From: Qu Wenruo <w...@suse.com>
commit fab273595507a9ec7035df6d5512a955d80a80ba upstream.
[BUG]
With v5.3 kernel, we can't convert to SINGLE profile:
# btrfs balance start -f -dconvert=single $mnt
ERROR: error during balancing '/mnt/btrfs': Invalid argument
# dmesg -t | tail
validate_convert_profile: data profile=0x1000000000000 allowed=0x20
is_valid=1 final=0x1000000000000 ret=1
BTRFS error (device dm-3): balance: invalid convert data profile single
[CAUSE]
With the extra debug output added, it shows that the @allowed bit is
lacking the special in-memory only SINGLE profile bit.
Thus we fail at that (profile & ~allowed) check.
This regression is caused by commit 081db89b13cb ("btrfs: use raid_attr
to get allowed profiles for balance conversion") and the fact that we
don't use any bit to indicate SINGLE profile on-disk, but uses special
in-memory only bit to help distinguish different profiles.
[FIX]
Add that BTRFS_AVAIL_ALLOC_BIT_SINGLE to @allowed, so the code should be
the same as it was and fix the regression.
Reported-by: Chris Murphy <li...@colorremedies.com>
Fixes: 081db89b13cb ("btrfs: use raid_attr to get allowed profiles for balance
conversion")
CC: sta...@vger.kernel.org # 5.3+
Reviewed-by: Anand Jain <anand.j...@oracle.com>
Signed-off-by: Qu Wenruo <w...@suse.com>
Reviewed-by: David Sterba <dste...@suse.com>
Signed-off-by: David Sterba <dste...@suse.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
fs/btrfs/volumes.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -4072,7 +4072,13 @@ int btrfs_balance(struct btrfs_fs_info *
}
num_devices = btrfs_num_devices(fs_info);
- allowed = 0;
+
+ /*
+ * SINGLE profile on-disk has no profile bit, but in-memory we have a
+ * special bit for it, to make it easier to distinguish. Thus we need
+ * to set it manually, or balance would refuse the profile.
+ */
+ allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
for (i = 0; i < ARRAY_SIZE(btrfs_raid_array); i++)
if (num_devices >= btrfs_raid_array[i].devs_min)
allowed |= btrfs_raid_array[i].bg_flag;
