On 2023/4/6 18:27, Greg KH wrote:
On Thu, Apr 06, 2023 at 06:13:05PM +0800, Gao Xiang wrote:
Hi Greg,
On 2023/4/6 18:03, Greg KH wrote:
On Thu, Apr 06, 2023 at 05:30:55PM +0800, Yangtao Li wrote:
Use kobject_is_added() instead of directly accessing the internal
variables of kobject. BTW kill kobject_del() directly, because
kobject_put() actually covers kobject removal automatically.
Signed-off-by: Yangtao Li <frank.li@xxxxxxxx>
---
fs/erofs/sysfs.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/fs/erofs/sysfs.c b/fs/erofs/sysfs.c
index 435e515c0792..daac23e32026 100644
--- a/fs/erofs/sysfs.c
+++ b/fs/erofs/sysfs.c
@@ -240,8 +240,7 @@ 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);
+ if (kobject_is_added(&sbi->s_kobj)) {
I do not understand why this check is even needed, I do not think it
should be there at all as obviously the kobject was registered if it now
needs to not be registered.
I think Yangtao sent a new patchset which missed the whole previous
background discussions as below:
https://lore.kernel.org/r/028a1b56-72c9-75f6-fb68-1dc5181bf2e8@xxxxxxxxxxxxxxxxx
It's needed because once a syzbot complaint as below:
https://lore.kernel.org/r/CAD-N9QXNx=p3-QoWzk6pCznF32CZy8kM3vvo8mamfZZ9CpUKdw@xxxxxxxxxxxxxx
I'd suggest including the previous backgrounds at least in the newer patchset,
otherwise it makes me explain again and again...
That would be good, as I do not think this is correct, it should be
fixed in a different way, see my response to the zonefs patch in this
series as a much simpler method to use.
Yes, but here (sbi->s_kobj) is not a kobject pointer (also at a quick
glance it seems that zonefs has similar code), and also we couldn't
just check the sbi is NULL or not here only, since sbi is already
non-NULL in this path and there are some others in sbi to free in
other functions.
s_kobj could be changed into a pointer if needed. I'm all fine with
either way since as you said, it's a boilerplate filesystem kobject
logic duplicated from somewhere. Hopefully Yangtao could help take
this task since he sent me patches about this multiple times.
Thanks,
Gao Xiang
thanks,
greg k-h
