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/crc32c.h>
  28 #include <linux/drbd.h>
  29 #include <linux/drbd_limits.h>
  30 #include <linux/dynamic_debug.h>
  31 #include "drbd_int.h"
  32 #include "drbd_wrappers.h"
  33
  34
  35 enum al_transaction_types {
  36         AL_TR_UPDATE = 0,
  37         AL_TR_INITIALIZED = 0xffff
  38 };
  39 /* all fields on disc in big endian */
  40 struct __packed al_transaction_on_disk {
  41         /* don't we all like magic */
  42         __be32  magic;
  43
  44         /* to identify the most recent transaction block
  45          * in the on disk ring buffer */
  46         __be32  tr_number;
  47
  48         /* checksum on the full 4k block, with this field set to 0. */
  49         __be32  crc32c;
  50
  51         /* type of transaction, special transaction types like:
  52          * purge-all, set-all-idle, set-all-active, ... to-be-defined
  53          * see also enum al_transaction_types */
  54         __be16  transaction_type;
  55
  56         /* we currently allow only a few thousand extents,
  57          * so 16bit will be enough for the slot number. */
  58
  59         /* how many updates in this transaction */
  60         __be16  n_updates;
  61
  62         /* maximum slot number, "al-extents" in drbd.conf speak.
  63          * Having this in each transaction should make reconfiguration
  64          * of that parameter easier. */
  65         __be16  context_size;
  66
  67         /* slot number the context starts with */
  68         __be16  context_start_slot_nr;
  69
  70         /* Some reserved bytes.  Expected usage is a 64bit counter of
  71          * sectors-written since device creation, and other data generation tag
  72          * supporting usage */
  73         __be32  __reserved[4];
  74
  75         /* --- 36 byte used --- */
  76
  77         /* Reserve space for up to AL_UPDATES_PER_TRANSACTION changes
  78          * in one transaction, then use the remaining byte in the 4k block for
  79          * context information.  "Flexible" number of updates per transaction
  80          * does not help, as we have to account for the case when all update
  81          * slots are used anyways, so it would only complicate code without
  82          * additional benefit.
  83          */
  84         __be16  update_slot_nr[AL_UPDATES_PER_TRANSACTION];
  85
  86         /* but the extent number is 32bit, which at an extent size of 4 MiB
  87          * allows to cover device sizes of up to 2**54 Byte (16 PiB) */
  88         __be32  update_extent_nr[AL_UPDATES_PER_TRANSACTION];
  89
  90         /* --- 420 bytes used (36 + 64*6) --- */
  91
  92         /* 4096 - 420 = 3676 = 919 * 4 */
  93         __be32  context[AL_CONTEXT_PER_TRANSACTION];
  94 };
  95
  96 struct update_odbm_work {
  97         struct drbd_work w;
  98         unsigned int enr;
  99 };
 100
 101 struct update_al_work {
 102         struct drbd_work w;
 103         struct completion event;
 104         int err;
 105 };
 106
 107 static int al_write_transaction(struct drbd_conf *mdev);
 108
 109 void *drbd_md_get_buffer(struct drbd_conf *mdev)
 110 {
 111         int r;
 112
 113         wait_event(mdev->misc_wait,
 114                    (r = atomic_cmpxchg(&mdev->md_io_in_use, 0, 1)) == 0 ||
 115                    mdev->state.disk <= D_FAILED);
 116
 117         return r ? NULL : page_address(mdev->md_io_page);
 118 }
 119
 120 void drbd_md_put_buffer(struct drbd_conf *mdev)
 121 {
 122         if (atomic_dec_and_test(&mdev->md_io_in_use))
 123                 wake_up(&mdev->misc_wait);
 124 }
 125
 126 void wait_until_done_or_force_detached(struct drbd_conf *mdev, struct drbd_backing_dev *bdev,
 127                                      unsigned int *done)
 128 {
 129         long dt;
 130
 131         rcu_read_lock();
 132         dt = rcu_dereference(bdev->disk_conf)->disk_timeout;
 133         rcu_read_unlock();
 134         dt = dt * HZ / 10;
 135         if (dt == 0)
 136                 dt = MAX_SCHEDULE_TIMEOUT;
 137
 138         dt = wait_event_timeout(mdev->misc_wait,
 139                         *done || test_bit(FORCE_DETACH, &mdev->flags), dt);
 140         if (dt == 0) {
 141                 dev_err(DEV, "meta-data IO operation timed out\n");
 142                 drbd_chk_io_error(mdev, 1, DRBD_FORCE_DETACH);
 143         }
 144 }
 145
 146 static int _drbd_md_sync_page_io(struct drbd_conf *mdev,
 147                                  struct drbd_backing_dev *bdev,
 148                                  struct page *page, sector_t sector,
 149                                  int rw, int size)
 150 {
 151         struct bio *bio;
 152         int err;
 153
 154         mdev->md_io.done = 0;
 155         mdev->md_io.error = -ENODEV;
 156
 157         if ((rw & WRITE) && !test_bit(MD_NO_FUA, &mdev->flags))
 158                 rw |= REQ_FUA | REQ_FLUSH;
