drivers/block/drbd/drbd_actlog.c

   1 /*
   2    drbd_actlog.c
   3
   4    This file is part of DRBD by Philipp Reisner and Lars Ellenberg.
   5
   6    Copyright (C) 2003-2008, LINBIT Information Technologies GmbH.
   7    Copyright (C) 2003-2008, Philipp Reisner <philipp.reisner@linbit.com>.
   8    Copyright (C) 2003-2008, 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/slab.h>
  27 #include <linux/drbd.h>
  28 #include "drbd_int.h"
  29 #include "drbd_wrappers.h"
  30
  31 /* We maintain a trivial checksum in our on disk activity log.
  32  * With that we can ensure correct operation even when the storage
  33  * device might do a partial (last) sector write while losing power.
  34  */
  35 struct __packed al_transaction {
  36         u32       magic;
  37         u32       tr_number;
  38         struct __packed {
  39                 u32 pos;
  40                 u32 extent; } updates[1 + AL_EXTENTS_PT];
  41         u32       xor_sum;
  42 };
  43
  44 struct update_odbm_work {
  45         struct drbd_work w;
  46         unsigned int enr;
  47 };
  48
  49 struct update_al_work {
  50         struct drbd_work w;
  51         struct lc_element *al_ext;
  52         struct completion event;
  53         unsigned int enr;
  54         /* if old_enr != LC_FREE, write corresponding bitmap sector, too */
  55         unsigned int old_enr;
  56 };
  57
  58 struct drbd_atodb_wait {
  59         atomic_t           count;
  60         struct completion  io_done;
  61         struct drbd_conf   *mdev;
  62         int                error;
  63 };
  64
  65
  66 int w_al_write_transaction(struct drbd_conf *, struct drbd_work *, int);
  67
  68 void *drbd_md_get_buffer(struct drbd_conf *mdev)
  69 {
  70         int r;
  71
  72         wait_event(mdev->misc_wait,
  73                    (r = atomic_cmpxchg(&mdev->md_io_in_use, 0, 1)) == 0 ||
  74                    mdev->state.disk <= D_FAILED);
  75
  76         return r ? NULL : page_address(mdev->md_io_page);
  77 }
  78
  79 void drbd_md_put_buffer(struct drbd_conf *mdev)
  80 {
  81         if (atomic_dec_and_test(&mdev->md_io_in_use))
  82                 wake_up(&mdev->misc_wait);
  83 }
  84
  85 static bool md_io_allowed(struct drbd_conf *mdev)
  86 {
  87         enum drbd_disk_state ds = mdev->state.disk;
  88         return ds >= D_NEGOTIATING || ds == D_ATTACHING;
  89 }
  90
  91 void wait_until_done_or_disk_failure(struct drbd_conf *mdev, struct drbd_backing_dev *bdev,
  92                                      unsigned int *done)
  93 {
  94         long dt = bdev->dc.disk_timeout * HZ / 10;
  95         if (dt == 0)
  96                 dt = MAX_SCHEDULE_TIMEOUT;
  97
  98         dt = wait_event_timeout(mdev->misc_wait, *done || !md_io_allowed(mdev), dt);
  99         if (dt == 0)
 100                 dev_err(DEV, "meta-data IO operation timed out\n");
 101 }
 102
 103 static int _drbd_md_sync_page_io(struct drbd_conf *mdev,
 104                                  struct drbd_backing_dev *bdev,
 105                                  struct page *page, sector_t sector,
 106                                  int rw, int size)
 107 {
 108         struct bio *bio;
 109         int ok;
 110
 111         mdev->md_io.done = 0;
 112         mdev->md_io.error = -ENODEV;
 113
 114         if ((rw & WRITE) && !test_bit(MD_NO_FUA, &mdev->flags))
 115                 rw |= REQ_FUA | REQ_FLUSH;
 116         rw |= REQ_SYNC;
 117
 118         bio = bio_alloc_drbd(GFP_NOIO);
 119         bio->bi_bdev = bdev->md_bdev;
 120         bio->bi_sector = sector;
 121         ok = (bio_add_page(bio, page, size, 0) == size);
 122         if (!ok)
 123                 goto out;
 124         bio->bi_private = &mdev->md_io;
 125         bio->bi_end_io = drbd_md_io_complete;
 126         bio->bi_rw = rw;
 127
 128         if (!get_ldev_if_state(mdev, D_ATTACHING)) {  /* Corresponding put_ldev in drbd_md_io_complete() */
 129                 dev_err(DEV, "ASSERT FAILED: get_ldev_if_state() == 1 in _drbd_md_sync_page_io()\n");
 130                 ok = 0;
 131                 goto out;
 132         }
 133
 134         bio_get(bio); /* one bio_put() is in the completion handler */
 135         atomic_inc(&mdev->md_io_in_use); /* drbd_md_put_buffer() is in the completion handler */
 136         if (drbd_insert_fault(mdev, (rw & WRITE) ? DRBD_FAULT_MD_WR : DRBD_FAULT_MD_RD))
 137                 bio_endio(bio, -EIO);
 138         else
 139                 submit_bio(rw, bio);
 140         wait_until_done_or_disk_failure(mdev, bdev, &mdev->md_io.done);
 141         ok = bio_flagged(bio, BIO_UPTODATE) && mdev->md_io.error == 0;
 142
 143  out:
 144         bio_put(bio);
 145         return ok;
 146 }
 147
 148 int drbd_md_sync_page_io(struct drbd_conf *mdev, struct drbd_backing_dev *bdev,
 149                          sector_t sector, int rw)
 150 {
 151         int logical_block_size, mask, ok;
 152         int offset = 0;
 153         struct page *iop = mdev->md_io_page;
 154
 155         D_ASSERT(atomic_read(&mdev->md_io_in_use) == 1);
 156
 157         BUG_ON(!bdev->md_bdev);
 158
 159         logical_block_size = bdev_logical_block_size(bdev->md_bdev);
 160         if (logical_block_size == 0)
 161                 logical_block_size = MD_SECTOR_SIZE;
 162
 163         /* in case logical_block_size != 512 [ s390 only? ] */
 164         if (logical_block_size != MD_SECTOR_SIZE) {
 165                 mask = (logical_block_size / MD_SECTOR_SIZE) - 1;
 166                 D_ASSERT(mask == 1 || mask == 3 || mask == 7);
 167                 D_ASSERT(logical_block_size == (mask+1) * MD_SECTOR_SIZE);
 168                 offset = sector & mask;
 169                 sector = sector & ~mask;
 170                 iop = mdev->md_io_tmpp;
 171
 172                 if (rw & WRITE) {
 173                         /* these are GFP_KERNEL pages, pre-allocated
 174                          * on device initialization */
 175                         void *p = page_address(mdev->md_io_page);
 176                         void *hp = page_address(mdev->md_io_tmpp);
 177
 178                         ok = _drbd_md_sync_page_io(mdev, bdev, iop, sector,
 179                                         READ, logical_block_size);
 180
 181                         if (unlikely(!ok)) {
 182                                 dev_err(DEV, "drbd_md_sync_page_io(,%llus,"
 183                                     "READ [logical_block_size!=512]) failed!\n",
 184                                     (unsigned long long)sector);
 185                                 return 0;
 186                         }
 187
