mount policy for subvols if root is remount,ro

[Goldwyn Rodrigues <rgoldwyn@suse.de>]

Hi,

I want to know if re-mounting the root filesystem read-only should
change subvolumes mounted as read-write to read-only as well? We do
allow mounting subvolumes RW _after_ the root filesystem is mounted RO.

 # mount /dev/vdb /mnt
 # mount -o ro,subvol=svro /dev/vdb /mnt/svro
 # mount -o rw,subvol=svrw /dev/vdb /mnt/svrw
 # mount -o remount,ro /dev/vdb /mnt
 # touch /mnt/f3
touch: cannot touch '/mnt/f3': Read-only file system

Changes subvolume to read-only as well.
 # touch /mnt/svrw/f3
touch: cannot touch '/mnt/svrw/f3': Read-only file system

However, remount of subvol as RW after remount,ro of root works:
 # mount -o remount,rw,subvol=svrw /dev/vdb /mnt/svrw
 # touch /mnt/svrw/f3

-- 
Goldwyn