1 /* 2 drbd_worker.c 3 4 This file is part of DRBD by Philipp Reisner and Lars Ellenberg. 5 6 Copyright (C) 2001-2008, LINBIT Information Technologies GmbH. 7 Copyright (C) 1999-2008, Philipp Reisner <philipp.reisner@linbit.com>. 8 Copyright (C) 2002-2008, Lars Ellenberg <lars.ellenberg@linbit.com>. 9 10 drbd is free software; you can redistribute it and/or modify 11 it under the terms of the GNU General Public License as published by 12 the Free Software Foundation; either version 2, or (at your option) 13 any later version. 14 15 drbd is distributed in the hope that it will be useful, 16 but WITHOUT ANY WARRANTY; without even the implied warranty of 17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 GNU General Public License for more details. 19 20 You should have received a copy of the GNU General Public License 21 along with drbd; see the file COPYING. If not, write to 22 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. 23 24 */ 25 26 #include <linux/module.h> 27 #include <linux/drbd.h> 28 #include <linux/sched.h> 29 #include <linux/wait.h> 30 #include <linux/mm.h> 31 #include <linux/memcontrol.h> 32 #include <linux/mm_inline.h> 33 #include <linux/slab.h> 34 #include <linux/random.h> 35 #include <linux/string.h> 36 #include <linux/scatterlist.h> 37 38 #include "drbd_int.h" 39 #include "drbd_protocol.h" 40 #include "drbd_req.h" 41 42 static int make_ov_request(struct drbd_device *, int); 43 static int make_resync_request(struct drbd_device *, int); 44 45 /* endio handlers: 46 * drbd_md_endio (defined here) 47 * drbd_request_endio (defined here) 48 * drbd_peer_request_endio (defined here) 49 * drbd_bm_endio (defined in drbd_bitmap.c) 50 * 51 * For all these callbacks, note the following: 52 * The callbacks will be called in irq context by the IDE drivers, 53 * and in Softirqs/Tasklets/BH context by the SCSI drivers. 54 * Try to get the locking right :) 55 * 56 */ 57 58 /* used for synchronous meta data and bitmap IO 59 * submitted by drbd_md_sync_page_io() 60 */ 61 void drbd_md_endio(struct bio *bio) 62 { 63 struct drbd_device *device; 64 65 device = bio->bi_private; 66 device->md_io.error = bio->bi_error; 67 68 /* We grabbed an extra reference in _drbd_md_sync_page_io() to be able 69 * to timeout on the lower level device, and eventually detach from it. 70 * If this io completion runs after that timeout expired, this 71 * drbd_md_put_buffer() may allow us to finally try and re-attach. 72 * During normal operation, this only puts that extra reference 73 * down to 1 again. 74 * Make sure we first drop the reference, and only then signal 75 * completion, or we may (in drbd_al_read_log()) cycle so fast into the 76 * next drbd_md_sync_page_io(), that we trigger the 77 * ASSERT(atomic_read(&device->md_io_in_use) == 1) there. 78 */ 79 drbd_md_put_buffer(device); 80 device->md_io.done = 1; 81 wake_up(&device->misc_wait); 82 bio_put(bio); 83 if (device->ldev) /* special case: drbd_md_read() during drbd_adm_attach() */ 84 put_ldev(device); 85 } 86 87 /* reads on behalf of the partner, 88 * "submitted" by the receiver 89 */ 90 static void drbd_endio_read_sec_final(struct drbd_peer_request *peer_req) __releases(local) 91 { 92 unsigned long flags = 0; 93 struct drbd_peer_device *peer_device = peer_req->peer_device; 94 struct drbd_device *device = peer_device->device; 95 96 spin_lock_irqsave(&device->resource->req_lock, flags); 97 device->read_cnt += peer_req->i.size >> 9; 98 list_del(&peer_req->w.list); 99 if (list_empty(&device->read_ee)) 100 wake_up(&device->ee_wait); 101 if (test_bit(__EE_WAS_ERROR, &peer_req->flags)) 102 __drbd_chk_io_error(device, DRBD_READ_ERROR); 103 spin_unlock_irqrestore(&device->resource->req_lock, flags); 104 105 drbd_queue_work(&peer_device->connection->sender_work, &peer_req->w); 106 put_ldev(device); 107 } 108 109 /* writes on behalf of the partner, or resync writes, 110 * "submitted" by the receiver, final stage. */ 111 void drbd_endio_write_sec_final(struct drbd_peer_request *peer_req) __releases(local) 112 { 113 unsigned long flags = 0; 114 struct drbd_peer_device *peer_device = peer_req->peer_device; 115 struct drbd_device *device = peer_device->device; 116 struct drbd_connection *connection = peer_device->connection; 117 struct drbd_interval i; 118 int do_wake; 119 u64 block_id; 120 int do_al_complete_io; 121 122 /* after we moved peer_req to done_ee, 123 * we may no longer access it, 124 * it may be freed/reused already! 125 * (as soon as we release the req_lock) */ 126 i = peer_req->i; 127 do_al_complete_io = peer_req->flags & EE_CALL_AL_COMPLETE_IO; 128 block_id = peer_req->block_id; 129 peer_req->flags &= ~EE_CALL_AL_COMPLETE_IO; 130 131 spin_lock_irqsave(&device->resource->req_lock, flags); 132 device->writ_cnt += peer_req->i.size >> 9; 133 list_move_tail(&peer_req->w.list, &device->done_ee); 134 135 /* 136 * Do not remove from the write_requests tree here: we did not send the 137 * Ack yet and did not wake possibly waiting conflicting requests. 138 * Removed from the tree from "drbd_process_done_ee" within the 139 * appropriate dw.cb (e_end_block/e_end_resync_block) or from 140 * _drbd_clear_done_ee. 141 */ 142 143 do_wake = list_empty(block_id == ID_SYNCER ? &device->sync_ee : &device->active_ee); 144 145 /* FIXME do we want to detach for failed REQ_DISCARD? 146 * ((peer_req->flags & (EE_WAS_ERROR|EE_IS_TRIM)) == EE_WAS_ERROR) */ 147 if (peer_req->flags & EE_WAS_ERROR) 148 __drbd_chk_io_error(device, DRBD_WRITE_ERROR); 149 150 if (connection->cstate >= C_WF_REPORT_PARAMS) { 151 kref_get(&device->kref); /* put is in drbd_send_acks_wf() */ 152 if (!queue_work(connection->ack_sender, &peer_device->send_acks_work)) 153 kref_put(&device->kref, drbd_destroy_device); 154 } 155 spin_unlock_irqrestore(&device->resource->req_lock, flags); 156 157 if (block_id == ID_SYNCER) 158 drbd_rs_complete_io(device, i.sector); 159 160 if (do_wake) 161 wake_up(&device->ee_wait); 162 163 if (do_al_complete_io) 164 drbd_al_complete_io(device, &i); 165 166 put_ldev(device); 167 } 168 169 /* writes on behalf of the partner, or resync writes, 170 * "submitted" by the receiver. 171 */ 172 void drbd_peer_request_endio(struct bio *bio) 173 { 174 struct drbd_peer_request *peer_req = bio->bi_private; 175 struct drbd_device *device = peer_req->peer_device->device; 176 int is_write = bio_data_dir(bio) == WRITE; 177 int is_discard = !!(bio->bi_rw & REQ_DISCARD); 178 179 if (bio->bi_error && __ratelimit(&drbd_ratelimit_state)) 180 drbd_warn(device, "%s: error=%d s=%llus\n", 181 is_write ? (is_discard ? "discard" : "write") 182 : "read", bio->bi_error, 183 (unsigned long long)peer_req->i.sector); 184 185 if (bio->bi_error) 186 set_bit(__EE_WAS_ERROR, &peer_req->flags); 187 188 bio_put(bio); /* no need for the bio anymore */ 189 if (atomic_dec_and_test(&peer_req->pending_bios)) { 190 if (is_write) 191 drbd_endio_write_sec_final(peer_req); 192 else 193 drbd_endio_read_sec_final(peer_req); 194 } 195 } 196 197 void drbd_panic_after_delayed_completion_of_aborted_request(struct drbd_device *device) 198 { 199 panic("drbd%u %s/%u potential random memory corruption caused by delayed completion of aborted local request\n", 200 device->minor, device->resource->name, device->vnr); 201 } 202 203 /* read, readA or write requests on R_PRIMARY coming from drbd_make_request 204 */ 205 void drbd_request_endio(struct bio *bio) 206 { 207 unsigned long flags; 208 struct drbd_request *req = bio->bi_private; 209 struct drbd_device *device = req->device; 210 struct bio_and_error m; 211 enum drbd_req_event what; 212 213 /* If this request was aborted locally before, 214 * but now was completed "successfully", 215 * chances are that this caused arbitrary data corruption. 216 * 217 * "aborting" requests, or force-detaching the disk, is intended for 218 * completely blocked/hung local backing devices which do no longer 219 * complete requests at all, not even do error completions. In this 220 * situation, usually a hard-reset and failover is the only way out. 221 * 222 * By "aborting", basically faking a local error-completion, 223 * we allow for a more graceful swichover by cleanly migrating services. 224 * Still the affected node has to be rebooted "soon". 225 * 226 * By completing these requests, we allow the upper layers to re-use 227 * the associated data pages. 228 * 229 * If later the local backing device "recovers", and now DMAs some data 230 * from disk into the original request pages, in the best case it will 231 * just put random data into unused pages; but typically it will corrupt 232 * meanwhile completely unrelated data, causing all sorts of damage. 233 * 234 * Which means delayed successful completion, 235 * especially for READ requests, 236 * is a reason to panic(). 