1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* -*- mode: c; c-basic-offset: 8; -*-
3 * vim: noexpandtab sw=8 ts=8 sts=0:
4 *
5 * Copyright (C) 2004, 2005 Oracle. All rights reserved.
6 */
7
8 #include <linux/kernel.h>
9 #include <linux/sched.h>
10 #include <linux/jiffies.h>
11 #include <linux/module.h>
12 #include <linux/fs.h>
13 #include <linux/bio.h>
14 #include <linux/blkdev.h>
15 #include <linux/delay.h>
16 #include <linux/file.h>
17 #include <linux/kthread.h>
18 #include <linux/configfs.h>
19 #include <linux/random.h>
20 #include <linux/crc32.h>
21 #include <linux/time.h>
22 #include <linux/debugfs.h>
23 #include <linux/slab.h>
24 #include <linux/bitmap.h>
25 #include <linux/ktime.h>
26 #include "heartbeat.h"
27 #include "tcp.h"
28 #include "nodemanager.h"
29 #include "quorum.h"
30
31 #include "masklog.h"
32
33
34 /*
35 * The first heartbeat pass had one global thread that would serialize all hb
36 * callback calls. This global serializing sem should only be removed once
37 * we've made sure that all callees can deal with being called concurrently
38 * from multiple hb region threads.
39 */
40 static DECLARE_RWSEM(o2hb_callback_sem);
41
42 /*
43 * multiple hb threads are watching multiple regions. A node is live
44 * whenever any of the threads sees activity from the node in its region.
45 */
46 static DEFINE_SPINLOCK(o2hb_live_lock);
47 static struct list_head o2hb_live_slots[O2NM_MAX_NODES];
48 static unsigned long o2hb_live_node_bitmap[BITS_TO_LONGS(O2NM_MAX_NODES)];
49 static LIST_HEAD(o2hb_node_events);
50 static DECLARE_WAIT_QUEUE_HEAD(o2hb_steady_queue);
51
52 /*
53 * In global heartbeat, we maintain a series of region bitmaps.
54 * - o2hb_region_bitmap allows us to limit the region number to max region.
55 * - o2hb_live_region_bitmap tracks live regions (seen steady iterations).
56 * - o2hb_quorum_region_bitmap tracks live regions that have seen all nodes
57 * heartbeat on it.
58 * - o2hb_failed_region_bitmap tracks the regions that have seen io timeouts.
59 */
60 static unsigned long o2hb_region_bitmap[BITS_TO_LONGS(O2NM_MAX_REGIONS)];
61 static unsigned long o2hb_live_region_bitmap[BITS_TO_LONGS(O2NM_MAX_REGIONS)];
62 static unsigned long o2hb_quorum_region_bitmap[BITS_TO_LONGS(O2NM_MAX_REGIONS)];
63 static unsigned long o2hb_failed_region_bitmap[BITS_TO_LONGS(O2NM_MAX_REGIONS)];
64
65 #define O2HB_DB_TYPE_LIVENODES 0
66 #define O2HB_DB_TYPE_LIVEREGIONS 1
67 #define O2HB_DB_TYPE_QUORUMREGIONS 2
68 #define O2HB_DB_TYPE_FAILEDREGIONS 3
69 #define O2HB_DB_TYPE_REGION_LIVENODES 4
70 #define O2HB_DB_TYPE_REGION_NUMBER 5
71 #define O2HB_DB_TYPE_REGION_ELAPSED_TIME 6
72 #define O2HB_DB_TYPE_REGION_PINNED 7
73 struct o2hb_debug_buf {
74 int db_type;
75 int db_size;
76 int db_len;
77 void *db_data;
78 };
79
80 static struct o2hb_debug_buf *o2hb_db_livenodes;
81 static struct o2hb_debug_buf *o2hb_db_liveregions;
82 static struct o2hb_debug_buf *o2hb_db_quorumregions;
83 static struct o2hb_debug_buf *o2hb_db_failedregions;
84
85 #define O2HB_DEBUG_DIR "o2hb"
86 #define O2HB_DEBUG_LIVENODES "livenodes"
87 #define O2HB_DEBUG_LIVEREGIONS "live_regions"
88 #define O2HB_DEBUG_QUORUMREGIONS "quorum_regions"
89 #define O2HB_DEBUG_FAILEDREGIONS "failed_regions"
90 #define O2HB_DEBUG_REGION_NUMBER "num"
91 #define O2HB_DEBUG_REGION_ELAPSED_TIME "elapsed_time_in_ms"
92 #define O2HB_DEBUG_REGION_PINNED "pinned"
93
94 static struct dentry *o2hb_debug_dir;
95
96 static LIST_HEAD(o2hb_all_regions);
97
98 static struct o2hb_callback {
99 struct list_head list;
100 } o2hb_callbacks[O2HB_NUM_CB];
101
102 static struct o2hb_callback *hbcall_from_type(enum o2hb_callback_type type);
103
104 enum o2hb_heartbeat_modes {
105 O2HB_HEARTBEAT_LOCAL = 0,
106 O2HB_HEARTBEAT_GLOBAL,
107 O2HB_HEARTBEAT_NUM_MODES,
108 };
109
110 static const char *o2hb_heartbeat_mode_desc[O2HB_HEARTBEAT_NUM_MODES] = {
111 "local", /* O2HB_HEARTBEAT_LOCAL */
112 "global", /* O2HB_HEARTBEAT_GLOBAL */
113 };
114
115 unsigned int o2hb_dead_threshold = O2HB_DEFAULT_DEAD_THRESHOLD;
116 static unsigned int o2hb_heartbeat_mode = O2HB_HEARTBEAT_LOCAL;
117
118 /*
119 * o2hb_dependent_users tracks the number of registered callbacks that depend
120 * on heartbeat. o2net and o2dlm are two entities that register this callback.
121 * However only o2dlm depends on the heartbeat. It does not want the heartbeat
122 * to stop while a dlm domain is still active.
123 */
124 static unsigned int o2hb_dependent_users;
125
126 /*
127 * In global heartbeat mode, all regions are pinned if there are one or more
128 * dependent users and the quorum region count is <= O2HB_PIN_CUT_OFF. All
129 * regions are unpinned if the region count exceeds the cut off or the number
130 * of dependent users falls to zero.
131 */
132 #define O2HB_PIN_CUT_OFF 3
133
134 /*
135 * In local heartbeat mode, we assume the dlm domain name to be the same as
136 * region uuid. This is true for domains created for the file system but not
137 * necessarily true for userdlm domains. This is a known limitation.
138 *
139 * In global heartbeat mode, we pin/unpin all o2hb regions. This solution
140 * works for both file system and userdlm domains.
141 */
142 static int o2hb_region_pin(const char *region_uuid);
143 static void o2hb_region_unpin(const char *region_uuid);
144
145 /* Only sets a new threshold if there are no active regions.
146 *
147 * No locking or otherwise interesting code is required for reading
148 * o2hb_dead_threshold as it can't change once regions are active and
149 * it's not interesting to anyone until then anyway. */
o2hb_dead_threshold_set(unsigned int threshold)150 static void o2hb_dead_threshold_set(unsigned int threshold)
151 {
152 if (threshold > O2HB_MIN_DEAD_THRESHOLD) {
153 spin_lock(&o2hb_live_lock);
154 if (list_empty(&o2hb_all_regions))
155 o2hb_dead_threshold = threshold;
156 spin_unlock(&o2hb_live_lock);
157 }
158 }
159
o2hb_global_heartbeat_mode_set(unsigned int hb_mode)160 static int o2hb_global_heartbeat_mode_set(unsigned int hb_mode)
161 {
162 int ret = -1;
163
164 if (hb_mode < O2HB_HEARTBEAT_NUM_MODES) {
165 spin_lock(&o2hb_live_lock);
166 if (list_empty(&o2hb_all_regions)) {
167 o2hb_heartbeat_mode = hb_mode;
168 ret = 0;
169 }
170 spin_unlock(&o2hb_live_lock);
171 }
172
173 return ret;
174 }
175
176 struct o2hb_node_event {
177 struct list_head hn_item;
178 enum o2hb_callback_type hn_event_type;
179 struct o2nm_node *hn_node;
180 int hn_node_num;
181 };
182
183 struct o2hb_disk_slot {
184 struct o2hb_disk_heartbeat_block *ds_raw_block;
185 u8 ds_node_num;
186 u64 ds_last_time;
187 u64 ds_last_generation;
188 u16 ds_equal_samples;
189 u16 ds_changed_samples;
190 struct list_head ds_live_item;
191 };
192
193 /* each thread owns a region.. when we're asked to tear down the region
194 * we ask the thread to stop, who cleans up the region */
195 struct o2hb_region {
196 struct config_item hr_item;
197
198 struct list_head hr_all_item;
199 unsigned hr_unclean_stop:1,
200 hr_aborted_start:1,
201 hr_item_pinned:1,
202 hr_item_dropped:1,
203 hr_node_deleted:1;
204
205 /* protected by the hr_callback_sem */
206 struct task_struct *hr_task;
207
208 unsigned int hr_blocks;
209 unsigned long long hr_start_block;
210
211 unsigned int hr_block_bits;
212 unsigned int hr_block_bytes;
213
214 unsigned int hr_slots_per_page;
215 unsigned int hr_num_pages;
216
217 struct page **hr_slot_data;
218 struct block_device *hr_bdev;
219 struct o2hb_disk_slot *hr_slots;
220
221 /* live node map of this region */
222 unsigned long hr_live_node_bitmap[BITS_TO_LONGS(O2NM_MAX_NODES)];
223 unsigned int hr_region_num;
224
225 struct dentry *hr_debug_dir;
226 struct o2hb_debug_buf *hr_db_livenodes;
227 struct o2hb_debug_buf *hr_db_regnum;
228 struct o2hb_debug_buf *hr_db_elapsed_time;
229 struct o2hb_debug_buf *hr_db_pinned;
230
231 /* let the person setting up hb wait for it to return until it
232 * has reached a 'steady' state. This will be fixed when we have
233 * a more complete api that doesn't lead to this sort of fragility. */
234 atomic_t hr_steady_iterations;
235
236 /* terminate o2hb thread if it does not reach steady state
237 * (hr_steady_iterations == 0) within hr_unsteady_iterations */
238 atomic_t hr_unsteady_iterations;
239
240 char hr_dev_name[BDEVNAME_SIZE];
241
242 unsigned int hr_timeout_ms;
243
244 /* randomized as the region goes up and down so that a node
245 * recognizes a node going up and down in one iteration */
246 u64 hr_generation;
247
248 struct delayed_work hr_write_timeout_work;
249 unsigned long hr_last_timeout_start;
250
251 /* negotiate timer, used to negotiate extending hb timeout. */
252 struct delayed_work hr_nego_timeout_work;
253 unsigned long hr_nego_node_bitmap[BITS_TO_LONGS(O2NM_MAX_NODES)];
254
255 /* Used during o2hb_check_slot to hold a copy of the block
256 * being checked because we temporarily have to zero out the
257 * crc field. */
258 struct o2hb_disk_heartbeat_block *hr_tmp_block;
259
260 /* Message key for negotiate timeout message. */
261 unsigned int hr_key;
262 struct list_head hr_handler_list;
263
264 /* last hb status, 0 for success, other value for error. */
265 int hr_last_hb_status;
266 };
267
268 struct o2hb_bio_wait_ctxt {
269 atomic_t wc_num_reqs;
270 struct completion wc_io_complete;
271 int wc_error;
272 };
273
274 #define O2HB_NEGO_TIMEOUT_MS (O2HB_MAX_WRITE_TIMEOUT_MS/2)
275
276 enum {
277 O2HB_NEGO_TIMEOUT_MSG = 1,
278 O2HB_NEGO_APPROVE_MSG = 2,
279 };
280
281 struct o2hb_nego_msg {
282 u8 node_num;
283 };
284
o2hb_write_timeout(struct work_struct * work)285 static void o2hb_write_timeout(struct work_struct *work)
286 {
287 int failed, quorum;
288 struct o2hb_region *reg =
289 container_of(work, struct o2hb_region,
290 hr_write_timeout_work.work);
291
292 mlog(ML_ERROR, "Heartbeat write timeout to device %s after %u "
293 "milliseconds\n", reg->hr_dev_name,
294 jiffies_to_msecs(jiffies - reg->hr_last_timeout_start));
295
296 if (o2hb_global_heartbeat_active()) {
297 spin_lock(&o2hb_live_lock);
298 if (test_bit(reg->hr_region_num, o2hb_quorum_region_bitmap))
299 set_bit(reg->hr_region_num, o2hb_failed_region_bitmap);
300 failed = bitmap_weight(o2hb_failed_region_bitmap,
301 O2NM_MAX_REGIONS);
302 quorum = bitmap_weight(o2hb_quorum_region_bitmap,
303 O2NM_MAX_REGIONS);
304 spin_unlock(&o2hb_live_lock);
305
306 mlog(ML_HEARTBEAT, "Number of regions %d, failed regions %d\n",
307 quorum, failed);
308
309 /*
310 * Fence if the number of failed regions >= half the number
311 * of quorum regions
312 */
313 if ((failed << 1) < quorum)
314 return;
315 }
316
317 o2quo_disk_timeout();
318 }
319
o2hb_arm_timeout(struct o2hb_region * reg)320 static void o2hb_arm_timeout(struct o2hb_region *reg)
321 {
322 /* Arm writeout only after thread reaches steady state */
323 if (atomic_read(®->hr_steady_iterations) != 0)
324 return;
325
326 mlog(ML_HEARTBEAT, "Queue write timeout for %u ms\n",
327 O2HB_MAX_WRITE_TIMEOUT_MS);
328
329 if (o2hb_global_heartbeat_active()) {
330 spin_lock(&o2hb_live_lock);
331 clear_bit(reg->hr_region_num, o2hb_failed_region_bitmap);
332 spin_unlock(&o2hb_live_lock);
333 }
334 cancel_delayed_work(®->hr_write_timeout_work);
335 schedule_delayed_work(®->hr_write_timeout_work,
336 msecs_to_jiffies(O2HB_MAX_WRITE_TIMEOUT_MS));
337
338 cancel_delayed_work(®->hr_nego_timeout_work);
339 /* negotiate timeout must be less than write timeout. */
340 schedule_delayed_work(®->hr_nego_timeout_work,
341 msecs_to_jiffies(O2HB_NEGO_TIMEOUT_MS));
342 memset(reg->hr_nego_node_bitmap, 0, sizeof(reg->hr_nego_node_bitmap));
343 }
344
o2hb_disarm_timeout(struct o2hb_region * reg)345 static void o2hb_disarm_timeout(struct o2hb_region *reg)
346 {
347 cancel_delayed_work_sync(®->hr_write_timeout_work);
348 cancel_delayed_work_sync(®->hr_nego_timeout_work);
349 }
350
o2hb_send_nego_msg(int key,int type,u8 target)351 static int o2hb_send_nego_msg(int key, int type, u8 target)
352 {
353 struct o2hb_nego_msg msg;
354 int status, ret;
355
356 msg.node_num = o2nm_this_node();
357 again:
358 ret = o2net_send_message(type, key, &msg, sizeof(msg),
359 target, &status);
360
361 if (ret == -EAGAIN || ret == -ENOMEM) {
362 msleep(100);
363 goto again;
364 }
365
366 return ret;
367 }
368
o2hb_nego_timeout(struct work_struct * work)369 static void o2hb_nego_timeout(struct work_struct *work)
370 {
371 unsigned long live_node_bitmap[BITS_TO_LONGS(O2NM_MAX_NODES)];
372 int master_node, i, ret;
373 struct o2hb_region *reg;
374
375 reg = container_of(work, struct o2hb_region, hr_nego_timeout_work.work);
376 /* don't negotiate timeout if last hb failed since it is very
377 * possible io failed. Should let write timeout fence self.
