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Date:   Wed, 21 Nov 2018 23:06:11 +0800
From:   Ming Lei <ming.lei@redhat.com>
To:     Christoph Hellwig <hch@lst.de>
Cc:     Jens Axboe <axboe@kernel.dk>, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        Theodore Ts'o <tytso@mit.edu>, Omar Sandoval <osandov@fb.com>,
        Sagi Grimberg <sagi@grimberg.me>,
        Dave Chinner <dchinner@redhat.com>,
        Kent Overstreet <kent.overstreet@gmail.com>,
        Mike Snitzer <snitzer@redhat.com>, dm-devel@redhat.com,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        linux-fsdevel@vger.kernel.org, Shaohua Li <shli@kernel.org>,
        linux-raid@vger.kernel.org, David Sterba <dsterba@suse.com>,
        linux-btrfs@vger.kernel.org,
        "Darrick J . Wong" <darrick.wong@oracle.com>,
        linux-xfs@vger.kernel.org, Gao Xiang <gaoxiang25@huawei.com>,
        linux-ext4@vger.kernel.org, Coly Li <colyli@suse.de>,
        linux-bcache@vger.kernel.org, Boaz Harrosh <ooo@electrozaur.com>,
        Bob Peterson <rpeterso@redhat.com>, cluster-devel@redhat.com
Subject: Re: [PATCH V11 02/19] block: introduce multi-page bvec helpers
Message-ID: <20181121150610.GA19111@ming.t460p>
References: <20181121032327.8434-1-ming.lei@redhat.com>
 <20181121032327.8434-3-ming.lei@redhat.com>
 <20181121131928.GA1640@lst.de>
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On Wed, Nov 21, 2018 at 02:19:28PM +0100, Christoph Hellwig wrote:
> On Wed, Nov 21, 2018 at 11:23:10AM +0800, Ming Lei wrote:
> > This patch introduces helpers of 'segment_iter_*' for multipage
> > bvec support.
> > 
> > The introduced helpers treate one bvec as real multi-page segment,
> > which may include more than one pages.
> 
> Unless I'm missing something these bvec vs segment names are exactly
> inverted vs how we use it elsewhere.
> 
> In the iterators we use segment for single-page bvec, and bvec for multi
> page ones, and here it is inverse.  Please switch it around.

bvec_iter_* is used for single-page bvec in current linus tree, and there are
lots of users now:

[linux]$ git grep -n "bvec_iter_*" ./ | wc
    191     995   13242

If we have to switch it first, it can be a big change, just wondering if Jens
is happy with that?

Thanks,
Ming