nilfs2: disallow remount of snapshot from/to a regular mount
Snapshots and regular ro/rw mounts are essentially-different within
the meaning whether the checkpoint is static or not and is marked with
a snapshot flag or not.
The current implemenation, however, allows to remount a snapshot to a
regular rw-mount if the checkpoint number equals the latest one.
This transition is actually impossible since changing a checkpoint to
a snapshot makes another checkpoint, thus the condition is never
satisfied.
This fixes the weird state of affairs, and specifically separates
snapshots and regular rw/ro-mounts.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
1 file changed