Btrfs: do not do balance in readonly mode
In normal cases, we would not be allowed to do balance in RO mode.
However, when we're using a seeding device and adding another device to sprout,
things will change:
$ mkfs.btrfs /dev/sdb7
$ btrfstune -S 1 /dev/sdb7
$ mount /dev/sdb7 /mnt/btrfs -o ro
$ btrfs fi bal /mnt/btrfs -----------------------> fail.
$ btrfs dev add /dev/sdb8 /mnt/btrfs
$ btrfs fi bal /mnt/btrfs -----------------------> works!
It should not be designed as an exception, and we'd better add another check for
mnt flags.
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Reviewed-by: Josef Bacik <josef@redhat.com>
1 file changed