From e1352c9610e3235f5e1b159038762d0c01c6ef36 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Mon, 16 Oct 2017 15:01:22 -0400 Subject: [PATCH] xprtrdma: Refactor rpcrdma_reply_handler some more Clean up: I'd like to be able to invoke the tail of rpcrdma_reply_handler in two different places. Split the tail out into its own helper function. Signed-off-by: Chuck Lever Signed-off-by: Anna Schumaker --- net/sunrpc/xprtrdma/rpc_rdma.c | 105 ++++++++++++++++++-------------- net/sunrpc/xprtrdma/xprt_rdma.h | 21 ++++--- 2 files changed, 69 insertions(+), 57 deletions(-) diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c index e355cd322a32..418bcc6b3e1d 100644 --- a/net/sunrpc/xprtrdma/rpc_rdma.c +++ b/net/sunrpc/xprtrdma/rpc_rdma.c @@ -1211,6 +1211,60 @@ rpcrdma_decode_error(struct rpcrdma_xprt *r_xprt, struct rpcrdma_rep *rep, return -EREMOTEIO; } +/* Perform XID lookup, reconstruction of the RPC reply, and + * RPC completion while holding the transport lock to ensure + * the rep, rqst, and rq_task pointers remain stable. + */ +void rpcrdma_complete_rqst(struct rpcrdma_rep *rep) +{ + struct rpcrdma_xprt *r_xprt = rep->rr_rxprt; + struct rpc_xprt *xprt = &r_xprt->rx_xprt; + struct rpc_rqst *rqst = rep->rr_rqst; + unsigned long cwnd; + int status; + + xprt->reestablish_timeout = 0; + + switch (rep->rr_proc) { + case rdma_msg: + status = rpcrdma_decode_msg(r_xprt, rep, rqst); + break; + case rdma_nomsg: + status = rpcrdma_decode_nomsg(r_xprt, rep); + break; + case rdma_error: + status = rpcrdma_decode_error(r_xprt, rep, rqst); + break; + default: + status = -EIO; + } + if (status < 0) + goto out_badheader; + +out: + spin_lock(&xprt->recv_lock); + cwnd = xprt->cwnd; + xprt->cwnd = atomic_read(&r_xprt->rx_buf.rb_credits) << RPC_CWNDSHIFT; + if (xprt->cwnd > cwnd) + xprt_release_rqst_cong(rqst->rq_task); + + xprt_complete_rqst(rqst->rq_task, status); + xprt_unpin_rqst(rqst); + spin_unlock(&xprt->recv_lock); + return; + +/* If the incoming reply terminated a pending RPC, the next + * RPC call will post a replacement receive buffer as it is + * being marshaled. + */ +out_badheader: + dprintk("RPC: %5u %s: invalid rpcrdma reply (type %u)\n", + rqst->rq_task->tk_pid, __func__, be32_to_cpu(rep->rr_proc)); + r_xprt->rx_stats.bad_reply_count++; + status = -EIO; + goto out; +} + /* Process received RPC/RDMA messages. * * Errors must result in the RPC task either being awakened, or @@ -1225,8 +1279,6 @@ rpcrdma_reply_handler(struct work_struct *work) struct rpc_xprt *xprt = &r_xprt->rx_xprt; struct rpcrdma_req *req; struct rpc_rqst *rqst; - unsigned long cwnd; - int status; __be32 *p; dprintk("RPC: %s: incoming rep %p\n", __func__, rep); @@ -1263,6 +1315,7 @@ rpcrdma_reply_handler(struct work_struct *work) spin_unlock(&xprt->recv_lock); req = rpcr_to_rdmar(rqst); req->rl_reply = rep; + rep->rr_rqst = rqst; dprintk("RPC: %s: reply %p completes request %p (xid 0x%08x)\n", __func__, rep, req, be32_to_cpu(rep->rr_xid)); @@ -1280,36 +1333,7 @@ rpcrdma_reply_handler(struct work_struct *work) &req->rl_registered); } - xprt->reestablish_timeout = 0; - - switch (rep->rr_proc) { - case rdma_msg: - status = rpcrdma_decode_msg(r_xprt, rep, rqst); - break; - case rdma_nomsg: - status = rpcrdma_decode_nomsg(r_xprt, rep); - break; - case rdma_error: - status = rpcrdma_decode_error(r_xprt, rep, rqst); - break; - default: - status = -EIO; - } - if (status < 0) - goto out_badheader; - -out: - spin_lock(&xprt->recv_lock); - cwnd = xprt->cwnd; - xprt->cwnd = atomic_read(&r_xprt->rx_buf.rb_credits) << RPC_CWNDSHIFT; - if (xprt->cwnd > cwnd) - xprt_release_rqst_cong(rqst->rq_task); - - xprt_complete_rqst(rqst->rq_task, status); - xprt_unpin_rqst(rqst); - spin_unlock(&xprt->recv_lock); - dprintk("RPC: %s: xprt_complete_rqst(0x%p, 0x%p, %d)\n", - __func__, xprt, rqst, status); + rpcrdma_complete_rqst(rep); return; out_badstatus: @@ -1325,20 +1349,8 @@ out_badversion: __func__, be32_to_cpu(rep->rr_vers)); goto repost; -/* If the incoming reply terminated a pending RPC, the next - * RPC call will post a replacement receive buffer as it is - * being marshaled. - */ -out_badheader: - dprintk("RPC: %5u %s: invalid rpcrdma reply (type %u)\n", - rqst->rq_task->tk_pid, __func__, be32_to_cpu(rep->rr_proc)); - r_xprt->rx_stats.bad_reply_count++; - status = -EIO; - goto out; - -/* The req was still available, but by the time the recv_lock - * was acquired, the rqst and task had been released. Thus the RPC - * has already been terminated. +/* The RPC transaction has already been terminated, or the header + * is corrupt. */ out_norqst: spin_unlock(&xprt->recv_lock); @@ -1348,7 +1360,6 @@ out_norqst: out_shortreply: dprintk("RPC: %s: short/invalid reply\n", __func__); - goto repost; /* If no pending RPC transaction was matched, post a replacement * receive buffer before returning. diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h index 858b4c52047d..d68a1351d95e 100644 --- a/net/sunrpc/xprtrdma/xprt_rdma.h +++ b/net/sunrpc/xprtrdma/xprt_rdma.h @@ -202,18 +202,17 @@ enum { }; /* - * struct rpcrdma_rep -- this structure encapsulates state required to recv - * and complete a reply, asychronously. It needs several pieces of - * state: - * o recv buffer (posted to provider) - * o ib_sge (also donated to provider) - * o status of reply (length, success or not) - * o bookkeeping state to get run by reply handler (list, etc) + * struct rpcrdma_rep -- this structure encapsulates state required + * to receive and complete an RPC Reply, asychronously. It needs + * several pieces of state: * - * These are allocated during initialization, per-transport instance. + * o receive buffer and ib_sge (donated to provider) + * o status of receive (success or not, length, inv rkey) + * o bookkeeping state to get run by reply handler (XDR stream) * - * N of these are associated with a transport instance, and stored in - * struct rpcrdma_buffer. N is the max number of outstanding requests. + * These structures are allocated during transport initialization. + * N of these are associated with a transport instance, managed by + * struct rpcrdma_buffer. N is the max number of outstanding RPCs. */ struct rpcrdma_rep { @@ -228,6 +227,7 @@ struct rpcrdma_rep { struct work_struct rr_work; struct xdr_buf rr_hdrbuf; struct xdr_stream rr_stream; + struct rpc_rqst *rr_rqst; struct list_head rr_list; struct ib_recv_wr rr_recv_wr; }; @@ -616,6 +616,7 @@ bool rpcrdma_prepare_send_sges(struct rpcrdma_ia *, struct rpcrdma_req *, void rpcrdma_unmap_sges(struct rpcrdma_ia *, struct rpcrdma_req *); int rpcrdma_marshal_req(struct rpcrdma_xprt *r_xprt, struct rpc_rqst *rqst); void rpcrdma_set_max_header_sizes(struct rpcrdma_xprt *); +void rpcrdma_complete_rqst(struct rpcrdma_rep *rep); void rpcrdma_reply_handler(struct work_struct *work); static inline void rpcrdma_set_xdrlen(struct xdr_buf *xdr, size_t len)