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 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 */ 51 static 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 */ 57 static DEFINE_SPINLOCK(o2hb_live_lock); 58 static struct list_head o2hb_live_slots[O2NM_MAX_NODES]; 59 static unsigned long o2hb_live_node_bitmap[BITS_TO_LONGS(O2NM_MAX_NODES)]; 60 static LIST_HEAD(o2hb_node_events); 61 static DECLARE_WAIT_QUEUE_HEAD(o2hb_steady_queue); 62 63 static LIST_HEAD(o2hb_all_regions); 64 65 static struct o2hb_callback { 66 struct list_head list; 67 } o2hb_callbacks[O2HB_NUM_CB]; 68 69 static struct o2hb_callback *hbcall_from_type(enum o2hb_callback_type type); 70 71 #define O2HB_DEFAULT_BLOCK_BITS 9 72 73 unsigned 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. */ 80 static 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 90 struct 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 97 struct 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 */ 109 struct 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 }; 152 153 struct o2hb_bio_wait_ctxt { 154 atomic_t wc_num_reqs; 155 struct completion wc_io_complete; 156 int wc_error; 157 }; 158 159 static 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 } 168 169 static 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(®->hr_write_timeout_work); 174 reg->hr_last_timeout_start = jiffies; 175 schedule_delayed_work(®->hr_write_timeout_work, 176 msecs_to_jiffies(O2HB_MAX_WRITE_TIMEOUT_MS)); 177 } 178 179 static void o2hb_disarm_write_timeout(struct o2hb_region *reg) 180 { 181 cancel_delayed_work(®->hr_write_timeout_work); 182 flush_scheduled_work(); 183 } 184 185 static 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); 190 wc->wc_error = 0; 191 } 192 193 /* Used in error paths too */ 194 static 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 } 206 207 static 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 } 216 217 static 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; 222 223 if (error) { 224 mlog(ML_ERROR, "IO Error %d\n", error); 225 wc->wc_error = error; 226 } 227 228 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. */ 237 static 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 } 296 297 bail: 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 */ 307 static 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 */ 322 323 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 } 329 /* Why is fls() 1-based???? */ 330 pow_two_sectors = 1 << (fls(max_sectors) - 1); 331 332 return pow_two_sectors; 333 } 334 335 static 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 } 355 356 static 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; 398 399 bail_and_wait: 400 o2hb_wait_on_io(reg, &wc); 401 if (wc.wc_error && !status) 402 status = wc.wc_error; 403 404 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 } 413 414 static 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; 437 bail: 438 return status; 439 } 440 441 static 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 } 459 460 static void o2hb_dump_slot(struct o2hb_disk_heartbeat_block *hb_block) 461 { 462 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)); 467 } 468 469 static 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. */ 482 static 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 = ®->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 } 502 503 static 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 = ®->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); 524 hb_block->hb_dead_ms = cpu_to_le32(o2hb_dead_threshold * O2HB_REGION_TIMEOUT_MS); 525 526 /* This step must always happen last! */ 527 hb_block->hb_cksum = cpu_to_le32(o2hb_compute_block_crc_le(reg, 528 hb_block)); 529 530 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)); 533 } 534 535 static 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 */ 550 static 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 } 595 596 static 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 } 612 613 static 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 } 643 644 static 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; 653 unsigned int dead_ms = o2hb_dead_threshold * O2HB_REGION_TIMEOUT_MS; 654 unsigned int slot_dead_ms; 655 656 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; 703 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)); 707 } 708 709 slot->ds_last_generation = le64_to_cpu(hb_block->hb_generation); 710 711 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, 717 slot->ds_equal_samples); 718 719 spin_lock(&o2hb_live_lock); 720 721 fire_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) { 726 mlog(ML_HEARTBEAT, "Node %d (id 0x%llx) joined my region\n", 727 slot->ds_node_num, (long long)slot->ds_last_generation); 728 729 /* 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; 743 744 /* 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 } 760 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 } 795 out: 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. */ 806 static 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 } 822 823 static int o2hb_do_disk_heartbeat(struct o2hb_region *reg) 824 { 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; 829 830 ret = o2nm_configured_node_map(configured_nodes, 831 sizeof(configured_nodes)); 832 if (ret) { 833 mlog_errno(ret); 834 return ret; 835 } 836 837 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"); 840 return -EINVAL; 841 } 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); 850 return ret; 851 } 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); 868 return ret; 869 } 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, ®->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); 884 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 } 892 893 o2hb_arm_write_timeout(reg); 894 895 /* let the person who launched us know when things