> On Sep 22, 2023, at 12:23 PM, Lorenzo Bianconi <lorenzo.bianconi@xxxxxxxxxx> wrote: > >> 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... > > ack, I agree. The positive / negative value is actually nailed into some of the thread infrastructure. Changing that might be more of schlep. I'm curious how Neil feels about this. > Regards, > Lorenzo > >> >>> >>>>> + - >>>>> + 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> >> -- Chuck Lever