 188                         memcpy(hp + offset*MD_SECTOR_SIZE, p, MD_SECTOR_SIZE);
 189                 }
 190         }
 191
 192         if (sector < drbd_md_first_sector(bdev) ||
 193             sector > drbd_md_last_sector(bdev))
 194                 dev_alert(DEV, "%s [%d]:%s(,%llus,%s) out of range md access!\n",
 195                      current->comm, current->pid, __func__,
 196                      (unsigned long long)sector, (rw & WRITE) ? "WRITE" : "READ");
 197
 198         ok = _drbd_md_sync_page_io(mdev, bdev, iop, sector, rw, logical_block_size);
 199         if (unlikely(!ok)) {
 200                 dev_err(DEV, "drbd_md_sync_page_io(,%llus,%s) failed!\n",
 201                     (unsigned long long)sector, (rw & WRITE) ? "WRITE" : "READ");
 202                 return 0;
 203         }
 204
 205         if (logical_block_size != MD_SECTOR_SIZE && !(rw & WRITE)) {
 206                 void *p = page_address(mdev->md_io_page);
 207                 void *hp = page_address(mdev->md_io_tmpp);
 208
 209                 memcpy(p, hp + offset*MD_SECTOR_SIZE, MD_SECTOR_SIZE);
 210         }
 211
 212         return ok;
 213 }
 214
 215 static struct lc_element *_al_get(struct drbd_conf *mdev, unsigned int enr)
 216 {
 217         struct lc_element *al_ext;
 218         struct lc_element *tmp;
 219         unsigned long     al_flags = 0;
 220         int wake;
 221
 222         spin_lock_irq(&mdev->al_lock);
 223         tmp = lc_find(mdev->resync, enr/AL_EXT_PER_BM_SECT);
 224         if (unlikely(tmp != NULL)) {
 225                 struct bm_extent  *bm_ext = lc_entry(tmp, struct bm_extent, lce);
 226                 if (test_bit(BME_NO_WRITES, &bm_ext->flags)) {
 227                         wake = !test_and_set_bit(BME_PRIORITY, &bm_ext->flags);
 228                         spin_unlock_irq(&mdev->al_lock);
 229                         if (wake)
 230                                 wake_up(&mdev->al_wait);
 231                         return NULL;
 232                 }
 233         }
 234         al_ext   = lc_get(mdev->act_log, enr);
 235         al_flags = mdev->act_log->flags;
 236         spin_unlock_irq(&mdev->al_lock);
 237
 238         /*
 239         if (!al_ext) {
 240                 if (al_flags & LC_STARVING)
 241                         dev_warn(DEV, "Have to wait for LRU element (AL too small?)\n");
 242                 if (al_flags & LC_DIRTY)
 243                         dev_warn(DEV, "Ongoing AL update (AL device too slow?)\n");
 244         }
 245         */
 246
 247         return al_ext;
 248 }
 249
 250 void drbd_al_begin_io(struct drbd_conf *mdev, sector_t sector)
 251 {
 252         unsigned int enr = (sector >> (AL_EXTENT_SHIFT-9));
 253         struct lc_element *al_ext;
 254         struct update_al_work al_work;
 255
 256         D_ASSERT(atomic_read(&mdev->local_cnt) > 0);
 257
 258         wait_event(mdev->al_wait, (al_ext = _al_get(mdev, enr)));
 259
 260         if (al_ext->lc_number != enr) {
 261                 /* drbd_al_write_transaction(mdev,al_ext,enr);
 262                  * recurses into generic_make_request(), which
 263                  * disallows recursion, bios being serialized on the
 264                  * current->bio_tail list now.
 265                  * we have to delegate updates to the activity log
 266                  * to the worker thread. */
 267                 init_completion(&al_work.event);
 268                 al_work.al_ext = al_ext;
 269                 al_work.enr = enr;
 270                 al_work.old_enr = al_ext->lc_number;
 271                 al_work.w.cb = w_al_write_transaction;
 272                 drbd_queue_work_front(&mdev->data.work, &al_work.w);
 273                 wait_for_completion(&al_work.event);
 274
 275                 mdev->al_writ_cnt++;
 276
 277                 spin_lock_irq(&mdev->al_lock);
 278                 lc_changed(mdev->act_log, al_ext);
 279                 spin_unlock_irq(&mdev->al_lock);
 280                 wake_up(&mdev->al_wait);
 281         }
 282 }
 283
 284 void drbd_al_complete_io(struct drbd_conf *mdev, sector_t sector)
 285 {
 286         unsigned int enr = (sector >> (AL_EXTENT_SHIFT-9));
 287         struct lc_element *extent;
 288         unsigned long flags;
 289
 290         spin_lock_irqsave(&mdev->al_lock, flags);
 291
 292         extent = lc_find(mdev->act_log, enr);
 293
 294         if (!extent) {
 295                 spin_unlock_irqrestore(&mdev->al_lock, flags);
 296                 dev_err(DEV, "al_complete_io() called on inactive extent %u\n", enr);
 297                 return;
 298         }
 299
 300         if (lc_put(mdev->act_log, extent) == 0)
 301                 wake_up(&mdev->al_wait);
 302
 303         spin_unlock_irqrestore(&mdev->al_lock, flags);
 304 }
 305
 306 #if (PAGE_SHIFT + 3) < (AL_EXTENT_SHIFT - BM_BLOCK_SHIFT)
 307 /* Currently BM_BLOCK_SHIFT, BM_EXT_SHIFT and AL_EXTENT_SHIFT
 308  * are still coupled, or assume too much about their relation.
 309  * Code below will not work if this is violated.
 310  * Will be cleaned up with some followup patch.
 311  */
 312 # error FIXME
 313 #endif
 314
 315 static unsigned int al_extent_to_bm_page(unsigned int al_enr)
 316 {
 317         return al_enr >>
 318                 /* bit to page */
 319                 ((PAGE_SHIFT + 3) -
 320                 /* al extent number to bit */
 321                  (AL_EXTENT_SHIFT - BM_BLOCK_SHIFT));
 322 }
 323
 324 static unsigned int rs_extent_to_bm_page(unsigned int rs_enr)
 325 {
 326         return rs_enr >>
 327                 /* bit to page */
 328                 ((PAGE_SHIFT + 3) -
 329                 /* al extent number to bit */
 330                  (BM_EXT_SHIFT - BM_BLOCK_SHIFT));
 331 }
 332
 333 int
 334 w_al_write_transaction(struct drbd_conf *mdev, struct drbd_work *w, int unused)
 335 {
 336         struct update_al_work *aw = container_of(w, struct update_al_work, w);
 337         struct lc_element *updated = aw->al_ext;
 338         const unsigned int new_enr = aw->enr;
 339         const unsigned int evicted = aw->old_enr;
 340         struct al_transaction *buffer;
 341         sector_t sector;
 342         int i, n, mx;
 343         unsigned int extent_nr;
 344         u32 xor_sum = 0;
 345
 346         if (!get_ldev(mdev)) {
 347                 dev_err(DEV,
 348                         "disk is %s, cannot start al transaction (-%d +%d)\n",
 349                         drbd_disk_str(mdev->state.disk), evicted, new_enr);
 350                 complete(&((struct update_al_work *)w)->event);
 351                 return 1;
 352         }
 353         /* do we have to do a bitmap write, first?
