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>
This commit is contained in:
Markus Armbruster 2012-07-10 11:12:50 +02:00 committed by Kevin Wolf
parent 856dcba23a
commit 2b584959ed
9 changed files with 12 additions and 77 deletions

12
block.h
View file

@ -257,18 +257,6 @@ int bdrv_has_zero_init(BlockDriverState *bs);
int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
int *pnum);
#define BIOS_ATA_TRANSLATION_AUTO 0
#define BIOS_ATA_TRANSLATION_NONE 1
#define BIOS_ATA_TRANSLATION_LBA 2
#define BIOS_ATA_TRANSLATION_LARGE 3
#define BIOS_ATA_TRANSLATION_RECHS 4
void bdrv_set_geometry_hint(BlockDriverState *bs,
int cyls, int heads, int secs);
void bdrv_set_translation_hint(BlockDriverState *bs, int translation);
void bdrv_get_geometry_hint(BlockDriverState *bs,
int *pcyls, int *pheads, int *psecs);
int bdrv_get_translation_hint(BlockDriverState *bs);
void bdrv_set_on_error(BlockDriverState *bs, BlockErrorAction on_read_error,
BlockErrorAction on_write_error);
BlockErrorAction bdrv_get_on_error(BlockDriverState *bs, int is_read);