AUTOFS and NFS not playing together nicely

[Edward Tomasz Napierała]

On 0419T1700, David Boyd wrote:
> At the risk of being dubbed insane, here goes:
> 
> On five FreeBSD 10.1-RELEASE-p9 production servers autofs(5) is enabled
> and working as advertised.  On the same servers nfs v3 clients are also
> fat, dumb and happy.
> 
> On a test server where autofs(5) is also enabled and working well, I am
> testing nfs v3 (later v4) server. Strange things are happening.
> 
> When nfs mountd(8) is running, the autofs(5) auto-mount (via automountd)
> function seems to work, but the autofs(5) auto-unmount (via
> autounmountd) never occurs.
> 
> Without nfs mountd(8), when the filesystem /disc is auto-mounted (via
> autoumountd), the mount(8) command shows status of (ufs, local,
> journaled soft-updates, auto-mounted) for the auto-mounted filesystem
> and after the autofs(5) timeout period (600 seconds) the filesystem is
> auto-unmounted (via autounmountd). No problem.
> 
> With nfs mountd(8) the mount(8) command shows (ufs, local, journaled
> soft-updates).  The auto-mounted filesystem is never (a long, long time)
> unmounted. Big problem.
> 
> Without nfs mountd(8) running, the mount(8) command "mount -o
> automounted /dev/ada0p8 /disc" mounts the filesystem and the mount(8)
> command shows (ufs, local, journaled soft-updates, automounted) for the
> manually mounted filesystem and after the autofs(5) timeout period (600
> seconds) the filesystem is auto-unmounted even though it was not mounted
> automatically.  No problem.
> 
> With nfs mountd(8), the mount(8) command "mount -o
> automounted /dev/ada0p8 /disc" mounts the filesystem but the mount(8)
> command shows (ufs, local, journaled soft-updates) and after the timeout
> period (600 seconds) the filesystem is remains mounted.  Big problem.
> 
> It appears that nfs mountd(8) is interferring with the mount(8)
> command's -o option processing but admittedly that is just a very weak
> SWAG.

That's an interesting bug.  I can reproduce it, but hadn't tracked
down the cause just yet.  I'll work on that shortly.  Thanks for
reporting!