 354          * TODO reduce maximum latency:
 355          * submit both bios, then wait for both,
 356          * instead of doing two synchronous sector writes.
 357          * For now, we must not write the transaction,
 358          * if we cannot write out the bitmap of the evicted extent. */
 359         if (mdev->state.conn < C_CONNECTED && evicted != LC_FREE)
 360                 drbd_bm_write_page(mdev, al_extent_to_bm_page(evicted));
 361
 362         /* The bitmap write may have failed, causing a state change. */
 363         if (mdev->state.disk < D_INCONSISTENT) {
 364                 dev_err(DEV,
 365                         "disk is %s, cannot write al transaction (-%d +%d)\n",
 366                         drbd_disk_str(mdev->state.disk), evicted, new_enr);
 367                 complete(&((struct update_al_work *)w)->event);
 368                 put_ldev(mdev);
 369                 return 1;
 370         }
 371
 372         buffer = drbd_md_get_buffer(mdev); /* protects md_io_buffer, al_tr_cycle, ... */
 373         if (!buffer) {
 374                 dev_err(DEV, "disk failed while waiting for md_io buffer\n");
 375                 complete(&((struct update_al_work *)w)->event);
 376                 put_ldev(mdev);
 377                 return 1;
 378         }
 379
 380         buffer->magic = __constant_cpu_to_be32(DRBD_MAGIC);
 381         buffer->tr_number = cpu_to_be32(mdev->al_tr_number);
 382
 383         n = lc_index_of(mdev->act_log, updated);
 384
 385         buffer->updates[0].pos = cpu_to_be32(n);
 386         buffer->updates[0].extent = cpu_to_be32(new_enr);
 387
 388         xor_sum ^= new_enr;
 389
 390         mx = min_t(int, AL_EXTENTS_PT,
 391                    mdev->act_log->nr_elements - mdev->al_tr_cycle);
 392         for (i = 0; i < mx; i++) {
 393                 unsigned idx = mdev->al_tr_cycle + i;
 394                 extent_nr = lc_element_by_index(mdev->act_log, idx)->lc_number;
 395                 buffer->updates[i+1].pos = cpu_to_be32(idx);
 396                 buffer->updates[i+1].extent = cpu_to_be32(extent_nr);
 397                 xor_sum ^= extent_nr;
 398         }
 399         for (; i < AL_EXTENTS_PT; i++) {
 400                 buffer->updates[i+1].pos = __constant_cpu_to_be32(-1);
 401                 buffer->updates[i+1].extent = __constant_cpu_to_be32(LC_FREE);
 402                 xor_sum ^= LC_FREE;
 403         }
 404         mdev->al_tr_cycle += AL_EXTENTS_PT;
 405         if (mdev->al_tr_cycle >= mdev->act_log->nr_elements)
 406                 mdev->al_tr_cycle = 0;
 407
 408         buffer->xor_sum = cpu_to_be32(xor_sum);
 409
 410         sector =  mdev->ldev->md.md_offset
 411                 + mdev->ldev->md.al_offset + mdev->al_tr_pos;
 412
 413         if (!drbd_md_sync_page_io(mdev, mdev->ldev, sector, WRITE))
 414                 drbd_chk_io_error(mdev, 1, true);
 415
 416         if (++mdev->al_tr_pos >
 417             div_ceil(mdev->act_log->nr_elements, AL_EXTENTS_PT))
 418                 mdev->al_tr_pos = 0;
 419
 420         D_ASSERT(mdev->al_tr_pos < MD_AL_MAX_SIZE);
 421         mdev->al_tr_number++;
 422
 423         drbd_md_put_buffer(mdev);
 424
 425         complete(&((struct update_al_work *)w)->event);
 426         put_ldev(mdev);
 427
 428         return 1;
 429 }
 430
 431 /**
 432  * drbd_al_read_tr() - Read a single transaction from the on disk activity log
 433  * @mdev:       DRBD device.
 434  * @bdev:       Block device to read form.
 435  * @b:          pointer to an al_transaction.
 436  * @index:      On disk slot of the transaction to read.
 437  *
 438  * Returns -1 on IO error, 0 on checksum error and 1 upon success.
 439  */
 440 static int drbd_al_read_tr(struct drbd_conf *mdev,
 441                            struct drbd_backing_dev *bdev,
 442                            struct al_transaction *b,
 443                            int index)
 444 {
 445         sector_t sector;
 446         int rv, i;
 447         u32 xor_sum = 0;
 448
 449         sector = bdev->md.md_offset + bdev->md.al_offset + index;
 450
 451         /* Dont process error normally,
 452          * as this is done before disk is attached! */
 453         if (!drbd_md_sync_page_io(mdev, bdev, sector, READ))
 454                 return -1;
 455
 456         rv = (be32_to_cpu(b->magic) == DRBD_MAGIC);
 457
 458         for (i = 0; i < AL_EXTENTS_PT + 1; i++)
 459                 xor_sum ^= be32_to_cpu(b->updates[i].extent);
 460         rv &= (xor_sum == be32_to_cpu(b->xor_sum));
 461
 462         return rv;
 463 }
 464
 465 /**
 466  * drbd_al_read_log() - Restores the activity log from its on disk representation.
 467  * @mdev:       DRBD device.
 468  * @bdev:       Block device to read form.
 469  *
 470  * Returns 1 on success, returns 0 when reading the log failed due to IO errors.
 471  */
 472 int drbd_al_read_log(struct drbd_conf *mdev, struct drbd_backing_dev *bdev)
 473 {
 474         struct al_transaction *buffer;
 475         int i;
 476         int rv;
 477         int mx;
 478         int active_extents = 0;
 479         int transactions = 0;
 480         int found_valid = 0;
 481         int from = 0;
 482         int to = 0;
 483         u32 from_tnr = 0;
 484         u32 to_tnr = 0;
 485         u32 cnr;
 486
 487         mx = div_ceil(mdev->act_log->nr_elements, AL_EXTENTS_PT);
 488
 489         /* lock out all other meta data io for now,
 490          * and make sure the page is mapped.
