xref: /openbmc/linux/fs/ocfs2/cluster/tcp.c (revision 2612e3bbc0386368a850140a6c9b990cd496a5ec)
1  // SPDX-License-Identifier: GPL-2.0-or-later
2  /*
3   *
4   * Copyright (C) 2004 Oracle.  All rights reserved.
5   *
6   * ----
7   *
8   * Callers for this were originally written against a very simple synchronus
9   * API.  This implementation reflects those simple callers.  Some day I'm sure
10   * we'll need to move to a more robust posting/callback mechanism.
11   *
12   * Transmit calls pass in kernel virtual addresses and block copying this into
13   * the socket's tx buffers via a usual blocking sendmsg.  They'll block waiting
14   * for a failed socket to timeout.  TX callers can also pass in a poniter to an
15   * 'int' which gets filled with an errno off the wire in response to the
16   * message they send.
17   *
18   * Handlers for unsolicited messages are registered.  Each socket has a page
19   * that incoming data is copied into.  First the header, then the data.
20   * Handlers are called from only one thread with a reference to this per-socket
21   * page.  This page is destroyed after the handler call, so it can't be
22   * referenced beyond the call.  Handlers may block but are discouraged from
23   * doing so.
24   *
25   * Any framing errors (bad magic, large payload lengths) close a connection.
26   *
27   * Our sock_container holds the state we associate with a socket.  It's current
28   * framing state is held there as well as the refcounting we do around when it
29   * is safe to tear down the socket.  The socket is only finally torn down from
30   * the container when the container loses all of its references -- so as long
31   * as you hold a ref on the container you can trust that the socket is valid
32   * for use with kernel socket APIs.
33   *
34   * Connections are initiated between a pair of nodes when the node with the
35   * higher node number gets a heartbeat callback which indicates that the lower
36   * numbered node has started heartbeating.  The lower numbered node is passive
37   * and only accepts the connection if the higher numbered node is heartbeating.
38   */
39  
40  #include <linux/kernel.h>
41  #include <linux/sched/mm.h>
42  #include <linux/jiffies.h>
43  #include <linux/slab.h>
44  #include <linux/idr.h>
45  #include <linux/kref.h>
46  #include <linux/net.h>
47  #include <linux/export.h>
48  #include <net/tcp.h>
49  #include <trace/events/sock.h>
50  
51  #include <linux/uaccess.h>
52  
53  #include "heartbeat.h"
54  #include "tcp.h"
55  #include "nodemanager.h"
56  #define MLOG_MASK_PREFIX ML_TCP
57  #include "masklog.h"
58  #include "quorum.h"
59  
60  #include "tcp_internal.h"
61  
62  #define SC_NODEF_FMT "node %s (num %u) at %pI4:%u"
63  #define SC_NODEF_ARGS(sc) sc->sc_node->nd_name, sc->sc_node->nd_num,	\
64  			  &sc->sc_node->nd_ipv4_address,		\
65  			  ntohs(sc->sc_node->nd_ipv4_port)
66  
67  /*
68   * In the following two log macros, the whitespace after the ',' just
69   * before ##args is intentional. Otherwise, gcc 2.95 will eat the
70   * previous token if args expands to nothing.
71   */
72  #define msglog(hdr, fmt, args...) do {					\
73  	typeof(hdr) __hdr = (hdr);					\
74  	mlog(ML_MSG, "[mag %u len %u typ %u stat %d sys_stat %d "	\
75  	     "key %08x num %u] " fmt,					\
76  	     be16_to_cpu(__hdr->magic), be16_to_cpu(__hdr->data_len), 	\
77  	     be16_to_cpu(__hdr->msg_type), be32_to_cpu(__hdr->status),	\
78  	     be32_to_cpu(__hdr->sys_status), be32_to_cpu(__hdr->key),	\
79  	     be32_to_cpu(__hdr->msg_num) ,  ##args);			\
80  } while (0)
81  
82  #define sclog(sc, fmt, args...) do {					\
83  	typeof(sc) __sc = (sc);						\
84  	mlog(ML_SOCKET, "[sc %p refs %d sock %p node %u page %p "	\
85  	     "pg_off %zu] " fmt, __sc,					\
86  	     kref_read(&__sc->sc_kref), __sc->sc_sock,	\
87  	    __sc->sc_node->nd_num, __sc->sc_page, __sc->sc_page_off ,	\
88  	    ##args);							\
89  } while (0)
90  
91  static DEFINE_RWLOCK(o2net_handler_lock);
92  static struct rb_root o2net_handler_tree = RB_ROOT;
93  
94  static struct o2net_node o2net_nodes[O2NM_MAX_NODES];
95  
96  /* XXX someday we'll need better accounting */
97  static struct socket *o2net_listen_sock;
98  
99  /*
100   * listen work is only queued by the listening socket callbacks on the
101   * o2net_wq.  teardown detaches the callbacks before destroying the workqueue.
102   * quorum work is queued as sock containers are shutdown.. stop_listening
103   * tears down all the node's sock containers, preventing future shutdowns
104   * and queued quroum work, before canceling delayed quorum work and
105   * destroying the work queue.
106   */
107  static struct workqueue_struct *o2net_wq;
108  static struct work_struct o2net_listen_work;
109  
110  static struct o2hb_callback_func o2net_hb_up, o2net_hb_down;
111  #define O2NET_HB_PRI 0x1
112  
113  static struct o2net_handshake *o2net_hand;
114  static struct o2net_msg *o2net_keep_req, *o2net_keep_resp;
115  
116  static int o2net_sys_err_translations[O2NET_ERR_MAX] =
117  		{[O2NET_ERR_NONE]	= 0,
118  		 [O2NET_ERR_NO_HNDLR]	= -ENOPROTOOPT,
119  		 [O2NET_ERR_OVERFLOW]	= -EOVERFLOW,
120  		 [O2NET_ERR_DIED]	= -EHOSTDOWN,};
121  
122  /* can't quite avoid *all* internal declarations :/ */
123  static void o2net_sc_connect_completed(struct work_struct *work);
124  static void o2net_rx_until_empty(struct work_struct *work);
125  static void o2net_shutdown_sc(struct work_struct *work);
126  static void o2net_listen_data_ready(struct sock *sk);
127  static void o2net_sc_send_keep_req(struct work_struct *work);
128  static void o2net_idle_timer(struct timer_list *t);
129  static void o2net_sc_postpone_idle(struct o2net_sock_container *sc);
130  static void o2net_sc_reset_idle_timer(struct o2net_sock_container *sc);
131  
132  #ifdef CONFIG_DEBUG_FS
o2net_init_nst(struct o2net_send_tracking * nst,u32 msgtype,u32 msgkey,struct task_struct * task,u8 node)133  static void o2net_init_nst(struct o2net_send_tracking *nst, u32 msgtype,
134  			   u32 msgkey, struct task_struct *task, u8 node)
135  {
136  	INIT_LIST_HEAD(&nst->st_net_debug_item);
137  	nst->st_task = task;
138  	nst->st_msg_type = msgtype;
139  	nst->st_msg_key = msgkey;
140  	nst->st_node = node;
141  }
142  
o2net_set_nst_sock_time(struct o2net_send_tracking * nst)143  static inline void o2net_set_nst_sock_time(struct o2net_send_tracking *nst)
144  {
145  	nst->st_sock_time = ktime_get();
146  }
147  
o2net_set_nst_send_time(struct o2net_send_tracking * nst)148  static inline void o2net_set_nst_send_time(struct o2net_send_tracking *nst)
149  {
150  	nst->st_send_time = ktime_get();
151  }
152  
o2net_set_nst_status_time(struct o2net_send_tracking * nst)153  static inline void o2net_set_nst_status_time(struct o2net_send_tracking *nst)
154  {
155  	nst->st_status_time = ktime_get();
156  }
157  
o2net_set_nst_sock_container(struct o2net_send_tracking * nst,struct o2net_sock_container * sc)158  static inline void o2net_set_nst_sock_container(struct o2net_send_tracking *nst,
159  						struct o2net_sock_container *sc)
160  {
161  	nst->st_sc = sc;
162  }
163  
o2net_set_nst_msg_id(struct o2net_send_tracking * nst,u32 msg_id)164  static inline void o2net_set_nst_msg_id(struct o2net_send_tracking *nst,
165  					u32 msg_id)
166  {
167  	nst->st_id = msg_id;
168  }
169  
o2net_set_sock_timer(struct o2net_sock_container * sc)170  static inline void o2net_set_sock_timer(struct o2net_sock_container *sc)
171  {
172  	sc->sc_tv_timer = ktime_get();
173  }
174  
o2net_set_data_ready_time(struct o2net_sock_container * sc)175  static inline void o2net_set_data_ready_time(struct o2net_sock_container *sc)
176  {
177  	sc->sc_tv_data_ready = ktime_get();
178  }
179  
o2net_set_advance_start_time(struct o2net_sock_container * sc)180  static inline void o2net_set_advance_start_time(struct o2net_sock_container *sc)
181  {
182  	sc->sc_tv_advance_start = ktime_get();
183  }
184  
o2net_set_advance_stop_time(struct o2net_sock_container * sc)185  static inline void o2net_set_advance_stop_time(struct o2net_sock_container *sc)
186  {
187  	sc->sc_tv_advance_stop = ktime_get();
188  }
189  
o2net_set_func_start_time(struct o2net_sock_container * sc)190  static inline void o2net_set_func_start_time(struct o2net_sock_container *sc)
191  {
192  	sc->sc_tv_func_start = ktime_get();
193  }
194  
o2net_set_func_stop_time(struct o2net_sock_container * sc)195  static inline void o2net_set_func_stop_time(struct o2net_sock_container *sc)
196  {
197  	sc->sc_tv_func_stop = ktime_get();
198  }
199  
200  #else  /* CONFIG_DEBUG_FS */
201  # define o2net_init_nst(a, b, c, d, e)
202  # define o2net_set_nst_sock_time(a)
203  # define o2net_set_nst_send_time(a)
204  # define o2net_set_nst_status_time(a)
205  # define o2net_set_nst_sock_container(a, b)
206  # define o2net_set_nst_msg_id(a, b)
207  # define o2net_set_sock_timer(a)
208  # define o2net_set_data_ready_time(a)
209  # define o2net_set_advance_start_time(a)
210  # define o2net_set_advance_stop_time(a)
211  # define o2net_set_func_start_time(a)
212  # define o2net_set_func_stop_time(a)
213  #endif /* CONFIG_DEBUG_FS */
214  
215  #ifdef CONFIG_OCFS2_FS_STATS
o2net_get_func_run_time(struct o2net_sock_container * sc)216  static ktime_t o2net_get_func_run_time(struct o2net_sock_container *sc)
217  {
218  	return ktime_sub(sc->sc_tv_func_stop, sc->sc_tv_func_start);
219  }
220  
o2net_update_send_stats(struct o2net_send_tracking * nst,struct o2net_sock_container * sc)221  static void o2net_update_send_stats(struct o2net_send_tracking *nst,
222  				    struct o2net_sock_container *sc)
223  {
224  	sc->sc_tv_status_total = ktime_add(sc->sc_tv_status_total,
225  					   ktime_sub(ktime_get(),
226  						     nst->st_status_time));
227  	sc->sc_tv_send_total = ktime_add(sc->sc_tv_send_total,
228  					 ktime_sub(nst->st_status_time,
229  						   nst->st_send_time));
230  	sc->sc_tv_acquiry_total = ktime_add(sc->sc_tv_acquiry_total,
231  					    ktime_sub(nst->st_send_time,
232  						      nst->st_sock_time));
233  	sc->sc_send_count++;
234  }
235  
