When btrfs_debug_feature_attr_group fails to be created,
btrfs_feature_attr_group is not removed.
Signed-off-by: Zhen Lei <[email protected]>
---
fs/btrfs/sysfs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index 699b54b3acaae0b..947125f2ceaaf96 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -2322,7 +2322,7 @@ int __init btrfs_init_sysfs(void)
#ifdef CONFIG_BTRFS_DEBUG
ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
if (ret)
- goto out2;
+ goto out_remove_group;
#endif
return 0;
--
2.25.1
On 2022/11/19 14:43, Zhen Lei wrote:
> When btrfs_debug_feature_attr_group fails to be created,
> btrfs_feature_attr_group is not removed.
>
> Signed-off-by: Zhen Lei <[email protected]>
Reviewed-by: Qu Wenruo <[email protected]>
Thanks,
Qu
> ---
> fs/btrfs/sysfs.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
> index 699b54b3acaae0b..947125f2ceaaf96 100644
> --- a/fs/btrfs/sysfs.c
> +++ b/fs/btrfs/sysfs.c
> @@ -2322,7 +2322,7 @@ int __init btrfs_init_sysfs(void)
> #ifdef CONFIG_BTRFS_DEBUG
> ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
> if (ret)
> - goto out2;
> + goto out_remove_group;
> #endif
>
> return 0;
On 2022/11/19 14:53, Qu Wenruo wrote:
>
>
> On 2022/11/19 14:43, Zhen Lei wrote:
>> When btrfs_debug_feature_attr_group fails to be created,
>> btrfs_feature_attr_group is not removed.
>>
>> Signed-off-by: Zhen Lei <[email protected]>
>
> Reviewed-by: Qu Wenruo <[email protected]>
Wait for a minute, should we call sysfs_unmerge_group() first before
calling sysfs_remove_group()?
As the sysfs_remove_group() will only remove the
btrfs_feature_attr_group, and kset_unregister() will only free
btrfs_kset, without removing the added btrfs_static_feature_attr_group.
I haven't yet find a function that will remove all children attrs in
just one go, or did I miss something?
Thanks,
Qu
>
> Thanks,
> Qu
>> ---
>> fs/btrfs/sysfs.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
>> index 699b54b3acaae0b..947125f2ceaaf96 100644
>> --- a/fs/btrfs/sysfs.c
>> +++ b/fs/btrfs/sysfs.c
>> @@ -2322,7 +2322,7 @@ int __init btrfs_init_sysfs(void)
>> #ifdef CONFIG_BTRFS_DEBUG
>> ret = sysfs_create_group(&btrfs_kset->kobj,
>> &btrfs_debug_feature_attr_group);
>> if (ret)
>> - goto out2;
>> + goto out_remove_group;
>> #endif
>> return 0;
On 2022/11/20 11:11, Qu Wenruo wrote:
>
>
> On 2022/11/19 14:53, Qu Wenruo wrote:
>>
>>
>> On 2022/11/19 14:43, Zhen Lei wrote:
>>> When btrfs_debug_feature_attr_group fails to be created,
>>> btrfs_feature_attr_group is not removed.
>>>
>>> Signed-off-by: Zhen Lei <[email protected]>
>>
>> Reviewed-by: Qu Wenruo <[email protected]>
>
> Wait for a minute, should we call sysfs_unmerge_group() first before
> calling sysfs_remove_group()?
>
> As the sysfs_remove_group() will only remove the
> btrfs_feature_attr_group, and kset_unregister() will only free
> btrfs_kset, without removing the added btrfs_static_feature_attr_group.
>
> I haven't yet find a function that will remove all children attrs in
> just one go, or did I miss something?
Oh, indeed I missed something.
The following call chain would properly handle every child of a kobj:
kset_unregister()
|- kobject_del()
|- __kobject_del()
|- sysfs_remove_dir()
|- kernfs_remove()
|- __kernfs_remove()
|- do { kernfs_leftmost_descendant(); } while (pos != kn)
The final do {} while () loop will unlink each child kernel_node and
free it.
This means, as long as we call kset_unregister(), we should be able to
free every child of it.
So with or without this patch, the error handling should be fine.
Although personally speaking, I'd prefer a more explicit cleanup (with
extra sysfs_unmerge_group() call) as going through the above call chain
is not that straightforward.
Thanks,
Qu
>
> Thanks,
> Qu
>>
>> Thanks,
>> Qu
>>> ---
>>> fs/btrfs/sysfs.c | 2 +-
>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
>>> index 699b54b3acaae0b..947125f2ceaaf96 100644
>>> --- a/fs/btrfs/sysfs.c
>>> +++ b/fs/btrfs/sysfs.c
>>> @@ -2322,7 +2322,7 @@ int __init btrfs_init_sysfs(void)
>>> #ifdef CONFIG_BTRFS_DEBUG
>>> ret = sysfs_create_group(&btrfs_kset->kobj,
>>> &btrfs_debug_feature_attr_group);
>>> if (ret)
>>> - goto out2;
>>> + goto out_remove_group;
>>> #endif
>>> return 0;
On 2022/11/20 11:29, Qu Wenruo wrote:
>
>
> On 2022/11/20 11:11, Qu Wenruo wrote:
>>
>>
>> On 2022/11/19 14:53, Qu Wenruo wrote:
>>>
>>>
>>> On 2022/11/19 14:43, Zhen Lei wrote:
>>>> When btrfs_debug_feature_attr_group fails to be created,
>>>> btrfs_feature_attr_group is not removed.
>>>>
>>>> Signed-off-by: Zhen Lei <[email protected]>
>>>
>>> Reviewed-by: Qu Wenruo <[email protected]>
>>
>> Wait for a minute, should we call sysfs_unmerge_group() first before calling sysfs_remove_group()?
>>
>> As the sysfs_remove_group() will only remove the btrfs_feature_attr_group, and kset_unregister() will only free btrfs_kset, without removing the added btrfs_static_feature_attr_group.
>>
>> I haven't yet find a function that will remove all children attrs in just one go, or did I miss something?
>
> Oh, indeed I missed something.
>
> The following call chain would properly handle every child of a kobj:
>
> kset_unregister()
> |- kobject_del()
> |- __kobject_del()
> |- sysfs_remove_dir()
> |- kernfs_remove()
> |- __kernfs_remove()
> |- do { kernfs_leftmost_descendant(); } while (pos != kn)
>
> The final do {} while () loop will unlink each child kernel_node and free it.
>
> This means, as long as we call kset_unregister(), we should be able to free every child of it.
OK, thanks.
>
>
> So with or without this patch, the error handling should be fine.
>
> Although personally speaking, I'd prefer a more explicit cleanup (with extra sysfs_unmerge_group() call) as going through the above call chain is not that straightforward.
Yes, with sysfs_unmerge_group(), the code logic is clearer.
>
> Thanks,
> Qu
>
>>
>> Thanks,
>> Qu
>>>
>>> Thanks,
>>> Qu
>>>> ---
>>>> fs/btrfs/sysfs.c | 2 +-
>>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
>>>> index 699b54b3acaae0b..947125f2ceaaf96 100644
>>>> --- a/fs/btrfs/sysfs.c
>>>> +++ b/fs/btrfs/sysfs.c
>>>> @@ -2322,7 +2322,7 @@ int __init btrfs_init_sysfs(void)
>>>> #ifdef CONFIG_BTRFS_DEBUG
>>>> ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
>>>> if (ret)
>>>> - goto out2;
>>>> + goto out_remove_group;
>>>> #endif
>>>> return 0;
> .
>
--
Regards,
Zhen Lei