 491          */
 492         buffer = drbd_md_get_buffer(mdev);
 493         if (!buffer)
 494                 return 0;
 495
 496         /* Find the valid transaction in the log */
 497         for (i = 0; i <= mx; i++) {
 498                 rv = drbd_al_read_tr(mdev, bdev, buffer, i);
 499                 if (rv == 0)
 500                         continue;
 501                 if (rv == -1) {
 502                         drbd_md_put_buffer(mdev);
 503                         return 0;
 504                 }
 505                 cnr = be32_to_cpu(buffer->tr_number);
 506
 507                 if (++found_valid == 1) {
 508                         from = i;
 509                         to = i;
 510                         from_tnr = cnr;
 511                         to_tnr = cnr;
 512                         continue;
 513                 }
 514                 if ((int)cnr - (int)from_tnr < 0) {
 515                         D_ASSERT(from_tnr - cnr + i - from == mx+1);
 516                         from = i;
 517                         from_tnr = cnr;
 518                 }
 519                 if ((int)cnr - (int)to_tnr > 0) {
 520                         D_ASSERT(cnr - to_tnr == i - to);
 521                         to = i;
 522                         to_tnr = cnr;
 523                 }
 524         }
 525
 526         if (!found_valid) {
 527                 dev_warn(DEV, "No usable activity log found.\n");
 528                 drbd_md_put_buffer(mdev);
 529                 return 1;
 530         }
 531
 532         /* Read the valid transactions.
 533          * dev_info(DEV, "Reading from %d to %d.\n",from,to); */
 534         i = from;
 535         while (1) {
 536                 int j, pos;
 537                 unsigned int extent_nr;
 538                 unsigned int trn;
 539
 540                 rv = drbd_al_read_tr(mdev, bdev, buffer, i);
 541                 ERR_IF(rv == 0) goto cancel;
 542                 if (rv == -1) {
 543                         drbd_md_put_buffer(mdev);
 544                         return 0;
 545                 }
 546
 547                 trn = be32_to_cpu(buffer->tr_number);
 548
 549                 spin_lock_irq(&mdev->al_lock);
 550
 551                 /* This loop runs backwards because in the cyclic
 552                    elements there might be an old version of the
 553                    updated element (in slot 0). So the element in slot 0
 554                    can overwrite old versions. */
 555                 for (j = AL_EXTENTS_PT; j >= 0; j--) {
 556                         pos = be32_to_cpu(buffer->updates[j].pos);
 557                         extent_nr = be32_to_cpu(buffer->updates[j].extent);
 558
 559                         if (extent_nr == LC_FREE)
 560                                 continue;
 561
 562                         lc_set(mdev->act_log, extent_nr, pos);
 563                         active_extents++;
 564                 }
 565                 spin_unlock_irq(&mdev->al_lock);
 566
 567                 transactions++;
 568
 569 cancel:
 570                 if (i == to)
 571                         break;
 572                 i++;
 573                 if (i > mx)
 574                         i = 0;
 575         }
 576
 577         mdev->al_tr_number = to_tnr+1;
 578         mdev->al_tr_pos = to;
 579         if (++mdev->al_tr_pos >
 580             div_ceil(mdev->act_log->nr_elements, AL_EXTENTS_PT))
 581                 mdev->al_tr_pos = 0;
 582
 583         /* ok, we are done with it */
 584         drbd_md_put_buffer(mdev);
 585
 586         dev_info(DEV, "Found %d transactions (%d active extents) in activity log.\n",
 587              transactions, active_extents);
 588
 589         return 1;
 590 }
 591
 592 /**
 593  * drbd_al_apply_to_bm() - Sets the bitmap to diry(1) where covered ba active AL extents
 594  * @mdev:       DRBD device.
 595  */
 596 void drbd_al_apply_to_bm(struct drbd_conf *mdev)
 597 {
 598         unsigned int enr;
 599         unsigned long add = 0;
 600         char ppb[10];
 601         int i, tmp;
 602
 603         wait_event(mdev->al_wait, lc_try_lock(mdev->act_log));
 604
 605         for (i = 0; i < mdev->act_log->nr_elements; i++) {
 606                 enr = lc_element_by_index(mdev->act_log, i)->lc_number;
 607                 if (enr == LC_FREE)
 608                         continue;
 609                 tmp = drbd_bm_ALe_set_all(mdev, enr);
 610                 dynamic_dev_dbg(DEV, "AL: set %d bits in extent %u\n", tmp, enr);
 611                 add += tmp;
 612         }
 613
 614         lc_unlock(mdev->act_log);
 615         wake_up(&mdev->al_wait);
 616
 617         dev_info(DEV, "Marked additional %s as out-of-sync based on AL.\n",
 618              ppsize(ppb, Bit2KB(add)));
 619 }
 620
 621 static int _try_lc_del(struct drbd_conf *mdev, struct lc_element *al_ext)
 622 {
 623         int rv;
 624
 625         spin_lock_irq(&mdev->al_lock);
 626         rv = (al_ext->refcnt == 0);
 627         if (likely(rv))
 628                 lc_del(mdev->act_log, al_ext);
 629         spin_unlock_irq(&mdev->al_lock);
 630
 631         return rv;
 632 }
 633
 634 /**
 635  * drbd_al_shrink() - Removes all active extents form the activity log
 636  * @mdev:       DRBD device.
 637  *
 638  * Removes all active extents form the activity log, waiting until
 639  * the reference count of each entry dropped to 0 first, of course.
 640  *
 641  * You need to lock mdev->act_log with lc_try_lock() / lc_unlock()
 642  */
 643 void drbd_al_shrink(struct drbd_conf *mdev)
 644 {
 645         struct lc_element *al_ext;
 646         int i;
 647
 648         D_ASSERT(test_bit(__LC_DIRTY, &mdev->act_log->flags));
 649
 650         for (i = 0; i < mdev->act_log->nr_elements; i++) {
 651                 al_ext = lc_element_by_index(mdev->act_log, i);
 652                 if (al_ext->lc_number == LC_FREE)
 653                         continue;
 654                 wait_event(mdev->al_wait, _try_lc_del(mdev, al_ext));
 655         }
 656
 657         wake_up(&mdev->al_wait);
 658 }
 659
 660 static int w_update_odbm(struct drbd_conf *mdev, struct drbd_work *w, int unused)
 661 {
 662         struct update_odbm_work *udw = container_of(w, struct update_odbm_work, w);
 663
 664         if (!get_ldev(mdev)) {
 665                 if (__ratelimit(&drbd_ratelimit_state))
 666                         dev_warn(DEV, "Can not update on disk bitmap, local IO disabled.\n");
 667                 kfree(udw);
 668                 return 1;
 669         }
 670
 671         drbd_bm_write_page(mdev, rs_extent_to_bm_page(udw->enr));
 672         put_ldev(mdev);
 673
 674         kfree(udw);
 675
 676         if (drbd_bm_total_weight(mdev) <= mdev->rs_failed) {
 677                 switch (mdev->state.conn) {
 678                 case C_SYNC_SOURCE:  case C_SYNC_TARGET:
 679                 case C_PAUSED_SYNC_S: case C_PAUSED_SYNC_T:
 680                         drbd_resync_finished(mdev);
 681                 default:
 682                         /* nothing to do */
 683                         break;
 684                 }
 685         }
 686         drbd_bcast_sync_progress(mdev);
 687
 688         return 1;
 689 }
 690
 691
 692 /* ATTENTION. The AL's extents are 4MB each, while the extents in the
 693  * resync LRU-cache are 16MB each.