o2net_update_recv_stats(struct o2net_sock_container * sc)236  static void o2net_update_recv_stats(struct o2net_sock_container *sc)
237  {
238  	sc->sc_tv_process_total = ktime_add(sc->sc_tv_process_total,
239  					    o2net_get_func_run_time(sc));
240  	sc->sc_recv_count++;
241  }
242  
243  #else
244  
245  # define o2net_update_send_stats(a, b)
246  
247  # define o2net_update_recv_stats(sc)
248  
249  #endif /* CONFIG_OCFS2_FS_STATS */
250  
o2net_reconnect_delay(void)251  static inline unsigned int o2net_reconnect_delay(void)
252  {
253  	return o2nm_single_cluster->cl_reconnect_delay_ms;
254  }
255  
o2net_keepalive_delay(void)256  static inline unsigned int o2net_keepalive_delay(void)
257  {
258  	return o2nm_single_cluster->cl_keepalive_delay_ms;
259  }
260  
o2net_idle_timeout(void)261  static inline unsigned int o2net_idle_timeout(void)
262  {
263  	return o2nm_single_cluster->cl_idle_timeout_ms;
264  }
265  
o2net_sys_err_to_errno(enum o2net_system_error err)266  static inline int o2net_sys_err_to_errno(enum o2net_system_error err)
267  {
268  	int trans;
269  	BUG_ON(err >= O2NET_ERR_MAX);
270  	trans = o2net_sys_err_translations[err];
271  
272  	/* Just in case we mess up the translation table above */
273  	BUG_ON(err != O2NET_ERR_NONE && trans == 0);
274  	return trans;
275  }
276  
o2net_nn_from_num(u8 node_num)277  static struct o2net_node * o2net_nn_from_num(u8 node_num)
278  {
279  	BUG_ON(node_num >= ARRAY_SIZE(o2net_nodes));
280  	return &o2net_nodes[node_num];
281  }
282  
o2net_num_from_nn(struct o2net_node * nn)283  static u8 o2net_num_from_nn(struct o2net_node *nn)
284  {
285  	BUG_ON(nn == NULL);
286  	return nn - o2net_nodes;
287  }
288  
289  /* ------------------------------------------------------------ */
290  
o2net_prep_nsw(struct o2net_node * nn,struct o2net_status_wait * nsw)291  static int o2net_prep_nsw(struct o2net_node *nn, struct o2net_status_wait *nsw)
292  {
293  	int ret;
294  
295  	spin_lock(&nn->nn_lock);
296  	ret = idr_alloc(&nn->nn_status_idr, nsw, 0, 0, GFP_ATOMIC);
297  	if (ret >= 0) {
298  		nsw->ns_id = ret;
299  		list_add_tail(&nsw->ns_node_item, &nn->nn_status_list);
300  	}
301  	spin_unlock(&nn->nn_lock);
302  	if (ret < 0)
303  		return ret;
304  
305  	init_waitqueue_head(&nsw->ns_wq);
306  	nsw->ns_sys_status = O2NET_ERR_NONE;
307  	nsw->ns_status = 0;
308  	return 0;
309  }
310  
o2net_complete_nsw_locked(struct o2net_node * nn,struct o2net_status_wait * nsw,enum o2net_system_error sys_status,s32 status)311  static void o2net_complete_nsw_locked(struct o2net_node *nn,
312  				      struct o2net_status_wait *nsw,
313  				      enum o2net_system_error sys_status,
314  				      s32 status)
315  {
316  	assert_spin_locked(&nn->nn_lock);
317  
318  	if (!list_empty(&nsw->ns_node_item)) {
319  		list_del_init(&nsw->ns_node_item);
320  		nsw->ns_sys_status = sys_status;
321  		nsw->ns_status = status;
322  		idr_remove(&nn->nn_status_idr, nsw->ns_id);
323  		wake_up(&nsw->ns_wq);
324  	}
325  }
326  
o2net_complete_nsw(struct o2net_node * nn,struct o2net_status_wait * nsw,u64 id,enum o2net_system_error sys_status,s32 status)327  static void o2net_complete_nsw(struct o2net_node *nn,
328  			       struct o2net_status_wait *nsw,
329  			       u64 id, enum o2net_system_error sys_status,
330  			       s32 status)
331  {
332  	spin_lock(&nn->nn_lock);
333  	if (nsw == NULL) {
334  		if (id > INT_MAX)
335  			goto out;
336  
337  		nsw = idr_find(&nn->nn_status_idr, id);
338  		if (nsw == NULL)
339  			goto out;
340  	}
341  
342  	o2net_complete_nsw_locked(nn, nsw, sys_status, status);
343  
344  out:
345  	spin_unlock(&nn->nn_lock);
346  	return;
347  }
348  
o2net_complete_nodes_nsw(struct o2net_node * nn)349  static void o2net_complete_nodes_nsw(struct o2net_node *nn)
350  {
351  	struct o2net_status_wait *nsw, *tmp;
352  	unsigned int num_kills = 0;
353  
354  	assert_spin_locked(&nn->nn_lock);
355  
356  	list_for_each_entry_safe(nsw, tmp, &nn->nn_status_list, ns_node_item) {
357  		o2net_complete_nsw_locked(nn, nsw, O2NET_ERR_DIED, 0);
358  		num_kills++;
359  	}
360  
361  	mlog(0, "completed %d messages for node %u\n", num_kills,
362  	     o2net_num_from_nn(nn));
363  }
364  
o2net_nsw_completed(struct o2net_node * nn,struct o2net_status_wait * nsw)365  static int o2net_nsw_completed(struct o2net_node *nn,
366  			       struct o2net_status_wait *nsw)
367  {
368  	int completed;
369  	spin_lock(&nn->nn_lock);
370  	completed = list_empty(&nsw->ns_node_item);
371  	spin_unlock(&nn->nn_lock);
372  	return completed;
373  }
374  
375  /* ------------------------------------------------------------ */
376  
sc_kref_release(struct kref * kref)377  static void sc_kref_release(struct kref *kref)
378  {
379  	struct o2net_sock_container *sc = container_of(kref,
380  					struct o2net_sock_container, sc_kref);
381  	BUG_ON(timer_pending(&sc->sc_idle_timeout));
382  
383  	sclog(sc, "releasing\n");
384  
385  	if (sc->sc_sock) {
386  		sock_release(sc->sc_sock);
387  		sc->sc_sock = NULL;
388  	}
389  
390  	o2nm_undepend_item(&sc->sc_node->nd_item);
391  	o2nm_node_put(sc->sc_node);
392  	sc->sc_node = NULL;
393  
394  	o2net_debug_del_sc(sc);
395  
396  	if (sc->sc_page)
397  		__free_page(sc->sc_page);
398  	kfree(sc);
399  }
400  
sc_put(struct o2net_sock_container * sc)401  static void sc_put(struct o2net_sock_container *sc)
402  {
403  	sclog(sc, "put\n");
404  	kref_put(&sc->sc_kref, sc_kref_release);
405  }
sc_get(struct o2net_sock_container * sc)406  static void sc_get(struct o2net_sock_container *sc)
407  {
408  	sclog(sc, "get\n");
409  	kref_get(&sc->sc_kref);
410  }
sc_alloc(struct o2nm_node * node)411  static struct o2net_sock_container *sc_alloc(struct o2nm_node *node)
412  {
413  	struct o2net_sock_container *sc, *ret = NULL;
414  	struct page *page = NULL;
415  	int status = 0;
416  
417  	page = alloc_page(GFP_NOFS);
418  	sc = kzalloc(sizeof(*sc), GFP_NOFS);
419  	if (sc == NULL || page == NULL)
420  		goto out;
421  
422  	kref_init(&sc->sc_kref);
423  	o2nm_node_get(node);
424  	sc->sc_node = node;
425  
426  	/* pin the node item of the remote node */
427  	status = o2nm_depend_item(&node->nd_item);
428  	if (status) {
429  		mlog_errno(status);
430  		o2nm_node_put(node);
431  		goto out;
432  	}
433  	INIT_WORK(&sc->sc_connect_work, o2net_sc_connect_completed);
434  	INIT_WORK(&sc->sc_rx_work, o2net_rx_until_empty);
435  	INIT_WORK(&sc->sc_shutdown_work, o2net_shutdown_sc);
436  	INIT_DELAYED_WORK(&sc->sc_keepalive_work, o2net_sc_send_keep_req);
437  
438  	timer_setup(&sc->sc_idle_timeout, o2net_idle_timer, 0);
439  
440  	sclog(sc, "alloced\n");
441  
442  	ret = sc;
443  	sc->sc_page = page;
444  	o2net_debug_add_sc(sc);
445  	sc = NULL;
446  	page = NULL;
447  
448  out:
449  	if (page)
450  		__free_page(page);
451  	kfree(sc);
452  
453  	return ret;
454  }
455  
456  /* ------------------------------------------------------------ */
457  
o2net_sc_queue_work(struct o2net_sock_container * sc,struct work_struct * work)458  static void o2net_sc_queue_work(struct o2net_sock_container *sc,
459  				struct work_struct *work)
460  {
461  	sc_get(sc);
462  	if (!queue_work(o2net_wq, work))
463  		sc_put(sc);
464  }
o2net_sc_queue_delayed_work(struct o2net_sock_container * sc,struct delayed_work * work,int delay)465  static void o2net_sc_queue_delayed_work(struct o2net_sock_container *sc,
466  					struct delayed_work *work,
467  					int delay)
468  {
469  	sc_get(sc);
470  	if (!queue_delayed_work(o2net_wq, work, delay))
471  		sc_put(sc);
472  }
o2net_sc_cancel_delayed_work(struct o2net_sock_container * sc,struct delayed_work * work)473  static void o2net_sc_cancel_delayed_work(struct o2net_sock_container *sc,
474  					 struct delayed_work *work)
475  {
476  	if (cancel_delayed_work(work))
477  		sc_put(sc);
478  }
479  
480  static atomic_t o2net_connected_peers = ATOMIC_INIT(0);
481  
o2net_num_connected_peers(void)482  int o2net_num_connected_peers(void)
483  {
484  	return atomic_read(&o2net_connected_peers);
485  }
486  
o2net_set_nn_state(struct o2net_node * nn,struct o2net_sock_container * sc,unsigned valid,int err)487  static void o2net_set_nn_state(struct o2net_node *nn,
488  			       struct o2net_sock_container *sc,
489  			       unsigned valid, int err)
490  {
491  	int was_valid = nn->nn_sc_valid;
492  	int was_err = nn->nn_persistent_error;
493  	struct o2net_sock_container *old_sc = nn->nn_sc;
494  
495  	assert_spin_locked(&nn->nn_lock);
496  
497  	if (old_sc && !sc)
498  		atomic_dec(&o2net_connected_peers);
499  	else if (!old_sc && sc)
500  		atomic_inc(&o2net_connected_peers);
501  
502  	/* the node num comparison and single connect/accept path should stop
503  	 * an non-null sc from being overwritten with another */
504  	BUG_ON(sc && nn->nn_sc && nn->nn_sc != sc);
505  	mlog_bug_on_msg(err && valid, "err %d valid %u\n", err, valid);
506  	mlog_bug_on_msg(valid && !sc, "valid %u sc %p\n", valid, sc);
507  
508  	if (was_valid && !valid && err == 0)
509  		err = -ENOTCONN;
510  
511  	mlog(ML_CONN, "node %u sc: %p -> %p, valid %u -> %u, err %d -> %d\n",
512  	     o2net_num_from_nn(nn), nn->nn_sc, sc, nn->nn_sc_valid, valid,
513  	     nn->nn_persistent_error, err);
514  
515  	nn->nn_sc = sc;
516  	nn->nn_sc_valid = valid ? 1 : 0;
517  	nn->nn_persistent_error = err;
518  
519  	/* mirrors o2net_tx_can_proceed() */
520  	if (nn->nn_persistent_error || nn->nn_sc_valid)
521  		wake_up(&nn->nn_sc_wq);
522  
523  	if (was_valid && !was_err && nn->nn_persistent_error) {
524  		o2quo_conn_err(o2net_num_from_nn(nn));
525  		queue_delayed_work(o2net_wq, &nn->nn_still_up,
526  				   msecs_to_jiffies(O2NET_QUORUM_DELAY_MS));
527  	}
528  
529  	if (was_valid && !valid) {
530  		if (old_sc)
531  			printk(KERN_NOTICE "o2net: No longer connected to "
532  				SC_NODEF_FMT "\n", SC_NODEF_ARGS(old_sc));
533  		o2net_complete_nodes_nsw(nn);
534  	}
535  
536  	if (!was_valid && valid) {
537  		o2quo_conn_up(o2net_num_from_nn(nn));
538  		cancel_delayed_work(&nn->nn_connect_expired);
539  		printk(KERN_NOTICE "o2net: %s " SC_NODEF_FMT "\n",
540  		       o2nm_this_node() > sc->sc_node->nd_num ?
