dm: convert ffs to __ffs
ffs counts bit starting with 1 (for the least significant bit), __ffs
counts bits starting with 0. This patch changes various occurrences of ffs
to __ffs and removes subtraction of 1 from the result.
Note that __ffs (unlike ffs) is not defined when called with zero
argument, but it is not called with zero argument in any of these cases.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
diff --git a/drivers/md/dm-cache-policy-cleaner.c b/drivers/md/dm-cache-policy-cleaner.c
index 240c9f0..c1612d4 100644
--- a/drivers/md/dm-cache-policy-cleaner.c
+++ b/drivers/md/dm-cache-policy-cleaner.c
@@ -83,7 +83,7 @@
static int alloc_hash(struct hash *hash, unsigned elts)
{
hash->nr_buckets = next_power(elts >> 4, 16);
- hash->hash_bits = ffs(hash->nr_buckets) - 1;
+ hash->hash_bits = __ffs(hash->nr_buckets);
hash->table = vzalloc(sizeof(*hash->table) * hash->nr_buckets);
return hash->table ? 0 : -ENOMEM;