qcow2: when dissecting qcow2, use btrfs clone ioctls for reflinking blocks to target

2015-01-19 20:24:09 +01:00
parent 1e20b41187
commit 1c7dd82563
4 changed files with 28 additions and 0 deletions
@@ -24,6 +24,7 @@
 #include "util.h"
 #include "sparse-endian.h"
 #include "qcow2-util.h"
+#include "btrfs-util.h"

 #define QCOW2_MAGIC 0x514649fb

@@ -85,6 +86,11 @@ static int copy_cluster(
                void *buffer) {

        ssize_t l;
+        int r;
+
+        r = btrfs_clone_range(sfd, soffset, dfd, doffset, cluster_size);
+        if (r >= 0)
+                return r;

        l = pread(sfd, buffer, cluster_size, soffset);
        if (l < 0)