1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2004, 2005 Oracle.  All rights reserved.
4  */
5 
6 #include <linux/kernel.h>
7 #include <linux/sched.h>
8 #include <linux/jiffies.h>
9 #include <linux/module.h>
10 #include <linux/fs.h>
11 #include <linux/bio.h>
12 #include <linux/blkdev.h>
13 #include <linux/delay.h>
14 #include <linux/file.h>
15 #include <linux/kthread.h>
16 #include <linux/configfs.h>
17 #include <linux/random.h>
18 #include <linux/crc32.h>
19 #include <linux/time.h>
20 #include <linux/debugfs.h>
21 #include <linux/slab.h>
22 #include <linux/bitmap.h>
23 #include <linux/ktime.h>
24 #include "heartbeat.h"
25 #include "tcp.h"
26 #include "nodemanager.h"
27 #include "quorum.h"
28 
29 #include "masklog.h"
30 
31 
32 /*
33  * The first heartbeat pass had one global thread that would serialize all hb
34  * callback calls.  This global serializing sem should only be removed once
35  * we've made sure that all callees can deal with being called concurrently
36  * from multiple hb region threads.
37  */
38 static DECLARE_RWSEM(o2hb_callback_sem);
39 
40 /*
41  * multiple hb threads are watching multiple regions.  A node is live
42  * whenever any of the threads sees activity from the node in its region.
43  */
44 static DEFINE_SPINLOCK(o2hb_live_lock);
45 static struct list_head o2hb_live_slots[O2NM_MAX_NODES];
46 static unsigned long o2hb_live_node_bitmap[BITS_TO_LONGS(O2NM_MAX_NODES)];
47 static LIST_HEAD(o2hb_node_events);
48 static DECLARE_WAIT_QUEUE_HEAD(o2hb_steady_queue);
49 
50 /*
51  * In global heartbeat, we maintain a series of region bitmaps.
52  * 	- o2hb_region_bitmap allows us to limit the region number to max region.
53  * 	- o2hb_live_region_bitmap tracks live regions (seen steady iterations).
54  * 	- o2hb_quorum_region_bitmap tracks live regions that have seen all nodes
55  * 		heartbeat on it.
56  * 	- o2hb_failed_region_bitmap tracks the regions that have seen io timeouts.
57  */
58 static unsigned long o2hb_region_bitmap[BITS_TO_LONGS(O2NM_MAX_REGIONS)];
59 static unsigned long o2hb_live_region_bitmap[BITS_TO_LONGS(O2NM_MAX_REGIONS)];
60 static unsigned long o2hb_quorum_region_bitmap[BITS_TO_LONGS(O2NM_MAX_REGIONS)];
61 static unsigned long o2hb_failed_region_bitmap[BITS_TO_LONGS(O2NM_MAX_REGIONS)];
62 
63 #define O2HB_DB_TYPE_LIVENODES		0
64 #define O2HB_DB_TYPE_LIVEREGIONS	1
65 #define O2HB_DB_TYPE_QUORUMREGIONS	2
66 #define O2HB_DB_TYPE_FAILEDREGIONS	3
67 #define O2HB_DB_TYPE_REGION_LIVENODES	4
68 #define O2HB_DB_TYPE_REGION_NUMBER	5
69 #define O2HB_DB_TYPE_REGION_ELAPSED_TIME	6
70 #define O2HB_DB_TYPE_REGION_PINNED	7
71 struct o2hb_debug_buf {
72 	int db_type;
73 	int db_size;
74 	int db_len;
75 	void *db_data;
76 };
77 
78 static struct o2hb_debug_buf *o2hb_db_livenodes;
79 static struct o2hb_debug_buf *o2hb_db_liveregions;
80 static struct o2hb_debug_buf *o2hb_db_quorumregions;
81 static struct o2hb_debug_buf *o2hb_db_failedregions;
82 
83 #define O2HB_DEBUG_DIR			"o2hb"
84 #define O2HB_DEBUG_LIVENODES		"livenodes"
85 #define O2HB_DEBUG_LIVEREGIONS		"live_regions"
86 #define O2HB_DEBUG_QUORUMREGIONS	"quorum_regions"
87 #define O2HB_DEBUG_FAILEDREGIONS	"failed_regions"
88 #define O2HB_DEBUG_REGION_NUMBER	"num"
89 #define O2HB_DEBUG_REGION_ELAPSED_TIME	"elapsed_time_in_ms"
90 #define O2HB_DEBUG_REGION_PINNED	"pinned"
91 
92 static struct dentry *o2hb_debug_dir;
93 
94 static LIST_HEAD(o2hb_all_regions);
95 
96 static struct o2hb_callback {
97 	struct list_head list;
98 } o2hb_callbacks[O2HB_NUM_CB];
99 
100 static struct o2hb_callback *hbcall_from_type(enum o2hb_callback_type type);
101 
102 enum o2hb_heartbeat_modes {
103 	O2HB_HEARTBEAT_LOCAL		= 0,
104 	O2HB_HEARTBEAT_GLOBAL,
105 	O2HB_HEARTBEAT_NUM_MODES,
106 };
107 
108 static const char *o2hb_heartbeat_mode_desc[O2HB_HEARTBEAT_NUM_MODES] = {
109 	"local",	/* O2HB_HEARTBEAT_LOCAL */
110 	"global",	/* O2HB_HEARTBEAT_GLOBAL */
111 };
112 
113 unsigned int o2hb_dead_threshold = O2HB_DEFAULT_DEAD_THRESHOLD;
114 static unsigned int o2hb_heartbeat_mode = O2HB_HEARTBEAT_LOCAL;
115 
116 /*
117  * o2hb_dependent_users tracks the number of registered callbacks that depend
118  * on heartbeat. o2net and o2dlm are two entities that register this callback.
119  * However only o2dlm depends on the heartbeat. It does not want the heartbeat
120  * to stop while a dlm domain is still active.
121  */
122 static unsigned int o2hb_dependent_users;
123 
124 /*
125  * In global heartbeat mode, all regions are pinned if there are one or more
126  * dependent users and the quorum region count is <= O2HB_PIN_CUT_OFF. All
127  * regions are unpinned if the region count exceeds the cut off or the number
128  * of dependent users falls to zero.
129  */
130 #define O2HB_PIN_CUT_OFF		3
131 
132 /*
133  * In local heartbeat mode, we assume the dlm domain name to be the same as
134  * region uuid. This is true for domains created for the file system but not
135  * necessarily true for userdlm domains. This is a known limitation.
136  *
137  * In global heartbeat mode, we pin/unpin all o2hb regions. This solution
138  * works for both file system and userdlm domains.
139  */
140 static int o2hb_region_pin(const char *region_uuid);
141 static void o2hb_region_unpin(const char *region_uuid);
142 
143 /* Only sets a new threshold if there are no active regions.
144  *
145  * No locking or otherwise interesting code is required for reading
146  * o2hb_dead_threshold as it can't change once regions are active and
147  * it's not interesting to anyone until then anyway. */
o2hb_dead_threshold_set(unsigned int threshold)148 static void o2hb_dead_threshold_set(unsigned int threshold)
149 {
150 	if (threshold > O2HB_MIN_DEAD_THRESHOLD) {
151 		spin_lock(&o2hb_live_lock);
152 		if (list_empty(&o2hb_all_regions))
153 			o2hb_dead_threshold = threshold;
154 		spin_unlock(&o2hb_live_lock);
155 	}
156 }
157 
o2hb_global_heartbeat_mode_set(unsigned int hb_mode)158 static int o2hb_global_heartbeat_mode_set(unsigned int hb_mode)
159 {
160 	int ret = -1;
161 
162 	if (hb_mode < O2HB_HEARTBEAT_NUM_MODES) {
163 		spin_lock(&o2hb_live_lock);
164 		if (list_empty(&o2hb_all_regions)) {
165 			o2hb_heartbeat_mode = hb_mode;
166 			ret = 0;
167 		}
168 		spin_unlock(&o2hb_live_lock);
169 	}
170 
171 	return ret;
172 }
173 
174 struct o2hb_node_event {
175 	struct list_head        hn_item;
176 	enum o2hb_callback_type hn_event_type;
177 	struct o2nm_node        *hn_node;
178 	int                     hn_node_num;
179 };
180 
181 struct o2hb_disk_slot {
182 	struct o2hb_disk_heartbeat_block *ds_raw_block;
183 	u8			ds_node_num;
184 	u64			ds_last_time;
185 	u64			ds_last_generation;
186 	u16			ds_equal_samples;
187 	u16			ds_changed_samples;
188 	struct list_head	ds_live_item;
189 };
190 
191 /* each thread owns a region.. when we're asked to tear down the region
192  * we ask the thread to stop, who cleans up the region */
193 struct o2hb_region {
194 	struct config_item	hr_item;
195 
196 	struct list_head	hr_all_item;
197 	unsigned		hr_unclean_stop:1,
198 				hr_aborted_start:1,
199 				hr_item_pinned:1,
200 				hr_item_dropped:1,
201 				hr_node_deleted:1;
202 
203 	/* protected by the hr_callback_sem */
204 	struct task_struct 	*hr_task;
205 
206 	unsigned int		hr_blocks;
207 	unsigned long long	hr_start_block;
208 
209 	unsigned int		hr_block_bits;
210 	unsigned int		hr_block_bytes;
211 
212 	unsigned int		hr_slots_per_page;
213 	unsigned int		hr_num_pages;
214 
215 	struct page             **hr_slot_data;
216 	struct block_device	*hr_bdev;
217 	struct o2hb_disk_slot	*hr_slots;
218 
219 	/* live node map of this region */
220 	unsigned long		hr_live_node_bitmap[BITS_TO_LONGS(O2NM_MAX_NODES)];
221 	unsigned int		hr_region_num;
222 
223 	struct dentry		*hr_debug_dir;
224 	struct o2hb_debug_buf	*hr_db_livenodes;
225 	struct o2hb_debug_buf	*hr_db_regnum;
226 	struct o2hb_debug_buf	*hr_db_elapsed_time;
227 	struct o2hb_debug_buf	*hr_db_pinned;
228 
229 	/* let the person setting up hb wait for it to return until it
230 	 * has reached a 'steady' state.  This will be fixed when we have
231 	 * a more complete api that doesn't lead to this sort of fragility. */
232 	atomic_t		hr_steady_iterations;
233 
234 	/* terminate o2hb thread if it does not reach steady state
235 	 * (hr_steady_iterations == 0) within hr_unsteady_iterations */
236 	atomic_t		hr_unsteady_iterations;
237 
238 	char			hr_dev_name[BDEVNAME_SIZE];
239 
240 	unsigned int		hr_timeout_ms;
241 
242 	/* randomized as the region goes up and down so that a node
243 	 * recognizes a node going up and down in one iteration */
244 	u64			hr_generation;
245 
246 	struct delayed_work	hr_write_timeout_work;
247 	unsigned long		hr_last_timeout_start;
248 
249 	/* negotiate timer, used to negotiate extending hb timeout. */
250 	struct delayed_work	hr_nego_timeout_work;
251 	unsigned long		hr_nego_node_bitmap[BITS_TO_LONGS(O2NM_MAX_NODES)];
252 
253 	/* Used during o2hb_check_slot to hold a copy of the block
254 	 * being checked because we temporarily have to zero out the
255 	 * crc field. */
256 	struct o2hb_disk_heartbeat_block *hr_tmp_block;
257 
258 	/* Message key for negotiate timeout message. */
259 	unsigned int		hr_key;
260 	struct list_head	hr_handler_list;
261 
262 	/* last hb status, 0 for success, other value for error. */
263 	int			hr_last_hb_status;
264 };
265 
266 struct o2hb_bio_wait_ctxt {
267 	atomic_t          wc_num_reqs;
268 	struct completion wc_io_complete;
269 	int               wc_error;
270 };
271 
272 #define O2HB_NEGO_TIMEOUT_MS (O2HB_MAX_WRITE_TIMEOUT_MS/2)
273 
274 enum {
275 	O2HB_NEGO_TIMEOUT_MSG = 1,
276 	O2HB_NEGO_APPROVE_MSG = 2,
277 };
278 
279 struct o2hb_nego_msg {
280 	u8 node_num;
281 };
282 
o2hb_write_timeout(struct work_struct * work)283 static void o2hb_write_timeout(struct work_struct *work)
284 {
285 	int failed, quorum;
286 	struct o2hb_region *reg =
287 		container_of(work, struct o2hb_region,
288 			     hr_write_timeout_work.work);
289 
290 	mlog(ML_ERROR, "Heartbeat write timeout to device %s after %u "
291 	     "milliseconds\n", reg->hr_dev_name,
292 	     jiffies_to_msecs(jiffies - reg->hr_last_timeout_start));
293 
294 	if (o2hb_global_heartbeat_active()) {
295 		spin_lock(&o2hb_live_lock);
296 		if (test_bit(reg->hr_region_num, o2hb_quorum_region_bitmap))
297 			set_bit(reg->hr_region_num, o2hb_failed_region_bitmap);
298 		failed = bitmap_weight(o2hb_failed_region_bitmap,
299 					O2NM_MAX_REGIONS);
300 		quorum = bitmap_weight(o2hb_quorum_region_bitmap,
301 					O2NM_MAX_REGIONS);
302 		spin_unlock(&o2hb_live_lock);
303 
304 		mlog(ML_HEARTBEAT, "Number of regions %d, failed regions %d\n",
305 		     quorum, failed);
306 
307 		/*
308 		 * Fence if the number of failed regions >= half the number
309 		 * of  quorum regions
310 		 */
311 		if ((failed << 1) < quorum)
312 			return;
313 	}
314 
315 	o2quo_disk_timeout();
316 }
317 
o2hb_arm_timeout(struct o2hb_region * reg)318 static void o2hb_arm_timeout(struct o2hb_region *reg)
319 {
320 	/* Arm writeout only after thread reaches steady state */
321 	if (atomic_read(&reg->hr_steady_iterations) != 0)
322 		return;
323 
324 	mlog(ML_HEARTBEAT, "Queue write timeout for %u ms\n",
325 	     O2HB_MAX_WRITE_TIMEOUT_MS);
326 
327 	if (o2hb_global_heartbeat_active()) {
328 		spin_lock(&o2hb_live_lock);
329 		clear_bit(reg->hr_region_num, o2hb_failed_region_bitmap);
330 		spin_unlock(&o2hb_live_lock);
331 	}
332 	cancel_delayed_work(&reg->hr_write_timeout_work);
333 	schedule_delayed_work(&reg->hr_write_timeout_work,
334 			      msecs_to_jiffies(O2HB_MAX_WRITE_TIMEOUT_MS));
335 
336 	cancel_delayed_work(&reg->hr_nego_timeout_work);
337 	/* negotiate timeout must be less than write timeout. */
338 	schedule_delayed_work(&reg->hr_nego_timeout_work,
339 			      msecs_to_jiffies(O2HB_NEGO_TIMEOUT_MS));
340 	memset(reg->hr_nego_node_bitmap, 0, sizeof(reg->hr_nego_node_bitmap));
341 }
342 
o2hb_disarm_timeout(struct o2hb_region * reg)343 static void o2hb_disarm_timeout(struct o2hb_region *reg)
344 {
345 	cancel_delayed_work_sync(&reg->hr_write_timeout_work);
346 	cancel_delayed_work_sync(&reg->hr_nego_timeout_work);
347 }
348 
o2hb_send_nego_msg(int key,int type,u8 target)349 static int o2hb_send_nego_msg(int key, int type, u8 target)
350 {
351 	struct o2hb_nego_msg msg;
352 	int status, ret;
353 
354 	msg.node_num = o2nm_this_node();
355 again:
356 	ret = o2net_send_message(type, key, &msg, sizeof(msg),
357 			target, &status);
358 
359 	if (ret == -EAGAIN || ret == -ENOMEM) {
360 		msleep(100);
361 		goto again;
362 	}
363 
364 	return ret;
365 }
366 
o2hb_nego_timeout(struct work_struct * work)367 static void o2hb_nego_timeout(struct work_struct *work)
368 {
369 	unsigned long live_node_bitmap[BITS_TO_LONGS(O2NM_MAX_NODES)];
370 	int master_node, i, ret;
371 	struct o2hb_region *reg;
372 
373 	reg = container_of(work, struct o2hb_region, hr_nego_timeout_work.work);
374 	/* don't negotiate timeout if last hb failed since it is very
375 	 * possible io failed. Should let write timeout fence self.
