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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 | #define O2HB_DEBUG_DIR "o2hb" |
66 | #define O2HB_DEBUG_LIVENODES "livenodes" |
67 | static struct dentry *o2hb_debug_dir; |
68 | static struct dentry *o2hb_debug_livenodes; |
69 | |
70 | static LIST_HEAD(o2hb_all_regions); |
71 | |
72 | static struct o2hb_callback { |
73 | struct list_head list; |
74 | } o2hb_callbacks[O2HB_NUM_CB]; |
75 | |
76 | static struct o2hb_callback *hbcall_from_type(enum o2hb_callback_type type); |
77 | |
78 | #define O2HB_DEFAULT_BLOCK_BITS 9 |
79 | |
80 | unsigned int o2hb_dead_threshold = O2HB_DEFAULT_DEAD_THRESHOLD; |
81 | |
82 | /* Only sets a new threshold if there are no active regions. |
83 | * |
84 | * No locking or otherwise interesting code is required for reading |
85 | * o2hb_dead_threshold as it can't change once regions are active and |
86 | * it's not interesting to anyone until then anyway. */ |
87 | static void o2hb_dead_threshold_set(unsigned int threshold) |
88 | { |
89 | if (threshold > O2HB_MIN_DEAD_THRESHOLD) { |
90 | spin_lock(&o2hb_live_lock); |
91 | if (list_empty(&o2hb_all_regions)) |
92 | o2hb_dead_threshold = threshold; |
93 | spin_unlock(&o2hb_live_lock); |
94 | } |
95 | } |
96 | |
97 | struct o2hb_node_event { |
98 | struct list_head hn_item; |
99 | enum o2hb_callback_type hn_event_type; |
100 | struct o2nm_node *hn_node; |
101 | int hn_node_num; |
102 | }; |
103 | |
104 | struct o2hb_disk_slot { |
105 | struct o2hb_disk_heartbeat_block *ds_raw_block; |
106 | u8 ds_node_num; |
107 | u64 ds_last_time; |
108 | u64 ds_last_generation; |
109 | u16 ds_equal_samples; |
110 | u16 ds_changed_samples; |
111 | struct list_head ds_live_item; |
112 | }; |
113 | |
114 | /* each thread owns a region.. when we're asked to tear down the region |
115 | * we ask the thread to stop, who cleans up the region */ |
116 | struct o2hb_region { |
117 | struct config_item hr_item; |
118 | |
119 | struct list_head hr_all_item; |
120 | unsigned hr_unclean_stop:1; |
121 | |
122 | /* protected by the hr_callback_sem */ |
123 | struct task_struct *hr_task; |
124 | |
125 | unsigned int hr_blocks; |
126 | unsigned long long hr_start_block; |
127 | |
128 | unsigned int hr_block_bits; |
129 | unsigned int hr_block_bytes; |
130 | |
131 | unsigned int hr_slots_per_page; |
132 | unsigned int hr_num_pages; |
133 | |
134 | struct page **hr_slot_data; |
135 | struct block_device *hr_bdev; |
136 | struct o2hb_disk_slot *hr_slots; |
137 | |
138 | /* let the person setting up hb wait for it to return until it |
139 | * has reached a 'steady' state. This will be fixed when we have |
140 | * a more complete api that doesn't lead to this sort of fragility. */ |
141 | atomic_t hr_steady_iterations; |
142 | |
143 | char hr_dev_name[BDEVNAME_SIZE]; |
144 | |
145 | unsigned int hr_timeout_ms; |
146 | |
147 | /* randomized as the region goes up and down so that a node |
148 | * recognizes a node going up and down in one iteration */ |
149 | u64 hr_generation; |
150 | |
151 | struct delayed_work hr_write_timeout_work; |
152 | unsigned long hr_last_timeout_start; |
153 | |
154 | /* Used during o2hb_check_slot to hold a copy of the block |
155 | * being checked because we temporarily have to zero out the |
156 | * crc field. */ |
157 | struct o2hb_disk_heartbeat_block *hr_tmp_block; |
158 | }; |
159 | |
160 | struct o2hb_bio_wait_ctxt { |
161 | atomic_t wc_num_reqs; |
162 | struct completion wc_io_complete; |
163 | int wc_error; |
164 | }; |
165 | |
166 | static void o2hb_write_timeout(struct work_struct *work) |
167 | { |
168 | struct o2hb_region *reg = |
169 | container_of(work, struct o2hb_region, |
170 | hr_write_timeout_work.work); |
171 | |
172 | mlog(ML_ERROR, "Heartbeat write timeout to device %s after %u " |
173 | "milliseconds\n", reg->hr_dev_name, |
174 | jiffies_to_msecs(jiffies - reg->hr_last_timeout_start)); |
175 | o2quo_disk_timeout(); |
176 | } |
177 | |
178 | static void o2hb_arm_write_timeout(struct o2hb_region *reg) |
179 | { |
180 | mlog(ML_HEARTBEAT, "Queue write timeout for %u ms\n", |
181 | O2HB_MAX_WRITE_TIMEOUT_MS); |
182 | |
183 | cancel_delayed_work(®->hr_write_timeout_work); |
184 | reg->hr_last_timeout_start = jiffies; |
185 | schedule_delayed_work(®->hr_write_timeout_work, |
186 | msecs_to_jiffies(O2HB_MAX_WRITE_TIMEOUT_MS)); |
187 | } |
188 | |
189 | static void o2hb_disarm_write_timeout(struct o2hb_region *reg) |
190 | { |
191 | cancel_delayed_work(®->hr_write_timeout_work); |
192 | flush_scheduled_work(); |
193 | } |
194 | |
195 | static inline void o2hb_bio_wait_init(struct o2hb_bio_wait_ctxt *wc) |
196 | { |
197 | atomic_set(&wc->wc_num_reqs, 1); |
198 | init_completion(&wc->wc_io_complete); |
199 | wc->wc_error = 0; |
200 | } |
201 | |
202 | /* Used in error paths too */ |
203 | static inline void o2hb_bio_wait_dec(struct o2hb_bio_wait_ctxt *wc, |
204 | unsigned int num) |
205 | { |
206 | /* sadly atomic_sub_and_test() isn't available on all platforms. The |
207 | * good news is that the fast path only completes one at a time */ |
208 | while(num--) { |
209 | if (atomic_dec_and_test(&wc->wc_num_reqs)) { |
210 | BUG_ON(num > 0); |
211 | complete(&wc->wc_io_complete); |
212 | } |
213 | } |
214 | } |
215 | |
216 | static void o2hb_wait_on_io(struct o2hb_region *reg, |
217 | struct o2hb_bio_wait_ctxt *wc) |
218 | { |
219 | struct address_space *mapping = reg->hr_bdev->bd_inode->i_mapping; |
220 | |
221 | blk_run_address_space(mapping); |
222 | o2hb_bio_wait_dec(wc, 1); |
223 | |
224 | wait_for_completion(&wc->wc_io_complete); |
225 | } |
226 | |
227 | static void o2hb_bio_end_io(struct bio *bio, |
228 | int error) |
229 | { |
230 | struct o2hb_bio_wait_ctxt *wc = bio->bi_private; |
231 | |
232 | if (error) { |
233 | mlog(ML_ERROR, "IO Error %d\n", error); |
234 | wc->wc_error = error; |
235 | } |
236 | |
237 | o2hb_bio_wait_dec(wc, 1); |
238 | bio_put(bio); |
239 | } |
240 | |
241 | /* Setup a Bio to cover I/O against num_slots slots starting at |
242 | * start_slot. */ |
243 | static struct bio *o2hb_setup_one_bio(struct o2hb_region *reg, |
244 | struct o2hb_bio_wait_ctxt *wc, |
245 | unsigned int *current_slot, |
246 | unsigned int max_slots) |
247 | { |
248 | int len, current_page; |
249 | unsigned int vec_len, vec_start; |
250 | unsigned int bits = reg->hr_block_bits; |
251 | unsigned int spp = reg->hr_slots_per_page; |
252 | unsigned int cs = *current_slot; |
253 | struct bio *bio; |
254 | struct page *page; |
255 | |
256 | /* Testing has shown this allocation to take long enough under |
257 | * GFP_KERNEL that the local node can get fenced. It would be |
258 | * nicest if we could pre-allocate these bios and avoid this |
259 | * all together. */ |
260 | bio = bio_alloc(GFP_ATOMIC, 16); |
261 | if (!bio) { |
262 | mlog(ML_ERROR, "Could not alloc slots BIO!\n"); |
263 | bio = ERR_PTR(-ENOMEM); |
264 | goto bail; |
265 | } |
266 | |
267 | /* Must put everything in 512 byte sectors for the bio... */ |
268 | bio->bi_sector = (reg->hr_start_block + cs) << (bits - 9); |
269 | bio->bi_bdev = reg->hr_bdev; |
270 | bio->bi_private = wc; |
271 | bio->bi_end_io = o2hb_bio_end_io; |
272 | |
273 | vec_start = (cs << bits) % PAGE_CACHE_SIZE; |
274 | while(cs < max_slots) { |
275 | current_page = cs / spp; |
276 | page = reg->hr_slot_data[current_page]; |
277 | |
278 | vec_len = min(PAGE_CACHE_SIZE - vec_start, |
279 | (max_slots-cs) * (PAGE_CACHE_SIZE/spp) ); |
280 | |
281 | mlog(ML_HB_BIO, "page %d, vec_len = %u, vec_start = %u\n", |
282 | current_page, vec_len, vec_start); |
283 | |
284 | len = bio_add_page(bio, page, vec_len, vec_start); |
285 | if (len != vec_len) break; |
286 | |
287 | cs += vec_len / (PAGE_CACHE_SIZE/spp); |
