1/* -*- mode: c; c-basic-offset: 8; -*-
   2 *
   3 * vim: noexpandtab sw=8 ts=8 sts=0:
   4 *
   5 * Copyright (C) 2004 Oracle.  All rights reserved.
   6 *
   7 * This program is free software; you can redistribute it and/or
   8 * modify it under the terms of the GNU General Public
   9 * License as published by the Free Software Foundation; either
  10 * version 2 of the License, or (at your option) any later version.
  11 *
  12 * This program is distributed in the hope that it will be useful,
  13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 * General Public License for more details.
  16 *
  17 * You should have received a copy of the GNU General Public
  18 * License along with this program; if not, write to the
  19 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  20 * Boston, MA 021110-1307, USA.
  21 *
  22 * ----
  23 *
  24 * Callers for this were originally written against a very simple synchronus
  25 * API.  This implementation reflects those simple callers.  Some day I'm sure
  26 * we'll need to move to a more robust posting/callback mechanism.
  27 *
  28 * Transmit calls pass in kernel virtual addresses and block copying this into
  29 * the socket's tx buffers via a usual blocking sendmsg.  They'll block waiting
  30 * for a failed socket to timeout.  TX callers can also pass in a poniter to an
  31 * 'int' which gets filled with an errno off the wire in response to the
  32 * message they send.
  33 *
  34 * Handlers for unsolicited messages are registered.  Each socket has a page
  35 * that incoming data is copied into.  First the header, then the data.
  36 * Handlers are called from only one thread with a reference to this per-socket
  37 * page.  This page is destroyed after the handler call, so it can't be
  38 * referenced beyond the call.  Handlers may block but are discouraged from
  39 * doing so.
  40 *
  41 * Any framing errors (bad magic, large payload lengths) close a connection.
  42 *
  43 * Our sock_container holds the state we associate with a socket.  It's current
  44 * framing state is held there as well as the refcounting we do around when it
  45 * is safe to tear down the socket.  The socket is only finally torn down from
  46 * the container when the container loses all of its references -- so as long
  47 * as you hold a ref on the container you can trust that the socket is valid
  48 * for use with kernel socket APIs.
  49 *
  50 * Connections are initiated between a pair of nodes when the node with the
  51 * higher node number gets a heartbeat callback which indicates that the lower
  52 * numbered node has started heartbeating.  The lower numbered node is passive
  53 * and only accepts the connection if the higher numbered node is heartbeating.
  54 */
  55
  56#include <linux/kernel.h>
  57#include <linux/sched/mm.h>
  58#include <linux/jiffies.h>
  59#include <linux/slab.h>
  60#include <linux/idr.h>
  61#include <linux/kref.h>
  62#include <linux/net.h>
  63#include <linux/export.h>
  64#include <net/tcp.h>
  65
  66#include <linux/uaccess.h>
  67
  68#include "heartbeat.h"
  69#include "tcp.h"
  70#include "nodemanager.h"
  71#define MLOG_MASK_PREFIX ML_TCP
  72#include "masklog.h"
  73#include "quorum.h"
  74
  75#include "tcp_internal.h"
  76
  77#define SC_NODEF_FMT "node %s (num %u) at %pI4:%u"
  78#define SC_NODEF_ARGS(sc) sc->sc_node->nd_name, sc->sc_node->nd_num,	\
  79			  &sc->sc_node->nd_ipv4_address,		\
  80			  ntohs(sc->sc_node->nd_ipv4_port)
  81
  82/*
  83 * In the following two log macros, the whitespace after the ',' just
  84 * before ##args is intentional. Otherwise, gcc 2.95 will eat the
  85 * previous token if args expands to nothing.
  86 */
  87#define msglog(hdr, fmt, args...) do {					\
  88	typeof(hdr) __hdr = (hdr);					\
  89	mlog(ML_MSG, "[mag %u len %u typ %u stat %d sys_stat %d "	\
  90	     "key %08x num %u] " fmt,					\
  91	     be16_to_cpu(__hdr->magic), be16_to_cpu(__hdr->data_len), 	\
  92	     be16_to_cpu(__hdr->msg_type), be32_to_cpu(__hdr->status),	\
  93	     be32_to_cpu(__hdr->sys_status), be32_to_cpu(__hdr->key),	\
  94	     be32_to_cpu(__hdr->msg_num) ,  ##args);			\
  95} while (0)
  96
  97#define sclog(sc, fmt, args...) do {					\
  98	typeof(sc) __sc = (sc);						\
  99	mlog(ML_SOCKET, "[sc %p refs %d sock %p node %u page %p "	\
 100	     "pg_off %zu] " fmt, __sc,					\
 101	     kref_read(&__sc->sc_kref), __sc->sc_sock,	\
 102	    __sc->sc_node->nd_num, __sc->sc_page, __sc->sc_page_off ,	\
 103	    ##args);							\
 104} while (0)
 105
 106static DEFINE_RWLOCK(o2net_handler_lock);
 107static struct rb_root o2net_handler_tree = RB_ROOT;
 108
 109static struct o2net_node o2net_nodes[O2NM_MAX_NODES];
 110
 111/* XXX someday we'll need better accounting */
 112static struct socket *o2net_listen_sock;
 113
 114/*
 115 * listen work is only queued by the listening socket callbacks on the
 116 * o2net_wq.  teardown detaches the callbacks before destroying the workqueue.
 117 * quorum work is queued as sock containers are shutdown.. stop_listening
 118 * tears down all the node's sock containers, preventing future shutdowns
 119 * and queued quroum work, before canceling delayed quorum work and
 120 * destroying the work queue.
 121 */
 122static struct workqueue_struct *o2net_wq;
 123static struct work_struct o2net_listen_work;
 124
 125static struct o2hb_callback_func o2net_hb_up, o2net_hb_down;
 126#define O2NET_HB_PRI 0x1
 127
 128static struct o2net_handshake *o2net_hand;
 129static struct o2net_msg *o2net_keep_req, *o2net_keep_resp;
 130
 131static int o2net_sys_err_translations[O2NET_ERR_MAX] =
 132		{[O2NET_ERR_NONE]	= 0,
 133		 [O2NET_ERR_NO_HNDLR]	= -ENOPROTOOPT,
 134		 [O2NET_ERR_OVERFLOW]	= -EOVERFLOW,
 135		 [O2NET_ERR_DIED]	= -EHOSTDOWN,};
 136
 137/* can't quite avoid *all* internal declarations :/ */
 138static void o2net_sc_connect_completed(struct work_struct *work);
 139static void o2net_rx_until_empty(struct work_struct *work);
 140static void o2net_shutdown_sc(struct work_struct *work);
 141static void o2net_listen_data_ready(struct sock *sk);
 142static void o2net_sc_send_keep_req(struct work_struct *work);
 143static void o2net_idle_timer(struct timer_list *t);
 144static void o2net_sc_postpone_idle(struct o2net_sock_container *sc);
 145static void o2net_sc_reset_idle_timer(struct o2net_sock_container *sc);
 146
 147#ifdef CONFIG_DEBUG_FS
 148static void o2net_init_nst(struct o2net_send_tracking *nst, u32 msgtype,
 149			   u32 msgkey, struct task_struct *task, u8 node)
 150{
 151	INIT_LIST_HEAD(&nst->st_net_debug_item);
 152	nst->st_task = task;
 153	nst->st_msg_type = msgtype;
 154	nst->st_msg_key = msgkey;
 155	nst->st_node = node;
 156}
 157
 158static inline void o2net_set_nst_sock_time(struct o2net_send_tracking *nst)
 159{
 160	nst->st_sock_time = ktime_get();
 161}
 162
 163static inline void o2net_set_nst_send_time(struct o2net_send_tracking *nst)
 164{
 165	nst->st_send_time = ktime_get();
 166}
 167
 168static inline void o2net_set_nst_status_time(struct o2net_send_tracking *nst)
 169{
 170	nst->st_status_time = ktime_get();
 171}
 172
 173static inline void o2net_set_nst_sock_container(struct o2net_send_tracking *nst,
 174						struct o2net_sock_container *sc)
 175{
 176	nst->st_sc = sc;
 177}
 178
 179static inline void o2net_set_nst_msg_id(struct o2net_send_tracking *nst,
 180					u32 msg_id)
 181{
 182	nst->st_id = msg_id;
 183}
 184
 185static inline void o2net_set_sock_timer(struct o2net_sock_container *sc)
 186{
 187	sc->sc_tv_timer = ktime_get();
 188}
 189
 190static inline void o2net_set_data_ready_time(struct o2net_sock_container *sc)
 191{
 192	sc->sc_tv_data_ready = ktime_get();
 193}
 194
 195static inline void o2net_set_advance_start_time(struct o2net_sock_container *sc)
 196{
 197	sc->sc_tv_advance_start = ktime_get();
 198}
 199
 200static inline void o2net_set_advance_stop_time(struct o2net_sock_container *sc)
 201{
 202	sc->sc_tv_advance_stop = ktime_get();
 203}
 204
 205static inline void o2net_set_func_start_time(struct o2net_sock_container *sc)
 206{
 207	sc->sc_tv_func_start = ktime_get();
 208}
 209
 210static inline void o2net_set_func_stop_time(struct o2net_sock_container *sc)
 211{
 212	sc->sc_tv_func_stop = ktime_get();
 213}
 214
 215#else  /* CONFIG_DEBUG_FS */
 216# define o2net_init_nst(a, b, c, d, e)
 217# define o2net_set_nst_sock_time(a)
 218# define o2net_set_nst_send_time(a)
 219# define o2net_set_nst_status_time(a)
 220# define o2net_set_nst_sock_container(a, b)
 221# define o2net_set_nst_msg_id(a, b)
 222# define o2net_set_sock_timer(a)
 223# define o2net_set_data_ready_time(a)
 224# define o2net_set_advance_start_time(a)
 225# define o2net_set_advance_stop_time(a)
 226# define o2net_set_func_start_time(a)
 227# define o2net_set_func_stop_time(a)
 228#endif /* CONFIG_DEBUG_FS */
 229
 230#ifdef CONFIG_OCFS2_FS_STATS
 231static ktime_t o2net_get_func_run_time(struct o2net_sock_container *sc)
 232{
 233	return ktime_sub(sc->sc_tv_func_stop, sc->sc_tv_func_start);
 234}
 235
 236static void o2net_update_send_stats(struct o2net_send_tracking *nst,
 237				    struct o2net_sock_container *sc)
 238{
 239	sc->sc_tv_status_total = ktime_add(sc->sc_tv_status_total,
 240					   ktime_sub(ktime_get(),
 241						     nst->st_status_time));
 242	sc->sc_tv_send_total = ktime_add(sc->sc_tv_send_total,
 243					 ktime_sub(nst->st_status_time,
 244						   nst->st_send_time));
 245	sc->sc_tv_acquiry_total = ktime_add(sc->sc_tv_acquiry_total,
 246					    ktime_sub(nst->st_send_time,
 247						      nst->st_sock_time));
 248	sc->sc_send_count++;
 249}
 250
 251static void o2net_update_recv_stats(struct o2net_sock_container *sc)
 252{
 253	sc->sc_tv_process_total = ktime_add(sc->sc_tv_process_total,
 254					    o2net_get_func_run_time(sc));
 255	sc->sc_recv_count++;
 256}
 257
 258#else
 259
 260# define o2net_update_send_stats(a, b)
 261
 262# define o2net_update_recv_stats(sc)
 263
 264#endif /* CONFIG_OCFS2_FS_STATS */
 265
 266static inline unsigned int o2net_reconnect_delay(void)
 267{
 268	return o2nm_single_cluster->cl_reconnect_delay_ms;
 269}
 270
 271static inline unsigned int o2net_keepalive_delay(void)
 272{
 273	return o2nm_single_cluster->cl_keepalive_delay_ms;
 274}
 275
 276static inline unsigned int o2net_idle_timeout(void)
 277{
 278	return o2nm_single_cluster->cl_idle_timeout_ms;
 279}
 280
 281static inline int o2net_sys_err_to_errno(enum o2net_system_error err)
 282{
 283	int trans;
 284	BUG_ON(err >= O2NET_ERR_MAX);
 285	trans = o2net_sys_err_translations[err];
 286
 287	/* Just in case we mess up the translation table above */
 288	BUG_ON(err != O2NET_ERR_NONE && trans == 0);
 289	return trans;
 290}
 291
 292static struct o2net_node * o2net_nn_from_num(u8 node_num)
 293{
 294	BUG_ON(node_num >= ARRAY_SIZE(o2net_nodes));
 295	return &o2net_nodes[node_num];
 296}
 297
 298static u8 o2net_num_from_nn(struct o2net_node *nn)
 299{
 300	BUG_ON(nn == NULL);
 301	return nn - o2net_nodes;
 302}
 303
 304/* ------------------------------------------------------------ */
 305
 306static int o2net_prep_nsw(struct o2net_node *nn, struct o2net_status_wait *nsw)
 307{
 308	int ret;
 309
 310	spin_lock(&nn->nn_lock);
 311	ret = idr_alloc(&nn->nn_status_idr, nsw, 0, 0, GFP_ATOMIC);
 312	if (ret >= 0) {
 313		nsw->ns_id = ret;
 314		list_add_tail(&nsw->ns_node_item, &nn->nn_status_list);
 
