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(®->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(®->hr_write_timeout_work);
333 schedule_delayed_work(®->hr_write_timeout_work,
334 msecs_to_jiffies(O2HB_MAX_WRITE_TIMEOUT_MS));
335
336 cancel_delayed_work(®->hr_nego_timeout_work);
337 /* negotiate timeout must be less than write timeout. */
338 schedule_delayed_work(®->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(®->hr_write_timeout_work);
346 cancel_delayed_work_sync(®->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(®->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(®->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(®->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(®->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(®->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(®->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, ¤t_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 = ®->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 = ®->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(®->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(®->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, ®->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(®->hr_steady_iterations) != 0) {
1166 if (!ret && own_slot_ok && !membership_change) {
1167 if (atomic_dec_and_test(®->hr_steady_iterations))
1168 wake_up(&o2hb_steady_queue);
1169 }
1170 }
1171
1172 if (atomic_read(®->hr_steady_iterations) != 0) {
1173 if (atomic_dec_and_test(®->hr_unsteady_iterations)) {
1174 printk(KERN_NOTICE "o2hb: Unable to stabilize "
1175 "heartbeat on region %s (%s)\n",
1176 config_item_name(®->hr_item),
1177 reg->hr_dev_name);
1178 atomic_set(®->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(®->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 INIT_LIST_HEAD(&o2hb_node_events);
1446
1447 memset(o2hb_live_node_bitmap, 0, sizeof(o2hb_live_node_bitmap));
1448 memset(o2hb_region_bitmap, 0, sizeof(o2hb_region_bitmap));
1449 memset(o2hb_live_region_bitmap, 0, sizeof(o2hb_live_region_bitmap));
1450 memset(o2hb_quorum_region_bitmap, 0, sizeof(o2hb_quorum_region_bitmap));
1451 memset(o2hb_failed_region_bitmap, 0, sizeof(o2hb_failed_region_bitmap));
1452
1453 o2hb_dependent_users = 0;
1454
1455 o2hb_debug_init();
1456 }
1457
1458 /* 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)1459 static void o2hb_fill_node_map_from_callback(unsigned long *map,
1460 unsigned bytes)
1461 {
1462 BUG_ON(bytes < (BITS_TO_LONGS(O2NM_MAX_NODES) * sizeof(unsigned long)));
1463
1464 memcpy(map, &o2hb_live_node_bitmap, bytes);
1465 }
1466
1467 /*
1468 * get a map of all nodes that are heartbeating in any regions
1469 */
o2hb_fill_node_map(unsigned long * map,unsigned bytes)1470 void o2hb_fill_node_map(unsigned long *map, unsigned bytes)
1471 {
1472 /* callers want to serialize this map and callbacks so that they
1473 * can trust that they don't miss nodes coming to the party */
1474 down_read(&o2hb_callback_sem);
1475 spin_lock(&o2hb_live_lock);
1476 o2hb_fill_node_map_from_callback(map, bytes);
1477 spin_unlock(&o2hb_live_lock);
1478 up_read(&o2hb_callback_sem);
1479 }
1480 EXPORT_SYMBOL_GPL(o2hb_fill_node_map);
1481
1482 /*
1483 * heartbeat configfs bits. The heartbeat set is a default set under
1484 * the cluster set in nodemanager.c.
1485 */
1486
to_o2hb_region(struct config_item * item)1487 static struct o2hb_region *to_o2hb_region(struct config_item *item)
1488 {
1489 return item ? container_of(item, struct o2hb_region, hr_item) : NULL;
1490 }
1491
1492 /* drop_item only drops its ref after killing the thread, nothing should
1493 * be using the region anymore. this has to clean up any state that
1494 * attributes might have built up. */
o2hb_region_release(struct config_item * item)1495 static void o2hb_region_release(struct config_item *item)
1496 {
1497 int i;
1498 struct page *page;
1499 struct o2hb_region *reg = to_o2hb_region(item);
1500
1501 mlog(ML_HEARTBEAT, "hb region release (%s)\n", reg->hr_dev_name);
1502
1503 kfree(reg->hr_tmp_block);
1504
1505 if (reg->hr_slot_data) {
1506 for (i = 0; i < reg->hr_num_pages; i++) {
1507 page = reg->hr_slot_data[i];
1508 if (page)
1509 __free_page(page);
1510 }
1511 kfree(reg->hr_slot_data);
1512 }
1513
1514 if (reg->hr_bdev)
1515 blkdev_put(reg->hr_bdev, FMODE_READ|FMODE_WRITE);
1516
1517 kfree(reg->hr_slots);
1518
1519 debugfs_remove_recursive(reg->hr_debug_dir);
1520 kfree(reg->hr_db_livenodes);
1521 kfree(reg->hr_db_regnum);
1522 kfree(reg->hr_db_elapsed_time);
1523 kfree(reg->hr_db_pinned);
1524
1525 spin_lock(&o2hb_live_lock);
1526 list_del(®->hr_all_item);
1527 spin_unlock(&o2hb_live_lock);
1528