378 */
379 if (reg->hr_last_hb_status)
380 return;
381
382 o2hb_fill_node_map(live_node_bitmap, sizeof(live_node_bitmap));
383 /* lowest node as master node to make negotiate decision. */
384 master_node = find_next_bit(live_node_bitmap, O2NM_MAX_NODES, 0);
385
386 if (master_node == o2nm_this_node()) {
387 if (!test_bit(master_node, reg->hr_nego_node_bitmap)) {
388 printk(KERN_NOTICE "o2hb: node %d hb write hung for %ds on region %s (%s).\n",
389 o2nm_this_node(), O2HB_NEGO_TIMEOUT_MS/1000,
390 config_item_name(®->hr_item), reg->hr_dev_name);
391 set_bit(master_node, reg->hr_nego_node_bitmap);
392 }
393 if (memcmp(reg->hr_nego_node_bitmap, live_node_bitmap,
394 sizeof(reg->hr_nego_node_bitmap))) {
395 /* check negotiate bitmap every second to do timeout
396 * approve decision.
397 */
398 schedule_delayed_work(®->hr_nego_timeout_work,
399 msecs_to_jiffies(1000));
400
401 return;
402 }
403
404 printk(KERN_NOTICE "o2hb: all nodes hb write hung, maybe region %s (%s) is down.\n",
405 config_item_name(®->hr_item), reg->hr_dev_name);
406 /* approve negotiate timeout request. */
407 o2hb_arm_timeout(reg);
408
409 i = -1;
410 while ((i = find_next_bit(live_node_bitmap,
411 O2NM_MAX_NODES, i + 1)) < O2NM_MAX_NODES) {
412 if (i == master_node)
413 continue;
414
415 mlog(ML_HEARTBEAT, "send NEGO_APPROVE msg to node %d\n", i);
416 ret = o2hb_send_nego_msg(reg->hr_key,
417 O2HB_NEGO_APPROVE_MSG, i);
418 if (ret)
419 mlog(ML_ERROR, "send NEGO_APPROVE msg to node %d fail %d\n",
420 i, ret);
421 }
422 } else {
423 /* negotiate timeout with master node. */
424 printk(KERN_NOTICE "o2hb: node %d hb write hung for %ds on region %s (%s), negotiate timeout with node %d.\n",
425 o2nm_this_node(), O2HB_NEGO_TIMEOUT_MS/1000, config_item_name(®->hr_item),
426 reg->hr_dev_name, master_node);
427 ret = o2hb_send_nego_msg(reg->hr_key, O2HB_NEGO_TIMEOUT_MSG,
428 master_node);
429 if (ret)
430 mlog(ML_ERROR, "send NEGO_TIMEOUT msg to node %d fail %d\n",
431 master_node, ret);
432 }
433 }
434
o2hb_nego_timeout_handler(struct o2net_msg * msg,u32 len,void * data,void ** ret_data)435 static int o2hb_nego_timeout_handler(struct o2net_msg *msg, u32 len, void *data,
436 void **ret_data)
437 {
438 struct o2hb_region *reg = data;
439 struct o2hb_nego_msg *nego_msg;
440
441 nego_msg = (struct o2hb_nego_msg *)msg->buf;
442 printk(KERN_NOTICE "o2hb: receive negotiate timeout message from node %d on region %s (%s).\n",
443 nego_msg->node_num, config_item_name(®->hr_item), reg->hr_dev_name);
444 if (nego_msg->node_num < O2NM_MAX_NODES)
445 set_bit(nego_msg->node_num, reg->hr_nego_node_bitmap);
446 else
447 mlog(ML_ERROR, "got nego timeout message from bad node.\n");
448
449 return 0;
450 }
451
o2hb_nego_approve_handler(struct o2net_msg * msg,u32 len,void * data,void ** ret_data)452 static int o2hb_nego_approve_handler(struct o2net_msg *msg, u32 len, void *data,
453 void **ret_data)
454 {
455 struct o2hb_region *reg = data;
456
457 printk(KERN_NOTICE "o2hb: negotiate timeout approved by master node on region %s (%s).\n",
458 config_item_name(®->hr_item), reg->hr_dev_name);
459 o2hb_arm_timeout(reg);
460 return 0;
461 }
462
o2hb_bio_wait_init(struct o2hb_bio_wait_ctxt * wc)463 static inline void o2hb_bio_wait_init(struct o2hb_bio_wait_ctxt *wc)
464 {
465 atomic_set(&wc->wc_num_reqs, 1);
466 init_completion(&wc->wc_io_complete);
467 wc->wc_error = 0;
468 }
469
470 /* Used in error paths too */
o2hb_bio_wait_dec(struct o2hb_bio_wait_ctxt * wc,unsigned int num)471 static inline void o2hb_bio_wait_dec(struct o2hb_bio_wait_ctxt *wc,
472 unsigned int num)
473 {
474 /* sadly atomic_sub_and_test() isn't available on all platforms. The
475 * good news is that the fast path only completes one at a time */
476 while(num--) {
477 if (atomic_dec_and_test(&wc->wc_num_reqs)) {
478 BUG_ON(num > 0);
479 complete(&wc->wc_io_complete);
480 }
481 }
482 }
483
o2hb_wait_on_io(struct o2hb_bio_wait_ctxt * wc)484 static void o2hb_wait_on_io(struct o2hb_bio_wait_ctxt *wc)
485 {
486 o2hb_bio_wait_dec(wc, 1);
487 wait_for_completion(&wc->wc_io_complete);
488 }
489
o2hb_bio_end_io(struct bio * bio)490 static void o2hb_bio_end_io(struct bio *bio)
491 {
492 struct o2hb_bio_wait_ctxt *wc = bio->bi_private;
493
494 if (bio->bi_status) {
495 mlog(ML_ERROR, "IO Error %d\n", bio->bi_status);
496 wc->wc_error = blk_status_to_errno(bio->bi_status);
497 }
498
499 o2hb_bio_wait_dec(wc, 1);
500 bio_put(bio);
501 }
502
503 /* Setup a Bio to cover I/O against num_slots slots starting at
504 * 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)505 static struct bio *o2hb_setup_one_bio(struct o2hb_region *reg,
506 struct o2hb_bio_wait_ctxt *wc,
507 unsigned int *current_slot,
508 unsigned int max_slots, int op,
509 int op_flags)
510 {
511 int len, current_page;
512 unsigned int vec_len, vec_start;
513 unsigned int bits = reg->hr_block_bits;
514 unsigned int spp = reg->hr_slots_per_page;
515 unsigned int cs = *current_slot;
516 struct bio *bio;
517 struct page *page;
518
519 /* Testing has shown this allocation to take long enough under
520 * GFP_KERNEL that the local node can get fenced. It would be
521 * nicest if we could pre-allocate these bios and avoid this
522 * all together. */
523 bio = bio_alloc(GFP_ATOMIC, 16);
524 if (!bio) {
525 mlog(ML_ERROR, "Could not alloc slots BIO!\n");
526 bio = ERR_PTR(-ENOMEM);
527 goto bail;
528 }
529
530 /* Must put everything in 512 byte sectors for the bio... */
531 bio->bi_iter.bi_sector = (reg->hr_start_block + cs) << (bits - 9);
532 bio_set_dev(bio, reg->hr_bdev);
533 bio->bi_private = wc;
534 bio->bi_end_io = o2hb_bio_end_io;
535 bio_set_op_attrs(bio, op, op_flags);
536
537 vec_start = (cs << bits) % PAGE_SIZE;
538 while(cs < max_slots) {
539 current_page = cs / spp;
540 page = reg->hr_slot_data[current_page];
541
542 vec_len = min(PAGE_SIZE - vec_start,
543 (max_slots-cs) * (PAGE_SIZE/spp) );
544
545 mlog(ML_HB_BIO, "page %d, vec_len = %u, vec_start = %u\n",
546 current_page, vec_len, vec_start);
547
548 len = bio_add_page(bio, page, vec_len, vec_start);
549 if (len != vec_len) break;
550
551 cs += vec_len / (PAGE_SIZE/spp);
552 vec_start = 0;
553 }
554
555 bail:
556 *current_slot = cs;
557 return bio;
558 }
559
o2hb_read_slots(struct o2hb_region * reg,unsigned int begin_slot,unsigned int max_slots)560 static int o2hb_read_slots(struct o2hb_region *reg,
561 unsigned int begin_slot,
562 unsigned int max_slots)
563 {
564 unsigned int current_slot = begin_slot;
565 int status;
566 struct o2hb_bio_wait_ctxt wc;
567 struct bio *bio;
568
569 o2hb_bio_wait_init(&wc);
570
571 while(current_slot < max_slots) {
572 bio = o2hb_setup_one_bio(reg, &wc, ¤t_slot, max_slots,
573 REQ_OP_READ, 0);
574 if (IS_ERR(bio)) {
575 status = PTR_ERR(bio);
576 mlog_errno(status);
577 goto bail_and_wait;
578 }
579
580 atomic_inc(&wc.wc_num_reqs);
581 submit_bio(bio);
582 }
583
584 status = 0;
585
586 bail_and_wait:
587 o2hb_wait_on_io(&wc);
588 if (wc.wc_error && !status)
589 status = wc.wc_error;
590
591 return status;
592 }
593
o2hb_issue_node_write(struct o2hb_region * reg,struct o2hb_bio_wait_ctxt * write_wc)594 static int o2hb_issue_node_write(struct o2hb_region *reg,
595 struct o2hb_bio_wait_ctxt *write_wc)
596 {
597 int status;
598 unsigned int slot;
599 struct bio *bio;
600
601 o2hb_bio_wait_init(write_wc);
602
603 slot = o2nm_this_node();
604
605 bio = o2hb_setup_one_bio(reg, write_wc, &slot, slot+1, REQ_OP_WRITE,
606 REQ_SYNC);
607 if (IS_ERR(bio)) {
608 status = PTR_ERR(bio);
609 mlog_errno(status);
610 goto bail;
611 }
612
613 atomic_inc(&write_wc->wc_num_reqs);
614 submit_bio(bio);
615
616 status = 0;
617 bail:
618 return status;
619 }
620
o2hb_compute_block_crc_le(struct o2hb_region * reg,struct o2hb_disk_heartbeat_block * hb_block)621 static u32 o2hb_compute_block_crc_le(struct o2hb_region *reg,
622 struct o2hb_disk_heartbeat_block *hb_block)
623 {
624 __le32 old_cksum;
625 u32 ret;
626
627 /* We want to compute the block crc with a 0 value in the
628 * hb_cksum field. Save it off here and replace after the
629 * crc. */
630 old_cksum = hb_block->hb_cksum;
631 hb_block->hb_cksum = 0;
632
633 ret = crc32_le(0, (unsigned char *) hb_block, reg->hr_block_bytes);
634
635 hb_block->hb_cksum = old_cksum;
636
637 return ret;
638 }
639
o2hb_dump_slot(struct o2hb_disk_heartbeat_block * hb_block)640 static void o2hb_dump_slot(struct o2hb_disk_heartbeat_block *hb_block)
641 {
642 mlog(ML_ERROR, "Dump slot information: seq = 0x%llx, node = %u, "
643 "cksum = 0x%x, generation 0x%llx\n",
644 (long long)le64_to_cpu(hb_block->hb_seq),
645 hb_block->hb_node, le32_to_cpu(hb_block->hb_cksum),
646 (long long)le64_to_cpu(hb_block->hb_generation));
647 }
648
o2hb_verify_crc(struct o2hb_region * reg,struct o2hb_disk_heartbeat_block * hb_block)649 static int o2hb_verify_crc(struct o2hb_region *reg,
650 struct o2hb_disk_heartbeat_block *hb_block)
651 {
652 u32 read, computed;
653
654 read = le32_to_cpu(hb_block->hb_cksum);
655 computed = o2hb_compute_block_crc_le(reg, hb_block);
656
657 return read == computed;
658 }
659
660 /*
661 * Compare the slot data with what we wrote in the last iteration.
