fs/ocfs2/cluster/tcp.c

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
o2net_init_nst
o2net_set_nst_sock_time
o2net_set_nst_send_time
o2net_set_nst_status_time
o2net_set_nst_sock_container
o2net_set_nst_msg_id
o2net_set_sock_timer
o2net_set_data_ready_time
o2net_set_advance_start_time
o2net_set_advance_stop_time
o2net_set_func_start_time
o2net_set_func_stop_time
o2net_get_func_run_time
o2net_update_send_stats
o2net_update_recv_stats
o2net_reconnect_delay
o2net_keepalive_delay
o2net_idle_timeout
o2net_sys_err_to_errno
o2net_nn_from_num
o2net_num_from_nn
o2net_prep_nsw
o2net_complete_nsw_locked
o2net_complete_nsw
o2net_complete_nodes_nsw
o2net_nsw_completed
sc_kref_release
sc_put
sc_get
sc_alloc
o2net_sc_queue_work
o2net_sc_queue_delayed_work
o2net_sc_cancel_delayed_work
o2net_num_connected_peers
o2net_set_nn_state
o2net_data_ready
o2net_state_change
o2net_register_callbacks
o2net_unregister_callbacks
o2net_ensure_shutdown
o2net_shutdown_sc
o2net_handler_cmp
o2net_handler_tree_lookup
o2net_handler_kref_release
o2net_handler_put
o2net_register_handler
o2net_unregister_handler_list
o2net_handler_get
o2net_recv_tcp_msg
o2net_send_tcp_msg
o2net_sendpage
o2net_init_msg
o2net_tx_can_proceed
o2net_fill_node_map
o2net_send_message_vec
o2net_send_message
o2net_send_status_magic
o2net_process_message
o2net_check_handshake
o2net_advance_rx
o2net_rx_until_empty
o2net_set_nodelay
o2net_set_usertimeout
o2net_initialize_handshake
o2net_sc_connect_completed
o2net_sc_send_keep_req
o2net_idle_timer
o2net_sc_reset_idle_timer
o2net_sc_postpone_idle
o2net_start_connect
o2net_connect_expired
o2net_still_up
o2net_disconnect_node
o2net_hb_node_down_cb
o2net_hb_node_up_cb
o2net_unregister_hb_callbacks
o2net_register_hb_callbacks
o2net_accept_one
o2net_accept_many
o2net_listen_data_ready
o2net_open_listening_sock
o2net_start_listening
o2net_stop_listening
o2net_init
o2net_exit
   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* -*- mode: c; c-basic-offset: 8; -*-
   3  *
   4  * vim: noexpandtab sw=8 ts=8 sts=0:
   5  *
   6  * Copyright (C) 2004 Oracle.  All rights reserved.
   7  *
   8  * ----
   9  *
  10  * Callers for this were originally written against a very simple synchronus
  11  * API.  This implementation reflects those simple callers.  Some day I'm sure
  12  * we'll need to move to a more robust posting/callback mechanism.
  13  *
  14  * Transmit calls pass in kernel virtual addresses and block copying this into
  15  * the socket's tx buffers via a usual blocking sendmsg.  They'll block waiting
  16  * for a failed socket to timeout.  TX callers can also pass in a poniter to an
  17  * 'int' which gets filled with an errno off the wire in response to the
  18  * message they send.
  19  *
  20  * Handlers for unsolicited messages are registered.  Each socket has a page
  21  * that incoming data is copied into.  First the header, then the data.
  22  * Handlers are called from only one thread with a reference to this per-socket
  23  * page.  This page is destroyed after the handler call, so it can't be
  24  * referenced beyond the call.  Handlers may block but are discouraged from
  25  * doing so.
  26  *
  27  * Any framing errors (bad magic, large payload lengths) close a connection.
  28  *
  29  * Our sock_container holds the state we associate with a socket.  It's current
  30  * framing state is held there as well as the refcounting we do around when it
  31  * is safe to tear down the socket.  The socket is only finally torn down from
  32  * the container when the container loses all of its references -- so as long
  33  * as you hold a ref on the container you can trust that the socket is valid
  34  * for use with kernel socket APIs.
  35  *
  36  * Connections are initiated between a pair of nodes when the node with the
  37  * higher node number gets a heartbeat callback which indicates that the lower
  38  * numbered node has started heartbeating.  The lower numbered node is passive
  39  * and only accepts the connection if the higher numbered node is heartbeating.
  40  */
  41 
  42 #include <linux/kernel.h>
  43 #include <linux/sched/mm.h>
  44 #include <linux/jiffies.h>
  45 #include <linux/slab.h>
  46 #include <linux/idr.h>
  47 #include <linux/kref.h>
  48 #include <linux/net.h>
  49 #include <linux/export.h>
  50 #include <net/tcp.h>
  51 
  52 #include <linux/uaccess.h>
  53 
  54 #include "heartbeat.h"
  55 #include "tcp.h"
  56 #include "nodemanager.h"
  57 #define MLOG_MASK_PREFIX ML_TCP
  58 #include "masklog.h"
  59 #include "quorum.h"
  60 
  61 #include "tcp_internal.h"
  62 
  63 #define SC_NODEF_FMT "node %s (num %u) at %pI4:%u"
  64 #define SC_NODEF_ARGS(sc) sc->sc_node->nd_name, sc->sc_node->nd_num,    \
  65                           &sc->sc_node->nd_ipv4_address,                \
  66                           ntohs(sc->sc_node->nd_ipv4_port)
  67 
  68 /*
  69  * In the following two log macros, the whitespace after the ',' just
  70  * before ##args is intentional. Otherwise, gcc 2.95 will eat the
  71  * previous token if args expands to nothing.
  72  */
  73 #define msglog(hdr, fmt, args...) do {                                  \
  74         typeof(hdr) __hdr = (hdr);                                      \
  75         mlog(ML_MSG, "[mag %u len %u typ %u stat %d sys_stat %d "       \
  76              "key %08x num %u] " fmt,                                   \
  77              be16_to_cpu(__hdr->magic), be16_to_cpu(__hdr->data_len),   \
  78              be16_to_cpu(__hdr->msg_type), be32_to_cpu(__hdr->status),  \
  79              be32_to_cpu(__hdr->sys_status), be32_to_cpu(__hdr->key),   \
  80              be32_to_cpu(__hdr->msg_num) ,  ##args);                    \
  81 } while (0)
  82 
  83 #define sclog(sc, fmt, args...) do {                                    \
  84         typeof(sc) __sc = (sc);                                         \
  85         mlog(ML_SOCKET, "[sc %p refs %d sock %p node %u page %p "       \
  86              "pg_off %zu] " fmt, __sc,                                  \
  87              kref_read(&__sc->sc_kref), __sc->sc_sock,  \
  88             __sc->sc_node->nd_num, __sc->sc_page, __sc->sc_page_off ,   \
  89             ##args);                                                    \
  90 } while (0)
  91 
  92 static DEFINE_RWLOCK(o2net_handler_lock);
  93 static struct rb_root o2net_handler_tree = RB_ROOT;
  94 
  95 static struct o2net_node o2net_nodes[O2NM_MAX_NODES];
  96 
  97 /* XXX someday we'll need better accounting */
  98 static struct socket *o2net_listen_sock;
  99 
 100 /*
 101  * listen work is only queued by the listening socket callbacks on the
 102  * o2net_wq.  teardown detaches the callbacks before destroying the workqueue.
 103  * quorum work is queued as sock containers are shutdown.. stop_listening
 104  * tears down all the node's sock containers, preventing future shutdowns
 105  * and queued quroum work, before canceling delayed quorum work and
 106  * destroying the work queue.
 107  */
 108 static struct workqueue_struct *o2net_wq;
 109 static struct work_struct o2net_listen_work;
 110 
 111 static struct o2hb_callback_func o2net_hb_up, o2net_hb_down;
 112 #define O2NET_HB_PRI 0x1
 113 
 114 static struct o2net_handshake *o2net_hand;
 115 static struct o2net_msg *o2net_keep_req, *o2net_keep_resp;
 116 
 117 static int o2net_sys_err_translations[O2NET_ERR_MAX] =
 118                 {[O2NET_ERR_NONE]       = 0,
 119                  [O2NET_ERR_NO_HNDLR]   = -ENOPROTOOPT,
 120                  [O2NET_ERR_OVERFLOW]   = -EOVERFLOW,
 121                  [O2NET_ERR_DIED]       = -EHOSTDOWN,};
 122 
 123 /* can't quite avoid *all* internal declarations :/ */
 124 static void o2net_sc_connect_completed(struct work_struct *work);
 125 static void o2net_rx_until_empty(struct work_struct *work);
 126 static void o2net_shutdown_sc(struct work_struct *work);
 127 static void o2net_listen_data_ready(struct sock *sk);
 128 static void o2net_sc_send_keep_req(struct work_struct *work);
 129 static void o2net_idle_timer(struct timer_list *t);
 130 static void o2net_sc_postpone_idle(struct o2net_sock_container *sc);
 131 static void o2net_sc_reset_idle_timer(struct o2net_sock_container *sc);
 132 
 133 #ifdef CONFIG_DEBUG_FS
 134 static void o2net_init_nst(struct o2net_send_tracking *nst, u32 msgtype,
 135                            u32 msgkey, struct task_struct *task, u8 node)
 136 {
 137         INIT_LIST_HEAD(&nst->st_net_debug_item);
 138         nst->st_task = task;
 139         nst->st_msg_type = msgtype;
 140         nst->st_msg_key = msgkey;
 141         nst->st_node = node;
 142 }
 143 
 144 static inline void o2net_set_nst_sock_time(struct o2net_send_tracking *nst)
 145 {
 146         nst->st_sock_time = ktime_get();
 147 }
 148 
 149 static inline void o2net_set_nst_send_time(struct o2net_send_tracking *nst)
 150 {
 151         nst->st_send_time = ktime_get();
 152 }
 153 
 154 static inline void o2net_set_nst_status_time(struct o2net_send_tracking *nst)
 155 {
 156         nst->st_status_time = ktime_get();
 157 }
 158 
 159 static inline void o2net_set_nst_sock_container(struct o2net_send_tracking *nst,
 160                                                 struct o2net_sock_container *sc)
 161 {
 162         nst->st_sc = sc;
 163 }
 164 
 165 static inline void o2net_set_nst_msg_id(struct o2net_send_tracking *nst,
 166                                         u32 msg_id)
 167 {
 168         nst->st_id = msg_id;
 169 }
 170 
 171 static inline void o2net_set_sock_timer(struct o2net_sock_container *sc)
 172 {
 173         sc->sc_tv_timer = ktime_get();
 174 }
 175 
 176 static inline void o2net_set_data_ready_time(struct o2net_sock_container *sc)
 177 {
 178         sc->sc_tv_data_ready = ktime_get();
 179 }
 180 
 181 static inline void o2net_set_advance_start_time(struct o2net_sock_container *sc)
 182 {
 183         sc->sc_tv_advance_start = ktime_get();
 184 }
 185 
 186 static inline void o2net_set_advance_stop_time(struct o2net_sock_container *sc)
 187 {
 188         sc->sc_tv_advance_stop = ktime_get();
 189 }
 190 
 191 static inline void o2net_set_func_start_time(struct o2net_sock_container *sc)
 192 {
 193         sc->sc_tv_func_start = ktime_get();
 194 }
 195 
 196 static inline void o2net_set_func_stop_time(struct o2net_sock_container *sc)
 197 {
 198         sc->sc_tv_func_stop = ktime_get();
 199 }
 200 
 201 #else  /* CONFIG_DEBUG_FS */
 202 # define o2net_init_nst(a, b, c, d, e)
 203 # define o2net_set_nst_sock_time(a)
 204 # define o2net_set_nst_send_time(a)
 205 # define o2net_set_nst_status_time(a)
 206 # define o2net_set_nst_sock_container(a, b)
 207 # define o2net_set_nst_msg_id(a, b)
 208 # define o2net_set_sock_timer(a)
 209 # define o2net_set_data_ready_time(a)
 210 # define o2net_set_advance_start_time(a)
 211 # define o2net_set_advance_stop_time(a)
 212 # define o2net_set_func_start_time(a)
 213 # define o2net_set_func_stop_time(a)
 214 #endif /* CONFIG_DEBUG_FS */
 215 
 216 #ifdef CONFIG_OCFS2_FS_STATS
 217 static ktime_t o2net_get_func_run_time(struct o2net_sock_container *sc)
 218 {
 219         return ktime_sub(sc->sc_tv_func_stop, sc->sc_tv_func_start);
 220 }
 221 
 222 static void o2net_update_send_stats(struct o2net_send_tracking *nst,
 223                                     struct o2net_sock_container *sc)
 224 {
 225         sc->sc_tv_status_total = ktime_add(sc->sc_tv_status_total,
