Re: [PATCH 3/5] nbd: use flags instead of bool

[Jens Axboe]

On 09/09/2016 10:04 AM, Joe Perches wrote:
> On Fri, 2016-09-09 at 07:55 -0600, Jens Axboe wrote:
> > On 09/08/2016 07:20 PM, Joe Perches wrote:
> > > On Thu, 2016-09-08 at 17:12 -0400, Josef Bacik wrote:
> > > > In preparation for some future changes, change a few of the state bools over to
> > > > normal bits to set/clear properly.
> > > []
> > > > diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
> > > []
> > > > @@ -41,8 +41,12 @@
> > > >
> > > >  #include <linux/nbd.h>
> > > >
> > > > +#define NBD_TIMEDOUT			0
> > > > +#define NBD_DISCONNECT_REQUESTED	1
> > > > +
> > > >  struct nbd_device {
> > > >  	u32 flags;
> > > +	unsigned long runtime_flags;
> > > Better to use DECLARE_BITMAP
>
> > It's a few flags, we know it fits in a long. There's no point to using
> > anything but that, and set/test/clear_bit().
>
> It lets the reader know how it's used.

The variable is called 'runtime_flags' - if that doesn't already tell
the reader how it's used, then I'd suggest the reader go read something
else.

I'm all for using established APIs where it makes sense. Declaring a
bitmap for a few fields isn't that.

--
Jens Axboe