Messages in this thread | | | Date | Mon, 13 Oct 2008 13:36:42 -0700 | From | Joel Becker <> | Subject | Re: [PATCH 4/4] jbd2: don't dirty original metadata buffer on abort |
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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 :-)
Joel
--
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 Oracle E-mail: joel.becker@oracle.com Phone: (650) 506-8127
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