blob: 305cba3681fe0126b4d1e33dd58c3b0cc3bea8a5 [file] [log] [blame]
Mark Fasheha7f6a5f2005-12-15 14:31:23 -08001/* -*- 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
37#include "heartbeat.h"
38#include "tcp.h"
39#include "nodemanager.h"
40#include "quorum.h"
41
42#include "masklog.h"
43
44
45/*
46 * The first heartbeat pass had one global thread that would serialize all hb
47 * callback calls. This global serializing sem should only be removed once
48 * we've made sure that all callees can deal with being called concurrently
49 * from multiple hb region threads.
50 */
51static DECLARE_RWSEM(o2hb_callback_sem);
52
53/*
54 * multiple hb threads are watching multiple regions. A node is live
55 * whenever any of the threads sees activity from the node in its region.
56 */
Ingo Molnar34af9462006-06-27 02:53:55 -070057static DEFINE_SPINLOCK(o2hb_live_lock);
Mark Fasheha7f6a5f2005-12-15 14:31:23 -080058static struct list_head o2hb_live_slots[O2NM_MAX_NODES];
59static unsigned long o2hb_live_node_bitmap[BITS_TO_LONGS(O2NM_MAX_NODES)];
60static LIST_HEAD(o2hb_node_events);
61static DECLARE_WAIT_QUEUE_HEAD(o2hb_steady_queue);
62
63static LIST_HEAD(o2hb_all_regions);
64
65static struct o2hb_callback {
66 struct list_head list;
67} o2hb_callbacks[O2HB_NUM_CB];
68
69static struct o2hb_callback *hbcall_from_type(enum o2hb_callback_type type);
70
71#define O2HB_DEFAULT_BLOCK_BITS 9
72
73unsigned int o2hb_dead_threshold = O2HB_DEFAULT_DEAD_THRESHOLD;
74
75/* Only sets a new threshold if there are no active regions.
76 *
77 * No locking or otherwise interesting code is required for reading
78 * o2hb_dead_threshold as it can't change once regions are active and
79 * it's not interesting to anyone until then anyway. */
80static void o2hb_dead_threshold_set(unsigned int threshold)
81{
82 if (threshold > O2HB_MIN_DEAD_THRESHOLD) {
83 spin_lock(&o2hb_live_lock);
84 if (list_empty(&o2hb_all_regions))
85 o2hb_dead_threshold = threshold;
86 spin_unlock(&o2hb_live_lock);
87 }
88}
89
90struct o2hb_node_event {
91 struct list_head hn_item;
92 enum o2hb_callback_type hn_event_type;
93 struct o2nm_node *hn_node;
94 int hn_node_num;
95};
96
97struct o2hb_disk_slot {
98 struct o2hb_disk_heartbeat_block *ds_raw_block;
99 u8 ds_node_num;
100 u64 ds_last_time;
101 u64 ds_last_generation;
102 u16 ds_equal_samples;
103 u16 ds_changed_samples;
104 struct list_head ds_live_item;
105};
106
107/* each thread owns a region.. when we're asked to tear down the region
108 * we ask the thread to stop, who cleans up the region */
109struct o2hb_region {
110 struct config_item hr_item;
111
112 struct list_head hr_all_item;
113 unsigned hr_unclean_stop:1;
114
115 /* protected by the hr_callback_sem */
116 struct task_struct *hr_task;
117
118 unsigned int hr_blocks;
119 unsigned long long hr_start_block;
120
121 unsigned int hr_block_bits;
122 unsigned int hr_block_bytes;
123
124 unsigned int hr_slots_per_page;
125 unsigned int hr_num_pages;
126
127 struct page **hr_slot_data;
128 struct block_device *hr_bdev;
129 struct o2hb_disk_slot *hr_slots;
130
131 /* let the person setting up hb wait for it to return until it
132 * has reached a 'steady' state. This will be fixed when we have
133 * a more complete api that doesn't lead to this sort of fragility. */
134 atomic_t hr_steady_iterations;
135
136 char hr_dev_name[BDEVNAME_SIZE];
137
138 unsigned int hr_timeout_ms;
139
140 /* randomized as the region goes up and down so that a node
141 * recognizes a node going up and down in one iteration */
142 u64 hr_generation;
143
144 struct work_struct hr_write_timeout_work;
145 unsigned long hr_last_timeout_start;
146
147 /* Used during o2hb_check_slot to hold a copy of the block
148 * being checked because we temporarily have to zero out the
149 * crc field. */
150 struct o2hb_disk_heartbeat_block *hr_tmp_block;
151};
152
153struct o2hb_bio_wait_ctxt {
154 atomic_t wc_num_reqs;
155 struct completion wc_io_complete;
Mark Fasheha9e2ae32006-03-24 14:20:17 -0800156 int wc_error;
Mark Fasheha7f6a5f2005-12-15 14:31:23 -0800157};
158
159static void o2hb_write_timeout(void *arg)
160{
161 struct o2hb_region *reg = arg;
162
163 mlog(ML_ERROR, "Heartbeat write timeout to device %s after %u "
164 "milliseconds\n", reg->hr_dev_name,
165 jiffies_to_msecs(jiffies - reg->hr_last_timeout_start));
166 o2quo_disk_timeout();
167}
168
169static void o2hb_arm_write_timeout(struct o2hb_region *reg)
170{
171 mlog(0, "Queue write timeout for %u ms\n", O2HB_MAX_WRITE_TIMEOUT_MS);
172
173 cancel_delayed_work(&reg->hr_write_timeout_work);
174 reg->hr_last_timeout_start = jiffies;
175 schedule_delayed_work(&reg->hr_write_timeout_work,
176 msecs_to_jiffies(O2HB_MAX_WRITE_TIMEOUT_MS));
177}
178
179static void o2hb_disarm_write_timeout(struct o2hb_region *reg)
180{
181 cancel_delayed_work(&reg->hr_write_timeout_work);
182 flush_scheduled_work();
183}
184
185static inline void o2hb_bio_wait_init(struct o2hb_bio_wait_ctxt *wc,
186 unsigned int num_ios)
187{
188 atomic_set(&wc->wc_num_reqs, num_ios);
189 init_completion(&wc->wc_io_complete);
Mark Fasheha9e2ae32006-03-24 14:20:17 -0800190 wc->wc_error = 0;
Mark Fasheha7f6a5f2005-12-15 14:31:23 -0800191}
192
193/* Used in error paths too */
194static inline void o2hb_bio_wait_dec(struct o2hb_bio_wait_ctxt *wc,
195 unsigned int num)
196{
197 /* sadly atomic_sub_and_test() isn't available on all platforms. The
198 * good news is that the fast path only completes one at a time */
199 while(num--) {
200 if (atomic_dec_and_test(&wc->wc_num_reqs)) {
201 BUG_ON(num > 0);
202 complete(&wc->wc_io_complete);
203 }
204 }
205}
206
207static void o2hb_wait_on_io(struct o2hb_region *reg,
208 struct o2hb_bio_wait_ctxt *wc)
209{
210 struct address_space *mapping = reg->hr_bdev->bd_inode->i_mapping;
211
212 blk_run_address_space(mapping);
213
214 wait_for_completion(&wc->wc_io_complete);
215}
216
217static int o2hb_bio_end_io(struct bio *bio,
218 unsigned int bytes_done,
219 int error)
220{
221 struct o2hb_bio_wait_ctxt *wc = bio->bi_private;
222
Mark Fasheha9e2ae32006-03-24 14:20:17 -0800223 if (error) {
Mark Fasheha7f6a5f2005-12-15 14:31:23 -0800224 mlog(ML_ERROR, "IO Error %d\n", error);
Mark Fasheha9e2ae32006-03-24 14:20:17 -0800225 wc->wc_error = error;
226 }
Mark Fasheha7f6a5f2005-12-15 14:31:23 -0800227
228 if (bio->bi_size)
229 return 1;
230
231 o2hb_bio_wait_dec(wc, 1);
232 return 0;
233}
234
235/* Setup a Bio to cover I/O against num_slots slots starting at
236 * start_slot. */
237static struct bio *o2hb_setup_one_bio(struct o2hb_region *reg,
238 struct o2hb_bio_wait_ctxt *wc,
239 unsigned int start_slot,
240 unsigned int num_slots)
241{
242 int i, nr_vecs, len, first_page, last_page;
243 unsigned int vec_len, vec_start;
244 unsigned int bits = reg->hr_block_bits;
245 unsigned int spp = reg->hr_slots_per_page;
246 struct bio *bio;
247 struct page *page;
248
249 nr_vecs = (num_slots + spp - 1) / spp;
250
251 /* Testing has shown this allocation to take long enough under
252 * GFP_KERNEL that the local node can get fenced. It would be
253 * nicest if we could pre-allocate these bios and avoid this
254 * all together. */
255 bio = bio_alloc(GFP_ATOMIC, nr_vecs);
256 if (!bio) {
257 mlog(ML_ERROR, "Could not alloc slots BIO!\n");
258 bio = ERR_PTR(-ENOMEM);
259 goto bail;
260 }
261
262 /* Must put everything in 512 byte sectors for the bio... */
263 bio->bi_sector = (reg->hr_start_block + start_slot) << (bits - 9);
264 bio->bi_bdev = reg->hr_bdev;
265 bio->bi_private = wc;
266 bio->bi_end_io = o2hb_bio_end_io;
267
268 first_page = start_slot / spp;
269 last_page = first_page + nr_vecs;
270 vec_start = (start_slot << bits) % PAGE_CACHE_SIZE;
271 for(i = first_page; i < last_page; i++) {
272 page = reg->hr_slot_data[i];
273
274 vec_len = PAGE_CACHE_SIZE;
275 /* last page might be short */
276 if (((i + 1) * spp) > (start_slot + num_slots))
277 vec_len = ((num_slots + start_slot) % spp) << bits;
278 vec_len -= vec_start;
279
280 mlog(ML_HB_BIO, "page %d, vec_len = %u, vec_start = %u\n",
281 i, vec_len, vec_start);
282
283 len = bio_add_page(bio, page, vec_len, vec_start);
284 if (len != vec_len) {
285 bio_put(bio);
286 bio = ERR_PTR(-EIO);
287
288 mlog(ML_ERROR, "Error adding page to bio i = %d, "
289 "vec_len = %u, len = %d\n, start = %u\n",
290 i, vec_len, len, vec_start);
291 goto bail;
292 }
293
294 vec_start = 0;
295 }
296
297bail:
298 return bio;
299}
300
301/*
302 * Compute the maximum number of sectors the bdev can handle in one bio,
303 * as a power of two.
