I am able to get it very frequent on both ARM/x86 with the same case and same logs. In particular just adding a msleep in unmount path before xfs_log_sbcount to trigger this path - this will definetely help. I am able to figure out the issue - there is an issue in callback and unmount path not in sync. unmount path does it work as required but there is a callback pending. In normal case I can see xfslogd is used to execute callbacks - while at the time of the issue the callback is called is called in the context of 'umount' process - which leads to destroying AIL and deallocating log and then using the same in callback path from xfs_buf_iodone_callbacks --> xfs_buf_iodone I have done some changes to get over this but further looking. Thanks & Regards, Amit Sahrawat On Tue, Sep 13, 2011 at 8:56 PM, Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: > On Thu, Sep 08, 2011 at 10:58:35PM +0530, Amit Sahrawat wrote: >> Since this is very hard to reproduce, to make it easy to debug. This >> can be reproduce by introducing msleep in the kernel xfs_umountfs() >> before xfs_log_sbcount(), just add a print before this function and >> sleep and the moment the print appear unplug the USB device, same >> scenario will be reproduced. >> CRASH will show the backtrace and return to normal shell, but when >> process state is checked, khubd will be shown in TASK-UNINTERRUPTIBLE >> state 'D'. >> Further if sync is issued that will also get converted to 'D' state, >> the back-trace for each of the task is same as mentioned in the >> previous mail. > > I've not been able to reproduce this using that method so far. > > _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
