diff options
| -rw-r--r-- | block/qcow2-cluster.c | 25 |
1 files changed, 16 insertions, 9 deletions
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index 239a997027..4f43d41132 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -817,7 +817,9 @@ static int handle_dependencies(BlockDriverState *bs, uint64_t guest_offset, * *host_offset is not zero, only physically contiguous clusters beginning at * this host offset are counted. * - * Note that guest_offset may not be cluster aligned. + * Note that guest_offset may not be cluster aligned. In this case, the + * returned *host_offset points to exact byte referenced by guest_offset and + * therefore isn't cluster aligned as well. * * Returns: * 0: if no allocated clusters are available at the given offset. @@ -845,6 +847,9 @@ 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 || offset_into_cluster(s, guest_offset) + == offset_into_cluster(s, *host_offset)); + /* * Calculate the number of clusters to look for. We stop at L2 table * boundaries to keep things simple. @@ -903,7 +908,8 @@ out: /* 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; + *host_offset = (cluster_offset & L2E_OFFSET_MASK) + + offset_into_cluster(s, guest_offset); } return ret; @@ -961,7 +967,9 @@ static int do_alloc_cluster_offset(BlockDriverState *bs, uint64_t guest_offset, * copy on write. If *host_offset is non-zero, clusters are only allocated if * the new allocation can match the specified host offset. * - * Note that guest_offset may not be cluster aligned. + * Note that guest_offset may not be cluster aligned. In this case, the + * returned *host_offset points to exact byte referenced by guest_offset and + * therefore isn't cluster aligned as well. * * Returns: * 0: if no clusters could be allocated. *bytes is set to 0, @@ -1026,7 +1034,7 @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset, } /* Allocate, if necessary at a given offset in the image file */ - alloc_cluster_offset = *host_offset; + alloc_cluster_offset = start_of_cluster(s, *host_offset); ret = do_alloc_cluster_offset(bs, guest_offset, &alloc_cluster_offset, &nb_clusters); if (ret < 0) { @@ -1062,12 +1070,10 @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset, >> BDRV_SECTOR_BITS; int nb_sectors = MIN(requested_sectors, avail_sectors); - *host_offset = alloc_cluster_offset; - *m = g_malloc0(sizeof(**m)); **m = (QCowL2Meta) { - .alloc_offset = *host_offset, + .alloc_offset = alloc_cluster_offset, .offset = start_of_cluster(s, guest_offset), .nb_clusters = nb_clusters, .nb_available = nb_sectors, @@ -1084,6 +1090,7 @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset, qemu_co_queue_init(&(*m)->dependent_requests); QLIST_INSERT_HEAD(&s->cluster_allocs, *m, next_in_flight); + *host_offset = alloc_cluster_offset + offset_into_cluster(s, guest_offset); *bytes = MIN(*bytes, (nb_sectors * BDRV_SECTOR_SIZE) - offset_into_cluster(s, guest_offset)); assert(*bytes != 0); @@ -1186,7 +1193,7 @@ again: nb_clusters -= keep_clusters; if (!*host_offset) { - *host_offset = cluster_offset; + *host_offset = start_of_cluster(s, cluster_offset); } } else if (cur_bytes == 0) { keep_clusters = 0; @@ -1228,7 +1235,7 @@ again: } if (!*host_offset) { - *host_offset = cluster_offset; + *host_offset = start_of_cluster(s, cluster_offset); } nb_clusters = size_to_clusters(s, cur_bytes + offset_into_cluster(s, offset)); |