376 	 */
377 	if (reg->hr_last_hb_status)
378 		return;
379 
380 	o2hb_fill_node_map(live_node_bitmap, sizeof(live_node_bitmap));
381 	/* lowest node as master node to make negotiate decision. */
382 	master_node = find_next_bit(live_node_bitmap, O2NM_MAX_NODES, 0);
383 
384 	if (master_node == o2nm_this_node()) {
385 		if (!test_bit(master_node, reg->hr_nego_node_bitmap)) {
386 			printk(KERN_NOTICE "o2hb: node %d hb write hung for %ds on region %s (%s).\n",
387 				o2nm_this_node(), O2HB_NEGO_TIMEOUT_MS/1000,
388 				config_item_name(&reg->hr_item), reg->hr_dev_name);
389 			set_bit(master_node, reg->hr_nego_node_bitmap);
390 		}
391 		if (memcmp(reg->hr_nego_node_bitmap, live_node_bitmap,
392 				sizeof(reg->hr_nego_node_bitmap))) {
393 			/* check negotiate bitmap every second to do timeout
394 			 * approve decision.
395 			 */
396 			schedule_delayed_work(&reg->hr_nego_timeout_work,
397 				msecs_to_jiffies(1000));
398 
399 			return;
400 		}
401 
402 		printk(KERN_NOTICE "o2hb: all nodes hb write hung, maybe region %s (%s) is down.\n",
403 			config_item_name(&reg->hr_item), reg->hr_dev_name);
404 		/* approve negotiate timeout request. */
405 		o2hb_arm_timeout(reg);
406 
407 		i = -1;
408 		while ((i = find_next_bit(live_node_bitmap,
409 				O2NM_MAX_NODES, i + 1)) < O2NM_MAX_NODES) {
410 			if (i == master_node)
411 				continue;
412 
413 			mlog(ML_HEARTBEAT, "send NEGO_APPROVE msg to node %d\n", i);
414 			ret = o2hb_send_nego_msg(reg->hr_key,
415 					O2HB_NEGO_APPROVE_MSG, i);
416 			if (ret)
417 				mlog(ML_ERROR, "send NEGO_APPROVE msg to node %d fail %d\n",
418 					i, ret);
419 		}
420 	} else {
421 		/* negotiate timeout with master node. */
422 		printk(KERN_NOTICE "o2hb: node %d hb write hung for %ds on region %s (%s), negotiate timeout with node %d.\n",
423 			o2nm_this_node(), O2HB_NEGO_TIMEOUT_MS/1000, config_item_name(&reg->hr_item),
424 			reg->hr_dev_name, master_node);
425 		ret = o2hb_send_nego_msg(reg->hr_key, O2HB_NEGO_TIMEOUT_MSG,
426 				master_node);
427 		if (ret)
428 			mlog(ML_ERROR, "send NEGO_TIMEOUT msg to node %d fail %d\n",
429 				master_node, ret);
430 	}
431 }
432 
o2hb_nego_timeout_handler(struct o2net_msg * msg,u32 len,void * data,void ** ret_data)433 static int o2hb_nego_timeout_handler(struct o2net_msg *msg, u32 len, void *data,
434 				void **ret_data)
435 {
436 	struct o2hb_region *reg = data;
437 	struct o2hb_nego_msg *nego_msg;
438 
439 	nego_msg = (struct o2hb_nego_msg *)msg->buf;
440 	printk(KERN_NOTICE "o2hb: receive negotiate timeout message from node %d on region %s (%s).\n",
441 		nego_msg->node_num, config_item_name(&reg->hr_item), reg->hr_dev_name);
442 	if (nego_msg->node_num < O2NM_MAX_NODES)
443 		set_bit(nego_msg->node_num, reg->hr_nego_node_bitmap);
444 	else
445 		mlog(ML_ERROR, "got nego timeout message from bad node.\n");
446 
447 	return 0;
448 }
449 
o2hb_nego_approve_handler(struct o2net_msg * msg,u32 len,void * data,void ** ret_data)450 static int o2hb_nego_approve_handler(struct o2net_msg *msg, u32 len, void *data,
451 				void **ret_data)
452 {
453 	struct o2hb_region *reg = data;
454 
455 	printk(KERN_NOTICE "o2hb: negotiate timeout approved by master node on region %s (%s).\n",
456 		config_item_name(&reg->hr_item), reg->hr_dev_name);
457 	o2hb_arm_timeout(reg);
458 	return 0;
459 }
460 
o2hb_bio_wait_init(struct o2hb_bio_wait_ctxt * wc)461 static inline void o2hb_bio_wait_init(struct o2hb_bio_wait_ctxt *wc)
462 {
463 	atomic_set(&wc->wc_num_reqs, 1);
464 	init_completion(&wc->wc_io_complete);
465 	wc->wc_error = 0;
466 }
467 
468 /* Used in error paths too */
o2hb_bio_wait_dec(struct o2hb_bio_wait_ctxt * wc,unsigned int num)469 static inline void o2hb_bio_wait_dec(struct o2hb_bio_wait_ctxt *wc,
470 				     unsigned int num)
471 {
472 	/* sadly atomic_sub_and_test() isn't available on all platforms.  The
473 	 * good news is that the fast path only completes one at a time */
474 	while(num--) {
475 		if (atomic_dec_and_test(&wc->wc_num_reqs)) {
476 			BUG_ON(num > 0);
477 			complete(&wc->wc_io_complete);
478 		}
479 	}
480 }
481 
o2hb_wait_on_io(struct o2hb_bio_wait_ctxt * wc)482 static void o2hb_wait_on_io(struct o2hb_bio_wait_ctxt *wc)
483 {
484 	o2hb_bio_wait_dec(wc, 1);
485 	wait_for_completion(&wc->wc_io_complete);
486 }
487 
o2hb_bio_end_io(struct bio * bio)488 static void o2hb_bio_end_io(struct bio *bio)
489 {
490 	struct o2hb_bio_wait_ctxt *wc = bio->bi_private;
491 
492 	if (bio->bi_status) {
493 		mlog(ML_ERROR, "IO Error %d\n", bio->bi_status);
494 		wc->wc_error = blk_status_to_errno(bio->bi_status);
495 	}
496 
497 	o2hb_bio_wait_dec(wc, 1);
498 	bio_put(bio);
499 }
500 
501 /* Setup a Bio to cover I/O against num_slots slots starting at
502  * start_slot. */
o2hb_setup_one_bio(struct o2hb_region * reg,struct o2hb_bio_wait_ctxt * wc,unsigned int * current_slot,unsigned int max_slots,int op,int op_flags)503 static struct bio *o2hb_setup_one_bio(struct o2hb_region *reg,
504 				      struct o2hb_bio_wait_ctxt *wc,
505 				      unsigned int *current_slot,
506 				      unsigned int max_slots, int op,
507 				      int op_flags)
508 {
509 	int len, current_page;
510 	unsigned int vec_len, vec_start;
511 	unsigned int bits = reg->hr_block_bits;
512 	unsigned int spp = reg->hr_slots_per_page;
513 	unsigned int cs = *current_slot;
514 	struct bio *bio;
515 	struct page *page;
516 
517 	/* Testing has shown this allocation to take long enough under
518 	 * GFP_KERNEL that the local node can get fenced. It would be
519 	 * nicest if we could pre-allocate these bios and avoid this
520 	 * all together. */
521 	bio = bio_alloc(GFP_ATOMIC, 16);
522 	if (!bio) {
523 		mlog(ML_ERROR, "Could not alloc slots BIO!\n");
524 		bio = ERR_PTR(-ENOMEM);
525 		goto bail;
526 	}
527 
528 	/* Must put everything in 512 byte sectors for the bio... */
529 	bio->bi_iter.bi_sector = (reg->hr_start_block + cs) << (bits - 9);
530 	bio_set_dev(bio, reg->hr_bdev);
531 	bio->bi_private = wc;
532 	bio->bi_end_io = o2hb_bio_end_io;
533 	bio_set_op_attrs(bio, op, op_flags);
534 
535 	vec_start = (cs << bits) % PAGE_SIZE;
536 	while(cs < max_slots) {
537 		current_page = cs / spp;
538 		page = reg->hr_slot_data[current_page];
539 
540 		vec_len = min(PAGE_SIZE - vec_start,
541 			      (max_slots-cs) * (PAGE_SIZE/spp) );
542 
543 		mlog(ML_HB_BIO, "page %d, vec_len = %u, vec_start = %u\n",
544 		     current_page, vec_len, vec_start);
545 
546 		len = bio_add_page(bio, page, vec_len, vec_start);
547 		if (len != vec_len) break;
548 
549 		cs += vec_len / (PAGE_SIZE/spp);
550 		vec_start = 0;
551 	}
552 
553 bail:
554 	*current_slot = cs;
555 	return bio;
556 }
557 
o2hb_read_slots(struct o2hb_region * reg,unsigned int begin_slot,unsigned int max_slots)558 static int o2hb_read_slots(struct o2hb_region *reg,
559 			   unsigned int begin_slot,
560 			   unsigned int max_slots)
561 {
562 	unsigned int current_slot = begin_slot;
563 	int status;
564 	struct o2hb_bio_wait_ctxt wc;
565 	struct bio *bio;
566 
567 	o2hb_bio_wait_init(&wc);
568 
569 	while(current_slot < max_slots) {
570 		bio = o2hb_setup_one_bio(reg, &wc, &current_slot, max_slots,
571 					 REQ_OP_READ, 0);
572 		if (IS_ERR(bio)) {
573 			status = PTR_ERR(bio);
574 			mlog_errno(status);
575 			goto bail_and_wait;
576 		}
577 
578 		atomic_inc(&wc.wc_num_reqs);
579 		submit_bio(bio);
580 	}
581 
582 	status = 0;
583 
584 bail_and_wait:
585 	o2hb_wait_on_io(&wc);
586 	if (wc.wc_error && !status)
587 		status = wc.wc_error;
588 
589 	return status;
590 }
591 
o2hb_issue_node_write(struct o2hb_region * reg,struct o2hb_bio_wait_ctxt * write_wc)592 static int o2hb_issue_node_write(struct o2hb_region *reg,
593 				 struct o2hb_bio_wait_ctxt *write_wc)
594 {
595 	int status;
596 	unsigned int slot;
597 	struct bio *bio;
598 
599 	o2hb_bio_wait_init(write_wc);
600 
601 	slot = o2nm_this_node();
602 
603 	bio = o2hb_setup_one_bio(reg, write_wc, &slot, slot+1, REQ_OP_WRITE,
604 				 REQ_SYNC);
605 	if (IS_ERR(bio)) {
606 		status = PTR_ERR(bio);
607 		mlog_errno(status);
608 		goto bail;
609 	}
610 
611 	atomic_inc(&write_wc->wc_num_reqs);
612 	submit_bio(bio);
613 
614 	status = 0;
615 bail:
616 	return status;
617 }
618 
o2hb_compute_block_crc_le(struct o2hb_region * reg,struct o2hb_disk_heartbeat_block * hb_block)619 static u32 o2hb_compute_block_crc_le(struct o2hb_region *reg,
620 				     struct o2hb_disk_heartbeat_block *hb_block)
621 {
622 	__le32 old_cksum;
623 	u32 ret;
624 
625 	/* We want to compute the block crc with a 0 value in the
626 	 * hb_cksum field. Save it off here and replace after the
627 	 * crc. */
628 	old_cksum = hb_block->hb_cksum;
629 	hb_block->hb_cksum = 0;
630 
631 	ret = crc32_le(0, (unsigned char *) hb_block, reg->hr_block_bytes);
632 
633 	hb_block->hb_cksum = old_cksum;
634 
635 	return ret;
636 }
637 
o2hb_dump_slot(struct o2hb_disk_heartbeat_block * hb_block)638 static void o2hb_dump_slot(struct o2hb_disk_heartbeat_block *hb_block)
639 {
640 	mlog(ML_ERROR, "Dump slot information: seq = 0x%llx, node = %u, "
641 	     "cksum = 0x%x, generation 0x%llx\n",
642 	     (long long)le64_to_cpu(hb_block->hb_seq),
643 	     hb_block->hb_node, le32_to_cpu(hb_block->hb_cksum),
644 	     (long long)le64_to_cpu(hb_block->hb_generation));
645 }
646 
o2hb_verify_crc(struct o2hb_region * reg,struct o2hb_disk_heartbeat_block * hb_block)647 static int o2hb_verify_crc(struct o2hb_region *reg,
648 			   struct o2hb_disk_heartbeat_block *hb_block)
649 {
650 	u32 read, computed;
651 
652 	read = le32_to_cpu(hb_block->hb_cksum);
653 	computed = o2hb_compute_block_crc_le(reg, hb_block);
654 
655 	return read == computed;
656 }
657 
658 /*
659  * Compare the slot data with what we wrote in the last iteration.