662 * If the match fails, print an appropriate error message. This is to
663 * detect errors like... another node hearting on the same slot,
664 * flaky device that is losing writes, etc.
665 * Returns 1 if check succeeds, 0 otherwise.
666 */
o2hb_check_own_slot(struct o2hb_region * reg)667 static int o2hb_check_own_slot(struct o2hb_region *reg)
668 {
669 struct o2hb_disk_slot *slot;
670 struct o2hb_disk_heartbeat_block *hb_block;
671 char *errstr;
672
673 slot = ®->hr_slots[o2nm_this_node()];
674 /* Don't check on our 1st timestamp */
675 if (!slot->ds_last_time)
676 return 0;
677
678 hb_block = slot->ds_raw_block;
679 if (le64_to_cpu(hb_block->hb_seq) == slot->ds_last_time &&
680 le64_to_cpu(hb_block->hb_generation) == slot->ds_last_generation &&
681 hb_block->hb_node == slot->ds_node_num)
682 return 1;
683
684 #define ERRSTR1 "Another node is heartbeating on device"
685 #define ERRSTR2 "Heartbeat generation mismatch on device"
686 #define ERRSTR3 "Heartbeat sequence mismatch on device"
687
688 if (hb_block->hb_node != slot->ds_node_num)
689 errstr = ERRSTR1;
690 else if (le64_to_cpu(hb_block->hb_generation) !=
691 slot->ds_last_generation)
692 errstr = ERRSTR2;
693 else
694 errstr = ERRSTR3;
695
696 mlog(ML_ERROR, "%s (%s): expected(%u:0x%llx, 0x%llx), "
697 "ondisk(%u:0x%llx, 0x%llx)\n", errstr, reg->hr_dev_name,
698 slot->ds_node_num, (unsigned long long)slot->ds_last_generation,
699 (unsigned long long)slot->ds_last_time, hb_block->hb_node,
700 (unsigned long long)le64_to_cpu(hb_block->hb_generation),
701 (unsigned long long)le64_to_cpu(hb_block->hb_seq));
702
703 return 0;
704 }
705
o2hb_prepare_block(struct o2hb_region * reg,u64 generation)706 static inline void o2hb_prepare_block(struct o2hb_region *reg,
707 u64 generation)
708 {
709 int node_num;
710 u64 cputime;
711 struct o2hb_disk_slot *slot;
712 struct o2hb_disk_heartbeat_block *hb_block;
713
714 node_num = o2nm_this_node();
715 slot = ®->hr_slots[node_num];
716
717 hb_block = (struct o2hb_disk_heartbeat_block *)slot->ds_raw_block;
718 memset(hb_block, 0, reg->hr_block_bytes);
719 /* TODO: time stuff */
720 cputime = ktime_get_real_seconds();
721 if (!cputime)
722 cputime = 1;
723
724 hb_block->hb_seq = cpu_to_le64(cputime);
725 hb_block->hb_node = node_num;
726 hb_block->hb_generation = cpu_to_le64(generation);
727 hb_block->hb_dead_ms = cpu_to_le32(o2hb_dead_threshold * O2HB_REGION_TIMEOUT_MS);
728
729 /* This step must always happen last! */
730 hb_block->hb_cksum = cpu_to_le32(o2hb_compute_block_crc_le(reg,
731 hb_block));
732
733 mlog(ML_HB_BIO, "our node generation = 0x%llx, cksum = 0x%x\n",
734 (long long)generation,
735 le32_to_cpu(hb_block->hb_cksum));
736 }
737
o2hb_fire_callbacks(struct o2hb_callback * hbcall,struct o2nm_node * node,int idx)738 static void o2hb_fire_callbacks(struct o2hb_callback *hbcall,
739 struct o2nm_node *node,
740 int idx)
741 {
742 struct o2hb_callback_func *f;
743
744 list_for_each_entry(f, &hbcall->list, hc_item) {
745 mlog(ML_HEARTBEAT, "calling funcs %p\n", f);
746 (f->hc_func)(node, idx, f->hc_data);
747 }
748 }
749
750 /* Will run the list in order until we process the passed event */
o2hb_run_event_list(struct o2hb_node_event * queued_event)751 static void o2hb_run_event_list(struct o2hb_node_event *queued_event)
752 {
753 struct o2hb_callback *hbcall;
754 struct o2hb_node_event *event;
755
756 /* Holding callback sem assures we don't alter the callback
757 * lists when doing this, and serializes ourselves with other
758 * processes wanting callbacks. */
759 down_write(&o2hb_callback_sem);
760
761 spin_lock(&o2hb_live_lock);
762 while (!list_empty(&o2hb_node_events)
763 && !list_empty(&queued_event->hn_item)) {
764 event = list_entry(o2hb_node_events.next,
765 struct o2hb_node_event,
766 hn_item);
767 list_del_init(&event->hn_item);
768 spin_unlock(&o2hb_live_lock);
769
770 mlog(ML_HEARTBEAT, "Node %s event for %d\n",
771 event->hn_event_type == O2HB_NODE_UP_CB ? "UP" : "DOWN",
772 event->hn_node_num);
773
774 hbcall = hbcall_from_type(event->hn_event_type);
775
776 /* We should *never* have gotten on to the list with a
777 * bad type... This isn't something that we should try
778 * to recover from. */
779 BUG_ON(IS_ERR(hbcall));
780
781 o2hb_fire_callbacks(hbcall, event->hn_node, event->hn_node_num);
782
783 spin_lock(&o2hb_live_lock);
784 }
785 spin_unlock(&o2hb_live_lock);
786
787 up_write(&o2hb_callback_sem);
788 }
789
o2hb_queue_node_event(struct o2hb_node_event * event,enum o2hb_callback_type type,struct o2nm_node * node,int node_num)790 static void o2hb_queue_node_event(struct o2hb_node_event *event,
791 enum o2hb_callback_type type,
792 struct o2nm_node *node,
793 int node_num)
794 {
795 assert_spin_locked(&o2hb_live_lock);
796
797 BUG_ON((!node) && (type != O2HB_NODE_DOWN_CB));
798
799 event->hn_event_type = type;
800 event->hn_node = node;
801 event->hn_node_num = node_num;
802
803 mlog(ML_HEARTBEAT, "Queue node %s event for node %d\n",
804 type == O2HB_NODE_UP_CB ? "UP" : "DOWN", node_num);
805
806 list_add_tail(&event->hn_item, &o2hb_node_events);
807 }
808
o2hb_shutdown_slot(struct o2hb_disk_slot * slot)809 static void o2hb_shutdown_slot(struct o2hb_disk_slot *slot)
810 {
811 struct o2hb_node_event event =
812 { .hn_item = LIST_HEAD_INIT(event.hn_item), };
813 struct o2nm_node *node;
814 int queued = 0;
815
816 node = o2nm_get_node_by_num(slot->ds_node_num);
817 if (!node)
818 return;
819
820 spin_lock(&o2hb_live_lock);
821 if (!list_empty(&slot->ds_live_item)) {
822 mlog(ML_HEARTBEAT, "Shutdown, node %d leaves region\n",
823 slot->ds_node_num);
824
825 list_del_init(&slot->ds_live_item);
826
827 if (list_empty(&o2hb_live_slots[slot->ds_node_num])) {
828 clear_bit(slot->ds_node_num, o2hb_live_node_bitmap);
829
830 o2hb_queue_node_event(&event, O2HB_NODE_DOWN_CB, node,
831 slot->ds_node_num);
832 queued = 1;
833 }
834 }
835 spin_unlock(&o2hb_live_lock);
836
837 if (queued)
838 o2hb_run_event_list(&event);
839
840 o2nm_node_put(node);
841 }
842
o2hb_set_quorum_device(struct o2hb_region * reg)843 static void o2hb_set_quorum_device(struct o2hb_region *reg)
844 {
845 if (!o2hb_global_heartbeat_active())
846 return;
847
848 /* Prevent race with o2hb_heartbeat_group_drop_item() */
849 if (kthread_should_stop())
850 return;
851
852 /* Tag region as quorum only after thread reaches steady state */
853 if (atomic_read(®->hr_steady_iterations) != 0)
854 return;
855
856 spin_lock(&o2hb_live_lock);
857
858 if (test_bit(reg->hr_region_num, o2hb_quorum_region_bitmap))
859 goto unlock;
860
861 /*
862 * A region can be added to the quorum only when it sees all
863 * live nodes heartbeat on it. In other words, the region has been
864 * added to all nodes.
865 */
866 if (memcmp(reg->hr_live_node_bitmap, o2hb_live_node_bitmap,
867 sizeof(o2hb_live_node_bitmap)))
868 goto unlock;
869
870 printk(KERN_NOTICE "o2hb: Region %s (%s) is now a quorum device\n",
871 config_item_name(®->hr_item), reg->hr_dev_name);
872
873 set_bit(reg->hr_region_num, o2hb_quorum_region_bitmap);
874
875 /*
876 * If global heartbeat active, unpin all regions if the
877 * region count > CUT_OFF
878 */
879 if (bitmap_weight(o2hb_quorum_region_bitmap,
880 O2NM_MAX_REGIONS) > O2HB_PIN_CUT_OFF)
881 o2hb_region_unpin(NULL);
882 unlock:
883 spin_unlock(&o2hb_live_lock);
884 }
885
o2hb_check_slot(struct o2hb_region * reg,struct o2hb_disk_slot * slot)886 static int o2hb_check_slot(struct o2hb_region *reg,
887 struct o2hb_disk_slot *slot)
888 {
889 int changed = 0, gen_changed = 0;
890 struct o2hb_node_event event =
891 { .hn_item = LIST_HEAD_INIT(event.hn_item), };
892 struct o2nm_node *node;
893 struct o2hb_disk_heartbeat_block *hb_block = reg->hr_tmp_block;
894 u64 cputime;
895 unsigned int dead_ms = o2hb_dead_threshold * O2HB_REGION_TIMEOUT_MS;
896 unsigned int slot_dead_ms;
897 int tmp;
898 int queued = 0;
899
900 memcpy(hb_block, slot->ds_raw_block, reg->hr_block_bytes);
901
902 /*
903 * If a node is no longer configured but is still in the livemap, we
904 * may need to clear that bit from the livemap.
