Subject: [PATCH] Add missing blk_trace_remove_sysfs to be in pair with
blk_trace_init_sysfs
From: Zdenek Kabelac <[email protected]>
Adds missing blk_trace_remove_sysfs() to be in pair with
blk_trace_init_sysfs() introduced in commit
1d54ad6da9192fed5dd3b60224d9f2dfea0dcd82.
Problem was noticed via kmemleak backtrace when some sysfs entries
were note properly destroyed during device removal:
unreferenced object 0xffff88001aa76640 (size 80):
comm "lvcreate", pid 2120, jiffies 4294885144
hex dump (first 32 bytes):
01 00 00 00 00 00 00 00 f0 65 a7 1a 00 88 ff ff .........e......
90 66 a7 1a 00 88 ff ff 86 1d 53 81 ff ff ff ff .f........S.....
backtrace:
[<ffffffff813f9cc6>] kmemleak_alloc+0x26/0x60
[<ffffffff8111d693>] kmem_cache_alloc+0x133/0x1c0
[<ffffffff81195891>] sysfs_new_dirent+0x41/0x120
[<ffffffff81194b0c>] sysfs_add_file_mode+0x3c/0xb0
[<ffffffff81197c81>] internal_create_group+0xc1/0x1a0
[<ffffffff81197d93>] sysfs_create_group+0x13/0x20
[<ffffffff810d8004>] blk_trace_init_sysfs+0x14/0x20
[<ffffffff8123f45c>] blk_register_queue+0x3c/0xf0
[<ffffffff812447e4>] add_disk+0x94/0x160
[<ffffffffa00d8b08>] dm_create+0x598/0x6e0 [dm_mod]
[<ffffffffa00de951>] dev_create+0x51/0x350 [dm_mod]
[<ffffffffa00de823>] ctl_ioctl+0x1a3/0x240 [dm_mod]
[<ffffffffa00de8f2>] dm_compat_ctl_ioctl+0x12/0x20 [dm_mod]
[<ffffffff81177bfd>] compat_sys_ioctl+0xcd/0x4f0
[<ffffffff81036ed8>] sysenter_dispatch+0x7/0x2c
[<ffffffffffffffff>] 0xffffffffffffffff
Signed-off-by: Zdenek Kabelac <[email protected]>
---
block/blk-sysfs.c | 2 ++
include/linux/blktrace_api.h | 2 ++
kernel/trace/blktrace.c | 5 +++++
3 files changed, 9 insertions(+), 0 deletions(-)
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index d3aa2aa..130b10c 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -447,6 +447,7 @@ int blk_register_queue(struct gendisk *disk)
if (ret) {
kobject_uevent(&q->kobj, KOBJ_REMOVE);
kobject_del(&q->kobj);
+ blk_trace_remove_sysfs(disk_to_dev(disk));
return ret;
}
@@ -465,6 +466,7 @@ void blk_unregister_queue(struct gendisk *disk)
kobject_uevent(&q->kobj, KOBJ_REMOVE);
kobject_del(&q->kobj);
+ blk_trace_remove_sysfs(disk_to_dev(disk));
kobject_put(&disk_to_dev(disk)->kobj);
}
}
diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h
index 7e4350e..622939a 100644
--- a/include/linux/blktrace_api.h
+++ b/include/linux/blktrace_api.h
@@ -198,6 +198,7 @@ extern int blk_trace_setup(struct request_queue
*q, char *name, dev_t dev,
char __user *arg);
extern int blk_trace_startstop(struct request_queue *q, int start);
extern int blk_trace_remove(struct request_queue *q);
+extern void blk_trace_remove_sysfs(struct device *dev);
extern int blk_trace_init_sysfs(struct device *dev);
extern struct attribute_group blk_trace_attr_group;
@@ -211,6 +212,7 @@ extern struct attribute_group blk_trace_attr_group;
# define blk_trace_startstop(q, start) (-ENOTTY)
# define blk_trace_remove(q) (-ENOTTY)
# define blk_add_trace_msg(q, fmt, ...) do { } while (0)
+# define blk_trace_remove_sysfs(struct device *dev) do { } while (0)
static inline int blk_trace_init_sysfs(struct device *dev)
{
return 0;
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 7a34cb5..b5b8e35 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -1653,6 +1653,11 @@ int blk_trace_init_sysfs(struct device *dev)
return sysfs_create_group(&dev->kobj, &blk_trace_attr_group);
}
+void blk_trace_remove_sysfs(struct device *dev)
+{
+ sysfs_remove_group(&dev->kobj, &blk_trace_attr_group);
+}
+
#endif /* CONFIG_BLK_DEV_IO_TRACE */
#ifdef CONFIG_EVENT_TRACING
--
1.6.4.4
Zdenek Kabelac wrote:
> Subject: [PATCH] Add missing blk_trace_remove_sysfs to be in pair with
> blk_trace_init_sysfs
> From: Zdenek Kabelac <[email protected]>
>
> Adds missing blk_trace_remove_sysfs() to be in pair with
> blk_trace_init_sysfs() introduced in commit
> 1d54ad6da9192fed5dd3b60224d9f2dfea0dcd82.
