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Date: Thu, 10 Nov 2016 21:07:17 +0100
From: Christoph Hellwig <hch@lst.de>
To: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Jens Axboe <axboe@fb.com>, Christoph Hellwig <hch@lst.de>,
        Mike Christie <mchristi@redhat.com>,
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Subject: Re: [patch] block: precedence bug in bio_set_op_attrs() macro
Message-ID: <20161110200717.GA21893@lst.de>
References: <20161110200438.GA22854@mwanda>
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On Thu, Nov 10, 2016 at 11:04:38PM +0300, Dan Carpenter wrote:
> This code causes a problem for flush_epd_write_bio() because | has
> higher precedence than ?: so it basically turns into:
> 
> 	((bio)->bi_opf |= REQ_SYNC;
> 
> Which is wrong.

Its is.  And while we're at it the macro should really be doing a
= instead of |=.

And we really should stop using it, at least in the block core even
ASAP.