1529 o2net_unregister_handler_list(®->hr_handler_list);
1530 kfree(reg);
1531 }
1532
o2hb_read_block_input(struct o2hb_region * reg,const char * page,unsigned long * ret_bytes,unsigned int * ret_bits)1533 static int o2hb_read_block_input(struct o2hb_region *reg,
1534 const char *page,
1535 unsigned long *ret_bytes,
1536 unsigned int *ret_bits)
1537 {
1538 unsigned long bytes;
1539 char *p = (char *)page;
1540
1541 bytes = simple_strtoul(p, &p, 0);
1542 if (!p || (*p && (*p != '\n')))
1543 return -EINVAL;
1544
1545 /* Heartbeat and fs min / max block sizes are the same. */
1546 if (bytes > 4096 || bytes < 512)
1547 return -ERANGE;
1548 if (hweight16(bytes) != 1)
1549 return -EINVAL;
1550
1551 if (ret_bytes)
1552 *ret_bytes = bytes;
1553 if (ret_bits)
1554 *ret_bits = ffs(bytes) - 1;
1555
1556 return 0;
1557 }
1558
o2hb_region_block_bytes_show(struct config_item * item,char * page)1559 static ssize_t o2hb_region_block_bytes_show(struct config_item *item,
1560 char *page)
1561 {
1562 return sprintf(page, "%u\n", to_o2hb_region(item)->hr_block_bytes);
1563 }
1564
o2hb_region_block_bytes_store(struct config_item * item,const char * page,size_t count)1565 static ssize_t o2hb_region_block_bytes_store(struct config_item *item,
1566 const char *page,
1567 size_t count)
1568 {
1569 struct o2hb_region *reg = to_o2hb_region(item);
1570 int status;
1571 unsigned long block_bytes;
1572 unsigned int block_bits;
1573
1574 if (reg->hr_bdev)
1575 return -EINVAL;
1576
1577 status = o2hb_read_block_input(reg, page, &block_bytes,
1578 &block_bits);
1579 if (status)
1580 return status;
1581
1582 reg->hr_block_bytes = (unsigned int)block_bytes;
1583 reg->hr_block_bits = block_bits;
1584
1585 return count;
1586 }
1587
o2hb_region_start_block_show(struct config_item * item,char * page)1588 static ssize_t o2hb_region_start_block_show(struct config_item *item,
1589 char *page)
1590 {
1591 return sprintf(page, "%llu\n", to_o2hb_region(item)->hr_start_block);
1592 }
1593
o2hb_region_start_block_store(struct config_item * item,const char * page,size_t count)1594 static ssize_t o2hb_region_start_block_store(struct config_item *item,
1595 const char *page,
1596 size_t count)
1597 {
1598 struct o2hb_region *reg = to_o2hb_region(item);
1599 unsigned long long tmp;
1600 char *p = (char *)page;
1601
1602 if (reg->hr_bdev)
1603 return -EINVAL;
1604
1605 tmp = simple_strtoull(p, &p, 0);
1606 if (!p || (*p && (*p != '\n')))
1607 return -EINVAL;
1608
1609 reg->hr_start_block = tmp;
1610
1611 return count;
1612 }
1613
o2hb_region_blocks_show(struct config_item * item,char * page)1614 static ssize_t o2hb_region_blocks_show(struct config_item *item, char *page)
1615 {
1616 return sprintf(page, "%d\n", to_o2hb_region(item)->hr_blocks);
1617 }
1618
o2hb_region_blocks_store(struct config_item * item,const char * page,size_t count)1619 static ssize_t o2hb_region_blocks_store(struct config_item *item,
1620 const char *page,
1621 size_t count)
1622 {
1623 struct o2hb_region *reg = to_o2hb_region(item);
1624 unsigned long tmp;
1625 char *p = (char *)page;
1626
1627 if (reg->hr_bdev)
1628 return -EINVAL;
1629
1630 tmp = simple_strtoul(p, &p, 0);
1631 if (!p || (*p && (*p != '\n')))
1632 return -EINVAL;
1633
1634 if (tmp > O2NM_MAX_NODES || tmp == 0)
1635 return -ERANGE;
1636
1637 reg->hr_blocks = (unsigned int)tmp;
1638
1639 return count;
1640 }
1641
o2hb_region_dev_show(struct config_item * item,char * page)1642 static ssize_t o2hb_region_dev_show(struct config_item *item, char *page)
1643 {
1644 unsigned int ret = 0;
1645
1646 if (to_o2hb_region(item)->hr_bdev)
1647 ret = sprintf(page, "%s\n", to_o2hb_region(item)->hr_dev_name);
1648
1649 return ret;
1650 }
1651
o2hb_init_region_params(struct o2hb_region * reg)1652 static void o2hb_init_region_params(struct o2hb_region *reg)
1653 {
1654 reg->hr_slots_per_page = PAGE_SIZE >> reg->hr_block_bits;
1655 reg->hr_timeout_ms = O2HB_REGION_TIMEOUT_MS;
1656
1657 mlog(ML_HEARTBEAT, "hr_start_block = %llu, hr_blocks = %u\n",
1658 reg->hr_start_block, reg->hr_blocks);
1659 mlog(ML_HEARTBEAT, "hr_block_bytes = %u, hr_block_bits = %u\n",
1660 reg->hr_block_bytes, reg->hr_block_bits);
1661 mlog(ML_HEARTBEAT, "hr_timeout_ms = %u\n", reg->hr_timeout_ms);
1662 mlog(ML_HEARTBEAT, "dead threshold = %u\n", o2hb_dead_threshold);
1663 }
1664
o2hb_map_slot_data(struct o2hb_region * reg)1665 static int o2hb_map_slot_data(struct o2hb_region *reg)
1666 {
1667 int i, j;
1668 unsigned int last_slot;
1669 unsigned int spp = reg->hr_slots_per_page;
1670 struct page *page;
1671 char *raw;
1672 struct o2hb_disk_slot *slot;
1673
1674 reg->hr_tmp_block = kmalloc(reg->hr_block_bytes, GFP_KERNEL);
1675 if (reg->hr_tmp_block == NULL)
