On Sat, Jul 24, 2021 at 04:38:45PM +0300, Vladimir Sementsov-Ogievskiy wrote:
> No logic change, just prepare for the following commit.
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy
> ---
> block/qcow2-cluster.c | 49 ---
> 1 file changed, 28 insertions(+), 21 deletions(-)
>
> diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
> index bd0597842f..967121c7e6 100644
> --- a/block/qcow2-cluster.c
> +++ b/block/qcow2-cluster.c
> @@ -1400,29 +1400,36 @@ static int handle_dependencies(BlockDriverState *bs,
> uint64_t guest_offset,
>
> if (end <= old_start || start >= old_end) {
> /* No intersection */
> -} else {
> -if (start < old_start) {
> -/* Stop at the start of a running allocation */
> -bytes = old_start - start;
> -} else {
> -bytes = 0;
> -}
> +continue;
> +}
>
> -/* Stop if already an l2meta exists. After yielding, it wouldn't
Pre-existing, but...
> - * be valid any more, so we'd have to clean up the old L2Metas
> - * and deal with requests depending on them before starting to
> - * gather new ones. Not worth the trouble. */
> -if (bytes == 0 && *m) {
> -*cur_bytes = 0;
> -return 0;
> -}
> +/* Conflict */
>
> -if (bytes == 0) {
> -/* Wait for the dependency to complete. We need to recheck
> - * the free/allocated clusters when we continue. */
> -qemu_co_queue_wait(_alloc->dependent_requests, >lock);
> -return -EAGAIN;
> -}
> +if (start < old_start) {
> +/* Stop at the start of a running allocation */
> +bytes = old_start - start;
> +} else {
> +bytes = 0;
> +}
> +
> +/*
> + * Stop if already an l2meta exists. After yielding, it wouldn't
...might as well fix the grammar: Stop if an l2meta already exists.
> + * be valid any more, so we'd have to clean up the old L2Metas
> + * and deal with requests depending on them before starting to
> + * gather new ones. Not worth the trouble.
> + */
> +if (bytes == 0 && *m) {
> +*cur_bytes = 0;
> +return 0;
> +}
> +
> +if (bytes == 0) {
> +/*
> + * Wait for the dependency to complete. We need to recheck
> + * the free/allocated clusters when we continue.
> + */
> +qemu_co_queue_wait(_alloc->dependent_requests, >lock);
> +return -EAGAIN;
So the change adds a short-circuiting 'continue', then reduces the
indentation of the rest of the loop body.
Reviewed-by: Eric Blake
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3266
Virtualization: qemu.org | libvirt.org
