?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
ocfs2: fix memory leak
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / ocfs2 / cluster / heartbeat.c
blob9f26ac9be2a45d38e340bed6d51164492fab0ca6
1 /* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
3 *
4 * Copyright (C) 2004, 2005 Oracle. All rights reserved.
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public
17 * License along with this program; if not, write to the
18 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 * Boston, MA 021110-1307, USA.
20 */
21
22 #include <linux/kernel.h>
23 #include <linux/sched.h>
24 #include <linux/jiffies.h>
25 #include <linux/module.h>
26 #include <linux/fs.h>
27 #include <linux/bio.h>
28 #include <linux/blkdev.h>
29 #include <linux/delay.h>
30 #include <linux/file.h>
31 #include <linux/kthread.h>
32 #include <linux/configfs.h>
33 #include <linux/random.h>
34 #include <linux/crc32.h>
35 #include <linux/time.h>
36 #include <linux/debugfs.h>
37 #include <linux/slab.h>
38
39 #include "heartbeat.h"
40 #include "tcp.h"
41 #include "nodemanager.h"
42 #include "quorum.h"
43
44 #include "masklog.h"
45
46
47 /*
48 * The first heartbeat pass had one global thread that would serialize all hb
49 * callback calls. This global serializing sem should only be removed once
50 * we've made sure that all callees can deal with being called concurrently
51 * from multiple hb region threads.
52 */
53 static DECLARE_RWSEM(o2hb_callback_sem);
54
55 /*
56 * multiple hb threads are watching multiple regions. A node is live
57 * whenever any of the threads sees activity from the node in its region.
58 */
59 static DEFINE_SPINLOCK(o2hb_live_lock);
60 static struct list_head o2hb_live_slots[O2NM_MAX_NODES];
61 static unsigned long o2hb_live_node_bitmap[BITS_TO_LONGS(O2NM_MAX_NODES)];
62 static LIST_HEAD(o2hb_node_events);
63 static DECLARE_WAIT_QUEUE_HEAD(o2hb_steady_queue);
64
65 /*
66 * In global heartbeat, we maintain a series of region bitmaps.
67 * - o2hb_region_bitmap allows us to limit the region number to max region.
68 * - o2hb_live_region_bitmap tracks live regions (seen steady iterations).
69 * - o2hb_quorum_region_bitmap tracks live regions that have seen all nodes
70 * heartbeat on it.
71 * - o2hb_failed_region_bitmap tracks the regions that have seen io timeouts.
72 */
73 static unsigned long o2hb_region_bitmap[BITS_TO_LONGS(O2NM_MAX_REGIONS)];
74 static unsigned long o2hb_live_region_bitmap[BITS_TO_LONGS(O2NM_MAX_REGIONS)];
75 static unsigned long o2hb_quorum_region_bitmap[BITS_TO_LONGS(O2NM_MAX_REGIONS)];
76 static unsigned long o2hb_failed_region_bitmap[BITS_TO_LONGS(O2NM_MAX_REGIONS)];
77
78 #define O2HB_DB_TYPE_LIVENODES 0
79 #define O2HB_DB_TYPE_LIVEREGIONS 1
80 #define O2HB_DB_TYPE_QUORUMREGIONS 2
81 #define O2HB_DB_TYPE_FAILEDREGIONS 3
82 #define O2HB_DB_TYPE_REGION_LIVENODES 4
83 #define O2HB_DB_TYPE_REGION_NUMBER 5
84 #define O2HB_DB_TYPE_REGION_ELAPSED_TIME 6
85 struct o2hb_debug_buf {
86 int db_type;
87 int db_size;
88 int db_len;
89 void *db_data;
90 };
91
92 static struct o2hb_debug_buf *o2hb_db_livenodes;
93 static struct o2hb_debug_buf *o2hb_db_liveregions;
94 static struct o2hb_debug_buf *o2hb_db_quorumregions;
95 static struct o2hb_debug_buf *o2hb_db_failedregions;
96
97 #define O2HB_DEBUG_DIR "o2hb"
98 #define O2HB_DEBUG_LIVENODES "livenodes"
99 #define O2HB_DEBUG_LIVEREGIONS "live_regions"
100 #define O2HB_DEBUG_QUORUMREGIONS "quorum_regions"
101 #define O2HB_DEBUG_FAILEDREGIONS "failed_regions"
102 #define O2HB_DEBUG_REGION_NUMBER "num"
103 #define O2HB_DEBUG_REGION_ELAPSED_TIME "elapsed_time_in_ms"
104
105 static struct dentry *o2hb_debug_dir;
106 static struct dentry *o2hb_debug_livenodes;
107 static struct dentry *o2hb_debug_liveregions;
108 static struct dentry *o2hb_debug_quorumregions;
109 static struct dentry *o2hb_debug_failedregions;
110
111 static LIST_HEAD(o2hb_all_regions);
112
113 static struct o2hb_callback {
114 struct list_head list;
115 } o2hb_callbacks[O2HB_NUM_CB];
116
117 static struct o2hb_callback *hbcall_from_type(enum o2hb_callback_type type);
118
119 #define O2HB_DEFAULT_BLOCK_BITS 9
120
121 enum o2hb_heartbeat_modes {
122 O2HB_HEARTBEAT_LOCAL = 0,
123 O2HB_HEARTBEAT_GLOBAL,
124 O2HB_HEARTBEAT_NUM_MODES,
125 };
126
127 char *o2hb_heartbeat_mode_desc[O2HB_HEARTBEAT_NUM_MODES] = {
128 "local", /* O2HB_HEARTBEAT_LOCAL */
129 "global", /* O2HB_HEARTBEAT_GLOBAL */
130 };
131
132 unsigned int o2hb_dead_threshold = O2HB_DEFAULT_DEAD_THRESHOLD;
133 unsigned int o2hb_heartbeat_mode = O2HB_HEARTBEAT_LOCAL;
134
135 /* Only sets a new threshold if there are no active regions.
136 *
137 * No locking or otherwise interesting code is required for reading
138 * o2hb_dead_threshold as it can't change once regions are active and
139 * it's not interesting to anyone until then anyway. */
140 static void o2hb_dead_threshold_set(unsigned int threshold)
141 {
142 if (threshold > O2HB_MIN_DEAD_THRESHOLD) {
143 spin_lock(&o2hb_live_lock);
144 if (list_empty(&o2hb_all_regions))
145 o2hb_dead_threshold = threshold;
146 spin_unlock(&o2hb_live_lock);
147 }
148 }
149
150 static int o2hb_global_hearbeat_mode_set(unsigned int hb_mode)
151 {
152 int ret = -1;
153
154 if (hb_mode < O2HB_HEARTBEAT_NUM_MODES) {
155 spin_lock(&o2hb_live_lock);
156 if (list_empty(&o2hb_all_regions)) {
157 o2hb_heartbeat_mode = hb_mode;
158 ret = 0;
159 }
160 spin_unlock(&o2hb_live_lock);
161 }
162
163 return ret;
164 }
165
166 struct o2hb_node_event {
167 struct list_head hn_item;
168 enum o2hb_callback_type hn_event_type;
169 struct o2nm_node *hn_node;
170 int hn_node_num;
171 };
172
173 struct o2hb_disk_slot {
174 struct o2hb_disk_heartbeat_block *ds_raw_block;
175 u8 ds_node_num;
176 u64 ds_last_time;
177 u64 ds_last_generation;
178 u16 ds_equal_samples;
179 u16 ds_changed_samples;
180 struct list_head ds_live_item;
181 };
182
183 /* each thread owns a region.. when we're asked to tear down the region
184 * we ask the thread to stop, who cleans up the region */
185 struct o2hb_region {
186 struct config_item hr_item;
187
188 struct list_head hr_all_item;
189 unsigned hr_unclean_stop:1;
190
191 /* protected by the hr_callback_sem */
192 struct task_struct *hr_task;
193
194 unsigned int hr_blocks;
195 unsigned long long hr_start_block;
196
197 unsigned int hr_block_bits;
198 unsigned int hr_block_bytes;
199
200 unsigned int hr_slots_per_page;
201 unsigned int hr_num_pages;
202
203 struct page **hr_slot_data;
204 struct block_device *hr_bdev;
205 struct o2hb_disk_slot *hr_slots;
206
207 /* live node map of this region */
208 unsigned long hr_live_node_bitmap[BITS_TO_LONGS(O2NM_MAX_NODES)];
209 unsigned int hr_region_num;
210
211 struct dentry *hr_debug_dir;
212 struct dentry *hr_debug_livenodes;
213 struct dentry *hr_debug_regnum;
214 struct dentry *hr_debug_elapsed_time;
215 struct o2hb_debug_buf *hr_db_livenodes;
216 struct o2hb_debug_buf *hr_db_regnum;
217 struct o2hb_debug_buf *hr_db_elapsed_time;
218
219 /* let the person setting up hb wait for it to return until it
220 * has reached a 'steady' state. This will be fixed when we have
221 * a more complete api that doesn't lead to this sort of fragility. */
222 atomic_t hr_steady_iterations;
223
224 char hr_dev_name[BDEVNAME_SIZE];
225
226 unsigned int hr_timeout_ms;
227
228 /* randomized as the region goes up and down so that a node
229 * recognizes a node going up and down in one iteration */
230 u64 hr_generation;
231
232 struct delayed_work hr_write_timeout_work;
233 unsigned long hr_last_timeout_start;
234
235 /* Used during o2hb_check_slot to hold a copy of the block
236 * being checked because we temporarily have to zero out the
237 * crc field. */
238 struct o2hb_disk_heartbeat_block *hr_tmp_block;
239 };
240
241 struct o2hb_bio_wait_ctxt {
242 atomic_t wc_num_reqs;
243 struct completion wc_io_complete;
244 int wc_error;
245 };
246
247 static int o2hb_pop_count(void *map, int count)
248 {
249 int i = -1, pop = 0;
250
251 while ((i = find_next_bit(map, count, i + 1)) < count)
252 pop++;
253 return pop;
254 }
255
256 static void o2hb_write_timeout(struct work_struct *work)
257 {
258 int failed, quorum;
259 unsigned long flags;
260 struct o2hb_region *reg =
261 container_of(work, struct o2hb_region,
262 hr_write_timeout_work.work);
263
264 mlog(ML_ERROR, "Heartbeat write timeout to device %s after %u "
265 "milliseconds\n", reg->hr_dev_name,
266 jiffies_to_msecs(jiffies - reg->hr_last_timeout_start));
267
268 if (o2hb_global_heartbeat_active()) {
269 spin_lock_irqsave(&o2hb_live_lock, flags);
270 if (test_bit(reg->hr_region_num, o2hb_quorum_region_bitmap))
271 set_bit(reg->hr_region_num, o2hb_failed_region_bitmap);
272 failed = o2hb_pop_count(&o2hb_failed_region_bitmap,
273 O2NM_MAX_REGIONS);
274 quorum = o2hb_pop_count(&o2hb_quorum_region_bitmap,
275 O2NM_MAX_REGIONS);
276 spin_unlock_irqrestore(&o2hb_live_lock, flags);
277
278 mlog(ML_HEARTBEAT, "Number of regions %d, failed regions %d\n",
279 quorum, failed);
280
281 /*
282 * Fence if the number of failed regions >= half the number
283 * of quorum regions
284 */
285 if ((failed << 1) < quorum)
286 return;
287 }
288
289 o2quo_disk_timeout();
290 }
291
292 static void o2hb_arm_write_timeout(struct o2hb_region *reg)
293 {
294 mlog(ML_HEARTBEAT, "Queue write timeout for %u ms\n",
295 O2HB_MAX_WRITE_TIMEOUT_MS);
296
297 if (o2hb_global_heartbeat_active()) {
298 spin_lock(&o2hb_live_lock);
299 clear_bit(reg->hr_region_num, o2hb_failed_region_bitmap);
300 spin_unlock(&o2hb_live_lock);
301 }
302 cancel_delayed_work(&reg->hr_write_timeout_work);
303 reg->hr_last_timeout_start = jiffies;
304 schedule_delayed_work(&reg->hr_write_timeout_work,
305 msecs_to_jiffies(O2HB_MAX_WRITE_TIMEOUT_MS));
306 }
307
308 static void o2hb_disarm_write_timeout(struct o2hb_region *reg)
309 {
310 cancel_delayed_work(&reg->hr_write_timeout_work);
311 flush_scheduled_work();
312 }
313
314 static inline void o2hb_bio_wait_init(struct o2hb_bio_wait_ctxt *wc)
315 {
316 atomic_set(&wc->wc_num_reqs, 1);
317 init_completion(&wc->wc_io_complete);
318 wc->wc_error = 0;
319 }
320
321 /* Used in error paths too */
322 static inline void o2hb_bio_wait_dec(struct o2hb_bio_wait_ctxt *wc,
323 unsigned int num)
