On Wed, 07/24 13:54, Jeff Cody wrote:
> This adds support for writing to VHDX image files, using coroutines.
> Writes into the BAT table goes through the VHDX log. Currently, BAT
> table writes occur when expanding a dynamic VHDX file, and allocating a
> new BAT entry.
>
> Signed-off-by: Jeff Cody <jc...@redhat.com>
> ---
> block/vhdx.c | 149
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 147 insertions(+), 2 deletions(-)
>
> diff --git a/block/vhdx.c b/block/vhdx.c
> index a8dd6d7..791c6dc 100644
> --- a/block/vhdx.c
> +++ b/block/vhdx.c
> @@ -831,7 +831,7 @@ static int vhdx_open(BlockDriverState *bs, QDict
> *options, int flags)
> vhdx_update_headers(bs, s, false, NULL);
> }
>
> - /* TODO: differencing files, write */
> + /* TODO: differencing files */
>
> return 0;
> fail:
> @@ -963,7 +963,45 @@ exit:
> return ret;
> }
>
> +/*
> + * Allocate a new payload block at the end of the file.
> + *
> + * Allocation will happen at 1MB alignment inside the file
> + *
> + * Returns the file offset start of the new payload block
> + */
> +static int vhdx_allocate_block(BlockDriverState *bs, BDRVVHDXState *s,
> + uint64_t *new_offset)
> +{
> + *new_offset = bdrv_getlength(bs->file);
>
> + /* per the spec, the address for a block is in units of 1MB */
> + if (*new_offset % (1024*1024)) {
> + *new_offset = ((*new_offset >> 20) + 1) << 20; /* round up to 1MB */
You can use ROUND_UP() macro here:
*new_offset = ROUND_UP(*new_offset, 1 << 20);
Fam
