diff options
Diffstat (limited to '')
| -rw-r--r-- | fs/ocfs2/cluster/tcp.c | 2195 |
1 files changed, 2195 insertions, 0 deletions
diff --git a/fs/ocfs2/cluster/tcp.c b/fs/ocfs2/cluster/tcp.c new file mode 100644 index 000000000..7d9eea7d4 --- /dev/null +++ b/fs/ocfs2/cluster/tcp.c @@ -0,0 +1,2195 @@ +/* -*- mode: c; c-basic-offset: 8; -*- + * + * vim: noexpandtab sw=8 ts=8 sts=0: + * + * Copyright (C) 2004 Oracle. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + * + * ---- + * + * Callers for this were originally written against a very simple synchronus + * API. This implementation reflects those simple callers. Some day I'm sure + * we'll need to move to a more robust posting/callback mechanism. + * + * Transmit calls pass in kernel virtual addresses and block copying this into + * the socket's tx buffers via a usual blocking sendmsg. They'll block waiting + * for a failed socket to timeout. TX callers can also pass in a poniter to an + * 'int' which gets filled with an errno off the wire in response to the + * message they send. + * + * Handlers for unsolicited messages are registered. Each socket has a page + * that incoming data is copied into. First the header, then the data. + * Handlers are called from only one thread with a reference to this per-socket + * page. This page is destroyed after the handler call, so it can't be + * referenced beyond the call. Handlers may block but are discouraged from + * doing so. + * + * Any framing errors (bad magic, large payload lengths) close a connection. + * + * Our sock_container holds the state we associate with a socket. It's current + * framing state is held there as well as the refcounting we do around when it + * is safe to tear down the socket. The socket is only finally torn down from + * the container when the container loses all of its references -- so as long + * as you hold a ref on the container you can trust that the socket is valid + * for use with kernel socket APIs. + * + * Connections are initiated between a pair of nodes when the node with the + * higher node number gets a heartbeat callback which indicates that the lower + * numbered node has started heartbeating. The lower numbered node is passive + * and only accepts the connection if the higher numbered node is heartbeating. + */ + +#include <linux/kernel.h> +#include <linux/sched/mm.h> +#include <linux/jiffies.h> +#include <linux/slab.h> +#include <linux/idr.h> +#include <linux/kref.h> +#include <linux/net.h> +#include <linux/export.h> +#include <net/tcp.h> + +#include <linux/uaccess.h> + +#include "heartbeat.h" +#include "tcp.h" +#include "nodemanager.h" +#define MLOG_MASK_PREFIX ML_TCP +#include "masklog.h" +#include "quorum.h" + +#include "tcp_internal.h" + +#define SC_NODEF_FMT "node %s (num %u) at %pI4:%u" +#define SC_NODEF_ARGS(sc) sc->sc_node->nd_name, sc->sc_node->nd_num, \ + &sc->sc_node->nd_ipv4_address, \ + ntohs(sc->sc_node->nd_ipv4_port) + +/* + * In the following two log macros, the whitespace after the ',' just + * before ##args is intentional. Otherwise, gcc 2.95 will eat the + * previous token if args expands to nothing. + */ +#define msglog(hdr, fmt, args...) do { \ + typeof(hdr) __hdr = (hdr); \ + mlog(ML_MSG, "[mag %u len %u typ %u stat %d sys_stat %d " \ + "key %08x num %u] " fmt, \ + be16_to_cpu(__hdr->magic), be16_to_cpu(__hdr->data_len), \ + be16_to_cpu(__hdr->msg_type), be32_to_cpu(__hdr->status), \ + be32_to_cpu(__hdr->sys_status), be32_to_cpu(__hdr->key), \ + be32_to_cpu(__hdr->msg_num) , ##args); \ +} while (0) + +#define sclog(sc, fmt, args...) do { \ + typeof(sc) __sc = (sc); \ + mlog(ML_SOCKET, "[sc %p refs %d sock %p node %u page %p " \ + "pg_off %zu] " fmt, __sc, \ + kref_read(&__sc->sc_kref), __sc->sc_sock, \ + __sc->sc_node->nd_num, __sc->sc_page, __sc->sc_page_off , \ + ##args); \ +} while (0) + +static DEFINE_RWLOCK(o2net_handler_lock); +static struct rb_root o2net_handler_tree = RB_ROOT; + +static struct o2net_node o2net_nodes[O2NM_MAX_NODES]; + +/* XXX someday we'll need better accounting */ +static struct socket *o2net_listen_sock; + +/* + * listen work is only queued by the listening socket callbacks on the + * o2net_wq. teardown detaches the callbacks before destroying the workqueue. + * quorum work is queued as sock containers are shutdown.. stop_listening + * tears down all the node's sock containers, preventing future shutdowns + * and queued quroum work, before canceling delayed quorum work and + * destroying the work queue. + */ +static struct workqueue_struct *o2net_wq; +static struct work_struct o2net_listen_work; + +static struct o2hb_callback_func o2net_hb_up, o2net_hb_down; +#define O2NET_HB_PRI 0x1 + +static struct o2net_handshake *o2net_hand; +static struct o2net_msg *o2net_keep_req, *o2net_keep_resp; + +static int o2net_sys_err_translations[O2NET_ERR_MAX] = + {[O2NET_ERR_NONE] = 0, + [O2NET_ERR_NO_HNDLR] = -ENOPROTOOPT, + [O2NET_ERR_OVERFLOW] = -EOVERFLOW, + [O2NET_ERR_DIED] = -EHOSTDOWN,}; + +/* can't quite avoid *all* internal declarations :/ */ +static void o2net_sc_connect_completed(struct work_struct *work); +static void o2net_rx_until_empty(struct work_struct *work); +static void o2net_shutdown_sc(struct work_struct *work); +static void o2net_listen_data_ready(struct sock *sk); +static void o2net_sc_send_keep_req(struct work_struct *work); +static void o2net_idle_timer(struct timer_list *t); +static void o2net_sc_postpone_idle(struct o2net_sock_container *sc); +static void o2net_sc_reset_idle_timer(struct o2net_sock_container *sc); + +#ifdef CONFIG_DEBUG_FS +static void o2net_init_nst(struct o2net_send_tracking *nst, u32 msgtype, + u32 msgkey, struct task_struct *task, u8 node) +{ + INIT_LIST_HEAD(&nst->st_net_debug_item); + nst->st_task = task; + nst->st_msg_type = msgtype; + nst->st_msg_key = msgkey; + nst->st_node = node; +} + +static inline void o2net_set_nst_sock_time(struct o2net_send_tracking *nst) +{ + nst->st_sock_time = ktime_get(); +} + +static inline void o2net_set_nst_send_time(struct o2net_send_tracking *nst) +{ + nst->st_send_time = ktime_get(); +} + +static inline void o2net_set_nst_status_time(struct o2net_send_tracking *nst) +{ + nst->st_status_time = ktime_get(); +} + +static inline void o2net_set_nst_sock_container(struct o2net_send_tracking *nst, + struct o2net_sock_container *sc) +{ + nst->st_sc = sc; +} + +static inline void o2net_set_nst_msg_id(struct o2net_send_tracking *nst, + u32 msg_id) +{ + nst->st_id = msg_id; +} + +static inline void o2net_set_sock_timer(struct o2net_sock_container *sc) +{ + sc->sc_tv_timer = ktime_get(); +} + +static inline void o2net_set_data_ready_time(struct o2net_sock_container *sc) +{ + sc->sc_tv_data_ready = ktime_get(); +} + +static inline void o2net_set_advance_start_time(struct o2net_sock_container *sc) +{ + sc->sc_tv_advance_start = ktime_get(); +} + +static inline void o2net_set_advance_stop_time(struct o2net_sock_container *sc) +{ + sc->sc_tv_advance_stop = ktime_get(); +} + +static inline void o2net_set_func_start_time(struct o2net_sock_container *sc) +{ + sc->sc_tv_func_start = ktime_get(); +} + +static inline void o2net_set_func_stop_time(struct o2net_sock_container *sc) +{ + sc->sc_tv_func_stop = ktime_get(); +} + +#else /* CONFIG_DEBUG_FS */ +# define o2net_init_nst(a, b, c, d, e) +# define o2net_set_nst_sock_time(a) +# define o2net_set_nst_send_time(a) +# define o2net_set_nst_status_time(a) +# define o2net_set_nst_sock_container(a, b) +# define o2net_set_nst_msg_id(a, b) +# define o2net_set_sock_timer(a) +# define o2net_set_data_ready_time(a) +# define o2net_set_advance_start_time(a) +# define o2net_set_advance_stop_time(a) +# define o2net_set_func_start_time(a) +# define o2net_set_func_stop_time(a) +#endif /* CONFIG_DEBUG_FS */ + +#ifdef CONFIG_OCFS2_FS_STATS +static ktime_t o2net_get_func_run_time(struct o2net_sock_container *sc) +{ + return ktime_sub(sc->sc_tv_func_stop, sc->sc_tv_func_start); +} + +static void o2net_update_send_stats(struct o2net_send_tracking *nst, + struct o2net_sock_container *sc) +{ + sc->sc_tv_status_total = ktime_add(sc->sc_tv_status_total, + ktime_sub(ktime_get(), + nst->st_status_time)); + sc->sc_tv_send_total = ktime_add(sc->sc_tv_send_total, + ktime_sub(nst->st_status_time, + nst->st_send_time)); + sc->sc_tv_acquiry_total = ktime_add(sc->sc_tv_acquiry_total, + ktime_sub(nst->st_send_time, + nst->st_sock_time)); + sc->sc_send_count++; +} + +static void o2net_update_recv_stats(struct o2net_sock_container *sc) +{ + sc->sc_tv_process_total = ktime_add(sc->sc_tv_process_total, + o2net_get_func_run_time(sc)); + sc->sc_recv_count++; +} + +#else + +# define o2net_update_send_stats(a, b) + +# define o2net_update_recv_stats(sc) + +#endif /* CONFIG_OCFS2_FS_STATS */ + +static inline unsigned int o2net_reconnect_delay(void) +{ + return o2nm_single_cluster->cl_reconnect_delay_ms; +} + +static inline unsigned int o2net_keepalive_delay(void) +{ + return o2nm_single_cluster->cl_keepalive_delay_ms; +} + +static inline unsigned int o2net_idle_timeout(void) +{ + return o2nm_single_cluster->cl_idle_timeout_ms; +} + +static inline int o2net_sys_err_to_errno(enum o2net_system_error err) +{ + int trans; + BUG_ON(err >= O2NET_ERR_MAX); + trans = o2net_sys_err_translations[err]; + + /* Just in case we mess up the translation table above */ + BUG_ON(err != O2NET_ERR_NONE && trans == 0); + return trans; +} + +static struct o2net_node * o2net_nn_from_num(u8 node_num) +{ + BUG_ON(node_num >= ARRAY_SIZE(o2net_nodes)); + return &o2net_nodes[node_num]; +} + +static u8 o2net_num_from_nn(struct o2net_node *nn) +{ + BUG_ON(nn == NULL); + return nn - o2net_nodes; +} + +/* ------------------------------------------------------------ */ + +static int o2net_prep_nsw(struct o2net_node *nn, struct o2net_status_wait *nsw) +{ + int ret; + + spin_lock(&nn->nn_lock); + ret = idr_alloc(&nn->nn_status_idr, nsw, 0, 0, GFP_ATOMIC); + if (ret >= 0) { + nsw->ns_id = ret; + list_add_tail(&nsw->ns_node_item, &nn->nn_status_list); + } + spin_unlock(&nn->nn_lock); + if (ret < 0) + return ret; + + init_waitqueue_head(&nsw->ns_wq); + nsw->ns_sys_status = O2NET_ERR_NONE; + nsw->ns_status = 0; + return 0; +} + +static void o2net_complete_nsw_locked(struct o2net_node *nn, + struct o2net_status_wait *nsw, + enum o2net_system_error sys_status, + s32 status) +{ + assert_spin_locked(&nn->nn_lock); + + if (!list_empty(&nsw->ns_node_item)) { + list_del_init(&nsw->ns_node_item); + nsw->ns_sys_status = sys_status; + nsw->ns_status = status; + idr_remove(&nn->nn_status_idr, nsw->ns_id); + wake_up(&nsw->ns_wq); + } +} + +static void o2net_complete_nsw(struct o2net_node *nn, + struct o2net_status_wait *nsw, + u64 id, enum o2net_system_error sys_status, + s32 status) +{ + spin_lock(&nn->nn_lock); + if (nsw == NULL) { + if (id > INT_MAX) + goto out; + + nsw = idr_find(&nn->nn_status_idr, id); + if (nsw == NULL) + goto out; + } + + o2net_complete_nsw_locked(nn, nsw, sys_status, status); + +out: + spin_unlock(&nn->nn_lock); + return; +} + +static void o2net_complete_nodes_nsw(struct o2net_node *nn) +{ + struct o2net_status_wait *nsw, *tmp; + unsigned int num_kills = 0; + + assert_spin_locked(&nn->nn_lock); + + list_for_each_entry_safe(nsw, tmp, &nn->nn_status_list, ns_node_item) { + o2net_complete_nsw_locked(nn, nsw, O2NET_ERR_DIED, 0); + num_kills++; + } + + mlog(0, "completed %d messages for node %u\n", num_kills, + o2net_num_from_nn(nn)); +} + +static int o2net_nsw_completed(struct o2net_node *nn, + struct o2net_status_wait *nsw) +{ + int completed; + spin_lock(&nn->nn_lock); + completed = list_empty(&nsw->ns_node_item); + spin_unlock(&nn->nn_lock); + return completed; +} + +/* ------------------------------------------------------------ */ + +static void sc_kref_release(struct kref *kref) +{ + struct o2net_sock_container *sc = container_of(kref, + struct o2net_sock_container, sc_kref); + BUG_ON(timer_pending(&sc->sc_idle_timeout)); + + sclog(sc, "releasing\n"); + + if (sc->sc_sock) { + sock_release(sc->sc_sock); + sc->sc_sock = NULL; + } + + o2nm_undepend_item(&sc->sc_node->nd_item); + o2nm_node_put(sc->sc_node); + sc->sc_node = NULL; + + o2net_debug_del_sc(sc); + + if (sc->sc_page) + __free_page(sc->sc_page); + kfree(sc); +} + +static void sc_put(struct o2net_sock_container *sc) +{ + sclog(sc, "put\n"); + kref_put(&sc->sc_kref, sc_kref_release); +} +static void sc_get(struct o2net_sock_container *sc) +{ + sclog(sc, "get\n"); + kref_get(&sc->sc_kref); +} +static struct o2net_sock_container *sc_alloc(struct o2nm_node *node) +{ + struct o2net_sock_container *sc, *ret = NULL; + struct page *page = NULL; + int status = 0; + + page = alloc_page(GFP_NOFS); + sc = kzalloc(sizeof(*sc), GFP_NOFS); + if (sc == NULL || page == NULL) + goto out; + + kref_init(&sc->sc_kref); + o2nm_node_get(node); + sc->sc_node = node; + + /* pin the node item of the remote node */ + status = o2nm_depend_item(&node->nd_item); + if (status) { + mlog_errno(status); + o2nm_node_put(node); + goto out; + } + INIT_WORK(&sc->sc_connect_work, o2net_sc_connect_completed); + INIT_WORK(&sc->sc_rx_work, o2net_rx_until_empty); + INIT_WORK(&sc->sc_shutdown_work, o2net_shutdown_sc); + INIT_DELAYED_WORK(&sc->sc_keepalive_work, o2net_sc_send_keep_req); + + timer_setup(&sc->sc_idle_timeout, o2net_idle_timer, 0); + + sclog(sc, "alloced\n"); + + ret = sc; + sc->sc_page = page; + o2net_debug_add_sc(sc); + sc = NULL; + page = NULL; + +out: + if (page) + __free_page(page); + kfree(sc); + + return ret; +} + +/* ------------------------------------------------------------ */ + +static void o2net_sc_queue_work(struct o2net_sock_container *sc, + struct work_struct *work) +{ + sc_get(sc); + if (!queue_work(o2net_wq, work)) + sc_put(sc); +} +static void o2net_sc_queue_delayed_work(struct o2net_sock_container *sc, + struct delayed_work *work, + int delay) +{ + sc_get(sc); + if (!queue_delayed_work(o2net_wq, work, delay)) + sc_put(sc); +} +static void o2net_sc_cancel_delayed_work(struct o2net_sock_container *sc, + struct delayed_work *work) +{ + if (cancel_delayed_work(work)) + sc_put(sc); +} + +static atomic_t o2net_connected_peers = ATOMIC_INIT(0); + +int o2net_num_connected_peers(void) +{ + return atomic_read(&o2net_connected_peers); +} + +static void o2net_set_nn_state(struct o2net_node *nn, + struct o2net_sock_container *sc, + unsigned valid, int err) +{ + int was_valid = nn->nn_sc_valid; + int was_err = nn->nn_persistent_error; + struct o2net_sock_container *old_sc = nn->nn_sc; + + assert_spin_locked(&nn->nn_lock); + + if (old_sc && !sc) + atomic_dec(&o2net_connected_peers); + else if (!old_sc && sc) + atomic_inc(&o2net_connected_peers); + + /* the node num comparison and single connect/accept path should stop + * an non-null sc from being overwritten with another */ + BUG_ON(sc && nn->nn_sc && nn->nn_sc != sc); + mlog_bug_on_msg(err && valid, "err %d valid %u\n", err, valid); + mlog_bug_on_msg(valid && !sc, "valid %u sc %p\n", valid, sc); + + if (was_valid && !valid && err == 0) + err = -ENOTCONN; + + mlog(ML_CONN, "node %u sc: %p -> %p, valid %u -> %u, err %d -> %d\n", + o2net_num_from_nn(nn), nn->nn_sc, sc, nn->nn_sc_valid, valid, + nn->nn_persistent_error, err); + + nn->nn_sc = sc; + nn->nn_sc_valid = valid ? 