On 2 Jun 2024, at 22:43, Matt Kinni wrote: > Wasn't sure if this was a bug or just an outdated manpage, but the > "mountpoint" option will _not_ stop a v4 client from mounting an > unmounted server directory in Fedora 40 with kernel 6.8.10-300 and > nfs-utils-2.6.4-0.rc6.fc40.x86_64, however it _does_ work as expected if > the client mounts with v3 instead: > > # setup > mkdir /mnt/nfs_localhost && mkdir /srv/somemountpoint > chmod 777 /srv/somemountpoint > > # in /etc/exports: > /srv *(rw,all_squash,fsid=0) > /srv/somemountpoint *(rw,all_squash,mountpoint) > > # in /etc/nfs.conf: > [nfsd] > port=20049 > vers3=y > vers4=y > > # try mounting with nfs v3 while /srv/somemountpoint is a plain dir: > mount localhost:/srv/somemountpoint /mnt/nfs_localhost -t nfs -o vers=3 > > (cmd output)> mount.nfs: mounting localhost:/srv/somemountpoint failed, > reason given by server: No such file or directory > (log says)> rpc.mountd[5313]: request to export an unmounted filesystem: > /srv/somemountpoint > > # so far so good > # but now try doing the same thing with v4: > mount localhost:/somemountpoint /mnt/nfs_localhost -t nfs -o vers=4.2 > (works without error) > > If I `mount -o bind /tmp /srv/somemountpoint` the v3 command works as > expected, but the v4 command always works regardless of whether the > underlying folder is a mount point or not. Is this intended behavior? > > The exports(5) manpage does not say anything about the "mountpoint" or > "mp" options not being valid for NFSv4, so I would expect the same > behavior regardless of what "-o vers=..." is supplied by the client > mount command. Hey Matt - I suspect think the option is working properly. Its not that /srv/somemountpoint is always being exported, its that the v4 mount is mounting the root (/srv) and walking into /srv/somemountpoint. If you're exporting /srv, /srv/somemountpoint going to be accessible. Maybe we need to update the manpage to clear up confusion there? Ben
