Re: [PATCH 5/5] block: revert back to synchronous request_queue removal

From: Luis Chamberlain
Date: Wed Apr 15 2020 - 09:20:56 EST


On Tue, Apr 14, 2020 at 11:46:44PM -0700, Christoph Hellwig wrote:
> On Tue, Apr 14, 2020 at 08:58:52PM +0000, Luis Chamberlain wrote:
> > > I think this needs a WARN_ON thrown in to enforece the calling context.
> >
> > I considered adding a might_sleep() but upon review with Bart, he noted
> > that this function already has a mutex_lock(), and if you look under the
> > hood of mutex_lock(), it has a might_sleep() at the very top. The
> > warning then is implicit.
>
> It might just be a personal preference, but I think the documentation
> value of a WARN_ON_ONCE or might_sleep with a comment at the top of
> the function is much higher than a blurb in a long kerneldoc text and
> a later mutex_lock.

Well I'm a fan of making this explicit, so sure will just sprinkle a
might_sleep(), even though we have a mutex_lock().

Luis