On Tue, 01/21 11:31, Jeff Cody wrote:
> If the top image to commit is the active layer, and also larger than
> the base image, then an I/O error will likely be returned during
> block-commit.
>
> For instance, if we have a base image with a virtual size 10G, and a
> active layer image of size 20G, then committing the snapshot via
> 'block-commit' will likely fail.
>
> This will automatically attempt to resize the base image, if the
> active layer image to be committed is larger.
>
> Signed-off-by: Jeff Cody <jc...@redhat.com>
> ---
> block/mirror.c | 36 ++++++++++++++++++++++++++++++++++++
> 1 file changed, 36 insertions(+)
>
> diff --git a/block/mirror.c b/block/mirror.c
> index 2932bab..528b61a 100644
> --- a/block/mirror.c
> +++ b/block/mirror.c
> @@ -630,11 +630,47 @@ void commit_active_start(BlockDriverState *bs,
> BlockDriverState *base,
> BlockDriverCompletionFunc *cb,
> void *opaque, Error **errp)
> {
> + int64_t length, base_length;
> + int orig_base_flags;
> +
> + orig_base_flags = bdrv_get_flags(base);
> +
> if (bdrv_reopen(base, bs->open_flags, errp)) {
> return;
> }
> +
> + length = bdrv_getlength(bs);
> + base_length = bdrv_getlength(base);
> +
> + if (length < 0 || base_length < 0) {
I prefer to add an error to errp here, at least tell which bdrv_getlength
failed helps.
> + goto error_restore_flags;
> + }
> +
> + if (length > base_length) {
> + if (bdrv_truncate(base, length) < 0) {
> + error_setg(errp, "Top image %s is larger than base image %s, and
> "
> + "resize of base image failed.",
> + bs->filename, base->filename);
> + goto error_restore_flags;
> + }
> + } else if (length < 0) {
> + goto error_restore_flags;
> + }
> +
> +
> bdrv_ref(base);
> mirror_start_job(bs, base, speed, 0, 0,
> on_error, on_error, cb, opaque, errp,
> &commit_active_job_driver, false, base);
> + if (error_is_set(errp)) {
> + goto error_restore_flags;
> + }
> +
> + return;
> +
> +error_restore_flags:
> + /* ignore error and errp for bdrv_reopen, because we want to propagate
> + * the original error */
> + bdrv_reopen(base, orig_base_flags, NULL);
Well, I hope this never fail. (But if it does, should we do anything else than
ignoring it?)
Thanks,
Fam
> + return;
> }
> --
> 1.8.3.1
>
