Re: [PATCH] NFS: Replace null dentries that appear in readdir's list [try #2]

Ian Kent
2006-08-22T03:33:31Z

On Mon, 21 Aug 2006, David Howells wrote:

>
> The NFS client's automounting facilities handle automatic expiration and
> implicit recursive unmounting of xdev submounts.
>
> For example, on my test machine:
>
> [root@andromeda ~]# /root/mount warthog:/ /warthog -o fsc
> [root@andromeda ~]# ls /warthog/warthog
> [root@andromeda ~]# cat /proc/mounts
> ...
> warthog:/ /warthog nfs rw,vers=3,rsize=32768,wsize=32768,hard,fsc,proto=tcp,timeo=600,retrans=2,sec=sys,addr=warthog 0 0
> warthog:/warthog /warthog/warthog nfs rw,vers=3,rsize=32768,wsize=32768,hard,fsc,proto=tcp,timeo=600,retrans=2,sec=sys,addr=warthog 0 0
> [root@andromeda ~]# umount /warthog/
> [root@andromeda ~]#
>
> The "ls" command caused the client to mount warthog:/warthog off of the server
> onto /warthog/warthog automatically. I was then able to just unmount
> /warthog, which took away /warthog/warthog also without me having to do
> anything special.
>

This is going to be fun after all.

There isn't any way to tell a nohide from a non-nohide mount from the
expots list.
There are inconsistencies with the contents of /proc/mounts between OS
versions (perhaps kernel version).
There is no way to tell a nohide mounted filesystem from the output of
/proc/mounts if it does happen to appear in it.

*sigh*

Ian