 226                                            ktime_sub(ktime_get(),
 227                                                      nst->st_status_time));
 228         sc->sc_tv_send_total = ktime_add(sc->sc_tv_send_total,
 229                                          ktime_sub(nst->st_status_time,
 230                                                    nst->st_send_time));
 231         sc->sc_tv_acquiry_total = ktime_add(sc->sc_tv_acquiry_total,
 232                                             ktime_sub(nst->st_send_time,
 233                                                       nst->st_sock_time));
 234         sc->sc_send_count++;
 235 }
 236 
 237 static void o2net_update_recv_stats(struct o2net_sock_container *sc)
 238 {
 239         sc->sc_tv_process_total = ktime_add(sc->sc_tv_process_total,
 240                                             o2net_get_func_run_time(sc));
 241         sc->sc_recv_count++;
 242 }
 243 
 244 #else
 245 
 246 # define o2net_update_send_stats(a, b)
 247 
 248 # define o2net_update_recv_stats(sc)
 249 
 250 #endif /* CONFIG_OCFS2_FS_STATS */
 251 
 252 static inline unsigned int o2net_reconnect_delay(void)
 253 {
 254         return o2nm_single_cluster->cl_reconnect_delay_ms;
 255 }
 256 
 257 static inline unsigned int o2net_keepalive_delay(void)
 258 {
 259         return o2nm_single_cluster->cl_keepalive_delay_ms;
 260 }
 261 
 262 static inline unsigned int o2net_idle_timeout(void)
 263 {
 264         return o2nm_single_cluster->cl_idle_timeout_ms;
 265 }
 266 
 267 static inline int o2net_sys_err_to_errno(enum o2net_system_error err)
 268 {
 269         int trans;
 270         BUG_ON(err >= O2NET_ERR_MAX);
 271         trans = o2net_sys_err_translations[err];
 272 
 273         /* Just in case we mess up the translation table above */
 274         BUG_ON(err != O2NET_ERR_NONE && trans == 0);
 275         return trans;
 276 }
 277 
 278 static struct o2net_node * o2net_nn_from_num(u8 node_num)
 279 {
 280         BUG_ON(node_num >= ARRAY_SIZE(o2net_nodes));
 281         return &o2net_nodes[node_num];
 282 }
 283 
 284 static u8 o2net_num_from_nn(struct o2net_node *nn)
 285 {
 286         BUG_ON(nn == NULL);
 287         return nn - o2net_nodes;
 288 }
 289 
 290 /* ------------------------------------------------------------ */
 291 
 292 static int o2net_prep_nsw(struct o2net_node *nn, struct o2net_status_wait *nsw)
 293 {
 294         int ret;
 295 
 296         spin_lock(&nn->nn_lock);
 297         ret = idr_alloc(&nn->nn_status_idr, nsw, 0, 0, GFP_ATOMIC);
 298         if (ret >= 0) {
 299                 nsw->ns_id = ret;
 300                 list_add_tail(&nsw->ns_node_item, &nn->nn_status_list);
 301         }
 302         spin_unlock(&nn->nn_lock);
 303         if (ret < 0)
 304                 return ret;
 305 
 306         init_waitqueue_head(&nsw->ns_wq);
 307         nsw->ns_sys_status = O2NET_ERR_NONE;
 308         nsw->ns_status = 0;
 309         return 0;
 310 }
 311 
 312 static void o2net_complete_nsw_locked(struct o2net_node *nn,
 313                                       struct o2net_status_wait *nsw,
 314                                       enum o2net_system_error sys_status,
 315                                       s32 status)
 316 {
 317         assert_spin_locked(&nn->nn_lock);
 318 
 319         if (!list_empty(&nsw->ns_node_item)) {
 320                 list_del_init(&nsw->ns_node_item);
 321                 nsw->ns_sys_status = sys_status;
 322                 nsw->ns_status = status;
 323                 idr_remove(&nn->nn_status_idr, nsw->ns_id);
 324                 wake_up(&nsw->ns_wq);
 325         }
 326 }
 327 
 328 static void o2net_complete_nsw(struct o2net_node *nn,
 329                                struct o2net_status_wait *nsw,
 330                                u64 id, enum o2net_system_error sys_status,
 331                                s32 status)
 332 {
 333         spin_lock(&nn->nn_lock);
 334         if (nsw == NULL) {
 335                 if (id > INT_MAX)
 336                         goto out;
 337 
 338                 nsw = idr_find(&nn->nn_status_idr, id);
 339                 if (nsw == NULL)
 340                         goto out;
 341         }
 342 
 343         o2net_complete_nsw_locked(nn, nsw, sys_status, status);
 344 
 345 out:
 346         spin_unlock(&nn->nn_lock);
 347         return;
 348 }
 349 
 350 static void o2net_complete_nodes_nsw(struct o2net_node *nn)
 351 {
 352         struct o2net_status_wait *nsw, *tmp;
 353         unsigned int num_kills = 0;
 354 
 355         assert_spin_locked(&nn->nn_lock);
 356 
 357         list_for_each_entry_safe(nsw, tmp, &nn->nn_status_list, ns_node_item) {
 358                 o2net_complete_nsw_locked(nn, nsw, O2NET_ERR_DIED, 0);
 359                 num_kills++;
 360         }
 361 
 362         mlog(0, "completed %d messages for node %u\n", num_kills,
 363              o2net_num_from_nn(nn));
 364 }
 365 
 366 static int o2net_nsw_completed(struct o2net_node *nn,
 367                                struct o2net_status_wait *nsw)
 368 {
 369         int completed;
 370         spin_lock(&nn->nn_lock);
 371         completed = list_empty(&nsw->ns_node_item);
 372         spin_unlock(&nn->nn_lock);
 373         return completed;
 374 }
 375 
 376 /* ------------------------------------------------------------ */
 377 
 378 static void sc_kref_release(struct kref *kref)
 379 {
 380         struct o2net_sock_container *sc = container_of(kref,
 381                                         struct o2net_sock_container, sc_kref);
 382         BUG_ON(timer_pending(&sc->sc_idle_timeout));
 383 
 384         sclog(sc, "releasing\n");
 385 
 386         if (sc->sc_sock) {
 387                 sock_release(sc->sc_sock);
 388                 sc->sc_sock = NULL;
 389         }
 390 
 391         o2nm_undepend_item(&sc->sc_node->nd_item);
 392         o2nm_node_put(sc->sc_node);
 393         sc->sc_node = NULL;
 394 
 395         o2net_debug_del_sc(sc);
 396 
 397         if (sc->sc_page)
 398                 __free_page(sc->sc_page);
 399         kfree(sc);
 400 }
 401 
 402 static void sc_put(struct o2net_sock_container *sc)
 403 {
 404         sclog(sc, "put\n");
 405         kref_put(&sc->sc_kref, sc_kref_release);
 406 }
 407 static void sc_get(struct o2net_sock_container *sc)
 408 {
 409         sclog(sc, "get\n");
 410         kref_get(&sc->sc_kref);
 411 }
 412 static struct o2net_sock_container *sc_alloc(struct o2nm_node *node)
 413 {
 414         struct o2net_sock_container *sc, *ret = NULL;
 415         struct page *page = NULL;
 416         int status = 0;
 417 
 418         page = alloc_page(GFP_NOFS);
 419         sc = kzalloc(sizeof(*sc), GFP_NOFS);
 420         if (sc == NULL || page == NULL)
 421                 goto out;
 422 
 423         kref_init(&sc->sc_kref);
 424         o2nm_node_get(node);
 425         sc->sc_node = node;
 426 
 427         /* pin the node item of the remote node */
 428         status = o2nm_depend_item(&node->nd_item);
 429         if (status) {
 430                 mlog_errno(status);
 431                 o2nm_node_put(node);
 432                 goto out;
 433         }
 434         INIT_WORK(&sc->sc_connect_work, o2net_sc_connect_completed);
 435         INIT_WORK(&sc->sc_rx_work, o2net_rx_until_empty);
 436         INIT_WORK(&sc->sc_shutdown_work, o2net_shutdown_sc);
 437         INIT_DELAYED_WORK(&sc->sc_keepalive_work, o2net_sc_send_keep_req);
 438 
 439         timer_setup(&sc->sc_idle_timeout, o2net_idle_timer, 0);
 440 
 441         sclog(sc, "alloced\n");
 442 
 443         ret = sc;
 444         sc->sc_page = page;
 445         o2net_debug_add_sc(sc);
 446         sc = NULL;
 447         page = NULL;
 448 
 449 out:
 450         if (page)
 451                 __free_page(page);
 452         kfree(sc);
 453 
 454         return ret;
 455 }
 456 
 457 /* ------------------------------------------------------------ */
 458 
 459 static void o2net_sc_queue_work(struct o2net_sock_container *sc,
 460                                 struct work_struct *work)
 461 {
 462         sc_get(sc);
 463         if (!queue_work(o2net_wq, work))
 464                 sc_put(sc);
 465 }
 466 static void o2net_sc_queue_delayed_work(struct o2net_sock_container *sc,
 467                                         struct delayed_work *work,
 468                                         int delay)
 469 {
 470         sc_get(sc);
 471         if (!queue_delayed_work(o2net_wq, work, delay))
 472                 sc_put(sc);
 473 }
 474 static void o2net_sc_cancel_delayed_work(struct o2net_sock_container *sc,
 475                                          struct delayed_work *work)
 476 {
 477         if (cancel_delayed_work(work))
 478                 sc_put(sc);
 479 }
 480 
 481 static atomic_t o2net_connected_peers = ATOMIC_INIT(0);
 482 
 483 int o2net_num_connected_peers(void)
 484 {
 485         return atomic_read(&o2net_connected_peers);
 486 }
 487 
 488 static void o2net_set_nn_state(struct o2net_node *nn,
 489                                struct o2net_sock_container *sc,
 490                                unsigned valid, int err)
 491 {
 492         int was_valid = nn->nn_sc_valid;
 493         int was_err = nn->nn_persistent_error;
 494         struct o2net_sock_container *old_sc = nn->nn_sc;
 495 
 496         assert_spin_locked(&nn->nn_lock);
 497 
 498         if (old_sc && !sc)
 499                 atomic_dec(&o2net_connected_peers);
 500         else if (!old_sc && sc)
 501                 atomic_inc(&o2net_connected_peers);
 502 
 503         /* the node num comparison and single connect/accept path should stop
 504          * an non-null sc from being overwritten with another */
 505         BUG_ON(sc && nn->nn_sc && nn->nn_sc != sc);
 506         mlog_bug_on_msg(err && valid, "err %d valid %u\n", err, valid);
 507         mlog_bug_on_msg(valid && !sc, "valid %u sc %p\n", valid, sc);
 508 
 509         if (was_valid && !valid && err == 0)
 510                 err = -ENOTCONN;
 511 
 512         mlog(ML_CONN, "node %u sc: %p -> %p, valid %u -> %u, err %d -> %d\n",
 513              o2net_num_from_nn(nn), nn->nn_sc, sc, nn->nn_sc_valid, valid,
 514              nn->nn_persistent_error, err);
 515 
 516         nn->nn_sc = sc;
 517         nn->nn_sc_valid = valid ? 1 : 0;
 518         nn->nn_persistent_error = err;
 519 
 520         /* mirrors o2net_tx_can_proceed() */
 521         if (nn->nn_persistent_error || nn->nn_sc_valid)
 522                 wake_up(&nn->nn_sc_wq);
 523 
 524         if (was_valid && !was_err && nn->nn_persistent_error) {
 525                 o2quo_conn_err(o2net_num_from_nn(nn));
 526                 queue_delayed_work(o2net_wq, &nn->nn_still_up,
 527                                    msecs_to_jiffies(O2NET_QUORUM_DELAY_MS));
 528         }
 529 
 530         if (was_valid && !valid) {
 531                 if (old_sc)
 532                         printk(KERN_NOTICE "o2net: No longer connected to "
 533                                 SC_NODEF_FMT "\n", SC_NODEF_ARGS(old_sc));
 534                 o2net_complete_nodes_nsw(nn);
 535         }
 536 
 537         if (!was_valid && valid) {
 538                 o2quo_conn_up(o2net_num_from_nn(nn));
 539                 cancel_delayed_work(&nn->nn_connect_expired);
 540                 printk(KERN_NOTICE "o2net: %s " SC_NODEF_FMT "\n",
 541                        o2nm_this_node() > sc->sc_node->nd_num ?
