Am 25.06.2020 um 17:22 hat Max Reitz geschrieben:
> This changes iotest 204's output, because blkdebug on top of a COW node
> used to make qemu-img map disregard the rest of the backing chain (the
> backing chain was broken by the filter). With this patch, the
> allocation in the base image is reported correctly.
>
> Signed-off-by: Max Reitz <mre...@redhat.com>
> @@ -3437,6 +3441,7 @@ static int img_rebase(int argc, char **argv)
> uint8_t *buf_old = NULL;
> uint8_t *buf_new = NULL;
> BlockDriverState *bs = NULL, *prefix_chain_bs = NULL;
> + BlockDriverState *unfiltered_bs;
> char *filename;
> const char *fmt, *cache, *src_cache, *out_basefmt, *out_baseimg;
> int c, flags, src_flags, ret;
> @@ -3571,6 +3576,8 @@ static int img_rebase(int argc, char **argv)
> }
> bs = blk_bs(blk);
>
> + unfiltered_bs = bdrv_skip_filters(bs);
> +
> if (out_basefmt != NULL) {
> if (bdrv_find_format(out_basefmt) == NULL) {
> error_report("Invalid format name: '%s'", out_basefmt);
> @@ -3582,7 +3589,7 @@ static int img_rebase(int argc, char **argv)
> /* For safe rebasing we need to compare old and new backing file */
> if (!unsafe) {
> QDict *options = NULL;
> - BlockDriverState *base_bs = backing_bs(bs);
> + BlockDriverState *base_bs = bdrv_cow_bs(unfiltered_bs);
>
> if (base_bs) {
> blk_old_backing = blk_new(qemu_get_aio_context(),
> @@ -3738,8 +3745,9 @@ static int img_rebase(int argc, char **argv)
> * If cluster wasn't changed since prefix_chain, we don't
> need
> * to take action
> */
> - ret = bdrv_is_allocated_above(backing_bs(bs),
> prefix_chain_bs,
> - false, offset, n, &n);
> + ret = bdrv_is_allocated_above(bdrv_cow_bs(unfiltered_bs),
> + prefix_chain_bs, false,
> + offset, n, &n);
> if (ret < 0) {
> error_report("error while reading image metadata: %s",
> strerror(-ret));
img_rebase() has these additional calls:
/* If the cluster is allocated, we don't need to take action */
ret = bdrv_is_allocated(bs, offset, n, &n);
And:
if (out_baseimg && *out_baseimg) {
ret = bdrv_change_backing_file(bs, out_baseimg, out_basefmt);
} else {
ret = bdrv_change_backing_file(bs, NULL, NULL);
}
Shouldn't they use unfiltered_bs?
(Not that it's likely that anyone would use 'qemu-img rebase' with a
filter, but while you're touching it...)
Kevin
