nbd: add tracepoints for send/receive timing
This adds four tracepoints to nbd, enabling separate tracing of payload
and header sending/receipt.
In the send path for headers that have already been sent, we also
explicitly initialize the handle so it can be referenced by the later
tracepoint.
Signed-off-by: Andrew Hall <hall@fb.com>
Signed-off-by: Matt Mullins <mmullins@fb.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 24cc10d..3e6c3d5d 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -513,6 +513,10 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index)
if (sent) {
if (sent >= sizeof(request)) {
skip = sent - sizeof(request);
+
+ /* initialize handle for tracing purposes */
+ handle = nbd_cmd_handle(cmd);
+
goto send_pages;
}
iov_iter_advance(&from, sent);
@@ -536,6 +540,7 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index)
(unsigned long long)blk_rq_pos(req) << 9, blk_rq_bytes(req));
result = sock_xmit(nbd, index, 1, &from,
(type == NBD_CMD_WRITE) ? MSG_MORE : 0, &sent);
+ trace_nbd_header_sent(req, handle);
if (result <= 0) {
if (was_interrupted(result)) {
/* If we havne't sent anything we can just return BUSY,
@@ -608,6 +613,7 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index)
bio = next;
}
out:
+ trace_nbd_payload_sent(req, handle);
nsock->pending = NULL;
nsock->sent = 0;
return 0;
@@ -655,6 +661,7 @@ static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index)
tag, req);
return ERR_PTR(-ENOENT);
}
+ trace_nbd_header_received(req, handle);
cmd = blk_mq_rq_to_pdu(req);
mutex_lock(&cmd->lock);
@@ -708,6 +715,7 @@ static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index)
}
}
out:
+ trace_nbd_payload_received(req, handle);
mutex_unlock(&cmd->lock);
return ret ? ERR_PTR(ret) : cmd;
}