this patch adds the ability for targets to stay sparse during
block migration (if the zero_blocks capability is set) and qemu-img convert
even if the target does not have has_zero_init = 1.
the series was especially developed for iSCSI, but it should also work
with other drivers with little or no adjustments. these adjustments
should be limited to providing block provisioning information through
get_block_info and/or honouring BDRV_REQ_MAY_UNMAP on writing zeroes.
there are also 4 patches which are fixes/enhancements for the get_block_status
API
discovered during development of this series.
v1->v2:
- moved block max_discard and max_write_zeroes to BlockDriverState
- added discard_alignment and write_zeroes_alignment to BlockDriverState
- added bdrv_has_discard_zeroes() and bdrv_has_discard_write_zeroes()
- added logic to bdrv_co_discard and bdrv_co_do_write_zeroes to honour
limit and alignment info.
- added support for -S 0 in qemu-img convert.
Peter Lieven (20):
block: make BdrvRequestFlags public
block: add flags to bdrv_*_write_zeroes
block: introduce BDRV_REQ_MAY_UNMAP request flag
block: introduce bdrv_has_discard_zeroes and
bdrv_has_discard_write_zeroes
block/raw: add bdrv_has_discard_zeroes and
bdrv_has_discard_write_zeroes
block: add discard and write_zeroes limits and alignment to
BlockDriverState
block: honour alignment and limit in bdrv_co_do_write_zeroes
block: honour alignment and limit in bdrv_co_discard
iscsi: simplify iscsi_co_discard
iscsi: set limits in BlockDriverState
iscsi: add bdrv_has_discard_zeroes and bdrv_has_discard_write_zeroes
iscsi: add bdrv_co_write_zeroes
block: introduce bdrv_zeroize
block/get_block_status: set *pnum = 0 on error
block/get_block_status: avoid segfault if there is no backing_hd
block/get_block_status: avoid redundant callouts on raw devices
block/get_block_status: fix BDRV_BLOCK_ZERO for unallocated blocks
qemu-img: add support for fully allocated images
qemu-img: conditionally zero out target on convert
block/raw: copy block limits and alignment information on raw_open
block-migration.c | 3 +-
block.c | 187 ++++++++++++++++++++++++++++++++++++---------
block/backup.c | 3 +-
block/iscsi.c | 148 +++++++++++++++++++++++++----------
block/qcow2.c | 2 +-
block/qed.c | 3 +-
block/raw_bsd.c | 65 ++++++++++------
block/vmdk.c | 3 +-
include/block/block.h | 19 ++++-
include/block/block_int.h | 27 ++++++-
qemu-img.c | 18 ++++-
qemu-io-cmds.c | 2 +-
12 files changed, 368 insertions(+), 112 deletions(-)
--
1.7.9.5
