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[17/17] qcow2-dirty-bitmap: add EXTRA_DATA_COMPATIBLE flag

Message ID 1455722949-17060-18-git-send-email-vsementsov@virtuozzo.com (mailing list archive)
State New, archived
Headers show

Commit Message

Vladimir Sementsov-Ogievskiy Feb. 17, 2016, 3:29 p.m. UTC 
If this flag is unset and exta data present the bitmap should be
read-only. For now just return error for this case.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 block/qcow2-dirty-bitmap.c | 8 ++++++++
 1 file changed, 8 insertions(+)
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Patch

diff --git a/block/qcow2-dirty-bitmap.c b/block/qcow2-dirty-bitmap.c
index cc104b5..a613565 100644
--- a/block/qcow2-dirty-bitmap.c
+++ b/block/qcow2-dirty-bitmap.c
@@ -43,6 +43,7 @@ 
 #define BME_RESERVED_FLAGS 0xfffffffc
 #define BME_FLAG_IN_USE 1
 #define BME_FLAG_AUTO   (1U << 1)
+#define BME_FLAG_EXTRA_DATA_COMPATIBLE   (1U << 1)
 
 /* bits [1, 8] U [56, 63] are reserved */
 #define BME_TABLE_ENTRY_RESERVED_MASK 0xff000000000001fe
@@ -331,6 +332,13 @@  static BdrvDirtyBitmap *load_bitmap(BlockDriverState *bs, QCow2Bitmap *bm,
         return NULL;
     }
 
+    if (!(bmh->flags & BME_FLAG_EXTRA_DATA_COMPATIBLE) &&
+            bmh->extra_data_size != 0) {
+        error_setg(errp, "Uncompatible extra data found for bitmap '%s'",
+                   bm->name);
+        return NULL;
+    }
+
     bitmap_table = g_try_malloc(bmh->bitmap_table_size * sizeof(uint64_t));
     if (bitmap_table == NULL) {
         error_setg_errno(errp, -ENOMEM,