Re: [Libguestfs] [PATCH nbdkit v5 FINAL 12/19] truncate: Implement extents for beyond end of truncated region.

--- filters/truncate/truncate.c | 55 +++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+)

+ + /* If the entire request is beyond the end of the underlying plugin + * then this is the easy case: return a hole. + */ + if (offset >= real_size_copy) + return nbdkit_add_extent (extents, offset, (uint64_t) count, + NBDKIT_EXTENT_ZERO|NBDKIT_EXTENT_HOLE);

+ + /* We're asked first for extents information about the plugin, then + * possibly (if truncating larger) for the hole after the plugin. + * Since we're not required to provide all of this information, the + * easiest thing is to only return data from the plugin. We will be + * called later about the hole. However we do need to make sure + * that the extents array is truncated to the real size, hence we + * have to create a new extents array, ask the plugin, then copy the + * returned data to the original array. + */ + extents2 = nbdkit_extents_new (0, real_size_copy);