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 max_sectors = max_pages << (PAGE_SHIFT - 9); 324 325 /* Why is fls() 1-based???? */ 326 pow_two_sectors = 1 << (fls(max_sectors) - 1); 327 328 return pow_two_sectors; 329 } 330 331 static inline void o2hb_compute_request_limits(struct o2hb_region *reg, 332 unsigned int num_slots, 333 unsigned int *num_bios, 334 unsigned int *slots_per_bio) 335 { 336 unsigned int max_sectors, io_sectors; 337 338 max_sectors = compute_max_sectors(reg->hr_bdev); 339 340 io_sectors = num_slots << (reg->hr_block_bits - 9); 341 342 *num_bios = (io_sectors + max_sectors - 1) / max_sectors; 343 *slots_per_bio = max_sectors >> (reg->hr_block_bits - 9); 344 345 mlog(ML_HB_BIO, "My io size is %u sectors for %u slots. This " 346 "device can handle %u sectors of I/O\n", io_sectors, num_slots, 347 max_sectors); 348 mlog(ML_HB_BIO, "Will need %u bios holding %u slots each\n", 349 *num_bios, *slots_per_bio); 350 } 351 352 static int o2hb_read_slots(struct o2hb_region *reg, 353 unsigned int max_slots) 354 { 355 unsigned int num_bios, slots_per_bio, start_slot, num_slots; 356 int i, status; 357 struct o2hb_bio_wait_ctxt wc; 358 struct bio **bios; 359 struct bio *bio; 360 361 o2hb_compute_request_limits(reg, max_slots, &num_bios, &slots_per_bio); 362 363 bios = kcalloc(num_bios, sizeof(struct bio *), GFP_KERNEL); 364 if (!bios) { 365 status = -ENOMEM; 366 mlog_errno(status); 367 return status; 368 } 369 370 o2hb_bio_wait_init(&wc, num_bios); 371 372 num_slots = slots_per_bio; 373 for(i = 0; i < num_bios; i++) { 374 start_slot = i * slots_per_bio; 375 376 /* adjust num_slots at last bio */ 377 if (max_slots < (start_slot + num_slots)) 378 num_slots = max_slots - start_slot; 379 380 bio = o2hb_setup_one_bio(reg, &wc, start_slot, num_slots); 381 if (IS_ERR(bio)) { 382 o2hb_bio_wait_dec(&wc, num_bios - i); 383 384 status = PTR_ERR(bio); 385 mlog_errno(status); 386 goto bail_and_wait; 387 } 388 bios[i] = bio; 389 390 submit_bio(READ, bio); 391 } 392 393 status = 0; 394 395 bail_and_wait: 396 o2hb_wait_on_io(reg, &wc); 397 if (wc.wc_error && !status) 398 status = wc.wc_error; 399 400 if (bios) { 401 for(i = 0; i < num_bios; i++) 402 if (bios[i]) 403 bio_put(bios[i]); 404 kfree(bios); 405 } 406 407 return status; 408 } 409 410 static int o2hb_issue_node_write(struct o2hb_region *reg, 411 struct bio **write_bio, 412 struct o2hb_bio_wait_ctxt *write_wc) 413 { 414 int status; 415 unsigned int slot; 416 struct bio *bio; 417 418 o2hb_bio_wait_init(write_wc, 1); 419 420 slot = o2nm_this_node(); 421 422 bio = o2hb_setup_one_bio(reg, write_wc, slot, 1); 423 if (IS_ERR(bio)) { 424 status = PTR_ERR(bio); 425 mlog_errno(status); 426 goto bail; 427 } 428 429 submit_bio(WRITE, bio); 430 431 *write_bio = bio; 432 status = 0; 433 bail: 434 return status; 435 } 436 437 static u32 o2hb_compute_block_crc_le(struct o2hb_region *reg, 438 struct o2hb_disk_heartbeat_block *hb_block) 439 { 440 __le32 old_cksum; 441 u32 ret; 442 443 /* We want to compute the block crc with a 0 value in the 444 * hb_cksum field. Save it off here and replace after the 445 * crc. */ 446 old_cksum = hb_block->hb_cksum; 447 hb_block->hb_cksum = 0; 448 449 ret = crc32_le(0, (unsigned char *) hb_block, reg->hr_block_bytes); 450 451 hb_block->hb_cksum = old_cksum; 452 453 return ret; 454 } 455 456 static void o2hb_dump_slot(struct o2hb_disk_heartbeat_block *hb_block) 457 { 458 mlog(ML_ERROR, "Dump slot information: seq = 0x%llx, node = %u, " 459 "cksum = 0x%x, generation 0x%llx\n", 460 (long long)le64_to_cpu(hb_block->hb_seq), 461 hb_block->hb_node, le32_to_cpu(hb_block->hb_cksum), 462 (long long)le64_to_cpu(hb_block->hb_generation)); 463 } 464 465 static int o2hb_verify_crc(struct o2hb_region *reg, 466 struct o2hb_disk_heartbeat_block *hb_block) 467 { 468 u32 read, computed; 469 470 read = le32_to_cpu(hb_block->hb_cksum); 471 computed = o2hb_compute_block_crc_le(reg, hb_block); 472 473 return read == computed; 474 } 475 476 /* We want to make sure that nobody is heartbeating on top of us -- 477 * this will help detect an invalid configuration. */ 478 static int o2hb_check_last_timestamp(struct o2hb_region *reg) 479 { 480 int node_num, ret; 481 struct o2hb_disk_slot *slot; 482 struct o2hb_disk_heartbeat_block *hb_block; 483 484 node_num = o2nm_this_node(); 485 486 ret = 1; 487 slot = ®->hr_slots[node_num]; 488 /* Don't check on our 1st timestamp */ 489 if (slot->ds_last_time) { 490 hb_block = slot->ds_raw_block; 491 492 if (le64_to_cpu(hb_block->hb_seq) != slot->ds_last_time) 493 ret = 0; 494 } 495 496 return ret; 497 } 498 499 static inline void o2hb_prepare_block(struct o2hb_region *reg, 500 u64 generation) 501 { 502 int node_num; 503 u64 cputime; 504 struct o2hb_disk_slot *slot; 505 struct o2hb_disk_heartbeat_block *hb_block; 506 507 node_num = o2nm_this_node(); 508 slot = ®->hr_slots[node_num]; 509 510 hb_block = (struct o2hb_disk_heartbeat_block *)slot->ds_raw_block; 511 memset(hb_block, 0, reg->hr_block_bytes); 512 /* TODO: time stuff */ 513 cputime = CURRENT_TIME.tv_sec; 514 if (!cputime) 515 cputime = 1; 516 517 hb_block->hb_seq = cpu_to_le64(cputime); 518 hb_block->hb_node = node_num; 519 hb_block->hb_generation = cpu_to_le64(generation); 520 hb_block->hb_dead_ms = cpu_to_le32(o2hb_dead_threshold * O2HB_REGION_TIMEOUT_MS); 521 522 /* This step must always happen last! */ 523 hb_block->hb_cksum = cpu_to_le32(o2hb_compute_block_crc_le(reg, 524 hb_block)); 525 526 mlog(ML_HB_BIO, "our node generation = 0x%llx, cksum = 0x%x\n", 527 (long long)cpu_to_le64(generation), 528 le32_to_cpu(hb_block->hb_cksum)); 529 } 530 531 static void o2hb_fire_callbacks(struct o2hb_callback *hbcall, 532 struct o2nm_node *node, 533 int idx) 534 { 535 struct list_head *iter; 536 struct o2hb_callback_func *f; 537 538 list_for_each(iter, &hbcall->list) { 539 f = list_entry(iter, struct o2hb_callback_func, hc_item); 540 mlog(ML_HEARTBEAT, "calling funcs %p\n", f); 541 (f->hc_func)(node, idx, f->hc_data); 542 } 543 } 544 545 /* Will run the list in order until we process the passed event */ 546 static void o2hb_run_event_list(struct o2hb_node_event *queued_event) 547 { 548 int empty; 549 struct o2hb_callback *hbcall; 550 struct o2hb_node_event *event; 551 552 spin_lock(&o2hb_live_lock); 553 empty = list_empty(&queued_event->hn_item); 554 spin_unlock(&o2hb_live_lock); 555 if (empty) 556 return; 557 558 /* Holding callback sem assures we don't alter the callback 559 * lists when doing this, and serializes ourselves with other 560 * processes wanting callbacks. */ 561 down_write(&o2hb_callback_sem); 562 563 spin_lock(&o2hb_live_lock); 564 while (!list_empty(&o2hb_node_events) 565 && !list_empty(&queued_event->hn_item)) { 566 event = list_entry(o2hb_node_events.next, 567 struct o2hb_node_event, 568 hn_item); 569 list_del_init(&event->hn_item); 570 spin_unlock(&o2hb_live_lock); 571 572 mlog(ML_HEARTBEAT, "Node %s event for %d\n", 573 event->hn_event_type == O2HB_NODE_UP_CB ? "UP" : "DOWN", 574 event->hn_node_num); 575 576 hbcall = hbcall_from_type(event->hn_event_type); 577 578 /* We should *never* have gotten on to the list with a 579 * bad type... This isn't something that we should try 580 * to recover from. */ 581 BUG_ON(IS_ERR(hbcall)); 582 583 o2hb_fire_callbacks(hbcall, event->hn_node, event->hn_node_num); 584 585 spin_lock(&o2hb_live_lock); 586 } 587 spin_unlock(&o2hb_live_lock); 588 589 up_write(&o2hb_callback_sem); 590 } 591 592 static void o2hb_queue_node_event(struct o2hb_node_event *event, 593 enum o2hb_callback_type type, 594 struct o2nm_node *node, 595 int node_num) 596 { 597 assert_spin_locked(&o2hb_live_lock); 598 599 event->hn_event_type = type; 600 event->hn_node = node; 601 event->hn_node_num = node_num; 602 603 mlog(ML_HEARTBEAT, "Queue node %s event for node %d\n", 604 type == O2HB_NODE_UP_CB ? "UP" : "DOWN", node_num); 605 606 list_add_tail(&event->hn_item, &o2hb_node_events); 607 } 608 609 static void o2hb_shutdown_slot(struct o2hb_disk_slot *slot) 610 { 611 struct o2hb_node_event event = 612 { .hn_item = LIST_HEAD_INIT(event.hn_item), }; 613 struct o2nm_node *node; 614 615 node = o2nm_get_node_by_num(slot->ds_node_num); 616 if (!node) 617 return; 618 619 spin_lock(&o2hb_live_lock); 620 if (!list_empty(&slot->ds_live_item)) { 621 mlog(ML_HEARTBEAT, "Shutdown, node %d leaves region\n", 622 slot->ds_node_num); 623 624 list_del_init(&slot->ds_live_item); 625 626 if (list_empty(&o2hb_live_slots[slot->ds_node_num])) { 627 clear_bit(slot->ds_node_num, o2hb_live_node_bitmap); 628 629 o2hb_queue_node_event(&event, O2HB_NODE_DOWN_CB, node, 630 slot->ds_node_num); 631 } 632 } 633 spin_unlock(&o2hb_live_lock); 634 635 o2hb_run_event_list(&event); 636 637 o2nm_node_put(node); 638 } 639 640 static int o2hb_check_slot(struct o2hb_region *reg, 641 struct o2hb_disk_slot *slot) 642 { 643 int changed = 0, gen_changed = 0; 644 struct o2hb_node_event event = 645 { .hn_item = LIST_HEAD_INIT(event.hn_item), }; 646 struct o2nm_node *node; 647 struct o2hb_disk_heartbeat_block *hb_block = reg->hr_tmp_block; 648 u64 cputime; 649 unsigned int dead_ms = o2hb_dead_threshold * O2HB_REGION_TIMEOUT_MS; 650 unsigned int slot_dead_ms; 651 652 memcpy(hb_block, slot->ds_raw_block, reg->hr_block_bytes); 653 654 /* Is this correct? Do we assume that the node doesn't exist 655 * if we're not configured for him? */ 656 node = o2nm_get_node_by_num(slot->ds_node_num); 657 if (!node) 658 return 0; 659 660 if (!o2hb_verify_crc(reg, hb_block)) { 661 /* all paths from here will drop o2hb_live_lock for 662 * us. */ 663 spin_lock(&o2hb_live_lock); 664 665 /* Don't print an error on the console in this case - 666 * a freshly formatted heartbeat area will not have a 667 * crc set on it. */ 668 if (list_empty(&slot->ds_live_item)) 669 goto out; 670 671 /* The node is live but pushed out a bad crc. We 672 * consider it a transient miss but don't populate any 673 * other values as they may be junk. */ 674 mlog(ML_ERROR, "Node %d has written a bad crc to %s\n", 675 slot->ds_node_num, reg->hr_dev_name); 676 o2hb_dump_slot(hb_block); 677 678 slot->ds_equal_samples++; 679 goto fire_callbacks; 680 } 681 682 /* we don't care if these wrap.. the state transitions below 683 * clear at the right places */ 684 cputime = le64_to_cpu(hb_block->hb_seq); 685 if (slot->ds_last_time != cputime) 686 slot->ds_changed_samples++; 687 else 688 slot->ds_equal_samples++; 689 slot->ds_last_time = cputime; 690 691 /* The node changed heartbeat generations. We assume this to 692 * mean it dropped off but came back before we timed out. We 693 * want to consider it down for the time being but don't want 694 * to lose any changed_samples state we might build up to 695 * considering it live again. */ 696 if (slot->ds_last_generation != le64_to_cpu(hb_block->hb_generation)) { 697 gen_changed = 1; 698 slot->ds_equal_samples = 0; 699 mlog(ML_HEARTBEAT, "Node %d changed generation (0x%llx " 700 "to 0x%llx)\n", slot->ds_node_num, 701 (long