[lkml]   [2008]   [Oct]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: [PATCH 4/4] jbd2: don't dirty original metadata buffer on abort
    On Fri, Oct 10, 2008 at 06:02:09PM +0900, Hidehiro Kawai wrote:
    > Currently, original metadata buffers are dirtied when they are
    > unfiled whether the journal has aborted or not. Eventually these
    > buffers will be written-back to the filesystem by pdflush. This
    > means some metadata buffers are written to the filesystem without
    > journaling if the journal aborts. So if both journal abort and
    > system crash happen at the same time, the filesystem would become
    > inconsistent state. Additionally, replaying journaled metadata
    > can overwrite the latest metadata on the filesystem partly.
    > Because, if the journal gets aborted, journaled metadata are
    > preserved and replayed during the next mount not to lose
    > uncheckpointed metadata. This would also break the consistency
    > of the filesystem.
    > This patch prevents original metadata buffers from being dirtied
    > on abort by clearing BH_JBDDirty flag from those buffers. Thus,
    > no metadata buffers are written to the filesystem without journaling.

    It's not my place to Ack such patches, but I noticed this bug
    during Plumbers, and Eric and Andreas pointed me to this patch, which
    fixes it quite nicely. Just $0.02 :-)



    Life's Little Instruction Book #94

    "Make it a habit to do nice things for people who
    will never find out."

    Joel Becker
    Principal Software Developer
    Phone: (650) 506-8127

     \ /
      Last update: 2008-10-13 22:41    [W:0.023 / U:129.384 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site