@@ -2616,10 +2616,11 @@ static int qcow2_truncate(BlockDriverState *bs, int64_t offset,
PreallocMode prealloc, Error **errp)
{
BDRVQcow2State *s = bs->opaque;
+ uint64_t old_length;
int64_t new_l1_size;
int ret;
- if (prealloc != PREALLOC_MODE_OFF) {
+ if (prealloc != PREALLOC_MODE_OFF && prealloc != PREALLOC_MODE_METADATA) {
error_setg(errp, "Unsupported preallocation mode '%s'",
PreallocMode_lookup[prealloc]);
return -ENOTSUP;
@@ -2636,8 +2637,10 @@ static int qcow2_truncate(BlockDriverState *bs, int64_t offset,
return -ENOTSUP;
}
+ old_length = bs->total_sectors * 512;
+
/* shrinking is currently not supported */
- if (offset < bs->total_sectors * 512) {
+ if (offset < old_length) {
error_setg(errp, "qcow2 doesn't support shrinking images yet");
return -ENOTSUP;
}
@@ -2649,6 +2652,23 @@ static int qcow2_truncate(BlockDriverState *bs, int64_t offset,
return ret;
}
+ switch (prealloc) {
+ case PREALLOC_MODE_OFF:
+ break;
+
+ case PREALLOC_MODE_METADATA:
+ ret = preallocate(bs, old_length, offset);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Preallocation failed, image may now "
+ "occupy more space than necessary");
+ return ret;
+ }
+ break;
+
+ default:
+ g_assert_not_reached();
+ }
+
/* write updated header.size */
offset = cpu_to_be64(offset);
ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, size),