long)slot->ds_last_generation, 702 (long long)le64_to_cpu(hb_block->hb_generation)); 703 } 704 705 slot->ds_last_generation = le64_to_cpu(hb_block->hb_generation); 706 707 mlog(ML_HEARTBEAT, "Slot %d gen 0x%llx cksum 0x%x " 708 "seq %llu last %llu changed %u equal %u\n", 709 slot->ds_node_num, (long long)slot->ds_last_generation, 710 le32_to_cpu(hb_block->hb_cksum), 711 (unsigned long long)le64_to_cpu(hb_block->hb_seq), 712 (unsigned long long)slot->ds_last_time, slot->ds_changed_samples, 713 slot->ds_equal_samples); 714 715 spin_lock(&o2hb_live_lock); 716 717 fire_callbacks: 718 /* dead nodes only come to life after some number of 719 * changes at any time during their dead time */ 720 if (list_empty(&slot->ds_live_item) && 721 slot->ds_changed_samples >= O2HB_LIVE_THRESHOLD) { 722 mlog(ML_HEARTBEAT, "Node %d (id 0x%llx) joined my region\n", 723 slot->ds_node_num, (long long)slot->ds_last_generation); 724 725 /* first on the list generates a callback */ 726 if (list_empty(&o2hb_live_slots[slot->ds_node_num])) { 727 set_bit(slot->ds_node_num, o2hb_live_node_bitmap); 728 729 o2hb_queue_node_event(&event, O2HB_NODE_UP_CB, node, 730 slot->ds_node_num); 731 732 changed = 1; 733 } 734 735 list_add_tail(&slot->ds_live_item, 736 &o2hb_live_slots[slot->ds_node_num]); 737 738 slot->ds_equal_samples = 0; 739 740 /* We want to be sure that all nodes agree on the 741 * number of milliseconds before a node will be 742 * considered dead. The self-fencing timeout is 743 * computed from this value, and a discrepancy might 744 * result in heartbeat calling a node dead when it 745 * hasn't self-fenced yet. */ 746 slot_dead_ms = le32_to_cpu(hb_block->hb_dead_ms); 747 if (slot_dead_ms && slot_dead_ms != dead_ms) { 748 /* TODO: Perhaps we can fail the region here. */ 749 mlog(ML_ERROR, "Node %d on device %s has a dead count " 750 "of %u ms, but our count is %u ms.\n" 751 "Please double check your configuration values " 752 "for 'O2CB_HEARTBEAT_THRESHOLD'\n", 753 slot->ds_node_num, reg->hr_dev_name, slot_dead_ms, 754 dead_ms); 755 } 756 goto out; 757 } 758 759 /* if the list is dead, we're done.. */ 760 if (list_empty(&slot->ds_live_item)) 761 goto out; 762 763 /* live nodes only go dead after enough consequtive missed 764 * samples.. reset the missed counter whenever we see 765 * activity */ 766 if (slot->ds_equal_samples >= o2hb_dead_threshold || gen_changed) { 767 mlog(ML_HEARTBEAT, "Node %d left my region\n", 768 slot->ds_node_num); 769 770 /* last off the live_slot generates a callback */ 771 list_del_init(&slot->ds_live_item); 772 if (list_empty(&o2hb_live_slots[slot->ds_node_num])) { 773 clear_bit(slot->ds_node_num, o2hb_live_node_bitmap); 774 775 o2hb_queue_node_event(&event, O2HB_NODE_DOWN_CB, node, 776 slot->ds_node_num); 777 778 changed = 1; 779 } 780 781 /* We don't clear this because the node is still 782 * actually writing new blocks. */ 783 if (!gen_changed) 784 slot->ds_changed_samples = 0; 785 goto out; 786 } 787 if (slot->ds_changed_samples) { 788 slot->ds_changed_samples = 0; 789 slot->ds_equal_samples = 0; 790 } 791 out: 792 spin_unlock(&o2hb_live_lock); 793 794 o2hb_run_event_list(&event); 795 796 o2nm_node_put(node); 797 return changed; 798 } 799 800 /* This could be faster if we just implmented a find_last_bit, but I 801 * don't think the circumstances warrant it. */ 802 static int o2hb_highest_node(unsigned long *nodes, 803 int numbits) 804 { 805 int highest, node; 806 807 highest = numbits; 808 node = -1; 809 while ((node = find_next_bit(nodes, numbits, node + 1)) != -1) { 810 if (node >= numbits) 811 break; 812 813 highest = node; 814 } 815 816 return highest; 817 } 818 819 static int o2hb_do_disk_heartbeat(struct o2hb_region *reg) 820 { 821 int i, ret, highest_node, change = 0; 822 unsigned long configured_nodes[BITS_TO_LONGS(O2NM_MAX_NODES)]; 823 struct bio *write_bio; 824 struct o2hb_bio_wait_ctxt write_wc; 825 826 ret = o2nm_configured_node_map(configured_nodes, 827 sizeof(configured_nodes)); 828 if (ret) { 829 mlog_errno(ret); 830 return ret; 831 } 832 833 highest_node = o2hb_highest_node(configured_nodes, O2NM_MAX_NODES); 834 if (highest_node >= O2NM_MAX_NODES) { 835 mlog(ML_NOTICE, "ocfs2_heartbeat: no configured nodes found!\n"); 836 return -EINVAL; 837 } 838 839 /* No sense in reading the slots of nodes that don't exist 840 * yet. Of course, if the node definitions have holes in them 841 * then we're reading an empty slot anyway... Consider this 842 * best-effort. */ 843 ret = o2hb_read_slots(reg, highest_node + 1); 844 if (ret < 0) { 845 mlog_errno(ret); 846 return ret; 847 } 848 849 /* With an up to date view of the slots, we can check that no 850 * other node has been improperly configured to heartbeat in 851 * our slot. */ 852 if (!o2hb_check_last_timestamp(reg)) 853 mlog(ML_ERROR, "Device \"%s\": another node is heartbeating " 854 "in our slot!