nullfs mount ignores readonly flag

[David Beck]

Hello,

A few experiments on 1.5 nullfs showed that it ignores the read-only flag:

/mnt: mkdir 1 2
/mnt: mount_null -o ro /mnt/1 /mnt/2
/mnt: mount
. ..
/mnt/1 on /mnt/2 (null, local, read-only)
/mnt: cd /mnt/1
/mnt/1: echo > k
/mnt/1: cd /mnt/2
/mnt/2: rm k
/mnt/2: ls
/mnt/2: cd /mnt/1
/mnt/1: ls -ltr
total 0
/mnt/1:
I could delete a file on a read-only filesystem. Oops.

Regards, David.