 159         rw |= REQ_SYNC;
 160
 161         bio = bio_alloc_drbd(GFP_NOIO);
 162         bio->bi_bdev = bdev->md_bdev;
 163         bio->bi_sector = sector;
 164         err = -EIO;
 165         if (bio_add_page(bio, page, size, 0) != size)
 166                 goto out;
 167         bio->bi_private = &mdev->md_io;
 168         bio->bi_end_io = drbd_md_io_complete;
 169         bio->bi_rw = rw;
 170
 171         if (!get_ldev_if_state(mdev, D_ATTACHING)) {  /* Corresponding put_ldev in drbd_md_io_complete() */
 172                 dev_err(DEV, "ASSERT FAILED: get_ldev_if_state() == 1 in _drbd_md_sync_page_io()\n");
 173                 err = -ENODEV;
 174                 goto out;
 175         }
 176
 177         bio_get(bio); /* one bio_put() is in the completion handler */
 178         atomic_inc(&mdev->md_io_in_use); /* drbd_md_put_buffer() is in the completion handler */
 179         if (drbd_insert_fault(mdev, (rw & WRITE) ? DRBD_FAULT_MD_WR : DRBD_FAULT_MD_RD))
 180                 bio_endio(bio, -EIO);
 181         else
 182                 submit_bio(rw, bio);
 183         wait_until_done_or_force_detached(mdev, bdev, &mdev->md_io.done);
 184         if (bio_flagged(bio, BIO_UPTODATE))
 185                 err = mdev->md_io.error;
 186
 187  out:
 188         bio_put(bio);
 189         return err;
 190 }
 191
 192 int drbd_md_sync_page_io(struct drbd_conf *mdev, struct drbd_backing_dev *bdev,
 193                          sector_t sector, int rw)
 194 {
 195         int err;
 196         struct page *iop = mdev->md_io_page;
 197
 198         D_ASSERT(atomic_read(&mdev->md_io_in_use) == 1);
 199
 200         BUG_ON(!bdev->md_bdev);
 201
 202         dev_dbg(DEV, "meta_data io: %s [%d]:%s(,%llus,%s)\n",
 203              current->comm, current->pid, __func__,
 204              (unsigned long long)sector, (rw & WRITE) ? "WRITE" : "READ");
 205
 206         if (sector < drbd_md_first_sector(bdev) ||
 207             sector + 7 > drbd_md_last_sector(bdev))
 208                 dev_alert(DEV, "%s [%d]:%s(,%llus,%s) out of range md access!\n",
 209                      current->comm, current->pid, __func__,
 210                      (unsigned long long)sector, (rw & WRITE) ? "WRITE" : "READ");
 211
 212         err = _drbd_md_sync_page_io(mdev, bdev, iop, sector, rw, MD_BLOCK_SIZE);
 213         if (err) {
 214                 dev_err(DEV, "drbd_md_sync_page_io(,%llus,%s) failed with error %d\n",
 215                     (unsigned long long)sector, (rw & WRITE) ? "WRITE" : "READ", err);
 216         }
 217         return err;
 218 }
 219
 220 static struct lc_element *_al_get(struct drbd_conf *mdev, unsigned int enr)
 221 {
 222         struct lc_element *al_ext;
 223         struct lc_element *tmp;
 224         int wake;
 225
 226         spin_lock_irq(&mdev->al_lock);
 227         tmp = lc_find(mdev->resync, enr/AL_EXT_PER_BM_SECT);
 228         if (unlikely(tmp != NULL)) {
 229                 struct bm_extent  *bm_ext = lc_entry(tmp, struct bm_extent, lce);
 230                 if (test_bit(BME_NO_WRITES, &bm_ext->flags)) {
 231                         wake = !test_and_set_bit(BME_PRIORITY, &bm_ext->flags);
 232                         spin_unlock_irq(&mdev->al_lock);
 233                         if (wake)
 234                                 wake_up(&mdev->al_wait);
 235                         return NULL;
 236                 }
 237         }
 238         al_ext = lc_get(mdev->act_log, enr);
 239         spin_unlock_irq(&mdev->al_lock);
 240         return al_ext;
 241 }
 242
 243 void drbd_al_begin_io(struct drbd_conf *mdev, struct drbd_interval *i)
 244 {
 245         /* for bios crossing activity log extent boundaries,
 246          * we may need to activate two extents in one go */
 247         unsigned first = i->sector >> (AL_EXTENT_SHIFT-9);
 248         unsigned last = i->size == 0 ? first : (i->sector + (i->size >> 9) - 1) >> (AL_EXTENT_SHIFT-9);
 249         unsigned enr;
 250         bool locked = false;
 251
 252
 253         D_ASSERT(first <= last);
 254         D_ASSERT(atomic_read(&mdev->local_cnt) > 0);
 255
 256         for (enr = first; enr <= last; enr++)
 257                 wait_event(mdev->al_wait, _al_get(mdev, enr) != NULL);
 258
 259         /* Serialize multiple transactions.
 260          * This uses test_and_set_bit, memory barrier is implicit.
 261          */
 262         wait_event(mdev->al_wait,
 263                         mdev->act_log->pending_changes == 0 ||
 264                         (locked = lc_try_lock_for_transaction(mdev->act_log)));
 265
 266         if (locked) {
 267                 /* drbd_al_write_transaction(mdev,al_ext,enr);
 268                  * recurses into generic_make_request(), which
 269                  * disallows recursion, bios being serialized on the
 270                  * current->bio_tail list now.
