diff options
Diffstat (limited to 'block/qcow2-cluster.c')
| -rw-r--r-- | block/qcow2-cluster.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index 1a67b2d928..9acc6ce4ae 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -1719,6 +1719,10 @@ out: * clusters (or subclusters) if necessary. The result can span a * combination of allocated and previously unallocated clusters. * + * Note that offset may not be cluster aligned. In this case, the returned + * *host_offset points to exact byte referenced by offset and therefore + * isn't cluster aligned as well. + * * On return, @host_offset is set to the beginning of the requested * area. This area is guaranteed to be contiguous on the qcow2 file * but it can be smaller than initially requested. In this case @bytes @@ -1736,9 +1740,9 @@ out: * * Return 0 on success and -errno in error cases */ -int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset, - unsigned int *bytes, uint64_t *host_offset, - QCowL2Meta **m) +int qcow2_alloc_host_offset(BlockDriverState *bs, uint64_t offset, + unsigned int *bytes, uint64_t *host_offset, + QCowL2Meta **m) { BDRVQcow2State *s = bs->opaque; uint64_t start, remaining; @@ -1759,7 +1763,7 @@ again: while (true) { if (*host_offset == INV_OFFSET && cluster_offset != INV_OFFSET) { - *host_offset = start_of_cluster(s, cluster_offset); + *host_offset = cluster_offset; } assert(remaining >= cur_bytes); @@ -1842,6 +1846,8 @@ again: *bytes -= remaining; assert(*bytes > 0); assert(*host_offset != INV_OFFSET); + assert(offset_into_cluster(s, *host_offset) == + offset_into_cluster(s, offset)); return 0; } |