288 | vec_start = 0; |
289 | } |
290 | |
291 | bail: |
292 | *current_slot = cs; |
293 | return bio; |
294 | } |
295 | |
296 | static int o2hb_read_slots(struct o2hb_region *reg, |
297 | unsigned int max_slots) |
298 | { |
299 | unsigned int current_slot=0; |
300 | int status; |
301 | struct o2hb_bio_wait_ctxt wc; |
302 | struct bio *bio; |
303 | |
304 | o2hb_bio_wait_init(&wc); |
305 | |
306 | while(current_slot < max_slots) { |
307 | bio = o2hb_setup_one_bio(reg, &wc, ¤t_slot, max_slots); |
308 | if (IS_ERR(bio)) { |
309 | status = PTR_ERR(bio); |
310 | mlog_errno(status); |
311 | goto bail_and_wait; |
312 | } |
313 | |
314 | atomic_inc(&wc.wc_num_reqs); |
315 | submit_bio(READ, bio); |
316 | } |
317 | |
318 | status = 0; |
319 | |
320 | bail_and_wait: |
321 | o2hb_wait_on_io(reg, &wc); |
322 | if (wc.wc_error && !status) |
323 | status = wc.wc_error; |
324 | |
325 | return status; |
326 | } |
327 | |
328 | static int o2hb_issue_node_write(struct o2hb_region *reg, |
329 | struct o2hb_bio_wait_ctxt *write_wc) |
330 | { |
331 | int status; |
332 | unsigned int slot; |
333 | struct bio *bio; |
334 | |
335 | o2hb_bio_wait_init(write_wc); |
336 | |
337 | slot = o2nm_this_node(); |
338 | |
339 | bio = o2hb_setup_one_bio(reg, write_wc, &slot, slot+1); |
340 | if (IS_ERR(bio)) { |
341 | status = PTR_ERR(bio); |
342 | mlog_errno(status); |
343 | goto bail; |
344 | } |
345 | |
346 | atomic_inc(&write_wc->wc_num_reqs); |
347 | submit_bio(WRITE, bio); |
348 | |
349 | status = 0; |
350 | bail: |
351 | return status; |
352 | } |
353 | |
354 | static u32 o2hb_compute_block_crc_le(struct o2hb_region *reg, |
355 | struct o2hb_disk_heartbeat_block *hb_block) |
356 | { |
357 | __le32 old_cksum; |
358 | u32 ret; |
359 | |
360 | /* We want to compute the block crc with a 0 value in the |
361 | * hb_cksum field. Save it off here and replace after the |
362 | * crc. */ |
363 | old_cksum = hb_block->hb_cksum; |
364 | hb_block->hb_cksum = 0; |
365 | |
366 | ret = crc32_le(0, (unsigned char *) hb_block, reg->hr_block_bytes); |
367 | |
368 | hb_block->hb_cksum = old_cksum; |
369 | |
370 | return ret; |
371 | } |
372 | |
373 | static void o2hb_dump_slot(struct o2hb_disk_heartbeat_block *hb_block) |
374 | { |
375 | mlog(ML_ERROR, "Dump slot information: seq = 0x%llx, node = %u, " |
376 | "cksum = 0x%x, generation 0x%llx\n", |
377 | (long long)le64_to_cpu(hb_block->hb_seq), |
378 | hb_block->hb_node, le32_to_cpu(hb_block->hb_cksum), |
379 | (long long)le64_to_cpu(hb_block->hb_generation)); |
380 | } |
381 | |
382 | static int o2hb_verify_crc(struct o2hb_region *reg, |
383 | struct o2hb_disk_heartbeat_block *hb_block) |
384 | { |
385 | u32 read, computed; |
386 | |
387 | read = le32_to_cpu(hb_block->hb_cksum); |
388 | computed = o2hb_compute_block_crc_le(reg, hb_block); |
389 | |
390 | return read == computed; |
391 | } |
392 | |
393 | /* We want to make sure that nobody is heartbeating on top of us -- |
394 | * this will help detect an invalid configuration. */ |
395 | static int o2hb_check_last_timestamp(struct o2hb_region *reg) |
396 | { |
397 | int node_num, ret; |
398 | struct o2hb_disk_slot *slot; |
399 | struct o2hb_disk_heartbeat_block *hb_block; |
400 | |
401 | node_num = o2nm_this_node(); |
402 | |
403 | ret = 1; |
404 | slot = ®->hr_slots[node_num]; |
405 | /* Don't check on our 1st timestamp */ |
406 | if (slot->ds_last_time) { |
407 | hb_block = slot->ds_raw_block; |
408 | |
409 | if (le64_to_cpu(hb_block->hb_seq) != slot->ds_last_time) |
410 | ret = 0; |
411 | } |
412 | |
413 | return ret; |
414 | } |
415 | |
416 | static inline void o2hb_prepare_block(struct o2hb_region *reg, |
417 | u64 generation) |
418 | { |
419 | int node_num; |
420 | u64 cputime; |
421 | struct o2hb_disk_slot *slot; |
422 | struct o2hb_disk_heartbeat_block *hb_block; |
423 | |
424 | node_num = o2nm_this_node(); |
425 | slot = ®->hr_slots[node_num]; |
426 | |
427 | hb_block = (struct o2hb_disk_heartbeat_block *)slot->ds_raw_block; |
428 | memset(hb_block, 0, reg->hr_block_bytes); |
429 | /* TODO: time stuff */ |
430 | cputime = CURRENT_TIME.tv_sec; |
431 | if (!cputime) |
432 | cputime = 1; |
433 | |
434 | hb_block->hb_seq = cpu_to_le64(cputime); |
435 | hb_block->hb_node = node_num; |
436 | hb_block->hb_generation = cpu_to_le64(generation); |
437 | hb_block->hb_dead_ms = cpu_to_le32(o2hb_dead_threshold * O2HB_REGION_TIMEOUT_MS); |
438 | |
439 | /* This step must always happen last! */ |
440 | hb_block->hb_cksum = cpu_to_le32(o2hb_compute_block_crc_le(reg, |
441 | hb_block)); |
442 | |
443 | mlog(ML_HB_BIO, "our node generation = 0x%llx, cksum = 0x%x\n", |
444 | (long long)generation, |
445 | le32_to_cpu(hb_block->hb_cksum)); |
446 | } |
447 | |
448 | static void o2hb_fire_callbacks(struct o2hb_callback *hbcall, |
449 | struct o2nm_node *node, |
450 | int idx) |
451 | { |
452 | struct list_head *iter; |
453 | struct o2hb_callback_func *f; |
454 | |
455 | list_for_each(iter, &hbcall->list) { |
456 | f = list_entry(iter, struct o2hb_callback_func, hc_item); |
457 | mlog(ML_HEARTBEAT, "calling funcs %p\n", f); |
458 | (f->hc_func)(node, idx, f->hc_data); |
459 | } |
460 | } |
461 | |
462 | /* Will run the list in order until we process the passed event */ |
463 | static void o2hb_run_event_list(struct o2hb_node_event *queued_event) |
464 | { |
465 | int empty; |
466 | struct o2hb_callback *hbcall; |
467 | struct o2hb_node_event *event; |
468 | |
469 | spin_lock(&o2hb_live_lock); |
470 | empty = list_empty(&queued_event->hn_item); |
471 | spin_unlock(&o2hb_live_lock); |
472 | if (empty) |
473 | return; |
474 | |
475 | /* Holding callback sem assures we don't alter the callback |
476 | * lists when doing this, and serializes ourselves with other |
477 | * processes wanting callbacks. */ |
478 | down_write(&o2hb_callback_sem); |
479 | |
480 | spin_lock(&o2hb_live_lock); |
481 | while (!list_empty(&o2hb_node_events) |
482 | && !list_empty(&queued_event->hn_item)) { |
483 | event = list_entry(o2hb_node_events.next, |
484 | struct o2hb_node_event, |
485 | hn_item); |
486 | list_del_init(&event->hn_item); |
487 | spin_unlock(&o2hb_live_lock); |
488 | |
489 | mlog(ML_HEARTBEAT, "Node %s event for %d\n", |
490 | event->hn_event_type == O2HB_NODE_UP_CB ? "UP" : "DOWN", |
491 | event->hn_node_num); |
492 | |
493 | hbcall = hbcall_from_type(event->hn_event_type); |
494 | |
495 | /* We should *never* have gotten on to the list with a |
496 | * bad type... This isn't something that we should try |
497 | * to recover from. */ |
498 | BUG_ON(IS_ERR(hbcall)); |
499 | |
500 | o2hb_fire_callbacks(hbcall, event->hn_node, event->hn_node_num); |
501 | |
502 | spin_lock(&o2hb_live_lock); |
503 | } |
504 | spin_unlock(&o2hb_live_lock); |
505 | |
506 | up_write(&o2hb_callback_sem); |
507 | } |
508 | |
509 | static void o2hb_queue_node_event(struct o2hb_node_event *event, |
510 | enum o2hb_callback_type type, |
511 | struct o2nm_node *node, |
512 | int node_num) |
513 | { |
514 | assert_spin_locked(&o2hb_live_lock); |
515 | |
516 | event->hn_event_type = type; |
517 | event->hn_node = node; |
518 | event->hn_node_num = node_num; |
519 | |
520 | mlog(ML_HEARTBEAT, "Queue node %s event for node %d\n", |
521 | type == O2HB_NODE_UP_CB ? "UP" : "DOWN", node_num); |
522 | |
523 | list_add_tail(&event->hn_item, &o2hb_node_events); |
524 | } |
525 | |
526 | static void o2hb_shutdown_slot(struct o2hb_disk_slot *slot) |
527 | { |
528 | struct o2hb_node_event event = |
529 | { .hn_item = LIST_HEAD_INIT(event.hn_item), }; |
530 | struct o2nm_node *node; |
531 | |
532 | node = o2nm_get_node_by_num(slot->ds_node_num); |
533 | if (!node) |
534 | return; |
535 | |
536 | spin_lock(&o2hb_live_lock); |
537 | if (!list_empty(&slot->ds_live_item)) { |