 694  * The caller of this function has to hold an get_ldev() reference.
 695  *
 696  * TODO will be obsoleted once we have a caching lru of the on disk bitmap
 697  */
 698 static void drbd_try_clear_on_disk_bm(struct drbd_conf *mdev, sector_t sector,
 699                                       int count, int success)
 700 {
 701         struct lc_element *e;
 702         struct update_odbm_work *udw;
 703
 704         unsigned int enr;
 705
 706         D_ASSERT(atomic_read(&mdev->local_cnt));
 707
 708         /* I simply assume that a sector/size pair never crosses
 709          * a 16 MB extent border. (Currently this is true...) */
 710         enr = BM_SECT_TO_EXT(sector);
 711
 712         e = lc_get(mdev->resync, enr);
 713         if (e) {
 714                 struct bm_extent *ext = lc_entry(e, struct bm_extent, lce);
 715                 if (ext->lce.lc_number == enr) {
 716                         if (success)
 717                                 ext->rs_left -= count;
 718                         else
 719                                 ext->rs_failed += count;
 720                         if (ext->rs_left < ext->rs_failed) {
 721                                 dev_warn(DEV, "BAD! sector=%llus enr=%u rs_left=%d "
 722                                     "rs_failed=%d count=%d cstate=%s\n",
 723                                      (unsigned long long)sector,
 724                                      ext->lce.lc_number, ext->rs_left,
 725                                      ext->rs_failed, count,
 726                                      drbd_conn_str(mdev->state.conn));
 727
 728                                 /* We don't expect to be able to clear more bits
 729                                  * than have been set when we originally counted
 730                                  * the set bits to cache that value in ext->rs_left.
 731                                  * Whatever the reason (disconnect during resync,
 732                                  * delayed local completion of an application write),
 733                                  * try to fix it up by recounting here. */
 734                                 ext->rs_left = drbd_bm_e_weight(mdev, enr);
 735                         }
 736                 } else {
 737                         /* Normally this element should be in the cache,
 738                          * since drbd_rs_begin_io() pulled it already in.
 739                          *
 740                          * But maybe an application write finished, and we set
 741                          * something outside the resync lru_cache in sync.
 742                          */
 743                         int rs_left = drbd_bm_e_weight(mdev, enr);
 744                         if (ext->flags != 0) {
 745                                 dev_warn(DEV, "changing resync lce: %d[%u;%02lx]"
 746                                      " -> %d[%u;00]\n",
 747                                      ext->lce.lc_number, ext->rs_left,
 748                                      ext->flags, enr, rs_left);
 749                                 ext->flags = 0;
 750                         }
 751                         if (ext->rs_failed) {
 752                                 dev_warn(DEV, "Kicking resync_lru element enr=%u "
 753                                      "out with rs_failed=%d\n",
 754                                      ext->lce.lc_number, ext->rs_failed);
 755                         }
 756                         ext->rs_left = rs_left;
 757                         ext->rs_failed = success ? 0 : count;
 758                         lc_changed(mdev->resync, &ext->lce);
 759                 }
 760                 lc_put(mdev->resync, &ext->lce);
 761                 /* no race, we are within the al_lock! */
 762
 763                 if (ext->rs_left == ext->rs_failed) {
 764                         ext->rs_failed = 0;
 765
 766                         udw = kmalloc(sizeof(*udw), GFP_ATOMIC);
 767                         if (udw) {
 768                                 udw->enr = ext->lce.lc_number;
 769                                 udw->w.cb = w_update_odbm;
 770                                 drbd_queue_work_front(&mdev->data.work, &udw->w);
 771                         } else {
 772                                 dev_warn(DEV, "Could not kmalloc an udw\n");
 773                         }
 774                 }
 775         } else {
 776                 dev_err(DEV, "lc_get() failed! locked=%d/%d flags=%lu\n",
 777                     mdev->resync_locked,
 778                     mdev->resync->nr_elements,
 779                     mdev->resync->flags);
 780         }
 781 }
 782
 783 void drbd_advance_rs_marks(struct drbd_conf *mdev, unsigned long still_to_go)
 784 {
 785         unsigned long now = jiffies;
 786         unsigned long last = mdev->rs_mark_time[mdev->rs_last_mark];
 787         int next = (mdev->rs_last_mark + 1) % DRBD_SYNC_MARKS;
 788         if (time_after_eq(now, last + DRBD_SYNC_MARK_STEP)) {
 789                 if (mdev->rs_mark_left[mdev->rs_last_mark] != still_to_go &&
 790                     mdev->state.conn != C_PAUSED_SYNC_T &&
 791                     mdev->state.conn != C_PAUSED_SYNC_S) {
 792                         mdev->rs_mark_time[next] = now;
 793                         mdev->rs_mark_left[next] = still_to_go;
 794                         mdev->rs_last_mark = next;
 795                 }
 796         }
 797 }
 798
 799 /* clear the bit corresponding to the piece of storage in question:
 800  * size byte of data starting from sector.  Only clear a bits of the affected
 801  * one ore more _aligned_ BM_BLOCK_SIZE blocks.
 802  *
 803  * called by worker on C_SYNC_TARGET and receiver on SyncSource.
 804  *
 805  */
 806 void __drbd_set_in_sync(struct drbd_conf *mdev, sector_t sector, int size,
 807                        const char *file, const unsigned int line)
 808 {
 809         /* Is called from worker and receiver context _only_ */
 810         unsigned long sbnr, ebnr, lbnr;
 811         unsigned long count = 0;
 812         sector_t esector, nr_sectors;
 813         int wake_up = 0;
 814         unsigned long flags;
 815
 816         if (size <= 0 || (size & 0x1ff) != 0 || size > DRBD_MAX_BIO_SIZE) {
 817                 dev_err(DEV, "drbd_set_in_sync: sector=%llus size=%d nonsense!\n",
 818                                 (unsigned long long)sector, size);
 819                 return;
 820         }
 821         nr_sectors = drbd_get_capacity(mdev->this_bdev);
 822         esector = sector + (size >> 9) - 1;
 823
 824         ERR_IF(sector >= nr_sectors) return;
 825         ERR_IF(esector >= nr_sectors) esector = (nr_sectors-1);
 826
 827         lbnr = BM_SECT_TO_BIT(nr_sectors-1);
 828
 829         /* we clear it (in sync).
 830          * round up start sector, round down end sector.  we make sure we only
 831          * clear full, aligned, BM_BLOCK_SIZE (4K) blocks */
 832         if (unlikely(esector < BM_SECT_PER_BIT-1))
 833                 return;
 834         if (unlikely(esector == (nr_sectors-1)))
 835                 ebnr = lbnr;
 836         else
 837                 ebnr = BM_SECT_TO_BIT(esector - (BM_SECT_PER_BIT-1));
 838         sbnr = BM_SECT_TO_BIT(sector + BM_SECT_PER_BIT-1);
 839
 840         if (sbnr > ebnr)
 841                 return;
 842
 843         /*
 844          * ok, (capacity & 7) != 0 sometimes, but who cares...
