xref: /linux/fs/ocfs2/cluster/tcp.c (revision 89721e3038d181bacbd6be54354b513fdf1b4f10)
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 proto_accept_arg arg = {
1788 		.flags = O_NONBLOCK,
1789 	};
1790 	struct o2net_node *nn;
1791 	unsigned int nofs_flag;
1792 
1793 	/*
1794 	 * sock_create_lite allocates the sock with GFP_KERNEL. We must
1795 	 * prevent the filesystem from being reentered by memory reclaim.
1796 	 */
1797 	nofs_flag = memalloc_nofs_save();
1798 
1799 	BUG_ON(sock == NULL);
1800 	*more = 0;
1801 	ret = sock_create_lite(sock->sk->sk_family, sock->sk->sk_type,
1802 			       sock->sk->sk_protocol, &new_sock);
1803 	if (ret)
1804 		goto out;
1805 
1806 	new_sock->type = sock->type;
1807 	new_sock->ops = sock->ops;
1808 	ret = sock->ops->accept(sock, new_sock, &arg);
1809 	if (ret < 0)
1810 		goto out;
1811 
1812 	*more = 1;
1813 	new_sock->sk->sk_allocation = GFP_ATOMIC;
1814 
1815 	tcp_sock_set_nodelay(new_sock->sk);
1816 	tcp_sock_set_user_timeout(new_sock->sk, O2NET_TCP_USER_TIMEOUT);
1817 
1818 	ret = new_sock->ops->getname(new_sock, (struct sockaddr *) &sin, 1);
1819 	if (ret < 0)
1820 		goto out;
1821 
1822 	node = o2nm_get_node_by_ip(sin.sin_addr.s_addr);
1823 	if (node == NULL) {
1824 		printk(KERN_NOTICE "o2net: Attempt to connect from unknown "
1825 		       "node at %pI4:%d\n", &sin.sin_addr.s_addr,
1826 		       ntohs(sin.sin_port));
1827 		ret = -EINVAL;
1828 		goto out;
1829 	}
1830 
1831 	if (o2nm_this_node() >= node->nd_num) {
1832 		local_node = o2nm_get_node_by_num(o2nm_this_node());
1833 		if (local_node)
1834 			printk(KERN_NOTICE "o2net: Unexpected connect attempt "
1835 					"seen at node '%s' (%u, %pI4:%d) from "
1836 					"node '%s' (%u, %pI4:%d)\n",
1837 					local_node->nd_name, local_node->nd_num,
1838 					&(local_node->nd_ipv4_address),
1839 					ntohs(local_node->nd_ipv4_port),
1840 					node->nd_name,
1841 					node->nd_num, &sin.sin_addr.s_addr,
1842 					ntohs(sin.sin_port));
1843 		ret = -EINVAL;
1844 		goto out;
1845 	}
1846 
1847 	/* this happens all the time when the other node sees our heartbeat
1848 	 * and tries to connect before we see their heartbeat */
1849 	if (!o2hb_check_node_heartbeating_from_callback(node->nd_num)) {
1850 		mlog(ML_CONN, "attempt to connect from node '%s' at "
1851 		     "%pI4:%d but it isn't heartbeating\n",
1852 		     node->nd_name, &sin.sin_addr.s_addr,
1853 		     ntohs(sin.sin_port));
1854 		ret = -EINVAL;
1855 		goto out;
1856 	}
1857 
1858 	nn = o2net_nn_from_num(node->nd_num);
1859 
1860 	spin_lock(&nn->nn_lock);
1861 	if (nn->nn_sc)
1862 		ret = -EBUSY;
1863 	else
1864 		ret = 0;
1865 	spin_unlock(&nn->nn_lock);
1866 	if (ret) {
1867 		printk(KERN_NOTICE "o2net: Attempt to connect from node '%s' "
1868 		       "at %pI4:%d but it already has an open connection\n",
1869 		       node->nd_name, &sin.sin_addr.s_addr,
1870 		       ntohs(sin.sin_port));
1871 		goto out;
1872 	}
1873 
