Commit 79c8264e authored Oct 01, 2019 by David Sterba

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 <dsterba@suse.com>

parent e62869be

fs/btrfs/misc.h

+11 −0

Original line number	Diff line number	Diff line
		@@ -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

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