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

Chuck Lever III
2022-10-31T18:47:44Z

> 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,
> 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>

--
Chuck Lever