905 */
906 node = o2nm_get_node_by_num(slot->ds_node_num);
907 if (!node) {
908 spin_lock(&o2hb_live_lock);
909 tmp = test_bit(slot->ds_node_num, o2hb_live_node_bitmap);
910 spin_unlock(&o2hb_live_lock);
911 if (!tmp)
912 return 0;
913 }
914
915 if (!o2hb_verify_crc(reg, hb_block)) {
916 /* all paths from here will drop o2hb_live_lock for
917 * us. */
918 spin_lock(&o2hb_live_lock);
919
920 /* Don't print an error on the console in this case -
921 * a freshly formatted heartbeat area will not have a
922 * crc set on it. */
923 if (list_empty(&slot->ds_live_item))
924 goto out;
925
926 /* The node is live but pushed out a bad crc. We
927 * consider it a transient miss but don't populate any
928 * other values as they may be junk. */
929 mlog(ML_ERROR, "Node %d has written a bad crc to %s\n",
930 slot->ds_node_num, reg->hr_dev_name);
931 o2hb_dump_slot(hb_block);
932
933 slot->ds_equal_samples++;
934 goto fire_callbacks;
935 }
936
937 /* we don't care if these wrap.. the state transitions below
938 * clear at the right places */
939 cputime = le64_to_cpu(hb_block->hb_seq);
940 if (slot->ds_last_time != cputime)
941 slot->ds_changed_samples++;
942 else
943 slot->ds_equal_samples++;
944 slot->ds_last_time = cputime;
945
946 /* The node changed heartbeat generations. We assume this to
947 * mean it dropped off but came back before we timed out. We
948 * want to consider it down for the time being but don't want
949 * to lose any changed_samples state we might build up to
950 * considering it live again. */
951 if (slot->ds_last_generation != le64_to_cpu(hb_block->hb_generation)) {
952 gen_changed = 1;
953 slot->ds_equal_samples = 0;
954 mlog(ML_HEARTBEAT, "Node %d changed generation (0x%llx "
955 "to 0x%llx)\n", slot->ds_node_num,
956 (long long)slot->ds_last_generation,
957 (long long)le64_to_cpu(hb_block->hb_generation));
958 }
959
960 slot->ds_last_generation = le64_to_cpu(hb_block->hb_generation);
961
962 mlog(ML_HEARTBEAT, "Slot %d gen 0x%llx cksum 0x%x "
963 "seq %llu last %llu changed %u equal %u\n",
964 slot->ds_node_num, (long long)slot->ds_last_generation,
965 le32_to_cpu(hb_block->hb_cksum),
966 (unsigned long long)le64_to_cpu(hb_block->hb_seq),
967 (unsigned long long)slot->ds_last_time, slot->ds_changed_samples,
968 slot->ds_equal_samples);
969
970 spin_lock(&o2hb_live_lock);
971
972 fire_callbacks:
973 /* dead nodes only come to life after some number of
974 * changes at any time during their dead time */
975 if (list_empty(&slot->ds_live_item) &&
976 slot->ds_changed_samples >= O2HB_LIVE_THRESHOLD) {
977 mlog(ML_HEARTBEAT, "Node %d (id 0x%llx) joined my region\n",
978 slot->ds_node_num, (long long)slot->ds_last_generation);
979
980 set_bit(slot->ds_node_num, reg->hr_live_node_bitmap);
981
982 /* first on the list generates a callback */
983 if (list_empty(&o2hb_live_slots[slot->ds_node_num])) {
984 mlog(ML_HEARTBEAT, "o2hb: Add node %d to live nodes "
985 "bitmap\n", slot->ds_node_num);
986 set_bit(slot->ds_node_num, o2hb_live_node_bitmap);
987
988 o2hb_queue_node_event(&event, O2HB_NODE_UP_CB, node,
989 slot->ds_node_num);
990
991 changed = 1;
992 queued = 1;
993 }
994
995 list_add_tail(&slot->ds_live_item,
996 &o2hb_live_slots[slot->ds_node_num]);
997
998 slot->ds_equal_samples = 0;
999
1000 /* We want to be sure that all nodes agree on the
1001 * number of milliseconds before a node will be
1002 * considered dead. The self-fencing timeout is
1003 * computed from this value, and a discrepancy might
1004 * result in heartbeat calling a node dead when it
1005 * hasn't self-fenced yet. */
1006 slot_dead_ms = le32_to_cpu(hb_block->hb_dead_ms);
1007 if (slot_dead_ms && slot_dead_ms != dead_ms) {
1008 /* TODO: Perhaps we can fail the region here. */
1009 mlog(ML_ERROR, "Node %d on device %s has a dead count "
1010 "of %u ms, but our count is %u ms.\n"
1011 "Please double check your configuration values "
1012 "for 'O2CB_HEARTBEAT_THRESHOLD'\n",
1013 slot->ds_node_num, reg->hr_dev_name, slot_dead_ms,
1014 dead_ms);
1015 }
1016 goto out;
1017 }
1018
1019 /* if the list is dead, we're done.. */
1020 if (list_empty(&slot->ds_live_item))
1021 goto out;
1022
1023 /* live nodes only go dead after enough consequtive missed
1024 * samples.. reset the missed counter whenever we see
1025 * activity */
1026 if (slot->ds_equal_samples >= o2hb_dead_threshold || gen_changed) {
1027 mlog(ML_HEARTBEAT, "Node %d left my region\n",
1028 slot->ds_node_num);
1029
1030 clear_bit(slot->ds_node_num, reg->hr_live_node_bitmap);
1031
1032 /* last off the live_slot generates a callback */
1033 list_del_init(&slot->ds_live_item);
1034 if (list_empty(&o2hb_live_slots[slot->ds_node_num])) {
1035 mlog(ML_HEARTBEAT, "o2hb: Remove node %d from live "
1036 "nodes bitmap\n", slot->ds_node_num);
1037 clear_bit(slot->ds_node_num, o2hb_live_node_bitmap);
1038
1039 /* node can be null */
1040 o2hb_queue_node_event(&event, O2HB_NODE_DOWN_CB,
1041 node, slot->ds_node_num);
1042
1043 changed = 1;
1044 queued = 1;
1045 }
1046
1047 /* We don't clear this because the node is still
1048 * actually writing new blocks. */
1049 if (!gen_changed)
1050 slot->ds_changed_samples = 0;
1051 goto out;
1052 }
1053 if (slot->ds_changed_samples) {
1054 slot->ds_changed_samples = 0;
1055 slot->ds_equal_samples = 0;
1056 }
1057 out:
1058 spin_unlock(&o2hb_live_lock);
1059
1060 if (queued)
1061 o2hb_run_event_list(&event);
1062
1063 if (node)
1064 o2nm_node_put(node);
1065 return changed;
1066 }
1067
o2hb_highest_node(unsigned long * nodes,int numbits)1068 static int o2hb_highest_node(unsigned long *nodes, int numbits)
1069 {
1070 return find_last_bit(nodes, numbits);
1071 }
1072
o2hb_lowest_node(unsigned long * nodes,int numbits)1073 static int o2hb_lowest_node(unsigned long *nodes, int numbits)
1074 {
1075 return find_first_bit(nodes, numbits);
1076 }
1077
o2hb_do_disk_heartbeat(struct o2hb_region * reg)1078 static int o2hb_do_disk_heartbeat(struct o2hb_region *reg)
1079 {
1080 int i, ret, highest_node, lowest_node;
1081 int membership_change = 0, own_slot_ok = 0;
1082 unsigned long configured_nodes[BITS_TO_LONGS(O2NM_MAX_NODES)];
1083 unsigned long live_node_bitmap[BITS_TO_LONGS(O2NM_MAX_NODES)];
1084 struct o2hb_bio_wait_ctxt write_wc;
1085
1086 ret = o2nm_configured_node_map(configured_nodes,
1087 sizeof(configured_nodes));
1088 if (ret) {
1089 mlog_errno(ret);
1090 goto bail;
1091 }
1092
1093 /*
1094 * If a node is not configured but is in the livemap, we still need
1095 * to read the slot so as to be able to remove it from the livemap.
1096 */
1097 o2hb_fill_node_map(live_node_bitmap, sizeof(live_node_bitmap));
1098 i = -1;
1099 while ((i = find_next_bit(live_node_bitmap,
1100 O2NM_MAX_NODES, i + 1)) < O2NM_MAX_NODES) {
1101 set_bit(i, configured_nodes);
1102 }
1103
1104 highest_node = o2hb_highest_node(configured_nodes, O2NM_MAX_NODES);
1105 lowest_node = o2hb_lowest_node(configured_nodes, O2NM_MAX_NODES);
1106 if (highest_node >= O2NM_MAX_NODES || lowest_node >= O2NM_MAX_NODES) {
1107 mlog(ML_NOTICE, "o2hb: No configured nodes found!\n");
1108 ret = -EINVAL;
1109 goto bail;
1110 }
1111
1112 /* No sense in reading the slots of nodes that don't exist
1113 * yet. Of course, if the node definitions have holes in them
1114 * then we're reading an empty slot anyway... Consider this
1115 * best-effort. */
1116 ret = o2hb_read_slots(reg, lowest_node, highest_node + 1);
1117 if (ret < 0) {
1118 mlog_errno(ret);
1119 goto bail;
1120 }
1121
1122 /* With an up to date view of the slots, we can check that no
1123 * other node has been improperly configured to heartbeat in
1124 * our slot. */
1125 own_slot_ok = o2hb_check_own_slot(reg);
1126
1127 /* fill in the proper info for our next heartbeat */
1128 o2hb_prepare_block(reg, reg->hr_generation);
1129
1130 ret = o2hb_issue_node_write(reg, &write_wc);
1131 if (ret < 0) {
1132 mlog_errno(ret);
1133 goto bail;
1134 }
1135
1136 i = -1;
1137 while((i = find_next_bit(configured_nodes,
1138 O2NM_MAX_NODES, i + 1)) < O2NM_MAX_NODES) {
1139 membership_change |= o2hb_check_slot(reg, ®->hr_slots[i]);
1140 }
1141
1142 /*
1143 * We have to be sure we've advertised ourselves on disk
1144 * before we can go to steady state. This ensures that
1145 * people we find in our steady state have seen us.
1146 */
1147 o2hb_wait_on_io(&write_wc);
1148 if (write_wc.wc_error) {
1149 /* Do not re-arm the write timeout on I/O error - we
1150 * can't be sure that the new block ever made it to
1151 * disk */
1152 mlog(ML_ERROR, "Write error %d on device \"%s\"\n",
1153 write_wc.wc_error, reg->hr_dev_name);
1154 ret = write_wc.wc_error;
1155 goto bail;
1156 }
1157
1158 /* Skip disarming the timeout if own slot has stale/bad data */
1159 if (own_slot_ok) {
1160 o2hb_set_quorum_device(reg);
1161 o2hb_arm_timeout(reg);
1162 reg->hr_last_timeout_start = jiffies;
1163 }
1164
1165 bail:
1166 /* let the person who launched us know when things are steady */
1167 if (atomic_read(®->hr_steady_iterations) != 0) {
1168 if (!ret && own_slot_ok && !membership_change) {
1169 if (atomic_dec_and_test(®->hr_steady_iterations))
1170 wake_up(&o2hb_steady_queue);
1171 }
1172 }
1173
1174 if (atomic_read(®->hr_steady_iterations) != 0) {
1175 if (atomic_dec_and_test(®->hr_unsteady_iterations)) {
1176 printk(KERN_NOTICE "o2hb: Unable to stabilize "
1177 "heartbeat on region %s (%s)\n",
1178 config_item_name(®->hr_item),
1179 reg->hr_dev_name);
1180 atomic_set(®->hr_steady_iterations, 0);
1181 reg->hr_aborted_start = 1;
1182 wake_up(&o2hb_steady_queue);
1183 ret = -EIO;
1184 }
1185 }
1186
1187 return ret;
1188 }
1189
1190 /*
1191 * we ride the region ref that the region dir holds. before the region
1192 * dir is removed and drops it ref it will wait to tear down this
1193 * thread.
1194 */
o2hb_thread(void * data)1195 static int o2hb_thread(void *data)
1196 {
1197 int i, ret;
1198 struct o2hb_region *reg = data;
1199 struct o2hb_bio_wait_ctxt write_wc;
1200 ktime_t before_hb, after_hb;
1201 unsigned int elapsed_msec;
1202
1203 mlog(ML_HEARTBEAT|ML_KTHREAD, "hb thread running\n");
1204
1205 set_user_nice(current, MIN_NICE);
1206
1207 /* Pin node */
1208 ret = o2nm_depend_this_node();
1209 if (ret) {
1210 mlog(ML_ERROR, "Node has been deleted, ret = %d\n", ret);
1211 reg->hr_node_deleted = 1;
1212 wake_up(&o2hb_steady_queue);
1213 return 0;
1214 }
1215
1216 while (!kthread_should_stop() &&
1217 !reg->hr_unclean_stop && !reg->hr_aborted_start) {
1218 /* We track the time spent inside
1219 * o2hb_do_disk_heartbeat so that we avoid more than
1220 * hr_timeout_ms between disk writes. On busy systems
1221 * this should result in a heartbeat which is less
1222 * likely to time itself out. */
1223 before_hb = ktime_get_real();
1224
1225 ret = o2hb_do_disk_heartbeat(reg);
1226 reg->hr_last_hb_status = ret;
1227
1228 after_hb = ktime_get_real();
1229
1230 elapsed_msec = (unsigned int)
1231 ktime_ms_delta(after_hb, before_hb);
1232
1233 mlog(ML_HEARTBEAT,
1234 "start = %lld, end = %lld, msec = %u, ret = %d\n",
1235 before_hb, after_hb, elapsed_msec, ret);
1236
1237 if (!kthread_should_stop() &&
1238 elapsed_msec < reg->hr_timeout_ms) {
1239 /* the kthread api has blocked signals for us so no
1240 * need to record the return value. */
1241 msleep_interruptible(reg->hr_timeout_ms - elapsed_msec);
1242 }
1243 }
1244
1245 o2hb_disarm_timeout(reg);
1246
1247 /* unclean stop is only used in very bad situation */
1248 for(i = 0; !reg->hr_unclean_stop && i < reg->hr_blocks; i++)
1249 o2hb_shutdown_slot(®->hr_slots[i]);
1250
1251 /* Explicit down notification - avoid forcing the other nodes
1252 * to timeout on this region when we could just as easily
1253 * write a clear generation - thus indicating to them that
1254 * this node has left this region.