\n", reg->hr_dev_name); 855 856 /* fill in the proper info for our next heartbeat */ 857 o2hb_prepare_block(reg, reg->hr_generation); 858 859 /* And fire off the write. Note that we don't wait on this I/O 860 * until later. */ 861 ret = o2hb_issue_node_write(reg, &write_bio, &write_wc); 862 if (ret < 0) { 863 mlog_errno(ret); 864 return ret; 865 } 866 867 i = -1; 868 while((i = find_next_bit(configured_nodes, O2NM_MAX_NODES, i + 1)) < O2NM_MAX_NODES) { 869 870 change |= o2hb_check_slot(reg, ®->hr_slots[i]); 871 } 872 873 /* 874 * We have to be sure we've advertised ourselves on disk 875 * before we can go to steady state. This ensures that 876 * people we find in our steady state have seen us. 877 */ 878 o2hb_wait_on_io(reg, &write_wc); 879 bio_put(write_bio); 880 if (write_wc.wc_error) { 881 /* Do not re-arm the write timeout on I/O error - we 882 * can't be sure that the new block ever made it to 883 * disk */ 884 mlog(ML_ERROR, "Write error %d on device \"%s\"\n", 885 write_wc.wc_error, reg->hr_dev_name); 886 return write_wc.wc_error; 887 } 888 889 o2hb_arm_write_timeout(reg); 890 891 /* let the person who launched us know when things are steady */ 892 if (!change && (atomic_read(®->hr_steady_iterations) != 0)) { 893 if (atomic_dec_and_test(®->hr_steady_iterations)) 894 wake_up(&o2hb_steady_queue); 895 } 896 897 return 0; 898 } 899 900 /* Subtract b from a, storing the result in a. a *must* have a larger 901 * value than b. */ 902 static void o2hb_tv_subtract(struct timeval *a, 903 struct timeval *b) 904 { 905 /* just return 0 when a is after b */ 906 if (a->tv_sec < b->tv_sec || 907 (a->tv_sec == b->tv_sec && a->tv_usec < b->tv_usec)) { 908 a->tv_sec = 0; 909 a->tv_usec = 0; 910 return; 911 } 912 913 a->tv_sec -= b->tv_sec; 914 a->tv_usec -= b->tv_usec; 915 while ( a->tv_usec < 0 ) { 916 a->tv_sec--; 917 a->tv_usec += 1000000; 918 } 919 } 920 921 static unsigned int o2hb_elapsed_msecs(struct timeval *start, 922 struct timeval *end) 923 { 924 struct timeval res = *end; 925 926 o2hb_tv_subtract(&res, start); 927 928 return res.tv_sec * 1000 + res.tv_usec / 1000; 929 } 930 931 /* 932 * we ride the region ref that the region dir holds. before the region 933 * dir is removed and drops it ref it will wait to tear down this 934 * thread. 935 */ 936 static int o2hb_thread(void *data) 937 { 938 int i, ret; 939 struct o2hb_region *reg = data; 940 struct bio *write_bio; 941 struct o2hb_bio_wait_ctxt write_wc; 942 struct timeval before_hb, after_hb; 943 unsigned int elapsed_msec; 944 945 mlog(ML_HEARTBEAT|ML_KTHREAD, "hb thread running\n"); 946 947 set_user_nice(current, -20); 948 949 while (!kthread_should_stop() && !reg->hr_unclean_stop) { 950 /* We track the time spent inside 951 * o2hb_do_disk_heartbeat so that we avoid more then 952 * hr_timeout_ms between disk writes. On busy systems 953 * this should result in a heartbeat which is less 954 * likely to time itself out. */ 955 do_gettimeofday(&before_hb); 956 957 i = 0; 958 do { 959 ret = o2hb_do_disk_heartbeat(reg); 960 } while (ret && ++i < 2); 961 962 do_gettimeofday(&after_hb); 963 elapsed_msec = o2hb_elapsed_msecs(&before_hb, &after_hb); 964 965 mlog(0, "start = %lu.%lu, end = %lu.%lu, msec = %u\n", 966 before_hb.tv_sec, (unsigned long) before_hb.tv_usec, 967 after_hb.tv_sec, (unsigned long) after_hb.tv_usec, 968 elapsed_msec); 969 970 if (elapsed_msec < reg->hr_timeout_ms) { 971 /* the kthread api has blocked signals for us so no 972 * need to record the return value. */ 973 msleep_interruptible(reg->hr_timeout_ms - elapsed_msec); 974 } 975 } 976 977 o2hb_disarm_write_timeout(reg); 978 979 /* unclean stop is only used in very bad situation */ 980 for(i = 0; !reg->hr_unclean_stop && i < reg->hr_blocks; i++) 981 o2hb_shutdown_slot(®->hr_slots[i]); 982 983 /* Explicit down notification - avoid forcing the other nodes 984 * to timeout on this region when we could just as easily 985 * write a clear generation - thus indicating to them that 986 * this node has left this region. 987 * 988 * XXX: Should we skip this on unclean_stop? */ 989 o2hb_prepare_block(reg, 0); 990 ret = o2hb_issue_node_write(reg, &write_bio, &write_wc); 991 if (ret == 0) { 992 o2hb_wait_on_io(reg, &write_wc); 993 bio_put(write_bio); 994 } else { 995 mlog_errno(ret); 996 } 997 998 mlog(ML_HEARTBEAT|ML_KTHREAD, "hb thread exiting\n"); 999 1000 return 0; 1001 } 1002 1003 void o2hb_init(void) 1004 { 1005 int i; 1006 1007 for (i = 0; i < ARRAY_SIZE(o2hb_callbacks); i++) 1008 INIT_LIST_HEAD(&o2hb_callbacks[i].list); 1009 1010 for (i = 0; i < ARRAY_SIZE(o2hb_live_slots); i++) 1011 INIT_LIST_HEAD(&o2hb_live_slots[i]); 1012 1013 INIT_LIST_HEAD(&o2hb_node_events); 1014 1015 memset(o2hb_live_node_bitmap, 0, sizeof(o2hb_live_node_bitmap)); 1016 } 1017 1018 /* if we're already in a callback then we're already serialized by the sem */ 1019 static void o2hb_fill_node_map_from_callback(unsigned long *map, 1020 unsigned bytes) 1021 { 1022 BUG_ON(bytes < (BITS_TO_LONGS(O2NM_MAX_NODES) * sizeof(unsigned long))); 1023 1024 memcpy(map, &o2hb_live_node_bitmap, bytes); 1025 } 1026 1027 /* 1028 * get a map of all nodes that are heartbeating in any regions 1029 */ 1030 void o2hb_fill_node_map(unsigned long *map, unsigned bytes) 1031 { 1032 /* callers want to serialize this map and callbacks so that they 1033 * can trust that they don't miss nodes coming to the party */ 1034 down_read(&o2hb_callback_sem); 1035 spin_lock(&o2hb_live_lock); 1036 o2hb_fill_node_map_from_callback(map, bytes); 1037 spin_unlock(&o2hb_live_lock); 1038 up_read(&o2hb_callback_sem); 1039 } 1040 EXPORT_SYMBOL_GPL(o2hb_fill_node_map); 1041 1042 /* 1043 * heartbeat configfs bits. The heartbeat set is a default set under 1044 * the cluster set in nodemanager.c. 1045 */ 1046 1047 static struct o2hb_region *to_o2hb_region(struct config_item *item) 1048 { 1049 return item ? container_of(item, struct o2hb_region, hr_item) : NULL; 1050 } 1051 1052 /* drop_item only drops its ref after killing the thread, nothing should 1053 * be using the region anymore. this has to clean up any state that 1054 * attributes might have built up. */ 