1 : 0; + nn->nn_persistent_error = err; + + /* mirrors o2net_tx_can_proceed() */ + if (nn->nn_persistent_error || nn->nn_sc_valid) + wake_up(&nn->nn_sc_wq); + + if (was_valid && !was_err && nn->nn_persistent_error) { + o2quo_conn_err(o2net_num_from_nn(nn)); + queue_delayed_work(o2net_wq, &nn->nn_still_up, + msecs_to_jiffies(O2NET_QUORUM_DELAY_MS)); + } + + if (was_valid && !valid) { + if (old_sc) + printk(KERN_NOTICE "o2net: No longer connected to " + SC_NODEF_FMT "\n", SC_NODEF_ARGS(old_sc)); + o2net_complete_nodes_nsw(nn); + } + + if (!was_valid && valid) { + o2quo_conn_up(o2net_num_from_nn(nn)); + cancel_delayed_work(&nn->nn_connect_expired); + printk(KERN_NOTICE "o2net: %s " SC_NODEF_FMT "\n", + o2nm_this_node() > sc->sc_node->nd_num ? + "Connected to" : "Accepted connection from", + SC_NODEF_ARGS(sc)); + } + + /* trigger the connecting worker func as long as we're not valid, + * it will back off if it shouldn't connect. This can be called + * from node config teardown and so needs to be careful about + * the work queue actually being up. */ + if (!valid && o2net_wq) { + unsigned long delay; + /* delay if we're within a RECONNECT_DELAY of the + * last attempt */ + delay = (nn->nn_last_connect_attempt + + msecs_to_jiffies(o2net_reconnect_delay())) + - jiffies; + if (delay > msecs_to_jiffies(o2net_reconnect_delay())) + delay = 0; + mlog(ML_CONN, "queueing conn attempt in %lu jiffies\n", delay); + queue_delayed_work(o2net_wq, &nn->nn_connect_work, delay); + + /* + * Delay the expired work after idle timeout. + * + * We might have lots of failed connection attempts that run + * through here but we only cancel the connect_expired work when + * a connection attempt succeeds. So only the first enqueue of + * the connect_expired work will do anything. The rest will see + * that it's already queued and do nothing. + */ + delay += msecs_to_jiffies(o2net_idle_timeout()); + queue_delayed_work(o2net_wq, &nn->nn_connect_expired, delay); + } + + /* keep track of the nn's sc ref for the caller */ + if ((old_sc == NULL) && sc) + sc_get(sc); + if (old_sc && (old_sc != sc)) { + o2net_sc_queue_work(old_sc, &old_sc->sc_shutdown_work); + sc_put(old_sc); + } +} + +/* see o2net_register_callbacks() */ +static void o2net_data_ready(struct sock *sk) +{ + void (*ready)(struct sock *sk); + struct o2net_sock_container *sc; + + read_lock_bh(&sk->sk_callback_lock); + sc = sk->sk_user_data; + if (sc) { + sclog(sc, "data_ready hit\n"); + o2net_set_data_ready_time(sc); + o2net_sc_queue_work(sc, &sc->sc_rx_work); + ready = sc->sc_data_ready; + } else { + ready = sk->sk_data_ready; + } + read_unlock_bh(&sk->sk_callback_lock); + + ready(sk); +} + +/* see o2net_register_callbacks() */ +static void o2net_state_change(struct sock *sk) +{ + void (*state_change)(struct sock *sk); + struct o2net_sock_container *sc; + + read_lock_bh(&sk->sk_callback_lock); + sc = sk->sk_user_data; + if (sc == NULL) { + state_change = sk->sk_state_change; + goto out; + } + + sclog(sc, "state_change to %d\n", sk->sk_state); + + state_change = sc->sc_state_change; + + switch(sk->sk_state) { + /* ignore connecting sockets as they make progress */ + case TCP_SYN_SENT: + case TCP_SYN_RECV: + break; + case TCP_ESTABLISHED: + o2net_sc_queue_work(sc, &sc->sc_connect_work); + break; + default: + printk(KERN_INFO "o2net: Connection to " SC_NODEF_FMT + " shutdown, state %d\n", + SC_NODEF_ARGS(sc), sk->sk_state); + o2net_sc_queue_work(sc, &sc->sc_shutdown_work); + break; + } +out: + read_unlock_bh(&sk->sk_callback_lock); + state_change(sk); +} + +/* + * we register callbacks so we can queue work on events before calling + * the original callbacks. our callbacks our careful to test user_data + * to discover when they've reaced with o2net_unregister_callbacks(). + */ +static void o2net_register_callbacks(struct sock *sk, + struct o2net_sock_container *sc) +{ + write_lock_bh(&sk->sk_callback_lock); + + /* accepted sockets inherit the old listen socket data ready */ + if (sk->sk_data_ready == o2net_listen_data_ready) { + sk->sk_data_ready = sk->sk_user_data; + sk->sk_user_data = NULL; + } + + BUG_ON(sk->sk_user_data != NULL); + sk->sk_user_data = sc; + sc_get(sc); + + sc->sc_data_ready = sk->sk_data_ready; + sc->sc_state_change = sk->sk_state_change; + sk->sk_data_ready = o2net_data_ready; + sk->sk_state_change = o2net_state_change; + + mutex_init(&sc->sc_send_lock); + + write_unlock_bh(&sk->sk_callback_lock); +} + +static int o2net_unregister_callbacks(struct sock *sk, + struct o2net_sock_container *sc) +{ + int ret = 0; + + write_lock_bh(&sk->sk_callback_lock); + if (sk->sk_user_data == sc) { + ret = 1; + sk->sk_user_data = NULL; + sk->sk_data_ready = sc->sc_data_ready; + sk->sk_state_change = sc->sc_state_change; + } + write_unlock_bh(&sk->sk_callback_lock); + + return ret; +} + +/* + * this is a little helper that is called by callers who have seen a problem + * with an sc and want to detach it from the nn if someone already hasn't beat + * them to it. if an error is given then the shutdown will be persistent + * and pending transmits will be canceled. + */ +static void o2net_ensure_shutdown(struct o2net_node *nn, + struct o2net_sock_container *sc, + int err) +{ + spin_lock(&nn->nn_lock); + if (nn->nn_sc == sc) + o2net_set_nn_state(nn, NULL, 0, err); + spin_unlock(&nn->nn_lock); +} + +/* + * This work queue function performs the blocking parts of socket shutdown. A + * few paths lead here. set_nn_state will trigger this callback if it sees an + * sc detached from the nn. state_change will also trigger this callback + * directly when it sees errors. In that case we need to call set_nn_state + * ourselves as state_change couldn't get the nn_lock and call set_nn_state + * itself. + */ +static void o2net_shutdown_sc(struct work_struct *work) +{ + struct o2net_sock_container *sc = + container_of(work, struct o2net_sock_container, + sc_shutdown_work); + struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num); + + sclog(sc, "shutting down\n"); + + /* drop the callbacks ref and call shutdown only once */ + if (o2net_unregister_callbacks(sc->sc_sock->sk, sc)) { + /* we shouldn't flush as we're in the thread, the + * races with pending sc work structs are harmless */ + del_timer_sync(&sc->sc_idle_timeout); + o2net_sc_cancel_delayed_work(sc, &sc->sc_keepalive_work); + sc_put(sc); + kernel_sock_shutdown(sc->sc_sock, SHUT_RDWR); + } + + /* not fatal so failed connects before the other guy has our + * heartbeat can be retried */ + o2net_ensure_shutdown(nn, sc, 0); + sc_put(sc); +} + +/* ------------------------------------------------------------ */ + +static int o2net_handler_cmp(struct o2net_msg_handler *nmh, u32 msg_type, + u32 key) +{ + int ret = memcmp(&nmh->nh_key, &key, sizeof(key)); + + if (ret == 0) + ret = memcmp(&nmh->nh_msg_type, &msg_type, sizeof(msg_type)); + + return ret; +} + +static struct o2net_msg_handler * +o2net_handler_tree_lookup(u32 msg_type, u32 key, struct rb_node ***ret_p, + struct rb_node **ret_parent) +{ + struct rb_node **p = &o2net_handler_tree.rb_node; + struct rb_node *parent = NULL; + struct o2net_msg_handler *nmh, *ret = NULL; + int cmp; + + while (*p) { + parent = *p; + nmh = rb_entry(parent, struct o2net_msg_handler, nh_node); + cmp = o2net_handler_cmp(nmh, msg_type, key); + + if (cmp < 0) + p = &(*p)->rb_left; + else if (cmp > 0) + p = &(*p)->rb_right; + else { + ret = nmh; + break; + } + } + + if (ret_p != NULL) + *ret_p = p; + if (ret_parent != NULL) + *ret_parent = parent; + + return ret; +} + +static void o2net_handler_kref_release(struct kref *kref) +{ + struct o2net_msg_handler *nmh; + nmh = container_of(kref, struct o2net_msg_handler, nh_kref); + + kfree(nmh); +} + +static void o2net_handler_put(struct o2net_msg_handler *nmh) +{ + kref_put(&nmh->nh_kref, o2net_handler_kref_release); +} + +/* max_len is protection for the handler func. incoming messages won't + * be given to the handler if their payload is