On Sun, Sep 24, 2023 at 03:52:28PM +0200, Lorenzo Bianconi wrote: > Introduce write_threads, write_maxblksize and write_maxconn netlink > commands similar to the ones available through the procfs. > > Signed-off-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx> > --- > Changes since v1: > - remove write_v4_end_grace command > - add write_maxblksize and write_maxconn netlink commands > > This patch can be tested with user-space tool reported below: > https://github.com/LorenzoBianconi/nfsd-netlink.git > --- > Documentation/netlink/specs/nfsd.yaml | 63 ++++++++++++ > fs/nfsd/netlink.c | 51 ++++++++++ > fs/nfsd/netlink.h | 9 ++ > fs/nfsd/nfsctl.c | 139 ++++++++++++++++++++++++++ > include/uapi/linux/nfsd_netlink.h | 15 +++ > 5 files changed, 277 insertions(+) This looks pretty close to me. A couple of comments below. > diff --git a/Documentation/netlink/specs/nfsd.yaml b/Documentation/netlink/specs/nfsd.yaml > index 403d3e3a04f3..10214fcec8a5 100644 > --- a/Documentation/netlink/specs/nfsd.yaml > +++ b/Documentation/netlink/specs/nfsd.yaml > @@ -62,6 +62,18 @@ attribute-sets: > name: compound-ops > type: u32 > multi-attr: true > + - > + name: server-attr Or, say, "control-plane" ? "server-attr" doesn't seem very self- explanatory or specific. > + attributes: > + - > + name: threads > + type: u32 > + - > + name: max-blksize > + type: u32 > + - > + name: max-conn > + type: u32 > > operations: > list: > @@ -72,3 +84,54 @@ 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: threads-get > + doc: dump the number of running threads > + attribute-set: server-attr > + dump: > + reply: > + attributes: > + - threads > + - > + name: max-blksize-set > + doc: set the nfs block size > + attribute-set: server-attr > + flags: [ admin-perm ] > + do: > + request: > + attributes: > + - max-blksize > + - > + name: max-blksize-get > + doc: dump the nfs block size > + attribute-set: server-attr > + dump: > + reply: > + attributes: > + - max-blksize > + - > + name: max-conn-set > + doc: set the max number of connections > + attribute-set: server-attr > + flags: [ admin-perm ] > + do: > + request: > + attributes: > + - max-conn > + - > + name: max-conn-get > + doc: dump the max number of connections > + attribute-set: server-attr > + dump: > + reply: > + attributes: > + - max-conn > diff --git a/fs/nfsd/netlink.c b/fs/nfsd/netlink.c > index 0e1d635ec5f9..f3dde1b1e162 100644 > --- a/fs/nfsd/netlink.c > +++ b/fs/nfsd/netlink.c > @@ -10,6 +10,21 @@ > > #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_U32, }, > +}; > + > +/* NFSD_CMD_MAX_BLKSIZE_SET - do */ > +static const struct nla_policy nfsd_max_blksize_set_nl_policy[NFSD_A_SERVER_ATTR_MAX_BLKSIZE + 1] = { > + [NFSD_A_SERVER_ATTR_MAX_BLKSIZE] = { .type = NLA_U32, }, > +}; > + > +/* NFSD_CMD_MAX_CONN_SET - do */ > +static const struct nla_policy nfsd_max_conn_set_nl_policy[NFSD_A_SERVER_ATTR_MAX_CONN + 1] = { > + [NFSD_A_SERVER_ATTR_MAX_CONN] = { .type = NLA_U32, }, > +}; > + > /* Ops table for nfsd */ > static const struct genl_split_ops nfsd_nl_ops[] = { > { > @@ -19,6 +34,42 @@ 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_THREADS_GET, > + .dumpit = nfsd_nl_threads_get_dumpit, > + .flags = GENL_CMD_CAP_DUMP, > + }, > + { > + .cmd = NFSD_CMD_MAX_BLKSIZE_SET, > + .doit = nfsd_nl_max_blksize_set_doit, > + .policy = nfsd_max_blksize_set_nl_policy, > + .maxattr = NFSD_A_SERVER_ATTR_MAX_BLKSIZE, > + .flags = GENL_ADMIN_PERM | GENL_CMD_CAP_DO, > + }, > + { > + .cmd = NFSD_CMD_MAX_BLKSIZE_GET, > + .dumpit = nfsd_nl_max_blksize_get_dumpit, > + .flags = GENL_CMD_CAP_DUMP, > + }, > + { > + .cmd = NFSD_CMD_MAX_CONN_SET, > + .doit = nfsd_nl_max_conn_set_doit, > + .policy = nfsd_max_conn_set_nl_policy, > + .maxattr = NFSD_A_SERVER_ATTR_MAX_CONN, > + .flags = GENL_ADMIN_PERM | GENL_CMD_CAP_DO, > + }, > + { > + .cmd = NFSD_CMD_MAX_CONN_GET, > + .dumpit = nfsd_nl_max_conn_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..41b95651c638 100644 > --- a/fs/nfsd/netlink.h > +++ b/fs/nfsd/netlink.h > @@ -16,6 +16,15 @@ 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_threads_get_dumpit(struct sk_buff *skb, > + struct netlink_callback *cb); > +int nfsd_nl_max_blksize_set_doit(struct sk_buff *skb, struct genl_info *info); > +int nfsd_nl_max_blksize_get_dumpit(struct sk_buff *skb, > + struct netlink_callback *cb); > +int nfsd_nl_max_conn_set_doit(struct sk_buff *skb, struct genl_info *info); > +int nfsd_nl_max_conn_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..0167b7fd0d63 100644 > --- a/fs/nfsd/nfsctl.c > +++ b/fs/nfsd/nfsctl.c > @@ -1694,6 +1694,145 @@ 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_u32(info->attrs[NFSD_A_SERVER_ATTR_THREADS]); I worry about what happens if someone sends down a value larger than 64K. While not a likely scenario, the behavior is not well defined, and I don't think the implicit type conversions are necessary. Can nthreads be u32? > + ret = nfsd_svc(nthreads, genl_info_net(info), get_current_cred()); > + return ret == nthreads ? 