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| author | Max Reitz <mreitz@redhat.com> | 2015-02-10 15:28:47 -0500 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2015-03-10 14:02:21 +0100 |
| commit | 2aabe7c7a16cee6b1b54592fa05b5f9c23c89bc0 (patch) | |
| tree | da45f57f7fcd1a09b6e2835c04cd93ff95737a37 /block/qcow2.h | |
| parent | 7324c10f96c821b00d691e2c8ced67d8536bf1d6 (diff) | |
| download | qemu-2aabe7c7a16cee6b1b54592fa05b5f9c23c89bc0.tar.gz | |
qcow2: Use unsigned addend for update_refcount()
update_refcount() and qcow2_update_cluster_refcount() currently take a
signed addend. At least one caller passes a value directly derived from
an absolute refcount that should be reached ("l2_refcount - 1" in
expand_zero_clusters_in_l1()). Therefore, the addend should be unsigned
as well; this will be especially important for 64 bit refcounts.
Because update_refcount() then no longer knows whether the refcount
should be increased or decreased, it now requires an additional flag
which specified exactly that. The same applies to
qcow2_update_cluster_refcount().
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.h')
| -rw-r--r-- | block/qcow2.h | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/block/qcow2.h b/block/qcow2.h index a33431f05a..40910d817d 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -459,6 +459,11 @@ static inline uint64_t l2meta_cow_end(QCowL2Meta *m) + (m->cow_end.nb_sectors << BDRV_SECTOR_BITS); } +static inline uint16_t refcount_diff(uint16_t r1, uint16_t r2) +{ + return r1 > r2 ? r1 - r2 : r2 - r1; +} + // FIXME Need qcow2_ prefix to global functions /* qcow2.c functions */ @@ -482,7 +487,8 @@ int qcow2_get_refcount(BlockDriverState *bs, int64_t cluster_index, uint16_t *refcount); int qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index, - int addend, enum qcow2_discard_type type); + uint16_t addend, bool decrease, + enum qcow2_discard_type type); int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size); int qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset, |