Re: [PATCH V2 2/2] fs/super.c: don't fool lockdep in freeze_super() and thaw_super() paths

From: Oleg Nesterov
Date: Fri Oct 07 2016 - 12:54:22 EST


On 10/06, Johannes Weiner wrote:
>
> On Tue, Oct 04, 2016 at 01:48:00PM +0200, Michal Hocko wrote:
> > Johannes is already looking into this
> > http://lkml.kernel.org/r/20161004093216.GA21170@xxxxxxxxxxx
> >
> > On Tue 04-10-16 13:43:43, Oleg Nesterov wrote:
> > > because of kernel bug:
> > >
> > > [ 2730.242537] run fstests generic/274 at 2016-10-04 05:17:34
> > > [ 2730.738352] XFS (loop1): Mounting V5 Filesystem
> > > [ 2730.741451] XFS (loop1): Ending clean mount
> > > [ 2744.508698] ------------[ cut here ]------------
> > > [ 2744.509190] kernel BUG at ./include/linux/swap.h:276!
> > >
> > > static inline void workingset_node_shadows_dec(struct radix_tree_node *node)
> > > {
> > > VM_BUG_ON(!workingset_node_shadows(node));
> > > node->count -= 1U << RADIX_TREE_COUNT_SHIFT;
>
> We tracked this one down and Linus merged a fix for this issue:
>
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=d3798ae8c6f3767c726403c2ca6ecc317752c9dd

Confirm, generic/274 no longer crashes the kernel.

Thanks.

Oleg.