diff options
| -rw-r--r-- | net/mptcp/protocol.c | 86 | ||||
| -rw-r--r-- | net/mptcp/protocol.h | 67 | ||||
| -rw-r--r-- | net/mptcp/subflow.c | 45 |
3 files changed, 194 insertions, 4 deletions
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 8cb582eee286..a033bf9c26ee 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -45,6 +45,9 @@ static struct percpu_counter mptcp_sockets_allocated; static void __mptcp_destroy_sock(struct sock *sk); static void __mptcp_check_send_data_fin(struct sock *sk); +DEFINE_PER_CPU(struct mptcp_delegated_action, mptcp_delegated_actions); +static struct net_device mptcp_napi_dev; + /* If msk has an initial subflow socket, and the MP_CAPABLE handshake has not * completed yet or has failed, return the subflow socket. * Otherwise return NULL. @@ -1506,7 +1509,9 @@ static void __mptcp_subflow_push_pending(struct sock *sk, struct sock *ssk) struct mptcp_sock *msk = mptcp_sk(sk); struct mptcp_sendmsg_info info; struct mptcp_data_frag *dfrag; + struct sock *xmit_ssk; int len, copied = 0; + bool first = true; info.flags = 0; while ((dfrag = mptcp_send_head(sk))) { @@ -1516,6 +1521,18 @@ static void __mptcp_subflow_push_pending(struct sock *sk, struct sock *ssk) while (len > 0) { int ret = 0; + /* the caller already invoked the packet scheduler, + * check for a different subflow usage only after + * spooling the first chunk of data + */ + xmit_ssk = first ? ssk : mptcp_subflow_get_send(mptcp_sk(sk)); + if (!xmit_ssk) + goto out; + if (xmit_ssk != ssk) { + mptcp_subflow_delegate(mptcp_subflow_ctx(xmit_ssk)); + goto out; + } + if (unlikely(mptcp_must_reclaim_memory(sk, ssk))) { __mptcp_update_wmem(sk); sk_mem_reclaim_partial(sk); @@ -1534,6 +1551,7 @@ static void __mptcp_subflow_push_pending(struct sock *sk, struct sock *ssk) msk->tx_pending_data -= ret; copied += ret; len -= ret; + first = false; } WRITE_ONCE(msk->first_pending, mptcp_send_next(sk)); } @@ -2242,7 +2260,6 @@ static void mptcp_worker(struct work_struct *work) if (unlikely(state == TCP_CLOSE)) goto unlock; - mptcp_push_pending(sk, 0); mptcp_check_data_fin_ack(sk); __mptcp_flush_join_list(msk); @@ -2901,10 +2918,12 @@ void __mptcp_check_push(struct sock *sk, struct sock *ssk) return; if (!sock_owned_by_user(sk)) { - if (mptcp_subflow_get_send(mptcp_sk(sk)) == ssk) + struct sock *xmit_ssk = mptcp_subflow_get_send(mptcp_sk(sk)); + + if (xmit_ssk == ssk) __mptcp_subflow_push_pending(sk, ssk); - else - mptcp_schedule_work(sk); + else if (xmit_ssk) + mptcp_subflow_delegate(mptcp_subflow_ctx(xmit_ssk)); } else { set_bit(MPTCP_PUSH_PENDING, &mptcp_sk(sk)->flags); } @@ -2955,6 +2974,20 @@ static void mptcp_release_cb(struct sock *sk) } } +void mptcp_subflow_process_delegated(struct sock *ssk) +{ + struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); + struct sock *sk = subflow->conn; + + mptcp_data_lock(sk); + if (!sock_owned_by_user(sk)) + __mptcp_subflow_push_pending(sk, ssk); + else + set_bit(MPTCP_PUSH_PENDING, &mptcp_sk(sk)->flags); + mptcp_data_unlock(sk); + mptcp_subflow_delegated_done(subflow); +} + static int mptcp_hash(struct sock *sk) { /* should never be called, @@ -3365,13 +3398,58 @@ static struct inet_protosw mptcp_protosw = { .flags = INET_PROTOSW_ICSK, }; +static int mptcp_napi_poll(struct napi_struct *napi, int budget) +{ + struct mptcp_delegated_action *delegated; + struct mptcp_subflow_context *subflow; + int work_done = 0; + + delegated = container_of(napi, struct mptcp_delegated_action, napi); + while ((subflow = mptcp_subflow_delegated_next(delegated)) != NULL) { + struct sock *ssk = mptcp_subflow_tcp_sock(subflow); + + bh_lock_sock_nested(ssk); + if (!sock_owned_by_user(ssk) && + mptcp_subflow_has_delegated_action(subflow)) + mptcp_subflow_process_delegated(ssk); + /* ... elsewhere tcp_release_cb_override already processed + * the action or will do at next