 271                  * we have to delegate updates to the activity log
 272                  * to the worker thread. */
 273
 274                 /* Double check: it may have been committed by someone else,
 275                  * while we have been waiting for the lock. */
 276                 if (mdev->act_log->pending_changes) {
 277                         bool write_al_updates;
 278
 279                         rcu_read_lock();
 280                         write_al_updates = rcu_dereference(mdev->ldev->disk_conf)->al_updates;
 281                         rcu_read_unlock();
 282
 283                         if (write_al_updates) {
 284                                 al_write_transaction(mdev);
 285                                 mdev->al_writ_cnt++;
 286                         }
 287
 288                         spin_lock_irq(&mdev->al_lock);
 289                         /* FIXME
 290                         if (err)
 291                                 we need an "lc_cancel" here;
 292                         */
 293                         lc_committed(mdev->act_log);
 294                         spin_unlock_irq(&mdev->al_lock);
 295                 }
 296                 lc_unlock(mdev->act_log);
 297                 wake_up(&mdev->al_wait);
 298         }
 299 }
 300
 301 void drbd_al_complete_io(struct drbd_conf *mdev, struct drbd_interval *i)
 302 {
 303         /* for bios crossing activity log extent boundaries,
 304          * we may need to activate two extents in one go */
 305         unsigned first = i->sector >> (AL_EXTENT_SHIFT-9);
 306         unsigned last = i->size == 0 ? first : (i->sector + (i->size >> 9) - 1) >> (AL_EXTENT_SHIFT-9);
 307         unsigned enr;
 308         struct lc_element *extent;
 309         unsigned long flags;
 310
 311         D_ASSERT(first <= last);
 312         spin_lock_irqsave(&mdev->al_lock, flags);
 313
 314         for (enr = first; enr <= last; enr++) {
 315                 extent = lc_find(mdev->act_log, enr);
 316                 if (!extent) {
 317                         dev_err(DEV, "al_complete_io() called on inactive extent %u\n", enr);
 318                         continue;
 319                 }
 320                 lc_put(mdev->act_log, extent);
 321         }
 322         spin_unlock_irqrestore(&mdev->al_lock, flags);
 323         wake_up(&mdev->al_wait);
 324 }
 325
 326 #if (PAGE_SHIFT + 3) < (AL_EXTENT_SHIFT - BM_BLOCK_SHIFT)
 327 /* Currently BM_BLOCK_SHIFT, BM_EXT_SHIFT and AL_EXTENT_SHIFT
 328  * are still coupled, or assume too much about their relation.
 329  * Code below will not work if this is violated.
 330  * Will be cleaned up with some followup patch.
 331  */
 332 # error FIXME
 333 #endif
 334
 335 static unsigned int al_extent_to_bm_page(unsigned int al_enr)
 336 {
 337         return al_enr >>
 338                 /* bit to page */
 339                 ((PAGE_SHIFT + 3) -
 340                 /* al extent number to bit */
 341                  (AL_EXTENT_SHIFT - BM_BLOCK_SHIFT));
 342 }
 343
 344 static unsigned int rs_extent_to_bm_page(unsigned int rs_enr)
 345 {
 346         return rs_enr >>
 347                 /* bit to page */
 348                 ((PAGE_SHIFT + 3) -
 349                 /* resync extent number to bit */
 350                  (BM_EXT_SHIFT - BM_BLOCK_SHIFT));
 351 }
 352
 353 static int
 354 _al_write_transaction(struct drbd_conf *mdev)
 355 {
 356         struct al_transaction_on_disk *buffer;
 357         struct lc_element *e;
 358         sector_t sector;
 359         int i, mx;
 360         unsigned extent_nr;
 361         unsigned crc = 0;
 362         int err = 0;
 363
 364         if (!get_ldev(mdev)) {
 365                 dev_err(DEV, "disk is %s, cannot start al transaction\n",
 366                         drbd_disk_str(mdev->state.disk));
 367                 return -EIO;
 368         }
 369
 370         /* The bitmap write may have failed, causing a state change. */
 371         if (mdev->state.disk < D_INCONSISTENT) {
 372                 dev_err(DEV,
 373                         "disk is %s, cannot write al transaction\n",
 374                         drbd_disk_str(mdev->state.disk));
 375                 put_ldev(mdev);
 376                 return -EIO;
 377         }
 378
 379         buffer = drbd_md_get_buffer(mdev); /* protects md_io_buffer, al_tr_cycle, ... */
 380         if (!buffer) {
 381                 dev_err(DEV, "disk failed while waiting for md_io buffer\n");
 382                 put_ldev(mdev);
 383                 return -ENODEV;
 384         }
 385
 386         memset(buffer, 0, sizeof(*buffer));
 387         buffer->magic = cpu_to_be32(DRBD_AL_MAGIC);
 388         buffer->tr_number = cpu_to_be32(mdev->al_tr_number);
 389
 390         i = 0;
 391
 392         /* Even though no one can start to change this list
 393          * once we set the LC_LOCKED -- from drbd_al_begin_io(),
 394          * lc_try_lock_for_transaction() --, someone may still
 395          * be in the process of changing it. */
 396         spin_lock_irq(&mdev->al_lock);
 397         list_for_each_entry(e, &mdev->act_log->to_be_changed, list) {
 398                 if (i == AL_UPDATES_PER_TRANSACTION) {
 399                         i++;
 400                         break;
 401                 }
 402                 buffer->update_slot_nr[i] = cpu_to_be16(e->lc_index);
 403                 buffer->update_extent_nr[i] = cpu_to_be32(e->lc_new_number);
 404                 if (e->lc_number != LC_FREE)
 405                         drbd_bm_mark_for_writeout(mdev,
 406                                         al_extent_to_bm_page(e->lc_number));
 407                 i++;
 408         }
 409         spin_unlock_irq(&mdev->al_lock);
 410         BUG_ON(i > AL_UPDATES_PER_TRANSACTION);
 411
 412         buffer->n_updates = cpu_to_be16(i);