 845          * we count rs_{total,left} in bits, not sectors.
 846          */
 847         count = drbd_bm_clear_bits(mdev, sbnr, ebnr);
 848         if (count && get_ldev(mdev)) {
 849                 drbd_advance_rs_marks(mdev, drbd_bm_total_weight(mdev));
 850                 spin_lock_irqsave(&mdev->al_lock, flags);
 851                 drbd_try_clear_on_disk_bm(mdev, sector, count, true);
 852                 spin_unlock_irqrestore(&mdev->al_lock, flags);
 853
 854                 /* just wake_up unconditional now, various lc_chaged(),
 855                  * lc_put() in drbd_try_clear_on_disk_bm(). */
 856                 wake_up = 1;
 857                 put_ldev(mdev);
 858         }
 859         if (wake_up)
 860                 wake_up(&mdev->al_wait);
 861 }
 862
 863 /*
 864  * this is intended to set one request worth of data out of sync.
 865  * affects at least 1 bit,
 866  * and at most 1+DRBD_MAX_BIO_SIZE/BM_BLOCK_SIZE bits.
 867  *
 868  * called by tl_clear and drbd_send_dblock (==drbd_make_request).
 869  * so this can be _any_ process.
 870  */
 871 int __drbd_set_out_of_sync(struct drbd_conf *mdev, sector_t sector, int size,
 872                             const char *file, const unsigned int line)
 873 {
 874         unsigned long sbnr, ebnr, lbnr, flags;
 875         sector_t esector, nr_sectors;
 876         unsigned int enr, count = 0;
 877         struct lc_element *e;
 878
 879         if (size <= 0 || (size & 0x1ff) != 0 || size > DRBD_MAX_BIO_SIZE) {
 880                 dev_err(DEV, "sector: %llus, size: %d\n",
 881                         (unsigned long long)sector, size);
 882                 return 0;
 883         }
 884
 885         if (!get_ldev(mdev))
 886                 return 0; /* no disk, no metadata, no bitmap to set bits in */
 887
 888         nr_sectors = drbd_get_capacity(mdev->this_bdev);
 889         esector = sector + (size >> 9) - 1;
 890
 891         ERR_IF(sector >= nr_sectors)
 892                 goto out;
 893         ERR_IF(esector >= nr_sectors)
 894                 esector = (nr_sectors-1);
 895
 896         lbnr = BM_SECT_TO_BIT(nr_sectors-1);
 897
 898         /* we set it out of sync,
 899          * we do not need to round anything here */
 900         sbnr = BM_SECT_TO_BIT(sector);
 901         ebnr = BM_SECT_TO_BIT(esector);
 902
 903         /* ok, (capacity & 7) != 0 sometimes, but who cares...
 904          * we count rs_{total,left} in bits, not sectors.  */
 905         spin_lock_irqsave(&mdev->al_lock, flags);
 906         count = drbd_bm_set_bits(mdev, sbnr, ebnr);
 907
 908         enr = BM_SECT_TO_EXT(sector);
 909         e = lc_find(mdev->resync, enr);
 910         if (e)
 911                 lc_entry(e, struct bm_extent, lce)->rs_left += count;
 912         spin_unlock_irqrestore(&mdev->al_lock, flags);
 913
 914 out:
 915         put_ldev(mdev);
 916
 917         return count;
 918 }
 919
 920 static
 921 struct bm_extent *_bme_get(struct drbd_conf *mdev, unsigned int enr)
 922 {
 923         struct lc_element *e;
 924         struct bm_extent *bm_ext;
 925         int wakeup = 0;
 926         unsigned long rs_flags;
 927
 928         spin_lock_irq(&mdev->al_lock);
 929         if (mdev->resync_locked > mdev->resync->nr_elements/2) {
 930                 spin_unlock_irq(&mdev->al_lock);
 931                 return NULL;
 932         }
 933         e = lc_get(mdev->resync, enr);
 934         bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL;
 935         if (bm_ext) {
 936                 if (bm_ext->lce.lc_number != enr) {
 937                         bm_ext->rs_left = drbd_bm_e_weight(mdev, enr);
 938                         bm_ext->rs_failed = 0;
 939                         lc_changed(mdev->resync, &bm_ext->lce);
 940                         wakeup = 1;
 941                 }
 942                 if (bm_ext->lce.refcnt == 1)
 943                         mdev->resync_locked++;
 944                 set_bit(BME_NO_WRITES, &bm_ext->flags);
 945         }
 946         rs_flags = mdev->resync->flags;
 947         spin_unlock_irq(&mdev->al_lock);
 948         if (wakeup)
 949                 wake_up(&mdev->al_wait);
 950
 951         if (!bm_ext) {
 952                 if (rs_flags & LC_STARVING)
 953                         dev_warn(DEV, "Have to wait for element"
 954                              " (resync LRU too small?)\n");
 955                 BUG_ON(rs_flags & LC_DIRTY);
 956         }
 957
 958         return bm_ext;
 959 }
 960
 961 static int _is_in_al(struct drbd_conf *mdev, unsigned int enr)
 962 {
 963         struct lc_element *al_ext;
 964         int rv = 0;
 965
 966         spin_lock_irq(&mdev->al_lock);
 967         if (unlikely(enr == mdev->act_log->new_number))
 968                 rv = 1;
 969         else {
 970                 al_ext = lc_find(mdev->act_log, enr);
 971                 if (al_ext) {
 972                         if (al_ext->refcnt)
 973                                 rv = 1;
 974                 }
 975         }
 976         spin_unlock_irq(&mdev->al_lock);
 977
 978         /*
 979         if (unlikely(rv)) {
 980                 dev_info(DEV, "Delaying sync read until app's write is done\n");
 981         }
 982         */
 983         return rv;
 984 }
 985
 986 /**
 987  * drbd_rs_begin_io() - Gets an extent in the resync LRU cache and sets it to BME_LOCKED
 988  * @mdev:       DRBD device.
 989  * @sector:     The sector number.
 990  *
 991  * This functions sleeps on al_wait. Returns 0 on success, -EINTR if interrupted.
 992  */
 993 int drbd_rs_begin_io(struct drbd_conf *mdev, sector_t sector)
 994 {
 995         unsigned int enr = BM_SECT_TO_EXT(sector);
 996         struct bm_extent *bm_ext;
 997         int i, sig;
 998         int sa = 200; /* Step aside 200 times, then grab the extent and let app-IO wait.