324 {
325 /* sadly atomic_sub_and_test() isn't available on all platforms. The
326 * good news is that the fast path only completes one at a time */
327 while(num--) {
328 if (atomic_dec_and_test(&wc->wc_num_reqs)) {
329 BUG_ON(num > 0);
330 complete(&wc->wc_io_complete);
331 }
332 }
333 }
334
335 static void o2hb_wait_on_io(struct o2hb_region *reg,
336 struct o2hb_bio_wait_ctxt *wc)
337 {
338 struct address_space *mapping = reg->hr_bdev->bd_inode->i_mapping;
339
340 blk_run_address_space(mapping);
341 o2hb_bio_wait_dec(wc, 1);
342
343 wait_for_completion(&wc->wc_io_complete);
344 }
345
346 static void o2hb_bio_end_io(struct bio *bio,
347 int error)
348 {
349 struct o2hb_bio_wait_ctxt *wc = bio->bi_private;
350
351 if (error) {
352 mlog(ML_ERROR, "IO Error %d\n", error);
353 wc->wc_error = error;
354 }
355
356 o2hb_bio_wait_dec(wc, 1);
357 bio_put(bio);
358 }
359
360 /* Setup a Bio to cover I/O against num_slots slots starting at
361 * start_slot. */
362 static struct bio *o2hb_setup_one_bio(struct o2hb_region *reg,
363 struct o2hb_bio_wait_ctxt *wc,
364 unsigned int *current_slot,
365 unsigned int max_slots)
366 {
367 int len, current_page;
368 unsigned int vec_len, vec_start;
369 unsigned int bits = reg->hr_block_bits;
370 unsigned int spp = reg->hr_slots_per_page;
371 unsigned int cs = *current_slot;
372 struct bio *bio;
373 struct page *page;
374
375 /* Testing has shown this allocation to take long enough under
376 * GFP_KERNEL that the local node can get fenced. It would be
377 * nicest if we could pre-allocate these bios and avoid this
378 * all together. */
379 bio = bio_alloc(GFP_ATOMIC, 16);
380 if (!bio) {
381 mlog(ML_ERROR, "Could not alloc slots BIO!\n");
382 bio = ERR_PTR(-ENOMEM);
383 goto bail;
384 }
385
386 /* Must put everything in 512 byte sectors for the bio... */
387 bio->bi_sector = (reg->hr_start_block + cs) << (bits - 9);
388 bio->bi_bdev = reg->hr_bdev;
389 bio->bi_private = wc;
390 bio->bi_end_io = o2hb_bio_end_io;
391
392 vec_start = (cs << bits) % PAGE_CACHE_SIZE;
393 while(cs < max_slots) {
394 current_page = cs / spp;
395 page = reg->hr_slot_data[current_page];
396
397 vec_len = min(PAGE_CACHE_SIZE - vec_start,
398 (max_slots-cs) * (PAGE_CACHE_SIZE/spp) );
399
400 mlog(ML_HB_BIO, "page %d, vec_len = %u, vec_start = %u\n",
401 current_page, vec_len, vec_start);
402
403 len = bio_add_page(bio, page, vec_len, vec_start);
404 if (len != vec_len) break;
405
406 cs += vec_len / (PAGE_CACHE_SIZE/spp);
407 vec_start = 0;
408 }
409
410 bail:
411 *current_slot = cs;
412 return bio;
413 }
414
415 static int o2hb_read_slots(struct o2hb_region *reg,
416 unsigned int max_slots)
417 {
418 unsigned int current_slot=0;
419 int status;
420 struct o2hb_bio_wait_ctxt wc;
421 struct bio *bio;
422
423 o2hb_bio_wait_init(&wc);
424
425 while(current_slot < max_slots) {
426 bio = o2hb_setup_one_bio(reg, &wc, &current_slot, max_slots);
427 if (IS_ERR(bio)) {
428 status = PTR_ERR(bio);
429 mlog_errno(status);
430 goto bail_and_wait;
431 }
432
433 atomic_inc(&wc.wc_num_reqs);
434 submit_bio(READ, bio);
435 }
436
437 status = 0;
438
439 bail_and_wait:
440 o2hb_wait_on_io(reg, &wc);
441 if (wc.wc_error && !status)
442 status = wc.wc_error;
443
444 return status;
445 }
446
447 static int o2hb_issue_node_write(struct o2hb_region *reg,
448 struct o2hb_bio_wait_ctxt *write_wc)
449 {
450 int status;
451 unsigned int slot;
452 struct bio *bio;
453
454 o2hb_bio_wait_init(write_wc);
455
456 slot = o2nm_this_node();
457
458 bio = o2hb_setup_one_bio(reg, write_wc, &slot, slot+1);
459 if (IS_ERR(bio)) {
460 status = PTR_ERR(bio);
461 mlog_errno(status);
462 goto bail;
463 }
464
465 atomic_inc(&write_wc->wc_num_reqs);
466 submit_bio(WRITE, bio);
467
468 status = 0;
469 bail:
470 return status;
471 }
472
473 static u32 o2hb_compute_block_crc_le(struct o2hb_region *reg,
474 struct o2hb_disk_heartbeat_block *hb_block)
475 {
476 __le32 old_cksum;
477 u32 ret;
478
479 /* We want to compute the block crc with a 0 value in the
480 * hb_cksum field. Save it off here and replace after the
481 * crc. */
482 old_cksum = hb_block->hb_cksum;
483 hb_block->hb_cksum = 0;
484
485 ret = crc32_le(0, (unsigned char *) hb_block, reg->hr_block_bytes);
486
487 hb_block->hb_cksum = old_cksum;
488
489 return ret;
490 }
491
492 static void o2hb_dump_slot(struct o2hb_disk_heartbeat_block *hb_block)
493 {
494 mlog(ML_ERROR, "Dump slot information: seq = 0x%llx, node = %u, "
495 "cksum = 0x%x, generation 0x%llx\n",
496 (long long)le64_to_cpu(hb_block->hb_seq),
497 hb_block->hb_node, le32_to_cpu(hb_block->hb_cksum),
498 (long long)le64_to_cpu(hb_block->hb_generation));
499 }
500
501 static int o2hb_verify_crc(struct o2hb_region *reg,
502 struct o2hb_disk_heartbeat_block *hb_block)
503 {
504 u32 read, computed;
505
506 read = le32_to_cpu(hb_block->hb_cksum);
507 computed = o2hb_compute_block_crc_le(reg, hb_block);
508
509 return read == computed;
510 }
511
512 /* We want to make sure that nobody is heartbeating on top of us --
513 * this will help detect an invalid configuration. */
514 static int o2hb_check_last_timestamp(struct o2hb_region *reg)
515 {
516 int node_num, ret;
517 struct o2hb_disk_slot *slot;
518 struct o2hb_disk_heartbeat_block *hb_block;
519
520 node_num = o2nm_this_node();
521
522 ret = 1;
523 slot = &reg->hr_slots[node_num];
524 /* Don't check on our 1st timestamp */
525 if (slot->ds_last_time) {
526 hb_block = slot->ds_raw_block;
527
528 if (le64_to_cpu(hb_block->hb_seq) != slot->ds_last_time)
529 ret = 0;
530 }
531
532 return ret;
533 }
534
535 static inline void o2hb_prepare_block(struct o2hb_region *reg,
536 u64 generation)
537 {
538 int node_num;
539 u64 cputime;
540 struct o2hb_disk_slot *slot;
541 struct o2hb_disk_heartbeat_block *hb_block;
542
543 node_num = o2nm_this_node();
544 slot = &reg->hr_slots[node_num];
545
546 hb_block = (struct o2hb_disk_heartbeat_block *)slot->ds_raw_block;
547 memset(hb_block, 0, reg->hr_block_bytes);
548 /* TODO: time stuff */
549 cputime = CURRENT_TIME.tv_sec;
550 if (!cputime)
551 cputime = 1;
552
553 hb_block->hb_seq = cpu_to_le64(cputime);
554 hb_block->hb_node = node_num;
555 hb_block->hb_generation = cpu_to_le64(generation);
556 hb_block->hb_dead_ms = cpu_to_le32(o2hb_dead_threshold * O2HB_REGION_TIMEOUT_MS);
557
558 /* This step must always happen last! */
559 hb_block->hb_cksum = cpu_to_le32(o2hb_compute_block_crc_le(reg,
560 hb_block));
561
562 mlog(ML_HB_BIO, "our node generation = 0x%llx, cksum = 0x%x\n",
563 (long long)generation,
564 le32_to_cpu(hb_block->hb_cksum));
565 }
566
567 static void o2hb_fire_callbacks(struct o2hb_callback *hbcall,
568 struct o2nm_node *node,
569 int idx)
570 {
571 struct list_head *iter;
572 struct o2hb_callback_func *f;
573
574 list_for_each(iter, &hbcall->list) {
575 f = list_entry(iter, struct o2hb_callback_func, hc_item);
576 mlog(ML_HEARTBEAT, "calling funcs %p\n", f);
577 (f->hc_func)(node, idx, f->hc_data);
578 }
579 }
580
581 /* Will run the list in order until we process the passed event */
582 static void o2hb_run_event_list(struct o2hb_node_event *queued_event)
583 {
584 int empty;
585 struct o2hb_callback *hbcall;
586 struct o2hb_node_event *event;
587
588 spin_lock(&o2hb_live_lock);
589 empty = list_empty(&queued_event->hn_item);
590 spin_unlock(&o2hb_live_lock);
591 if (empty)
592 return;
593
594 /* Holding callback sem assures we don't alter the callback
595 * lists when doing this, and serializes ourselves with other
596 * processes wanting callbacks. */
597 down_write(&o2hb_callback_sem);
598
599 spin_lock(&o2hb_live_lock);
600 while (!list_empty(&o2hb_node_events)
601 && !list_empty(&queued_event->hn_item)) {
602 event = list_entry(o2hb_node_events.next,
603 struct o2hb_node_event,
604 hn_item);
605 list_del_init(&event->hn_item);
606 spin_unlock(&o2hb_live_lock);
607
608 mlog(ML_HEARTBEAT, "Node %s event for %d\n",
609 event->hn_event_type == O2HB_NODE_UP_CB ? "UP" : "DOWN",
610 event->hn_node_num);
611
612 hbcall = hbcall_from_type(event->hn_event_type);
613
614 /* We should *never* have gotten on to the list with a
615 * bad type... This isn't something that we should try
616 * to recover from. */
617 BUG_ON(IS_ERR(hbcall));
618
619 o2hb_fire_callbacks(hbcall, event->hn_node, event->hn_node_num);
620
621 spin_lock(&o2hb_live_lock);
622 }
623 spin_unlock(&o2hb_live_lock);
624
625 up_write(&o2hb_callback_sem);
626 }
627
628 static void o2hb_queue_node_event(struct o2hb_node_event *event,
629 enum o2hb_callback_type type,
630 struct o2nm_node *node,
631 int node_num)
632 {
633 assert_spin_locked(&o2hb_live_lock);
634
635 BUG_ON((!node) && (type != O2HB_NODE_DOWN_CB));
636
637 event->hn_event_type = type;
638 event->hn_node = node;
639 event->hn_node_num = node_num;
640
641 mlog(ML_HEARTBEAT, "Queue node %s event for node %d\n",
642 type == O2HB_NODE_UP_CB ? "UP" : "DOWN", node_num);
643
644 list_add_tail(&event->hn_item, &o2hb_node_events);
645 }
646
647 static void o2hb_shutdown_slot(struct o2hb_disk_slot *slot)
648 {
649 struct o2hb_node_event event =
650 { .hn_item = LIST_HEAD_INIT(event.hn_item), };
651 struct o2nm_node *node;
652
653 node = o2nm_get_node_by_num(slot->ds_node_num);
654 if (!node)
655 return;
656
657 spin_lock(&o2hb_live_lock);
658 if (!list_empty(&slot->ds_live_item)) {
659 mlog(ML_HEARTBEAT, "Shutdown, node %d leaves region\n",
660 slot->ds_node_num);
661
662 list_del_init(&slot->ds_live_item);
663
664 if (list_empty(&o2hb_live_slots[slot->ds_node_num])) {
665 clear_bit(slot->ds_node_num, o2hb_live_node_bitmap);
666
667 o2hb_queue_node_event(&event, O2HB_NODE_DOWN_CB, node,
668 slot->ds_node_num);
669 }
670 }
671 spin_unlock(&o2hb_live_lock);
672
673 o2hb_run_event_list(&event);
674
675 o2nm_node_put(node);
676 }
677
678 static void o2hb_set_quorum_device(struct o2hb_region *reg,
679 struct o2hb_disk_slot *slot)
680 {
681 assert_spin_locked(&o2hb_live_lock);
682
683 if (!o2hb_global_heartbeat_active())
684 return;
685
686 if (test_bit(reg->hr_region_num, o2hb_quorum_region_bitmap))
687 return;
688
689 /*
690 * A region can be added to the quorum only when it sees all
691 * live nodes heartbeat on it. In other words, the region has been
692 * added to all nodes.
