Re: [PATCH v2 08/10] svcrdma: Add backward direction service for RPC/RDMA transport

From: Chuck Lever <chuck.lever@oracle.com>
To: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Linux NFS Mailing List <linux-nfs@vger.kernel.org>
Subject: Re: [PATCH v2 08/10] svcrdma: Add backward direction service for RPC/RDMA transport
Date: Mon, 1 Jun 2015 16:45:26 -0400	[thread overview]
Message-ID: <C2428536-0784-4C42-B678-F2173C6CAB89@oracle.com> (raw)
In-Reply-To: <20150601202641.GD26972@fieldses.org>

On Jun 1, 2015, at 4:26 PM, J. Bruce Fields <bfields@fieldses.org> wrote:

> On Tue, May 26, 2015 at 01:49:45PM -0400, Chuck Lever wrote:
>> Introduce some pre-requisite infrastructure needed for handling
>> RPC/RDMA bi-direction on the client side.
>> 
>> On NFSv4.1 mount points, the client uses this transport endpoint to
>> receive backward direction calls and route replies back to the
>> NFS server.
> 
> Am I missing something, or is this pretty much dead code for now?
> 
> In which case, I'd rather wait on it.

When I submit the client-side backchannel patches, should I submit
this patch through Anna and request your Acked-by?

