On Wed, Jun 03, 2020 at 01:56:20PM -0700, James Bottomley wrote:
> The store of state_in_sysfs is already done in kobject_add_internal().
> It's an existing flag people already use to tell if the kobject has
> been exposed in sysfs. However, it's set after the sysfs directory
> creation succeeds. This is the code with some debugging removed:
>
> error = create_dir(kobj);
> if (error) {
> kobj_kset_leave(kobj);
> kobject_put(parent);
> kobj->parent = NULL;
> ...
> } else
> kobj->state_in_sysfs = 1;
I was thinking most probably this will need a lock or a
smp_store_release() ..
> > It feels more robust to stick with the put though..
>
> possibly ... like I said, the only concern with the put path is that
> ->release has state expectations that aren't met if
> kobject_init_and_add fails.
Certainly error unwind bugs related to put and release will exist, but
I suspect switching to kfree won't solve them, just move them to the
next function that fails and needs a put based unwind?
At least the patches I reviewed for RDM a from Wang Hai were all
correct and didn't seem to have release based errors.
Jason
