bloc/qcow2: drop dirty_bitmaps_loaded state variable

This variable doesn't work as it should, because it is actually cleared
in qcow2_co_invalidate_cache() by memset(). Drop it, as the following
patch will introduce new behavior.
Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: NJohn Snow <jsnow@redhat.com>
Signed-off-by: NJohn Snow <jsnow@redhat.com>

block/qcow2.c

@@ -1153,7 +1153,6 @@ static int coroutine_fn qcow2_do_open(BlockDriverState *bs, QDict *options,
     uint64_t ext_end;
     uint64_t l1_vm_state_index;
     bool update_header = false;
-    bool header_updated = false;
 
     ret = bdrv_pread(bs->file, 0, &header, sizeof(header));
     if (ret < 0) {
@@ -1492,23 +1491,9 @@ static int coroutine_fn qcow2_do_open(BlockDriverState *bs, QDict *options,
         s->autoclear_features &= QCOW2_AUTOCLEAR_MASK;
     }
 
-    if (s->dirty_bitmaps_loaded) {
-        /* It's some kind of reopen. There are no known cases where we need to
-         * reload bitmaps in such a situation, so it's safer to skip them.
-         *
-         * Moreover, if we have some readonly bitmaps and we are reopening for
-         * rw we should reopen bitmaps correspondingly.
-         */
-        if (bdrv_has_readonly_bitmaps(bs) &&
-            !bdrv_is_read_only(bs) && !(bdrv_get_flags(bs) & BDRV_O_INACTIVE))
-        {
-            qcow2_reopen_bitmaps_rw_hint(bs, &header_updated, &local_err);
-        }
-    } else {
-        header_updated = qcow2_load_dirty_bitmaps(bs, &local_err);
-        s->dirty_bitmaps_loaded = true;
+    if (qcow2_load_dirty_bitmaps(bs, &local_err)) {
+        update_header = false;
     }
-    update_header = update_header && !header_updated;
     if (local_err != NULL) {
         error_propagate(errp, local_err);
         ret = -EINVAL;

block/qcow2.h

@@ -300,7 +300,6 @@ typedef struct BDRVQcow2State {
     uint32_t nb_bitmaps;
     uint64_t bitmap_directory_size;
     uint64_t bitmap_directory_offset;
-    bool dirty_bitmaps_loaded;
 
     int flags;
     int qcow_version;