1676 return -ENOMEM;
1677
1678 reg->hr_slots = kcalloc(reg->hr_blocks,
1679 sizeof(struct o2hb_disk_slot), GFP_KERNEL);
1680 if (reg->hr_slots == NULL)
1681 return -ENOMEM;
1682
1683 for(i = 0; i < reg->hr_blocks; i++) {
1684 slot = ®->hr_slots[i];
1685 slot->ds_node_num = i;
1686 INIT_LIST_HEAD(&slot->ds_live_item);
1687 slot->ds_raw_block = NULL;
1688 }
1689
1690 reg->hr_num_pages = (reg->hr_blocks + spp - 1) / spp;
1691 mlog(ML_HEARTBEAT, "Going to require %u pages to cover %u blocks "
1692 "at %u blocks per page\n",
1693 reg->hr_num_pages, reg->hr_blocks, spp);
1694
1695 reg->hr_slot_data = kcalloc(reg->hr_num_pages, sizeof(struct page *),
1696 GFP_KERNEL);
1697 if (!reg->hr_slot_data)
1698 return -ENOMEM;
1699
1700 for(i = 0; i < reg->hr_num_pages; i++) {
1701 page = alloc_page(GFP_KERNEL);
1702 if (!page)
1703 return -ENOMEM;
1704
1705 reg->hr_slot_data[i] = page;
1706
1707 last_slot = i * spp;
1708 raw = page_address(page);
1709 for (j = 0;
1710 (j < spp) && ((j + last_slot) < reg->hr_blocks);
1711 j++) {
1712 BUG_ON((j + last_slot) >= reg->hr_blocks);
1713
1714 slot = ®->hr_slots[j + last_slot];
1715 slot->ds_raw_block =
1716 (struct o2hb_disk_heartbeat_block *) raw;
1717
1718 raw += reg->hr_block_bytes;
1719 }
1720 }
1721
1722 return 0;
1723 }
1724
1725 /* Read in all the slots available and populate the tracking
1726 * structures so that we can start with a baseline idea of what's
1727 * there. */
o2hb_populate_slot_data(struct o2hb_region * reg)1728 static int o2hb_populate_slot_data(struct o2hb_region *reg)
1729 {
1730 int ret, i;
1731 struct o2hb_disk_slot *slot;
1732 struct o2hb_disk_heartbeat_block *hb_block;
1733
1734 ret = o2hb_read_slots(reg, 0, reg->hr_blocks);
1735 if (ret)
1736 goto out;
1737
1738 /* We only want to get an idea of the values initially in each
1739 * slot, so we do no verification - o2hb_check_slot will
1740 * actually determine if each configured slot is valid and
1741 * whether any values have changed. */
1742 for(i = 0; i < reg->hr_blocks; i++) {
1743 slot = ®->hr_slots[i];
1744 hb_block = (struct o2hb_disk_heartbeat_block *) slot->ds_raw_block;
1745
1746 /* Only fill the values that o2hb_check_slot uses to
1747 * determine changing slots */
1748 slot->ds_last_time = le64_to_cpu(hb_block->hb_seq);
1749 slot->ds_last_generation = le64_to_cpu(hb_block->hb_generation);
1750 }
1751
1752 out:
1753 return ret;
1754 }
1755
1756 /* 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)1757 static ssize_t o2hb_region_dev_store(struct config_item *item,
1758 const char *page,
1759 size_t count)
1760 {
1761 struct o2hb_region *reg = to_o2hb_region(item);
1762 struct task_struct *hb_task;
1763 long fd;
1764 int sectsize;
1765 char *p = (char *)page;
1766 struct fd f;
1767 ssize_t ret = -EINVAL;
1768 int live_threshold;
1769
1770 if (reg->hr_bdev)
1771 goto out;
1772
1773 /* We can't heartbeat without having had our node number
1774 * configured yet. */
1775 if (o2nm_this_node() == O2NM_MAX_NODES)
1776 goto out;
1777
1778 fd = simple_strtol(p, &p, 0);
1779 if (!p || (*p && (*p != '\n')))
1780 goto out;
1781
1782 if (fd < 0 || fd >= INT_MAX)
1783 goto out;
1784
1785 f = fdget(fd);
1786 if (f.file == NULL)
1787 goto out;
1788
1789 if (reg->hr_blocks == 0 || reg->hr_start_block == 0 ||
1790 reg->hr_block_bytes == 0)
1791 goto out2;
1792
1793 if (!S_ISBLK(f.file->f_mapping->host->i_mode))
1794 goto out2;
1795
1796 reg->hr_bdev = blkdev_get_by_dev(f.file->f_mapping->host->i_rdev,
1797 FMODE_WRITE | FMODE_READ, NULL);
1798 if (IS_ERR(reg->hr_bdev)) {
1799 ret = PTR_ERR(reg->hr_bdev);
1800 reg->hr_bdev = NULL;
1801 goto out2;
1802 }
1803
1804 bdevname(reg->hr_bdev, reg->hr_dev_name);
1805
1806 sectsize = bdev_logical_block_size(reg->hr_bdev);
1807 if (sectsize != reg->hr_block_bytes) {
1808 mlog(ML_ERROR,
1809 "blocksize %u incorrect for device, expected %d",
1810 reg->hr_block_bytes, sectsize);
1811 ret = -EINVAL;
1812 goto out3;
1813 }
1814
1815 o2hb_init_region_params(reg);
1816
1817 /* Generation of zero is invalid */
1818 do {
1819 get_random_bytes(®->hr_generation,
1820 sizeof(reg->hr_generation));
1821 } while (reg->hr_generation == 0);
1822
1823 ret = o2hb_map_slot_data(reg);
1824 if (ret) {
1825 mlog_errno(ret);
1826 goto out3;
1827 }
1828
1829 ret = o2hb_populate_slot_data(reg);
1830 if (ret) {
1831 mlog_errno(ret);
1832 goto out3;
1833 }
1834
1835 INIT_DELAYED_WORK(®->hr_write_timeout_work, o2hb_write_timeout);
1836 INIT_DELAYED_WORK(®->hr_nego_timeout_work, o2hb_nego_timeout);
1837
1838 /*
1839 * A node is considered live after it has beat LIVE_THRESHOLD
1840 * times. We're not steady until we've given them a chance
1841 * _after_ our first read.