 999                          200 times -> 20 seconds. */
1000
1001 retry:
1002         sig = wait_event_interruptible(mdev->al_wait,
1003                         (bm_ext = _bme_get(mdev, enr)));
1004         if (sig)
1005                 return -EINTR;
1006
1007         if (test_bit(BME_LOCKED, &bm_ext->flags))
1008                 return 0;
1009
1010         for (i = 0; i < AL_EXT_PER_BM_SECT; i++) {
1011                 sig = wait_event_interruptible(mdev->al_wait,
1012                                                !_is_in_al(mdev, enr * AL_EXT_PER_BM_SECT + i) ||
1013                                                test_bit(BME_PRIORITY, &bm_ext->flags));
1014
1015                 if (sig || (test_bit(BME_PRIORITY, &bm_ext->flags) && sa)) {
1016                         spin_lock_irq(&mdev->al_lock);
1017                         if (lc_put(mdev->resync, &bm_ext->lce) == 0) {
1018                                 bm_ext->flags = 0; /* clears BME_NO_WRITES and eventually BME_PRIORITY */
1019                                 mdev->resync_locked--;
1020                                 wake_up(&mdev->al_wait);
1021                         }
1022                         spin_unlock_irq(&mdev->al_lock);
1023                         if (sig)
1024                                 return -EINTR;
1025                         if (schedule_timeout_interruptible(HZ/10))
1026                                 return -EINTR;
1027                         if (sa && --sa == 0)
1028                                 dev_warn(DEV,"drbd_rs_begin_io() stepped aside for 20sec."
1029                                          "Resync stalled?\n");
1030                         goto retry;
1031                 }
1032         }
1033         set_bit(BME_LOCKED, &bm_ext->flags);
1034         return 0;
1035 }
1036
1037 /**
1038  * drbd_try_rs_begin_io() - Gets an extent in the resync LRU cache, does not sleep
1039  * @mdev:       DRBD device.
1040  * @sector:     The sector number.
1041  *
1042  * Gets an extent in the resync LRU cache, sets it to BME_NO_WRITES, then
1043  * tries to set it to BME_LOCKED. Returns 0 upon success, and -EAGAIN
1044  * if there is still application IO going on in this area.
1045  */
1046 int drbd_try_rs_begin_io(struct drbd_conf *mdev, sector_t sector)
1047 {
1048         unsigned int enr = BM_SECT_TO_EXT(sector);
1049         const unsigned int al_enr = enr*AL_EXT_PER_BM_SECT;
1050         struct lc_element *e;
1051         struct bm_extent *bm_ext;
1052         int i;
1053
1054         spin_lock_irq(&mdev->al_lock);
1055         if (mdev->resync_wenr != LC_FREE && mdev->resync_wenr != enr) {
1056                 /* in case you have very heavy scattered io, it may
1057                  * stall the syncer undefined if we give up the ref count
1058                  * when we try again and requeue.
1059                  *
1060                  * if we don't give up the refcount, but the next time
1061                  * we are scheduled this extent has been "synced" by new
1062                  * application writes, we'd miss the lc_put on the
1063                  * extent we keep the refcount on.
1064                  * so we remembered which extent we had to try again, and
1065                  * if the next requested one is something else, we do
1066                  * the lc_put here...
1067                  * we also have to wake_up
1068                  */
1069                 e = lc_find(mdev->resync, mdev->resync_wenr);
1070                 bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL;
1071                 if (bm_ext) {
1072                         D_ASSERT(!test_bit(BME_LOCKED, &bm_ext->flags));
1073                         D_ASSERT(test_bit(BME_NO_WRITES, &bm_ext->flags));
1074                         clear_bit(BME_NO_WRITES, &bm_ext->flags);
1075                         mdev->resync_wenr = LC_FREE;
1076                         if (lc_put(mdev->resync, &bm_ext->lce) == 0)
1077                                 mdev->resync_locked--;
1078                         wake_up(&mdev->al_wait);
1079                 } else {
1080                         dev_alert(DEV, "LOGIC BUG\n");
1081                 }
1082         }
1083         /* TRY. */
1084         e = lc_try_get(mdev->resync, enr);
1085         bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL;
1086         if (bm_ext) {
1087                 if (test_bit(BME_LOCKED, &bm_ext->flags))
1088                         goto proceed;
1089                 if (!test_and_set_bit(BME_NO_WRITES, &bm_ext->flags)) {
1090                         mdev->resync_locked++;
1091                 } else {
1092                         /* we did set the BME_NO_WRITES,
1093                          * but then could not set BME_LOCKED,
1094                          * so we tried again.
1095                          * drop the extra reference. */
1096                         bm_ext->lce.refcnt--;
1097                         D_ASSERT(bm_ext->lce.refcnt > 0);
1098                 }
1099                 goto check_al;
1100         } else {
1101                 /* do we rather want to try later? */
1102                 if (mdev->resync_locked > mdev->resync->nr_elements-3)
1103                         goto try_again;
1104                 /* Do or do not. There is no try. -- Yoda */
1105                 e = lc_get(mdev->resync, enr);
1106                 bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL;
1107                 if (!bm_ext) {
1108                         const unsigned long rs_flags = mdev->resync->flags;
1109                         if (rs_flags & LC_STARVING)
1110                                 dev_warn(DEV, "Have to wait for element"
1111                                      " (resync LRU too small?)\n");
1112                         BUG_ON(rs_flags & LC_DIRTY);
1113                         goto try_again;
1114                 }
1115                 if (bm_ext->lce.lc_number != enr) {
1116                         bm_ext->rs_left = drbd_bm_e_weight(mdev, enr);
1117                         bm_ext->rs_failed = 0;
1118                         lc_changed(mdev->resync, &bm_ext->lce);
1119                         wake_up(&mdev->al_wait);
1120                         D_ASSERT(test_bit(BME_LOCKED, &bm_ext->flags) == 0);
1121                 }
1122                 set_bit(BME_NO_WRITES, &bm_ext->flags);
1123                 D_ASSERT(bm_ext->lce.refcnt == 1);
1124                 mdev->resync_locked++;
1125                 goto check_al;
1126         }
1127 check_al:
1128         for (i = 0; i < AL_EXT_PER_BM_SECT; i++) {
1129                 if (unlikely(al_enr+i == mdev->act_log->new_number))
1130                         goto try_again;
1131                 if (lc_is_used(mdev->act_log, al_enr+i))
1132                         goto try_again;
1133         }
1134         set_bit(BME_LOCKED, &bm_ext->flags);
1135 proceed:
1136         mdev->resync_wenr = LC_FREE;
1137         spin_unlock_irq(&mdev->al_lock);
1138         return 0;
1139
1140 try_again:
1141         if (bm_ext)
1142                 mdev->resync_wenr = enr;
1143         spin_unlock_irq(&mdev->al_lock);
1144         return -EAGAIN;
1145 }
1146
1147 void drbd_rs_complete_io(struct drbd_conf *mdev, sector_t sector)
1148 {
1149         unsigned int enr = BM_SECT_TO_EXT(sector);
1150         struct lc_element *e;
1151         struct bm_extent *bm_ext;
1152         unsigned long flags;
1153
1154         spin_lock_irqsave(&mdev->al_lock, flags);
1155         e = lc_find(mdev->resync, enr);
1156         bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL;
1157         if (!bm_ext) {
1158                 spin_unlock_irqrestore(&mdev->al_lock, flags);
1159                 if (__ratelimit(&drbd_ratelimit_state))
1160                         dev_err(DEV, "drbd_rs_complete_io() called, but extent not found\n");
1161                 return;
1162         }
1163
1164         if (bm_ext->lce.refcnt == 0) {
1165                 spin_unlock_irqrestore(&mdev->al_lock, flags);
1166                 dev_err(DEV, "drbd_rs_complete_io(,%llu [=%u]) called, "
1167                     "but refcnt is 0!?\n",
1168                     (unsigned long long)sector, enr);
1169                 return;
1170         }
1171
1172         if (lc_put(mdev->resync, &bm_ext->lce) == 0) {
1173                 bm_ext->flags = 0; /* clear BME_LOCKED, BME_NO_WRITES and BME_PRIORITY */
1174                 mdev->resync_locked--;
1175                 wake_up(&mdev->al_wait);
1176         }
1177
1178         spin_unlock_irqrestore(&mdev->al_lock, flags);
1179 }
1180
1181 /**
1182  * drbd_rs_cancel_all() - Removes all extents from the resync LRU (even BME_LOCKED)
1183  * @mdev:       DRBD device.
