Look only for clusters that start at a given physical offset.
Signed-off-by: Kevin Wolf <kw...@redhat.com>
---
block/qcow2-cluster.c | 26 ++++++++++++++++++--------
1 files changed, 18 insertions(+), 8 deletions(-)
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 5ce2c88..90fe36c 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -827,8 +827,6 @@ static int handle_dependencies(BlockDriverState *bs,
uint64_t guest_offset,
* the length of the area that can be written to.
*
* -errno: in error cases
- *
- * TODO Make non-zero host_offset behave like describe above
*/
static int handle_copied(BlockDriverState *bs, uint64_t guest_offset,
uint64_t *host_offset, uint64_t *bytes, QCowL2Meta **m)
@@ -843,7 +841,6 @@ static int handle_copied(BlockDriverState *bs, uint64_t
guest_offset,
trace_qcow2_handle_copied(qemu_coroutine_self(), guest_offset,
*host_offset,
*bytes);
- assert(*host_offset == 0);
/*
* Calculate the number of clusters to look for. We stop at L2 table
@@ -867,6 +864,15 @@ static int handle_copied(BlockDriverState *bs, uint64_t
guest_offset,
if (qcow2_get_cluster_type(cluster_offset) == QCOW2_CLUSTER_NORMAL
&& (cluster_offset & QCOW_OFLAG_COPIED))
{
+ /* If a specific host_offset is required, check it */
+ if (*host_offset != 0
+ && (cluster_offset & L2E_OFFSET_MASK) != *host_offset)
+ {
+ *bytes = 0;
+ ret = 0;
+ goto out;
+ }
+
/* We keep all QCOW_OFLAG_COPIED clusters */
keep_clusters =
count_contiguous_clusters(nb_clusters, s->cluster_size,
@@ -880,19 +886,22 @@ static int handle_copied(BlockDriverState *bs, uint64_t
guest_offset,
ret = 1;
} else {
- cluster_offset = 0;
ret = 0;
}
- cluster_offset &= L2E_OFFSET_MASK;
- *host_offset = cluster_offset;
-
/* Cleanup */
+out:
pret = qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table);
if (pret < 0) {
return pret;
}
+ /* Only return a host offset if we actually made progress. Otherwise we
+ * would make requirements for handle_alloc() that it can't fulfill */
+ if (ret) {
+ *host_offset = cluster_offset & L2E_OFFSET_MASK;
+ }
+
return ret;
}
@@ -1162,7 +1171,6 @@ again:
/*
* 2. Count contiguous COPIED clusters.
- * TODO: Consider cluster_offset if set in step 1c.
*/
ret = handle_copied(bs, offset, &cluster_offset, &cur_bytes, m);
if (ret < 0) {
@@ -1175,6 +1183,8 @@ again:
if (!*host_offset) {
*host_offset = cluster_offset;
}
+ } else if (cur_bytes == 0) {
+ goto done;
} else {
keep_clusters = 0;
}
--
1.7.6.5