1842 * The default threshold is bare minimum so as to limit the delay
1843 * during mounts. For global heartbeat, the threshold doubled for the
1844 * first region.
1845 */
1846 live_threshold = O2HB_LIVE_THRESHOLD;
1847 if (o2hb_global_heartbeat_active()) {
1848 spin_lock(&o2hb_live_lock);
1849 if (bitmap_weight(o2hb_region_bitmap, O2NM_MAX_REGIONS) == 1)
1850 live_threshold <<= 1;
1851 spin_unlock(&o2hb_live_lock);
1852 }
1853 ++live_threshold;
1854 atomic_set(®->hr_steady_iterations, live_threshold);
1855 /* unsteady_iterations is triple the steady_iterations */
1856 atomic_set(®->hr_unsteady_iterations, (live_threshold * 3));
1857
1858 hb_task = kthread_run(o2hb_thread, reg, "o2hb-%s",
1859 reg->hr_item.ci_name);
1860 if (IS_ERR(hb_task)) {
1861 ret = PTR_ERR(hb_task);
1862 mlog_errno(ret);
1863 goto out3;
1864 }
1865
1866 spin_lock(&o2hb_live_lock);
1867 reg->hr_task = hb_task;
1868 spin_unlock(&o2hb_live_lock);
1869
1870 ret = wait_event_interruptible(o2hb_steady_queue,
1871 atomic_read(®->hr_steady_iterations) == 0 ||
1872 reg->hr_node_deleted);
1873 if (ret) {
1874 atomic_set(®->hr_steady_iterations, 0);
1875 reg->hr_aborted_start = 1;
1876 }
1877
1878 if (reg->hr_aborted_start) {
1879 ret = -EIO;
1880 goto out3;
1881 }
1882
1883 if (reg->hr_node_deleted) {
1884 ret = -EINVAL;
1885 goto out3;
1886 }
1887
1888 /* Ok, we were woken. Make sure it wasn't by drop_item() */
1889 spin_lock(&o2hb_live_lock);
1890 hb_task = reg->hr_task;
1891 if (o2hb_global_heartbeat_active())
1892 set_bit(reg->hr_region_num, o2hb_live_region_bitmap);
1893 spin_unlock(&o2hb_live_lock);
1894
1895 if (hb_task)
1896 ret = count;
1897 else
1898 ret = -EIO;
1899
1900 if (hb_task && o2hb_global_heartbeat_active())
1901 printk(KERN_NOTICE "o2hb: Heartbeat started on region %s (%s)\n",
1902 config_item_name(®->hr_item), reg->hr_dev_name);
1903
1904 out3:
1905 if (ret < 0) {
1906 blkdev_put(reg->hr_bdev, FMODE_READ | FMODE_WRITE);
1907 reg->hr_bdev = NULL;
1908 }
1909 out2:
1910 fdput(f);
1911 out:
1912 return ret;
1913 }
1914
o2hb_region_pid_show(struct config_item * item,char * page)1915 static ssize_t o2hb_region_pid_show(struct config_item *item, char *page)
1916 {
1917 struct o2hb_region *reg = to_o2hb_region(item);
1918 pid_t pid = 0;
1919
1920 spin_lock(&o2hb_live_lock);
1921 if (reg->hr_task)
1922 pid = task_pid_nr(reg->hr_task);
1923 spin_unlock(&o2hb_live_lock);
1924
1925 if (!pid)
1926 return 0;
1927
1928 return sprintf(page, "%u\n", pid);
1929 }
1930
1931 CONFIGFS_ATTR(o2hb_region_, block_bytes);
1932 CONFIGFS_ATTR(o2hb_region_, start_block);
1933 CONFIGFS_ATTR(o2hb_region_, blocks);
1934 CONFIGFS_ATTR(o2hb_region_, dev);
1935 CONFIGFS_ATTR_RO(o2hb_region_, pid);
1936
1937 static struct configfs_attribute *o2hb_region_attrs[] = {
1938 &o2hb_region_attr_block_bytes,
1939 &o2hb_region_attr_start_block,
1940 &o2hb_region_attr_blocks,
1941 &o2hb_region_attr_dev,
1942 &o2hb_region_attr_pid,
1943 NULL,
1944 };
1945
1946 static struct configfs_item_operations o2hb_region_item_ops = {
1947 .release = o2hb_region_release,
1948 };
1949
1950 static const struct config_item_type o2hb_region_type = {
1951 .ct_item_ops = &o2hb_region_item_ops,
1952 .ct_attrs = o2hb_region_attrs,
1953 .ct_owner = THIS_MODULE,
1954 };
1955
1956 /* heartbeat set */
1957
1958 struct o2hb_heartbeat_group {
1959 struct config_group hs_group;
1960 /* some stuff? */
1961 };
1962
to_o2hb_heartbeat_group(struct config_group * group)1963 static struct o2hb_heartbeat_group *to_o2hb_heartbeat_group(struct config_group *group)
1964 {
1965 return group ?