660  * If the match fails, print an appropriate error message. This is to
661  * detect errors like... another node hearting on the same slot,
662  * flaky device that is losing writes, etc.
663  * Returns 1 if check succeeds, 0 otherwise.
664  */
o2hb_check_own_slot(struct o2hb_region * reg)665 static int o2hb_check_own_slot(struct o2hb_region *reg)
666 {
667 	struct o2hb_disk_slot *slot;
668 	struct o2hb_disk_heartbeat_block *hb_block;
669 	char *errstr;
670 
671 	slot = &reg->hr_slots[o2nm_this_node()];
672 	/* Don't check on our 1st timestamp */
673 	if (!slot->ds_last_time)
674 		return 0;
675 
676 	hb_block = slot->ds_raw_block;
677 	if (le64_to_cpu(hb_block->hb_seq) == slot->ds_last_time &&
678 	    le64_to_cpu(hb_block->hb_generation) == slot->ds_last_generation &&
679 	    hb_block->hb_node == slot->ds_node_num)
680 		return 1;
681 
682 #define ERRSTR1		"Another node is heartbeating on device"
683 #define ERRSTR2		"Heartbeat generation mismatch on device"
684 #define ERRSTR3		"Heartbeat sequence mismatch on device"
685 
686 	if (hb_block->hb_node != slot->ds_node_num)
687 		errstr = ERRSTR1;
688 	else if (le64_to_cpu(hb_block->hb_generation) !=
689 		 slot->ds_last_generation)
690 		errstr = ERRSTR2;
691 	else
692 		errstr = ERRSTR3;
693 
694 	mlog(ML_ERROR, "%s (%s): expected(%u:0x%llx, 0x%llx), "
695 	     "ondisk(%u:0x%llx, 0x%llx)\n", errstr, reg->hr_dev_name,
696 	     slot->ds_node_num, (unsigned long long)slot->ds_last_generation,
697 	     (unsigned long long)slot->ds_last_time, hb_block->hb_node,
698 	     (unsigned long long)le64_to_cpu(hb_block->hb_generation),
699 	     (unsigned long long)le64_to_cpu(hb_block->hb_seq));
700 
701 	return 0;
702 }
703 
o2hb_prepare_block(struct o2hb_region * reg,u64 generation)704 static inline void o2hb_prepare_block(struct o2hb_region *reg,
705 				      u64 generation)
706 {
707 	int node_num;
708 	u64 cputime;
709 	struct o2hb_disk_slot *slot;
710 	struct o2hb_disk_heartbeat_block *hb_block;
711 
712 	node_num = o2nm_this_node();
713 	slot = &reg->hr_slots[node_num];
714 
715 	hb_block = (struct o2hb_disk_heartbeat_block *)slot->ds_raw_block;
716 	memset(hb_block, 0, reg->hr_block_bytes);
717 	/* TODO: time stuff */
718 	cputime = ktime_get_real_seconds();
719 	if (!cputime)
720 		cputime = 1;
721 
722 	hb_block->hb_seq = cpu_to_le64(cputime);
723 	hb_block->hb_node = node_num;
724 	hb_block->hb_generation = cpu_to_le64(generation);
725 	hb_block->hb_dead_ms = cpu_to_le32(o2hb_dead_threshold * O2HB_REGION_TIMEOUT_MS);
726 
727 	/* This step must always happen last! */
728 	hb_block->hb_cksum = cpu_to_le32(o2hb_compute_block_crc_le(reg,
729 								   hb_block));
730 
731 	mlog(ML_HB_BIO, "our node generation = 0x%llx, cksum = 0x%x\n",
732 	     (long long)generation,
733 	     le32_to_cpu(hb_block->hb_cksum));
734 }
735 
o2hb_fire_callbacks(struct o2hb_callback * hbcall,struct o2nm_node * node,int idx)736 static void o2hb_fire_callbacks(struct o2hb_callback *hbcall,
737 				struct o2nm_node *node,
738 				int idx)
739 {
740 	struct o2hb_callback_func *f;
741 
742 	list_for_each_entry(f, &hbcall->list, hc_item) {
743 		mlog(ML_HEARTBEAT, "calling funcs %p\n", f);
744 		(f->hc_func)(node, idx, f->hc_data);
745 	}
746 }
747 
748 /* Will run the list in order until we process the passed event */
o2hb_run_event_list(struct o2hb_node_event * queued_event)749 static void o2hb_run_event_list(struct o2hb_node_event *queued_event)
750 {
751 	struct o2hb_callback *hbcall;
752 	struct o2hb_node_event *event;
753 
754 	/* Holding callback sem assures we don't alter the callback
755 	 * lists when doing this, and serializes ourselves with other
756 	 * processes wanting callbacks. */
757 	down_write(&o2hb_callback_sem);
758 
759 	spin_lock(&o2hb_live_lock);
760 	while (!list_empty(&o2hb_node_events)
761 	       && !list_empty(&queued_event->hn_item)) {
762 		event = list_entry(o2hb_node_events.next,
763 				   struct o2hb_node_event,
764 				   hn_item);
765 		list_del_init(&event->hn_item);
766 		spin_unlock(&o2hb_live_lock);
767 
768 		mlog(ML_HEARTBEAT, "Node %s event for %d\n",
769 		     event->hn_event_type == O2HB_NODE_UP_CB ? "UP" : "DOWN",
770 		     event->hn_node_num);
771 
772 		hbcall = hbcall_from_type(event->hn_event_type);
773 
774 		/* We should *never* have gotten on to the list with a
775 		 * bad type... This isn't something that we should try
776 		 * to recover from. */
777 		BUG_ON(IS_ERR(hbcall));
778 
779 		o2hb_fire_callbacks(hbcall, event->hn_node, event->hn_node_num);
780 
781 		spin_lock(&o2hb_live_lock);
782 	}
783 	spin_unlock(&o2hb_live_lock);
784 
785 	up_write(&o2hb_callback_sem);
786 }
787 
o2hb_queue_node_event(struct o2hb_node_event * event,enum o2hb_callback_type type,struct o2nm_node * node,int node_num)788 static void o2hb_queue_node_event(struct o2hb_node_event *event,
789 				  enum o2hb_callback_type type,
790 				  struct o2nm_node *node,
791 				  int node_num)
792 {
793 	assert_spin_locked(&o2hb_live_lock);
794 
795 	BUG_ON((!node) && (type != O2HB_NODE_DOWN_CB));
796 
797 	event->hn_event_type = type;
798 	event->hn_node = node;
799 	event->hn_node_num = node_num;
800 
801 	mlog(ML_HEARTBEAT, "Queue node %s event for node %d\n",
802 	     type == O2HB_NODE_UP_CB ? "UP" : "DOWN", node_num);
803 
804 	list_add_tail(&event->hn_item, &o2hb_node_events);
805 }
806 
o2hb_shutdown_slot(struct o2hb_disk_slot * slot)807 static void o2hb_shutdown_slot(struct o2hb_disk_slot *slot)
808 {
809 	struct o2hb_node_event event =
810 		{ .hn_item = LIST_HEAD_INIT(event.hn_item), };
811 	struct o2nm_node *node;
812 	int queued = 0;
813 
814 	node = o2nm_get_node_by_num(slot->ds_node_num);
815 	if (!node)
816 		return;
817 
818 	spin_lock(&o2hb_live_lock);
819 	if (!list_empty(&slot->ds_live_item)) {
820 		mlog(ML_HEARTBEAT, "Shutdown, node %d leaves region\n",
821 		     slot->ds_node_num);
822 
823 		list_del_init(&slot->ds_live_item);
824 
825 		if (list_empty(&o2hb_live_slots[slot->ds_node_num])) {
826 			clear_bit(slot->ds_node_num, o2hb_live_node_bitmap);
827 
828 			o2hb_queue_node_event(&event, O2HB_NODE_DOWN_CB, node,
829 					      slot->ds_node_num);
830 			queued = 1;
831 		}
832 	}
833 	spin_unlock(&o2hb_live_lock);
834 
835 	if (queued)
836 		o2hb_run_event_list(&event);
837 
838 	o2nm_node_put(node);
839 }
840 
o2hb_set_quorum_device(struct o2hb_region * reg)841 static void o2hb_set_quorum_device(struct o2hb_region *reg)
842 {
843 	if (!o2hb_global_heartbeat_active())
844 		return;
845 
846 	/* Prevent race with o2hb_heartbeat_group_drop_item() */
847 	if (kthread_should_stop())
848 		return;
849 
850 	/* Tag region as quorum only after thread reaches steady state */
851 	if (atomic_read(&reg->hr_steady_iterations) != 0)
852 		return;
853 
854 	spin_lock(&o2hb_live_lock);
855 
856 	if (test_bit(reg->hr_region_num, o2hb_quorum_region_bitmap))
857 		goto unlock;
858 
859 	/*
860 	 * A region can be added to the quorum only when it sees all
861 	 * live nodes heartbeat on it. In other words, the region has been
862 	 * added to all nodes.
863 	 */
864 	if (memcmp(reg->hr_live_node_bitmap, o2hb_live_node_bitmap,
865 		   sizeof(o2hb_live_node_bitmap)))
866 		goto unlock;
867 
868 	printk(KERN_NOTICE "o2hb: Region %s (%s) is now a quorum device\n",
869 	       config_item_name(&reg->hr_item), reg->hr_dev_name);
870 
871 	set_bit(reg->hr_region_num, o2hb_quorum_region_bitmap);
872 
873 	/*
874 	 * If global heartbeat active, unpin all regions if the
875 	 * region count > CUT_OFF
876 	 */
877 	if (bitmap_weight(o2hb_quorum_region_bitmap,
878 			   O2NM_MAX_REGIONS) > O2HB_PIN_CUT_OFF)
879 		o2hb_region_unpin(NULL);
880 unlock:
881 	spin_unlock(&o2hb_live_lock);
882 }
883 
o2hb_check_slot(struct o2hb_region * reg,struct o2hb_disk_slot * slot)884 static int o2hb_check_slot(struct o2hb_region *reg,
885 			   struct o2hb_disk_slot *slot)
886 {
887 	int changed = 0, gen_changed = 0;
888 	struct o2hb_node_event event =
889 		{ .hn_item = LIST_HEAD_INIT(event.hn_item), };
890 	struct o2nm_node *node;
891 	struct o2hb_disk_heartbeat_block *hb_block = reg->hr_tmp_block;
892 	u64 cputime;
893 	unsigned int dead_ms = o2hb_dead_threshold * O2HB_REGION_TIMEOUT_MS;
894 	unsigned int slot_dead_ms;
895 	int tmp;
896 	int queued = 0;
897 
898 	memcpy(hb_block, slot->ds_raw_block, reg->hr_block_bytes);
899 
900 	/*
901 	 * If a node is no longer configured but is still in the livemap, we
902 	 * may need to clear that bit from the livemap.
