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. thanks, greg k-h