release_sock(). + * In both case must dequeue the subflow here - on the same + * CPU that scheduled it. + */ + bh_unlock_sock(ssk); + sock_put(ssk); + + if (++work_done == budget) + return budget; + } + + /* always provide a 0 'work_done' argument, so that napi_complete_done + * will not try accessing the NULL napi->dev ptr + */ + napi_complete_done(napi, 0); + return work_done; +} + void __init mptcp_proto_init(void) { + struct mptcp_delegated_action *delegated; + int cpu; + mptcp_prot.h.hashinfo = tcp_prot.h.hashinfo; if (percpu_counter_init(&mptcp_sockets_allocated, 0, GFP_KERNEL)) panic("Failed to allocate MPTCP pcpu counter\n"); + init_dummy_netdev(&mptcp_napi_dev); + for_each_possible_cpu(cpu) { + delegated = per_cpu_ptr(&mptcp_delegated_actions, cpu); + INIT_LIST_HEAD(&delegated->head); + netif_tx_napi_add(&mptcp_napi_dev, &delegated->napi, mptcp_napi_poll, + NAPI_POLL_WEIGHT); + napi_enable(&delegated->napi); + } + mptcp_subflow_init(); mptcp_pm_init(); mptcp_token_init(); diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 871534df6140..1460705aaad0 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -378,6 +378,15 @@ enum mptcp_data_avail { MPTCP_SUBFLOW_OOO_DATA }; +struct mptcp_delegated_action { + struct napi_struct napi; + struct list_head head; +}; + +DECLARE_PER_CPU(struct mptcp_delegated_action, mptcp_delegated_actions); + +#define MPTCP_DELEGATE_SEND 0 + /* MPTCP subflow context */ struct mptcp_subflow_context { struct list_head node;/* conn_list of subflows */ @@ -415,6 +424,9 @@ struct mptcp_subflow_context { u8 local_id; u8 remote_id; + long delegated_status; + struct list_head delegated_node; /* link into delegated_action, protected by local BH */ + struct sock *tcp_sock; /* tcp sk backpointer */ struct sock *conn; /* parent mptcp_sock */ const struct inet_connection_sock_af_ops *icsk_af_ops; @@ -463,6 +475,61 @@ static inline void mptcp_add_pending_subflow(struct mptcp_sock *msk, spin_unlock_bh(&msk->join_list_lock); } +void mptcp_subflow_process_delegated(struct sock *ssk); + +static inline void mptcp_subflow_delegate(struct mptcp_subflow_context *subflow) +{ + struct mptcp_delegated_action *delegated; + bool schedule; + + /* The implied barrier pairs with mptcp_subflow_delegated_done(), and + * ensures the below list check sees list updates done prior to status + * bit changes + */ + if (!test_and_set_bit(MPTCP_DELEGATE_SEND, &subflow->delegated_status)) { + /* still on delegated list from previous scheduling */ + if (!list_empty(&subflow->delegated_node)) + return; + + /* the caller held the subflow bh socket lock */ + lockdep_assert_in_softirq(); + + delegated = this_cpu_ptr(&mptcp_delegated_actions); + schedule = list_empty(&delegated->head); + list_add_tail(&subflow->delegated_node, &delegated->head); + sock_hold(mptcp_subflow_tcp_sock(subflow)); + if (schedule) + napi_schedule(&delegated->napi); + } +} + +static inline struct mptcp_subflow_context * +mptcp_subflow_delegated_next(struct mptcp_delegated_action *delegated) +{ + struct mptcp_subflow_context *ret; + + if (list_empty(&delegated->head)) + return NULL; + + ret = list_first_entry(&delegated->head, struct mptcp_subflow_context, delegated_node); + list_del_init(&ret->delegated_node); + return ret; +} + +static inline bool mptcp_subflow_has_delegated_action(const struct mptcp_subflow_context *subflow) +{ + return test_bit(MPTCP_DELEGATE_SEND, &subflow->delegated_status); +} + +static inline void mptcp_subflow_delegated_done(struct mptcp_subflow_context *subflow) +{ + /* pairs with mptcp_subflow_delegate, ensures delegate_node is updated before + * touching the status bit + */ + smp_wmb(); + clear_bit(MPTCP_DELEGATE_SEND, &subflow->delegated_status); +} + int mptcp_is_enabled(struct net *net); unsigned int mptcp_get_add_addr_timeout(struct net *net); void mptcp_subflow_fully_established(struct