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authorMax Reitz <mreitz@redhat.com>2017-05-04 01:11:17 +0200
committerKevin Wolf <kwolf@redhat.com>2017-05-11 12:08:24 +0200
commit92413c16be8eee53a3b60739f2a28a1463651f47 (patch)
tree2640e046094d04c39103213efe716a1f9ab08f30 /block
parentde9efdb33454ae952c72ed826c54981d498b6c10 (diff)
qcow2: Fix preallocation size formula
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 <eblake@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'block')
-rw-r--r--block/qcow2.c9
1 files changed, 5 insertions, 4 deletions
diff --git a/block/qcow2.c b/block/qcow2.c
index 1c2697732b..8caf800529 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,