Messages in this thread | | | Date | Thu, 9 Jul 2009 19:39:00 +0200 | From | Jens Axboe <> | Subject | Re: [PATCH 2/4] block: use the same failfast bits for bio and request |
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On Thu, Jul 09 2009, Jeff Garzik wrote: > Christoph Hellwig wrote: >> On Thu, Jul 09, 2009 at 09:45:24AM +0900, Tejun Heo wrote: >>> What's more disturbing to me is the different between RQ and BIO >>> flags. __REQ_* are bit positions, REQ_* are masks while BIO_* are bit >>> positions. Sadly it seems it's already too late to change that. I >>> personally an not a big fan of simple accessors or flags defined as >>> bit positions. They seem to obscure things without much benefit. >> >> flags as bit positions generally only make sense if you use >> test/set/clear_bit, otherwise they just confuse things. And the >> accessors are pretty annoying, especially in the block layer. Trying to >> find the places where a BIO flag has an actual effect is pretty painful >> due to the mix of the different flags and the accessors. > > Indeed -- the accessors mean in practice that you always have at least > _two_ things to grep for, just to catch all accesses. Block layer is > pretty bad about that style of usage :/
Yeah, I'm not too fond of it either, it does add to the confusion. I'll sanitize it.
-- Jens Axboe
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