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authorKevin Wolf <kwolf@redhat.com>2013-03-26 17:50:07 +0100
committerStefan Hajnoczi <stefanha@redhat.com>2013-03-28 11:52:43 +0100
commitc53ede9f6d8f0de7939eea676c1398c4073ff35e (patch)
treea4038c3fc23becffe5ccb20a040622d8d47a9542 /block/qcow2-cluster.c
parentacb0467f8df7e9dbc8bbcb9a2e1e8cfe17f79691 (diff)
qcow2: handle_copied(): Get rid of keep_clusters parameter
Now *bytes is used to return the length of the area that can be written to without performing an allocation or COW. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'block/qcow2-cluster.c')
-rw-r--r--block/qcow2-cluster.c23
1 files changed, 13 insertions, 10 deletions
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index d640328b5c..5e5465dcac 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -831,19 +831,17 @@ static int handle_dependencies(BlockDriverState *bs, uint64_t guest_offset,
*
* -errno: in error cases
*
- * TODO Get rid of keep_clusters parameter
- * TODO Make bytes behave like described above
* 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,
- unsigned int *keep_clusters)
+ uint64_t *host_offset, uint64_t *bytes, QCowL2Meta **m)
{
BDRVQcowState *s = bs->opaque;
int l2_index;
uint64_t cluster_offset;
uint64_t *l2_table;
unsigned int nb_clusters;
+ unsigned int keep_clusters;
int ret, pret;
trace_qcow2_handle_copied(qemu_coroutine_self(), guest_offset, *host_offset,
@@ -873,17 +871,19 @@ static int handle_copied(BlockDriverState *bs, uint64_t guest_offset,
&& (cluster_offset & QCOW_OFLAG_COPIED))
{
/* We keep all QCOW_OFLAG_COPIED clusters */
- *keep_clusters =
+ keep_clusters =
count_contiguous_clusters(nb_clusters, s->cluster_size,
&l2_table[l2_index], 0,
QCOW_OFLAG_COPIED | QCOW_OFLAG_ZERO);
- assert(*keep_clusters <= nb_clusters);
+ assert(keep_clusters <= nb_clusters);
+
+ *bytes = MIN(*bytes,
+ keep_clusters * s->cluster_size
+ - offset_into_cluster(s, guest_offset));
ret = 1;
} else {
- *keep_clusters = 0;
cluster_offset = 0;
-
ret = 0;
}
@@ -1168,16 +1168,19 @@ again:
* TODO: Consider cluster_offset if set in step 1c.
*/
uint64_t tmp_bytes = cur_bytes;
- ret = handle_copied(bs, offset, &cluster_offset, &tmp_bytes, m,
- &keep_clusters);
+ ret = handle_copied(bs, offset, &cluster_offset, &tmp_bytes, m);
if (ret < 0) {
return ret;
} else if (ret) {
+ keep_clusters =
+ size_to_clusters(s, tmp_bytes + offset_into_cluster(s, offset));
nb_clusters -= keep_clusters;
if (!*host_offset) {
*host_offset = cluster_offset;
}
+ } else {
+ keep_clusters = 0;
}
/* If there is something left to allocate, do that now */