541  		       "Connected to" : "Accepted connection from",
542  		       SC_NODEF_ARGS(sc));
543  	}
544  
545  	/* trigger the connecting worker func as long as we're not valid,
546  	 * it will back off if it shouldn't connect.  This can be called
547  	 * from node config teardown and so needs to be careful about
548  	 * the work queue actually being up. */
549  	if (!valid && o2net_wq) {
550  		unsigned long delay;
551  		/* delay if we're within a RECONNECT_DELAY of the
552  		 * last attempt */
553  		delay = (nn->nn_last_connect_attempt +
554  			 msecs_to_jiffies(o2net_reconnect_delay()))
555  			- jiffies;
556  		if (delay > msecs_to_jiffies(o2net_reconnect_delay()))
557  			delay = 0;
558  		mlog(ML_CONN, "queueing conn attempt in %lu jiffies\n", delay);
559  		queue_delayed_work(o2net_wq, &nn->nn_connect_work, delay);
560  
561  		/*
562  		 * Delay the expired work after idle timeout.
563  		 *
564  		 * We might have lots of failed connection attempts that run
565  		 * through here but we only cancel the connect_expired work when
566  		 * a connection attempt succeeds.  So only the first enqueue of
567  		 * the connect_expired work will do anything.  The rest will see
568  		 * that it's already queued and do nothing.
569  		 */
570  		delay += msecs_to_jiffies(o2net_idle_timeout());
571  		queue_delayed_work(o2net_wq, &nn->nn_connect_expired, delay);
572  	}
573  
574  	/* keep track of the nn's sc ref for the caller */
575  	if ((old_sc == NULL) && sc)
576  		sc_get(sc);
577  	if (old_sc && (old_sc != sc)) {
578  		o2net_sc_queue_work(old_sc, &old_sc->sc_shutdown_work);
579  		sc_put(old_sc);
580  	}
581  }
582  
583  /* see o2net_register_callbacks() */
o2net_data_ready(struct sock * sk)584  static void o2net_data_ready(struct sock *sk)
585  {
586  	void (*ready)(struct sock *sk);
587  	struct o2net_sock_container *sc;
588  
589  	trace_sk_data_ready(sk);
590  
591  	read_lock_bh(&sk->sk_callback_lock);
592  	sc = sk->sk_user_data;
593  	if (sc) {
594  		sclog(sc, "data_ready hit\n");
595  		o2net_set_data_ready_time(sc);
596  		o2net_sc_queue_work(sc, &sc->sc_rx_work);
597  		ready = sc->sc_data_ready;
598  	} else {
599  		ready = sk->sk_data_ready;
600  	}
601  	read_unlock_bh(&sk->sk_callback_lock);
602  
603  	ready(sk);
604  }
605  
606  /* see o2net_register_callbacks() */
o2net_state_change(struct sock * sk)607  static void o2net_state_change(struct sock *sk)
608  {
609  	void (*state_change)(struct sock *sk);
610  	struct o2net_sock_container *sc;
611  
612  	read_lock_bh(&sk->sk_callback_lock);
613  	sc = sk->sk_user_data;
614  	if (sc == NULL) {
615  		state_change = sk->sk_state_change;
616  		goto out;
617  	}
618  
619  	sclog(sc, "state_change to %d\n", sk->sk_state);
620  
621  	state_change = sc->sc_state_change;
622  
623  	switch(sk->sk_state) {
624  	/* ignore connecting sockets as they make progress */
625  	case TCP_SYN_SENT:
626  	case TCP_SYN_RECV:
627  		break;
628  	case TCP_ESTABLISHED:
629  		o2net_sc_queue_work(sc, &sc->sc_connect_work);
630  		break;
631  	default:
632  		printk(KERN_INFO "o2net: Connection to " SC_NODEF_FMT
633  			" shutdown, state %d\n",
634  			SC_NODEF_ARGS(sc), sk->sk_state);
635  		o2net_sc_queue_work(sc, &sc->sc_shutdown_work);
636  		break;
637  	}
638  out:
639  	read_unlock_bh(&sk->sk_callback_lock);
640  	state_change(sk);
641  }
642  
643  /*
644   * we register callbacks so we can queue work on events before calling
645   * the original callbacks.  our callbacks our careful to test user_data
646   * to discover when they've reaced with o2net_unregister_callbacks().
647   */
o2net_register_callbacks(struct sock * sk,struct o2net_sock_container * sc)648  static void o2net_register_callbacks(struct sock *sk,
649  				     struct o2net_sock_container *sc)
650  {
651  	write_lock_bh(&sk->sk_callback_lock);
652  
653  	/* accepted sockets inherit the old listen socket data ready */
654  	if (sk->sk_data_ready == o2net_listen_data_ready) {
655  		sk->sk_data_ready = sk->sk_user_data;
656  		sk->sk_user_data = NULL;
657  	}
658  
659  	BUG_ON(sk->sk_user_data != NULL);
660  	sk->sk_user_data = sc;
661  	sc_get(sc);
662  
663  	sc->sc_data_ready = sk->sk_data_ready;
664  	sc->sc_state_change = sk->sk_state_change;
665  	sk->sk_data_ready = o2net_data_ready;
666  	sk->sk_state_change = o2net_state_change;
667  
668  	mutex_init(&sc->sc_send_lock);
669  
670  	write_unlock_bh(&sk->sk_callback_lock);
671  }
672  
o2net_unregister_callbacks(struct sock * sk,struct o2net_sock_container * sc)673  static int o2net_unregister_callbacks(struct sock *sk,
674  			           struct o2net_sock_container *sc)
675  {
676  	int ret = 0;
677  
678  	write_lock_bh(&sk->sk_callback_lock);
679  	if (sk->sk_user_data == sc) {
680  		ret = 1;
681  		sk->sk_user_data = NULL;
682  		sk->sk_data_ready = sc->sc_data_ready;
683  		sk->sk_state_change = sc->sc_state_change;
684  	}
685  	write_unlock_bh(&sk->sk_callback_lock);
686  
687  	return ret;
688  }
689  
690  /*
691   * this is a little helper that is called by callers who have seen a problem
692   * with an sc and want to detach it from the nn if someone already hasn't beat
693   * them to it.  if an error is given then the shutdown will be persistent
694   * and pending transmits will be canceled.
695   */
o2net_ensure_shutdown(struct o2net_node * nn,struct o2net_sock_container * sc,int err)696  static void o2net_ensure_shutdown(struct o2net_node *nn,
697  			           struct o2net_sock_container *sc,
698  				   int err)
699  {
700  	spin_lock(&nn->nn_lock);
701  	if (nn->nn_sc == sc)
702  		o2net_set_nn_state(nn, NULL, 0, err);
703  	spin_unlock(&nn->nn_lock);
704  }
705  
706  /*
707   * This work queue function performs the blocking parts of socket shutdown.  A
708   * few paths lead here.  set_nn_state will trigger this callback if it sees an
709   * sc detached from the nn.  state_change will also trigger this callback
710   * directly when it sees errors.  In that case we need to call set_nn_state
711   * ourselves as state_change couldn't get the nn_lock and call set_nn_state
712   * itself.
713   */
o2net_shutdown_sc(struct work_struct * work)714  static void o2net_shutdown_sc(struct work_struct *work)
715  {
716  	struct o2net_sock_container *sc =
717  		container_of(work, struct o2net_sock_container,
718  			     sc_shutdown_work);
719  	struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
720  
721  	sclog(sc, "shutting down\n");
722  
723  	/* drop the callbacks ref and call shutdown only once */
724  	if (o2net_unregister_callbacks(sc->sc_sock->sk, sc)) {
725  		/* we shouldn't flush as we're in the thread, the
726  		 * races with pending sc work structs are harmless */
727  		del_timer_sync(&sc->sc_idle_timeout);
728  		o2net_sc_cancel_delayed_work(sc, &sc->sc_keepalive_work);
729  		sc_put(sc);
730  		kernel_sock_shutdown(sc->sc_sock, SHUT_RDWR);
731  	}
732  
733  	/* not fatal so failed connects before the other guy has our
734  	 * heartbeat can be retried */
735  	o2net_ensure_shutdown(nn, sc, 0);
736  	sc_put(sc);
737  }
738  
739  /* ------------------------------------------------------------ */
740  
o2net_handler_cmp(struct o2net_msg_handler * nmh,u32 msg_type,u32 key)741  static int o2net_handler_cmp(struct o2net_msg_handler *nmh, u32 msg_type,
742  			     u32 key)
743  {
744  	int ret = memcmp(&nmh->nh_key, &key, sizeof(key));
745  
746  	if (ret == 0)
747  		ret = memcmp(&nmh->nh_msg_type, &msg_type, sizeof(msg_type));
748  
749  	return ret;
750  }
751  
752  static struct o2net_msg_handler *
o2net_handler_tree_lookup(u32 msg_type,u32 key,struct rb_node *** ret_p,struct rb_node ** ret_parent)753  o2net_handler_tree_lookup(u32 msg_type, u32 key, struct rb_node ***ret_p,
754  			  struct rb_node **ret_parent)
755  {
756  	struct rb_node **p = &o2net_handler_tree.rb_node;
757  	struct rb_node *parent = NULL;
758  	struct o2net_msg_handler *nmh, *ret = NULL;
759  	int cmp;
760  
761  	while (*p) {
762  		parent = *p;
763  		nmh = rb_entry(parent, struct o2net_msg_handler, nh_node);
764  		cmp = o2net_handler_cmp(nmh, msg_type, key);
765  
766  		if (cmp < 0)
767  			p = &(*p)->rb_left;
768  		else if (cmp > 0)
769  			p = &(*p)->rb_right;
770  		else {
771  			ret = nmh;
772  			break;
773  		}
774  	}
775  
776  	if (ret_p != NULL)
777  		*ret_p = p;
778  	if (ret_parent != NULL)
779  		*ret_parent = parent;
780  
781  	return ret;
782  }
783  
o2net_handler_kref_release(struct kref * kref)784  static void o2net_handler_kref_release(struct kref *kref)
785  {
786  	struct o2net_msg_handler *nmh;
