diff mbox

[PULL,25/35] qcow2: Reduce is_zero() rounding

Message ID 20171026131741.5059-26-kwolf@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Kevin Wolf Oct. 26, 2017, 1:17 p.m. UTC 
From: 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>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qcow2.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)
diff mbox

Patch

diff --git a/block/qcow2.c b/block/qcow2.c
index 29d0a50955..fbf9464d3a 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -2976,22 +2976,16 @@  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;
 }