On Fri, 2023-09-22 at 16:06 +0000, Chuck Lever III wrote: > > > On Sep 22, 2023, at 12:04 PM, Jeff Layton <jlayton@xxxxxxxxxx> wrote: > > > > 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! > > No argument. > > But I thought you could echo a negative number of threads in /proc/fs/nfsd/threads > to reduce the thread count. Maybe this field should be an s32? > 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... > > > > + - > > > + 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> > > > -- > Chuck Lever > > -- Jeff Layton <jlayton@xxxxxxxxxx>
