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xprtrdma: Split xprt_rdma_send_request

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Clean up. @rqst is set up differently for backchannel Replies. For
example, rqst->rq_task and task->tk_client are both NULL. So it is
easier to understand and maintain this code path if it is separated.

Also, we can get rid of the confusing rl_connect_cookie hack in
rpcrdma_bc_receive_call.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
This commit is contained in:
Chuck Lever 2017-12-14 20:57:31 -05:00 committed by Anna Schumaker
parent 6c537f2c7c
commit cf73daf527
4 changed files with 50 additions and 32 deletions
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48
net/sunrpc/xprtrdma/backchannel.c
View File

@ -187,13 +187,7 @@ size_t xprt_rdma_bc_maxpayload(struct rpc_xprt *xprt)
return maxmsg - RPCRDMA_HDRLEN_MIN;
}
/**
* rpcrdma_bc_marshal_reply - Send backwards direction reply
* @rqst: buffer containing RPC reply data
*
* Returns zero on success.
*/
int rpcrdma_bc_marshal_reply(struct rpc_rqst *rqst)
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);
@ -220,6 +214,43 @@ int rpcrdma_bc_marshal_reply(struct rpc_rqst *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 rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
int rc;
if (!xprt_connected(rqst->rq_xprt))
goto drop_connection;
rc = rpcrdma_bc_marshal_reply(rqst);
if (rc < 0)
goto failed_marshal;
if (rpcrdma_ep_post(&r_xprt->rx_ia, &r_xprt->rx_ep, req))
goto drop_connection;
return 0;
failed_marshal:
if (rc != -ENOTCONN)
return rc;
drop_connection:
xprt_disconnect_done(rqst->rq_xprt);
return -ENOTCONN;
}
/**
* xprt_rdma_bc_destroy - Release resources for handling backchannel requests
* @xprt: transport associated with these backchannel resources
@ -330,9 +361,6 @@ void rpcrdma_bc_receive_call(struct rpcrdma_xprt *r_xprt,
__func__, rep, req);
req->rl_reply = rep;
/* Defeat the retransmit detection logic in send_request */
req->rl_connect_cookie = 0;
/* Queue rqst for ULP's callback service */
bc_serv = xprt->bc_serv;
spin_lock(&bc_serv->sv_cb_lock);

5
net/sunrpc/xprtrdma/rpc_rdma.c
View File

@ -754,11 +754,6 @@ rpcrdma_marshal_req(struct rpcrdma_xprt *r_xprt, struct rpc_rqst *rqst)
__be32 *p;
int ret;
#if defined(CONFIG_SUNRPC_BACKCHANNEL)
if (test_bit(RPC_BC_PA_IN_USE, &rqst->rq_bc_pa_state))
return rpcrdma_bc_marshal_reply(rqst);
#endif
rpcrdma_set_xdrlen(&req->rl_hdrbuf, 0);
xdr_init_encode(xdr, &req->rl_hdrbuf,
req->rl_rdmabuf->rg_base);

27
net/sunrpc/xprtrdma/transport.c
View File

@ -699,22 +699,12 @@ xprt_rdma_free(struct rpc_task *task)
*
* Caller holds the transport's write lock.
*
* Return values:
* 0: The request has been sent
* ENOTCONN: Caller needs to invoke connect logic then call again
* ENOBUFS: Call again later to send the request
* EIO: A permanent error occurred. The request was not sent,
* and don't try it again
*
* send_request invokes the meat of RPC RDMA. It must do the following:
*
* 1. Marshal the RPC request into an RPC RDMA request, which means
* putting a header in front of data, and creating IOVs for RDMA
* from those in the request.
* 2. In marshaling, detect opportunities for RDMA, and use them.
* 3. Post a recv message to set up asynch completion, then send
* the request (rpcrdma_ep_post).
* 4. No partial sends are possible in the RPC-RDMA protocol (as in UDP).
* Returns:
* %0 if the RPC message has been sent
* %-ENOTCONN if the caller should reconnect and call again
* %-ENOBUFS if the caller should call again later
* %-EIO if a permanent error occurred and the request was not
* sent. Do not try to send this message again.
*/
static int
xprt_rdma_send_request(struct rpc_task *task)
@ -725,6 +715,11 @@ xprt_rdma_send_request(struct rpc_task *task)
struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
int rc = 0;
#if defined(CONFIG_SUNRPC_BACKCHANNEL)
if (unlikely(!rqst->rq_buffer))
return xprt_rdma_bc_send_reply(rqst);
#endif /* CONFIG_SUNRPC_BACKCHANNEL */
if (!xprt_connected(xprt))
goto drop_connection;

2
net/sunrpc/xprtrdma/xprt_rdma.h
View File

@ -666,7 +666,7 @@ int xprt_rdma_bc_up(struct svc_serv *, struct net *);
size_t xprt_rdma_bc_maxpayload(struct rpc_xprt *);
int rpcrdma_bc_post_recv(struct rpcrdma_xprt *, unsigned int);
void rpcrdma_bc_receive_call(struct rpcrdma_xprt *, struct rpcrdma_rep *);
int rpcrdma_bc_marshal_reply(struct rpc_rqst *);
int xprt_rdma_bc_send_reply(struct rpc_rqst *rqst);
void xprt_rdma_bc_free_rqst(struct rpc_rqst *);
void xprt_rdma_bc_destroy(struct rpc_xprt *, unsigned int);
#endif /* CONFIG_SUNRPC_BACKCHANNEL */