 542                        "Connected to" : "Accepted connection from",
 543                        SC_NODEF_ARGS(sc));
 544         }
 545 
 546         /* trigger the connecting worker func as long as we're not valid,
 547          * it will back off if it shouldn't connect.  This can be called
 548          * from node config teardown and so needs to be careful about
 549          * the work queue actually being up. */
 550         if (!valid && o2net_wq) {
 551                 unsigned long delay;
 552                 /* delay if we're within a RECONNECT_DELAY of the
 553                  * last attempt */
 554                 delay = (nn->nn_last_connect_attempt +
 555                          msecs_to_jiffies(o2net_reconnect_delay()))
 556                         - jiffies;
 557                 if (delay > msecs_to_jiffies(o2net_reconnect_delay()))
 558                         delay = 0;
 559                 mlog(ML_CONN, "queueing conn attempt in %lu jiffies\n", delay);
 560                 queue_delayed_work(o2net_wq, &nn->nn_connect_work, delay);
 561 
 562                 /*
 563                  * Delay the expired work after idle timeout.
 564                  *
 565                  * We might have lots of failed connection attempts that run
 566                  * through here but we only cancel the connect_expired work when
 567                  * a connection attempt succeeds.  So only the first enqueue of
 568                  * the connect_expired work will do anything.  The rest will see
 569                  * that it's already queued and do nothing.
 570                  */
 571                 delay += msecs_to_jiffies(o2net_idle_timeout());
 572                 queue_delayed_work(o2net_wq, &nn->nn_connect_expired, delay);
 573         }
 574 
 575         /* keep track of the nn's sc ref for the caller */
 576         if ((old_sc == NULL) && sc)
 577                 sc_get(sc);
 578         if (old_sc && (old_sc != sc)) {
 579                 o2net_sc_queue_work(old_sc, &old_sc->sc_shutdown_work);
 580                 sc_put(old_sc);
 581         }
 582 }
 583 
 584 /* see o2net_register_callbacks() */
 585 static void o2net_data_ready(struct sock *sk)
 586 {
 587         void (*ready)(struct sock *sk);
 588         struct o2net_sock_container *sc;
 589 
 590         read_lock_bh(&sk->sk_callback_lock);
 591         sc = sk->sk_user_data;
 592         if (sc) {
 593                 sclog(sc, "data_ready hit\n");
 594                 o2net_set_data_ready_time(sc);
 595                 o2net_sc_queue_work(sc, &sc->sc_rx_work);
 596                 ready = sc->sc_data_ready;
 597         } else {
 598                 ready = sk->sk_data_ready;
 599         }
 600         read_unlock_bh(&sk->sk_callback_lock);
 601 
 602         ready(sk);
 603 }
 604 
 605 /* see o2net_register_callbacks() */
 606 static void o2net_state_change(struct sock *sk)
 607 {
 608         void (*state_change)(struct sock *sk);
 609         struct o2net_sock_container *sc;
 610 
 611         read_lock_bh(&sk->sk_callback_lock);
 612         sc = sk->sk_user_data;
 613         if (sc == NULL) {
 614                 state_change = sk->sk_state_change;
 615                 goto out;
 616         }
 617 
 618         sclog(sc, "state_change to %d\n", sk->sk_state);
 619 
 620         state_change = sc->sc_state_change;
 621 
 622         switch(sk->sk_state) {
 623         /* ignore connecting sockets as they make progress */
 624         case TCP_SYN_SENT:
 625         case TCP_SYN_RECV:
 626                 break;
 627         case TCP_ESTABLISHED:
 628                 o2net_sc_queue_work(sc, &sc->sc_connect_work);
 629                 break;
 630         default:
 631                 printk(KERN_INFO "o2net: Connection to " SC_NODEF_FMT
 632                         " shutdown, state %d\n",
 633                         SC_NODEF_ARGS(sc), sk->sk_state);
 634                 o2net_sc_queue_work(sc, &sc->sc_shutdown_work);
 635                 break;
 636         }
 637 out:
 638         read_unlock_bh(&sk->sk_callback_lock);
 639         state_change(sk);
 640 }
 641 
 642 /*
 643  * we register callbacks so we can queue work on events before calling
 644  * the original callbacks.  our callbacks our careful to test user_data
 645  * to discover when they've reaced with o2net_unregister_callbacks().
 646  */
 647 static void o2net_register_callbacks(struct sock *sk,
 648                                      struct o2net_sock_container *sc)
 649 {
 650         write_lock_bh(&sk->sk_callback_lock);
 651 
 652         /* accepted sockets inherit the old listen socket data ready */
 653         if (sk->sk_data_ready == o2net_listen_data_ready) {
 654                 sk->sk_data_ready = sk->sk_user_data;
 655                 sk->sk_user_data = NULL;
 656         }
 657 
 658         BUG_ON(sk->sk_user_data != NULL);
 659         sk->sk_user_data = sc;
 660         sc_get(sc);
 661 
 662         sc->sc_data_ready = sk->sk_data_ready;
 663         sc->sc_state_change = sk->sk_state_change;
 664         sk->sk_data_ready = o2net_data_ready;
 665         sk->sk_state_change = o2net_state_change;
 666 
 667         mutex_init(&sc->sc_send_lock);
 668 
 669         write_unlock_bh(&sk->sk_callback_lock);
 670 }
 671 
 672 static int o2net_unregister_callbacks(struct sock *sk,
 673                                    struct o2net_sock_container *sc)
 674 {
 675         int ret = 0;
 676 
 677         write_lock_bh(&sk->sk_callback_lock);
 678         if (sk->sk_user_data == sc) {
 679                 ret = 1;
 680                 sk->sk_user_data = NULL;
 681                 sk->sk_data_ready = sc->sc_data_ready;
 682                 sk->sk_state_change = sc->sc_state_change;
 683         }
 684         write_unlock_bh(&sk->sk_callback_lock);
 685 
 686         return ret;
 687 }
 688 
 689 /*
 690  * this is a little helper that is called by callers who have seen a problem
 691  * with an sc and want to detach it from the nn if someone already hasn't beat
 692  * them to it.  if an error is given then the shutdown will be persistent
 693  * and pending transmits will be canceled.
 694  */
 695 static void o2net_ensure_shutdown(struct o2net_node *nn,
 696                                    struct o2net_sock_container *sc,
 697                                    int err)
 698 {
 699         spin_lock(&nn->nn_lock);
 700         if (nn->nn_sc == sc)
 701                 o2net_set_nn_state(nn, NULL, 0, err);
 702         spin_unlock(&nn->nn_lock);
 703 }
 704 
 705 /*
 706  * This work queue function performs the blocking parts of socket shutdown.  A
 707  * few paths lead here.  set_nn_state will trigger this callback if it sees an
 708  * sc detached from the nn.  state_change will also trigger this callback
 709  * directly when it sees errors.  In that case we need to call set_nn_state
 710  * ourselves as state_change couldn't get the nn_lock and call set_nn_state
 711  * itself.
