On 05/27/2016 02:14 AM, zhangzhiming wrote: > Hi, i modified my code for qcow2 resize, and delete some code related to > qemu monitor. > > and thanks for the review. > > zhangzhiming > zhangzhimin...@meituan.com <mailto:zhangzhimin...@meituan.com>
Still missing a Signed-off-by designation, so it can't be applied as-is.
>
> ---
> block.c | 19 +++++++++++++++++++
> block/qcow2-cluster.c | 29 +++++++++++++++++++++++++++++
> block/qcow2-snapshot.c | 34 ++++++++++++++++++++++++----------
> block/qcow2.c | 29 ++++++++++++++++++++---------
> block/qcow2.h | 1 +
> include/block/snapshot.h | 1 +
> 6 files changed, 94 insertions(+), 19 deletions(-)
>
> diff --git a/block.c b/block.c
> index 18a497f..729f820 100644
> --- a/block.c
> +++ b/block.c
> @@ -2631,6 +2631,25 @@ int bdrv_truncate(BlockDriverState *bs, int64_t offset)
> return ret;
> }
>
> +int bdrv_apply_snapshot(BlockDriverState *bs, const char *snapshot_id,
> + uint64_t snapshot_size)
> +{
> + int ret = bdrv_snapshot_goto(bs, snapshot_id);
> + if (ret < 0) {
> + return ret;
> + }
> +
> + ret = refresh_total_sectors(bs, snapshot_size >> BDRV_SECTOR_BITS);
> + if (ret < 0) {
> + return ret;
> + }
> + bdrv_dirty_bitmap_truncate(bs); /* void return */
> + if (bs->blk) {
> + blk_dev_resize_cb(bs->blk); /* void return too */
The comments don't add anything here.
> + }
> + return ret;
> +}
> +
> /**
> * Length of a allocated file in bytes. Sparse files are counted by actual
> * allocated space. Return < 0 if error or unknown.
> diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
> index 31ecc10..e4c5c05 100644
> --- a/block/qcow2-cluster.c
> +++ b/block/qcow2-cluster.c
> @@ -31,6 +31,35 @@
> #include "block/qcow2.h"
> #include "trace.h"
>
> +int shrink_l1_table(BlockDriverState *bs, int64_t new_l1_size)
> +{
> + BDRVQcow2State *s = bs->opaque;
> + int64_t old_l1_size = s->l1_size;
> + s->l1_size = new_l1_size;
> + int ret = qcow2_update_snapshot_refcount(bs, s->l1_table_offset,
> + s->l1_size, 1);
Indentation is off.
> + if (ret < 0) {
> + return ret;
> + }
> +
> + s->l1_size = old_l1_size;
> + ret = qcow2_update_snapshot_refcount(bs, s->l1_table_offset,
> + s->l1_size, -1);
and again.
> + if (ret < 0) {
> + return ret;
> + }
> + s->l1_size = new_l1_size;
> +
> +++ b/block/qcow2-snapshot.c
> @@ -552,10 +562,12 @@ int qcow2_snapshot_goto(BlockDriverState *bs, const
> char *snapshot_id)
> * Now update the in-memory L1 table to be in sync with the on-disk one.
> We
> * need to do this even if updating refcounts failed.
> */
> - for(i = 0;i < s->l1_size; i++) {
> + memset(s->l1_table, 0, s->l1_size*sizeof(uint64_t));
> + for(i = 0;i < sn->l1_size; i++) {
As long as you are touching this, use the preferred spacing:
for (i = 0; i < sn->l1_size; i++) {
> s->l1_table[i] = be64_to_cpu(sn_l1_table[i]);
> }
>
> +
> if (ret < 0) {
Why the added blank line?
> +++ b/block/qcow2.c
> @@ -2501,22 +2501,33 @@ static int qcow2_truncate(BlockDriverState *bs,
> int64_t offset)
> return -EINVAL;
> }
>
> - /* cannot proceed if image has snapshots */
> - if (s->nb_snapshots) {
> - error_report("Can't resize an image which has snapshots");
> + bool v3_truncate = (s->qcow_version == 3);
> +
> + /* cannot proceed if image has snapshots and qcow_version is not 3*/
Space before */
> + if (!v3_truncate && s->nb_snapshots) {
> + error_report("Can't resize an image which has snapshots and "
> + "qcow_version is not 3");
> return -ENOTSUP;
> }
>
> - /* shrinking is currently not supported */
> - if (offset < bs->total_sectors * 512) {
> - error_report("qcow2 doesn't support shrinking images yet");
> + /* shrinking is supported from version 3*/
and again
> + if (!v3_truncate && offset < bs->total_sectors * 512) {
> + error_report("qcow2 doesn't support shrinking images yet while"
> + " qcow_version is not 3");
> return -ENOTSUP;
> }
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
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