bdrv_is_allocated_above() returns true in the case even for completel
zeroed areas as BDRV_BLOCK_ALLOCATED flag is set in both cases.
The patch stops using bdrv_is_allocated_above() wrapper and switches to
bdrv_get_block_status_above() to distinguish zeroed areas and areas with
data to avoid extra IO operations if possible.
Signed-off-by: Denis V. Lunev <d...@openvz.org>
CC: Stefan Hajnoczi <stefa...@redhat.com>
CC: Fam Zheng <f...@redhat.com>
CC: Kevin Wolf <kw...@redhat.com>
CC: Max Reitz <mre...@redhat.com>
CC: Jeff Cody <jc...@redhat.com>
---
block/mirror.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/block/mirror.c b/block/mirror.c
index e0b3f41..da55375 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -548,14 +548,15 @@ static void mirror_throttle(MirrorBlockJob *s)
static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s)
{
- int64_t sector_num, end;
+ int64_t sector_num, end, alloc_mask;
BlockDriverState *base = s->base;
BlockDriverState *bs = blk_bs(s->common.blk);
BlockDriverState *target_bs = blk_bs(s->target);
- int ret, n;
+ int n;
end = s->bdev_length / BDRV_SECTOR_SIZE;
+ alloc_mask = BDRV_BLOCK_ALLOCATED;
if (base == NULL && !bdrv_has_zero_init(target_bs)) {
if (!bdrv_can_write_zeroes_with_unmap(target_bs)) {
bdrv_set_dirty_bitmap(s->dirty_bitmap, 0, end);
@@ -583,6 +584,8 @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s)
}
mirror_drain(s);
+
+ alloc_mask = BDRV_BLOCK_DATA;
}
/* First part, loop on the sectors and initialize the dirty bitmap. */
@@ -590,6 +593,8 @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s)
/* Just to make sure we are not exceeding int limit. */
int nb_sectors = MIN(INT_MAX >> BDRV_SECTOR_BITS,
end - sector_num);
+ int64_t status;
+ BlockDriverState *file;
mirror_throttle(s);
@@ -597,13 +602,14 @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob
*s)
return 0;
}
- ret = bdrv_is_allocated_above(bs, base, sector_num, nb_sectors, &n);
- if (ret < 0) {
- return ret;
+ status = bdrv_get_block_status_above(bs, base, sector_num,
+ nb_sectors, &n, &file);
+ if (status < 0) {
+ return status;
}
assert(n > 0);
- if (ret == 1) {
+ if (status & alloc_mask) {
bdrv_set_dirty_bitmap(s->dirty_bitmap, sector_num, n);
}
sector_num += n;
--
2.7.4
