On 5/16/19 8:27 AM, Vladimir Sementsov-Ogievskiy wrote:
> Add new optional parameter making possible to merge bitmaps from
> different nodes. It is needed to maintain external snapshots during
> incremental backup chain history.
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
> ---
> qapi/block-core.json | 13 ++++++++++---
> block/dirty-bitmap.c | 9 ++++++---
> blockdev.c | 46 ++++++++++++++++++++++++++++++--------------
> 3 files changed, 48 insertions(+), 20 deletions(-)
>
> diff --git a/qapi/block-core.json b/qapi/block-core.json
> index 7ccbfff9d0..933b50771a 100644
> --- a/qapi/block-core.json
> +++ b/qapi/block-core.json
> @@ -2006,16 +2006,23 @@
> ##
> # @BlockDirtyBitmapMerge:
> #
> -# @node: name of device/node which the bitmap is tracking
> +# @node: name of device/node which the @target and @bitmaps bitmaps are
> +# tracking
> #
> # @target: name of the destination dirty bitmap
> #
> -# @bitmaps: name(s) of the source dirty bitmap(s)
> +# @bitmaps: name(s) of the source dirty bitmap(s). The field is optional
> +# since 4.1.
> +#
> +# @external-bitmaps: additional list of source dirty bitmaps with specified
> +# nodes, which allows merging bitmaps between different
> +# nodes. (Since: 4.1)
> #
> # Since: 4.0
> ##
> { 'struct': 'BlockDirtyBitmapMerge',
> - 'data': { 'node': 'str', 'target': 'str', 'bitmaps': ['str'] } }
> + 'data': { 'node': 'str', 'target': 'str', '*bitmaps': ['str'],
> + '*external-bitmaps': ['BlockDirtyBitmap'] } }
>
I guess you can specify one, or both, or maybe neither! Seems fine.
> ##
> # @block-dirty-bitmap-add:
> diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
> index 59e6ebb861..49646a30e6 100644
> --- a/block/dirty-bitmap.c
> +++ b/block/dirty-bitmap.c
> @@ -816,10 +816,10 @@ void bdrv_merge_dirty_bitmap(BdrvDirtyBitmap *dest,
> const BdrvDirtyBitmap *src,
> {
> bool ret;
>
> - /* only bitmaps from one bds are supported */
> - assert(dest->mutex == src->mutex);
> -
> qemu_mutex_lock(dest->mutex);
> + if (src->mutex != dest->mutex) {
> + qemu_mutex_lock(src->mutex);
> + }
>
> if (bdrv_dirty_bitmap_check(dest, BDRV_BITMAP_DEFAULT, errp)) {
> goto out;
> @@ -845,4 +845,7 @@ void bdrv_merge_dirty_bitmap(BdrvDirtyBitmap *dest, const
> BdrvDirtyBitmap *src,
>
> out:
> qemu_mutex_unlock(dest->mutex);
> + if (src->mutex != dest->mutex) {
> + qemu_mutex_unlock(src->mutex);
> + }
> }
> diff --git a/blockdev.c b/blockdev.c
> index 79fbac8450..8d37ce5943 100644
> --- a/blockdev.c
> +++ b/blockdev.c
> @@ -2112,11 +2112,9 @@ static void
> block_dirty_bitmap_disable_abort(BlkActionState *common)
> }
> }
>
> -static BdrvDirtyBitmap *do_block_dirty_bitmap_merge(const char *node,
> - const char *target,
> - strList *bitmaps,
> - HBitmap **backup,
> - Error **errp);
> +static BdrvDirtyBitmap *do_block_dirty_bitmap_merge(
> + const char *node, const char *target, strList *bitmaps,
> + BlockDirtyBitmapList *external_bitmaps, HBitmap **backup, Error
> **errp);
>
You know, that's actually a much smarter way to reflow these ...
> static void block_dirty_bitmap_merge_prepare(BlkActionState *common,
> Error **errp)
> @@ -2132,8 +2130,9 @@ static void
> block_dirty_bitmap_merge_prepare(BlkActionState *common,
> action = common->action->u.block_dirty_bitmap_merge.data;
>
> state->bitmap = do_block_dirty_bitmap_merge(action->node, action->target,
> - action->bitmaps,
> &state->backup,
> - errp);
> + action->bitmaps,
> + action->external_bitmaps,
> + &state->backup, errp);
> }
>
> static void abort_prepare(BlkActionState *common, Error **errp)
> @@ -2965,15 +2964,14 @@ void qmp_block_dirty_bitmap_disable(const char *node,
> const char *name,
> bdrv_disable_dirty_bitmap(bitmap);
> }
>
> -static BdrvDirtyBitmap *do_block_dirty_bitmap_merge(const char *node,
> - const char *target,
> - strList *bitmaps,
> - HBitmap **backup,
> - Error **errp)
> +static BdrvDirtyBitmap *do_block_dirty_bitmap_merge(
> + const char *node, const char *target, strList *bitmaps,
> + BlockDirtyBitmapList *external_bitmaps, HBitmap **backup, Error
> **errp)
> {
> BlockDriverState *bs;
> BdrvDirtyBitmap *dst, *src, *anon;
> strList *lst;
> + BlockDirtyBitmapList *ext_lst;
> Error *local_err = NULL;
>
> dst = block_dirty_bitmap_lookup(node, target, &bs, errp);
> @@ -3003,6 +3001,22 @@ static BdrvDirtyBitmap
> *do_block_dirty_bitmap_merge(const char *node,
> }
> }
>
> + for (ext_lst = external_bitmaps; ext_lst; ext_lst = ext_lst->next) {
> + src = block_dirty_bitmap_lookup(ext_lst->value->node,
> + ext_lst->value->name, NULL, errp);
> + if (!src) {
> + dst = NULL;
> + goto out;
> + }
> +
> + bdrv_merge_dirty_bitmap(anon, src, NULL, &local_err);
> + if (local_err) {
> + error_propagate(errp, local_err);
> + dst = NULL;
> + goto out;
> + }
> + }
> +
> /* Merge into dst; dst is unchanged on failure. */
> bdrv_merge_dirty_bitmap(dst, anon, backup, errp);
>
> @@ -3012,9 +3026,13 @@ static BdrvDirtyBitmap
> *do_block_dirty_bitmap_merge(const char *node,
> }
>
> void qmp_block_dirty_bitmap_merge(const char *node, const char *target,
> - strList *bitmaps, Error **errp)
> + bool has_bitmaps, strList *bitmaps,
> + bool has_external_bitmaps,
> + BlockDirtyBitmapList *external_bitmaps,
> + Error **errp)
> {
> - do_block_dirty_bitmap_merge(node, target, bitmaps, NULL, errp);
> + do_block_dirty_bitmap_merge(node, target, bitmaps, external_bitmaps,
> NULL,
> + errp);
> }
>
> BlockDirtyBitmapSha256 *qmp_x_debug_block_dirty_bitmap_sha256(const char
> *node,
>
I don't think I like the name "external-bitmaps" but I guess I don't
really have a better suggestion. Technically you can use this for
node-local source bitmaps too, it's just that it's a more verbose way to
specify them. (They're like "fully-qualified" bitmap identifiers instead
of the local/relative references we've been using.)
Well, I can't hold you up if I have no better ideas.
Reviewed-by: John Snow <js...@redhat.com>
