@@ -455,6 +455,8 @@ static void coroutine_fn mirror_run(void *opaque)
if (!s->is_none_mode) {
/* First part, loop on the sectors and initialize the dirty bitmap. */
BlockDriverState *base = s->base;
+ bool mark_all_dirty = s->base == NULL && !bdrv_has_zero_init(s->target);
+
for (sector_num = 0; sector_num < end; ) {
/* Just to make sure we are not exceeding int limit. */
int nb_sectors = MIN(INT_MAX >> BDRV_SECTOR_BITS,
@@ -477,7 +479,7 @@ static void coroutine_fn mirror_run(void *opaque)
}
assert(n > 0);
- if (ret == 1) {
+ if (ret == 1 || mark_all_dirty) {
bdrv_set_dirty_bitmap(s->dirty_bitmap, sector_num, n);
}
sector_num += n;
During mirror, if the target device does not support zero init, a mirror may result in a corrupted image for sync="full" mode. This is due to how the initial dirty bitmap is set up prior to copying data - we did not mark sectors as dirty that are unallocated. This means those unallocated sectors are skipped over on the target, and for a device without zero init, invalid data may reside in those holes. If both of the following conditions are true, then we will explicitly mark all sectors as dirty: 1.) sync = "full" 2.) bdrv_has_zero_init(target) == false If the target does support zero init, but a target image is passed in with data already present (i.e. an "existing" image), it is assumed the data present in the existing image is valid data for those sectors. Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 91ed4bc5bda7e2b09eb508b07c83f4071fe0b3c9.1443705220.git.jcody@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com> --- block/mirror.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)