538 | mlog(ML_HEARTBEAT, "Shutdown, node %d leaves region\n", |
539 | slot->ds_node_num); |
540 | |
541 | list_del_init(&slot->ds_live_item); |
542 | |
543 | if (list_empty(&o2hb_live_slots[slot->ds_node_num])) { |
544 | clear_bit(slot->ds_node_num, o2hb_live_node_bitmap); |
545 | |
546 | o2hb_queue_node_event(&event, O2HB_NODE_DOWN_CB, node, |
547 | slot->ds_node_num); |
548 | } |
549 | } |
550 | spin_unlock(&o2hb_live_lock); |
551 | |
552 | o2hb_run_event_list(&event); |
553 | |
554 | o2nm_node_put(node); |
555 | } |
556 | |
557 | static int o2hb_check_slot(struct o2hb_region *reg, |
558 | struct o2hb_disk_slot *slot) |
559 | { |
560 | int changed = 0, gen_changed = 0; |
561 | struct o2hb_node_event event = |
562 | { .hn_item = LIST_HEAD_INIT(event.hn_item), }; |
563 | struct o2nm_node *node; |
564 | struct o2hb_disk_heartbeat_block *hb_block = reg->hr_tmp_block; |
565 | u64 cputime; |
566 | unsigned int dead_ms = o2hb_dead_threshold * O2HB_REGION_TIMEOUT_MS; |
567 | unsigned int slot_dead_ms; |
568 | |
569 | memcpy(hb_block, slot->ds_raw_block, reg->hr_block_bytes); |
570 | |
571 | /* Is this correct? Do we assume that the node doesn't exist |
572 | * if we're not configured for him? */ |
573 | node = o2nm_get_node_by_num(slot->ds_node_num); |
574 | if (!node) |
575 | return 0; |
576 | |
577 | if (!o2hb_verify_crc(reg, hb_block)) { |
578 | /* all paths from here will drop o2hb_live_lock for |
579 | * us. */ |
580 | spin_lock(&o2hb_live_lock); |
581 | |
582 | /* Don't print an error on the console in this case - |
583 | * a freshly formatted heartbeat area will not have a |
584 | * crc set on it. */ |
585 | if (list_empty(&slot->ds_live_item)) |
586 | goto out; |
587 | |
588 | /* The node is live but pushed out a bad crc. We |
589 | * consider it a transient miss but don't populate any |
590 | * other values as they may be junk. */ |
591 | mlog(ML_ERROR, "Node %d has written a bad crc to %s\n", |
592 | slot->ds_node_num, reg->hr_dev_name); |
593 | o2hb_dump_slot(hb_block); |
594 | |
595 | slot->ds_equal_samples++; |
596 | goto fire_callbacks; |
597 | } |
598 | |
599 | /* we don't care if these wrap.. the state transitions below |
600 | * clear at the right places */ |
601 | cputime = le64_to_cpu(hb_block->hb_seq); |
602 | if (slot->ds_last_time != cputime) |
603 | slot->ds_changed_samples++; |
604 | else |
605 | slot->ds_equal_samples++; |
606 | slot->ds_last_time = cputime; |
607 | |
608 | /* The node changed heartbeat generations. We assume this to |
609 | * mean it dropped off but came back before we timed out. We |
610 | * want to consider it down for the time being but don't want |
611 | * to lose any changed_samples state we might build up to |
612 | * considering it live again. */ |
613 | if (slot->ds_last_generation != le64_to_cpu(hb_block->hb_generation)) { |
614 | gen_changed = 1; |
615 | slot->ds_equal_samples = 0; |
616 | mlog(ML_HEARTBEAT, "Node %d changed generation (0x%llx " |
617 | "to 0x%llx)\n", slot->ds_node_num, |
618 | (long long)slot->ds_last_generation, |
619 | (long long)le64_to_cpu(hb_block->hb_generation)); |
620 | } |
621 | |
622 | slot->ds_last_generation = le64_to_cpu(hb_block->hb_generation); |
623 | |
624 | mlog(ML_HEARTBEAT, "Slot %d gen 0x%llx cksum 0x%x " |
625 | "seq %llu last %llu changed %u equal %u\n", |
626 | slot->ds_node_num, (long long)slot->ds_last_generation, |
627 | le32_to_cpu(hb_block->hb_cksum), |
628 | (unsigned long long)le64_to_cpu(hb_block->hb_seq), |
629 | (unsigned long long)slot->ds_last_time, slot->ds_changed_samples, |
630 | slot->ds_equal_samples); |
631 | |
632 | spin_lock(&o2hb_live_lock); |
633 | |
634 | fire_callbacks: |
635 | /* dead nodes only come to life after some number of |
636 | * changes at any time during their dead time */ |
637 | if (list_empty(&slot->ds_live_item) && |
638 | slot->ds_changed_samples >= O2HB_LIVE_THRESHOLD) { |
639 | mlog(ML_HEARTBEAT, "Node %d (id 0x%llx) joined my region\n", |
640 | slot->ds_node_num, (long long)slot->ds_last_generation); |
641 | |
642 | /* first on the list generates a callback */ |
643 | if (list_empty(&o2hb_live_slots[slot->ds_node_num])) { |
644 | set_bit(slot->ds_node_num, o2hb_live_node_bitmap); |
645 | |
646 | o2hb_queue_node_event(&event, O2HB_NODE_UP_CB, node, |
647 | slot->ds_node_num); |
648 | |
649 | changed = 1; |
650 | } |
651 | |
652 | list_add_tail(&slot->ds_live_item, |
653 | &o2hb_live_slots[slot->ds_node_num]); |
654 | |
655 | slot->ds_equal_samples = 0; |
656 | |
657 | /* We want to be sure that all nodes agree on the |
658 | * number of milliseconds before a node will be |
659 | * considered dead. The self-fencing timeout is |
660 | * computed from this value, and a discrepancy might |
661 | * result in heartbeat calling a node dead when it |
662 | * hasn't self-fenced yet. */ |
663 | slot_dead_ms = le32_to_cpu(hb_block->hb_dead_ms); |
664 | if (slot_dead_ms && slot_dead_ms != dead_ms) { |
665 | /* TODO: Perhaps we can fail the region here. */ |
666 | mlog(ML_ERROR, "Node %d on device %s has a dead count " |
667 | "of %u ms, but our count is %u ms.\n" |
668 | "Please double check your configuration values " |
669 | "for 'O2CB_HEARTBEAT_THRESHOLD'\n", |
670 | slot->ds_node_num, reg->hr_dev_name, slot_dead_ms, |
671 | dead_ms); |
672 | } |
673 | goto out; |
674 | } |
675 | |
676 | /* if the list is dead, we're done.. */ |
677 | if (list_empty(&slot->ds_live_item)) |
678 | goto out; |
679 | |
680 | /* live nodes only go dead after enough consequtive missed |
681 | * samples.. reset the missed counter whenever we see |
682 | * activity */ |
683 | if (slot->ds_equal_samples >= o2hb_dead_threshold || gen_changed) { |
684 | mlog(ML_HEARTBEAT, "Node %d left my region\n", |
685 | slot->ds_node_num); |
686 | |
687 | /* last off the live_slot generates a callback */ |
688 | list_del_init(&slot->ds_live_item); |
689 | if (list_empty(&o2hb_live_slots[slot->ds_node_num])) { |
690 | clear_bit(slot->ds_node_num, o2hb_live_node_bitmap); |
691 | |
692 | o2hb_queue_node_event(&event, O2HB_NODE_DOWN_CB, node, |
693 | slot->ds_node_num); |
694 | |
695 | changed = 1; |
696 | } |
697 | |
698 | /* We don't clear this because the node is still |
699 | * actually writing new blocks. */ |
700 | if (!gen_changed) |
701 | slot->ds_changed_samples = 0; |
702 | goto out; |
703 | } |
704 | if (slot->ds_changed_samples) { |
705 | slot->ds_changed_samples = 0; |
706 | slot->ds_equal_samples = 0; |
707 | } |
708 | out: |
709 | spin_unlock(&o2hb_live_lock); |
710 | |
711 | o2hb_run_event_list(&event); |
712 | |
713 | o2nm_node_put(node); |
714 | return changed; |
715 | } |
716 | |
717 | /* This could be faster if we just implmented a find_last_bit, but I |
718 | * don't think the circumstances warrant it. */ |
719 | static int o2hb_highest_node(unsigned long *nodes, |
720 | int numbits) |
721 | { |
722 | int highest, node; |
723 | |
724 | highest = numbits; |
725 | node = -1; |
726 | while ((node = find_next_bit(nodes, numbits, node + 1)) != -1) { |
727 | if (node >= numbits) |
728 | break; |
729 | |
730 | highest = node; |
731 | } |
732 | |
733 | return highest; |
734 | } |
735 | |
736 | static int o2hb_do_disk_heartbeat(struct o2hb_region *reg) |
737 | { |
738 | int i, ret, highest_node, change = 0; |
739 | unsigned long configured_nodes[BITS_TO_LONGS(O2NM_MAX_NODES)]; |
740 | struct o2hb_bio_wait_ctxt write_wc; |
741 | |
742 | ret = o2nm_configured_node_map(configured_nodes, |
743 | sizeof(configured_nodes)); |
744 | if (ret) { |
745 | mlog_errno(ret); |
746 | return ret; |
747 | } |
748 | |
749 | highest_node = o2hb_highest_node(configured_nodes, O2NM_MAX_NODES); |
750 | if (highest_node >= O2NM_MAX_NODES) { |
751 | mlog(ML_NOTICE, "ocfs2_heartbeat: no configured nodes found!\n"); |