 
 
 
 
 
 
 
 
 
 
 
 315	}
 316	spin_unlock(&nn->nn_lock);
 317	if (ret < 0)
 318		return ret;
 319
 320	init_waitqueue_head(&nsw->ns_wq);
 321	nsw->ns_sys_status = O2NET_ERR_NONE;
 322	nsw->ns_status = 0;
 323	return 0;
 324}
 325
 326static void o2net_complete_nsw_locked(struct o2net_node *nn,
 327				      struct o2net_status_wait *nsw,
 328				      enum o2net_system_error sys_status,
 329				      s32 status)
 330{
 331	assert_spin_locked(&nn->nn_lock);
 332
 333	if (!list_empty(&nsw->ns_node_item)) {
 334		list_del_init(&nsw->ns_node_item);
 335		nsw->ns_sys_status = sys_status;
 336		nsw->ns_status = status;
 337		idr_remove(&nn->nn_status_idr, nsw->ns_id);
 338		wake_up(&nsw->ns_wq);
 339	}
 340}
 341
 342static void o2net_complete_nsw(struct o2net_node *nn,
 343			       struct o2net_status_wait *nsw,
 344			       u64 id, enum o2net_system_error sys_status,
 345			       s32 status)
 346{
 347	spin_lock(&nn->nn_lock);
 348	if (nsw == NULL) {
 349		if (id > INT_MAX)
 350			goto out;
 351
 352		nsw = idr_find(&nn->nn_status_idr, id);
 353		if (nsw == NULL)
 354			goto out;
 355	}
 356
 357	o2net_complete_nsw_locked(nn, nsw, sys_status, status);
 358
 359out:
 360	spin_unlock(&nn->nn_lock);
 361	return;
 362}
 363
 364static void o2net_complete_nodes_nsw(struct o2net_node *nn)
 365{
 366	struct o2net_status_wait *nsw, *tmp;
 367	unsigned int num_kills = 0;
 368
 369	assert_spin_locked(&nn->nn_lock);
 370
 371	list_for_each_entry_safe(nsw, tmp, &nn->nn_status_list, ns_node_item) {
 372		o2net_complete_nsw_locked(nn, nsw, O2NET_ERR_DIED, 0);
 373		num_kills++;
 374	}
 375
 376	mlog(0, "completed %d messages for node %u\n", num_kills,
 377	     o2net_num_from_nn(nn));
 378}
 379
 380static int o2net_nsw_completed(struct o2net_node *nn,
 381			       struct o2net_status_wait *nsw)
 382{
 383	int completed;
 384	spin_lock(&nn->nn_lock);
 385	completed = list_empty(&nsw->ns_node_item);
 386	spin_unlock(&nn->nn_lock);
 387	return completed;
 388}
 389
 390/* ------------------------------------------------------------ */
 391
 392static void sc_kref_release(struct kref *kref)
 393{
 394	struct o2net_sock_container *sc = container_of(kref,
 395					struct o2net_sock_container, sc_kref);
 396	BUG_ON(timer_pending(&sc->sc_idle_timeout));
 397
 398	sclog(sc, "releasing\n");
 399
 400	if (sc->sc_sock) {
 401		sock_release(sc->sc_sock);
 402		sc->sc_sock = NULL;
 403	}
 404
 405	o2nm_undepend_item(&sc->sc_node->nd_item);
 406	o2nm_node_put(sc->sc_node);
 407	sc->sc_node = NULL;
 408
 409	o2net_debug_del_sc(sc);
 410
 411	if (sc->sc_page)
 412		__free_page(sc->sc_page);
 413	kfree(sc);
 414}
 415
 416static void sc_put(struct o2net_sock_container *sc)
 417{
 418	sclog(sc, "put\n");
 419	kref_put(&sc->sc_kref, sc_kref_release);
 420}
 421static void sc_get(struct o2net_sock_container *sc)
 422{
 423	sclog(sc, "get\n");
 424	kref_get(&sc->sc_kref);
 425}
 426static struct o2net_sock_container *sc_alloc(struct o2nm_node *node)
 427{
 428	struct o2net_sock_container *sc, *ret = NULL;
 429	struct page *page = NULL;
 430	int status = 0;
 431
 432	page = alloc_page(GFP_NOFS);
 433	sc = kzalloc(sizeof(*sc), GFP_NOFS);
 434	if (sc == NULL || page == NULL)
 435		goto out;
 436
 437	kref_init(&sc->sc_kref);
 438	o2nm_node_get(node);
 439	sc->sc_node = node;
 440
 441	/* pin the node item of the remote node */
 442	status = o2nm_depend_item(&node->nd_item);
 443	if (status) {
 444		mlog_errno(status);
 445		o2nm_node_put(node);
 446		goto out;
 447	}
 448	INIT_WORK(&sc->sc_connect_work, o2net_sc_connect_completed);
 449	INIT_WORK(&sc->sc_rx_work, o2net_rx_until_empty);
 450	INIT_WORK(&sc->sc_shutdown_work, o2net_shutdown_sc);
 451	INIT_DELAYED_WORK(&sc->sc_keepalive_work, o2net_sc_send_keep_req);
 452
 453	timer_setup(&sc->sc_idle_timeout, o2net_idle_timer, 0);
 