693 */
694 if (memcmp(reg->hr_live_node_bitmap, o2hb_live_node_bitmap,
695 sizeof(o2hb_live_node_bitmap)))
696 return;
697
698 if (slot->ds_changed_samples < O2HB_LIVE_THRESHOLD)
699 return;
700
701 printk(KERN_NOTICE "o2hb: Region %s is now a quorum device\n",
702 config_item_name(&reg->hr_item));
703
704 set_bit(reg->hr_region_num, o2hb_quorum_region_bitmap);
705 }
706
707 static int o2hb_check_slot(struct o2hb_region *reg,
708 struct o2hb_disk_slot *slot)
709 {
710 int changed = 0, gen_changed = 0;
711 struct o2hb_node_event event =
712 { .hn_item = LIST_HEAD_INIT(event.hn_item), };
713 struct o2nm_node *node;
714 struct o2hb_disk_heartbeat_block *hb_block = reg->hr_tmp_block;
715 u64 cputime;
716 unsigned int dead_ms = o2hb_dead_threshold * O2HB_REGION_TIMEOUT_MS;
717 unsigned int slot_dead_ms;
718 int tmp;
719
720 memcpy(hb_block, slot->ds_raw_block, reg->hr_block_bytes);
721
722 /*
723 * If a node is no longer configured but is still in the livemap, we
724 * may need to clear that bit from the livemap.
725 */
726 node = o2nm_get_node_by_num(slot->ds_node_num);
727 if (!node) {
728 spin_lock(&o2hb_live_lock);
729 tmp = test_bit(slot->ds_node_num, o2hb_live_node_bitmap);
730 spin_unlock(&o2hb_live_lock);
731 if (!tmp)
732 return 0;
733 }
734
735 if (!o2hb_verify_crc(reg, hb_block)) {
736 /* all paths from here will drop o2hb_live_lock for
737 * us. */
738 spin_lock(&o2hb_live_lock);
739
740 /* Don't print an error on the console in this case -
741 * a freshly formatted heartbeat area will not have a
742 * crc set on it. */
743 if (list_empty(&slot->ds_live_item))
744 goto out;
745
746 /* The node is live but pushed out a bad crc. We
747 * consider it a transient miss but don't populate any
748 * other values as they may be junk. */
749 mlog(ML_ERROR, "Node %d has written a bad crc to %s\n",
750 slot->ds_node_num, reg->hr_dev_name);
751 o2hb_dump_slot(hb_block);
752
753 slot->ds_equal_samples++;
754 goto fire_callbacks;
755 }
756
757 /* we don't care if these wrap.. the state transitions below
758 * clear at the right places */
759 cputime = le64_to_cpu(hb_block->hb_seq);
760 if (slot->ds_last_time != cputime)
761 slot->ds_changed_samples++;
762 else
763 slot->ds_equal_samples++;
764 slot->ds_last_time = cputime;
765
766 /* The node changed heartbeat generations. We assume this to
767 * mean it dropped off but came back before we timed out. We
768 * want to consider it down for the time being but don't want
769 * to lose any changed_samples state we might build up to
770 * considering it live again. */
771 if (slot->ds_last_generation != le64_to_cpu(hb_block->hb_generation)) {
772 gen_changed = 1;
773 slot->ds_equal_samples = 0;
774 mlog(ML_HEARTBEAT, "Node %d changed generation (0x%llx "
775 "to 0x%llx)\n", slot->ds_node_num,
776 (long long)slot->ds_last_generation,
777 (long long)le64_to_cpu(hb_block->hb_generation));
778 }
779
780 slot->ds_last_generation = le64_to_cpu(hb_block->hb_generation);
781
782 mlog(ML_HEARTBEAT, "Slot %d gen 0x%llx cksum 0x%x "
783 "seq %llu last %llu changed %u equal %u\n",
784 slot->ds_node_num, (long long)slot->ds_last_generation,
785 le32_to_cpu(hb_block->hb_cksum),
786 (unsigned long long)le64_to_cpu(hb_block->hb_seq),
787 (unsigned long long)slot->ds_last_time, slot->ds_changed_samples,
788 slot->ds_equal_samples);
789
790 spin_lock(&o2hb_live_lock);
791
792 fire_callbacks:
793 /* dead nodes only come to life after some number of
794 * changes at any time during their dead time */
795 if (list_empty(&slot->ds_live_item) &&
796 slot->ds_changed_samples >= O2HB_LIVE_THRESHOLD) {
797 mlog(ML_HEARTBEAT, "Node %d (id 0x%llx) joined my region\n",
798 slot->ds_node_num, (long long)slot->ds_last_generation);
799
800 set_bit(slot->ds_node_num, reg->hr_live_node_bitmap);
801
802 /* first on the list generates a callback */
803 if (list_empty(&o2hb_live_slots[slot->ds_node_num])) {
804 mlog(ML_HEARTBEAT, "o2hb: Add node %d to live nodes "
805 "bitmap\n", slot->ds_node_num);
806 set_bit(slot->ds_node_num, o2hb_live_node_bitmap);
807
808 o2hb_queue_node_event(&event, O2HB_NODE_UP_CB, node,
809 slot->ds_node_num);
810
811 changed = 1;
812 }
813
814 list_add_tail(&slot->ds_live_item,
815 &o2hb_live_slots[slot->ds_node_num]);
816
817 slot->ds_equal_samples = 0;
818
819 /* We want to be sure that all nodes agree on the
820 * number of milliseconds before a node will be
821 * considered dead. The self-fencing timeout is
822 * computed from this value, and a discrepancy might
823 * result in heartbeat calling a node dead when it
824 * hasn't self-fenced yet. */
825 slot_dead_ms = le32_to_cpu(hb_block->hb_dead_ms);
826 if (slot_dead_ms && slot_dead_ms != dead_ms) {
827 /* TODO: Perhaps we can fail the region here. */
828 mlog(ML_ERROR, "Node %d on device %s has a dead count "
829 "of %u ms, but our count is %u ms.\n"
830 "Please double check your configuration values "
831 "for 'O2CB_HEARTBEAT_THRESHOLD'\n",
832 slot->ds_node_num, reg->hr_dev_name, slot_dead_ms,
833 dead_ms);
834 }
835 goto out;
836 }
837
838 /* if the list is dead, we're done.. */
839 if (list_empty(&slot->ds_live_item))
840 goto out;
841
842 /* live nodes only go dead after enough consequtive missed
843 * samples.. reset the missed counter whenever we see
844 * activity */
845 if (slot->ds_equal_samples >= o2hb_dead_threshold || gen_changed) {
846 mlog(ML_HEARTBEAT, "Node %d left my region\n",
847 slot->ds_node_num);
848
849 clear_bit(slot->ds_node_num, reg->hr_live_node_bitmap);
850
851 /* last off the live_slot generates a callback */
852 list_del_init(&slot->ds_live_item);
853 if (list_empty(&o2hb_live_slots[slot->ds_node_num])) {
854 mlog(ML_HEARTBEAT, "o2hb: Remove node %d from live "
855 "nodes bitmap\n", slot->ds_node_num);
856 clear_bit(slot->ds_node_num, o2hb_live_node_bitmap);
857
858 /* node can be null */
859 o2hb_queue_node_event(&event, O2HB_NODE_DOWN_CB,
860 node, slot->ds_node_num);
861
862 changed = 1;
863 }
864
865 /* We don't clear this because the node is still
866 * actually writing new blocks. */
867 if (!gen_changed)
868 slot->ds_changed_samples = 0;
869 goto out;
870 }
871 if (slot->ds_changed_samples) {
872 slot->ds_changed_samples = 0;
873 slot->ds_equal_samples = 0;
874 }
875 out:
876 o2hb_set_quorum_device(reg, slot);
877
878 spin_unlock(&o2hb_live_lock);
879
880 o2hb_run_event_list(&event);
881
882 if (node)
883 o2nm_node_put(node);
884 return changed;
885 }
886
887 /* This could be faster if we just implmented a find_last_bit, but I
888 * don't think the circumstances warrant it. */
889 static int o2hb_highest_node(unsigned long *nodes,
890 int numbits)
891 {
892 int highest, node;
893
894 highest = numbits;
895 node = -1;
896 while ((node = find_next_bit(nodes, numbits, node + 1)) != -1) {
897 if (node >= numbits)
898 break;
899
900 highest = node;
901 }
902
903 return highest;
904 }
905
906 static int o2hb_do_disk_heartbeat(struct o2hb_region *reg)
907 {
908 int i, ret, highest_node, change = 0;
909 unsigned long configured_nodes[BITS_TO_LONGS(O2NM_MAX_NODES)];
910 unsigned long live_node_bitmap[BITS_TO_LONGS(O2NM_MAX_NODES)];
911 struct o2hb_bio_wait_ctxt write_wc;
912
913 ret = o2nm_configured_node_map(configured_nodes,
914 sizeof(configured_nodes));
915 if (ret) {
916 mlog_errno(ret);
917 return ret;
918 }
919
920 /*
921 * If a node is not configured but is in the livemap, we still need
922 * to read the slot so as to be able to remove it from the livemap.