304 *
305 * Stolen from oracleasm, thanks Joel!
306 */
307static int compute_max_sectors(struct block_device *bdev)
308{
309 int max_pages, max_sectors, pow_two_sectors;
310
311 struct request_queue *q;
312
313 q = bdev_get_queue(bdev);
314 max_pages = q->max_sectors >> (PAGE_SHIFT - 9);
315 if (max_pages > BIO_MAX_PAGES)
316 max_pages = BIO_MAX_PAGES;
317 if (max_pages > q->max_phys_segments)
318 max_pages = q->max_phys_segments;
319 if (max_pages > q->max_hw_segments)
320 max_pages = q->max_hw_segments;
321 max_pages--; /* Handle I/Os that straddle a page */
322
Mathieu Avila471e3f52006-09-13 11:11:27 -0700323 if (max_pages) {
324 max_sectors = max_pages << (PAGE_SHIFT - 9);
325 } else {
326 /* If BIO contains 1 or less than 1 page. */
327 max_sectors = q->max_sectors;
328 }
Mark Fasheha7f6a5f2005-12-15 14:31:23 -0800329 /* Why is fls() 1-based???? */
330 pow_two_sectors = 1 << (fls(max_sectors) - 1);
331
332 return pow_two_sectors;
333}
334
335static inline void o2hb_compute_request_limits(struct o2hb_region *reg,
336 unsigned int num_slots,
337 unsigned int *num_bios,
338 unsigned int *slots_per_bio)
339{
340 unsigned int max_sectors, io_sectors;
341
342 max_sectors = compute_max_sectors(reg->hr_bdev);
343
344 io_sectors = num_slots << (reg->hr_block_bits - 9);
345
346 *num_bios = (io_sectors + max_sectors - 1) / max_sectors;
347 *slots_per_bio = max_sectors >> (reg->hr_block_bits - 9);
348
349 mlog(ML_HB_BIO, "My io size is %u sectors for %u slots. This "
350 "device can handle %u sectors of I/O\n", io_sectors, num_slots,
351 max_sectors);
352 mlog(ML_HB_BIO, "Will need %u bios holding %u slots each\n",
353 *num_bios, *slots_per_bio);
354}
355
356static int o2hb_read_slots(struct o2hb_region *reg,
357 unsigned int max_slots)
358{
359 unsigned int num_bios, slots_per_bio, start_slot, num_slots;
360 int i, status;
361 struct o2hb_bio_wait_ctxt wc;
362 struct bio **bios;
363 struct bio *bio;
364
365 o2hb_compute_request_limits(reg, max_slots, &num_bios, &slots_per_bio);
366
367 bios = kcalloc(num_bios, sizeof(struct bio *), GFP_KERNEL);
368 if (!bios) {
369 status = -ENOMEM;
370 mlog_errno(status);
371 return status;
372 }
373
374 o2hb_bio_wait_init(&wc, num_bios);
375
376 num_slots = slots_per_bio;
377 for(i = 0; i < num_bios; i++) {
378 start_slot = i * slots_per_bio;
379
380 /* adjust num_slots at last bio */
381 if (max_slots < (start_slot + num_slots))
382 num_slots = max_slots - start_slot;
383
384 bio = o2hb_setup_one_bio(reg, &wc, start_slot, num_slots);
385 if (IS_ERR(bio)) {
386 o2hb_bio_wait_dec(&wc, num_bios - i);
387
388 status = PTR_ERR(bio);
389 mlog_errno(status);
390 goto bail_and_wait;
391 }
392 bios[i] = bio;
393
394 submit_bio(READ, bio);
395 }
396
397 status = 0;
398
399bail_and_wait:
400 o2hb_wait_on_io(reg, &wc);
Mark Fasheha9e2ae32006-03-24 14:20:17 -0800401 if (wc.wc_error && !status)
402 status = wc.wc_error;
Mark Fasheha7f6a5f2005-12-15 14:31:23 -0800403
404 if (bios) {
405 for(i = 0; i < num_bios; i++)
406 if (bios[i])
407 bio_put(bios[i]);
408 kfree(bios);
409 }
410
411 return status;
412}
413
414static int o2hb_issue_node_write(struct o2hb_region *reg,
415 struct bio **write_bio,
416 struct o2hb_bio_wait_ctxt *write_wc)
417{
418 int status;
419 unsigned int slot;
420 struct bio *bio;
421
422 o2hb_bio_wait_init(write_wc, 1);
423
424 slot = o2nm_this_node();
425
426 bio = o2hb_setup_one_bio(reg, write_wc, slot, 1);
427 if (IS_ERR(bio)) {
428 status = PTR_ERR(bio);
429 mlog_errno(status);
430 goto bail;
431 }
432
433 submit_bio(WRITE, bio);
434
435 *write_bio = bio;
436 status = 0;
437bail:
438 return status;
439}
440
441static u32 o2hb_compute_block_crc_le(struct o2hb_region *reg,
442 struct o2hb_disk_heartbeat_block *hb_block)
443{
444 __le32 old_cksum;
445 u32 ret;
446
447 /* We want to compute the block crc with a 0 value in the
448 * hb_cksum field. Save it off here and replace after the
449 * crc. */
450 old_cksum = hb_block->hb_cksum;
451 hb_block->hb_cksum = 0;
452
453 ret = crc32_le(0, (unsigned char *) hb_block, reg->hr_block_bytes);
454
455 hb_block->hb_cksum = old_cksum;
456
457 return ret;
458}
459
460static void o2hb_dump_slot(struct o2hb_disk_heartbeat_block *hb_block)
461{
Mark Fasheh70bacbd2006-03-02 11:10:05 -0800462 mlog(ML_ERROR, "Dump slot information: seq = 0x%llx, node = %u, "
463 "cksum = 0x%x, generation 0x%llx\n",
464 (long long)le64_to_cpu(hb_block->hb_seq),
465 hb_block->hb_node, le32_to_cpu(hb_block->hb_cksum),
466 (long long)le64_to_cpu(hb_block->hb_generation));
Mark Fasheha7f6a5f2005-12-15 14:31:23 -0800467}
468
469static int o2hb_verify_crc(struct o2hb_region *reg,
470 struct o2hb_disk_heartbeat_block *hb_block)
471{
472 u32 read, computed;
473
474 read = le32_to_cpu(hb_block->hb_cksum);
475 computed = o2hb_compute_block_crc_le(reg, hb_block);
476
477 return read == computed;
478}
479
480/* We want to make sure that nobody is heartbeating on top of us --
481 * this will help detect an invalid configuration. */
482static int o2hb_check_last_timestamp(struct o2hb_region *reg)
483{
484 int node_num, ret;
485 struct o2hb_disk_slot *slot;
486 struct o2hb_disk_heartbeat_block *hb_block;
487
488 node_num = o2nm_this_node();
489
490 ret = 1;
491 slot = &reg->hr_slots[node_num];
492 /* Don't check on our 1st timestamp */
493 if (slot->ds_last_time) {
494 hb_block = slot->ds_raw_block;
495
496 if (le64_to_cpu(hb_block->hb_seq) != slot->ds_last_time)
497 ret = 0;
498 }
499
500 return ret;
501}
502
503static inline void o2hb_prepare_block(struct o2hb_region *reg,
504 u64 generation)
505{
506 int node_num;
507 u64 cputime;
508 struct o2hb_disk_slot *slot;
509 struct o2hb_disk_heartbeat_block *hb_block;
510
511 node_num = o2nm_this_node();
512 slot = &reg->hr_slots[node_num];
513
514 hb_block = (struct o2hb_disk_heartbeat_block *)slot->ds_raw_block;
515 memset(hb_block, 0, reg->hr_block_bytes);
516 /* TODO: time stuff */
517 cputime = CURRENT_TIME.tv_sec;
518 if (!cputime)
519 cputime = 1;
520
521 hb_block->hb_seq = cpu_to_le64(cputime);
522 hb_block->hb_node = node_num;
523 hb_block->hb_generation = cpu_to_le64(generation);
