aboutsummaryrefslogtreecommitdiff
path: root/block/qcow2-cluster.c
diff options
context:
space:
mode:
authorMax Reitz <mreitz@redhat.com>2015-02-10 15:28:47 -0500
committerKevin Wolf <kwolf@redhat.com>2015-03-10 14:02:21 +0100
commit2aabe7c7a16cee6b1b54592fa05b5f9c23c89bc0 (patch)
treeda45f57f7fcd1a09b6e2835c04cd93ff95737a37 /block/qcow2-cluster.c
parent7324c10f96c821b00d691e2c8ced67d8536bf1d6 (diff)
qcow2: Use unsigned addend for update_refcount()
update_refcount() and qcow2_update_cluster_refcount() currently take a signed addend. At least one caller passes a value directly derived from an absolute refcount that should be reached ("l2_refcount - 1" in expand_zero_clusters_in_l1()). Therefore, the addend should be unsigned as well; this will be especially important for 64 bit refcounts. Because update_refcount() then no longer knows whether the refcount should be increased or decreased, it now requires an additional flag which specified exactly that. The same applies to qcow2_update_cluster_refcount(). Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'block/qcow2-cluster.c')
-rw-r--r--block/qcow2-cluster.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index ee50500a07..405329adb5 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -1707,7 +1707,8 @@ static int expand_zero_clusters_in_l1(BlockDriverState *bs, uint64_t *l1_table,
/* For shared L2 tables, set the refcount accordingly (it is
* already 1 and needs to be l2_refcount) */
ret = qcow2_update_cluster_refcount(bs,
- offset >> s->cluster_bits, l2_refcount - 1,
+ offset >> s->cluster_bits,
+ refcount_diff(1, l2_refcount), false,
QCOW2_DISCARD_OTHER);
if (ret < 0) {
qcow2_free_clusters(bs, offset, s->cluster_size,