923 */
924 o2hb_fill_node_map(live_node_bitmap, sizeof(live_node_bitmap));
925 i = -1;
926 while ((i = find_next_bit(live_node_bitmap,
927 O2NM_MAX_NODES, i + 1)) < O2NM_MAX_NODES) {
928 set_bit(i, configured_nodes);
929 }
930
931 highest_node = o2hb_highest_node(configured_nodes, O2NM_MAX_NODES);
932 if (highest_node >= O2NM_MAX_NODES) {
933 mlog(ML_NOTICE, "ocfs2_heartbeat: no configured nodes found!\n");
934 return -EINVAL;
935 }
936
937 /* No sense in reading the slots of nodes that don't exist
938 * yet. Of course, if the node definitions have holes in them
939 * then we're reading an empty slot anyway... Consider this
940 * best-effort. */
941 ret = o2hb_read_slots(reg, highest_node + 1);
942 if (ret < 0) {
943 mlog_errno(ret);
944 return ret;
945 }
946
947 /* With an up to date view of the slots, we can check that no
948 * other node has been improperly configured to heartbeat in
949 * our slot. */
950 if (!o2hb_check_last_timestamp(reg))
951 mlog(ML_ERROR, "Device \"%s\": another node is heartbeating "
952 "in our slot!\n", reg->hr_dev_name);
953
954 /* fill in the proper info for our next heartbeat */
955 o2hb_prepare_block(reg, reg->hr_generation);
956
957 /* And fire off the write. Note that we don't wait on this I/O
958 * until later. */
959 ret = o2hb_issue_node_write(reg, &write_wc);
960 if (ret < 0) {
961 mlog_errno(ret);
962 return ret;
963 }
964
965 i = -1;
966 while((i = find_next_bit(configured_nodes, O2NM_MAX_NODES, i + 1)) < O2NM_MAX_NODES) {
967
968 change |= o2hb_check_slot(reg, &reg->hr_slots[i]);
969 }
970
971 /*
972 * We have to be sure we've advertised ourselves on disk
973 * before we can go to steady state. This ensures that
974 * people we find in our steady state have seen us.
975 */
976 o2hb_wait_on_io(reg, &write_wc);
977 if (write_wc.wc_error) {
978 /* Do not re-arm the write timeout on I/O error - we
979 * can't be sure that the new block ever made it to
980 * disk */
981 mlog(ML_ERROR, "Write error %d on device \"%s\"\n",
982 write_wc.wc_error, reg->hr_dev_name);
983 return write_wc.wc_error;
984 }
985
986 o2hb_arm_write_timeout(reg);
987
988 /* let the person who launched us know when things are steady */
989 if (!change && (atomic_read(&reg->hr_steady_iterations) != 0)) {
990 if (atomic_dec_and_test(&reg->hr_steady_iterations))
991 wake_up(&o2hb_steady_queue);
992 }
993
994 return 0;
995 }
996
997 /* Subtract b from a, storing the result in a. a *must* have a larger
998 * value than b. */
999 static void o2hb_tv_subtract(struct timeval *a,
1000 struct timeval *b)
1001 {
1002 /* just return 0 when a is after b */
1003 if (a->tv_sec < b->tv_sec ||
1004 (a->tv_sec == b->tv_sec && a->tv_usec < b->tv_usec)) {
1005 a->tv_sec = 0;
1006 a->tv_usec = 0;
1007 return;
1008 }
1009
1010 a->tv_sec -= b->tv_sec;
1011 a->tv_usec -= b->tv_usec;
1012 while ( a->tv_usec < 0 ) {
1013 a->tv_sec--;
1014 a->tv_usec += 1000000;
1015 }
1016 }
1017
1018 static unsigned int o2hb_elapsed_msecs(struct timeval *start,
1019 struct timeval *end)
1020 {
1021 struct timeval res = *end;
1022
1023 o2hb_tv_subtract(&res, start);
1024
1025 return res.tv_sec * 1000 + res.tv_usec / 1000;
1026 }
1027
1028 /*
1029 * we ride the region ref that the region dir holds. before the region
1030 * dir is removed and drops it ref it will wait to tear down this
1031 * thread.
1032 */
1033 static int o2hb_thread(void *data)
1034 {
1035 int i, ret;
1036 struct o2hb_region *reg = data;
1037 struct o2hb_bio_wait_ctxt write_wc;
1038 struct timeval before_hb, after_hb;
1039 unsigned int elapsed_msec;
1040
1041 mlog(ML_HEARTBEAT|ML_KTHREAD, "hb thread running\n");
1042
1043 set_user_nice(current, -20);
1044
1045 while (!kthread_should_stop() && !reg->hr_unclean_stop) {
1046 /* We track the time spent inside
1047 * o2hb_do_disk_heartbeat so that we avoid more than
1048 * hr_timeout_ms between disk writes. On busy systems
1049 * this should result in a heartbeat which is less
1050 * likely to time itself out. */
1051 do_gettimeofday(&before_hb);
1052
1053 i = 0;
1054 do {
1055 ret = o2hb_do_disk_heartbeat(reg);
1056 } while (ret && ++i < 2);
1057
1058 do_gettimeofday(&after_hb);
1059 elapsed_msec = o2hb_elapsed_msecs(&before_hb, &after_hb);
1060
1061 mlog(ML_HEARTBEAT,
1062 "start = %lu.%lu, end = %lu.%lu, msec = %u\n",
1063 before_hb.tv_sec, (unsigned long) before_hb.tv_usec,
1064 after_hb.tv_sec, (unsigned long) after_hb.tv_usec,
1065 elapsed_msec);
1066
1067 if (elapsed_msec < reg->hr_timeout_ms) {
1068 /* the kthread api has blocked signals for us so no
1069 * need to record the return value. */
1070 msleep_interruptible(reg->hr_timeout_ms - elapsed_msec);
1071 }
1072 }
1073
1074 o2hb_disarm_write_timeout(reg);
1075
1076 /* unclean stop is only used in very bad situation */
1077 for(i = 0; !reg->hr_unclean_stop && i < reg->hr_blocks; i++)
1078 o2hb_shutdown_slot(&reg->hr_slots[i]);
1079
1080 /* Explicit down notification - avoid forcing the other nodes
1081 * to timeout on this region when we could just as easily
1082 * write a clear generation - thus indicating to them that
1083 * this node has left this region.
1084 *
1085 * XXX: Should we skip this on unclean_stop? */
1086 o2hb_prepare_block(reg, 0);
1087 ret = o2hb_issue_node_write(reg, &write_wc);
1088 if (ret == 0) {
1089 o2hb_wait_on_io(reg, &write_wc);
1090 } else {
1091 mlog_errno(ret);
1092 }
1093
1094 mlog(ML_HEARTBEAT|ML_KTHREAD, "hb thread exiting\n");
1095
1096 return 0;
1097 }
1098
1099 #ifdef CONFIG_DEBUG_FS
1100 static int o2hb_debug_open(struct inode *inode, struct file *file)
1101 {
1102 struct o2hb_debug_buf *db = inode->i_private;
1103 struct o2hb_region *reg;
1104 unsigned long map[BITS_TO_LONGS(O2NM_MAX_NODES)];
1105 char *buf = NULL;
1106 int i = -1;
1107 int out = 0;
1108
1109 /* max_nodes should be the largest bitmap we pass here */
1110 BUG_ON(sizeof(map) < db->db_size);
1111
1112 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
1113 if (!buf)
1114 goto bail;
1115
1116 switch (db->db_type) {
1117 case O2HB_DB_TYPE_LIVENODES:
1118 case O2HB_DB_TYPE_LIVEREGIONS:
1119 case O2HB_DB_TYPE_QUORUMREGIONS:
1120 case O2HB_DB_TYPE_FAILEDREGIONS:
1121 spin_lock(&o2hb_live_lock);
1122 memcpy(map, db->db_data, db->db_size);
1123 spin_unlock(&o2hb_live_lock);
1124 break;
1125
1126 case O2HB_DB_TYPE_REGION_LIVENODES:
1127 spin_lock(&o2hb_live_lock);
1128 reg = (struct o2hb_region *)db->db_data;
1129 memcpy(map, reg->hr_live_node_bitmap, db->db_size);
1130 spin_unlock(&o2hb_live_lock);
1131 break;
1132
1133 case O2HB_DB_TYPE_REGION_NUMBER:
1134 reg = (struct o2hb_region *)db->db_data;
1135 out += snprintf(buf + out, PAGE_SIZE - out, "%d\n",
1136 reg->hr_region_num);
1137 goto done;
1138
1139 case O2HB_DB_TYPE_REGION_ELAPSED_TIME:
1140 reg = (struct o2hb_region *)db->db_data;
1141 out += snprintf(buf + out, PAGE_SIZE - out, "%u\n",
1142 jiffies_to_msecs(jiffies -
1143 reg->hr_last_timeout_start));
1144 goto done;
1145
1146 default:
1147 goto done;
1148 }
1149
1150 while ((i = find_next_bit(map, db->db_len, i + 1)) < db->db_len)
1151 out += snprintf(buf + out, PAGE_SIZE - out, "%d ", i);
1152 out += snprintf(buf + out, PAGE_SIZE - out, "\n");
1153
1154 done:
1155 i_size_write(inode, out);
1156
1157 file->private_data = buf;
1158
1159 return 0;
1160 bail:
1161 return -ENOMEM;
1162 }
1163
1164 static int o2hb_debug_release(struct inode *inode, struct file *file)
1165 {
1166 kfree(file->private_data);
1167 return 0;
1168 }
1169
1170 static ssize_t o2hb_debug_read(struct file *file, char __user *buf,
1171 size_t nbytes, loff_t *ppos)
1172 {
1173 return simple_read_from_buffer(buf, nbytes, ppos, file->private_data,
1174 i_size_read(file->f_mapping->host));
1175 }
1176 #else
1177 static int o2hb_debug_open(struct inode *inode, struct file *file)
1178 {
1179 return 0;
1180 }
1181 static int o2hb_debug_release(struct inode *inode, struct file *file)
1182 {
1183 return 0;
1184 }
1185 static ssize_t o2hb_debug_read(struct file *file, char __user *buf,
1186 size_t nbytes, loff_t *ppos)
1187 {
1188 return 0;
1189 }
1190 #endif /* CONFIG_DEBUG_FS */
1191
1192 static const struct file_operations o2hb_debug_fops = {
1193 .open = o2hb_debug_open,
1194 .release = o2hb_debug_release,
1195 .read = o2hb_debug_read,
1196 .llseek = generic_file_llseek,
1197 };
1198
1199 void o2hb_exit(void)
1200 {
1201 kfree(o2hb_db_livenodes);
1202 kfree(o2hb_db_liveregions);
1203 kfree(o2hb_db_quorumregions);
1204 kfree(o2hb_db_failedregions);
1205 debugfs_remove(o2hb_debug_failedregions);
1206 debugfs_remove(o2hb_debug_quorumregions);
1207 debugfs_remove(o2hb_debug_liveregions);
1208 debugfs_remove(o2hb_debug_livenodes);
1209 debugfs_remove(o2hb_debug_dir);
1210 }
1211
1212 static struct dentry *o2hb_debug_create(const char *name, struct dentry *dir,
1213 struct o2hb_debug_buf **db, int db_len,
1214 int type, int size, int len, void *data)
1215 {
1216 *db = kmalloc(db_len, GFP_KERNEL);
1217 if (!*db)
1218 return NULL;
1219
1220 (*db)->db_type = type;
1221 (*db)->db_size = size;
1222 (*db)->db_len = len;
1223 (*db)->db_data = data;
1224
1225 return debugfs_create_file(name, S_IFREG|S_IRUSR, dir, *db,
1226 &o2hb_debug_fops);
1227 }
1228
1229 static int o2hb_debug_init(void)
1230 {
1231 int ret = -ENOMEM;
