When calculating the number of reftable entries, we should actually use
the number of refblocks and not (wrongly[1]) re-calculate it.
[1] "Wrongly" means: Dividing the number of clusters by the number of
entries per refblock and rounding down instead of up.
Reported-by: Eric Blake <ebl...@redhat.com>
Signed-off-by: Max Reitz <mre...@redhat.com>
---
block/qcow2.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/block/qcow2.c b/block/qcow2.c
index 5c1573c999..f5a72a4d2d 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -2139,7 +2139,7 @@ static int qcow2_create2(const char *filename, int64_t
total_size,
* too, as long as the bulk is allocated here). Therefore, using
* floating point arithmetic is fine. */
int64_t meta_size = 0;
- uint64_t nreftablee, nrefblocke, nl1e, nl2e;
+ uint64_t nreftablee, nrefblocke, nl1e, nl2e, refblock_count;
int64_t aligned_total_size = align_offset(total_size, cluster_size);
int refblock_bits, refblock_size;
/* refcount entry size in bytes */
@@ -2182,11 +2182,12 @@ static int qcow2_create2(const char *filename, int64_t
total_size,
nrefblocke = (aligned_total_size + meta_size + cluster_size)
/ (cluster_size - rces - rces * sizeof(uint64_t)
/ cluster_size);
- meta_size += DIV_ROUND_UP(nrefblocke, refblock_size) * cluster_size;
+ refblock_count = DIV_ROUND_UP(nrefblocke, refblock_size);
+ meta_size += refblock_count * cluster_size;
/* total size of refcount tables */
- nreftablee = nrefblocke / refblock_size;
- nreftablee = align_offset(nreftablee, cluster_size / sizeof(uint64_t));
+ nreftablee = align_offset(refblock_count,
+ cluster_size / sizeof(uint64_t));
meta_size += nreftablee * sizeof(uint64_t);
qemu_opt_set_number(opts, BLOCK_OPT_SIZE,
--
2.12.2