1874 	sc = sc_alloc(node);
1875 	if (sc == NULL) {
1876 		ret = -ENOMEM;
1877 		goto out;
1878 	}
1879 
1880 	sc->sc_sock = new_sock;
1881 	new_sock = NULL;
1882 
1883 	spin_lock(&nn->nn_lock);
1884 	atomic_set(&nn->nn_timeout, 0);
1885 	o2net_set_nn_state(nn, sc, 0, 0);
1886 	spin_unlock(&nn->nn_lock);
1887 
1888 	o2net_register_callbacks(sc->sc_sock->sk, sc);
1889 	o2net_sc_queue_work(sc, &sc->sc_rx_work);
1890 
1891 	o2net_initialize_handshake();
1892 	o2net_sendpage(sc, o2net_hand, sizeof(*o2net_hand));
1893 
1894 out:
1895 	if (new_sock)
1896 		sock_release(new_sock);
1897 	if (node)
1898 		o2nm_node_put(node);
1899 	if (local_node)
1900 		o2nm_node_put(local_node);
1901 	if (sc)
1902 		sc_put(sc);
1903 
1904 	memalloc_nofs_restore(nofs_flag);
1905 	return ret;
1906 }
1907 
1908 /*
1909  * This function is invoked in response to one or more
1910  * pending accepts at softIRQ level. We must drain the
1911  * entire que before returning.
1912  */
1913 
o2net_accept_many(struct work_struct * work)1914 static void o2net_accept_many(struct work_struct *work)
1915 {
1916 	struct socket *sock = o2net_listen_sock;
1917 	int	more;
1918 
1919 	/*
1920 	 * It is critical to note that due to interrupt moderation
1921 	 * at the network driver level, we can't assume to get a
1922 	 * softIRQ for every single conn since tcp SYN packets
1923 	 * can arrive back-to-back, and therefore many pending
1924 	 * accepts may result in just 1 softIRQ. If we terminate
1925 	 * the o2net_accept_one() loop upon seeing an err, what happens
1926 	 * to the rest of the conns in the queue? If no new SYN
1927 	 * arrives for hours, no softIRQ  will be delivered,
1928 	 * and the connections will just sit in the queue.
1929 	 */
1930 
1931 	for (;;) {
1932 		o2net_accept_one(sock, &more);
1933 		if (!more)
1934 			break;
1935 		cond_resched();
1936 	}
1937 }
1938 
o2net_listen_data_ready(struct sock * sk)1939 static void o2net_listen_data_ready(struct sock *sk)
1940 {
1941 	void (*ready)(struct sock *sk);
1942 
1943 	trace_sk_data_ready(sk);
1944 
1945 	read_lock_bh(&sk->sk_callback_lock);
1946 	ready = sk->sk_user_data;
1947 	if (ready == NULL) { /* check for teardown race */
1948 		ready = sk->sk_data_ready;
1949 		goto out;
1950 	}
1951 
1952 	/* This callback may called twice when a new connection
1953 	 * is  being established as a child socket inherits everything
1954 	 * from a parent LISTEN socket, including the data_ready cb of
1955 	 * the parent. This leads to a hazard. In o2net_accept_one()
1956 	 * we are still initializing the child socket but have not
1957 	 * changed the inherited data_ready callback yet when
1958 	 * data starts arriving.
1959 	 * We avoid this hazard by checking the state.
1960 	 * For the listening socket,  the state will be TCP_LISTEN; for the new
1961 	 * socket, will be  TCP_ESTABLISHED. Also, in this case,
1962 	 * sk->sk_user_data is not a valid function pointer.