 712  */
 713 static void o2net_shutdown_sc(struct work_struct *work)
 714 {
 715         struct o2net_sock_container *sc =
 716                 container_of(work, struct o2net_sock_container,
 717                              sc_shutdown_work);
 718         struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
 719 
 720         sclog(sc, "shutting down\n");
 721 
 722         /* drop the callbacks ref and call shutdown only once */
 723         if (o2net_unregister_callbacks(sc->sc_sock->sk, sc)) {
 724                 /* we shouldn't flush as we're in the thread, the
 725                  * races with pending sc work structs are harmless */
 726                 del_timer_sync(&sc->sc_idle_timeout);
 727                 o2net_sc_cancel_delayed_work(sc, &sc->sc_keepalive_work);
 728                 sc_put(sc);
 729                 kernel_sock_shutdown(sc->sc_sock, SHUT_RDWR);
 730         }
 731 
 732         /* not fatal so failed connects before the other guy has our
 733          * heartbeat can be retried */
 734         o2net_ensure_shutdown(nn, sc, 0);
 735         sc_put(sc);
 736 }
 737 
 738 /* ------------------------------------------------------------ */
 739 
 740 static int o2net_handler_cmp(struct o2net_msg_handler *nmh, u32 msg_type,
 741                              u32 key)
 742 {
 743         int ret = memcmp(&nmh->nh_key, &key, sizeof(key));
 744 
 745         if (ret == 0)
 746                 ret = memcmp(&nmh->nh_msg_type, &msg_type, sizeof(msg_type));
 747 
 748         return ret;
 749 }
 750 
 751 static struct o2net_msg_handler *
 752 o2net_handler_tree_lookup(u32 msg_type, u32 key, struct rb_node ***ret_p,
 753                           struct rb_node **ret_parent)
 754 {
 755         struct rb_node **p = &o2net_handler_tree.rb_node;
 756         struct rb_node *parent = NULL;
 757         struct o2net_msg_handler *nmh, *ret = NULL;
 758         int cmp;
 759 
 760         while (*p) {
 761                 parent = *p;
 762                 nmh = rb_entry(parent, struct o2net_msg_handler, nh_node);
 763                 cmp = o2net_handler_cmp(nmh, msg_type, key);
 764 
 765                 if (cmp < 0)
 766                         p = &(*p)->rb_left;
 767                 else if (cmp > 0)
 768                         p = &(*p)->rb_right;
 769                 else {
 770                         ret = nmh;
 771                         break;
 772                 }
 773         }
 774 
 775         if (ret_p != NULL)
 776                 *ret_p = p;
 777         if (ret_parent != NULL)
 778                 *ret_parent = parent;
 779 
 780         return ret;
 781 }
 782 
 783 static void o2net_handler_kref_release(struct kref *kref)
 784 {
 785         struct o2net_msg_handler *nmh;
 786         nmh = container_of(kref, struct o2net_msg_handler, nh_kref);
 787 
 788         kfree(nmh);
 789 }
 790 
 791 static void o2net_handler_put(struct o2net_msg_handler *nmh)
 792 {
 793         kref_put(&nmh->nh_kref, o2net_handler_kref_release);
 794 }
 795 
 796 /* max_len is protection for the handler func.  incoming messages won't
 797  * be given to the handler if their payload is longer than the max. */
 798 int o2net_register_handler(u32 msg_type, u32 key, u32 max_len,
 799                            o2net_msg_handler_func *func, void *data,
 800                            o2net_post_msg_handler_func *post_func,
 801                            struct list_head *unreg_list)
 802 {
 803         struct o2net_msg_handler *nmh = NULL;
 804         struct rb_node **p, *parent;
 805         int ret = 0;
 806 
 807         if (max_len > O2NET_MAX_PAYLOAD_BYTES) {
 808                 mlog(0, "max_len for message handler out of range: %u\n",
 809                         max_len);
 810                 ret = -EINVAL;
 811                 goto out;
 812         }
 813 
 814         if (!msg_type) {
 815                 mlog(0, "no message type provided: %u, %p\n", msg_type, func);
 816                 ret = -EINVAL;
 817                 goto out;
 818 
 819         }
 820         if (!func) {
 821                 mlog(0, "no message handler provided: %u, %p\n",
 822                        msg_type, func);
 823                 ret = -EINVAL;
 824                 goto out;
 825         }
 826 
 827         nmh = kzalloc(sizeof(struct o2net_msg_handler), GFP_NOFS);
 828         if (nmh == NULL) {
 829                 ret = -ENOMEM;
 830                 goto out;
 831         }
 832 
 833         nmh->nh_func = func;
 834         nmh->nh_func_data = data;
 835         nmh->nh_post_func = post_func;
 836         nmh->nh_msg_type = msg_type;
 837         nmh->nh_max_len = max_len;
 838         nmh->nh_key = key;
 839         /* the tree and list get this ref.. they're both removed in
 840          * unregister when this ref is dropped */
 841         kref_init(&nmh->nh_kref);
 842         INIT_LIST_HEAD(&nmh->nh_unregister_item);
 843 
 844         write_lock(&o2net_handler_lock);
 845         if (o2net_handler_tree_lookup(msg_type, key, &p, &parent))
 846                 ret = -EEXIST;
 847         else {
 848                 rb_link_node(&nmh->nh_node, parent, p);
 849                 rb_insert_color(&nmh->nh_node, &o2net_handler_tree);
 850                 list_add_tail(&nmh->nh_unregister_item, unreg_list);
 851 
 852                 mlog(ML_TCP, "registered handler func %p type %u key %08x\n",
 853                      func, msg_type, key);
 854                 /* we've had some trouble with handlers seemingly vanishing. */
 855                 mlog_bug_on_msg(o2net_handler_tree_lookup(msg_type, key, &p,
 856                                                           &parent) == NULL,
 857                                 "couldn't find handler we *just* registered "
 858                                 "for type %u key %08x\n", msg_type, key);
 859         }
 860         write_unlock(&o2net_handler_lock);
 861 
 862 out:
 863         if (ret)
 864                 kfree(nmh);
 865 
 866         return ret;
 867 }
 868 EXPORT_SYMBOL_GPL(o2net_register_handler);
 869 
 870 void o2net_unregister_handler_list(struct list_head *list)
 871 {
 872         struct o2net_msg_handler *nmh, *n;
 873 
 874         write_lock(&o2net_handler_lock);
 875         list_for_each_entry_safe(nmh, n, list, nh_unregister_item) {
 876                 mlog(ML_TCP, "unregistering handler func %p type %u key %08x\n",
 877                      nmh->nh_func, nmh->nh_msg_type, nmh->nh_key);
 878                 rb_erase(&nmh->nh_node, &o2net_handler_tree);
 879                 list_del_init(&nmh->nh_unregister_item);
 880                 kref_put(&nmh->nh_kref, o2net_handler_kref_release);
 881         }
 882         write_unlock(&o2net_handler_lock);
 883 }
 884 EXPORT_SYMBOL_GPL(o2net_unregister_handler_list);
 885 
 886 static struct o2net_msg_handler *o2net_handler_get(u32 msg_type, u32 key)
 887 {
 888         struct o2net_msg_handler *nmh;
 889 
 890         read_lock(&o2net_handler_lock);
 891         nmh = o2net_handler_tree_lookup(msg_type, key, NULL, NULL);
 892         if (nmh)
 893                 kref_get(&nmh->nh_kref);
 894         read_unlock(&o2net_handler_lock);
 895 
 896         return nmh;
 897 }
 898 
 899 /* ------------------------------------------------------------ */
 900 
 901 static int o2net_recv_tcp_msg(struct socket *sock, void *data, size_t len)
 902 {
 903         struct kvec vec = { .iov_len = len, .iov_base = data, };
 904         struct msghdr msg = { .msg_flags = MSG_DONTWAIT, };
 905         iov_iter_kvec(&msg.msg_iter, READ, &vec, 1, len);
 906         return sock_recvmsg(sock, &msg, MSG_DONTWAIT);
 907 }
 908 
 909 static int o2net_send_tcp_msg(struct socket *sock, struct kvec *vec,
 910                               size_t veclen, size_t total)
 911 {
 912         int ret;
 913         struct msghdr msg = {.msg_flags = 0,};
 914 
 915         if (sock == NULL) {
 916                 ret = -EINVAL;
 917                 goto out;
 918         }
 919 
 920         ret = kernel_sendmsg(sock, &msg, vec, veclen, total);
 921         if (likely(ret == total))
 922                 return 0;
 923         mlog(ML_ERROR, "sendmsg returned %d instead of %zu\n", ret, total);
 924         if (ret >= 0)
 925                 ret = -EPIPE; /* should be smarter, I bet */
 926 out:
 927         mlog(0, "returning error: %d\n", ret);
 928         return ret;
 929 }
 930 
 931 static void o2net_sendpage(struct o2net_sock_container *sc,
 932                            void *kmalloced_virt,
 933                            size_t size)
 934 {
 935         struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
 936         ssize_t ret;
 937 
 938         while (1) {
 939                 mutex_lock(&sc->sc_send_lock);
 940                 ret = sc->sc_sock->ops->sendpage(sc->sc_sock,
 941                                                  virt_to_page(kmalloced_virt),
 942                                                  offset_in_page(kmalloced_virt),
 943                                                  size, MSG_DONTWAIT);
 944                 mutex_unlock(&sc->sc_send_lock);
 945                 if (ret == size)
 946                         break;
 947                 if (ret == (ssize_t)-EAGAIN) {
 948                         mlog(0, "sendpage of size %zu to " SC_NODEF_FMT
 949                              " returned EAGAIN\n", size, SC_NODEF_ARGS(sc));
 950                         cond_resched();
 951                         continue;
 952                 }
 953                 mlog(ML_ERROR, "sendpage of size %zu to " SC_NODEF_FMT
 954                      " failed with %zd\n", size, SC_NODEF_ARGS(sc), ret);
 955                 o2net_ensure_shutdown(nn, sc, 0);
 956                 break;
 957         }
 958 }
 959 
 960 static void o2net_init_msg(struct o2net_msg *msg, u16 data_len, u16 msg_type, u32 key)
 961 {
 962         memset(msg, 0, sizeof(struct o2net_msg));
 963         msg->magic = cpu_to_be16(O2NET_MSG_MAGIC);
 964         msg->data_len = cpu_to_be16(data_len);
 965         msg->msg_type = cpu_to_be16(msg_type);
 966         msg->sys_status = cpu_to_be32(O2NET_ERR_NONE);
 967         msg->status = 0;
 968         msg->key = cpu_to_be32(key);
 969 }
 970 
 971 static int o2net_tx_can_proceed(struct o2net_node *nn,
 972                                 struct o2net_sock_container **sc_ret,
 973                                 int *error)
 974 {
 975         int ret = 0;
 976 
 977         spin_lock(&nn->nn_lock);
 978         if (nn->nn_persistent_error) {
 979                 ret = 1;
 980                 *sc_ret = NULL;
 981                 *error = nn->nn_persistent_error;
 982         } else if (nn->nn_sc_valid) {
 983                 kref_get(&nn->nn_sc->sc_kref);
 984 
 985                 ret = 1;
 986                 *sc_ret = nn->nn_sc;
 987                 *error = 0;
 988         }
 989         spin_unlock(&nn->nn_lock);
 990 
 991         return ret;
 992 }
 993 
 994 /* Get a map of all nodes to which this node is currently connected to */
 995 void o2net_fill_node_map(unsigned long *map, unsigned bytes)
 996 {
 997         struct o2net_sock_container *sc;
 998         int node, ret;
 999 
1000         BUG_ON(bytes < (BITS_TO_LONGS(O2NM_MAX_NODES) * sizeof(unsigned long)));