903 	 */
904 	node = o2nm_get_node_by_num(slot->ds_node_num);
905 	if (!node) {
906 		spin_lock(&o2hb_live_lock);
907 		tmp = test_bit(slot->ds_node_num, o2hb_live_node_bitmap);
908 		spin_unlock(&o2hb_live_lock);
909 		if (!tmp)
910 			return 0;
911 	}
912 
913 	if (!o2hb_verify_crc(reg, hb_block)) {
914 		/* all paths from here will drop o2hb_live_lock for
915 		 * us. */
916 		spin_lock(&o2hb_live_lock);
917 
918 		/* Don't print an error on the console in this case -
919 		 * a freshly formatted heartbeat area will not have a
920 		 * crc set on it. */
921 		if (list_empty(&slot->ds_live_item))
922 			goto out;
923 
924 		/* The node is live but pushed out a bad crc. We
925 		 * consider it a transient miss but don't populate any
926 		 * other values as they may be junk. */
927 		mlog(ML_ERROR, "Node %d has written a bad crc to %s\n",
928 		     slot->ds_node_num, reg->hr_dev_name);
929 		o2hb_dump_slot(hb_block);
930 
931 		slot->ds_equal_samples++;
932 		goto fire_callbacks;
933 	}
934 
935 	/* we don't care if these wrap.. the state transitions below
936 	 * clear at the right places */
937 	cputime = le64_to_cpu(hb_block->hb_seq);
938 	if (slot->ds_last_time != cputime)
939 		slot->ds_changed_samples++;
940 	else
941 		slot->ds_equal_samples++;
942 	slot->ds_last_time = cputime;
943 
944 	/* The node changed heartbeat generations. We assume this to
945 	 * mean it dropped off but came back before we timed out. We
946 	 * want to consider it down for the time being but don't want
947 	 * to lose any changed_samples state we might build up to
948 	 * considering it live again. */
949 	if (slot->ds_last_generation != le64_to_cpu(hb_block->hb_generation)) {
950 		gen_changed = 1;
951 		slot->ds_equal_samples = 0;
952 		mlog(ML_HEARTBEAT, "Node %d changed generation (0x%llx "
953 		     "to 0x%llx)\n", slot->ds_node_num,
954 		     (long long)slot->ds_last_generation,
955 		     (long long)le64_to_cpu(hb_block->hb_generation));
956 	}
957 
958 	slot->ds_last_generation = le64_to_cpu(hb_block->hb_generation);
959 
960 	mlog(ML_HEARTBEAT, "Slot %d gen 0x%llx cksum 0x%x "
961 	     "seq %llu last %llu changed %u equal %u\n",
962 	     slot->ds_node_num, (long long)slot->ds_last_generation,
963 	     le32_to_cpu(hb_block->hb_cksum),
964 	     (unsigned long long)le64_to_cpu(hb_block->hb_seq),
965 	     (unsigned long long)slot->ds_last_time, slot->ds_changed_samples,
966 	     slot->ds_equal_samples);
967 
968 	spin_lock(&o2hb_live_lock);
969 
970 fire_callbacks:
971 	/* dead nodes only come to life after some number of
972 	 * changes at any time during their dead time */
973 	if (list_empty(&slot->ds_live_item) &&
974 	    slot->ds_changed_samples >= O2HB_LIVE_THRESHOLD) {
975 		mlog(ML_HEARTBEAT, "Node %d (id 0x%llx) joined my region\n",
976 		     slot->ds_node_num, (long long)slot->ds_last_generation);
977 
978 		set_bit(slot->ds_node_num, reg->hr_live_node_bitmap);
979 
980 		/* first on the list generates a callback */
981 		if (list_empty(&o2hb_live_slots[slot->ds_node_num])) {
982 			mlog(ML_HEARTBEAT, "o2hb: Add node %d to live nodes "
983 			     "bitmap\n", slot->ds_node_num);
984 			set_bit(slot->ds_node_num, o2hb_live_node_bitmap);
985 
986 			o2hb_queue_node_event(&event, O2HB_NODE_UP_CB, node,
987 					      slot->ds_node_num);
988 
989 			changed = 1;
990 			queued = 1;
991 		}
992 
993 		list_add_tail(&slot->ds_live_item,
994 			      &o2hb_live_slots[slot->ds_node_num]);
995 
996 		slot->ds_equal_samples = 0;
997 
998 		/* We want to be sure that all nodes agree on the
999 		 * number of milliseconds before a node will be
1000 		 * considered dead. The self-fencing timeout is
1001 		 * computed from this value, and a discrepancy might
1002 		 * result in heartbeat calling a node dead when it
1003 		 * hasn't self-fenced yet. */
1004 		slot_dead_ms = le32_to_cpu(hb_block->hb_dead_ms);
1005 		if (slot_dead_ms && slot_dead_ms != dead_ms) {
1006 			/* TODO: Perhaps we can fail the region here. */
1007 			mlog(ML_ERROR, "Node %d on device %s has a dead count "
1008 			     "of %u ms, but our count is %u ms.\n"
1009 			     "Please double check your configuration values "
1010 			     "for 'O2CB_HEARTBEAT_THRESHOLD'\n",
1011 			     slot->ds_node_num, reg->hr_dev_name, slot_dead_ms,
1012 			     dead_ms);
1013 		}
1014 		goto out;
1015 	}
1016 
1017 	/* if the list is dead, we're done.. */
1018 	if (list_empty(&slot->ds_live_item))
1019 		goto out;
1020 
1021 	/* live nodes only go dead after enough consequtive missed
1022 	 * samples..  reset the missed counter whenever we see
1023 	 * activity */
1024 	if (slot->ds_equal_samples >= o2hb_dead_threshold || gen_changed) {
1025 		mlog(ML_HEARTBEAT, "Node %d left my region\n",
1026 		     slot->ds_node_num);
1027 
1028 		clear_bit(slot->ds_node_num, reg->hr_live_node_bitmap);
1029 
1030 		/* last off the live_slot generates a callback */
1031 		list_del_init(&slot->ds_live_item);
1032 		if (list_empty(&o2hb_live_slots[slot->ds_node_num])) {
1033 			mlog(ML_HEARTBEAT, "o2hb: Remove node %d from live "
1034 			     "nodes bitmap\n", slot->ds_node_num);
1035 			clear_bit(slot->ds_node_num, o2hb_live_node_bitmap);
1036 
1037 			/* node can be null */
1038 			o2hb_queue_node_event(&event, O2HB_NODE_DOWN_CB,
1039 					      node, slot->ds_node_num);
1040 
1041 			changed = 1;
1042 			queued = 1;
1043 		}
1044 
1045 		/* We don't clear this because the node is still
1046 		 * actually writing new blocks. */
1047 		if (!gen_changed)
1048 			slot->ds_changed_samples = 0;
1049 		goto out;
1050 	}
1051 	if (slot->ds_changed_samples) {
1052 		slot->ds_changed_samples = 0;
1053 		slot->ds_equal_samples = 0;
1054 	}
1055 out:
1056 	spin_unlock(&o2hb_live_lock);
1057 
1058 	if (queued)
1059 		o2hb_run_event_list(&event);
1060 
1061 	if (node)
1062 		o2nm_node_put(node);
1063 	return changed;
1064 }
1065 
o2hb_highest_node(unsigned long * nodes,int numbits)1066 static int o2hb_highest_node(unsigned long *nodes, int numbits)
1067 {
1068 	return find_last_bit(nodes, numbits);
1069 }
1070 
o2hb_lowest_node(unsigned long * nodes,int numbits)1071 static int o2hb_lowest_node(unsigned long *nodes, int numbits)
1072 {
1073 	return find_first_bit(nodes, numbits);
1074 }
1075 
o2hb_do_disk_heartbeat(struct o2hb_region * reg)1076 static int o2hb_do_disk_heartbeat(struct o2hb_region *reg)
1077 {
1078 	int i, ret, highest_node, lowest_node;
1079 	int membership_change = 0, own_slot_ok = 0;
1080 	unsigned long configured_nodes[BITS_TO_LONGS(O2NM_MAX_NODES)];
1081 	unsigned long live_node_bitmap[BITS_TO_LONGS(O2NM_MAX_NODES)];
1082 	struct o2hb_bio_wait_ctxt write_wc;
1083 
1084 	ret = o2nm_configured_node_map(configured_nodes,
1085 				       sizeof(configured_nodes));
1086 	if (ret) {
1087 		mlog_errno(ret);
1088 		goto bail;
1089 	}
1090 
1091 	/*
1092 	 * If a node is not configured but is in the livemap, we still need
1093 	 * to read the slot so as to be able to remove it from the livemap.
1094 	 */
1095 	o2hb_fill_node_map(live_node_bitmap, sizeof(live_node_bitmap));
1096 	i = -1;
1097 	while ((i = find_next_bit(live_node_bitmap,
1098 				  O2NM_MAX_NODES, i + 1)) < O2NM_MAX_NODES) {
1099 		set_bit(i, configured_nodes);
1100 	}
1101 
1102 	highest_node = o2hb_highest_node(configured_nodes, O2NM_MAX_NODES);
1103 	lowest_node = o2hb_lowest_node(configured_nodes, O2NM_MAX_NODES);
1104 	if (highest_node >= O2NM_MAX_NODES || lowest_node >= O2NM_MAX_NODES) {
1105 		mlog(ML_NOTICE, "o2hb: No configured nodes found!\n");
1106 		ret = -EINVAL;
1107 		goto bail;
1108 	}
1109 
1110 	/* No sense in reading the slots of nodes that don't exist
1111 	 * yet. Of course, if the node definitions have holes in them
1112 	 * then we're reading an empty slot anyway... Consider this
1113 	 * best-effort. */
1114 	ret = o2hb_read_slots(reg, lowest_node, highest_node + 1);
1115 	if (ret < 0) {
1116 		mlog_errno(ret);
1117 		goto bail;
1118 	}
1119 
1120 	/* With an up to date view of the slots, we can check that no
1121 	 * other node has been improperly configured to heartbeat in
1122 	 * our slot. */
1123 	own_slot_ok = o2hb_check_own_slot(reg);
1124 
1125 	/* fill in the proper info for our next heartbeat */
1126 	o2hb_prepare_block(reg, reg->hr_generation);
1127 
1128 	ret = o2hb_issue_node_write(reg, &write_wc);
1129 	if (ret < 0) {
1130 		mlog_errno(ret);
1131 		goto bail;
1132 	}
1133 
1134 	i = -1;
1135 	while((i = find_next_bit(configured_nodes,
1136 				 O2NM_MAX_NODES, i + 1)) < O2NM_MAX_NODES) {
1137 		membership_change |= o2hb_check_slot(reg, &reg->hr_slots[i]);
1138 	}
1139 
1140 	/*
1141 	 * We have to be sure we've advertised ourselves on disk
1142 	 * before we can go to steady state.  This ensures that
1143 	 * people we find in our steady state have seen us.
1144 	 */
1145 	o2hb_wait_on_io(&write_wc);
1146 	if (write_wc.wc_error) {
1147 		/* Do not re-arm the write timeout on I/O error - we
1148 		 * can't be sure that the new block ever made it to
1149 		 * disk */
1150 		mlog(ML_ERROR, "Write error %d on device \"%s\"\n",
1151 		     write_wc.wc_error, reg->hr_dev_name);
1152 		ret = write_wc.wc_error;
1153 		goto bail;
1154 	}
1155 
1156 	/* Skip disarming the timeout if own slot has stale/bad data */
1157 	if (own_slot_ok) {
1158 		o2hb_set_quorum_device(reg);
1159 		o2hb_arm_timeout(reg);
1160 		reg->hr_last_timeout_start = jiffies;
1161 	}
1162 
1163 bail:
1164 	/* let the person who launched us know when things are steady */
1165 	if (atomic_read(&reg->hr_steady_iterations) != 0) {
1166 		if (!ret && own_slot_ok && !membership_change) {
1167 			if (atomic_dec_and_test(&reg->hr_steady_iterations))
1168 				wake_up(&o2hb_steady_queue);
1169 		}
1170 	}
1171 
1172 	if (atomic_read(&reg->hr_steady_iterations) != 0) {
1173 		if (atomic_dec_and_test(&reg->hr_unsteady_iterations)) {
1174 			printk(KERN_NOTICE "o2hb: Unable to stabilize "
1175 			       "heartbeat on region %s (%s)\n",
1176 			       config_item_name(&reg->hr_item),
1177 			       reg->hr_dev_name);
1178 			atomic_set(&reg->hr_steady_iterations, 0);
1179 			reg->hr_aborted_start = 1;
1180 			wake_up(&o2hb_steady_queue);
1181 			ret = -EIO;
1182 		}
1183 	}
1184 
1185 	return ret;
1186 }
1187 
1188 /*
1189  * we ride the region ref that the region dir holds.  before the region
1190  * dir is removed and drops it ref it will wait to tear down this
1191  * thread.
1192  */
o2hb_thread(void * data)1193 static int o2hb_thread(void *data)
1194 {
1195 	int i, ret;
1196 	struct o2hb_region *reg = data;
1197 	struct o2hb_bio_wait_ctxt write_wc;
1198 	ktime_t before_hb, after_hb;
1199 	unsigned int elapsed_msec;
1200 
1201 	mlog(ML_HEARTBEAT|ML_KTHREAD, "hb thread running\n");
1202 
1203 	set_user_nice(current, MIN_NICE);
1204 
1205 	/* Pin node */
1206 	ret = o2nm_depend_this_node();
1207 	if (ret) {
1208 		mlog(ML_ERROR, "Node has been deleted, ret = %d\n", ret);
1209 		reg->hr_node_deleted = 1;
1210 		wake_up(&o2hb_steady_queue);
1211 		return 0;
1212 	}
1213 
1214 	while (!kthread_should_stop() &&
1215 	       !reg->hr_unclean_stop && !reg->hr_aborted_start) {
1216 		/* We track the time spent inside
1217 		 * o2hb_do_disk_heartbeat so that we avoid more than
1218 		 * hr_timeout_ms between disk writes. On busy systems
1219 		 * this should result in a heartbeat which is less
1220 		 * likely to time itself out. */
1221 		before_hb = ktime_get_real();
1222 
1223 		ret = o2hb_do_disk_heartbeat(reg);
1224 		reg->hr_last_hb_status = ret;
1225 
1226 		after_hb = ktime_get_real();
1227 
1228 		elapsed_msec = (unsigned int)
1229 				ktime_ms_delta(after_hb, before_hb);
1230 
1231 		mlog(ML_HEARTBEAT,
1232 		     "start = %lld, end = %lld, msec = %u, ret = %d\n",
1233 		     before_hb, after_hb, elapsed_msec, ret);
1234 
1235 		if (!kthread_should_stop() &&
1236 		    elapsed_msec < reg->hr_timeout_ms) {
1237 			/* the kthread api has blocked signals for us so no
1238 			 * need to record the return value. */
1239 			msleep_interruptible(reg->hr_timeout_ms - elapsed_msec);
1240 		}
1241 	}
1242 
1243 	o2hb_disarm_timeout(reg);
1244 
1245 	/* unclean stop is only used in very bad situation */
1246 	for(i = 0; !reg->hr_unclean_stop && i < reg->hr_blocks; i++)
1247 		o2hb_shutdown_slot(&reg->hr_slots[i]);
1248 
1249 	/* Explicit down notification - avoid forcing the other nodes
1250 	 * to timeout on this region when we could just as easily
1251 	 * write a clear generation - thus indicating to them that
1252 	 * this node has left this region.
