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 <ce3g8...@umail.furryterror.org>
---
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