1001 
1002         memset(map, 0, bytes);
1003         for (node = 0; node < O2NM_MAX_NODES; ++node) {
1004                 if (!o2net_tx_can_proceed(o2net_nn_from_num(node), &sc, &ret))
1005                         continue;
1006                 if (!ret) {
1007                         set_bit(node, map);
1008                         sc_put(sc);
1009                 }
1010         }
1011 }
1012 EXPORT_SYMBOL_GPL(o2net_fill_node_map);
1013 
1014 int o2net_send_message_vec(u32 msg_type, u32 key, struct kvec *caller_vec,
1015                            size_t caller_veclen, u8 target_node, int *status)
1016 {
1017         int ret = 0;
1018         struct o2net_msg *msg = NULL;
1019         size_t veclen, caller_bytes = 0;
1020         struct kvec *vec = NULL;
1021         struct o2net_sock_container *sc = NULL;
1022         struct o2net_node *nn = o2net_nn_from_num(target_node);
1023         struct o2net_status_wait nsw = {
1024                 .ns_node_item = LIST_HEAD_INIT(nsw.ns_node_item),
1025         };
1026         struct o2net_send_tracking nst;
1027 
1028         o2net_init_nst(&nst, msg_type, key, current, target_node);
1029 
1030         if (o2net_wq == NULL) {
1031                 mlog(0, "attempt to tx without o2netd running\n");
1032                 ret = -ESRCH;
1033                 goto out;
1034         }
1035 
1036         if (caller_veclen == 0) {
1037                 mlog(0, "bad kvec array length\n");
1038                 ret = -EINVAL;
1039                 goto out;
1040         }
1041 
1042         caller_bytes = iov_length((struct iovec *)caller_vec, caller_veclen);
1043         if (caller_bytes > O2NET_MAX_PAYLOAD_BYTES) {
1044                 mlog(0, "total payload len %zu too large\n", caller_bytes);
1045                 ret = -EINVAL;
1046                 goto out;
1047         }
1048 
1049         if (target_node == o2nm_this_node()) {
1050                 ret = -ELOOP;
1051                 goto out;
1052         }
1053 
1054         o2net_debug_add_nst(&nst);
1055 
1056         o2net_set_nst_sock_time(&nst);
1057 
1058         wait_event(nn->nn_sc_wq, o2net_tx_can_proceed(nn, &sc, &ret));
1059         if (ret)
1060                 goto out;
1061 
1062         o2net_set_nst_sock_container(&nst, sc);
1063 
1064         veclen = caller_veclen + 1;
1065         vec = kmalloc_array(veclen, sizeof(struct kvec), GFP_ATOMIC);
1066         if (vec == NULL) {
1067                 mlog(0, "failed to %zu element kvec!\n", veclen);
1068                 ret = -ENOMEM;
1069                 goto out;
1070         }
1071 
1072         msg = kmalloc(sizeof(struct o2net_msg), GFP_ATOMIC);
1073         if (!msg) {
1074                 mlog(0, "failed to allocate a o2net_msg!\n");
1075                 ret = -ENOMEM;
1076                 goto out;
1077         }
1078 
1079         o2net_init_msg(msg, caller_bytes, msg_type, key);
1080 
1081         vec[0].iov_len = sizeof(struct o2net_msg);
1082         vec[0].iov_base = msg;
1083         memcpy(&vec[1], caller_vec, caller_veclen * sizeof(struct kvec));
1084 
1085         ret = o2net_prep_nsw(nn, &nsw);
1086         if (ret)
1087                 goto out;
1088 
1089         msg->msg_num = cpu_to_be32(nsw.ns_id);
1090         o2net_set_nst_msg_id(&nst, nsw.ns_id);
1091 
1092         o2net_set_nst_send_time(&nst);
1093 
1094         /* finally, convert the message header to network byte-order
1095          * and send */
1096         mutex_lock(&sc->sc_send_lock);
1097         ret = o2net_send_tcp_msg(sc->sc_sock, vec, veclen,
1098                                  sizeof(struct o2net_msg) + caller_bytes);
1099         mutex_unlock(&sc->sc_send_lock);
1100         msglog(msg, "sending returned %d\n", ret);
1101         if (ret < 0) {
1102                 mlog(0, "error returned from o2net_send_tcp_msg=%d\n", ret);
1103                 goto out;
1104         }
1105 
1106         /* wait on other node's handler */
1107         o2net_set_nst_status_time(&nst);
1108         wait_event(nsw.ns_wq, o2net_nsw_completed(nn, &nsw));
1109 
1110         o2net_update_send_stats(&nst, sc);
1111 
1112         /* Note that we avoid overwriting the callers status return
1113          * variable if a system error was reported on the other
1114          * side. Callers beware. */
1115         ret = o2net_sys_err_to_errno(nsw.ns_sys_status);
1116         if (status && !ret)
1117                 *status = nsw.ns_status;
1118 
1119         mlog(0, "woken, returning system status %d, user status %d\n",
1120              ret, nsw.ns_status);
1121 out:
1122         o2net_debug_del_nst(&nst); /* must be before dropping sc and node */
1123         if (sc)
1124                 sc_put(sc);
1125         kfree(vec);
1126         kfree(msg);
1127         o2net_complete_nsw(nn, &nsw, 0, 0, 0);
1128         return ret;
1129 }
1130 EXPORT_SYMBOL_GPL(o2net_send_message_vec);
1131 
1132 int o2net_send_message(u32 msg_type, u32 key, void *data, u32 len,
1133                        u8 target_node, int *status)
1134 {
1135         struct kvec vec = {
1136                 .iov_base = data,
1137                 .iov_len = len,
1138         };
1139         return o2net_send_message_vec(msg_type, key, &vec, 1,
1140                                       target_node, status);
1141 }
1142 EXPORT_SYMBOL_GPL(o2net_send_message);
1143 
1144 static int o2net_send_status_magic(struct socket *sock, struct o2net_msg *hdr,
1145                                    enum o2net_system_error syserr, int err)
1146 {
1147         struct kvec vec = {
1148                 .iov_base = hdr,
1149                 .iov_len = sizeof(struct o2net_msg),
1150         };
1151 
1152         BUG_ON(syserr >= O2NET_ERR_MAX);
1153 
1154         /* leave other fields intact from the incoming message, msg_num
1155          * in particular */
1156         hdr->sys_status = cpu_to_be32(syserr);
1157         hdr->status = cpu_to_be32(err);
1158         hdr->magic = cpu_to_be16(O2NET_MSG_STATUS_MAGIC);  // twiddle the magic
1159         hdr->data_len = 0;
1160 
1161         msglog(hdr, "about to send status magic %d\n", err);
1162         /* hdr has been in host byteorder this whole time */
1163         return o2net_send_tcp_msg(sock, &vec, 1, sizeof(struct o2net_msg));
1164 }
1165 
1166 /* this returns -errno if the header was unknown or too large, etc.
1167  * after this is called the buffer us reused for the next message */
1168 static int o2net_process_message(struct o2net_sock_container *sc,
1169                                  struct o2net_msg *hdr)
1170 {
1171         struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
1172         int ret = 0, handler_status;
1173         enum  o2net_system_error syserr;
1174         struct o2net_msg_handler *nmh = NULL;
1175         void *ret_data = NULL;
1176 
1177         msglog(hdr, "processing message\n");
1178 
1179         o2net_sc_postpone_idle(sc);
1180 
1181         switch(be16_to_cpu(hdr->magic)) {
1182                 case O2NET_MSG_STATUS_MAGIC:
1183                         /* special type for returning message status */
1184                         o2net_complete_nsw(nn, NULL,
1185                                            be32_to_cpu(hdr->msg_num),
1186                                            be32_to_cpu(hdr->sys_status),
1187                                            be32_to_cpu(hdr->status));
1188                         goto out;
1189                 case O2NET_MSG_KEEP_REQ_MAGIC:
1190                         o2net_sendpage(sc, o2net_keep_resp,
1191                                        sizeof(*o2net_keep_resp));
1192                         goto out;
1193                 case O2NET_MSG_KEEP_RESP_MAGIC:
1194                         goto out;
1195                 case O2NET_MSG_MAGIC:
1196                         break;
1197                 default:
1198                         msglog(hdr, "bad magic\n");
1199                         ret = -EINVAL;
1200                         goto out;
1201                         break;
1202         }
1203 
1204         /* find a handler for it */
1205         handler_status = 0;
1206         nmh = o2net_handler_get(be16_to_cpu(hdr->msg_type),
1207                                 be32_to_cpu(hdr->key));
1208         if (!nmh) {
1209                 mlog(ML_TCP, "couldn't find handler for type %u key %08x\n",
1210                      be16_to_cpu(hdr->msg_type), be32_to_cpu(hdr->key));
1211                 syserr = O2NET_ERR_NO_HNDLR;
1212                 goto out_respond;
1213         }
1214 
1215         syserr = O2NET_ERR_NONE;
1216 
1217         if (be16_to_cpu(hdr->data_len) > nmh->nh_max_len)
1218                 syserr = O2NET_ERR_OVERFLOW;
1219 
1220         if (syserr != O2NET_ERR_NONE)
1221                 goto out_respond;
1222 
1223         o2net_set_func_start_time(sc);
1224         sc->sc_msg_key = be32_to_cpu(hdr->key);
1225         sc->sc_msg_type = be16_to_cpu(hdr->msg_type);
1226         handler_status = (nmh->nh_func)(hdr, sizeof(struct o2net_msg) +
1227                                              be16_to_cpu(hdr->data_len),
1228                                         nmh->nh_func_data, &ret_data);
1229         o2net_set_func_stop_time(sc);
1230 
1231         o2net_update_recv_stats(sc);
1232 
1233 out_respond:
1234         /* this destroys the hdr, so don't use it after this */
1235         mutex_lock(&sc->sc_send_lock);
1236         ret = o2net_send_status_magic(sc->sc_sock, hdr, syserr,
1237                                       handler_status);
1238         mutex_unlock(&sc->sc_send_lock);
1239         hdr = NULL;
1240         mlog(0, "sending handler status %d, syserr %d returned %d\n",
1241              handler_status, syserr, ret);
1242 
1243         if (nmh) {
1244                 BUG_ON(ret_data != NULL && nmh->nh_post_func == NULL);
1245                 if (nmh->nh_post_func)
1246                         (nmh->nh_post_func)(handler_status, nmh->nh_func_data,
1247                                             ret_data);
1248         }
1249 
1250 out:
1251         if (nmh)
1252                 o2net_handler_put(nmh);
1253         return ret;
1254 }
1255 
1256 static int o2net_check_handshake(struct o2net_sock_container *sc)
1257 {
1258         struct o2net_handshake *hand = page_address(sc->sc_page);
1259         struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
1260 
1261         if (hand->protocol_version != cpu_to_be64(O2NET_PROTOCOL_VERSION)) {
1262                 printk(KERN_NOTICE "o2net: " SC_NODEF_FMT " Advertised net "
1263                        "protocol version %llu but %llu is required. "
1264                        "Disconnecting.\n", SC_NODEF_ARGS(sc),
1265                        (unsigned long long)be64_to_cpu(hand->protocol_version),
1266                        O2NET_PROTOCOL_VERSION);
1267 
1268                 /* don't bother reconnecting if its the wrong version. */
1269                 o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1270                 return -1;
1271         }
1272 
1273         /*
1274          * Ensure timeouts are consistent with other nodes, otherwise
1275          * we can end up with one node thinking that the other must be down,
1276          * but isn't. This can ultimately cause corruption.
