On Wed, 12/16 19:33, Paolo Bonzini wrote:
> Do not use bdrv_drain, since by itself it does not guarantee
> anything.
>
> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
> ---
> block/snapshot.c | 23 ++++++++++++++---------
> 1 file changed, 14 insertions(+), 9 deletions(-)
>
> diff --git a/block/snapshot.c b/block/snapshot.c
> index 6e9fa8d..2d86b88 100644
> --- a/block/snapshot.c
> +++ b/block/snapshot.c
> @@ -229,6 +229,8 @@ int bdrv_snapshot_delete(BlockDriverState *bs,
> Error **errp)
> {
> BlockDriver *drv = bs->drv;
> + int ret;
> +
> if (!drv) {
> error_setg(errp, QERR_DEVICE_HAS_NO_MEDIUM,
> bdrv_get_device_name(bs));
> return -ENOMEDIUM;
> @@ -239,18 +241,21 @@ int bdrv_snapshot_delete(BlockDriverState *bs,
> }
>
> /* drain all pending i/o before deleting snapshot */
> - bdrv_drain(bs);
> + bdrv_drained_begin(bs);
>
> if (drv->bdrv_snapshot_delete) {
> - return drv->bdrv_snapshot_delete(bs, snapshot_id, name, errp);
> + ret = drv->bdrv_snapshot_delete(bs, snapshot_id, name, errp);
> + } else if (bs->file) {
> + ret = bdrv_snapshot_delete(bs->file->bs, snapshot_id, name, errp);
> + } else {
> + error_setg(errp, "Block format '%s' used by device '%s' "
> + "does not support internal snapshot deletion",
> + drv->format_name, bdrv_get_device_name(bs));
> + ret = -ENOTSUP;
> }
> - if (bs->file) {
> - return bdrv_snapshot_delete(bs->file->bs, snapshot_id, name, errp);
> - }
> - error_setg(errp, "Block format '%s' used by device '%s' "
> - "does not support internal snapshot deletion",
> - drv->format_name, bdrv_get_device_name(bs));
> - return -ENOTSUP;
> +
> + bdrv_drained_end(bs);
> + return ret;
> }
>
> int bdrv_snapshot_delete_by_id_or_name(BlockDriverState *bs,
> --
> 2.5.0
>
>
Reviewed-by: Fam Zheng <f...@redhat.com>