Mark Fasheh0db638f2006-05-09 15:09:35 -0700524 hb_block->hb_dead_ms = cpu_to_le32(o2hb_dead_threshold * O2HB_REGION_TIMEOUT_MS);
Mark Fasheha7f6a5f2005-12-15 14:31:23 -0800525
526 /* This step must always happen last! */
527 hb_block->hb_cksum = cpu_to_le32(o2hb_compute_block_crc_le(reg,
528 hb_block));
529
Mark Fasheh70bacbd2006-03-02 11:10:05 -0800530 mlog(ML_HB_BIO, "our node generation = 0x%llx, cksum = 0x%x\n",
531 (long long)cpu_to_le64(generation),
532 le32_to_cpu(hb_block->hb_cksum));
Mark Fasheha7f6a5f2005-12-15 14:31:23 -0800533}
534
535static void o2hb_fire_callbacks(struct o2hb_callback *hbcall,
536 struct o2nm_node *node,
537 int idx)
538{
539 struct list_head *iter;
540 struct o2hb_callback_func *f;
541
542 list_for_each(iter, &hbcall->list) {
543 f = list_entry(iter, struct o2hb_callback_func, hc_item);
544 mlog(ML_HEARTBEAT, "calling funcs %p\n", f);
545 (f->hc_func)(node, idx, f->hc_data);
546 }
547}
548
549/* Will run the list in order until we process the passed event */
550static void o2hb_run_event_list(struct o2hb_node_event *queued_event)
551{
552 int empty;
553 struct o2hb_callback *hbcall;
554 struct o2hb_node_event *event;
555
556 spin_lock(&o2hb_live_lock);
557 empty = list_empty(&queued_event->hn_item);
558 spin_unlock(&o2hb_live_lock);
559 if (empty)
560 return;
561
562 /* Holding callback sem assures we don't alter the callback
563 * lists when doing this, and serializes ourselves with other
564 * processes wanting callbacks. */
565 down_write(&o2hb_callback_sem);
566
567 spin_lock(&o2hb_live_lock);
568 while (!list_empty(&o2hb_node_events)
569 && !list_empty(&queued_event->hn_item)) {
570 event = list_entry(o2hb_node_events.next,
571 struct o2hb_node_event,
572 hn_item);
573 list_del_init(&event->hn_item);
574 spin_unlock(&o2hb_live_lock);
575
576 mlog(ML_HEARTBEAT, "Node %s event for %d\n",
577 event->hn_event_type == O2HB_NODE_UP_CB ? "UP" : "DOWN",
578 event->hn_node_num);
579
580 hbcall = hbcall_from_type(event->hn_event_type);
581
582 /* We should *never* have gotten on to the list with a
583 * bad type... This isn't something that we should try
584 * to recover from. */
585 BUG_ON(IS_ERR(hbcall));
586
587 o2hb_fire_callbacks(hbcall, event->hn_node, event->hn_node_num);
588
589 spin_lock(&o2hb_live_lock);
590 }
591 spin_unlock(&o2hb_live_lock);
592
593 up_write(&o2hb_callback_sem);
594}
595
596static void o2hb_queue_node_event(struct o2hb_node_event *event,
597 enum o2hb_callback_type type,
598 struct o2nm_node *node,
599 int node_num)
600{
601 assert_spin_locked(&o2hb_live_lock);
602
603 event->hn_event_type = type;
604 event->hn_node = node;
605 event->hn_node_num = node_num;
606
607 mlog(ML_HEARTBEAT, "Queue node %s event for node %d\n",
608 type == O2HB_NODE_UP_CB ? "UP" : "DOWN", node_num);
609
610 list_add_tail(&event->hn_item, &o2hb_node_events);
611}
612
613static void o2hb_shutdown_slot(struct o2hb_disk_slot *slot)
614{
615 struct o2hb_node_event event =
616 { .hn_item = LIST_HEAD_INIT(event.hn_item), };
617 struct o2nm_node *node;
618
619 node = o2nm_get_node_by_num(slot->ds_node_num);
620 if (!node)
621 return;
622
623 spin_lock(&o2hb_live_lock);
624 if (!list_empty(&slot->ds_live_item)) {
625 mlog(ML_HEARTBEAT, "Shutdown, node %d leaves region\n",
626 slot->ds_node_num);
627
628 list_del_init(&slot->ds_live_item);
629
630 if (list_empty(&o2hb_live_slots[slot->ds_node_num])) {
631 clear_bit(slot->ds_node_num, o2hb_live_node_bitmap);
632
633 o2hb_queue_node_event(&event, O2HB_NODE_DOWN_CB, node,
634 slot->ds_node_num);
635 }
636 }
637 spin_unlock(&o2hb_live_lock);
638
639 o2hb_run_event_list(&event);
640
641 o2nm_node_put(node);
642}
643
644static int o2hb_check_slot(struct o2hb_region *reg,
645 struct o2hb_disk_slot *slot)
646{
647 int changed = 0, gen_changed = 0;
648 struct o2hb_node_event event =
649 { .hn_item = LIST_HEAD_INIT(event.hn_item), };
650 struct o2nm_node *node;
651 struct o2hb_disk_heartbeat_block *hb_block = reg->hr_tmp_block;
652 u64 cputime;
Mark Fasheh0db638f2006-05-09 15:09:35 -0700653 unsigned int dead_ms = o2hb_dead_threshold * O2HB_REGION_TIMEOUT_MS;
654 unsigned int slot_dead_ms;
Mark Fasheha7f6a5f2005-12-15 14:31:23 -0800655
656 memcpy(hb_block, slot->ds_raw_block, reg->hr_block_bytes);
657
658 /* Is this correct? Do we assume that the node doesn't exist
659 * if we're not configured for him? */
660 node = o2nm_get_node_by_num(slot->ds_node_num);
661 if (!node)
662 return 0;
663
664 if (!o2hb_verify_crc(reg, hb_block)) {
665 /* all paths from here will drop o2hb_live_lock for
666 * us. */
667 spin_lock(&o2hb_live_lock);
668
669 /* Don't print an error on the console in this case -
670 * a freshly formatted heartbeat area will not have a
671 * crc set on it. */
672 if (list_empty(&slot->ds_live_item))
673 goto out;
674
675 /* The node is live but pushed out a bad crc. We
676 * consider it a transient miss but don't populate any
677 * other values as they may be junk. */
678 mlog(ML_ERROR, "Node %d has written a bad crc to %s\n",
679 slot->ds_node_num, reg->hr_dev_name);
680 o2hb_dump_slot(hb_block);
681
682 slot->ds_equal_samples++;
683 goto fire_callbacks;
684 }
685
686 /* we don't care if these wrap.. the state transitions below
687 * clear at the right places */
688 cputime = le64_to_cpu(hb_block->hb_seq);
689 if (slot->ds_last_time != cputime)
690 slot->ds_changed_samples++;
691 else
692 slot->ds_equal_samples++;
693 slot->ds_last_time = cputime;
694
695 /* The node changed heartbeat generations. We assume this to
696 * mean it dropped off but came back before we timed out. We
697 * want to consider it down for the time being but don't want
698 * to lose any changed_samples state we might build up to
699 * considering it live again. */
700 if (slot->ds_last_generation != le64_to_cpu(hb_block->hb_generation)) {
701 gen_changed = 1;
702 slot->ds_equal_samples = 0;
Mark Fasheh70bacbd2006-03-02 11:10:05 -0800703 mlog(ML_HEARTBEAT, "Node %d changed generation (0x%llx "
704 "to 0x%llx)\n", slot->ds_node_num,
705 (long long)slot->ds_last_generation,
706 (long long)le64_to_cpu(hb_block->hb_generation));
Mark Fasheha7f6a5f2005-12-15 14:31:23 -0800707 }
708
