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Date:   Thu, 25 May 2023 14:34:31 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Johannes Thumshirn <Johannes.Thumshirn@wdc.com>
Cc:     Christoph Hellwig <hch@lst.de>, Chris Mason <clm@fb.com>,
        Josef Bacik <josef@toxicpanda.com>,
        David Sterba <dsterba@suse.com>,
        Naohiro Aota <Naohiro.Aota@wdc.com>,
        "linux-btrfs@vger.kernel.org" <linux-btrfs@vger.kernel.org>
Subject: Re: [PATCH 11/14] btrfs: atomically insert the new extent in
 btrfs_split_ordered_extent
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References: <20230524150317.1767981-1-hch@lst.de> <20230524150317.1767981-12-hch@lst.de> <f574b91a-14f2-7d79-4b7f-8d625fdcde6c@wdc.com>
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On Thu, May 25, 2023 at 12:30:41PM +0000, Johannes Thumshirn wrote:
> I wonder if we couldn't reduce the code duplication between btrfs_split_ordered_extent
> and the new insert_ordered_extent function. The different lock ordering currently makes
> it impossible, though.

The interesting thing about the split case is that we really want to
do a removal and two inserts in an atomic fashion.  In the end
there's not really much code in insert_ordered_extent anyway, and
the decision where to split up btrfs_alloc_ordered_extent was at
least partially based on that tradeoff.