> --b.
> 
>> 
>> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
>> ---
>> 
>> include/linux/sunrpc/svc_rdma.h          |    6 +++
>> include/linux/sunrpc/xprt.h              |    1 +
>> net/sunrpc/xprtrdma/svc_rdma.c           |    6 +++
>> net/sunrpc/xprtrdma/svc_rdma_transport.c |   59 ++++++++++++++++++++++++++++++
>> 4 files changed, 71 insertions(+), 1 deletions(-)
>> 
>> diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h
>> index cb94ee4..0e7234d 100644
>> --- a/include/linux/sunrpc/svc_rdma.h
>> +++ b/include/linux/sunrpc/svc_rdma.h
>> @@ -231,9 +231,13 @@ extern void svc_rdma_put_frmr(struct svcxprt_rdma *,
>> 			      struct svc_rdma_fastreg_mr *);
>> extern void svc_sq_reap(struct svcxprt_rdma *);
>> extern void svc_rq_reap(struct svcxprt_rdma *);
>> -extern struct svc_xprt_class svc_rdma_class;
>> extern void svc_rdma_prep_reply_hdr(struct svc_rqst *);
>> 
>> +extern struct svc_xprt_class svc_rdma_class;
>> +#ifdef CONFIG_SUNRPC_BACKCHANNEL
>> +extern struct svc_xprt_class svc_rdma_bc_class;
>> +#endif
>> +
>> /* svc_rdma.c */
>> extern int svc_rdma_init(void);
>> extern void svc_rdma_cleanup(void);
>> diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
>> index 8b93ef5..693f9f1 100644
>> --- a/include/linux/sunrpc/xprt.h
>> +++ b/include/linux/sunrpc/xprt.h
>> @@ -150,6 +150,7 @@ enum xprt_transports {
>> 	XPRT_TRANSPORT_TCP	= IPPROTO_TCP,
>> 	XPRT_TRANSPORT_BC_TCP	= IPPROTO_TCP | XPRT_TRANSPORT_BC,
>> 	XPRT_TRANSPORT_RDMA	= 256,
>> +	XPRT_TRANSPORT_BC_RDMA	= XPRT_TRANSPORT_RDMA | XPRT_TRANSPORT_BC,
>> 	XPRT_TRANSPORT_LOCAL	= 257,
>> };
>> 
>> diff --git a/net/sunrpc/xprtrdma/svc_rdma.c b/net/sunrpc/xprtrdma/svc_rdma.c
>> index 8eedb60..7a18ae4 100644
>> --- a/net/sunrpc/xprtrdma/svc_rdma.c
>> +++ b/net/sunrpc/xprtrdma/svc_rdma.c
>> @@ -244,6 +244,9 @@ void svc_rdma_cleanup(void)
>> 		unregister_sysctl_table(svcrdma_table_header);
>> 		svcrdma_table_header = NULL;
>> 	}
>> +#ifdef CONFIG_SUNRPC_BACKCHANNEL
>> +	svc_unreg_xprt_class(&svc_rdma_bc_class);
>> +#endif
>> 	svc_unreg_xprt_class(&svc_rdma_class);
>> 	kmem_cache_destroy(svc_rdma_map_cachep);
>> 	kmem_cache_destroy(svc_rdma_ctxt_cachep);
>> @@ -291,6 +294,9 @@ int svc_rdma_init(void)
>> 
>> 	/* Register RDMA with the SVC transport switch */
>> 	svc_reg_xprt_class(&svc_rdma_class);
>> +#ifdef CONFIG_SUNRPC_BACKCHANNEL
>> +	svc_reg_xprt_class(&svc_rdma_bc_class);
>> +#endif
>> 	return 0;
>>  err1:
>> 	kmem_cache_destroy(svc_rdma_map_cachep);
>> diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c
>> index 3b4c2ff..9b8bccd 100644
>> --- a/net/sunrpc/xprtrdma/svc_rdma_transport.c
>> +++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c
>> @@ -56,6 +56,7 @@
>> 
>> #define RPCDBG_FACILITY	RPCDBG_SVCXPRT
>> 
>> +static struct svcxprt_rdma *rdma_create_xprt(struct svc_serv *, int);
>> static struct svc_xprt *svc_rdma_create(struct svc_serv *serv,
>> 					struct net *net,
>> 					struct sockaddr *sa, int salen,
>> @@ -95,6 +96,64 @@ struct svc_xprt_class svc_rdma_class = {
>> 	.xcl_ident = XPRT_TRANSPORT_RDMA,
>> };
>> 
>> +#if defined(CONFIG_SUNRPC_BACKCHANNEL)
>> +static struct svc_xprt *svc_rdma_bc_create(struct svc_serv *, struct net *,
>> +					   struct sockaddr *, int, int);
>> +static void svc_rdma_bc_detach(struct svc_xprt *);
>> +static void svc_rdma_bc_free(struct svc_xprt *);
>> +
>> +static struct svc_xprt_ops svc_rdma_bc_ops = {
>> +	.xpo_create = svc_rdma_bc_create,
>> +	.xpo_detach = svc_rdma_bc_detach,
>> +	.xpo_free = svc_rdma_bc_free,
>> +	.xpo_prep_reply_hdr = svc_rdma_prep_reply_hdr,
>> +	.xpo_secure_port = svc_rdma_secure_port,
>> +};
>> +
>> +struct svc_xprt_class svc_rdma_bc_class = {
>> +	.xcl_name = "rdma-bc",
>> +	.xcl_owner = THIS_MODULE,
>> +	.xcl_ops = &svc_rdma_bc_ops,
>> +	.xcl_max_payload = (1024 - RPCRDMA_HDRLEN_MIN),
>> +	.xcl_ident = XPRT_TRANSPORT_BC_RDMA,
>> +};
>> +
>> +static struct svc_xprt *svc_rdma_bc_create(struct svc_serv *serv,
>> +					   struct net *net,
>> +					   struct sockaddr *sa, int salen,
>> +					   int flags)
>> +{
>> +	struct svcxprt_rdma *cma_xprt;
>> +	struct svc_xprt *xprt;
>> +
>> +	cma_xprt = rdma_create_xprt(serv, 0);
>> +	if (!cma_xprt)
>> +		return ERR_PTR(-ENOMEM);
>> +	xprt = &cma_xprt->sc_xprt;
>> +
>> +	svc_xprt_init(net, &svc_rdma_bc_class, xprt, serv);
>> +	serv->sv_bc_xprt = xprt;
>> +
>> +	dprintk("svcrdma: %s(%p)\n", __func__, xprt);
>> +	return xprt;
>> +}
>> +
>> +static void svc_rdma_bc_detach(struct svc_xprt *xprt)
>> +{
>> +	dprintk("svcrdma: %s(%p)\n", __func__, xprt);
>> +}
>> +
>> +static void svc_rdma_bc_free(struct svc_xprt *xprt)
>> +{
>> +	struct svcxprt_rdma *rdma =
>> +		container_of(xprt, struct svcxprt_rdma, sc_xprt);
>> +
>> +	dprintk("svcrdma: %s(%p)\n", __func__, xprt);
>> +	if (xprt)
>> +		kfree(rdma);
>> +}
>> +#endif	/* CONFIG_SUNRPC_BACKCHANNEL */
>> +
>> struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *xprt)
>> {
>> 	struct svc_rdma_op_ctxt *ctxt;

--
Chuck Lever
chuck[dot]lever[at]oracle[dot]com