1055 static void o2hb_region_release(struct config_item *item) 1056 { 1057 int i; 1058 struct page *page; 1059 struct o2hb_region *reg = to_o2hb_region(item); 1060 1061 if (reg->hr_tmp_block) 1062 kfree(reg->hr_tmp_block); 1063 1064 if (reg->hr_slot_data) { 1065 for (i = 0; i < reg->hr_num_pages; i++) { 1066 page = reg->hr_slot_data[i]; 1067 if (page) 1068 __free_page(page); 1069 } 1070 kfree(reg->hr_slot_data); 1071 } 1072 1073 if (reg->hr_bdev) 1074 blkdev_put(reg->hr_bdev); 1075 1076 if (reg->hr_slots) 1077 kfree(reg->hr_slots); 1078 1079 spin_lock(&o2hb_live_lock); 1080 list_del(®->hr_all_item); 1081 spin_unlock(&o2hb_live_lock); 1082 1083 kfree(reg); 1084 } 1085 1086 static int o2hb_read_block_input(struct o2hb_region *reg, 1087 const char *page, 1088 size_t count, 1089 unsigned long *ret_bytes, 1090 unsigned int *ret_bits) 1091 { 1092 unsigned long bytes; 1093 char *p = (char *)page; 1094 1095 bytes = simple_strtoul(p, &p, 0); 1096 if (!p || (*p && (*p != '\n'))) 1097 return -EINVAL; 1098 1099 /* Heartbeat and fs min / max block sizes are the same. */ 1100 if (bytes > 4096 || bytes < 512) 1101 return -ERANGE; 1102 if (hweight16(bytes) != 1) 1103 return -EINVAL; 1104 1105 if (ret_bytes) 1106 *ret_bytes = bytes; 1107 if (ret_bits) 1108 *ret_bits = ffs(bytes) - 1; 1109 1110 return 0; 1111 } 1112 1113 static ssize_t o2hb_region_block_bytes_read(struct o2hb_region *reg, 1114 char *page) 1115 { 1116 return sprintf(page, "%u\n", reg->hr_block_bytes); 1117 } 1118 1119 static ssize_t o2hb_region_block_bytes_write(struct o2hb_region *reg, 1120 const char *page, 1121 size_t count) 1122 { 1123 int status; 1124 unsigned long block_bytes; 1125 unsigned int block_bits; 1126 1127 if (reg->hr_bdev) 1128 return -EINVAL; 1129 1130 status = o2hb_read_block_input(reg, page, count, 1131 &block_bytes, &block_bits); 1132 if (status) 1133 return status; 1134 1135 reg->hr_block_bytes = (unsigned int)block_bytes; 1136 reg->hr_block_bits = block_bits; 1137 1138 return count; 1139 } 1140 1141 static ssize_t o2hb_region_start_block_read(struct o2hb_region *reg, 1142 char *page) 1143 { 1144 return sprintf(page, "%llu\n", reg->hr_start_block); 1145 } 1146 1147 static ssize_t o2hb_region_start_block_write(struct o2hb_region *reg, 1148 const char *page, 1149 size_t count) 1150 { 1151 unsigned long long tmp; 1152 char *p = (char *)page; 1153 1154 if (reg->hr_bdev) 1155 return -EINVAL; 1156 1157 tmp = simple_strtoull(p, &p, 0); 1158 if (!p || (*p && (*p != '\n'))) 1159 return -EINVAL; 1160 1161 reg->hr_start_block = tmp; 1162 1163 return count; 1164 } 1165 1166 static ssize_t o2hb_region_blocks_read(struct o2hb_region *reg, 1167 char *page) 1168 { 1169 return sprintf(page, "%d\n", reg->hr_blocks); 1170 } 1171 1172 static ssize_t o2hb_region_blocks_write(struct o2hb_region *reg, 1173 const char *page, 1174 size_t count) 1175 { 1176 unsigned long tmp; 1177 char *p = (char *)page; 1178 1179 if (reg->hr_bdev) 1180 return -EINVAL; 1181 1182 tmp = simple_strtoul(p, &p, 0); 1183 if (!p || (*p && (*p != '\n'))) 1184 return -EINVAL; 1185 1186 if (tmp > O2NM_MAX_NODES || tmp == 0) 1187 return -ERANGE; 1188 1189 reg->hr_blocks = (unsigned int)tmp; 1190 1191 return count; 1192 } 1193 1194 static ssize_t o2hb_region_dev_read(struct o2hb_region *reg, 1195 char *page) 1196 { 1197 unsigned int ret = 0; 1198 1199 if (reg->hr_bdev) 1200 ret = sprintf(page, "%s\n", reg->hr_dev_name); 1201 1202 return ret; 1203 } 1204 1205 static void o2hb_init_region_params(struct o2hb_region *reg) 1206 { 1207 reg->hr_slots_per_page = PAGE_CACHE_SIZE >> reg->hr_block_bits; 1208 reg->hr_timeout_ms = O2HB_REGION_TIMEOUT_MS; 1209 1210 mlog(ML_HEARTBEAT, "hr_start_block = %llu, hr_blocks = %u\n", 1211 reg->hr_start_block, reg->hr_blocks); 1212 mlog(ML_HEARTBEAT, "hr_block_bytes = %u, hr_block_bits = %u\n", 1213 reg->hr_block_bytes, reg->hr_block_bits); 1214 mlog(ML_HEARTBEAT, "hr_timeout_ms = %u\n", reg->hr_timeout_ms); 1215 mlog(ML_HEARTBEAT, "dead threshold = %u\n", o2hb_dead_threshold); 1216 } 1217 1218 static int o2hb_map_slot_data(struct o2hb_region *reg) 1219 { 1220 int i, j; 1221 unsigned int last_slot; 1222 unsigned int spp = reg->hr_slots_per_page; 1223 struct page *page; 1224 char *raw; 1225 struct o2hb_disk_slot *slot; 1226 1227 reg->hr_tmp_block = kmalloc(reg->hr_block_bytes, GFP_KERNEL); 1228 if (reg->hr_tmp_block == NULL) { 1229 mlog_errno(-ENOMEM); 1230 return -ENOMEM; 1231 } 1232 1233 reg->hr_slots = kcalloc(reg->hr_blocks, 1234 sizeof(struct o2hb_disk_slot), GFP_KERNEL); 1235 if (reg->hr_slots == NULL) { 1236 mlog_errno(-ENOMEM); 1237 return -ENOMEM; 1238 } 1239 1240 for(i = 0; i < reg->hr_blocks; i++) { 1241 slot = ®->hr_slots[i]; 1242 slot->ds_node_num = i; 1243 INIT_LIST_HEAD(&slot->ds_live_item); 1244 slot->ds_raw_block = NULL; 1245 } 1246 1247 reg->hr_num_pages = (reg->hr_blocks + spp - 1) / spp; 1248 mlog(ML_HEARTBEAT, "Going to require %u pages to cover %u blocks " 1249 "at %u blocks per page\n", 1250 reg->hr_num_pages, reg->hr_blocks, spp); 1251 1252 reg->hr_slot_data = kcalloc(reg->hr_num_pages, sizeof(struct page *), 1253 GFP_KERNEL); 1254 if (!reg->hr_slot_data) { 1255 mlog_errno(-ENOMEM); 1256 return -ENOMEM; 1257 } 1258 1259 for(i = 0; i < reg->hr_num_pages; i++) { 1260 page = alloc_page(GFP_KERNEL); 1261 if (!page) { 1262 mlog_errno(-ENOMEM); 1263 return -ENOMEM; 1264 } 1265 1266 reg->hr_slot_data[i] = page; 1267 1268 last_slot = i * spp; 1269 raw = page_address(page); 1270 for (j = 0; 1271 (j < spp) && ((j + last_slot) < reg->hr_blocks); 1272 j++) { 1273 BUG_ON((j + last_slot) >= reg->hr_blocks); 1274 1275 slot = ®->hr_slots[j + last_slot]; 1276 slot->ds_raw_block = 1277 (struct o2hb_disk_heartbeat_block *) raw; 1278 1279 raw += reg->hr_block_bytes; 1280 } 1281 } 1282 1283 return 0; 1284 } 1285 1286 /* Read in all the slots available and populate the tracking 1287 * structures so that we can start with a baseline idea of what's 1288 * there. */ 1289 static int o2hb_populate_slot_data(struct o2hb_region *reg) 1290 { 1291 int ret, i; 1292 struct o2hb_disk_slot *slot; 1293 struct o2hb_disk_heartbeat_block *hb_block; 1294 1295 mlog_entry_void(); 1296 1297 ret = o2hb_read_slots(reg, reg->hr_blocks); 1298 if (ret) { 1299 mlog_errno(ret); 1300 goto out; 1301 } 1302 1303 /* We only want to get an idea of the values initially in each 1304 * slot, so we do no verification - o2hb_check_slot will 1305 * actually determine if each configured slot is valid and 1306 * whether any values have changed. */ 1307 for(i = 0; i < reg->hr_blocks; i++) { 1308 slot = ®->hr_slots[i]; 1309 hb_block = (struct o2hb_disk_heartbeat_block *) slot->ds_raw_block; 1310 1311 /* Only fill the values that o2hb_check_slot uses to 1312 * determine changing slots */ 1313 slot->ds_last_time = le64_to_cpu(hb_block->hb_seq); 1314 slot->ds_last_generation = le64_to_cpu(hb_block->hb_generation); 1315 } 1316 1317 out: 1318 mlog_exit(ret); 1319 return ret; 1320 } 1321 1322 /* this is acting as commit; we set up all of hr_bdev and hr_task or nothing */ 1323 static ssize_t o2hb_region_dev_write(struct o2hb_region *reg, 1324 const char *page, 1325 size_t count) 1326 { 1327 long fd; 1328 int sectsize; 1329 char *p = (char *)page; 1330 struct file *filp = NULL; 1331 struct inode *inode = NULL; 1332 ssize_t ret = -EINVAL; 1333 1334 if (reg->hr_bdev) 1335 goto out; 1336 1337 /* We can't heartbeat without having had our node number 1338 * configured yet. */ 1339 if (o2nm_this_node() == O2NM_MAX_NODES) 1340 goto out; 1341 1342 fd = simple_strtol(p, &p, 0); 1343 if (!p || (*p && (*p != '\n'))) 1344 goto out; 1345 1346 if (fd < 0 || fd >= INT_MAX) 1347 goto out; 1348 1349 filp = fget(fd); 1350 if (filp == NULL) 1351 goto out; 1352 1353 if (reg->hr_blocks == 0 || reg->hr_start_block == 0 || 1354 reg->hr_block_bytes == 0) 1355 goto out; 1356 1357 inode = igrab(filp->f_mapping->host); 1358 if (inode == NULL) 1359 goto out; 1360 1361 if (!S_ISBLK(inode->i_mode)) 1362 goto out; 1363 1364 reg->hr_bdev = I_BDEV(filp->f_mapping->host); 1365 ret = blkdev_get(reg->hr_bdev, FMODE_WRITE | FMODE_READ, 0); 1366 if (ret) { 1367 reg->hr_bdev = NULL; 1368 goto out; 1369 } 1370 inode = NULL; 1371 1372 bdevname(reg->hr_bdev, reg->hr_dev_name); 1373 1374 sectsize = bdev_hardsect_size(reg->hr_bdev); 1375 if (sectsize != reg->hr_block_bytes) { 1376 mlog(ML_ERROR, 1377 "blocksize %u incorrect for device, expected %d", 1378 reg->hr_block_bytes, sectsize); 1379 ret = -EINVAL; 1380 goto out; 1381 } 1382 1383 o2hb_init_region_params(reg); 1384 1385 /* Generation of zero is invalid */ 1386 do { 1387 get_random_bytes(®->hr_generation, 1388 sizeof(reg->hr_generation)); 1389 } while (reg->hr_generation == 0); 1390 1391 ret = o2hb_map_slot_data(reg); 1392 if (ret) { 1393 mlog_errno(ret); 1394 goto out; 1395 } 1396 1397 ret = o2hb_populate_slot_data(reg); 1398 if (ret) { 1399 mlog_errno(ret); 1400 goto out; 1401 } 1402 1403 INIT_WORK(®->hr_write_timeout_work, o2hb_write_timeout, reg); 1404 1405 /* 1406 * A node is considered live after it has beat LIVE_THRESHOLD 1407 * times. We're not steady until we've given them a chance 1408 * _after_ our first read. 1409 */ 1410 atomic_set(®->hr_steady_iterations, O2HB_LIVE_THRESHOLD + 1); 1411 1412 reg->hr_task = kthread_run(o2hb_thread, reg, "o2hb-%s", 1413 reg->hr_item.ci_name); 1414 if (IS_ERR(reg->hr_task)) { 1415 ret = PTR_ERR(reg->hr_task); 1416 mlog_errno(ret); 1417 reg->hr_task = NULL; 1418 goto out; 1419 } 1420 1421 ret = wait_event_interruptible(o2hb_steady_queue, 1422 atomic_read(®->hr_steady_iterations) == 0); 1423 if (ret) { 1424 kthread_stop(reg->hr_task); 1425 reg->hr_task = NULL; 1426 goto out; 1427 } 1428 1429 ret = count; 1430 out: 1431 if (filp) 1432 fput(filp); 1433 if (inode) 1434 iput(inode); 1435 if (ret < 0) { 1436 if (reg->hr_bdev) { 1437 blkdev_put(reg->hr_bdev); 1438 reg->hr_bdev = NULL; 1439 } 1440 } 1441 return ret; 1442 } 1443 1444 struct o2hb_region_attribute { 1445 struct configfs_attribute attr; 1446 ssize_t (*show)(struct o2hb_region *, char *); 1447 ssize_t (*store)(struct o2hb_region *, const char *, size_t); 1448 }; 1449 1450 static struct o2hb_region_attribute o2hb_region_attr_block_bytes = { 1451 .attr = { .ca_owner = THIS_MODULE, 1452 .ca_name = "block_bytes", 1453 .ca_mode = S_IRUGO | S_IWUSR }, 1454 .show = o2hb_region_block_bytes_read, 1455 .store = o2hb_region_block_bytes_write, 1456 }; 1457 1458 static struct o2hb_region_attribute o2hb_region_attr_start_block = { 1459 .attr = { .ca_owner = THIS_MODULE, 1460 .ca_name = "start_block", 1461 .ca_mode = S_IRUGO | S_IWUSR }, 1462 .show = o2hb_region_start_block_read, 1463 .store = o2hb_region_start_block_write, 1464 }; 1465 1466 static struct o2hb_region_attribute o2hb_region_attr_blocks = { 1467 .attr = { .ca_owner = THIS_MODULE, 1468 .ca_name = "blocks", 1469 .ca_mode = S_IRUGO | S_IWUSR }, 1470 .show = o2hb_region_blocks_read, 1471 .store = o2hb_region_blocks_write, 1472 }; 1473 1474 static struct o2hb_region_attribute