1253 	 */
1254 	if (!reg->hr_unclean_stop && !reg->hr_aborted_start) {
1255 		o2hb_prepare_block(reg, 0);
1256 		ret = o2hb_issue_node_write(reg, &write_wc);
1257 		if (ret == 0)
1258 			o2hb_wait_on_io(&write_wc);
1259 		else
1260 			mlog_errno(ret);
1261 	}
1262 
1263 	/* Unpin node */
1264 	o2nm_undepend_this_node();
1265 
1266 	mlog(ML_HEARTBEAT|ML_KTHREAD, "o2hb thread exiting\n");
1267 
1268 	return 0;
1269 }
1270 
1271 #ifdef CONFIG_DEBUG_FS
o2hb_debug_open(struct inode * inode,struct file * file)1272 static int o2hb_debug_open(struct inode *inode, struct file *file)
1273 {
1274 	struct o2hb_debug_buf *db = inode->i_private;
1275 	struct o2hb_region *reg;
1276 	unsigned long map[BITS_TO_LONGS(O2NM_MAX_NODES)];
1277 	unsigned long lts;
1278 	char *buf = NULL;
1279 	int i = -1;
1280 	int out = 0;
1281 
1282 	/* max_nodes should be the largest bitmap we pass here */
1283 	BUG_ON(sizeof(map) < db->db_size);
1284 
1285 	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
1286 	if (!buf)
1287 		goto bail;
1288 
1289 	switch (db->db_type) {
1290 	case O2HB_DB_TYPE_LIVENODES:
1291 	case O2HB_DB_TYPE_LIVEREGIONS:
1292 	case O2HB_DB_TYPE_QUORUMREGIONS:
1293 	case O2HB_DB_TYPE_FAILEDREGIONS:
1294 		spin_lock(&o2hb_live_lock);
1295 		memcpy(map, db->db_data, db->db_size);
1296 		spin_unlock(&o2hb_live_lock);
1297 		break;
1298 
1299 	case O2HB_DB_TYPE_REGION_LIVENODES:
1300 		spin_lock(&o2hb_live_lock);
1301 		reg = (struct o2hb_region *)db->db_data;
1302 		memcpy(map, reg->hr_live_node_bitmap, db->db_size);
1303 		spin_unlock(&o2hb_live_lock);
1304 		break;
1305 
1306 	case O2HB_DB_TYPE_REGION_NUMBER:
1307 		reg = (struct o2hb_region *)db->db_data;
1308 		out += scnprintf(buf + out, PAGE_SIZE - out, "%d\n",
1309 				reg->hr_region_num);
1310 		goto done;
1311 
1312 	case O2HB_DB_TYPE_REGION_ELAPSED_TIME:
1313 		reg = (struct o2hb_region *)db->db_data;
1314 		lts = reg->hr_last_timeout_start;
1315 		/* If 0, it has never been set before */
1316 		if (lts)
1317 			lts = jiffies_to_msecs(jiffies - lts);
1318 		out += scnprintf(buf + out, PAGE_SIZE - out, "%lu\n", lts);
1319 		goto done;
1320 
1321 	case O2HB_DB_TYPE_REGION_PINNED:
1322 		reg = (struct o2hb_region *)db->db_data;
1323 		out += scnprintf(buf + out, PAGE_SIZE - out, "%u\n",
1324 				!!reg->hr_item_pinned);
1325 		goto done;
1326 
1327 	default:
1328 		goto done;
1329 	}
1330 
1331 	while ((i = find_next_bit(map, db->db_len, i + 1)) < db->db_len)
1332 		out += scnprintf(buf + out, PAGE_SIZE - out, "%d ", i);
1333 	out += scnprintf(buf + out, PAGE_SIZE - out, "\n");
1334 
1335 done:
1336 	i_size_write(inode, out);
1337 
1338 	file->private_data = buf;
1339 
1340 	return 0;
1341 bail:
1342 	return -ENOMEM;
1343 }
1344 
o2hb_debug_release(struct inode * inode,struct file * file)1345 static int o2hb_debug_release(struct inode *inode, struct file *file)
1346 {
1347 	kfree(file->private_data);
1348 	return 0;
1349 }
1350 
o2hb_debug_read(struct file * file,char __user * buf,size_t nbytes,loff_t * ppos)1351 static ssize_t o2hb_debug_read(struct file *file, char __user *buf,
1352 				 size_t nbytes, loff_t *ppos)
1353 {
1354 	return simple_read_from_buffer(buf, nbytes, ppos, file->private_data,
1355 				       i_size_read(file->f_mapping->host));
1356 }
1357 #else
o2hb_debug_open(struct inode * inode,struct file * file)1358 static int o2hb_debug_open(struct inode *inode, struct file *file)
1359 {
1360 	return 0;
1361 }
o2hb_debug_release(struct inode * inode,struct file * file)1362 static int o2hb_debug_release(struct inode *inode, struct file *file)
1363 {
1364 	return 0;
1365 }
o2hb_debug_read(struct file * file,char __user * buf,size_t nbytes,loff_t * ppos)1366 static ssize_t o2hb_debug_read(struct file *file, char __user *buf,
1367 			       size_t nbytes, loff_t *ppos)
1368 {
1369 	return 0;
1370 }
1371 #endif  /* CONFIG_DEBUG_FS */
1372 
1373 static const struct file_operations o2hb_debug_fops = {
1374 	.open =		o2hb_debug_open,
1375 	.release =	o2hb_debug_release,
1376 	.read =		o2hb_debug_read,
1377 	.llseek =	generic_file_llseek,
1378 };
1379 
o2hb_exit(void)1380 void o2hb_exit(void)
1381 {
1382 	debugfs_remove_recursive(o2hb_debug_dir);
1383 	kfree(o2hb_db_livenodes);
1384 	kfree(o2hb_db_liveregions);
1385 	kfree(o2hb_db_quorumregions);
1386 	kfree(o2hb_db_failedregions);
1387 }
1388 
o2hb_debug_create(const char * name,struct dentry * dir,struct o2hb_debug_buf ** db,int db_len,int type,int size,int len,void * data)1389 static void o2hb_debug_create(const char *name, struct dentry *dir,
1390 			      struct o2hb_debug_buf **db, int db_len, int type,
1391 			      int size, int len, void *data)
1392 {
1393 	*db = kmalloc(db_len, GFP_KERNEL);
1394 	if (!*db)
1395 		return;
1396 
1397 	(*db)->db_type = type;
1398 	(*db)->db_size = size;
1399 	(*db)->db_len = len;
1400 	(*db)->db_data = data;
1401 
1402 	debugfs_create_file(name, S_IFREG|S_IRUSR, dir, *db, &o2hb_debug_fops);
1403 }
1404 
o2hb_debug_init(void)1405 static void o2hb_debug_init(void)
1406 {
1407 	o2hb_debug_dir = debugfs_create_dir(O2HB_DEBUG_DIR, NULL);
1408 
1409 	o2hb_debug_create(O2HB_DEBUG_LIVENODES, o2hb_debug_dir,
1410 			  &o2hb_db_livenodes, sizeof(*o2hb_db_livenodes),
1411 			  O2HB_DB_TYPE_LIVENODES, sizeof(o2hb_live_node_bitmap),
1412 			  O2NM_MAX_NODES, o2hb_live_node_bitmap);
1413 
1414 	o2hb_debug_create(O2HB_DEBUG_LIVEREGIONS, o2hb_debug_dir,
1415 			  &o2hb_db_liveregions, sizeof(*o2hb_db_liveregions),
1416 			  O2HB_DB_TYPE_LIVEREGIONS,
1417 			  sizeof(o2hb_live_region_bitmap), O2NM_MAX_REGIONS,
1418 			  o2hb_live_region_bitmap);
1419 
1420 	o2hb_debug_create(O2HB_DEBUG_QUORUMREGIONS, o2hb_debug_dir,
1421 			  &o2hb_db_quorumregions,
1422 			  sizeof(*o2hb_db_quorumregions),
1423 			  O2HB_DB_TYPE_QUORUMREGIONS,
1424 			  sizeof(o2hb_quorum_region_bitmap), O2NM_MAX_REGIONS,
1425 			  o2hb_quorum_region_bitmap);
1426 
1427 	o2hb_debug_create(O2HB_DEBUG_FAILEDREGIONS, o2hb_debug_dir,
1428 			  &o2hb_db_failedregions,
1429 			  sizeof(*o2hb_db_failedregions),
1430 			  O2HB_DB_TYPE_FAILEDREGIONS,
1431 			  sizeof(o2hb_failed_region_bitmap), O2NM_MAX_REGIONS,
1432 			  o2hb_failed_region_bitmap);
1433 }
1434 
o2hb_init(void)1435 void o2hb_init(void)
1436 {
1437 	int i;
1438 
1439 	for (i = 0; i < ARRAY_SIZE(o2hb_callbacks); i++)
1440 		INIT_LIST_HEAD(&o2hb_callbacks[i].list);
1441 
1442 	for (i = 0; i < ARRAY_SIZE(o2hb_live_slots); i++)
1443 		INIT_LIST_HEAD(&o2hb_live_slots[i]);
1444 
1445 	memset(o2hb_live_node_bitmap, 0, sizeof(o2hb_live_node_bitmap));
1446 	memset(o2hb_region_bitmap, 0, sizeof(o2hb_region_bitmap));
1447 	memset(o2hb_live_region_bitmap, 0, sizeof(o2hb_live_region_bitmap));
1448 	memset(o2hb_quorum_region_bitmap, 0, sizeof(o2hb_quorum_region_bitmap));
1449 	memset(o2hb_failed_region_bitmap, 0, sizeof(o2hb_failed_region_bitmap));
1450 
1451 	o2hb_dependent_users = 0;
1452 
1453 	o2hb_debug_init();
1454 }
1455 
1456 /* if we're already in a callback then we're already serialized by the sem */
o2hb_fill_node_map_from_callback(unsigned long * map,unsigned bytes)1457 static void o2hb_fill_node_map_from_callback(unsigned long *map,
1458 					     unsigned bytes)
1459 {
1460 	BUG_ON(bytes < (BITS_TO_LONGS(O2NM_MAX_NODES) * sizeof(unsigned long)));
1461 
1462 	memcpy(map, &o2hb_live_node_bitmap, bytes);
1463 }
1464 
1465 /*
1466  * get a map of all nodes that are heartbeating in any regions
1467  */
o2hb_fill_node_map(unsigned long * map,unsigned bytes)1468 void o2hb_fill_node_map(unsigned long *map, unsigned bytes)
1469 {
1470 	/* callers want to serialize this map and callbacks so that they
1471 	 * can trust that they don't miss nodes coming to the party */
1472 	down_read(&o2hb_callback_sem);
1473 	spin_lock(&o2hb_live_lock);
1474 	o2hb_fill_node_map_from_callback(map, bytes);
1475 	spin_unlock(&o2hb_live_lock);
1476 	up_read(&o2hb_callback_sem);
1477 }
1478 EXPORT_SYMBOL_GPL(o2hb_fill_node_map);
1479 
1480 /*
1481  * heartbeat configfs bits.  The heartbeat set is a default set under
1482  * the cluster set in nodemanager.c.