 
 454
 455	sclog(sc, "alloced\n");
 456
 457	ret = sc;
 458	sc->sc_page = page;
 459	o2net_debug_add_sc(sc);
 460	sc = NULL;
 461	page = NULL;
 462
 463out:
 464	if (page)
 465		__free_page(page);
 466	kfree(sc);
 467
 468	return ret;
 469}
 470
 471/* ------------------------------------------------------------ */
 472
 473static void o2net_sc_queue_work(struct o2net_sock_container *sc,
 474				struct work_struct *work)
 475{
 476	sc_get(sc);
 477	if (!queue_work(o2net_wq, work))
 478		sc_put(sc);
 479}
 480static void o2net_sc_queue_delayed_work(struct o2net_sock_container *sc,
 481					struct delayed_work *work,
 482					int delay)
 483{
 484	sc_get(sc);
 485	if (!queue_delayed_work(o2net_wq, work, delay))
 486		sc_put(sc);
 487}
 488static void o2net_sc_cancel_delayed_work(struct o2net_sock_container *sc,
 489					 struct delayed_work *work)
 490{
 491	if (cancel_delayed_work(work))
 492		sc_put(sc);
 493}
 494
 495static atomic_t o2net_connected_peers = ATOMIC_INIT(0);
 496
 497int o2net_num_connected_peers(void)
 498{
 499	return atomic_read(&o2net_connected_peers);
 500}
 501
 502static void o2net_set_nn_state(struct o2net_node *nn,
 503			       struct o2net_sock_container *sc,
 504			       unsigned valid, int err)
 505{
 506	int was_valid = nn->nn_sc_valid;
 507	int was_err = nn->nn_persistent_error;
 508	struct o2net_sock_container *old_sc = nn->nn_sc;
 509
 510	assert_spin_locked(&nn->nn_lock);
 511
 512	if (old_sc && !sc)
 513		atomic_dec(&o2net_connected_peers);
 514	else if (!old_sc && sc)
 515		atomic_inc(&o2net_connected_peers);
 516
 517	/* the node num comparison and single connect/accept path should stop
 518	 * an non-null sc from being overwritten with another */
 519	BUG_ON(sc && nn->nn_sc && nn->nn_sc != sc);
 520	mlog_bug_on_msg(err && valid, "err %d valid %u\n", err, valid);
 521	mlog_bug_on_msg(valid && !sc, "valid %u sc %p\n", valid, sc);
 522
 523	if (was_valid && !valid && err == 0)
 524		err = -ENOTCONN;
 525
 526	mlog(ML_CONN, "node %u sc: %p -> %p, valid %u -> %u, err %d -> %d\n",
 527	     o2net_num_from_nn(nn), nn->nn_sc, sc, nn->nn_sc_valid, valid,
 528	     nn->nn_persistent_error, err);
 529
 530	nn->nn_sc = sc;
 531	nn->nn_sc_valid = valid ? 1 : 0;
 532	nn->nn_persistent_error = err;
 533
 534	/* mirrors o2net_tx_can_proceed() */
 535	if (nn->nn_persistent_error || nn->nn_sc_valid)
 536		wake_up(&nn->nn_sc_wq);
 537
 538	if (was_valid && !was_err && nn->nn_persistent_error) {
 539		o2quo_conn_err(o2net_num_from_nn(nn));
 540		queue_delayed_work(o2net_wq, &nn->nn_still_up,
 541				   msecs_to_jiffies(O2NET_QUORUM_DELAY_MS));
 542	}
 543
 544	if (was_valid && !valid) {
 545		if (old_sc)
 546			printk(KERN_NOTICE "o2net: No longer connected to "
 547				SC_NODEF_FMT "\n", SC_NODEF_ARGS(old_sc));
 548		o2net_complete_nodes_nsw(nn);
 549	}
 550
 551	if (!was_valid && valid) {
 552		o2quo_conn_up(o2net_num_from_nn(nn));
 553		cancel_delayed_work(&nn->nn_connect_expired);
 554		printk(KERN_NOTICE "o2net: %s " SC_NODEF_FMT "\n",
 555		       o2nm_this_node() > sc->sc_node->nd_num ?
 556		       "Connected to" : "Accepted connection from",
 557		       SC_NODEF_ARGS(sc));
 558	}
 559
 560	/* trigger the connecting worker func as long as we're not valid,
 561	 * it will back off if it shouldn't connect.  This can be called
 562	 * from node config teardown and so needs to be careful about
 563	 * the work queue actually being up. */
 564	if (!valid && o2net_wq) {
 565		unsigned long delay;
 566		/* delay if we're within a RECONNECT_DELAY of the
 567		 * last attempt */
 568		delay = (nn->nn_last_connect_attempt +
 569			 msecs_to_jiffies(o2net_reconnect_delay()))
 570			- jiffies;
 571		if (delay > msecs_to_jiffies(o2net_reconnect_delay()))
 572			delay = 0;
 573		mlog(ML_CONN, "queueing conn attempt in %lu jiffies\n", delay);
 574		queue_delayed_work(o2net_wq, &nn->nn_connect_work, delay);
 575
 576		/*
 577		 * Delay the expired work after idle timeout.
 578		 *
 579		 * We might have lots of failed connection attempts that run
 580		 * through here but we only cancel the connect_expired work when
 581		 * a connection attempt succeeds.  So only the first enqueue of
 582		 * the connect_expired work will do anything.  The rest will see
 583		 * that it's already queued and do nothing.
 584		 */
 585		delay += msecs_to_jiffies(o2net_idle_timeout());
 586		queue_delayed_work(o2net_wq, &nn->nn_connect_expired, delay);
 587	}
 588
 589	/* keep track of the nn's sc ref for the caller */
 590	if ((old_sc == NULL) && sc)
 591		sc_get(sc);
 592	if (old_sc && (old_sc != sc)) {
 593		o2net_sc_queue_work(old_sc, &old_sc->sc_shutdown_work);
 594		sc_put(old_sc);
 595	}
 596}
 597
 598/* see o2net_register_callbacks() */
 599static void o2net_data_ready(struct sock *sk)
 600{
 601	void (*ready)(struct sock *sk);
 602	struct o2net_sock_container *sc;
 603
 604	read_lock_bh(&sk->sk_callback_lock);
 605	sc = sk->sk_user_data;
 606	if (sc) {
 607		sclog(sc, "data_ready hit\n");
 608		o2net_set_data_ready_time(sc);
 609		o2net_sc_queue_work(sc, &sc->sc_rx_work);
 610		ready = sc->sc_data_ready;
 611	} else {
 612		ready = sk->sk_data_ready;
 613	}
 614	read_unlock_bh(&sk->sk_callback_lock);
 615
 616	ready(sk);
 617}
 618
 619/* see o2net_register_callbacks() */
 620static void o2net_state_change(struct sock *sk)
 621{
 622	void (*state_change)(struct sock *sk);
 623	struct o2net_sock_container *sc;
 624
 625	read_lock_bh(&sk->sk_callback_lock);
 626	sc = sk->sk_user_data;
 627	if (sc == NULL) {
 628		state_change = sk->sk_state_change;
 629		goto out;
 630	}
 631
 632	sclog(sc, "state_change to %d\n", sk->sk_state);
 633
 634	state_change = sc->sc_state_change;
 635
 636	switch(sk->sk_state) {
 637	/* ignore connecting sockets as they make progress */
 638	case TCP_SYN_SENT:
 639	case TCP_SYN_RECV:
 640		break;
 641	case TCP_ESTABLISHED:
 642		o2net_sc_queue_work(sc, &sc->sc_connect_work);
 643		break;
 644	default:
 645		printk(KERN_INFO "o2net: Connection to " SC_NODEF_FMT
 646			" shutdown, state %d\n",
 647			SC_NODEF_ARGS(sc), sk->sk_state);
 648		o2net_sc_queue_work(sc, &sc->sc_shutdown_work);
 649		break;
 650	}
 651out:
 652	read_unlock_bh(&sk->sk_callback_lock);
 653	state_change(sk);
 654}
 655
 656/*
 657 * we register callbacks so we can queue work on events before calling
 658 * the original callbacks.  our callbacks our careful to test user_data
 659 * to discover when they've reaced with o2net_unregister_callbacks().
 660 */
 661static void o2net_register_callbacks(struct sock *sk,
 662				     struct o2net_sock_container *sc)
 663{
 664	write_lock_bh(&sk->sk_callback_lock);
 665
 666	/* accepted sockets inherit the old listen socket data ready */
 667	if (sk->sk_data_ready == o2net_listen_data_ready) {
 668		sk->sk_data_ready = sk->sk_user_data;
 669		sk->sk_user_data = NULL;
 670	}
 671
 672	BUG_ON(sk->sk_user_data != NULL);
 673	sk->sk_user_data = sc;
 674	sc_get(sc);
 675
 676	sc->sc_data_ready = sk->sk_data_ready;
 677	sc->sc_state_change = sk->sk_state_change;
 678	sk->sk_data_ready = o2net_data_ready;
 679	sk->sk_state_change = o2net_state_change;
 680
 681	mutex_init(&sc->sc_send_lock);
 682
 683	write_unlock_bh(&sk->sk_callback_lock);
 684}
 685
 686static int o2net_unregister_callbacks(struct sock *sk,
 687			           struct o2net_sock_container *sc)
 688{
 689	int ret = 0;
 690
 691	write_lock_bh(&sk->sk_callback_lock);
 692	if (sk->sk_user_data == sc) {
 693		ret = 1;
 694		sk->sk_user_data = NULL;
 695		sk->sk_data_ready = sc->sc_data_ready;
 696		sk->sk_state_change = sc->sc_state_change;
 697	}
 698	write_unlock_bh(&sk->sk_callback_lock);
 699
 700	return ret;
 701}
 702
 703/*
 704 * this is a little helper that is called by callers who have seen a problem
 705 * with an sc and want to detach it from the nn if someone already hasn't beat
 706 * them to it.  if an error is given then the shutdown will be persistent
 707 * and pending transmits will be canceled.
 708 */
 709static void o2net_ensure_shutdown(struct o2net_node *nn,
 710			           struct o2net_sock_container *sc,
 711				   int err)
 712{
 713	spin_lock(&nn->nn_lock);
 714	if (nn->nn_sc == sc)
 715		o2net_set_nn_state(nn, NULL, 0, err);
 716	spin_unlock(&nn->nn_lock);
 717}
 718
 719/*
 720 * This work queue function performs the blocking parts of socket shutdown.  A
 721 * few paths lead here.  set_nn_state will trigger this callback if it sees an
 722 * sc detached from the nn.  state_change will also trigger this callback
 723 * directly when it sees errors.  In that case we need to call set_nn_state
 724 * ourselves as state_change couldn't get the nn_lock and call set_nn_state
 725 * itself.
 726 */
 727static void o2net_shutdown_sc(struct work_struct *work)
 728{
 729	struct o2net_sock_container *sc =
 730		container_of(work, struct o2net_sock_container,
 731			     sc_shutdown_work);
 732	struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
 733
 734	sclog(sc, "shutting down\n");
 735
 736	/* drop the callbacks ref and call shutdown only once */
 737	if (o2net_unregister_callbacks(sc->sc_sock->sk, sc)) {
 738		/* we shouldn't flush as we're in the thread, the
 739		 * races with pending sc work structs are harmless */
 740		del_timer_sync(&sc->sc_idle_timeout);
 741		o2net_sc_cancel_delayed_work(sc, &sc->sc_keepalive_work);
 742		sc_put(sc);
 743		kernel_sock_shutdown(sc->sc_sock, SHUT_RDWR);
 744	}
 745
 746	/* not fatal so failed connects before the other guy has our
 747	 * heartbeat can be retried */
 748	o2net_ensure_shutdown(nn, sc, 0);
 749	sc_put(sc);
 750}
 751
 752/* ------------------------------------------------------------ */
 753
 754static int o2net_handler_cmp(struct o2net_msg_handler *nmh, u32 msg_type,
 755			     u32 key)
 756{
 757	int ret = memcmp(&nmh->nh_key, &key, sizeof(key));
 758
 759	if (ret == 0)
 760		ret = memcmp(&nmh->nh_msg_type, &msg_type, sizeof(msg_type));
 761
 762	return ret;
 763}
 764
 765static struct o2net_msg_handler *
 766o2net_handler_tree_lookup(u32 msg_type, u32 key, struct rb_node ***ret_p,
 767			  struct rb_node **ret_parent)
 768{
 769	struct rb_node **p = &o2net_handler_tree.rb_node;
 770	struct rb_node *parent = NULL;
 771	struct o2net_msg_handler *nmh, *ret = NULL;
 772	int cmp;
 773
 774	while (*p) {
 775		parent = *p;
 776		nmh = rb_entry(parent, struct o2net_msg_handler, nh_node);
 777		cmp = o2net_handler_cmp(nmh, msg_type, key);
 778
 779		if (cmp < 0)
 780			p = &(*p)->rb_left;
 781		else if (cmp > 0)
 782			p = &(*p)->rb_right;
 783		else {
 784			ret = nmh;
 785			break;
 786		}
 787	}
 788
 789	if (ret_p != NULL)
 790		*ret_p = p;
 791	if (ret_parent != NULL)
 792		*ret_parent = parent;
 793
 794	return ret;
 795}
 796
 797static void o2net_handler_kref_release(struct kref *kref)
 798{
 799	struct o2net_msg_handler *nmh;
 800	nmh = container_of(kref, struct o2net_msg_handler, nh_kref);
 801
 802	kfree(nmh);
 803}
 804
 805static void o2net_handler_put(struct o2net_msg_handler *nmh)
 806{
 807	kref_put(&nmh->nh_kref, o2net_handler_kref_release);
 808}
 809
 810/* max_len is protection for the handler func.  incoming messages won't
 811 * be given to the handler if their payload is longer than the max. */
 812int o2net_register_handler(u32 msg_type, u32 key, u32 max_len,
 813			   o2net_msg_handler_func *func, void *data,
 814			   o2net_post_msg_handler_func *post_func,
 815			   struct list_head *unreg_list)
 816{
 817	struct o2net_msg_handler *nmh = NULL;
 818	struct rb_node **p, *parent;
 819	int ret = 0;
 820
 821	if (max_len > O2NET_MAX_PAYLOAD_BYTES) {
 822		mlog(0, "max_len for message handler out of range: %u\n",
 823			max_len);
 824		ret = -EINVAL;
 825		goto out;
 826	}
 827
 828	if (!msg_type) {
 829		mlog(0, "no message type provided: %u, %p\n", msg_type, func);
 830		ret = -EINVAL;
 831		goto out;
 832
 833	}
 834	if (!func) {
 835		mlog(0, "no message handler provided: %u, %p\n",
 836		       msg_type, func);
 837		ret = -EINVAL;
 838		goto out;
 839	}
 840
 841       	nmh = kzalloc(sizeof(struct o2net_msg_handler), GFP_NOFS);
 842	if (nmh == NULL) {
 843		ret = -ENOMEM;
 844		goto out;
 845	}
 846
 847	nmh->nh_func = func;
 848	nmh->nh_func_data = data;
 849	nmh->nh_post_func = post_func;
 850	nmh->nh_msg_type = msg_type;
 851	nmh->nh_max_len = max_len;
 852	nmh->nh_key = key;
 853	/* the tree and list get this ref.. they're both removed in
 854	 * unregister when this ref is dropped */
 855	kref_init(&nmh->nh_kref);
 856	INIT_LIST_HEAD(&nmh->nh_unregister_item);
 857
 858	write_lock(&o2net_handler_lock);
 859	if (o2net_handler_tree_lookup(msg_type, key, &p, &parent))
 860		ret = -EEXIST;
 861	else {
 862	        rb_link_node(&nmh->nh_node, parent, p);
 863		rb_insert_color(&nmh->nh_node, &o2net_handler_tree);
 864		list_add_tail(&nmh->nh_unregister_item, unreg_list);
 865
 866		mlog(ML_TCP, "registered handler func %p type %u key %08x\n",
 867		     func, msg_type, key);
 868		/* we've had some trouble with handlers seemingly vanishing. */
 869		mlog_bug_on_msg(o2net_handler_tree_lookup(msg_type, key, &p,
 870							  &parent) == NULL,
 871			        "couldn't find handler we *just* registered "
 872				"for type %u key %08x\n", msg_type, key);
 873	}
 874	write_unlock(&o2net_handler_lock);
 875	if (ret)
 876		goto out;
 877
 878out:
 879	if (ret)
 880		kfree(nmh);
 881
 882	return ret;
 883}
 884EXPORT_SYMBOL_GPL(o2net_register_handler);
 885
 886void o2net_unregister_handler_list(struct list_head *list)
 887{
 888	struct o2net_msg_handler *nmh, *n;
 889
 890	write_lock(&o2net_handler_lock);
 891	list_for_each_entry_safe(nmh, n, list, nh_unregister_item) {
 892		mlog(ML_TCP, "unregistering handler func %p type %u key %08x\n",
 893		     nmh->nh_func, nmh->nh_msg_type, nmh->nh_key);
 894		rb_erase(&nmh->nh_node, &o2net_handler_tree);
 895		list_del_init(&nmh->nh_unregister_item);
 896		kref_put(&nmh->nh_kref, o2net_handler_kref_release);
 897	}
 898	write_unlock(&o2net_handler_lock);
 899}
 900EXPORT_SYMBOL_GPL(o2net_unregister_handler_list);
 901
 902static struct o2net_msg_handler *o2net_handler_get(u32 msg_type, u32 key)
 903{
 904	struct o2net_msg_handler *nmh;
 905
 906	read_lock(&o2net_handler_lock);
 907	nmh = o2net_handler_tree_lookup(msg_type, key, NULL, NULL);
 908	if (nmh)
 909		kref_get(&nmh->nh_kref);
 910	read_unlock(&o2net_handler_lock);
 911
 912	return nmh;
 913}
 914
 915/* ------------------------------------------------------------ */
 916
 917static int o2net_recv_tcp_msg(struct socket *sock, void *data, size_t len)
 918{
 919	struct kvec vec = { .iov_len = len, .iov_base = data, };
 920	struct msghdr msg = { .msg_flags = MSG_DONTWAIT, };
 921	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &vec, 1, len);
 922	return sock_recvmsg(sock, &msg, MSG_DONTWAIT);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 923}
 924
 925static int o2net_send_tcp_msg(struct socket *sock, struct kvec *vec,
 926			      size_t veclen, size_t total)
 927{
 928	int ret;
 929	struct msghdr msg = {.msg_flags = 0,};
 