1255 */
1256 if (!reg->hr_unclean_stop && !reg->hr_aborted_start) {
1257 o2hb_prepare_block(reg, 0);
1258 ret = o2hb_issue_node_write(reg, &write_wc);
1259 if (ret == 0)
1260 o2hb_wait_on_io(&write_wc);
1261 else
1262 mlog_errno(ret);
1263 }
1264
1265 /* Unpin node */
1266 o2nm_undepend_this_node();
1267
1268 mlog(ML_HEARTBEAT|ML_KTHREAD, "o2hb thread exiting\n");
1269
1270 return 0;
1271 }
1272
1273 #ifdef CONFIG_DEBUG_FS
o2hb_debug_open(struct inode * inode,struct file * file)1274 static int o2hb_debug_open(struct inode *inode, struct file *file)
1275 {
1276 struct o2hb_debug_buf *db = inode->i_private;
1277 struct o2hb_region *reg;
1278 unsigned long map[BITS_TO_LONGS(O2NM_MAX_NODES)];
1279 unsigned long lts;
1280 char *buf = NULL;
1281 int i = -1;
1282 int out = 0;
1283
1284 /* max_nodes should be the largest bitmap we pass here */
1285 BUG_ON(sizeof(map) < db->db_size);
1286
1287 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
1288 if (!buf)
1289 goto bail;
1290
1291 switch (db->db_type) {
1292 case O2HB_DB_TYPE_LIVENODES:
1293 case O2HB_DB_TYPE_LIVEREGIONS:
1294 case O2HB_DB_TYPE_QUORUMREGIONS:
1295 case O2HB_DB_TYPE_FAILEDREGIONS:
1296 spin_lock(&o2hb_live_lock);
1297 memcpy(map, db->db_data, db->db_size);
1298 spin_unlock(&o2hb_live_lock);
1299 break;
1300
1301 case O2HB_DB_TYPE_REGION_LIVENODES:
1302 spin_lock(&o2hb_live_lock);
1303 reg = (struct o2hb_region *)db->db_data;
1304 memcpy(map, reg->hr_live_node_bitmap, db->db_size);
1305 spin_unlock(&o2hb_live_lock);
1306 break;
1307
1308 case O2HB_DB_TYPE_REGION_NUMBER:
1309 reg = (struct o2hb_region *)db->db_data;
1310 out += scnprintf(buf + out, PAGE_SIZE - out, "%d\n",
1311 reg->hr_region_num);
1312 goto done;
1313
1314 case O2HB_DB_TYPE_REGION_ELAPSED_TIME:
1315 reg = (struct o2hb_region *)db->db_data;
1316 lts = reg->hr_last_timeout_start;
1317 /* If 0, it has never been set before */
1318 if (lts)
1319 lts = jiffies_to_msecs(jiffies - lts);
1320 out += scnprintf(buf + out, PAGE_SIZE - out, "%lu\n", lts);
1321 goto done;
1322
1323 case O2HB_DB_TYPE_REGION_PINNED:
1324 reg = (struct o2hb_region *)db->db_data;
1325 out += scnprintf(buf + out, PAGE_SIZE - out, "%u\n",
1326 !!reg->hr_item_pinned);
1327 goto done;
1328
1329 default:
1330 goto done;
1331 }
1332
1333 while ((i = find_next_bit(map, db->db_len, i + 1)) < db->db_len)
1334 out += scnprintf(buf + out, PAGE_SIZE - out, "%d ", i);
1335 out += scnprintf(buf + out, PAGE_SIZE - out, "\n");
1336
1337 done:
1338 i_size_write(inode, out);
1339
1340 file->private_data = buf;
1341
1342 return 0;
1343 bail:
1344 return -ENOMEM;
1345 }
1346
o2hb_debug_release(struct inode * inode,struct file * file)1347 static int o2hb_debug_release(struct inode *inode, struct file *file)
1348 {
1349 kfree(file->private_data);
1350 return 0;
1351 }
1352
o2hb_debug_read(struct file * file,char __user * buf,size_t nbytes,loff_t * ppos)1353 static ssize_t o2hb_debug_read(struct file *file, char __user *buf,
1354 size_t nbytes, loff_t *ppos)
1355 {
1356 return simple_read_from_buffer(buf, nbytes, ppos, file->private_data,
1357 i_size_read(file->f_mapping->host));
1358 }
1359 #else
o2hb_debug_open(struct inode * inode,struct file * file)1360 static int o2hb_debug_open(struct inode *inode, struct file *file)
1361 {
1362 return 0;
1363 }
o2hb_debug_release(struct inode * inode,struct file * file)1364 static int o2hb_debug_release(struct inode *inode, struct file *file)
1365 {
1366 return 0;
1367 }
o2hb_debug_read(struct file * file,char __user * buf,size_t nbytes,loff_t * ppos)1368 static ssize_t o2hb_debug_read(struct file *file, char __user *buf,
1369 size_t nbytes, loff_t *ppos)
1370 {
1371 return 0;
1372 }
1373 #endif /* CONFIG_DEBUG_FS */
1374
1375 static const struct file_operations o2hb_debug_fops = {
1376 .open = o2hb_debug_open,
1377 .release = o2hb_debug_release,
1378 .read = o2hb_debug_read,
1379 .llseek = generic_file_llseek,
1380 };
1381
o2hb_exit(void)1382 void o2hb_exit(void)
1383 {
1384 debugfs_remove_recursive(o2hb_debug_dir);
1385 kfree(o2hb_db_livenodes);
1386 kfree(o2hb_db_liveregions);
1387 kfree(o2hb_db_quorumregions);
1388 kfree(o2hb_db_failedregions);
1389 }
1390
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)1391 static void o2hb_debug_create(const char *name, struct dentry *dir,
1392 struct o2hb_debug_buf **db, int db_len, int type,
1393 int size, int len, void *data)
1394 {
1395 *db = kmalloc(db_len, GFP_KERNEL);
1396 if (!*db)
1397 return;
1398
1399 (*db)->db_type = type;
1400 (*db)->db_size = size;
1401 (*db)->db_len = len;
1402 (*db)->db_data = data;
1403
1404 debugfs_create_file(name, S_IFREG|S_IRUSR, dir, *db, &o2hb_debug_fops);
1405 }
1406
o2hb_debug_init(void)1407 static void o2hb_debug_init(void)
1408 {
1409 o2hb_debug_dir = debugfs_create_dir(O2HB_DEBUG_DIR, NULL);
1410
1411 o2hb_debug_create(O2HB_DEBUG_LIVENODES, o2hb_debug_dir,
1412 &o2hb_db_livenodes, sizeof(*o2hb_db_livenodes),
1413 O2HB_DB_TYPE_LIVENODES, sizeof(o2hb_live_node_bitmap),
1414 O2NM_MAX_NODES, o2hb_live_node_bitmap);
1415
1416 o2hb_debug_create(O2HB_DEBUG_LIVEREGIONS, o2hb_debug_dir,
1417 &o2hb_db_liveregions, sizeof(*o2hb_db_liveregions),
1418 O2HB_DB_TYPE_LIVEREGIONS,
1419 sizeof(o2hb_live_region_bitmap), O2NM_MAX_REGIONS,
1420 o2hb_live_region_bitmap);
1421
1422 o2hb_debug_create(O2HB_DEBUG_QUORUMREGIONS, o2hb_debug_dir,
1423 &o2hb_db_quorumregions,
1424 sizeof(*o2hb_db_quorumregions),
1425 O2HB_DB_TYPE_QUORUMREGIONS,
1426 sizeof(o2hb_quorum_region_bitmap), O2NM_MAX_REGIONS,
1427 o2hb_quorum_region_bitmap);
1428
1429 o2hb_debug_create(O2HB_DEBUG_FAILEDREGIONS, o2hb_debug_dir,
1430 &o2hb_db_failedregions,
1431 sizeof(*o2hb_db_failedregions),
1432 O2HB_DB_TYPE_FAILEDREGIONS,
1433 sizeof(o2hb_failed_region_bitmap), O2NM_MAX_REGIONS,
1434 o2hb_failed_region_bitmap);
1435 }
1436
o2hb_init(void)1437 void o2hb_init(void)
1438 {
1439 int i;
1440
1441 for (i = 0; i < ARRAY_SIZE(o2hb_callbacks); i++)
1442 INIT_LIST_HEAD(&o2hb_callbacks[i].list);
1443
1444 for (i = 0; i < ARRAY_SIZE(o2hb_live_slots); i++)
1445 INIT_LIST_HEAD(&o2hb_live_slots[i]);
1446
1447 INIT_LIST_HEAD(&o2hb_node_events);
1448
1449 memset(o2hb_live_node_bitmap, 0, sizeof(o2hb_live_node_bitmap));
1450 memset(o2hb_region_bitmap, 0, sizeof(o2hb_region_bitmap));
1451 memset(o2hb_live_region_bitmap, 0, sizeof(o2hb_live_region_bitmap));
1452 memset(o2hb_quorum_region_bitmap, 0, sizeof(o2hb_quorum_region_bitmap));
1453 memset(o2hb_failed_region_bitmap, 0, sizeof(o2hb_failed_region_bitmap));
1454
1455 o2hb_dependent_users = 0;
1456
1457 o2hb_debug_init();
1458 }
1459
1460 /* 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)1461 static void o2hb_fill_node_map_from_callback(unsigned long *map,
1462 unsigned bytes)
1463 {
1464 BUG_ON(bytes < (BITS_TO_LONGS(O2NM_MAX_NODES) * sizeof(unsigned long)));
1465
1466 memcpy(map, &o2hb_live_node_bitmap, bytes);
1467 }
1468
1469 /*
1470 * get a map of all nodes that are heartbeating in any regions
1471 */
o2hb_fill_node_map(unsigned long * map,unsigned bytes)1472 void o2hb_fill_node_map(unsigned long *map, unsigned bytes)
1473 {
1474 /* callers want to serialize this map and callbacks so that they
1475 * can trust that they don't miss nodes coming to the party */
1476 down_read(&o2hb_callback_sem);
1477 spin_lock(&o2hb_live_lock);
1478 o2hb_fill_node_map_from_callback(map, bytes);
1479 spin_unlock(&o2hb_live_lock);
1480 up_read(&o2hb_callback_sem);
1481 }
1482 EXPORT_SYMBOL_GPL(o2hb_fill_node_map);
1483
1484 /*
1485 * heartbeat configfs bits. The heartbeat set is a default set under
1486 * the cluster set in nodemanager.c.
