commit 8f1efd00c4b2aa2b75fd20b5ee592ed47d33d5a7
author Kevin Wolf <kwolf@redhat.com> Tue Oct 18 17:12:44 2011 +0200
committer Kevin Wolf <kwolf@redhat.com> Fri Oct 21 17:34:13 2011 +0200
tree 67370db95d1325123be57ca02cab22dc2d8e9885
parent 41521fa4a60344eaad433db1ab4597ba6bf78f69

qcow2: Fix bdrv_write_compressed error handling

If during allocation of compressed clusters the cluster was already allocated
uncompressed, fail and properly release the l2_table (the latter avoids a
failed assertion).

While at it, make it return some real error numbers instead of -1.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>

block/qcow2-cluster.c

diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 2f76311..f4e049f 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -568,8 +568,10 @@
     }
 
     cluster_offset = be64_to_cpu(l2_table[l2_index]);
-    if (cluster_offset & QCOW_OFLAG_COPIED)
-        return cluster_offset & ~QCOW_OFLAG_COPIED;
+    if (cluster_offset & QCOW_OFLAG_COPIED) {
+        qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table);
+        return 0;
+    }
 
     if (cluster_offset)
         qcow2_free_any_clusters(bs, cluster_offset, 1);