Re: btrfs bio linked list corruption.

From: Dave Jones
Date: Tue Oct 11 2016 - 11:50:52 EST


On Tue, Oct 11, 2016 at 11:20:41AM -0400, Chris Mason wrote:
>
>
> On 10/11/2016 11:19 AM, Dave Jones wrote:
> > On Tue, Oct 11, 2016 at 04:11:39PM +0100, Al Viro wrote:
> > > On Tue, Oct 11, 2016 at 10:45:08AM -0400, Dave Jones wrote:
> > > > This is from Linus' current tree, with Al's iovec fixups on top.
> > >
> > > Those iovec fixups are in the current tree...
> >
> > ah yeah, git quietly dropped my local copy when I rebased so I didn't notice.
> >
> > > TBH, I don't see anything
> > > in splice-related stuff that could come anywhere near that (short of
> > > some general memory corruption having random effects of that sort).
> > >
> > > Could you try to bisect that sucker, or is it too hard to reproduce?
> >
> > Only hit it the once overnight so far. Will see if I can find a better way to
> > reproduce today.
>
> This call trace is reading metadata so we can finish the truncate. I'd
> say adding more memory pressure would make it happen more often.

That story checks out. There were a bunch of oom's in the log before this.

Dave