1487 */
1488
to_o2hb_region(struct config_item * item)1489 static struct o2hb_region *to_o2hb_region(struct config_item *item)
1490 {
1491 return item ? container_of(item, struct o2hb_region, hr_item) : NULL;
1492 }
1493
1494 /* drop_item only drops its ref after killing the thread, nothing should
1495 * be using the region anymore. this has to clean up any state that
1496 * attributes might have built up. */
o2hb_region_release(struct config_item * item)1497 static void o2hb_region_release(struct config_item *item)
1498 {
1499 int i;
1500 struct page *page;
1501 struct o2hb_region *reg = to_o2hb_region(item);
1502
1503 mlog(ML_HEARTBEAT, "hb region release (%s)\n", reg->hr_dev_name);
1504
1505 kfree(reg->hr_tmp_block);
1506
1507 if (reg->hr_slot_data) {
1508 for (i = 0; i < reg->hr_num_pages; i++) {
1509 page = reg->hr_slot_data[i];
1510 if (page)
1511 __free_page(page);
1512 }
1513 kfree(reg->hr_slot_data);
1514 }
1515
1516 if (reg->hr_bdev)
1517 blkdev_put(reg->hr_bdev, FMODE_READ|FMODE_WRITE);
1518
1519 kfree(reg->hr_slots);
1520
1521 debugfs_remove_recursive(reg->hr_debug_dir);
1522 kfree(reg->hr_db_livenodes);
1523 kfree(reg->hr_db_regnum);
1524 kfree(reg->hr_db_elapsed_time);
1525 kfree(reg->hr_db_pinned);
1526
1527 spin_lock(&o2hb_live_lock);
1528 list_del(®->hr_all_item);
1529 spin_unlock(&o2hb_live_lock);
1530
1531 o2net_unregister_handler_list(®->hr_handler_list);
1532 kfree(reg);
1533 }
1534
o2hb_read_block_input(struct o2hb_region * reg,const char * page,unsigned long * ret_bytes,unsigned int * ret_bits)1535 static int o2hb_read_block_input(struct o2hb_region *reg,
1536 const char *page,
1537 unsigned long *ret_bytes,
1538 unsigned int *ret_bits)
1539 {
1540 unsigned long bytes;
1541 char *p = (char *)page;
1542
1543 bytes = simple_strtoul(p, &p, 0);
1544 if (!p || (*p && (*p != '\n')))
1545 return -EINVAL;
1546
1547 /* Heartbeat and fs min / max block sizes are the same. */
1548 if (bytes > 4096 || bytes < 512)
1549 return -ERANGE;
1550 if (hweight16(bytes) != 1)
1551 return -EINVAL;
1552
1553 if (ret_bytes)
1554 *ret_bytes = bytes;
1555 if (ret_bits)
1556 *ret_bits = ffs(bytes) - 1;
1557
1558 return 0;
1559 }
1560
o2hb_region_block_bytes_show(struct config_item * item,char * page)1561 static ssize_t o2hb_region_block_bytes_show(struct config_item *item,
1562 char *page)
1563 {
1564 return sprintf(page, "%u\n", to_o2hb_region(item)->hr_block_bytes);
1565 }
1566
o2hb_region_block_bytes_store(struct config_item * item,const char * page,size_t count)1567 static ssize_t o2hb_region_block_bytes_store(struct config_item *item,
1568 const char *page,
1569 size_t count)
1570 {
1571 struct o2hb_region *reg = to_o2hb_region(item);
1572 int status;
1573 unsigned long block_bytes;
1574 unsigned int block_bits;
1575
1576 if (reg->hr_bdev)
1577 return -EINVAL;
1578
1579 status = o2hb_read_block_input(reg, page, &block_bytes,
1580 &block_bits);
1581 if (status)
1582 return status;
1583
1584 reg->hr_block_bytes = (unsigned int)block_bytes;
1585 reg->hr_block_bits = block_bits;
1586
1587 return count;
1588 }
1589
o2hb_region_start_block_show(struct config_item * item,char * page)1590 static ssize_t o2hb_region_start_block_show(struct config_item *item,
1591 char *page)
1592 {
1593 return sprintf(page, "%llu\n", to_o2hb_region(item)->hr_start_block);
1594 }
1595
o2hb_region_start_block_store(struct config_item * item,const char * page,size_t count)1596 static ssize_t o2hb_region_start_block_store(struct config_item *item,
1597 const char *page,
1598 size_t count)
1599 {
1600 struct o2hb_region *reg = to_o2hb_region(item);
1601 unsigned long long tmp;
1602 char *p = (char *)page;
1603
1604 if (reg->hr_bdev)
1605 return -EINVAL;
1606
1607 tmp = simple_strtoull(p, &p, 0);
1608 if (!p || (*p && (*p != '\n')))
1609 return -EINVAL;
1610
1611 reg->hr_start_block = tmp;
1612
1613 return count;
1614 }
1615
o2hb_region_blocks_show(struct config_item * item,char * page)1616 static ssize_t o2hb_region_blocks_show(struct config_item *item, char *page)
1617 {
1618 return sprintf(page, "%d\n", to_o2hb_region(item)->hr_blocks);
1619 }
1620
o2hb_region_blocks_store(struct config_item * item,const char * page,size_t count)1621 static ssize_t o2hb_region_blocks_store(struct config_item *item,
1622 const char *page,
1623 size_t count)
1624 {
1625 struct o2hb_region *reg = to_o2hb_region(item);
1626 unsigned long tmp;
1627 char *p = (char *)page;
1628
1629 if (reg->hr_bdev)
1630 return -EINVAL;
1631
1632 tmp = simple_strtoul(p, &p, 0);
1633 if (!p || (*p && (*p != '\n')))
1634 return -EINVAL;
1635
1636 if (tmp > O2NM_MAX_NODES || tmp == 0)
1637 return -ERANGE;
1638
1639 reg->hr_blocks = (unsigned int)tmp;
1640
1641 return count;
1642 }
1643
o2hb_region_dev_show(struct config_item * item,char * page)1644 static ssize_t o2hb_region_dev_show(struct config_item *item, char *page)
1645 {
1646 unsigned int ret = 0;
1647
1648 if (to_o2hb_region(item)->hr_bdev)
1649 ret = sprintf(page, "%s\n", to_o2hb_region(item)->hr_dev_name);
1650
1651 return ret;
1652 }
1653
o2hb_init_region_params(struct o2hb_region * reg)1654 static void o2hb_init_region_params(struct o2hb_region *reg)
1655 {
1656 reg->hr_slots_per_page = PAGE_SIZE >> reg->hr_block_bits;
1657 reg->hr_timeout_ms = O2HB_REGION_TIMEOUT_MS;
1658
1659 mlog(ML_HEARTBEAT, "hr_start_block = %llu, hr_blocks = %u\n",
1660 reg->hr_start_block, reg->hr_blocks);
1661 mlog(ML_HEARTBEAT, "hr_block_bytes = %u, hr_block_bits = %u\n",
1662 reg->hr_block_bytes, reg->hr_block_bits);
1663 mlog(ML_HEARTBEAT, "hr_timeout_ms = %u\n", reg->hr_timeout_ms);
1664 mlog(ML_HEARTBEAT, "dead threshold = %u\n", o2hb_dead_threshold);
1665 }
1666
o2hb_map_slot_data(struct o2hb_region * reg)1667 static int o2hb_map_slot_data(struct o2hb_region *reg)
1668 {
1669 int i, j;
1670 unsigned int last_slot;
1671 unsigned int spp = reg->hr_slots_per_page;
1672 struct page *page;
1673 char *raw;
1674 struct o2hb_disk_slot *slot;
1675
1676 reg->hr_tmp_block = kmalloc(reg->hr_block_bytes, GFP_KERNEL);
1677 if (reg->hr_tmp_block == NULL)
1678 return -ENOMEM;
1679
1680 reg->hr_slots = kcalloc(reg->hr_blocks,
1681 sizeof(struct o2hb_disk_slot), GFP_KERNEL);
1682 if (reg->hr_slots == NULL)
1683 return -ENOMEM;
1684
1685 for(i = 0; i < reg->hr_blocks; i++) {
1686 slot = ®->hr_slots[i];
1687 slot->ds_node_num = i;
1688 INIT_LIST_HEAD(&slot->ds_live_item);
1689 slot->ds_raw_block = NULL;
1690 }
1691
1692 reg->hr_num_pages = (reg->hr_blocks + spp - 1) / spp;
1693 mlog(ML_HEARTBEAT, "Going to require %u pages to cover %u blocks "
1694 "at %u blocks per page\n",
1695 reg->hr_num_pages, reg->hr_blocks, spp);
1696
1697 reg->hr_slot_data = kcalloc(reg->hr_num_pages, sizeof(struct page *),
1698 GFP_KERNEL);
1699 if (!reg->hr_slot_data)
1700 return -ENOMEM;
1701
1702 for(i = 0; i < reg->hr_num_pages; i++) {
1703 page = alloc_page(GFP_KERNEL);
1704 if (!page)
1705 return -ENOMEM;
1706
1707 reg->hr_slot_data[i] = page;
1708
1709 last_slot = i * spp;
1710 raw = page_address(page);
1711 for (j = 0;
1712 (j < spp) && ((j + last_slot) < reg->hr_blocks);
1713 j++) {
1714 BUG_ON((j + last_slot) >= reg->hr_blocks);
1715
1716 slot = ®->hr_slots[j + last_slot];
1717 slot->ds_raw_block =
1718 (struct o2hb_disk_heartbeat_block *) raw;
1719
1720 raw += reg->hr_block_bytes;
1721 }
1722 }
1723
1724 return 0;
1725 }
1726
1727 /* Read in all the slots available and populate the tracking
1728 * structures so that we can start with a baseline idea of what's
1729 * there. */
o2hb_populate_slot_data(struct o2hb_region * reg)1730 static int o2hb_populate_slot_data(struct o2hb_region *reg)
1731 {
1732 int ret, i;
1733 struct o2hb_disk_slot *slot;
1734 struct o2hb_disk_heartbeat_block *hb_block;
1735
1736 ret = o2hb_read_slots(reg, 0, reg->hr_blocks);
1737 if (ret)
1738 goto out;
1739
1740 /* We only want to get an idea of the values initially in each
1741 * slot, so we do no verification - o2hb_check_slot will
1742 * actually determine if each configured slot is valid and
1743 * whether any values have changed. */
1744 for(i = 0; i < reg->hr_blocks; i++) {
1745 slot = ®->hr_slots[i];
1746 hb_block = (struct o2hb_disk_heartbeat_block *) slot->ds_raw_block;
1747
1748 /* Only fill the values that o2hb_check_slot uses to
1749 * determine changing slots */
1750 slot->ds_last_time = le64_to_cpu(hb_block->hb_seq);
1751 slot->ds_last_generation = le64_to_cpu(hb_block->hb_generation);
1752 }
1753
1754 out:
1755 return ret;
1756 }
1757
1758 /* 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)1759 static ssize_t o2hb_region_dev_store(struct config_item *item,
1760 const char *page,
1761 size_t count)
1762 {
1763 struct o2hb_region *reg = to_o2hb_region(item);
1764 struct task_struct *hb_task;
1765 long fd;
1766 int sectsize;
1767 char *p = (char *)page;
1768 struct fd f;
1769 ssize_t ret = -EINVAL;
1770 int live_threshold;
1771
1772 if (reg->hr_bdev)
1773 goto out;
1774
1775 /* We can't heartbeat without having had our node number
1776 * configured yet. */
1777 if (o2nm_this_node() == O2NM_MAX_NODES)
1778 goto out;
1779
1780 fd = simple_strtol(p, &p, 0);
1781 if (!p || (*p && (*p != '\n')))
1782 goto out;
1783
1784 if (fd < 0 || fd >= INT_MAX)
1785 goto out;
1786
1787 f = fdget(fd);
1788 if (f.file == NULL)
1789 goto out;
1790
1791 if (reg->hr_blocks == 0 || reg->hr_start_block == 0 ||
1792 reg->hr_block_bytes == 0)
1793 goto out2;
1794
1795 if (!S_ISBLK(f.file->f_mapping->host->i_mode))
1796 goto out2;
1797
1798 reg->hr_bdev = blkdev_get_by_dev(f.file->f_mapping->host->i_rdev,
1799 FMODE_WRITE | FMODE_READ, NULL);
1800 if (IS_ERR(reg->hr_bdev)) {
1801 ret = PTR_ERR(reg->hr_bdev);
1802 reg->hr_bdev = NULL;
1803 goto out2;
1804 }
1805
1806 bdevname(reg->hr_bdev, reg->hr_dev_name);
1807
1808 sectsize = bdev_logical_block_size(reg->hr_bdev);
1809 if (sectsize != reg->hr_block_bytes) {
1810 mlog(ML_ERROR,
1811 "blocksize %u incorrect for device, expected %d",
1812 reg->hr_block_bytes, sectsize);
1813 ret = -EINVAL;
1814 goto out3;
1815 }
1816
1817 o2hb_init_region_params(reg);
1818
1819 /* Generation of zero is invalid */
1820 do {
1821 get_random_bytes(®->hr_generation,
1822 sizeof(reg->hr_generation));
1823 } while (reg->hr_generation == 0);
1824
1825 ret = o2hb_map_slot_data(reg);
1826 if (ret) {
1827 mlog_errno(ret);
1828 goto out3;
1829 }
1830
1831 ret = o2hb_populate_slot_data(reg);
1832 if (ret) {
1833 mlog_errno(ret);
1834 goto out3;
1835 }
1836
1837 INIT_DELAYED_WORK(®->hr_write_timeout_work, o2hb_write_timeout);
1838 INIT_DELAYED_WORK(®->hr_nego_timeout_work, o2hb_nego_timeout);
1839
1840 /*
1841 * A node is considered live after it has beat LIVE_THRESHOLD
1842 * times. We're not steady until we've given them a chance
1843 * _after_ our first read.
1844 * The default threshold is bare minimum so as to limit the delay
1845 * during mounts. For global heartbeat, the threshold doubled for the
1846 * first region.
