Add a helper function which correctly calculates the byte size of a
refcount array for any refcount order, and use that function.
Signed-off-by: Max Reitz <mre...@redhat.com>
---
block/qcow2-refcount.c | 39 ++++++++++++++++++++++++++++-----------
1 file changed, 28 insertions(+), 11 deletions(-)
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index 16652da..cfb4807 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -1132,6 +1132,20 @@ fail:
/* refcount checking functions */
+static size_t refcount_array_byte_size(BDRVQcowState *s, uint64_t entries)
+{
+ if (s->refcount_order < 3) {
+ /* sub-byte width */
+ int shift = 3 - s->refcount_order;
+ return (entries + (1 << shift) - 1) >> shift;
+ } else if (s->refcount_order == 3) {
+ /* byte width */
+ return entries;
+ } else {
+ /* multiple bytes wide */
+ return entries << (s->refcount_order - 3);
+ }
+}
/*
* Increases the refcount for a range of clusters in a given refcount table.
@@ -1161,12 +1175,13 @@ static int inc_refcounts(BlockDriverState *bs,
k = cluster_offset >> s->cluster_bits;
if (k >= *refcount_table_size) {
int64_t old_refcount_table_size = *refcount_table_size;
+ size_t new_byte_size;
void *new_refcount_table;
*refcount_table_size = k + 1;
- new_refcount_table = g_try_realloc(*refcount_table,
- *refcount_table_size *
- s->refcount_bits / 8);
+ new_byte_size = refcount_array_byte_size(s, *refcount_table_size);
+
+ new_refcount_table = g_try_realloc(*refcount_table, new_byte_size);
if (!new_refcount_table) {
*refcount_table_size = old_refcount_table_size;
res->check_errors++;
@@ -1547,6 +1562,7 @@ static int check_refblocks(BlockDriverState *bs,
BdrvCheckResult *res,
if (fix & BDRV_FIX_ERRORS) {
int64_t old_nb_clusters = *nb_clusters;
+ size_t new_byte_size;
void *new_refcount_table;
if (offset > INT64_MAX - s->cluster_size) {
@@ -1567,9 +1583,9 @@ static int check_refblocks(BlockDriverState *bs,
BdrvCheckResult *res,
*nb_clusters = size_to_clusters(s, size);
assert(*nb_clusters >= old_nb_clusters);
+ new_byte_size = refcount_array_byte_size(s, *nb_clusters);
new_refcount_table = g_try_realloc(*refcount_table,
- *nb_clusters *
- s->refcount_bits / 8);
+ new_byte_size);
if (!new_refcount_table) {
*nb_clusters = old_nb_clusters;
res->check_errors++;
@@ -1640,7 +1656,8 @@ static int calculate_refcounts(BlockDriverState *bs,
BdrvCheckResult *res,
int ret;
if (!*refcount_table) {
- *refcount_table = g_try_malloc0(*nb_clusters * s->refcount_bits / 8);
+ size_t byte_size = refcount_array_byte_size(s, *nb_clusters);
+ *refcount_table = g_try_malloc0(byte_size);
if (*nb_clusters && *refcount_table == NULL) {
res->check_errors++;
return -ENOMEM;
@@ -1805,6 +1822,7 @@ static int64_t alloc_clusters_imrt(BlockDriverState *bs,
* accordingly to append free clusters at the end of the image */
if (contiguous_free_clusters < cluster_count) {
int64_t old_imrt_nb_clusters = *imrt_nb_clusters;
+ size_t new_byte_size;
void *new_refcount_table;
/* contiguous_free_clusters clusters are already empty at the image
end;
@@ -1814,9 +1832,8 @@ static int64_t alloc_clusters_imrt(BlockDriverState *bs,
* may exceed old_imrt_nb_clusters if *first_free_cluster pointed
beyond
* the image end) */
*imrt_nb_clusters = cluster + cluster_count - contiguous_free_clusters;
- new_refcount_table = g_try_realloc(*refcount_table,
- *imrt_nb_clusters *
- s->refcount_bits / 8);
+ new_byte_size = refcount_array_byte_size(s, *imrt_nb_clusters);
+ new_refcount_table = g_try_realloc(*refcount_table, new_byte_size);
if (!new_refcount_table) {
*imrt_nb_clusters = old_imrt_nb_clusters;
return -ENOMEM;
@@ -1943,8 +1960,8 @@ write_refblocks:
memcpy(on_disk_refblock, (void *)((uintptr_t)*refcount_table +
(refblock_index << s->refcount_block_bits)),
- MIN(s->refcount_block_size, *nb_clusters - refblock_start)
- * s->refcount_bits / 8);
+ refcount_array_byte_size(s, MIN(s->refcount_block_size,
+ *nb_clusters -
refblock_start)));
ret = bdrv_write(bs->file, refblock_offset / BDRV_SECTOR_SIZE,
(void *)on_disk_refblock, s->cluster_sectors);
--
1.9.3