752 | return -EINVAL; |
753 | } |
754 | |
755 | /* No sense in reading the slots of nodes that don't exist |
756 | * yet. Of course, if the node definitions have holes in them |
757 | * then we're reading an empty slot anyway... Consider this |
758 | * best-effort. */ |
759 | ret = o2hb_read_slots(reg, highest_node + 1); |
760 | if (ret < 0) { |
761 | mlog_errno(ret); |
762 | return ret; |
763 | } |
764 | |
765 | /* With an up to date view of the slots, we can check that no |
766 | * other node has been improperly configured to heartbeat in |
767 | * our slot. */ |
768 | if (!o2hb_check_last_timestamp(reg)) |
769 | mlog(ML_ERROR, "Device \"%s\": another node is heartbeating " |
770 | "in our slot!\n", reg->hr_dev_name); |
771 | |
772 | /* fill in the proper info for our next heartbeat */ |
773 | o2hb_prepare_block(reg, reg->hr_generation); |
774 | |
775 | /* And fire off the write. Note that we don't wait on this I/O |
776 | * until later. */ |
777 | ret = o2hb_issue_node_write(reg, &write_wc); |
778 | if (ret < 0) { |
779 | mlog_errno(ret); |
780 | return ret; |
781 | } |
782 | |
783 | i = -1; |
784 | while((i = find_next_bit(configured_nodes, O2NM_MAX_NODES, i + 1)) < O2NM_MAX_NODES) { |
785 | |
786 | change |= o2hb_check_slot(reg, ®->hr_slots[i]); |
787 | } |
788 | |
789 | /* |
790 | * We have to be sure we've advertised ourselves on disk |
791 | * before we can go to steady state. This ensures that |
792 | * people we find in our steady state have seen us. |
793 | */ |
794 | o2hb_wait_on_io(reg, &write_wc); |
795 | if (write_wc.wc_error) { |
796 | /* Do not re-arm the write timeout on I/O error - we |
797 | * can't be sure that the new block ever made it to |
798 | * disk */ |
799 | mlog(ML_ERROR, "Write error %d on device \"%s\"\n", |
800 | write_wc.wc_error, reg->hr_dev_name); |
801 | return write_wc.wc_error; |
802 | } |
803 | |
804 | o2hb_arm_write_timeout(reg); |
805 | |
806 | /* let the person who launched us know when things are steady */ |
807 | if (!change && (atomic_read(®->hr_steady_iterations) != 0)) { |
808 | if (atomic_dec_and_test(®->hr_steady_iterations)) |
809 | wake_up(&o2hb_steady_queue); |
810 | } |
811 | |
812 | return 0; |
813 | } |
814 | |
815 | /* Subtract b from a, storing the result in a. a *must* have a larger |
816 | * value than b. */ |
817 | static void o2hb_tv_subtract(struct timeval *a, |
818 | struct timeval *b) |
819 | { |
820 | /* just return 0 when a is after b */ |
821 | if (a->tv_sec < b->tv_sec || |
822 | (a->tv_sec == b->tv_sec && a->tv_usec < b->tv_usec)) { |
823 | a->tv_sec = 0; |
824 | a->tv_usec = 0; |
825 | return; |
826 | } |
827 | |
828 | a->tv_sec -= b->tv_sec; |
829 | a->tv_usec -= b->tv_usec; |
830 | while ( a->tv_usec < 0 ) { |
831 | a->tv_sec--; |
832 | a->tv_usec += 1000000; |
833 | } |
834 | } |
835 | |
836 | static unsigned int o2hb_elapsed_msecs(struct timeval *start, |
837 | struct timeval *end) |
838 | { |
839 | struct timeval res = *end; |
840 | |
841 | o2hb_tv_subtract(&res, start); |
842 | |
843 | return res.tv_sec * 1000 + res.tv_usec / 1000; |
844 | } |
845 | |
846 | /* |
847 | * we ride the region ref that the region dir holds. before the region |
848 | * dir is removed and drops it ref it will wait to tear down this |
849 | * thread. |
850 | */ |
851 | static int o2hb_thread(void *data) |
852 | { |
853 | int i, ret; |
854 | struct o2hb_region *reg = data; |
855 | struct o2hb_bio_wait_ctxt write_wc; |
856 | struct timeval before_hb, after_hb; |
857 | unsigned int elapsed_msec; |
858 | |
859 | mlog(ML_HEARTBEAT|ML_KTHREAD, "hb thread running\n"); |
860 | |
861 | set_user_nice(current, -20); |
862 | |
863 | while (!kthread_should_stop() && !reg->hr_unclean_stop) { |
864 | /* We track the time spent inside |
865 | * o2hb_do_disk_heartbeat so that we avoid more than |
866 | * hr_timeout_ms between disk writes. On busy systems |
867 | * this should result in a heartbeat which is less |
868 | * likely to time itself out. */ |
869 | do_gettimeofday(&before_hb); |
870 | |
871 | i = 0; |
872 | do { |
873 | ret = o2hb_do_disk_heartbeat(reg); |
874 | } while (ret && ++i < 2); |
875 | |
876 | do_gettimeofday(&after_hb); |
877 | elapsed_msec = o2hb_elapsed_msecs(&before_hb, &after_hb); |
878 | |
879 | mlog(ML_HEARTBEAT, |
880 | "start = %lu.%lu, end = %lu.%lu, msec = %u\n", |
881 | before_hb.tv_sec, (unsigned long) before_hb.tv_usec, |
882 | after_hb.tv_sec, (unsigned long) after_hb.tv_usec, |
883 | elapsed_msec); |
884 | |
885 | if (elapsed_msec < reg->hr_timeout_ms) { |
886 | /* the kthread api has blocked signals for us so no |
887 | * need to record the return value. */ |
888 | msleep_interruptible(reg->hr_timeout_ms - elapsed_msec); |
889 | } |
890 | } |
891 | |
892 | o2hb_disarm_write_timeout(reg); |
893 | |
894 | /* unclean stop is only used in very bad situation */ |
895 | for(i = 0; !reg->hr_unclean_stop && i < reg->hr_blocks; i++) |
896 | o2hb_shutdown_slot(®->hr_slots[i]); |
897 | |
898 | /* Explicit down notification - avoid forcing the other nodes |
899 | * to timeout on this region when we could just as easily |
900 | * write a clear generation - thus indicating to them that |
901 | * this node has left this region. |
902 | * |
903 | * XXX: Should we skip this on unclean_stop? */ |
904 | o2hb_prepare_block(reg, 0); |
905 | ret = o2hb_issue_node_write(reg, &write_wc); |
906 | if (ret == 0) { |
907 | o2hb_wait_on_io(reg, &write_wc); |
908 | } else { |
909 | mlog_errno(ret); |
910 | } |
911 | |
912 | mlog(ML_HEARTBEAT|ML_KTHREAD, "hb thread exiting\n"); |
913 | |
914 | return 0; |
915 | } |
916 | |
917 | #ifdef CONFIG_DEBUG_FS |
918 | static int o2hb_debug_open(struct inode *inode, struct file *file) |
919 | { |
920 | unsigned long map[BITS_TO_LONGS(O2NM_MAX_NODES)]; |
921 | char *buf = NULL; |
922 | int i = -1; |
923 | int out = 0; |
924 | |
925 | buf = kmalloc(PAGE_SIZE, GFP_KERNEL); |
926 | if (!buf) |
927 | goto bail; |
928 | |
929 | o2hb_fill_node_map(map, sizeof(map)); |
930 | |
931 | while ((i = find_next_bit(map, O2NM_MAX_NODES, i + 1)) < O2NM_MAX_NODES) |
932 | out += snprintf(buf + out, PAGE_SIZE - out, "%d ", i); |
933 | out += snprintf(buf + out, PAGE_SIZE - out, "\n"); |
934 | |
935 | i_size_write(inode, out); |
936 | |
937 | file->private_data = buf; |
938 | |
939 | return 0; |
940 | bail: |
941 | return -ENOMEM; |
942 | } |
943 | |
944 | static int o2hb_debug_release(struct inode *inode, struct file *file) |
945 | { |
946 | kfree(file->private_data); |
947 | return 0; |
948 | } |
949 | |
950 | static ssize_t o2hb_debug_read(struct file *file, char __user *buf, |
951 | size_t nbytes, loff_t *ppos) |
952 | { |
953 | return simple_read_from_buffer(buf, nbytes, ppos, file->private_data, |
954 | i_size_read(file->f_mapping->host)); |
955 | } |
956 | #else |
957 | static int o2hb_debug_open(struct inode *inode, struct file *file) |
958 | { |
959 | return 0; |
960 | } |
961 | static int o2hb_debug_release(struct inode *inode, struct file *file) |
962 | { |
963 | return 0; |
964 | } |
965 | static ssize_t o2hb_debug_read(struct file *file, char __user *buf, |
966 | size_t nbytes, loff_t *ppos) |
967 | { |
968 | return 0; |
969 | } |
970 | #endif /* CONFIG_DEBUG_FS */ |
971 | |
972 | static const struct file_operations o2hb_debug_fops = { |
973 | .open = o2hb_debug_open, |
974 | .release = o2hb_debug_release, |
975 | .read = o2hb_debug_read, |
976 | .llseek = generic_file_llseek, |
977 | }; |
978 | |
979 | void o2hb_exit(void) |
980 | { |
981 | if (o2hb_debug_livenodes) |
982 | debugfs_remove(o2hb_debug_livenodes); |
983 | if (o2hb_debug_dir) |
984 | debugfs_remove(o2hb_debug_dir); |
985 | } |
986 | |
987 | int o2hb_init(void) |
988 | { |
989 | int i; |
