2.5.68: NFS3+exported /mnt/cdrom+eject: system lockup

I have tried this on Red Hat 9 with 2.5.68 kernel (no modules), nfs-utils version 1.0.1.

NFS3 server was running on the box and it was exporting a mounted /mnt/cdrom to the world. On "umount /mnt/cdrom" it reported "device busy". On "eject /mnt/cdrom" it locked the system hard.

One of the previous 2.5.x kernels that I've tried was .65 and that one would lock up on NFS startup. So, things are better, but not yet completely good.

What kind of information would help debugging this?

Bojan

> NFS3 server was running on the box and it was exporting a > mounted /mnt/cdrom to the world. On "umount /mnt/cdrom" it > reported "device busy". On "eject /mnt/cdrom" it locked the > system hard.

> What kind of information would help debugging this?

The only bug there is the hard crash. You are never allowed to unmount a device that has been exported.

Cheers,
Trond

What about not being able to unmount a filesystem that was once exported, but now it's not? I've been experiencing this problem since a long time ago:

I have a volume/partition exported via NFS:

/data 192.168.0.100(rw,no_root_squash) 192.168.0.0/24(ro)

However, during shutdown (it's a RH9 box), I do get "can't unmount, device is busy" errors while unmounting this filesystem *after* the NFS server has been stopped and all shares unexported.

This does only occurs if the shared NFS volume has been used by other clients on the LAN. If no client tries to mount/use the share, this doesn't happen.

Anyways, I'm having problems with NFS on 2.5... many programs fail when accessing files over NFS, normally, programs that perform heavy file seeks, writes and reads, like "oggdec" or "lame". They usually can't complete without exitting with errors.

More information can be provided on detail :-)

Please AVOID sending me WORD, EXCEL or POWERPOINT attachments.
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> However, during shutdown (it's a RH9 box), I do get "can't > unmount, device is busy" errors while unmounting this > filesystem *after* the NFS server has been stopped and all > shares unexported.

That's a known bug and I believe Neil is looking into it.

> Anyways, I'm having problems with NFS on 2.5... many programs > fail when accessing files over NFS, normally, programs that > perform heavy file seeks, writes and reads, like "oggdec" or > "lame". They usually can't complete without exitting with > errors.

I'll take on any NFS client problems. If you are having problems with a 2.5.x client failing against a 2.4.x server (note! 2.5.x servers are still way too buggy) or a non-linux server, then please send me a full bugreport.

Cheers,
Trond

Yeah, I guessed that much. I was actually expecting another "device busy", which is OK. Crash, not OK :-)

Anyway, I have observed other strange stuff too, like not being able to unmount /mnt/cdrom while it's being exported. Workaround: stop NFS, unmount, start NFS. Not sure if this is normal or not...

Bojan

> Anyway, I have observed other strange stuff too, like not being > able to unmount /mnt/cdrom while it's being
> exported.

That is *correct* behaviour. If the partition is exported, then it is in use.

> Workaround: stop NFS, unmount, start NFS. Not sure if this is > normal or not...

Either that, or you unexport it, then umount.

Cheers,
Trond

Quoting Trond Myklebust <[email protected]>:

Yeah, realised that on my way to work. Sorry, I must be on drugs :-(

So, the only real problem is that crash.

Bojan