/* hbitmap_create_meta:
* Create a "meta" hbitmap to track dirtiness of the bits in this HBitmap.
diff --git a/block/backup.c b/block/backup.c
index 8630d32926..9bfd3f7189 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -458,7 +458,7 @@ static void
backup_incremental_init_copy_bitmap(BackupBlockJob *job)
break;
}
- offset = bdrv_dirty_bitmap_next_zero(job->sync_bitmap, offset);
+ offset = bdrv_dirty_bitmap_next_zero(job->sync_bitmap, offset, -1);
if (offset == -1) {
hbitmap_set(job->copy_bitmap, cluster, end - cluster);
break;
diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index c9b8a6fd52..037ae62726 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -785,9 +785,10 @@ 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)
+int64_t bdrv_dirty_bitmap_next_zero(BdrvDirtyBitmap *bitmap, uint64_t offset,
+ int64_t end)
{
- return hbitmap_next_zero(bitmap->bitmap, offset);
+ return hbitmap_next_zero(bitmap->bitmap, offset, end);
}
void bdrv_merge_dirty_bitmap(BdrvDirtyBitmap *dest, const BdrvDirtyBitmap *src,
diff --git a/nbd/server.c b/nbd/server.c
index ea5fe0eb33..07920d123b 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -1952,7 +1952,7 @@ static unsigned int bitmap_to_extents(BdrvDirtyBitmap
*bitmap, uint64_t offset,
assert(begin < overall_end && nb_extents);
while (begin < overall_end && i < nb_extents) {
if (dirty) {
- end = bdrv_dirty_bitmap_next_zero(bitmap, begin);
+ end = bdrv_dirty_bitmap_next_zero(bitmap, begin, -1);
} else {
bdrv_set_dirty_iter(it, begin);
end = bdrv_dirty_iter_next(it);
diff --git a/tests/test-hbitmap.c b/tests/test-hbitmap.c
index 5e67ac1d3a..6b6a40bddd 100644
--- a/tests/test-hbitmap.c
+++ b/tests/test-hbitmap.c
@@ -939,7 +939,7 @@ static void test_hbitmap_iter_and_reset(TestHBitmapData
*data,
static void test_hbitmap_next_zero_check(TestHBitmapData *data, int64_t start)
{
- int64_t ret1 = hbitmap_next_zero(data->hb, start);
+ int64_t ret1 = hbitmap_next_zero(data->hb, start, -1);
int64_t ret2 = start;
for ( ; ret2 < data->size && hbitmap_get(data->hb, ret2); ret2++) {
;
diff --git a/util/hbitmap.c b/util/hbitmap.c
index bcd304041a..1687372504 100644
--- a/util/hbitmap.c
+++ b/util/hbitmap.c
@@ -53,6 +53,9 @@
*/
struct HBitmap {
+ /* Size of the bitmap, as requested in hbitmap_alloc. */
+ uint64_t orig_size;
+
/* Number of total bits in the bottom level. */
uint64_t size;
@@ -192,16 +195,26 @@ void hbitmap_iter_init(HBitmapIter *hbi, const HBitmap *hb, uint64_t first)
}
}
-int64_t hbitmap_next_zero(const HBitmap *hb, uint64_t start)
+int64_t hbitmap_next_zero(const HBitmap *hb, uint64_t start, int64_t end)
{
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);
+ unsigned start_bit_offset;
+ uint64_t end_bit, sz;
int64_t res;
+ if (start >= hb->orig_size || (end != -1 && end <= start)) {
+ return -1;
+ }
+
+ end_bit = end == -1 ? hb->size : ((end - 1) >> hb->granularity) + 1;
+ sz = (end_bit + BITS_PER_LONG - 1) >> BITS_PER_LEVEL;
+
+ /* There may be some zero bits in @cur before @start. We are not interested
+ * in them, let's set them.
+ */
+ start_bit_offset = (start >> hb->granularity) & (BITS_PER_LONG - 1);
cur |= (1UL << start_bit_offset) - 1;
assert((start >> hb->granularity) < hb->size);
@@ -218,7 +231,7 @@ int64_t hbitmap_next_zero(const HBitmap *hb, uint64_t start)
}
res = (pos << BITS_PER_LEVEL) + ctol(cur);
- if (res >= hb->size) {
+ if (res >= end_bit) {
return -1;
}
@@ -652,6 +665,8 @@ HBitmap *hbitmap_alloc(uint64_t size, int granularity)
HBitmap *hb = g_new0(struct HBitmap, 1);
unsigned i;
+ hb->orig_size = size;
+
assert(granularity >= 0 && granularity < 64);
size = (size + (1ULL << granularity) - 1) >> granularity;
assert(size <= ((uint64_t)1 << HBITMAP_LOG_MAX_SIZE));