787  	nmh = container_of(kref, struct o2net_msg_handler, nh_kref);
788  
789  	kfree(nmh);
790  }
791  
o2net_handler_put(struct o2net_msg_handler * nmh)792  static void o2net_handler_put(struct o2net_msg_handler *nmh)
793  {
794  	kref_put(&nmh->nh_kref, o2net_handler_kref_release);
795  }
796  
797  /* max_len is protection for the handler func.  incoming messages won't
798   * be given to the handler if their payload is longer than the max. */
o2net_register_handler(u32 msg_type,u32 key,u32 max_len,o2net_msg_handler_func * func,void * data,o2net_post_msg_handler_func * post_func,struct list_head * unreg_list)799  int o2net_register_handler(u32 msg_type, u32 key, u32 max_len,
800  			   o2net_msg_handler_func *func, void *data,
801  			   o2net_post_msg_handler_func *post_func,
802  			   struct list_head *unreg_list)
803  {
804  	struct o2net_msg_handler *nmh = NULL;
805  	struct rb_node **p, *parent;
806  	int ret = 0;
807  
808  	if (max_len > O2NET_MAX_PAYLOAD_BYTES) {
809  		mlog(0, "max_len for message handler out of range: %u\n",
810  			max_len);
811  		ret = -EINVAL;
812  		goto out;
813  	}
814  
815  	if (!msg_type) {
816  		mlog(0, "no message type provided: %u, %p\n", msg_type, func);
817  		ret = -EINVAL;
818  		goto out;
819  
820  	}
821  	if (!func) {
822  		mlog(0, "no message handler provided: %u, %p\n",
823  		       msg_type, func);
824  		ret = -EINVAL;
825  		goto out;
826  	}
827  
828         	nmh = kzalloc(sizeof(struct o2net_msg_handler), GFP_NOFS);
829  	if (nmh == NULL) {
830  		ret = -ENOMEM;
831  		goto out;
832  	}
833  
834  	nmh->nh_func = func;
835  	nmh->nh_func_data = data;
836  	nmh->nh_post_func = post_func;
837  	nmh->nh_msg_type = msg_type;
838  	nmh->nh_max_len = max_len;
839  	nmh->nh_key = key;
840  	/* the tree and list get this ref.. they're both removed in
841  	 * unregister when this ref is dropped */
842  	kref_init(&nmh->nh_kref);
843  	INIT_LIST_HEAD(&nmh->nh_unregister_item);
844  
845  	write_lock(&o2net_handler_lock);
846  	if (o2net_handler_tree_lookup(msg_type, key, &p, &parent))
847  		ret = -EEXIST;
848  	else {
849  	        rb_link_node(&nmh->nh_node, parent, p);
850  		rb_insert_color(&nmh->nh_node, &o2net_handler_tree);
851  		list_add_tail(&nmh->nh_unregister_item, unreg_list);
852  
853  		mlog(ML_TCP, "registered handler func %p type %u key %08x\n",
854  		     func, msg_type, key);
855  		/* we've had some trouble with handlers seemingly vanishing. */
856  		mlog_bug_on_msg(o2net_handler_tree_lookup(msg_type, key, &p,
857  							  &parent) == NULL,
858  			        "couldn't find handler we *just* registered "
859  				"for type %u key %08x\n", msg_type, key);
860  	}
861  	write_unlock(&o2net_handler_lock);
862  
863  out:
864  	if (ret)
865  		kfree(nmh);
866  
867  	return ret;
868  }
869  EXPORT_SYMBOL_GPL(o2net_register_handler);
870  
o2net_unregister_handler_list(struct list_head * list)871  void o2net_unregister_handler_list(struct list_head *list)
872  {
873  	struct o2net_msg_handler *nmh, *n;
874  
875  	write_lock(&o2net_handler_lock);
876  	list_for_each_entry_safe(nmh, n, list, nh_unregister_item) {
877  		mlog(ML_TCP, "unregistering handler func %p type %u key %08x\n",
878  		     nmh->nh_func, nmh->nh_msg_type, nmh->nh_key);
879  		rb_erase(&nmh->nh_node, &o2net_handler_tree);
880  		list_del_init(&nmh->nh_unregister_item);
881  		kref_put(&nmh->nh_kref, o2net_handler_kref_release);
882  	}
883  	write_unlock(&o2net_handler_lock);
884  }
885  EXPORT_SYMBOL_GPL(o2net_unregister_handler_list);
886  
o2net_handler_get(u32 msg_type,u32 key)887  static struct o2net_msg_handler *o2net_handler_get(u32 msg_type, u32 key)
888  {
889  	struct o2net_msg_handler *nmh;
890  
891  	read_lock(&o2net_handler_lock);
892  	nmh = o2net_handler_tree_lookup(msg_type, key, NULL, NULL);
893  	if (nmh)
894  		kref_get(&nmh->nh_kref);
895  	read_unlock(&o2net_handler_lock);
896  
897  	return nmh;
898  }
899  
900  /* ------------------------------------------------------------ */
901  
o2net_recv_tcp_msg(struct socket * sock,void * data,size_t len)902  static int o2net_recv_tcp_msg(struct socket *sock, void *data, size_t len)
903  {
904  	struct kvec vec = { .iov_len = len, .iov_base = data, };
905  	struct msghdr msg = { .msg_flags = MSG_DONTWAIT, };
906  	iov_iter_kvec(&msg.msg_iter, ITER_DEST, &vec, 1, len);
907  	return sock_recvmsg(sock, &msg, MSG_DONTWAIT);
908  }
909  
o2net_send_tcp_msg(struct socket * sock,struct kvec * vec,size_t veclen,size_t total)910  static int o2net_send_tcp_msg(struct socket *sock, struct kvec *vec,
911  			      size_t veclen, size_t total)
912  {
913  	int ret;
914  	struct msghdr msg = {.msg_flags = 0,};
915  
916  	if (sock == NULL) {
917  		ret = -EINVAL;
918  		goto out;
919  	}
920  
921  	ret = kernel_sendmsg(sock, &msg, vec, veclen, total);
922  	if (likely(ret == total))
923  		return 0;
924  	mlog(ML_ERROR, "sendmsg returned %d instead of %zu\n", ret, total);
925  	if (ret >= 0)
926  		ret = -EPIPE; /* should be smarter, I bet */
927  out:
928  	mlog(0, "returning error: %d\n", ret);
929  	return ret;
930  }
931  
o2net_sendpage(struct o2net_sock_container * sc,void * virt,size_t size)932  static void o2net_sendpage(struct o2net_sock_container *sc,
933  			   void *virt, size_t size)
934  {
935  	struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
936  	struct msghdr msg = {};
937  	struct bio_vec bv;
938  	ssize_t ret;
939  
940  	bvec_set_virt(&bv, virt, size);
941  	iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, &bv, 1, size);
942  
943  	while (1) {
944  		msg.msg_flags = MSG_DONTWAIT | MSG_SPLICE_PAGES;
945  		mutex_lock(&sc->sc_send_lock);
946  		ret = sock_sendmsg(sc->sc_sock, &msg);
947  		mutex_unlock(&sc->sc_send_lock);
948  
949  		if (ret == size)
950  			break;
951  		if (ret == (ssize_t)-EAGAIN) {
952  			mlog(0, "sendpage of size %zu to " SC_NODEF_FMT
953  			     " returned EAGAIN\n", size, SC_NODEF_ARGS(sc));
954  			cond_resched();
955  			continue;
956  		}
957  		mlog(ML_ERROR, "sendpage of size %zu to " SC_NODEF_FMT
958  		     " failed with %zd\n", size, SC_NODEF_ARGS(sc), ret);
959  		o2net_ensure_shutdown(nn, sc, 0);
960  		break;
961  	}
962  }
963  
o2net_init_msg(struct o2net_msg * msg,u16 data_len,u16 msg_type,u32 key)964  static void o2net_init_msg(struct o2net_msg *msg, u16 data_len, u16 msg_type, u32 key)
965  {
966  	memset(msg, 0, sizeof(struct o2net_msg));
967  	msg->magic = cpu_to_be16(O2NET_MSG_MAGIC);
968  	msg->data_len = cpu_to_be16(data_len);
969  	msg->msg_type = cpu_to_be16(msg_type);
970  	msg->sys_status = cpu_to_be32(O2NET_ERR_NONE);
971  	msg->status = 0;
972  	msg->key = cpu_to_be32(key);
973  }
974  
o2net_tx_can_proceed(struct o2net_node * nn,struct o2net_sock_container ** sc_ret,int * error)975  static int o2net_tx_can_proceed(struct o2net_node *nn,
976  			        struct o2net_sock_container **sc_ret,
977  				int *error)
978  {
979  	int ret = 0;
980  
981  	spin_lock(&nn->nn_lock);
982  	if (nn->nn_persistent_error) {
983  		ret = 1;
984  		*sc_ret = NULL;
985  		*error = nn->nn_persistent_error;
986  	} else if (nn->nn_sc_valid) {
987  		kref_get(&nn->nn_sc->sc_kref);
988  
989  		ret = 1;
990  		*sc_ret = nn->nn_sc;
991  		*error = 0;
992  	}
993  	spin_unlock(&nn->nn_lock);
994  
995  	return ret;
996  }
997  
998  /* Get a map of all nodes to which this node is currently connected to */
o2net_fill_node_map(unsigned long * map,unsigned int bits)999  void o2net_fill_node_map(unsigned long *map, unsigned int bits)
1000  {
1001  	struct o2net_sock_container *sc;
1002  	int node, ret;
1003  
1004  	bitmap_zero(map, bits);
1005  	for (node = 0; node < O2NM_MAX_NODES; ++node) {
1006  		if (!o2net_tx_can_proceed(o2net_nn_from_num(node), &sc, &ret))
1007  			continue;
1008  		if (!ret) {
1009  			set_bit(node, map);
1010  			sc_put(sc);
1011  		}
1012  	}
1013  }
1014  EXPORT_SYMBOL_GPL(o2net_fill_node_map);
1015  
o2net_send_message_vec(u32 msg_type,u32 key,struct kvec * caller_vec,size_t caller_veclen,u8 target_node,int * status)1016  int o2net_send_message_vec(u32 msg_type, u32 key, struct kvec *caller_vec,
1017  			   size_t caller_veclen, u8 target_node, int *status)
1018  {
1019  	int ret = 0;
1020  	struct o2net_msg *msg = NULL;
1021  	size_t veclen, caller_bytes = 0;
1022  	struct kvec *vec = NULL;
1023  	struct o2net_sock_container *sc = NULL;
1024  	struct o2net_node *nn = o2net_nn_from_num(target_node);
1025  	struct o2net_status_wait nsw = {
1026  		.ns_node_item = LIST_HEAD_INIT(nsw.ns_node_item),
1027  	};
1028  	struct o2net_send_tracking nst;
1029  