1963 	 */
1964 
1965 	if (sk->sk_state == TCP_LISTEN) {
1966 		queue_work(o2net_wq, &o2net_listen_work);
1967 	} else {
1968 		ready = NULL;
1969 	}
1970 
1971 out:
1972 	read_unlock_bh(&sk->sk_callback_lock);
1973 	if (ready != NULL)
1974 		ready(sk);
1975 }
1976 
o2net_open_listening_sock(__be32 addr,__be16 port)1977 static int o2net_open_listening_sock(__be32 addr, __be16 port)
1978 {
1979 	struct socket *sock = NULL;
1980 	int ret;
1981 	struct sockaddr_in sin = {
1982 		.sin_family = PF_INET,
1983 		.sin_addr = { .s_addr = addr },
1984 		.sin_port = port,
1985 	};
1986 
1987 	ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
1988 	if (ret < 0) {
1989 		printk(KERN_ERR "o2net: Error %d while creating socket\n", ret);
1990 		goto out;
1991 	}
1992 
1993 	sock->sk->sk_allocation = GFP_ATOMIC;
1994 
1995 	write_lock_bh(&sock->sk->sk_callback_lock);
1996 	sock->sk->sk_user_data = sock->sk->sk_data_ready;
1997 	sock->sk->sk_data_ready = o2net_listen_data_ready;
1998 	write_unlock_bh(&sock->sk->sk_callback_lock);
1999 
2000 	o2net_listen_sock = sock;
2001 	INIT_WORK(&o2net_listen_work, o2net_accept_many);
2002 
2003 	sock->sk->sk_reuse = SK_CAN_REUSE;
2004 	ret = sock->ops->bind(sock, (struct sockaddr *)&sin, sizeof(sin));
2005 	if (ret < 0) {
2006 		printk(KERN_ERR "o2net: Error %d while binding socket at "
2007 		       "%pI4:%u\n", ret, &addr, ntohs(port));
2008 		goto out;
2009 	}
2010 
2011 	ret = sock->ops->listen(sock, 64);
2012 	if (ret < 0)
2013 		printk(KERN_ERR "o2net: Error %d while listening on %pI4:%u\n",
2014 		       ret, &addr, ntohs(port));
2015 
2016 out:
2017 	if (ret) {
2018 		o2net_listen_sock = NULL;
2019 		if (sock)
2020 			sock_release(sock);
2021 	}
2022 	return ret;
2023 }
2024 
2025 /*
2026  * called from node manager when we should bring up our network listening
2027  * socket.  node manager handles all the serialization to only call this
2028  * once and to match it with o2net_stop_listening().  note,
2029  * o2nm_this_node() doesn't work yet as we're being called while it
2030  * is being set up.
2031  */
o2net_start_listening(struct o2nm_node * node)2032 int o2net_start_listening(struct o2nm_node *node)
2033 {
2034 	int ret = 0;
2035 
2036 	BUG_ON(o2net_wq != NULL);
2037 	BUG_ON(o2net_listen_sock != NULL);
2038 
2039 	mlog(ML_KTHREAD, "starting o2net thread...\n");
2040 	o2net_wq = alloc_ordered_workqueue("o2net", WQ_MEM_RECLAIM);
2041 	if (o2net_wq == NULL) {
2042 		mlog(ML_ERROR, "unable to launch o2net thread\n");
2043 		return -ENOMEM; /* ? */
2044 	}
2045 
2046 	ret = o2net_open_listening_sock(node->nd_ipv4_address,
2047 					node->nd_ipv4_port);
2048 	if (ret) {
2049 		destroy_workqueue(o2net_wq);
2050 		o2net_wq = NULL;
2051 	} else
2052 		o2quo_conn_up(node->nd_num);
2053 
2054 	return ret;
2055 }
2056 
2057 /* again, o2nm_this_node() doesn't work here as we're involved in