>
> Problem was noticed via kmemleak backtrace when some sysfs entries
> were note properly destroyed during device removal:
>
Thanks for reporting and fixing this!
> @@ -465,6 +466,7 @@ void blk_unregister_queue(struct gendisk *disk)
>
> kobject_uevent(&q->kobj, KOBJ_REMOVE);
> kobject_del(&q->kobj);
> + blk_trace_remove_sysfs(disk_to_dev(disk));
This should be moved outside of 'if'.
> kobject_put(&disk_to_dev(disk)->kobj);
> }
> }
2009/9/22 Li Zefan <[email protected]>:
> Zdenek Kabelac wrote:
>> Subject: [PATCH] Add missing blk_trace_remove_sysfs to be in pair with
>> blk_trace_init_sysfs
>> From: Zdenek Kabelac <[email protected]>
>>
>> Adds missing blk_trace_remove_sysfs() to be in pair with
>> blk_trace_init_sysfs() introduced in commit
>> 1d54ad6da9192fed5dd3b60224d9f2dfea0dcd82.
>>
>> Problem was noticed via kmemleak backtrace when some sysfs entries
>> were note properly destroyed during ?device removal:
>>
>
> Thanks for reporting and fixing this!
>
>> @@ -465,6 +466,7 @@ void blk_unregister_queue(struct gendisk *disk)
>>
>> ? ? ? ? ? ? ? kobject_uevent(&q->kobj, KOBJ_REMOVE);
>> ? ? ? ? ? ? ? kobject_del(&q->kobj);
>> + ? ? ? ? ? ? blk_trace_remove_sysfs(disk_to_dev(disk));
>
> This should be moved outside of 'if'.
>
I was not really sure about the proper place - if it could be placed
before if() or after the if(){} - as I've not checked in depth
connection between kobj and sysfs. It's somewhat unclear why all the
kobject operation are only within this if(){} block - so I've thought
there is some reason...
IMHO only elv_unregister_queue() should be probably in the if(){} block.
Feel free to update/fix.
Zdenek
>>> Subject: [PATCH] Add missing blk_trace_remove_sysfs to be in pair with
>>> blk_trace_init_sysfs
>>> From: Zdenek Kabelac <[email protected]>
>>>
>>> Adds missing blk_trace_remove_sysfs() to be in pair with
>>> blk_trace_init_sysfs() introduced in commit
>>> 1d54ad6da9192fed5dd3b60224d9f2dfea0dcd82.
>>>
>>> Problem was noticed via kmemleak backtrace when some sysfs entries
>>> were note properly destroyed during device removal:
>>>
>> Thanks for reporting and fixing this!
>>
>>> @@ -465,6 +466,7 @@ void blk_unregister_queue(struct gendisk *disk)
>>>
>>> kobject_uevent(&q->kobj, KOBJ_REMOVE);
>>> kobject_del(&q->kobj);
>>> + blk_trace_remove_sysfs(disk_to_dev(disk));
>> This should be moved outside of 'if'.
