On Sun, Aug 06, 2023 at 10:11:45PM +0800, Zorro Lang wrote: > On Mon, Jul 24, 2023 at 08:29:26AM -0700, Christoph Hellwig wrote: > > Test the removal of the underlying device when the file system still > > has dirty data. > > > > Signed-off-by: Christoph Hellwig <hch@xxxxxx> > > --- > > After I merge this case, it always hit a kernel warning about a "possible > circular locking dependency detected", no matter on ext4 [1] or xfs. This > test isn't hang actually. But it always fail this test (got a .dmesg file). > Any ideas about that? That's because xfs and ext4 do the blkdev_put of the non-main devices in ->put_super and thus inside s_umount. It's actually an old issue, we now just trigger it reliably. We'll need to move the dropping into ->kill_sb after dropping ->s_umount. This has been on my plate for a while.
