Currently, the command: btrfs balance start -dconvert=single,soft . on a Raspberry Pi produces the following kernel message: BTRFS error (device mmcblk0p2): balance: invalid convert data profile single This fails because we use is_power_of_2(unsigned long) to validate the new data profile, the constant for 'single' profile uses bit 48, and there are only 32 bits in a long on ARM. Fix by open-coding the check using u64 variables. Tested by completing the original balance command on several Raspberry Pis. Signed-off-by: Zygo Blaxell <ce3g8jdj@xxxxxxxxxxxxxxxxxxxxx> --- fs/btrfs/volumes.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 88a323a453d8..252c6049c6b7 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -3906,7 +3906,11 @@ static int alloc_profile_is_valid(u64 flags, int extended) return !extended; /* "0" is valid for usual profiles */ /* true if exactly one bit set */ - return is_power_of_2(flags); + /* + * Don't use is_power_of_2(unsigned long) because it won't work + * for the single profile (1ULL << 48) on 32-bit CPUs. + */ + return flags != 0 && (flags & (flags - 1)) == 0; } static inline int balance_need_close(struct btrfs_fs_info *fs_info) -- 2.20.1
