Re: [Bug? Report] kref problem

Greg KH
2006-03-16T17:18:10Z

On Thu, Mar 16, 2006 at 08:07:57PM +0300, Artem B. Bityutskiy wrote:
> On Thu, 2006-03-16 at 08:53 -0800, Greg KH wrote:
> > > static void a_release(struct kobject *kobj)
> > > {
> > > struct my_obj_a *a;
> > >
> > > printk("%s\n", __FUNCTION__);
> > > a = container_of(kobj, struct my_obj_a, kobj);
> > > sysfs_remove_dir(&a->kobj);
> >
> > Woah, don't do that here, the kobject core already does this. A release
> > function is for you to release the memory you have created with this
> > kobject, not to mess with sysfs.
> So do you mean this (attached) ? Anyway I end up with -1 kref.

No file was attached :(

Care to try again?

> My real task is: I have sysfs directory /sys/A which corresponds to my
> module, to my subsystem. There I want to create subdirectories
> like /sys/A/B/ and delete them from time to time.

What kind of subsystem are you creating that you are using raw kobjects?

> So the problem is that whenver I remove B I end up with A's kref
> decremented.

And does A go away? Or is it still there in sysfs?

> The attached test
> demonstrates this. P;ease, look at its output:
>
> a inited, kref 1
> b inited, kref 1
> dir A created, A kref 1, B kref 1
> dir B created, A kref 1, B kref 1
> dir B removed, A kref 1, B kref 1
> b_release
> a_release <--- What is this? I removed B, not A ???
> kobj B put, A kref 0, B kref 0
> dir A removed, A kref 0, B kref 0
> kobj A put, A kref -1, B kref 0

-ENOFILE :(

thanks,

greg k-h