1966 container_of(group, struct o2hb_heartbeat_group, hs_group)
1967 : NULL;
1968 }
1969
o2hb_debug_region_init(struct o2hb_region * reg,struct dentry * parent)1970 static void o2hb_debug_region_init(struct o2hb_region *reg,
1971 struct dentry *parent)
1972 {
1973 struct dentry *dir;
1974
1975 dir = debugfs_create_dir(config_item_name(®->hr_item), parent);
1976 reg->hr_debug_dir = dir;
1977
1978 o2hb_debug_create(O2HB_DEBUG_LIVENODES, dir, &(reg->hr_db_livenodes),
1979 sizeof(*(reg->hr_db_livenodes)),
1980 O2HB_DB_TYPE_REGION_LIVENODES,
1981 sizeof(reg->hr_live_node_bitmap), O2NM_MAX_NODES,
1982 reg);
1983
1984 o2hb_debug_create(O2HB_DEBUG_REGION_NUMBER, dir, &(reg->hr_db_regnum),
1985 sizeof(*(reg->hr_db_regnum)),
1986 O2HB_DB_TYPE_REGION_NUMBER, 0, O2NM_MAX_NODES, reg);
1987
1988 o2hb_debug_create(O2HB_DEBUG_REGION_ELAPSED_TIME, dir,
1989 &(reg->hr_db_elapsed_time),
1990 sizeof(*(reg->hr_db_elapsed_time)),
1991 O2HB_DB_TYPE_REGION_ELAPSED_TIME, 0, 0, reg);
1992
1993 o2hb_debug_create(O2HB_DEBUG_REGION_PINNED, dir, &(reg->hr_db_pinned),
1994 sizeof(*(reg->hr_db_pinned)),
1995 O2HB_DB_TYPE_REGION_PINNED, 0, 0, reg);
1996
1997 }
1998
o2hb_heartbeat_group_make_item(struct config_group * group,const char * name)1999 static struct config_item *o2hb_heartbeat_group_make_item(struct config_group *group,
2000 const char *name)
2001 {
2002 struct o2hb_region *reg = NULL;
2003 int ret;
2004
2005 reg = kzalloc(sizeof(struct o2hb_region), GFP_KERNEL);
2006 if (reg == NULL)
2007 return ERR_PTR(-ENOMEM);
2008
2009 if (strlen(name) > O2HB_MAX_REGION_NAME_LEN) {
2010 ret = -ENAMETOOLONG;
2011 goto free;
2012 }
2013
2014 spin_lock(&o2hb_live_lock);
2015 reg->hr_region_num = 0;
2016 if (o2hb_global_heartbeat_active()) {
2017 reg->hr_region_num = find_first_zero_bit(o2hb_region_bitmap,
2018 O2NM_MAX_REGIONS);
2019 if (reg->hr_region_num >= O2NM_MAX_REGIONS) {
2020 spin_unlock(&o2hb_live_lock);
2021 ret = -EFBIG;
2022 goto free;
2023 }
2024 set_bit(reg->hr_region_num, o2hb_region_bitmap);
2025 }
2026 list_add_tail(®->hr_all_item, &o2hb_all_regions);
2027 spin_unlock(&o2hb_live_lock);
2028
2029 config_item_init_type_name(®->hr_item, name, &o2hb_region_type);
2030
2031 /* this is the same way to generate msg key as dlm, for local heartbeat,
2032 * name is also the same, so make initial crc value different to avoid
2033 * message key conflict.
2034 */
2035 reg->hr_key = crc32_le(reg->hr_region_num + O2NM_MAX_REGIONS,
2036 name, strlen(name));
2037 INIT_LIST_HEAD(®->hr_handler_list);
2038 ret = o2net_register_handler(O2HB_NEGO_TIMEOUT_MSG, reg->hr_key,
2039 sizeof(struct o2hb_nego_msg),
2040 o2hb_nego_timeout_handler,
2041 reg, NULL, ®->hr_handler_list);
2042 if (ret)
2043 goto remove_item;
2044
2045 ret = o2net_register_handler(O2HB_NEGO_APPROVE_MSG, reg->hr_key,
2046 sizeof(struct o2hb_nego_msg),
2047 o2hb_nego_approve_handler,
2048 reg, NULL, ®->hr_handler_list);
2049 if (ret)
2050 goto unregister_handler;
2051
2052 o2hb_debug_region_init(reg, o2hb_debug_dir);
2053
2054 return ®->hr_item;
2055
2056 unregister_handler:
2057 o2net_unregister_handler_list(®->hr_handler_list);
2058 remove_item:
2059 spin_lock(&o2hb_live_lock);
2060 list_del(®->hr_all_item);
2061 if (o2hb_global_heartbeat_active())
2062 clear_bit(reg->hr_region_num, o2hb_region_bitmap);
2063 spin_unlock(&o2hb_live_lock);
2064 free:
2065 kfree(reg);
2066 return ERR_PTR(ret);
2067 }
2068
o2hb_heartbeat_group_drop_item(struct config_group * group,struct config_item * item)2069 static void o2hb_heartbeat_group_drop_item(struct config_group *group,
2070 struct config_item *item)
2071 {
2072 struct task_struct *hb_task;
2073 struct o2hb_region *reg = to_o2hb_region(item);
2074 int quorum_region = 0;
2075
2076 /* stop the thread when the user removes the region dir */
2077 spin_lock(&o2hb_live_lock);
2078 hb_task = reg->hr_task;
2079 reg->hr_task = NULL;
2080 reg->hr_item_dropped = 1;
2081 spin_unlock(&o2hb_live_lock);
2082
2083 if (hb_task)
2084 kthread_stop(hb_task);
2085
2086 if (o2hb_global_heartbeat_active()) {
2087 spin_lock(&o2hb_live_lock);
2088 clear_bit(reg->hr_region_num, o2hb_region_bitmap);
2089 clear_bit(reg->hr_region_num, o2hb_live_region_bitmap);
2090 if (test_bit(reg->hr_region_num, o2hb_quorum_region_bitmap))
2091 quorum_region = 1;
2092 clear_bit(reg->hr_region_num, o2hb_quorum_region_bitmap);
2093 spin_unlock(&o2hb_live_lock);
2094 printk(KERN_NOTICE "o2hb: Heartbeat %s on region %s (%s)\n",
2095 ((atomic_read(®->hr_steady_iterations) == 0) ?
