Re: [PATCH] gfs2: Stop using rhashtable_walk_peek

[Andreas Gruenbacher]

On 28 March 2018 at 23:53, NeilBrown <neilb@xxxxxxxx> wrote:
> Thank for this patch!
> The above looks a bit fragile to me.
> gfs2_glock_iter_next() (And hence gfs2_glock_seq_start()) will sometimes
> exit with gl_held true, and sometimes with it false.
> gfs2_glock_seq_stop() assumes that it is false.
> Normally gfs2_glock_seq_next() will normally be called between these
> two and will clear gl_held, but I don't think there is a hard guarantee
> of that.
> Maybe we should always 'put' gi->gl in iter_next if gl_held??

Another problem is that gfs2_glock_seq_stop only does a lockref_get
which is not allowed because the lockref may have been marked dead in
the meantime. We'll have to take a reference on each lock in
gfs2_glock_iter_next instead. Revised patch to follow tomorrow.

Thanks,
Andreas