 413         for ( ; i < AL_UPDATES_PER_TRANSACTION; i++) {
 414                 buffer->update_slot_nr[i] = cpu_to_be16(-1);
 415                 buffer->update_extent_nr[i] = cpu_to_be32(LC_FREE);
 416         }
 417
 418         buffer->context_size = cpu_to_be16(mdev->act_log->nr_elements);
 419         buffer->context_start_slot_nr = cpu_to_be16(mdev->al_tr_cycle);
 420
 421         mx = min_t(int, AL_CONTEXT_PER_TRANSACTION,
 422                    mdev->act_log->nr_elements - mdev->al_tr_cycle);
 423         for (i = 0; i < mx; i++) {
 424                 unsigned idx = mdev->al_tr_cycle + i;
 425                 extent_nr = lc_element_by_index(mdev->act_log, idx)->lc_number;
 426                 buffer->context[i] = cpu_to_be32(extent_nr);
 427         }
 428         for (; i < AL_CONTEXT_PER_TRANSACTION; i++)
 429                 buffer->context[i] = cpu_to_be32(LC_FREE);
 430
 431         mdev->al_tr_cycle += AL_CONTEXT_PER_TRANSACTION;
 432         if (mdev->al_tr_cycle >= mdev->act_log->nr_elements)
 433                 mdev->al_tr_cycle = 0;
 434
 435         sector =  mdev->ldev->md.md_offset
 436                 + mdev->ldev->md.al_offset
 437                 + mdev->al_tr_pos * (MD_BLOCK_SIZE>>9);
 438
 439         crc = crc32c(0, buffer, 4096);
 440         buffer->crc32c = cpu_to_be32(crc);
 441
 442         if (drbd_bm_write_hinted(mdev))
 443                 err = -EIO;
 444                 /* drbd_chk_io_error done already */
 445         else if (drbd_md_sync_page_io(mdev, mdev->ldev, sector, WRITE)) {
 446                 err = -EIO;
 447                 drbd_chk_io_error(mdev, 1, DRBD_META_IO_ERROR);
 448         } else {
 449                 /* advance ringbuffer position and transaction counter */
 450                 mdev->al_tr_pos = (mdev->al_tr_pos + 1) % (MD_AL_SECTORS*512/MD_BLOCK_SIZE);
 451                 mdev->al_tr_number++;
 452         }
 453
 454         drbd_md_put_buffer(mdev);
 455         put_ldev(mdev);
 456
 457         return err;
 458 }
 459
 460
 461 static int w_al_write_transaction(struct drbd_work *w, int unused)
 462 {
 463         struct update_al_work *aw = container_of(w, struct update_al_work, w);
 464         struct drbd_conf *mdev = w->mdev;
 465         int err;
 466
 467         err = _al_write_transaction(mdev);
 468         aw->err = err;
 469         complete(&aw->event);
 470
 471         return err != -EIO ? err : 0;
 472 }
 473
 474 /* Calls from worker context (see w_restart_disk_io()) need to write the
 475    transaction directly. Others came through generic_make_request(),
 476    those need to delegate it to the worker. */
 477 static int al_write_transaction(struct drbd_conf *mdev)
 478 {
 479         struct update_al_work al_work;
 480
 481         if (current == mdev->tconn->worker.task)
 482                 return _al_write_transaction(mdev);
 483
 484         init_completion(&al_work.event);
 485         al_work.w.cb = w_al_write_transaction;
 486         al_work.w.mdev = mdev;
 487         drbd_queue_work_front(&mdev->tconn->sender_work, &al_work.w);
 488         wait_for_completion(&al_work.event);
 489
 490         return al_work.err;
 491 }
 492
 493 static int _try_lc_del(struct drbd_conf *mdev, struct lc_element *al_ext)
 494 {
 495         int rv;
 496
 497         spin_lock_irq(&mdev->al_lock);
 498         rv = (al_ext->refcnt == 0);
 499         if (likely(rv))
 500                 lc_del(mdev->act_log, al_ext);
 501         spin_unlock_irq(&mdev->al_lock);
 502
 503         return rv;
 504 }
 505
 506 /**
 507  * drbd_al_shrink() - Removes all active extents form the activity log
 508  * @mdev:       DRBD device.
 509  *
 510  * Removes all active extents form the activity log, waiting until
 511  * the reference count of each entry dropped to 0 first, of course.
 512  *
 513  * You need to lock mdev->act_log with lc_try_lock() / lc_unlock()
 514  */
 515 void drbd_al_shrink(struct drbd_conf *mdev)
 516 {
 517         struct lc_element *al_ext;
 518         int i;
 519
 520         D_ASSERT(test_bit(__LC_LOCKED, &mdev->act_log->flags));
 521
 522         for (i = 0; i < mdev->act_log->nr_elements; i++) {
 523                 al_ext = lc_element_by_index(mdev->act_log, i);
 524                 if (al_ext->lc_number == LC_FREE)
 525                         continue;
 526                 wait_event(mdev->al_wait, _try_lc_del(mdev, al_ext));
 527         }
 528
 529         wake_up(&mdev->al_wait);
 530 }
 531
 532 static int w_update_odbm(struct drbd_work *w, int unused)
 533 {
 534         struct update_odbm_work *udw = container_of(w, struct update_odbm_work, w);
 535         struct drbd_conf *mdev = w->mdev;
 536         struct sib_info sib = { .sib_reason = SIB_SYNC_PROGRESS, };
 537
 538         if (!get_ldev(mdev)) {
 539                 if (__ratelimit(&drbd_ratelimit_state))
 540                         dev_warn(DEV, "Can not update on disk bitmap, local IO disabled.\n");
 541                 kfree(udw);
 542                 return 0;
 543         }
 544
 545         drbd_bm_write_page(mdev, rs_extent_to_bm_page(udw->enr));
 546         put_ldev(mdev);
 547
 548         kfree(udw);
 549
 550         if (drbd_bm_total_weight(mdev) <= mdev->rs_failed) {
 551                 switch (mdev->state.conn) {
 552                 case C_SYNC_SOURCE:  case C_SYNC_TARGET:
 553                 case C_PAUSED_SYNC_S: case C_PAUSED_SYNC_T:
 554                         drbd_resync_finished(mdev);
 555                 default:
 556                         /* nothing to do */
 557                         break;
 558                 }
 559         }
 560         drbd_bcast_event(mdev, &sib);
 561
 562         return 0;
 563 }
 564
 565
 566 /* ATTENTION. The AL's extents are 4MB each, while the extents in the
 567  * resync LRU-cache are 16MB each.
