Re: [PATCH 4/4] ext4: call blkdev_issue_flush on fsync

[Jens Axboe]

On Tue, May 20 2008, Jamie Lokier wrote:
> Does WRITE_BARRIER always cause a flush?  It does not have to
> according to Documentation/block/barrier.txt.  There are caveats about
> tagged queuing "not yet implemented" in the text, but can we rely on
> that?  The documentation is older than the current implementation;
> those caveats might no longer apply.

It does, if you use ordered tags then that assumes write through
caching (or ordered tag + drain + flush after completion).

-- 
Jens Axboe

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/