 
 
 
 930
 931	if (sock == NULL) {
 932		ret = -EINVAL;
 933		goto out;
 934	}
 935
 936	ret = kernel_sendmsg(sock, &msg, vec, veclen, total);
 937	if (likely(ret == total))
 938		return 0;
 939	mlog(ML_ERROR, "sendmsg returned %d instead of %zu\n", ret, total);
 940	if (ret >= 0)
 941		ret = -EPIPE; /* should be smarter, I bet */
 
 
 
 
 
 
 
 942out:
 943	mlog(0, "returning error: %d\n", ret);
 
 944	return ret;
 945}
 946
 947static void o2net_sendpage(struct o2net_sock_container *sc,
 948			   void *kmalloced_virt,
 949			   size_t size)
 950{
 951	struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
 952	ssize_t ret;
 953
 954	while (1) {
 955		mutex_lock(&sc->sc_send_lock);
 956		ret = sc->sc_sock->ops->sendpage(sc->sc_sock,
 957						 virt_to_page(kmalloced_virt),
 958						 offset_in_page(kmalloced_virt),
 959						 size, MSG_DONTWAIT);
 960		mutex_unlock(&sc->sc_send_lock);
 961		if (ret == size)
 962			break;
 963		if (ret == (ssize_t)-EAGAIN) {
 964			mlog(0, "sendpage of size %zu to " SC_NODEF_FMT
 965			     " returned EAGAIN\n", size, SC_NODEF_ARGS(sc));
 966			cond_resched();
 967			continue;
 968		}
 969		mlog(ML_ERROR, "sendpage of size %zu to " SC_NODEF_FMT
 970		     " failed with %zd\n", size, SC_NODEF_ARGS(sc), ret);
 971		o2net_ensure_shutdown(nn, sc, 0);
 972		break;
 973	}
 974}
 975
 976static void o2net_init_msg(struct o2net_msg *msg, u16 data_len, u16 msg_type, u32 key)
 977{
 978	memset(msg, 0, sizeof(struct o2net_msg));
 979	msg->magic = cpu_to_be16(O2NET_MSG_MAGIC);
 980	msg->data_len = cpu_to_be16(data_len);
 981	msg->msg_type = cpu_to_be16(msg_type);
 982	msg->sys_status = cpu_to_be32(O2NET_ERR_NONE);
 983	msg->status = 0;
 984	msg->key = cpu_to_be32(key);
 985}
 986
 987static int o2net_tx_can_proceed(struct o2net_node *nn,
 988			        struct o2net_sock_container **sc_ret,
 989				int *error)
 990{
 991	int ret = 0;
 992
 993	spin_lock(&nn->nn_lock);
 994	if (nn->nn_persistent_error) {
 995		ret = 1;
 996		*sc_ret = NULL;
 997		*error = nn->nn_persistent_error;
 998	} else if (nn->nn_sc_valid) {
 999		kref_get(&nn->nn_sc->sc_kref);
1000
1001		ret = 1;
1002		*sc_ret = nn->nn_sc;
1003		*error = 0;
1004	}
1005	spin_unlock(&nn->nn_lock);
1006
1007	return ret;
1008}
1009
1010/* Get a map of all nodes to which this node is currently connected to */
1011void o2net_fill_node_map(unsigned long *map, unsigned bytes)
1012{
1013	struct o2net_sock_container *sc;
1014	int node, ret;
1015
1016	BUG_ON(bytes < (BITS_TO_LONGS(O2NM_MAX_NODES) * sizeof(unsigned long)));
1017
1018	memset(map, 0, bytes);
1019	for (node = 0; node < O2NM_MAX_NODES; ++node) {
1020		if (!o2net_tx_can_proceed(o2net_nn_from_num(node), &sc, &ret))
1021			continue;
1022		if (!ret) {
1023			set_bit(node, map);
1024			sc_put(sc);
1025		}
1026	}
1027}
1028EXPORT_SYMBOL_GPL(o2net_fill_node_map);
1029
1030int o2net_send_message_vec(u32 msg_type, u32 key, struct kvec *caller_vec,
1031			   size_t caller_veclen, u8 target_node, int *status)
1032{
1033	int ret = 0;
1034	struct o2net_msg *msg = NULL;
1035	size_t veclen, caller_bytes = 0;
1036	struct kvec *vec = NULL;
1037	struct o2net_sock_container *sc = NULL;
1038	struct o2net_node *nn = o2net_nn_from_num(target_node);
1039	struct o2net_status_wait nsw = {
1040		.ns_node_item = LIST_HEAD_INIT(nsw.ns_node_item),
1041	};
1042	struct o2net_send_tracking nst;
1043
1044	o2net_init_nst(&nst, msg_type, key, current, target_node);
1045
1046	if (o2net_wq == NULL) {
1047		mlog(0, "attempt to tx without o2netd running\n");
1048		ret = -ESRCH;
1049		goto out;
1050	}
1051
1052	if (caller_veclen == 0) {
1053		mlog(0, "bad kvec array length\n");
1054		ret = -EINVAL;
1055		goto out;
1056	}
1057
1058	caller_bytes = iov_length((struct iovec *)caller_vec, caller_veclen);
1059	if (caller_bytes > O2NET_MAX_PAYLOAD_BYTES) {
1060		mlog(0, "total payload len %zu too large\n", caller_bytes);
1061		ret = -EINVAL;
1062		goto out;
1063	}
1064
1065	if (target_node == o2nm_this_node()) {
1066		ret = -ELOOP;
1067		goto out;
1068	}
1069
1070	o2net_debug_add_nst(&nst);
1071
1072	o2net_set_nst_sock_time(&nst);
1073
1074	wait_event(nn->nn_sc_wq, o2net_tx_can_proceed(nn, &sc, &ret));
1075	if (ret)
1076		goto out;
1077
1078	o2net_set_nst_sock_container(&nst, sc);
1079
1080	veclen = caller_veclen + 1;
1081	vec = kmalloc(sizeof(struct kvec) * veclen, GFP_ATOMIC);
1082	if (vec == NULL) {
1083		mlog(0, "failed to %zu element kvec!\n", veclen);
1084		ret = -ENOMEM;
1085		goto out;
1086	}
1087
1088	msg = kmalloc(sizeof(struct o2net_msg), GFP_ATOMIC);
1089	if (!msg) {
1090		mlog(0, "failed to allocate a o2net_msg!\n");
1091		ret = -ENOMEM;
1092		goto out;
1093	}
1094
1095	o2net_init_msg(msg, caller_bytes, msg_type, key);
1096
1097	vec[0].iov_len = sizeof(struct o2net_msg);
1098	vec[0].iov_base = msg;
1099	memcpy(&vec[1], caller_vec, caller_veclen * sizeof(struct kvec));
1100
1101	ret = o2net_prep_nsw(nn, &nsw);
1102	if (ret)
1103		goto out;
1104
1105	msg->msg_num = cpu_to_be32(nsw.ns_id);
1106	o2net_set_nst_msg_id(&nst, nsw.ns_id);
1107
1108	o2net_set_nst_send_time(&nst);
1109
1110	/* finally, convert the message header to network byte-order
1111	 * and send */
1112	mutex_lock(&sc->sc_send_lock);
1113	ret = o2net_send_tcp_msg(sc->sc_sock, vec, veclen,
1114				 sizeof(struct o2net_msg) + caller_bytes);
1115	mutex_unlock(&sc->sc_send_lock);
1116	msglog(msg, "sending returned %d\n", ret);
1117	if (ret < 0) {
1118		mlog(0, "error returned from o2net_send_tcp_msg=%d\n", ret);
1119		goto out;
1120	}
1121
1122	/* wait on other node's handler */
1123	o2net_set_nst_status_time(&nst);
1124	wait_event(nsw.ns_wq, o2net_nsw_completed(nn, &nsw));
1125
1126	o2net_update_send_stats(&nst, sc);
1127
1128	/* Note that we avoid overwriting the callers status return
1129	 * variable if a system error was reported on the other
1130	 * side. Callers beware. */
1131	ret = o2net_sys_err_to_errno(nsw.ns_sys_status);
1132	if (status && !ret)
1133		*status = nsw.ns_status;
1134
1135	mlog(0, "woken, returning system status %d, user status %d\n",
1136	     ret, nsw.ns_status);
1137out:
1138	o2net_debug_del_nst(&nst); /* must be before dropping sc and node */
1139	if (sc)
1140		sc_put(sc);
1141	kfree(vec);
1142	kfree(msg);
 
