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Commit 83128a60 authored by Chuck Lever's avatar Chuck Lever Committed by Anna Schumaker
Browse files

xprtrdma: Add support for sending backward direction RPC replies 



Backward direction RPC replies are sent via the client transport's
send_request method, the same way forward direction RPC calls are
sent.

Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Reviewed-by: default avatarSagi Grimberg <sagig@mellanox.com>
Tested-By: default avatarDevesh Sharma <devesh.sharma@avagotech.com>
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
parent 124fa17d

net/sunrpc/xprtrdma/backchannel.c

+45 −0
Original line number Diff line number Diff line
@@ -169,6 +169,51 @@ int xprt_rdma_bc_setup(struct rpc_xprt *xprt, unsigned int reqs) 
	return -ENOMEM;

}



/**

 * 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)

{

	struct rpc_xprt *xprt = rqst->rq_xprt;

	struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);

	struct rpcrdma_req *req = rpcr_to_rdmar(rqst);

	struct rpcrdma_msg *headerp;

	size_t rpclen;



	headerp = rdmab_to_msg(req->rl_rdmabuf);

	headerp->rm_xid = rqst->rq_xid;

	headerp->rm_vers = rpcrdma_version;

	headerp->rm_credit =

			cpu_to_be32(r_xprt->rx_buf.rb_bc_srv_max_requests);

	headerp->rm_type = rdma_msg;

	headerp->rm_body.rm_chunks[0] = xdr_zero;

	headerp->rm_body.rm_chunks[1] = xdr_zero;

	headerp->rm_body.rm_chunks[2] = xdr_zero;



	rpclen = rqst->rq_svec[0].iov_len;



	pr_info("RPC:       %s: rpclen %zd headerp 0x%p lkey 0x%x\n",

		__func__, rpclen, headerp, rdmab_lkey(req->rl_rdmabuf));

	pr_info("RPC:       %s: RPC/RDMA: %*ph\n",

		__func__, (int)RPCRDMA_HDRLEN_MIN, headerp);

	pr_info("RPC:       %s:      RPC: %*ph\n",

		__func__, (int)rpclen, rqst->rq_svec[0].iov_base);



	req->rl_send_iov[0].addr = rdmab_addr(req->rl_rdmabuf);

	req->rl_send_iov[0].length = RPCRDMA_HDRLEN_MIN;

	req->rl_send_iov[0].lkey = rdmab_lkey(req->rl_rdmabuf);



	req->rl_send_iov[1].addr = rdmab_addr(req->rl_sendbuf);

	req->rl_send_iov[1].length = rpclen;

	req->rl_send_iov[1].lkey = rdmab_lkey(req->rl_sendbuf);



	req->rl_niovs = 2;

	return 0;

}



/**

 * xprt_rdma_bc_destroy - Release resources for handling backchannel requests

 * @xprt: transport associated with these backchannel resources

net/sunrpc/xprtrdma/rpc_rdma.c

+5 −0
Original line number Diff line number Diff line
@@ -441,6 +441,11 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst) 
	enum rpcrdma_chunktype rtype, wtype;

	struct rpcrdma_msg *headerp;



#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



	/*

	 * rpclen gets amount of data in first buffer, which is the

	 * pre-registered buffer.

net/sunrpc/xprtrdma/xprt_rdma.h

+1 −0
Original line number Diff line number Diff line
@@ -520,6 +520,7 @@ void xprt_rdma_cleanup(void); 
#if defined(CONFIG_SUNRPC_BACKCHANNEL)

int xprt_rdma_bc_setup(struct rpc_xprt *, unsigned int);

int rpcrdma_bc_post_recv(struct rpcrdma_xprt *, unsigned int);

int rpcrdma_bc_marshal_reply(struct rpc_rqst *);

void xprt_rdma_bc_free_rqst(struct rpc_rqst *);

void xprt_rdma_bc_destroy(struct rpc_xprt *, unsigned int);

#endif	/* CONFIG_SUNRPC_BACKCHANNEL */