 568  * The caller of this function has to hold an get_ldev() reference.
 569  *
 570  * TODO will be obsoleted once we have a caching lru of the on disk bitmap
 571  */
 572 static void drbd_try_clear_on_disk_bm(struct drbd_conf *mdev, sector_t sector,
 573                                       int count, int success)
 574 {
 575         struct lc_element *e;
 576         struct update_odbm_work *udw;
 577
 578         unsigned int enr;
 579
 580         D_ASSERT(atomic_read(&mdev->local_cnt));
 581
 582         /* I simply assume that a sector/size pair never crosses
 583          * a 16 MB extent border. (Currently this is true...) */
 584         enr = BM_SECT_TO_EXT(sector);
 585
 586         e = lc_get(mdev->resync, enr);
 587         if (e) {
 588                 struct bm_extent *ext = lc_entry(e, struct bm_extent, lce);
 589                 if (ext->lce.lc_number == enr) {
 590                         if (success)
 591                                 ext->rs_left -= count;
 592                         else
 593                                 ext->rs_failed += count;
 594                         if (ext->rs_left < ext->rs_failed) {
 595                                 dev_warn(DEV, "BAD! sector=%llus enr=%u rs_left=%d "
 596                                     "rs_failed=%d count=%d cstate=%s\n",
 597                                      (unsigned long long)sector,
 598                                      ext->lce.lc_number, ext->rs_left,
 599                                      ext->rs_failed, count,
 600                                      drbd_conn_str(mdev->state.conn));
 601
 602                                 /* We don't expect to be able to clear more bits
 603                                  * than have been set when we originally counted
 604                                  * the set bits to cache that value in ext->rs_left.
 605                                  * Whatever the reason (disconnect during resync,
 606                                  * delayed local completion of an application write),
 607                                  * try to fix it up by recounting here. */
 608                                 ext->rs_left = drbd_bm_e_weight(mdev, enr);
 609                         }
 610                 } else {
 611                         /* Normally this element should be in the cache,
 612                          * since drbd_rs_begin_io() pulled it already in.
 613                          *
 614                          * But maybe an application write finished, and we set
 615                          * something outside the resync lru_cache in sync.
 616                          */
 617                         int rs_left = drbd_bm_e_weight(mdev, enr);
 618                         if (ext->flags != 0) {
 619                                 dev_warn(DEV, "changing resync lce: %d[%u;%02lx]"
 620                                      " -> %d[%u;00]\n",
 621                                      ext->lce.lc_number, ext->rs_left,
 622                                      ext->flags, enr, rs_left);
 623                                 ext->flags = 0;
 624                         }
 625                         if (ext->rs_failed) {
 626                                 dev_warn(DEV, "Kicking resync_lru element enr=%u "
 627                                      "out with rs_failed=%d\n",
 628                                      ext->lce.lc_number, ext->rs_failed);
 629                         }
 630                         ext->rs_left = rs_left;
 631                         ext->rs_failed = success ? 0 : count;
 632                         /* we don't keep a persistent log of the resync lru,
 633                          * we can commit any change right away. */
 634                         lc_committed(mdev->resync);
 635                 }
 636                 lc_put(mdev->resync, &ext->lce);
 637                 /* no race, we are within the al_lock! */
 638
 639                 if (ext->rs_left == ext->rs_failed) {
 640                         ext->rs_failed = 0;
 641
 642                         udw = kmalloc(sizeof(*udw), GFP_ATOMIC);
 643                         if (udw) {
 644                                 udw->enr = ext->lce.lc_number;
 645                                 udw->w.cb = w_update_odbm;
 646                                 udw->w.mdev = mdev;
 647                                 drbd_queue_work_front(&mdev->tconn->sender_work, &udw->w);
 648                         } else {
 649                                 dev_warn(DEV, "Could not kmalloc an udw\n");
 650                         }
 651                 }
 652         } else {
 653                 dev_err(DEV, "lc_get() failed! locked=%d/%d flags=%lu\n",
 654                     mdev->resync_locked,
 655                     mdev->resync->nr_elements,
 656                     mdev->resync->flags);
 657         }
 658 }
 659
 660 void drbd_advance_rs_marks(struct drbd_conf *mdev, unsigned long still_to_go)
 661 {
 662         unsigned long now = jiffies;
 663         unsigned long last = mdev->rs_mark_time[mdev->rs_last_mark];
 664         int next = (mdev->rs_last_mark + 1) % DRBD_SYNC_MARKS;
 665         if (time_after_eq(now, last + DRBD_SYNC_MARK_STEP)) {
 666                 if (mdev->rs_mark_left[mdev->rs_last_mark] != still_to_go &&
 667                     mdev->state.conn != C_PAUSED_SYNC_T &&
 668                     mdev->state.conn != C_PAUSED_SYNC_S) {
 669                         mdev->rs_mark_time[next] = now;
 670                         mdev->rs_mark_left[next] = still_to_go;
 671                         mdev->rs_last_mark = next;
 672                 }
 673         }
 674 }
 675
 676 /* clear the bit corresponding to the piece of storage in question:
 677  * size byte of data starting from sector.  Only clear a bits of the affected
 678  * one ore more _aligned_ BM_BLOCK_SIZE blocks.