1277          */
1278         if (be32_to_cpu(hand->o2net_idle_timeout_ms) !=
1279                                 o2net_idle_timeout()) {
1280                 printk(KERN_NOTICE "o2net: " SC_NODEF_FMT " uses a network "
1281                        "idle timeout of %u ms, but we use %u ms locally. "
1282                        "Disconnecting.\n", SC_NODEF_ARGS(sc),
1283                        be32_to_cpu(hand->o2net_idle_timeout_ms),
1284                        o2net_idle_timeout());
1285                 o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1286                 return -1;
1287         }
1288 
1289         if (be32_to_cpu(hand->o2net_keepalive_delay_ms) !=
1290                         o2net_keepalive_delay()) {
1291                 printk(KERN_NOTICE "o2net: " SC_NODEF_FMT " uses a keepalive "
1292                        "delay of %u ms, but we use %u ms locally. "
1293                        "Disconnecting.\n", SC_NODEF_ARGS(sc),
1294                        be32_to_cpu(hand->o2net_keepalive_delay_ms),
1295                        o2net_keepalive_delay());
1296                 o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1297                 return -1;
1298         }
1299 
1300         if (be32_to_cpu(hand->o2hb_heartbeat_timeout_ms) !=
1301                         O2HB_MAX_WRITE_TIMEOUT_MS) {
1302                 printk(KERN_NOTICE "o2net: " SC_NODEF_FMT " uses a heartbeat "
1303                        "timeout of %u ms, but we use %u ms locally. "
1304                        "Disconnecting.\n", SC_NODEF_ARGS(sc),
1305                        be32_to_cpu(hand->o2hb_heartbeat_timeout_ms),
1306                        O2HB_MAX_WRITE_TIMEOUT_MS);
1307                 o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1308                 return -1;
1309         }
1310 
1311         sc->sc_handshake_ok = 1;
1312 
1313         spin_lock(&nn->nn_lock);
1314         /* set valid and queue the idle timers only if it hasn't been
1315          * shut down already */
1316         if (nn->nn_sc == sc) {
1317                 o2net_sc_reset_idle_timer(sc);
1318                 atomic_set(&nn->nn_timeout, 0);
1319                 o2net_set_nn_state(nn, sc, 1, 0);
1320         }
1321         spin_unlock(&nn->nn_lock);
1322 
1323         /* shift everything up as though it wasn't there */
1324         sc->sc_page_off -= sizeof(struct o2net_handshake);
1325         if (sc->sc_page_off)
1326                 memmove(hand, hand + 1, sc->sc_page_off);
1327 
1328         return 0;
1329 }
1330 
1331 /* this demuxes the queued rx bytes into header or payload bits and calls
1332  * handlers as each full message is read off the socket.  it returns -error,
1333  * == 0 eof, or > 0 for progress made.*/
1334 static int o2net_advance_rx(struct o2net_sock_container *sc)
1335 {
1336         struct o2net_msg *hdr;
1337         int ret = 0;
1338         void *data;
1339         size_t datalen;
1340 
1341         sclog(sc, "receiving\n");
1342         o2net_set_advance_start_time(sc);
1343 
1344         if (unlikely(sc->sc_handshake_ok == 0)) {
1345                 if(sc->sc_page_off < sizeof(struct o2net_handshake)) {
1346                         data = page_address(sc->sc_page) + sc->sc_page_off;
1347                         datalen = sizeof(struct o2net_handshake) - sc->sc_page_off;
1348                         ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen);
1349                         if (ret > 0)
1350                                 sc->sc_page_off += ret;
1351                 }
1352 
1353                 if (sc->sc_page_off == sizeof(struct o2net_handshake)) {
1354                         o2net_check_handshake(sc);
1355                         if (unlikely(sc->sc_handshake_ok == 0))
1356                                 ret = -EPROTO;
1357                 }
1358                 goto out;
1359         }
1360 
1361         /* do we need more header? */
1362         if (sc->sc_page_off < sizeof(struct o2net_msg)) {
1363                 data = page_address(sc->sc_page) + sc->sc_page_off;
1364                 datalen = sizeof(struct o2net_msg) - sc->sc_page_off;
1365                 ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen);
1366                 if (ret > 0) {
1367                         sc->sc_page_off += ret;
1368                         /* only swab incoming here.. we can
1369                          * only get here once as we cross from
1370                          * being under to over */
1371                         if (sc->sc_page_off == sizeof(struct o2net_msg)) {
1372                                 hdr = page_address(sc->sc_page);
1373                                 if (be16_to_cpu(hdr->data_len) >
1374                                     O2NET_MAX_PAYLOAD_BYTES)
1375                                         ret = -EOVERFLOW;
1376                         }
1377                 }
1378                 if (ret <= 0)
1379                         goto out;
1380         }
1381 
1382         if (sc->sc_page_off < sizeof(struct o2net_msg)) {
1383                 /* oof, still don't have a header */
1384                 goto out;
1385         }
1386 
1387         /* this was swabbed above when we first read it */
1388         hdr = page_address(sc->sc_page);
1389 
1390         msglog(hdr, "at page_off %zu\n", sc->sc_page_off);
1391 
1392         /* do we need more payload? */
1393         if (sc->sc_page_off - sizeof(struct o2net_msg) < be16_to_cpu(hdr->data_len)) {
1394                 /* need more payload */
1395                 data = page_address(sc->sc_page) + sc->sc_page_off;
1396                 datalen = (sizeof(struct o2net_msg) + be16_to_cpu(hdr->data_len)) -
1397                           sc->sc_page_off;
1398                 ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen);
1399                 if (ret > 0)
1400                         sc->sc_page_off += ret;
1401                 if (ret <= 0)
1402                         goto out;
1403         }
1404 
1405         if (sc->sc_page_off - sizeof(struct o2net_msg) == be16_to_cpu(hdr->data_len)) {
1406                 /* we can only get here once, the first time we read
1407                  * the payload.. so set ret to progress if the handler
1408                  * works out. after calling this the message is toast */
1409                 ret = o2net_process_message(sc, hdr);
1410                 if (ret == 0)
1411                         ret = 1;
1412                 sc->sc_page_off = 0;
1413         }
1414 
1415 out:
1416         sclog(sc, "ret = %d\n", ret);
1417         o2net_set_advance_stop_time(sc);
1418         return ret;
1419 }
1420 
1421 /* this work func is triggerd by data ready.  it reads until it can read no
1422  * more.  it interprets 0, eof, as fatal.  if data_ready hits while we're doing
1423  * our work the work struct will be marked and we'll be called again. */
1424 static void o2net_rx_until_empty(struct work_struct *work)
1425 {
1426         struct o2net_sock_container *sc =
1427                 container_of(work, struct o2net_sock_container, sc_rx_work);
1428         int ret;
1429 
1430         do {
1431                 ret = o2net_advance_rx(sc);
1432         } while (ret > 0);
1433 
1434         if (ret <= 0 && ret != -EAGAIN) {
1435                 struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
1436                 sclog(sc, "saw error %d, closing\n", ret);
1437                 /* not permanent so read failed handshake can retry */
1438                 o2net_ensure_shutdown(nn, sc, 0);
1439         }
1440 
1441         sc_put(sc);
1442 }
1443 
1444 static int o2net_set_nodelay(struct socket *sock)
1445 {
1446         int val = 1;
1447 
1448         return kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY,
1449                                     (void *)&val, sizeof(val));
1450 }
1451 
1452 static int o2net_set_usertimeout(struct socket *sock)
1453 {
1454         int user_timeout = O2NET_TCP_USER_TIMEOUT;
1455 
1456         return kernel_setsockopt(sock, SOL_TCP, TCP_USER_TIMEOUT,
1457                                 (void *)&user_timeout, sizeof(user_timeout));
1458 }
1459 
1460 static void o2net_initialize_handshake(void)
1461 {
1462         o2net_hand->o2hb_heartbeat_timeout_ms = cpu_to_be32(
1463                 O2HB_MAX_WRITE_TIMEOUT_MS);
1464         o2net_hand->o2net_idle_timeout_ms = cpu_to_be32(o2net_idle_timeout());
1465         o2net_hand->o2net_keepalive_delay_ms = cpu_to_be32(
1466                 o2net_keepalive_delay());
1467         o2net_hand->o2net_reconnect_delay_ms = cpu_to_be32(
1468                 o2net_reconnect_delay());
1469 }
1470 
1471 /* ------------------------------------------------------------ */
1472 
1473 /* called when a connect completes and after a sock is accepted.  the
1474  * rx path will see the response and mark the sc valid */
1475 static void o2net_sc_connect_completed(struct work_struct *work)
1476 {
1477         struct o2net_sock_container *sc =
1478                 container_of(work, struct o2net_sock_container,
1479                              sc_connect_work);
1480 
1481         mlog(ML_MSG, "sc sending handshake with ver %llu id %llx\n",
1482               (unsigned long long)O2NET_PROTOCOL_VERSION,
1483               (unsigned long long)be64_to_cpu(o2net_hand->connector_id));
1484 
1485         o2net_initialize_handshake();
1486         o2net_sendpage(sc, o2net_hand, sizeof(*o2net_hand));
1487         sc_put(sc);
1488 }
1489 
1490 /* this is called as a work_struct func. */
1491 static void o2net_sc_send_keep_req(struct work_struct *work)
1492 {
1493         struct o2net_sock_container *sc =
1494                 container_of(work, struct o2net_sock_container,
1495                              sc_keepalive_work.work);
1496 
1497         o2net_sendpage(sc, o2net_keep_req, sizeof(*o2net_keep_req));
1498         sc_put(sc);
1499 }
1500 
1501 /* socket shutdown does a del_timer_sync against this as it tears down.
1502  * we can't start this timer until we've got to the point in sc buildup
1503  * where shutdown is going to be involved */
1504 static void o2net_idle_timer(struct timer_list *t)
1505 {
1506         struct o2net_sock_container *sc = from_timer(sc, t, sc_idle_timeout);
1507         struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
1508 #ifdef CONFIG_DEBUG_FS
1509         unsigned long msecs = ktime_to_ms(ktime_get()) -
1510                 ktime_to_ms(sc->sc_tv_timer);
1511 #else
1512         unsigned long msecs = o2net_idle_timeout();
1513 #endif
1514 
1515         printk(KERN_NOTICE "o2net: Connection to " SC_NODEF_FMT " has been "
1516                "idle for %lu.%lu secs.\n",
1517                SC_NODEF_ARGS(sc), msecs / 1000, msecs % 1000);
1518 
1519         /* idle timerout happen, don't shutdown the connection, but
1520          * make fence decision. Maybe the connection can recover before
1521          * the decision is made.
1522          */
1523         atomic_set(&nn->nn_timeout, 1);
1524         o2quo_conn_err(o2net_num_from_nn(nn));
1525         queue_delayed_work(o2net_wq, &nn->nn_still_up,
1526                         msecs_to_jiffies(O2NET_QUORUM_DELAY_MS));
1527 
1528         o2net_sc_reset_idle_timer(sc);
1529 
1530 }
1531 
1532 static void o2net_sc_reset_idle_timer(struct o2net_sock_container *sc)
1533 {
1534         o2net_sc_cancel_delayed_work(sc, &sc->sc_keepalive_work);
1535         o2net_sc_queue_delayed_work(sc, &sc->sc_keepalive_work,
1536                       msecs_to_jiffies(o2net_keepalive_delay()));
1537         o2net_set_sock_timer(sc);
1538         mod_timer(&sc->sc_idle_timeout,
1539                jiffies + msecs_to_jiffies(o2net_idle_timeout()));
1540 }
1541 
1542 static void o2net_sc_postpone_idle(struct o2net_sock_container *sc)
1543 {
1544         struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
1545 
1546         /* clear fence decision since the connection recover from timeout*/
1547         if (atomic_read(&nn->nn_timeout)) {
1548                 o2quo_conn_up(o2net_num_from_nn(nn));
1549                 cancel_delayed_work(&nn->nn_still_up);
1550                 atomic_set(&nn->nn_timeout, 0);
1551         }
1552 
1553         /* Only push out an existing timer */
1554         if (timer_pending(&sc->sc_idle_timeout))
1555                 o2net_sc_reset_idle_timer(sc);
1556 }
1557 
1558 /* this work func is kicked whenever a path sets the nn state which doesn't
1559  * have valid set.  This includes seeing hb come up, losing a connection,
1560  * having a connect attempt fail, etc. This centralizes the logic which decides
1561  * if a connect attempt should be made or if we should give up and all future
1562  * transmit attempts should fail */
1563 static void o2net_start_connect(struct work_struct *work)
1564 {
1565         struct o2net_node *nn =
1566                 container_of(work, struct o2net_node, nn_connect_work.work);
1567         struct o2net_sock_container *sc = NULL;
1568         struct o2nm_node *node = NULL, *mynode = NULL;
1569         struct socket *sock = NULL;
1570         struct sockaddr_in myaddr = {0, }, remoteaddr = {0, };
1571         int ret = 0, stop;
1572         unsigned int timeout;
1573         unsigned int noio_flag;
1574 
1575         /*
1576          * sock_create allocates the sock with GFP_KERNEL. We must set
1577          * per-process flag PF_MEMALLOC_NOIO so that all allocations done
1578          * by this process are done as if GFP_NOIO was specified. So we
1579          * are not reentering filesystem while doing memory reclaim.
1580          */
1581         noio_flag = memalloc_noio_save();
1582         /* if we're greater we initiate tx, otherwise we accept */
1583         if (o2nm_this_node() <= o2net_num_from_nn(nn))
1584                 goto out;
1585 
1586         /* watch for racing with tearing a node down */
1587         node = o2nm_get_node_by_num(o2net_num_from_nn(nn));
1588         if (node == NULL)
1589                 goto out;
1590 
1591         mynode = o2nm_get_node_by_num(o2nm_this_node());
1592         if (mynode == NULL)
1593                 goto out;
1594 
1595         spin_lock(&nn->nn_lock);
1596         /*
1597          * see if we already have one pending or have given up.
1598          * For nn_timeout, it is set when we close the connection
1599          * because of the idle time out. So it means that we have
1600          * at least connected to that node successfully once,
1601          * now try to connect to it again.
