nullfs mount ignores readonly flag

[Matthew Dillon]

    I expect there will be things that need working on.  That's one of
    them.  Hmm.  We will probably have to hold the namecache entry for
    normal files and use the namecache's mount point to check for the
    read-only filesystem status.  No biggy (we already do this for 
    directories to maintain the CD path), but it may take a few days to
    fix.

					-Matt
					Matthew Dillon 
					<dillon at xxxxxxxxxxxxx>

: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.