1847 */
1848 live_threshold = O2HB_LIVE_THRESHOLD;
1849 if (o2hb_global_heartbeat_active()) {
1850 spin_lock(&o2hb_live_lock);
1851 if (bitmap_weight(o2hb_region_bitmap, O2NM_MAX_REGIONS) == 1)
1852 live_threshold <<= 1;
1853 spin_unlock(&o2hb_live_lock);
1854 }
1855 ++live_threshold;
1856 atomic_set(®->hr_steady_iterations, live_threshold);
1857 /* unsteady_iterations is triple the steady_iterations */
1858 atomic_set(®->hr_unsteady_iterations, (live_threshold * 3));
1859
1860 hb_task = kthread_run(o2hb_thread, reg, "o2hb-%s",
1861 reg->hr_item.ci_name);
1862 if (IS_ERR(hb_task)) {
1863 ret = PTR_ERR(hb_task);
1864 mlog_errno(ret);
1865 goto out3;
1866 }
1867
1868 spin_lock(&o2hb_live_lock);
1869 reg->hr_task = hb_task;
1870 spin_unlock(&o2hb_live_lock);
1871
1872 ret = wait_event_interruptible(o2hb_steady_queue,
1873 atomic_read(®->hr_steady_iterations) == 0 ||
1874 reg->hr_node_deleted);
1875 if (ret) {
1876 atomic_set(®->hr_steady_iterations, 0);
1877 reg->hr_aborted_start = 1;
1878 }
1879
1880 if (reg->hr_aborted_start) {
1881 ret = -EIO;
1882 goto out3;
1883 }
1884
1885 if (reg->hr_node_deleted) {
1886 ret = -EINVAL;
1887 goto out3;
1888 }
1889
1890 /* Ok, we were woken. Make sure it wasn't by drop_item() */
1891 spin_lock(&o2hb_live_lock);
1892 hb_task = reg->hr_task;
1893 if (o2hb_global_heartbeat_active())
1894 set_bit(reg->hr_region_num, o2hb_live_region_bitmap);
1895 spin_unlock(&o2hb_live_lock);
1896
1897 if (hb_task)
1898 ret = count;
1899 else
1900 ret = -EIO;
1901
1902 if (hb_task && o2hb_global_heartbeat_active())
1903 printk(KERN_NOTICE "o2hb: Heartbeat started on region %s (%s)\n",
1904 config_item_name(®->hr_item), reg->hr_dev_name);
1905
1906 out3:
1907 if (ret < 0) {
1908 blkdev_put(reg->hr_bdev, FMODE_READ | FMODE_WRITE);
1909 reg->hr_bdev = NULL;
1910 }
1911 out2:
1912 fdput(f);
1913 out:
1914 return ret;
1915 }
1916
o2hb_region_pid_show(struct config_item * item,char * page)1917 static ssize_t o2hb_region_pid_show(struct config_item *item, char *page)
1918 {
1919 struct o2hb_region *reg = to_o2hb_region(item);
1920 pid_t pid = 0;
1921
1922 spin_lock(&o2hb_live_lock);
1923 if (reg->hr_task)
1924 pid = task_pid_nr(reg->hr_task);
1925 spin_unlock(&o2hb_live_lock);
1926
1927 if (!pid)
1928 return 0;
1929
1930 return sprintf(page, "%u\n", pid);
1931 }
1932
1933 CONFIGFS_ATTR(o2hb_region_, block_bytes);
1934 CONFIGFS_ATTR(o2hb_region_, start_block);
1935 CONFIGFS_ATTR(o2hb_region_, blocks);
1936 CONFIGFS_ATTR(o2hb_region_, dev);
1937 CONFIGFS_ATTR_RO(o2hb_region_, pid);
1938
1939 static struct configfs_attribute *o2hb_region_attrs[] = {
1940 &o2hb_region_attr_block_bytes,
1941 &o2hb_region_attr_start_block,
1942 &o2hb_region_attr_blocks,
1943 &o2hb_region_attr_dev,
1944 &o2hb_region_attr_pid,
1945 NULL,
1946 };
1947
1948 static struct configfs_item_operations o2hb_region_item_ops = {
1949 .release = o2hb_region_release,
1950 };
1951
1952 static const struct config_item_type o2hb_region_type = {
1953 .ct_item_ops = &o2hb_region_item_ops,
1954 .ct_attrs = o2hb_region_attrs,
1955 .ct_owner = THIS_MODULE,
1956 };
1957
1958 /* heartbeat set */
1959
1960 struct o2hb_heartbeat_group {
1961 struct config_group hs_group;
1962 /* some stuff? */
1963 };
1964
to_o2hb_heartbeat_group(struct config_group * group)1965 static struct o2hb_heartbeat_group *to_o2hb_heartbeat_group(struct config_group *group)
1966 {
1967 return group ?
1968 container_of(group, struct o2hb_heartbeat_group, hs_group)
1969 : NULL;
1970 }
1971
o2hb_debug_region_init(struct o2hb_region * reg,struct dentry * parent)1972 static void o2hb_debug_region_init(struct o2hb_region *reg,
1973 struct dentry *parent)
1974 {
1975 struct dentry *dir;
1976
1977 dir = debugfs_create_dir(config_item_name(®->hr_item), parent);
1978 reg->hr_debug_dir = dir;
1979
1980 o2hb_debug_create(O2HB_DEBUG_LIVENODES, dir, &(reg->hr_db_livenodes),
1981 sizeof(*(reg->hr_db_livenodes)),
1982 O2HB_DB_TYPE_REGION_LIVENODES,
1983 sizeof(reg->hr_live_node_bitmap), O2NM_MAX_NODES,
1984 reg);
1985
1986 o2hb_debug_create(O2HB_DEBUG_REGION_NUMBER, dir, &(reg->hr_db_regnum),
1987 sizeof(*(reg->hr_db_regnum)),
1988 O2HB_DB_TYPE_REGION_NUMBER, 0, O2NM_MAX_NODES, reg);
1989
1990 o2hb_debug_create(O2HB_DEBUG_REGION_ELAPSED_TIME, dir,
1991 &(reg->hr_db_elapsed_time),
1992 sizeof(*(reg->hr_db_elapsed_time)),
1993 O2HB_DB_TYPE_REGION_ELAPSED_TIME, 0, 0, reg);
1994
1995 o2hb_debug_create(O2HB_DEBUG_REGION_PINNED, dir, &(reg->hr_db_pinned),
1996 sizeof(*(reg->hr_db_pinned)),
1997 O2HB_DB_TYPE_REGION_PINNED, 0, 0, reg);
1998
1999 }
2000
o2hb_heartbeat_group_make_item(struct config_group * group,const char * name)2001 static struct config_item *o2hb_heartbeat_group_make_item(struct config_group *group,
2002 const char *name)
2003 {
2004 struct o2hb_region *reg = NULL;
2005 int ret;
2006
2007 reg = kzalloc(sizeof(struct o2hb_region), GFP_KERNEL);
2008 if (reg == NULL)
2009 return ERR_PTR(-ENOMEM);
2010
2011 if (strlen(name) > O2HB_MAX_REGION_NAME_LEN) {
2012 ret = -ENAMETOOLONG;
2013 goto free;
2014 }
2015
2016 spin_lock(&o2hb_live_lock);
2017 reg->hr_region_num = 0;
2018 if (o2hb_global_heartbeat_active()) {
2019 reg->hr_region_num = find_first_zero_bit(o2hb_region_bitmap,
2020 O2NM_MAX_REGIONS);
2021 if (reg->hr_region_num >= O2NM_MAX_REGIONS) {
2022 spin_unlock(&o2hb_live_lock);
2023 ret = -EFBIG;
2024 goto free;
2025 }
2026 set_bit(reg->hr_region_num, o2hb_region_bitmap);
2027 }
2028 list_add_tail(®->hr_all_item, &o2hb_all_regions);
2029 spin_unlock(&o2hb_live_lock);
2030
2031 config_item_init_type_name(®->hr_item, name, &o2hb_region_type);
2032
2033 /* this is the same way to generate msg key as dlm, for local heartbeat,
2034 * name is also the same, so make initial crc value different to avoid
2035 * message key conflict.
2036 */
2037 reg->hr_key = crc32_le(reg->hr_region_num + O2NM_MAX_REGIONS,
2038 name, strlen(name));
2039 INIT_LIST_HEAD(®->hr_handler_list);
2040 ret = o2net_register_handler(O2HB_NEGO_TIMEOUT_MSG, reg->hr_key,
2041 sizeof(struct o2hb_nego_msg),
2042 o2hb_nego_timeout_handler,
2043 reg, NULL, ®->hr_handler_list);
2044 if (ret)
2045 goto remove_item;
2046
2047 ret = o2net_register_handler(O2HB_NEGO_APPROVE_MSG, reg->hr_key,
2048 sizeof(struct o2hb_nego_msg),
2049 o2hb_nego_approve_handler,
2050 reg, NULL, ®->hr_handler_list);
2051 if (ret)
2052 goto unregister_handler;
2053
2054 o2hb_debug_region_init(reg, o2hb_debug_dir);
2055
2056 return ®->hr_item;
2057
2058 unregister_handler:
2059 o2net_unregister_handler_list(®->hr_handler_list);
2060 remove_item:
2061 spin_lock(&o2hb_live_lock);
2062 list_del(®->hr_all_item);
2063 if (o2hb_global_heartbeat_active())
2064 clear_bit(reg->hr_region_num, o2hb_region_bitmap);
2065 spin_unlock(&o2hb_live_lock);
2066 free:
2067 kfree(reg);
2068 return ERR_PTR(ret);
2069 }
2070
o2hb_heartbeat_group_drop_item(struct config_group * group,struct config_item * item)2071 static void o2hb_heartbeat_group_drop_item(struct config_group *group,
2072 struct config_item *item)
2073 {
2074 struct task_struct *hb_task;
2075 struct o2hb_region *reg = to_o2hb_region(item);
2076 int quorum_region = 0;
2077
2078 /* stop the thread when the user removes the region dir */
2079 spin_lock(&o2hb_live_lock);
2080 hb_task = reg->hr_task;
2081 reg->hr_task = NULL;
2082 reg->hr_item_dropped = 1;
2083 spin_unlock(&o2hb_live_lock);
2084
2085 if (hb_task)
2086 kthread_stop(hb_task);
2087
2088 if (o2hb_global_heartbeat_active()) {
2089 spin_lock(&o2hb_live_lock);
2090 clear_bit(reg->hr_region_num, o2hb_region_bitmap);
2091 clear_bit(reg->hr_region_num, o2hb_live_region_bitmap);
2092 if (test_bit(reg->hr_region_num, o2hb_quorum_region_bitmap))
2093 quorum_region = 1;
2094 clear_bit(reg->hr_region_num, o2hb_quorum_region_bitmap);
2095 spin_unlock(&o2hb_live_lock);
2096 printk(KERN_NOTICE "o2hb: Heartbeat %s on region %s (%s)\n",
2097 ((atomic_read(®->hr_steady_iterations) == 0) ?
2098 "stopped" : "start aborted"), config_item_name(item),
2099 reg->hr_dev_name);
2100 }
2101
2102 /*
2103 * If we're racing a dev_write(), we need to wake them. They will
2104 * check reg->hr_task
2105 */
2106 if (atomic_read(®->hr_steady_iterations) != 0) {
2107 reg->hr_aborted_start = 1;
2108 atomic_set(®->hr_steady_iterations, 0);
2109 wake_up(&o2hb_steady_queue);
2110 }
2111
2112 config_item_put(item);
2113
2114 if (!o2hb_global_heartbeat_active() || !quorum_region)
2115 return;
2116
2117 /*
2118 * If global heartbeat active and there are dependent users,
2119 * pin all regions if quorum region count <= CUT_OFF
2120 */
2121 spin_lock(&o2hb_live_lock);
2122
2123 if (!o2hb_dependent_users)
2124 goto unlock;
2125
2126 if (bitmap_weight(o2hb_quorum_region_bitmap,
2127 O2NM_MAX_REGIONS) <= O2HB_PIN_CUT_OFF)
2128 o2hb_region_pin(NULL);
2129
2130 unlock:
2131 spin_unlock(&o2hb_live_lock);
2132 }
2133
o2hb_heartbeat_group_dead_threshold_show(struct config_item * item,char * page)2134 static ssize_t o2hb_heartbeat_group_dead_threshold_show(struct config_item *item,
2135 char *page)
2136 {
2137 return sprintf(page, "%u\n", o2hb_dead_threshold);
2138 }
2139
o2hb_heartbeat_group_dead_threshold_store(struct config_item * item,const char * page,size_t count)2140 static ssize_t o2hb_heartbeat_group_dead_threshold_store(struct config_item *item,
2141 const char *page, size_t count)
2142 {
2143 unsigned long tmp;
2144 char *p = (char *)page;
2145
2146 tmp = simple_strtoul(p, &p, 10);
2147 if (!p || (*p && (*p != '\n')))
2148 return -EINVAL;
2149
2150 /* this will validate ranges for us. */
2151 o2hb_dead_threshold_set((unsigned int) tmp);
2152
2153 return count;
2154 }
2155
o2hb_heartbeat_group_mode_show(struct config_item * item,char * page)2156 static ssize_t o2hb_heartbeat_group_mode_show(struct config_item *item,
2157 char *page)
2158 {
2159 return sprintf(page, "%s\n",
2160 o2hb_heartbeat_mode_desc[o2hb_heartbeat_mode]);
2161 }
2162
o2hb_heartbeat_group_mode_store(struct config_item * item,const char * page,size_t count)2163 static ssize_t o2hb_heartbeat_group_mode_store(struct config_item *item,
2164 const char *page, size_t count)
2165 {
2166 unsigned int i;
2167 int ret;
2168 size_t len;
2169
2170 len = (page[count - 1] == '\n') ? count - 1 : count;
2171 if (!len)
2172 return -EINVAL;
2173
2174 for (i = 0; i < O2HB_HEARTBEAT_NUM_MODES; ++i) {
2175 if (strncasecmp(page, o2hb_heartbeat_mode_desc[i], len))
2176 continue;
2177
2178 ret = o2hb_global_heartbeat_mode_set(i);
2179 if (!ret)
2180 printk(KERN_NOTICE "o2hb: Heartbeat mode set to %s\n",
2181 o2hb_heartbeat_mode_desc[i]);
2182 return count;
2183 }
2184
2185 return -EINVAL;
2186
2187 }
2188
2189 CONFIGFS_ATTR(o2hb_heartbeat_group_, dead_threshold);
2190 CONFIGFS_ATTR(o2hb_heartbeat_group_, mode);
2191
2192 static struct configfs_attribute *o2hb_heartbeat_group_attrs[] = {
2193 &o2hb_heartbeat_group_attr_dead_threshold,
2194 &o2hb_heartbeat_group_attr_mode,
2195 NULL,
2196 };
2197
2198 static struct configfs_group_operations o2hb_heartbeat_group_group_ops = {
2199 .make_item = o2hb_heartbeat_group_make_item,
2200 .drop_item = o2hb_heartbeat_group_drop_item,
2201 };
2202
2203 static const struct config_item_type o2hb_heartbeat_group_type = {
2204 .ct_group_ops = &o2hb_heartbeat_group_group_ops,
2205 .ct_attrs = o2hb_heartbeat_group_attrs,
2206 .ct_owner = THIS_MODULE,
2207 };
2208
2209 /* this is just here to avoid touching group in heartbeat.h which the
2210 * entire damn world #includes */
o2hb_alloc_hb_set(void)2211 struct config_group *o2hb_alloc_hb_set(void)
2212 {
2213 struct o2hb_heartbeat_group *hs = NULL;
2214 struct config_group *ret = NULL;
2215
2216 hs = kzalloc(sizeof(struct o2hb_heartbeat_group), GFP_KERNEL);
2217 if (hs == NULL)
2218 goto out;
2219
2220 config_group_init_type_name(&hs->hs_group, "heartbeat",
2221 &o2hb_heartbeat_group_type);
2222
2223 ret = &hs->hs_group;
2224 out:
2225 if (ret == NULL)
2226 kfree(hs);
2227 return ret;
2228 }
2229
o2hb_free_hb_set(struct config_group * group)2230 void o2hb_free_hb_set(struct config_group *group)
2231 {
2232 struct o2hb_heartbeat_group *hs = to_o2hb_heartbeat_group(group);
2233 kfree(hs);
2234 }
2235
2236 /* hb callback registration and issuing */
2237
hbcall_from_type(enum o2hb_callback_type type)2238 static struct o2hb_callback *hbcall_from_type(enum o2hb_callback_type type)
2239 {
2240 if (type == O2HB_NUM_CB)
2241 return ERR_PTR(-EINVAL);
2242
2243 return &o2hb_callbacks[type];
2244 }
2245
o2hb_setup_callback(struct o2hb_callback_func * hc,enum o2hb_callback_type type,o2hb_cb_func * func,void * data,int priority)2246 void o2hb_setup_callback(struct o2hb_callback_func *hc,
2247 enum o2hb_callback_type type,
2248 o2hb_cb_func *func,
2249 void *data,
2250 int priority)
2251 {
2252 INIT_LIST_HEAD(&hc->hc_item);
2253 hc->hc_func = func;
2254 hc->hc_data = data;
2255 hc->hc_priority = priority;
2256 hc->hc_type = type;
2257 hc->hc_magic = O2HB_CB_MAGIC;
2258 }
2259 EXPORT_SYMBOL_GPL(o2hb_setup_callback);
2260
2261 /*
2262 * In local heartbeat mode, region_uuid passed matches the dlm domain name.