1602          */
1603         timeout = atomic_read(&nn->nn_timeout);
1604         stop = (nn->nn_sc ||
1605                 (nn->nn_persistent_error &&
1606                 (nn->nn_persistent_error != -ENOTCONN || timeout == 0)));
1607         spin_unlock(&nn->nn_lock);
1608         if (stop)
1609                 goto out;
1610 
1611         nn->nn_last_connect_attempt = jiffies;
1612 
1613         sc = sc_alloc(node);
1614         if (sc == NULL) {
1615                 mlog(0, "couldn't allocate sc\n");
1616                 ret = -ENOMEM;
1617                 goto out;
1618         }
1619 
1620         ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
1621         if (ret < 0) {
1622                 mlog(0, "can't create socket: %d\n", ret);
1623                 goto out;
1624         }
1625         sc->sc_sock = sock; /* freed by sc_kref_release */
1626 
1627         sock->sk->sk_allocation = GFP_ATOMIC;
1628 
1629         myaddr.sin_family = AF_INET;
1630         myaddr.sin_addr.s_addr = mynode->nd_ipv4_address;
1631         myaddr.sin_port = htons(0); /* any port */
1632 
1633         ret = sock->ops->bind(sock, (struct sockaddr *)&myaddr,
1634                               sizeof(myaddr));
1635         if (ret) {
1636                 mlog(ML_ERROR, "bind failed with %d at address %pI4\n",
1637                      ret, &mynode->nd_ipv4_address);
1638                 goto out;
1639         }
1640 
1641         ret = o2net_set_nodelay(sc->sc_sock);
1642         if (ret) {
1643                 mlog(ML_ERROR, "setting TCP_NODELAY failed with %d\n", ret);
1644                 goto out;
1645         }
1646 
1647         ret = o2net_set_usertimeout(sock);
1648         if (ret) {
1649                 mlog(ML_ERROR, "set TCP_USER_TIMEOUT failed with %d\n", ret);
1650                 goto out;
1651         }
1652 
1653         o2net_register_callbacks(sc->sc_sock->sk, sc);
1654 
1655         spin_lock(&nn->nn_lock);
1656         /* handshake completion will set nn->nn_sc_valid */
1657         o2net_set_nn_state(nn, sc, 0, 0);
1658         spin_unlock(&nn->nn_lock);
1659 
1660         remoteaddr.sin_family = AF_INET;
1661         remoteaddr.sin_addr.s_addr = node->nd_ipv4_address;
1662         remoteaddr.sin_port = node->nd_ipv4_port;
1663 
1664         ret = sc->sc_sock->ops->connect(sc->sc_sock,
1665                                         (struct sockaddr *)&remoteaddr,
1666                                         sizeof(remoteaddr),
1667                                         O_NONBLOCK);
1668         if (ret == -EINPROGRESS)
1669                 ret = 0;
1670 
1671 out:
1672         if (ret && sc) {
1673                 printk(KERN_NOTICE "o2net: Connect attempt to " SC_NODEF_FMT
1674                        " failed with errno %d\n", SC_NODEF_ARGS(sc), ret);
1675                 /* 0 err so that another will be queued and attempted
1676                  * from set_nn_state */
1677                 o2net_ensure_shutdown(nn, sc, 0);
1678         }
1679         if (sc)
1680                 sc_put(sc);
1681         if (node)
1682                 o2nm_node_put(node);
1683         if (mynode)
1684                 o2nm_node_put(mynode);
1685 
1686         memalloc_noio_restore(noio_flag);
1687         return;
1688 }
1689 
1690 static void o2net_connect_expired(struct work_struct *work)
1691 {
1692         struct o2net_node *nn =
1693                 container_of(work, struct o2net_node, nn_connect_expired.work);
1694 
1695         spin_lock(&nn->nn_lock);
1696         if (!nn->nn_sc_valid) {
1697                 printk(KERN_NOTICE "o2net: No connection established with "
1698                        "node %u after %u.%u seconds, check network and"
1699                        " cluster configuration.\n",
1700                      o2net_num_from_nn(nn),
1701                      o2net_idle_timeout() / 1000,
1702                      o2net_idle_timeout() % 1000);
1703 
1704                 o2net_set_nn_state(nn, NULL, 0, 0);
1705         }
1706         spin_unlock(&nn->nn_lock);
1707 }
1708 
1709 static void o2net_still_up(struct work_struct *work)
1710 {
1711         struct o2net_node *nn =
1712                 container_of(work, struct o2net_node, nn_still_up.work);
1713 
1714         o2quo_hb_still_up(o2net_num_from_nn(nn));
1715 }
1716 
1717 /* ------------------------------------------------------------ */
1718 
1719 void o2net_disconnect_node(struct o2nm_node *node)
1720 {
1721         struct o2net_node *nn = o2net_nn_from_num(node->nd_num);
1722 
1723         /* don't reconnect until it's heartbeating again */
1724         spin_lock(&nn->nn_lock);
1725         atomic_set(&nn->nn_timeout, 0);
1726         o2net_set_nn_state(nn, NULL, 0, -ENOTCONN);
1727         spin_unlock(&nn->nn_lock);
1728 
1729         if (o2net_wq) {
1730                 cancel_delayed_work(&nn->nn_connect_expired);
1731                 cancel_delayed_work(&nn->nn_connect_work);
1732                 cancel_delayed_work(&nn->nn_still_up);
1733                 flush_workqueue(o2net_wq);
1734         }
1735 }
1736 
1737 static void o2net_hb_node_down_cb(struct o2nm_node *node, int node_num,
1738                                   void *data)
1739 {
1740         o2quo_hb_down(node_num);
1741 
1742         if (!node)
1743                 return;
1744 
1745         if (node_num != o2nm_this_node())
1746                 o2net_disconnect_node(node);
1747 
1748         BUG_ON(atomic_read(&o2net_connected_peers) < 0);
1749 }
1750 
1751 static void o2net_hb_node_up_cb(struct o2nm_node *node, int node_num,
1752                                 void *data)
1753 {
1754         struct o2net_node *nn = o2net_nn_from_num(node_num);
1755 
1756         o2quo_hb_up(node_num);
1757 
1758         BUG_ON(!node);
1759 
1760         /* ensure an immediate connect attempt */
1761         nn->nn_last_connect_attempt = jiffies -
1762                 (msecs_to_jiffies(o2net_reconnect_delay()) + 1);
1763 
1764         if (node_num != o2nm_this_node()) {
1765                 /* believe it or not, accept and node heartbeating testing
1766                  * can succeed for this node before we got here.. so
1767                  * only use set_nn_state to clear the persistent error
1768                  * if that hasn't already happened */
1769                 spin_lock(&nn->nn_lock);
1770                 atomic_set(&nn->nn_timeout, 0);
1771                 if (nn->nn_persistent_error)
1772                         o2net_set_nn_state(nn, NULL, 0, 0);
1773                 spin_unlock(&nn->nn_lock);
1774         }
1775 }
1776 
1777 void o2net_unregister_hb_callbacks(void)
1778 {
1779         o2hb_unregister_callback(NULL, &o2net_hb_up);
1780         o2hb_unregister_callback(NULL, &o2net_hb_down);
1781 }
1782 
1783 int o2net_register_hb_callbacks(void)
1784 {
1785         int ret;
1786 
1787         o2hb_setup_callback(&o2net_hb_down, O2HB_NODE_DOWN_CB,
1788                             o2net_hb_node_down_cb, NULL, O2NET_HB_PRI);
1789         o2hb_setup_callback(&o2net_hb_up, O2HB_NODE_UP_CB,
1790                             o2net_hb_node_up_cb, NULL, O2NET_HB_PRI);
1791 
1792         ret = o2hb_register_callback(NULL, &o2net_hb_up);
1793         if (ret == 0)
1794                 ret = o2hb_register_callback(NULL, &o2net_hb_down);
1795 
1796         if (ret)
1797                 o2net_unregister_hb_callbacks();
1798 
1799         return ret;
1800 }
1801 
1802 /* ------------------------------------------------------------ */
1803 
1804 static int o2net_accept_one(struct socket *sock, int *more)
1805 {
1806         int ret;
1807         struct sockaddr_in sin;
1808         struct socket *new_sock = NULL;
1809         struct o2nm_node *node = NULL;
1810         struct o2nm_node *local_node = NULL;
1811         struct o2net_sock_container *sc = NULL;
1812         struct o2net_node *nn;
1813         unsigned int noio_flag;
1814 
1815         /*
1816          * sock_create_lite allocates the sock with GFP_KERNEL. We must set
1817          * per-process flag PF_MEMALLOC_NOIO so that all allocations done
1818          * by this process are done as if GFP_NOIO was specified. So we
1819          * are not reentering filesystem while doing memory reclaim.
1820          */
1821         noio_flag = memalloc_noio_save();
1822 
1823         BUG_ON(sock == NULL);
1824         *more = 0;
1825         ret = sock_create_lite(sock->sk->sk_family, sock->sk->sk_type,
1826                                sock->sk->sk_protocol, &new_sock);
1827         if (ret)
1828                 goto out;
1829 
1830         new_sock->type = sock->type;
1831         new_sock->ops = sock->ops;
1832         ret = sock->ops->accept(sock, new_sock, O_NONBLOCK, false);
1833         if (ret < 0)
1834                 goto out;
1835 
1836         *more = 1;
1837         new_sock->sk->sk_allocation = GFP_ATOMIC;
1838 
1839         ret = o2net_set_nodelay(new_sock);
1840         if (ret) {
1841                 mlog(ML_ERROR, "setting TCP_NODELAY failed with %d\n", ret);
1842                 goto out;
1843         }
1844 
1845         ret = o2net_set_usertimeout(new_sock);
1846         if (ret) {
1847                 mlog(ML_ERROR, "set TCP_USER_TIMEOUT failed with %d\n", ret);
1848                 goto out;
1849         }
1850 
1851         ret = new_sock->ops->getname(new_sock, (struct sockaddr *) &sin, 1);
1852         if (ret < 0)
1853                 goto out;
1854 
1855         node = o2nm_get_node_by_ip(sin.sin_addr.s_addr);
1856         if (node == NULL) {
1857                 printk(KERN_NOTICE "o2net: Attempt to connect from unknown "
1858                        "node at %pI4:%d\n", &sin.sin_addr.s_addr,
1859                        ntohs(sin.sin_port));
1860                 ret = -EINVAL;
1861                 goto out;
1862         }
1863 
1864         if (o2nm_this_node() >= node->nd_num) {
1865                 local_node = o2nm_get_node_by_num(o2nm_this_node());
1866                 if (local_node)
1867                         printk(KERN_NOTICE "o2net: Unexpected connect attempt "
1868                                         "seen at node '%s' (%u, %pI4:%d) from "
1869                                         "node '%s' (%u, %pI4:%d)\n",
1870                                         local_node->nd_name, local_node->nd_num,
1871                                         &(local_node->nd_ipv4_address),
1872                                         ntohs(local_node->nd_ipv4_port),
1873                                         node->nd_name,
1874                                         node->nd_num, &sin.sin_addr.s_addr,
1875                                         ntohs(sin.sin_port));
1876                 ret = -EINVAL;
1877                 goto out;
1878         }
1879 
1880         /* this happens all the time when the other node sees our heartbeat
1881          * and tries to connect before we see their heartbeat */
1882         if (!o2hb_check_node_heartbeating_from_callback(node->nd_num)) {
1883                 mlog(ML_CONN, "attempt to connect from node '%s' at "
1884                      "%pI4:%d but it isn't heartbeating\n",
1885                      node->nd_name, &sin.sin_addr.s_addr,
1886                      ntohs(sin.sin_port));
1887                 ret = -EINVAL;
1888                 goto out;
1889         }
1890 
1891         nn = o2net_nn_from_num(node->nd_num);
1892 
1893         spin_lock(&nn->nn_lock);
1894         if (nn->nn_sc)
1895                 ret = -EBUSY;
1896         else
1897                 ret = 0;
1898         spin_unlock(&nn->nn_lock);
1899         if (ret) {
1900                 printk(KERN_NOTICE "o2net: Attempt to connect from node '%s' "
1901                        "at %pI4:%d but it already has an open connection\n",
1902                        node->nd_name, &sin.sin_addr.s_addr,
1903                        ntohs(sin.sin_port));
1904                 goto out;
1905         }
1906 
1907         sc = sc_alloc(node);
1908         if (sc == NULL) {
1909                 ret = -ENOMEM;
1910                 goto out;
1911         }
1912 
1913         sc->sc_sock = new_sock;
1914         new_sock = NULL;
1915 
1916         spin_lock(&nn->nn_lock);
1917         atomic_set(&nn->nn_timeout, 0);
1918         o2net_set_nn_state(nn, sc, 0, 0);
1919         spin_unlock(&nn->nn_lock);
1920 
1921         o2net_register_callbacks(sc->sc_sock->sk, sc);
1922         o2net_sc_queue_work(sc, &sc->sc_rx_work);
1923 
1924         o2net_initialize_handshake();
1925         o2net_sendpage(sc, o2net_hand, sizeof(*o2net_hand));
1926 
1927 out:
1928         if (new_sock)
1929                 sock_release(new_sock);
1930         if (node)
1931                 o2nm_node_put(node);
1932         if (local_node)
1933                 o2nm_node_put(local_node);
1934         if (sc)
1935                 sc_put(sc);
1936 
1937         memalloc_noio_restore(noio_flag);
1938         return ret;
1939 }
1940 
1941 /*
1942  * This function is invoked in response to one or more
1943  * pending accepts at softIRQ level. We must drain the
1944  * entire que before returning.
