lkml.org 
[lkml]   [2019]   [Oct]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 5.3 085/112] btrfs: fix balance convert to single on 32-bit host CPUs
Date
From: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>

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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/btrfs/volumes.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -3854,7 +3854,11 @@ static int alloc_profile_is_valid(u64 fl
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)

\
 
 \ /
  Last update: 2019-10-17 00:04    [W:0.320 / U:0.244 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site