2096 "stopped" : "start aborted"), config_item_name(item),
2097 reg->hr_dev_name);
2098 }
2099
2100 /*
2101 * If we're racing a dev_write(), we need to wake them. They will
2102 * check reg->hr_task
2103 */
2104 if (atomic_read(®->hr_steady_iterations) != 0) {
2105 reg->hr_aborted_start = 1;
2106 atomic_set(®->hr_steady_iterations, 0);
2107 wake_up(&o2hb_steady_queue);
2108 }
2109
2110 config_item_put(item);
2111
2112 if (!o2hb_global_heartbeat_active() || !quorum_region)
2113 return;
2114
2115 /*
2116 * If global heartbeat active and there are dependent users,
2117 * pin all regions if quorum region count <= CUT_OFF
2118 */
2119 spin_lock(&o2hb_live_lock);
2120
2121 if (!o2hb_dependent_users)
2122 goto unlock;
2123
2124 if (bitmap_weight(o2hb_quorum_region_bitmap,
2125 O2NM_MAX_REGIONS) <= O2HB_PIN_CUT_OFF)
2126 o2hb_region_pin(NULL);
2127
2128 unlock:
2129 spin_unlock(&o2hb_live_lock);
2130 }
2131
o2hb_heartbeat_group_dead_threshold_show(struct config_item * item,char * page)2132 static ssize_t o2hb_heartbeat_group_dead_threshold_show(struct config_item *item,
2133 char *page)
2134 {
2135 return sprintf(page, "%u\n", o2hb_dead_threshold);
2136 }
2137
o2hb_heartbeat_group_dead_threshold_store(struct config_item * item,const char * page,size_t count)2138 static ssize_t o2hb_heartbeat_group_dead_threshold_store(struct config_item *item,
2139 const char *page, size_t count)
2140 {
2141 unsigned long tmp;
2142 char *p = (char *)page;
2143
2144 tmp = simple_strtoul(p, &p, 10);
2145 if (!p || (*p && (*p != '\n')))
2146 return -EINVAL;
2147
2148 /* this will validate ranges for us. */
2149 o2hb_dead_threshold_set((unsigned int) tmp);
2150
2151 return count;
2152 }
2153
o2hb_heartbeat_group_mode_show(struct config_item * item,char * page)2154 static ssize_t o2hb_heartbeat_group_mode_show(struct config_item *item,
2155 char *page)
2156 {
2157 return sprintf(page, "%s\n",
2158 o2hb_heartbeat_mode_desc[o2hb_heartbeat_mode]);
2159 }
2160
o2hb_heartbeat_group_mode_store(struct config_item * item,const char * page,size_t count)2161 static ssize_t o2hb_heartbeat_group_mode_store(struct config_item *item,
2162 const char *page, size_t count)
2163 {
2164 unsigned int i;
2165 int ret;
2166 size_t len;
2167
2168 len = (page[count - 1] == '\n') ? count - 1 : count;
2169 if (!len)
2170 return -EINVAL;
2171
2172 for (i = 0; i < O2HB_HEARTBEAT_NUM_MODES; ++i) {
2173 if (strncasecmp(page, o2hb_heartbeat_mode_desc[i], len))
2174 continue;
2175
2176 ret = o2hb_global_heartbeat_mode_set(i);
2177 if (!ret)
2178 printk(KERN_NOTICE "o2hb: Heartbeat mode set to %s\n",
2179 o2hb_heartbeat_mode_desc[i]);
2180 return count;
2181 }
2182
2183 return -EINVAL;
2184
2185 }
2186
2187 CONFIGFS_ATTR(o2hb_heartbeat_group_, dead_threshold);
2188 CONFIGFS_ATTR(o2hb_heartbeat_group_, mode);
2189
2190 static struct configfs_attribute *o2hb_heartbeat_group_attrs[] = {
2191 &o2hb_heartbeat_group_attr_dead_threshold,
2192 &o2hb_heartbeat_group_attr_mode,
2193 NULL,
2194 };
2195
2196 static struct configfs_group_operations o2hb_heartbeat_group_group_ops = {
2197 .make_item = o2hb_heartbeat_group_make_item,
2198 .drop_item = o2hb_heartbeat_group_drop_item,
2199 };
2200
2201 static const struct config_item_type o2hb_heartbeat_group_type = {
2202 .ct_group_ops = &o2hb_heartbeat_group_group_ops,
2203 .ct_attrs = o2hb_heartbeat_group_attrs,
2204 .ct_owner = THIS_MODULE,
2205 };
2206
2207 /* this is just here to avoid touching group in heartbeat.h which the
2208 * entire damn world #includes */
o2hb_alloc_hb_set(void)2209 struct config_group *o2hb_alloc_hb_set(void)
2210 {
2211 struct o2hb_heartbeat_group *hs = NULL;
2212 struct config_group *ret = NULL;
2213
2214 hs = kzalloc(sizeof(struct o2hb_heartbeat_group), GFP_KERNEL);
2215 if (hs == NULL)
2216 goto out;
2217
2218 config_group_init_type_name(&hs->hs_group, "heartbeat",
2219 &o2hb_heartbeat_group_type);
2220
2221 ret = &hs->hs_group;
2222 out:
2223 if (ret == NULL)
2224 kfree(hs);
2225 return ret;
2226 }
2227
o2hb_free_hb_set(struct config_group * group)2228 void o2hb_free_hb_set(struct config_group *group)
2229 {
2230 struct o2hb_heartbeat_group *hs = to_o2hb_heartbeat_group(group);
2231 kfree(hs);
2232 }
2233
2234 /* hb callback registration and issuing */
2235
hbcall_from_type(enum o2hb_callback_type type)2236 static struct o2hb_callback *hbcall_from_type(enum o2hb_callback_type type)
2237 {
2238 if (type == O2HB_NUM_CB)
2239 return ERR_PTR(-EINVAL);
2240
2241 return &o2hb_callbacks[type];
2242 }
2243
o2hb_setup_callback(struct o2hb_callback_func * hc,enum o2hb_callback_type type,o2hb_cb_func * func,void * data,int priority)2244 void o2hb_setup_callback(struct o2hb_callback_func *hc,
2245 enum o2hb_callback_type type,
2246 o2hb_cb_func *func,
2247 void *data,
2248 int priority)
2249 {
2250 INIT_LIST_HEAD(&hc->hc_item);
2251 hc->hc_func = func;
2252 hc->hc_data = data;
2253 hc->hc_priority = priority;
2254 hc->hc_type = type;
2255 hc->hc_magic = O2HB_CB_MAGIC;
2256 }
2257 EXPORT_SYMBOL_GPL(o2hb_setup_callback);
2258
2259 /*
2260 * In local heartbeat mode, region_uuid passed matches the dlm domain name.
