From 9908c30997b8a73c95f836170b9998dae9aa3f4a Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Tue, 14 Apr 2009 13:59:34 +0800 Subject: [PATCH] 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: Li Zefan Acked-by: "Theodore Ts'o" Cc: Arnaldo Carvalho de Melo Cc: Shawn Du Cc: Jens Axboe LKML-Reference: <49E42646.4060608@cn.fujitsu.com> Signed-off-by: Ingo Molnar --- kernel/trace/blktrace.c | 39 +++++++++++++++++++++++++-------------- 1 file changed, 25 insertions(+), 14 deletions(-) diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index e932654cf590..d10989880520 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -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) -- 2.34.1