Commit 9956688a authored by Max Reitz's avatar Max Reitz
Browse files

vhdx: Fix .bdrv_has_zero_init() 



Fixed VHDX images cannot guarantee to be zero-initialized.  If the image
has the "fixed" subformat, forward the call to the underlying storage
node.

Reported-by: default avatarStefano Garzarella <sgarzare@redhat.com>
Signed-off-by: default avatarMax Reitz <mreitz@redhat.com>
Message-id: 20190724171239.8764-9-mreitz@redhat.com
Reviewed-by: default avatarMaxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: default avatarMax Reitz <mreitz@redhat.com>
parent 0a28bf28

block/vhdx.c

+25 −1
Original line number Diff line number Diff line
@@ -2075,6 +2075,30 @@ static int coroutine_fn vhdx_co_check(BlockDriverState *bs, 
    return 0;

}



static int vhdx_has_zero_init(BlockDriverState *bs)

{

    BDRVVHDXState *s = bs->opaque;

    int state;



    /*

     * Check the subformat: Fixed images have all BAT entries present,

     * dynamic images have none (right after creation).  It is

     * therefore enough to check the first BAT entry.

     */

    if (!s->bat_entries) {

        return 1;

    }



    state = s->bat[0] & VHDX_BAT_STATE_BIT_MASK;

    if (state == PAYLOAD_BLOCK_FULLY_PRESENT) {

        /* Fixed subformat */

        return bdrv_has_zero_init(bs->file->bs);

    }



    /* Dynamic subformat */

    return 1;

}



static QemuOptsList vhdx_create_opts = {

    .name = "vhdx-create-opts",

    .head = QTAILQ_HEAD_INITIALIZER(vhdx_create_opts.head),
@@ -2128,7 +2152,7 @@ static BlockDriver bdrv_vhdx = { 
    .bdrv_co_create_opts    = vhdx_co_create_opts,

    .bdrv_get_info          = vhdx_get_info,

    .bdrv_co_check          = vhdx_co_check,

    .bdrv_has_zero_init     = bdrv_has_zero_init_1,

    .bdrv_has_zero_init     = vhdx_has_zero_init,



    .create_opts            = &vhdx_create_opts,

};