1030  	o2net_init_nst(&nst, msg_type, key, current, target_node);
1031  
1032  	if (o2net_wq == NULL) {
1033  		mlog(0, "attempt to tx without o2netd running\n");
1034  		ret = -ESRCH;
1035  		goto out;
1036  	}
1037  
1038  	if (caller_veclen == 0) {
1039  		mlog(0, "bad kvec array length\n");
1040  		ret = -EINVAL;
1041  		goto out;
1042  	}
1043  
1044  	caller_bytes = iov_length((struct iovec *)caller_vec, caller_veclen);
1045  	if (caller_bytes > O2NET_MAX_PAYLOAD_BYTES) {
1046  		mlog(0, "total payload len %zu too large\n", caller_bytes);
1047  		ret = -EINVAL;
1048  		goto out;
1049  	}
1050  
1051  	if (target_node == o2nm_this_node()) {
1052  		ret = -ELOOP;
1053  		goto out;
1054  	}
1055  
1056  	o2net_debug_add_nst(&nst);
1057  
1058  	o2net_set_nst_sock_time(&nst);
1059  
1060  	wait_event(nn->nn_sc_wq, o2net_tx_can_proceed(nn, &sc, &ret));
1061  	if (ret)
1062  		goto out;
1063  
1064  	o2net_set_nst_sock_container(&nst, sc);
1065  
1066  	veclen = caller_veclen + 1;
1067  	vec = kmalloc_array(veclen, sizeof(struct kvec), GFP_ATOMIC);
1068  	if (vec == NULL) {
1069  		mlog(0, "failed to %zu element kvec!\n", veclen);
1070  		ret = -ENOMEM;
1071  		goto out;
1072  	}
1073  
1074  	msg = kmalloc(sizeof(struct o2net_msg), GFP_ATOMIC);
1075  	if (!msg) {
1076  		mlog(0, "failed to allocate a o2net_msg!\n");
1077  		ret = -ENOMEM;
1078  		goto out;
1079  	}
1080  
1081  	o2net_init_msg(msg, caller_bytes, msg_type, key);
1082  
1083  	vec[0].iov_len = sizeof(struct o2net_msg);
1084  	vec[0].iov_base = msg;
1085  	memcpy(&vec[1], caller_vec, caller_veclen * sizeof(struct kvec));
1086  
1087  	ret = o2net_prep_nsw(nn, &nsw);
1088  	if (ret)
1089  		goto out;
1090  
1091  	msg->msg_num = cpu_to_be32(nsw.ns_id);
1092  	o2net_set_nst_msg_id(&nst, nsw.ns_id);
1093  
1094  	o2net_set_nst_send_time(&nst);
1095  
1096  	/* finally, convert the message header to network byte-order
1097  	 * and send */
1098  	mutex_lock(&sc->sc_send_lock);
1099  	ret = o2net_send_tcp_msg(sc->sc_sock, vec, veclen,
1100  				 sizeof(struct o2net_msg) + caller_bytes);
1101  	mutex_unlock(&sc->sc_send_lock);
1102  	msglog(msg, "sending returned %d\n", ret);
1103  	if (ret < 0) {
1104  		mlog(0, "error returned from o2net_send_tcp_msg=%d\n", ret);
1105  		goto out;
1106  	}
1107  
1108  	/* wait on other node's handler */
1109  	o2net_set_nst_status_time(&nst);
1110  	wait_event(nsw.ns_wq, o2net_nsw_completed(nn, &nsw));
1111  
1112  	o2net_update_send_stats(&nst, sc);
1113  
1114  	/* Note that we avoid overwriting the callers status return
1115  	 * variable if a system error was reported on the other
1116  	 * side. Callers beware. */
1117  	ret = o2net_sys_err_to_errno(nsw.ns_sys_status);
1118  	if (status && !ret)
1119  		*status = nsw.ns_status;
1120  
1121  	mlog(0, "woken, returning system status %d, user status %d\n",
1122  	     ret, nsw.ns_status);
1123  out:
1124  	o2net_debug_del_nst(&nst); /* must be before dropping sc and node */
1125  	if (sc)
1126  		sc_put(sc);
1127  	kfree(vec);
1128  	kfree(msg);
1129  	o2net_complete_nsw(nn, &nsw, 0, 0, 0);
1130  	return ret;
1131  }
1132  EXPORT_SYMBOL_GPL(o2net_send_message_vec);
1133  
o2net_send_message(u32 msg_type,u32 key,void * data,u32 len,u8 target_node,int * status)1134  int o2net_send_message(u32 msg_type, u32 key, void *data, u32 len,
1135  		       u8 target_node, int *status)
1136  {
1137  	struct kvec vec = {
1138  		.iov_base = data,
1139  		.iov_len = len,
1140  	};
1141  	return o2net_send_message_vec(msg_type, key, &vec, 1,
1142  				      target_node, status);
1143  }
1144  EXPORT_SYMBOL_GPL(o2net_send_message);
1145  
o2net_send_status_magic(struct socket * sock,struct o2net_msg * hdr,enum o2net_system_error syserr,int err)1146  static int o2net_send_status_magic(struct socket *sock, struct o2net_msg *hdr,
1147  				   enum o2net_system_error syserr, int err)
1148  {
1149  	struct kvec vec = {
1150  		.iov_base = hdr,
1151  		.iov_len = sizeof(struct o2net_msg),
1152  	};
1153  
1154  	BUG_ON(syserr >= O2NET_ERR_MAX);
1155  
1156  	/* leave other fields intact from the incoming message, msg_num
1157  	 * in particular */
1158  	hdr->sys_status = cpu_to_be32(syserr);
1159  	hdr->status = cpu_to_be32(err);
1160  	hdr->magic = cpu_to_be16(O2NET_MSG_STATUS_MAGIC);  // twiddle the magic
1161  	hdr->data_len = 0;
1162  
1163  	msglog(hdr, "about to send status magic %d\n", err);
1164  	/* hdr has been in host byteorder this whole time */
1165  	return o2net_send_tcp_msg(sock, &vec, 1, sizeof(struct o2net_msg));
1166  }
1167  
1168  /* this returns -errno if the header was unknown or too large, etc.
1169   * after this is called the buffer us reused for the next message */
o2net_process_message(struct o2net_sock_container * sc,struct o2net_msg * hdr)1170  static int o2net_process_message(struct o2net_sock_container *sc,
1171  				 struct o2net_msg *hdr)
1172  {
1173  	struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
1174  	int ret = 0, handler_status;
1175  	enum  o2net_system_error syserr;
1176  	struct o2net_msg_handler *nmh = NULL;
1177  	void *ret_data = NULL;
1178  
1179  	msglog(hdr, "processing message\n");
1180  
1181  	o2net_sc_postpone_idle(sc);
1182  
1183  	switch(be16_to_cpu(hdr->magic)) {
1184  		case O2NET_MSG_STATUS_MAGIC:
1185  			/* special type for returning message status */
1186  			o2net_complete_nsw(nn, NULL,
1187  					   be32_to_cpu(hdr->msg_num),
1188  					   be32_to_cpu(hdr->sys_status),
1189  					   be32_to_cpu(hdr->status));
1190  			goto out;
1191  		case O2NET_MSG_KEEP_REQ_MAGIC:
1192  			o2net_sendpage(sc, o2net_keep_resp,
1193  				       sizeof(*o2net_keep_resp));
1194  			goto out;
1195  		case O2NET_MSG_KEEP_RESP_MAGIC:
1196  			goto out;
1197  		case O2NET_MSG_MAGIC:
1198  			break;
1199  		default:
1200  			msglog(hdr, "bad magic\n");
1201  			ret = -EINVAL;
1202  			goto out;
1203  	}
1204  
1205  	/* find a handler for it */
1206  	handler_status = 0;
1207  	nmh = o2net_handler_get(be16_to_cpu(hdr->msg_type),
1208  				be32_to_cpu(hdr->key));
1209  	if (!nmh) {
1210  		mlog(ML_TCP, "couldn't find handler for type %u key %08x\n",
1211  		     be16_to_cpu(hdr->msg_type), be32_to_cpu(hdr->key));
1212  		syserr = O2NET_ERR_NO_HNDLR;
1213  		goto out_respond;
1214  	}
1215  
1216  	syserr = O2NET_ERR_NONE;
1217  
1218  	if (be16_to_cpu(hdr->data_len) > nmh->nh_max_len)
1219  		syserr = O2NET_ERR_OVERFLOW;
1220  
1221  	if (syserr != O2NET_ERR_NONE)
1222  		goto out_respond;
1223  
1224  	o2net_set_func_start_time(sc);
1225  	sc->sc_msg_key = be32_to_cpu(hdr->key);
1226  	sc->sc_msg_type = be16_to_cpu(hdr->msg_type);
1227  	handler_status = (nmh->nh_func)(hdr, sizeof(struct o2net_msg) +
1228  					     be16_to_cpu(hdr->data_len),
1229  					nmh->nh_func_data, &ret_data);
1230  	o2net_set_func_stop_time(sc);
1231  
1232  	o2net_update_recv_stats(sc);
1233  
1234  out_respond:
1235  	/* this destroys the hdr, so don't use it after this */
1236  	mutex_lock(&sc->sc_send_lock);
1237  	ret = o2net_send_status_magic(sc->sc_sock, hdr, syserr,
1238  				      handler_status);
1239  	mutex_unlock(&sc->sc_send_lock);
1240  	hdr = NULL;
1241  	mlog(0, "sending handler status %d, syserr %d returned %d\n",
1242  	     handler_status, syserr, ret);
1243  
1244  	if (nmh) {
1245  		BUG_ON(ret_data != NULL && nmh->nh_post_func == NULL);
1246  		if (nmh->nh_post_func)
1247  			(nmh->nh_post_func)(handler_status, nmh->nh_func_data,
1248  					    ret_data);
1249  	}
1250  
1251  out:
1252  	if (nmh)
1253  		o2net_handler_put(nmh);
1254  	return ret;
1255  }
1256  
o2net_check_handshake(struct o2net_sock_container * sc)1257  static int o2net_check_handshake(struct o2net_sock_container *sc)
1258  {
1259  	struct o2net_handshake *hand = page_address(sc->sc_page);
1260  	struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
1261  
1262  	if (hand->protocol_version != cpu_to_be64(O2NET_PROTOCOL_VERSION)) {
1263  		printk(KERN_NOTICE "o2net: " SC_NODEF_FMT " Advertised net "
1264  		       "protocol version %llu but %llu is required. "
1265  		       "Disconnecting.\n", SC_NODEF_ARGS(sc),
1266  		       (unsigned long long)be64_to_cpu(hand->protocol_version),
1267  		       O2NET_PROTOCOL_VERSION);
1268  
1269  		/* don't bother reconnecting if its the wrong version. */
1270  		o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1271  		return -1;
1272  	}
1273  
1274  	/*
1275  	 * Ensure timeouts are consistent with other nodes, otherwise
1276  	 * we can end up with one node thinking that the other must be down,
1277  	 * but isn't. This can ultimately cause corruption.