237 * 238 * We assume that a delayed *error* completion is OK, 239 * though we still will complain noisily about it. 240 */ 241 if (unlikely(req->rq_state & RQ_LOCAL_ABORTED)) { 242 if (__ratelimit(&drbd_ratelimit_state)) 243 drbd_emerg(device, "delayed completion of aborted local request; disk-timeout may be too aggressive\n"); 244 245 if (!bio->bi_error) 246 drbd_panic_after_delayed_completion_of_aborted_request(device); 247 } 248 249 /* to avoid recursion in __req_mod */ 250 if (unlikely(bio->bi_error)) { 251 if (bio->bi_rw & REQ_DISCARD) 252 what = (bio->bi_error == -EOPNOTSUPP) 253 ? DISCARD_COMPLETED_NOTSUPP 254 : DISCARD_COMPLETED_WITH_ERROR; 255 else 256 what = (bio_data_dir(bio) == WRITE) 257 ? WRITE_COMPLETED_WITH_ERROR 258 : (bio_rw(bio) == READ) 259 ? READ_COMPLETED_WITH_ERROR 260 : READ_AHEAD_COMPLETED_WITH_ERROR; 261 } else 262 what = COMPLETED_OK; 263 264 bio_put(req->private_bio); 265 req->private_bio = ERR_PTR(bio->bi_error); 266 267 /* not req_mod(), we need irqsave here! */ 268 spin_lock_irqsave(&device->resource->req_lock, flags); 269 __req_mod(req, what, &m); 270 spin_unlock_irqrestore(&device->resource->req_lock, flags); 271 put_ldev(device); 272 273 if (m.bio) 274 complete_master_bio(device, &m); 275 } 276 277 void drbd_csum_ee(struct crypto_ahash *tfm, struct drbd_peer_request *peer_req, void *digest) 278 { 279 AHASH_REQUEST_ON_STACK(req, tfm); 280 struct scatterlist sg; 281 struct page *page = peer_req->pages; 282 struct page *tmp; 283 unsigned len; 284 285 ahash_request_set_tfm(req, tfm); 286 ahash_request_set_callback(req, 0, NULL, NULL); 287 288 sg_init_table(&sg, 1); 289 crypto_ahash_init(req); 290 291 while ((tmp = page_chain_next(page))) { 292 /* all but the last page will be fully used */ 293 sg_set_page(&sg, page, PAGE_SIZE, 0); 294 ahash_request_set_crypt(req, &sg, NULL, sg.length); 295 crypto_ahash_update(req); 296 page = tmp; 297 } 298 /* and now the last, possibly only partially used page */ 299 len = peer_req->i.size & (PAGE_SIZE - 1); 300 sg_set_page(&sg, page, len ?: PAGE_SIZE, 0); 301 ahash_request_set_crypt(req, &sg, digest, sg.length); 302 crypto_ahash_finup(req); 303 ahash_request_zero(req); 304 } 305 306 void drbd_csum_bio(struct crypto_ahash *tfm, struct bio *bio, void *digest) 307 { 308 AHASH_REQUEST_ON_STACK(req, tfm); 309 struct scatterlist sg; 310 struct bio_vec bvec; 311 struct bvec_iter iter; 312 313 ahash_request_set_tfm(req, tfm); 314 ahash_request_set_callback(req, 0, NULL, NULL); 315 316 sg_init_table(&sg, 1); 317 crypto_ahash_init(req); 318 319 bio_for_each_segment(bvec, bio, iter) { 320 sg_set_page(&sg, bvec.bv_page, bvec.bv_len, bvec.bv_offset); 321 ahash_request_set_crypt(req, &sg, NULL, sg.length); 322 crypto_ahash_update(req); 323 } 324 ahash_request_set_crypt(req, NULL, digest, 0); 325 crypto_ahash_final(req); 326 ahash_request_zero(req); 327 } 328 329 /* MAYBE merge common code with w_e_end_ov_req */ 330 static int w_e_send_csum(struct drbd_work *w, int cancel) 331 { 332 struct drbd_peer_request *peer_req = container_of(w, struct drbd_peer_request, w); 333 struct drbd_peer_device *peer_device = peer_req->peer_device; 334 struct drbd_device *device = peer_device->device; 335 int digest_size; 336 void *digest; 337 int err = 0; 338 339 if (unlikely(cancel)) 340 goto out; 341 342 if (unlikely((peer_req->flags & EE_WAS_ERROR) != 0)) 343 goto out; 344 345 digest_size = crypto_ahash_digestsize(peer_device->connection->csums_tfm); 346 digest = kmalloc(digest_size, GFP_NOIO); 347 if (digest) { 348 sector_t sector = peer_req->i.sector; 349 unsigned int size = peer_req->i.size; 350 drbd_csum_ee(peer_device->connection->csums_tfm, peer_req, digest); 351 /* Free peer_req and pages before send. 352 * In case we block on congestion, we could otherwise run into 353 * some distributed deadlock, if the other side blocks on 354 * congestion as well, because our receiver blocks in 355 * drbd_alloc_pages due to pp_in_use > max_buffers. */ 356 drbd_free_peer_req(device, peer_req); 357 peer_req = NULL; 358 inc_rs_pending(device); 359 err = drbd_send_drequest_csum(peer_device, sector, size, 360 digest, digest_size, 361 P_CSUM_RS_REQUEST); 362 kfree(digest); 363 } else { 364 drbd_err(device, "kmalloc() of digest failed.\n"); 365 err = -ENOMEM; 366 } 367 368 out: 369 if (peer_req) 370 drbd_free_peer_req(device, peer_req); 371 372 if (unlikely(err)) 373 drbd_err(device, "drbd_send_drequest(..., csum) failed\n"); 374 return err; 375 } 376 377 #define GFP_TRY (__GFP_HIGHMEM | __GFP_NOWARN) 378 379 static int read_for_csum(struct drbd_peer_device *peer_device, sector_t sector, int size) 380 { 381 struct drbd_device *device = peer_device->device; 382 struct drbd_peer_request *peer_req; 383 384 if (!get_ldev(device)) 385 return -EIO; 386 387 /* GFP_TRY, because if there is no memory available right now, this may 388 * be rescheduled for later. It is "only" background resync, after all. */ 389 peer_req = drbd_alloc_peer_req(peer_device, ID_SYNCER /* unused */, sector, 390 size, true /* has real payload */, GFP_TRY); 391 if (!peer_req) 392 goto defer; 393 394 peer_req->w.cb = w_e_send_csum; 395 spin_lock_irq(&device->resource->req_lock); 396 list_add_tail(&peer_req->w.list, &device->read_ee); 397 spin_unlock_irq(&device->resource->req_lock); 398 399 atomic_add(size >> 9, &device->rs_sect_ev); 400 if (drbd_submit_peer_request(device, peer_req, READ, DRBD_FAULT_RS_RD) == 0) 401 return 0; 402 403 /* If it failed because of ENOMEM, retry should help. If it failed 404 * because bio_add_page failed (probably broken lower level driver), 405 * retry may or may not help. 406 * If it does not, you may need to force disconnect. */ 407 spin_lock_irq(&device->resource->req_lock); 408 list_del(&peer_req->w.list); 409 spin_unlock_irq(&device->resource->req_lock); 410 411 drbd_free_peer_req(device, peer_req); 412 defer: 413 put_ldev(device); 414 return -EAGAIN; 415 } 416 417 int w_resync_timer(struct drbd_work *w, int cancel) 418 { 419 struct drbd_device *device = 420 container_of(w, struct drbd_device, resync_work); 421 422 switch (device->state.conn) { 423 case C_VERIFY_S: 424 make_ov_request(device, cancel); 425 break; 426 case C_SYNC_TARGET: 427 make_resync_request(device, cancel); 428 break; 429 } 430 431 return 0; 432 } 433 434 void resync_timer_fn(unsigned long data) 435 { 436 struct drbd_device *device = (struct drbd_device *) data; 437 438 drbd_queue_work_if_unqueued( 439 &first_peer_device(device)->connection->sender_work, 440 &device->resync_work); 441 } 442 443 static void fifo_set(struct fifo_buffer *fb, int value) 444 { 445 int i; 446 447 for (i = 0; i < fb->size; i++) 448 fb->values[i] = value; 449 } 450 451 static int fifo_push(struct fifo_buffer *fb, int value) 452 { 453 int ov; 454 455 ov = fb->values[fb->head_index]; 456 fb->values[fb->head_index++] = value; 457 458 if (fb->head_index >= fb->size) 459 fb->head_index = 0; 460 461 return ov; 462 } 463 464 static void fifo_add_val(struct fifo_buffer *fb, int value) 465 { 466 int i; 467 468 for (i = 0; i < fb->size; i++) 469 fb->values[i] += value; 470 } 471 472 struct fifo_buffer *fifo_alloc(int fifo_size) 473 { 474 struct fifo_buffer *fb; 475 476 fb = kzalloc(sizeof(struct fifo_buffer) + sizeof(int) * fifo_size, GFP_NOIO); 477 if (!fb) 478 return NULL; 479 480 fb->head_index = 0; 481 fb->size = fifo_size; 482 fb->total = 0; 483 484 return fb; 485 } 486 487 static int drbd_rs_controller(struct drbd_device *device, unsigned int sect_in) 488 { 489 struct disk_conf *dc; 490 unsigned int want; /* The number of sectors we want in-flight */ 491 int req_sect; /* Number of sectors to request in this turn */ 492 int correction; /* Number of sectors more we need in-flight */ 493 int cps; /* correction per invocation of drbd_rs_controller() */ 494 int steps; /* Number of time steps to plan ahead */ 495 int curr_corr; 496 int max_sect; 497 struct fifo_buffer *plan; 498 499 dc = rcu_dereference(device->ldev->disk_conf); 500 plan = rcu_dereference(device->rs_plan_s); 501 502 steps = plan->size; /* (dc->c_plan_ahead * 10 * SLEEP_TIME) / HZ; */ 503 504 if (device->rs_in_flight + sect_in == 0) { /* At start of resync */ 505 want = ((dc->resync_rate * 2 * SLEEP_TIME) / HZ) * steps; 506 } else { /* normal path */ 507 want = dc->c_fill_target ? dc->c_fill_target : 508 sect_in * dc->c_delay_target * HZ / (SLEEP_TIME * 10); 509 } 510 511 correction = want - device->rs_in_flight - plan->total; 512 513 /* Plan ahead */ 514 cps = correction / steps; 515 fifo_add_val(plan, cps); 516 plan->total += cps * steps; 517 518 /* What we do in this step */ 519 curr_corr = fifo_push(plan, 0); 520 plan->total -= curr_corr; 521 522 req_sect = sect_in + curr_corr; 523 if (req_sect < 0) 524 req_sect = 0; 525 526 max_sect = (dc->c_max_rate * 2 * SLEEP_TIME) / HZ; 527 if (req_sect > max_sect) 528 req_sect = max_sect; 529 530 /* 531 drbd_warn(device, "si=%u if=%d wa=%u co=%d st=%d cps=%d pl=%d cc=%d rs=%d\n", 532 sect_in, device->rs_in_flight, want, correction, 533 steps, cps, device->rs_planed, curr_corr, req_sect); 534 */ 535 536 return req_sect; 537 } 538 539 static int drbd_rs_number_requests(struct drbd_device *device) 540 { 541 unsigned int sect_in; /* Number of sectors that came in since the last turn */ 542 int number, mxb; 543 544 sect_in = atomic_xchg(&device->rs_sect_in, 0); 545 device->rs_in_flight -= sect_in; 546 547 rcu_read_lock(); 548 mxb = drbd_get_max_buffers(device) / 2; 549 if (rcu_dereference(device->rs_plan_s)->size) { 550 number = drbd_rs_controller(device, sect_in) >> (BM_BLOCK_SHIFT - 9); 551 device->c_sync_rate = number * HZ * (BM_BLOCK_SIZE / 1024) / SLEEP_TIME; 552 } else { 553 device->c_sync_rate = rcu_dereference(device->ldev->disk_conf)->resync_rate; 554 number = SLEEP_TIME * device->c_sync_rate / ((BM_BLOCK_SIZE / 1024) * HZ); 555 } 556 rcu_read_unlock(); 557 558 /* Don't have more than "max-buffers"/2 in-flight. 