On Tue, 22 Sep 2026, Jeff Layton wrote:
> Currently much of nfsd's administration is serialized under the global
> nfsd_mutex, even though most of the objects managed under it are
> segregated by net namespace.
>
> This patchset does a couple of small cleanups and then adds a new
> per-net mutex and moves all of the appropriate per-net data structures
> to be protected by it instead of the global mutex. The filecache is
> given its own mutex, and the global mutex is renamed and left for
> managing just the few remaning global objects.
>
> I also had an LLM cook up some selftests so we can hopefully keep all of
> this working properly in the future.
>
> Please consider for v7.4.
Thanks for doing this Jeff - it is long past time :-)
It all looks good to me - except the selftests which I didn't look at.
Thanks,
NeilBrown
>
> Thanks,
> Jeff
>
> Signed-off-by: Jeff Layton <jlayton@kernel.org>
> ---
> Jeff Layton (8):
> nfsd: clear NFSD_NET_UP before dropping the generic resource reference
> nfsd: make max_blksize a per-namespace setting
> nfsd: move the control plane to a per-namespace mutex
> nfsd: rename nfsd_mutex to nfsd_global_mutex
> nfsd: give the open file cache its own mutex
> selftests/nfsd: factor the netlink plumbing into a shared header
> selftests/nfsd: add cross-namespace isolation tests
> selftests/nfsd: add a cross-namespace control-plane soak
>
> fs/nfsd/export.c | 22 +-
> fs/nfsd/filecache.c | 36 +-
> fs/nfsd/netns.h | 16 +
> fs/nfsd/nfs4proc.c | 4 +-
> fs/nfsd/nfs4state.c | 8 +-
> fs/nfsd/nfsctl.c | 129 ++---
> fs/nfsd/nfsd.h | 4 +-
> fs/nfsd/nfssvc.c | 146 ++++--
> tools/testing/selftests/nfsd/Makefile | 2 +
> tools/testing/selftests/nfsd/config | 6 +
> tools/testing/selftests/nfsd/nfsd_netlink.h | 319 ++++++++++++
> .../testing/selftests/nfsd/nfsd_netlink_listener.c | 301 +----------
> tools/testing/selftests/nfsd/nfsd_netns_isolation | Bin 0 -> 49192 bytes
> .../testing/selftests/nfsd/nfsd_netns_isolation.c | 450 ++++++++++++++++
> tools/testing/selftests/nfsd/nfsd_netns_stress | Bin 0 -> 39232 bytes
> tools/testing/selftests/nfsd/nfsd_netns_stress.c | 572 +++++++++++++++++++++
> tools/testing/selftests/nfsd/settings | 2 +-
> 17 files changed, 1580 insertions(+), 437 deletions(-)
> ---
> base-commit: aeaddc6a3711283c09a9183068897d4fe1fb464f
> change-id: 20260918-nfsd-per-net-mutex-8655764940ac
>
> Best regards,
> --
> Jeff Layton <jlayton@kernel.org>
>
>