The /proc/mounts output for all MDT and OST devices shows "ro" (read-only) all the time, even when the devices are working properly. This caused confusion when trying to debug an OST that had actually gone read-only. This is because the "shadow" mountpoints on the server have MS_RDONLY set to prevent users/admins trying to write into these devices, which are only for "statfs" (df) and possibly ioctl() calls (LU-137).

It would be better to define our own .show_options method in obdclass/obd_mount_server.c::super_operations. It can do an internal dt_statfs() to get the current filesystem state and print "rw" or "ro" as appropriate. It would also be good to print out the rest of the mount options that were used.