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 A69ED4174B for ; Fri, 22 Sep 2023 16:21:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 788D6C433C9; Fri, 22 Sep 2023 16:21:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1695399670; bh=zazNQXoj5im2iyaGFiFYc6WtzRlNv5ulNROPQJdzs3U=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=gaHd8eBbGPsK9Bug2m9xUeA0ZNneE9l0Ey4Fh9y+FiKCBA2lFAmMYGMBk7h0Y2VZO 4l9eVXiTFtOW+uSwd1bLZLPaMUvwd1vHv9Ij2ABQoanpGZpA16hAS8UfWI7lgoIFqU /ed71UAtjMzMSVyDqPdTNXCJApYJYqZgg+XEbXGqnTLdT0XQTd0AK7HMdu1rh5IGLY 8aSMdcTxnPAVkI1hnGdLSBonS7N1MULGtGUl2kdl8JGBQWq4Mv/x6u7e7X2Ap6fEKg G3QYAae5/lqfXc7H1N381Mno3bre+lT1vtuFosEHBMBB+2XARmf27kyRIHA2hz/swZ M3BAZS9TO9S3A== Message-ID: Subject: Re: [PATCH] NFSD: convert write_threads and write_v4_end_grace to netlink commands From: Jeff Layton To: Chuck Lever III Cc: Lorenzo Bianconi , Linux NFS Mailing List , Lorenzo Bianconi , Neil Brown , "netdev@vger.kernel.org" Date: Fri, 22 Sep 2023 12:21:08 -0400 In-Reply-To: References: Content-Type: text/plain; charset="ISO-8859-15" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.48.4 (3.48.4-1.fc38) Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Fri, 2023-09-22 at 16:06 +0000, Chuck Lever III wrote: >=20 > > On Sep 22, 2023, at 12:04 PM, Jeff Layton wrote: > >=20 > > On Fri, 2023-09-22 at 14:44 +0200, Lorenzo Bianconi wrote: > > > Introduce write_threads and write_v4_end_grace netlink commands simil= ar > > > to the ones available through the procfs. > > > Introduce nfsd_nl_server_status_get_dumpit netlink command in order t= o > > > report global server metadata. > > >=20 > > > Signed-off-by: Lorenzo Bianconi > > > --- > > > This patch can be tested with user-space tool reported below: > > > https://github.com/LorenzoBianconi/nfsd-netlink.git > > > --- > > > Documentation/netlink/specs/nfsd.yaml | 33 +++++++++ > > > fs/nfsd/netlink.c | 30 ++++++++ > > > fs/nfsd/netlink.h | 5 ++ > > > fs/nfsd/nfsctl.c | 98 ++++++++++++++++++++++++++= + > > > include/uapi/linux/nfsd_netlink.h | 11 +++ > > > 5 files changed, 177 insertions(+) > > >=20 > > > diff --git a/Documentation/netlink/specs/nfsd.yaml b/Documentation/ne= tlink/specs/nfsd.yaml > > > index 403d3e3a04f3..fa1204892703 100644 > > > --- a/Documentation/netlink/specs/nfsd.yaml > > > +++ b/Documentation/netlink/specs/nfsd.yaml > > > @@ -62,6 +62,15 @@ attribute-sets: > > > name: compound-ops > > > type: u32 > > > multi-attr: true > > > + - > > > + name: server-attr > > > + attributes: > > > + - > > > + name: threads > > > + type: u16 > >=20 > > 65k threads ought to be enough for anybody! >=20 > No argument. >=20 > But I thought you could echo a negative number of threads in /proc/fs/nfs= d/threads > to reduce the thread count. Maybe this field should be an s32? >=20 Yuck! I think I'd rather see this implemented as a declarative field. Let's have this specify an explicit number of threads with 0 meaning shutdown. If someone wants to reduce the number, they can do the math in userland. That also jives better with the SERVICE_STATUS_GET... >=20 > > > + - > > > + name: v4-grace > > > + type: u8 > > >=20 > > > operations: > > > list: > > > @@ -72,3 +81,27 @@ operations: > > > dump: > > > pre: nfsd-nl-rpc-status-get-start > > > post: nfsd-nl-rpc-status-get-done > > > + - > > > + name: threads-set > > > + doc: set the number of running threads > > > + attribute-set: server-attr > > > + flags: [ admin-perm ] > > > + do: > > > + request: > > > + attributes: > > > + - threads > > > + - > > > + name: v4-grace-release > > > + doc: release the grace period for nfsd's v4 lock manager > > > + attribute-set: server-attr > > > + flags: [ admin-perm ] > > > + do: > > > + request: > > > + attributes: > > > + - v4-grace > > > + - > > > + name: server-status-get > > > + doc: dump server status info > > > + attribute-set: server-attr > > > + dump: > > > + pre: nfsd-nl-server-status-get-start > > > diff --git a/fs/nfsd/netlink.c b/fs/nfsd/netlink.c > > > index 0e1d635ec5f9..783a34e69354 100644 > > > --- a/fs/nfsd/netlink.c > > > +++ b/fs/nfsd/netlink.c > > > @@ -10,6 +10,16 @@ > > >=20 > > > #include > > >=20 > > > +/* NFSD_CMD_THREADS_SET - do */ > > > +static const struct nla_policy nfsd_threads_set_nl_policy[NFSD_A_SER= VER_ATTR_THREADS + 1] =3D { > > > + [NFSD_A_SERVER_ATTR_THREADS] =3D { .type =3D NLA_U16, }, > > > +}; > > > + > > > +/* NFSD_CMD_V4_GRACE_RELEASE - do */ > > > +static const struct nla_policy nfsd_v4_grace_release_nl_policy[NFSD_= A_SERVER_ATTR_V4_GRACE + 1] =3D { > > > + [NFSD_A_SERVER_ATTR_V4_GRACE] =3D { .type =3D NLA_U8, }, > > > +}; > > > + > > > /* Ops table for nfsd */ > > > static const struct genl_split_ops nfsd_nl_ops[] =3D { > > > { > > > @@ -19,6 +29,26 @@ static const struct genl_split_ops nfsd_nl_ops[] = =3D { > > > .done =3D nfsd_nl_rpc_status_get_done, > > > .flags =3D GENL_CMD_CAP_DUMP, > > > }, > > > + { > > > + .cmd =3D NFSD_CMD_THREADS_SET, > > > + .doit =3D nfsd_nl_threads_set_doit, > > > + .policy =3D nfsd_threads_set_nl_policy, > > > + .maxattr =3D NFSD_A_SERVER_ATTR_THREADS, > > > + .flags =3D GENL_ADMIN_PERM | GENL_CMD_CAP_DO, > > > + }, > > > + { > > > + .cmd =3D NFSD_CMD_V4_GRACE_RELEASE, > > > + .doit =3D nfsd_nl_v4_grace_release_doit, > > > + .policy =3D nfsd_v4_grace_release_nl_policy, > > > + .maxattr =3D NFSD_A_SERVER_ATTR_V4_GRACE, > > > + .flags =3D GENL_ADMIN_PERM | GENL_CMD_CAP_DO, > > > + }, > > > + { > > > + .cmd =3D NFSD_CMD_SERVER_STATUS_GET, > > > + .start =3D nfsd_nl_server_status_get_start, > > > + .dumpit =3D nfsd_nl_server_status_get_dumpit, > > > + .flags =3D GENL_CMD_CAP_DUMP, > > > + }, > > > }; > > >=20 > > > struct genl_family nfsd_nl_family __ro_after_init =3D { > > > diff --git a/fs/nfsd/netlink.h b/fs/nfsd/netlink.h > > > index d83dd6bdee92..2e98061fbb0a 100644 > > > --- a/fs/nfsd/netlink.h > > > +++ b/fs/nfsd/netlink.h > > > @@ -12,10 +12,15 @@ > > > #include > > >=20 > > > int nfsd_nl_rpc_status_get_start(struct netlink_callback *cb); > > > +int nfsd_nl_server_status_get_start(struct netlink_callback *cb); > > > int nfsd_nl_rpc_status_get_done(struct netlink_callback *cb); > > >=20 > > > int nfsd_nl_rpc_status_get_dumpit(struct sk_buff *skb, > > > struct netlink_callback *cb); > > > +int nfsd_nl_threads_set_doit(struct sk_buff *skb, struct genl_info *= info); > > > +int nfsd_nl_v4_grace_release_doit(struct sk_buff *skb, struct genl_i= nfo *info); > > > +int nfsd_nl_server_status_get_dumpit(struct sk_buff *skb, > > > + struct netlink_callback *cb); > > >=20 > > > extern struct genl_family nfsd_nl_family; > > >=20 > > > diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c > > > index b71744e355a8..c631b59b7a4f 100644 > > > --- a/fs/nfsd/nfsctl.c > > > +++ b/fs/nfsd/nfsctl.c > > > @@ -1694,6 +1694,104 @@ int nfsd_nl_rpc_status_get_done(struct netlin= k_callback *cb) > > > return 0; > > > } > > >=20 > > > +/** > > > + * nfsd_nl_threads_set_doit - set the number of running threads > > > + * @skb: reply buffer > > > + * @info: netlink metadata and command arguments > > > + * > > > + * Return 0 on success or a negative errno. > > > + */ > > > +int nfsd_nl_threads_set_doit(struct sk_buff *skb, struct genl_info *= info) > > > +{ > > > + u16 nthreads; > > > + int ret; > > > + > > > + if (!info->attrs[NFSD_A_SERVER_ATTR_THREADS]) > > > + return -EINVAL; > > > + > > > + nthreads =3D nla_get_u16(info->attrs[NFSD_A_SERVER_ATTR_THREADS]); > > > + > > > + ret =3D nfsd_svc(nthreads, genl_info_net(info), get_current_cred())= ; > > > + return ret =3D=3D nthreads ? 