559 * Otherwise we may cause the remote site to stall on drbd_alloc_pages(), 560 * potentially causing a distributed deadlock on congestion during 561 * online-verify or (checksum-based) resync, if max-buffers, 562 * socket buffer sizes and resync rate settings are mis-configured. */ 563 564 /* note that "number" is in units of "BM_BLOCK_SIZE" (which is 4k), 565 * mxb (as used here, and in drbd_alloc_pages on the peer) is 566 * "number of pages" (typically also 4k), 567 * but "rs_in_flight" is in "sectors" (512 Byte). */ 568 if (mxb - device->rs_in_flight/8 < number) 569 number = mxb - device->rs_in_flight/8; 570 571 return number; 572 } 573 574 static int make_resync_request(struct drbd_device *const device, int cancel) 575 { 576 struct drbd_peer_device *const peer_device = first_peer_device(device); 577 struct drbd_connection *const connection = peer_device ? peer_device->connection : NULL; 578 unsigned long bit; 579 sector_t sector; 580 const sector_t capacity = drbd_get_capacity(device->this_bdev); 581 int max_bio_size; 582 int number, rollback_i, size; 583 int align, requeue = 0; 584 int i = 0; 585 586 if (unlikely(cancel)) 587 return 0; 588 589 if (device->rs_total == 0) { 590 /* empty resync? */ 591 drbd_resync_finished(device); 592 return 0; 593 } 594 595 if (!get_ldev(device)) { 596 /* Since we only need to access device->rsync a 597 get_ldev_if_state(device,D_FAILED) would be sufficient, but 598 to continue resync with a broken disk makes no sense at 599 all */ 600 drbd_err(device, "Disk broke down during resync!\n"); 601 return 0; 602 } 603 604 max_bio_size = queue_max_hw_sectors(device->rq_queue) << 9; 605 number = drbd_rs_number_requests(device); 606 if (number <= 0) 607 goto requeue; 608 609 for (i = 0; i < number; i++) { 610 /* Stop generating RS requests when half of the send buffer is filled, 611 * but notify TCP that we'd like to have more space. */ 612 mutex_lock(&connection->data.mutex); 613 if (connection->data.socket) { 614 struct sock *sk = connection->data.socket->sk; 615 int queued = sk->sk_wmem_queued; 616 int sndbuf = sk->sk_sndbuf; 617 if (queued > sndbuf / 2) { 618 requeue = 1; 619 if (sk->sk_socket) 620 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 621 } 622 } else 623 requeue = 1; 624 mutex_unlock(&connection->data.mutex); 625 if (requeue) 626 goto requeue; 627 628 next_sector: 629 size = BM_BLOCK_SIZE; 630 bit = drbd_bm_find_next(device, device->bm_resync_fo); 631 632 if (bit == DRBD_END_OF_BITMAP) { 633 device->bm_resync_fo = drbd_bm_bits(device); 634 put_ldev(device); 635 return 0; 636 } 637 638 sector = BM_BIT_TO_SECT(bit); 639 640 if (drbd_try_rs_begin_io(device, sector)) { 641 device->bm_resync_fo = bit; 642 goto requeue; 643 } 644 device->bm_resync_fo = bit + 1; 645 646 if (unlikely(drbd_bm_test_bit(device, bit) == 0)) { 647 drbd_rs_complete_io(device, sector); 648 goto next_sector; 649 } 650 651 #if DRBD_MAX_BIO_SIZE > BM_BLOCK_SIZE 652 /* try to find some adjacent bits. 653 * we stop if we have already the maximum req size. 654 * 655 * Additionally always align bigger requests, in order to 656 * be prepared for all stripe sizes of software RAIDs. 657 */ 658 align = 1; 659 rollback_i = i; 660 while (i < number) { 661 if (size + BM_BLOCK_SIZE > max_bio_size) 662 break; 663 664 /* Be always aligned */ 665 if (sector & ((1<<(align+3))-1)) 666 break; 667 668 /* do not cross extent boundaries */ 669 if (((bit+1) & BM_BLOCKS_PER_BM_EXT_MASK) == 0) 670 break; 671 /* now, is it actually dirty, after all? 672 * caution, drbd_bm_test_bit is tri-state for some 673 * obscure reason; ( b == 0 ) would get the out-of-band 674 * only accidentally right because of the "oddly sized" 675 * adjustment below */ 676 if (drbd_bm_test_bit(device, bit+1) != 1) 677 break; 678 bit++; 679 size += BM_BLOCK_SIZE; 680 if ((BM_BLOCK_SIZE << align) <= size) 681 align++; 682 i++; 683 } 684 /* if we merged some, 685 * reset the offset to start the next drbd_bm_find_next from */ 686 if (size > BM_BLOCK_SIZE) 687 device->bm_resync_fo = bit + 1; 688 #endif 689 690 /* adjust very last sectors, in case we are oddly sized */ 691 if (sector + (size>>9) > capacity) 692 size = (capacity-sector)<<9; 693 694 if (device->use_csums) { 695 switch (read_for_csum(peer_device, sector, size)) { 696 case -EIO: /* Disk failure */ 697 put_ldev(device); 698 return -EIO; 699 case -EAGAIN: /* allocation failed, or ldev busy */ 700 drbd_rs_complete_io(device, sector); 701 device->bm_resync_fo = BM_SECT_TO_BIT(sector); 702 i = rollback_i; 703 goto requeue; 704 case 0: 705 /* everything ok */ 706 break; 707 default: 708 BUG(); 709 } 710 } else { 711 int err; 712 713 inc_rs_pending(device); 714 err = drbd_send_drequest(peer_device, P_RS_DATA_REQUEST, 715 sector, size, ID_SYNCER); 716 if (err) { 717 drbd_err(device, "drbd_send_drequest() failed, aborting...\n"); 718 dec_rs_pending(device); 719 put_ldev(device); 720 return err; 721 } 722 } 723 } 724 725 if (device->bm_resync_fo >= drbd_bm_bits(device)) { 726 /* last syncer _request_ was sent, 727 * but the P_RS_DATA_REPLY not yet received. sync will end (and 728 * next sync group will resume), as soon as we receive the last 729 * resync data block, and the last bit is cleared. 730 * until then resync "work" is "inactive" ... 731 */ 732 put_ldev(device); 733 return 0; 734 } 735 736 requeue: 737 device->rs_in_flight += (i << (BM_BLOCK_SHIFT - 9)); 738 mod_timer(&device->resync_timer, jiffies + SLEEP_TIME); 739 put_ldev(device); 740 return 0; 741 } 742 743 static int make_ov_request(struct drbd_device *device, int cancel) 744 { 745 int number, i, size; 746 sector_t sector; 747 const sector_t capacity = drbd_get_capacity(device->this_bdev); 748 bool stop_sector_reached = false; 749 750 if (unlikely(cancel)) 751 return 1; 752 753 number = drbd_rs_number_requests(device); 754 755 sector = device->ov_position; 756 for (i = 0; i < number; i++) { 757 if (sector >= capacity) 758 return 1; 759 760 /* We check for "finished" only in the reply path: 761 * w_e_end_ov_reply(). 762 * We need to send at least one request out. */ 763 stop_sector_reached = i > 0 764 && verify_can_do_stop_sector(device) 765 && sector >= device->ov_stop_sector; 766 if (stop_sector_reached) 767 break; 768 769 size = BM_BLOCK_SIZE; 770 771 if (drbd_try_rs_begin_io(device, sector)) { 772 device->ov_position = sector; 773 goto requeue; 774 } 775 776 if (sector + (size>>9) > capacity) 777 size = (capacity-sector)<<9; 778 779 inc_rs_pending(device); 780 if (drbd_send_ov_request(first_peer_device(device), sector, size)) { 781 dec_rs_pending(device); 782 return 0; 783 } 784 sector += BM_SECT_PER_BIT; 785 } 786 device->ov_position = sector; 787 788 requeue: 789 device->rs_in_flight += (i << (BM_BLOCK_SHIFT - 9)); 790 if (i == 0 || !stop_sector_reached) 791 mod_timer(&device->resync_timer, jiffies + SLEEP_TIME); 792 return 1; 793 } 794 795 int w_ov_finished(struct drbd_work *w, int cancel) 796 { 797 struct drbd_device_work *dw = 798 container_of(w, struct drbd_device_work, w); 799 struct drbd_device *device = dw->device; 800 kfree(dw); 801 ov_out_of_sync_print(device); 802 drbd_resync_finished(device); 803 804 return 0; 805 } 806 807 static int w_resync_finished(struct drbd_work *w, int cancel) 808 { 809 struct drbd_device_work *dw = 810 container_of(w, struct drbd_device_work, w); 811 struct drbd_device *device = dw->device; 812 kfree(dw); 813 814 drbd_resync_finished(device); 815 816 return 0; 817 } 818 819 static void ping_peer(struct drbd_device *device) 820 { 821 struct drbd_connection *connection = first_peer_device(device)->connection; 822 823 clear_bit(GOT_PING_ACK, &connection->flags); 824 request_ping(connection); 825 wait_event(connection->ping_wait, 826 test_bit(GOT_PING_ACK, &connection->flags) || device->state.conn < C_CONNECTED); 827 } 828 829 int drbd_resync_finished(struct drbd_device *device) 830 { 831 unsigned long db, dt, dbdt; 832 unsigned long n_oos; 833 union drbd_state os, ns; 834 struct drbd_device_work *dw; 835 char *khelper_cmd = NULL; 836 int verify_done = 0; 837 838 /* Remove all elements from the resync LRU. Since future actions 839 * might set bits in the (main) bitmap, then the entries in the 840 * resync LRU would be wrong. */ 841 if (drbd_rs_del_all(device)) { 842 /* In case this is not possible now, most probably because 843 * there are P_RS_DATA_REPLY Packets lingering on the worker's 844 * queue (or even the read operations for those packets 845 * is not finished by now). Retry in 100ms. */ 846 847 schedule_timeout_interruptible(HZ / 10); 848 dw = kmalloc(sizeof(struct drbd_device_work), GFP_ATOMIC); 849 if (dw) { 850 dw->w.cb = w_resync_finished; 851 dw->device = device; 852 drbd_queue_work(&first_peer_device(device)->connection->sender_work, 853 &dw->w); 854 return 1; 855 } 856 drbd_err(device, "Warn failed to drbd_rs_del_all() and to kmalloc(dw).\n"); 857 } 858 859 dt = (jiffies - device->rs_start - device->rs_paused) / HZ; 860 if (dt <= 0) 861 dt = 1; 862 863 db = device->rs_total; 864 /* adjust for verify start and stop sectors, respective reached position */ 865 if (device->state.conn == C_VERIFY_S || device->state.conn == C_VERIFY_T) 866 db -= device->ov_left; 867 868 dbdt = Bit2KB(db/dt); 869 device->rs_paused /= HZ; 870 871 if (!get_ldev(device)) 872 goto out; 873 874 ping_peer(device); 875 876 spin_lock_irq(&device->resource->req_lock); 877 os = drbd_read_state(device); 878 879 verify_done = (os.conn == C_VERIFY_S || os.conn == C_VERIFY_T); 880 881 /* This protects us against multiple calls (that can happen in the presence 882 of application IO), and against connectivity loss just before we arrive here. */ 883 if (os.conn <= C_CONNECTED) 884 goto out_unlock; 885 886 ns = os; 887 ns.conn = C_CONNECTED; 888 889 drbd_info(device, "%s done (total %lu sec; paused %lu sec; %lu K/sec)\n", 890 verify_done ? "Online verify" : "Resync", 891 dt + device->rs_paused, device->rs_paused, dbdt); 892 893 n_oos = drbd_bm_total_weight(device); 894 895 if (os.conn == C_VERIFY_S || os.conn == C_VERIFY_T) { 896 if (n_oos) { 897 drbd_alert(device, "Online verify found %lu %dk block out of sync!\n", 898 n_oos, Bit2KB(1)); 899 khelper_cmd = "out-of-sync"; 900 } 901 } else { 902 D_ASSERT(device, (n_oos - device->rs_failed) == 0); 903 904 if (os.conn == C_SYNC_TARGET || os.conn == C_PAUSED_SYNC_T) 905 khelper_cmd = "after-resync-target"; 906 907 if (device->use_csums && device->rs_total) { 908 const unsigned long s = device->rs_same_csum; 909 const unsigned long t = device->rs_total; 910 const int ratio = 911 (t == 0) ? 0 : 912 (t < 100000) ? ((s*100)/t) : (s/(t/100)); 913 drbd_info(device, "%u %% had equal checksums, eliminated: %luK; " 914 "transferred %luK total %luK\n", 915 ratio, 916 Bit2KB(device->rs_same_csum), 917 Bit2KB(device->rs_total - device->rs_same_csum), 918 Bit2KB(device->rs_total)); 919 } 920 } 921 922 if (device->rs_failed) { 923 drbd_info(device, " %lu failed blocks\n", device->rs_failed); 924 925 if (os.conn == C_SYNC_TARGET || os.conn == C_PAUSED_SYNC_T) { 926 ns.disk = D_INCONSISTENT; 927 ns.pdsk = D_UP_TO_DATE; 928 } else { 929 ns.disk = D_UP_TO_DATE; 930 ns.pdsk = D_INCONSISTENT; 931 } 932 } else { 933 ns.disk = D_UP_TO_DATE; 934 ns.pdsk = D_UP_TO_DATE; 935 936 if (os.conn == C_SYNC_TARGET || os.conn == C_PAUSED_SYNC_T) { 937 if (device->p_uuid) { 938 int i; 939 for (i = UI_BITMAP ; i <= UI_HISTORY_END ; i++) 940 _drbd_uuid_set(device, i, device->p_uuid[i]); 941 drbd_uuid_set(device, UI_BITMAP, device->ldev->md.uuid[UI_CURRENT]); 942 _drbd_uuid_set(device, UI_CURRENT, device->p_uuid[UI_CURRENT]); 943 } else { 944 drbd_err(device, "device->p_uuid is NULL! BUG\n"); 945 } 946 } 947 948 if (!(os.conn == C_VERIFY_S || os.conn == C_VERIFY_T)) { 949 /* for verify runs, we don't update uuids here, 950 * so there would be nothing to report. */ 951 drbd_uuid_set_bm(device, 0UL); 952 drbd_print_uuids(device, "updated UUIDs"); 953 if (device->p_uuid) { 954 /* Now the two UUID sets are equal, update what we 955 * know of the peer. */ 956 int i; 957 for (i = UI_CURRENT ; i <= UI_HISTORY_END ; i++) 958 device->p_uuid[i] = device->ldev->md.uuid[i]; 959 } 960 } 961 } 962 963 _drbd_set_state(device, ns, CS_VERBOSE, NULL); 964 out_unlock: 965 spin_unlock_irq(&device->resource->req_lock); 966 put_ldev(device); 967 out: 968 device->rs_total = 0; 969 device->rs_failed = 0; 970 device->rs_paused = 0; 971 972 /* reset start sector, if we reached end of device */ 973 if (verify_done && device->ov_left == 0) 974 device->ov_start_sector = 0; 975 976 drbd_md_sync(device); 977 978 if (khelper_cmd) 979 drbd_khelper(device, khelper_cmd); 980 981 return 1; 982 } 983 984 /* helper */ 985 static void move_to_net_ee_or_free(struct drbd_device *device, struct drbd_peer_request *peer_req) 986 { 987 if (drbd_peer_req_has_active_page(peer_req)) { 988 /* This might happen if sendpage() has not finished */ 989 int i = (peer_req->i.size + PAGE_SIZE -1) >> PAGE_SHIFT; 990 atomic_add(i, &device->pp_in_use_by_net); 991 atomic_sub(i, &device->pp_in_use); 992 spin_lock_irq(&device->resource->req_lock); 993 list_add_tail(&peer_req->w.list, &device->net_ee); 994 spin_unlock_irq(&device->resource->req_lock); 995 wake_up(&drbd_pp_wait); 996 } else 997 drbd_free_peer_req(device, peer_req); 998 } 999 1000 /** 1001 * w_e_end_data_req() - Worker callback, to send a P_DATA_REPLY packet in response to a P_DATA_REQUEST 1002 * @device: DRBD device. 1003 * @w: work object. 1004 * @cancel: The connection will be closed anyways 1005 */ 1006 int w_e_end_data_req(struct drbd_work *w, int cancel) 1007 { 1008 struct drbd_peer_request *peer_req = container_of(w, struct drbd_peer_request, w); 1009 struct drbd_peer_device *peer_device = peer_req->peer_device; 1010 struct drbd_device *device = peer_device->device; 1011 int err; 1012 1013 if (unlikely(cancel)) { 1014 drbd_free_peer_req(device, peer_req); 1015 dec_unacked(device); 1016 return 0; 1017 } 1018 1019 if (likely((peer_req->flags & EE_WAS_ERROR) == 0)) { 1020 err = drbd_send_block(peer_device, P_DATA_REPLY, peer_req); 1021 } else { 1022 if (__ratelimit(&drbd_ratelimit_state)) 1023 drbd_err(device, "Sending NegDReply. sector=%llus.\n", 1024 (unsigned long long)peer_req->i.sector); 1025 1026 err = drbd_send_ack(peer_device, P_NEG_DREPLY, peer_req); 1027 } 1028 1029 dec_unacked(device); 1030 1031 move_to_net_ee_or_free(device, peer_req); 1032 1033 if (unlikely(err)) 1034 drbd_err(device, "drbd_send_block() failed\n"); 1035 return err; 1036 } 1037 1038 /** 1039 * w_e_end_rsdata_req() - Worker callback to send a P_RS_DATA_REPLY packet in response to a P_RS_DATA_REQUEST 1040 * @w: work object. 1041 * @cancel: The connection will be closed anyways 1042 */ 1043 int w_e_end_rsdata_req(struct drbd_work *w, int cancel) 1044 { 1045 struct drbd_peer_request *peer_req = container_of(w, struct drbd_peer_request, w); 1046 struct drbd_peer_device *peer_device = peer_req->peer_device; 1047 struct drbd_device *device = peer_device->device; 1048 int err; 1049 1050 if (unlikely(cancel)) { 1051 drbd_free_peer_req(device, peer_req); 1052 dec_unacked(device); 1053 return 0; 1054 } 1055 1056 if (get_ldev_if_state(device, D_FAILED)) { 1057 drbd_rs_complete_io(device, peer_req->i.sector); 1058 put_ldev(device); 1059 } 1060 1061 if (device->state.conn == C_AHEAD) { 1062 err = drbd_send_ack(peer_device, P_RS_CANCEL, peer_req); 1063 } else if (likely((peer_req->flags & EE_WAS_ERROR) == 0)) { 1064 if (likely(device->state.pdsk >= D_INCONSISTENT)) { 1065 inc_rs_pending(device); 1066 err = drbd_send_block(peer_device, P_RS_DATA_REPLY, peer_req); 1067 } else { 1068 if (__ratelimit(&drbd_ratelimit_state)) 1069 drbd_err(device, "Not sending RSDataReply, " 1070 "partner DISKLESS!\n"); 1071 err = 0; 1072 } 1073 } else { 1074 if (__ratelimit(&drbd_ratelimit_state)) 1075 drbd_err(device, "Sending NegRSDReply. sector %llus.