Messages in this thread Patch in this message | | | Date | Mon, 13 Apr 2009 18:51:29 +0800 | From | Li Zefan <> | Subject | [PATCH] blktrace: move trace/ dir to /sys/block/sda/ |
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Impact: allow ftrace-plugin blktrace to trace device-mapper devices
blktrace can't trace a single partition, so it makes no sense to have one trace/ dir in each /sys/block/sda/sdaX. Move it to /sys/block/sda/.
Thus we 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> --- block/blk-sysfs.c | 7 ++++++- fs/partitions/check.c | 3 --- include/linux/blktrace_api.h | 7 ++++++- kernel/trace/blktrace.c | 7 ++++++- 4 files changed, 18 insertions(+), 6 deletions(-)
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 73f36be..8653d71 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; diff --git a/fs/partitions/check.c b/fs/partitions/check.c index 99e33ef..445fd2f 100644 --- a/fs/partitions/check.c +++ b/fs/partitions/check.c @@ -295,9 +295,6 @@ static struct attribute_group part_attr_group = { static struct attribute_group *part_attr_groups[] = { &part_attr_group, -#ifdef CONFIG_BLK_DEV_IO_TRACE - &blk_trace_attr_group, -#endif NULL }; diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h index d960889..518e32a 100644 --- a/include/linux/blktrace_api.h +++ b/include/linux/blktrace_api.h @@ -197,7 +197,7 @@ extern int blk_trace_setup(struct request_queue *q, char *name, dev_t dev, extern int blk_trace_startstop(struct request_queue *q, int start); extern int blk_trace_remove(struct request_queue *q); -extern struct attribute_group blk_trace_attr_group; +extern int blk_trace_init_sysfs(struct device *dev); #else /* !CONFIG_BLK_DEV_IO_TRACE */ #define blk_trace_ioctl(bdev, cmd, arg) (-ENOTTY) @@ -209,6 +209,11 @@ extern struct attribute_group blk_trace_attr_group; #define blk_trace_remove(q) (-ENOTTY) #define blk_add_trace_msg(q, fmt, ...) do { } while (0) +static inline int blk_trace_init_sysfs(struct device *dev) +{ + return 0; +} + #endif /* CONFIG_BLK_DEV_IO_TRACE */ #endif /* __KERNEL__ */ #endif diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index 2b98195..9bae35f 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -1420,7 +1420,7 @@ static struct attribute *blk_trace_attrs[] = { NULL }; -struct attribute_group blk_trace_attr_group = { +static struct attribute_group blk_trace_attr_group = { .name = "trace", .attrs = blk_trace_attrs, }; @@ -1620,3 +1620,8 @@ out: return ret ? ret : count; } +int blk_trace_init_sysfs(struct device *dev) +{ + return sysfs_create_group(&dev->kobj, &blk_trace_attr_group); +} + -- 1.5.4.rc3
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