diff options
| -rw-r--r-- | block/qcow2-bitmap.c | 10 | ||||
| -rw-r--r-- | block/qcow2.c | 14 |
2 files changed, 21 insertions, 3 deletions
diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c index f45e46c..efa10c6 100644 --- a/block/qcow2-bitmap.c +++ b/block/qcow2-bitmap.c @@ -1449,6 +1449,16 @@ bool qcow2_can_store_new_dirty_bitmap(BlockDriverState *bs, bool found; Qcow2BitmapList *bm_list; + if (s->qcow_version < 3) { + /* Without autoclear_features, we would always have to assume + * that a program without persistent dirty bitmap support has + * accessed this qcow2 file when opening it, and would thus + * have to drop all dirty bitmaps (defeating their purpose). + */ + error_setg(errp, "Cannot store dirty bitmaps in qcow2 v2 files"); + goto fail; + } + if (check_constraints_on_bitmap(bs, name, granularity, errp) != 0) { goto fail; } diff --git a/block/qcow2.c b/block/qcow2.c index 4348b2c..1f80961 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -302,9 +302,17 @@ static int qcow2_read_extensions(BlockDriverState *bs, uint64_t start_offset, } if (!(s->autoclear_features & QCOW2_AUTOCLEAR_BITMAPS)) { - warn_report("a program lacking bitmap support " - "modified this file, so all bitmaps are now " - "considered inconsistent"); + if (s->qcow_version < 3) { + /* Let's be a bit more specific */ + warn_report("This qcow2 v2 image contains bitmaps, but " + "they may have been modified by a program " + "without persistent bitmap support; so now " + "they must all be considered inconsistent"); + } else { + warn_report("a program lacking bitmap support " + "modified this file, so all bitmaps are now " + "considered inconsistent"); + } error_printf("Some clusters may be leaked, " "run 'qemu-img check -r' on the image " "file to fix."); |