\n", 1076 (unsigned long long)peer_req->i.sector); 1077 1078 err = drbd_send_ack(peer_device, P_NEG_RS_DREPLY, peer_req); 1079 1080 /* update resync data with failure */ 1081 drbd_rs_failed_io(device, peer_req->i.sector, peer_req->i.size); 1082 } 1083 1084 dec_unacked(device); 1085 1086 move_to_net_ee_or_free(device, peer_req); 1087 1088 if (unlikely(err)) 1089 drbd_err(device, "drbd_send_block() failed\n"); 1090 return err; 1091 } 1092 1093 int w_e_end_csum_rs_req(struct drbd_work *w, int cancel) 1094 { 1095 struct drbd_peer_request *peer_req = container_of(w, struct drbd_peer_request, w); 1096 struct drbd_peer_device *peer_device = peer_req->peer_device; 1097 struct drbd_device *device = peer_device->device; 1098 struct digest_info *di; 1099 int digest_size; 1100 void *digest = NULL; 1101 int err, eq = 0; 1102 1103 if (unlikely(cancel)) { 1104 drbd_free_peer_req(device, peer_req); 1105 dec_unacked(device); 1106 return 0; 1107 } 1108 1109 if (get_ldev(device)) { 1110 drbd_rs_complete_io(device, peer_req->i.sector); 1111 put_ldev(device); 1112 } 1113 1114 di = peer_req->digest; 1115 1116 if (likely((peer_req->flags & EE_WAS_ERROR) == 0)) { 1117 /* quick hack to try to avoid a race against reconfiguration. 1118 * a real fix would be much more involved, 1119 * introducing more locking mechanisms */ 1120 if (peer_device->connection->csums_tfm) { 1121 digest_size = crypto_ahash_digestsize(peer_device->connection->csums_tfm); 1122 D_ASSERT(device, digest_size == di->digest_size); 1123 digest = kmalloc(digest_size, GFP_NOIO); 1124 } 1125 if (digest) { 1126 drbd_csum_ee(peer_device->connection->csums_tfm, peer_req, digest); 1127 eq = !memcmp(digest, di->digest, digest_size); 1128 kfree(digest); 1129 } 1130 1131 if (eq) { 1132 drbd_set_in_sync(device, peer_req->i.sector, peer_req->i.size); 1133 /* rs_same_csums unit is BM_BLOCK_SIZE */ 1134 device->rs_same_csum += peer_req->i.size >> BM_BLOCK_SHIFT; 1135 err = drbd_send_ack(peer_device, P_RS_IS_IN_SYNC, peer_req); 1136 } else { 1137 inc_rs_pending(device); 1138 peer_req->block_id = ID_SYNCER; /* By setting block_id, digest pointer becomes invalid! */ 1139 peer_req->flags &= ~EE_HAS_DIGEST; /* This peer request no longer has a digest pointer */ 1140 kfree(di); 1141 err = drbd_send_block(peer_device, P_RS_DATA_REPLY, peer_req); 1142 } 1143 } else { 1144 err = drbd_send_ack(peer_device, P_NEG_RS_DREPLY, peer_req); 1145 if (__ratelimit(&drbd_ratelimit_state)) 1146 drbd_err(device, "Sending NegDReply. I guess it gets messy.\n"); 1147 } 1148 1149 dec_unacked(device); 1150 move_to_net_ee_or_free(device, peer_req); 1151 1152 if (unlikely(err)) 1153 drbd_err(device, "drbd_send_block/ack() failed\n"); 1154 return err; 1155 } 1156 1157 int w_e_end_ov_req(struct drbd_work *w, int cancel) 1158 { 1159 struct drbd_peer_request *peer_req = container_of(w, struct drbd_peer_request, w); 1160 struct drbd_peer_device *peer_device = peer_req->peer_device; 1161 struct drbd_device *device = peer_device->device; 1162 sector_t sector = peer_req->i.sector; 1163 unsigned int size = peer_req->i.size; 1164 int digest_size; 1165 void *digest; 1166 int err = 0; 1167 1168 if (unlikely(cancel)) 1169 goto out; 1170 1171 digest_size = crypto_ahash_digestsize(peer_device->connection->verify_tfm); 1172 digest = kmalloc(digest_size, GFP_NOIO); 1173 if (!digest) { 1174 err = 1; /* terminate the connection in case the allocation failed */ 1175 goto out; 1176 } 1177 1178 if (likely(!(peer_req->flags & EE_WAS_ERROR))) 1179 drbd_csum_ee(peer_device->connection->verify_tfm, peer_req, digest); 1180 else 1181 memset(digest, 0, digest_size); 1182 1183 /* Free e and pages before send. 1184 * In case we block on congestion, we could otherwise run into 1185 * some distributed deadlock, if the other side blocks on 1186 * congestion as well, because our receiver blocks in 1187 * drbd_alloc_pages due to pp_in_use > max_buffers. */ 1188 drbd_free_peer_req(device, peer_req); 1189 peer_req = NULL; 1190 inc_rs_pending(device); 1191 err = drbd_send_drequest_csum(peer_device, sector, size, digest, digest_size, P_OV_REPLY); 1192 if (err) 1193 dec_rs_pending(device); 1194 kfree(digest); 1195 1196 out: 1197 if (peer_req) 1198 drbd_free_peer_req(device, peer_req); 1199 dec_unacked(device); 1200 return err; 1201 } 1202 1203 void drbd_ov_out_of_sync_found(struct drbd_device *device, sector_t sector, int size) 1204 { 1205 if (device->ov_last_oos_start + device->ov_last_oos_size == sector) { 1206 device->ov_last_oos_size += size>>9; 1207 } else { 1208 device->ov_last_oos_start = sector; 1209 device->ov_last_oos_size = size>>9; 1210 } 1211 drbd_set_out_of_sync(device, sector, size); 1212 } 1213 1214 int w_e_end_ov_reply(struct drbd_work *w, int cancel) 1215 { 1216 struct drbd_peer_request *peer_req = container_of(w, struct drbd_peer_request, w); 1217 struct drbd_peer_device *peer_device = peer_req->peer_device; 1218 struct drbd_device *device = peer_device->device; 1219 struct digest_info *di; 1220 void *digest; 1221 sector_t sector = peer_req->i.sector; 1222 unsigned int size = peer_req->i.size; 1223 int digest_size; 1224 int err, eq = 0; 1225 bool stop_sector_reached = false; 1226 1227 if (unlikely(cancel)) { 1228 drbd_free_peer_req(device, peer_req); 1229 dec_unacked(device); 1230 return 0; 1231 } 1232 1233 /* after "cancel", because after drbd_disconnect/drbd_rs_cancel_all 1234 * the resync lru has been cleaned up already */ 1235 if (get_ldev(device)) { 1236 drbd_rs_complete_io(device, peer_req->i.sector); 1237 put_ldev(device); 1238 } 1239 1240 di = peer_req->digest; 1241 1242 if (likely((peer_req->flags & EE_WAS_ERROR) == 0)) { 1243 digest_size = crypto_ahash_digestsize(peer_device->connection->verify_tfm); 1244 digest = kmalloc(digest_size, GFP_NOIO); 1245 if (digest) { 1246 drbd_csum_ee(peer_device->connection->verify_tfm, peer_req, digest); 1247 1248 D_ASSERT(device, digest_size == di->digest_size); 1249 eq = !memcmp(digest, di->digest, digest_size); 1250 kfree(digest); 1251 } 1252 } 1253 1254 /* Free peer_req and pages before send. 1255 * In case we block on congestion, we could otherwise run into 1256 * some distributed deadlock, if the other side blocks on 1257 * congestion as well, because our receiver blocks in 1258 * drbd_alloc_pages due to pp_in_use > max_buffers. */ 1259 drbd_free_peer_req(device, peer_req); 1260 if (!eq) 1261 drbd_ov_out_of_sync_found(device, sector, size); 1262 else 1263 ov_out_of_sync_print(device); 1264 1265 err = drbd_send_ack_ex(peer_device, P_OV_RESULT, sector, size, 1266 eq ? ID_IN_SYNC : ID_OUT_OF_SYNC); 1267 1268 dec_unacked(device); 1269 1270 --device->ov_left; 1271 1272 /* let's advance progress step marks only for every other megabyte */ 1273 if ((device->ov_left & 0x200) == 0x200) 1274 drbd_advance_rs_marks(device, device->ov_left); 1275 1276 stop_sector_reached = verify_can_do_stop_sector(device) && 1277 (sector + (size>>9)) >= device->ov_stop_sector; 1278 1279 if (device->ov_left == 0 || stop_sector_reached) { 1280 ov_out_of_sync_print(device); 1281 drbd_resync_finished(device); 1282 } 1283 1284 return err; 1285 } 1286 1287 /* FIXME 1288 * We need to track the number of pending barrier acks, 1289 * and to be able to wait for them. 1290 * See also comment in drbd_adm_attach before drbd_suspend_io. 1291 */ 1292 static int drbd_send_barrier(struct drbd_connection *connection) 1293 { 1294 struct p_barrier *p; 1295 struct drbd_socket *sock; 1296 1297 sock = &connection->data; 1298 p = conn_prepare_command(connection, sock); 1299 if (!p) 1300 return -EIO; 1301 p->barrier = connection->send.current_epoch_nr; 1302 p->pad = 0; 1303 connection->send.current_epoch_writes = 0; 1304 connection->send.last_sent_barrier_jif = jiffies; 1305 1306 return conn_send_command(connection, sock, P_BARRIER, sizeof(*p), NULL, 0); 1307 } 1308 1309 int w_send_write_hint(struct drbd_work *w, int cancel) 1310 { 1311 struct drbd_device *device = 1312 container_of(w, struct drbd_device, unplug_work); 1313 struct drbd_socket *sock; 1314 1315 if (cancel) 1316 return 0; 1317 sock = &first_peer_device(device)->connection->data; 1318 if (!drbd_prepare_command(first_peer_device(device), sock)) 1319 return -EIO; 1320 return drbd_send_command(first_peer_device(device), sock, P_UNPLUG_REMOTE, 0, NULL, 0); 1321 } 1322 1323 static void re_init_if_first_write(struct drbd_connection *connection, unsigned int epoch) 1324 { 1325 if (!connection->send.seen_any_write_yet) { 1326 connection->send.seen_any_write_yet = true; 1327 connection->send.current_epoch_nr = epoch; 1328 connection->send.current_epoch_writes = 0; 1329 connection->send.last_sent_barrier_jif = jiffies; 1330 } 1331 } 1332 1333 static void maybe_send_barrier(struct drbd_connection *connection, unsigned int epoch) 1334 { 1335 /* re-init if first write on this connection */ 1336 if (!connection->send.seen_any_write_yet) 1337 return; 1338 if (connection->send.current_epoch_nr != epoch) { 1339 if (connection->send.current_epoch_writes) 1340 drbd_send_barrier(connection); 1341 connection->send.current_epoch_nr = epoch; 1342 } 1343 } 1344 1345 int w_send_out_of_sync(struct drbd_work *w, int cancel) 1346 { 1347 struct drbd_request *req = container_of(w, struct drbd_request, w); 1348 struct drbd_device *device = req->device; 1349 struct drbd_peer_device *const peer_device = first_peer_device(device); 1350 struct drbd_connection *const connection = peer_device->connection; 1351 int err; 1352 1353 if (unlikely(cancel)) { 1354 req_mod(req, SEND_CANCELED); 1355 return 0; 1356 } 1357 req->pre_send_jif = jiffies; 1358 1359 /* this time, no connection->send.current_epoch_writes++; 1360 * If it was sent, it was the closing barrier for the last 1361 * replicated epoch, before we went into AHEAD mode. 1362 * No more barriers will be sent, until we leave AHEAD mode again. */ 1363 maybe_send_barrier(connection, req->epoch); 1364 1365 err = drbd_send_out_of_sync(peer_device, req); 1366 req_mod(req, OOS_HANDED_TO_NETWORK); 1367 1368 return err; 1369 } 1370 1371 /** 1372 * w_send_dblock() - Worker callback to send a P_DATA packet in order to mirror a write request 1373 * @w: work object. 