>>
>
> I was not really sure about the proper place - if it could be placed
> before if() or after the if(){} - as I've not checked in depth
Just use the reverse order against blk_register_queue() should be fine.
> connection between kobj and sysfs. It's somewhat unclear why all the
> kobject operation are only within this if(){} block - so I've thought
> there is some reason...
> IMHO only elv_unregister_queue() should be probably in the if(){} block.
>
Seems it's a bug to put kobject_put(dev->kobj) in the if block.
I created a stacked device (mdadm) and kmemleak still reported leaks
even after I fixed the blktrace issue. And then I moved kobejct_put()
outside the if, no more leaks reports.
> Feel free to update/fix.
>
2009/9/24 Li Zefan <[email protected]>:
>>>> Subject: [PATCH] Add missing blk_trace_remove_sysfs to be in pair with
>>>> blk_trace_init_sysfs
>>>> From: Zdenek Kabelac <[email protected]>
>>>>
>>>> Adds missing blk_trace_remove_sysfs() to be in pair with
>>>> blk_trace_init_sysfs() introduced in commit
>>>> 1d54ad6da9192fed5dd3b60224d9f2dfea0dcd82.
>>>>
>>>> Problem was noticed via kmemleak backtrace when some sysfs entries
>>>> were note properly destroyed during ?device removal:
>>>>
>>> Thanks for reporting and fixing this!
>>>
>>>> @@ -465,6 +466,7 @@ void blk_unregister_queue(struct gendisk *disk)
>>>>
>>>> ? ? ? ? ? ? ? kobject_uevent(&q->kobj, KOBJ_REMOVE);
>>>> ? ? ? ? ? ? ? kobject_del(&q->kobj);
>>>> + ? ? ? ? ? ? blk_trace_remove_sysfs(disk_to_dev(disk));
>>> This should be moved outside of 'if'.
>>>
>>
>> I was not really sure about the proper place - if it could be placed
>> before if() or after the if(){} - as I've not checked in depth
>
> Just use the reverse order against blk_register_queue() should be fine.
Yes - I think the order of release is correct.
>
>> connection between kobj and sysfs. It's somewhat unclear why all the
>> kobject operation are only within this if(){} block - so I've thought
>> there is some reason...
>> IMHO only elv_unregister_queue() should be probably in the if(){} block.
>>
>
> Seems it's a bug to put kobject_put(dev->kobj) in the if block.
>
> I created a stacked device (mdadm) and kmemleak still reported leaks
> even after I fixed the blktrace issue. And then I moved kobejct_put()
> outside the if, no more leaks reports.
>
Ok - I didn't have a testcase where the request_fn would be NULL.
So in this case I propose this patch:
---
Add missing blk_trace_remove_sysfs to be in pair with blk_trace_init_sysfs
introduced in commit 1d54ad6da9192fed5dd3b60224d9f2dfea0dcd82.
Release kobject also in case the request_fn is NULL.
Problem was noticed via kmemleak backtrace when some sysfs entries were
note properly destroyed during device removal:
unreferenced object 0xffff88001aa76640 (size 80):
comm "lvcreate", pid 2120, jiffies 4294885144
hex dump (first 32 bytes):
01 00 00 00 00 00 00 00 f0 65 a7 1a 00 88 ff ff .........e......
90 66 a7 1a 00 88 ff ff 86 1d 53 81 ff ff ff ff .f........S.....
