[Qemu-devel] [6212] Fix compressed qcow2 (Gleb Natapov)

[Anthony Liguori <anthony@codemonkey.ws>]

Revision: 6212
          http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=6212
Author:   aliguori
Date:     2009-01-07 16:43:13 +0000 (Wed, 07 Jan 2009)

Log Message:
-----------
Fix compressed qcow2 (Gleb Natapov)

Correctly calculate number of contiguous clusters.

Acked-by: Kevin Wolf <kwolf@suse.de>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

Modified Paths:
--------------
    trunk/block-qcow2.c

Modified: trunk/block-qcow2.c
===================================================================
--- trunk/block-qcow2.c	2009-01-07 16:41:47 UTC (rev 6211)
+++ trunk/block-qcow2.c	2009-01-07 16:43:13 UTC (rev 6212)
@@ -620,6 +620,9 @@
     int i;
     uint64_t offset = be64_to_cpu(l2_table[0]) & ~mask;
 
+    if (!offset)
+        return 0;
+
     for (i = 0; i < nb_clusters; i++)
         if (offset + i * cluster_size != (be64_to_cpu(l2_table[i]) & ~mask))
             break;
@@ -981,6 +984,12 @@
     /* how many available clusters ? */
 
     while (i < nb_clusters) {
+        i += count_contiguous_clusters(nb_clusters - i, s->cluster_size,
+                &l2_table[l2_index + i], 0);
+
+        if(be64_to_cpu(l2_table[l2_index + i]))
+            break;
+
         i += count_contiguous_free_clusters(nb_clusters - i,
                 &l2_table[l2_index + i]);
 
@@ -989,12 +998,6 @@
         if ((cluster_offset & QCOW_OFLAG_COPIED) ||
                 (cluster_offset & QCOW_OFLAG_COMPRESSED))
             break;
-
-        i += count_contiguous_clusters(nb_clusters - i, s->cluster_size,
-                &l2_table[l2_index + i], 0);
-
-        if(be64_to_cpu(l2_table[l2_index + i]))
-            break;
     }
     nb_clusters = i;