We are still using an internal hbitmap that tracks a size in sectors, with the granularity scaled down accordingly, because it lets us use a shortcut for our iterators which are currently sector-based. But there's no reason we can't track the dirty bitmap size in bytes, since it is an internal-only variable.
Signed-off-by: Eric Blake <ebl...@redhat.com> --- block/dirty-bitmap.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c index 32698d5..a413df1 100644 --- a/block/dirty-bitmap.c +++ b/block/dirty-bitmap.c @@ -41,7 +41,7 @@ struct BdrvDirtyBitmap { 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) */ + int64_t size; /* Size of the bitmap, in bytes */ bool disabled; /* Bitmap is read-only */ int active_iterators; /* How many iterators are active */ QLIST_ENTRY(BdrvDirtyBitmap) list; @@ -79,24 +79,26 @@ BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs, { int64_t bitmap_size; BdrvDirtyBitmap *bitmap; - uint32_t sector_granularity; - assert((granularity & (granularity - 1)) == 0); + assert(is_power_of_2(granularity) && granularity >= BDRV_SECTOR_SIZE); if (name && bdrv_find_dirty_bitmap(bs, name)) { error_setg(errp, "Bitmap already exists: %s", name); return NULL; } - sector_granularity = granularity >> BDRV_SECTOR_BITS; - assert(sector_granularity); - bitmap_size = bdrv_nb_sectors(bs); + bitmap_size = bdrv_getlength(bs); if (bitmap_size < 0) { error_setg_errno(errp, -bitmap_size, "could not get length of device"); errno = -bitmap_size; return NULL; } bitmap = g_new0(BdrvDirtyBitmap, 1); - bitmap->bitmap = hbitmap_alloc(bitmap_size, ctz32(sector_granularity)); + /* + * TODO - let hbitmap track full granularity. For now, it is tracking + * only sector granularity, as a shortcut for our iterators. + */ + bitmap->bitmap = hbitmap_alloc(bitmap_size >> BDRV_SECTOR_BITS, + ctz32(granularity) - BDRV_SECTOR_BITS); bitmap->size = bitmap_size; bitmap->name = g_strdup(name); bitmap->disabled = false; @@ -246,12 +248,13 @@ BdrvDirtyBitmap *bdrv_reclaim_dirty_bitmap(BlockDriverState *bs, void bdrv_dirty_bitmap_truncate(BlockDriverState *bs) { BdrvDirtyBitmap *bitmap; - uint64_t size = bdrv_nb_sectors(bs); + int64_t size = bdrv_getlength(bs); + assert(size >= 0); QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) { assert(!bdrv_dirty_bitmap_frozen(bitmap)); assert(!bitmap->active_iterators); - hbitmap_truncate(bitmap->bitmap, size); + hbitmap_truncate(bitmap->bitmap, size >> BDRV_SECTOR_BITS); bitmap->size = size; } } @@ -419,7 +422,7 @@ void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out) hbitmap_reset_all(bitmap->bitmap); } else { HBitmap *backup = bitmap->bitmap; - bitmap->bitmap = hbitmap_alloc(bitmap->size, + bitmap->bitmap = hbitmap_alloc(bitmap->size >> BDRV_SECTOR_BITS, hbitmap_granularity(backup)); *out = backup; } -- 2.9.3