It's not safe to use resources pointed to by the @send_wr of
ib_post_send() _after_ that function returns. Those resources are
typically freed by the Send completion handler, which can run before
ib_post_send() returns.
Thus the trace points currently around ib_post_send() in the
client's RPC/RDMA transport are a hazard, even when they are
disabled. Rearrange them so that they touch the Work Request only
_before_ ib_post_send() is invoked.
Fixes: ab03eff58eb5 ("xprtrdma: Add trace points in RPC Call transmit paths")
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
include/trace/events/rpcrdma.h | 12 ++++--------
net/sunrpc/xprtrdma/verbs.c | 2 +-
2 files changed, 5 insertions(+), 9 deletions(-)
diff --git a/include/trace/events/rpcrdma.h b/include/trace/events/rpcrdma.h
index 051f26fedc4d..72f043876019 100644
--- a/include/trace/events/rpcrdma.h
+++ b/include/trace/events/rpcrdma.h
@@ -692,11 +692,10 @@
TRACE_EVENT(xprtrdma_post_send,
TP_PROTO(
- const struct rpcrdma_req *req,
- int status
+ const struct rpcrdma_req *req
),
- TP_ARGS(req, status),
+ TP_ARGS(req),
TP_STRUCT__entry(
__field(const void *, req)
@@ -705,7 +704,6 @@
__field(unsigned int, client_id)
__field(int, num_sge)
__field(int, signaled)
- __field(int, status)
),
TP_fast_assign(
@@ -718,15 +716,13 @@
__entry->sc = req->rl_sendctx;
__entry->num_sge = req->rl_wr.num_sge;
__entry->signaled = req->rl_wr.send_flags & IB_SEND_SIGNALED;
- __entry->status = status;
),
- TP_printk("task:%u@%u req=%p sc=%p (%d SGE%s) %sstatus=%d",
+ TP_printk("task:%u@%u req=%p sc=%p (%d SGE%s) %s",
__entry->task_id, __entry->client_id,
__entry->req, __entry->sc, __entry->num_sge,
(__entry->num_sge == 1 ? "" : "s"),
- (__entry->signaled ? "signaled " : ""),
- __entry->status
+ (__entry->signaled ? "signaled" : "")
)
);
diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index 29ae982d69cf..05c4d3a9cda2 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -1356,8 +1356,8 @@ int rpcrdma_post_sends(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req)
--ep->re_send_count;
}
+ trace_xprtrdma_post_send(req);
rc = frwr_send(r_xprt, req);
- trace_xprtrdma_post_send(req, rc);
if (rc)
return -ENOTCONN;
return 0;
