Re: [PATCHv2 09/17] nvme: add Clang context annotations for nvme_subsystems_lock

[Nilay Shroff]

On 6/26/26 12:15 PM, Christoph Hellwig wrote:
> > -static LIST_HEAD(nvme_subsystems);
> > +static __guarded_by(&nvme_subsystems_lock) LIST_HEAD(nvme_subsystems);
>
> Having the guard_by before the LIST_HEAD makes this a real mess to
> read.
>
> Can we add a
>
> #define LIST_HEAD_GUARDED(_list, _lock) \
> 	__guarded_by(_lock) LIST_HEAD(_list)
>
> and use that instead?  And maybe do these after the lock declaration.
> While the compiler doesn't care, that's much easier to follow for
> humans.
Makes sense. Will add this helper macro in next patchset.

> > +	/*
> > +	 * Initializing subsys->ctrls list doesn't need to be protected
> > +	 * using @nvme_subsystems_lock. So suppress the Clang's warning
> > +	 * declaring context_unsafe.
> > +	 */
> > +	context_unsafe(INIT_LIST_HEAD(&subsys->ctrls));
>
> This could also use a helper.
Maybe INIT_LIST_HEAD_UNSAFE() helper as I suggested in the earlier
message ?

BTW, I think these helpers should be added in include/linux/list.h so
it will be helpful in general for other kernel code as well.

Thanks,
--Nilay