diff options
Diffstat (limited to 'block/qcow2-cluster.c')
| -rw-r--r-- | block/qcow2-cluster.c | 28 |
1 files changed, 13 insertions, 15 deletions
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index 1d09f5454e..8c4b4005ff 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -736,19 +736,16 @@ static int get_cluster_table(BlockDriverState *bs, uint64_t offset, /* * alloc_compressed_cluster_offset * - * For a given offset of the disk image, return cluster offset in - * qcow2 file. - * - * If the offset is not found, allocate a new compressed cluster. - * - * Return the cluster offset if successful, - * Return 0, otherwise. + * For a given offset on the virtual disk, allocate a new compressed cluster + * and put the host offset of the cluster into *host_offset. If a cluster is + * already allocated at the offset, return an error. * + * Return 0 on success and -errno in error cases */ - -uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs, - uint64_t offset, - int compressed_size) +int qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs, + uint64_t offset, + int compressed_size, + uint64_t *host_offset) { BDRVQcow2State *s = bs->opaque; int l2_index, ret; @@ -758,7 +755,7 @@ uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs, ret = get_cluster_table(bs, offset, &l2_slice, &l2_index); if (ret < 0) { - return 0; + return ret; } /* Compression can't overwrite anything. Fail if the cluster was already @@ -766,13 +763,13 @@ uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs, cluster_offset = be64_to_cpu(l2_slice[l2_index]); if (cluster_offset & L2E_OFFSET_MASK) { qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice); - return 0; + return -EIO; } cluster_offset = qcow2_alloc_bytes(bs, compressed_size); if (cluster_offset < 0) { qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice); - return 0; + return cluster_offset; } nb_csectors = ((cluster_offset + compressed_size - 1) >> 9) - @@ -790,7 +787,8 @@ uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs, l2_slice[l2_index] = cpu_to_be64(cluster_offset); qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice); - return cluster_offset; + *host_offset = cluster_offset & s->cluster_offset_mask; + return 0; } static int perform_cow(BlockDriverState *bs, QCowL2Meta *m) |