Re: 3.17.0+ files disappearing after playing old dos game on nfsroot laptop

[Hans de Bruin]

On 10/25/2014 04:55 PM, Eric W. Biederman wrote:
> Hans de Bruin <jmdebruin@xxxxxxxxx> writes:
>
> > On 10/24/2014 08:18 PM, Eric W. Biederman wrote:
>
> [...]
>
> > > At this point I don't know enough to reproduce this.
> > > What does /proc/mounts look like before you start dosemu?
> >
> > bash-4.2$ cat /proc/mounts
> > rootfs / rootfs rw 0 0
> > 10.10.0.1:/nfs/root/psion_14.1 / nfs
> > rw,relatime,vers=3,rsize=4096,wsize=4096,namlen=255,hard,nolock,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=10.10.0.1,mountvers=3,mountproto=tcp,local_lock=all,addr=10.10.0.1
> > 0 0
> > devtmpfs /dev devtmpfs rw,relatime,size=1031016k,nr_inodes=220978,mode=755 0 0
> > proc /proc proc rw,relatime 0 0
> > sysfs /sys sysfs rw,relatime 0 0
> > tmpfs /run tmpfs rw,relatime,mode=755 0 0
> > devpts /dev/pts devpts rw,relatime,gid=5,mode=620 0 0
> > cgroup /sys/fs/cgroup cgroup rw,relatime,cpu 0 0
> > /dev/shm /tmp tmpfs rw,relatime,size=524288k 0 0
> > /dev/shm /dev/shm tmpfs rw,relatime,size=524288k 0 0
> > nfs:/nfs/usr/slackware-14.1/usr /usr nfs
> > ro,relatime,vers=3,rsize=262144,wsize=262144,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=10.10.0.1,mountvers=3,mountport=38337,mountproto=udp,local_lock=none,addr=10.10.0.1
> > 0 0
> > nfs:/nfs/home /home nfs
> > rw,relatime,vers=3,rsize=262144,wsize=262144,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=10.10.0.1,mountvers=3,mountport=38337,mountproto=udp,local_lock=none,addr=10.10.0.1
> > 0 0
> > nfs:/nfs/mp3 /mp3 nfs
> > rw,relatime,vers=3,rsize=262144,wsize=262144,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=10.10.0.1,mountvers=3,mountport=38337,mountproto=udp,local_lock=none,addr=10.10.0.1
> > 0 0
> > nfs:/nfs/src /usr/src nfs
> > rw,relatime,vers=3,rsize=262144,wsize=262144,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=10.10.0.1,mountvers=3,mountport=38337,mountproto=udp,local_lock=none,addr=10.10.0.1
> > 0 0
> > nfs:/nfs/video /video nfs
> > rw,relatime,vers=3,rsize=262144,wsize=262144,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=10.10.0.1,mountvers=3,mountport=38337,mountproto=udp,local_lock=none,addr=10.10.0.1
> > 0 0
> >
> > I now know why I do not see any file in /usr after running dosemu. The whole
> > /usr mount disappears in /proc/mounts. When I remount it I have a usable laptop
> > again. Running dosemu a second time does not remove the mount again. In the mean
> > time I have seen /usr disappear after running other programs like xterm and
> > firefox. But until now never after remouting it.
>
> That is interesting.

boot
run dosemu -> /usr unmounted
mount /usr
run dosemu -> /usr still mounted
sync; echo 3 > /proc/sys/vm/drop_caches
run dosemu -> /usr unmounted

> It sounds like occassionally your /home mount disappears as well.

I have not seen that happening

...

> I expect what needs to happen is to confirm that nfs directory entry
> revalidation is buggy, and at least for the short term re-add the nfs
> logic that will avoid dropping a dentry if it is a mount point, or
> path to a mount point, to avoid the nfs bugs.

ok, I will go in waiting mode.

--
Hans


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/