o2hb_region_attr_dev = { 1475 .attr = { .ca_owner = THIS_MODULE, 1476 .ca_name = "dev", 1477 .ca_mode = S_IRUGO | S_IWUSR }, 1478 .show = o2hb_region_dev_read, 1479 .store = o2hb_region_dev_write, 1480 }; 1481 1482 static struct configfs_attribute *o2hb_region_attrs[] = { 1483 &o2hb_region_attr_block_bytes.attr, 1484 &o2hb_region_attr_start_block.attr, 1485 &o2hb_region_attr_blocks.attr, 1486 &o2hb_region_attr_dev.attr, 1487 NULL, 1488 }; 1489 1490 static ssize_t o2hb_region_show(struct config_item *item, 1491 struct configfs_attribute *attr, 1492 char *page) 1493 { 1494 struct o2hb_region *reg = to_o2hb_region(item); 1495 struct o2hb_region_attribute *o2hb_region_attr = 1496 container_of(attr, struct o2hb_region_attribute, attr); 1497 ssize_t ret = 0; 1498 1499 if (o2hb_region_attr->show) 1500 ret = o2hb_region_attr->show(reg, page); 1501 return ret; 1502 } 1503 1504 static ssize_t o2hb_region_store(struct config_item *item, 1505 struct configfs_attribute *attr, 1506 const char *page, size_t count) 1507 { 1508 struct o2hb_region *reg = to_o2hb_region(item); 1509 struct o2hb_region_attribute *o2hb_region_attr = 1510 container_of(attr, struct o2hb_region_attribute, attr); 1511 ssize_t ret = -EINVAL; 1512 1513 if (o2hb_region_attr->store) 1514 ret = o2hb_region_attr->store(reg, page, count); 1515 return ret; 1516 } 1517 1518 static struct configfs_item_operations o2hb_region_item_ops = { 1519 .release = o2hb_region_release, 1520 .show_attribute = o2hb_region_show, 1521 .store_attribute = o2hb_region_store, 1522 }; 1523 1524 static struct config_item_type o2hb_region_type = { 1525 .ct_item_ops = &o2hb_region_item_ops, 1526 .ct_attrs = o2hb_region_attrs, 1527 .ct_owner = THIS_MODULE, 1528 }; 1529 1530 /* heartbeat set */ 1531 1532 struct o2hb_heartbeat_group { 1533 struct config_group hs_group; 1534 /* some stuff? */ 1535 }; 1536 1537 static struct o2hb_heartbeat_group *to_o2hb_heartbeat_group(struct config_group *group) 1538 { 1539 return group ? 1540 container_of(group, struct o2hb_heartbeat_group, hs_group) 1541 : NULL; 1542 } 1543 1544 static struct config_item *o2hb_heartbeat_group_make_item(struct config_group *group, 1545 const char *name) 1546 { 1547 struct o2hb_region *reg = NULL; 1548 struct config_item *ret = NULL; 1549 1550 reg = kcalloc(1, sizeof(struct o2hb_region), GFP_KERNEL); 1551 if (reg == NULL) 1552 goto out; /* ENOMEM */ 1553 1554 config_item_init_type_name(®->hr_item, name, &o2hb_region_type); 1555 1556 ret = ®->hr_item; 1557 1558 spin_lock(&o2hb_live_lock); 1559 list_add_tail(®->hr_all_item, &o2hb_all_regions); 1560 spin_unlock(&o2hb_live_lock); 1561 out: 1562 if (ret == NULL) 1563 kfree(reg); 1564 1565 return ret; 1566 } 1567 1568 static void o2hb_heartbeat_group_drop_item(struct config_group *group, 1569 struct config_item *item) 1570 { 1571 struct o2hb_region *reg = to_o2hb_region(item); 1572 1573 /* stop the thread when the user removes the region dir */ 1574 if (reg->hr_task) { 1575 kthread_stop(reg->hr_task); 1576 reg->hr_task = NULL; 1577 } 1578 1579 config_item_put(item); 1580 } 1581 1582 struct o2hb_heartbeat_group_attribute { 1583 struct configfs_attribute attr; 1584 ssize_t (*show)(struct o2hb_heartbeat_group *, char *); 1585 ssize_t (*store)(struct o2hb_heartbeat_group *, const char *, size_t); 1586 }; 1587 1588 static ssize_t o2hb_heartbeat_group_show(struct config_item *item, 1589 struct configfs_attribute *attr, 1590 char *page) 1591 { 1592 struct o2hb_heartbeat_group *reg = to_o2hb_heartbeat_group(to_config_group(item)); 1593 struct o2hb_heartbeat_group_attribute *o2hb_heartbeat_group_attr = 1594 container_of(attr, struct o2hb_heartbeat_group_attribute, attr); 1595 ssize_t ret = 0; 1596 1597 if (o2hb_heartbeat_group_attr->show) 1598 ret = o2hb_heartbeat_group_attr->show(reg, page); 1599 return ret; 1600 } 1601 1602 static ssize_t o2hb_heartbeat_group_store(struct config_item *item, 1603 struct configfs_attribute *attr, 1604 const char *page, size_t count) 1605 { 1606 struct o2hb_heartbeat_group *reg = to_o2hb_heartbeat_group(to_config_group(item)); 1607 struct o2hb_heartbeat_group_attribute *o2hb_heartbeat_group_attr = 1608 container_of(attr, struct o2hb_heartbeat_group_attribute, attr); 1609 ssize_t ret = -EINVAL; 1610 1611 if (o2hb_heartbeat_group_attr->store) 1612 ret = o2hb_heartbeat_group_attr->store(reg, page, count); 1613 return ret; 1614 } 1615 1616 static ssize_t o2hb_heartbeat_group_threshold_show(struct o2hb_heartbeat_group *group, 1617 char *page) 1618 { 1619 return sprintf(page, "%u\n", o2hb_dead_threshold); 1620 } 1621 1622 static ssize_t o2hb_heartbeat_group_threshold_store(struct o2hb_heartbeat_group *group, 1623 const char *page, 1624 size_t count) 1625 { 1626 unsigned long tmp; 1627 char *p = (char *)page; 1628 1629 tmp = simple_strtoul(p, &p, 10); 1630 if (!p || (*p && (*p != '\n'))) 1631 return -EINVAL; 1632 1633 /* this will validate ranges for us. */ 1634 o2hb_dead_threshold_set((unsigned int) tmp); 1635 1636 return count; 1637 } 1638 1639 static struct o2hb_heartbeat_group_attribute o2hb_heartbeat_group_attr_threshold = { 1640 .attr = { .ca_owner = THIS_MODULE, 1641 .ca_name = "dead_threshold", 1642 .ca_mode = S_IRUGO | S_IWUSR }, 1643 .show = o2hb_heartbeat_group_threshold_show, 1644 .store = o2hb_heartbeat_group_threshold_store, 1645 }; 1646 1647 static struct configfs_attribute *o2hb_heartbeat_group_attrs[] = { 1648 &o2hb_heartbeat_group_attr_threshold.attr, 1649 NULL, 1650 }; 1651 1652 static struct