backtrace:
[<ffffffff813f9cc6>] kmemleak_alloc+0x26/0x60
[<ffffffff8111d693>] kmem_cache_alloc+0x133/0x1c0
[<ffffffff81195891>] sysfs_new_dirent+0x41/0x120
[<ffffffff81194b0c>] sysfs_add_file_mode+0x3c/0xb0
[<ffffffff81197c81>] internal_create_group+0xc1/0x1a0
[<ffffffff81197d93>] sysfs_create_group+0x13/0x20
[<ffffffff810d8004>] blk_trace_init_sysfs+0x14/0x20
[<ffffffff8123f45c>] blk_register_queue+0x3c/0xf0
[<ffffffff812447e4>] add_disk+0x94/0x160
[<ffffffffa00d8b08>] dm_create+0x598/0x6e0 [dm_mod]
[<ffffffffa00de951>] dev_create+0x51/0x350 [dm_mod]
[<ffffffffa00de823>] ctl_ioctl+0x1a3/0x240 [dm_mod]
[<ffffffffa00de8f2>] dm_compat_ctl_ioctl+0x12/0x20 [dm_mod]
[<ffffffff81177bfd>] compat_sys_ioctl+0xcd/0x4f0
[<ffffffff81036ed8>] sysenter_dispatch+0x7/0x2c
[<ffffffffffffffff>] 0xffffffffffffffff
Signed-off-by: Zdenek Kabelac <[email protected]>
---
block/blk-sysfs.c | 11 ++++++-----
include/linux/blktrace_api.h | 2 ++
kernel/trace/blktrace.c | 5 +++++
3 files changed, 13 insertions(+), 5 deletions(-)
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index b78c9c3..8a6d81a 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -452,6 +452,7 @@ int blk_register_queue(struct gendisk *disk)
if (ret) {
kobject_uevent(&q->kobj, KOBJ_REMOVE);
kobject_del(&q->kobj);
+ blk_trace_remove_sysfs(disk_to_dev(disk));
return ret;
}
@@ -465,11 +466,11 @@ void blk_unregister_queue(struct gendisk *disk)
if (WARN_ON(!q))
return;
- if (q->request_fn) {
+ if (q->request_fn)
elv_unregister_queue(q);
- kobject_uevent(&q->kobj, KOBJ_REMOVE);
- kobject_del(&q->kobj);
- kobject_put(&disk_to_dev(disk)->kobj);
- }
+ kobject_uevent(&q->kobj, KOBJ_REMOVE);
+ kobject_del(&q->kobj);
+ blk_trace_remove_sysfs(disk_to_dev(disk));
+ kobject_put(&disk_to_dev(disk)->kobj);
}
diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h
index 7e4350e..622939a 100644
--- a/include/linux/blktrace_api.h
+++ b/include/linux/blktrace_api.h
@@ -198,6 +198,7 @@ extern int blk_trace_setup(struct request_queue
*q, char *name, dev_t dev,
char __user *arg);
extern int blk_trace_startstop(struct request_queue *q, int start);
extern int blk_trace_remove(struct request_queue *q);
+extern void blk_trace_remove_sysfs(struct device *dev);
extern int blk_trace_init_sysfs(struct device *dev);
extern struct attribute_group blk_trace_attr_group;
@@ -211,6 +212,7 @@ extern struct attribute_group blk_trace_attr_group;
# define blk_trace_startstop(q, start) (-ENOTTY)
# define blk_trace_remove(q) (-ENOTTY)
# define blk_add_trace_msg(q, fmt, ...) do { } while (0)
+# define blk_trace_remove_sysfs(struct device *dev) do { } while (0)
static inline int blk_trace_init_sysfs(struct device *dev)
{
return 0;
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 3eb159c..60b5c5a 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -1657,6 +1657,11 @@ int blk_trace_init_sysfs(struct device *dev)
return sysfs_create_group(&dev->kobj, &blk_trace_attr_group);
}
+void blk_trace_remove_sysfs(struct device *dev)
+{
+ sysfs_remove_group(&dev->kobj, &blk_trace_attr_group);
+}
+
#endif /* CONFIG_BLK_DEV_IO_TRACE */
#ifdef CONFIG_EVENT_TRACING
--
1.6.4.4
>>> connection between kobj and sysfs. It's somewhat unclear why all the
>>> kobject operation are only within this if(){} block - so I've thought
>>> there is some reason...
>>> IMHO only elv_unregister_queue() should be probably in the if(){} block.
>>>
>> Seems it's a bug to put kobject_put(dev->kobj) in the if block.
>>
>> I created a stacked device (mdadm) and kmemleak still reported leaks
>> even after I fixed the blktrace issue. And then I moved kobejct_put()
>> outside the if, no more leaks reports.
>>
>
> Ok - I didn't have a testcase where the request_fn would be NULL.
