[Qemu-block] [PATCH v2 2/4] block/qcow2-bitmap: Don't check size for IN_USE bitmap

[Vladimir Sementsov-Ogievskiy]

We are going to allow image resize when there are persistent bitmaps.
It may lead to appearing of inconsistent bitmaps (IN_USE=1) with
inconsistent size. But we still want to load them as inconsistent.

Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
---
 block/qcow2-bitmap.c | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
index 6adbe06b4d..141bc1e52c 100644
--- a/block/qcow2-bitmap.c
+++ b/block/qcow2-bitmap.c
@@ -462,10 +462,25 @@ static int check_dir_entry(BlockDriverState *bs, 
Qcow2BitmapDirEntry *entry)
         return len;
     }
 
-    fail = (phys_bitmap_bytes > BME_MAX_PHYS_SIZE) ||
-           (len > ((phys_bitmap_bytes * 8) << entry->granularity_bits));
+    if (phys_bitmap_bytes > BME_MAX_PHYS_SIZE) {
+        return -EINVAL;
+    }
 
-    return fail ? -EINVAL : 0;
+    if (!(entry->flags & BME_FLAG_IN_USE) &&
+        (len > ((phys_bitmap_bytes * 8) << entry->granularity_bits)))
+    {
+        /*
+         * We've loaded valid bitmap (IN_USE not set) or we are going to store
+         * valid bitmap. But allocated bitmap table size is not enough to store
+         * such bitmap.
+         *
+         * Note, that it's OK to have invalid bitmap with invalid size during 
to
+         * bitmap was not correctly saved after image resize.
+         */
+        return -EINVAL;
+    }
+
+    return 0;
 }
 
 static inline void bitmap_directory_to_be(uint8_t *dir, size_t size)
-- 
2.18.0