commit f88676c149d3c7cde2710c137aa5ef31e7f92eb4
author Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Fri Sep 27 15:23:50 2019 +0300
committer John Snow <jsnow@redhat.com> Thu Oct 17 17:02:32 2019 -0400
tree 571c7320deee46d80811cd84b552740fc48fba1e
parent 5752f89a788537cccc7a8e05904fb1b4ddf5eb43

block/qcow2-bitmap: get rid of bdrv_has_changed_persistent_bitmaps

Firstly, no reason to optimize failure path. Then, function name is
ambiguous: it checks for readonly and similar things, but someone may
think that it will ignore normal bitmaps which was just unchanged, and
this is in bad relation with the fact that we should drop IN_USE flag
for unchanged bitmaps in the image.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20190927122355.7344-5-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>

block/qcow2-bitmap.c

diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
index 99812b4..6dfc083 100644
--- a/block/qcow2-bitmap.c
+++ b/block/qcow2-bitmap.c
@@ -1464,16 +1464,7 @@
     Qcow2Bitmap *bm;
     QSIMPLEQ_HEAD(, Qcow2BitmapTable) drop_tables;
     Qcow2BitmapTable *tb, *tb_next;
-
-    if (!bdrv_has_changed_persistent_bitmaps(bs)) {
-        /* nothing to do */
-        return;
-    }
-
-    if (!can_write(bs)) {
-        error_setg(errp, "No write access");
-        return;
-    }
+    bool need_write = false;
 
     QSIMPLEQ_INIT(&drop_tables);
 
@@ -1499,6 +1490,8 @@
             continue;
         }
 
+        need_write = true;
+
         if (check_constraints_on_bitmap(bs, name, granularity, errp) < 0) {
             error_prepend(errp, "Bitmap '%s' doesn't satisfy the constraints: ",
                           name);
@@ -1537,6 +1530,15 @@
         bm->dirty_bitmap = bitmap;
     }
 
+    if (!need_write) {
+        goto success;
+    }
+
+    if (!can_write(bs)) {
+        error_setg(errp, "No write access");
+        goto fail;
+    }
+
     /* allocate clusters and store bitmaps */
     QSIMPLEQ_FOREACH(bm, bm_list, entry) {
         if (bm->dirty_bitmap == NULL) {
@@ -1578,6 +1580,7 @@
         bdrv_release_dirty_bitmap(bm->dirty_bitmap);
     }
 
+success:
     bitmap_list_free(bm_list);
     return;