Check subcluster bitmap of the l2 entry for different types of
clusters:
- for compressed it must be zero
- for allocated check consistency of two parts of the bitmap
- for unallocated all subclusters should be unallocated
(or zero-plain)
For unallocated clusters we can safely fix the entry by making it
zero-plain.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
Reviewed-by: Eric Blake <ebl...@redhat.com>
---
block/qcow2-refcount.c | 30 +++++++++++++++++++++++++++++-
1 file changed, 29 insertions(+), 1 deletion(-)
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index f48c5e1b5d..062ec48a15 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -1681,6 +1681,7 @@ static int check_refcounts_l2(BlockDriverState *bs,
BdrvCheckResult *res,
uint64_t coffset;
int csize;
l2_entry = get_l2_entry(s, l2_table, i);
+ uint64_t l2_bitmap = get_l2_bitmap(s, l2_table, i);
switch (qcow2_get_cluster_type(bs, l2_entry)) {
case QCOW2_CLUSTER_COMPRESSED:
@@ -1700,6 +1701,14 @@ static int check_refcounts_l2(BlockDriverState *bs,
BdrvCheckResult *res,
break;
}
+ if (l2_bitmap) {
+ fprintf(stderr, "ERROR compressed cluster %d with non-zero "
+ "subcluster allocation bitmap, entry=0x%" PRIx64 "\n",
+ i, l2_entry);
+ res->corruptions++;
+ break;
+ }
+
/* Mark cluster as used */
qcow2_parse_compressed_l2_entry(bs, l2_entry, &coffset, &csize);
ret = qcow2_inc_refcounts_imrt(
@@ -1727,13 +1736,19 @@ static int check_refcounts_l2(BlockDriverState *bs,
BdrvCheckResult *res,
{
uint64_t offset = l2_entry & L2E_OFFSET_MASK;
+ if ((l2_bitmap >> 32) & l2_bitmap) {
+ res->corruptions++;
+ fprintf(stderr, "ERROR offset=%" PRIx64 ": Allocated "
+ "cluster has corrupted subcluster allocation bitmap\n",
+ offset);
+ }
+
/* Correct offsets are cluster aligned */
if (offset_into_cluster(s, offset)) {
bool contains_data;
res->corruptions++;
if (has_subclusters(s)) {
- uint64_t l2_bitmap = get_l2_bitmap(s, l2_table, i);
contains_data = (l2_bitmap & QCOW_L2_BITMAP_ALL_ALLOC);
} else {
contains_data = !(l2_entry & QCOW_OFLAG_ZERO);
@@ -1800,6 +1815,19 @@ static int check_refcounts_l2(BlockDriverState *bs,
BdrvCheckResult *res,
case QCOW2_CLUSTER_ZERO_PLAIN:
case QCOW2_CLUSTER_UNALLOCATED:
+ if (l2_bitmap & QCOW_L2_BITMAP_ALL_ALLOC) {
+ res->corruptions++;
+ fprintf(stderr, "%s: Unallocated "
+ "cluster has non-zero subcluster allocation map\n",
+ fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR");
+ if (fix & BDRV_FIX_ERRORS) {
+ ret = fix_l2_entry_by_zero(bs, res, l2_offset, l2_table, i,
+ active, &metadata_overlap);
+ if (metadata_overlap) {
+ return ret;
+ }
+ }
+ }
break;
default:
--
2.29.2