2261 * In global heartbeat mode, region_uuid passed is NULL.
2262 *
2263 * In local, we only pin the matching region. In global we pin all the active
2264 * regions.
2265 */
o2hb_region_pin(const char * region_uuid)2266 static int o2hb_region_pin(const char *region_uuid)
2267 {
2268 int ret = 0, found = 0;
2269 struct o2hb_region *reg;
2270 char *uuid;
2271
2272 assert_spin_locked(&o2hb_live_lock);
2273
2274 list_for_each_entry(reg, &o2hb_all_regions, hr_all_item) {
2275 if (reg->hr_item_dropped)
2276 continue;
2277
2278 uuid = config_item_name(®->hr_item);
2279
2280 /* local heartbeat */
2281 if (region_uuid) {
2282 if (strcmp(region_uuid, uuid))
2283 continue;
2284 found = 1;
2285 }
2286
2287 if (reg->hr_item_pinned || reg->hr_item_dropped)
2288 goto skip_pin;
2289
2290 /* Ignore ENOENT only for local hb (userdlm domain) */
2291 ret = o2nm_depend_item(®->hr_item);
2292 if (!ret) {
2293 mlog(ML_CLUSTER, "Pin region %s\n", uuid);
2294 reg->hr_item_pinned = 1;
2295 } else {
2296 if (ret == -ENOENT && found)
2297 ret = 0;
2298 else {
2299 mlog(ML_ERROR, "Pin region %s fails with %d\n",
2300 uuid, ret);
2301 break;
2302 }
2303 }
2304 skip_pin:
2305 if (found)
2306 break;
2307 }
2308
2309 return ret;
2310 }
2311
2312 /*
2313 * In local heartbeat mode, region_uuid passed matches the dlm domain name.
2314 * In global heartbeat mode, region_uuid passed is NULL.
2315 *
2316 * In local, we only unpin the matching region. In global we unpin all the
2317 * active regions.
2318 */
o2hb_region_unpin(const char * region_uuid)2319 static void o2hb_region_unpin(const char *region_uuid)
2320 {
2321 struct o2hb_region *reg;
2322 char *uuid;
2323 int found = 0;
2324
2325 assert_spin_locked(&o2hb_live_lock);
2326
2327 list_for_each_entry(reg, &o2hb_all_regions, hr_all_item) {
2328 if (reg->hr_item_dropped)
2329 continue;
2330
2331 uuid = config_item_name(®->hr_item);
2332 if (region_uuid) {
2333 if (strcmp(region_uuid, uuid))
2334 continue;
2335 found = 1;
2336 }
2337
2338 if (reg->hr_item_pinned) {
2339 mlog(ML_CLUSTER, "Unpin region %s\n", uuid);
2340 o2nm_undepend_item(®->hr_item);
2341 reg->hr_item_pinned = 0;
2342 }
2343 if (found)
2344 break;
2345 }
2346 }
2347
o2hb_region_inc_user(const char * region_uuid)2348 static int o2hb_region_inc_user(const char *region_uuid)
2349 {
2350 int ret = 0;
2351
2352 spin_lock(&o2hb_live_lock);
2353
2354 /* local heartbeat */
2355 if (!o2hb_global_heartbeat_active()) {
2356 ret = o2hb_region_pin(region_uuid);
2357 goto unlock;
2358 }
2359
2360 /*
2361 * if global heartbeat active and this is the first dependent user,
2362 * pin all regions if quorum region count <= CUT_OFF
2363 */
2364 o2hb_dependent_users++;
2365 if (o2hb_dependent_users > 1)
2366 goto unlock;
2367
2368 if (bitmap_weight(o2hb_quorum_region_bitmap,
2369 O2NM_MAX_REGIONS) <= O2HB_PIN_CUT_OFF)
2370 ret = o2hb_region_pin(NULL);
2371
2372 unlock:
2373 spin_unlock(&o2hb_live_lock);
2374 return ret;
2375 }
2376
o2hb_region_dec_user(const char * region_uuid)2377 static void o2hb_region_dec_user(const char *region_uuid)
2378 {
2379 spin_lock(&o2hb_live_lock);
2380
2381 /* local heartbeat */
2382 if (!o2hb_global_heartbeat_active()) {
2383 o2hb_region_unpin(region_uuid);
2384 goto unlock;
2385 }
2386
2387 /*
2388 * if global heartbeat active and there are no dependent users,
2389 * unpin all quorum regions
2390 */
2391 o2hb_dependent_users--;
2392 if (!o2hb_dependent_users)
2393 o2hb_region_unpin(NULL);
2394
2395 unlock:
2396 spin_unlock(&o2hb_live_lock);
2397 }
2398
o2hb_register_callback(const char * region_uuid,struct o2hb_callback_func * hc)2399 int o2hb_register_callback(const char *region_uuid,
2400 struct o2hb_callback_func *hc)
2401 {
2402 struct o2hb_callback_func *f;
2403 struct o2hb_callback *hbcall;
2404 int ret;
2405
2406 BUG_ON(hc->hc_magic != O2HB_CB_MAGIC);
2407 BUG_ON(!list_empty(&hc->hc_item));
2408
2409 hbcall = hbcall_from_type(hc->hc_type);
2410 if (IS_ERR(hbcall)) {
2411 ret = PTR_ERR(hbcall);
2412 goto out;
2413 }
2414
2415 if (region_uuid) {
