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Date: Thu, 4 May 2023 04:34:43 +0100
From: Matthew Wilcox <willy@infradead.org>
To: Christoph Hellwig <hch@lst.de>
Cc: akpm@linux-foundation.org, jack@suse.cz, linux-fsdevel@vger.kernel.org,
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Subject: Re: [PATCH 1/2] filemap: fix the conditional folio_put in
 filemap_fault
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On Wed, May 03, 2023 at 05:49:36PM +0200, Christoph Hellwig wrote:
> On Wed, May 03, 2023 at 04:48:20PM +0100, Matthew Wilcox wrote:
> > > -		folio_put(folio);
> > 
> > Why not simply:
> > 
> > -	if (folio)
> > +	if (!IS_ERR_OR_NULL(folio))
> 
> no need for the OR_NULL.

Right.  I didn't read the whole function.

> But I find the extra label way easier to
> reason about, and it's exactly the same amount of code.

If it were easy to reason about, it would have a less ugly name.