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From:   David Howells <dhowells@redhat.com>
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To:     Christoph Hellwig <hch@lst.de>
Cc:     dhowells@redhat.com, Qu Wenruo <quwenruo.btrfs@gmx.com>,
        Andreas Dilger <adilger@dilger.ca>,
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        "Theodore Y. Ts'o" <tytso@mit.edu>,
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Subject: Re: Problems with determining data presence by examining extents?
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Date:   Fri, 17 Jan 2020 16:43:38 +0000
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Christoph Hellwig <hch@lst.de> wrote:

> File systems usually pad zeroes where they have to, typically for
> sub-blocksize writes.   Disabling this would break data integrity.

I understand that.  I can, however, round up the netfs I/O granule size and
alignment to a multiple of the cachefile I/O block size.  Also, I'm doing DIO,
so I have to use block size multiples.

But if the filesystem can avoid bridging large, appropriately sized and
aligned blocks, then I can use it.

David