Messages in this thread | | | Date | Tue, 2 Aug 2011 20:16:01 +0800 | From | Wu Fengguang <> | Subject | Re: xfstests 073 regression |
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On Tue, Aug 02, 2011 at 08:04:45PM +0800, Dave Chinner wrote: > On Tue, Aug 02, 2011 at 07:44:28PM +0800, Wu Fengguang wrote: > > On Tue, Aug 02, 2011 at 12:52:42AM +0800, Christoph Hellwig wrote: > > > wb_check_background_flush is indeed what we're hitting. > > > > That means s_umount is NOT held by another queued writeback work. > > Right. We already kind of knew that was ocurring because there's > a remount,ro going on.
Yes, and even better if it can be confirmed with a full sysrq-t trace.
> > > > > See the trace output using a patch inspired by Curt's below: > > > > > > # tracer: nop > > > # > > > # TASK-PID CPU# TIMESTAMP FUNCTION > > > # | | | | | > > > <...>-4279 [000] 113.034052: writeback_grab_super_failed: bdi 7:0: sb_dev 0:0 nr_pages=9223372036854775807 sync_mode=0 kupdate=0 range_cyclic=1 background=1 reason=wb_check_background_flush > > > <...>-4279 [000] 113.034052: writeback_grab_super_failed: bdi 7:0: sb_dev 0:0 nr_pages=9223372036854775807 sync_mode=0 kupdate=0 range_cyclic=1 background=1 reason=wb_check_background_flush > > > <...>-4279 [000] 113.034052: writeback_grab_super_failed: bdi 7:0: sb_dev 0:0 nr_pages=9223372036854775807 sync_mode=0 kupdate=0 range_cyclic=1 background=1 reason=wb_check_background_flush > > > > What's that bdi 7:0? And sb_dev=0:0, nr_pages=9223372036854775807=0x7fffffffffffffff. > > > > All are indicating some special bdi/inode. > > #define LOOP_MAJOR 7 > > It's a loop device. xfstests uses them quite a lot.
Yeah, it is.
> Maybe it would be a good idea to run xfstests on an xfs filesystem > in your regular writeback testing cycle to get decent coverage of > this case?
I've run xfstests case 073 on two of my boxes, however still cannot reproduce the problem. This is the script I used, anything wrong with it?
#!/bin/sh
export TEST_DEV=/dev/sda5 export TEST_DIR=/mnt/test
export SCRATCH_DEV=/dev/sda6 export SCRATCH_MNT=/mnt/scratch
mount $TEST_DEV $TEST_DIR
./check 073
And the interesting thing is, that test case always fails in one box and succeed in another.
Thanks, Fengguang
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