0 : ret; > > > +} > > > + > > > +/** > > > + * nfsd_nl_v4_grace_release_doit - release the nfs4 grace period > > > + * @skb: reply buffer > > > + * @info: netlink metadata and command arguments > > > + * > > > + * Return 0 on success or a negative errno. > > > + */ > > > +int nfsd_nl_v4_grace_release_doit(struct sk_buff *skb, struct genl_i= nfo *info) > > > +{ > > > +#ifdef CONFIG_NFSD_V4 > > > + struct nfsd_net *nn =3D net_generic(genl_info_net(info), nfsd_net_i= d); > > > + > > > + if (!info->attrs[NFSD_A_SERVER_ATTR_V4_GRACE]) > > > + return -EINVAL; > > > + > > > + if (nla_get_u8(info->attrs[NFSD_A_SERVER_ATTR_V4_GRACE])) > > > + nfsd4_end_grace(nn); > > > + > >=20 > > To be clear here. Issuing this with anything but 0 will end the grace > > period. A value of 0 is ignored. It might be best to make the value not > > matter at all. Do we have to send down a value at all? > >=20 > > > + return 0; > > > +#else > > > + return -EOPNOTSUPP; > > > +#endif /* CONFIG_NFSD_V4 */ > > > +} > > > + > > > +/** > > > + * nfsd_nl_server_status_get_start - Prepare server_status_get dumpi= t > > > + * @cb: netlink metadata and command arguments > > > + * > > > + * Return values: > > > + * %0: The server_status_get command may proceed > > > + * %-ENODEV: There is no NFSD running in this namespace > > > + */ > > > +int nfsd_nl_server_status_get_start(struct netlink_callback *cb) > > > +{ > > > + struct nfsd_net *nn =3D net_generic(sock_net(cb->skb->sk), nfsd_net= _id); > > > + > > > + return nn->nfsd_serv ? 0 : -ENODEV; > > > +} > > > + > > > +/** > > > + * nfsd_nl_server_status_get_dumpit - dump server status info > > > + * @skb: reply buffer > > > + * @cb: netlink metadata and command arguments > > > + * > > > + * Returns the size of the reply or a negative errno. > > > + */ > > > +int nfsd_nl_server_status_get_dumpit(struct sk_buff *skb, > > > + struct netlink_callback *cb) > > > +{ > > > + struct net *net =3D sock_net(skb->sk); > > > +#ifdef CONFIG_NFSD_V4 > > > + struct nfsd_net *nn =3D net_generic(net, nfsd_net_id); > > > +#endif /* CONFIG_NFSD_V4 */ > > > + void *hdr; > > > + > > > + if (cb->args[0]) /* already consumed */ > > > + return 0; > > > + > > > + hdr =3D genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg= _seq, > > > + &nfsd_nl_family, NLM_F_MULTI, > > > + NFSD_CMD_SERVER_STATUS_GET); > > > + if (!hdr) > > > + return -ENOBUFS; > > > + > > > + if (nla_put_u16(skb, NFSD_A_SERVER_ATTR_THREADS, nfsd_nrthreads(net= ))) > > > + return -ENOBUFS; > > > +#ifdef CONFIG_NFSD_V4 > > > + if (nla_put_u8(skb, NFSD_A_SERVER_ATTR_V4_GRACE, !nn->grace_ended)) > > > + return -ENOBUFS; > > > +#endif /* CONFIG_NFSD_V4 */ > > > + > > > + genlmsg_end(skb, hdr); > > > + cb->args[0] =3D 1; > > > + > > > + return skb->len; > > > +} > > > + > > > /** > > > * nfsd_net_init - Prepare the nfsd_net portion of a new net namespac= e > > > * @net: a freshly-created network namespace > > > diff --git a/include/uapi/linux/nfsd_netlink.h b/include/uapi/linux/n= fsd_netlink.h > > > index c8ae72466ee6..b82fbc53d336 100644 > > > --- a/include/uapi/linux/nfsd_netlink.h > > > +++ b/include/uapi/linux/nfsd_netlink.h > > > @@ -29,8 +29,19 @@ enum { > > > NFSD_A_RPC_STATUS_MAX =3D (__NFSD_A_RPC_STATUS_MAX - 1) > > > }; > > >=20 > > > +enum { > > > + NFSD_A_SERVER_ATTR_THREADS =3D 1, > > > + NFSD_A_SERVER_ATTR_V4_GRACE, > > > + > > > + __NFSD_A_SERVER_ATTR_MAX, > > > + NFSD_A_SERVER_ATTR_MAX =3D (__NFSD_A_SERVER_ATTR_MAX - 1) > > > +}; > > > + > > > enum { > > > NFSD_CMD_RPC_STATUS_GET =3D 1, > > > + NFSD_CMD_THREADS_SET, > > > + NFSD_CMD_V4_GRACE_RELEASE, > > > + NFSD_CMD_SERVER_STATUS_GET, > > >=20 > > > __NFSD_CMD_MAX, > > > NFSD_CMD_MAX =3D (__NFSD_CMD_MAX - 1) > >=20 > > --=20 > > Jeff Layton >=20 >=20 > -- > Chuck Lever >=20 >=20 --=20 Jeff Layton