 
1143	o2net_complete_nsw(nn, &nsw, 0, 0, 0);
1144	return ret;
1145}
1146EXPORT_SYMBOL_GPL(o2net_send_message_vec);
1147
1148int o2net_send_message(u32 msg_type, u32 key, void *data, u32 len,
1149		       u8 target_node, int *status)
1150{
1151	struct kvec vec = {
1152		.iov_base = data,
1153		.iov_len = len,
1154	};
1155	return o2net_send_message_vec(msg_type, key, &vec, 1,
1156				      target_node, status);
1157}
1158EXPORT_SYMBOL_GPL(o2net_send_message);
1159
1160static int o2net_send_status_magic(struct socket *sock, struct o2net_msg *hdr,
1161				   enum o2net_system_error syserr, int err)
1162{
1163	struct kvec vec = {
1164		.iov_base = hdr,
1165		.iov_len = sizeof(struct o2net_msg),
1166	};
1167
1168	BUG_ON(syserr >= O2NET_ERR_MAX);
1169
1170	/* leave other fields intact from the incoming message, msg_num
1171	 * in particular */
1172	hdr->sys_status = cpu_to_be32(syserr);
1173	hdr->status = cpu_to_be32(err);
1174	hdr->magic = cpu_to_be16(O2NET_MSG_STATUS_MAGIC);  // twiddle the magic
1175	hdr->data_len = 0;
1176
1177	msglog(hdr, "about to send status magic %d\n", err);
1178	/* hdr has been in host byteorder this whole time */
1179	return o2net_send_tcp_msg(sock, &vec, 1, sizeof(struct o2net_msg));
1180}
1181
1182/* this returns -errno if the header was unknown or too large, etc.
1183 * after this is called the buffer us reused for the next message */
1184static int o2net_process_message(struct o2net_sock_container *sc,
1185				 struct o2net_msg *hdr)
1186{
1187	struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
1188	int ret = 0, handler_status;
1189	enum  o2net_system_error syserr;
1190	struct o2net_msg_handler *nmh = NULL;
1191	void *ret_data = NULL;
1192
1193	msglog(hdr, "processing message\n");
1194
1195	o2net_sc_postpone_idle(sc);
1196
1197	switch(be16_to_cpu(hdr->magic)) {
1198		case O2NET_MSG_STATUS_MAGIC:
1199			/* special type for returning message status */
1200			o2net_complete_nsw(nn, NULL,
1201					   be32_to_cpu(hdr->msg_num),
1202					   be32_to_cpu(hdr->sys_status),
1203					   be32_to_cpu(hdr->status));
1204			goto out;
1205		case O2NET_MSG_KEEP_REQ_MAGIC:
1206			o2net_sendpage(sc, o2net_keep_resp,
1207				       sizeof(*o2net_keep_resp));
1208			goto out;
1209		case O2NET_MSG_KEEP_RESP_MAGIC:
1210			goto out;
1211		case O2NET_MSG_MAGIC:
1212			break;
1213		default:
1214			msglog(hdr, "bad magic\n");
1215			ret = -EINVAL;
1216			goto out;
1217			break;
1218	}
1219
1220	/* find a handler for it */
1221	handler_status = 0;
1222	nmh = o2net_handler_get(be16_to_cpu(hdr->msg_type),
1223				be32_to_cpu(hdr->key));
1224	if (!nmh) {
1225		mlog(ML_TCP, "couldn't find handler for type %u key %08x\n",
1226		     be16_to_cpu(hdr->msg_type), be32_to_cpu(hdr->key));
1227		syserr = O2NET_ERR_NO_HNDLR;
1228		goto out_respond;
1229	}
1230
1231	syserr = O2NET_ERR_NONE;
1232
1233	if (be16_to_cpu(hdr->data_len) > nmh->nh_max_len)
1234		syserr = O2NET_ERR_OVERFLOW;
1235
1236	if (syserr != O2NET_ERR_NONE)
1237		goto out_respond;
1238
1239	o2net_set_func_start_time(sc);
1240	sc->sc_msg_key = be32_to_cpu(hdr->key);
1241	sc->sc_msg_type = be16_to_cpu(hdr->msg_type);
1242	handler_status = (nmh->nh_func)(hdr, sizeof(struct o2net_msg) +
1243					     be16_to_cpu(hdr->data_len),
1244					nmh->nh_func_data, &ret_data);
1245	o2net_set_func_stop_time(sc);
1246
1247	o2net_update_recv_stats(sc);
1248
1249out_respond:
1250	/* this destroys the hdr, so don't use it after this */
1251	mutex_lock(&sc->sc_send_lock);
1252	ret = o2net_send_status_magic(sc->sc_sock, hdr, syserr,
1253				      handler_status);
1254	mutex_unlock(&sc->sc_send_lock);
1255	hdr = NULL;
1256	mlog(0, "sending handler status %d, syserr %d returned %d\n",
1257	     handler_status, syserr, ret);
1258
1259	if (nmh) {
1260		BUG_ON(ret_data != NULL && nmh->nh_post_func == NULL);
1261		if (nmh->nh_post_func)
1262			(nmh->nh_post_func)(handler_status, nmh->nh_func_data,
1263					    ret_data);
1264	}
1265
1266out:
1267	if (nmh)
1268		o2net_handler_put(nmh);
1269	return ret;
1270}
1271
1272static int o2net_check_handshake(struct o2net_sock_container *sc)
1273{
1274	struct o2net_handshake *hand = page_address(sc->sc_page);
1275	struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
1276
1277	if (hand->protocol_version != cpu_to_be64(O2NET_PROTOCOL_VERSION)) {
1278		printk(KERN_NOTICE "o2net: " SC_NODEF_FMT " Advertised net "
1279		       "protocol version %llu but %llu is required. "
1280		       "Disconnecting.\n", SC_NODEF_ARGS(sc),
1281		       (unsigned long long)be64_to_cpu(hand->protocol_version),
1282		       O2NET_PROTOCOL_VERSION);
1283
1284		/* don't bother reconnecting if its the wrong version. */
1285		o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1286		return -1;
1287	}
1288
1289	/*
1290	 * Ensure timeouts are consistent with other nodes, otherwise
1291	 * we can end up with one node thinking that the other must be down,
1292	 * but isn't. This can ultimately cause corruption.
1293	 */
1294	if (be32_to_cpu(hand->o2net_idle_timeout_ms) !=
1295				o2net_idle_timeout()) {
1296		printk(KERN_NOTICE "o2net: " SC_NODEF_FMT " uses a network "
1297		       "idle timeout of %u ms, but we use %u ms locally. "
1298		       "Disconnecting.\n", SC_NODEF_ARGS(sc),
1299		       be32_to_cpu(hand->o2net_idle_timeout_ms),
1300		       o2net_idle_timeout());
1301		o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1302		return -1;
1303	}
1304
1305	if (be32_to_cpu(hand->o2net_keepalive_delay_ms) !=
1306			o2net_keepalive_delay()) {
1307		printk(KERN_NOTICE "o2net: " SC_NODEF_FMT " uses a keepalive "
1308		       "delay of %u ms, but we use %u ms locally. "
1309		       "Disconnecting.\n", SC_NODEF_ARGS(sc),
1310		       be32_to_cpu(hand->o2net_keepalive_delay_ms),
1311		       o2net_keepalive_delay());
1312		o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1313		return -1;
1314	}
1315
1316	if (be32_to_cpu(hand->o2hb_heartbeat_timeout_ms) !=
1317			O2HB_MAX_WRITE_TIMEOUT_MS) {
1318		printk(KERN_NOTICE "o2net: " SC_NODEF_FMT " uses a heartbeat "
1319		       "timeout of %u ms, but we use %u ms locally. "
1320		       "Disconnecting.\n", SC_NODEF_ARGS(sc),
1321		       be32_to_cpu(hand->o2hb_heartbeat_timeout_ms),
1322		       O2HB_MAX_WRITE_TIMEOUT_MS);
1323		o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1324		return -1;
1325	}
1326
1327	sc->sc_handshake_ok = 1;
1328
1329	spin_lock(&nn->nn_lock);
1330	/* set valid and queue the idle timers only if it hasn't been
1331	 * shut down already */
1332	if (nn->nn_sc == sc) {
1333		o2net_sc_reset_idle_timer(sc);
1334		atomic_set(&nn->nn_timeout, 0);
1335		o2net_set_nn_state(nn, sc, 1, 0);
1336	}
1337	spin_unlock(&nn->nn_lock);
1338
1339	/* shift everything up as though it wasn't there */
1340	sc->sc_page_off -= sizeof(struct o2net_handshake);
1341	if (sc->sc_page_off)
1342		memmove(hand, hand + 1, sc->sc_page_off);
1343
1344	return 0;
1345}
1346
1347/* this demuxes the queued rx bytes into header or payload bits and calls
1348 * handlers as each full message is read off the socket.  it returns -error,
1349 * == 0 eof, or > 0 for progress made.*/
1350static int o2net_advance_rx(struct o2net_sock_container *sc)
1351{
1352	struct o2net_msg *hdr;
1353	int ret = 0;
1354	void *data;
1355	size_t datalen;
1356
1357	sclog(sc, "receiving\n");
1358	o2net_set_advance_start_time(sc);
1359
1360	if (unlikely(sc->sc_handshake_ok == 0)) {
1361		if(sc->sc_page_off < sizeof(struct o2net_handshake)) {
1362			data = page_address(sc->sc_page) + sc->sc_page_off;
1363			datalen = sizeof(struct o2net_handshake) - sc->sc_page_off;
1364			ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen);
1365			if (ret > 0)
1366				sc->sc_page_off += ret;
1367		}
1368
1369		if (sc->sc_page_off == sizeof(struct o2net_handshake)) {
1370			o2net_check_handshake(sc);
1371			if (unlikely(sc->sc_handshake_ok == 0))
1372				ret = -EPROTO;
1373		}
1374		goto out;
1375	}
1376
1377	/* do we need more header? */
1378	if (sc->sc_page_off < sizeof(struct o2net_msg)) {
1379		data = page_address(sc->sc_page) + sc->sc_page_off;
1380		datalen = sizeof(struct o2net_msg) - sc->sc_page_off;
1381		ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen);
1382		if (ret > 0) {
1383			sc->sc_page_off += ret;
1384			/* only swab incoming here.. we can
1385			 * only get here once as we cross from
1386			 * being under to over */
1387			if (sc->sc_page_off == sizeof(struct o2net_msg)) {
1388				hdr = page_address(sc->sc_page);
1389				if (be16_to_cpu(hdr->data_len) >
1390				    O2NET_MAX_PAYLOAD_BYTES)
1391					ret = -EOVERFLOW;
1392			}
1393		}
1394		if (ret <= 0)
1395			goto out;
1396	}
1397
1398	if (sc->sc_page_off < sizeof(struct o2net_msg)) {
1399		/* oof, still don't have a header */
1400		goto out;
1401	}
1402
1403	/* this was swabbed above when we first read it */
1404	hdr = page_address(sc->sc_page);
1405
1406	msglog(hdr, "at page_off %zu\n", sc->sc_page_off);
1407
1408	/* do we need more payload? */
1409	if (sc->sc_page_off - sizeof(struct o2net_msg) < be16_to_cpu(hdr->data_len)) {
1410		/* need more payload */
1411		data = page_address(sc->sc_page) + sc->sc_page_off;
1412		datalen = (sizeof(struct o2net_msg) + be16_to_cpu(hdr->data_len)) -
1413			  sc->sc_page_off;
1414		ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen);
1415		if (ret > 0)
1416			sc->sc_page_off += ret;
1417		if (ret <= 0)
1418			goto out;
1419	}
1420
1421	if (sc->sc_page_off - sizeof(struct o2net_msg) == be16_to_cpu(hdr->data_len)) {
1422		/* we can only get here once, the first time we read
1423		 * the payload.. so set ret to progress if the handler
1424		 * works out. after calling this the message is toast */
1425		ret = o2net_process_message(sc, hdr);
1426		if (ret == 0)
1427			ret = 1;
1428		sc->sc_page_off = 0;
1429	}
1430
1431out:
1432	sclog(sc, "ret = %d\n", ret);
1433	o2net_set_advance_stop_time(sc);
1434	return ret;
1435}
1436
1437/* this work func is triggerd by data ready.  it reads until it can read no
1438 * more.  it interprets 0, eof, as fatal.  if data_ready hits while we're doing
1439 * our work the work struct will be marked and we'll be called again. */
1440static void o2net_rx_until_empty(struct work_struct *work)
1441{
1442	struct o2net_sock_container *sc =
1443		container_of(work, struct o2net_sock_container, sc_rx_work);
1444	int ret;
1445
1446	do {
1447		ret = o2net_advance_rx(sc);
1448	} while (ret > 0);
1449
1450	if (ret <= 0 && ret != -EAGAIN) {
1451		struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
1452		sclog(sc, "saw error %d, closing\n", ret);
1453		/* not permanent so read failed handshake can retry */
1454		o2net_ensure_shutdown(nn, sc, 0);
1455	}
1456
1457	sc_put(sc);
1458}
1459
1460static int o2net_set_nodelay(struct socket *sock)
1461{
1462	int val = 1;
 
