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    SubjectRe: ext2 question
       Date: Tue, 18 May 1999 20:20:36 +0200
    From: Manfred Spraul <manfreds@colorfullife.com>

    No: use a mixed system:
    currently: the first 12 blocks direct, then 256 blocks indirect,
    then 65536 blocks indirect, etc.
    you replace the constants 12, 256 with 2 variables, everything else
    remains unchanged.

    otherwise:
    clear 'extents possible',
    start a new block group (i.e. switch from direct to
    indirect or from indirect to double indirect);
    use the current system.

    Oh, I see. Yes, that will will work, and it's pretty clever. In the
    worst case we might have a one or two extents in the inode before we get
    forced to swtich to an indirect scheme, but the direct extents describe
    less than 12 blocks you can convert the direct extents to direct blocks,
    and if it direct extents describe more than 12 blocks they were a win
    anyway.

    Since the vast majority of files are written either sequentially, or
    with enough preallocation that the extent wouldn't be a problem, it's a
    nice solution.

    I'll have to think about it some more, but off-hand that's a very
    interesting strategy.

    - Ted

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