709 slot->ds_last_generation = le64_to_cpu(hb_block->hb_generation);
710
Mark Fasheh70bacbd2006-03-02 11:10:05 -0800711 mlog(ML_HEARTBEAT, "Slot %d gen 0x%llx cksum 0x%x "
712 "seq %llu last %llu changed %u equal %u\n",
713 slot->ds_node_num, (long long)slot->ds_last_generation,
714 le32_to_cpu(hb_block->hb_cksum),
715 (unsigned long long)le64_to_cpu(hb_block->hb_seq),
716 (unsigned long long)slot->ds_last_time, slot->ds_changed_samples,
Mark Fasheha7f6a5f2005-12-15 14:31:23 -0800717 slot->ds_equal_samples);
718
719 spin_lock(&o2hb_live_lock);
720
721fire_callbacks:
722 /* dead nodes only come to life after some number of
723 * changes at any time during their dead time */
724 if (list_empty(&slot->ds_live_item) &&
725 slot->ds_changed_samples >= O2HB_LIVE_THRESHOLD) {
Mark Fasheh70bacbd2006-03-02 11:10:05 -0800726 mlog(ML_HEARTBEAT, "Node %d (id 0x%llx) joined my region\n",
727 slot->ds_node_num, (long long)slot->ds_last_generation);
Mark Fasheha7f6a5f2005-12-15 14:31:23 -0800728
729 /* first on the list generates a callback */
730 if (list_empty(&o2hb_live_slots[slot->ds_node_num])) {
731 set_bit(slot->ds_node_num, o2hb_live_node_bitmap);
732
733 o2hb_queue_node_event(&event, O2HB_NODE_UP_CB, node,
734 slot->ds_node_num);
735
736 changed = 1;
737 }
738
739 list_add_tail(&slot->ds_live_item,
740 &o2hb_live_slots[slot->ds_node_num]);
741
742 slot->ds_equal_samples = 0;
Mark Fasheh0db638f2006-05-09 15:09:35 -0700743
744 /* We want to be sure that all nodes agree on the
745 * number of milliseconds before a node will be
746 * considered dead. The self-fencing timeout is
747 * computed from this value, and a discrepancy might
748 * result in heartbeat calling a node dead when it
749 * hasn't self-fenced yet. */
750 slot_dead_ms = le32_to_cpu(hb_block->hb_dead_ms);
751 if (slot_dead_ms && slot_dead_ms != dead_ms) {
752 /* TODO: Perhaps we can fail the region here. */
753 mlog(ML_ERROR, "Node %d on device %s has a dead count "
754 "of %u ms, but our count is %u ms.\n"
755 "Please double check your configuration values "
756 "for 'O2CB_HEARTBEAT_THRESHOLD'\n",
757 slot->ds_node_num, reg->hr_dev_name, slot_dead_ms,
758 dead_ms);
759 }
Mark Fasheha7f6a5f2005-12-15 14:31:23 -0800760 goto out;
761 }
762
763 /* if the list is dead, we're done.. */
764 if (list_empty(&slot->ds_live_item))
765 goto out;
766
767 /* live nodes only go dead after enough consequtive missed
768 * samples.. reset the missed counter whenever we see
769 * activity */
770 if (slot->ds_equal_samples >= o2hb_dead_threshold || gen_changed) {
771 mlog(ML_HEARTBEAT, "Node %d left my region\n",
772 slot->ds_node_num);
773
774 /* last off the live_slot generates a callback */
775 list_del_init(&slot->ds_live_item);
776 if (list_empty(&o2hb_live_slots[slot->ds_node_num])) {
777 clear_bit(slot->ds_node_num, o2hb_live_node_bitmap);
778
779 o2hb_queue_node_event(&event, O2HB_NODE_DOWN_CB, node,
780 slot->ds_node_num);
781
782 changed = 1;
783 }
784
785 /* We don't clear this because the node is still
786 * actually writing new blocks. */
787 if (!gen_changed)
788 slot->ds_changed_samples = 0;
789 goto out;
790 }
791 if (slot->ds_changed_samples) {
792 slot->ds_changed_samples = 0;
793 slot->ds_equal_samples = 0;
794 }
795out:
796 spin_unlock(&o2hb_live_lock);
797
798 o2hb_run_event_list(&event);
799
800 o2nm_node_put(node);
801 return changed;
802}
803
804/* This could be faster if we just implmented a find_last_bit, but I
805 * don't think the circumstances warrant it. */
806static int o2hb_highest_node(unsigned long *nodes,
807 int numbits)
808{
809 int highest, node;
810
811 highest = numbits;
812 node = -1;
813 while ((node = find_next_bit(nodes, numbits, node + 1)) != -1) {
814 if (node >= numbits)
815 break;
816
817 highest = node;
818 }
819
820 return highest;
821}
822
Mark Fasheha9e2ae32006-03-24 14:20:17 -0800823static int o2hb_do_disk_heartbeat(struct o2hb_region *reg)
Mark Fasheha7f6a5f2005-12-15 14:31:23 -0800824{
825 int i, ret, highest_node, change = 0;
826 unsigned long configured_nodes[BITS_TO_LONGS(O2NM_MAX_NODES)];
827 struct bio *write_bio;
828 struct o2hb_bio_wait_ctxt write_wc;
829
Mark Fasheha9e2ae32006-03-24 14:20:17 -0800830 ret = o2nm_configured_node_map(configured_nodes,
831 sizeof(configured_nodes));
832 if (ret) {
833 mlog_errno(ret);
834 return ret;
835 }
Mark Fasheha7f6a5f2005-12-15 14:31:23 -0800836
837 highest_node = o2hb_highest_node(configured_nodes, O2NM_MAX_NODES);
838 if (highest_node >= O2NM_MAX_NODES) {
839 mlog(ML_NOTICE, "ocfs2_heartbeat: no configured nodes found!\n");
Mark Fasheha9e2ae32006-03-24 14:20:17 -0800840 return -EINVAL;
Mark Fasheha7f6a5f2005-12-15 14:31:23 -0800841 }
842
843 /* No sense in reading the slots of nodes that don't exist
844 * yet. Of course, if the node definitions have holes in them
845 * then we're reading an empty slot anyway... Consider this
846 * best-effort. */
847 ret = o2hb_read_slots(reg, highest_node + 1);
848 if (ret < 0) {
849 mlog_errno(ret);
Mark Fasheha9e2ae32006-03-24 14:20:17 -0800850 return ret;
Mark Fasheha7f6a5f2005-12-15 14:31:23 -0800851 }
852
853 /* With an up to date view of the slots, we can check that no
854 * other node has been improperly configured to heartbeat in
855 * our slot. */
856 if (!o2hb_check_last_timestamp(reg))
857 mlog(ML_ERROR, "Device \"%s\": another node is heartbeating "
858 "in our slot!\n", reg->hr_dev_name);
859
860 /* fill in the proper info for our next heartbeat */
861 o2hb_prepare_block(reg, reg->hr_generation);
862
863 /* And fire off the write. Note that we don't wait on this I/O
864 * until later. */
865 ret = o2hb_issue_node_write(reg, &write_bio, &write_wc);
866 if (ret < 0) {
867 mlog_errno(ret);
Mark Fasheha9e2ae32006-03-24 14:20:17 -0800868 return ret;
Mark Fasheha7f6a5f2005-12-15 14:31:23 -0800869 }
870
871 i = -1;
872 while((i = find_next_bit(configured_nodes, O2NM_MAX_NODES, i + 1)) < O2NM_MAX_NODES) {
873
874 change |= o2hb_check_slot(reg, &reg->hr_slots[i]);
875 }
876
877 /*
878 * We have to be sure we've advertised ourselves on disk
879 * before we can go to steady state. This ensures that
880 * people we find in our steady state have seen us.