1232
1233 o2hb_debug_dir = debugfs_create_dir(O2HB_DEBUG_DIR, NULL);
1234 if (!o2hb_debug_dir) {
1235 mlog_errno(ret);
1236 goto bail;
1237 }
1238
1239 o2hb_debug_livenodes = o2hb_debug_create(O2HB_DEBUG_LIVENODES,
1240 o2hb_debug_dir,
1241 &o2hb_db_livenodes,
1242 sizeof(*o2hb_db_livenodes),
1243 O2HB_DB_TYPE_LIVENODES,
1244 sizeof(o2hb_live_node_bitmap),
1245 O2NM_MAX_NODES,
1246 o2hb_live_node_bitmap);
1247 if (!o2hb_debug_livenodes) {
1248 mlog_errno(ret);
1249 goto bail;
1250 }
1251
1252 o2hb_debug_liveregions = o2hb_debug_create(O2HB_DEBUG_LIVEREGIONS,
1253 o2hb_debug_dir,
1254 &o2hb_db_liveregions,
1255 sizeof(*o2hb_db_liveregions),
1256 O2HB_DB_TYPE_LIVEREGIONS,
1257 sizeof(o2hb_live_region_bitmap),
1258 O2NM_MAX_REGIONS,
1259 o2hb_live_region_bitmap);
1260 if (!o2hb_debug_liveregions) {
1261 mlog_errno(ret);
1262 goto bail;
1263 }
1264
1265 o2hb_debug_quorumregions =
1266 o2hb_debug_create(O2HB_DEBUG_QUORUMREGIONS,
1267 o2hb_debug_dir,
1268 &o2hb_db_quorumregions,
1269 sizeof(*o2hb_db_quorumregions),
1270 O2HB_DB_TYPE_QUORUMREGIONS,
1271 sizeof(o2hb_quorum_region_bitmap),
1272 O2NM_MAX_REGIONS,
1273 o2hb_quorum_region_bitmap);
1274 if (!o2hb_debug_quorumregions) {
1275 mlog_errno(ret);
1276 goto bail;
1277 }
1278
1279 o2hb_debug_failedregions =
1280 o2hb_debug_create(O2HB_DEBUG_FAILEDREGIONS,
1281 o2hb_debug_dir,
1282 &o2hb_db_failedregions,
1283 sizeof(*o2hb_db_failedregions),
1284 O2HB_DB_TYPE_FAILEDREGIONS,
1285 sizeof(o2hb_failed_region_bitmap),
1286 O2NM_MAX_REGIONS,
1287 o2hb_failed_region_bitmap);
1288 if (!o2hb_debug_failedregions) {
1289 mlog_errno(ret);
1290 goto bail;
1291 }
1292
1293 ret = 0;
1294 bail:
1295 if (ret)
1296 o2hb_exit();
1297
1298 return ret;
1299 }
1300
1301 int o2hb_init(void)
1302 {
1303 int i;
1304
1305 for (i = 0; i < ARRAY_SIZE(o2hb_callbacks); i++)
1306 INIT_LIST_HEAD(&o2hb_callbacks[i].list);
1307
1308 for (i = 0; i < ARRAY_SIZE(o2hb_live_slots); i++)
1309 INIT_LIST_HEAD(&o2hb_live_slots[i]);
1310
1311 INIT_LIST_HEAD(&o2hb_node_events);
1312
1313 memset(o2hb_live_node_bitmap, 0, sizeof(o2hb_live_node_bitmap));
1314 memset(o2hb_region_bitmap, 0, sizeof(o2hb_region_bitmap));
1315 memset(o2hb_live_region_bitmap, 0, sizeof(o2hb_live_region_bitmap));
1316 memset(o2hb_quorum_region_bitmap, 0, sizeof(o2hb_quorum_region_bitmap));
1317 memset(o2hb_failed_region_bitmap, 0, sizeof(o2hb_failed_region_bitmap));
1318
1319 return o2hb_debug_init();
1320 }
1321
1322 /* if we're already in a callback then we're already serialized by the sem */
1323 static void o2hb_fill_node_map_from_callback(unsigned long *map,
1324 unsigned bytes)
1325 {
1326 BUG_ON(bytes < (BITS_TO_LONGS(O2NM_MAX_NODES) * sizeof(unsigned long)));
1327
1328 memcpy(map, &o2hb_live_node_bitmap, bytes);
1329 }
1330
1331 /*
1332 * get a map of all nodes that are heartbeating in any regions
1333 */
1334 void o2hb_fill_node_map(unsigned long *map, unsigned bytes)
1335 {
1336 /* callers want to serialize this map and callbacks so that they
1337 * can trust that they don't miss nodes coming to the party */
1338 down_read(&o2hb_callback_sem);
1339 spin_lock(&o2hb_live_lock);
1340 o2hb_fill_node_map_from_callback(map, bytes);
1341 spin_unlock(&o2hb_live_lock);
1342 up_read(&o2hb_callback_sem);
1343 }
1344 EXPORT_SYMBOL_GPL(o2hb_fill_node_map);
1345
1346 /*
1347 * heartbeat configfs bits. The heartbeat set is a default set under
1348 * the cluster set in nodemanager.c.
1349 */
1350
1351 static struct o2hb_region *to_o2hb_region(struct config_item *item)
1352 {
1353 return item ? container_of(item, struct o2hb_region, hr_item) : NULL;
1354 }
1355
1356 /* drop_item only drops its ref after killing the thread, nothing should
1357 * be using the region anymore. this has to clean up any state that
1358 * attributes might have built up. */
1359 static void o2hb_region_release(struct config_item *item)
1360 {
1361 int i;
1362 struct page *page;
1363 struct o2hb_region *reg = to_o2hb_region(item);
1364
1365 if (reg->hr_tmp_block)
1366 kfree(reg->hr_tmp_block);
1367
1368 if (reg->hr_slot_data) {
1369 for (i = 0; i < reg->hr_num_pages; i++) {
1370 page = reg->hr_slot_data[i];
1371 if (page)
1372 __free_page(page);
1373 }
1374 kfree(reg->hr_slot_data);
1375 }
1376
1377 if (reg->hr_bdev)
1378 blkdev_put(reg->hr_bdev, FMODE_READ|FMODE_WRITE);
1379
1380 if (reg->hr_slots)
1381 kfree(reg->hr_slots);
1382
1383 kfree(reg->hr_db_regnum);
1384 kfree(reg->hr_db_livenodes);
1385 debugfs_remove(reg->hr_debug_livenodes);
1386 debugfs_remove(reg->hr_debug_regnum);
1387 debugfs_remove(reg->hr_debug_elapsed_time);
1388 debugfs_remove(reg->hr_debug_dir);
1389
1390 spin_lock(&o2hb_live_lock);
1391 list_del(&reg->hr_all_item);
1392 spin_unlock(&o2hb_live_lock);
1393
1394 kfree(reg);
1395 }
1396
1397 static int o2hb_read_block_input(struct o2hb_region *reg,
1398 const char *page,
1399 size_t count,
1400 unsigned long *ret_bytes,
1401 unsigned int *ret_bits)
1402 {
1403 unsigned long bytes;
1404 char *p = (char *)page;
1405
1406 bytes = simple_strtoul(p, &p, 0);
1407 if (!p || (*p && (*p != '\n')))
1408 return -EINVAL;
1409
1410 /* Heartbeat and fs min / max block sizes are the same. */
1411 if (bytes > 4096 || bytes < 512)
1412 return -ERANGE;
1413 if (hweight16(bytes) != 1)
1414 return -EINVAL;
1415
1416 if (ret_bytes)
1417 *ret_bytes = bytes;
1418 if (ret_bits)
1419 *ret_bits = ffs(bytes) - 1;
1420
1421 return 0;
1422 }
1423
1424 static ssize_t o2hb_region_block_bytes_read(struct o2hb_region *reg,
1425 char *page)
1426 {
1427 return sprintf(page, "%u\n", reg->hr_block_bytes);
1428 }
1429
1430 static ssize_t o2hb_region_block_bytes_write(struct o2hb_region *reg,
1431 const char *page,
1432 size_t count)
1433 {
1434 int status;
1435 unsigned long block_bytes;
1436 unsigned int block_bits;
1437
1438 if (reg->hr_bdev)
1439 return -EINVAL;
1440
1441 status = o2hb_read_block_input(reg, page, count,
1442 &block_bytes, &block_bits);
1443 if (status)
1444 return status;
1445
1446 reg->hr_block_bytes = (unsigned int)block_bytes;
1447 reg->hr_block_bits = block_bits;
1448
1449 return count;
1450 }
1451
1452 static ssize_t o2hb_region_start_block_read(struct o2hb_region *reg,
1453 char *page)
1454 {
1455 return sprintf(page, "%llu\n", reg->hr_start_block);
1456 }
1457
1458 static ssize_t o2hb_region_start_block_write(struct o2hb_region *reg,
1459 const char *page,
1460 size_t count)
1461 {
1462 unsigned long long tmp;
1463 char *p = (char *)page;
1464
1465 if (reg->hr_bdev)
1466 return -EINVAL;
1467
1468 tmp = simple_strtoull(p, &p, 0);
1469 if (!p || (*p && (*p != '\n')))
1470 return -EINVAL;
1471
1472 reg->hr_start_block = tmp;
1473
1474 return count;
1475 }
1476
1477 static ssize_t o2hb_region_blocks_read(struct o2hb_region *reg,
1478 char *page)
1479 {
1480 return sprintf(page, "%d\n", reg->hr_blocks);
1481 }
1482
1483 static ssize_t o2hb_region_blocks_write(struct o2hb_region *reg,
1484 const char *page,
1485 size_t count)
1486 {
1487 unsigned long tmp;
1488 char *p = (char *)page;
1489
1490 if (reg->hr_bdev)
1491 return -EINVAL;
1492
1493 tmp = simple_strtoul(p, &p, 0);
1494 if (!p || (*p && (*p != '\n')))
1495 return -EINVAL;
1496
1497 if (tmp > O2NM_MAX_NODES || tmp == 0)
1498 return -ERANGE;
1499
1500 reg->hr_blocks = (unsigned int)tmp;
1501
1502 return count;
1503 }
1504
1505 static ssize_t o2hb_region_dev_read(struct o2hb_region *reg,
1506 char *page)
1507 {
1508 unsigned int ret = 0;
1509
1510 if (reg->hr_bdev)
1511 ret = sprintf(page, "%s\n", reg->hr_dev_name);
1512
1513 return ret;
1514 }
1515
1516 static void o2hb_init_region_params(struct o2hb_region *reg)
1517 {
1518 reg->hr_slots_per_page = PAGE_CACHE_SIZE >> reg->hr_block_bits;
1519 reg->hr_timeout_ms = O2HB_REGION_TIMEOUT_MS;
1520
1521 mlog(ML_HEARTBEAT, "hr_start_block = %llu, hr_blocks = %u\n",
1522 reg->hr_start_block, reg->hr_blocks);
1523 mlog(ML_HEARTBEAT, "hr_block_bytes = %u, hr_block_bits = %u\n",
1524 reg->hr_block_bytes, reg->hr_block_bits);
1525 mlog(ML_HEARTBEAT, "hr_timeout_ms = %u\n", reg->hr_timeout_ms);
1526 mlog(ML_HEARTBEAT, "dead threshold = %u\n", o2hb_dead_threshold);
1527 }
1528
1529 static int o2hb_map_slot_data(struct o2hb_region *reg)
1530 {
1531 int i, j;
1532 unsigned int last_slot;
1533 unsigned int spp = reg->hr_slots_per_page;
1534 struct page *page;
1535 char *raw;
1536 struct o2hb_disk_slot *slot;
1537
1538 reg->hr_tmp_block = kmalloc(reg->hr_block_bytes, GFP_KERNEL);
1539 if (reg->hr_tmp_block == NULL) {
1540 mlog_errno(-ENOMEM);
1541 return -ENOMEM;
1542 }
1543
1544 reg->hr_slots = kcalloc(reg->hr_blocks,
1545 sizeof(struct o2hb_disk_slot), GFP_KERNEL);
1546 if (reg->hr_slots == NULL) {
1547 mlog_errno(-ENOMEM);
1548 return -ENOMEM;
1549 }
1550
1551 for(i = 0; i < reg->hr_blocks; i++) {
1552 slot = &reg->hr_slots[i];
1553 slot->ds_node_num = i;
1554 INIT_LIST_HEAD(&slot->ds_live_item);
1555 slot->ds_raw_block = NULL;
1556 }
1557
1558 reg->hr_num_pages = (reg->hr_blocks + spp - 1) / spp;
1559 mlog(ML_HEARTBEAT, "Going to require %u pages to cover %u blocks "
1560 "at %u blocks per page\n",
1561 reg->hr_num_pages, reg->hr_blocks, spp);
1562
1563 reg->hr_slot_data = kcalloc(reg->hr_num_pages, sizeof(struct page *),
1564 GFP_KERNEL);
1565 if (!reg->hr_slot_data) {