1184  */
1185 void drbd_rs_cancel_all(struct drbd_conf *mdev)
1186 {
1187         spin_lock_irq(&mdev->al_lock);
1188
1189         if (get_ldev_if_state(mdev, D_FAILED)) { /* Makes sure ->resync is there. */
1190                 lc_reset(mdev->resync);
1191                 put_ldev(mdev);
1192         }
1193         mdev->resync_locked = 0;
1194         mdev->resync_wenr = LC_FREE;
1195         spin_unlock_irq(&mdev->al_lock);
1196         wake_up(&mdev->al_wait);
1197 }
1198
1199 /**
1200  * drbd_rs_del_all() - Gracefully remove all extents from the resync LRU
1201  * @mdev:       DRBD device.
1202  *
1203  * Returns 0 upon success, -EAGAIN if at least one reference count was
1204  * not zero.
1205  */
1206 int drbd_rs_del_all(struct drbd_conf *mdev)
1207 {
1208         struct lc_element *e;
1209         struct bm_extent *bm_ext;
1210         int i;
1211
1212         spin_lock_irq(&mdev->al_lock);
1213
1214         if (get_ldev_if_state(mdev, D_FAILED)) {
1215                 /* ok, ->resync is there. */
1216                 for (i = 0; i < mdev->resync->nr_elements; i++) {
1217                         e = lc_element_by_index(mdev->resync, i);
1218                         bm_ext = lc_entry(e, struct bm_extent, lce);
1219                         if (bm_ext->lce.lc_number == LC_FREE)
1220                                 continue;
1221                         if (bm_ext->lce.lc_number == mdev->resync_wenr) {
1222                                 dev_info(DEV, "dropping %u in drbd_rs_del_all, apparently"
1223                                      " got 'synced' by application io\n",
1224                                      mdev->resync_wenr);
1225                                 D_ASSERT(!test_bit(BME_LOCKED, &bm_ext->flags));
1226                                 D_ASSERT(test_bit(BME_NO_WRITES, &bm_ext->flags));
1227                                 clear_bit(BME_NO_WRITES, &bm_ext->flags);
1228                                 mdev->resync_wenr = LC_FREE;
1229                                 lc_put(mdev->resync, &bm_ext->lce);
1230                         }
1231                         if (bm_ext->lce.refcnt != 0) {
1232                                 dev_info(DEV, "Retrying drbd_rs_del_all() later. "
1233                                      "refcnt=%d\n", bm_ext->lce.refcnt);
1234                                 put_ldev(mdev);
1235                                 spin_unlock_irq(&mdev->al_lock);
1236                                 return -EAGAIN;
1237                         }
1238                         D_ASSERT(!test_bit(BME_LOCKED, &bm_ext->flags));
1239                         D_ASSERT(!test_bit(BME_NO_WRITES, &bm_ext->flags));
1240                         lc_del(mdev->resync, &bm_ext->lce);
1241                 }
1242                 D_ASSERT(mdev->resync->used == 0);
1243                 put_ldev(mdev);
1244         }
1245         spin_unlock_irq(&mdev->al_lock);
1246         wake_up(&mdev->al_wait);
1247
1248         return 0;
1249 }
1250
1251 /**
1252  * drbd_rs_failed_io() - Record information on a failure to resync the specified blocks
1253  * @mdev:       DRBD device.
1254  * @sector:     The sector number.
1255  * @size:       Size of failed IO operation, in byte.
1256  */
1257 void drbd_rs_failed_io(struct drbd_conf *mdev, sector_t sector, int size)
1258 {
1259         /* Is called from worker and receiver context _only_ */
1260         unsigned long sbnr, ebnr, lbnr;
1261         unsigned long count;
1262         sector_t esector, nr_sectors;
1263         int wake_up = 0;
1264
1265         if (size <= 0 || (size & 0x1ff) != 0 || size > DRBD_MAX_BIO_SIZE) {
1266                 dev_err(DEV, "drbd_rs_failed_io: sector=%llus size=%d nonsense!\n",
1267                                 (unsigned long long)sector, size);
1268                 return;
1269         }
1270         nr_sectors = drbd_get_capacity(mdev->this_bdev);
1271         esector = sector + (size >> 9) - 1;
1272
1273         ERR_IF(sector >= nr_sectors) return;
1274         ERR_IF(esector >= nr_sectors) esector = (nr_sectors-1);
1275
1276         lbnr = BM_SECT_TO_BIT(nr_sectors-1);
1277
1278         /*
1279          * round up start sector, round down end sector.  we make sure we only
1280          * handle full, aligned, BM_BLOCK_SIZE (4K) blocks */
1281         if (unlikely(esector < BM_SECT_PER_BIT-1))
1282                 return;
1283         if (unlikely(esector == (nr_sectors-1)))
1284                 ebnr = lbnr;
1285         else
1286                 ebnr = BM_SECT_TO_BIT(esector - (BM_SECT_PER_BIT-1));
1287         sbnr = BM_SECT_TO_BIT(sector + BM_SECT_PER_BIT-1);
1288
1289         if (sbnr > ebnr)
1290                 return;
1291
1292         /*
1293          * ok, (capacity & 7) != 0 sometimes, but who cares...
1294          * we count rs_{total,left} in bits, not sectors.
1295          */
1296         spin_lock_irq(&mdev->al_lock);
1297         count = drbd_bm_count_bits(mdev, sbnr, ebnr);
1298         if (count) {
1299                 mdev->rs_failed += count;
1300
1301                 if (get_ldev(mdev)) {
1302                         drbd_try_clear_on_disk_bm(mdev, sector, count, false);
1303                         put_ldev(mdev);
1304                 }
1305
1306                 /* just wake_up unconditional now, various lc_chaged(),
1307                  * lc_put() in drbd_try_clear_on_disk_bm(). */
1308                 wake_up = 1;
1309         }
1310         spin_unlock_irq(&mdev->al_lock);
1311         if (wake_up)
1312                 wake_up(&mdev->al_wait);
1313 }