Hello everyone,
I have a NAS with an ext4 filesystem that I access using NFSv4. From
time to time (about once in a month), the the ext4 driver crashes and I
can't access the file system in any way until I reboot.

As I have no further experience in filesystems, maybe you can help me.
The system is currently in "blocked" state, so I can do any experiments
you ask me to if you need more data.

For starters, I am attaching a dmesg output, maybe this already gives
you an idea on what might be wrong.

Mount flags are
"rw,usrjquota=aquota.user,jqfmt=vfsv0,user_xattr,data=ordered,delalloc,noacl"

Kernel is
Linux QNAPBackup 2.6.33.2 #1 Fri Jul 26 11:32:35 CST 2013 armv5tel unknown

I have already asked in the manufacturer's forum (
http://forum.qnap.com/viewtopic.php?f=25&t=88179&p=397077#p387790 ), but
got no reply there in over a month, so I'm counting on your help

Regards,
Lenz Weber