990 | |
991 | for (i = 0; i < ARRAY_SIZE(o2hb_callbacks); i++) |
992 | INIT_LIST_HEAD(&o2hb_callbacks[i].list); |
993 | |
994 | for (i = 0; i < ARRAY_SIZE(o2hb_live_slots); i++) |
995 | INIT_LIST_HEAD(&o2hb_live_slots[i]); |
996 | |
997 | INIT_LIST_HEAD(&o2hb_node_events); |
998 | |
999 | memset(o2hb_live_node_bitmap, 0, sizeof(o2hb_live_node_bitmap)); |
1000 | |
1001 | o2hb_debug_dir = debugfs_create_dir(O2HB_DEBUG_DIR, NULL); |
1002 | if (!o2hb_debug_dir) { |
1003 | mlog_errno(-ENOMEM); |
1004 | return -ENOMEM; |
1005 | } |
1006 | |
1007 | o2hb_debug_livenodes = debugfs_create_file(O2HB_DEBUG_LIVENODES, |
1008 | S_IFREG|S_IRUSR, |
1009 | o2hb_debug_dir, NULL, |
1010 | &o2hb_debug_fops); |
1011 | if (!o2hb_debug_livenodes) { |
1012 | mlog_errno(-ENOMEM); |
1013 | debugfs_remove(o2hb_debug_dir); |
1014 | return -ENOMEM; |
1015 | } |
1016 | |
1017 | return 0; |
1018 | } |
1019 | |
1020 | /* if we're already in a callback then we're already serialized by the sem */ |
1021 | static void o2hb_fill_node_map_from_callback(unsigned long *map, |
1022 | unsigned bytes) |
1023 | { |
1024 | BUG_ON(bytes < (BITS_TO_LONGS(O2NM_MAX_NODES) * sizeof(unsigned long))); |
1025 | |
1026 | memcpy(map, &o2hb_live_node_bitmap, bytes); |
1027 | } |
1028 | |
1029 | /* |
1030 | * get a map of all nodes that are heartbeating in any regions |
1031 | */ |
1032 | void o2hb_fill_node_map(unsigned long *map, unsigned bytes) |
1033 | { |
1034 | /* callers want to serialize this map and callbacks so that they |
1035 | * can trust that they don't miss nodes coming to the party */ |
1036 | down_read(&o2hb_callback_sem); |
1037 | spin_lock(&o2hb_live_lock); |
1038 | o2hb_fill_node_map_from_callback(map, bytes); |
1039 | spin_unlock(&o2hb_live_lock); |
1040 | up_read(&o2hb_callback_sem); |
1041 | } |
1042 | EXPORT_SYMBOL_GPL(o2hb_fill_node_map); |
1043 | |
1044 | /* |
1045 | * heartbeat configfs bits. The heartbeat set is a default set under |
1046 | * the cluster set in nodemanager.c. |
1047 | */ |
1048 | |
1049 | static struct o2hb_region *to_o2hb_region(struct config_item *item) |
1050 | { |
1051 | return item ? container_of(item, struct o2hb_region, hr_item) : NULL; |
1052 | } |
1053 | |
1054 | /* drop_item only drops its ref after killing the thread, nothing should |
1055 | * be using the region anymore. this has to clean up any state that |
1056 | * attributes might have built up. */ |
1057 | static void o2hb_region_release(struct config_item *item) |
1058 | { |
1059 | int i; |
1060 | struct page *page; |
1061 | struct o2hb_region *reg = to_o2hb_region(item); |
1062 | |
1063 | if (reg->hr_tmp_block) |
1064 | kfree(reg->hr_tmp_block); |
1065 | |
1066 | if (reg->hr_slot_data) { |
1067 | for (i = 0; i < reg->hr_num_pages; i++) { |
1068 | page = reg->hr_slot_data[i]; |
1069 | if (page) |
1070 | __free_page(page); |
1071 | } |
1072 | kfree(reg->hr_slot_data); |
1073 | } |
1074 | |
1075 | if (reg->hr_bdev) |
1076 | blkdev_put(reg->hr_bdev, FMODE_READ|FMODE_WRITE); |
1077 | |
1078 | if (reg->hr_slots) |
1079 | kfree(reg->hr_slots); |
1080 | |
1081 | spin_lock(&o2hb_live_lock); |
1082 | list_del(®->hr_all_item); |
1083 | spin_unlock(&o2hb_live_lock); |
1084 | |
1085 | kfree(reg); |
1086 | } |
1087 | |
1088 | static int o2hb_read_block_input(struct o2hb_region *reg, |
1089 | const char *page, |
1090 | size_t count, |
1091 | unsigned long *ret_bytes, |
1092 | unsigned int *ret_bits) |
1093 | { |
1094 | unsigned long bytes; |
1095 | char *p = (char *)page; |
1096 | |
1097 | bytes = simple_strtoul(p, &p, 0); |
1098 | if (!p || (*p && (*p != '\n'))) |
1099 | return -EINVAL; |
1100 | |
1101 | /* Heartbeat and fs min / max block sizes are the same. */ |
1102 | if (bytes > 4096 || bytes < 512) |
1103 | return -ERANGE; |
1104 | if (hweight16(bytes) != 1) |
1105 | return -EINVAL; |
1106 | |
1107 | if (ret_bytes) |
1108 | *ret_bytes = bytes; |
1109 | if (ret_bits) |
1110 | *ret_bits = ffs(bytes) - 1; |
1111 | |
1112 | return 0; |
1113 | } |
1114 | |
1115 | static ssize_t o2hb_region_block_bytes_read(struct o2hb_region *reg, |
1116 | char *page) |
1117 | { |
1118 | return sprintf(page, "%u\n", reg->hr_block_bytes); |
1119 | } |
1120 | |
1121 | static ssize_t o2hb_region_block_bytes_write(struct o2hb_region *reg, |
1122 | const char *page, |
1123 | size_t count) |
1124 | { |
1125 | int status; |
1126 | unsigned long block_bytes; |
1127 | unsigned int block_bits; |
1128 | |
1129 | if (reg->hr_bdev) |
1130 | return -EINVAL; |
1131 | |
1132 | status = o2hb_read_block_input(reg, page, count, |
1133 | &block_bytes, &block_bits); |
1134 | if (status) |
1135 | return status; |
1136 | |
1137 | reg->hr_block_bytes = (unsigned int)block_bytes; |
1138 | reg->hr_block_bits = block_bits; |
1139 | |
1140 | return count; |
1141 | } |
1142 | |
1143 | static ssize_t o2hb_region_start_block_read(struct o2hb_region *reg, |
1144 | char *page) |
1145 | { |
1146 | return sprintf(page, "%llu\n", reg->hr_start_block); |
1147 | } |
1148 | |
1149 | static ssize_t o2hb_region_start_block_write(struct o2hb_region *reg, |
1150 | const char *page, |
1151 | size_t count) |
1152 | { |
1153 | unsigned long long tmp; |
1154 | char *p = (char *)page; |
1155 | |
1156 | if (reg->hr_bdev) |
1157 | return -EINVAL; |
1158 | |
1159 | tmp = simple_strtoull(p, &p, 0); |
1160 | if (!p || (*p && (*p != '\n'))) |
1161 | return -EINVAL; |
1162 | |
1163 | reg->hr_start_block = tmp; |
1164 | |
1165 | return count; |
1166 | } |
1167 | |
1168 | static ssize_t o2hb_region_blocks_read(struct o2hb_region *reg, |
1169 | char *page) |
1170 | { |
1171 | return sprintf(page, "%d\n", reg->hr_blocks); |
1172 | } |
1173 | |
1174 | static ssize_t o2hb_region_blocks_write(struct o2hb_region *reg, |
1175 | const char *page, |
1176 | size_t count) |
1177 | { |
1178 | unsigned long tmp; |
1179 | char *p = (char *)page; |
1180 | |
1181 | if (reg->hr_bdev) |
1182 | return -EINVAL; |
1183 | |
1184 | tmp = simple_strtoul(p, &p, 0); |
1185 | if (!p || (*p && (*p != '\n'))) |
1186 | return -EINVAL; |
1187 | |
1188 | if (tmp > O2NM_MAX_NODES || tmp == 0) |
1189 | return -ERANGE; |
1190 | |
1191 | reg->hr_blocks = (unsigned int)tmp; |
1192 | |
1193 | return count; |
1194 | } |
1195 | |
1196 | static ssize_t o2hb_region_dev_read(struct o2hb_region *reg, |
1197 | char *page) |
1198 | { |
1199 | unsigned int ret = 0; |
1200 | |
1201 | if (reg->hr_bdev) |
1202 | ret = sprintf(page, "%s\n", reg->hr_dev_name); |
1203 | |
1204 | return ret; |
1205 | } |
1206 | |
1207 | static void o2hb_init_region_params(struct o2hb_region *reg) |
1208 | { |
1209 | reg->hr_slots_per_page = PAGE_CACHE_SIZE >> reg->hr_block_bits; |
1210 | reg->hr_timeout_ms = O2HB_REGION_TIMEOUT_MS; |
1211 | |
1212 | mlog(ML_HEARTBEAT, "hr_start_block = %llu, hr_blocks = %u\n", |
1213 | reg->hr_start_block, reg->hr_blocks); |
1214 | mlog(ML_HEARTBEAT, "hr_block_bytes = %u, hr_block_bits = %u\n", |
1215 | reg->hr_block_bytes, reg->hr_block_bits); |
1216 | mlog(ML_HEARTBEAT, "hr_timeout_ms = %u\n", reg->hr_timeout_ms); |
1217 | mlog(ML_HEARTBEAT, "dead threshold = %u\n", o2hb_dead_threshold); |
1218 | } |
1219 | |
1220 | static int o2hb_map_slot_data(struct o2hb_region *reg) |
1221 | { |
1222 | int i, j; |
1223 | unsigned int last_slot; |
1224 | unsigned int spp = reg->hr_slots_per_page; |
1225 | struct page *page; |
1226 | char *raw; |
1227 | struct o2hb_disk_slot *slot; |
1228 | |
1229 | reg->hr_tmp_block = kmalloc(reg->hr_block_bytes, GFP_KERNEL); |
1230 | if (reg->hr_tmp_block == NULL) { |
1231 | mlog_errno(-ENOMEM); |
1232 | return -ENOMEM; |
1233 | } |
1234 | |
1235 | reg->hr_slots = kcalloc(reg->hr_blocks, |
1236 | sizeof(struct o2hb_disk_slot), GFP_KERNEL); |
1237 | if (reg->hr_slots == NULL) { |
1238 | mlog_errno(-ENOMEM); |
