Re: [PATCH RFC] fs: xfs: Fix xfs_trans_read_buf event tracing

Dave Chinner
2015-02-19T21:38:16Z

On Thu, Feb 19, 2015 at 12:20:28PM -0500, Brian Foster wrote:
> On Thu, Feb 19, 2015 at 06:54:33PM +0530, Pratyush Anand wrote:
> > My root file system is xfs. As soon as I enable event for
> > xfs_trans_read_buf `echo xfs:xfs_trans_read_buf >>
> > /sys/kernel/debug/tracing/set_event`, I see a kernel panic.
> >
> > A little bit of debugging shows that bp->b_fspriv is NULL many a time
> > when trace_xfs_trans_read_buf(bp->b_fspriv) is called.
> >
> > I do not have any idea about xfs filesystem. So, I am not sure, if it
> > is expected to have bp->b_fspriv = NULL at this location.
> >
> > This patch fixes the issue, until we have a better fix.
> >
> > Signed-off-by: Pratyush Anand <panand@redhat.com>
> > ---
>
> A fix for this has been posted here:
>
> http://oss.sgi.com/archives/xfs/2015-02/msg00101.html

It's already in the 3.20-rc0 kernel, and it was marked as a stable
patch so should be fixed in the next 3.19 stable kernel.

Cheers,

Dave.
--
Dave Chinner
david@fromorbit.com