From: Darrick J. Wong <djwong@xxxxxxxxxx>
The fuse_request_{send,end} tracepoints capture the value of
req->in.h.unique in the trace output. It would be really nice if we
could use this to match a request to its response for debugging and
latency analysis, but the call to trace_fuse_request_send occurs before
the unique id has been set:
fuse_request_send: connection 8388608 req 0 opcode 1 (FUSE_LOOKUP) len 107
fuse_request_end: connection 8388608 req 6 len 16 error -2
Move the callsites to trace_fuse_request_send to after the unique id has
been set, or right before we decide to cancel a request having not set
one.
Signed-off-by: "Darrick J. Wong" <djwong@xxxxxxxxxx>
---
fs/fuse/dev.c | 6 +++++-
fs/fuse/dev_uring.c | 8 +++++++-
2 files changed, 12 insertions(+), 2 deletions(-)
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 5387e4239d6aa6..8dd74cbfbcc6fc 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -376,10 +376,15 @@ static void fuse_dev_queue_req(struct fuse_iqueue *fiq, struct fuse_req *req)
if (fiq->connected) {
if (req->in.h.opcode != FUSE_NOTIFY_REPLY)
req->in.h.unique = fuse_get_unique_locked(fiq);
+
+ /* tracepoint captures in.h.unique */
+ trace_fuse_request_send(req);
+
list_add_tail(&req->list, &fiq->pending);
fuse_dev_wake_and_unlock(fiq);
} else {
spin_unlock(&fiq->lock);
+ trace_fuse_request_send(req);
req->out.h.error = -ENOTCONN;
clear_bit(FR_PENDING, &req->flags);
fuse_request_end(req);
@@ -398,7 +403,6 @@ static void fuse_send_one(struct fuse_iqueue *fiq, struct fuse_req *req)
req->in.h.len = sizeof(struct fuse_in_header) +
fuse_len_args(req->args->in_numargs,
(struct fuse_arg *) req->args->in_args);
- trace_fuse_request_send(req);
fiq->ops->send_req(fiq, req);
}
diff --git a/fs/fuse/dev_uring.c b/fs/fuse/dev_uring.c
index 249b210becb1cc..14f263d4419392 100644
--- a/fs/fuse/dev_uring.c
+++ b/fs/fuse/dev_uring.c
@@ -7,6 +7,7 @@
#include "fuse_i.h"
#include "dev_uring_i.h"
#include "fuse_dev_i.h"
+#include "fuse_trace.h"
#include <linux/fs.h>
#include <linux/io_uring/cmd.h>
@@ -1265,12 +1266,17 @@ void fuse_uring_queue_fuse_req(struct fuse_iqueue *fiq, struct fuse_req *req)
err = -EINVAL;
queue = fuse_uring_task_to_queue(ring);
- if (!queue)
+ if (!queue) {
+ trace_fuse_request_send(req);
goto err;
+ }
if (req->in.h.opcode != FUSE_NOTIFY_REPLY)
req->in.h.unique = fuse_get_unique(fiq);
+ /* tracepoint captures in.h.unique */
+ trace_fuse_request_send(req);
+
spin_lock(&queue->lock);
err = -ENOTCONN;
if (unlikely(queue->stopped))
