block: Geometry and translation hints are now useless, purge them

There are two producers of these hints: drive_init() on behalf of
-drive, and hd_geometry_guess().

The only consumer of the hint is hd_geometry_guess().

The callers of hd_geometry_guess() call it only when drive_init()
didn't set the hints.  Therefore, drive_init()'s hints are never used.

Thus, hd_geometry_guess() only ever sees hints it produced itself in a
prior call.  Only the first call computes something, subsequent calls
just repeat the first call's results.  However, hd_geometry_guess() is
never called more than once: the device models don't, and the block
device is destroyed on unplug.  Thus, dropping the repeat feature
doesn't break anything now.

If a block device wasn't destroyed on unplug and could be reused with
a new device, then repeating old results would be wrong.  Thus,
dropping the repeat feature prevents future breakage.

This renders the hints unused.  Purge them from the block layer.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/hw/pc.c b/hw/pc.c
index 89a0c661db..77b12b4c11 100644
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -44,6 +44,7 @@
 #include "kvm.h"
 #include "xen.h"
 #include "blockdev.h"
+#include "hw/block-common.h"
 #include "ui/qemu-spice.h"
 #include "memory.h"
 #include "exec-memory.h"