@@ -675,10 +675,42 @@ int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m)
* Also flush bs->file to get the right order for L2 and refcount update.
*/
if (j != 0) {
+ int64_t old_start = 0, old_end = -2;
+ int count = 0;
for (i = 0; i < j; i++) {
- qcow2_free_any_clusters(bs,
- be64_to_cpu(old_cluster[i]) & ~QCOW_OFLAG_COPIED, 1);
+ old_cluster[i] = be64_to_cpu(old_cluster[i]) & ~QCOW_OFLAG_COPIED;
}
+ // XXX sort old_cluster
+ for (i = 0; i < j; i++) {
+ int64_t cluster = old_cluster[i];
+
+ /* group if contiguos */
+ if (old_end + 1 == (cluster >> s->cluster_bits)) {
+ ++old_end;
+ continue;
+ }
+
+ /* handle */
+ if (old_end > 0) {
+ qcow2_free_any_clusters(bs, old_start << s->cluster_bits, old_end - old_start + 1);
+ count += old_end - old_start + 1;
+ }
+ old_end = -2;
+
+ /* handle compressed separately */
+ if ((cluster & QCOW_OFLAG_COMPRESSED)) {
+ qcow2_free_any_clusters(bs, cluster, 1);
+ continue;
+ }
+
+ /* start a new group */
+ old_start = old_end = cluster >> s->cluster_bits;
+ }
+ if (old_end > 0) {
+ qcow2_free_any_clusters(bs, old_start << s->cluster_bits, old_end - old_start + 1);
+ count += old_end - old_start + 1;
+ }
+ assert(count == j);
}
ret = 0;
Well, I think this is the first real improve patch. Is more a RFC than a patch. Yes, some lines are terrible! It collapses refcount decrement during cow. From a first check time executing 015 test passed from about 600 seconds to 70. This at least prove that refcount updates counts! Some doubt: 1- place the code in qcow2-refcount.c as it update only refcount and not cluster? 2- allow some sort of "begin transaction" / "commit" / "rollback" like databases instead? 3- allow changing tables from different coroutines? 1) If you have a sequence like (1, 2, 4) probably these clusters are all in the same l2 table but with this code you get two write instead of one. I'm thinking about a function in qcow2-refcount.c that accept an array of cluster instead of a start + len. Signed-off-by: Frediano Ziglio <freddy77@gmail.com> --- block/qcow2-cluster.c | 36 ++++++++++++++++++++++++++++++++++-- 1 files changed, 34 insertions(+), 2 deletions(-)