diff options
| -rw-r--r-- | block/dirty-bitmap.c | 5 | ||||
| -rw-r--r-- | include/block/dirty-bitmap.h | 1 | ||||
| -rw-r--r-- | include/qemu/hbitmap.h | 8 | ||||
| -rw-r--r-- | tests/test-hbitmap.c | 61 | ||||
| -rw-r--r-- | util/hbitmap.c | 39 |
5 files changed, 114 insertions, 0 deletions
diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c index bd04e991b1..7879d13ddb 100644 --- a/block/dirty-bitmap.c +++ b/block/dirty-bitmap.c @@ -715,3 +715,8 @@ char *bdrv_dirty_bitmap_sha256(const BdrvDirtyBitmap *bitmap, Error **errp) { return hbitmap_sha256(bitmap->bitmap, errp); } + +int64_t bdrv_dirty_bitmap_next_zero(BdrvDirtyBitmap *bitmap, uint64_t offset) +{ + return hbitmap_next_zero(bitmap->bitmap, offset); +} diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h index 3579a7597c..a591c27213 100644 --- a/include/block/dirty-bitmap.h +++ b/include/block/dirty-bitmap.h @@ -91,5 +91,6 @@ 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_zero(BdrvDirtyBitmap *bitmap, uint64_t start); #endif diff --git a/include/qemu/hbitmap.h b/include/qemu/hbitmap.h index 81e78043d1..6b6490ecad 100644 --- a/include/qemu/hbitmap.h +++ b/include/qemu/hbitmap.h @@ -292,6 +292,14 @@ void hbitmap_iter_init(HBitmapIter *hbi, const HBitmap *hb, uint64_t first); */ unsigned long hbitmap_iter_skip_words(HBitmapIter *hbi); +/* hbitmap_next_zero: + * @hb: The HBitmap to operate on + * @start: The bit to start from. + * + * Find next not dirty bit. + */ +int64_t hbitmap_next_zero(const HBitmap *hb, uint64_t start); + /* hbitmap_create_meta: * Create a "meta" hbitmap to track dirtiness of the bits in this HBitmap. * The caller owns the created bitmap and must call hbitmap_free_meta(hb) to diff --git a/tests/test-hbitmap.c b/tests/test-hbitmap.c index af41642346..9091c639b3 100644 --- a/tests/test-hbitmap.c +++ b/tests/test-hbitmap.c @@ -925,6 +925,61 @@ static void test_hbitmap_iter_and_reset(TestHBitmapData *data, hbitmap_iter_next(&hbi); } +static void test_hbitmap_next_zero_check(TestHBitmapData *data, int64_t start) +{ + int64_t ret1 = hbitmap_next_zero(data->hb, start); + int64_t ret2 = start; + for ( ; ret2 < data->size && hbitmap_get(data->hb, ret2); ret2++) { + ; + } + if (ret2 == data->size) { + ret2 = -1; + } + + g_assert_cmpint(ret1, ==, ret2); +} + +static void test_hbitmap_next_zero_do(TestHBitmapData *data, int granularity) +{ + hbitmap_test_init(data, L3, granularity); + test_hbitmap_next_zero_check(data, 0); + test_hbitmap_next_zero_check(data, L3 - 1); + + hbitmap_set(data->hb, L2, 1); + test_hbitmap_next_zero_check(data, 0); + test_hbitmap_next_zero_check(data, L2 - 1); + test_hbitmap_next_zero_check(data, L2); + test_hbitmap_next_zero_check(data, L2 + 1); + + hbitmap_set(data->hb, L2 + 5, L1); + test_hbitmap_next_zero_check(data, 0); + test_hbitmap_next_zero_check(data, L2 + 1); + test_hbitmap_next_zero_check(data, L2 + 2); + test_hbitmap_next_zero_check(data, L2 + 5); + test_hbitmap_next_zero_check(data, L2 + L1 - 1); + test_hbitmap_next_zero_check(data, L2 + L1); + + hbitmap_set(data->hb, L2 * 2, L3 - L2 * 2); + test_hbitmap_next_zero_check(data, L2 * 2 - L1); + test_hbitmap_next_zero_check(data, L2 * 2 - 2); + test_hbitmap_next_zero_check(data, L2 * 2 - 1); + test_hbitmap_next_zero_check(data, L2 * 2); + test_hbitmap_next_zero_check(data, L3 - 1); + + hbitmap_set(data->hb, 0, L3); + test_hbitmap_next_zero_check(data, 0); +} + +static void test_hbitmap_next_zero_0(TestHBitmapData *data, const void *unused) +{ + test_hbitmap_next_zero_do(data, 0); +} + +static void test_hbitmap_next_zero_4(TestHBitmapData *data, const void *unused) +{ + test_hbitmap_next_zero_do(data, 4); +} + int main(int argc, char **argv) { g_test_init(&argc, &argv, NULL); @@ -985,6 +1040,12 @@ int main(int argc, char **argv) hbitmap_test_add("/hbitmap/iter/iter_and_reset", test_hbitmap_iter_and_reset); + + hbitmap_test_add("/hbitmap/next_zero/next_zero_0", + test_hbitmap_next_zero_0); + hbitmap_test_add("/hbitmap/next_zero/next_zero_4", + test_hbitmap_next_zero_4); + g_test_run(); return 0; diff --git a/util/hbitmap.c b/util/hbitmap.c index 2f9d0fdbd0..289778a55c 100644 --- a/util/hbitmap.c +++ b/util/hbitmap.c @@ -188,6 +188,45 @@ void hbitmap_iter_init(HBitmapIter *hbi, const HBitmap *hb, uint64_t first) } } +int64_t hbitmap_next_zero(const HBitmap *hb, uint64_t start) +{ + size_t pos = (start >> hb->granularity) >> BITS_PER_LEVEL; + unsigned long *last_lev = hb->levels[HBITMAP_LEVELS - 1]; + uint64_t sz = hb->sizes[HBITMAP_LEVELS - 1]; + unsigned long cur = last_lev[pos]; + unsigned start_bit_offset = + (start >> hb->granularity) & (BITS_PER_LONG - 1); + int64_t res; + + cur |= (1UL << start_bit_offset) - 1; + assert((start >> hb->granularity) < hb->size); + + if (cur == (unsigned long)-1) { + do { + pos++; + } while (pos < sz && last_lev[pos] == (unsigned long)-1); + + if (pos >= sz) { + return -1; + } + + cur = last_lev[pos]; + } + + res = (pos << BITS_PER_LEVEL) + ctol(cur); + if (res >= hb->size) { + return -1; + } + + res = res << hb->granularity; + if (res < start) { + assert(((start - res) >> hb->granularity) == 0); + return start; + } + + return res; +} + bool hbitmap_empty(const HBitmap *hb) { return hb->count == 0; |