are steady */ 896 if (!change && (atomic_read(®->hr_steady_iterations) != 0)) { 897 if (atomic_dec_and_test(®->hr_steady_iterations)) 898 wake_up(&o2hb_steady_queue); 899 } 900 901 return 0; 902 } 903 904 /* Subtract b from a, storing the result in a. a *must* have a larger 905 * value than b. */ 906 static 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 } 924 925 static 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 */ 940 static 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); 960 961 i = 0; 962 do { 963 ret = o2hb_do_disk_heartbeat(reg); 964 } while (ret && ++i < 2); 965 966 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", 970 before_hb.tv_sec, (unsigned long) before_hb.tv_usec, 971 after_hb.tv_sec, (unsigned long) after_hb.tv_usec, 972 elapsed_msec); 973 974 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(®->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 1007 void 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 */ 1023 static 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 */ 1034 void 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 } 1044 EXPORT_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 1051 static 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. */ 1059 static 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(®->hr_all_item); 1085 spin_unlock(&o2hb_live_lock); 1086 1087 kfree(reg); 1088 } 1089 1090 static 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 1117 static 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 1123 static 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 1145 static 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 1151 static 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 1170 static 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 1176 static 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 1198 static 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 1209 static 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 1222 static 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 = ®->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 = ®->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. */ 1293 static 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 = ®->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 1321 out: 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 */ 1327 static 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(®->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(®->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(®->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(®->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; 1434 out: 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 1448 struct 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 1454 static 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 1462 static 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 1470 static 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 1478 static 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 1486 static 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 1494 static 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 1508 static 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 1522 static 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 1528 static 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 1536 struct o2hb_heartbeat_group { 1537 struct config_group hs_group; 1538 /* some stuff? */ 1539 }; 1540 1541 static 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 1548 static 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(®->hr_item, name, &o2hb_region_type); 1559 1560 ret = ®->hr_item; 1561 1562 spin_lock(&o2hb_live_lock); 1563 list_add_tail(®->hr_all_item, &o2hb_all_regions); 1564 spin_unlock(&o2hb_live_lock); 1565 out: 1566 if (ret == NULL) 1567 kfree(reg); 1568 1569 return ret; 1570 } 1571 1572 static 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 1586 struct 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 1592 static 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 1606 static 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 1620 static 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 1626 static 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 1643 static 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 1651 static struct configfs_attribute *o2hb_heartbeat_group_attrs[] = { 1652 &o2hb_heartbeat_group_attr_threshold.attr, 1653 NULL, 1654 }; 1655 1656 static 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 1661 static 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 1666 static 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 */ 1675 struct 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; 1688 out: 1689 if (ret == NULL) 1690 kfree(hs); 1691 return ret; 1692 } 1693 1694 void 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 1702 static 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 1710 void 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 } 1723 EXPORT_SYMBOL_GPL(o2hb_setup_callback); 1724 1725 int 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; 1755 out: 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 } 1760 EXPORT_SYMBOL_GPL(o2hb_register_callback); 1761 1762 int 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 } 1780 EXPORT_SYMBOL_GPL(o2hb_unregister_callback); 1781 1782 int 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 } 1796 EXPORT_SYMBOL_GPL(o2hb_check_node_heartbeating); 1797 1798 int 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 } 1812 EXPORT_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. */ 1816 int 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 } 1829 EXPORT_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 */ 1835 void 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 } 1848 EXPORT_SYMBOL_GPL(o2hb_stop_all_regions); 1849