longer than the max. */ +int o2net_register_handler(u32 msg_type, u32 key, u32 max_len, + o2net_msg_handler_func *func, void *data, + o2net_post_msg_handler_func *post_func, + struct list_head *unreg_list) +{ + struct o2net_msg_handler *nmh = NULL; + struct rb_node **p, *parent; + int ret = 0; + + if (max_len > O2NET_MAX_PAYLOAD_BYTES) { + mlog(0, "max_len for message handler out of range: %u\n", + max_len); + ret = -EINVAL; + goto out; + } + + if (!msg_type) { + mlog(0, "no message type provided: %u, %p\n", msg_type, func); + ret = -EINVAL; + goto out; + + } + if (!func) { + mlog(0, "no message handler provided: %u, %p\n", + msg_type, func); + ret = -EINVAL; + goto out; + } + + nmh = kzalloc(sizeof(struct o2net_msg_handler), GFP_NOFS); + if (nmh == NULL) { + ret = -ENOMEM; + goto out; + } + + nmh->nh_func = func; + nmh->nh_func_data = data; + nmh->nh_post_func = post_func; + nmh->nh_msg_type = msg_type; + nmh->nh_max_len = max_len; + nmh->nh_key = key; + /* the tree and list get this ref.. they're both removed in + * unregister when this ref is dropped */ + kref_init(&nmh->nh_kref); + INIT_LIST_HEAD(&nmh->nh_unregister_item); + + write_lock(&o2net_handler_lock); + if (o2net_handler_tree_lookup(msg_type, key, &p, &parent)) + ret = -EEXIST; + else { + rb_link_node(&nmh->nh_node, parent, p); + rb_insert_color(&nmh->nh_node, &o2net_handler_tree); + list_add_tail(&nmh->nh_unregister_item, unreg_list); + + mlog(ML_TCP, "registered handler func %p type %u key %08x\n", + func, msg_type, key); + /* we've had some trouble with handlers seemingly vanishing. */ + mlog_bug_on_msg(o2net_handler_tree_lookup(msg_type, key, &p, + &parent) == NULL, + "couldn't find handler we *just* registered " + "for type %u key %08x\n", msg_type, key); + } + write_unlock(&o2net_handler_lock); + +out: + if (ret) + kfree(nmh); + + return ret; +} +EXPORT_SYMBOL_GPL(o2net_register_handler); + +void o2net_unregister_handler_list(struct list_head *list) +{ + struct o2net_msg_handler *nmh, *n; + + write_lock(&o2net_handler_lock); + list_for_each_entry_safe(nmh, n, list, nh_unregister_item) { + mlog(ML_TCP, "unregistering handler func %p type %u key %08x\n", + nmh->nh_func, nmh->nh_msg_type, nmh->nh_key); + rb_erase(&nmh->nh_node, &o2net_handler_tree); + list_del_init(&nmh->nh_unregister_item); + kref_put(&nmh->nh_kref, o2net_handler_kref_release); + } + write_unlock(&o2net_handler_lock); +} +EXPORT_SYMBOL_GPL(o2net_unregister_handler_list); + +static struct o2net_msg_handler *o2net_handler_get(u32 msg_type, u32 key) +{ + struct o2net_msg_handler *nmh; + + read_lock(&o2net_handler_lock); + nmh = o2net_handler_tree_lookup(msg_type, key, NULL, NULL); + if (nmh) + kref_get(&nmh->nh_kref); + read_unlock(&o2net_handler_lock); + + return nmh; +} + +/* ------------------------------------------------------------ */ + +static int o2net_recv_tcp_msg(struct socket *sock, void *data, size_t len) +{ + struct kvec vec = { .iov_len = len, .iov_base = data, }; + struct msghdr msg = { .msg_flags = MSG_DONTWAIT, }; + iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &vec, 1, len); + return sock_recvmsg(sock, &msg, MSG_DONTWAIT); +} + +static int o2net_send_tcp_msg(struct socket *sock, struct kvec *vec, + size_t veclen, size_t total) +{ + int ret; + struct msghdr msg = {.msg_flags = 0,}; + + if (sock == NULL) { + ret = -EINVAL; + goto out; + } + + ret = kernel_sendmsg(sock, &msg, vec, veclen, total); + if (likely(ret == total)) + return 0; + mlog(ML_ERROR, "sendmsg returned %d instead of %zu\n", ret, total); + if (ret >= 0) + ret = -EPIPE; /* should be smarter, I bet */ +out: + mlog(0, "returning error: %d\n", ret); + return ret; +} + +static void o2net_sendpage(struct o2net_sock_container *sc, + void *kmalloced_virt, + size_t size) +{ + struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num); + ssize_t ret; + + while (1) { + mutex_lock(&sc->sc_send_lock); + ret = sc->sc_sock->ops->sendpage(sc->sc_sock, + virt_to_page(kmalloced_virt), + offset_in_page(kmalloced_virt), + size, MSG_DONTWAIT); + mutex_unlock(&sc->sc_send_lock); + if (ret == size) + break; + if (ret == (ssize_t)-EAGAIN) { + mlog(0, "sendpage of size %zu to " SC_NODEF_FMT + " returned EAGAIN\n", size, SC_NODEF_ARGS(sc)); + cond_resched(); + continue; + } + mlog(ML_ERROR, "sendpage of size %zu to " SC_NODEF_FMT + " failed with %zd\n", size, SC_NODEF_ARGS(sc), ret); + o2net_ensure_shutdown(nn, sc, 0); + break; + } +} + +static void o2net_init_msg(struct o2net_msg *msg, u16 data_len, u16 msg_type, u32 key) +{ + memset(msg, 0, sizeof(struct o2net_msg)); + msg->magic = cpu_to_be16(O2NET_MSG_MAGIC); + msg->data_len = cpu_to_be16(data_len); + msg->msg_type = cpu_to_be16(msg_type); + msg->sys_status = cpu_to_be32(O2NET_ERR_NONE); + msg->status = 0; + msg->key = cpu_to_be32(key); +} + +static int o2net_tx_can_proceed(struct o2net_node *nn, + struct o2net_sock_container **sc_ret, + int *error) +{ + int ret = 0; + + spin_lock(&nn->nn_lock); + if (nn->nn_persistent_error) { + ret = 1; + *sc_ret = NULL; + *error = nn->nn_persistent_error; + } else if (nn->nn_sc_valid) { + kref_get(&nn->nn_sc->sc_kref); + + ret = 1; + *sc_ret = nn->nn_sc; + *error = 0; + } + spin_unlock(&nn->nn_lock); + + return ret; +} + +/* Get a map of all nodes to which this node is currently connected to */ +void o2net_fill_node_map(unsigned long *map, unsigned bytes) +{ + struct o2net_sock_container *sc; + int node, ret; + + BUG_ON(bytes < (BITS_TO_LONGS(O2NM_MAX_NODES) * sizeof(unsigned long))); + + memset(map, 0, bytes); + for (node = 0; node < O2NM_MAX_NODES; ++node) { + if (!o2net_tx_can_proceed(o2net_nn_from_num(node), &sc, &ret)) + continue; + if (!ret) { + set_bit(node, map); + sc_put(sc); + } + } +} +EXPORT_SYMBOL_GPL(o2net_fill_node_map); + +int o2net_send_message_vec(u32 msg_type, u32 key, struct kvec *caller_vec, + size_t caller_veclen, u8 target_node, int *status) +{ + int ret = 0; + struct o2net_msg *msg = NULL; + size_t veclen, caller_bytes = 0; + struct kvec *vec = NULL; + struct o2net_sock_container *sc = NULL; + struct o2net_node *nn = o2net_nn_from_num(target_node); + struct o2net_status_wait nsw = { + .ns_node_item = LIST_HEAD_INIT(nsw.ns_node_item), + }; + struct o2net_send_tracking nst; + + o2net_init_nst(&nst, msg_type, key, current, target_node); + + if (o2net_wq == NULL) { + mlog(0, "attempt to tx without o2netd running\n"); + ret = -ESRCH; + goto out; + } + + if (caller_veclen == 0) { + mlog(0, "bad kvec array length\n"); + ret = -EINVAL; + goto out; + } + + caller_bytes = iov_length((struct iovec *)caller_vec, caller_veclen); + if (caller_bytes > O2NET_MAX_PAYLOAD_BYTES) { + mlog(0, "total payload len %zu too large\n", caller_bytes); + ret = -EINVAL; + goto out; + } + + if (target_node == o2nm_this_node()) { + ret = -ELOOP; + goto out; + } + + o2net_debug_add_nst(&nst); + + o2net_set_nst_sock_time(&nst); + + wait_event(nn->nn_sc_wq, o2net_tx_can_proceed(nn, &sc, &ret)); + if (ret) + goto out; + + o2net_set_nst_sock_container(&nst, sc); + + veclen = caller_veclen + 1; + vec = kmalloc_array(veclen, sizeof(struct kvec), GFP_ATOMIC); + if (vec == NULL) { + mlog(0, "failed to %zu element kvec!\n", veclen); + ret = -ENOMEM; + goto out; + } + + msg = kmalloc(sizeof(struct o2net_msg), GFP_ATOMIC); + if (!msg) { + mlog(0, "failed to allocate a o2net_msg!