881 */
882 o2hb_wait_on_io(reg, &write_wc);
883 bio_put(write_bio);
Mark Fasheha9e2ae32006-03-24 14:20:17 -0800884 if (write_wc.wc_error) {
885 /* Do not re-arm the write timeout on I/O error - we
886 * can't be sure that the new block ever made it to
887 * disk */
888 mlog(ML_ERROR, "Write error %d on device \"%s\"\n",
889 write_wc.wc_error, reg->hr_dev_name);
890 return write_wc.wc_error;
891 }
892
Mark Fasheha7f6a5f2005-12-15 14:31:23 -0800893 o2hb_arm_write_timeout(reg);
894
895 /* let the person who launched us know when things are steady */
896 if (!change && (atomic_read(&reg->hr_steady_iterations) != 0)) {
897 if (atomic_dec_and_test(&reg->hr_steady_iterations))
898 wake_up(&o2hb_steady_queue);
899 }
Mark Fasheha9e2ae32006-03-24 14:20:17 -0800900
901 return 0;
Mark Fasheha7f6a5f2005-12-15 14:31:23 -0800902}
903
904/* Subtract b from a, storing the result in a. a *must* have a larger
905 * value than b. */
906static void o2hb_tv_subtract(struct timeval *a,
907 struct timeval *b)
908{
909 /* just return 0 when a is after b */
910 if (a->tv_sec < b->tv_sec ||
911 (a->tv_sec == b->tv_sec && a->tv_usec < b->tv_usec)) {
912 a->tv_sec = 0;
913 a->tv_usec = 0;
914 return;
915 }
916
917 a->tv_sec -= b->tv_sec;
918 a->tv_usec -= b->tv_usec;
919 while ( a->tv_usec < 0 ) {
920 a->tv_sec--;
921 a->tv_usec += 1000000;
922 }
923}
924
925static unsigned int o2hb_elapsed_msecs(struct timeval *start,
926 struct timeval *end)
927{
928 struct timeval res = *end;
929
930 o2hb_tv_subtract(&res, start);
931
932 return res.tv_sec * 1000 + res.tv_usec / 1000;
933}
934
935/*
936 * we ride the region ref that the region dir holds. before the region
937 * dir is removed and drops it ref it will wait to tear down this
938 * thread.
939 */
940static int o2hb_thread(void *data)
941{
942 int i, ret;
943 struct o2hb_region *reg = data;
944 struct bio *write_bio;
945 struct o2hb_bio_wait_ctxt write_wc;
946 struct timeval before_hb, after_hb;
947 unsigned int elapsed_msec;
948
949 mlog(ML_HEARTBEAT|ML_KTHREAD, "hb thread running\n");
950
951 set_user_nice(current, -20);
952
953 while (!kthread_should_stop() && !reg->hr_unclean_stop) {
954 /* We track the time spent inside
955 * o2hb_do_disk_heartbeat so that we avoid more then
956 * hr_timeout_ms between disk writes. On busy systems
957 * this should result in a heartbeat which is less
958 * likely to time itself out. */
959 do_gettimeofday(&before_hb);
960
Mark Fasheha9e2ae32006-03-24 14:20:17 -0800961 i = 0;
962 do {
963 ret = o2hb_do_disk_heartbeat(reg);
964 } while (ret && ++i < 2);
Mark Fasheha7f6a5f2005-12-15 14:31:23 -0800965
966 do_gettimeofday(&after_hb);
967 elapsed_msec = o2hb_elapsed_msecs(&before_hb, &after_hb);
968
969 mlog(0, "start = %lu.%lu, end = %lu.%lu, msec = %u\n",
Mark Fasheh215c7f92006-02-01 16:42:10 -0800970 before_hb.tv_sec, (unsigned long) before_hb.tv_usec,
971 after_hb.tv_sec, (unsigned long) after_hb.tv_usec,
972 elapsed_msec);
Mark Fasheha7f6a5f2005-12-15 14:31:23 -0800973
974 if (elapsed_msec < reg->hr_timeout_ms) {
975 /* the kthread api has blocked signals for us so no
976 * need to record the return value. */
977 msleep_interruptible(reg->hr_timeout_ms - elapsed_msec);
978 }
979 }
980
981 o2hb_disarm_write_timeout(reg);
982
983 /* unclean stop is only used in very bad situation */
984 for(i = 0; !reg->hr_unclean_stop && i < reg->hr_blocks; i++)
985 o2hb_shutdown_slot(&reg->hr_slots[i]);
986
987 /* Explicit down notification - avoid forcing the other nodes
988 * to timeout on this region when we could just as easily
989 * write a clear generation - thus indicating to them that
990 * this node has left this region.
991 *
992 * XXX: Should we skip this on unclean_stop? */
993 o2hb_prepare_block(reg, 0);
994 ret = o2hb_issue_node_write(reg, &write_bio, &write_wc);
995 if (ret == 0) {
996 o2hb_wait_on_io(reg, &write_wc);
997 bio_put(write_bio);
998 } else {
999 mlog_errno(ret);
1000 }
1001
1002 mlog(ML_HEARTBEAT|ML_KTHREAD, "hb thread exiting\n");
1003
1004 return 0;
1005}
1006
1007void o2hb_init(void)
1008{
1009 int i;
1010
1011 for (i = 0; i < ARRAY_SIZE(o2hb_callbacks); i++)
1012 INIT_LIST_HEAD(&o2hb_callbacks[i].list);
1013
1014 for (i = 0; i < ARRAY_SIZE(o2hb_live_slots); i++)
1015 INIT_LIST_HEAD(&o2hb_live_slots[i]);
1016
1017 INIT_LIST_HEAD(&o2hb_node_events);
1018
1019 memset(o2hb_live_node_bitmap, 0, sizeof(o2hb_live_node_bitmap));
1020}
1021
1022/* if we're already in a callback then we're already serialized by the sem */
1023static void o2hb_fill_node_map_from_callback(unsigned long *map,
1024 unsigned bytes)
1025{
1026 BUG_ON(bytes < (BITS_TO_LONGS(O2NM_MAX_NODES) * sizeof(unsigned long)));
1027
1028 memcpy(map, &o2hb_live_node_bitmap, bytes);
1029}
1030
1031/*
1032 * get a map of all nodes that are heartbeating in any regions
1033 */
1034void o2hb_fill_node_map(unsigned long *map, unsigned bytes)
1035{
1036 /* callers want to serialize this map and callbacks so that they
1037 * can trust that they don't miss nodes coming to the party */
1038 down_read(&o2hb_callback_sem);
1039 spin_lock(&o2hb_live_lock);
1040 o2hb_fill_node_map_from_callback(map, bytes);
1041 spin_unlock(&o2hb_live_lock);
1042 up_read(&o2hb_callback_sem);
1043}
1044EXPORT_SYMBOL_GPL(o2hb_fill_node_map);
1045
1046/*
1047 * heartbeat configfs bits. The heartbeat set is a default set under
1048 * the cluster set in nodemanager.c.
1049 */
1050
1051static struct o2hb_region *to_o2hb_region(struct config_item *item)
1052{
1053 return item ? container_of(item, struct o2hb_region, hr_item) : NULL;
1054}
1055
1056/* drop_item only drops its ref after killing the thread, nothing should
1057 * be using the region anymore. this has to clean up any state that
1058 * attributes might have built up. */
1059static void o2hb_region_release(struct config_item *item)
1060{
1061 int i;
1062 struct page *page;
1063 struct o2hb_region *reg = to_o2hb_region(item);
1064
1065 if (reg->hr_tmp_block)
1066 kfree(reg->hr_tmp_block);
1067
1068 if (reg->hr_slot_data) {
1069 for (i = 0; i < reg->hr_num_pages; i++) {
1070 page = reg->hr_slot_data[i];
1071 if (page)
1072 __free_page(page);
1073 }
1074 kfree(reg->hr_slot_data);
1075 }
1076
1077 if (reg->hr_bdev)
1078 blkdev_put(reg->hr_bdev);
1079
1080 if (reg->hr_slots)
1081 kfree(reg->hr_slots);
1082
1083 spin_lock(&o2hb_live_lock);
1084 list_del(&reg->hr_all_item);
1085 spin_unlock(&o2hb_live_lock);
1086
1087 kfree(reg);
1088}
1089
1090static int o2hb_read_block_input(struct o2hb_region *reg,
1091 const char *page,
1092 size_t count,
1093 unsigned long *ret_bytes,
1094 unsigned int *ret_bits)
1095{
1096 unsigned long bytes;
1097 char *p = (char *)page;
1098
1099 bytes = simple_strtoul(p, &p, 0);
1100 if (!p || (*p && (*p != '\n')))
1101 return -EINVAL;
1102
1103 /* Heartbeat and fs min / max block sizes are the same. */
1104 if (bytes > 4096 || bytes < 512)
1105 return -ERANGE;
1106 if (hweight16(bytes) != 1)
1107 return -EINVAL;
1108
1109 if (ret_bytes)
1110 *ret_bytes = bytes;
1111 if (ret_bits)
1112 *ret_bits = ffs(bytes) - 1;
1113
1114 return 0;
1115}
1116
1117static ssize_t o2hb_region_block_bytes_read(struct o2hb_region *reg,
1118 char *page)
1119{
1120 return sprintf(page, "%u\n", reg->hr_block_bytes);
1121}
1122
1123static ssize_t o2hb_region_block_bytes_write(struct o2hb_region *reg,
1124 const char *page,
1125 size_t count)
1126{
1127 int status;
1128 unsigned long block_bytes;
1129 unsigned int block_bits;