1566 mlog_errno(-ENOMEM);
1567 return -ENOMEM;
1568 }
1569
1570 for(i = 0; i < reg->hr_num_pages; i++) {
1571 page = alloc_page(GFP_KERNEL);
1572 if (!page) {
1573 mlog_errno(-ENOMEM);
1574 return -ENOMEM;
1575 }
1576
1577 reg->hr_slot_data[i] = page;
1578
1579 last_slot = i * spp;
1580 raw = page_address(page);
1581 for (j = 0;
1582 (j < spp) && ((j + last_slot) < reg->hr_blocks);
1583 j++) {
1584 BUG_ON((j + last_slot) >= reg->hr_blocks);
1585
1586 slot = &reg->hr_slots[j + last_slot];
1587 slot->ds_raw_block =
1588 (struct o2hb_disk_heartbeat_block *) raw;
1589
1590 raw += reg->hr_block_bytes;
1591 }
1592 }
1593
1594 return 0;
1595 }
1596
1597 /* Read in all the slots available and populate the tracking
1598 * structures so that we can start with a baseline idea of what's
1599 * there. */
1600 static int o2hb_populate_slot_data(struct o2hb_region *reg)
1601 {
1602 int ret, i;
1603 struct o2hb_disk_slot *slot;
1604 struct o2hb_disk_heartbeat_block *hb_block;
1605
1606 mlog_entry_void();
1607
1608 ret = o2hb_read_slots(reg, reg->hr_blocks);
1609 if (ret) {
1610 mlog_errno(ret);
1611 goto out;
1612 }
1613
1614 /* We only want to get an idea of the values initially in each
1615 * slot, so we do no verification - o2hb_check_slot will
1616 * actually determine if each configured slot is valid and
1617 * whether any values have changed. */
1618 for(i = 0; i < reg->hr_blocks; i++) {
1619 slot = &reg->hr_slots[i];
1620 hb_block = (struct o2hb_disk_heartbeat_block *) slot->ds_raw_block;
1621
1622 /* Only fill the values that o2hb_check_slot uses to
1623 * determine changing slots */
1624 slot->ds_last_time = le64_to_cpu(hb_block->hb_seq);
1625 slot->ds_last_generation = le64_to_cpu(hb_block->hb_generation);
1626 }
1627
1628 out:
1629 mlog_exit(ret);
1630 return ret;
1631 }
1632
1633 /* this is acting as commit; we set up all of hr_bdev and hr_task or nothing */
1634 static ssize_t o2hb_region_dev_write(struct o2hb_region *reg,
1635 const char *page,
1636 size_t count)
1637 {
1638 struct task_struct *hb_task;
1639 long fd;
1640 int sectsize;
1641 char *p = (char *)page;
1642 struct file *filp = NULL;
1643 struct inode *inode = NULL;
1644 ssize_t ret = -EINVAL;
1645
1646 if (reg->hr_bdev)
1647 goto out;
1648
1649 /* We can't heartbeat without having had our node number
1650 * configured yet. */
1651 if (o2nm_this_node() == O2NM_MAX_NODES)
1652 goto out;
1653
1654 fd = simple_strtol(p, &p, 0);
1655 if (!p || (*p && (*p != '\n')))
1656 goto out;
1657
1658 if (fd < 0 || fd >= INT_MAX)
1659 goto out;
1660
1661 filp = fget(fd);
1662 if (filp == NULL)
1663 goto out;
1664
1665 if (reg->hr_blocks == 0 || reg->hr_start_block == 0 ||
1666 reg->hr_block_bytes == 0)
1667 goto out;
1668
1669 inode = igrab(filp->f_mapping->host);
1670 if (inode == NULL)
1671 goto out;
1672
1673 if (!S_ISBLK(inode->i_mode))
1674 goto out;
1675
1676 reg->hr_bdev = I_BDEV(filp->f_mapping->host);
1677 ret = blkdev_get(reg->hr_bdev, FMODE_WRITE | FMODE_READ);
1678 if (ret) {
1679 reg->hr_bdev = NULL;
1680 goto out;
1681 }
1682 inode = NULL;
1683
1684 bdevname(reg->hr_bdev, reg->hr_dev_name);
1685
1686 sectsize = bdev_logical_block_size(reg->hr_bdev);
1687 if (sectsize != reg->hr_block_bytes) {
1688 mlog(ML_ERROR,
1689 "blocksize %u incorrect for device, expected %d",
1690 reg->hr_block_bytes, sectsize);
1691 ret = -EINVAL;
1692 goto out;
1693 }
1694
1695 o2hb_init_region_params(reg);
1696
1697 /* Generation of zero is invalid */
1698 do {
1699 get_random_bytes(&reg->hr_generation,
1700 sizeof(reg->hr_generation));
1701 } while (reg->hr_generation == 0);
1702
1703 ret = o2hb_map_slot_data(reg);
1704 if (ret) {
1705 mlog_errno(ret);
1706 goto out;
1707 }
1708
1709 ret = o2hb_populate_slot_data(reg);
1710 if (ret) {
1711 mlog_errno(ret);
1712 goto out;
1713 }
1714
1715 INIT_DELAYED_WORK(&reg->hr_write_timeout_work, o2hb_write_timeout);
1716
1717 /*
1718 * A node is considered live after it has beat LIVE_THRESHOLD
1719 * times. We're not steady until we've given them a chance
1720 * _after_ our first read.
1721 */
1722 atomic_set(&reg->hr_steady_iterations, O2HB_LIVE_THRESHOLD + 1);
1723
1724 hb_task = kthread_run(o2hb_thread, reg, "o2hb-%s",
1725 reg->hr_item.ci_name);
1726 if (IS_ERR(hb_task)) {
1727 ret = PTR_ERR(hb_task);
1728 mlog_errno(ret);
1729 goto out;
1730 }
1731
1732 spin_lock(&o2hb_live_lock);
1733 reg->hr_task = hb_task;
1734 spin_unlock(&o2hb_live_lock);
1735
1736 ret = wait_event_interruptible(o2hb_steady_queue,
1737 atomic_read(&reg->hr_steady_iterations) == 0);
1738 if (ret) {
1739 /* We got interrupted (hello ptrace!). Clean up */
1740 spin_lock(&o2hb_live_lock);
1741 hb_task = reg->hr_task;
1742 reg->hr_task = NULL;
1743 spin_unlock(&o2hb_live_lock);
1744
1745 if (hb_task)
1746 kthread_stop(hb_task);
1747 goto out;
1748 }
1749
1750 /* Ok, we were woken. Make sure it wasn't by drop_item() */
1751 spin_lock(&o2hb_live_lock);
1752 hb_task = reg->hr_task;
1753 if (o2hb_global_heartbeat_active())
1754 set_bit(reg->hr_region_num, o2hb_live_region_bitmap);
1755 spin_unlock(&o2hb_live_lock);
1756
1757 if (hb_task)
1758 ret = count;
1759 else
1760 ret = -EIO;
1761
1762 if (hb_task && o2hb_global_heartbeat_active())
1763 printk(KERN_NOTICE "o2hb: Heartbeat started on region %s\n",
1764 config_item_name(&reg->hr_item));
1765
1766 out:
1767 if (filp)
1768 fput(filp);
1769 if (inode)
1770 iput(inode);
1771 if (ret < 0) {
1772 if (reg->hr_bdev) {
1773 blkdev_put(reg->hr_bdev, FMODE_READ|FMODE_WRITE);
1774 reg->hr_bdev = NULL;
1775 }
1776 }
1777 return ret;
1778 }
1779
1780 static ssize_t o2hb_region_pid_read(struct o2hb_region *reg,
1781 char *page)
1782 {
1783 pid_t pid = 0;
1784
1785 spin_lock(&o2hb_live_lock);
1786 if (reg->hr_task)
1787 pid = task_pid_nr(reg->hr_task);
1788 spin_unlock(&o2hb_live_lock);
1789
1790 if (!pid)
1791 return 0;
1792
1793 return sprintf(page, "%u\n", pid);
1794 }
1795
1796 struct o2hb_region_attribute {
1797 struct configfs_attribute attr;
1798 ssize_t (*show)(struct o2hb_region *, char *);
1799 ssize_t (*store)(struct o2hb_region *, const char *, size_t);
1800 };
1801
1802 static struct o2hb_region_attribute o2hb_region_attr_block_bytes = {
1803 .attr = { .ca_owner = THIS_MODULE,
1804 .ca_name = "block_bytes",
1805 .ca_mode = S_IRUGO | S_IWUSR },
1806 .show = o2hb_region_block_bytes_read,
1807 .store = o2hb_region_block_bytes_write,
1808 };
1809
1810 static struct o2hb_region_attribute o2hb_region_attr_start_block = {
1811 .attr = { .ca_owner = THIS_MODULE,
1812 .ca_name = "start_block",
1813 .ca_mode = S_IRUGO | S_IWUSR },
1814 .show = o2hb_region_start_block_read,
1815 .store = o2hb_region_start_block_write,
1816 };
1817
1818 static struct o2hb_region_attribute o2hb_region_attr_blocks = {
1819 .attr = { .ca_owner = THIS_MODULE,
1820 .ca_name = "blocks",
1821 .ca_mode = S_IRUGO | S_IWUSR },
1822 .show = o2hb_region_blocks_read,
1823 .store = o2hb_region_blocks_write,
1824 };
1825
1826 static struct o2hb_region_attribute o2hb_region_attr_dev = {
1827 .attr = { .ca_owner = THIS_MODULE,
1828 .ca_name = "dev",
1829 .ca_mode = S_IRUGO | S_IWUSR },
1830 .show = o2hb_region_dev_read,
1831 .store = o2hb_region_dev_write,
1832 };
1833
1834 static struct o2hb_region_attribute o2hb_region_attr_pid = {
1835 .attr = { .ca_owner = THIS_MODULE,
1836 .ca_name = "pid",
1837 .ca_mode = S_IRUGO | S_IRUSR },
1838 .show = o2hb_region_pid_read,
1839 };
1840
1841 static struct configfs_attribute *o2hb_region_attrs[] = {
1842 &o2hb_region_attr_block_bytes.attr,
1843 &o2hb_region_attr_start_block.attr,
1844 &o2hb_region_attr_blocks.attr,
1845 &o2hb_region_attr_dev.attr,
1846 &o2hb_region_attr_pid.attr,
1847 NULL,
1848 };
1849
1850 static ssize_t o2hb_region_show(struct config_item *item,
1851 struct configfs_attribute *attr,
1852 char *page)
1853 {
1854 struct o2hb_region *reg = to_o2hb_region(item);
1855 struct o2hb_region_attribute *o2hb_region_attr =
1856 container_of(attr, struct o2hb_region_attribute, attr);
1857 ssize_t ret = 0;
1858
1859 if (o2hb_region_attr->show)
1860 ret = o2hb_region_attr->show(reg, page);
1861 return ret;
1862 }
1863
1864 static ssize_t o2hb_region_store(struct config_item *item,
1865 struct configfs_attribute *attr,
1866 const char *page, size_t count)
1867 {
1868 struct o2hb_region *reg = to_o2hb_region(item);
1869 struct o2hb_region_attribute *o2hb_region_attr =
1870 container_of(attr, struct o2hb_region_attribute, attr);
1871 ssize_t ret = -EINVAL;
1872
1873 if (o2hb_region_attr->store)
1874 ret = o2hb_region_attr->store(reg, page, count);
1875 return ret;
1876 }
1877
1878 static struct configfs_item_operations o2hb_region_item_ops = {
1879 .release = o2hb_region_release,
1880 .show_attribute = o2hb_region_show,
1881 .store_attribute = o2hb_region_store,
1882 };
1883
1884 static struct config_item_type o2hb_region_type = {
1885 .ct_item_ops = &o2hb_region_item_ops,
1886 .ct_attrs = o2hb_region_attrs,
1887 .ct_owner = THIS_MODULE,
1888 };
1889
1890 /* heartbeat set */
1891
1892 struct o2hb_heartbeat_group {
1893 struct config_group hs_group;
1894 /* some stuff? */
1895 };
1896
1897 static struct o2hb_heartbeat_group *to_o2hb_heartbeat_group(struct config_group *group)
1898 {
1899 return group ?
