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[Qemu-block] [PATCH v9 04/10] block: Support meta dirty bitmap
From: |
John Snow |
Subject: |
[Qemu-block] [PATCH v9 04/10] block: Support meta dirty bitmap |
Date: |
Tue, 4 Oct 2016 18:52:38 -0400 |
From: Fam Zheng <address@hidden>
The added group of operations enables tracking of the changed bits in
the dirty bitmap.
Signed-off-by: Fam Zheng <address@hidden>
Reviewed-by: Max Reitz <address@hidden>
Signed-off-by: John Snow <address@hidden>
---
block/dirty-bitmap.c | 52 ++++++++++++++++++++++++++++++++++++++++++++
include/block/dirty-bitmap.h | 9 ++++++++
2 files changed, 61 insertions(+)
diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index c572dfa..9c6febb 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -38,6 +38,7 @@
*/
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) */
@@ -103,6 +104,56 @@ 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.
+ * @chunk_size: how many bytes of bitmap data does each bit in the meta bitmap
+ * track.
+ */
+void bdrv_create_meta_dirty_bitmap(BdrvDirtyBitmap *bitmap,
+ int chunk_size)
+{
+ assert(!bitmap->meta);
+ bitmap->meta = hbitmap_create_meta(bitmap->bitmap,
+ chunk_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 sectors_per_bit = 1 << hbitmap_granularity(bitmap->meta);
+
+ /* 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 += sectors_per_bit) {
+ 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;
@@ -233,6 +284,7 @@ static void
bdrv_do_release_matching_dirty_bitmap(BlockDriverState *bs,
if ((!bitmap || bm == bitmap) && (!only_named || bm->name)) {
assert(!bm->active_iterators);
assert(!bdrv_dirty_bitmap_frozen(bm));
+ assert(!bm->meta);
QLIST_REMOVE(bm, list);
hbitmap_free(bm->bitmap);
g_free(bm->name);
diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
index 0ef927d..69c500b 100644
--- a/include/block/dirty-bitmap.h
+++ b/include/block/dirty-bitmap.h
@@ -8,6 +8,9 @@ BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs,
uint32_t granularity,
const char *name,
Error **errp);
+void bdrv_create_meta_dirty_bitmap(BdrvDirtyBitmap *bitmap,
+ int chunk_size);
+void bdrv_release_meta_dirty_bitmap(BdrvDirtyBitmap *bitmap);
int bdrv_dirty_bitmap_create_successor(BlockDriverState *bs,
BdrvDirtyBitmap *bitmap,
Error **errp);
@@ -36,6 +39,12 @@ void bdrv_set_dirty_bitmap(BdrvDirtyBitmap *bitmap,
int64_t cur_sector, int64_t nr_sectors);
void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap,
int64_t cur_sector, int64_t 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);
--
2.7.4
- [Qemu-block] [PATCH v9 00/10] Dirty bitmap changes for migration/persistence work, John Snow, 2016/10/04
- [Qemu-block] [PATCH v9 03/10] tests: Add test code for meta bitmap, John Snow, 2016/10/04
- [Qemu-block] [PATCH v9 02/10] HBitmap: Introduce "meta" bitmap to track bit changes, John Snow, 2016/10/04
- [Qemu-block] [PATCH v9 05/10] block: Add two dirty bitmap getters, John Snow, 2016/10/04
- [Qemu-block] [PATCH v9 01/10] block: Hide HBitmap in block dirty bitmap interface, John Snow, 2016/10/04
- [Qemu-block] [PATCH v9 08/10] block: BdrvDirtyBitmap serialization interface, John Snow, 2016/10/04
- [Qemu-block] [PATCH v9 04/10] block: Support meta dirty bitmap,
John Snow <=
- [Qemu-block] [PATCH v9 06/10] block: Assert that bdrv_release_dirty_bitmap succeeded, John Snow, 2016/10/04
- [Qemu-block] [PATCH v9 10/10] block: More operations for meta dirty bitmap, John Snow, 2016/10/04
- [Qemu-block] [PATCH v9 07/10] hbitmap: serialization, John Snow, 2016/10/04
- [Qemu-block] [PATCH v9 09/10] tests: Add test code for hbitmap serialization, John Snow, 2016/10/04