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Date: Wed, 26 Oct 2016 16:02:30 +0200
From: Christoph Hellwig <hch@lst.de>
To: Bob Peterson <rpeterso@redhat.com>
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        axboe@fb.com, kent overstreet <kent.overstreet@gmail.com>,
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Subject: Re: [PATCH 5/6] iomap: implement direct I/O
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On Wed, Oct 26, 2016 at 09:53:43AM -0400, Bob Peterson wrote:
> It's unlikely, but bio_alloc can return NULL; shouldn't the code be
> checking for that?

No, a sleeping bio_alloc can not return NULL.  If it did our I/O
code would break down badly - take a look at the implementation,
the bio_alloc_bioset documentation even explains this in detail.

> | +		if (dio->error)
> | +			return 0;
> | +
> | +		bio = bio_alloc(GFP_KERNEL, nr_pages);
> 
> Same here. Also: the code that follows is nearly identical; do you want to make
> it a macro or inline function or something?

I'll take a look, but having another helper needed to follow for a
trivial struct initialization doesn't seem all that useful.