2263 * In global heartbeat mode, region_uuid passed is NULL.
2264 *
2265 * In local, we only pin the matching region. In global we pin all the active
2266 * regions.
2267 */
o2hb_region_pin(const char * region_uuid)2268 static int o2hb_region_pin(const char *region_uuid)
2269 {
2270 int ret = 0, found = 0;
2271 struct o2hb_region *reg;
2272 char *uuid;
2273
2274 assert_spin_locked(&o2hb_live_lock);
2275
2276 list_for_each_entry(reg, &o2hb_all_regions, hr_all_item) {
2277 if (reg->hr_item_dropped)
2278 continue;
2279
2280 uuid = config_item_name(®->hr_item);
2281
2282 /* local heartbeat */
2283 if (region_uuid) {
2284 if (strcmp(region_uuid, uuid))
2285 continue;
2286 found = 1;
2287 }
2288
2289 if (reg->hr_item_pinned || reg->hr_item_dropped)
2290 goto skip_pin;
2291
2292 /* Ignore ENOENT only for local hb (userdlm domain) */
2293 ret = o2nm_depend_item(®->hr_item);
2294 if (!ret) {
2295 mlog(ML_CLUSTER, "Pin region %s\n", uuid);
2296 reg->hr_item_pinned = 1;
2297 } else {
2298 if (ret == -ENOENT && found)
2299 ret = 0;
2300 else {
2301 mlog(ML_ERROR, "Pin region %s fails with %d\n",
2302 uuid, ret);
2303 break;
2304 }
2305 }
2306 skip_pin:
2307 if (found)
2308 break;
2309 }
2310
2311 return ret;
2312 }
2313
2314 /*
2315 * In local heartbeat mode, region_uuid passed matches the dlm domain name.
2316 * In global heartbeat mode, region_uuid passed is NULL.
2317 *
2318 * In local, we only unpin the matching region. In global we unpin all the
2319 * active regions.
2320 */
o2hb_region_unpin(const char * region_uuid)2321 static void o2hb_region_unpin(const char *region_uuid)
2322 {
2323 struct o2hb_region *reg;
2324 char *uuid;
2325 int found = 0;
2326
2327 assert_spin_locked(&o2hb_live_lock);
2328
2329 list_for_each_entry(reg, &o2hb_all_regions, hr_all_item) {
2330 if (reg->hr_item_dropped)
2331 continue;
2332
2333 uuid = config_item_name(®->hr_item);
2334 if (region_uuid) {
2335 if (strcmp(region_uuid, uuid))
2336 continue;
2337 found = 1;
2338 }
2339
2340 if (reg->hr_item_pinned) {
2341 mlog(ML_CLUSTER, "Unpin region %s\n", uuid);
2342 o2nm_undepend_item(®->hr_item);
2343 reg->hr_item_pinned = 0;
2344 }
2345 if (found)
2346 break;
2347 }
2348 }
2349
o2hb_region_inc_user(const char * region_uuid)2350 static int o2hb_region_inc_user(const char *region_uuid)
2351 {
2352 int ret = 0;
2353
2354 spin_lock(&o2hb_live_lock);
2355
2356 /* local heartbeat */
2357 if (!o2hb_global_heartbeat_active()) {
2358 ret = o2hb_region_pin(region_uuid);
2359 goto unlock;
2360 }
2361
2362 /*
2363 * if global heartbeat active and this is the first dependent user,
2364 * pin all regions if quorum region count <= CUT_OFF
2365 */
2366 o2hb_dependent_users++;
2367 if (o2hb_dependent_users > 1)
2368 goto unlock;
2369
2370 if (bitmap_weight(o2hb_quorum_region_bitmap,
2371 O2NM_MAX_REGIONS) <= O2HB_PIN_CUT_OFF)
2372 ret = o2hb_region_pin(NULL);
2373
2374 unlock:
2375 spin_unlock(&o2hb_live_lock);
2376 return ret;
2377 }
2378
o2hb_region_dec_user(const char * region_uuid)2379 static void o2hb_region_dec_user(const char *region_uuid)
2380 {
2381 spin_lock(&o2hb_live_lock);
2382
2383 /* local heartbeat */
2384 if (!o2hb_global_heartbeat_active()) {
2385 o2hb_region_unpin(region_uuid);
2386 goto unlock;
2387 }
2388
2389 /*
2390 * if global heartbeat active and there are no dependent users,
2391 * unpin all quorum regions
2392 */
2393 o2hb_dependent_users--;
2394 if (!o2hb_dependent_users)
2395 o2hb_region_unpin(NULL);
2396
2397 unlock:
2398 spin_unlock(&o2hb_live_lock);
2399 }
2400
o2hb_register_callback(const char * region_uuid,struct o2hb_callback_func * hc)2401 int o2hb_register_callback(const char *region_uuid,
2402 struct o2hb_callback_func *hc)
2403 {
2404 struct o2hb_callback_func *f;
2405 struct o2hb_callback *hbcall;
2406 int ret;
2407
2408 BUG_ON(hc->hc_magic != O2HB_CB_MAGIC);
2409 BUG_ON(!list_empty(&hc->hc_item));
2410
2411 hbcall = hbcall_from_type(hc->hc_type);
2412 if (IS_ERR(hbcall)) {
2413 ret = PTR_ERR(hbcall);
2414 goto out;
2415 }
2416
2417 if (region_uuid) {
2418 ret = o2hb_region_inc_user(region_uuid);
2419 if (ret) {
2420 mlog_errno(ret);
2421 goto out;
2422 }
2423 }
2424
2425 down_write(&o2hb_callback_sem);
2426
2427 list_for_each_entry(f, &hbcall->list, hc_item) {
2428 if (hc->hc_priority < f->hc_priority) {
2429 list_add_tail(&hc->hc_item, &f->hc_item);
2430 break;
2431 }
2432 }
2433 if (list_empty(&hc->hc_item))
2434 list_add_tail(&hc->hc_item, &hbcall->list);
2435
2436 up_write(&o2hb_callback_sem);
2437 ret = 0;
2438 out:
2439 mlog(ML_CLUSTER, "returning %d on behalf of %p for funcs %p\n",
2440 ret, __builtin_return_address(0), hc);
2441 return ret;
2442 }
2443 EXPORT_SYMBOL_GPL(o2hb_register_callback);
2444
o2hb_unregister_callback(const char * region_uuid,struct o2hb_callback_func * hc)2445 void o2hb_unregister_callback(const char *region_uuid,
2446 struct o2hb_callback_func *hc)
2447 {
2448 BUG_ON(hc->hc_magic != O2HB_CB_MAGIC);
2449
2450 mlog(ML_CLUSTER, "on behalf of %p for funcs %p\n",
2451 __builtin_return_address(0), hc);
2452
2453 /* XXX Can this happen _with_ a region reference? */
2454 if (list_empty(&hc->hc_item))
2455 return;
2456
2457 if (region_uuid)
2458 o2hb_region_dec_user(region_uuid);
2459
2460 down_write(&o2hb_callback_sem);
2461
2462 list_del_init(&hc->hc_item);
2463
2464 up_write(&o2hb_callback_sem);
2465 }
2466 EXPORT_SYMBOL_GPL(o2hb_unregister_callback);
2467
o2hb_check_node_heartbeating_no_sem(u8 node_num)2468 int o2hb_check_node_heartbeating_no_sem(u8 node_num)
2469 {
2470 unsigned long testing_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
2471
2472 spin_lock(&o2hb_live_lock);
2473 o2hb_fill_node_map_from_callback(testing_map, sizeof(testing_map));
2474 spin_unlock(&o2hb_live_lock);
2475 if (!test_bit(node_num, testing_map)) {
2476 mlog(ML_HEARTBEAT,
2477 "node (%u) does not have heartbeating enabled.\n",
2478 node_num);
2479 return 0;
2480 }
2481
2482 return 1;
2483 }
2484 EXPORT_SYMBOL_GPL(o2hb_check_node_heartbeating_no_sem);
2485
o2hb_check_node_heartbeating_from_callback(u8 node_num)2486 int o2hb_check_node_heartbeating_from_callback(u8 node_num)
2487 {
2488 unsigned long testing_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
2489
2490 o2hb_fill_node_map_from_callback(testing_map, sizeof(testing_map));
2491 if (!test_bit(node_num, testing_map)) {
2492 mlog(ML_HEARTBEAT,
2493 "node (%u) does not have heartbeating enabled.\n",
2494 node_num);
2495 return 0;
2496 }
2497
2498 return 1;
2499 }
2500 EXPORT_SYMBOL_GPL(o2hb_check_node_heartbeating_from_callback);
2501
2502 /*
2503 * this is just a hack until we get the plumbing which flips file systems
2504 * read only and drops the hb ref instead of killing the node dead.
2505 */
o2hb_stop_all_regions(void)2506 void o2hb_stop_all_regions(void)
2507 {
2508 struct o2hb_region *reg;
2509
2510 mlog(ML_ERROR, "stopping heartbeat on all active regions.\n");
2511
2512 spin_lock(&o2hb_live_lock);
2513
2514 list_for_each_entry(reg, &o2hb_all_regions, hr_all_item)
2515 reg->hr_unclean_stop = 1;
2516
2517 spin_unlock(&o2hb_live_lock);
2518 }
2519 EXPORT_SYMBOL_GPL(o2hb_stop_all_regions);
2520
o2hb_get_all_regions(char * region_uuids,u8 max_regions)2521 int o2hb_get_all_regions(char *region_uuids, u8 max_regions)
2522 {
2523 struct o2hb_region *reg;
2524 int numregs = 0;
2525 char *p;
2526
2527 spin_lock(&o2hb_live_lock);
2528
2529 p = region_uuids;
2530 list_for_each_entry(reg, &o2hb_all_regions, hr_all_item) {
2531 if (reg->hr_item_dropped)
2532 continue;
2533
2534 mlog(0, "Region: %s\n", config_item_name(®->hr_item));
2535 if (numregs < max_regions) {
2536 memcpy(p, config_item_name(®->hr_item),
2537 O2HB_MAX_REGION_NAME_LEN);
2538 p += O2HB_MAX_REGION_NAME_LEN;
2539 }
2540 numregs++;
2541 }
2542
2543 spin_unlock(&o2hb_live_lock);
2544
2545 return numregs;
2546 }
2547 EXPORT_SYMBOL_GPL(o2hb_get_all_regions);
2548
o2hb_global_heartbeat_active(void)2549 int o2hb_global_heartbeat_active(void)
2550 {
2551 return (o2hb_heartbeat_mode == O2HB_HEARTBEAT_GLOBAL);
2552 }
2553 EXPORT_SYMBOL(o2hb_global_heartbeat_active);
2554