1374 * @cancel: The connection will be closed anyways 1375 */ 1376 int w_send_dblock(struct drbd_work *w, int cancel) 1377 { 1378 struct drbd_request *req = container_of(w, struct drbd_request, w); 1379 struct drbd_device *device = req->device; 1380 struct drbd_peer_device *const peer_device = first_peer_device(device); 1381 struct drbd_connection *connection = peer_device->connection; 1382 int err; 1383 1384 if (unlikely(cancel)) { 1385 req_mod(req, SEND_CANCELED); 1386 return 0; 1387 } 1388 req->pre_send_jif = jiffies; 1389 1390 re_init_if_first_write(connection, req->epoch); 1391 maybe_send_barrier(connection, req->epoch); 1392 connection->send.current_epoch_writes++; 1393 1394 err = drbd_send_dblock(peer_device, req); 1395 req_mod(req, err ? SEND_FAILED : HANDED_OVER_TO_NETWORK); 1396 1397 return err; 1398 } 1399 1400 /** 1401 * w_send_read_req() - Worker callback to send a read request (P_DATA_REQUEST) packet 1402 * @w: work object. 1403 * @cancel: The connection will be closed anyways 1404 */ 1405 int w_send_read_req(struct drbd_work *w, int cancel) 1406 { 1407 struct drbd_request *req = container_of(w, struct drbd_request, w); 1408 struct drbd_device *device = req->device; 1409 struct drbd_peer_device *const peer_device = first_peer_device(device); 1410 struct drbd_connection *connection = peer_device->connection; 1411 int err; 1412 1413 if (unlikely(cancel)) { 1414 req_mod(req, SEND_CANCELED); 1415 return 0; 1416 } 1417 req->pre_send_jif = jiffies; 1418 1419 /* Even read requests may close a write epoch, 1420 * if there was any yet. */ 1421 maybe_send_barrier(connection, req->epoch); 1422 1423 err = drbd_send_drequest(peer_device, P_DATA_REQUEST, req->i.sector, req->i.size, 1424 (unsigned long)req); 1425 1426 req_mod(req, err ? SEND_FAILED : HANDED_OVER_TO_NETWORK); 1427 1428 return err; 1429 } 1430 1431 int w_restart_disk_io(struct drbd_work *w, int cancel) 1432 { 1433 struct drbd_request *req = container_of(w, struct drbd_request, w); 1434 struct drbd_device *device = req->device; 1435 1436 if (bio_data_dir(req->master_bio) == WRITE && req->rq_state & RQ_IN_ACT_LOG) 1437 drbd_al_begin_io(device, &req->i); 1438 1439 drbd_req_make_private_bio(req, req->master_bio); 1440 req->private_bio->bi_bdev = device->ldev->backing_bdev; 1441 generic_make_request(req->private_bio); 1442 1443 return 0; 1444 } 1445 1446 static int _drbd_may_sync_now(struct drbd_device *device) 1447 { 1448 struct drbd_device *odev = device; 1449 int resync_after; 1450 1451 while (1) { 1452 if (!odev->ldev || odev->state.disk == D_DISKLESS) 1453 return 1; 1454 rcu_read_lock(); 1455 resync_after = rcu_dereference(odev->ldev->disk_conf)->resync_after; 1456 rcu_read_unlock(); 1457 if (resync_after == -1) 1458 return 1; 1459 odev = minor_to_device(resync_after); 1460 if (!odev) 1461 return 1; 1462 if ((odev->state.conn >= C_SYNC_SOURCE && 1463 odev->state.conn <= C_PAUSED_SYNC_T) || 1464 odev->state.aftr_isp || odev->state.peer_isp || 1465 odev->state.user_isp) 1466 return 0; 1467 } 1468 } 1469 1470 /** 1471 * drbd_pause_after() - Pause resync on all devices that may not resync now 1472 * @device: DRBD device. 1473 * 1474 * Called from process context only (admin command and after_state_ch). 1475 */ 1476 static bool drbd_pause_after(struct drbd_device *device) 1477 { 1478 bool changed = false; 1479 struct drbd_device *odev; 1480 int i; 1481 1482 rcu_read_lock(); 1483 idr_for_each_entry(&drbd_devices, odev, i) { 1484 if (odev->state.conn == C_STANDALONE && odev->state.disk == D_DISKLESS) 1485 continue; 1486 if (!_drbd_may_sync_now(odev) && 1487 _drbd_set_state(_NS(odev, aftr_isp, 1), 1488 CS_HARD, NULL) != SS_NOTHING_TO_DO) 1489 changed = true; 1490 } 1491 rcu_read_unlock(); 1492 1493 return changed; 1494 } 1495 1496 /** 1497 * drbd_resume_next() - Resume resync on all devices that may resync now 1498 * @device: DRBD device. 1499 * 1500 * Called from process context only (admin command and worker). 1501 */ 1502 static bool drbd_resume_next(struct drbd_device *device) 1503 { 1504 bool changed = false; 1505 struct drbd_device *odev; 1506 int i; 1507 1508 rcu_read_lock(); 1509 idr_for_each_entry(&drbd_devices, odev, i) { 1510 if (odev->state.conn == C_STANDALONE && odev->state.disk == D_DISKLESS) 1511 continue; 1512 if (odev->state.aftr_isp) { 1513 if (_drbd_may_sync_now(odev) && 1514 _drbd_set_state(_NS(odev, aftr_isp, 0), 1515 CS_HARD, NULL) != SS_NOTHING_TO_DO) 1516 changed = true; 1517 } 1518 } 1519 rcu_read_unlock(); 1520 return changed; 1521 } 1522 1523 void resume_next_sg(struct drbd_device *device) 1524 { 1525 lock_all_resources(); 1526 drbd_resume_next(device); 1527 unlock_all_resources(); 1528 } 1529 1530 void suspend_other_sg(struct drbd_device *device) 1531 { 1532 lock_all_resources(); 1533 drbd_pause_after(device); 1534 unlock_all_resources(); 1535 } 1536 1537 /* caller must lock_all_resources() */ 1538 enum drbd_ret_code drbd_resync_after_valid(struct drbd_device *device, int o_minor) 1539 { 1540 struct drbd_device *odev; 1541 int resync_after; 1542 1543 if (o_minor == -1) 1544 return NO_ERROR; 1545 if (o_minor < -1 || o_minor > MINORMASK) 1546 return ERR_RESYNC_AFTER; 1547 1548 /* check for loops */ 1549 odev = minor_to_device(o_minor); 1550 while (1) { 1551 if (odev == device) 1552 return ERR_RESYNC_AFTER_CYCLE; 1553 1554 /* You are free to depend on diskless, non-existing, 1555 * or not yet/no longer existing minors. 1556 * We only reject dependency loops. 1557 * We cannot follow the dependency chain beyond a detached or 1558 * missing minor. 1559 */ 1560 if (!odev || !odev->ldev || odev->state.disk == D_DISKLESS) 1561 return NO_ERROR; 1562 1563 rcu_read_lock(); 1564 resync_after = rcu_dereference(odev->ldev->disk_conf)->resync_after; 1565 rcu_read_unlock(); 1566 /* dependency chain ends here, no cycles. */ 1567 if (resync_after == -1) 1568 return NO_ERROR; 1569 1570 /* follow the dependency chain */ 1571 odev = minor_to_device(resync_after); 1572 } 1573 } 1574 1575 /* caller must lock_all_resources() */ 1576 void drbd_resync_after_changed(struct drbd_device *device) 1577 { 1578 int changed; 1579 1580 do { 1581 changed = drbd_pause_after(device); 1582 changed |= drbd_resume_next(device); 1583 } while (changed); 1584 } 1585 1586 void drbd_rs_controller_reset(struct drbd_device *device) 1587 { 1588 struct gendisk *disk = device->ldev->backing_bdev->bd_contains->bd_disk; 1589 struct fifo_buffer *plan; 1590 1591 atomic_set(&device->rs_sect_in, 0); 1592 atomic_set(&device->rs_sect_ev, 0); 1593 device->rs_in_flight = 0; 1594 device->rs_last_events = 1595 (int)part_stat_read(&disk->part0, sectors[0]) + 1596 (int)part_stat_read(&disk->part0, sectors[1]); 1597 1598 /* Updating the RCU protected object in place is necessary since 1599 this function gets called from atomic context. 1600 It is valid since all other updates also lead to an completely 1601 empty fifo */ 1602 rcu_read_lock(); 1603 plan = rcu_dereference(device->rs_plan_s); 1604 plan->total = 0; 1605 fifo_set(plan, 0); 1606 rcu_read_unlock(); 1607 } 1608 1609 void start_resync_timer_fn(unsigned long data) 1610 { 1611 struct drbd_device *device = (struct drbd_device *) data; 1612 drbd_device_post_work(device, RS_START); 1613 } 1614 1615 static void do_start_resync(struct drbd_device *device) 1616 { 1617 if (atomic_read(&device->unacked_cnt) || atomic_read(&device->rs_pending_cnt)) { 1618 drbd_warn(device, "postponing start_resync ...