• David Woodhouse's avatar
    Btrfs: RAID5 and RAID6 · 53b381b3
    David Woodhouse authored
    This builds on David Woodhouse's original Btrfs raid5/6 implementation.
    The code has changed quite a bit, blame Chris Mason for any bugs.
    Read/modify/write is done after the higher levels of the filesystem have
    prepared a given bio.  This means the higher layers are not responsible
    for building full stripes, and they don't need to query for the topology
    of the extents that may get allocated during delayed allocation runs.
    It also means different files can easily share the same stripe.
    But, it does expose us to incorrect parity if we crash or lose power
    while doing a read/modify/write cycle.  This will be addressed in a
    later commit.
    Scrub is unable to repair crc errors on raid5/6 chunks.
    Discard does not work on raid5/6 (yet)
    The stripe size is fixed at 64KiB per disk.  This will be tunable
    in a later commit.
    Signed-off-by: default avatarChris Mason <chris.mason@fusionio.com>
Makefile 657 Bytes