1278  	 */
1279  	if (be32_to_cpu(hand->o2net_idle_timeout_ms) !=
1280  				o2net_idle_timeout()) {
1281  		printk(KERN_NOTICE "o2net: " SC_NODEF_FMT " uses a network "
1282  		       "idle timeout of %u ms, but we use %u ms locally. "
1283  		       "Disconnecting.\n", SC_NODEF_ARGS(sc),
1284  		       be32_to_cpu(hand->o2net_idle_timeout_ms),
1285  		       o2net_idle_timeout());
1286  		o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1287  		return -1;
1288  	}
1289  
1290  	if (be32_to_cpu(hand->o2net_keepalive_delay_ms) !=
1291  			o2net_keepalive_delay()) {
1292  		printk(KERN_NOTICE "o2net: " SC_NODEF_FMT " uses a keepalive "
1293  		       "delay of %u ms, but we use %u ms locally. "
1294  		       "Disconnecting.\n", SC_NODEF_ARGS(sc),
1295  		       be32_to_cpu(hand->o2net_keepalive_delay_ms),
1296  		       o2net_keepalive_delay());
1297  		o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1298  		return -1;
1299  	}
1300  
1301  	if (be32_to_cpu(hand->o2hb_heartbeat_timeout_ms) !=
1302  			O2HB_MAX_WRITE_TIMEOUT_MS) {
1303  		printk(KERN_NOTICE "o2net: " SC_NODEF_FMT " uses a heartbeat "
1304  		       "timeout of %u ms, but we use %u ms locally. "
1305  		       "Disconnecting.\n", SC_NODEF_ARGS(sc),
1306  		       be32_to_cpu(hand->o2hb_heartbeat_timeout_ms),
1307  		       O2HB_MAX_WRITE_TIMEOUT_MS);
1308  		o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1309  		return -1;
1310  	}
1311  
1312  	sc->sc_handshake_ok = 1;
1313  
1314  	spin_lock(&nn->nn_lock);
1315  	/* set valid and queue the idle timers only if it hasn't been
1316  	 * shut down already */
1317  	if (nn->nn_sc == sc) {
1318  		o2net_sc_reset_idle_timer(sc);
1319  		atomic_set(&nn->nn_timeout, 0);
1320  		o2net_set_nn_state(nn, sc, 1, 0);
1321  	}
1322  	spin_unlock(&nn->nn_lock);
1323  
1324  	/* shift everything up as though it wasn't there */
1325  	sc->sc_page_off -= sizeof(struct o2net_handshake);
1326  	if (sc->sc_page_off)
1327  		memmove(hand, hand + 1, sc->sc_page_off);
1328  
1329  	return 0;
1330  }
1331  
1332  /* this demuxes the queued rx bytes into header or payload bits and calls
1333   * handlers as each full message is read off the socket.  it returns -error,
1334   * == 0 eof, or > 0 for progress made.*/
o2net_advance_rx(struct o2net_sock_container * sc)1335  static int o2net_advance_rx(struct o2net_sock_container *sc)
1336  {
1337  	struct o2net_msg *hdr;
1338  	int ret = 0;
1339  	void *data;
1340  	size_t datalen;
1341  
1342  	sclog(sc, "receiving\n");
1343  	o2net_set_advance_start_time(sc);
1344  
1345  	if (unlikely(sc->sc_handshake_ok == 0)) {
1346  		if(sc->sc_page_off < sizeof(struct o2net_handshake)) {
1347  			data = page_address(sc->sc_page) + sc->sc_page_off;
1348  			datalen = sizeof(struct o2net_handshake) - sc->sc_page_off;
1349  			ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen);
1350  			if (ret > 0)
1351  				sc->sc_page_off += ret;
1352  		}
1353  
1354  		if (sc->sc_page_off == sizeof(struct o2net_handshake)) {
1355  			o2net_check_handshake(sc);
1356  			if (unlikely(sc->sc_handshake_ok == 0))
1357  				ret = -EPROTO;
1358  		}
1359  		goto out;
1360  	}
1361  
1362  	/* do we need more header? */
1363  	if (sc->sc_page_off < sizeof(struct o2net_msg)) {
1364  		data = page_address(sc->sc_page) + sc->sc_page_off;
1365  		datalen = sizeof(struct o2net_msg) - sc->sc_page_off;
1366  		ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen);
1367  		if (ret > 0) {
1368  			sc->sc_page_off += ret;
1369  			/* only swab incoming here.. we can
1370  			 * only get here once as we cross from
1371  			 * being under to over */
1372  			if (sc->sc_page_off == sizeof(struct o2net_msg)) {
1373  				hdr = page_address(sc->sc_page);
1374  				if (be16_to_cpu(hdr->data_len) >
1375  				    O2NET_MAX_PAYLOAD_BYTES)
1376  					ret = -EOVERFLOW;
1377  			}
1378  		}
1379  		if (ret <= 0)
1380  			goto out;
1381  	}
1382  
1383  	if (sc->sc_page_off < sizeof(struct o2net_msg)) {
1384  		/* oof, still don't have a header */
1385  		goto out;
1386  	}
1387  
1388  	/* this was swabbed above when we first read it */
1389  	hdr = page_address(sc->sc_page);
1390  
1391  	msglog(hdr, "at page_off %zu\n", sc->sc_page_off);
1392  
1393  	/* do we need more payload? */
1394  	if (sc->sc_page_off - sizeof(struct o2net_msg) < be16_to_cpu(hdr->data_len)) {
1395  		/* need more payload */
1396  		data = page_address(sc->sc_page) + sc->sc_page_off;
1397  		datalen = (sizeof(struct o2net_msg) + be16_to_cpu(hdr->data_len)) -
1398  			  sc->sc_page_off;
1399  		ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen);
1400  		if (ret > 0)
1401  			sc->sc_page_off += ret;
1402  		if (ret <= 0)
1403  			goto out;
1404  	}
1405  
1406  	if (sc->sc_page_off - sizeof(struct o2net_msg) == be16_to_cpu(hdr->data_len)) {
1407  		/* we can only get here once, the first time we read
1408  		 * the payload.. so set ret to progress if the handler
1409  		 * works out. after calling this the message is toast */
1410  		ret = o2net_process_message(sc, hdr);
1411  		if (ret == 0)
1412  			ret = 1;
1413  		sc->sc_page_off = 0;
1414  	}
1415  
1416  out:
1417  	sclog(sc, "ret = %d\n", ret);
1418  	o2net_set_advance_stop_time(sc);
1419  	return ret;
1420  }
1421  
1422  /* this work func is triggerd by data ready.  it reads until it can read no
1423   * more.  it interprets 0, eof, as fatal.  if data_ready hits while we're doing
1424   * our work the work struct will be marked and we'll be called again. */
o2net_rx_until_empty(struct work_struct * work)1425  static void o2net_rx_until_empty(struct work_struct *work)
1426  {
1427  	struct o2net_sock_container *sc =
1428  		container_of(work, struct o2net_sock_container, sc_rx_work);
1429  	int ret;
1430  
1431  	do {
1432  		ret = o2net_advance_rx(sc);
1433  	} while (ret > 0);
1434  
1435  	if (ret <= 0 && ret != -EAGAIN) {
1436  		struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
1437  		sclog(sc, "saw error %d, closing\n", ret);
1438  		/* not permanent so read failed handshake can retry */
1439  		o2net_ensure_shutdown(nn, sc, 0);
1440  	}
1441  
1442  	sc_put(sc);
1443  }
1444  
o2net_initialize_handshake(void)1445  static void o2net_initialize_handshake(void)
1446  {
1447  	o2net_hand->o2hb_heartbeat_timeout_ms = cpu_to_be32(
1448  		O2HB_MAX_WRITE_TIMEOUT_MS);
1449  	o2net_hand->o2net_idle_timeout_ms = cpu_to_be32(o2net_idle_timeout());
1450  	o2net_hand->o2net_keepalive_delay_ms = cpu_to_be32(
1451  		o2net_keepalive_delay());
1452  	o2net_hand->o2net_reconnect_delay_ms = cpu_to_be32(
1453  		o2net_reconnect_delay());
1454  }
1455  
1456  /* ------------------------------------------------------------ */
1457  
1458  /* called when a connect completes and after a sock is accepted.  the
1459   * rx path will see the response and mark the sc valid */
o2net_sc_connect_completed(struct work_struct * work)1460  static void o2net_sc_connect_completed(struct work_struct *work)
1461  {
1462  	struct o2net_sock_container *sc =
1463  		container_of(work, struct o2net_sock_container,
1464  			     sc_connect_work);
1465  
1466  	mlog(ML_MSG, "sc sending handshake with ver %llu id %llx\n",
1467                (unsigned long long)O2NET_PROTOCOL_VERSION,
1468  	      (unsigned long long)be64_to_cpu(o2net_hand->connector_id));
1469  
1470  	o2net_initialize_handshake();
1471  	o2net_sendpage(sc, o2net_hand, sizeof(*o2net_hand));
1472  	sc_put(sc);
1473  }
1474  
1475  /* this is called as a work_struct func. */
o2net_sc_send_keep_req(struct work_struct * work)1476  static void o2net_sc_send_keep_req(struct work_struct *work)
1477  {
1478  	struct o2net_sock_container *sc =
1479  		container_of(work, struct o2net_sock_container,
1480  			     sc_keepalive_work.work);
1481  
1482  	o2net_sendpage(sc, o2net_keep_req, sizeof(*o2net_keep_req));
1483  	sc_put(sc);
1484  }
1485  
1486  /* socket shutdown does a del_timer_sync against this as it tears down.
1487   * we can't start this timer until we've got to the point in sc buildup
1488   * where shutdown is going to be involved */
o2net_idle_timer(struct timer_list * t)1489  static void o2net_idle_timer(struct timer_list *t)
1490  {
1491  	struct o2net_sock_container *sc = from_timer(sc, t, sc_idle_timeout);
1492  	struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
1493  #ifdef CONFIG_DEBUG_FS
1494  	unsigned long msecs = ktime_to_ms(ktime_get()) -
1495  		ktime_to_ms(sc->sc_tv_timer);
1496  #else
1497  	unsigned long msecs = o2net_idle_timeout();
1498  #endif
1499  
1500  	printk(KERN_NOTICE "o2net: Connection to " SC_NODEF_FMT " has been "
1501  	       "idle for %lu.%lu secs.\n",
1502  	       SC_NODEF_ARGS(sc), msecs / 1000, msecs % 1000);
1503  
1504  	/* idle timerout happen, don't shutdown the connection, but
1505  	 * make fence decision. Maybe the connection can recover before
1506  	 * the decision is made.
1507  	 */
1508  	atomic_set(&nn->nn_timeout, 1);
1509  	o2quo_conn_err(o2net_num_from_nn(nn));
1510  	queue_delayed_work(o2net_wq, &nn->nn_still_up,
1511  			msecs_to_jiffies(O2NET_QUORUM_DELAY_MS));
1512  
1513  	o2net_sc_reset_idle_timer(sc);
1514  
1515  }
1516  
o2net_sc_reset_idle_timer(struct o2net_sock_container * sc)1517  static void o2net_sc_reset_idle_timer(struct o2net_sock_container *sc)
1518  {
1519  	o2net_sc_cancel_delayed_work(sc, &sc->sc_keepalive_work);
1520  	o2net_sc_queue_delayed_work(sc, &sc->sc_keepalive_work,
1521  		      msecs_to_jiffies(o2net_keepalive_delay()));
1522  	o2net_set_sock_timer(sc);
1523  	mod_timer(&sc->sc_idle_timeout,
1524  	       jiffies + msecs_to_jiffies(o2net_idle_timeout()));
1525  }
1526  
o2net_sc_postpone_idle(struct o2net_sock_container * sc)1527  static void o2net_sc_postpone_idle(struct o2net_sock_container *sc)
1528  {
1529  	struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
1530  
1531  	/* clear fence decision since the connection recover from timeout*/
1532  	if (atomic_read(&nn->nn_timeout)) {
1533  		o2quo_conn_up(o2net_num_from_nn(nn));
1534  		cancel_delayed_work(&nn->nn_still_up);
1535  		atomic_set(&nn->nn_timeout, 0);
1536  	}
1537  
1538  	/* Only push out an existing timer */
1539  	if (timer_pending(&sc->sc_idle_timeout))
1540  		o2net_sc_reset_idle_timer(sc);
1541  }
1542  
1543  /* this work func is kicked whenever a path sets the nn state which doesn't
1544   * have valid set.  This includes seeing hb come up, losing a connection,
1545   * having a connect attempt fail, etc. This centralizes the logic which decides
1546   * if a connect attempt should be made or if we should give up and all future
1547   * transmit attempts should fail */
o2net_start_connect(struct work_struct * work)1548  static void o2net_start_connect(struct work_struct *work)
1549  {
1550  	struct o2net_node *nn =
1551  		container_of(work, struct o2net_node, nn_connect_work.work);
1552  	struct o2net_sock_container *sc = NULL;
1553  	struct o2nm_node *node = NULL, *mynode = NULL;
1554  	struct socket *sock = NULL;
1555  	struct sockaddr_in myaddr = {0, }, remoteaddr = {0, };
1556  	int ret = 0, stop;
1557  	unsigned int timeout;
1558  	unsigned int nofs_flag;
1559  
1560  	/*
1561  	 * sock_create allocates the sock with GFP_KERNEL. We must
1562  	 * prevent the filesystem from being reentered by memory reclaim.
1563  	 */
1564  	nofs_flag = memalloc_nofs_save();
1565  	/* if we're greater we initiate tx, otherwise we accept */
1566  	if (o2nm_this_node() <= o2net_num_from_nn(nn))
1567  		goto out;
1568  
1569  	/* watch for racing with tearing a node down */
1570  	node = o2nm_get_node_by_num(o2net_num_from_nn(nn));
1571  	if (node == NULL)
1572  		goto out;
1573  
1574  	mynode = o2nm_get_node_by_num(o2nm_this_node());
1575  	if (mynode == NULL)
1576  		goto out;
1577  
1578  	spin_lock(&nn->nn_lock);
1579  	/*
1580  	 * see if we already have one pending or have given up.
1581  	 * For nn_timeout, it is set when we close the connection
1582  	 * because of the idle time out. So it means that we have
1583  	 * at least connected to that node successfully once,
1584  	 * now try to connect to it again.
