[Qemu-devel] [PATCHv3 00/20] block: logical block provisioning enhancements

[Peter Lieven]

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.

v2->v3:
 - fix merge conflict in block/qcow2_cluster.c
 - changed return type of bdrv_has_discard_zeroes and
   bdrv_has_discard_write_zeroes to bool.
 - moved alignment and limits info to a BlockLimits struct (Paolo).
 - added magic constanst for default maximum in bdrv_co_do_write_zeroes
   and bdrv_co_discard (Eric).
 - bdrv_co_do_write_zeroes: allocating the bounce buffer only once (Eric),
   fixed bounce iov_len in the fall back path.
 - bdrv_zeroize: added inline docu (Eric) and do not mask flags passed
   to bdrv_write_zeroes (Eric).
 - qemu-img: changed the default hint for -S (min_sparse) in the usage
   help to 4k. not changing the default as it is unclear why this default
   was set. size suffixes are already supported (Eric).

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 BlockLimits structure to BlockDriverState
  block: honour BlockLimits in bdrv_co_do_write_zeroes
  block: honour BlockLimits 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 BlockLimits on raw_open

 block-migration.c         |    3 +-
 block.c                   |  205 +++++++++++++++++++++++++++++++++++++--------
 block/backup.c            |    3 +-
 block/iscsi.c             |  152 ++++++++++++++++++++++++---------
 block/qcow2-cluster.c     |    2 +-
 block/qcow2.c             |    2 +-
 block/qed.c               |    3 +-
 block/raw_bsd.c           |   62 ++++++++------
 block/vmdk.c              |    3 +-
 include/block/block.h     |   19 ++++-
 include/block/block_int.h |   32 ++++++-
 qemu-img.c                |   18 +++-
 qemu-io-cmds.c            |    2 +-
 13 files changed, 393 insertions(+), 113 deletions(-)

-- 
1.7.9.5