\n"); + ret = -ENOMEM; + goto out; + } + + o2net_init_msg(msg, caller_bytes, msg_type, key); + + vec[0].iov_len = sizeof(struct o2net_msg); + vec[0].iov_base = msg; + memcpy(&vec[1], caller_vec, caller_veclen * sizeof(struct kvec)); + + ret = o2net_prep_nsw(nn, &nsw); + if (ret) + goto out; + + msg->msg_num = cpu_to_be32(nsw.ns_id); + o2net_set_nst_msg_id(&nst, nsw.ns_id); + + o2net_set_nst_send_time(&nst); + + /* finally, convert the message header to network byte-order + * and send */ + mutex_lock(&sc->sc_send_lock); + ret = o2net_send_tcp_msg(sc->sc_sock, vec, veclen, + sizeof(struct o2net_msg) + caller_bytes); + mutex_unlock(&sc->sc_send_lock); + msglog(msg, "sending returned %d\n", ret); + if (ret < 0) { + mlog(0, "error returned from o2net_send_tcp_msg=%d\n", ret); + goto out; + } + + /* wait on other node's handler */ + o2net_set_nst_status_time(&nst); + wait_event(nsw.ns_wq, o2net_nsw_completed(nn, &nsw)); + + o2net_update_send_stats(&nst, sc); + + /* Note that we avoid overwriting the callers status return + * variable if a system error was reported on the other + * side. Callers beware. */ + ret = o2net_sys_err_to_errno(nsw.ns_sys_status); + if (status && !ret) + *status = nsw.ns_status; + + mlog(0, "woken, returning system status %d, user status %d\n", + ret, nsw.ns_status); +out: + o2net_debug_del_nst(&nst); /* must be before dropping sc and node */ + if (sc) + sc_put(sc); + kfree(vec); + kfree(msg); + o2net_complete_nsw(nn, &nsw, 0, 0, 0); + return ret; +} +EXPORT_SYMBOL_GPL(o2net_send_message_vec); + +int o2net_send_message(u32 msg_type, u32 key, void *data, u32 len, + u8 target_node, int *status) +{ + struct kvec vec = { + .iov_base = data, + .iov_len = len, + }; + return o2net_send_message_vec(msg_type, key, &vec, 1, + target_node, status); +} +EXPORT_SYMBOL_GPL(o2net_send_message); + +static int o2net_send_status_magic(struct socket *sock, struct o2net_msg *hdr, + enum o2net_system_error syserr, int err) +{ + struct kvec vec = { + .iov_base = hdr, + .iov_len = sizeof(struct o2net_msg), + }; + + BUG_ON(syserr >= O2NET_ERR_MAX); + + /* leave other fields intact from the incoming message, msg_num + * in particular */ + hdr->sys_status = cpu_to_be32(syserr); + hdr->status = cpu_to_be32(err); + hdr->magic = cpu_to_be16(O2NET_MSG_STATUS_MAGIC); // twiddle the magic + hdr->data_len = 0; + + msglog(hdr, "about to send status magic %d\n", err); + /* hdr has been in host byteorder this whole time */ + return o2net_send_tcp_msg(sock, &vec, 1, sizeof(struct o2net_msg)); +} + +/* this returns -errno if the header was unknown or too large, etc. + * after this is called the buffer us reused for the next message */ +static int o2net_process_message(struct o2net_sock_container *sc, + struct o2net_msg *hdr) +{ + struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num); + int ret = 0, handler_status; + enum o2net_system_error syserr; + struct o2net_msg_handler *nmh = NULL; + void *ret_data = NULL; + + msglog(hdr, "processing message\n"); + + o2net_sc_postpone_idle(sc); + + switch(be16_to_cpu(hdr->magic)) { + case O2NET_MSG_STATUS_MAGIC: + /* special type for returning message status */ + o2net_complete_nsw(nn, NULL, + be32_to_cpu(hdr->msg_num), + be32_to_cpu(hdr->sys_status), + be32_to_cpu(hdr->status)); + goto out; + case O2NET_MSG_KEEP_REQ_MAGIC: + o2net_sendpage(sc, o2net_keep_resp, + sizeof(*o2net_keep_resp)); + goto out; + case O2NET_MSG_KEEP_RESP_MAGIC: + goto out; + case O2NET_MSG_MAGIC: + break; + default: + msglog(hdr, "bad magic\n"); + ret = -EINVAL; + goto out; + break; + } + + /* find a handler for it */ + handler_status = 0; + nmh = o2net_handler_get(be16_to_cpu(hdr->msg_type), + be32_to_cpu(hdr->key)); + if (!nmh) { + mlog(ML_TCP, "couldn't find handler for type %u key %08x\n", + be16_to_cpu(hdr->msg_type), be32_to_cpu(hdr->key)); + syserr = O2NET_ERR_NO_HNDLR; + goto out_respond; + } + + syserr = O2NET_ERR_NONE; + + if (be16_to_cpu(hdr->data_len) > nmh->nh_max_len) + syserr = O2NET_ERR_OVERFLOW; + + if (syserr != O2NET_ERR_NONE) + goto out_respond; + + o2net_set_func_start_time(sc); + sc->sc_msg_key = be32_to_cpu(hdr->key); + sc->sc_msg_type = be16_to_cpu(hdr->msg_type); + handler_status = (nmh->nh_func)(hdr, sizeof(struct o2net_msg) + + be16_to_cpu(hdr->data_len), + nmh->nh_func_data, &ret_data); + o2net_set_func_stop_time(sc); + + o2net_update_recv_stats(sc); + +out_respond: + /* this destroys the hdr, so don't use it after this */ + mutex_lock(&sc->sc_send_lock); + ret = o2net_send_status_magic(sc->sc_sock, hdr, syserr, + handler_status); + mutex_unlock(&sc->sc_send_lock); + hdr = NULL; + mlog(0, "sending handler status %d, syserr %d returned %d\n", + handler_status, syserr, ret); + + if (nmh) { + BUG_ON(ret_data != NULL && nmh->nh_post_func == NULL); + if (nmh->nh_post_func) + (nmh->nh_post_func)(handler_status, nmh->nh_func_data, + ret_data); + } + +out: + if (nmh) + o2net_handler_put(nmh); + return ret; +} + +static int o2net_check_handshake(struct o2net_sock_container *sc) +{ + struct o2net_handshake *hand = page_address(sc->sc_page); + struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num); + + if (hand->protocol_version != cpu_to_be64(O2NET_PROTOCOL_VERSION)) { + printk(KERN_NOTICE "o2net: " SC_NODEF_FMT " Advertised net " + "protocol version %llu but %llu is required. " + "Disconnecting.\n", SC_NODEF_ARGS(sc), + (unsigned long long)be64_to_cpu(hand->protocol_version), + O2NET_PROTOCOL_VERSION); + + /* don't bother reconnecting if its the wrong version. */ + o2net_ensure_shutdown(nn, sc, -ENOTCONN); + return -1; + } + + /* + * Ensure timeouts are consistent with other nodes, otherwise + * we can end up with one node thinking that the other must be down, + * but isn't. This can ultimately cause corruption. + */ + if (be32_to_cpu(hand->o2net_idle_timeout_ms) != + o2net_idle_timeout()) { + printk(KERN_NOTICE "o2net: " SC_NODEF_FMT " uses a network " + "idle timeout of %u ms, but we use %u ms locally. " + "Disconnecting.\n", SC_NODEF_ARGS(sc), + be32_to_cpu(hand->o2net_idle_timeout_ms), + o2net_idle_timeout()); + o2net_ensure_shutdown(nn, sc, -ENOTCONN); + return -1; + } + + if (be32_to_cpu(hand->o2net_keepalive_delay_ms) != + o2net_keepalive_delay()) { + printk(KERN_NOTICE "o2net: " SC_NODEF_FMT " uses a keepalive " + "delay of %u ms, but we use %u ms locally. " + "Disconnecting.\n", SC_NODEF_ARGS(sc), + be32_to_cpu(hand->o2net_keepalive_delay_ms), + o2net_keepalive_delay()); + o2net_ensure_shutdown(nn, sc, -ENOTCONN); + return -1; + } + + if (be32_to_cpu(hand->o2hb_heartbeat_timeout_ms) != + O2HB_MAX_WRITE_TIMEOUT_MS) { + printk(KERN_NOTICE "o2net: " SC_NODEF_FMT " uses a heartbeat " + "timeout of %u ms, but we use %u ms locally. " + "Disconnecting.\n", SC_NODEF_ARGS(sc), + be32_to_cpu(hand->o2hb_heartbeat_timeout_ms), + O2HB_MAX_WRITE_TIMEOUT_MS); + o2net_ensure_shutdown(nn, sc, -ENOTCONN); + return -1; + } + + sc->sc_handshake_ok = 1; + + spin_lock(&nn->nn_lock); + /* set valid and queue the idle timers only if it hasn't been + * shut down already */ + if (nn->nn_sc == sc) { + o2net_sc_reset_idle_timer(sc); + atomic_set(&nn->nn_timeout, 0); + o2net_set_nn_state(nn, sc, 1, 0); + } + spin_unlock(&nn->nn_lock); + + /* shift everything up as though it wasn't there */ + sc->sc_page_off -= sizeof(struct o2net_handshake); + if (sc->sc_page_off) + memmove(hand, hand + 1, sc->sc_page_off); + + return 0; +} + +/* this demuxes the queued rx bytes into header or payload bits and calls + * handlers as each full message is read off the socket. it returns -error, + * == 0 eof, or > 0 for progress made.