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, 7 insertions, 1 deletions

diff --git a/block/mirror.c b/block/mirror.c
index b33f4bb1d6..eaf0fe7858 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -621,6 +621,7 @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s)
     BlockDriverState *bs = s->source;
     BlockDriverState *target_bs = blk_bs(s->target);
     int ret, n;
+    int64_t count;
 
     end = s->bdev_length / BDRV_SECTOR_SIZE;
 
@@ -670,11 +671,16 @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s)
             return 0;
         }
 
-        ret = bdrv_is_allocated_above(bs, base, sector_num, nb_sectors, &n);
+        ret = bdrv_is_allocated_above(bs, base, sector_num * BDRV_SECTOR_SIZE,
+                                      nb_sectors * BDRV_SECTOR_SIZE, &count);
         if (ret < 0) {
             return ret;
         }
 
+        /* TODO: Relax this once bdrv_is_allocated_above and dirty
+         * bitmaps no longer require sector alignment. */
+        assert(QEMU_IS_ALIGNED(count, BDRV_SECTOR_SIZE));
+        n = count >> BDRV_SECTOR_BITS;
         assert(n > 0);
         if (ret == 1) {
             bdrv_set_dirty_bitmap(s->dirty_bitmap, sector_num, n);