Commit ea106722 authored by Matt Mullins's avatar Matt Mullins Committed by Alexei Starovoitov
Browse files

nbd: trace sending nbd requests 



This adds a tracepoint that can both observe the nbd request being sent
to the server, as well as modify that request , e.g., setting a flag in
the request that will cause the server to collect detailed tracing data.

The struct request * being handled is included to permit correlation
with the block tracepoints.

Signed-off-by: default avatarMatt Mullins <mmullins@fb.com>
Reviewed-by: default avatarJosef Bacik <josef@toxicpanda.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 9df1c28b

MAINTAINERS

+1 −0
Original line number Diff line number Diff line
@@ -10741,6 +10741,7 @@ L: linux-block@vger.kernel.org 
L:	nbd@other.debian.org

F:	Documentation/blockdev/nbd.txt

F:	drivers/block/nbd.c

F:	include/trace/events/nbd.h

F:	include/uapi/linux/nbd.h



NETWORK DROP MONITOR

drivers/block/nbd.c

+5 −0
Original line number Diff line number Diff line
@@ -44,6 +44,9 @@ 
#include <linux/nbd-netlink.h>

#include <net/genetlink.h>



#define CREATE_TRACE_POINTS

#include <trace/events/nbd.h>



static DEFINE_IDR(nbd_index_idr);

static DEFINE_MUTEX(nbd_index_mutex);

static int nbd_total_devices = 0;
@@ -526,6 +529,8 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index) 
	handle = nbd_cmd_handle(cmd);

	memcpy(request.handle, &handle, sizeof(handle));



	trace_nbd_send_request(&request, nbd->index, blk_mq_rq_from_pdu(cmd));



	dev_dbg(nbd_to_dev(nbd), "request %p: sending control (%s@%llu,%uB)\n",

		req, nbdcmd_to_ascii(type),

		(unsigned long long)blk_rq_pos(req) << 9, blk_rq_bytes(req));

include/trace/events/nbd.h

0 → 100644
+56 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

#undef TRACE_SYSTEM

#define TRACE_SYSTEM nbd



#if !defined(_TRACE_NBD_H) || defined(TRACE_HEADER_MULTI_READ)

#define _TRACE_NBD_H



#include <linux/tracepoint.h>



DECLARE_EVENT_CLASS(nbd_send_request,



	TP_PROTO(struct nbd_request *nbd_request, int index,

		 struct request *rq),



	TP_ARGS(nbd_request, index, rq),



	TP_STRUCT__entry(

		__field(struct nbd_request *, nbd_request)

		__field(u64, dev_index)

		__field(struct request *, request)

	),



	TP_fast_assign(

		__entry->nbd_request = 0;

		__entry->dev_index = index;

		__entry->request = rq;

	),



	TP_printk("nbd%lld: request %p", __entry->dev_index, __entry->request)

);



#ifdef DEFINE_EVENT_WRITABLE

#undef NBD_DEFINE_EVENT

#define NBD_DEFINE_EVENT(template, call, proto, args, size)		\

	DEFINE_EVENT_WRITABLE(template, call, PARAMS(proto),		\

			      PARAMS(args), size)

#else

#undef NBD_DEFINE_EVENT

#define NBD_DEFINE_EVENT(template, call, proto, args, size)		\

	DEFINE_EVENT(template, call, PARAMS(proto), PARAMS(args))

#endif



NBD_DEFINE_EVENT(nbd_send_request, nbd_send_request,



	TP_PROTO(struct nbd_request *nbd_request, int index,

		 struct request *rq),



	TP_ARGS(nbd_request, index, rq),



	sizeof(struct nbd_request)

);



#endif



/* This part must be outside protection */

#include <trace/define_trace.h>

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