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btrfs: add 64bit safe helper for power of two checks

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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>
This commit is contained in:
David Sterba 2019-10-01 19:40:15 +02:00
parent e62869be1e
commit 79c8264e44
1 changed files with 11 additions and 0 deletions
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11
fs/btrfs/misc.h
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@ -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