| From 5c358beda21878632188810166bc552f0716d0ad Mon Sep 17 00:00:00 2001 |
| From: Zygo Blaxell <ce3g8jdj@umail.furryterror.org> |
| Date: Thu, 12 Sep 2019 19:55:01 -0400 |
| Subject: [PATCH] btrfs: fix balance convert to single on 32-bit host CPUs |
| |
| commit 7a54789074a54f64addf5b49bf1994f478337a83 upstream. |
| |
| 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. |
| |
| Fixes: 818255feece6 ("btrfs: use common helper instead of open coding a bit test") |
| CC: stable@vger.kernel.org # 4.20+ |
| Signed-off-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org> |
| Reviewed-by: David Sterba <dsterba@suse.com> |
| Signed-off-by: David Sterba <dsterba@suse.com> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c |
| index 8508f6028c8d..4075b1b95105 100644 |
| --- a/fs/btrfs/volumes.c |
| +++ b/fs/btrfs/volumes.c |
| @@ -3857,7 +3857,11 @@ 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) |
| -- |
| 2.7.4 |
| |