1483  */
1484 
to_o2hb_region(struct config_item * item)1485 static struct o2hb_region *to_o2hb_region(struct config_item *item)
1486 {
1487 	return item ? container_of(item, struct o2hb_region, hr_item) : NULL;
1488 }
1489 
1490 /* drop_item only drops its ref after killing the thread, nothing should
1491  * be using the region anymore.  this has to clean up any state that
1492  * attributes might have built up. */
o2hb_region_release(struct config_item * item)1493 static void o2hb_region_release(struct config_item *item)
1494 {
1495 	int i;
1496 	struct page *page;
1497 	struct o2hb_region *reg = to_o2hb_region(item);
1498 
1499 	mlog(ML_HEARTBEAT, "hb region release (%s)\n", reg->hr_dev_name);
1500 
1501 	kfree(reg->hr_tmp_block);
1502 
1503 	if (reg->hr_slot_data) {
1504 		for (i = 0; i < reg->hr_num_pages; i++) {
1505 			page = reg->hr_slot_data[i];
1506 			if (page)
1507 				__free_page(page);
1508 		}
1509 		kfree(reg->hr_slot_data);
1510 	}
1511 
1512 	if (reg->hr_bdev)
1513 		blkdev_put(reg->hr_bdev, FMODE_READ|FMODE_WRITE);
1514 
1515 	kfree(reg->hr_slots);
1516 
1517 	debugfs_remove_recursive(reg->hr_debug_dir);
1518 	kfree(reg->hr_db_livenodes);
1519 	kfree(reg->hr_db_regnum);
1520 	kfree(reg->hr_db_elapsed_time);
1521 	kfree(reg->hr_db_pinned);
1522 
1523 	spin_lock(&o2hb_live_lock);
1524 	list_del(&reg->hr_all_item);
1525 	spin_unlock(&o2hb_live_lock);
1526 
1527 	o2net_unregister_handler_list(&reg->hr_handler_list);
1528 	kfree(reg);
1529 }
1530 
o2hb_read_block_input(struct o2hb_region * reg,const char * page,unsigned long * ret_bytes,unsigned int * ret_bits)1531 static int o2hb_read_block_input(struct o2hb_region *reg,
1532 				 const char *page,
1533 				 unsigned long *ret_bytes,
1534 				 unsigned int *ret_bits)
1535 {
1536 	unsigned long bytes;
1537 	char *p = (char *)page;
1538 
1539 	bytes = simple_strtoul(p, &p, 0);
1540 	if (!p || (*p && (*p != '\n')))
1541 		return -EINVAL;
1542 
1543 	/* Heartbeat and fs min / max block sizes are the same. */
1544 	if (bytes > 4096 || bytes < 512)
1545 		return -ERANGE;
1546 	if (hweight16(bytes) != 1)
1547 		return -EINVAL;
1548 
1549 	if (ret_bytes)
1550 		*ret_bytes = bytes;
1551 	if (ret_bits)
1552 		*ret_bits = ffs(bytes) - 1;
1553 
1554 	return 0;
1555 }
1556 
o2hb_region_block_bytes_show(struct config_item * item,char * page)1557 static ssize_t o2hb_region_block_bytes_show(struct config_item *item,
1558 					    char *page)
1559 {
1560 	return sprintf(page, "%u\n", to_o2hb_region(item)->hr_block_bytes);
1561 }
1562 
o2hb_region_block_bytes_store(struct config_item * item,const char * page,size_t count)1563 static ssize_t o2hb_region_block_bytes_store(struct config_item *item,
1564 					     const char *page,
1565 					     size_t count)
1566 {
1567 	struct o2hb_region *reg = to_o2hb_region(item);
1568 	int status;
1569 	unsigned long block_bytes;
1570 	unsigned int block_bits;
1571 
1572 	if (reg->hr_bdev)
1573 		return -EINVAL;
1574 
1575 	status = o2hb_read_block_input(reg, page, &block_bytes,
1576 				       &block_bits);
1577 	if (status)
1578 		return status;
1579 
1580 	reg->hr_block_bytes = (unsigned int)block_bytes;
1581 	reg->hr_block_bits = block_bits;
1582 
1583 	return count;
1584 }
1585 
o2hb_region_start_block_show(struct config_item * item,char * page)1586 static ssize_t o2hb_region_start_block_show(struct config_item *item,
1587 					    char *page)
1588 {
1589 	return sprintf(page, "%llu\n", to_o2hb_region(item)->hr_start_block);
1590 }
1591 
o2hb_region_start_block_store(struct config_item * item,const char * page,size_t count)1592 static ssize_t o2hb_region_start_block_store(struct config_item *item,
1593 					     const char *page,
1594 					     size_t count)
1595 {
1596 	struct o2hb_region *reg = to_o2hb_region(item);
1597 	unsigned long long tmp;
1598 	char *p = (char *)page;
1599 	ssize_t ret;
1600 
1601 	if (reg->hr_bdev)
1602 		return -EINVAL;
1603 
1604 	ret = kstrtoull(p, 0, &tmp);
1605 	if (ret)
1606 		return -EINVAL;
1607 
1608 	reg->hr_start_block = tmp;
1609 
1610 	return count;
1611 }
1612 
o2hb_region_blocks_show(struct config_item * item,char * page)1613 static ssize_t o2hb_region_blocks_show(struct config_item *item, char *page)
1614 {
1615 	return sprintf(page, "%d\n", to_o2hb_region(item)->hr_blocks);
1616 }
1617 
o2hb_region_blocks_store(struct config_item * item,const char * page,size_t count)1618 static ssize_t o2hb_region_blocks_store(struct config_item *item,
1619 					const char *page,
1620 					size_t count)
1621 {
1622 	struct o2hb_region *reg = to_o2hb_region(item);
1623 	unsigned long tmp;
1624 	char *p = (char *)page;
1625 
1626 	if (reg->hr_bdev)
1627 		return -EINVAL;
1628 
1629 	tmp = simple_strtoul(p, &p, 0);
1630 	if (!p || (*p && (*p != '\n')))
1631 		return -EINVAL;
1632 
1633 	if (tmp > O2NM_MAX_NODES || tmp == 0)
1634 		return -ERANGE;
1635 
1636 	reg->hr_blocks = (unsigned int)tmp;
1637 
1638 	return count;
1639 }
1640 
o2hb_region_dev_show(struct config_item * item,char * page)1641 static ssize_t o2hb_region_dev_show(struct config_item *item, char *page)
1642 {
1643 	unsigned int ret = 0;
1644 
1645 	if (to_o2hb_region(item)->hr_bdev)
1646 		ret = sprintf(page, "%s\n", to_o2hb_region(item)->hr_dev_name);
1647 
1648 	return ret;
1649 }
1650 
o2hb_init_region_params(struct o2hb_region * reg)1651 static void o2hb_init_region_params(struct o2hb_region *reg)
1652 {
1653 	reg->hr_slots_per_page = PAGE_SIZE >> reg->hr_block_bits;
1654 	reg->hr_timeout_ms = O2HB_REGION_TIMEOUT_MS;
1655 
1656 	mlog(ML_HEARTBEAT, "hr_start_block = %llu, hr_blocks = %u\n",
1657 	     reg->hr_start_block, reg->hr_blocks);
1658 	mlog(ML_HEARTBEAT, "hr_block_bytes = %u, hr_block_bits = %u\n",
1659 	     reg->hr_block_bytes, reg->hr_block_bits);
1660 	mlog(ML_HEARTBEAT, "hr_timeout_ms = %u\n", reg->hr_timeout_ms);
1661 	mlog(ML_HEARTBEAT, "dead threshold = %u\n", o2hb_dead_threshold);
1662 }
1663 
o2hb_map_slot_data(struct o2hb_region * reg)1664 static int o2hb_map_slot_data(struct o2hb_region *reg)
1665 {
1666 	int i, j;
1667 	unsigned int last_slot;
1668 	unsigned int spp = reg->hr_slots_per_page;
1669 	struct page *page;
1670 	char *raw;
1671 	struct o2hb_disk_slot *slot;
1672 
1673 	reg->hr_tmp_block = kmalloc(reg->hr_block_bytes, GFP_KERNEL);
1674 	if (reg->hr_tmp_block == NULL)
1675 		return -ENOMEM;
1676 
1677 	reg->hr_slots = kcalloc(reg->hr_blocks,
1678 				sizeof(struct o2hb_disk_slot), GFP_KERNEL);
1679 	if (reg->hr_slots == NULL)
1680 		return -ENOMEM;
1681 
1682 	for(i = 0; i < reg->hr_blocks; i++) {
1683 		slot = &reg->hr_slots[i];
1684 		slot->ds_node_num = i;
1685 		INIT_LIST_HEAD(&slot->ds_live_item);
1686 		slot->ds_raw_block = NULL;
1687 	}
1688 
1689 	reg->hr_num_pages = (reg->hr_blocks + spp - 1) / spp;
1690 	mlog(ML_HEARTBEAT, "Going to require %u pages to cover %u blocks "
1691 			   "at %u blocks per page\n",
1692 	     reg->hr_num_pages, reg->hr_blocks, spp);
1693 
1694 	reg->hr_slot_data = kcalloc(reg->hr_num_pages, sizeof(struct page *),
1695 				    GFP_KERNEL);
1696 	if (!reg->hr_slot_data)
1697 		return -ENOMEM;
1698 
1699 	for(i = 0; i < reg->hr_num_pages; i++) {
1700 		page = alloc_page(GFP_KERNEL);
1701 		if (!page)
1702 			return -ENOMEM;
1703 
1704 		reg->hr_slot_data[i] = page;
1705 
1706 		last_slot = i * spp;
1707 		raw = page_address(page);
1708 		for (j = 0;
1709 		     (j < spp) && ((j + last_slot) < reg->hr_blocks);
1710 		     j++) {
1711 			BUG_ON((j + last_slot) >= reg->hr_blocks);
1712 
1713 			slot = &reg->hr_slots[j + last_slot];
1714 			slot->ds_raw_block =
1715 				(struct o2hb_disk_heartbeat_block *) raw;
1716 
1717 			raw += reg->hr_block_bytes;
1718 		}
1719 	}
1720 
1721 	return 0;
1722 }
1723 
1724 /* Read in all the slots available and populate the tracking
1725  * structures so that we can start with a baseline idea of what's
1726  * there. */
o2hb_populate_slot_data(struct o2hb_region * reg)1727 static int o2hb_populate_slot_data(struct o2hb_region *reg)
1728 {
1729 	int ret, i;
1730 	struct o2hb_disk_slot *slot;
1731 	struct o2hb_disk_heartbeat_block *hb_block;
1732 
1733 	ret = o2hb_read_slots(reg, 0, reg->hr_blocks);
1734 	if (ret)
1735 		goto out;
1736 
1737 	/* We only want to get an idea of the values initially in each
1738 	 * slot, so we do no verification - o2hb_check_slot will
1739 	 * actually determine if each configured slot is valid and
1740 	 * whether any values have changed. */
1741 	for(i = 0; i < reg->hr_blocks; i++) {
1742 		slot = &reg->hr_slots[i];
1743 		hb_block = (struct o2hb_disk_heartbeat_block *) slot->ds_raw_block;
1744 
1745 		/* Only fill the values that o2hb_check_slot uses to
1746 		 * determine changing slots */
1747 		slot->ds_last_time = le64_to_cpu(hb_block->hb_seq);
1748 		slot->ds_last_generation = le64_to_cpu(hb_block->hb_generation);
1749 	}
1750 
1751 out:
1752 	return ret;
1753 }
1754 
1755 /* this is acting as commit; we set up all of hr_bdev and hr_task or nothing */
o2hb_region_dev_store(struct config_item * item,const char * page,size_t count)1756 static ssize_t o2hb_region_dev_store(struct config_item *item,
1757 				     const char *page,
1758 				     size_t count)
1759 {
1760 	struct o2hb_region *reg = to_o2hb_region(item);
1761 	struct task_struct *hb_task;
1762 	long fd;
1763 	int sectsize;
1764 	char *p = (char *)page;
1765 	struct fd f;
1766 	ssize_t ret = -EINVAL;
1767 	int live_threshold;
1768 
1769 	if (reg->hr_bdev)
1770 		goto out;
1771 
1772 	/* We can't heartbeat without having had our node number
1773 	 * configured yet. */
1774 	if (o2nm_this_node() == O2NM_MAX_NODES)
1775 		goto out;
1776 
1777 	fd = simple_strtol(p, &p, 0);
1778 	if (!p || (*p && (*p != '\n')))
1779 		goto out;
1780 
1781 	if (fd < 0 || fd >= INT_MAX)
1782 		goto out;
1783 
1784 	f = fdget(fd);
1785 	if (f.file == NULL)
1786 		goto out;
1787 
1788 	if (reg->hr_blocks == 0 || reg->hr_start_block == 0 ||
1789 	    reg->hr_block_bytes == 0)
1790 		goto out2;
1791 
1792 	if (!S_ISBLK(f.file->f_mapping->host->i_mode))
1793 		goto out2;
1794 
1795 	reg->hr_bdev = blkdev_get_by_dev(f.file->f_mapping->host->i_rdev,
1796 					 FMODE_WRITE | FMODE_READ, NULL);
1797 	if (IS_ERR(reg->hr_bdev)) {
1798 		ret = PTR_ERR(reg->hr_bdev);
1799 		reg->hr_bdev = NULL;
1800 		goto out2;
1801 	}
1802 
1803 	bdevname(reg->hr_bdev, reg->hr_dev_name);
1804 
1805 	sectsize = bdev_logical_block_size(reg->hr_bdev);
1806 	if (sectsize != reg->hr_block_bytes) {
1807 		mlog(ML_ERROR,
1808 		     "blocksize %u incorrect for device, expected %d",
1809 		     reg->hr_block_bytes, sectsize);
1810 		ret = -EINVAL;
1811 		goto out3;
1812 	}
1813 
1814 	o2hb_init_region_params(reg);
1815 
1816 	/* Generation of zero is invalid */
1817 	do {
1818 		get_random_bytes(&reg->hr_generation,
1819 				 sizeof(reg->hr_generation));
1820 	} while (reg->hr_generation == 0);
1821 
1822 	ret = o2hb_map_slot_data(reg);
1823 	if (ret) {
1824 		mlog_errno(ret);
1825 		goto out3;
1826 	}
1827 
1828 	ret = o2hb_populate_slot_data(reg);
1829 	if (ret) {
1830 		mlog_errno(ret);
1831 		goto out3;
1832 	}
1833 
1834 	INIT_DELAYED_WORK(&reg->hr_write_timeout_work, o2hb_write_timeout);
1835 	INIT_DELAYED_WORK(&reg->hr_nego_timeout_work, o2hb_nego_timeout);
1836 
1837 	/*
1838 	 * A node is considered live after it has beat LIVE_THRESHOLD
1839 	 * times.  We're not steady until we've given them a chance
1840 	 * _after_ our first read.
1841 	 * The default threshold is bare minimum so as to limit the delay
1842 	 * during mounts. For global heartbeat, the threshold doubled for the
1843 	 * first region.