mptcp_subflow_context *subflow, diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 1ca0c82b0dbd..721059916c96 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -18,12 +18,15 @@ #include <net/tcp.h> #if IS_ENABLED(CONFIG_MPTCP_IPV6) #include <net/ip6_route.h> +#include <net/transp_v6.h> #endif #include <net/mptcp.h> #include <uapi/linux/mptcp.h> #include "protocol.h" #include "mib.h" +static void mptcp_subflow_ops_undo_override(struct sock *ssk); + static void SUBFLOW_REQ_INC_STATS(struct request_sock *req, enum linux_mptcp_mib_field field) { @@ -428,6 +431,7 @@ drop: static struct tcp_request_sock_ops subflow_request_sock_ipv6_ops; static struct inet_connection_sock_af_ops subflow_v6_specific; static struct inet_connection_sock_af_ops subflow_v6m_specific; +static struct proto tcpv6_prot_override; static int subflow_v6_conn_request(struct sock *sk, struct sk_buff *skb) { @@ -509,6 +513,8 @@ static void subflow_ulp_fallback(struct sock *sk, icsk->icsk_ulp_ops = NULL; rcu_assign_pointer(icsk->icsk_ulp_data, NULL); tcp_sk(sk)->is_mptcp = 0; + + mptcp_subflow_ops_undo_override(sk); } static void subflow_drop_ctx(struct sock *ssk) @@ -682,6 +688,7 @@ dispose_child: } static struct inet_connection_sock_af_ops subflow_specific; +static struct proto tcp_prot_override; enum mapping_status { MAPPING_OK, @@ -1203,6 +1210,25 @@ static void mptcp_attach_cgroup(struct sock *parent, struct sock *child) #endif /* CONFIG_SOCK_CGROUP_DATA */ } +static void mptcp_subflow_ops_override(struct sock *ssk) +{ +#if IS_ENABLED(CONFIG_MPTCP_IPV6) + if (ssk->sk_prot == &tcpv6_prot) + ssk->sk_prot = &tcpv6_prot_override; + else +#endif + ssk->sk_prot = &tcp_prot_override; +} + +static void mptcp_subflow_ops_undo_override(struct sock *ssk) +{ +#if IS_ENABLED(CONFIG_MPTCP_IPV6) + if (ssk->sk_prot == &tcpv6_prot_override) + ssk->sk_prot = &tcpv6_prot; + else +#endif + ssk->sk_prot = &tcp_prot; +} int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock) { struct mptcp_subflow_context *subflow; @@ -1258,6 +1284,7 @@ int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock) *new_sock = sf; sock_hold(sk); subflow->conn = sk; + mptcp_subflow_ops_override(sf->sk); return 0; } @@ -1274,6 +1301,7 @@ static struct mptcp_subflow_context *subflow_create_ctx(struct sock *sk, rcu_assign_pointer(icsk->icsk_ulp_data, ctx); INIT_LIST_HEAD(&ctx->node); + INIT_LIST_HEAD(&ctx->delegated_node); pr_debug("subflow=%p", ctx); @@ -1386,6 +1414,7 @@ static void subflow_ulp_release(struct sock *ssk) sock_put(sk); } + mptcp_subflow_ops_undo_override(ssk); if (release) kfree_rcu(ctx, rcu); } @@ -1439,6 +1468,16 @@ static void subflow_ulp_clone(const struct request_sock *req, } } +static void tcp_release_cb_override(struct sock *ssk) +{ + struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); + + if (mptcp_subflow_has_delegated_action(subflow)) + mptcp_subflow_process_delegated(ssk); + + tcp_release_cb(ssk); +} + static struct tcp_ulp_ops subflow_ulp_ops __read_mostly = { .name = "mptcp", .owner = THIS_MODULE, @@ -1479,6 +1518,9 @@ void __init mptcp_subflow_init(void) subflow_specific.syn_recv_sock = subflow_syn_recv_sock; subflow_specific.sk_rx_dst_set = subflow_finish_connect; + tcp_prot_override = tcp_prot; + tcp_prot_override.release_cb = tcp_release_cb_override; + #if IS_ENABLED(CONFIG_MPTCP_IPV6) subflow_request_sock_ipv6_ops = tcp_request_sock_ipv6_ops; subflow_request_sock_ipv6_ops.route_req = subflow_v6_route_req; @@ -1494,6 +1536,9 @@ void __init mptcp_subflow_init(void) subflow_v6m_specific.net_header_len = ipv4_specific.net_header_len; subflow_v6m_specific.mtu_reduced = ipv4_specific.mtu_reduced; subflow_v6m_specific.net_frag_header_len = 0; + + tcpv6_prot_override = tcpv6_prot; + tcpv6_prot_override.release_cb = tcp_release_cb_override; #endif mptcp_diag_subflow_init(&subflow_ulp_ops); |