configfs_item_operations o2hb_hearbeat_group_item_ops = { 1653 .show_attribute = o2hb_heartbeat_group_show, 1654 .store_attribute = o2hb_heartbeat_group_store, 1655 }; 1656 1657 static struct configfs_group_operations o2hb_heartbeat_group_group_ops = { 1658 .make_item = o2hb_heartbeat_group_make_item, 1659 .drop_item = o2hb_heartbeat_group_drop_item, 1660 }; 1661 1662 static struct config_item_type o2hb_heartbeat_group_type = { 1663 .ct_group_ops = &o2hb_heartbeat_group_group_ops, 1664 .ct_item_ops = &o2hb_hearbeat_group_item_ops, 1665 .ct_attrs = o2hb_heartbeat_group_attrs, 1666 .ct_owner = THIS_MODULE, 1667 }; 1668 1669 /* this is just here to avoid touching group in heartbeat.h which the 1670 * entire damn world #includes */ 1671 struct config_group *o2hb_alloc_hb_set(void) 1672 { 1673 struct o2hb_heartbeat_group *hs = NULL; 1674 struct config_group *ret = NULL; 1675 1676 hs = kcalloc(1, sizeof(struct o2hb_heartbeat_group), GFP_KERNEL); 1677 if (hs == NULL) 1678 goto out; 1679 1680 config_group_init_type_name(&hs->hs_group, "heartbeat", 1681 &o2hb_heartbeat_group_type); 1682 1683 ret = &hs->hs_group; 1684 out: 1685 if (ret == NULL) 1686 kfree(hs); 1687 return ret; 1688 } 1689 1690 void o2hb_free_hb_set(struct config_group *group) 1691 { 1692 struct o2hb_heartbeat_group *hs = to_o2hb_heartbeat_group(group); 1693 kfree(hs); 1694 } 1695 1696 /* hb callback registration and issueing */ 1697 1698 static struct o2hb_callback *hbcall_from_type(enum o2hb_callback_type type) 1699 { 1700 if (type == O2HB_NUM_CB) 1701 return ERR_PTR(-EINVAL); 1702 1703 return &o2hb_callbacks[type]; 1704 } 1705 1706 void o2hb_setup_callback(struct o2hb_callback_func *hc, 1707 enum o2hb_callback_type type, 1708 o2hb_cb_func *func, 1709 void *data, 1710 int priority) 1711 { 1712 INIT_LIST_HEAD(&hc->hc_item); 1713 hc->hc_func = func; 1714 hc->hc_data = data; 1715 hc->hc_priority = priority; 1716 hc->hc_type = type; 1717 hc->hc_magic = O2HB_CB_MAGIC; 1718 } 1719 EXPORT_SYMBOL_GPL(o2hb_setup_callback); 1720 1721 int o2hb_register_callback(struct o2hb_callback_func *hc) 1722 { 1723 struct o2hb_callback_func *tmp; 1724 struct list_head *iter; 1725 struct o2hb_callback *hbcall; 1726 int ret; 1727 1728 BUG_ON(hc->hc_magic != O2HB_CB_MAGIC); 1729 BUG_ON(!list_empty(&hc->hc_item)); 1730 1731 hbcall = hbcall_from_type(hc->hc_type); 1732 if (IS_ERR(hbcall)) { 1733 ret = PTR_ERR(hbcall); 1734 goto out; 1735 } 1736 1737 down_write(&o2hb_callback_sem); 1738 1739 list_for_each(iter, &hbcall->list) { 1740 tmp = list_entry(iter, struct o2hb_callback_func, hc_item); 1741 if (hc->hc_priority < tmp->hc_priority) { 1742 list_add_tail(&hc->hc_item, iter); 1743 break; 1744 } 1745 } 1746 if (list_empty(&hc->hc_item)) 1747 list_add_tail(&hc->hc_item, &hbcall->list); 1748 1749 up_write(&o2hb_callback_sem); 1750 ret = 0; 1751 out: 1752 mlog(ML_HEARTBEAT, "returning %d on behalf of %p for funcs %p\n", 1753 ret, __builtin_return_address(0), hc); 1754 return ret; 1755 } 1756 EXPORT_SYMBOL_GPL(o2hb_register_callback); 1757 1758 int o2hb_unregister_callback(struct o2hb_callback_func *hc) 1759 { 1760 BUG_ON(hc->hc_magic != O2HB_CB_MAGIC); 1761 1762 mlog(ML_HEARTBEAT, "on behalf of %p for funcs %p\n", 1763 __builtin_return_address(0), hc); 1764 1765 if (list_empty(&hc->hc_item)) 1766 return 0; 1767 1768 down_write(&o2hb_callback_sem); 1769 1770 list_del_init(&hc->hc_item); 1771 1772 up_write(&o2hb_callback_sem); 1773 1774 return 0; 1775 } 1776 EXPORT_SYMBOL_GPL(o2hb_unregister_callback); 1777 1778 int o2hb_check_node_heartbeating(u8 node_num) 1779 { 1780 unsigned long testing_map[BITS_TO_LONGS(O2NM_MAX_NODES)]; 1781 1782 o2hb_fill_node_map(testing_map, sizeof(testing_map)); 1783 if (!test_bit(node_num, testing_map)) { 1784 mlog(ML_HEARTBEAT, 1785 "node (%u) does not have heartbeating enabled.\n", 1786 node_num); 1787 return 0; 1788 } 1789 1790 return 1; 1791 } 1792 EXPORT_SYMBOL_GPL(o2hb_check_node_heartbeating); 1793 1794 int o2hb_check_node_heartbeating_from_callback(u8 node_num) 1795 { 1796 unsigned long testing_map[BITS_TO_LONGS(O2NM_MAX_NODES)]; 1797 1798 o2hb_fill_node_map_from_callback(testing_map, sizeof(testing_map)); 1799 if (!test_bit(node_num, testing_map)) { 1800 mlog(ML_HEARTBEAT, 1801 "node (%u) does not have heartbeating enabled.\n", 1802 node_num); 1803 return 0; 1804 } 1805 1806 return 1; 1807 } 1808 EXPORT_SYMBOL_GPL(o2hb_check_node_heartbeating_from_callback); 1809 1810 /* Makes sure our local node is configured with a node number, and is 1811 * heartbeating. */ 1812 int o2hb_check_local_node_heartbeating(void) 1813 { 1814 u8 node_num; 1815 1816 /* if this node was set then we have networking */ 1817 node_num = o2nm_this_node(); 1818 if (node_num == O2NM_MAX_NODES) { 1819 mlog(ML_HEARTBEAT, "this node has not been configured.\n"); 1820 return 0; 1821 } 1822 1823 return o2hb_check_node_heartbeating(node_num); 1824 } 1825 EXPORT_SYMBOL_GPL(o2hb_check_local_node_heartbeating); 1826 1827 /* 1828 * this is just a hack until we get the plumbing which flips file systems 1829 * read only and drops the hb ref instead of killing the node dead. 1830 */ 1831 void o2hb_stop_all_regions(void) 1832 { 1833 struct o2hb_region *reg; 1834 1835 mlog(ML_ERROR, "stopping heartbeat on all active regions.\n"); 1836 1837 spin_lock(&o2hb_live_lock); 1838 1839 list_for_each_entry(reg, &o2hb_all_regions, hr_all_item) 1840 reg->hr_unclean_stop = 1; 1841 1842 spin_unlock(&o2hb_live_lock); 1843 } 1844 EXPORT_SYMBOL_GPL(o2hb_stop_all_regions); 1845