[PATCH v2 06/22] SUNRPC: Add a transport-specific private field in rpc_rqst
From: Chuck Lever <chuck.lever@oracle.com>
Date: 2016-08-23 17:52:53
Also in:
linux-rdma
Subsystem:
kernel nfsd, sunrpc, and lockd servers, networking [general], nfs, sunrpc, and lockd clients, the rest · Maintainers:
Chuck Lever, Jeff Layton, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Trond Myklebust, Anna Schumaker, Linus Torvalds
Currently there's a hidden and indirect mechanism for finding the rpcrdma_req that goes with an rpc_rqst. It depends on getting from the rq_buffer pointer in struct rpc_rqst to the struct rpcrdma_regbuf that controls that buffer, and then to the struct rpcrdma_req it goes with. This was done back in the day to avoid the need to add a per-rqst pointer or to alter the buf_free API when support for RPC-over-RDMA was introduced. I'm about to change the way regbuf's work to support larger inline thresholds. Now is a good time to replace this indirect mechanism with something that is more straightforward. I guess this should be considered a clean up. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> --- include/linux/sunrpc/xprt.h | 1 + net/sunrpc/xprtrdma/backchannel.c | 6 ++---- net/sunrpc/xprtrdma/transport.c | 2 +- net/sunrpc/xprtrdma/verbs.c | 1 - net/sunrpc/xprtrdma/xprt_rdma.h | 13 +++++++------ 5 files changed, 11 insertions(+), 12 deletions(-)
diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index 46f069e..a5da60b 100644
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h@@ -83,6 +83,7 @@ struct rpc_rqst { void (*rq_release_snd_buf)(struct rpc_rqst *); /* release rq_enc_pages */ struct list_head rq_list; + void *rq_xprtdata; /* Per-xprt private data */ void *rq_buffer; /* Call XDR encode buffer */ size_t rq_callsize; void *rq_rbuffer; /* Reply XDR decode buffer */
diff --git a/net/sunrpc/xprtrdma/backchannel.c b/net/sunrpc/xprtrdma/backchannel.c
index d3cfaf2..c4904f8 100644
--- a/net/sunrpc/xprtrdma/backchannel.c
+++ b/net/sunrpc/xprtrdma/backchannel.c@@ -55,11 +55,9 @@ static int rpcrdma_bc_setup_rqst(struct rpcrdma_xprt *r_xprt, rb = rpcrdma_alloc_regbuf(ia, size, GFP_KERNEL); if (IS_ERR(rb)) goto out_fail; - rb->rg_owner = req; req->rl_sendbuf = rb; - /* so that rpcr_to_rdmar works when receiving a request */ - rqst->rq_buffer = (void *)req->rl_sendbuf->rg_base; - xdr_buf_init(&rqst->rq_snd_buf, rqst->rq_buffer, size); + xdr_buf_init(&rqst->rq_snd_buf, rb->rg_base, size); + rpcrdma_set_xprtdata(rqst, req); return 0; out_fail:
diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c
index 136caf3..d83bffa 100644
--- a/net/sunrpc/xprtrdma/transport.c
+++ b/net/sunrpc/xprtrdma/transport.c@@ -523,6 +523,7 @@ xprt_rdma_allocate(struct rpc_task *task) out: dprintk("RPC: %s: size %zd, request 0x%p\n", __func__, size, req); req->rl_connect_cookie = 0; /* our reserved value */ + rpcrdma_set_xprtdata(rqst, req); rqst->rq_buffer = req->rl_sendbuf->rg_base; rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_rcvsize; return 0;
@@ -559,7 +560,6 @@ out_sendbuf: rb = rpcrdma_alloc_regbuf(&r_xprt->rx_ia, size, flags); if (IS_ERR(rb)) goto out_fail; - rb->rg_owner = req; r_xprt->rx_stats.hardway_register_count += size; rpcrdma_free_regbuf(&r_xprt->rx_ia, req->rl_sendbuf);
diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index 536d0be..baf7f43 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c@@ -1191,7 +1191,6 @@ rpcrdma_alloc_regbuf(struct rpcrdma_ia *ia, size_t size, gfp_t flags) iov->length = size; iov->lkey = ia->ri_pd->local_dma_lkey; rb->rg_size = size; - rb->rg_owner = NULL; return rb; out_free:
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index 296d9ab..99b6839 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h@@ -113,7 +113,6 @@ struct rpcrdma_ep { struct rpcrdma_regbuf { size_t rg_size; - struct rpcrdma_req *rg_owner; struct ib_sge rg_iov; __be32 rg_base[0] __attribute__ ((aligned(256))); };
@@ -297,14 +296,16 @@ struct rpcrdma_req { struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS]; }; +static inline void +rpcrdma_set_xprtdata(struct rpc_rqst *rqst, struct rpcrdma_req *req) +{ + rqst->rq_xprtdata = req; +} + static inline struct rpcrdma_req * rpcr_to_rdmar(struct rpc_rqst *rqst) { - void *buffer = rqst->rq_buffer; - struct rpcrdma_regbuf *rb; - - rb = container_of(buffer, struct rpcrdma_regbuf, rg_base); - return rb->rg_owner; + return rqst->rq_xprtdata; } /*