1130
1131 if (reg->hr_bdev)
1132 return -EINVAL;
1133
1134 status = o2hb_read_block_input(reg, page, count,
1135 &block_bytes, &block_bits);
1136 if (status)
1137 return status;
1138
1139 reg->hr_block_bytes = (unsigned int)block_bytes;
1140 reg->hr_block_bits = block_bits;
1141
1142 return count;
1143}
1144
1145static ssize_t o2hb_region_start_block_read(struct o2hb_region *reg,
1146 char *page)
1147{
1148 return sprintf(page, "%llu\n", reg->hr_start_block);
1149}
1150
1151static ssize_t o2hb_region_start_block_write(struct o2hb_region *reg,
1152 const char *page,
1153 size_t count)
1154{
1155 unsigned long long tmp;
1156 char *p = (char *)page;
1157
1158 if (reg->hr_bdev)
1159 return -EINVAL;
1160
1161 tmp = simple_strtoull(p, &p, 0);
1162 if (!p || (*p && (*p != '\n')))
1163 return -EINVAL;
1164
1165 reg->hr_start_block = tmp;
1166
1167 return count;
1168}
1169
1170static ssize_t o2hb_region_blocks_read(struct o2hb_region *reg,
1171 char *page)
1172{
1173 return sprintf(page, "%d\n", reg->hr_blocks);
1174}
1175
1176static ssize_t o2hb_region_blocks_write(struct o2hb_region *reg,
1177 const char *page,
1178 size_t count)
1179{
1180 unsigned long tmp;
1181 char *p = (char *)page;
1182
1183 if (reg->hr_bdev)
1184 return -EINVAL;
1185
1186 tmp = simple_strtoul(p, &p, 0);
1187 if (!p || (*p && (*p != '\n')))
1188 return -EINVAL;
1189
1190 if (tmp > O2NM_MAX_NODES || tmp == 0)
1191 return -ERANGE;
1192
1193 reg->hr_blocks = (unsigned int)tmp;
1194
1195 return count;
1196}
1197
1198static ssize_t o2hb_region_dev_read(struct o2hb_region *reg,
1199 char *page)
1200{
1201 unsigned int ret = 0;
1202
1203 if (reg->hr_bdev)
1204 ret = sprintf(page, "%s\n", reg->hr_dev_name);
1205
1206 return ret;
1207}
1208
1209static void o2hb_init_region_params(struct o2hb_region *reg)
1210{
1211 reg->hr_slots_per_page = PAGE_CACHE_SIZE >> reg->hr_block_bits;
1212 reg->hr_timeout_ms = O2HB_REGION_TIMEOUT_MS;
1213
1214 mlog(ML_HEARTBEAT, "hr_start_block = %llu, hr_blocks = %u\n",
1215 reg->hr_start_block, reg->hr_blocks);
1216 mlog(ML_HEARTBEAT, "hr_block_bytes = %u, hr_block_bits = %u\n",
1217 reg->hr_block_bytes, reg->hr_block_bits);
1218 mlog(ML_HEARTBEAT, "hr_timeout_ms = %u\n", reg->hr_timeout_ms);
1219 mlog(ML_HEARTBEAT, "dead threshold = %u\n", o2hb_dead_threshold);
1220}
1221
1222static int o2hb_map_slot_data(struct o2hb_region *reg)
1223{
1224 int i, j;
1225 unsigned int last_slot;
1226 unsigned int spp = reg->hr_slots_per_page;
1227 struct page *page;
1228 char *raw;
1229 struct o2hb_disk_slot *slot;
1230
1231 reg->hr_tmp_block = kmalloc(reg->hr_block_bytes, GFP_KERNEL);
1232 if (reg->hr_tmp_block == NULL) {
1233 mlog_errno(-ENOMEM);
1234 return -ENOMEM;
1235 }
1236
1237 reg->hr_slots = kcalloc(reg->hr_blocks,
1238 sizeof(struct o2hb_disk_slot), GFP_KERNEL);
1239 if (reg->hr_slots == NULL) {
1240 mlog_errno(-ENOMEM);
1241 return -ENOMEM;
1242 }
1243
1244 for(i = 0; i < reg->hr_blocks; i++) {
1245 slot = &reg->hr_slots[i];
1246 slot->ds_node_num = i;
1247 INIT_LIST_HEAD(&slot->ds_live_item);
1248 slot->ds_raw_block = NULL;
1249 }
1250
1251 reg->hr_num_pages = (reg->hr_blocks + spp - 1) / spp;
1252 mlog(ML_HEARTBEAT, "Going to require %u pages to cover %u blocks "
1253 "at %u blocks per page\n",
1254 reg->hr_num_pages, reg->hr_blocks, spp);
1255
1256 reg->hr_slot_data = kcalloc(reg->hr_num_pages, sizeof(struct page *),
1257 GFP_KERNEL);
1258 if (!reg->hr_slot_data) {
1259 mlog_errno(-ENOMEM);
1260 return -ENOMEM;
1261 }
1262
1263 for(i = 0; i < reg->hr_num_pages; i++) {
1264 page = alloc_page(GFP_KERNEL);
1265 if (!page) {
1266 mlog_errno(-ENOMEM);
1267 return -ENOMEM;
1268 }
1269
1270 reg->hr_slot_data[i] = page;
1271
1272 last_slot = i * spp;
1273 raw = page_address(page);
1274 for (j = 0;
1275 (j < spp) && ((j + last_slot) < reg->hr_blocks);
1276 j++) {
1277 BUG_ON((j + last_slot) >= reg->hr_blocks);
1278
1279 slot = &reg->hr_slots[j + last_slot];
1280 slot->ds_raw_block =
1281 (struct o2hb_disk_heartbeat_block *) raw;
1282
1283 raw += reg->hr_block_bytes;
1284 }
1285 }
1286
1287 return 0;
1288}
1289
1290/* Read in all the slots available and populate the tracking
1291 * structures so that we can start with a baseline idea of what's
1292 * there. */
1293static int o2hb_populate_slot_data(struct o2hb_region *reg)
1294{
1295 int ret, i;
1296 struct o2hb_disk_slot *slot;
1297 struct o2hb_disk_heartbeat_block *hb_block;
1298
1299 mlog_entry_void();
1300
1301 ret = o2hb_read_slots(reg, reg->hr_blocks);
1302 if (ret) {
1303 mlog_errno(ret);
1304 goto out;
1305 }
1306
1307 /* We only want to get an idea of the values initially in each
1308 * slot, so we do no verification - o2hb_check_slot will
1309 * actually determine if each configured slot is valid and
1310 * whether any values have changed. */
1311 for(i = 0; i < reg->hr_blocks; i++) {
1312 slot = &reg->hr_slots[i];
1313 hb_block = (struct o2hb_disk_heartbeat_block *) slot->ds_raw_block;
1314
1315 /* Only fill the values that o2hb_check_slot uses to
1316 * determine changing slots */
1317 slot->ds_last_time = le64_to_cpu(hb_block->hb_seq);
1318 slot->ds_last_generation = le64_to_cpu(hb_block->hb_generation);
1319 }
1320
1321out:
1322 mlog_exit(ret);
1323 return ret;
1324}
1325
1326/* this is acting as commit; we set up all of hr_bdev and hr_task or nothing */
1327static ssize_t o2hb_region_dev_write(struct o2hb_region *reg,
1328 const char *page,
1329 size_t count)
1330{
1331 long fd;
1332 int sectsize;
1333 char *p = (char *)page;
1334 struct file *filp = NULL;
1335 struct inode *inode = NULL;
1336 ssize_t ret = -EINVAL;
1337
1338 if (reg->hr_bdev)
1339 goto out;
1340
1341 /* We can't heartbeat without having had our node number
1342 * configured yet. */
1343 if (o2nm_this_node() == O2NM_MAX_NODES)
1344 goto out;
1345
1346 fd = simple_strtol(p, &p, 0);
1347 if (!p || (*p && (*p != '\n')))
1348 goto out;
1349
1350 if (fd < 0 || fd >= INT_MAX)
1351 goto out;
1352
1353 filp = fget(fd);
1354 if (filp == NULL)
1355 goto out;
1356
1357 if (reg->hr_blocks == 0 || reg->hr_start_block == 0 ||
1358 reg->hr_block_bytes == 0)
1359 goto out;
1360
1361 inode = igrab(filp->f_mapping->host);
1362 if (inode == NULL)
1363 goto out;
1364
1365 if (!S_ISBLK(inode->i_mode))
1366 goto out;
1367
1368 reg->hr_bdev = I_BDEV(filp->f_mapping->host);
1369 ret = blkdev_get(reg->hr_bdev, FMODE_WRITE | FMODE_READ, 0);
1370 if (ret) {
1371 reg->hr_bdev = NULL;
1372 goto out;
1373 }
1374 inode = NULL;
1375
1376 bdevname(reg->hr_bdev, reg->hr_dev_name);
1377
1378 sectsize = bdev_hardsect_size(reg->hr_bdev);
1379 if (sectsize != reg->hr_block_bytes) {
1380 mlog(ML_ERROR,
1381 "blocksize %u incorrect for device, expected %d",
1382 reg->hr_block_bytes, sectsize);
1383 ret = -EINVAL;
1384 goto out;
1385 }
1386
1387 o2hb_init_region_params(reg);
1388
1389 /* Generation of zero is invalid */
1390 do {
1391 get_random_bytes(&reg->hr_generation,
1392 sizeof(reg->hr_generation));
1393 } while (reg->hr_generation == 0);
1394
1395 ret = o2hb_map_slot_data(reg);
1396 if (ret) {
1397 mlog_errno(ret);
1398 goto out;
1399 }
1400
1401 ret = o2hb_populate_slot_data(reg);
1402 if (ret) {
1403 mlog_errno(ret);
1404 goto out;
1405 }
1406
1407 INIT_WORK(&reg->hr_write_timeout_work, o2hb_write_timeout, reg);
1408
1409 /*
1410 * A node is considered live after it has beat LIVE_THRESHOLD
1411 * times. We're not steady until we've given them a chance
1412 * _after_ our first read.
