> On Sep 22, 2023, at 12:20 PM, Lorenzo Bianconi <lorenzo.bianconi@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! > > maybe u8 is fine here :) 32-bit is the usual for this kind of interface. I don't think we need to go with 16-bit. >>> + - >>> + 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 > > I tried to be aligned with write_v4_end_grace() here but supporting just 1 (or > any other non-zero value) and skipping 'Y/y'. If we send 0 it should skip the > release action. > >> matter at all. Do we have to send down a value at all? > > I am not sure if ynl supports a doit operation with a request with no parameters. > @Chuck, Jakub: any input here? I think it does, I might have done something like that for one of the handshake protocol commands. But I think Jeff's right, end_grace might be better postponed. Pick any of the others that you think might be easy to implement instead. > Regards, > Lorenzo > >> >>> + 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