\n"); 1619 device->start_resync_timer.expires = jiffies + HZ/10; 1620 add_timer(&device->start_resync_timer); 1621 return; 1622 } 1623 1624 drbd_start_resync(device, C_SYNC_SOURCE); 1625 clear_bit(AHEAD_TO_SYNC_SOURCE, &device->flags); 1626 } 1627 1628 static bool use_checksum_based_resync(struct drbd_connection *connection, struct drbd_device *device) 1629 { 1630 bool csums_after_crash_only; 1631 rcu_read_lock(); 1632 csums_after_crash_only = rcu_dereference(connection->net_conf)->csums_after_crash_only; 1633 rcu_read_unlock(); 1634 return connection->agreed_pro_version >= 89 && /* supported? */ 1635 connection->csums_tfm && /* configured? */ 1636 (csums_after_crash_only == 0 /* use for each resync? */ 1637 || test_bit(CRASHED_PRIMARY, &device->flags)); /* or only after Primary crash? */ 1638 } 1639 1640 /** 1641 * drbd_start_resync() - Start the resync process 1642 * @device: DRBD device. 1643 * @side: Either C_SYNC_SOURCE or C_SYNC_TARGET 1644 * 1645 * This function might bring you directly into one of the 1646 * C_PAUSED_SYNC_* states. 1647 */ 1648 void drbd_start_resync(struct drbd_device *device, enum drbd_conns side) 1649 { 1650 struct drbd_peer_device *peer_device = first_peer_device(device); 1651 struct drbd_connection *connection = peer_device ? peer_device->connection : NULL; 1652 union drbd_state ns; 1653 int r; 1654 1655 if (device->state.conn >= C_SYNC_SOURCE && device->state.conn < C_AHEAD) { 1656 drbd_err(device, "Resync already running!\n"); 1657 return; 1658 } 1659 1660 if (!test_bit(B_RS_H_DONE, &device->flags)) { 1661 if (side == C_SYNC_TARGET) { 1662 /* Since application IO was locked out during C_WF_BITMAP_T and 1663 C_WF_SYNC_UUID we are still unmodified. Before going to C_SYNC_TARGET 1664 we check that we might make the data inconsistent. */ 1665 r = drbd_khelper(device, "before-resync-target"); 1666 r = (r >> 8) & 0xff; 1667 if (r > 0) { 1668 drbd_info(device, "before-resync-target handler returned %d, " 1669 "dropping connection.\n", r); 1670 conn_request_state(connection, NS(conn, C_DISCONNECTING), CS_HARD); 1671 return; 1672 } 1673 } else /* C_SYNC_SOURCE */ { 1674 r = drbd_khelper(device, "before-resync-source"); 1675 r = (r >> 8) & 0xff; 1676 if (r > 0) { 1677 if (r == 3) { 1678 drbd_info(device, "before-resync-source handler returned %d, " 1679 "ignoring. Old userland tools?", r); 1680 } else { 1681 drbd_info(device, "before-resync-source handler returned %d, " 1682 "dropping connection.\n", r); 1683 conn_request_state(connection, 1684 NS(conn, C_DISCONNECTING), CS_HARD); 1685 return; 1686 } 1687 } 1688 } 1689 } 1690 1691 if (current == connection->worker.task) { 1692 /* The worker should not sleep waiting for state_mutex, 1693 that can take long */ 1694 if (!mutex_trylock(device->state_mutex)) { 1695 set_bit(B_RS_H_DONE, &device->flags); 1696 device->start_resync_timer.expires = jiffies + HZ/5; 1697 add_timer(&device->start_resync_timer); 1698 return; 1699 } 1700 } else { 1701 mutex_lock(device->state_mutex); 1702 } 1703 1704 lock_all_resources(); 1705 clear_bit(B_RS_H_DONE, &device->flags); 1706 /* Did some connection breakage or IO error race with us? */ 1707 if (device->state.conn < C_CONNECTED 1708 || !get_ldev_if_state(device, D_NEGOTIATING)) { 1709 unlock_all_resources(); 1710 goto out; 1711 } 1712 1713 ns = drbd_read_state(device); 1714 1715 ns.aftr_isp = !_drbd_may_sync_now(device); 1716 1717 ns.conn = side; 1718 1719 if (side == C_SYNC_TARGET) 1720 ns.disk = D_INCONSISTENT; 1721 else /* side == C_SYNC_SOURCE */ 1722 ns.pdsk = D_INCONSISTENT; 1723 1724 r = _drbd_set_state(device, ns, CS_VERBOSE, NULL); 1725 ns = drbd_read_state(device); 1726 1727 if (ns.conn < C_CONNECTED) 1728 r = SS_UNKNOWN_ERROR; 1729 1730 if (r == SS_SUCCESS) { 1731 unsigned long tw = drbd_bm_total_weight(device); 1732 unsigned long now = jiffies; 1733 int i; 1734 1735 device->rs_failed = 0; 1736 device->rs_paused = 0; 1737 device->rs_same_csum = 0; 1738 device->rs_last_sect_ev = 0; 1739 device->rs_total = tw; 1740 device->rs_start = now; 1741 for (i = 0; i < DRBD_SYNC_MARKS; i++) { 1742 device->rs_mark_left[i] = tw; 1743 device->rs_mark_time[i] = now; 1744 } 1745 drbd_pause_after(device); 1746 /* Forget potentially stale cached per resync extent bit-counts. 1747 * Open coded drbd_rs_cancel_all(device), we already have IRQs 1748 * disabled, and know the disk state is ok. */ 1749 spin_lock(&device->al_lock); 1750 lc_reset(device->resync); 1751 device->resync_locked = 0; 1752 device->resync_wenr = LC_FREE; 1753 spin_unlock(&device->al_lock); 1754 } 1755 unlock_all_resources(); 1756 1757 if (r == SS_SUCCESS) { 1758 wake_up(&device->al_wait); /* for lc_reset() above */ 1759 /* reset rs_last_bcast when a resync or verify is started, 1760 * to deal with potential jiffies wrap. */ 1761 device->rs_last_bcast = jiffies - HZ; 1762 1763 drbd_info(device, "Began resync as %s (will sync %lu KB [%lu bits set]).\n", 1764 drbd_conn_str(ns.conn), 1765 (unsigned long) device->rs_total << (BM_BLOCK_SHIFT-10), 1766 (unsigned long) device->rs_total); 1767 if (side == C_SYNC_TARGET) { 1768 device->bm_resync_fo = 0; 1769 device->use_csums = use_checksum_based_resync(connection, device); 1770 } else { 1771 device->use_csums = 0; 1772 } 1773 1774 /* Since protocol 96, we must serialize drbd_gen_and_send_sync_uuid 1775 * with w_send_oos, or the sync target will get confused as to 1776 * how much bits to resync. We cannot do that always, because for an 1777 * empty resync and protocol < 95, we need to do it here, as we call 1778 * drbd_resync_finished from here in that case. 1779 * We drbd_gen_and_send_sync_uuid here for protocol < 96, 1780 * and from after_state_ch otherwise. */ 1781 if (side == C_SYNC_SOURCE && connection->agreed_pro_version < 96) 1782 drbd_gen_and_send_sync_uuid(peer_device); 1783 1784 if (connection->agreed_pro_version < 95 && device->rs_total == 0) { 1785 /* This still has a race (about when exactly the peers 1786 * detect connection loss) that can lead to a full sync 1787 * on next handshake. In 8.3.9 we fixed this with explicit 1788 * resync-finished notifications, but the fix 1789 * introduces a protocol change. Sleeping for some 1790 * time longer than the ping interval + timeout on the 1791 * SyncSource, to give the SyncTarget the chance to 1792 * detect connection loss, then waiting for a ping 1793 * response (implicit in drbd_resync_finished) reduces 1794 * the race considerably, but does not solve it. */ 1795 if (side == C_SYNC_SOURCE) { 1796 struct net_conf *nc; 1797 int timeo; 1798 1799 rcu_read_lock(); 1800 nc = rcu_dereference(connection->net_conf); 1801 timeo = nc->ping_int * HZ + nc->ping_timeo * HZ / 9; 1802 rcu_read_unlock(); 1803 schedule_timeout_interruptible(timeo); 1804 } 1805 drbd_resync_finished(device); 1806 } 1807 1808 drbd_rs_controller_reset(device); 1809 /* ns.conn may already be != device->state.conn, 1810 * we may have been paused in between, or become paused until 1811 * the timer triggers. 1812 * No matter, that is handled in resync_timer_fn() */ 1813 if (ns.conn == C_SYNC_TARGET) 1814 mod_timer(&device->resync_timer, jiffies); 1815 1816 drbd_md_sync(device); 1817 } 1818 put_ldev(device); 1819 out: 1820 mutex_unlock(device->state_mutex); 1821 } 1822 1823 static void update_on_disk_bitmap(struct drbd_device *device, bool resync_done) 1824 { 1825 struct sib_info sib = { .sib_reason = SIB_SYNC_PROGRESS, }; 1826 device->rs_last_bcast = jiffies; 1827 1828 if (!get_ldev(device)) 1829 return; 1830 1831 drbd_bm_write_lazy(device, 0); 1832 if (resync_done && is_sync_state(device->state.conn)) 1833 drbd_resync_finished(device); 1834 1835 drbd_bcast_event(device, &sib); 1836 /* update timestamp, in case it took a while to write out stuff */ 1837 device->rs_last_bcast = jiffies; 1838 put_ldev(device); 1839 } 1840 1841 static void drbd_ldev_destroy(struct drbd_device *device) 1842 { 1843 lc_destroy(device->resync); 1844 device->resync = NULL; 1845 lc_destroy(device->act_log); 1846 device->act_log = NULL; 1847 1848 __acquire(local); 1849 drbd_backing_dev_free(device, device->ldev); 1850 device->ldev = NULL; 1851 __release(local); 1852 1853 clear_bit(GOING_DISKLESS, &device->flags); 1854 wake_up(&device->misc_wait); 1855 } 1856 1857 static void go_diskless(struct drbd_device *device) 1858 { 1859 D_ASSERT(device, device->state.disk == D_FAILED); 1860 /* we cannot assert local_cnt == 0 here, as get_ldev_if_state will 1861 * inc/dec it frequently. Once we are D_DISKLESS, no one will touch 1862 * the protected members anymore, though, so once put_ldev reaches zero 1863 * again, it will be safe to free them. */ 1864 1865 /* Try to write changed bitmap pages, read errors may have just 1866 * set some bits outside the area covered by the activity log. 1867 * 1868 * If we have an IO error during the bitmap writeout, 1869 * we will want a full sync next time, just in case. 1870 * (Do we want a specific meta data flag for this?) 1871 * 1872 * If that does not make it to stable storage either, 1873 * we cannot do anything about that anymore. 