1463
1464	return kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY,
1465				    (void *)&val, sizeof(val));
1466}
1467
1468static int o2net_set_usertimeout(struct socket *sock)
1469{
1470	int user_timeout = O2NET_TCP_USER_TIMEOUT;
 
 
 
 
 
 
 
 
 
1471
1472	return kernel_setsockopt(sock, SOL_TCP, TCP_USER_TIMEOUT,
1473				(void *)&user_timeout, sizeof(user_timeout));
1474}
1475
1476static void o2net_initialize_handshake(void)
1477{
1478	o2net_hand->o2hb_heartbeat_timeout_ms = cpu_to_be32(
1479		O2HB_MAX_WRITE_TIMEOUT_MS);
1480	o2net_hand->o2net_idle_timeout_ms = cpu_to_be32(o2net_idle_timeout());
1481	o2net_hand->o2net_keepalive_delay_ms = cpu_to_be32(
1482		o2net_keepalive_delay());
1483	o2net_hand->o2net_reconnect_delay_ms = cpu_to_be32(
1484		o2net_reconnect_delay());
1485}
1486
1487/* ------------------------------------------------------------ */
1488
1489/* called when a connect completes and after a sock is accepted.  the
1490 * rx path will see the response and mark the sc valid */
1491static void o2net_sc_connect_completed(struct work_struct *work)
1492{
1493	struct o2net_sock_container *sc =
1494		container_of(work, struct o2net_sock_container,
1495			     sc_connect_work);
1496
1497	mlog(ML_MSG, "sc sending handshake with ver %llu id %llx\n",
1498              (unsigned long long)O2NET_PROTOCOL_VERSION,
1499	      (unsigned long long)be64_to_cpu(o2net_hand->connector_id));
1500
1501	o2net_initialize_handshake();
1502	o2net_sendpage(sc, o2net_hand, sizeof(*o2net_hand));
1503	sc_put(sc);
1504}
1505
1506/* this is called as a work_struct func. */
1507static void o2net_sc_send_keep_req(struct work_struct *work)
1508{
1509	struct o2net_sock_container *sc =
1510		container_of(work, struct o2net_sock_container,
1511			     sc_keepalive_work.work);
1512
1513	o2net_sendpage(sc, o2net_keep_req, sizeof(*o2net_keep_req));
1514	sc_put(sc);
1515}
1516
1517/* socket shutdown does a del_timer_sync against this as it tears down.
1518 * we can't start this timer until we've got to the point in sc buildup
1519 * where shutdown is going to be involved */
1520static void o2net_idle_timer(struct timer_list *t)
1521{
1522	struct o2net_sock_container *sc = from_timer(sc, t, sc_idle_timeout);
1523	struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
 
1524#ifdef CONFIG_DEBUG_FS
1525	unsigned long msecs = ktime_to_ms(ktime_get()) -
1526		ktime_to_ms(sc->sc_tv_timer);
1527#else
1528	unsigned long msecs = o2net_idle_timeout();
1529#endif
1530
1531	printk(KERN_NOTICE "o2net: Connection to " SC_NODEF_FMT " has been "
1532	       "idle for %lu.%lu secs.\n",
1533	       SC_NODEF_ARGS(sc), msecs / 1000, msecs % 1000);
1534
1535	/* idle timerout happen, don't shutdown the connection, but
1536	 * make fence decision. Maybe the connection can recover before
1537	 * the decision is made.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1538	 */
1539	atomic_set(&nn->nn_timeout, 1);
1540	o2quo_conn_err(o2net_num_from_nn(nn));
1541	queue_delayed_work(o2net_wq, &nn->nn_still_up,
1542			msecs_to_jiffies(O2NET_QUORUM_DELAY_MS));
1543
1544	o2net_sc_reset_idle_timer(sc);
1545
 
1546}
1547
1548static void o2net_sc_reset_idle_timer(struct o2net_sock_container *sc)
1549{
1550	o2net_sc_cancel_delayed_work(sc, &sc->sc_keepalive_work);
1551	o2net_sc_queue_delayed_work(sc, &sc->sc_keepalive_work,
1552		      msecs_to_jiffies(o2net_keepalive_delay()));
1553	o2net_set_sock_timer(sc);
1554	mod_timer(&sc->sc_idle_timeout,
1555	       jiffies + msecs_to_jiffies(o2net_idle_timeout()));
1556}
1557
1558static void o2net_sc_postpone_idle(struct o2net_sock_container *sc)
1559{
1560	struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
1561
1562	/* clear fence decision since the connection recover from timeout*/
1563	if (atomic_read(&nn->nn_timeout)) {
1564		o2quo_conn_up(o2net_num_from_nn(nn));
1565		cancel_delayed_work(&nn->nn_still_up);
1566		atomic_set(&nn->nn_timeout, 0);
1567	}
1568
1569	/* Only push out an existing timer */
1570	if (timer_pending(&sc->sc_idle_timeout))
1571		o2net_sc_reset_idle_timer(sc);
1572}
1573
1574/* this work func is kicked whenever a path sets the nn state which doesn't
1575 * have valid set.  This includes seeing hb come up, losing a connection,
1576 * having a connect attempt fail, etc. This centralizes the logic which decides
1577 * if a connect attempt should be made or if we should give up and all future
1578 * transmit attempts should fail */
1579static void o2net_start_connect(struct work_struct *work)
1580{
1581	struct o2net_node *nn =
1582		container_of(work, struct o2net_node, nn_connect_work.work);
1583	struct o2net_sock_container *sc = NULL;
1584	struct o2nm_node *node = NULL, *mynode = NULL;
1585	struct socket *sock = NULL;
1586	struct sockaddr_in myaddr = {0, }, remoteaddr = {0, };
1587	int ret = 0, stop;
1588	unsigned int timeout;
1589	unsigned int noio_flag;
1590
1591	/*
1592	 * sock_create allocates the sock with GFP_KERNEL. We must set
1593	 * per-process flag PF_MEMALLOC_NOIO so that all allocations done
1594	 * by this process are done as if GFP_NOIO was specified. So we
1595	 * are not reentering filesystem while doing memory reclaim.
1596	 */
1597	noio_flag = memalloc_noio_save();
1598	/* if we're greater we initiate tx, otherwise we accept */
1599	if (o2nm_this_node() <= o2net_num_from_nn(nn))
1600		goto out;
1601
1602	/* watch for racing with tearing a node down */
1603	node = o2nm_get_node_by_num(o2net_num_from_nn(nn));
1604	if (node == NULL)
 
1605		goto out;
 
1606
1607	mynode = o2nm_get_node_by_num(o2nm_this_node());
1608	if (mynode == NULL)
 
1609		goto out;
 