1239 | return -ENOMEM; |
1240 | } |
1241 | |
1242 | for(i = 0; i < reg->hr_blocks; i++) { |
1243 | slot = ®->hr_slots[i]; |
1244 | slot->ds_node_num = i; |
1245 | INIT_LIST_HEAD(&slot->ds_live_item); |
1246 | slot->ds_raw_block = NULL; |
1247 | } |
1248 | |
1249 | reg->hr_num_pages = (reg->hr_blocks + spp - 1) / spp; |
1250 | mlog(ML_HEARTBEAT, "Going to require %u pages to cover %u blocks " |
1251 | "at %u blocks per page\n", |
1252 | reg->hr_num_pages, reg->hr_blocks, spp); |
1253 | |
1254 | reg->hr_slot_data = kcalloc(reg->hr_num_pages, sizeof(struct page *), |
1255 | GFP_KERNEL); |
1256 | if (!reg->hr_slot_data) { |
1257 | mlog_errno(-ENOMEM); |
1258 | return -ENOMEM; |
1259 | } |
1260 | |
1261 | for(i = 0; i < reg->hr_num_pages; i++) { |
1262 | page = alloc_page(GFP_KERNEL); |
1263 | if (!page) { |
1264 | mlog_errno(-ENOMEM); |
1265 | return -ENOMEM; |
1266 | } |
1267 | |
1268 | reg->hr_slot_data[i] = page; |
1269 | |
1270 | last_slot = i * spp; |
1271 | raw = page_address(page); |
1272 | for (j = 0; |
1273 | (j < spp) && ((j + last_slot) < reg->hr_blocks); |
1274 | j++) { |
1275 | BUG_ON((j + last_slot) >= reg->hr_blocks); |
1276 | |
1277 | slot = ®->hr_slots[j + last_slot]; |
1278 | slot->ds_raw_block = |
1279 | (struct o2hb_disk_heartbeat_block *) raw; |
1280 | |
1281 | raw += reg->hr_block_bytes; |
1282 | } |
1283 | } |
1284 | |
1285 | return 0; |
1286 | } |
1287 | |
1288 | /* Read in all the slots available and populate the tracking |
1289 | * structures so that we can start with a baseline idea of what's |
1290 | * there. */ |
1291 | static int o2hb_populate_slot_data(struct o2hb_region *reg) |
1292 | { |
1293 | int ret, i; |
1294 | struct o2hb_disk_slot *slot; |
1295 | struct o2hb_disk_heartbeat_block *hb_block; |
1296 | |
1297 | mlog_entry_void(); |
1298 | |
1299 | ret = o2hb_read_slots(reg, reg->hr_blocks); |
1300 | if (ret) { |
1301 | mlog_errno(ret); |
1302 | goto out; |
1303 | } |
1304 | |
1305 | /* We only want to get an idea of the values initially in each |
1306 | * slot, so we do no verification - o2hb_check_slot will |
1307 | * actually determine if each configured slot is valid and |
1308 | * whether any values have changed. */ |
1309 | for(i = 0; i < reg->hr_blocks; i++) { |
1310 | slot = ®->hr_slots[i]; |
1311 | hb_block = (struct o2hb_disk_heartbeat_block *) slot->ds_raw_block; |
1312 | |
1313 | /* Only fill the values that o2hb_check_slot uses to |
1314 | * determine changing slots */ |
1315 | slot->ds_last_time = le64_to_cpu(hb_block->hb_seq); |
1316 | slot->ds_last_generation = le64_to_cpu(hb_block->hb_generation); |
1317 | } |
1318 | |
1319 | out: |
1320 | mlog_exit(ret); |
1321 | return ret; |
1322 | } |
1323 | |
1324 | /* this is acting as commit; we set up all of hr_bdev and hr_task or nothing */ |
1325 | static ssize_t o2hb_region_dev_write(struct o2hb_region *reg, |
1326 | const char *page, |
1327 | size_t count) |
1328 | { |
1329 | struct task_struct *hb_task; |
1330 | long fd; |
1331 | int sectsize; |
1332 | char *p = (char *)page; |
1333 | struct file *filp = NULL; |
1334 | struct inode *inode = NULL; |
1335 | ssize_t ret = -EINVAL; |
1336 | |
1337 | if (reg->hr_bdev) |
1338 | goto out; |
1339 | |
1340 | /* We can't heartbeat without having had our node number |
1341 | * configured yet. */ |
1342 | if (o2nm_this_node() == O2NM_MAX_NODES) |
1343 | goto out; |
1344 | |
1345 | fd = simple_strtol(p, &p, 0); |
1346 | if (!p || (*p && (*p != '\n'))) |
1347 | goto out; |
1348 | |
1349 | if (fd < 0 || fd >= INT_MAX) |
1350 | goto out; |
1351 | |
1352 | filp = fget(fd); |
1353 | if (filp == NULL) |
1354 | goto out; |
1355 | |
1356 | if (reg->hr_blocks == 0 || reg->hr_start_block == 0 || |
1357 | reg->hr_block_bytes == 0) |
1358 | goto out; |
1359 | |
1360 | inode = igrab(filp->f_mapping->host); |
1361 | if (inode == NULL) |
1362 | goto out; |
1363 | |
1364 | if (!S_ISBLK(inode->i_mode)) |
1365 | goto out; |
1366 | |
1367 | reg->hr_bdev = I_BDEV(filp->f_mapping->host); |
1368 | ret = blkdev_get(reg->hr_bdev, FMODE_WRITE | FMODE_READ); |
1369 | if (ret) { |
1370 | reg->hr_bdev = NULL; |
1371 | goto out; |
1372 | } |
1373 | inode = NULL; |
1374 | |
1375 | bdevname(reg->hr_bdev, reg->hr_dev_name); |
1376 | |
1377 | sectsize = bdev_logical_block_size(reg->hr_bdev); |
1378 | if (sectsize != reg->hr_block_bytes) { |
1379 | mlog(ML_ERROR, |
1380 | "blocksize %u incorrect for device, expected %d", |
1381 | reg->hr_block_bytes, sectsize); |
1382 | ret = -EINVAL; |
1383 | goto out; |
1384 | } |
1385 | |
1386 | o2hb_init_region_params(reg); |
1387 | |
1388 | /* Generation of zero is invalid */ |
1389 | do { |
1390 | get_random_bytes(®->hr_generation, |
1391 | sizeof(reg->hr_generation)); |
1392 | } while (reg->hr_generation == 0); |
1393 | |
1394 | ret = o2hb_map_slot_data(reg); |
1395 | if (ret) { |
1396 | mlog_errno(ret); |
1397 | goto out; |
1398 | } |
1399 | |
1400 | ret = o2hb_populate_slot_data(reg); |
1401 | if (ret) { |
1402 | mlog_errno(ret); |
1403 | goto out; |
1404 | } |
1405 | |
1406 | INIT_DELAYED_WORK(®->hr_write_timeout_work, o2hb_write_timeout); |
1407 | |
1408 | /* |
1409 | * A node is considered live after it has beat LIVE_THRESHOLD |
1410 | * times. We're not steady until we've given them a chance |
1411 | * _after_ our first read. |
1412 | */ |
1413 | atomic_set(®->hr_steady_iterations, O2HB_LIVE_THRESHOLD + 1); |
1414 | |
1415 | hb_task = kthread_run(o2hb_thread, reg, "o2hb-%s", |
1416 | reg->hr_item.ci_name); |
1417 | if (IS_ERR(hb_task)) { |
1418 | ret = PTR_ERR(hb_task); |
1419 | mlog_errno(ret); |
1420 | goto out; |
1421 | } |
1422 | |
1423 | spin_lock(&o2hb_live_lock); |
1424 | reg->hr_task = hb_task; |
1425 | spin_unlock(&o2hb_live_lock); |
1426 | |
1427 | ret = wait_event_interruptible(o2hb_steady_queue, |
1428 | atomic_read(®->hr_steady_iterations) == 0); |
1429 | if (ret) { |
1430 | /* We got interrupted (hello ptrace!). Clean up */ |
1431 | spin_lock(&o2hb_live_lock); |
1432 | hb_task = reg->hr_task; |
1433 | reg->hr_task = NULL; |
1434 | spin_unlock(&o2hb_live_lock); |
1435 | |
1436 | if (hb_task) |
1437 | kthread_stop(hb_task); |
1438 | goto out; |
1439 | } |
1440 | |
1441 | /* Ok, we were woken. Make sure it wasn't by drop_item() */ |
1442 | spin_lock(&o2hb_live_lock); |
1443 | hb_task = reg->hr_task; |
1444 | spin_unlock(&o2hb_live_lock); |
1445 | |
1446 | if (hb_task) |
1447 | ret = count; |
1448 | else |
1449 | ret = -EIO; |
1450 | |
1451 | out: |
1452 | if (filp) |
1453 | fput(filp); |
1454 | if (inode) |
1455 | iput(inode); |
1456 | if (ret < 0) { |
1457 | if (reg->hr_bdev) { |
1458 | blkdev_put(reg->hr_bdev, FMODE_READ|FMODE_WRITE); |
1459 | reg->hr_bdev = NULL; |
1460 | } |
1461 | } |
1462 | return ret; |
1463 | } |
1464 | |
1465 | static ssize_t o2hb_region_pid_read(struct o2hb_region *reg, |
1466 | char *page) |
1467 | { |
1468 | pid_t pid = 0; |
1469 | |
1470 | spin_lock(&o2hb_live_lock); |
1471 | if (reg->hr_task) |
1472 | pid = task_pid_nr(reg->hr_task); |
1473 | spin_unlock(&o2hb_live_lock); |
1474 | |
1475 | if (!pid) |
1476 | return 0; |
1477 | |
1478 | return sprintf(page, "%u\n", pid); |
1479 | } |
1480 | |
1481 | struct o2hb_region_attribute { |
1482 | struct configfs_attribute attr; |
1483 | ssize_t (*show)(struct o2hb_region *, char *); |
1484 | ssize_t (*store)(struct o2hb_region *, const char *, size_t); |
1485 | }; |
1486 | |
1487 | static struct o2hb_region_attribute o2hb_region_attr_block_bytes = { |
1488 | .attr = { .ca_owner = THIS_MODULE, |
1489 | .ca_name = "block_bytes", |
1490 | .ca_mode = S_IRUGO | S_IWUSR }, |
1491 | .show = o2hb_region_block_bytes_read, |
1492 | .store = o2hb_region_block_bytes_write, |
1493 | }; |
1494 | |
1495 | static struct o2hb_region_attribute o2hb_region_attr_start_block = { |
