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Date:   Sun, 27 Feb 2022 14:09:39 -0800
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Subject: Re: [PATCH 2/6] iov_iter: new iov_iter_pin_pages*(), for FOLL_PIN
 pages
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To:     Jens Axboe <axboe@kernel.dk>, jhubbard.send.patches@gmail.com,
        Jan Kara <jack@suse.cz>, Christoph Hellwig <hch@infradead.org>,
        Dave Chinner <dchinner@redhat.com>,
        "Darrick J . Wong" <djwong@kernel.org>,
        Theodore Ts'o <tytso@mit.edu>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Miklos Szeredi <miklos@szeredi.hu>,
        Andrew Morton <akpm@linux-foundation.org>,
        Chaitanya Kulkarni <kch@nvidia.com>
Cc:     linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        linux-xfs@vger.kernel.org, linux-mm@kvack.org,
        LKML <linux-kernel@vger.kernel.org>
References: <20220227093434.2889464-1-jhubbard@nvidia.com>
 <20220227093434.2889464-3-jhubbard@nvidia.com>
 <06469550-a679-145f-b16e-2f1ffc0b07af@kernel.dk>
From:   John Hubbard <jhubbard@nvidia.com>
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On 2/27/22 13:57, Jens Axboe wrote:
...
>> +			return res;
>> +		return (res == n ? len : res * PAGE_SIZE) - *start;
> 
> Trying to be clever like that just makes the code a lot less readable. I
> should not have to reason about a return value. Same in the other
> function.
> 

No argument there. This was shamelessly lifted from
iov_iter_get_pages(), and I initially calculated that keeping it
identical to that known-good code, where possible, was better than
fixing it up.

However, I'll go ahead and simplify it--with pleasure--based on this
feedback.


thanks,
-- 
John Hubbard
NVIDIA