1610
1611	spin_lock(&nn->nn_lock);
1612	/*
1613	 * see if we already have one pending or have given up.
1614	 * For nn_timeout, it is set when we close the connection
1615	 * because of the idle time out. So it means that we have
1616	 * at least connected to that node successfully once,
1617	 * now try to connect to it again.
1618	 */
1619	timeout = atomic_read(&nn->nn_timeout);
1620	stop = (nn->nn_sc ||
1621		(nn->nn_persistent_error &&
1622		(nn->nn_persistent_error != -ENOTCONN || timeout == 0)));
1623	spin_unlock(&nn->nn_lock);
1624	if (stop)
1625		goto out;
1626
1627	nn->nn_last_connect_attempt = jiffies;
1628
1629	sc = sc_alloc(node);
1630	if (sc == NULL) {
1631		mlog(0, "couldn't allocate sc\n");
1632		ret = -ENOMEM;
1633		goto out;
1634	}
1635
1636	ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
1637	if (ret < 0) {
1638		mlog(0, "can't create socket: %d\n", ret);
1639		goto out;
1640	}
1641	sc->sc_sock = sock; /* freed by sc_kref_release */
1642
1643	sock->sk->sk_allocation = GFP_ATOMIC;
1644
1645	myaddr.sin_family = AF_INET;
1646	myaddr.sin_addr.s_addr = mynode->nd_ipv4_address;
1647	myaddr.sin_port = htons(0); /* any port */
1648
1649	ret = sock->ops->bind(sock, (struct sockaddr *)&myaddr,
1650			      sizeof(myaddr));
1651	if (ret) {
1652		mlog(ML_ERROR, "bind failed with %d at address %pI4\n",
1653		     ret, &mynode->nd_ipv4_address);
1654		goto out;
1655	}
1656
1657	ret = o2net_set_nodelay(sc->sc_sock);
1658	if (ret) {
1659		mlog(ML_ERROR, "setting TCP_NODELAY failed with %d\n", ret);
1660		goto out;
1661	}
1662
1663	ret = o2net_set_usertimeout(sock);
1664	if (ret) {
1665		mlog(ML_ERROR, "set TCP_USER_TIMEOUT failed with %d\n", ret);
1666		goto out;
1667	}
1668
1669	o2net_register_callbacks(sc->sc_sock->sk, sc);
1670
1671	spin_lock(&nn->nn_lock);
1672	/* handshake completion will set nn->nn_sc_valid */
1673	o2net_set_nn_state(nn, sc, 0, 0);
1674	spin_unlock(&nn->nn_lock);
1675
1676	remoteaddr.sin_family = AF_INET;
1677	remoteaddr.sin_addr.s_addr = node->nd_ipv4_address;
1678	remoteaddr.sin_port = node->nd_ipv4_port;
1679
1680	ret = sc->sc_sock->ops->connect(sc->sc_sock,
1681					(struct sockaddr *)&remoteaddr,
1682					sizeof(remoteaddr),
1683					O_NONBLOCK);
1684	if (ret == -EINPROGRESS)
1685		ret = 0;
1686
1687out:
1688	if (ret && sc) {
1689		printk(KERN_NOTICE "o2net: Connect attempt to " SC_NODEF_FMT
1690		       " failed with errno %d\n", SC_NODEF_ARGS(sc), ret);
1691		/* 0 err so that another will be queued and attempted
1692		 * from set_nn_state */
1693		o2net_ensure_shutdown(nn, sc, 0);
 
1694	}
1695	if (sc)
1696		sc_put(sc);
1697	if (node)
1698		o2nm_node_put(node);
1699	if (mynode)
1700		o2nm_node_put(mynode);
1701
1702	memalloc_noio_restore(noio_flag);
1703	return;
1704}
1705
1706static void o2net_connect_expired(struct work_struct *work)
1707{
1708	struct o2net_node *nn =
1709		container_of(work, struct o2net_node, nn_connect_expired.work);
1710
1711	spin_lock(&nn->nn_lock);
1712	if (!nn->nn_sc_valid) {
1713		printk(KERN_NOTICE "o2net: No connection established with "
1714		       "node %u after %u.%u seconds, check network and"
1715		       " cluster configuration.\n",
1716		     o2net_num_from_nn(nn),
1717		     o2net_idle_timeout() / 1000,
1718		     o2net_idle_timeout() % 1000);
1719
1720		o2net_set_nn_state(nn, NULL, 0, 0);
1721	}
1722	spin_unlock(&nn->nn_lock);
1723}
1724
1725static void o2net_still_up(struct work_struct *work)
1726{
1727	struct o2net_node *nn =
1728		container_of(work, struct o2net_node, nn_still_up.work);
1729
1730	o2quo_hb_still_up(o2net_num_from_nn(nn));
1731}
1732
1733/* ------------------------------------------------------------ */
1734
1735void o2net_disconnect_node(struct o2nm_node *node)
1736{
1737	struct o2net_node *nn = o2net_nn_from_num(node->nd_num);
1738
1739	/* don't reconnect until it's heartbeating again */
1740	spin_lock(&nn->nn_lock);
1741	atomic_set(&nn->nn_timeout, 0);
1742	o2net_set_nn_state(nn, NULL, 0, -ENOTCONN);
1743	spin_unlock(&nn->nn_lock);
1744
1745	if (o2net_wq) {
1746		cancel_delayed_work(&nn->nn_connect_expired);
1747		cancel_delayed_work(&nn->nn_connect_work);
1748		cancel_delayed_work(&nn->nn_still_up);
1749		flush_workqueue(o2net_wq);
1750	}
1751}
1752
1753static void o2net_hb_node_down_cb(struct o2nm_node *node, int node_num,
1754				  void *data)
1755{
1756	o2quo_hb_down(node_num);
1757
1758	if (!node)
1759		return;
1760
1761	if (node_num != o2nm_this_node())
1762		o2net_disconnect_node(node);
1763
1764	BUG_ON(atomic_read(&o2net_connected_peers) < 0);
1765}
1766
1767static void o2net_hb_node_up_cb(struct o2nm_node *node, int node_num,
1768				void *data)
1769{
1770	struct o2net_node *nn = o2net_nn_from_num(node_num);
1771
1772	o2quo_hb_up(node_num);
1773
1774	BUG_ON(!node);
1775
1776	/* ensure an immediate connect attempt */
1777	nn->nn_last_connect_attempt = jiffies -
1778		(msecs_to_jiffies(o2net_reconnect_delay()) + 1);
1779
1780	if (node_num != o2nm_this_node()) {
1781		/* believe it or not, accept and node hearbeating testing
1782		 * can succeed for this node before we got here.. so
1783		 * only use set_nn_state to clear the persistent error
1784		 * if that hasn't already happened */
1785		spin_lock(&nn->nn_lock);
1786		atomic_set(&nn->nn_timeout, 0);
1787		if (nn->nn_persistent_error)
1788			o2net_set_nn_state(nn, NULL, 0, 0);
1789		spin_unlock(&nn->nn_lock);
1790	}
1791}
1792
1793void o2net_unregister_hb_callbacks(void)
1794{
1795	o2hb_unregister_callback(NULL, &o2net_hb_up);
1796	o2hb_unregister_callback(NULL, &o2net_hb_down);
1797}
1798
1799int o2net_register_hb_callbacks(void)
1800{
1801	int ret;
1802
1803	o2hb_setup_callback(&o2net_hb_down, O2HB_NODE_DOWN_CB,
1804			    o2net_hb_node_down_cb, NULL, O2NET_HB_PRI);
1805	o2hb_setup_callback(&o2net_hb_up, O2HB_NODE_UP_CB,
1806			    o2net_hb_node_up_cb, NULL, O2NET_HB_PRI);
1807
1808	ret = o2hb_register_callback(NULL, &o2net_hb_up);
1809	if (ret == 0)
1810		ret = o2hb_register_callback(NULL, &o2net_hb_down);
1811
1812	if (ret)
1813		o2net_unregister_hb_callbacks();
1814
1815	return ret;
1816}
1817
1818/* ------------------------------------------------------------ */
1819
1820static int o2net_accept_one(struct socket *sock, int *more)
1821{
1822	int ret;
1823	struct sockaddr_in sin;
1824	struct socket *new_sock = NULL;
1825	struct o2nm_node *node = NULL;
1826	struct o2nm_node *local_node = NULL;
1827	struct o2net_sock_container *sc = NULL;
1828	struct o2net_node *nn;
1829	unsigned int noio_flag;
1830
1831	/*
1832	 * sock_create_lite allocates the sock with GFP_KERNEL. We must set
1833	 * per-process flag PF_MEMALLOC_NOIO so that all allocations done
1834	 * by this process are done as if GFP_NOIO was specified. So we
1835	 * are not reentering filesystem while doing memory reclaim.
1836	 */
1837	noio_flag = memalloc_noio_save();
1838
1839	BUG_ON(sock == NULL);
1840	*more = 0;
1841	ret = sock_create_lite(sock->sk->sk_family, sock->sk->sk_type,
1842			       sock->sk->sk_protocol, &new_sock);
1843	if (ret)
1844		goto out;
1845
1846	new_sock->type = sock->type;
1847	new_sock->ops = sock->ops;
1848	ret = sock->ops->accept(sock, new_sock, O_NONBLOCK, false);
1849	if (ret < 0)
1850		goto out;
1851
1852	*more = 1;
1853	new_sock->sk->sk_allocation = GFP_ATOMIC;
1854
1855	ret = o2net_set_nodelay(new_sock);
1856	if (ret) {
1857		mlog(ML_ERROR, "setting TCP_NODELAY failed with %d\n", ret);
1858		goto out;
1859	}
1860
1861	ret = o2net_set_usertimeout(new_sock);
1862	if (ret) {
1863		mlog(ML_ERROR, "set TCP_USER_TIMEOUT failed with %d\n", ret);
1864		goto out;
1865	}
1866
1867	ret = new_sock->ops->getname(new_sock, (struct sockaddr *) &sin, 1);
1868	if (ret < 0)
1869		goto out;
1870
1871	node = o2nm_get_node_by_ip(sin.sin_addr.s_addr);
1872	if (node == NULL) {
1873		printk(KERN_NOTICE "o2net: Attempt to connect from unknown "
1874		       "node at %pI4:%d\n", &sin.sin_addr.s_addr,
1875		       ntohs(sin.sin_port));
1876		ret = -EINVAL;
1877		goto out;
1878	}
1879
1880	if (o2nm_this_node() >= node->nd_num) {
1881		local_node = o2nm_get_node_by_num(o2nm_this_node());
1882		if (local_node)
1883			printk(KERN_NOTICE "o2net: Unexpected connect attempt "
1884					"seen at node '%s' (%u, %pI4:%d) from "
1885					"node '%s' (%u, %pI4:%d)\n",
1886					local_node->nd_name, local_node->nd_num,
1887					&(local_node->nd_ipv4_address),
1888					ntohs(local_node->nd_ipv4_port),
1889					node->nd_name,
1890					node->nd_num, &sin.sin_addr.s_addr,
1891					ntohs(sin.sin_port));
1892		ret = -EINVAL;
1893		goto out;
1894	}
1895
1896	/* this happens all the time when the other node sees our heartbeat
1897	 * and tries to connect before we see their heartbeat */
1898	if (!o2hb_check_node_heartbeating_from_callback(node->nd_num)) {
1899		mlog(ML_CONN, "attempt to connect from node '%s' at "
1900		     "%pI4:%d but it isn't heartbeating\n",
1901		     node->nd_name, &sin.sin_addr.s_addr,
1902		     ntohs(sin.sin_port));
1903		ret = -EINVAL;
1904		goto out;
1905	}
1906
1907	nn = o2net_nn_from_num(node->nd_num);
1908
1909	spin_lock(&nn->nn_lock);
1910	if (nn->nn_sc)
1911		ret = -EBUSY;
1912	else
1913		ret = 0;
1914	spin_unlock(&nn->nn_lock);
1915	if (ret) {
1916		printk(KERN_NOTICE "o2net: Attempt to connect from node '%s' "
1917		       "at %pI4:%d but it already has an open connection\n",
1918		       node->nd_name, &sin.sin_addr.s_addr,
1919		       ntohs(sin.sin_port));
1920		goto out;
1921	}
1922
1923	sc = sc_alloc(node);
1924	if (sc == NULL) {
1925		ret = -ENOMEM;
1926		goto out;
1927	}
1928
1929	sc->sc_sock = new_sock;
1930	new_sock = NULL;
1931
1932	spin_lock(&nn->nn_lock);
1933	atomic_set(&nn->nn_timeout, 0);
1934	o2net_set_nn_state(nn, sc, 0, 0);
1935	spin_unlock(&nn->nn_lock);
1936
1937	o2net_register_callbacks(sc->sc_sock->sk, sc);
1938	o2net_sc_queue_work(sc, &sc->sc_rx_work);
1939
1940	o2net_initialize_handshake();
1941	o2net_sendpage(sc, o2net_hand, sizeof(*o2net_hand));
1942
1943out:
1944	if (new_sock)
1945		sock_release(new_sock);
1946	if (node)
1947		o2nm_node_put(node);
1948	if (local_node)
1949		o2nm_node_put(local_node);
1950	if (sc)
1951		sc_put(sc);
1952
1953	memalloc_noio_restore(noio_flag);
1954	return ret;
1955}
1956
1957/*
1958 * This function is invoked in response to one or more
1959 * pending accepts at softIRQ level. We must drain the
1960 * entire que before returning.
1961 */
1962
1963static void o2net_accept_many(struct work_struct *work)
1964{
1965	struct socket *sock = o2net_listen_sock;
1966	int	more;
1967	int	err;
1968
1969	/*
1970	 * It is critical to note that due to interrupt moderation
1971	 * at the network driver level, we can't assume to get a
1972	 * softIRQ for every single conn since tcp SYN packets
1973	 * can arrive back-to-back, and therefore many pending
1974	 * accepts may result in just 1 softIRQ. If we terminate
1975	 * the o2net_accept_one() loop upon seeing an err, what happens
1976	 * to the rest of the conns in the queue? If no new SYN
1977	 * arrives for hours, no softIRQ  will be delivered,
1978	 * and the connections will just sit in the queue.
1979	 */
1980
1981	for (;;) {
1982		err = o2net_accept_one(sock, &more);
1983		if (!more)
1984			break;
1985		cond_resched();
1986	}
1987}
1988
1989static void o2net_listen_data_ready(struct sock *sk)
1990{
1991	void (*ready)(struct sock *sk);
1992
1993	read_lock_bh(&sk->sk_callback_lock);
1994	ready = sk->sk_user_data;
1995	if (ready == NULL) { /* check for teardown race */
1996		ready = sk->sk_data_ready;
1997		goto out;
1998	}
1999
2000	/* This callback may called twice when a new connection
2001	 * is  being established as a child socket inherits everything
2002	 * from a parent LISTEN socket, including the data_ready cb of
2003	 * the parent. This leads to a hazard. In o2net_accept_one()
2004	 * we are still initializing the child socket but have not
2005	 * changed the inherited data_ready callback yet when
2006	 * data starts arriving.
2007	 * We avoid this hazard by checking the state.
2008	 * For the listening socket,  the state will be TCP_LISTEN; for the new
2009	 * socket, will be  TCP_ESTABLISHED. Also, in this case,
2010	 * sk->sk_user_data is not a valid function pointer.
2011	 */
2012
2013	if (sk->sk_state == TCP_LISTEN) {
 
