From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CF0C918F2C9 for ; Wed, 26 Jun 2024 16:50:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719420622; cv=none; b=homqDvkbodyQWKKFdOaBdyJt6Oyaicnav2JbROH6/k4o50WO0hiJTuSK62mdCXUnkEkTm049TYXyTT+5w4k9g1seiSc5G0kPSXMn+v7KCNVfK4i8S/KeDT1VTbyaavmzrtqyP/O0MdCn31ziy6Ul7EQie9EJb6wJTJ8uZSzNv+Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719420622; c=relaxed/simple; bh=mE15WwKaNh6H95xQH0sEkor66Do1M4TRC1Q8dHbh2qI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=WpF8YmE50iKPN4CfWmjjyu2mnHhR4q+CysG3N1s0ugGMdpUzMk0CoVBicaA6vVrBiQRpqzv9JJtxK01B6XBeT+af3m8fSjBuIZPCGQK525XnGwvc9d4c7vX5L8SAY6kD+ceIJnidVooVdCSIJ5z9liffA9i06nnY6SVk4+eH3ZI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TtbVI9Ej; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="TtbVI9Ej" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 29C49C116B1; Wed, 26 Jun 2024 16:50:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1719420622; bh=mE15WwKaNh6H95xQH0sEkor66Do1M4TRC1Q8dHbh2qI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=TtbVI9Ej7LHeUNzOayp1OhtcGaqibmLhQpNI2GK8sLMKyfdoewgRMXhkvNGV9P62D kYHQaF7LoHBBv5YUvh6bmDerUAGNUQTJoCApvsYg2lK3w8+vTbNHiXKKHGA1ldlFU6 em9SEyL5uJaGRuhjNexBz6EU4kVpuEfRiqqxq0oyLXx+9iNAr4B3dWtBIK3eTNBLkr tynQMpN4W3iHO5+tNcjoLHwuijseql+UH04wxVYl9mB3Msk1PGQbv7+VPKWrTcC6za SCb518oSweBAXtMVXpwtlFP7GiMZD9KflnMJeAir01Hp+QdA6PcSYy5CtJdw2nxKIH 1dkHFhPBzodPQ== Date: Wed, 26 Jun 2024 12:50:21 -0400 From: Mike Snitzer To: NeilBrown Cc: linux-nfs@vger.kernel.org, Jeff Layton , Chuck Lever , Trond Myklebust , snitzer@hammerspace.com Subject: Re: [PATCH v7 05/20] nfs_common: add NFS LOCALIO auxiliary protocol enablement Message-ID: References: <20240624162741.68216-1-snitzer@kernel.org> <20240624162741.68216-6-snitzer@kernel.org> <171935838369.14261.10478134782573516898@noble.neil.brown.name> Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <171935838369.14261.10478134782573516898@noble.neil.brown.name> On Wed, Jun 26, 2024 at 09:33:03AM +1000, NeilBrown wrote: > On Tue, 25 Jun 2024, Mike Snitzer wrote: > > First use is in nfsd, to add access to a global nfsd_uuids list that > > will be used to identify local nfsd instances. > > > > nfsd_uuids is protected by nfsd_mutex or RCU read lock. List is > > composed of nfsd_uuid_t instances that are managed as nfsd creates > > them (per network namespace). > > > > nfsd_uuid_is_local() will be used to search all local nfsd for the > > client specified nfsd uuid. > > > > This commit also adds all the nfs_client members required to implement > > the entire localio feature (which depends on the LOCALIO protocol). > > > > Signed-off-by: Mike Snitzer > > --- > > fs/nfs/client.c | 8 +++++ > > fs/nfs_common/Makefile | 3 ++ > > fs/nfs_common/nfslocalio.c | 72 ++++++++++++++++++++++++++++++++++++++ > > fs/nfsd/netns.h | 4 +++ > > fs/nfsd/nfssvc.c | 12 ++++++- > > include/linux/nfs_fs_sb.h | 9 +++++ > > include/linux/nfslocalio.h | 39 +++++++++++++++++++++ > > 7 files changed, 146 insertions(+), 1 deletion(-) > > create mode 100644 fs/nfs_common/nfslocalio.c > > create mode 100644 include/linux/nfslocalio.h > > > > diff --git a/fs/nfs/client.c b/fs/nfs/client.c > > index de77848ae654..bcdf8d42cbc7 100644 > > --- a/fs/nfs/client.c > > +++ b/fs/nfs/client.c > > @@ -178,6 +178,14 @@ struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_init) > > clp->cl_max_connect = cl_init->max_connect ? cl_init->max_connect : 1; > > clp->cl_net = get_net(cl_init->net); > > > > +#if IS_ENABLED(CONFIG_NFS_LOCALIO) > > + seqlock_init(&clp->cl_boot_lock); > > + ktime_get_real_ts64(&clp->cl_nfssvc_boot); > > + clp->cl_rpcclient_localio = ERR_PTR(-EINVAL); > > + clp->nfsd_open_local_fh = NULL; > > + clp->cl_nfssvc_net = NULL; > > +#endif /* CONFIG_NFS_LOCALIO */ > > + > > clp->cl_principal = "*"; > > clp->cl_xprtsec = cl_init->xprtsec; > > return clp; > > diff --git a/fs/nfs_common/Makefile b/fs/nfs_common/Makefile > > index 119c75ab9fd0..d81623b76aba 100644 > > --- a/fs/nfs_common/Makefile > > +++ b/fs/nfs_common/Makefile > > @@ -6,5 +6,8 @@ > > obj-$(CONFIG_NFS_ACL_SUPPORT) += nfs_acl.o > > nfs_acl-objs := nfsacl.o > > > > +obj-$(CONFIG_NFS_COMMON_LOCALIO_SUPPORT) += nfs_localio.o > > +nfs_localio-objs := nfslocalio.o > > + > > obj-$(CONFIG_GRACE_PERIOD) += grace.o > > obj-$(CONFIG_NFS_V4_2_SSC_HELPER) += nfs_ssc.o > > diff --git a/fs/nfs_common/nfslocalio.c b/fs/nfs_common/nfslocalio.c > > new file mode 100644 > > index 000000000000..755b84b742a6 > > --- /dev/null > > +++ b/fs/nfs_common/nfslocalio.c > > @@ -0,0 +1,72 @@ > > +// SPDX-License-Identifier: GPL-2.0-only > > +/* > > + * Copyright (C) 2024 Mike Snitzer > > + */ > > + > > +#include > > +#include > > +#include > > + > > +MODULE_LICENSE("GPL"); > > +MODULE_DESCRIPTION("NFS localio protocol bypass support"); > > + > > +/* > > + * Global list of nfsd_uuid_t instances, add/remove > > + * is protected by fs/nfsd/nfssvc.c:nfsd_mutex. > > + * Reads are protected by RCU read lock (see below). > > + */ > > +LIST_HEAD(nfsd_uuids); > > +EXPORT_SYMBOL(nfsd_uuids); > > + > > +/* Must be called with RCU read lock held. */ > > +static const uuid_t * nfsd_uuid_lookup(const uuid_t *uuid, > > + struct net **netp) > > +{ > > + nfsd_uuid_t *nfsd_uuid; > > + > > + list_for_each_entry_rcu(nfsd_uuid, &nfsd_uuids, list) > > + if (uuid_equal(&nfsd_uuid->uuid, uuid)) { > > + *netp = nfsd_uuid->net; > > + return &nfsd_uuid->uuid; > > + } > > + > > + return &uuid_null; > > +} > > + > > +bool nfsd_uuid_is_local(const uuid_t *uuid, struct net **netp) > > +{ > > + const uuid_t *nfsd_uuid; > > + > > + rcu_read_lock(); > > + nfsd_uuid = nfsd_uuid_lookup(uuid, netp); > > + rcu_read_unlock(); > > + > > + return !uuid_is_null(nfsd_uuid); > > This is still unsafe. You can only safely dereference nfsd_uuid while > still holding the rcu_read_lock. Fixed, thanks.