Messages in this thread | | | Date | Sun, 23 Jan 2011 17:15:00 +0100 | From | Harald Braumann <> | Subject | Re: Deadlock on concurrent remount-ro and mdadm --stop (2.6.37) |
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On Fri, Jan 21, 2011 at 01:47:54PM +0100, Harald Braumann wrote: > On shutdown `umountroot' and `mdadm-raid' are executed concurrently. The > actual commands are: > mount -o remount,ro / > mdadm --stop --scan > > This seems to trigger a deadlock in the kernel. Dumping blocked tasks (sysrq-W) > gives: > > md126_raid5: call trace: > md_super_wait > autoremove_wake_function > bitmap_unplug > ... > > mount: call trace: > sync_page > io_schedule > sync_page
I've now disable parallel boot in my system, so umountroot and mdadm shouldn't be called cuncurrently anymore. But I still get lock-ups on mdadm --stop. Umountroot is called before mdadm --stop, and all other filesystems are unmounted before that, so I guess there should be no `sync_page' in progress anymore. But I also have swap on the raid, so maybe there's a problem?
As not even the magic SysRQ keys work, I can't provide any more details. Any suggestions how I could debug this problem?
Cheers, harry
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