq_xid; |
|
*p++ = rpcrdma_version; |
|
*p++ = cpu_to_be32(r_xprt->rx_buf.rb_bc_srv_max_requests); |
|
*p++ = rdma_msg; |
|
*p++ = xdr_zero; |
|
*p++ = xdr_zero; |
|
*p = xdr_zero; |
|
|
|
if (rpcrdma_prepare_send_sges(r_xprt, req, RPCRDMA_HDRLEN_MIN, |
|
&rqst->rq_snd_buf, rpcrdma_noch_pullup)) |
|
return -EIO; |
|
|
|
trace_xprtrdma_cb_reply(r_xprt, rqst); |
|
return 0; |
|
} |
|
|
|
/** |
|
* xprt_rdma_bc_send_reply - marshal and send a backchannel reply |
|
* @rqst: RPC rqst with a backchannel RPC reply in rq_snd_buf |
|
* |
|
* Caller holds the transport's write lock. |
|
* |
|
* Returns: |
|
* %0 if the RPC message has been sent |
|
* %-ENOTCONN if the caller should reconnect and call again |
|
* %-EIO if a permanent error occurred and the request was not |
|
* sent. Do not try to send this message again. |
|
*/ |
|
int xprt_rdma_bc_send_reply(struct rpc_rqst *rqst) |
|
{ |
|
struct rpc_xprt *xprt = rqst->rq_xprt; |
|
struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt); |
|
struct rpcrdma_req *req = rpcr_to_rdmar(rqst); |
|
int rc; |
|
|
|
if (!xprt_connected(xprt)) |
|
return -ENOTCONN; |
|
|
|
if (!xprt_request_get_cong(xprt, rqst)) |
|
return -EBADSLT; |
|
|
|
rc = rpcrdma_bc_marshal_reply(rqst); |
|
if (rc < 0) |
|
goto failed_marshal; |
|
|
|
if (rpcrdma_post_sends(r_xprt, req)) |
|
goto drop_connection; |
|
return 0; |
|
|
|
failed_marshal: |
|
if (rc != -ENOTCONN) |
|
return rc; |
|
drop_connection: |
|
xprt_rdma_close(xprt); |
|
return -ENOTCONN; |
|
} |
|
|
|
/** |
|
* xprt_rdma_bc_destroy - Release resources for handling backchannel requests |
|
* @xprt: transport associated with these backchannel resources |
|
* @reqs: number of incoming requests to destroy; ignored |
|
*/ |
|
void xprt_rdma_bc_destroy(struct rpc_xprt *xprt, unsigned int reqs) |
|
{ |
|
struct rpc_rqst *rqst, *tmp; |
|
|
|
spin_lock(&xprt->bc_pa_lock); |
|
list_for_each_entry_safe(rqst, tmp, &xprt->bc_pa_list, rq_bc_pa_list) { |
|
list_del(&rqst->rq_bc_pa_list); |
|
spin_unlock(&xprt->bc_pa_lock); |
|
|
|
rpcrdma_req_destroy(rpcr_to_rdmar(rqst)); |
|
|
|
spin_lock(&xprt->bc_pa_lock); |
|
} |
|
spin_unlock(&xprt->bc_pa_lock); |
|
} |
|
|
|
/** |
|
* xprt_rdma_bc_free_rqst - Release a backchannel rqst |
|
* @rqst: request to release |
|
*/ |
|
void xprt_rdma_bc_free_rqst(struct rpc_rqst *rqst) |
|
{ |
|
struct rpcrdma_req *req = rpcr_to_rdmar(rqst); |
|
struct rpc_xprt *xprt = rqst->rq_xprt; |
|
|
|
rpcrdma_recv_buffer_put(req->rl_reply); |
|
req->rl_reply = NULL; |
|
|
|
spin_lock(&xprt->bc_pa_lock); |
|
list_add_tail(&rqst->rq_bc_pa_list, &xprt->bc_pa_list); |
|
spin_unlock(&xprt->bc_pa_lock); |
|
xprt_put(xprt); |
|
} |
|
|
|
static struct rpc_rqst *rpcrdma_bc_rqst_get(struct rpcrdma_xprt *r_xprt) |
|
{ |
|
struct rpc_xprt *xprt = &r_xprt->rx_xprt; |
|
struct rpcrdma_req *req; |
|
struct rpc_rqst *rqst; |
|
size_t size; |
|
|
|
spin_lock(&xprt->bc_pa_lock); |
|
rqst = list_first_entry_or_null(&xprt->bc_pa_list, struct rpc_rqst, |
|
rq_bc_pa_list); |
|
if (!rqst) |
|
goto create_req; |
