On 22.11.19 17:05, Kevin Wolf wrote:
> This adds a no_fallback parameter to bdrv_co_truncate(), bdrv_truncate()
> and blk_truncate() in preparation for a fix that potentially needs to
> zero-write the new area. no_fallback will use BDRV_REQ_NO_FALLBACK for
> this operation and lets the truncate fail if an efficient zero write
> isn't possible.
> 
> Only qmp_block_resize() passes true for this parameter because it is a
> blocking monitor command, so we don't want to add more potentially slow
> I/O operations to it than we already have.
> 
> All other users will accept even a slow fallback to avoid failure.
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  include/block/block.h          |  5 +++--
>  include/sysemu/block-backend.h |  2 +-
>  block/block-backend.c          |  4 ++--
>  block/commit.c                 |  4 ++--
>  block/crypto.c                 |  4 ++--
>  block/io.c                     | 16 ++++++++++++----
>  block/mirror.c                 |  2 +-
>  block/parallels.c              |  6 +++---
>  block/qcow.c                   |  4 ++--
>  block/qcow2-refcount.c         |  2 +-
>  block/qcow2.c                  | 19 +++++++++++--------
>  block/qed.c                    |  2 +-
>  block/raw-format.c             |  2 +-
>  block/vdi.c                    |  2 +-
>  block/vhdx-log.c               |  2 +-
>  block/vhdx.c                   |  6 +++---
>  block/vmdk.c                   | 10 ++++++----
>  block/vpc.c                    |  2 +-
>  blockdev.c                     |  2 +-
>  qemu-img.c                     |  2 +-
>  qemu-io-cmds.c                 |  2 +-
>  tests/test-block-iothread.c    |  6 +++---
>  22 files changed, 60 insertions(+), 46 deletions(-)

With the typo pointed out by Eric fixed:

Reviewed-by: Max Reitz <mreitz@redhat.com>