 679  *
 680  * called by worker on C_SYNC_TARGET and receiver on SyncSource.
 681  *
 682  */
 683 void __drbd_set_in_sync(struct drbd_conf *mdev, sector_t sector, int size,
 684                        const char *file, const unsigned int line)
 685 {
 686         /* Is called from worker and receiver context _only_ */
 687         unsigned long sbnr, ebnr, lbnr;
 688         unsigned long count = 0;
 689         sector_t esector, nr_sectors;
 690         int wake_up = 0;
 691         unsigned long flags;
 692
 693         if (size <= 0 || !IS_ALIGNED(size, 512) || size > DRBD_MAX_BIO_SIZE) {
 694                 dev_err(DEV, "drbd_set_in_sync: sector=%llus size=%d nonsense!\n",
 695                                 (unsigned long long)sector, size);
 696                 return;
 697         }
 698
 699         if (!get_ldev(mdev))
 700                 return; /* no disk, no metadata, no bitmap to clear bits in */
 701
 702         nr_sectors = drbd_get_capacity(mdev->this_bdev);
 703         esector = sector + (size >> 9) - 1;
 704
 705         if (!expect(sector < nr_sectors))
 706                 goto out;
 707         if (!expect(esector < nr_sectors))
 708                 esector = nr_sectors - 1;
 709
 710         lbnr = BM_SECT_TO_BIT(nr_sectors-1);
 711
 712         /* we clear it (in sync).
 713          * round up start sector, round down end sector.  we make sure we only
 714          * clear full, aligned, BM_BLOCK_SIZE (4K) blocks */
 715         if (unlikely(esector < BM_SECT_PER_BIT-1))
 716                 goto out;
 717         if (unlikely(esector == (nr_sectors-1)))
 718                 ebnr = lbnr;
 719         else
 720                 ebnr = BM_SECT_TO_BIT(esector - (BM_SECT_PER_BIT-1));
 721         sbnr = BM_SECT_TO_BIT(sector + BM_SECT_PER_BIT-1);
 722
 723         if (sbnr > ebnr)
 724                 goto out;
 725
 726         /*
 727          * ok, (capacity & 7) != 0 sometimes, but who cares...
 728          * we count rs_{total,left} in bits, not sectors.
 729          */
 730         count = drbd_bm_clear_bits(mdev, sbnr, ebnr);
 731         if (count) {
 732                 drbd_advance_rs_marks(mdev, drbd_bm_total_weight(mdev));
 733                 spin_lock_irqsave(&mdev->al_lock, flags);
 734                 drbd_try_clear_on_disk_bm(mdev, sector, count, true);
 735                 spin_unlock_irqrestore(&mdev->al_lock, flags);
 736
 737                 /* just wake_up unconditional now, various lc_chaged(),
 738                  * lc_put() in drbd_try_clear_on_disk_bm(). */
 739                 wake_up = 1;
 740         }
 741 out:
 742         put_ldev(mdev);
 743         if (wake_up)
 744                 wake_up(&mdev->al_wait);
 745 }
 746
 747 /*
 748  * this is intended to set one request worth of data out of sync.
 749  * affects at least 1 bit,
 750  * and at most 1+DRBD_MAX_BIO_SIZE/BM_BLOCK_SIZE bits.
 751  *
 752  * called by tl_clear and drbd_send_dblock (==drbd_make_request).
 753  * so this can be _any_ process.
 754  */
 755 int __drbd_set_out_of_sync(struct drbd_conf *mdev, sector_t sector, int size,
 756                             const char *file, const unsigned int line)
 757 {
 758         unsigned long sbnr, ebnr, flags;
 759         sector_t esector, nr_sectors;
 760         unsigned int enr, count = 0;
 761         struct lc_element *e;
 762
 763         /* this should be an empty REQ_FLUSH */
 764         if (size == 0)
 765                 return 0;
 766
 767         if (size < 0 || !IS_ALIGNED(size, 512) || size > DRBD_MAX_BIO_SIZE) {
 768                 dev_err(DEV, "sector: %llus, size: %d\n",
 769                         (unsigned long long)sector, size);
 770                 return 0;
 771         }
 772
 773         if (!get_ldev(mdev))
 774                 return 0; /* no disk, no metadata, no bitmap to set bits in */
 775
 776         nr_sectors = drbd_get_capacity(mdev->this_bdev);
 777         esector = sector + (size >> 9) - 1;
 778
 779         if (!expect(sector < nr_sectors))
 780                 goto out;
 781         if (!expect(esector < nr_sectors))
 782                 esector = nr_sectors - 1;
 783
 784         /* we set it out of sync,
 785          * we do not need to round anything here */
 786         sbnr = BM_SECT_TO_BIT(sector);
 787         ebnr = BM_SECT_TO_BIT(esector);
 788
 789         /* ok, (capacity & 7) != 0 sometimes, but who cares...
