diff options
| author | Alberto Garcia <berto@igalia.com> | 2018-05-28 17:01:28 +0200 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2018-05-29 20:09:17 +0200 |
| commit | 7af5eea9b34ffb7a9a9fc25ba71998a02b76e159 (patch) | |
| tree | 9501a0b5d3c2e3898b9d21ae93e72875415e65fc | |
| parent | e609fa71e89c81fbe2670411be62da95dfb093e0 (diff) | |
qcow2: Fix Coverity warning when calculating the refcount cache size
MIN_REFCOUNT_CACHE_SIZE is 4 and the cluster size is guaranteed to be
at most 2MB, so the minimum refcount cache size (in bytes) is always
going to fit in a 32-bit integer.
Coverity doesn't know that, and since we're storing the result in a
uint64_t (*refcount_cache_size) it thinks that we need the 64 bits and
that we probably want to do a 64-bit multiplication to prevent the
result from being truncated.
This is a false positive in this case, but it's a fair warning.
We could do a 64-bit multiplication to get rid of it, but since we
know that a 32-bit variable is enough to store this value let's simply
reuse min_refcount_cache, make it a normal int and stop doing casts.
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
| -rw-r--r-- | block/qcow2.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/block/qcow2.c b/block/qcow2.c index 6d532470a8..a007dc4246 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -768,6 +768,7 @@ static void read_cache_sizes(BlockDriverState *bs, QemuOpts *opts, BDRVQcow2State *s = bs->opaque; uint64_t combined_cache_size; bool l2_cache_size_set, refcount_cache_size_set, combined_cache_size_set; + int min_refcount_cache = MIN_REFCOUNT_CACHE_SIZE * s->cluster_size; combined_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_CACHE_SIZE); l2_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_L2_CACHE_SIZE); @@ -804,8 +805,6 @@ static void read_cache_sizes(BlockDriverState *bs, QemuOpts *opts, } else { uint64_t virtual_disk_size = bs->total_sectors * BDRV_SECTOR_SIZE; uint64_t max_l2_cache = virtual_disk_size / (s->cluster_size / 8); - uint64_t min_refcount_cache = - (uint64_t) MIN_REFCOUNT_CACHE_SIZE * s->cluster_size; /* Assign as much memory as possible to the L2 cache, and * use the remainder for the refcount cache */ @@ -825,7 +824,7 @@ static void read_cache_sizes(BlockDriverState *bs, QemuOpts *opts, * s->cluster_size); } if (!refcount_cache_size_set) { - *refcount_cache_size = MIN_REFCOUNT_CACHE_SIZE * s->cluster_size; + *refcount_cache_size = min_refcount_cache; } } |