*/ +static int o2net_advance_rx(struct o2net_sock_container *sc) +{ + struct o2net_msg *hdr; + int ret = 0; + void *data; + size_t datalen; + + sclog(sc, "receiving\n"); + o2net_set_advance_start_time(sc); + + if (unlikely(sc->sc_handshake_ok == 0)) { + if(sc->sc_page_off < sizeof(struct o2net_handshake)) { + data = page_address(sc->sc_page) + sc->sc_page_off; + datalen = sizeof(struct o2net_handshake) - sc->sc_page_off; + ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen); + if (ret > 0) + sc->sc_page_off += ret; + } + + if (sc->sc_page_off == sizeof(struct o2net_handshake)) { + o2net_check_handshake(sc); + if (unlikely(sc->sc_handshake_ok == 0)) + ret = -EPROTO; + } + goto out; + } + + /* do we need more header? */ + if (sc->sc_page_off < sizeof(struct o2net_msg)) { + data = page_address(sc->sc_page) + sc->sc_page_off; + datalen = sizeof(struct o2net_msg) - sc->sc_page_off; + ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen); + if (ret > 0) { + sc->sc_page_off += ret; + /* only swab incoming here.. we can + * only get here once as we cross from + * being under to over */ + if (sc->sc_page_off == sizeof(struct o2net_msg)) { + hdr = page_address(sc->sc_page); + if (be16_to_cpu(hdr->data_len) > + O2NET_MAX_PAYLOAD_BYTES) + ret = -EOVERFLOW; + } + } + if (ret <= 0) + goto out; + } + + if (sc->sc_page_off < sizeof(struct o2net_msg)) { + /* oof, still don't have a header */ + goto out; + } + + /* this was swabbed above when we first read it */ + hdr = page_address(sc->sc_page); + + msglog(hdr, "at page_off %zu\n", sc->sc_page_off); + + /* do we need more payload? */ + if (sc->sc_page_off - sizeof(struct o2net_msg) < be16_to_cpu(hdr->data_len)) { + /* need more payload */ + data = page_address(sc->sc_page) + sc->sc_page_off; + datalen = (sizeof(struct o2net_msg) + be16_to_cpu(hdr->data_len)) - + sc->sc_page_off; + ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen); + if (ret > 0) + sc->sc_page_off += ret; + if (ret <= 0) + goto out; + } + + if (sc->sc_page_off - sizeof(struct o2net_msg) == be16_to_cpu(hdr->data_len)) { + /* we can only get here once, the first time we read + * the payload.. so set ret to progress if the handler + * works out. after calling this the message is toast */ + ret = o2net_process_message(sc, hdr); + if (ret == 0) + ret = 1; + sc->sc_page_off = 0; + } + +out: + sclog(sc, "ret = %d\n", ret); + o2net_set_advance_stop_time(sc); + return ret; +} + +/* this work func is triggerd by data ready. it reads until it can read no + * more. it interprets 0, eof, as fatal. if data_ready hits while we're doing + * our work the work struct will be marked and we'll be called again. */ +static void o2net_rx_until_empty(struct work_struct *work) +{ + struct o2net_sock_container *sc = + container_of(work, struct o2net_sock_container, sc_rx_work); + int ret; + + do { + ret = o2net_advance_rx(sc); + } while (ret > 0); + + if (ret <= 0 && ret != -EAGAIN) { + struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num); + sclog(sc, "saw error %d, closing\n", ret); + /* not permanent so read failed handshake can retry */ + o2net_ensure_shutdown(nn, sc, 0); + } + + sc_put(sc); +} + +static int o2net_set_nodelay(struct socket *sock) +{ + int val = 1; + + return kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY, + (void *)&val, sizeof(val)); +} + +static int o2net_set_usertimeout(struct socket *sock) +{ + int user_timeout = O2NET_TCP_USER_TIMEOUT; + + return kernel_setsockopt(sock, SOL_TCP, TCP_USER_TIMEOUT, + (void *)&user_timeout, sizeof(user_timeout)); +} + +static void o2net_initialize_handshake(void) +{ + o2net_hand->o2hb_heartbeat_timeout_ms = cpu_to_be32( + O2HB_MAX_WRITE_TIMEOUT_MS); + o2net_hand->o2net_idle_timeout_ms = cpu_to_be32(o2net_idle_timeout()); + o2net_hand->o2net_keepalive_delay_ms = cpu_to_be32( + o2net_keepalive_delay()); + o2net_hand->o2net_reconnect_delay_ms = cpu_to_be32( + o2net_reconnect_delay()); +} + +/* ------------------------------------------------------------ */ + +/* called when a connect completes and after a sock is accepted. the + * rx path will see the response and mark the sc valid */ +static void o2net_sc_connect_completed(struct work_struct *work) +{ + struct o2net_sock_container *sc = + container_of(work, struct o2net_sock_container, + sc_connect_work); + + mlog(ML_MSG, "sc sending handshake with ver %llu id %llx\n", + (unsigned long long)O2NET_PROTOCOL_VERSION, + (unsigned long long)be64_to_cpu(o2net_hand->connector_id)); + + o2net_initialize_handshake(); + o2net_sendpage(sc, o2net_hand, sizeof(*o2net_hand)); + sc_put(sc); +} + +/* this is called as a work_struct func. */ +static void o2net_sc_send_keep_req(struct work_struct *work) +{ + struct o2net_sock_container *sc = + container_of(work, struct o2net_sock_container, + sc_keepalive_work.work); + + o2net_sendpage(sc, o2net_keep_req, sizeof(*o2net_keep_req)); + sc_put(sc); +} + +/* socket shutdown does a del_timer_sync against this as it tears down. + * we can't start this timer until we've got to the point in sc buildup + * where shutdown is going to be involved */ +static void o2net_idle_timer(struct timer_list *t) +{ + struct o2net_sock_container *sc = from_timer(sc, t, sc_idle_timeout); + struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num); +#ifdef CONFIG_DEBUG_FS + unsigned long msecs = ktime_to_ms(ktime_get()) - + ktime_to_ms(sc->sc_tv_timer); +#else + unsigned long msecs = o2net_idle_timeout(); +#endif + + printk(KERN_NOTICE "o2net: Connection to " SC_NODEF_FMT " has been " + "idle for %lu.%lu secs.\n", + SC_NODEF_ARGS(sc), msecs / 1000, msecs % 1000); + + /* idle timerout happen, don't shutdown the connection, but + * make fence decision. Maybe the connection can recover before + * the decision is made. + */ + atomic_set(&nn->nn_timeout, 1); + o2quo_conn_err(o2net_num_from_nn(nn)); + queue_delayed_work(o2net_wq, &nn->nn_still_up, + msecs_to_jiffies(O2NET_QUORUM_DELAY_MS)); + + o2net_sc_reset_idle_timer(sc); + +} + +static void o2net_sc_reset_idle_timer(struct o2net_sock_container *sc) +{ + o2net_sc_cancel_delayed_work(sc, &sc->sc_keepalive_work); + o2net_sc_queue_delayed_work(sc, &sc->sc_keepalive_work, + msecs_to_jiffies(o2net_keepalive_delay())); + o2net_set_sock_timer(sc); + mod_timer(&sc->sc_idle_timeout, + jiffies + msecs_to_jiffies(o2net_idle_timeout())); +} + +static void o2net_sc_postpone_idle(struct o2net_sock_container *sc) +{ + struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num); + + /* clear fence decision since the connection recover from timeout*/ + if (atomic_read(&nn->nn_timeout)) { + o2quo_conn_up(o2net_num_from_nn(nn)); + cancel_delayed_work(&nn->nn_still_up); + atomic_set(&nn->nn_timeout, 0); + } + + /* Only push out an existing timer */ + if (timer_pending(&sc->sc_idle_timeout)) + o2net_sc_reset_idle_timer(sc); +} + +/* this work func is kicked whenever a path sets the nn state which doesn't + * have valid set. This includes seeing hb come up, losing a connection, + * having a connect attempt fail, etc. This centralizes the logic which decides + * if a connect attempt should be made or if we should give up and all future + * transmit attempts should fail */ +static void o2net_start_connect(struct work_struct *work) +{ + struct o2net_node *nn = + container_of(work, struct o2net_node, nn_connect_work.work); + struct o2net_sock_container *sc = NULL; + struct o2nm_node *node = NULL, *mynode = NULL; + struct socket *sock = NULL; + struct sockaddr_in myaddr = {0, }, remoteaddr = {0, }; + int ret = 0, stop; + unsigned int timeout; + unsigned int noio_flag; + + /* + * sock_create allocates the sock with GFP_KERNEL. We must set + * per-process flag PF_MEMALLOC_NOIO so that all allocations done + * by this process are done as if GFP_NOIO was specified. So we + * are not reentering filesystem while doing memory reclaim. + */ + noio_flag = memalloc_noio_save(); + /* if we're greater we initiate tx, otherwise we accept */ + if (o2nm_this_node() <= o2net_num_from_nn(nn)) + goto out; + + /* watch for racing with tearing a node down */ + node = o2nm_get_node_by_num(o2net_num_from_nn(nn)); + if (node == NULL) + goto out; + + mynode = o2nm_get_node_by_num(o2nm_this_node()); + if (mynode == NULL) + goto out; + + spin_lock(&nn->nn_lock); + /* + * see