On Fri, 2023-09-22 at 14:44 +0200, Lorenzo Bianconi wrote: > Introduce write_threads and write_v4_end_grace netlink commands similar > to the ones available through the procfs. > Introduce nfsd_nl_server_status_get_dumpit netlink command in order to > report global server metadata. > > Signed-off-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx> > --- > 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(+) > > diff --git a/Documentation/netlink/specs/nfsd.yaml b/Documentation/netlink/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 65k threads ought to be enough for anybody! > + - > + name: v4-grace > + type: u8 > > 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 @@ > > #include <uapi/linux/nfsd_netlink.h> > > +/* NFSD_CMD_THREADS_SET - do */ > +static const struct nla_policy nfsd_threads_set_nl_policy[NFSD_A_SERVER_ATTR_THREADS + 1] = { > + [NFSD_A_SERVER_ATTR_THREADS] = { .type = 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] = { > + [NFSD_A_SERVER_ATTR_V4_GRACE] = { .type = NLA_U8, }, > +}; > + > /* Ops table for nfsd */ > static const struct genl_split_ops nfsd_nl_ops[] = { > { > @@ -19,6 +29,26 @@ static const struct genl_split_ops nfsd_nl_ops[] = { > .done = nfsd_nl_rpc_status_get_done, > .flags = GENL_CMD_CAP_DUMP, > }, > + { > + .cmd = NFSD_CMD_THREADS_SET, > + .doit = nfsd_nl_threads_set_doit, > + .policy = nfsd_threads_set_nl_policy, > + .maxattr = NFSD_A_SERVER_ATTR_THREADS, > + .flags = GENL_ADMIN_PERM | GENL_CMD_CAP_DO, > + }, > + { > + .cmd = NFSD_CMD_V4_GRACE_RELEASE, > + .doit = nfsd_nl_v4_grace_release_doit, > + .policy = nfsd_v4_grace_release_nl_policy, > + .maxattr = NFSD_A_SERVER_ATTR_V4_GRACE, > + .flags = GENL_ADMIN_PERM | GENL_CMD_CAP_DO, > + }, > + { > + .cmd = NFSD_CMD_SERVER_STATUS_GET, > + .start = nfsd_nl_server_status_get_start, > + .dumpit = nfsd_nl_server_status_get_dumpit, > + .flags = GENL_CMD_CAP_DUMP, > + }, > }; > > struct genl_family nfsd_nl_family __ro_after_init = { > 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 <uapi/linux/nfsd_netlink.h> > > 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); > > 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_info *info); > +int nfsd_nl_server_status_get_dumpit(struct sk_buff *skb, > + struct netlink_callback *cb); > > extern struct genl_family nfsd_nl_family; > > 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 netlink_callback *cb) > return 0; > } > > +/** > + * 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 = nla_get_u16(info->attrs[NFSD_A_SERVER_ATTR_THREADS]); > + > + ret = nfsd_svc(nthreads, genl_info_net(info), get_current_cred()); > + return ret == 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_info *info) > +{ > +#ifdef CONFIG_NFSD_V4 > + struct nfsd_net *nn = net_generic(genl_info_net(info), nfsd_net_id); > + > + 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); > + 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? > + return 0; > +#else > + return -EOPNOTSUPP; > +#endif /* CONFIG_NFSD_V4 */ > +} > + > +/** > + * nfsd_nl_server_status_get_start - Prepare server_status_get dumpit > + * @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 = 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 = sock_net(skb->sk); > +#ifdef CONFIG_NFSD_V4 > + struct nfsd_net *nn = net_generic(net, nfsd_net_id); > +#endif /* CONFIG_NFSD_V4 */ > + void *hdr; > + > + if (cb->args[0]) /* already consumed */ > + return 0; > + > + hdr = 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] = 1; > + > + return skb->len; > +} > + > /** > * nfsd_net_init - Prepare the nfsd_net portion of a new net namespace > * @net: a freshly-created network namespace > diff --git a/include/uapi/linux/nfsd_netlink.h b/include/uapi/linux/nfsd_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 = (__NFSD_A_RPC_STATUS_MAX - 1) > }; > > +enum { > + NFSD_A_SERVER_ATTR_THREADS = 1, > + NFSD_A_SERVER_ATTR_V4_GRACE, > + > + __NFSD_A_SERVER_ATTR_MAX, > + NFSD_A_SERVER_ATTR_MAX = (__NFSD_A_SERVER_ATTR_MAX - 1) > +}; > + > enum { > NFSD_CMD_RPC_STATUS_GET = 1, > + NFSD_CMD_THREADS_SET, > + NFSD_CMD_V4_GRACE_RELEASE, > + NFSD_CMD_SERVER_STATUS_GET, > > __NFSD_CMD_MAX, > NFSD_CMD_MAX = (__NFSD_CMD_MAX - 1) -- Jeff Layton <jlayton@xxxxxxxxxx>