1844 	 */
1845 	live_threshold = O2HB_LIVE_THRESHOLD;
1846 	if (o2hb_global_heartbeat_active()) {
1847 		spin_lock(&o2hb_live_lock);
1848 		if (bitmap_weight(o2hb_region_bitmap, O2NM_MAX_REGIONS) == 1)
1849 			live_threshold <<= 1;
1850 		spin_unlock(&o2hb_live_lock);
1851 	}
1852 	++live_threshold;
1853 	atomic_set(&reg->hr_steady_iterations, live_threshold);
1854 	/* unsteady_iterations is triple the steady_iterations */
1855 	atomic_set(&reg->hr_unsteady_iterations, (live_threshold * 3));
1856 
1857 	hb_task = kthread_run(o2hb_thread, reg, "o2hb-%s",
1858 			      reg->hr_item.ci_name);
1859 	if (IS_ERR(hb_task)) {
1860 		ret = PTR_ERR(hb_task);
1861 		mlog_errno(ret);
1862 		goto out3;
1863 	}
1864 
1865 	spin_lock(&o2hb_live_lock);
1866 	reg->hr_task = hb_task;
1867 	spin_unlock(&o2hb_live_lock);
1868 
1869 	ret = wait_event_interruptible(o2hb_steady_queue,
1870 				atomic_read(&reg->hr_steady_iterations) == 0 ||
1871 				reg->hr_node_deleted);
1872 	if (ret) {
1873 		atomic_set(&reg->hr_steady_iterations, 0);
1874 		reg->hr_aborted_start = 1;
1875 	}
1876 
1877 	if (reg->hr_aborted_start) {
1878 		ret = -EIO;
1879 		goto out3;
1880 	}
1881 
1882 	if (reg->hr_node_deleted) {
1883 		ret = -EINVAL;
1884 		goto out3;
1885 	}
1886 
1887 	/* Ok, we were woken.  Make sure it wasn't by drop_item() */
1888 	spin_lock(&o2hb_live_lock);
1889 	hb_task = reg->hr_task;
1890 	if (o2hb_global_heartbeat_active())
1891 		set_bit(reg->hr_region_num, o2hb_live_region_bitmap);
1892 	spin_unlock(&o2hb_live_lock);
1893 
1894 	if (hb_task)
1895 		ret = count;
1896 	else
1897 		ret = -EIO;
1898 
1899 	if (hb_task && o2hb_global_heartbeat_active())
1900 		printk(KERN_NOTICE "o2hb: Heartbeat started on region %s (%s)\n",
1901 		       config_item_name(&reg->hr_item), reg->hr_dev_name);
1902 
1903 out3:
1904 	if (ret < 0) {
1905 		blkdev_put(reg->hr_bdev, FMODE_READ | FMODE_WRITE);
1906 		reg->hr_bdev = NULL;
1907 	}
1908 out2:
1909 	fdput(f);
1910 out:
1911 	return ret;
1912 }
1913 
o2hb_region_pid_show(struct config_item * item,char * page)1914 static ssize_t o2hb_region_pid_show(struct config_item *item, char *page)
1915 {
1916 	struct o2hb_region *reg = to_o2hb_region(item);
1917 	pid_t pid = 0;
1918 
1919 	spin_lock(&o2hb_live_lock);
1920 	if (reg->hr_task)
1921 		pid = task_pid_nr(reg->hr_task);
1922 	spin_unlock(&o2hb_live_lock);
1923 
1924 	if (!pid)
1925 		return 0;
1926 
1927 	return sprintf(page, "%u\n", pid);
1928 }
1929 
1930 CONFIGFS_ATTR(o2hb_region_, block_bytes);
1931 CONFIGFS_ATTR(o2hb_region_, start_block);
1932 CONFIGFS_ATTR(o2hb_region_, blocks);
1933 CONFIGFS_ATTR(o2hb_region_, dev);
1934 CONFIGFS_ATTR_RO(o2hb_region_, pid);
1935 
1936 static struct configfs_attribute *o2hb_region_attrs[] = {
1937 	&o2hb_region_attr_block_bytes,
1938 	&o2hb_region_attr_start_block,
1939 	&o2hb_region_attr_blocks,
1940 	&o2hb_region_attr_dev,
1941 	&o2hb_region_attr_pid,
1942 	NULL,
1943 };
1944 
1945 static struct configfs_item_operations o2hb_region_item_ops = {
1946 	.release		= o2hb_region_release,
1947 };
1948 
1949 static const struct config_item_type o2hb_region_type = {
1950 	.ct_item_ops	= &o2hb_region_item_ops,
1951 	.ct_attrs	= o2hb_region_attrs,
1952 	.ct_owner	= THIS_MODULE,
1953 };
1954 
1955 /* heartbeat set */
1956 
1957 struct o2hb_heartbeat_group {
1958 	struct config_group hs_group;
1959 	/* some stuff? */
1960 };
1961 
to_o2hb_heartbeat_group(struct config_group * group)1962 static struct o2hb_heartbeat_group *to_o2hb_heartbeat_group(struct config_group *group)
1963 {
1964 	return group ?
1965 		container_of(group, struct o2hb_heartbeat_group, hs_group)
1966 		: NULL;
1967 }
1968 
o2hb_debug_region_init(struct o2hb_region * reg,struct dentry * parent)1969 static void o2hb_debug_region_init(struct o2hb_region *reg,
1970 				   struct dentry *parent)
1971 {
1972 	struct dentry *dir;
1973 
1974 	dir = debugfs_create_dir(config_item_name(&reg->hr_item), parent);
1975 	reg->hr_debug_dir = dir;
1976 
1977 	o2hb_debug_create(O2HB_DEBUG_LIVENODES, dir, &(reg->hr_db_livenodes),
1978 			  sizeof(*(reg->hr_db_livenodes)),
1979 			  O2HB_DB_TYPE_REGION_LIVENODES,
1980 			  sizeof(reg->hr_live_node_bitmap), O2NM_MAX_NODES,
1981 			  reg);
1982 
1983 	o2hb_debug_create(O2HB_DEBUG_REGION_NUMBER, dir, &(reg->hr_db_regnum),
1984 			  sizeof(*(reg->hr_db_regnum)),
1985 			  O2HB_DB_TYPE_REGION_NUMBER, 0, O2NM_MAX_NODES, reg);
1986 
1987 	o2hb_debug_create(O2HB_DEBUG_REGION_ELAPSED_TIME, dir,
1988 			  &(reg->hr_db_elapsed_time),
1989 			  sizeof(*(reg->hr_db_elapsed_time)),
1990 			  O2HB_DB_TYPE_REGION_ELAPSED_TIME, 0, 0, reg);
1991 
1992 	o2hb_debug_create(O2HB_DEBUG_REGION_PINNED, dir, &(reg->hr_db_pinned),
1993 			  sizeof(*(reg->hr_db_pinned)),
1994 			  O2HB_DB_TYPE_REGION_PINNED, 0, 0, reg);
1995 
1996 }
1997 
o2hb_heartbeat_group_make_item(struct config_group * group,const char * name)1998 static struct config_item *o2hb_heartbeat_group_make_item(struct config_group *group,
1999 							  const char *name)
2000 {
2001 	struct o2hb_region *reg = NULL;
2002 	int ret;
2003 
2004 	reg = kzalloc(sizeof(struct o2hb_region), GFP_KERNEL);
2005 	if (reg == NULL)
2006 		return ERR_PTR(-ENOMEM);
2007 
2008 	if (strlen(name) > O2HB_MAX_REGION_NAME_LEN) {
2009 		ret = -ENAMETOOLONG;
2010 		goto free;
2011 	}
2012 
2013 	spin_lock(&o2hb_live_lock);
2014 	reg->hr_region_num = 0;
2015 	if (o2hb_global_heartbeat_active()) {
2016 		reg->hr_region_num = find_first_zero_bit(o2hb_region_bitmap,
2017 							 O2NM_MAX_REGIONS);
2018 		if (reg->hr_region_num >= O2NM_MAX_REGIONS) {
2019 			spin_unlock(&o2hb_live_lock);
2020 			ret = -EFBIG;
2021 			goto free;
2022 		}
2023 		set_bit(reg->hr_region_num, o2hb_region_bitmap);
2024 	}
2025 	list_add_tail(&reg->hr_all_item, &o2hb_all_regions);
2026 	spin_unlock(&o2hb_live_lock);
2027 
2028 	config_item_init_type_name(&reg->hr_item, name, &o2hb_region_type);
2029 
2030 	/* this is the same way to generate msg key as dlm, for local heartbeat,
2031 	 * name is also the same, so make initial crc value different to avoid
2032 	 * message key conflict.
2033 	 */
2034 	reg->hr_key = crc32_le(reg->hr_region_num + O2NM_MAX_REGIONS,
2035 		name, strlen(name));
2036 	INIT_LIST_HEAD(&reg->hr_handler_list);
2037 	ret = o2net_register_handler(O2HB_NEGO_TIMEOUT_MSG, reg->hr_key,
2038 			sizeof(struct o2hb_nego_msg),
2039 			o2hb_nego_timeout_handler,
2040 			reg, NULL, &reg->hr_handler_list);
2041 	if (ret)
2042 		goto remove_item;
2043 
2044 	ret = o2net_register_handler(O2HB_NEGO_APPROVE_MSG, reg->hr_key,
2045 			sizeof(struct o2hb_nego_msg),
2046 			o2hb_nego_approve_handler,
2047 			reg, NULL, &reg->hr_handler_list);
2048 	if (ret)
2049 		goto unregister_handler;
2050 
2051 	o2hb_debug_region_init(reg, o2hb_debug_dir);
2052 
2053 	return &reg->hr_item;
2054 
2055 unregister_handler:
2056 	o2net_unregister_handler_list(&reg->hr_handler_list);
2057 remove_item:
2058 	spin_lock(&o2hb_live_lock);
2059 	list_del(&reg->hr_all_item);
2060 	if (o2hb_global_heartbeat_active())
2061 		clear_bit(reg->hr_region_num, o2hb_region_bitmap);
2062 	spin_unlock(&o2hb_live_lock);
2063 free:
2064 	kfree(reg);
2065 	return ERR_PTR(ret);
2066 }
2067 
o2hb_heartbeat_group_drop_item(struct config_group * group,struct config_item * item)2068 static void o2hb_heartbeat_group_drop_item(struct config_group *group,
2069 					   struct config_item *item)
2070 {
2071 	struct task_struct *hb_task;
2072 	struct o2hb_region *reg = to_o2hb_region(item);
2073 	int quorum_region = 0;
2074 
2075 	/* stop the thread when the user removes the region dir */
2076 	spin_lock(&o2hb_live_lock);
2077 	hb_task = reg->hr_task;
2078 	reg->hr_task = NULL;
2079 	reg->hr_item_dropped = 1;
2080 	spin_unlock(&o2hb_live_lock);
2081 
2082 	if (hb_task)
2083 		kthread_stop(hb_task);
2084 
2085 	if (o2hb_global_heartbeat_active()) {
2086 		spin_lock(&o2hb_live_lock);
2087 		clear_bit(reg->hr_region_num, o2hb_region_bitmap);
2088 		clear_bit(reg->hr_region_num, o2hb_live_region_bitmap);
2089 		if (test_bit(reg->hr_region_num, o2hb_quorum_region_bitmap))
2090 			quorum_region = 1;
2091 		clear_bit(reg->hr_region_num, o2hb_quorum_region_bitmap);
2092 		spin_unlock(&o2hb_live_lock);
2093 		printk(KERN_NOTICE "o2hb: Heartbeat %s on region %s (%s)\n",
2094 		       ((atomic_read(&reg->hr_steady_iterations) == 0) ?
2095 			"stopped" : "start aborted"), config_item_name(item),
2096 		       reg->hr_dev_name);
2097 	}
2098 
2099 	/*
2100 	 * If we're racing a dev_write(), we need to wake them.  They will
2101 	 * check reg->hr_task
2102 	 */
2103 	if (atomic_read(&reg->hr_steady_iterations) != 0) {
2104 		reg->hr_aborted_start = 1;
2105 		atomic_set(&reg->hr_steady_iterations, 0);
2106 		wake_up(&o2hb_steady_queue);
2107 	}
2108 
2109 	config_item_put(item);
2110 
2111 	if (!o2hb_global_heartbeat_active() || !quorum_region)
2112 		return;
2113 
2114 	/*
2115 	 * If global heartbeat active and there are dependent users,
2116 	 * pin all regions if quorum region count <= CUT_OFF
2117 	 */
2118 	spin_lock(&o2hb_live_lock);
2119 
2120 	if (!o2hb_dependent_users)
2121 		goto unlock;
2122 
2123 	if (bitmap_weight(o2hb_quorum_region_bitmap,
2124 			   O2NM_MAX_REGIONS) <= O2HB_PIN_CUT_OFF)
2125 		o2hb_region_pin(NULL);
2126 
2127 unlock:
2128 	spin_unlock(&o2hb_live_lock);
2129 }
2130 
o2hb_heartbeat_group_dead_threshold_show(struct config_item * item,char * page)2131 static ssize_t o2hb_heartbeat_group_dead_threshold_show(struct config_item *item,
2132 		char *page)
2133 {
2134 	return sprintf(page, "%u\n", o2hb_dead_threshold);
2135 }
2136 
o2hb_heartbeat_group_dead_threshold_store(struct config_item * item,const char * page,size_t count)2137 static ssize_t o2hb_heartbeat_group_dead_threshold_store(struct config_item *item,
2138 		const char *page, size_t count)
2139 {
2140 	unsigned long tmp;
2141 	char *p = (char *)page;
2142 
2143 	tmp = simple_strtoul(p, &p, 10);
2144 	if (!p || (*p && (*p != '\n')))
2145                 return -EINVAL;
2146 
2147 	/* this will validate ranges for us. */
2148 	o2hb_dead_threshold_set((unsigned int) tmp);
2149 
2150 	return count;
2151 }
2152 
o2hb_heartbeat_group_mode_show(struct config_item * item,char * page)2153 static ssize_t o2hb_heartbeat_group_mode_show(struct config_item *item,
2154 		char *page)
2155 {
2156 	return sprintf(page, "%s\n",
2157 		       o2hb_heartbeat_mode_desc[o2hb_heartbeat_mode]);
2158 }
2159 
o2hb_heartbeat_group_mode_store(struct config_item * item,const char * page,size_t count)2160 static ssize_t o2hb_heartbeat_group_mode_store(struct config_item *item,
2161 		const char *page, size_t count)
2162 {
2163 	unsigned int i;
2164 	int ret;
2165 	size_t len;
2166 
2167 	len = (page[count - 1] == '\n') ? count - 1 : count;
2168 	if (!len)
2169 		return -EINVAL;
2170 
2171 	for (i = 0; i < O2HB_HEARTBEAT_NUM_MODES; ++i) {
2172 		if (strncasecmp(page, o2hb_heartbeat_mode_desc[i], len))
2173 			continue;
2174 
2175 		ret = o2hb_global_heartbeat_mode_set(i);
2176 		if (!ret)
2177 			printk(KERN_NOTICE "o2hb: Heartbeat mode set to %s\n",
2178 			       o2hb_heartbeat_mode_desc[i]);
2179 		return count;
2180 	}
2181 
2182 	return -EINVAL;
2183 
2184 }
2185 
2186 CONFIGFS_ATTR(o2hb_heartbeat_group_, dead_threshold);
2187 CONFIGFS_ATTR(o2hb_heartbeat_group_, mode);
2188 
2189 static struct configfs_attribute *o2hb_heartbeat_group_attrs[] = {
2190 	&o2hb_heartbeat_group_attr_dead_threshold,
2191 	&o2hb_heartbeat_group_attr_mode,
2192 	NULL,
2193 };
2194 
2195 static struct configfs_group_operations o2hb_heartbeat_group_group_ops = {
2196 	.make_item	= o2hb_heartbeat_group_make_item,
2197 	.drop_item	= o2hb_heartbeat_group_drop_item,
2198 };
2199 
2200 static const struct config_item_type o2hb_heartbeat_group_type = {
2201 	.ct_group_ops	= &o2hb_heartbeat_group_group_ops,
2202 	.ct_attrs	= o2hb_heartbeat_group_attrs,
2203 	.ct_owner	= THIS_MODULE,
2204 };
2205 
2206 /* this is just here to avoid touching group in heartbeat.h which the
2207  * entire damn world #includes */
o2hb_alloc_hb_set(void)2208 struct config_group *o2hb_alloc_hb_set(void)
2209 {
2210 	struct o2hb_heartbeat_group *hs = NULL;
2211 	struct config_group *ret = NULL;
2212 
2213 	hs = kzalloc(sizeof(struct o2hb_heartbeat_group), GFP_KERNEL);
2214 	if (hs == NULL)
2215 		goto out;
2216 
2217 	config_group_init_type_name(&hs->hs_group, "heartbeat",
2218 				    &o2hb_heartbeat_group_type);
2219 
2220 	ret = &hs->hs_group;
2221 out:
2222 	if (ret == NULL)
2223 		kfree(hs);
2224 	return ret;
2225 }
2226 
o2hb_free_hb_set(struct config_group * group)2227 void o2hb_free_hb_set(struct config_group *group)
2228 {
2229 	struct o2hb_heartbeat_group *hs = to_o2hb_heartbeat_group(group);
2230 	kfree(hs);
2231 }
2232 
2233 /* hb callback registration and issuing */
2234 
hbcall_from_type(enum o2hb_callback_type type)2235 static struct o2hb_callback *hbcall_from_type(enum o2hb_callback_type type)
2236 {
2237 	if (type == O2HB_NUM_CB)
2238 		return ERR_PTR(-EINVAL);
2239 
2240 	return &o2hb_callbacks[type];
2241 }
2242 
o2hb_setup_callback(struct o2hb_callback_func * hc,enum o2hb_callback_type type,o2hb_cb_func * func,void * data,int priority)2243 void o2hb_setup_callback(struct o2hb_callback_func *hc,
2244 			 enum o2hb_callback_type type,
2245 			 o2hb_cb_func *func,
2246 			 void *data,
2247 			 int priority)
2248 {
2249 	INIT_LIST_HEAD(&hc->hc_item);
2250 	hc->hc_func = func;
2251 	hc->hc_data = data;
2252 	hc->hc_priority = priority;
2253 	hc->hc_type = type;
2254 	hc->hc_magic = O2HB_CB_MAGIC;
2255 }
2256 EXPORT_SYMBOL_GPL(o2hb_setup_callback);
2257 
2258 /*
2259  * In local heartbeat mode, region_uuid passed matches the dlm domain name.