Here you are ;)
mdadm --create --level=linear --raid-devices=1 --force /dev/md0 /dev/sda6
> So in this case I propose this patch:
>
Looks good.
Reviewed-by: Li Zefan <[email protected]>
> ---
> Add missing blk_trace_remove_sysfs to be in pair with blk_trace_init_sysfs
> introduced in commit 1d54ad6da9192fed5dd3b60224d9f2dfea0dcd82.
> Release kobject also in case the request_fn is NULL.
>
> Problem was noticed via kmemleak backtrace when some sysfs entries were
> note properly destroyed during device removal:
>
> unreferenced object 0xffff88001aa76640 (size 80):
> comm "lvcreate", pid 2120, jiffies 4294885144
> hex dump (first 32 bytes):
> 01 00 00 00 00 00 00 00 f0 65 a7 1a 00 88 ff ff .........e......
> 90 66 a7 1a 00 88 ff ff 86 1d 53 81 ff ff ff ff .f........S.....
> backtrace:
> [<ffffffff813f9cc6>] kmemleak_alloc+0x26/0x60
> [<ffffffff8111d693>] kmem_cache_alloc+0x133/0x1c0
> [<ffffffff81195891>] sysfs_new_dirent+0x41/0x120
> [<ffffffff81194b0c>] sysfs_add_file_mode+0x3c/0xb0
> [<ffffffff81197c81>] internal_create_group+0xc1/0x1a0
> [<ffffffff81197d93>] sysfs_create_group+0x13/0x20
> [<ffffffff810d8004>] blk_trace_init_sysfs+0x14/0x20
> [<ffffffff8123f45c>] blk_register_queue+0x3c/0xf0
> [<ffffffff812447e4>] add_disk+0x94/0x160
> [<ffffffffa00d8b08>] dm_create+0x598/0x6e0 [dm_mod]
> [<ffffffffa00de951>] dev_create+0x51/0x350 [dm_mod]
> [<ffffffffa00de823>] ctl_ioctl+0x1a3/0x240 [dm_mod]
> [<ffffffffa00de8f2>] dm_compat_ctl_ioctl+0x12/0x20 [dm_mod]
> [<ffffffff81177bfd>] compat_sys_ioctl+0xcd/0x4f0
> [<ffffffff81036ed8>] sysenter_dispatch+0x7/0x2c
> [<ffffffffffffffff>] 0xffffffffffffffff
>
> Signed-off-by: Zdenek Kabelac <[email protected]>
> ---
> block/blk-sysfs.c | 11 ++++++-----
> include/linux/blktrace_api.h | 2 ++
> kernel/trace/blktrace.c | 5 +++++
> 3 files changed, 13 insertions(+), 5 deletions(-)
>
> diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
> index b78c9c3..8a6d81a 100644
> --- a/block/blk-sysfs.c
> +++ b/block/blk-sysfs.c
> @@ -452,6 +452,7 @@ int blk_register_queue(struct gendisk *disk)
> if (ret) {
> kobject_uevent(&q->kobj, KOBJ_REMOVE);
> kobject_del(&q->kobj);
> + blk_trace_remove_sysfs(disk_to_dev(disk));
> return ret;
> }
>
> @@ -465,11 +466,11 @@ void blk_unregister_queue(struct gendisk *disk)
> if (WARN_ON(!q))
> return;
>
> - if (q->request_fn) {
> + if (q->request_fn)
> elv_unregister_queue(q);
>
> - kobject_uevent(&q->kobj, KOBJ_REMOVE);
> - kobject_del(&q->kobj);
> - kobject_put(&disk_to_dev(disk)->kobj);
> - }
> + kobject_uevent(&q->kobj, KOBJ_REMOVE);
> + kobject_del(&q->kobj);
> + blk_trace_remove_sysfs(disk_to_dev(disk));
> + kobject_put(&disk_to_dev(disk)->kobj);
> }
> diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h
> index 7e4350e..622939a 100644
> --- a/include/linux/blktrace_api.h
> +++ b/include/linux/blktrace_api.h
> @@ -198,6 +198,7 @@ extern int blk_trace_setup(struct request_queue
> *q, char *name, dev_t dev,
> char __user *arg);
> extern int blk_trace_startstop(struct request_queue *q, int start);
> extern int blk_trace_remove(struct request_queue *q);
> +extern void blk_trace_remove_sysfs(struct device *dev);