2058  * tearing it down */
o2net_stop_listening(struct o2nm_node * node)2059 void o2net_stop_listening(struct o2nm_node *node)
2060 {
2061 	struct socket *sock = o2net_listen_sock;
2062 	size_t i;
2063 
2064 	BUG_ON(o2net_wq == NULL);
2065 	BUG_ON(o2net_listen_sock == NULL);
2066 
2067 	/* stop the listening socket from generating work */
2068 	write_lock_bh(&sock->sk->sk_callback_lock);
2069 	sock->sk->sk_data_ready = sock->sk->sk_user_data;
2070 	sock->sk->sk_user_data = NULL;
2071 	write_unlock_bh(&sock->sk->sk_callback_lock);
2072 
2073 	for (i = 0; i < ARRAY_SIZE(o2net_nodes); i++) {
2074 		struct o2nm_node *node = o2nm_get_node_by_num(i);
2075 		if (node) {
2076 			o2net_disconnect_node(node);
2077 			o2nm_node_put(node);
2078 		}
2079 	}
2080 
2081 	/* finish all work and tear down the work queue */
2082 	mlog(ML_KTHREAD, "waiting for o2net thread to exit....\n");
2083 	destroy_workqueue(o2net_wq);
2084 	o2net_wq = NULL;
2085 
2086 	sock_release(o2net_listen_sock);
2087 	o2net_listen_sock = NULL;
2088 
2089 	o2quo_conn_err(node->nd_num);
2090 }
2091 
2092 /* ------------------------------------------------------------ */
2093 
o2net_init(void)2094 int o2net_init(void)
2095 {
2096 	struct folio *folio;
2097 	void *p;
2098 	unsigned long i;
2099 
2100 	o2quo_init();
2101 	o2net_debugfs_init();
2102 
2103 	folio = folio_alloc(GFP_KERNEL | __GFP_ZERO, 0);
2104 	if (!folio)
2105 		goto out;
2106 
2107 	p = folio_address(folio);
2108 	o2net_hand = p;
2109 	p += sizeof(struct o2net_handshake);
2110 	o2net_keep_req = p;
2111 	p += sizeof(struct o2net_msg);
2112 	o2net_keep_resp = p;
2113 
2114 	o2net_hand->protocol_version = cpu_to_be64(O2NET_PROTOCOL_VERSION);
2115 	o2net_hand->connector_id = cpu_to_be64(1);
2116 
2117 	o2net_keep_req->magic = cpu_to_be16(O2NET_MSG_KEEP_REQ_MAGIC);
2118 	o2net_keep_resp->magic = cpu_to_be16(O2NET_MSG_KEEP_RESP_MAGIC);
2119 
2120 	for (i = 0; i < ARRAY_SIZE(o2net_nodes); i++) {
2121 		struct o2net_node *nn = o2net_nn_from_num(i);
2122 
2123 		atomic_set(&nn->nn_timeout, 0);
2124 		spin_lock_init(&nn->nn_lock);
2125 		INIT_DELAYED_WORK(&nn->nn_connect_work, o2net_start_connect);
2126 		INIT_DELAYED_WORK(&nn->nn_connect_expired,
2127 				  o2net_connect_expired);
2128 		INIT_DELAYED_WORK(&nn->nn_still_up, o2net_still_up);
2129 		/* until we see hb from a node we'll return einval */
2130 		nn->nn_persistent_error = -ENOTCONN;
2131 		init_waitqueue_head(&nn->nn_sc_wq);
2132 		idr_init(&nn->nn_status_idr);
2133 		INIT_LIST_HEAD(&nn->nn_status_list);
2134 	}
2135 
2136 	return 0;
2137 
2138 out:
2139 	o2net_debugfs_exit();
2140 	o2quo_exit();
2141 	return -ENOMEM;
2142 }
2143 
o2net_exit(void)2144 void o2net_exit(void)
2145 {
2146 	o2quo_exit();
2147 	o2net_debugfs_exit();
2148 	folio_put(virt_to_folio(o2net_hand));
2149 }
2150