diff options
Diffstat (limited to 'block/qcow2-bitmap.c')
| -rw-r--r-- | block/qcow2-bitmap.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c index 98294a7696..ef9ef628a0 100644 --- a/block/qcow2-bitmap.c +++ b/block/qcow2-bitmap.c @@ -142,6 +142,13 @@ static int check_table_entry(uint64_t entry, int cluster_size) return 0; } +static int64_t get_bitmap_bytes_needed(int64_t len, uint32_t granularity) +{ + int64_t num_bits = DIV_ROUND_UP(len, granularity); + + return DIV_ROUND_UP(num_bits, 8); +} + static int check_constraints_on_bitmap(BlockDriverState *bs, const char *name, uint32_t granularity, @@ -150,6 +157,7 @@ static int check_constraints_on_bitmap(BlockDriverState *bs, BDRVQcow2State *s = bs->opaque; int granularity_bits = ctz32(granularity); int64_t len = bdrv_getlength(bs); + int64_t bitmap_bytes; assert(granularity > 0); assert((granularity & (granularity - 1)) == 0); @@ -171,9 +179,9 @@ static int check_constraints_on_bitmap(BlockDriverState *bs, return -EINVAL; } - if ((len > (uint64_t)BME_MAX_PHYS_SIZE << granularity_bits) || - (len > (uint64_t)BME_MAX_TABLE_SIZE * s->cluster_size << - granularity_bits)) + bitmap_bytes = get_bitmap_bytes_needed(len, granularity); + if ((bitmap_bytes > (uint64_t)BME_MAX_PHYS_SIZE) || + (bitmap_bytes > (uint64_t)BME_MAX_TABLE_SIZE * s->cluster_size)) { error_setg(errp, "Too much space will be occupied by the bitmap. " "Use larger granularity"); |