|
list_del(&rqst->rq_bc_pa_list); |
|
spin_unlock(&xprt->bc_pa_lock); |
|
return rqst; |
|
|
|
create_req: |
|
spin_unlock(&xprt->bc_pa_lock); |
|
|
|
/* Set a limit to prevent a remote from overrunning our resources. |
|
*/ |
|
if (xprt->bc_alloc_count >= RPCRDMA_BACKWARD_WRS) |
|
return NULL; |
|
|
|
size = min_t(size_t, r_xprt->rx_ep->re_inline_recv, PAGE_SIZE); |
|
req = rpcrdma_req_create(r_xprt, size, GFP_KERNEL); |
|
if (!req) |
|
return NULL; |
|
if (rpcrdma_req_setup(r_xprt, req)) { |
|
rpcrdma_req_destroy(req); |
|
return NULL; |
|
} |
|
|
|
xprt->bc_alloc_count++; |
|
rqst = &req->rl_slot; |
|
rqst->rq_xprt = xprt; |
|
__set_bit(RPC_BC_PA_IN_USE, &rqst->rq_bc_pa_state); |
|
xdr_buf_init(&rqst->rq_snd_buf, rdmab_data(req->rl_sendbuf), size); |
|
return rqst; |
|
} |
|
|
|
/** |
|
* rpcrdma_bc_receive_call - Handle a reverse-direction Call |
|
* @r_xprt: transport receiving the call |
|
* @rep: receive buffer containing the call |
|
* |
|
* Operational assumptions: |
|
* o Backchannel credits are ignored, just as the NFS server |
|
* forechannel currently does |
|
* o The ULP manages a replay cache (eg, NFSv4.1 sessions). |
|
* No replay detection is done at the transport level |
|
*/ |
|
void rpcrdma_bc_receive_call(struct rpcrdma_xprt *r_xprt, |
|
struct rpcrdma_rep *rep) |
|
{ |
|
struct rpc_xprt *xprt = &r_xprt->rx_xprt; |
|
struct svc_serv *bc_serv; |
|
struct rpcrdma_req *req; |
|
struct rpc_rqst *rqst; |
|
struct xdr_buf *buf; |
|
size_t size; |
|
__be32 *p; |
|
|
|
p = xdr_inline_decode(&rep->rr_stream, 0); |
|
size = xdr_stream_remaining(&rep->rr_stream); |
|
|
|
#ifdef RPCRDMA_BACKCHANNEL_DEBUG |
|
pr_info("RPC: %s: callback XID %08x, length=%u\n", |
|
__func__, be32_to_cpup(p), size); |
|
pr_info("RPC: %s: %*ph\n", __func__, size, p); |
|
#endif |
|
|
|
rqst = rpcrdma_bc_rqst_get(r_xprt); |
|
if (!rqst) |
|
goto out_overflow; |
|
|
|
rqst->rq_reply_bytes_recvd = 0; |
|
rqst->rq_xid = *p; |
|
|
|
rqst->rq_private_buf.len = size; |
|
|
|
buf = &rqst->rq_rcv_buf; |
|
memset(buf, 0, sizeof(*buf)); |
|
buf->head[0].iov_base = p; |
|
buf->head[0].iov_len = size; |
|
buf->len = size; |
|
|
|
/* The receive buffer has to be hooked to the rpcrdma_req |
|
* so that it is not released while the req is pointing |
|
* to its buffer, and so that it can be reposted after |
|
* the Upper Layer is done decoding it. |
|
*/ |
|
req = rpcr_to_rdmar(rqst); |
|
req->rl_reply = rep; |
|
trace_xprtrdma_cb_call(r_xprt, rqst); |
|
|
|
/* Queue rqst for ULP's callback service */ |
|
bc_serv = xprt->bc_serv; |
|
xprt_get(xprt); |
|
spin_lock(&bc_serv->sv_cb_lock); |
|
list_add(&rqst->rq_bc_list, &bc_serv->sv_cb_list); |
|
spin_unlock(&bc_serv->sv_cb_lock); |
|
|
|
wake_up(&bc_serv->sv_cb_waitq); |
|
|
|
r_xprt->rx_stats.bcall_count++; |
|
return; |
|
|
|
out_overflow: |
|
pr_warn("RPC/RDMA backchannel overflow\n"); |
|
xprt_force_disconnect(xprt); |
|
/* This receive buffer gets reposted automatically |
|
* when the connection is re-established. |
|
*/ |
|
return; |
|
}
|
|
|