1874 * 1875 * We still need to check if both bitmap and ldev are present, we may 1876 * end up here after a failed attach, before ldev was even assigned. 1877 */ 1878 if (device->bitmap && device->ldev) { 1879 /* An interrupted resync or similar is allowed to recounts bits 1880 * while we detach. 1881 * Any modifications would not be expected anymore, though. 1882 */ 1883 if (drbd_bitmap_io_from_worker(device, drbd_bm_write, 1884 "detach", BM_LOCKED_TEST_ALLOWED)) { 1885 if (test_bit(WAS_READ_ERROR, &device->flags)) { 1886 drbd_md_set_flag(device, MDF_FULL_SYNC); 1887 drbd_md_sync(device); 1888 } 1889 } 1890 } 1891 1892 drbd_force_state(device, NS(disk, D_DISKLESS)); 1893 } 1894 1895 static int do_md_sync(struct drbd_device *device) 1896 { 1897 drbd_warn(device, "md_sync_timer expired! Worker calls drbd_md_sync().\n"); 1898 drbd_md_sync(device); 1899 return 0; 1900 } 1901 1902 /* only called from drbd_worker thread, no locking */ 1903 void __update_timing_details( 1904 struct drbd_thread_timing_details *tdp, 1905 unsigned int *cb_nr, 1906 void *cb, 1907 const char *fn, const unsigned int line) 1908 { 1909 unsigned int i = *cb_nr % DRBD_THREAD_DETAILS_HIST; 1910 struct drbd_thread_timing_details *td = tdp + i; 1911 1912 td->start_jif = jiffies; 1913 td->cb_addr = cb; 1914 td->caller_fn = fn; 1915 td->line = line; 1916 td->cb_nr = *cb_nr; 1917 1918 i = (i+1) % DRBD_THREAD_DETAILS_HIST; 1919 td = tdp + i; 1920 memset(td, 0, sizeof(*td)); 1921 1922 ++(*cb_nr); 1923 } 1924 1925 static void do_device_work(struct drbd_device *device, const unsigned long todo) 1926 { 1927 if (test_bit(MD_SYNC, &todo)) 1928 do_md_sync(device); 1929 if (test_bit(RS_DONE, &todo) || 1930 test_bit(RS_PROGRESS, &todo)) 1931 update_on_disk_bitmap(device, test_bit(RS_DONE, &todo)); 1932 if (test_bit(GO_DISKLESS, &todo)) 1933 go_diskless(device); 1934 if (test_bit(DESTROY_DISK, &todo)) 1935 drbd_ldev_destroy(device); 1936 if (test_bit(RS_START, &todo)) 1937 do_start_resync(device); 1938 } 1939 1940 #define DRBD_DEVICE_WORK_MASK \ 1941 ((1UL << GO_DISKLESS) \ 1942 |(1UL << DESTROY_DISK) \ 1943 |(1UL << MD_SYNC) \ 1944 |(1UL << RS_START) \ 1945 |(1UL << RS_PROGRESS) \ 1946 |(1UL << RS_DONE) \ 1947 ) 1948 1949 static unsigned long get_work_bits(unsigned long *flags) 1950 { 1951 unsigned long old, new; 1952 do { 1953 old = *flags; 1954 new = old & ~DRBD_DEVICE_WORK_MASK; 1955 } while (cmpxchg(flags, old, new) != old); 1956 return old & DRBD_DEVICE_WORK_MASK; 1957 } 1958 1959 static void do_unqueued_work(struct drbd_connection *connection) 1960 { 1961 struct drbd_peer_device *peer_device; 1962 int vnr; 1963 1964 rcu_read_lock(); 1965 idr_for_each_entry(&connection->peer_devices, peer_device, vnr) { 1966 struct drbd_device *device = peer_device->device; 1967 unsigned long todo = get_work_bits(&device->flags); 1968 if (!todo) 1969 continue; 1970 1971 kref_get(&device->kref); 1972 rcu_read_unlock(); 1973 do_device_work(device, todo); 1974 kref_put(&device->kref, drbd_destroy_device); 1975 rcu_read_lock(); 1976 } 1977 rcu_read_unlock(); 1978 } 1979 1980 static bool dequeue_work_batch(struct drbd_work_queue *queue, struct list_head *work_list) 1981 { 1982 spin_lock_irq(&queue->q_lock); 1983 list_splice_tail_init(&queue->q, work_list); 1984 spin_unlock_irq(&queue->q_lock); 1985 return !list_empty(work_list); 1986 } 1987 1988 static void wait_for_work(struct drbd_connection *connection, struct list_head *work_list) 1989 { 1990 DEFINE_WAIT(wait); 1991 struct net_conf *nc; 1992 int uncork, cork; 1993 1994 dequeue_work_batch(&connection->sender_work, work_list); 1995 if (!list_empty(work_list)) 1996 return; 1997 1998 /* Still nothing to do? 1999 * Maybe we still need to close the current epoch, 2000 * even if no new requests are queued yet. 2001 * 2002 * Also, poke TCP, just in case. 2003 * Then wait for new work (or signal). */ 2004 rcu_read_lock(); 2005 nc = rcu_dereference(connection->net_conf); 2006 uncork = nc ? nc->tcp_cork : 0; 2007 rcu_read_unlock(); 2008 if (uncork) { 2009 mutex_lock(&connection->data.mutex); 2010 if (connection->data.socket) 2011 drbd_tcp_uncork(connection->data.socket); 2012 mutex_unlock(&connection->data.mutex); 2013 } 2014 2015 for (;;) { 2016 int send_barrier; 2017 prepare_to_wait(&connection->sender_work.q_wait, &wait, TASK_INTERRUPTIBLE); 2018 spin_lock_irq(&connection->resource->req_lock); 2019 spin_lock(&connection->sender_work.q_lock); /* FIXME get rid of this one? */ 2020 if (!list_empty(&connection->sender_work.q)) 2021 list_splice_tail_init(&connection->sender_work.q, work_list); 2022 spin_unlock(&connection->sender_work.q_lock); /* FIXME get rid of this one? */ 2023 if (!list_empty(work_list) || signal_pending(current)) { 2024 spin_unlock_irq(&connection->resource->req_lock); 2025 break; 2026 } 2027 2028 /* We found nothing new to do, no to-be-communicated request, 2029 * no other work item. We may still need to close the last 2030 * epoch. Next incoming request epoch will be connection -> 2031 * current transfer log epoch number. If that is different 2032 * from the epoch of the last request we communicated, it is 2033 * safe to send the epoch separating barrier now. 2034 */ 2035 send_barrier = 2036 atomic_read(&connection->current_tle_nr) != 2037 connection->send.current_epoch_nr; 2038 spin_unlock_irq(&connection->resource->req_lock); 2039 2040 if (send_barrier) 2041 maybe_send_barrier(connection, 2042 connection->send.current_epoch_nr + 1); 2043 2044 if (test_bit(DEVICE_WORK_PENDING, &connection->flags)) 2045 break; 2046 2047 /* drbd_send() may have called flush_signals() */ 2048 if (get_t_state(&connection->worker) != RUNNING) 2049 break; 2050 2051 schedule(); 2052 /* may be woken up for other things but new work, too, 2053 * e.g. if the current epoch got closed. 2054 * In which case we send the barrier above. */ 2055 } 2056 finish_wait(&connection->sender_work.q_wait, &wait); 2057 2058 /* someone may have changed the config while we have been waiting above. */ 2059 rcu_read_lock(); 2060 nc = rcu_dereference(connection->net_conf); 2061 cork = nc ? nc->tcp_cork : 0; 2062 rcu_read_unlock(); 2063 mutex_lock(&connection->data.mutex); 2064 if (connection->data.socket) { 2065 if (cork) 2066 drbd_tcp_cork(connection->data.socket); 2067 else if (!uncork) 2068 drbd_tcp_uncork(connection->data.socket); 2069 } 2070 mutex_unlock(&connection->data.mutex); 2071 } 2072 2073 int drbd_worker(struct drbd_thread *thi) 2074 { 2075 struct drbd_connection *connection = thi->connection; 2076 struct drbd_work *w = NULL; 2077 struct drbd_peer_device *peer_device; 2078 LIST_HEAD(work_list); 2079 int vnr; 2080 2081 while (get_t_state(thi) == RUNNING) { 2082 drbd_thread_current_set_cpu(thi); 2083 2084 if (list_empty(&work_list)) { 2085 update_worker_timing_details(connection, wait_for_work); 2086 wait_for_work(connection, &work_list); 2087 } 2088 2089 if (test_and_clear_bit(DEVICE_WORK_PENDING, &connection->flags)) { 2090 update_worker_timing_details(connection, do_unqueued_work); 2091 do_unqueued_work(connection); 2092 } 2093 2094 if (signal_pending(current)) { 2095 flush_signals(current); 2096 if (get_t_state(thi) == RUNNING) { 2097 drbd_warn(connection, "Worker got an unexpected signal\n"); 2098 continue; 2099 } 2100 break; 2101 } 2102 2103 if (get_t_state(thi) != RUNNING) 2104 break; 2105 2106 if (!list_empty(&work_list)) { 2107 w = list_first_entry(&work_list, struct drbd_work, list); 2108 list_del_init(&w->list); 2109 update_worker_timing_details(connection, w->cb); 2110 if (w->cb(w, connection->cstate < C_WF_REPORT_PARAMS) == 0) 2111 continue; 2112 if (connection->cstate >= C_WF_REPORT_PARAMS) 2113 conn_request_state(connection, NS(conn, C_NETWORK_FAILURE), CS_HARD); 2114 } 2115 } 2116 2117 do { 2118 if (test_and_clear_bit(DEVICE_WORK_PENDING, &connection->flags)) { 2119 update_worker_timing_details(connection, do_unqueued_work); 2120 do_unqueued_work(connection); 2121 } 2122 if (!list_empty(&work_list)) { 2123 w = list_first_entry(&work_list, struct drbd_work, list); 2124 list_del_init(&w->list); 2125 update_worker_timing_details(connection, w->cb); 2126 w->cb(w, 1); 2127 } else 2128 dequeue_work_batch(&connection->sender_work, &work_list); 2129 } while (!list_empty(&work_list) || test_bit(DEVICE_WORK_PENDING, &connection->flags)); 2130 2131 rcu_read_lock(); 2132 idr_for_each_entry(&connection->peer_devices, peer_device, vnr) { 2133 struct drbd_device *device = peer_device->device; 2134 D_ASSERT(device, device->state.disk == D_DISKLESS && device->state.conn == C_STANDALONE); 2135 kref_get(&device->kref); 2136 rcu_read_unlock(); 2137 drbd_device_cleanup(device); 2138 kref_put(&device->kref, drbd_destroy_device); 2139 rcu_read_lock(); 2140 } 2141 rcu_read_unlock(); 2142 2143 return 0; 2144 } 2145