1585  	 */
1586  	timeout = atomic_read(&nn->nn_timeout);
1587  	stop = (nn->nn_sc ||
1588  		(nn->nn_persistent_error &&
1589  		(nn->nn_persistent_error != -ENOTCONN || timeout == 0)));
1590  	spin_unlock(&nn->nn_lock);
1591  	if (stop)
1592  		goto out;
1593  
1594  	nn->nn_last_connect_attempt = jiffies;
1595  
1596  	sc = sc_alloc(node);
1597  	if (sc == NULL) {
1598  		mlog(0, "couldn't allocate sc\n");
1599  		ret = -ENOMEM;
1600  		goto out;
1601  	}
1602  
1603  	ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
1604  	if (ret < 0) {
1605  		mlog(0, "can't create socket: %d\n", ret);
1606  		goto out;
1607  	}
1608  	sc->sc_sock = sock; /* freed by sc_kref_release */
1609  
1610  	sock->sk->sk_allocation = GFP_ATOMIC;
1611  	sock->sk->sk_use_task_frag = false;
1612  
1613  	myaddr.sin_family = AF_INET;
1614  	myaddr.sin_addr.s_addr = mynode->nd_ipv4_address;
1615  	myaddr.sin_port = htons(0); /* any port */
1616  
1617  	ret = sock->ops->bind(sock, (struct sockaddr *)&myaddr,
1618  			      sizeof(myaddr));
1619  	if (ret) {
1620  		mlog(ML_ERROR, "bind failed with %d at address %pI4\n",
1621  		     ret, &mynode->nd_ipv4_address);
1622  		goto out;
1623  	}
1624  
1625  	tcp_sock_set_nodelay(sc->sc_sock->sk);
1626  	tcp_sock_set_user_timeout(sock->sk, O2NET_TCP_USER_TIMEOUT);
1627  
1628  	o2net_register_callbacks(sc->sc_sock->sk, sc);
1629  
1630  	spin_lock(&nn->nn_lock);
1631  	/* handshake completion will set nn->nn_sc_valid */
1632  	o2net_set_nn_state(nn, sc, 0, 0);
1633  	spin_unlock(&nn->nn_lock);
1634  
1635  	remoteaddr.sin_family = AF_INET;
1636  	remoteaddr.sin_addr.s_addr = node->nd_ipv4_address;
1637  	remoteaddr.sin_port = node->nd_ipv4_port;
1638  
1639  	ret = sc->sc_sock->ops->connect(sc->sc_sock,
1640  					(struct sockaddr *)&remoteaddr,
1641  					sizeof(remoteaddr),
1642  					O_NONBLOCK);
1643  	if (ret == -EINPROGRESS)
1644  		ret = 0;
1645  
1646  out:
1647  	if (ret && sc) {
1648  		printk(KERN_NOTICE "o2net: Connect attempt to " SC_NODEF_FMT
1649  		       " failed with errno %d\n", SC_NODEF_ARGS(sc), ret);
1650  		/* 0 err so that another will be queued and attempted
1651  		 * from set_nn_state */
1652  		o2net_ensure_shutdown(nn, sc, 0);
1653  	}
1654  	if (sc)
1655  		sc_put(sc);
1656  	if (node)
1657  		o2nm_node_put(node);
1658  	if (mynode)
1659  		o2nm_node_put(mynode);
1660  
1661  	memalloc_nofs_restore(nofs_flag);
1662  	return;
1663  }
1664  
o2net_connect_expired(struct work_struct * work)1665  static void o2net_connect_expired(struct work_struct *work)
1666  {
1667  	struct o2net_node *nn =
1668  		container_of(work, struct o2net_node, nn_connect_expired.work);
1669  
1670  	spin_lock(&nn->nn_lock);
1671  	if (!nn->nn_sc_valid) {
1672  		printk(KERN_NOTICE "o2net: No connection established with "
1673  		       "node %u after %u.%u seconds, check network and"
1674  		       " cluster configuration.\n",
1675  		     o2net_num_from_nn(nn),
1676  		     o2net_idle_timeout() / 1000,
1677  		     o2net_idle_timeout() % 1000);
1678  
1679  		o2net_set_nn_state(nn, NULL, 0, 0);
1680  	}
1681  	spin_unlock(&nn->nn_lock);
1682  }
1683  
o2net_still_up(struct work_struct * work)1684  static void o2net_still_up(struct work_struct *work)
1685  {
1686  	struct o2net_node *nn =
1687  		container_of(work, struct o2net_node, nn_still_up.work);
1688  
1689  	o2quo_hb_still_up(o2net_num_from_nn(nn));
1690  }
1691  
1692  /* ------------------------------------------------------------ */
1693  
o2net_disconnect_node(struct o2nm_node * node)1694  void o2net_disconnect_node(struct o2nm_node *node)
1695  {
1696  	struct o2net_node *nn = o2net_nn_from_num(node->nd_num);
1697  
1698  	/* don't reconnect until it's heartbeating again */
1699  	spin_lock(&nn->nn_lock);
1700  	atomic_set(&nn->nn_timeout, 0);
1701  	o2net_set_nn_state(nn, NULL, 0, -ENOTCONN);
1702  	spin_unlock(&nn->nn_lock);
1703  
1704  	if (o2net_wq) {
1705  		cancel_delayed_work(&nn->nn_connect_expired);
1706  		cancel_delayed_work(&nn->nn_connect_work);
1707  		cancel_delayed_work(&nn->nn_still_up);
1708  		flush_workqueue(o2net_wq);
1709  	}
1710  }
1711  
o2net_hb_node_down_cb(struct o2nm_node * node,int node_num,void * data)1712  static void o2net_hb_node_down_cb(struct o2nm_node *node, int node_num,
1713  				  void *data)
1714  {
1715  	o2quo_hb_down(node_num);
1716  
1717  	if (!node)
1718  		return;
1719  
1720  	if (node_num != o2nm_this_node())
1721  		o2net_disconnect_node(node);
1722  
1723  	BUG_ON(atomic_read(&o2net_connected_peers) < 0);
1724  }
1725  
o2net_hb_node_up_cb(struct o2nm_node * node,int node_num,void * data)1726  static void o2net_hb_node_up_cb(struct o2nm_node *node, int node_num,
1727  				void *data)
1728  {
1729  	struct o2net_node *nn = o2net_nn_from_num(node_num);
1730  
1731  	o2quo_hb_up(node_num);
1732  
1733  	BUG_ON(!node);
1734  
1735  	/* ensure an immediate connect attempt */
1736  	nn->nn_last_connect_attempt = jiffies -
1737  		(msecs_to_jiffies(o2net_reconnect_delay()) + 1);
1738  
1739  	if (node_num != o2nm_this_node()) {
1740  		/* believe it or not, accept and node heartbeating testing
1741  		 * can succeed for this node before we got here.. so
1742  		 * only use set_nn_state to clear the persistent error
1743  		 * if that hasn't already happened */
1744  		spin_lock(&nn->nn_lock);
1745  		atomic_set(&nn->nn_timeout, 0);
1746  		if (nn->nn_persistent_error)
1747  			o2net_set_nn_state(nn, NULL, 0, 0);
1748  		spin_unlock(&nn->nn_lock);
1749  	}
1750  }
1751  
o2net_unregister_hb_callbacks(void)1752  void o2net_unregister_hb_callbacks(void)
1753  {
1754  	o2hb_unregister_callback(NULL, &o2net_hb_up);
1755  	o2hb_unregister_callback(NULL, &o2net_hb_down);
1756  }
1757  
o2net_register_hb_callbacks(void)1758  int o2net_register_hb_callbacks(void)
1759  {
1760  	int ret;
1761  
1762  	o2hb_setup_callback(&o2net_hb_down, O2HB_NODE_DOWN_CB,
1763  			    o2net_hb_node_down_cb, NULL, O2NET_HB_PRI);
1764  	o2hb_setup_callback(&o2net_hb_up, O2HB_NODE_UP_CB,
1765  			    o2net_hb_node_up_cb, NULL, O2NET_HB_PRI);
1766  
1767  	ret = o2hb_register_callback(NULL, &o2net_hb_up);
1768  	if (ret == 0)
1769  		ret = o2hb_register_callback(NULL, &o2net_hb_down);
1770  
1771  	if (ret)
1772  		o2net_unregister_hb_callbacks();
1773  
1774  	return ret;
1775  }
1776  
1777  /* ------------------------------------------------------------ */
1778  
o2net_accept_one(struct socket * sock,int * more)1779  static int o2net_accept_one(struct socket *sock, int *more)
1780  {
1781  	int ret;
1782  	struct sockaddr_in sin;
1783  	struct socket *new_sock = NULL;
1784  	struct o2nm_node *node = NULL;
1785  	struct o2nm_node *local_node = NULL;
1786  	struct o2net_sock_container *sc = NULL;
1787  	struct o2net_node *nn;
1788  	unsigned int nofs_flag;
1789  
1790  	/*
1791  	 * sock_create_lite allocates the sock with GFP_KERNEL. We must
1792  	 * prevent the filesystem from being reentered by memory reclaim.
1793  	 */
1794  	nofs_flag = memalloc_nofs_save();
1795  
1796  	BUG_ON(sock == NULL);
1797  	*more = 0;
1798  	ret = sock_create_lite(sock->sk->sk_family, sock->sk->sk_type,
1799  			       sock->sk->sk_protocol, &new_sock);
1800  	if (ret)
1801  		goto out;
1802  
1803  	new_sock->type = sock->type;
1804  	new_sock->ops = sock->ops;
1805  	ret = sock->ops->accept(sock, new_sock, O_NONBLOCK, false);
1806  	if (ret < 0)
1807  		goto out;
1808  
1809  	*more = 1;
1810  	new_sock->sk->sk_allocation = GFP_ATOMIC;
1811  
1812  	tcp_sock_set_nodelay(new_sock->sk);
1813  	tcp_sock_set_user_timeout(new_sock->sk, O2NET_TCP_USER_TIMEOUT);
1814  
1815  	ret = new_sock->ops->getname(new_sock, (struct sockaddr *) &sin, 1);
1816  	if (ret < 0)
1817  		goto out;
1818  
1819  	node = o2nm_get_node_by_ip(sin.sin_addr.s_addr);
1820  	if (node == NULL) {
1821  		printk(KERN_NOTICE "o2net: Attempt to connect from unknown "
1822  		       "node at %pI4:%d\n", &sin.sin_addr.s_addr,
1823  		       ntohs(sin.sin_port));
1824  		ret = -EINVAL;
1825  		goto out;
1826  	}
1827  
1828  	if (o2nm_this_node() >= node->nd_num) {
1829  		local_node = o2nm_get_node_by_num(o2nm_this_node());
1830  		if (local_node)
1831  			printk(KERN_NOTICE "o2net: Unexpected connect attempt "
1832  					"seen at node '%s' (%u, %pI4:%d) from "
1833  					"node '%s' (%u, %pI4:%d)\n",
1834  					local_node->nd_name, local_node->nd_num,
1835  					&(local_node->nd_ipv4_address),
1836  					ntohs(local_node->nd_ipv4_port),
1837  					node->nd_name,
1838  					node->nd_num, &sin.sin_addr.s_addr,
1839  					ntohs(sin.sin_port));
1840  		ret = -EINVAL;
1841  		goto out;
1842  	}
1843  
1844  	/* this happens all the time when the other node sees our heartbeat
1845  	 * and tries to connect before we see their heartbeat */
1846  	if (!o2hb_check_node_heartbeating_from_callback(node->nd_num)) {
1847  		mlog(ML_CONN, "attempt to connect from node '%s' at "
1848  		     "%pI4:%d but it isn't heartbeating\n",
1849  		     node->nd_name, &sin.sin_addr.s_addr,
1850  		     ntohs(sin.sin_port));
1851  		ret = -EINVAL;
1852  		goto out;
1853  	}
1854  
1855  	nn = o2net_nn_from_num(node->nd_num);
1856  
1857  	spin_lock(&nn->nn_lock);
1858  	if (nn->nn_sc)
1859  		ret = -EBUSY;
1860  	else
1861  		ret = 0;
1862  	spin_unlock(&nn->nn_lock);
1863  	if (ret) {
1864  		printk(KERN_NOTICE "o2net: Attempt to connect from node '%s' "
1865  		       "at %pI4:%d but it already has an open connection\n",
1866  		       node->nd_name, &sin.sin_addr.s_addr,
1867  		       ntohs(sin.sin_port));
1868  		goto out;
1869  	}
1870  
1871  	sc = sc_alloc(node);
1872  	if (sc == NULL) {
1873  		ret = -ENOMEM;
1874  		goto out;
1875  	}
1876  
1877  	sc->sc_sock = new_sock;
1878  	new_sock = NULL;
1879  
1880  	spin_lock(&nn->nn_lock);
1881  	atomic_set(&nn->nn_timeout, 0);
1882  	o2net_set_nn_state(nn, sc, 0, 0);
1883  	spin_unlock(&nn->nn_lock);
1884  
1885  	o2net_register_callbacks(sc->sc_sock->sk, sc);
1886  	o2net_sc_queue_work(sc, &sc->sc_rx_work);
1887  
1888  	o2net_initialize_handshake();
1889  	o2net_sendpage(sc, o2net_hand, sizeof(*o2net_hand));
1890  
1891  out:
1892  	if (new_sock)
1893  		sock_release(new_sock);
1894  	if (node)
1895  		o2nm_node_put(node);
1896  	if (local_node)
1897  		o2nm_node_put(local_node);
1898  	if (sc)
1899  		sc_put(sc);
1900  
1901  	memalloc_nofs_restore(nofs_flag);
1902  	return ret;
1903  }
1904  
1905  /*
1906   * This function is invoked in response to one or more
1907   * pending accepts at softIRQ level. We must drain the
1908   * entire que before returning.