> extern int blk_trace_init_sysfs(struct device *dev);
>
> extern struct attribute_group blk_trace_attr_group;
> @@ -211,6 +212,7 @@ extern struct attribute_group blk_trace_attr_group;
> # define blk_trace_startstop(q, start) (-ENOTTY)
> # define blk_trace_remove(q) (-ENOTTY)
> # define blk_add_trace_msg(q, fmt, ...) do { } while (0)
> +# define blk_trace_remove_sysfs(struct device *dev) do { } while (0)
> static inline int blk_trace_init_sysfs(struct device *dev)
> {
> return 0;
> diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
> index 3eb159c..60b5c5a 100644
> --- a/kernel/trace/blktrace.c
> +++ b/kernel/trace/blktrace.c
> @@ -1657,6 +1657,11 @@ int blk_trace_init_sysfs(struct device *dev)
> return sysfs_create_group(&dev->kobj, &blk_trace_attr_group);
> }
>
> +void blk_trace_remove_sysfs(struct device *dev)
> +{
> + sysfs_remove_group(&dev->kobj, &blk_trace_attr_group);
> +}
> +
> #endif /* CONFIG_BLK_DEV_IO_TRACE */
>
> #ifdef CONFIG_EVENT_TRACING
On Thu, Sep 24 2009, Zdenek Kabelac wrote:
> 2009/9/24 Li Zefan <[email protected]>:
> >>>> Subject: [PATCH] Add missing blk_trace_remove_sysfs to be in pair with
> >>>> blk_trace_init_sysfs
> >>>> From: Zdenek Kabelac <[email protected]>
> >>>>
> >>>> Adds missing blk_trace_remove_sysfs() to be in pair with
> >>>> blk_trace_init_sysfs() introduced in commit
> >>>> 1d54ad6da9192fed5dd3b60224d9f2dfea0dcd82.
> >>>>
> >>>> Problem was noticed via kmemleak backtrace when some sysfs entries
> >>>> were note properly destroyed during ?device removal:
> >>>>
> >>> Thanks for reporting and fixing this!
> >>>
> >>>> @@ -465,6 +466,7 @@ void blk_unregister_queue(struct gendisk *disk)
> >>>>
> >>>> ? ? ? ? ? ? ? kobject_uevent(&q->kobj, KOBJ_REMOVE);
> >>>> ? ? ? ? ? ? ? kobject_del(&q->kobj);
> >>>> + ? ? ? ? ? ? blk_trace_remove_sysfs(disk_to_dev(disk));
> >>> This should be moved outside of 'if'.
> >>>
> >>
> >> I was not really sure about the proper place - if it could be placed
> >> before if() or after the if(){} - as I've not checked in depth
> >
> > Just use the reverse order against blk_register_queue() should be fine.
>
> Yes - I think the order of release is correct.
>
> >
> >> connection between kobj and sysfs. It's somewhat unclear why all the
> >> kobject operation are only within this if(){} block - so I've thought
> >> there is some reason...
> >> IMHO only elv_unregister_queue() should be probably in the if(){} block.
> >>
> >
> > Seems it's a bug to put kobject_put(dev->kobj) in the if block.
> >
> > I created a stacked device (mdadm) and kmemleak still reported leaks
> > even after I fixed the blktrace issue. And then I moved kobejct_put()
> > outside the if, no more leaks reports.
> >
>
> Ok - I didn't have a testcase where the request_fn would be NULL.
> So in this case I propose this patch:
>
> ---
> Add missing blk_trace_remove_sysfs to be in pair with blk_trace_init_sysfs
> introduced in commit 1d54ad6da9192fed5dd3b60224d9f2dfea0dcd82.
> Release kobject also in case the request_fn is NULL.
>
> Problem was noticed via kmemleak backtrace when some sysfs entries were
> note properly destroyed during device removal:
Thanks, this looks good now, applied.
--
Jens Axboe