From 09fa7fdc08f3edc26fd143bd7f3f6a863e6f1f17 Mon Sep 17 00:00:00 2001
From: John Snow <jsnow@redhat.com>
Date: Wed, 3 Apr 2019 22:42:50 +0200
Subject: [PATCH 155/163] block/qcow2-bitmap: Don't check size for IN_USE
 bitmap

RH-Author: John Snow <jsnow@redhat.com>
Message-id: <20190403224253.5251-3-jsnow@redhat.com>
Patchwork-id: 85435
O-Subject: [RHEL-7.7 qemu-kvm-rhev PATCH 2/5] block/qcow2-bitmap: Don't check size for IN_USE bitmap
Bugzilla: 1666884
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
RH-Acked-by: Max Reitz <mreitz@redhat.com>
RH-Acked-by: Sergio Lopez Pascual <slp@redhat.com>

From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

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 <vsementsov@virtuozzo.com>
Message-id: 20190311185147.52309-3-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
(cherry picked from commit bf5f0cf5d819cce45dd578a19386d8b60022654f)
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 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 4d093da..fe4a6a2 100644
--- a/block/qcow2-bitmap.c
+++ b/block/qcow2-bitmap.c
@@ -464,10 +464,25 @@ 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 a valid bitmap (IN_USE not set) or we are going to
+         * store a valid bitmap, but the allocated bitmap table size is not
+         * enough to store this bitmap.
+         *
+         * Note, that it's OK to have an invalid bitmap with invalid size due
+         * to a bitmap that was not correctly saved after image resize.
+         */
+        return -EINVAL;
+    }
+
+    return 0;
 }
 
 static inline void bitmap_directory_to_be(uint8_t *dir, size_t size)
-- 
1.8.3.1