1413 */
1414 atomic_set(&reg->hr_steady_iterations, O2HB_LIVE_THRESHOLD + 1);
1415
1416 reg->hr_task = kthread_run(o2hb_thread, reg, "o2hb-%s",
1417 reg->hr_item.ci_name);
1418 if (IS_ERR(reg->hr_task)) {
1419 ret = PTR_ERR(reg->hr_task);
1420 mlog_errno(ret);
1421 reg->hr_task = NULL;
1422 goto out;
1423 }
1424
1425 ret = wait_event_interruptible(o2hb_steady_queue,
1426 atomic_read(&reg->hr_steady_iterations) == 0);
1427 if (ret) {
1428 kthread_stop(reg->hr_task);
1429 reg->hr_task = NULL;
1430 goto out;
1431 }
1432
1433 ret = count;
1434out:
1435 if (filp)
1436 fput(filp);
1437 if (inode)
1438 iput(inode);
1439 if (ret < 0) {
1440 if (reg->hr_bdev) {
1441 blkdev_put(reg->hr_bdev);
1442 reg->hr_bdev = NULL;
1443 }
1444 }
1445 return ret;
1446}
1447
1448struct o2hb_region_attribute {
1449 struct configfs_attribute attr;
1450 ssize_t (*show)(struct o2hb_region *, char *);
1451 ssize_t (*store)(struct o2hb_region *, const char *, size_t);
1452};
1453
1454static struct o2hb_region_attribute o2hb_region_attr_block_bytes = {
1455 .attr = { .ca_owner = THIS_MODULE,
1456 .ca_name = "block_bytes",
1457 .ca_mode = S_IRUGO | S_IWUSR },
1458 .show = o2hb_region_block_bytes_read,
1459 .store = o2hb_region_block_bytes_write,
1460};
1461
1462static struct o2hb_region_attribute o2hb_region_attr_start_block = {
1463 .attr = { .ca_owner = THIS_MODULE,
1464 .ca_name = "start_block",
1465 .ca_mode = S_IRUGO | S_IWUSR },
1466 .show = o2hb_region_start_block_read,
1467 .store = o2hb_region_start_block_write,
1468};
1469
1470static struct o2hb_region_attribute o2hb_region_attr_blocks = {
1471 .attr = { .ca_owner = THIS_MODULE,
1472 .ca_name = "blocks",
1473 .ca_mode = S_IRUGO | S_IWUSR },
1474 .show = o2hb_region_blocks_read,
1475 .store = o2hb_region_blocks_write,
1476};
1477
1478static struct o2hb_region_attribute o2hb_region_attr_dev = {
1479 .attr = { .ca_owner = THIS_MODULE,
1480 .ca_name = "dev",
1481 .ca_mode = S_IRUGO | S_IWUSR },
1482 .show = o2hb_region_dev_read,
1483 .store = o2hb_region_dev_write,
1484};
1485
1486static struct configfs_attribute *o2hb_region_attrs[] = {
1487 &o2hb_region_attr_block_bytes.attr,
1488 &o2hb_region_attr_start_block.attr,
1489 &o2hb_region_attr_blocks.attr,
1490 &o2hb_region_attr_dev.attr,
1491 NULL,
1492};
1493
1494static ssize_t o2hb_region_show(struct config_item *item,
1495 struct configfs_attribute *attr,
1496 char *page)
1497{
1498 struct o2hb_region *reg = to_o2hb_region(item);
1499 struct o2hb_region_attribute *o2hb_region_attr =
1500 container_of(attr, struct o2hb_region_attribute, attr);
1501 ssize_t ret = 0;
1502
1503 if (o2hb_region_attr->show)
1504 ret = o2hb_region_attr->show(reg, page);
1505 return ret;
1506}
1507
1508static ssize_t o2hb_region_store(struct config_item *item,
1509 struct configfs_attribute *attr,
1510 const char *page, size_t count)
1511{
1512 struct o2hb_region *reg = to_o2hb_region(item);
1513 struct o2hb_region_attribute *o2hb_region_attr =
1514 container_of(attr, struct o2hb_region_attribute, attr);
1515 ssize_t ret = -EINVAL;
1516
1517 if (o2hb_region_attr->store)
1518 ret = o2hb_region_attr->store(reg, page, count);
1519 return ret;
1520}
1521
1522static struct configfs_item_operations o2hb_region_item_ops = {
1523 .release = o2hb_region_release,
1524 .show_attribute = o2hb_region_show,
1525 .store_attribute = o2hb_region_store,
1526};
1527
1528static struct config_item_type o2hb_region_type = {
1529 .ct_item_ops = &o2hb_region_item_ops,
1530 .ct_attrs = o2hb_region_attrs,
1531 .ct_owner = THIS_MODULE,
1532};
1533
1534/* heartbeat set */
1535
1536struct o2hb_heartbeat_group {
1537 struct config_group hs_group;
1538 /* some stuff? */
1539};
1540
1541static struct o2hb_heartbeat_group *to_o2hb_heartbeat_group(struct config_group *group)
1542{
1543 return group ?
1544 container_of(group, struct o2hb_heartbeat_group, hs_group)
1545 : NULL;
1546}
1547
1548static struct config_item *o2hb_heartbeat_group_make_item(struct config_group *group,
1549 const char *name)
1550{
1551 struct o2hb_region *reg = NULL;
1552 struct config_item *ret = NULL;
1553
1554 reg = kcalloc(1, sizeof(struct o2hb_region), GFP_KERNEL);
1555 if (reg == NULL)
1556 goto out; /* ENOMEM */
1557
1558 config_item_init_type_name(&reg->hr_item, name, &o2hb_region_type);
1559
1560 ret = &reg->hr_item;
1561
1562 spin_lock(&o2hb_live_lock);
1563 list_add_tail(&reg->hr_all_item, &o2hb_all_regions);
1564 spin_unlock(&o2hb_live_lock);
1565out:
1566 if (ret == NULL)
1567 kfree(reg);
1568
1569 return ret;
1570}
1571
1572static void o2hb_heartbeat_group_drop_item(struct config_group *group,
1573 struct config_item *item)
1574{
1575 struct o2hb_region *reg = to_o2hb_region(item);
1576
1577 /* stop the thread when the user removes the region dir */
1578 if (reg->hr_task) {
1579 kthread_stop(reg->hr_task);
1580 reg->hr_task = NULL;
1581 }
1582
1583 config_item_put(item);
1584}
1585
1586struct o2hb_heartbeat_group_attribute {
1587 struct configfs_attribute attr;
1588 ssize_t (*show)(struct o2hb_heartbeat_group *, char *);
1589 ssize_t (*store)(struct o2hb_heartbeat_group *, const char *, size_t);
1590};
1591
1592static ssize_t o2hb_heartbeat_group_show(struct config_item *item,
1593 struct configfs_attribute *attr,
1594 char *page)
1595{
1596 struct o2hb_heartbeat_group *reg = to_o2hb_heartbeat_group(to_config_group(item));
1597 struct o2hb_heartbeat_group_attribute *o2hb_heartbeat_group_attr =
1598 container_of(attr, struct o2hb_heartbeat_group_attribute, attr);
1599 ssize_t ret = 0;
1600
1601 if (o2hb_heartbeat_group_attr->show)
1602 ret = o2hb_heartbeat_group_attr->show(reg, page);
1603 return ret;
1604}
1605
1606static ssize_t o2hb_heartbeat_group_store(struct config_item *item,
1607 struct configfs_attribute *attr,
1608 const char *page, size_t count)
1609{
1610 struct o2hb_heartbeat_group *reg = to_o2hb_heartbeat_group(to_config_group(item));
1611 struct o2hb_heartbeat_group_attribute *o2hb_heartbeat_group_attr =
1612 container_of(attr, struct o2hb_heartbeat_group_attribute, attr);
1613 ssize_t ret = -EINVAL;
1614
1615 if (o2hb_heartbeat_group_attr->store)
1616 ret = o2hb_heartbeat_group_attr->store(reg, page, count);
1617 return ret;
1618}
1619
1620static ssize_t o2hb_heartbeat_group_threshold_show(struct o2hb_heartbeat_group *group,
1621 char *page)
1622{
1623 return sprintf(page, "%u\n", o2hb_dead_threshold);
1624}
1625