1900 container_of(group, struct o2hb_heartbeat_group, hs_group)
1901 : NULL;
1902 }
1903
1904 static int o2hb_debug_region_init(struct o2hb_region *reg, struct dentry *dir)
1905 {
1906 int ret = -ENOMEM;
1907
1908 reg->hr_debug_dir =
1909 debugfs_create_dir(config_item_name(&reg->hr_item), dir);
1910 if (!reg->hr_debug_dir) {
1911 mlog_errno(ret);
1912 goto bail;
1913 }
1914
1915 reg->hr_debug_livenodes =
1916 o2hb_debug_create(O2HB_DEBUG_LIVENODES,
1917 reg->hr_debug_dir,
1918 &(reg->hr_db_livenodes),
1919 sizeof(*(reg->hr_db_livenodes)),
1920 O2HB_DB_TYPE_REGION_LIVENODES,
1921 sizeof(reg->hr_live_node_bitmap),
1922 O2NM_MAX_NODES, reg);
1923 if (!reg->hr_debug_livenodes) {
1924 mlog_errno(ret);
1925 goto bail;
1926 }
1927
1928 reg->hr_debug_regnum =
1929 o2hb_debug_create(O2HB_DEBUG_REGION_NUMBER,
1930 reg->hr_debug_dir,
1931 &(reg->hr_db_regnum),
1932 sizeof(*(reg->hr_db_regnum)),
1933 O2HB_DB_TYPE_REGION_NUMBER,
1934 0, O2NM_MAX_NODES, reg);
1935 if (!reg->hr_debug_regnum) {
1936 mlog_errno(ret);
1937 goto bail;
1938 }
1939
1940 reg->hr_debug_elapsed_time =
1941 o2hb_debug_create(O2HB_DEBUG_REGION_ELAPSED_TIME,
1942 reg->hr_debug_dir,
1943 &(reg->hr_db_elapsed_time),
1944 sizeof(*(reg->hr_db_elapsed_time)),
1945 O2HB_DB_TYPE_REGION_ELAPSED_TIME,
1946 0, 0, reg);
1947 if (!reg->hr_debug_elapsed_time) {
1948 mlog_errno(ret);
1949 goto bail;
1950 }
1951
1952 ret = 0;
1953 bail:
1954 return ret;
1955 }
1956
1957 static struct config_item *o2hb_heartbeat_group_make_item(struct config_group *group,
1958 const char *name)
1959 {
1960 struct o2hb_region *reg = NULL;
1961 int ret;
1962
1963 reg = kzalloc(sizeof(struct o2hb_region), GFP_KERNEL);
1964 if (reg == NULL)
1965 return ERR_PTR(-ENOMEM);
1966
1967 if (strlen(name) > O2HB_MAX_REGION_NAME_LEN) {
1968 ret = -ENAMETOOLONG;
1969 goto free;
1970 }
1971
1972 spin_lock(&o2hb_live_lock);
1973 reg->hr_region_num = 0;
1974 if (o2hb_global_heartbeat_active()) {
1975 reg->hr_region_num = find_first_zero_bit(o2hb_region_bitmap,
1976 O2NM_MAX_REGIONS);
1977 if (reg->hr_region_num >= O2NM_MAX_REGIONS) {
1978 spin_unlock(&o2hb_live_lock);
1979 ret = -EFBIG;
1980 goto free;
1981 }
1982 set_bit(reg->hr_region_num, o2hb_region_bitmap);
1983 }
1984 list_add_tail(&reg->hr_all_item, &o2hb_all_regions);
1985 spin_unlock(&o2hb_live_lock);
1986
1987 config_item_init_type_name(&reg->hr_item, name, &o2hb_region_type);
1988
1989 ret = o2hb_debug_region_init(reg, o2hb_debug_dir);
1990 if (ret) {
1991 config_item_put(&reg->hr_item);
1992 goto free;
1993 }
1994
1995 return &reg->hr_item;
1996 free:
1997 kfree(reg);
1998 return ERR_PTR(ret);
1999 }
2000
2001 static void o2hb_heartbeat_group_drop_item(struct config_group *group,
2002 struct config_item *item)
2003 {
2004 struct task_struct *hb_task;
2005 struct o2hb_region *reg = to_o2hb_region(item);
2006
2007 /* stop the thread when the user removes the region dir */
2008 spin_lock(&o2hb_live_lock);
2009 if (o2hb_global_heartbeat_active()) {
2010 clear_bit(reg->hr_region_num, o2hb_region_bitmap);
2011 clear_bit(reg->hr_region_num, o2hb_live_region_bitmap);
2012 }
2013 hb_task = reg->hr_task;
2014 reg->hr_task = NULL;
2015 spin_unlock(&o2hb_live_lock);
2016
2017 if (hb_task)
2018 kthread_stop(hb_task);
2019
2020 /*
2021 * If we're racing a dev_write(), we need to wake them. They will
2022 * check reg->hr_task
2023 */
2024 if (atomic_read(&reg->hr_steady_iterations) != 0) {
2025 atomic_set(&reg->hr_steady_iterations, 0);
2026 wake_up(&o2hb_steady_queue);
2027 }
2028
2029 if (o2hb_global_heartbeat_active())
2030 printk(KERN_NOTICE "o2hb: Heartbeat stopped on region %s\n",
2031 config_item_name(&reg->hr_item));
2032 config_item_put(item);
2033 }
2034
2035 struct o2hb_heartbeat_group_attribute {
2036 struct configfs_attribute attr;
2037 ssize_t (*show)(struct o2hb_heartbeat_group *, char *);
2038 ssize_t (*store)(struct o2hb_heartbeat_group *, const char *, size_t);
2039 };
2040
2041 static ssize_t o2hb_heartbeat_group_show(struct config_item *item,
2042 struct configfs_attribute *attr,
2043 char *page)
2044 {
2045 struct o2hb_heartbeat_group *reg = to_o2hb_heartbeat_group(to_config_group(item));
2046 struct o2hb_heartbeat_group_attribute *o2hb_heartbeat_group_attr =
2047 container_of(attr, struct o2hb_heartbeat_group_attribute, attr);
2048 ssize_t ret = 0;
2049
2050 if (o2hb_heartbeat_group_attr->show)
2051 ret = o2hb_heartbeat_group_attr->show(reg, page);
2052 return ret;
2053 }
2054
2055 static ssize_t o2hb_heartbeat_group_store(struct config_item *item,
2056 struct configfs_attribute *attr,
2057 const char *page, size_t count)
2058 {
2059 struct o2hb_heartbeat_group *reg = to_o2hb_heartbeat_group(to_config_group(item));
2060 struct o2hb_heartbeat_group_attribute *o2hb_heartbeat_group_attr =
2061 container_of(attr, struct o2hb_heartbeat_group_attribute, attr);
2062 ssize_t ret = -EINVAL;
2063
2064 if (o2hb_heartbeat_group_attr->store)
2065 ret = o2hb_heartbeat_group_attr->store(reg, page, count);
2066 return ret;
2067 }
2068
2069 static ssize_t o2hb_heartbeat_group_threshold_show(struct o2hb_heartbeat_group *group,
2070 char *page)
2071 {
2072 return sprintf(page, "%u\n", o2hb_dead_threshold);
2073 }
2074
2075 static ssize_t o2hb_heartbeat_group_threshold_store(struct o2hb_heartbeat_group *group,
2076 const char *page,
2077 size_t count)
2078 {
2079 unsigned long tmp;
2080 char *p = (char *)page;
2081
2082 tmp = simple_strtoul(p, &p, 10);
2083 if (!p || (*p && (*p != '\n')))
2084 return -EINVAL;
2085
2086 /* this will validate ranges for us. */
2087 o2hb_dead_threshold_set((unsigned int) tmp);
2088
2089 return count;
2090 }
2091
2092 static
2093 ssize_t o2hb_heartbeat_group_mode_show(struct o2hb_heartbeat_group *group,
2094 char *page)
2095 {
2096 return sprintf(page, "%s\n",
2097 o2hb_heartbeat_mode_desc[o2hb_heartbeat_mode]);
2098 }
2099
2100 static
2101 ssize_t o2hb_heartbeat_group_mode_store(struct o2hb_heartbeat_group *group,
2102 const char *page, size_t count)
2103 {
2104 unsigned int i;
2105 int ret;
2106 size_t len;
2107
2108 len = (page[count - 1] == '\n') ? count - 1 : count;
2109 if (!len)
2110 return -EINVAL;
2111
2112 for (i = 0; i < O2HB_HEARTBEAT_NUM_MODES; ++i) {
2113 if (strnicmp(page, o2hb_heartbeat_mode_desc[i], len))
2114 continue;
2115
2116 ret = o2hb_global_hearbeat_mode_set(i);
2117 if (!ret)
2118 printk(KERN_NOTICE "o2hb: Heartbeat mode set to %s\n",
2119 o2hb_heartbeat_mode_desc[i]);
2120 return count;
2121 }
2122
2123 return -EINVAL;
2124
2125 }
2126
2127 static struct o2hb_heartbeat_group_attribute o2hb_heartbeat_group_attr_threshold = {
2128 .attr = { .ca_owner = THIS_MODULE,
2129 .ca_name = "dead_threshold",
2130 .ca_mode = S_IRUGO | S_IWUSR },
2131 .show = o2hb_heartbeat_group_threshold_show,
2132 .store = o2hb_heartbeat_group_threshold_store,
2133 };
2134
2135 static struct o2hb_heartbeat_group_attribute o2hb_heartbeat_group_attr_mode = {
2136 .attr = { .ca_owner = THIS_MODULE,
2137 .ca_name = "mode",
2138 .ca_mode = S_IRUGO | S_IWUSR },
2139 .show = o2hb_heartbeat_group_mode_show,
2140 .store = o2hb_heartbeat_group_mode_store,
2141 };
2142
2143 static struct configfs_attribute *o2hb_heartbeat_group_attrs[] = {
2144 &o2hb_heartbeat_group_attr_threshold.attr,
2145 &o2hb_heartbeat_group_attr_mode.attr,
2146 NULL,
2147 };
2148
2149 static struct configfs_item_operations o2hb_hearbeat_group_item_ops = {
2150 .show_attribute = o2hb_heartbeat_group_show,
2151 .store_attribute = o2hb_heartbeat_group_store,
2152 };
2153
2154 static struct configfs_group_operations o2hb_heartbeat_group_group_ops = {
2155 .make_item = o2hb_heartbeat_group_make_item,
