> 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? >> + - >> + 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
