We have bdrv_dirty_bitmap_next_zero, let's add corresponding bdrv_dirty_bitmap_next_dirty, which is more comfortable to use than bitmap iterators in some cases. It will be used in the following commit.
Signed-off-by: Vladimir Sementsov-Ogievskiy <[email protected]> --- include/block/dirty-bitmap.h | 2 ++ include/qemu/hbitmap.h | 13 ++++++++ block/dirty-bitmap.c | 6 ++++ util/hbitmap.c | 61 +++++++++++++++++++----------------- 4 files changed, 54 insertions(+), 28 deletions(-) diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h index 493c4566d3..d1310ee76e 100644 --- a/include/block/dirty-bitmap.h +++ b/include/block/dirty-bitmap.h @@ -108,6 +108,8 @@ bool bdrv_has_changed_persistent_bitmaps(BlockDriverState *bs); BdrvDirtyBitmap *bdrv_dirty_bitmap_next(BlockDriverState *bs, BdrvDirtyBitmap *bitmap); char *bdrv_dirty_bitmap_sha256(const BdrvDirtyBitmap *bitmap, Error **errp); +int64_t bdrv_dirty_bitmap_next_dirty(BdrvDirtyBitmap *bitmap, int64_t offset, + int64_t bytes); int64_t bdrv_dirty_bitmap_next_zero(BdrvDirtyBitmap *bitmap, int64_t offset, int64_t bytes); bool bdrv_dirty_bitmap_next_dirty_area(BdrvDirtyBitmap *bitmap, diff --git a/include/qemu/hbitmap.h b/include/qemu/hbitmap.h index 5149ac7721..80ecabe8e2 100644 --- a/include/qemu/hbitmap.h +++ b/include/qemu/hbitmap.h @@ -299,6 +299,19 @@ void hbitmap_iter_init(HBitmapIter *hbi, const HBitmap *hb, uint64_t first); */ unsigned long hbitmap_iter_skip_words(HBitmapIter *hbi); +/* + * hbitmap_next_dirty: + * + * Find next dirty bit within selected range. If not found, return -1. + * + * @hb: The HBitmap to operate on + * @start: The bit to start from. + * @count: Number of bits to proceed. If @start+@count > bitmap size, the whole + * bitmap is looked through. You can use UINT64_MAX as @count to search up to + * the bitmap end. + */ +int64_t hbitmap_next_dirty(const HBitmap *hb, int64_t start, int64_t count); + /* hbitmap_next_zero: * * Find next not dirty bit within selected range. If not found, return -1. diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c index eeccdb48f5..efe3a39d49 100644 --- a/block/dirty-bitmap.c +++ b/block/dirty-bitmap.c @@ -802,6 +802,12 @@ char *bdrv_dirty_bitmap_sha256(const BdrvDirtyBitmap *bitmap, Error **errp) return hbitmap_sha256(bitmap->bitmap, errp); } +int64_t bdrv_dirty_bitmap_next_dirty(BdrvDirtyBitmap *bitmap, int64_t offset, + int64_t bytes) +{ + return hbitmap_next_zero(bitmap->bitmap, offset, bytes); +} + int64_t bdrv_dirty_bitmap_next_zero(BdrvDirtyBitmap *bitmap, int64_t offset, int64_t bytes) { diff --git a/util/hbitmap.c b/util/hbitmap.c index c08751fb50..3f2d7451ce 100644 --- a/util/hbitmap.c +++ b/util/hbitmap.c @@ -193,6 +193,30 @@ void hbitmap_iter_init(HBitmapIter *hbi, const HBitmap *hb, uint64_t first) } } +int64_t hbitmap_next_dirty(const HBitmap *hb, int64_t start, int64_t count) +{ + HBitmapIter hbi; + int64_t firt_dirty_off; + uint64_t end; + + assert(start >= 0 && count >= 0); + + if (start >= hb->orig_size || count == 0) { + return -1; + } + + end = count > hb->orig_size - start ? hb->orig_size : start + count; + + hbitmap_iter_init(&hbi, hb, start); + firt_dirty_off = hbitmap_iter_next(&hbi); + + if (firt_dirty_off < 0 || firt_dirty_off >= end) { + return -1; + } + + return MAX(start, firt_dirty_off); +} + int64_t hbitmap_next_zero(const HBitmap *hb, int64_t start, int64_t count) { size_t pos = (start >> hb->granularity) >> BITS_PER_LEVEL; @@ -248,40 +272,21 @@ int64_t hbitmap_next_zero(const HBitmap *hb, int64_t start, int64_t count) bool hbitmap_next_dirty_area(const HBitmap *hb, int64_t *start, int64_t *count) { - HBitmapIter hbi; - int64_t firt_dirty_off, area_end; - uint32_t granularity = 1UL << hb->granularity; - uint64_t end; - - assert(*start >= 0 && *count >= 0); - - if (*start >= hb->orig_size || *count == 0) { - return false; - } - - end = *count > hb->orig_size - *start ? hb->orig_size : *start + *count; - - hbitmap_iter_init(&hbi, hb, *start); - firt_dirty_off = hbitmap_iter_next(&hbi); + int64_t area_start, area_end; - if (firt_dirty_off < 0 || firt_dirty_off >= end) { + area_start = hbitmap_next_dirty(hb, *start, *count); + if (area_start < 0) { return false; } - if (firt_dirty_off + granularity >= end) { - area_end = end; - } else { - area_end = hbitmap_next_zero(hb, firt_dirty_off + granularity, - end - firt_dirty_off - granularity); - if (area_end < 0) { - area_end = end; - } + area_end = QEMU_ALIGN_UP(area_start + 1, 1UL << hb->granularity); + area_end = hbitmap_next_zero(hb, area_end, *start + *count - area_end); + if (area_end < 0) { + area_end = MIN(hb->orig_size, *start + *count); } - if (firt_dirty_off > *start) { - *start = firt_dirty_off; - } - *count = area_end - *start; + *start = area_start; + *count = area_end - area_start; return true; } -- 2.18.0