1909   */
1910  
o2net_accept_many(struct work_struct * work)1911  static void o2net_accept_many(struct work_struct *work)
1912  {
1913  	struct socket *sock = o2net_listen_sock;
1914  	int	more;
1915  
1916  	/*
1917  	 * It is critical to note that due to interrupt moderation
1918  	 * at the network driver level, we can't assume to get a
1919  	 * softIRQ for every single conn since tcp SYN packets
1920  	 * can arrive back-to-back, and therefore many pending
1921  	 * accepts may result in just 1 softIRQ. If we terminate
1922  	 * the o2net_accept_one() loop upon seeing an err, what happens
1923  	 * to the rest of the conns in the queue? If no new SYN
1924  	 * arrives for hours, no softIRQ  will be delivered,
1925  	 * and the connections will just sit in the queue.
1926  	 */
1927  
1928  	for (;;) {
1929  		o2net_accept_one(sock, &more);
1930  		if (!more)
1931  			break;
1932  		cond_resched();
1933  	}
1934  }
1935  
o2net_listen_data_ready(struct sock * sk)1936  static void o2net_listen_data_ready(struct sock *sk)
1937  {
1938  	void (*ready)(struct sock *sk);
1939  
1940  	trace_sk_data_ready(sk);
1941  
1942  	read_lock_bh(&sk->sk_callback_lock);
1943  	ready = sk->sk_user_data;
1944  	if (ready == NULL) { /* check for teardown race */
1945  		ready = sk->sk_data_ready;
1946  		goto out;
1947  	}
1948  
1949  	/* This callback may called twice when a new connection
1950  	 * is  being established as a child socket inherits everything
1951  	 * from a parent LISTEN socket, including the data_ready cb of
1952  	 * the parent. This leads to a hazard. In o2net_accept_one()
1953  	 * we are still initializing the child socket but have not
1954  	 * changed the inherited data_ready callback yet when
1955  	 * data starts arriving.
1956  	 * We avoid this hazard by checking the state.
1957  	 * For the listening socket,  the state will be TCP_LISTEN; for the new
1958  	 * socket, will be  TCP_ESTABLISHED. Also, in this case,
1959  	 * sk->sk_user_data is not a valid function pointer.
1960  	 */
1961  
1962  	if (sk->sk_state == TCP_LISTEN) {
1963  		queue_work(o2net_wq, &o2net_listen_work);
1964  	} else {
1965  		ready = NULL;
1966  	}
1967  
1968  out:
1969  	read_unlock_bh(&sk->sk_callback_lock);
1970  	if (ready != NULL)
1971  		ready(sk);
1972  }
1973  
o2net_open_listening_sock(__be32 addr,__be16 port)1974  static int o2net_open_listening_sock(__be32 addr, __be16 port)
1975  {
1976  	struct socket *sock = NULL;
1977  	int ret;
1978  	struct sockaddr_in sin = {
1979  		.sin_family = PF_INET,
1980  		.sin_addr = { .s_addr = addr },
1981  		.sin_port = port,
1982  	};
1983  
1984  	ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
1985  	if (ret < 0) {
1986  		printk(KERN_ERR "o2net: Error %d while creating socket\n", ret);
1987  		goto out;
1988  	}
1989  
1990  	sock->sk->sk_allocation = GFP_ATOMIC;
1991  
1992  	write_lock_bh(&sock->sk->sk_callback_lock);
1993  	sock->sk->sk_user_data = sock->sk->sk_data_ready;
1994  	sock->sk->sk_data_ready = o2net_listen_data_ready;
1995  	write_unlock_bh(&sock->sk->sk_callback_lock);
1996  
1997  	o2net_listen_sock = sock;
1998  	INIT_WORK(&o2net_listen_work, o2net_accept_many);
1999  
2000  	sock->sk->sk_reuse = SK_CAN_REUSE;
2001  	ret = sock->ops->bind(sock, (struct sockaddr *)&sin, sizeof(sin));
2002  	if (ret < 0) {
2003  		printk(KERN_ERR "o2net: Error %d while binding socket at "
2004  		       "%pI4:%u\n", ret, &addr, ntohs(port));
2005  		goto out;
2006  	}
2007  
2008  	ret = sock->ops->listen(sock, 64);
2009  	if (ret < 0)
2010  		printk(KERN_ERR "o2net: Error %d while listening on %pI4:%u\n",
2011  		       ret, &addr, ntohs(port));
2012  
2013  out:
2014  	if (ret) {
2015  		o2net_listen_sock = NULL;
2016  		if (sock)
2017  			sock_release(sock);
2018  	}
2019  	return ret;
2020  }
2021  
2022  /*
2023   * called from node manager when we should bring up our network listening
2024   * socket.  node manager handles all the serialization to only call this
2025   * once and to match it with o2net_stop_listening().  note,
2026   * o2nm_this_node() doesn't work yet as we're being called while it
2027   * is being set up.
2028   */
o2net_start_listening(struct o2nm_node * node)2029  int o2net_start_listening(struct o2nm_node *node)
2030  {
2031  	int ret = 0;
2032  
2033  	BUG_ON(o2net_wq != NULL);
2034  	BUG_ON(o2net_listen_sock != NULL);
2035  
2036  	mlog(ML_KTHREAD, "starting o2net thread...\n");
2037  	o2net_wq = alloc_ordered_workqueue("o2net", WQ_MEM_RECLAIM);
2038  	if (o2net_wq == NULL) {
2039  		mlog(ML_ERROR, "unable to launch o2net thread\n");
2040  		return -ENOMEM; /* ? */
2041  	}
2042  
2043  	ret = o2net_open_listening_sock(node->nd_ipv4_address,
2044  					node->nd_ipv4_port);
2045  	if (ret) {
2046  		destroy_workqueue(o2net_wq);
2047  		o2net_wq = NULL;
2048  	} else
2049  		o2quo_conn_up(node->nd_num);
2050  
2051  	return ret;
2052  }
2053  
2054  /* again, o2nm_this_node() doesn't work here as we're involved in
2055   * tearing it down */
o2net_stop_listening(struct o2nm_node * node)2056  void o2net_stop_listening(struct o2nm_node *node)
2057  {
2058  	struct socket *sock = o2net_listen_sock;
2059  	size_t i;
2060  
2061  	BUG_ON(o2net_wq == NULL);
2062  	BUG_ON(o2net_listen_sock == NULL);
2063  
2064  	/* stop the listening socket from generating work */
2065  	write_lock_bh(&sock->sk->sk_callback_lock);
2066  	sock->sk->sk_data_ready = sock->sk->sk_user_data;
2067  	sock->sk->sk_user_data = NULL;
2068  	write_unlock_bh(&sock->sk->sk_callback_lock);
2069  
2070  	for (i = 0; i < ARRAY_SIZE(o2net_nodes); i++) {
2071  		struct o2nm_node *node = o2nm_get_node_by_num(i);
2072  		if (node) {
2073  			o2net_disconnect_node(node);
2074  			o2nm_node_put(node);
2075  		}
2076  	}
2077  
2078  	/* finish all work and tear down the work queue */
2079  	mlog(ML_KTHREAD, "waiting for o2net thread to exit....\n");
2080  	destroy_workqueue(o2net_wq);
2081  	o2net_wq = NULL;
2082  
2083  	sock_release(o2net_listen_sock);
2084  	o2net_listen_sock = NULL;
2085  
2086  	o2quo_conn_err(node->nd_num);
2087  }
2088  
2089  /* ------------------------------------------------------------ */
2090  
o2net_init(void)2091  int o2net_init(void)
2092  {
2093  	struct folio *folio;
2094  	void *p;
2095  	unsigned long i;
2096  
2097  	o2quo_init();
2098  	o2net_debugfs_init();
2099  
2100  	folio = folio_alloc(GFP_KERNEL | __GFP_ZERO, 0);
2101  	if (!folio)
2102  		goto out;
2103  
2104  	p = folio_address(folio);
2105  	o2net_hand = p;
2106  	p += sizeof(struct o2net_handshake);
2107  	o2net_keep_req = p;
2108  	p += sizeof(struct o2net_msg);
2109  	o2net_keep_resp = p;
2110  
2111  	o2net_hand->protocol_version = cpu_to_be64(O2NET_PROTOCOL_VERSION);
2112  	o2net_hand->connector_id = cpu_to_be64(1);
2113  
2114  	o2net_keep_req->magic = cpu_to_be16(O2NET_MSG_KEEP_REQ_MAGIC);
2115  	o2net_keep_resp->magic = cpu_to_be16(O2NET_MSG_KEEP_RESP_MAGIC);
2116  
2117  	for (i = 0; i < ARRAY_SIZE(o2net_nodes); i++) {
2118  		struct o2net_node *nn = o2net_nn_from_num(i);
2119  
2120  		atomic_set(&nn->nn_timeout, 0);
2121  		spin_lock_init(&nn->nn_lock);
2122  		INIT_DELAYED_WORK(&nn->nn_connect_work, o2net_start_connect);
2123  		INIT_DELAYED_WORK(&nn->nn_connect_expired,
2124  				  o2net_connect_expired);
2125  		INIT_DELAYED_WORK(&nn->nn_still_up, o2net_still_up);
2126  		/* until we see hb from a node we'll return einval */
2127  		nn->nn_persistent_error = -ENOTCONN;
2128  		init_waitqueue_head(&nn->nn_sc_wq);
2129  		idr_init(&nn->nn_status_idr);
2130  		INIT_LIST_HEAD(&nn->nn_status_list);
2131  	}
2132  
2133  	return 0;
2134  
2135  out:
2136  	o2net_debugfs_exit();
2137  	o2quo_exit();
2138  	return -ENOMEM;
2139  }
2140  
o2net_exit(void)2141  void o2net_exit(void)
2142  {
2143  	o2quo_exit();
2144  	o2net_debugfs_exit();
2145  	folio_put(virt_to_folio(o2net_hand));
2146  }
2147