1496 | .attr = { .ca_owner = THIS_MODULE, |
1497 | .ca_name = "start_block", |
1498 | .ca_mode = S_IRUGO | S_IWUSR }, |
1499 | .show = o2hb_region_start_block_read, |
1500 | .store = o2hb_region_start_block_write, |
1501 | }; |
1502 | |
1503 | static struct o2hb_region_attribute o2hb_region_attr_blocks = { |
1504 | .attr = { .ca_owner = THIS_MODULE, |
1505 | .ca_name = "blocks", |
1506 | .ca_mode = S_IRUGO | S_IWUSR }, |
1507 | .show = o2hb_region_blocks_read, |
1508 | .store = o2hb_region_blocks_write, |
1509 | }; |
1510 | |
1511 | static struct o2hb_region_attribute o2hb_region_attr_dev = { |
1512 | .attr = { .ca_owner = THIS_MODULE, |
1513 | .ca_name = "dev", |
1514 | .ca_mode = S_IRUGO | S_IWUSR }, |
1515 | .show = o2hb_region_dev_read, |
1516 | .store = o2hb_region_dev_write, |
1517 | }; |
1518 | |
1519 | static struct o2hb_region_attribute o2hb_region_attr_pid = { |
1520 | .attr = { .ca_owner = THIS_MODULE, |
1521 | .ca_name = "pid", |
1522 | .ca_mode = S_IRUGO | S_IRUSR }, |
1523 | .show = o2hb_region_pid_read, |
1524 | }; |
1525 | |
1526 | static struct configfs_attribute *o2hb_region_attrs[] = { |
1527 | &o2hb_region_attr_block_bytes.attr, |
1528 | &o2hb_region_attr_start_block.attr, |
1529 | &o2hb_region_attr_blocks.attr, |
1530 | &o2hb_region_attr_dev.attr, |
1531 | &o2hb_region_attr_pid.attr, |
1532 | NULL, |
1533 | }; |
1534 | |
1535 | static ssize_t o2hb_region_show(struct config_item *item, |
1536 | struct configfs_attribute *attr, |
1537 | char *page) |
1538 | { |
1539 | struct o2hb_region *reg = to_o2hb_region(item); |
1540 | struct o2hb_region_attribute *o2hb_region_attr = |
1541 | container_of(attr, struct o2hb_region_attribute, attr); |
1542 | ssize_t ret = 0; |
1543 | |
1544 | if (o2hb_region_attr->show) |
1545 | ret = o2hb_region_attr->show(reg, page); |
1546 | return ret; |
1547 | } |
1548 | |
1549 | static ssize_t o2hb_region_store(struct config_item *item, |
1550 | struct configfs_attribute *attr, |
1551 | const char *page, size_t count) |
1552 | { |
1553 | struct o2hb_region *reg = to_o2hb_region(item); |
1554 | struct o2hb_region_attribute *o2hb_region_attr = |
1555 | container_of(attr, struct o2hb_region_attribute, attr); |
1556 | ssize_t ret = -EINVAL; |
1557 | |
1558 | if (o2hb_region_attr->store) |
1559 | ret = o2hb_region_attr->store(reg, page, count); |
1560 | return ret; |
1561 | } |
1562 | |
1563 | static struct configfs_item_operations o2hb_region_item_ops = { |
1564 | .release = o2hb_region_release, |
1565 | .show_attribute = o2hb_region_show, |
1566 | .store_attribute = o2hb_region_store, |
1567 | }; |
1568 | |
1569 | static struct config_item_type o2hb_region_type = { |
1570 | .ct_item_ops = &o2hb_region_item_ops, |
1571 | .ct_attrs = o2hb_region_attrs, |
1572 | .ct_owner = THIS_MODULE, |
1573 | }; |
1574 | |
1575 | /* heartbeat set */ |
1576 | |
1577 | struct o2hb_heartbeat_group { |
1578 | struct config_group hs_group; |
1579 | /* some stuff? */ |
1580 | }; |
1581 | |
1582 | static struct o2hb_heartbeat_group *to_o2hb_heartbeat_group(struct config_group *group) |
1583 | { |
1584 | return group ? |
1585 | container_of(group, struct o2hb_heartbeat_group, hs_group) |
1586 | : NULL; |
1587 | } |
1588 | |
1589 | static struct config_item *o2hb_heartbeat_group_make_item(struct config_group *group, |
1590 | const char *name) |
1591 | { |
1592 | struct o2hb_region *reg = NULL; |
1593 | |
1594 | reg = kzalloc(sizeof(struct o2hb_region), GFP_KERNEL); |
1595 | if (reg == NULL) |
1596 | return ERR_PTR(-ENOMEM); |
1597 | |
1598 | config_item_init_type_name(®->hr_item, name, &o2hb_region_type); |
1599 | |
1600 | spin_lock(&o2hb_live_lock); |
1601 | list_add_tail(®->hr_all_item, &o2hb_all_regions); |
1602 | spin_unlock(&o2hb_live_lock); |
1603 | |
1604 | return ®->hr_item; |
1605 | } |
1606 | |
1607 | static void o2hb_heartbeat_group_drop_item(struct config_group *group, |
1608 | struct config_item *item) |
1609 | { |
1610 | struct task_struct *hb_task; |
1611 | struct o2hb_region *reg = to_o2hb_region(item); |
1612 | |
1613 | /* stop the thread when the user removes the region dir */ |
1614 | spin_lock(&o2hb_live_lock); |
1615 | hb_task = reg->hr_task; |
1616 | reg->hr_task = NULL; |
1617 | spin_unlock(&o2hb_live_lock); |
1618 | |
1619 | if (hb_task) |
1620 | kthread_stop(hb_task); |
1621 | |
1622 | /* |
1623 | * If we're racing a dev_write(), we need to wake them. They will |
1624 | * check reg->hr_task |
1625 | */ |
1626 | if (atomic_read(®->hr_steady_iterations) != 0) { |
1627 | atomic_set(®->hr_steady_iterations, 0); |
1628 | wake_up(&o2hb_steady_queue); |
1629 | } |
1630 | |
1631 | config_item_put(item); |
1632 | } |
1633 | |
1634 | struct o2hb_heartbeat_group_attribute { |
1635 | struct configfs_attribute attr; |
1636 | ssize_t (*show)(struct o2hb_heartbeat_group *, char *); |
1637 | ssize_t (*store)(struct o2hb_heartbeat_group *, const char *, size_t); |
1638 | }; |
1639 | |
1640 | static ssize_t o2hb_heartbeat_group_show(struct config_item *item, |
1641 | struct configfs_attribute *attr, |
1642 | char *page) |
1643 | { |
1644 | struct o2hb_heartbeat_group *reg = to_o2hb_heartbeat_group(to_config_group(item)); |
1645 | struct o2hb_heartbeat_group_attribute *o2hb_heartbeat_group_attr = |
1646 | container_of(attr, struct o2hb_heartbeat_group_attribute, attr); |
1647 | ssize_t ret = 0; |
1648 | |
1649 | if (o2hb_heartbeat_group_attr->show) |
1650 | ret = o2hb_heartbeat_group_attr->show(reg, page); |
1651 | return ret; |
1652 | } |
1653 | |
1654 | static ssize_t o2hb_heartbeat_group_store(struct config_item *item, |
1655 | struct configfs_attribute *attr, |
1656 | const char *page, size_t count) |
1657 | { |
1658 | struct o2hb_heartbeat_group *reg = to_o2hb_heartbeat_group(to_config_group(item)); |
1659 | struct o2hb_heartbeat_group_attribute *o2hb_heartbeat_group_attr = |
1660 | container_of(attr, struct o2hb_heartbeat_group_attribute, attr); |
1661 | ssize_t ret = -EINVAL; |
1662 | |
1663 | if (o2hb_heartbeat_group_attr->store) |
1664 | ret = o2hb_heartbeat_group_attr->store(reg, page, count); |
1665 | return ret; |
1666 | } |
1667 | |
1668 | static ssize_t o2hb_heartbeat_group_threshold_show(struct o2hb_heartbeat_group *group, |
1669 | char *page) |
1670 | { |
1671 | return sprintf(page, "%u\n", o2hb_dead_threshold); |
1672 | } |
1673 | |
1674 | static ssize_t o2hb_heartbeat_group_threshold_store(struct o2hb_heartbeat_group *group, |
1675 | const char *page, |
1676 | size_t count) |
1677 | { |
1678 | unsigned long tmp; |
1679 | char *p = (char *)page; |
1680 | |
1681 | tmp = simple_strtoul(p, &p, 10); |
1682 | if (!p || (*p && (*p != '\n'))) |
1683 | return -EINVAL; |
1684 | |
1685 | /* this will validate ranges for us. */ |
1686 | o2hb_dead_threshold_set((unsigned int) tmp); |
1687 | |
1688 | return count; |
1689 | } |
1690 | |
1691 | static struct o2hb_heartbeat_group_attribute o2hb_heartbeat_group_attr_threshold = { |
1692 | .attr = { .ca_owner = THIS_MODULE, |
1693 | .ca_name = "dead_threshold", |
1694 | .ca_mode = S_IRUGO | S_IWUSR }, |
1695 | .show = o2hb_heartbeat_group_threshold_show, |
1696 | .store = o2hb_heartbeat_group_threshold_store, |
1697 | }; |
1698 | |
1699 | static struct configfs_attribute *o2hb_heartbeat_group_attrs[] = { |
1700 | &o2hb_heartbeat_group_attr_threshold.attr, |
1701 | NULL, |
1702 | }; |
1703 | |
1704 | static struct configfs_item_operations o2hb_hearbeat_group_item_ops = { |
1705 | .show_attribute = o2hb_heartbeat_group_show, |
1706 | .store_attribute = o2hb_heartbeat_group_store, |
1707 | }; |
1708 | |
1709 | static struct configfs_group_operations o2hb_heartbeat_group_group_ops = { |
1710 | .make_item = o2hb_heartbeat_group_make_item, |
