Commit 472eca53 authored by Johannes Thumshirn's avatar Johannes Thumshirn Committed by Jens Axboe
Browse files

blktrace: factor out recording a blktrace event 



Factor out the recording of a blktrace event into its own function,
deduplicating the code.

This also enables recording different versions of the blktrace protocol
later on.

Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDamien Le Moal <dlemoal@kernel.org>
Reviewed-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent a65988a0

kernel/trace/blktrace.c

+49 −40
Original line number Diff line number Diff line
@@ -63,6 +63,34 @@ static int blk_probes_ref; 
static void blk_register_tracepoints(void);

static void blk_unregister_tracepoints(void);



static void record_blktrace_event(struct blk_io_trace *t, pid_t pid, int cpu,

				  sector_t sector, int bytes, u32 what,

				  dev_t dev, int error, u64 cgid,

				  ssize_t cgid_len, void *pdu_data, int pdu_len)



{

	/*

	 * These two are not needed in ftrace as they are in the

	 * generic trace_entry, filled by tracing_generic_entry_update,

	 * but for the trace_event->bin() synthesizer benefit we do it

	 * here too.

	 */

	t->cpu = cpu;

	t->pid = pid;



	t->sector = sector;

	t->bytes = bytes;

	t->action = what;

	t->device = dev;

	t->error = error;

	t->pdu_len = pdu_len + cgid_len;



	if (cgid_len)

		memcpy((void *)t + sizeof(*t), &cgid, cgid_len);

	if (pdu_len)

		memcpy((void *)t + sizeof(*t) + cgid_len, pdu_data, pdu_len);

}



/*

 * Send out a notify message.

 */
@@ -87,7 +115,12 @@ static void trace_note(struct blk_trace *bt, pid_t pid, int action, 
		if (!event)

			return;

		t = ring_buffer_event_data(event);

		goto record_it;

		record_blktrace_event(t, pid, cpu, 0, 0,

				      action | (cgid ? __BLK_TN_CGROUP : 0),

				      bt->dev, 0, cgid, cgid_len, (void *)data,

				      len);

		trace_buffer_unlock_commit(blk_tr, buffer, event, trace_ctx);

		return;

	}



	if (!bt->rchan)
@@ -97,18 +130,11 @@ static void trace_note(struct blk_trace *bt, pid_t pid, int action, 
	if (t) {

		t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;

		t->time = ktime_to_ns(ktime_get());

record_it:

		t->device = bt->dev;

		t->action = action | (cgid ? __BLK_TN_CGROUP : 0);

		t->pid = pid;

		t->cpu = cpu;

		t->pdu_len = len + cgid_len;

		if (cgid_len)

			memcpy((void *)t + sizeof(*t), &cgid, cgid_len);

		memcpy((void *) t + sizeof(*t) + cgid_len, data, len);



		if (blk_tracer)

			trace_buffer_unlock_commit(blk_tr, buffer, event, trace_ctx);

		record_blktrace_event(t, pid, cpu, 0, 0,

				      action | (cgid ? __BLK_TN_CGROUP : 0),

				      bt->dev, 0, cgid, cgid_len, (void *)data,

				      len);

	}

}
@@ -263,7 +289,12 @@ static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes, 
		if (!event)

			return;

		t = ring_buffer_event_data(event);

		goto record_it;



		record_blktrace_event(t, pid, cpu, sector, bytes, what, bt->dev,

				      error, cgid, cgid_len, pdu_data, pdu_len);



		trace_buffer_unlock_commit(blk_tr, buffer, event, trace_ctx);

		return;

	}



	if (unlikely(tsk->btrace_seq != blktrace_seq))
@@ -282,32 +313,10 @@ static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes, 
		t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;

		t->sequence = ++(*sequence);

		t->time = ktime_to_ns(ktime_get());

record_it:

		/*

		 * These two are not needed in ftrace as they are in the

		 * generic trace_entry, filled by tracing_generic_entry_update,

		 * but for the trace_event->bin() synthesizer benefit we do it

		 * here too.

		 */

		t->cpu = cpu;

		t->pid = pid;



		t->sector = sector;

		t->bytes = bytes;

		t->action = what;

		t->device = bt->dev;

		t->error = error;

		t->pdu_len = pdu_len + cgid_len;



		if (cgid_len)

			memcpy((void *)t + sizeof(*t), &cgid, cgid_len);

		if (pdu_len)

			memcpy((void *)t + sizeof(*t) + cgid_len, pdu_data, pdu_len);



		if (blk_tracer) {

			trace_buffer_unlock_commit(blk_tr, buffer, event, trace_ctx);

			return;

		}

		record_blktrace_event(t, pid, cpu, sector, bytes, what,

				      bt->dev, error, cgid, cgid_len,

				      pdu_data, pdu_len);

	}



	local_irq_restore(flags);