[Libguestfs] [PATCH nbdkit 3/8] server: Implement Block Status requests to read allocation status.

[Richard W.M. Jones]

On Sat, Mar 23, 2019 at 11:51:15AM -0500, Eric Blake wrote:
> > +  /* Send each block descriptor. */
> > +  for (i = 0; i < nr_extents; ++i) {
> 
> Where does the list terminate after 1 extent if REQ_ONE was set? Also,
> if REQ_ONE is set but the plugin provided coalesced status beyond the
> request, this would need to clamp the answer to the requested length.

Yes this version was very broken - hence the other thread about qemu
not being able to handle when we send multiple extents in response to
REQ_ONE.  It also didn't obey the general rules about what extents
we're allowed to return in the other case.  This is all fixed in the
next iteration.

Rich.

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