Re: SPAM: Re: XFS corruption during power-blackout

[Andi Kleen <ak@xxxxxxx>]

Chris Wedgwood <cw@xxxxxxxx> writes:

> If caching is enabled I still lose data.  Linux does have a concept of
> write barriers but these are presently not implemented for XFS right
> now.

I implemented them some time ago for log writes in XFS. Not for fsync though,
although fsync usually does a log write afterwards so it should work
in practice too. fdatasync might not.

Don't know if the code hasn't bit rotted away and it also was a bit
dumb. It was definitely there at some point.

But then a lot of ATA disks and SCSI don't support barriers. Or at least
the IDE barrier tests fails on several of my machines.

-Andi