Merge remote-tracking branch 'remotes/ericb/tags/pull-bitmaps-2020-08-03' into staging

bitmaps patches for 2020-08-03

- fix bitmap migration involving read-only bitmap from backing chain

# gpg: Signature made Mon 03 Aug 2020 15:06:51 BST
# gpg:                using RSA key 71C2CC22B1C4602927D2F3AAA7A16B4A2527436A
# gpg: Good signature from "Eric Blake <eblake@redhat.com>" [full]
# gpg:                 aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>" [full]
# gpg:                 aka "[jpeg image of size 6874]" [full]
# Primary key fingerprint: 71C2 CC22 B1C4 6029 27D2  F3AA A7A1 6B4A 2527 436A

* remotes/ericb/tags/pull-bitmaps-2020-08-03:
  iotests/169: Test source cont with backing bmap
  qcow2: Release read-only bitmaps when inactivated

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 19 insertions, 4 deletions

diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
index 1f38806ca6..8c34b2aef7 100644
--- a/block/qcow2-bitmap.c
+++ b/block/qcow2-bitmap.c
@@ -1562,11 +1562,22 @@ void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs,
         Qcow2Bitmap *bm;
 
         if (!bdrv_dirty_bitmap_get_persistence(bitmap) ||
-            bdrv_dirty_bitmap_readonly(bitmap) ||
             bdrv_dirty_bitmap_inconsistent(bitmap)) {
             continue;
         }
 
+        if (bdrv_dirty_bitmap_readonly(bitmap)) {
+            /*
+             * Store the bitmap in the associated Qcow2Bitmap so it
+             * can be released later
+             */
+            bm = find_bitmap_by_name(bm_list, name);
+            if (bm) {
+                bm->dirty_bitmap = bitmap;
+            }
+            continue;
+        }
+
         need_write = true;
 
         if (check_constraints_on_bitmap(bs, name, granularity, errp) < 0) {
@@ -1618,7 +1629,9 @@ void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs,
 
     /* allocate clusters and store bitmaps */
     QSIMPLEQ_FOREACH(bm, bm_list, entry) {
-        if (bm->dirty_bitmap == NULL) {
+        BdrvDirtyBitmap *bitmap = bm->dirty_bitmap;
+
+        if (bitmap == NULL || bdrv_dirty_bitmap_readonly(bitmap)) {
             continue;
         }
 
@@ -1641,6 +1654,7 @@ void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs,
         g_free(tb);
     }
 
+success:
     if (release_stored) {
         QSIMPLEQ_FOREACH(bm, bm_list, entry) {
             if (bm->dirty_bitmap == NULL) {
@@ -1651,13 +1665,14 @@ void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs,
         }
     }
 
-success:
     bitmap_list_free(bm_list);
     return;
 
 fail:
     QSIMPLEQ_FOREACH(bm, bm_list, entry) {
-        if (bm->dirty_bitmap == NULL || bm->table.offset == 0) {
+        if (bm->dirty_bitmap == NULL || bm->table.offset == 0 ||
+            bdrv_dirty_bitmap_readonly(bm->dirty_bitmap))
+        {
             continue;
         }