[Qemu-devel] [PATCH v6 23/24] qcow2: Relax is_zero() assertion

[Eric Blake <eblake@redhat.com>]

Now that bdrv_is_allocated accepts non-aligned inputs, we can
remove the TODO added in earlier refactoring.

Signed-off-by: Eric Blake <eblake@redhat.com>

---
v6: new patch [Kevin]
---
 block/qcow2.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/block/qcow2.c b/block/qcow2.c
index 092a3cabdb..92cb9f9bfa 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -3003,22 +3003,16 @@ static bool is_zero(BlockDriverState *bs, int64_t offset, int64_t bytes)
 {
     int64_t nr;
     int res;
-    int64_t start;
-
-    /* TODO: Widening to sector boundaries should only be needed as
-     * long as we can't query finer granularity. */
-    start = QEMU_ALIGN_DOWN(offset, BDRV_SECTOR_SIZE);
-    bytes = QEMU_ALIGN_UP(offset + bytes, BDRV_SECTOR_SIZE) - start;

     /* Clamp to image length, before checking status of underlying sectors */
-    if (start + bytes > bs->total_sectors * BDRV_SECTOR_SIZE) {
-        bytes = bs->total_sectors * BDRV_SECTOR_SIZE - start;
+    if (offset + bytes > bs->total_sectors * BDRV_SECTOR_SIZE) {
+        bytes = bs->total_sectors * BDRV_SECTOR_SIZE - offset;
     }

     if (!bytes) {
         return true;
     }
-    res = bdrv_block_status_above(bs, NULL, start, bytes, &nr, NULL, NULL);
+    res = bdrv_block_status_above(bs, NULL, offset, bytes, &nr, NULL, NULL);
     return res >= 0 && (res & BDRV_BLOCK_ZERO) && nr == bytes;
 }

-- 
2.13.6