[v3,14/16] qcow2: Fix v3 snapshot table entry compliancy
diff mbox series

Message ID 20191011152814.14791-15-mreitz@redhat.com
State New
Headers show
Series
  • qcow2: Let check -r all repair some snapshot bits
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Commit Message

Max Reitz Oct. 11, 2019, 3:28 p.m. UTC
qcow2 v3 images require every snapshot table entry to have at least 16
bytes of extra data.  If they do not, let qemu-img check -r all fix it.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 block/qcow2-snapshot.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

Comments

Eric Blake Oct. 11, 2019, 4:32 p.m. UTC | #1
On 10/11/19 10:28 AM, Max Reitz wrote:
> qcow2 v3 images require every snapshot table entry to have at least 16
> bytes of extra data.  If they do not, let qemu-img check -r all fix it.
> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> Reviewed-by: Eric Blake <eblake@redhat.com>
> ---
>   block/qcow2-snapshot.c | 18 ++++++++++++++++++
>   1 file changed, 18 insertions(+)
> 
> diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c
> index dac8a778e4..5ab64da1ec 100644
> --- a/block/qcow2-snapshot.c
> +++ b/block/qcow2-snapshot.c
> @@ -516,6 +516,24 @@ int coroutine_fn qcow2_check_read_snapshot_table(BlockDriverState *bs,
>           result->corruptions -= nb_clusters_reduced;
>       }
>   
> +    /*
> +     * All of v3 images' snapshot table entries need to have at least
> +     * 16 bytes of extra data.
> +     */
> +    if (s->qcow_version >= 3) {
> +        int i;
> +        for (i = 0; i < s->nb_snapshots; i++) {
> +            if (s->snapshots[i].extra_data_size <
> +                sizeof_field(QCowSnapshotExtraData, vm_state_size_large) +
> +                sizeof_field(QCowSnapshotExtraData, disk_size))
> +            {

Another stylistic place where sizeof(QCowSnapshotExtraData) would be 
more compact.  Doesn't change R-b

Patch
diff mbox series

diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c
index dac8a778e4..5ab64da1ec 100644
--- a/block/qcow2-snapshot.c
+++ b/block/qcow2-snapshot.c
@@ -516,6 +516,24 @@  int coroutine_fn qcow2_check_read_snapshot_table(BlockDriverState *bs,
         result->corruptions -= nb_clusters_reduced;
     }
 
+    /*
+     * All of v3 images' snapshot table entries need to have at least
+     * 16 bytes of extra data.
+     */
+    if (s->qcow_version >= 3) {
+        int i;
+        for (i = 0; i < s->nb_snapshots; i++) {
+            if (s->snapshots[i].extra_data_size <
+                sizeof_field(QCowSnapshotExtraData, vm_state_size_large) +
+                sizeof_field(QCowSnapshotExtraData, disk_size))
+            {
+                result->corruptions++;
+                fprintf(stderr, "%s snapshot table entry %i is incomplete\n",
+                        fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR", i);
+            }
+        }
+    }
+
     return 0;
 }