2023-04-04 14:37:04

by 李扬韬

Subject: [PATCH 2/2] erofs: remove unnecessary kobject_del()

kobject_put() actually covers kobject removal automatically, which is
single stage removal. So it is safe to kill kobject_del() directly.

Signed-off-by: Yangtao Li <[email protected]>
---
fs/erofs/sysfs.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/fs/erofs/sysfs.c b/fs/erofs/sysfs.c
index 435e515c0792..c3ba981b4472 100644
--- a/fs/erofs/sysfs.c
+++ b/fs/erofs/sysfs.c
@@ -240,11 +240,8 @@ void erofs_unregister_sysfs(struct super_block *sb)
{
struct erofs_sb_info *sbi = EROFS_SB(sb);

- if (sbi->s_kobj.state_in_sysfs) {
- kobject_del(&sbi->s_kobj);
- kobject_put(&sbi->s_kobj);
- wait_for_completion(&sbi->s_kobj_unregister);
- }
+ kobject_put(&sbi->s_kobj);
+ wait_for_completion(&sbi->s_kobj_unregister);
}

int __init erofs_init_sysfs(void)
--
2.35.1

2023-04-06 03:56:37

by Gao Xiang

Subject: Re: [PATCH 2/2] erofs: remove unnecessary kobject_del()

Hi Yangtao,

On 2023/4/4 22:21, Yangtao Li wrote:
> kobject_put() actually covers kobject removal automatically, which is
> single stage removal. So it is safe to kill kobject_del() directly.
>
> Signed-off-by: Yangtao Li <[email protected]>

Would you mind taking a look at
commit a942da24abc5 ("fs: erofs: add sanity check for kobject in erofs_unregister_sysfs")

, which could be "git-blame"ed (I'd suggest looking into these
blame first), and the related discussion was:

https://lore.kernel.org/r/CAD-N9QXNx=p3-QoWzk6pCznF32CZy8kM3vvo8mamfZZ9CpUKdw@mail.gmail.com
https://lore.kernel.org/r/[email protected]

TL;DR: I guess it could be fixed as below if kobject_del() could
be killed safely:

if (sbi->s_kobj.state_in_sysfs) {
kobject_put(&sbi->s_kobj);
wait_for_completion(&sbi->s_kobj_unregister);
}

Thanks,
Gao Xiang


> ---
> fs/erofs/sysfs.c | 7 ++-----
> 1 file changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/fs/erofs/sysfs.c b/fs/erofs/sysfs.c
> index 435e515c0792..c3ba981b4472 100644
> --- a/fs/erofs/sysfs.c
> +++ b/fs/erofs/sysfs.c
> @@ -240,11 +240,8 @@ void erofs_unregister_sysfs(struct super_block *sb)
> {
> struct erofs_sb_info *sbi = EROFS_SB(sb);
>
> - if (sbi->s_kobj.state_in_sysfs) {
> - kobject_del(&sbi->s_kobj);
> - kobject_put(&sbi->s_kobj);
> - wait_for_completion(&sbi->s_kobj_unregister);
> - }
> + kobject_put(&sbi->s_kobj);
> + wait_for_completion(&sbi->s_kobj_unregister);
> }
>
> int __init erofs_init_sysfs(void)

2023-04-06 09:45:28

by 李扬韬

Subject: Re: [PATCH 2/2] erofs: remove unnecessary kobject_del()

HI Gao Xiang,

> Would you mind taking a look at
> commit a942da24abc5 ("fs: erofs: add sanity check for kobject in erofs_unregister_sysfs")
>
> , which could be "git-blame"ed (I'd suggest looking into these
> blame first), and the related discussion was:
>
> https://lore.kernel.org/r/CAD-N9QXNx=p3-QoWzk6pCznF32CZy8kM3vvo8mamfZZ9CpUKdw@mail.gmail.com
> https://lore.kernel.org/r/[email protected]

> TL;DR: I guess it could be fixed as below if kobject_del() could
> : be killed safely:
>
> if (sbi->s_kobj.state_in_sysfs) {
> kobject_put(&sbi->s_kobj);
> wait_for_completion(&sbi->s_kobj_unregister);
> }

Thanks for your review and detailed explanation.

MBR,
Yangtao