[Qemu-devel] [PATCH 15/29] block/dirty-bitmap: introduce persistent bitmaps

[Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]

Add field 'persistent' to BdrvDirtyBitmap. Store all persistent bitmaps
of the BDS in bdrv_close().

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 block.c                      |  2 ++
 block/dirty-bitmap.c         | 42 ++++++++++++++++++++++++++++++++++++++++++
 include/block/dirty-bitmap.h |  5 +++++
 3 files changed, 49 insertions(+)

diff --git a/block.c b/block.c
index 30d64e6..fdef1b2 100644
--- a/block.c
+++ b/block.c
@@ -2155,6 +2155,8 @@ static void bdrv_close(BlockDriverState *bs)
     bdrv_flush(bs);
     bdrv_drain(bs); /* in case flush left pending I/O */
 
+    /* save and release persistent dirty bitmaps */
+    bdrv_finalize_persistent_dirty_bitmaps(bs);
     bdrv_release_named_dirty_bitmaps(bs);
     assert(QLIST_EMPTY(&bs->dirty_bitmaps));
 
diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index 83415e1..6df7fe1 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -44,6 +44,7 @@ struct BdrvDirtyBitmap {
     int64_t size;               /* Size of the bitmap (Number of sectors) */
     bool disabled;              /* Bitmap is read-only */
     int active_iterators;       /* How many iterators are active */
+    bool persistent;            /* bitmap must be saved to owner disk image */
     QLIST_ENTRY(BdrvDirtyBitmap) list;
 };
 
@@ -70,6 +71,8 @@ void bdrv_dirty_bitmap_make_anon(BdrvDirtyBitmap *bitmap)
     assert(!bdrv_dirty_bitmap_frozen(bitmap));
     g_free(bitmap->name);
     bitmap->name = NULL;
+
+    bitmap->persistent = false;
 }
 
 BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs,
@@ -238,6 +241,8 @@ BdrvDirtyBitmap *bdrv_dirty_bitmap_abdicate(BlockDriverState *bs,
     bitmap->name = NULL;
     successor->name = name;
     bitmap->successor = NULL;
+    successor->persistent = bitmap->persistent;
+    bitmap->persistent = false;
     bdrv_release_dirty_bitmap(bs, bitmap);
 
     return successor;
@@ -555,3 +560,40 @@ bool bdrv_load_check_dirty_bitmap(BlockDriverState *file, const char *name)
     }
     return false;
 }
+
+void bdrv_store_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap,
+                             Error **errp)
+{
+    if (bs == NULL || bs->drv == NULL ||
+            bs->drv->bdrv_dirty_bitmap_store == NULL) {
+        error_setg(errp, "Storing bitmap is unsupported for the format.");
+        return;
+    }
+
+    bs->drv->bdrv_dirty_bitmap_store(bs, bitmap, errp);
+}
+
+void bdrv_dirty_bitmap_set_persistance(BdrvDirtyBitmap *bitmap,
+                                                bool persistent)
+{
+    bitmap->persistent = persistent;
+}
+
+void bdrv_finalize_persistent_dirty_bitmaps(BlockDriverState *bs)
+{
+    BdrvDirtyBitmap *bm, *bm_next;
+
+    QLIST_FOREACH_SAFE(bm, &bs->dirty_bitmaps, list, bm_next) {
+        if (bm->persistent) {
+            if (!bdrv_is_read_only(bs) &&
+                     !(bdrv_get_flags(bs) & BDRV_O_INACTIVE)) {
+                Error *local_err = NULL;
+                bdrv_store_dirty_bitmap(bs, bm, &local_err);
+                if (local_err) {
+                    error_report_err(local_err);
+                }
+            }
+            bdrv_release_dirty_bitmap(bs, bm);
+        }
+    }
+}
diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
index 6007c64..05aa7f9 100644
--- a/include/block/dirty-bitmap.h
+++ b/include/block/dirty-bitmap.h
@@ -76,5 +76,10 @@ void bdrv_dirty_bitmap_deserialize_ones(BdrvDirtyBitmap *bitmap,
 void bdrv_dirty_bitmap_deserialize_finish(BdrvDirtyBitmap *bitmap);
 
 bool bdrv_load_check_dirty_bitmap(BlockDriverState *file, const char *name);
+void bdrv_dirty_bitmap_set_persistance(BdrvDirtyBitmap *bitmap,
+                                                bool persistent);
+void bdrv_store_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap,
+                             Error **errp);
+void bdrv_finalize_persistent_dirty_bitmaps(BlockDriverState *bs);
 
 #endif
-- 
1.8.3.1