Commit 9908c309 authored by Li Zefan's avatar Li Zefan Committed by Ingo Molnar
Browse files

blktrace: support per-partition tracing for ftrace plugin 



The previous patch adds support to trace a single partition for
relay+ioctl blktrace, and this patch is for ftrace plugin blktrace:

  # echo 1 > /sys/block/sda/sda7/enable
  # cat start_lba
  102398373
  # cat end_lba
  102703545

Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
Acked-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Shawn Du <duyuyang@gmail.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
LKML-Reference: <49E42646.4060608@cn.fujitsu.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent d0deef5b

kernel/trace/blktrace.c

+25 −14
Original line number Diff line number Diff line
@@ -403,6 +403,23 @@ static struct rchan_callbacks blk_relay_callbacks = { 
	.remove_buf_file	= blk_remove_buf_file_callback,

};



static void blk_trace_setup_lba(struct blk_trace *bt,

				struct block_device *bdev)

{

	struct hd_struct *part = NULL;



	if (bdev)

		part = bdev->bd_part;



	if (part) {

		bt->start_lba = part->start_sect;

		bt->end_lba = part->start_sect + part->nr_sects;

	} else {

		bt->start_lba = 0;

		bt->end_lba = -1ULL;

	}

}



/*

 * Setup everything required to start tracing

 */
@@ -413,7 +430,6 @@ int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, 
	struct blk_trace *old_bt, *bt = NULL;

	struct dentry *dir = NULL;

	int ret, i;

	struct hd_struct *part = NULL;



	if (!buts->buf_size || !buts->buf_nr)

		return -EINVAL;
@@ -482,14 +498,7 @@ int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, 
	if (!bt->act_mask)

		bt->act_mask = (u16) -1;



	if (bdev)

		part = bdev->bd_part;



	if (part) {

		bt->start_lba = part->start_sect;

		bt->end_lba = part->start_sect + part->nr_sects;

	} else

		bt->end_lba = -1ULL;

	blk_trace_setup_lba(bt, bdev);



	/* overwrite with user settings */

	if (buts->start_lba)
@@ -1370,7 +1379,8 @@ static int blk_trace_remove_queue(struct request_queue *q) 
/*

 * Setup everything required to start tracing

 */

static int blk_trace_setup_queue(struct request_queue *q, dev_t dev)

static int blk_trace_setup_queue(struct request_queue *q,

				 struct block_device *bdev)

{

	struct blk_trace *old_bt, *bt = NULL;

	int ret = -ENOMEM;
@@ -1383,9 +1393,10 @@ static int blk_trace_setup_queue(struct request_queue *q, dev_t dev) 
	if (!bt->msg_data)

		goto free_bt;



	bt->dev = dev;

	bt->dev = bdev->bd_dev;

	bt->act_mask = (u16)-1;

	bt->end_lba = -1ULL;



	blk_trace_setup_lba(bt, bdev);



	old_bt = xchg(&q->blk_trace, bt);

	if (old_bt != NULL) {
@@ -1602,7 +1613,7 @@ static ssize_t sysfs_blk_trace_attr_store(struct device *dev, 


	if (attr == &dev_attr_enable) {

		if (value)

			ret = blk_trace_setup_queue(q, bdev->bd_dev);

			ret = blk_trace_setup_queue(q, bdev);

		else

			ret = blk_trace_remove_queue(q);

		goto out_unlock_bdev;
@@ -1610,7 +1621,7 @@ static ssize_t sysfs_blk_trace_attr_store(struct device *dev, 


	ret = 0;

	if (q->blk_trace == NULL)

		ret = blk_trace_setup_queue(q, bdev->bd_dev);

		ret = blk_trace_setup_queue(q, bdev);



	if (ret == 0) {

		if (attr == &dev_attr_act_mask)

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