From 79c8264e443471eb2748c93680acce54d14d2225 Mon Sep 17 00:00:00 2001 From: David Sterba Date: Tue, 1 Oct 2019 19:40:15 +0200 Subject: [PATCH] btrfs: add 64bit safe helper for power of two checks As is_power_of_two takes unsigned long, it's not safe on 32bit architectures, but we could pass any u64 value in seveal places. Add a separate helper and also an alias that better expresses the purpose for which the helper is used. Signed-off-by: David Sterba --- fs/btrfs/misc.h | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/fs/btrfs/misc.h b/fs/btrfs/misc.h index 7d564924dfeb..72bab64ecf60 100644 --- a/fs/btrfs/misc.h +++ b/fs/btrfs/misc.h @@ -47,4 +47,15 @@ static inline u64 div_factor_fine(u64 num, int factor) return div_u64(num, 100); } +/* Copy of is_power_of_two that is 64bit safe */ +static inline bool is_power_of_two_u64(u64 n) +{ + return n != 0 && (n & (n - 1)) == 0; +} + +static inline bool has_single_bit_set(u64 n) +{ + return is_power_of_two_u64(n); +} + #endif