1711 | .drop_item = o2hb_heartbeat_group_drop_item, |
1712 | }; |
1713 | |
1714 | static struct config_item_type o2hb_heartbeat_group_type = { |
1715 | .ct_group_ops = &o2hb_heartbeat_group_group_ops, |
1716 | .ct_item_ops = &o2hb_hearbeat_group_item_ops, |
1717 | .ct_attrs = o2hb_heartbeat_group_attrs, |
1718 | .ct_owner = THIS_MODULE, |
1719 | }; |
1720 | |
1721 | /* this is just here to avoid touching group in heartbeat.h which the |
1722 | * entire damn world #includes */ |
1723 | struct config_group *o2hb_alloc_hb_set(void) |
1724 | { |
1725 | struct o2hb_heartbeat_group *hs = NULL; |
1726 | struct config_group *ret = NULL; |
1727 | |
1728 | hs = kzalloc(sizeof(struct o2hb_heartbeat_group), GFP_KERNEL); |
1729 | if (hs == NULL) |
1730 | goto out; |
1731 | |
1732 | config_group_init_type_name(&hs->hs_group, "heartbeat", |
1733 | &o2hb_heartbeat_group_type); |
1734 | |
1735 | ret = &hs->hs_group; |
1736 | out: |
1737 | if (ret == NULL) |
1738 | kfree(hs); |
1739 | return ret; |
1740 | } |
1741 | |
1742 | void o2hb_free_hb_set(struct config_group *group) |
1743 | { |
1744 | struct o2hb_heartbeat_group *hs = to_o2hb_heartbeat_group(group); |
1745 | kfree(hs); |
1746 | } |
1747 | |
1748 | /* hb callback registration and issueing */ |
1749 | |
1750 | static struct o2hb_callback *hbcall_from_type(enum o2hb_callback_type type) |
1751 | { |
1752 | if (type == O2HB_NUM_CB) |
1753 | return ERR_PTR(-EINVAL); |
1754 | |
1755 | return &o2hb_callbacks[type]; |
1756 | } |
1757 | |
1758 | void o2hb_setup_callback(struct o2hb_callback_func *hc, |
1759 | enum o2hb_callback_type type, |
1760 | o2hb_cb_func *func, |
1761 | void *data, |
1762 | int priority) |
1763 | { |
1764 | INIT_LIST_HEAD(&hc->hc_item); |
1765 | hc->hc_func = func; |
1766 | hc->hc_data = data; |
1767 | hc->hc_priority = priority; |
1768 | hc->hc_type = type; |
1769 | hc->hc_magic = O2HB_CB_MAGIC; |
1770 | } |
1771 | EXPORT_SYMBOL_GPL(o2hb_setup_callback); |
1772 | |
1773 | static struct o2hb_region *o2hb_find_region(const char *region_uuid) |
1774 | { |
1775 | struct o2hb_region *p, *reg = NULL; |
1776 | |
1777 | assert_spin_locked(&o2hb_live_lock); |
1778 | |
1779 | list_for_each_entry(p, &o2hb_all_regions, hr_all_item) { |
1780 | if (!strcmp(region_uuid, config_item_name(&p->hr_item))) { |
1781 | reg = p; |
1782 | break; |
1783 | } |
1784 | } |
1785 | |
1786 | return reg; |
1787 | } |
1788 | |
1789 | static int o2hb_region_get(const char *region_uuid) |
1790 | { |
1791 | int ret = 0; |
1792 | struct o2hb_region *reg; |
1793 | |
1794 | spin_lock(&o2hb_live_lock); |
1795 | |
1796 | reg = o2hb_find_region(region_uuid); |
1797 | if (!reg) |
1798 | ret = -ENOENT; |
1799 | spin_unlock(&o2hb_live_lock); |
1800 | |
1801 | if (ret) |
1802 | goto out; |
1803 | |
1804 | ret = o2nm_depend_this_node(); |
1805 | if (ret) |
1806 | goto out; |
1807 | |
1808 | ret = o2nm_depend_item(®->hr_item); |
1809 | if (ret) |
1810 | o2nm_undepend_this_node(); |
1811 | |
1812 | out: |
1813 | return ret; |
1814 | } |
1815 | |
1816 | static void o2hb_region_put(const char *region_uuid) |
1817 | { |
1818 | struct o2hb_region *reg; |
1819 | |
1820 | spin_lock(&o2hb_live_lock); |
1821 | |
1822 | reg = o2hb_find_region(region_uuid); |
1823 | |
1824 | spin_unlock(&o2hb_live_lock); |
1825 | |
1826 | if (reg) { |
1827 | o2nm_undepend_item(®->hr_item); |
1828 | o2nm_undepend_this_node(); |
1829 | } |
1830 | } |
1831 | |
1832 | int o2hb_register_callback(const char *region_uuid, |
1833 | struct o2hb_callback_func *hc) |
1834 | { |
1835 | struct o2hb_callback_func *tmp; |
1836 | struct list_head *iter; |
1837 | struct o2hb_callback *hbcall; |
1838 | int ret; |
1839 | |
1840 | BUG_ON(hc->hc_magic != O2HB_CB_MAGIC); |
1841 | BUG_ON(!list_empty(&hc->hc_item)); |
1842 | |
1843 | hbcall = hbcall_from_type(hc->hc_type); |
1844 | if (IS_ERR(hbcall)) { |
1845 | ret = PTR_ERR(hbcall); |
1846 | goto out; |
1847 | } |
1848 | |
1849 | if (region_uuid) { |
1850 | ret = o2hb_region_get(region_uuid); |
1851 | if (ret) |
1852 | goto out; |
1853 | } |
1854 | |
1855 | down_write(&o2hb_callback_sem); |
1856 | |
1857 | list_for_each(iter, &hbcall->list) { |
1858 | tmp = list_entry(iter, struct o2hb_callback_func, hc_item); |
1859 | if (hc->hc_priority < tmp->hc_priority) { |
1860 | list_add_tail(&hc->hc_item, iter); |
1861 | break; |
1862 | } |
1863 | } |
1864 | if (list_empty(&hc->hc_item)) |
1865 | list_add_tail(&hc->hc_item, &hbcall->list); |
1866 | |
1867 | up_write(&o2hb_callback_sem); |
1868 | ret = 0; |
1869 | out: |
1870 | mlog(ML_HEARTBEAT, "returning %d on behalf of %p for funcs %p\n", |
1871 | ret, __builtin_return_address(0), hc); |
1872 | return ret; |
1873 | } |
1874 | EXPORT_SYMBOL_GPL(o2hb_register_callback); |
1875 | |
1876 | void o2hb_unregister_callback(const char *region_uuid, |
1877 | struct o2hb_callback_func *hc) |
1878 | { |
1879 | BUG_ON(hc->hc_magic != O2HB_CB_MAGIC); |
1880 | |
1881 | mlog(ML_HEARTBEAT, "on behalf of %p for funcs %p\n", |
1882 | __builtin_return_address(0), hc); |
1883 | |
1884 | /* XXX Can this happen _with_ a region reference? */ |
1885 | if (list_empty(&hc->hc_item)) |
1886 | return; |
1887 | |
1888 | if (region_uuid) |
1889 | o2hb_region_put(region_uuid); |
1890 | |
1891 | down_write(&o2hb_callback_sem); |
1892 | |
1893 | list_del_init(&hc->hc_item); |
1894 | |
1895 | up_write(&o2hb_callback_sem); |
1896 | } |
1897 | EXPORT_SYMBOL_GPL(o2hb_unregister_callback); |
1898 | |
1899 | int o2hb_check_node_heartbeating(u8 node_num) |
1900 | { |
1901 | unsigned long testing_map[BITS_TO_LONGS(O2NM_MAX_NODES)]; |
1902 | |
1903 | o2hb_fill_node_map(testing_map, sizeof(testing_map)); |
1904 | if (!test_bit(node_num, testing_map)) { |
1905 | mlog(ML_HEARTBEAT, |
1906 | "node (%u) does not have heartbeating enabled.\n", |
1907 | node_num); |
1908 | return 0; |
1909 | } |
1910 | |
1911 | return 1; |
1912 | } |
1913 | EXPORT_SYMBOL_GPL(o2hb_check_node_heartbeating); |
1914 | |
1915 | int o2hb_check_node_heartbeating_from_callback(u8 node_num) |
1916 | { |
1917 | unsigned long testing_map[BITS_TO_LONGS(O2NM_MAX_NODES)]; |
1918 | |
1919 | o2hb_fill_node_map_from_callback(testing_map, sizeof(testing_map)); |
1920 | if (!test_bit(node_num, testing_map)) { |
1921 | mlog(ML_HEARTBEAT, |
1922 | "node (%u) does not have heartbeating enabled.\n", |
1923 | node_num); |
1924 | return 0; |
1925 | } |
1926 | |
1927 | return 1; |
1928 | } |
1929 | EXPORT_SYMBOL_GPL(o2hb_check_node_heartbeating_from_callback); |
1930 | |
1931 | /* Makes sure our local node is configured with a node number, and is |
1932 | * heartbeating. */ |
1933 | int o2hb_check_local_node_heartbeating(void) |
1934 | { |
1935 | u8 node_num; |
1936 | |
1937 | /* if this node was set then we have networking */ |
1938 | node_num = o2nm_this_node(); |
1939 | if (node_num == O2NM_MAX_NODES) { |
1940 | mlog(ML_HEARTBEAT, "this node has not been configured.\n"); |
1941 | return 0; |
1942 | } |
1943 | |
1944 | return o2hb_check_node_heartbeating(node_num); |
1945 | } |
1946 | EXPORT_SYMBOL_GPL(o2hb_check_local_node_heartbeating); |
1947 | |
1948 | /* |
1949 | * this is just a hack until we get the plumbing which flips file systems |
1950 | * read only and drops the hb ref instead of killing the node dead. |
1951 | */ |
1952 | void o2hb_stop_all_regions(void) |
1953 | { |
1954 | struct o2hb_region *reg; |
1955 | |
1956 | mlog(ML_ERROR, "stopping heartbeat on all active regions.\n"); |
1957 | |
1958 | spin_lock(&o2hb_live_lock); |
1959 | |
1960 | list_for_each_entry(reg, &o2hb_all_regions, hr_all_item) |
1961 | reg->hr_unclean_stop = 1; |
1962 | |
1963 | spin_unlock(&o2hb_live_lock); |
1964 | } |
1965 | EXPORT_SYMBOL_GPL(o2hb_stop_all_regions); |
1966 |
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