2156 .drop_item = o2hb_heartbeat_group_drop_item,
2157 };
2158
2159 static struct config_item_type o2hb_heartbeat_group_type = {
2160 .ct_group_ops = &o2hb_heartbeat_group_group_ops,
2161 .ct_item_ops = &o2hb_hearbeat_group_item_ops,
2162 .ct_attrs = o2hb_heartbeat_group_attrs,
2163 .ct_owner = THIS_MODULE,
2164 };
2165
2166 /* this is just here to avoid touching group in heartbeat.h which the
2167 * entire damn world #includes */
2168 struct config_group *o2hb_alloc_hb_set(void)
2169 {
2170 struct o2hb_heartbeat_group *hs = NULL;
2171 struct config_group *ret = NULL;
2172
2173 hs = kzalloc(sizeof(struct o2hb_heartbeat_group), GFP_KERNEL);
2174 if (hs == NULL)
2175 goto out;
2176
2177 config_group_init_type_name(&hs->hs_group, "heartbeat",
2178 &o2hb_heartbeat_group_type);
2179
2180 ret = &hs->hs_group;
2181 out:
2182 if (ret == NULL)
2183 kfree(hs);
2184 return ret;
2185 }
2186
2187 void o2hb_free_hb_set(struct config_group *group)
2188 {
2189 struct o2hb_heartbeat_group *hs = to_o2hb_heartbeat_group(group);
2190 kfree(hs);
2191 }
2192
2193 /* hb callback registration and issueing */
2194
2195 static struct o2hb_callback *hbcall_from_type(enum o2hb_callback_type type)
2196 {
2197 if (type == O2HB_NUM_CB)
2198 return ERR_PTR(-EINVAL);
2199
2200 return &o2hb_callbacks[type];
2201 }
2202
2203 void o2hb_setup_callback(struct o2hb_callback_func *hc,
2204 enum o2hb_callback_type type,
2205 o2hb_cb_func *func,
2206 void *data,
2207 int priority)
2208 {
2209 INIT_LIST_HEAD(&hc->hc_item);
2210 hc->hc_func = func;
2211 hc->hc_data = data;
2212 hc->hc_priority = priority;
2213 hc->hc_type = type;
2214 hc->hc_magic = O2HB_CB_MAGIC;
2215 }
2216 EXPORT_SYMBOL_GPL(o2hb_setup_callback);
2217
2218 static struct o2hb_region *o2hb_find_region(const char *region_uuid)
2219 {
2220 struct o2hb_region *p, *reg = NULL;
2221
2222 assert_spin_locked(&o2hb_live_lock);
2223
2224 list_for_each_entry(p, &o2hb_all_regions, hr_all_item) {
2225 if (!strcmp(region_uuid, config_item_name(&p->hr_item))) {
2226 reg = p;
2227 break;
2228 }
2229 }
2230
2231 return reg;
2232 }
2233
2234 static int o2hb_region_get(const char *region_uuid)
2235 {
2236 int ret = 0;
2237 struct o2hb_region *reg;
2238
2239 spin_lock(&o2hb_live_lock);
2240
2241 reg = o2hb_find_region(region_uuid);
2242 if (!reg)
2243 ret = -ENOENT;
2244 spin_unlock(&o2hb_live_lock);
2245
2246 if (ret)
2247 goto out;
2248
2249 ret = o2nm_depend_this_node();
2250 if (ret)
2251 goto out;
2252
2253 ret = o2nm_depend_item(&reg->hr_item);
2254 if (ret)
2255 o2nm_undepend_this_node();
2256
2257 out:
2258 return ret;
2259 }
2260
2261 static void o2hb_region_put(const char *region_uuid)
2262 {
2263 struct o2hb_region *reg;
2264
2265 spin_lock(&o2hb_live_lock);
2266
2267 reg = o2hb_find_region(region_uuid);
2268
2269 spin_unlock(&o2hb_live_lock);
2270
2271 if (reg) {
2272 o2nm_undepend_item(&reg->hr_item);
2273 o2nm_undepend_this_node();
2274 }
2275 }
2276
2277 int o2hb_register_callback(const char *region_uuid,
2278 struct o2hb_callback_func *hc)
2279 {
2280 struct o2hb_callback_func *tmp;
2281 struct list_head *iter;
2282 struct o2hb_callback *hbcall;
2283 int ret;
2284
2285 BUG_ON(hc->hc_magic != O2HB_CB_MAGIC);
2286 BUG_ON(!list_empty(&hc->hc_item));
2287
2288 hbcall = hbcall_from_type(hc->hc_type);
2289 if (IS_ERR(hbcall)) {
2290 ret = PTR_ERR(hbcall);
2291 goto out;
2292 }
2293
2294 if (region_uuid) {
2295 ret = o2hb_region_get(region_uuid);
2296 if (ret)
2297 goto out;
2298 }
2299
2300 down_write(&o2hb_callback_sem);
2301
2302 list_for_each(iter, &hbcall->list) {
2303 tmp = list_entry(iter, struct o2hb_callback_func, hc_item);
2304 if (hc->hc_priority < tmp->hc_priority) {
2305 list_add_tail(&hc->hc_item, iter);
2306 break;
2307 }
2308 }
2309 if (list_empty(&hc->hc_item))
2310 list_add_tail(&hc->hc_item, &hbcall->list);
2311
2312 up_write(&o2hb_callback_sem);
2313 ret = 0;
2314 out:
2315 mlog(ML_HEARTBEAT, "returning %d on behalf of %p for funcs %p\n",
2316 ret, __builtin_return_address(0), hc);
2317 return ret;
2318 }
2319 EXPORT_SYMBOL_GPL(o2hb_register_callback);
2320
2321 void o2hb_unregister_callback(const char *region_uuid,
2322 struct o2hb_callback_func *hc)
2323 {
2324 BUG_ON(hc->hc_magic != O2HB_CB_MAGIC);
2325
2326 mlog(ML_HEARTBEAT, "on behalf of %p for funcs %p\n",
2327 __builtin_return_address(0), hc);
2328
2329 /* XXX Can this happen _with_ a region reference? */
2330 if (list_empty(&hc->hc_item))
2331 return;
2332
2333 if (region_uuid)
2334 o2hb_region_put(region_uuid);
2335
2336 down_write(&o2hb_callback_sem);
2337
2338 list_del_init(&hc->hc_item);
2339
2340 up_write(&o2hb_callback_sem);
2341 }
2342 EXPORT_SYMBOL_GPL(o2hb_unregister_callback);
2343
2344 int o2hb_check_node_heartbeating(u8 node_num)
2345 {
2346 unsigned long testing_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
2347
2348 o2hb_fill_node_map(testing_map, sizeof(testing_map));
2349 if (!test_bit(node_num, testing_map)) {
2350 mlog(ML_HEARTBEAT,
2351 "node (%u) does not have heartbeating enabled.\n",
2352 node_num);
2353 return 0;
2354 }
2355
2356 return 1;
2357 }
2358 EXPORT_SYMBOL_GPL(o2hb_check_node_heartbeating);
2359
2360 int o2hb_check_node_heartbeating_from_callback(u8 node_num)
2361 {
2362 unsigned long testing_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
2363
2364 o2hb_fill_node_map_from_callback(testing_map, sizeof(testing_map));
2365 if (!test_bit(node_num, testing_map)) {
2366 mlog(ML_HEARTBEAT,
2367 "node (%u) does not have heartbeating enabled.\n",
2368 node_num);
2369 return 0;
2370 }
2371
2372 return 1;
2373 }
2374 EXPORT_SYMBOL_GPL(o2hb_check_node_heartbeating_from_callback);
2375
2376 /* Makes sure our local node is configured with a node number, and is
2377 * heartbeating. */
2378 int o2hb_check_local_node_heartbeating(void)
2379 {
2380 u8 node_num;
2381
2382 /* if this node was set then we have networking */
2383 node_num = o2nm_this_node();
2384 if (node_num == O2NM_MAX_NODES) {
2385 mlog(ML_HEARTBEAT, "this node has not been configured.\n");
2386 return 0;
2387 }
2388
2389 return o2hb_check_node_heartbeating(node_num);
2390 }
2391 EXPORT_SYMBOL_GPL(o2hb_check_local_node_heartbeating);
2392
2393 /*
2394 * this is just a hack until we get the plumbing which flips file systems
2395 * read only and drops the hb ref instead of killing the node dead.
2396 */
2397 void o2hb_stop_all_regions(void)
2398 {
2399 struct o2hb_region *reg;
2400
2401 mlog(ML_ERROR, "stopping heartbeat on all active regions.\n");
2402
2403 spin_lock(&o2hb_live_lock);
2404
2405 list_for_each_entry(reg, &o2hb_all_regions, hr_all_item)
2406 reg->hr_unclean_stop = 1;
2407
2408 spin_unlock(&o2hb_live_lock);
2409 }
2410 EXPORT_SYMBOL_GPL(o2hb_stop_all_regions);
2411
2412 int o2hb_get_all_regions(char *region_uuids, u8 max_regions)
2413 {
2414 struct o2hb_region *reg;
2415 int numregs = 0;
2416 char *p;
2417
2418 spin_lock(&o2hb_live_lock);
2419
2420 p = region_uuids;
2421 list_for_each_entry(reg, &o2hb_all_regions, hr_all_item) {
2422 mlog(0, "Region: %s\n", config_item_name(&reg->hr_item));
2423 if (numregs < max_regions) {
2424 memcpy(p, config_item_name(&reg->hr_item),
2425 O2HB_MAX_REGION_NAME_LEN);
2426 p += O2HB_MAX_REGION_NAME_LEN;
2427 }
2428 numregs++;
2429 }
2430
2431 spin_unlock(&o2hb_live_lock);
2432
2433 return numregs;
2434 }
2435 EXPORT_SYMBOL_GPL(o2hb_get_all_regions);
2436
2437 int o2hb_global_heartbeat_active(void)
2438 {
2439 return (o2hb_heartbeat_mode == O2HB_HEARTBEAT_GLOBAL);
2440 }
2441 EXPORT_SYMBOL(o2hb_global_heartbeat_active);
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree