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authorLi Zefan <lizf@cn.fujitsu.com>2009-04-14 14:00:05 +0800
committerIngo Molnar <mingo@elte.hu>2009-04-16 10:10:59 +0200
commit1d54ad6da9192fed5dd3b60224d9f2dfea0dcd82 (patch)
treefd5917f144ec820b933795bedd7eddea96bee374 /block/blk-sysfs.c
parent9908c30997b8a73c95f836170b9998dae9aa3f4a (diff)
downloadlwn-1d54ad6da9192fed5dd3b60224d9f2dfea0dcd82.tar.gz
lwn-1d54ad6da9192fed5dd3b60224d9f2dfea0dcd82.zip
blktrace: add trace/ to /sys/block/sda
Impact: allow ftrace-plugin blktrace to trace device-mapper devices To trace a single partition: # echo 1 > /sys/block/sda/sda1/enable To trace the whole sda instead: # echo 1 > /sys/block/sda/enable Thus we also fix an issue reported by Ted, that ftrace-plugin blktrace can't be used to trace device-mapper devices. Now: # echo 1 > /sys/block/dm-0/trace/enable echo: write error: No such device or address # mount -t ext4 /dev/dm-0 /mnt # echo 1 > /sys/block/dm-0/trace/enable # echo blk > /debug/tracing/current_tracer Reported-by: Theodore Tso <tytso@mit.edu> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: "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: <49E42665.6020506@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'block/blk-sysfs.c')
-rw-r--r--block/blk-sysfs.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 73f36beff5cd..8653d710b39e 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -387,16 +387,21 @@ struct kobj_type blk_queue_ktype = {
int blk_register_queue(struct gendisk *disk)
{
int ret;
+ struct device *dev = disk_to_dev(disk);
struct request_queue *q = disk->queue;
if (WARN_ON(!q))
return -ENXIO;
+ ret = blk_trace_init_sysfs(dev);
+ if (ret)
+ return ret;
+
if (!q->request_fn)
return 0;
- ret = kobject_add(&q->kobj, kobject_get(&disk_to_dev(disk)->kobj),
+ ret = kobject_add(&q->kobj, kobject_get(&dev->kobj),
"%s", "queue");
if (ret < 0)
return ret;