 790          * we count rs_{total,left} in bits, not sectors.  */
 791         spin_lock_irqsave(&mdev->al_lock, flags);
 792         count = drbd_bm_set_bits(mdev, sbnr, ebnr);
 793
 794         enr = BM_SECT_TO_EXT(sector);
 795         e = lc_find(mdev->resync, enr);
 796         if (e)
 797                 lc_entry(e, struct bm_extent, lce)->rs_left += count;
 798         spin_unlock_irqrestore(&mdev->al_lock, flags);
 799
 800 out:
 801         put_ldev(mdev);
 802
 803         return count;
 804 }
 805
 806 static
 807 struct bm_extent *_bme_get(struct drbd_conf *mdev, unsigned int enr)
 808 {
 809         struct lc_element *e;
 810         struct bm_extent *bm_ext;
 811         int wakeup = 0;
 812         unsigned long rs_flags;
 813
 814         spin_lock_irq(&mdev->al_lock);
 815         if (mdev->resync_locked > mdev->resync->nr_elements/2) {
 816                 spin_unlock_irq(&mdev->al_lock);
 817                 return NULL;
 818         }
 819         e = lc_get(mdev->resync, enr);
 820         bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL;
 821         if (bm_ext) {
 822                 if (bm_ext->lce.lc_number != enr) {
 823                         bm_ext->rs_left = drbd_bm_e_weight(mdev, enr);
 824                         bm_ext->rs_failed = 0;
 825                         lc_committed(mdev->resync);
 826                         wakeup = 1;
 827                 }
 828                 if (bm_ext->lce.refcnt == 1)
 829                         mdev->resync_locked++;
 830                 set_bit(BME_NO_WRITES, &bm_ext->flags);
 831         }
 832         rs_flags = mdev->resync->flags;
 833         spin_unlock_irq(&mdev->al_lock);
 834         if (wakeup)
 835                 wake_up(&mdev->al_wait);
 836
 837         if (!bm_ext) {
 838                 if (rs_flags & LC_STARVING)
 839                         dev_warn(DEV, "Have to wait for element"
 840                              " (resync LRU too small?)\n");
 841                 BUG_ON(rs_flags & LC_LOCKED);
 842         }
 843
 844         return bm_ext;
 845 }
 846
 847 static int _is_in_al(struct drbd_conf *mdev, unsigned int enr)
 848 {
 849         int rv;
 850
 851         spin_lock_irq(&mdev->al_lock);
 852         rv = lc_is_used(mdev->act_log, enr);
 853         spin_unlock_irq(&mdev->al_lock);
 854
 855         return rv;
 856 }
 857
 858 /**
 859  * drbd_rs_begin_io() - Gets an extent in the resync LRU cache and sets it to BME_LOCKED
 860  * @mdev:       DRBD device.
 861  * @sector:     The sector number.
 862  *
 863  * This functions sleeps on al_wait. Returns 0 on success, -EINTR if interrupted.
 864  */
 865 int drbd_rs_begin_io(struct drbd_conf *mdev, sector_t sector)
 866 {
 867         unsigned int enr = BM_SECT_TO_EXT(sector);
 868         struct bm_extent *bm_ext;
 869         int i, sig;
 870         int sa = 200; /* Step aside 200 times, then grab the extent and let app-IO wait.
 871                          200 times -> 20 seconds. */
 872
 873 retry:
 874         sig = wait_event_interruptible(mdev->al_wait,
 875                         (bm_ext = _bme_get(mdev, enr)));
 876         if (sig)
 877                 return -EINTR;
 878
 879         if (test_bit(BME_LOCKED, &bm_ext->flags))
 880                 return 0;
 881
 882         for (i = 0; i < AL_EXT_PER_BM_SECT; i++) {
 883                 sig = wait_event_interruptible(mdev->al_wait,
 884                                                !_is_in_al(mdev, enr * AL_EXT_PER_BM_SECT + i) ||
 885                                                test_bit(BME_PRIORITY, &bm_ext->flags));
 886
 887                 if (sig || (test_bit(BME_PRIORITY, &bm_ext->flags) && sa)) {
 888                         spin_lock_irq(&mdev->al_lock);
 889                         if (lc_put(mdev->resync, &bm_ext->lce) == 0) {
 890                                 bm_ext->flags = 0; /* clears BME_NO_WRITES and eventually BME_PRIORITY */
 891                                 mdev->resync_locked--;
 892                                 wake_up(&mdev->al_wait);
 893                         }
 894                         spin_unlock_irq(&mdev->al_lock);
 895                         if (sig)
 896                                 return -EINTR;
 897                         if (schedule_timeout_interruptible(HZ/10))
 898                                 return -EINTR;
 899                         if (sa && --sa == 0)
 900                                 dev_warn(DEV,"drbd_rs_begin_io() stepped aside for 20sec."
 901                                          "Resync stalled?\n");
 902                         goto retry;
 903                 }
 904         }
 905         set_bit(BME_LOCKED, &bm_ext->flags);
 906         return 0;
 907 }
 908
 909 /**
 910  * drbd_try_rs_begin_io() - Gets an extent in the resync LRU cache, does not sleep
 911  * @mdev:       DRBD device.
 912  * @sector:     The sector number.
 913  *
 914  * Gets an extent in the resync LRU cache, sets it to BME_NO_WRITES, then
 915  * tries to set it to BME_LOCKED. Returns 0 upon success, and -EAGAIN
 916  * if there is still application IO going on in this area.
 917  */
 918 int drbd_try_rs_begin_io(struct drbd_conf *mdev, sector_t sector)
 919 {
 920         unsigned int enr = BM_SECT_TO_EXT(sector);
 921         const unsigned int al_enr = enr*AL_EXT_PER_BM_SECT;
 922         struct lc_element *e;
 923         struct bm_extent *bm_ext;
 924         int i;
 925
 926         spin_lock_irq(&mdev->al_lock);
 927         if (mdev->resync_wenr != LC_FREE && mdev->resync_wenr != enr) {
 928                 /* in case you have very heavy scattered io, it may
 929                  * stall the syncer undefined if we give up the ref count
 930                  * when we try again and requeue.