2416 ret = o2hb_region_inc_user(region_uuid);
2417 if (ret) {
2418 mlog_errno(ret);
2419 goto out;
2420 }
2421 }
2422
2423 down_write(&o2hb_callback_sem);
2424
2425 list_for_each_entry(f, &hbcall->list, hc_item) {
2426 if (hc->hc_priority < f->hc_priority) {
2427 list_add_tail(&hc->hc_item, &f->hc_item);
2428 break;
2429 }
2430 }
2431 if (list_empty(&hc->hc_item))
2432 list_add_tail(&hc->hc_item, &hbcall->list);
2433
2434 up_write(&o2hb_callback_sem);
2435 ret = 0;
2436 out:
2437 mlog(ML_CLUSTER, "returning %d on behalf of %p for funcs %p\n",
2438 ret, __builtin_return_address(0), hc);
2439 return ret;
2440 }
2441 EXPORT_SYMBOL_GPL(o2hb_register_callback);
2442
o2hb_unregister_callback(const char * region_uuid,struct o2hb_callback_func * hc)2443 void o2hb_unregister_callback(const char *region_uuid,
2444 struct o2hb_callback_func *hc)
2445 {
2446 BUG_ON(hc->hc_magic != O2HB_CB_MAGIC);
2447
2448 mlog(ML_CLUSTER, "on behalf of %p for funcs %p\n",
2449 __builtin_return_address(0), hc);
2450
2451 /* XXX Can this happen _with_ a region reference? */
2452 if (list_empty(&hc->hc_item))
2453 return;
2454
2455 if (region_uuid)
2456 o2hb_region_dec_user(region_uuid);
2457
2458 down_write(&o2hb_callback_sem);
2459
2460 list_del_init(&hc->hc_item);
2461
2462 up_write(&o2hb_callback_sem);
2463 }
2464 EXPORT_SYMBOL_GPL(o2hb_unregister_callback);
2465
o2hb_check_node_heartbeating_no_sem(u8 node_num)2466 int o2hb_check_node_heartbeating_no_sem(u8 node_num)
2467 {
2468 unsigned long testing_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
2469
2470 spin_lock(&o2hb_live_lock);
2471 o2hb_fill_node_map_from_callback(testing_map, sizeof(testing_map));
2472 spin_unlock(&o2hb_live_lock);
2473 if (!test_bit(node_num, testing_map)) {
2474 mlog(ML_HEARTBEAT,
2475 "node (%u) does not have heartbeating enabled.\n",
2476 node_num);
2477 return 0;
2478 }
2479
2480 return 1;
2481 }
2482 EXPORT_SYMBOL_GPL(o2hb_check_node_heartbeating_no_sem);
2483
o2hb_check_node_heartbeating_from_callback(u8 node_num)2484 int o2hb_check_node_heartbeating_from_callback(u8 node_num)
2485 {
2486 unsigned long testing_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
2487
2488 o2hb_fill_node_map_from_callback(testing_map, sizeof(testing_map));
2489 if (!test_bit(node_num, testing_map)) {
2490 mlog(ML_HEARTBEAT,
2491 "node (%u) does not have heartbeating enabled.\n",
2492 node_num);
2493 return 0;
2494 }
2495
2496 return 1;
2497 }
2498 EXPORT_SYMBOL_GPL(o2hb_check_node_heartbeating_from_callback);
2499
2500 /*
2501 * this is just a hack until we get the plumbing which flips file systems
2502 * read only and drops the hb ref instead of killing the node dead.
2503 */
o2hb_stop_all_regions(void)2504 void o2hb_stop_all_regions(void)
2505 {
2506 struct o2hb_region *reg;
2507
2508 mlog(ML_ERROR, "stopping heartbeat on all active regions.\n");
2509
2510 spin_lock(&o2hb_live_lock);
2511
2512 list_for_each_entry(reg, &o2hb_all_regions, hr_all_item)
2513 reg->hr_unclean_stop = 1;
2514
2515 spin_unlock(&o2hb_live_lock);
2516 }
2517 EXPORT_SYMBOL_GPL(o2hb_stop_all_regions);
2518
o2hb_get_all_regions(char * region_uuids,u8 max_regions)2519 int o2hb_get_all_regions(char *region_uuids, u8 max_regions)
2520 {
2521 struct o2hb_region *reg;
2522 int numregs = 0;
2523 char *p;
2524
2525 spin_lock(&o2hb_live_lock);
2526
2527 p = region_uuids;
2528 list_for_each_entry(reg, &o2hb_all_regions, hr_all_item) {
2529 if (reg->hr_item_dropped)
2530 continue;
2531
2532 mlog(0, "Region: %s\n", config_item_name(®->hr_item));
2533 if (numregs < max_regions) {
2534 memcpy(p, config_item_name(®->hr_item),
2535 O2HB_MAX_REGION_NAME_LEN);
2536 p += O2HB_MAX_REGION_NAME_LEN;
2537 }
2538 numregs++;
2539 }
2540
2541 spin_unlock(&o2hb_live_lock);
2542
2543 return numregs;
2544 }
2545 EXPORT_SYMBOL_GPL(o2hb_get_all_regions);
2546
o2hb_global_heartbeat_active(void)2547 int o2hb_global_heartbeat_active(void)
2548 {
2549 return (o2hb_heartbeat_mode == O2HB_HEARTBEAT_GLOBAL);
2550 }
2551 EXPORT_SYMBOL(o2hb_global_heartbeat_active);
2552