Messages in this thread | | | Subject | Re: [PATCH 1/3] nbd: support FLUSH requests | From | Alex Bligh <> | Date | Tue, 12 Feb 2013 17:37:04 +0000 |
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Paolo,
> Add support for a new flag that the server can pass. If the flag is > enabled, we translate REQ_FLUSH requests into the NBD_CMD_FLUSH > command. > > Cc: <nbd-general@lists.sf.net> > Cc: Paul Clements <Paul.Clements@steeleye.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > Signed-off-by: Alex Bligh <alex@alex.org.uk> > [ Removed FUA support for reasons similar to those outlined in > https://lkml.org/lkml/2010/8/17/234 for virtio - Paolo ] > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
For my education, why remove the FUA stuff? The link you posted was for virtio drivers, and says:
> > Hmmm... the underlying storage could be md/dm RAIDs in which case FUA > > should be cheaper than FLUSH. > > If someone ever wrote a virtio-blk backend that sits directly ontop > of the Linux block layer that would be true.
In this case we don't know what the backend is sitting on top of a-priori. It might be the current nbd server code, but it might not be.
-- Alex Bligh
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