2260  * In global heartbeat mode, region_uuid passed is NULL.
2261  *
2262  * In local, we only pin the matching region. In global we pin all the active
2263  * regions.
2264  */
o2hb_region_pin(const char * region_uuid)2265 static int o2hb_region_pin(const char *region_uuid)
2266 {
2267 	int ret = 0, found = 0;
2268 	struct o2hb_region *reg;
2269 	char *uuid;
2270 
2271 	assert_spin_locked(&o2hb_live_lock);
2272 
2273 	list_for_each_entry(reg, &o2hb_all_regions, hr_all_item) {
2274 		if (reg->hr_item_dropped)
2275 			continue;
2276 
2277 		uuid = config_item_name(&reg->hr_item);
2278 
2279 		/* local heartbeat */
2280 		if (region_uuid) {
2281 			if (strcmp(region_uuid, uuid))
2282 				continue;
2283 			found = 1;
2284 		}
2285 
2286 		if (reg->hr_item_pinned || reg->hr_item_dropped)
2287 			goto skip_pin;
2288 
2289 		/* Ignore ENOENT only for local hb (userdlm domain) */
2290 		ret = o2nm_depend_item(&reg->hr_item);
2291 		if (!ret) {
2292 			mlog(ML_CLUSTER, "Pin region %s\n", uuid);
2293 			reg->hr_item_pinned = 1;
2294 		} else {
2295 			if (ret == -ENOENT && found)
2296 				ret = 0;
2297 			else {
2298 				mlog(ML_ERROR, "Pin region %s fails with %d\n",
2299 				     uuid, ret);
2300 				break;
2301 			}
2302 		}
2303 skip_pin:
2304 		if (found)
2305 			break;
2306 	}
2307 
2308 	return ret;
2309 }
2310 
2311 /*
2312  * In local heartbeat mode, region_uuid passed matches the dlm domain name.
2313  * In global heartbeat mode, region_uuid passed is NULL.
2314  *
2315  * In local, we only unpin the matching region. In global we unpin all the
2316  * active regions.
2317  */
o2hb_region_unpin(const char * region_uuid)2318 static void o2hb_region_unpin(const char *region_uuid)
2319 {
2320 	struct o2hb_region *reg;
2321 	char *uuid;
2322 	int found = 0;
2323 
2324 	assert_spin_locked(&o2hb_live_lock);
2325 
2326 	list_for_each_entry(reg, &o2hb_all_regions, hr_all_item) {
2327 		if (reg->hr_item_dropped)
2328 			continue;
2329 
2330 		uuid = config_item_name(&reg->hr_item);
2331 		if (region_uuid) {
2332 			if (strcmp(region_uuid, uuid))
2333 				continue;
2334 			found = 1;
2335 		}
2336 
2337 		if (reg->hr_item_pinned) {
2338 			mlog(ML_CLUSTER, "Unpin region %s\n", uuid);
2339 			o2nm_undepend_item(&reg->hr_item);
2340 			reg->hr_item_pinned = 0;
2341 		}
2342 		if (found)
2343 			break;
2344 	}
2345 }
2346 
o2hb_region_inc_user(const char * region_uuid)2347 static int o2hb_region_inc_user(const char *region_uuid)
2348 {
2349 	int ret = 0;
2350 
2351 	spin_lock(&o2hb_live_lock);
2352 
2353 	/* local heartbeat */
2354 	if (!o2hb_global_heartbeat_active()) {
2355 	    ret = o2hb_region_pin(region_uuid);
2356 	    goto unlock;
2357 	}
2358 
2359 	/*
2360 	 * if global heartbeat active and this is the first dependent user,
2361 	 * pin all regions if quorum region count <= CUT_OFF
2362 	 */
2363 	o2hb_dependent_users++;
2364 	if (o2hb_dependent_users > 1)
2365 		goto unlock;
2366 
2367 	if (bitmap_weight(o2hb_quorum_region_bitmap,
2368 			   O2NM_MAX_REGIONS) <= O2HB_PIN_CUT_OFF)
2369 		ret = o2hb_region_pin(NULL);
2370 
2371 unlock:
2372 	spin_unlock(&o2hb_live_lock);
2373 	return ret;
2374 }
2375 
o2hb_region_dec_user(const char * region_uuid)2376 static void o2hb_region_dec_user(const char *region_uuid)
2377 {
2378 	spin_lock(&o2hb_live_lock);
2379 
2380 	/* local heartbeat */
2381 	if (!o2hb_global_heartbeat_active()) {
2382 	    o2hb_region_unpin(region_uuid);
2383 	    goto unlock;
2384 	}
2385 
2386 	/*
2387 	 * if global heartbeat active and there are no dependent users,
2388 	 * unpin all quorum regions
2389 	 */
2390 	o2hb_dependent_users--;
2391 	if (!o2hb_dependent_users)
2392 		o2hb_region_unpin(NULL);
2393 
2394 unlock:
2395 	spin_unlock(&o2hb_live_lock);
2396 }
2397 
o2hb_register_callback(const char * region_uuid,struct o2hb_callback_func * hc)2398 int o2hb_register_callback(const char *region_uuid,
2399 			   struct o2hb_callback_func *hc)
2400 {
2401 	struct o2hb_callback_func *f;
2402 	struct o2hb_callback *hbcall;
2403 	int ret;
2404 
2405 	BUG_ON(hc->hc_magic != O2HB_CB_MAGIC);
2406 	BUG_ON(!list_empty(&hc->hc_item));
2407 
2408 	hbcall = hbcall_from_type(hc->hc_type);
2409 	if (IS_ERR(hbcall)) {
2410 		ret = PTR_ERR(hbcall);
2411 		goto out;
2412 	}
2413 
2414 	if (region_uuid) {
2415 		ret = o2hb_region_inc_user(region_uuid);
2416 		if (ret) {
2417 			mlog_errno(ret);
2418 			goto out;
2419 		}
2420 	}
2421 
2422 	down_write(&o2hb_callback_sem);
2423 
2424 	list_for_each_entry(f, &hbcall->list, hc_item) {
2425 		if (hc->hc_priority < f->hc_priority) {
2426 			list_add_tail(&hc->hc_item, &f->hc_item);
2427 			break;
2428 		}
2429 	}
2430 	if (list_empty(&hc->hc_item))
2431 		list_add_tail(&hc->hc_item, &hbcall->list);
2432 
2433 	up_write(&o2hb_callback_sem);
2434 	ret = 0;
2435 out:
2436 	mlog(ML_CLUSTER, "returning %d on behalf of %p for funcs %p\n",
2437 	     ret, __builtin_return_address(0), hc);
2438 	return ret;
2439 }
2440 EXPORT_SYMBOL_GPL(o2hb_register_callback);
2441 
o2hb_unregister_callback(const char * region_uuid,struct o2hb_callback_func * hc)2442 void o2hb_unregister_callback(const char *region_uuid,
2443 			      struct o2hb_callback_func *hc)
2444 {
2445 	BUG_ON(hc->hc_magic != O2HB_CB_MAGIC);
2446 
2447 	mlog(ML_CLUSTER, "on behalf of %p for funcs %p\n",
2448 	     __builtin_return_address(0), hc);
2449 
2450 	/* XXX Can this happen _with_ a region reference? */
2451 	if (list_empty(&hc->hc_item))
2452 		return;
2453 
2454 	if (region_uuid)
2455 		o2hb_region_dec_user(region_uuid);
2456 
2457 	down_write(&o2hb_callback_sem);
2458 
2459 	list_del_init(&hc->hc_item);
2460 
2461 	up_write(&o2hb_callback_sem);
2462 }
2463 EXPORT_SYMBOL_GPL(o2hb_unregister_callback);
2464 
o2hb_check_node_heartbeating_no_sem(u8 node_num)2465 int o2hb_check_node_heartbeating_no_sem(u8 node_num)
2466 {
2467 	unsigned long testing_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
2468 
2469 	spin_lock(&o2hb_live_lock);
2470 	o2hb_fill_node_map_from_callback(testing_map, sizeof(testing_map));
2471 	spin_unlock(&o2hb_live_lock);
2472 	if (!test_bit(node_num, testing_map)) {
2473 		mlog(ML_HEARTBEAT,
2474 		     "node (%u) does not have heartbeating enabled.\n",
2475 		     node_num);
2476 		return 0;
2477 	}
2478 
2479 	return 1;
2480 }
2481 EXPORT_SYMBOL_GPL(o2hb_check_node_heartbeating_no_sem);
2482 
o2hb_check_node_heartbeating_from_callback(u8 node_num)2483 int o2hb_check_node_heartbeating_from_callback(u8 node_num)
2484 {
2485 	unsigned long testing_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
2486 
2487 	o2hb_fill_node_map_from_callback(testing_map, sizeof(testing_map));
2488 	if (!test_bit(node_num, testing_map)) {
2489 		mlog(ML_HEARTBEAT,
2490 		     "node (%u) does not have heartbeating enabled.\n",
2491 		     node_num);
2492 		return 0;
2493 	}
2494 
2495 	return 1;
2496 }
2497 EXPORT_SYMBOL_GPL(o2hb_check_node_heartbeating_from_callback);
2498 
2499 /*
2500  * this is just a hack until we get the plumbing which flips file systems
2501  * read only and drops the hb ref instead of killing the node dead.
2502  */
o2hb_stop_all_regions(void)2503 void o2hb_stop_all_regions(void)
2504 {
2505 	struct o2hb_region *reg;
2506 
2507 	mlog(ML_ERROR, "stopping heartbeat on all active regions.\n");
2508 
2509 	spin_lock(&o2hb_live_lock);
2510 
2511 	list_for_each_entry(reg, &o2hb_all_regions, hr_all_item)
2512 		reg->hr_unclean_stop = 1;
2513 
2514 	spin_unlock(&o2hb_live_lock);
2515 }
2516 EXPORT_SYMBOL_GPL(o2hb_stop_all_regions);
2517 
o2hb_get_all_regions(char * region_uuids,u8 max_regions)2518 int o2hb_get_all_regions(char *region_uuids, u8 max_regions)
2519 {
2520 	struct o2hb_region *reg;
2521 	int numregs = 0;
2522 	char *p;
2523 
2524 	spin_lock(&o2hb_live_lock);
2525 
2526 	p = region_uuids;
2527 	list_for_each_entry(reg, &o2hb_all_regions, hr_all_item) {
2528 		if (reg->hr_item_dropped)
2529 			continue;
2530 
2531 		mlog(0, "Region: %s\n", config_item_name(&reg->hr_item));
2532 		if (numregs < max_regions) {
2533 			memcpy(p, config_item_name(&reg->hr_item),
2534 			       O2HB_MAX_REGION_NAME_LEN);
2535 			p += O2HB_MAX_REGION_NAME_LEN;
2536 		}
2537 		numregs++;
2538 	}
2539 
2540 	spin_unlock(&o2hb_live_lock);
2541 
2542 	return numregs;
2543 }
2544 EXPORT_SYMBOL_GPL(o2hb_get_all_regions);
2545 
o2hb_global_heartbeat_active(void)2546 int o2hb_global_heartbeat_active(void)
2547 {
2548 	return (o2hb_heartbeat_mode == O2HB_HEARTBEAT_GLOBAL);
2549 }
2550 EXPORT_SYMBOL(o2hb_global_heartbeat_active);
2551