if we already have one pending or have given up. + * For nn_timeout, it is set when we close the connection + * because of the idle time out. So it means that we have + * at least connected to that node successfully once, + * now try to connect to it again. + */ + timeout = atomic_read(&nn->nn_timeout); + stop = (nn->nn_sc || + (nn->nn_persistent_error && + (nn->nn_persistent_error != -ENOTCONN || timeout == 0))); + spin_unlock(&nn->nn_lock); + if (stop) + goto out; + + nn->nn_last_connect_attempt = jiffies; + + sc = sc_alloc(node); + if (sc == NULL) { + mlog(0, "couldn't allocate sc\n"); + ret = -ENOMEM; + goto out; + } + + ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock); + if (ret < 0) { + mlog(0, "can't create socket: %d\n", ret); + goto out; + } + sc->sc_sock = sock; /* freed by sc_kref_release */ + + sock->sk->sk_allocation = GFP_ATOMIC; + + myaddr.sin_family = AF_INET; + myaddr.sin_addr.s_addr = mynode->nd_ipv4_address; + myaddr.sin_port = htons(0); /* any port */ + + ret = sock->ops->bind(sock, (struct sockaddr *)&myaddr, + sizeof(myaddr)); + if (ret) { + mlog(ML_ERROR, "bind failed with %d at address %pI4\n", + ret, &mynode->nd_ipv4_address); + goto out; + } + + ret = o2net_set_nodelay(sc->sc_sock); + if (ret) { + mlog(ML_ERROR, "setting TCP_NODELAY failed with %d\n", ret); + goto out; + } + + ret = o2net_set_usertimeout(sock); + if (ret) { + mlog(ML_ERROR, "set TCP_USER_TIMEOUT failed with %d\n", ret); + goto out; + } + + o2net_register_callbacks(sc->sc_sock->sk, sc); + + spin_lock(&nn->nn_lock); + /* handshake completion will set nn->nn_sc_valid */ + o2net_set_nn_state(nn, sc, 0, 0); + spin_unlock(&nn->nn_lock); + + remoteaddr.sin_family = AF_INET; + remoteaddr.sin_addr.s_addr = node->nd_ipv4_address; + remoteaddr.sin_port = node->nd_ipv4_port; + + ret = sc->sc_sock->ops->connect(sc->sc_sock, + (struct sockaddr *)&remoteaddr, + sizeof(remoteaddr), + O_NONBLOCK); + if (ret == -EINPROGRESS) + ret = 0; + +out: + if (ret && sc) { + printk(KERN_NOTICE "o2net: Connect attempt to " SC_NODEF_FMT + " failed with errno %d\n", SC_NODEF_ARGS(sc), ret); + /* 0 err so that another will be queued and attempted + * from set_nn_state */ + o2net_ensure_shutdown(nn, sc, 0); + } + if (sc) + sc_put(sc); + if (node) + o2nm_node_put(node); + if (mynode) + o2nm_node_put(mynode); + + memalloc_noio_restore(noio_flag); + return; +} + +static void o2net_connect_expired(struct work_struct *work) +{ + struct o2net_node *nn = + container_of(work, struct o2net_node, nn_connect_expired.work); + + spin_lock(&nn->nn_lock); + if (!nn->nn_sc_valid) { + printk(KERN_NOTICE "o2net: No connection established with " + "node %u after %u.%u seconds, check network and" + " cluster configuration.\n", + o2net_num_from_nn(nn), + o2net_idle_timeout() / 1000, + o2net_idle_timeout() % 1000); + + o2net_set_nn_state(nn, NULL, 0, 0); + } + spin_unlock(&nn->nn_lock); +} + +static void o2net_still_up(struct work_struct *work) +{ + struct o2net_node *nn = + container_of(work, struct o2net_node, nn_still_up.work); + + o2quo_hb_still_up(o2net_num_from_nn(nn)); +} + +/* ------------------------------------------------------------ */ + +void o2net_disconnect_node(struct o2nm_node *node) +{ + struct o2net_node *nn = o2net_nn_from_num(node->nd_num); + + /* don't reconnect until it's heartbeating again */ + spin_lock(&nn->nn_lock); + atomic_set(&nn->nn_timeout, 0); + o2net_set_nn_state(nn, NULL, 0, -ENOTCONN); + spin_unlock(&nn->nn_lock); + + if (o2net_wq) { + cancel_delayed_work(&nn->nn_connect_expired); + cancel_delayed_work(&nn->nn_connect_work); + cancel_delayed_work(&nn->nn_still_up); + flush_workqueue(o2net_wq); + } +} + +static void o2net_hb_node_down_cb(struct o2nm_node *node, int node_num, + void *data) +{ + o2quo_hb_down(node_num); + + if (!node) + return; + + if (node_num != o2nm_this_node()) + o2net_disconnect_node(node); + + BUG_ON(atomic_read(&o2net_connected_peers) < 0); +} + +static void o2net_hb_node_up_cb(struct o2nm_node *node, int node_num, + void *data) +{ + struct o2net_node *nn = o2net_nn_from_num(node_num); + + o2quo_hb_up(node_num); + + BUG_ON(!node); + + /* ensure an immediate connect attempt */ + nn->nn_last_connect_attempt = jiffies - + (msecs_to_jiffies(o2net_reconnect_delay()) + 1); + + if (node_num != o2nm_this_node()) { + /* believe it or not, accept and node hearbeating testing + * can succeed for this node before we got here.. so + * only use set_nn_state to clear the persistent error + * if that hasn't already happened */ + spin_lock(&nn->nn_lock); + atomic_set(&nn->nn_timeout, 0); + if (nn->nn_persistent_error) + o2net_set_nn_state(nn, NULL, 0, 0); + spin_unlock(&nn->nn_lock); + } +} + +void o2net_unregister_hb_callbacks(void) +{ + o2hb_unregister_callback(NULL, &o2net_hb_up); + o2hb_unregister_callback(NULL, &o2net_hb_down); +} + +int o2net_register_hb_callbacks(void) +{ + int ret; + + o2hb_setup_callback(&o2net_hb_down, O2HB_NODE_DOWN_CB, + o2net_hb_node_down_cb, NULL, O2NET_HB_PRI); + o2hb_setup_callback(&o2net_hb_up, O2HB_NODE_UP_CB, + o2net_hb_node_up_cb, NULL, O2NET_HB_PRI); + + ret = o2hb_register_callback(NULL, &o2net_hb_up); + if (ret == 0) + ret = o2hb_register_callback(NULL, &o2net_hb_down); + + if (ret) + o2net_unregister_hb_callbacks(); + + return ret; +} + +/* ------------------------------------------------------------ */ + +static int o2net_accept_one(struct socket *sock, int *more) +{ + int ret; + struct sockaddr_in sin; + struct socket *new_sock = NULL; + struct o2nm_node *node = NULL; + struct o2nm_node *local_node = NULL; + struct o2net_sock_container *sc = NULL; + struct o2net_node *nn; + unsigned int noio_flag; + + /* + * sock_create_lite allocates the sock with GFP_KERNEL. We must set + * per-process flag PF_MEMALLOC_NOIO so that all allocations done + * by this process are done as if GFP_NOIO was specified. So we + * are not reentering filesystem while doing memory reclaim. + */ + noio_flag = memalloc_noio_save(); + + BUG_ON(sock == NULL); + *more = 0; + ret = sock_create_lite(sock->sk->sk_family, sock->sk->sk_type, + sock->sk->sk_protocol, &new_sock); + if (ret) + goto out; + + new_sock->type = sock->type; + new_sock->ops = sock->ops; + ret = sock->ops->accept(sock, new_sock, O_NONBLOCK, false); + if (ret < 0) + goto out; + + *more = 1; + new_sock->sk->sk_allocation = GFP_ATOMIC; + + ret = o2net_set_nodelay(new_sock); + if (ret) { + mlog(ML_ERROR, "setting TCP_NODELAY failed with %d\n", ret); + goto out; + } + + ret = o2net_set_usertimeout(new_sock); + if (ret) { + mlog(ML_ERROR, "set TCP_USER_TIMEOUT failed with %d\n", ret); + goto out; + } + + ret = new_sock->ops->getname(new_sock, (struct sockaddr *) &sin, 1); + if (ret < 0) + goto out; + + node = o2nm_get_node_by_ip(sin.sin_addr.s_addr); + if (node == NULL) { + printk(KERN_NOTICE "o2net: Attempt to connect from unknown " + "node at %pI4:%d\n", &sin.sin_addr.s_addr, + ntohs(sin.sin_port)); + ret = -EINVAL; + goto out; + } + + if (o2nm_this_node() >= node->nd_num) { + local_node = o2nm_get_node_by_num(o2nm_this_node()); + if (local_node) + printk(KERN_NOTICE "o2net: Unexpected connect attempt " + "seen at node '%s' (%u, %pI4:%d) from " + "node '%s' (%u, %pI4:%d)\n", + local_node->nd_name, local_node->nd_num, + &(local_node->nd_ipv4_address), + ntohs(local_node->nd_ipv4_port), + node->nd_name, + node->nd_num, &sin.sin_addr.s_addr, + ntohs(sin.sin_port)); + ret = -EINVAL; + goto out; + } + + /* this happens all the time when the other node sees our heartbeat + * and tries to connect before we see their heartbeat */ + if (!o2hb_check_node_heartbeating_from_callback(node->nd_num)) { + mlog(ML_CONN, "attempt to connect from node '%s' at " + "%pI4:%d but it isn't