2014		queue_work(o2net_wq, &o2net_listen_work);
2015	} else {
2016		ready = NULL;
2017	}
2018
2019out:
2020	read_unlock_bh(&sk->sk_callback_lock);
2021	if (ready != NULL)
2022		ready(sk);
2023}
2024
2025static int o2net_open_listening_sock(__be32 addr, __be16 port)
2026{
2027	struct socket *sock = NULL;
2028	int ret;
2029	struct sockaddr_in sin = {
2030		.sin_family = PF_INET,
2031		.sin_addr = { .s_addr = addr },
2032		.sin_port = port,
2033	};
2034
2035	ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
2036	if (ret < 0) {
2037		printk(KERN_ERR "o2net: Error %d while creating socket\n", ret);
2038		goto out;
2039	}
2040
2041	sock->sk->sk_allocation = GFP_ATOMIC;
2042
2043	write_lock_bh(&sock->sk->sk_callback_lock);
2044	sock->sk->sk_user_data = sock->sk->sk_data_ready;
2045	sock->sk->sk_data_ready = o2net_listen_data_ready;
2046	write_unlock_bh(&sock->sk->sk_callback_lock);
2047
2048	o2net_listen_sock = sock;
2049	INIT_WORK(&o2net_listen_work, o2net_accept_many);
2050
2051	sock->sk->sk_reuse = SK_CAN_REUSE;
2052	ret = sock->ops->bind(sock, (struct sockaddr *)&sin, sizeof(sin));
2053	if (ret < 0) {
2054		printk(KERN_ERR "o2net: Error %d while binding socket at "
2055		       "%pI4:%u\n", ret, &addr, ntohs(port)); 
2056		goto out;
2057	}
2058
2059	ret = sock->ops->listen(sock, 64);
2060	if (ret < 0)
2061		printk(KERN_ERR "o2net: Error %d while listening on %pI4:%u\n",
2062		       ret, &addr, ntohs(port));
 
2063
2064out:
2065	if (ret) {
2066		o2net_listen_sock = NULL;
2067		if (sock)
2068			sock_release(sock);
2069	}
2070	return ret;
2071}
2072
2073/*
2074 * called from node manager when we should bring up our network listening
2075 * socket.  node manager handles all the serialization to only call this
2076 * once and to match it with o2net_stop_listening().  note,
2077 * o2nm_this_node() doesn't work yet as we're being called while it
2078 * is being set up.
2079 */
2080int o2net_start_listening(struct o2nm_node *node)
2081{
2082	int ret = 0;
2083
2084	BUG_ON(o2net_wq != NULL);
2085	BUG_ON(o2net_listen_sock != NULL);
2086
2087	mlog(ML_KTHREAD, "starting o2net thread...\n");
2088	o2net_wq = alloc_ordered_workqueue("o2net", WQ_MEM_RECLAIM);
2089	if (o2net_wq == NULL) {
2090		mlog(ML_ERROR, "unable to launch o2net thread\n");
2091		return -ENOMEM; /* ? */
2092	}
2093
2094	ret = o2net_open_listening_sock(node->nd_ipv4_address,
2095					node->nd_ipv4_port);
2096	if (ret) {
2097		destroy_workqueue(o2net_wq);
2098		o2net_wq = NULL;
2099	} else
2100		o2quo_conn_up(node->nd_num);
2101
2102	return ret;
2103}
2104
2105/* again, o2nm_this_node() doesn't work here as we're involved in
2106 * tearing it down */
2107void o2net_stop_listening(struct o2nm_node *node)
2108{
2109	struct socket *sock = o2net_listen_sock;
2110	size_t i;
2111
2112	BUG_ON(o2net_wq == NULL);
2113	BUG_ON(o2net_listen_sock == NULL);
2114
2115	/* stop the listening socket from generating work */
2116	write_lock_bh(&sock->sk->sk_callback_lock);
2117	sock->sk->sk_data_ready = sock->sk->sk_user_data;
2118	sock->sk->sk_user_data = NULL;
2119	write_unlock_bh(&sock->sk->sk_callback_lock);
2120
2121	for (i = 0; i < ARRAY_SIZE(o2net_nodes); i++) {
2122		struct o2nm_node *node = o2nm_get_node_by_num(i);
2123		if (node) {
2124			o2net_disconnect_node(node);
2125			o2nm_node_put(node);
2126		}
2127	}
2128
2129	/* finish all work and tear down the work queue */
2130	mlog(ML_KTHREAD, "waiting for o2net thread to exit....\n");
2131	destroy_workqueue(o2net_wq);
2132	o2net_wq = NULL;
2133
2134	sock_release(o2net_listen_sock);
2135	o2net_listen_sock = NULL;
2136
2137	o2quo_conn_err(node->nd_num);
2138}
2139
2140/* ------------------------------------------------------------ */
2141
2142int o2net_init(void)
2143{
2144	unsigned long i;
2145
2146	o2quo_init();
2147
2148	if (o2net_debugfs_init())
2149		goto out;
2150
2151	o2net_hand = kzalloc(sizeof(struct o2net_handshake), GFP_KERNEL);
2152	o2net_keep_req = kzalloc(sizeof(struct o2net_msg), GFP_KERNEL);
2153	o2net_keep_resp = kzalloc(sizeof(struct o2net_msg), GFP_KERNEL);
2154	if (!o2net_hand || !o2net_keep_req || !o2net_keep_resp)
2155		goto out;
 
 
 
 
2156
2157	o2net_hand->protocol_version = cpu_to_be64(O2NET_PROTOCOL_VERSION);
2158	o2net_hand->connector_id = cpu_to_be64(1);
2159
2160	o2net_keep_req->magic = cpu_to_be16(O2NET_MSG_KEEP_REQ_MAGIC);
2161	o2net_keep_resp->magic = cpu_to_be16(O2NET_MSG_KEEP_RESP_MAGIC);
2162
2163	for (i = 0; i < ARRAY_SIZE(o2net_nodes); i++) {
2164		struct o2net_node *nn = o2net_nn_from_num(i);
2165
2166		atomic_set(&nn->nn_timeout, 0);
2167		spin_lock_init(&nn->nn_lock);
2168		INIT_DELAYED_WORK(&nn->nn_connect_work, o2net_start_connect);
2169		INIT_DELAYED_WORK(&nn->nn_connect_expired,
2170				  o2net_connect_expired);
2171		INIT_DELAYED_WORK(&nn->nn_still_up, o2net_still_up);
2172		/* until we see hb from a node we'll return einval */
2173		nn->nn_persistent_error = -ENOTCONN;
2174		init_waitqueue_head(&nn->nn_sc_wq);
2175		idr_init(&nn->nn_status_idr);
2176		INIT_LIST_HEAD(&nn->nn_status_list);
2177	}
2178
2179	return 0;
2180
2181out:
2182	kfree(o2net_hand);
2183	kfree(o2net_keep_req);
2184	kfree(o2net_keep_resp);
2185	o2net_debugfs_exit();
2186	o2quo_exit();
2187	return -ENOMEM;
2188}
2189
2190void o2net_exit(void)
2191{
2192	o2quo_exit();
2193	kfree(o2net_hand);
2194	kfree(o2net_keep_req);
2195	kfree(o2net_keep_resp);
2196	o2net_debugfs_exit();
2197}