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| author | Max Reitz <mreitz@redhat.com> | 2017-05-04 01:11:17 +0200 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2017-05-11 12:08:24 +0200 |
| commit | 92413c16be8eee53a3b60739f2a28a1463651f47 (patch) | |
| tree | 2640e046094d04c39103213efe716a1f9ab08f30 /block/qcow2.c | |
| parent | de9efdb33454ae952c72ed826c54981d498b6c10 (diff) | |
| download | qemu-92413c16be8eee53a3b60739f2a28a1463651f47.tar.gz | |
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/qcow2.c')
| -rw-r--r-- | block/qcow2.c | 9 |
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, |