From: Chuck Lever <chuck.lever@oracle.com>
Date: Mon, 16 Oct 2017 15:01:22 -0400
Subject: xprtrdma: Refactor rpcrdma_reply_handler some more
Patch-mainline: v4.15-rc1
Git-commit: e1352c9610e3235f5e1b159038762d0c01c6ef36
References: bsc#1103992 FATE#326009
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 <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
net/sunrpc/xprtrdma/rpc_rdma.c | 105 ++++++++++++++++++++++------------------
net/sunrpc/xprtrdma/xprt_rdma.h | 25 ++++-----
2 files changed, 71 insertions(+), 59 deletions(-)
--- a/net/sunrpc/xprtrdma/rpc_rdma.c
+++ b/net/sunrpc/xprtrdma/rpc_rdma.c
@@ -1211,6 +1211,60 @@ rpcrdma_decode_error(struct rpcrdma_xprt
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
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
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
&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.
--- 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)
- *
- * These are allocated during initialization, per-transport instance.
- *
- * N of these are associated with a transport instance, and stored in
- * struct rpcrdma_buffer. N is the max number of outstanding requests.
+ * struct rpcrdma_rep -- this structure encapsulates state required
+ * to receive and complete an RPC Reply, asychronously. It needs
+ * several pieces of state:
+ *
+ * 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)
+ *
+ * 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 rp
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)