heartbeating\n", + node->nd_name, &sin.sin_addr.s_addr, + ntohs(sin.sin_port)); + ret = -EINVAL; + goto out; + } + + nn = o2net_nn_from_num(node->nd_num); + + spin_lock(&nn->nn_lock); + if (nn->nn_sc) + ret = -EBUSY; + else + ret = 0; + spin_unlock(&nn->nn_lock); + if (ret) { + printk(KERN_NOTICE "o2net: Attempt to connect from node '%s' " + "at %pI4:%d but it already has an open connection\n", + node->nd_name, &sin.sin_addr.s_addr, + ntohs(sin.sin_port)); + goto out; + } + + sc = sc_alloc(node); + if (sc == NULL) { + ret = -ENOMEM; + goto out; + } + + sc->sc_sock = new_sock; + new_sock = NULL; + + spin_lock(&nn->nn_lock); + atomic_set(&nn->nn_timeout, 0); + o2net_set_nn_state(nn, sc, 0, 0); + spin_unlock(&nn->nn_lock); + + o2net_register_callbacks(sc->sc_sock->sk, sc); + o2net_sc_queue_work(sc, &sc->sc_rx_work); + + o2net_initialize_handshake(); + o2net_sendpage(sc, o2net_hand, sizeof(*o2net_hand)); + +out: + if (new_sock) + sock_release(new_sock); + if (node) + o2nm_node_put(node); + if (local_node) + o2nm_node_put(local_node); + if (sc) + sc_put(sc); + + memalloc_noio_restore(noio_flag); + return ret; +} + +/* + * This function is invoked in response to one or more + * pending accepts at softIRQ level. We must drain the + * entire que before returning. + */ + +static void o2net_accept_many(struct work_struct *work) +{ + struct socket *sock = o2net_listen_sock; + int more; + int err; + + /* + * It is critical to note that due to interrupt moderation + * at the network driver level, we can't assume to get a + * softIRQ for every single conn since tcp SYN packets + * can arrive back-to-back, and therefore many pending + * accepts may result in just 1 softIRQ. If we terminate + * the o2net_accept_one() loop upon seeing an err, what happens + * to the rest of the conns in the queue? If no new SYN + * arrives for hours, no softIRQ will be delivered, + * and the connections will just sit in the queue. + */ + + for (;;) { + err = o2net_accept_one(sock, &more); + if (!more) + break; + cond_resched(); + } +} + +static void o2net_listen_data_ready(struct sock *sk) +{ + void (*ready)(struct sock *sk); + + read_lock_bh(&sk->sk_callback_lock); + ready = sk->sk_user_data; + if (ready == NULL) { /* check for teardown race */ + ready = sk->sk_data_ready; + goto out; + } + + /* This callback may called twice when a new connection + * is being established as a child socket inherits everything + * from a parent LISTEN socket, including the data_ready cb of + * the parent. This leads to a hazard. In o2net_accept_one() + * we are still initializing the child socket but have not + * changed the inherited data_ready callback yet when + * data starts arriving. + * We avoid this hazard by checking the state. + * For the listening socket, the state will be TCP_LISTEN; for the new + * socket, will be TCP_ESTABLISHED. Also, in this case, + * sk->sk_user_data is not a valid function pointer. + */ + + if (sk->sk_state == TCP_LISTEN) { + queue_work(o2net_wq, &o2net_listen_work); + } else { + ready = NULL; + } + +out: + read_unlock_bh(&sk->sk_callback_lock); + if (ready != NULL) + ready(sk); +} + +static int o2net_open_listening_sock(__be32 addr, __be16 port) +{ + struct socket *sock = NULL; + int ret; + struct sockaddr_in sin = { + .sin_family = PF_INET, + .sin_addr = { .s_addr = addr }, + .sin_port = port, + }; + + ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock); + if (ret < 0) { + printk(KERN_ERR "o2net: Error %d while creating socket\n", ret); + goto out; + } + + sock->sk->sk_allocation = GFP_ATOMIC; + + write_lock_bh(&sock->sk->sk_callback_lock); + sock->sk->sk_user_data = sock->sk->sk_data_ready; + sock->sk->sk_data_ready = o2net_listen_data_ready; + write_unlock_bh(&sock->sk->sk_callback_lock); + + o2net_listen_sock = sock; + INIT_WORK(&o2net_listen_work, o2net_accept_many); + + sock->sk->sk_reuse = SK_CAN_REUSE; + ret = sock->ops->bind(sock, (struct sockaddr *)&sin, sizeof(sin)); + if (ret < 0) { + printk(KERN_ERR "o2net: Error %d while binding socket at " + "%pI4:%u\n", ret, &addr, ntohs(port)); + goto out; + } + + ret = sock->ops->listen(sock, 64); + if (ret < 0) + printk(KERN_ERR "o2net: Error %d while listening on %pI4:%u\n", + ret, &addr, ntohs(port)); + +out: + if (ret) { + o2net_listen_sock = NULL; + if (sock) + sock_release(sock); + } + return ret; +} + +/* + * called from node manager when we should bring up our network listening + * socket. node manager handles all the serialization to only call this + * once and to match it with o2net_stop_listening(). note, + * o2nm_this_node() doesn't work yet as we're being called while it + * is being set up. + */ +int o2net_start_listening(struct o2nm_node *node) +{ + int ret = 0; + + BUG_ON(o2net_wq != NULL); + BUG_ON(o2net_listen_sock != NULL); + + mlog(ML_KTHREAD, "starting o2net thread...\n"); + o2net_wq = alloc_ordered_workqueue("o2net", WQ_MEM_RECLAIM); + if (o2net_wq == NULL) { + mlog(ML_ERROR, "unable to launch o2net thread\n"); + return -ENOMEM; /* ? */ + } + + ret = o2net_open_listening_sock(node->nd_ipv4_address, + node->nd_ipv4_port); + if (ret) { + destroy_workqueue(o2net_wq); + o2net_wq = NULL; + } else + o2quo_conn_up(node->nd_num); + + return ret; +} + +/* again, o2nm_this_node() doesn't work here as we're involved in + * tearing it down */ +void o2net_stop_listening(struct o2nm_node *node) +{ + struct socket *sock = o2net_listen_sock; + size_t i; + + BUG_ON(o2net_wq == NULL); + BUG_ON(o2net_listen_sock == NULL); + + /* stop the listening socket from generating work */ + write_lock_bh(&sock->sk->sk_callback_lock); + sock->sk->sk_data_ready = sock->sk->sk_user_data; + sock->sk->sk_user_data = NULL; + write_unlock_bh(&sock->sk->sk_callback_lock); + + for (i = 0; i < ARRAY_SIZE(o2net_nodes); i++) { + struct o2nm_node *node = o2nm_get_node_by_num(i); + if (node) { + o2net_disconnect_node(node); + o2nm_node_put(node); + } + } + + /* finish all work and tear down the work queue */ + mlog(ML_KTHREAD, "waiting for o2net thread to exit....\n"); + destroy_workqueue(o2net_wq); + o2net_wq = NULL; + + sock_release(o2net_listen_sock); + o2net_listen_sock = NULL; + + o2quo_conn_err(node->nd_num); +} + +/* ------------------------------------------------------------ */ + +int o2net_init(void) +{ + unsigned long i; + + o2quo_init(); + + if (o2net_debugfs_init()) + goto out; + + o2net_hand = kzalloc(sizeof(struct o2net_handshake), GFP_KERNEL); + o2net_keep_req = kzalloc(sizeof(struct o2net_msg), GFP_KERNEL); + o2net_keep_resp = kzalloc(sizeof(struct o2net_msg), GFP_KERNEL); + if (!o2net_hand || !o2net_keep_req || !o2net_keep_resp) + goto out; + + o2net_hand->protocol_version = cpu_to_be64(O2NET_PROTOCOL_VERSION); + o2net_hand->connector_id = cpu_to_be64(1); + + o2net_keep_req->magic = cpu_to_be16(O2NET_MSG_KEEP_REQ_MAGIC); + o2net_keep_resp->magic = cpu_to_be16(O2NET_MSG_KEEP_RESP_MAGIC); + + for (i = 0; i < ARRAY_SIZE(o2net_nodes); i++) { + struct o2net_node *nn = o2net_nn_from_num(i); + + atomic_set(&nn->nn_timeout, 0); + spin_lock_init(&nn->nn_lock); + INIT_DELAYED_WORK(&nn->nn_connect_work, o2net_start_connect); + INIT_DELAYED_WORK(&nn->nn_connect_expired, + o2net_connect_expired); + INIT_DELAYED_WORK(&nn->nn_still_up, o2net_still_up); + /* until we see hb from a node we'll return einval */ + nn->nn_persistent_error = -ENOTCONN; + init_waitqueue_head(&nn->nn_sc_wq); + idr_init(&nn->nn_status_idr); + INIT_LIST_HEAD(&nn->nn_status_list); + } + + return 0; + +out: + kfree(o2net_hand); + kfree(o2net_keep_req); + kfree(o2net_keep_resp); + o2net_debugfs_exit(); + o2quo_exit(); + return -ENOMEM; +} + +void o2net_exit(void) +{ + o2quo_exit(); + kfree(o2net_hand); + kfree(o2net_keep_req); + kfree(o2net_keep_resp); + o2net_debugfs_exit(); +} |