1945  */
1946 
1947 static void o2net_accept_many(struct work_struct *work)
1948 {
1949         struct socket *sock = o2net_listen_sock;
1950         int     more;
1951         int     err;
1952 
1953         /*
1954          * It is critical to note that due to interrupt moderation
1955          * at the network driver level, we can't assume to get a
1956          * softIRQ for every single conn since tcp SYN packets
1957          * can arrive back-to-back, and therefore many pending
1958          * accepts may result in just 1 softIRQ. If we terminate
1959          * the o2net_accept_one() loop upon seeing an err, what happens
1960          * to the rest of the conns in the queue? If no new SYN
1961          * arrives for hours, no softIRQ  will be delivered,
1962          * and the connections will just sit in the queue.
1963          */
1964 
1965         for (;;) {
1966                 err = o2net_accept_one(sock, &more);
1967                 if (!more)
1968                         break;
1969                 cond_resched();
1970         }
1971 }
1972 
1973 static void o2net_listen_data_ready(struct sock *sk)
1974 {
1975         void (*ready)(struct sock *sk);
1976 
1977         read_lock_bh(&sk->sk_callback_lock);
1978         ready = sk->sk_user_data;
1979         if (ready == NULL) { /* check for teardown race */
1980                 ready = sk->sk_data_ready;
1981                 goto out;
1982         }
1983 
1984         /* This callback may called twice when a new connection
1985          * is  being established as a child socket inherits everything
1986          * from a parent LISTEN socket, including the data_ready cb of
1987          * the parent. This leads to a hazard. In o2net_accept_one()
1988          * we are still initializing the child socket but have not
1989          * changed the inherited data_ready callback yet when
1990          * data starts arriving.
1991          * We avoid this hazard by checking the state.
1992          * For the listening socket,  the state will be TCP_LISTEN; for the new
1993          * socket, will be  TCP_ESTABLISHED. Also, in this case,
1994          * sk->sk_user_data is not a valid function pointer.
1995          */
1996 
1997         if (sk->sk_state == TCP_LISTEN) {
1998                 queue_work(o2net_wq, &o2net_listen_work);
1999         } else {
2000                 ready = NULL;
2001         }
2002 
2003 out:
2004         read_unlock_bh(&sk->sk_callback_lock);
2005         if (ready != NULL)
2006                 ready(sk);
2007 }
2008 
2009 static int o2net_open_listening_sock(__be32 addr, __be16 port)
2010 {
2011         struct socket *sock = NULL;
2012         int ret;
2013         struct sockaddr_in sin = {
2014                 .sin_family = PF_INET,
2015                 .sin_addr = { .s_addr = addr },
2016                 .sin_port = port,
2017         };
2018 
2019         ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
2020         if (ret < 0) {
2021                 printk(KERN_ERR "o2net: Error %d while creating socket\n", ret);
2022                 goto out;
2023         }
2024 
2025         sock->sk->sk_allocation = GFP_ATOMIC;
2026 
2027         write_lock_bh(&sock->sk->sk_callback_lock);
2028         sock->sk->sk_user_data = sock->sk->sk_data_ready;
2029         sock->sk->sk_data_ready = o2net_listen_data_ready;
2030         write_unlock_bh(&sock->sk->sk_callback_lock);
2031 
2032         o2net_listen_sock = sock;
2033         INIT_WORK(&o2net_listen_work, o2net_accept_many);
2034 
2035         sock->sk->sk_reuse = SK_CAN_REUSE;
2036         ret = sock->ops->bind(sock, (struct sockaddr *)&sin, sizeof(sin));
2037         if (ret < 0) {
2038                 printk(KERN_ERR "o2net: Error %d while binding socket at "
2039                        "%pI4:%u\n", ret, &addr, ntohs(port)); 
2040                 goto out;
2041         }
2042 
2043         ret = sock->ops->listen(sock, 64);
2044         if (ret < 0)
2045                 printk(KERN_ERR "o2net: Error %d while listening on %pI4:%u\n",
2046                        ret, &addr, ntohs(port));
2047 
2048 out:
2049         if (ret) {
2050                 o2net_listen_sock = NULL;
2051                 if (sock)
2052                         sock_release(sock);
2053         }
2054         return ret;
2055 }
2056 
2057 /*
2058  * called from node manager when we should bring up our network listening
2059  * socket.  node manager handles all the serialization to only call this
2060  * once and to match it with o2net_stop_listening().  note,
2061  * o2nm_this_node() doesn't work yet as we're being called while it
2062  * is being set up.
2063  */
2064 int o2net_start_listening(struct o2nm_node *node)
2065 {
2066         int ret = 0;
2067 
2068         BUG_ON(o2net_wq != NULL);
2069         BUG_ON(o2net_listen_sock != NULL);
2070 
2071         mlog(ML_KTHREAD, "starting o2net thread...\n");
2072         o2net_wq = alloc_ordered_workqueue("o2net", WQ_MEM_RECLAIM);
2073         if (o2net_wq == NULL) {
2074                 mlog(ML_ERROR, "unable to launch o2net thread\n");
2075                 return -ENOMEM; /* ? */
2076         }
2077 
2078         ret = o2net_open_listening_sock(node->nd_ipv4_address,
2079                                         node->nd_ipv4_port);
2080         if (ret) {
2081                 destroy_workqueue(o2net_wq);
2082                 o2net_wq = NULL;
2083         } else
2084                 o2quo_conn_up(node->nd_num);
2085 
2086         return ret;
2087 }
2088 
2089 /* again, o2nm_this_node() doesn't work here as we're involved in
2090  * tearing it down */
2091 void o2net_stop_listening(struct o2nm_node *node)
2092 {
2093         struct socket *sock = o2net_listen_sock;
2094         size_t i;
2095 
2096         BUG_ON(o2net_wq == NULL);
2097         BUG_ON(o2net_listen_sock == NULL);
2098 
2099         /* stop the listening socket from generating work */
2100         write_lock_bh(&sock->sk->sk_callback_lock);
2101         sock->sk->sk_data_ready = sock->sk->sk_user_data;
2102         sock->sk->sk_user_data = NULL;
2103         write_unlock_bh(&sock->sk->sk_callback_lock);
2104 
2105         for (i = 0; i < ARRAY_SIZE(o2net_nodes); i++) {
2106                 struct o2nm_node *node = o2nm_get_node_by_num(i);
2107                 if (node) {
2108                         o2net_disconnect_node(node);
2109                         o2nm_node_put(node);
2110                 }
2111         }
2112 
2113         /* finish all work and tear down the work queue */
2114         mlog(ML_KTHREAD, "waiting for o2net thread to exit....\n");
2115         destroy_workqueue(o2net_wq);
2116         o2net_wq = NULL;
2117 
2118         sock_release(o2net_listen_sock);
2119         o2net_listen_sock = NULL;
2120 
2121         o2quo_conn_err(node->nd_num);
2122 }
2123 
2124 /* ------------------------------------------------------------ */
2125 
2126 int o2net_init(void)
2127 {
2128         unsigned long i;
2129 
2130         o2quo_init();
2131 
2132         o2net_debugfs_init();
2133 
2134         o2net_hand = kzalloc(sizeof(struct o2net_handshake), GFP_KERNEL);
2135         o2net_keep_req = kzalloc(sizeof(struct o2net_msg), GFP_KERNEL);
2136         o2net_keep_resp = kzalloc(sizeof(struct o2net_msg), GFP_KERNEL);
2137         if (!o2net_hand || !o2net_keep_req || !o2net_keep_resp)
2138                 goto out;
2139 
2140         o2net_hand->protocol_version = cpu_to_be64(O2NET_PROTOCOL_VERSION);
2141         o2net_hand->connector_id = cpu_to_be64(1);
2142 
2143         o2net_keep_req->magic = cpu_to_be16(O2NET_MSG_KEEP_REQ_MAGIC);
2144         o2net_keep_resp->magic = cpu_to_be16(O2NET_MSG_KEEP_RESP_MAGIC);
2145 
2146         for (i = 0; i < ARRAY_SIZE(o2net_nodes); i++) {
2147                 struct o2net_node *nn = o2net_nn_from_num(i);
2148 
2149                 atomic_set(&nn->nn_timeout, 0);
2150                 spin_lock_init(&nn->nn_lock);
2151                 INIT_DELAYED_WORK(&nn->nn_connect_work, o2net_start_connect);
2152                 INIT_DELAYED_WORK(&nn->nn_connect_expired,
2153                                   o2net_connect_expired);
2154                 INIT_DELAYED_WORK(&nn->nn_still_up, o2net_still_up);
2155                 /* until we see hb from a node we'll return einval */
2156                 nn->nn_persistent_error = -ENOTCONN;
2157                 init_waitqueue_head(&nn->nn_sc_wq);
2158                 idr_init(&nn->nn_status_idr);
2159                 INIT_LIST_HEAD(&nn->nn_status_list);
2160         }
2161 
2162         return 0;
2163 
2164 out:
2165         kfree(o2net_hand);
2166         kfree(o2net_keep_req);
2167         kfree(o2net_keep_resp);
2168         o2net_debugfs_exit();
2169         o2quo_exit();
2170         return -ENOMEM;
2171 }
2172 
2173 void o2net_exit(void)
2174 {
2175         o2quo_exit();
2176         kfree(o2net_hand);
2177         kfree(o2net_keep_req);
2178         kfree(o2net_keep_resp);
2179         o2net_debugfs_exit();
2180 }
/* [<][>][^][v][top][bottom][index][help] */
root/fs/ocfs2/cluster/tcp.c

DEFINITIONS
