On 20.01.2016 09:11, Fam Zheng wrote:
The added group of operations enables tracking of the changed bits in
the dirty bitmap.
Signed-off-by: Fam Zheng <f...@redhat.com>
---
block/dirty-bitmap.c | 51 ++++++++++++++++++++++++++++++++++++++++++++
include/block/dirty-bitmap.h | 9 ++++++++
2 files changed, 60 insertions(+)
diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index bd7758b..d75dcf7 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -37,6 +37,7 @@
*/
struct BdrvDirtyBitmap {
HBitmap *bitmap; /* Dirty sector bitmap implementation */
+ HBitmap *meta; /* Meta dirty bitmap */
BdrvDirtyBitmap *successor; /* Anonymous child; implies frozen status */
char *name; /* Optional non-empty unique ID */
int64_t size; /* Size of the bitmap (Number of sectors) */
@@ -102,6 +103,56 @@ BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState
*bs,
return bitmap;
}
+/* bdrv_create_meta_dirty_bitmap
+ *
+ * Create a meta dirty bitmap that tracks the changes of bits in @bitmap. I.e.
+ * when a dirty status bit in @bitmap is changed (either from reset to set or
+ * the other way around), its respective meta dirty bitmap bit will be marked
+ * dirty as well.
+ *
+ * @bitmap: the block dirty bitmap for which to create a meta dirty bitmap.
+ * @granularity: how many bytes of bitmap data does each bit in the meta bitmap
+ * track.
+ */
+void bdrv_create_meta_dirty_bitmap(BdrvDirtyBitmap *bitmap,
+ int granularity)
+{
+ assert(!bitmap->meta);
+ bitmap->meta = hbitmap_create_meta(bitmap->bitmap,
+ BDRV_SECTOR_SIZE * BITS_PER_BYTE);
+}
+
+void bdrv_release_meta_dirty_bitmap(BdrvDirtyBitmap *bitmap)
+{
+ assert(bitmap->meta);
+ hbitmap_free_meta(bitmap->bitmap);
+ bitmap->meta = NULL;
+}
+
+int bdrv_dirty_bitmap_get_meta(BlockDriverState *bs,
+ BdrvDirtyBitmap *bitmap, int64_t sector,
+ int nb_sectors)
+{
+ uint64_t i;
+ int gran = bdrv_dirty_bitmap_granularity(bitmap) >> BDRV_SECTOR_BITS;
+
+ /* To optimize: we can make hbitmap to internally check the range in a
+ * coarse level, or at least do it word by word. */
+ for (i = sector; i < sector + nb_sectors; i += gran) {
+ if (hbitmap_get(bitmap->meta, i)) {
+ return true;
+ }
+ }
+ return false;
+}
+
+void bdrv_dirty_bitmap_reset_meta(BlockDriverState *bs,
+ BdrvDirtyBitmap *bitmap, int64_t sector,
+ int nb_sectors)
+{
+ hbitmap_reset(bitmap->meta, sector, nb_sectors);
+}
+
bool bdrv_dirty_bitmap_frozen(BdrvDirtyBitmap *bitmap)
{
return bitmap->successor;
diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
index 120bac6..d9b281a 100644
--- a/include/block/dirty-bitmap.h
+++ b/include/block/dirty-bitmap.h
@@ -9,6 +9,9 @@ BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs,
uint32_t granularity,
const char *name,
Error **errp);
+void bdrv_create_meta_dirty_bitmap(BdrvDirtyBitmap *bitmap,
+ int granularity);
+void bdrv_release_meta_dirty_bitmap(BdrvDirtyBitmap *bitmap);
int bdrv_dirty_bitmap_create_successor(BlockDriverState *bs,
BdrvDirtyBitmap *bitmap,
Error **errp);
@@ -35,6 +38,12 @@ void bdrv_set_dirty_bitmap(BdrvDirtyBitmap *bitmap,
int64_t cur_sector, int nr_sectors);
void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap,
int64_t cur_sector, int nr_sectors);
+int bdrv_dirty_bitmap_get_meta(BlockDriverState *bs,
+ BdrvDirtyBitmap *bitmap, int64_t sector,
+ int nb_sectors);
+void bdrv_dirty_bitmap_reset_meta(BlockDriverState *bs,
+ BdrvDirtyBitmap *bitmap, int64_t sector,
+ int nb_sectors);
BdrvDirtyBitmapIter *bdrv_dirty_iter_new(BdrvDirtyBitmap *bitmap,
uint64_t first_sector);
void bdrv_dirty_iter_free(BdrvDirtyBitmapIter *iter);
In my migration series I need iterators, get granularity, and something
like hbitmap_count for meta bitmaps. You can add them here if you want,
or I can add them in my series.
--
Best regards,
Vladimir
* now, @virtuozzo.com instead of @parallels.com. Sorry for this inconvenience.