[Qemu-devel] [PATCH v9 20/20] dirty-bitmap: Convert internal hbitmap size/granularity

[Eric Blake <eblake@redhat.com>]

Now that all callers are using byte-based interfaces, there's no
reason for our internal hbitmap to remain with sector-based
granularity.  It also simplifies our internal scaling, since we
already know that hbitmap widens requests out to granularity
boundaries.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>

---
v9: no change
v8: rebase to earlier truncate changes (R-b kept)
v7: rebase to dirty_iter_next cleanup (no semantic change, R-b kept)
v6: no change
v5: fix bdrv_dirty_bitmap_truncate [John]
v4: rebase to earlier changes, include serialization, R-b dropped
v3: no change
v2: no change
---
 block/dirty-bitmap.c | 62 +++++++++++++++-------------------------------------
 1 file changed, 18 insertions(+), 44 deletions(-)

diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index 58a3f330a9..bd04e991b1 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -38,7 +38,7 @@
  */
 struct BdrvDirtyBitmap {
     QemuMutex *mutex;
-    HBitmap *bitmap;            /* Dirty sector bitmap implementation */
+    HBitmap *bitmap;            /* Dirty bitmap implementation */
     HBitmap *meta;              /* Meta dirty bitmap */
     BdrvDirtyBitmap *successor; /* Anonymous child; implies frozen status */
     char *name;                 /* Optional non-empty unique ID */
@@ -130,12 +130,7 @@ BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs,
     }
     bitmap = g_new0(BdrvDirtyBitmap, 1);
     bitmap->mutex = &bs->dirty_bitmap_mutex;
-    /*
-     * TODO - let hbitmap track full granularity. For now, it is tracking
-     * only sector granularity, as a shortcut for our iterators.
-     */
-    bitmap->bitmap = hbitmap_alloc(DIV_ROUND_UP(bitmap_size, BDRV_SECTOR_SIZE),
-                                   ctz32(granularity) - BDRV_SECTOR_BITS);
+    bitmap->bitmap = hbitmap_alloc(bitmap_size, ctz32(granularity));
     bitmap->size = bitmap_size;
     bitmap->name = g_strdup(name);
     bitmap->disabled = false;
@@ -312,7 +307,7 @@ void bdrv_dirty_bitmap_truncate(BlockDriverState *bs, int64_t bytes)
     QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) {
         assert(!bdrv_dirty_bitmap_frozen(bitmap));
         assert(!bitmap->active_iterators);
-        hbitmap_truncate(bitmap->bitmap, DIV_ROUND_UP(bytes, BDRV_SECTOR_SIZE));
+        hbitmap_truncate(bitmap->bitmap, bytes);
         bitmap->size = bytes;
     }
     bdrv_dirty_bitmaps_unlock(bs);
@@ -442,7 +437,7 @@ bool bdrv_get_dirty_locked(BlockDriverState *bs, BdrvDirtyBitmap *bitmap,
                            int64_t offset)
 {
     if (bitmap) {
-        return hbitmap_get(bitmap->bitmap, offset >> BDRV_SECTOR_BITS);
+        return hbitmap_get(bitmap->bitmap, offset);
     } else {
         return false;
     }
@@ -470,7 +465,7 @@ uint32_t bdrv_get_default_bitmap_granularity(BlockDriverState *bs)

 uint32_t bdrv_dirty_bitmap_granularity(const BdrvDirtyBitmap *bitmap)
 {
-    return BDRV_SECTOR_SIZE << hbitmap_granularity(bitmap->bitmap);
+    return 1U << hbitmap_granularity(bitmap->bitmap);
 }

 BdrvDirtyBitmapIter *bdrv_dirty_iter_new(BdrvDirtyBitmap *bitmap)
@@ -503,20 +498,16 @@ void bdrv_dirty_iter_free(BdrvDirtyBitmapIter *iter)

 int64_t bdrv_dirty_iter_next(BdrvDirtyBitmapIter *iter)
 {
-    int64_t ret = hbitmap_iter_next(&iter->hbi);
-    return ret < 0 ? -1 : ret * BDRV_SECTOR_SIZE;
+    return hbitmap_iter_next(&iter->hbi);
 }

 /* Called within bdrv_dirty_bitmap_lock..unlock */
 void bdrv_set_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap,
                                   int64_t offset, int64_t bytes)
 {
-    int64_t end_sector = DIV_ROUND_UP(offset + bytes, BDRV_SECTOR_SIZE);
-
     assert(bdrv_dirty_bitmap_enabled(bitmap));
     assert(!bdrv_dirty_bitmap_readonly(bitmap));
-    hbitmap_set(bitmap->bitmap, offset >> BDRV_SECTOR_BITS,
-                end_sector - (offset >> BDRV_SECTOR_BITS));
+    hbitmap_set(bitmap->bitmap, offset, bytes);
 }

 void bdrv_set_dirty_bitmap(BdrvDirtyBitmap *bitmap,
@@ -531,12 +522,9 @@ void bdrv_set_dirty_bitmap(BdrvDirtyBitmap *bitmap,
 void bdrv_reset_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap,
                                     int64_t offset, int64_t bytes)
 {
-    int64_t end_sector = DIV_ROUND_UP(offset + bytes, BDRV_SECTOR_SIZE);
-
     assert(bdrv_dirty_bitmap_enabled(bitmap));
     assert(!bdrv_dirty_bitmap_readonly(bitmap));
-    hbitmap_reset(bitmap->bitmap, offset >> BDRV_SECTOR_BITS,
-                  end_sector - (offset >> BDRV_SECTOR_BITS));
+    hbitmap_reset(bitmap->bitmap, offset, bytes);
 }

