Anthony, please ignore this pull request, I'll rework and resubmit later.
On Wed, 25 Apr 2012, Christoph Hellwig wrote: > On Tue, Apr 24, 2012 at 12:28:35PM +0100, Stefano Stabellini wrote: > > xen_disk: use bdrv_aio_flush instead of bdrv_flush > > This one seems completely broken, as it just queues up the flushes and > writes without any ordering between them. Linux filesystems absolutely > rely on a REQ_FUA request which gets mapped to BLKIF_OP_FLUSH_DISKCACHE > to flush the data it actually sent. > > I'm not sure who actually expects the preflush, but the only point > in ever doing it would be to sequence it properly vs the write. I see.. I need to make sure that the bdrv_aio_flush is fully completed before issuing any reads or writes, not just ordered correctly: calling bdrv_aio_flush before bdrv_aio_readv/writev is not enough.
