block: Make bdrv_is_allocated_above() byte-based

We are gradually moving away from sector-based interfaces, towards
byte-based.  In the common case, allocation is unlikely to ever use
values that are not naturally sector-aligned, but it is possible
that byte-based values will let us be more precise about allocation
at the end of an unaligned file that can do byte-based access.

Changing the signature of the function to use int64_t *pnum ensures
that the compiler enforces that all callers are updated.  For now,
the io.c layer still assert()s that all callers are sector-aligned,
but that can be relaxed when a later patch implements byte-based
block status.  Therefore, for the most part this patch is just the
addition of scaling at the callers followed by inverse scaling at
bdrv_is_allocated().  But some code, particularly stream_run(),
gets a lot simpler because it no longer has to mess with sectors.
Leave comments where we can further simplify by switching to
byte-based iterations, once later patches eliminate the need for
sector-aligned operations.

For ease of review, bdrv_is_allocated() was tackled separately.

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

1 files changed, 12 insertions, 5 deletions

diff --git a/block/replication.c b/block/replication.c
index 8f3aba7a20..bf4462c8e7 100644
--- a/block/replication.c
+++ b/block/replication.c
@@ -264,7 +264,8 @@ static coroutine_fn int replication_co_writev(BlockDriverState *bs,
     BdrvChild *top = bs->file;
     BdrvChild *base = s->secondary_disk;
     BdrvChild *target;
-    int ret, n;
+    int ret;
+    int64_t n;
 
     ret = replication_get_io_status(s);
     if (ret < 0) {
@@ -283,14 +284,20 @@ static coroutine_fn int replication_co_writev(BlockDriverState *bs,
      */
     qemu_iovec_init(&hd_qiov, qiov->niov);
     while (remaining_sectors > 0) {
-        ret = bdrv_is_allocated_above(top->bs, base->bs, sector_num,
-                                      remaining_sectors, &n);
+        int64_t count;
+
+        ret = bdrv_is_allocated_above(top->bs, base->bs,
+                                      sector_num * BDRV_SECTOR_SIZE,
+                                      remaining_sectors * BDRV_SECTOR_SIZE,
+                                      &count);
         if (ret < 0) {
             goto out1;
         }
 
+        assert(QEMU_IS_ALIGNED(count, BDRV_SECTOR_SIZE));
+        n = count >> BDRV_SECTOR_BITS;
         qemu_iovec_reset(&hd_qiov);
-        qemu_iovec_concat(&hd_qiov, qiov, bytes_done, n * BDRV_SECTOR_SIZE);
+        qemu_iovec_concat(&hd_qiov, qiov, bytes_done, count);
 
         target = ret ? top : base;
         ret = bdrv_co_writev(target, sector_num, n, &hd_qiov);
@@ -300,7 +307,7 @@ static coroutine_fn int replication_co_writev(BlockDriverState *bs,
 
         remaining_sectors -= n;
         sector_num += n;
-        bytes_done += n * BDRV_SECTOR_SIZE;
+        bytes_done += count;
     }
 
 out1: