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>
diff --git a/block/mirror.c b/block/mirror.c
index b33f4bb..eaf0fe7 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -621,6 +621,7 @@
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 @@
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);
