Re: INFO: task mount:11202 blocked for more than 120 seconds

From: Christian Kujau
Date: Fri Mar 07 2008 - 18:46:54 EST


On Sat, 8 Mar 2008, David Chinner wrote:
Well, if that is hung there, something else must be holding on to
the iolock it's waiting on. What are the other D state processes in the
machine?

I have 7 processes in D state so far:

$ ps auxww [....]
root 9844 0.0 0.0 0 0 ? D Mar06 0:22 [pdflush]
root 2697 0.0 0.0 4712 460 ? D Mar07 0:00 sync
root 8342 0.0 0.0 1780 440 ? D Mar07 0:01 /bin/rm -rf /data/md1/stuff
root 12494 0.0 0.0 11124 1228 ? D Mar07 0:14 /usr/bin/rsync root 15008 0.0 0.0 4712 460 ? D Mar07 0:00 sync
root 11202 0.0 0.0 5012 764 ? D Mar07 0:00 mount -o remount,ro /data/md1
root 15936 0.0 0.0 4712 460 ? D Mar07 0:00 sync

At one point I did a sysrq-D and put the results in:
http://nerdbynature.de/bits/2.6.25-rc4/hung_task/kern.log.gz
(grep for "SysRq : Show Locks Held" and "SysRq : Show Blocked State")

Also, the iolock can be held across I/O so it's possible you've lost an I/O.
Any I/O errors in the syslog?

No, no I/O errors at all. See the kern.log above, I could even do dd(1) from the md1 (dm-crypt on raid1), no errors either.

thanks,
Christian.
--
BOFH excuse #233:

TCP/IP UDP alarm threshold is set too low.
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