On Fri, Oct 13, 2023 at 11:22:03AM -0400, Daniel Jordan wrote: > Hi, > > On Sat, Oct 07, 2023 at 11:52:33AM +0800, Wang Jinchao wrote: > > Signed-off-by: Wang Jinchao <wangjinchao@xxxxxxxxxxx> > > The Fixes: tag should be near your Signed-off-by:, and the subject of > the patch should be something descriptive like > > padata: Fix refcnt handling in padata_free_shell() > > Here's some documentation about this: > > https://docs.kernel.org/process/5.Posting.html#patch-formatting-and-changelogs > Updated in patch v4. > > Acked-by: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx> > > --- > > V3: > > Include Daniel's ack > > > > V2: https://lore.kernel.org/all/ZRTLHY5A+VqIKhA2@fedora/ > > To satisfy Sparse, use rcu_dereference_protected. > > Reported-by: kernel test robot <lkp@xxxxxxxxx> > > Closes: https://lore.kernel.org/oe-kbuild-all/202309270829.xHgTOMKw-lkp@xxxxxxxxx/ > > These two tags can also go near your SoB. > >From intel kernel test robot: If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202309270829.xHgTOMKw-lkp@xxxxxxxxx/ So I updated the patch without these tags. > > V1: https://lore.kernel.org/all/ZRE4XvOOhz4HSOgR@fedora/ > > > > kernel/padata.c | 6 +++++- > > 1 file changed, 5 insertions(+), 1 deletion(-) > > > > diff --git a/kernel/padata.c b/kernel/padata.c > > index 222d60195de6..79d04a97ded6 100644 > > --- a/kernel/padata.c > > +++ b/kernel/padata.c > > @@ -1102,12 +1102,16 @@ EXPORT_SYMBOL(padata_alloc_shell); > > */ > > void padata_free_shell(struct padata_shell *ps) > > { > > + struct parallel_data *pd; > > + > > if (!ps) > > return; > > > > mutex_lock(&ps->pinst->lock); > > list_del(&ps->list); > > - padata_free_pd(rcu_dereference_protected(ps->pd, 1)); > > + pd = rcu_dereference_protected(ps->pd, 1); > > + if (refcount_dec_and_test(&pd->refcnt)) > > + padata_free_pd(rcu_dereference_protected(ps->pd, 1)); > > As Herbert points out, this version changes the code by > rcu-dereferencing pd twice. Usually previous acks are dropped when > introducing new changes, but you can have it back by only > rcu-dereferencing once and addressing the other comments above. Thanks for your and Herbert's acks, which were included in patch v4. I know Herbert has acked my patch from your email; however, I have not received Herbert's acknowledgment email, and I do not know why. > > > mutex_unlock(&ps->pinst->lock); > > > > kfree(ps); > > -- > > 2.40.0 > >