0 : ret; > +} > + > +static int nfsd_nl_get_dump(struct sk_buff *skb, struct netlink_callback *cb, > + int cmd, int attr, u32 val) > +{ > + 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, cmd); > + if (!hdr) > + return -ENOBUFS; > + > + if (nla_put_u32(skb, attr, val)) > + return -ENOBUFS; > + > + genlmsg_end(skb, hdr); > + cb->args[0] = 1; > + > + return skb->len; > +} > + > +/** > + * nfsd_nl_threads_get_dumpit - dump the number of running threads > + * @skb: reply buffer > + * @cb: netlink metadata and command arguments > + * > + * Returns the size of the reply or a negative errno. > + */ > +int nfsd_nl_threads_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb) > +{ > + return nfsd_nl_get_dump(skb, cb, NFSD_CMD_THREADS_GET, > + NFSD_A_SERVER_ATTR_THREADS, > + nfsd_nrthreads(sock_net(skb->sk))); > +} > + > +/** > + * nfsd_nl_max_blksize_set_doit - set the nfs block size > + * @skb: reply buffer > + * @info: netlink metadata and command arguments > + * > + * Return 0 on success or a negative errno. > + */ > +int nfsd_nl_max_blksize_set_doit(struct sk_buff *skb, struct genl_info *info) > +{ > + struct nfsd_net *nn = net_generic(genl_info_net(info), nfsd_net_id); > + int ret = 0; > + > + if (!info->attrs[NFSD_A_SERVER_ATTR_MAX_BLKSIZE]) > + return -EINVAL; > + > + mutex_lock(&nfsd_mutex); > + if (nn->nfsd_serv) { > + ret = -EBUSY; > + goto out; > + } > + > + nfsd_max_blksize = nla_get_u32(info->attrs[NFSD_A_SERVER_ATTR_MAX_BLKSIZE]); > + nfsd_max_blksize = max_t(int, nfsd_max_blksize, 1024); > + nfsd_max_blksize = min_t(int, nfsd_max_blksize, NFSSVC_MAXBLKSIZE); > + nfsd_max_blksize &= ~1023; > +out: > + mutex_unlock(&nfsd_mutex); > + > + return ret; > +} > + > +/** > + * nfsd_nl_max_blksize_get_dumpit - dump the nfs block size > + * @skb: reply buffer > + * @cb: netlink metadata and command arguments > + * > + * Returns the size of the reply or a negative errno. > + */ > +int nfsd_nl_max_blksize_get_dumpit(struct sk_buff *skb, > + struct netlink_callback *cb) > +{ > + return nfsd_nl_get_dump(skb, cb, NFSD_CMD_MAX_BLKSIZE_GET, > + NFSD_A_SERVER_ATTR_MAX_BLKSIZE, > + nfsd_max_blksize); > +} > + > +/** > + * nfsd_nl_max_conn_set_doit - set the max number of connections > + * @skb: reply buffer > + * @info: netlink metadata and command arguments > + * > + * Return 0 on success or a negative errno. > + */ > +int nfsd_nl_max_conn_set_doit(struct sk_buff *skb, struct genl_info *info) > +{ > + struct nfsd_net *nn = net_generic(genl_info_net(info), nfsd_net_id); > + > + if (!info->attrs[NFSD_A_SERVER_ATTR_MAX_CONN]) > + return -EINVAL; > + > + nn->max_connections = nla_get_u32(info->attrs[NFSD_A_SERVER_ATTR_MAX_CONN]); > + > + return 0; > +} > + > +/** > + * nfsd_nl_max_conn_get_dumpit - dump the max number of connections > + * @skb: reply buffer > + * @cb: netlink metadata and command arguments > + * > + * Returns the size of the reply or a negative errno. > + */ > +int nfsd_nl_max_conn_get_dumpit(struct sk_buff *skb, > + struct netlink_callback *cb) > +{ > + struct nfsd_net *nn = net_generic(sock_net(cb->skb->sk), nfsd_net_id); > + > + return nfsd_nl_get_dump(skb, cb, NFSD_CMD_MAX_CONN_GET, > + NFSD_A_SERVER_ATTR_MAX_CONN, > + nn->max_connections); > +} > + > /** > * 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..59d0aa22ba94 100644 > --- a/include/uapi/linux/nfsd_netlink.h > +++ b/include/uapi/linux/nfsd_netlink.h > @@ -29,8 +29,23 @@ enum { > NFSD_A_RPC_STATUS_MAX = (__NFSD_A_RPC_STATUS_MAX - 1) > }; > > +enum { > + NFSD_A_SERVER_ATTR_THREADS = 1, > + NFSD_A_SERVER_ATTR_MAX_BLKSIZE, > + NFSD_A_SERVER_ATTR_MAX_CONN, > + > + __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_THREADS_GET, > + NFSD_CMD_MAX_BLKSIZE_SET, > + NFSD_CMD_MAX_BLKSIZE_GET, > + NFSD_CMD_MAX_CONN_SET, > + NFSD_CMD_MAX_CONN_GET, > > __NFSD_CMD_MAX, > NFSD_CMD_MAX = (__NFSD_CMD_MAX - 1) > -- > 2.41.0 > -- Chuck Lever
