Re: [PATCH 0/4] (RESEND) ext3[34] barrier changes

From: Theodore Tso
Date: Mon May 19 2008 - 10:50:24 EST

On Mon, May 19, 2008 at 09:26:41AM -0400, Chris Mason wrote:
> >
> > Didn't ext4 have some new checksum trick to avoid them?
> I didn't think checksumming avoided barriers completely. Just the barrier
> before the commit block, not the barrier after.

Funny thing, I was looking in this over the weekend. It currently
avoids barriers entirely if journal_async_commit is enabled (which is
not the default); if enabled, it effectively forces barrier=0. This
is IMHO a bug.

I'm working on a patch where "barrier=1" will use a barrier before and
after, and "barrier=1,journal_async_commit" will use a barrier after.

- Ted
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at