1626static ssize_t o2hb_heartbeat_group_threshold_store(struct o2hb_heartbeat_group *group,
1627 const char *page,
1628 size_t count)
1629{
1630 unsigned long tmp;
1631 char *p = (char *)page;
1632
1633 tmp = simple_strtoul(p, &p, 10);
1634 if (!p || (*p && (*p != '\n')))
1635 return -EINVAL;
1636
1637 /* this will validate ranges for us. */
1638 o2hb_dead_threshold_set((unsigned int) tmp);
1639
1640 return count;
1641}
1642
1643static struct o2hb_heartbeat_group_attribute o2hb_heartbeat_group_attr_threshold = {
1644 .attr = { .ca_owner = THIS_MODULE,
1645 .ca_name = "dead_threshold",
1646 .ca_mode = S_IRUGO | S_IWUSR },
1647 .show = o2hb_heartbeat_group_threshold_show,
1648 .store = o2hb_heartbeat_group_threshold_store,
1649};
1650
1651static struct configfs_attribute *o2hb_heartbeat_group_attrs[] = {
1652 &o2hb_heartbeat_group_attr_threshold.attr,
1653 NULL,
1654};
1655
1656static struct configfs_item_operations o2hb_hearbeat_group_item_ops = {
1657 .show_attribute = o2hb_heartbeat_group_show,
1658 .store_attribute = o2hb_heartbeat_group_store,
1659};
1660
1661static struct configfs_group_operations o2hb_heartbeat_group_group_ops = {
1662 .make_item = o2hb_heartbeat_group_make_item,
1663 .drop_item = o2hb_heartbeat_group_drop_item,
1664};
1665
1666static struct config_item_type o2hb_heartbeat_group_type = {
1667 .ct_group_ops = &o2hb_heartbeat_group_group_ops,
1668 .ct_item_ops = &o2hb_hearbeat_group_item_ops,
1669 .ct_attrs = o2hb_heartbeat_group_attrs,
1670 .ct_owner = THIS_MODULE,
1671};
1672
1673/* this is just here to avoid touching group in heartbeat.h which the
1674 * entire damn world #includes */
1675struct config_group *o2hb_alloc_hb_set(void)
1676{
1677 struct o2hb_heartbeat_group *hs = NULL;
1678 struct config_group *ret = NULL;
1679
1680 hs = kcalloc(1, sizeof(struct o2hb_heartbeat_group), GFP_KERNEL);
1681 if (hs == NULL)
1682 goto out;
1683
1684 config_group_init_type_name(&hs->hs_group, "heartbeat",
1685 &o2hb_heartbeat_group_type);
1686
1687 ret = &hs->hs_group;
1688out:
1689 if (ret == NULL)
1690 kfree(hs);
1691 return ret;
1692}
1693
1694void o2hb_free_hb_set(struct config_group *group)
1695{
1696 struct o2hb_heartbeat_group *hs = to_o2hb_heartbeat_group(group);
1697 kfree(hs);
1698}
1699
1700/* hb callback registration and issueing */
1701
1702static struct o2hb_callback *hbcall_from_type(enum o2hb_callback_type type)
1703{
1704 if (type == O2HB_NUM_CB)
1705 return ERR_PTR(-EINVAL);
1706
1707 return &o2hb_callbacks[type];
1708}
1709
1710void o2hb_setup_callback(struct o2hb_callback_func *hc,
1711 enum o2hb_callback_type type,
1712 o2hb_cb_func *func,
1713 void *data,
1714 int priority)
1715{
1716 INIT_LIST_HEAD(&hc->hc_item);
1717 hc->hc_func = func;
1718 hc->hc_data = data;
1719 hc->hc_priority = priority;
1720 hc->hc_type = type;
1721 hc->hc_magic = O2HB_CB_MAGIC;
1722}
1723EXPORT_SYMBOL_GPL(o2hb_setup_callback);
1724
1725int o2hb_register_callback(struct o2hb_callback_func *hc)
1726{
1727 struct o2hb_callback_func *tmp;
1728 struct list_head *iter;
1729 struct o2hb_callback *hbcall;
1730 int ret;
1731
1732 BUG_ON(hc->hc_magic != O2HB_CB_MAGIC);
1733 BUG_ON(!list_empty(&hc->hc_item));
1734
1735 hbcall = hbcall_from_type(hc->hc_type);
1736 if (IS_ERR(hbcall)) {
1737 ret = PTR_ERR(hbcall);
1738 goto out;
1739 }
1740
1741 down_write(&o2hb_callback_sem);
1742
1743 list_for_each(iter, &hbcall->list) {
1744 tmp = list_entry(iter, struct o2hb_callback_func, hc_item);
1745 if (hc->hc_priority < tmp->hc_priority) {
1746 list_add_tail(&hc->hc_item, iter);
1747 break;
1748 }
1749 }
1750 if (list_empty(&hc->hc_item))
1751 list_add_tail(&hc->hc_item, &hbcall->list);
1752
1753 up_write(&o2hb_callback_sem);
1754 ret = 0;
1755out:
1756 mlog(ML_HEARTBEAT, "returning %d on behalf of %p for funcs %p\n",
1757 ret, __builtin_return_address(0), hc);
1758 return ret;
1759}
1760EXPORT_SYMBOL_GPL(o2hb_register_callback);
1761
1762int o2hb_unregister_callback(struct o2hb_callback_func *hc)
1763{
1764 BUG_ON(hc->hc_magic != O2HB_CB_MAGIC);
1765
1766 mlog(ML_HEARTBEAT, "on behalf of %p for funcs %p\n",
1767 __builtin_return_address(0), hc);
1768
1769 if (list_empty(&hc->hc_item))
1770 return 0;
1771
1772 down_write(&o2hb_callback_sem);
1773
1774 list_del_init(&hc->hc_item);
1775
1776 up_write(&o2hb_callback_sem);
1777
1778 return 0;
1779}
1780EXPORT_SYMBOL_GPL(o2hb_unregister_callback);
1781
1782int o2hb_check_node_heartbeating(u8 node_num)
1783{
1784 unsigned long testing_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
1785
1786 o2hb_fill_node_map(testing_map, sizeof(testing_map));
1787 if (!test_bit(node_num, testing_map)) {
1788 mlog(ML_HEARTBEAT,
1789 "node (%u) does not have heartbeating enabled.\n",
1790 node_num);
1791 return 0;
1792 }
1793
1794 return 1;
1795}
1796EXPORT_SYMBOL_GPL(o2hb_check_node_heartbeating);
1797
1798int o2hb_check_node_heartbeating_from_callback(u8 node_num)
1799{
1800 unsigned long testing_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
1801
1802 o2hb_fill_node_map_from_callback(testing_map, sizeof(testing_map));
1803 if (!test_bit(node_num, testing_map)) {
1804 mlog(ML_HEARTBEAT,
1805 "node (%u) does not have heartbeating enabled.\n",
1806 node_num);
1807 return 0;
1808 }
1809
1810 return 1;
1811}
1812EXPORT_SYMBOL_GPL(o2hb_check_node_heartbeating_from_callback);
1813
1814/* Makes sure our local node is configured with a node number, and is
1815 * heartbeating. */
1816int o2hb_check_local_node_heartbeating(void)
1817{
1818 u8 node_num;
1819
1820 /* if this node was set then we have networking */
1821 node_num = o2nm_this_node();
1822 if (node_num == O2NM_MAX_NODES) {
1823 mlog(ML_HEARTBEAT, "this node has not been configured.\n");
1824 return 0;
1825 }
1826
1827 return o2hb_check_node_heartbeating(node_num);
1828}
1829EXPORT_SYMBOL_GPL(o2hb_check_local_node_heartbeating);
1830
1831/*
1832 * this is just a hack until we get the plumbing which flips file systems
1833 * read only and drops the hb ref instead of killing the node dead.
1834 */
1835void o2hb_stop_all_regions(void)
1836{
1837 struct o2hb_region *reg;
1838
1839 mlog(ML_ERROR, "stopping heartbeat on all active regions.\n");
1840
1841 spin_lock(&o2hb_live_lock);
1842
1843 list_for_each_entry(reg, &o2hb_all_regions, hr_all_item)
1844 reg->hr_unclean_stop = 1;
1845
1846 spin_unlock(&o2hb_live_lock);
1847}
1848EXPORT_SYMBOL_GPL(o2hb_stop_all_regions);