 void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap,
@@ -556,8 +544,7 @@ void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out)
         hbitmap_reset_all(bitmap->bitmap);
     } else {
         HBitmap *backup = bitmap->bitmap;
-        bitmap->bitmap = hbitmap_alloc(DIV_ROUND_UP(bitmap->size,
-                                                    BDRV_SECTOR_SIZE),
+        bitmap->bitmap = hbitmap_alloc(bitmap->size,
                                        hbitmap_granularity(backup));
         *out = backup;
     }
@@ -576,51 +563,40 @@ void bdrv_undo_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *in)
 uint64_t bdrv_dirty_bitmap_serialization_size(const BdrvDirtyBitmap *bitmap,
                                               uint64_t offset, uint64_t bytes)
 {
-    assert(QEMU_IS_ALIGNED(offset | bytes, BDRV_SECTOR_SIZE));
-    return hbitmap_serialization_size(bitmap->bitmap,
-                                      offset >> BDRV_SECTOR_BITS,
-                                      bytes >> BDRV_SECTOR_BITS);
+    return hbitmap_serialization_size(bitmap->bitmap, offset, bytes);
 }

 uint64_t bdrv_dirty_bitmap_serialization_align(const BdrvDirtyBitmap *bitmap)
 {
-    return hbitmap_serialization_align(bitmap->bitmap) * BDRV_SECTOR_SIZE;
+    return hbitmap_serialization_align(bitmap->bitmap);
 }

 void bdrv_dirty_bitmap_serialize_part(const BdrvDirtyBitmap *bitmap,
                                       uint8_t *buf, uint64_t offset,
                                       uint64_t bytes)
 {
-    assert(QEMU_IS_ALIGNED(offset | bytes, BDRV_SECTOR_SIZE));
-    hbitmap_serialize_part(bitmap->bitmap, buf, offset >> BDRV_SECTOR_BITS,
-                           bytes >> BDRV_SECTOR_BITS);
+    hbitmap_serialize_part(bitmap->bitmap, buf, offset, bytes);
 }

 void bdrv_dirty_bitmap_deserialize_part(BdrvDirtyBitmap *bitmap,
                                         uint8_t *buf, uint64_t offset,
                                         uint64_t bytes, bool finish)
 {
-    assert(QEMU_IS_ALIGNED(offset | bytes, BDRV_SECTOR_SIZE));
-    hbitmap_deserialize_part(bitmap->bitmap, buf, offset >> BDRV_SECTOR_BITS,
-                             bytes >> BDRV_SECTOR_BITS, finish);
+    hbitmap_deserialize_part(bitmap->bitmap, buf, offset, bytes, finish);
 }

 void bdrv_dirty_bitmap_deserialize_zeroes(BdrvDirtyBitmap *bitmap,
                                           uint64_t offset, uint64_t bytes,
                                           bool finish)
 {
-    assert(QEMU_IS_ALIGNED(offset | bytes, BDRV_SECTOR_SIZE));
-    hbitmap_deserialize_zeroes(bitmap->bitmap, offset >> BDRV_SECTOR_BITS,
-                               bytes >> BDRV_SECTOR_BITS, finish);
+    hbitmap_deserialize_zeroes(bitmap->bitmap, offset, bytes, finish);
 }

 void bdrv_dirty_bitmap_deserialize_ones(BdrvDirtyBitmap *bitmap,
                                         uint64_t offset, uint64_t bytes,
                                         bool finish)
 {
-    assert(QEMU_IS_ALIGNED(offset | bytes, BDRV_SECTOR_SIZE));
-    hbitmap_deserialize_ones(bitmap->bitmap, offset >> BDRV_SECTOR_BITS,
-                             bytes >> BDRV_SECTOR_BITS, finish);
+    hbitmap_deserialize_ones(bitmap->bitmap, offset, bytes, finish);
 }

 void bdrv_dirty_bitmap_deserialize_finish(BdrvDirtyBitmap *bitmap)
@@ -631,7 +607,6 @@ void bdrv_dirty_bitmap_deserialize_finish(BdrvDirtyBitmap *bitmap)
 void bdrv_set_dirty(BlockDriverState *bs, int64_t offset, int64_t bytes)
 {
     BdrvDirtyBitmap *bitmap;
-    int64_t end_sector = DIV_ROUND_UP(offset + bytes, BDRV_SECTOR_SIZE);

     if (QLIST_EMPTY(&bs->dirty_bitmaps)) {
         return;
@@ -643,8 +618,7 @@ void bdrv_set_dirty(BlockDriverState *bs, int64_t offset, int64_t bytes)
             continue;
         }
         assert(!bdrv_dirty_bitmap_readonly(bitmap));
-        hbitmap_set(bitmap->bitmap, offset >> BDRV_SECTOR_BITS,
-                    end_sector - (offset >> BDRV_SECTOR_BITS));
+        hbitmap_set(bitmap->bitmap, offset, bytes);
     }
     bdrv_dirty_bitmaps_unlock(bs);
 }
@@ -654,12 +628,12 @@ void bdrv_set_dirty(BlockDriverState *bs, int64_t offset, int64_t bytes)
  */
 void bdrv_set_dirty_iter(BdrvDirtyBitmapIter *iter, int64_t offset)
 {
-    hbitmap_iter_init(&iter->hbi, iter->hbi.hb, offset >> BDRV_SECTOR_BITS);
+    hbitmap_iter_init(&iter->hbi, iter->hbi.hb, offset);
 }

 int64_t bdrv_get_dirty_count(BdrvDirtyBitmap *bitmap)
 {
-    return hbitmap_count(bitmap->bitmap) << BDRV_SECTOR_BITS;
+    return hbitmap_count(bitmap->bitmap);
 }

 int64_t bdrv_get_meta_dirty_count(BdrvDirtyBitmap *bitmap)
-- 
2.13.5