Re: [PATCH v2] nfsd: fix net-namespace logic in __nfsd_file_cache_purge

[Petr Vorel <pvorel@suse.cz>]

> > On Oct 31, 2022, at 2:46 PM, Jeff Layton <jlayton@kernel.org> wrote:

> > On Mon, 2022-10-31 at 19:45 +0100, Petr Vorel wrote:

> >>>> On Oct 31, 2022, at 11:49 AM, Jeff Layton <jlayton@kernel.org> wrote:

> >>>> If the namespace doesn't match the one in "net", then we'll continue,
> >>>> but that doesn't cause another rhashtable_walk_next call, so it will
> >>>> loop infinitely.

> >>>> Fixes: ce502f81ba88 ("NFSD: Convert the filecache to use rhashtable")
> >>>> Reported-by: Petr Vorel <pvorel@suse.cz>
> >>>> Signed-off-by: Jeff Layton <jlayton@kernel.org>
> >>>> ---
> >>>> fs/nfsd/filecache.c | 5 ++---
> >>>> 1 file changed, 2 insertions(+), 3 deletions(-)

> >>> Thank you! Applied and pushed to for-rc. I'll send a PR in a few days.

> >> Thanks for a quick action!


> > No problem. 

> >> What a shame you didn't put link to the report, which contains reproducer.
> >> https://lore.kernel.org/ltp/Y1%2FP8gDAcWC%2F+VR3@pevik/

> >> Kind regards,
> >> Petr


> > Chuck, could you add that link to the changelog when you merge it?

> In progress, I'll push the update in a moment.

Thanks a lot!

Kind regards,
Petr



> > Thanks,
> > Jeff

> >>>> The v1 patch applies cleanly to v6.0, but not to Chuck's for-next
> >>>> branch. This one should be suitable there.
> >>>> diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
> >>>> index 98c6b5f51bc8..4a8aa7cd8354 100644
> >>>> --- a/fs/nfsd/filecache.c
> >>>> +++ b/fs/nfsd/filecache.c
> >>>> @@ -890,9 +890,8 @@ __nfsd_file_cache_purge(struct net *net)

> >>>> 		nf = rhashtable_walk_next(&iter);
> >>>> 		while (!IS_ERR_OR_NULL(nf)) {
> >>>> -			if (net && nf->nf_net != net)
> >>>> -				continue;
> >>>> -			nfsd_file_unhash_and_dispose(nf, &dispose);
> >>>> +			if (!net || nf->nf_net == net)
> >>>> +				nfsd_file_unhash_and_dispose(nf, &dispose);
> >>>> 			nf = rhashtable_walk_next(&iter);
> >>>> 		}

> >>>> -- 
> >>>> 2.38.1

> > -- 
> > Jeff Layton <jlayton@kernel.org>