diff options
| -rw-r--r-- | block-qcow2.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/block-qcow2.c b/block-qcow2.c index 894b05a30e..9e69ddf0a0 100644 --- a/block-qcow2.c +++ b/block-qcow2.c @@ -1462,6 +1462,7 @@ static int qcow_create(const char *filename, int64_t total_size, const char *backing_file, int flags) { int fd, header_size, backing_filename_len, l1_size, i, shift, l2_bits; + int ref_clusters; QCowHeader header; uint64_t tmp, offset; QCowCreateState s1, *s = &s1; @@ -1502,22 +1503,28 @@ static int qcow_create(const char *filename, int64_t total_size, offset += align_offset(l1_size * sizeof(uint64_t), s->cluster_size); s->refcount_table = qemu_mallocz(s->cluster_size); - s->refcount_block = qemu_mallocz(s->cluster_size); s->refcount_table_offset = offset; header.refcount_table_offset = cpu_to_be64(offset); header.refcount_table_clusters = cpu_to_be32(1); offset += s->cluster_size; - - s->refcount_table[0] = cpu_to_be64(offset); s->refcount_block_offset = offset; - offset += s->cluster_size; + + /* count how many refcount blocks needed */ + tmp = offset >> s->cluster_bits; + ref_clusters = (tmp >> (s->cluster_bits - REFCOUNT_SHIFT)) + 1; + for (i=0; i < ref_clusters; i++) { + s->refcount_table[i] = cpu_to_be64(offset); + offset += s->cluster_size; + } + + s->refcount_block = qemu_mallocz(ref_clusters * s->cluster_size); /* update refcounts */ create_refcount_update(s, 0, header_size); create_refcount_update(s, s->l1_table_offset, l1_size * sizeof(uint64_t)); create_refcount_update(s, s->refcount_table_offset, s->cluster_size); - create_refcount_update(s, s->refcount_block_offset, s->cluster_size); + create_refcount_update(s, s->refcount_block_offset, ref_clusters * s->cluster_size); /* write all the data */ write(fd, &header, sizeof(header)); @@ -1533,7 +1540,7 @@ static int qcow_create(const char *filename, int64_t total_size, write(fd, s->refcount_table, s->cluster_size); lseek(fd, s->refcount_block_offset, SEEK_SET); - write(fd, s->refcount_block, s->cluster_size); + write(fd, s->refcount_block, ref_clusters * s->cluster_size); qemu_free(s->refcount_table); qemu_free(s->refcount_block); |