 931                  *
 932                  * if we don't give up the refcount, but the next time
 933                  * we are scheduled this extent has been "synced" by new
 934                  * application writes, we'd miss the lc_put on the
 935                  * extent we keep the refcount on.
 936                  * so we remembered which extent we had to try again, and
 937                  * if the next requested one is something else, we do
 938                  * the lc_put here...
 939                  * we also have to wake_up
 940                  */
 941                 e = lc_find(mdev->resync, mdev->resync_wenr);
 942                 bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL;
 943                 if (bm_ext) {
 944                         D_ASSERT(!test_bit(BME_LOCKED, &bm_ext->flags));
 945                         D_ASSERT(test_bit(BME_NO_WRITES, &bm_ext->flags));
 946                         clear_bit(BME_NO_WRITES, &bm_ext->flags);
 947                         mdev->resync_wenr = LC_FREE;
 948                         if (lc_put(mdev->resync, &bm_ext->lce) == 0)
 949                                 mdev->resync_locked--;
 950                         wake_up(&mdev->al_wait);
 951                 } else {
 952                         dev_alert(DEV, "LOGIC BUG\n");
 953                 }
 954         }
 955         /* TRY. */
 956         e = lc_try_get(mdev->resync, enr);
 957         bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL;
 958         if (bm_ext) {
 959                 if (test_bit(BME_LOCKED, &bm_ext->flags))
 960                         goto proceed;
 961                 if (!test_and_set_bit(BME_NO_WRITES, &bm_ext->flags)) {
 962                         mdev->resync_locked++;
 963                 } else {
 964                         /* we did set the BME_NO_WRITES,
 965                          * but then could not set BME_LOCKED,
 966                          * so we tried again.
 967                          * drop the extra reference. */
 968                         bm_ext->lce.refcnt--;
 969                         D_ASSERT(bm_ext->lce.refcnt > 0);
 970                 }
 971                 goto check_al;
 972         } else {
 973                 /* do we rather want to try later? */
 974                 if (mdev->resync_locked > mdev->resync->nr_elements-3)
 975                         goto try_again;
 976                 /* Do or do not. There is no try. -- Yoda */
 977                 e = lc_get(mdev->resync, enr);
 978                 bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL;
 979                 if (!bm_ext) {
 980                         const unsigned long rs_flags = mdev->resync->flags;
 981                         if (rs_flags & LC_STARVING)
 982                                 dev_warn(DEV, "Have to wait for element"
 983                                      " (resync LRU too small?)\n");
 984                         BUG_ON(rs_flags & LC_LOCKED);
 985                         goto try_again;
 986                 }
 987                 if (bm_ext->lce.lc_number != enr) {
 988                         bm_ext->rs_left = drbd_bm_e_weight(mdev, enr);
 989                         bm_ext->rs_failed = 0;
 990                         lc_committed(mdev->resync);
 991                         wake_up(&mdev->al_wait);
 992                         D_ASSERT(test_bit(BME_LOCKED, &bm_ext->flags) == 0);
 993                 }
 994                 set_bit(BME_NO_WRITES, &bm_ext->flags);
 995                 D_ASSERT(bm_ext->lce.refcnt == 1);
 996                 mdev->resync_locked++;
 997                 goto check_al;
 998         }
 999 check_al:
1000         for (i = 0; i < AL_EXT_PER_BM_SECT; i++) {
1001                 if (lc_is_used(mdev->act_log, al_enr+i))
1002                         goto try_again;
1003         }
1004         set_bit(BME_LOCKED, &bm_ext->flags);
1005 proceed:
1006         mdev->resync_wenr = LC_FREE;
1007         spin_unlock_irq(&mdev->al_lock);
1008         return 0;
1009
1010 try_again:
1011         if (bm_ext)
1012                 mdev->resync_wenr = enr;
1013         spin_unlock_irq(&mdev->al_lock);
1014         return -EAGAIN;
1015 }
1016
1017 void drbd_rs_complete_io(struct drbd_conf *mdev, sector_t sector)
1018 {
1019         unsigned int enr = BM_SECT_TO_EXT(sector);
1020         struct lc_element *e;
1021         struct bm_extent *bm_ext;
1022         unsigned long flags;
1023
1024         spin_lock_irqsave(&mdev->al_lock, flags);
1025         e = lc_find(mdev->resync, enr);
1026         bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL;
1027         if (!bm_ext) {
1028                 spin_unlock_irqrestore(&mdev->al_lock, flags);
1029                 if (__ratelimit(&drbd_ratelimit_state))
1030                         dev_err(DEV, "drbd_rs_complete_io() called, but extent not found\n");
1031                 return;
1032         }
1033
1034         if (bm_ext->lce.refcnt == 0) {
1035                 spin_unlock_irqrestore(&mdev->al_lock, flags);
1036                 dev_err(DEV, "drbd_rs_complete_io(,%llu [=%u]) called, "
1037                     "but refcnt is 0!?\n",
1038                     (unsigned long long)sector, enr);
1039                 return;
1040         }
1041
1042         if (lc_put(mdev->resync, &bm_ext->lce) == 0) {
1043                 bm_ext->flags = 0; /* clear BME_LOCKED, BME_NO_WRITES and BME_PRIORITY */
1044                 mdev->resync_locked--;
1045                 wake_up(&mdev->al_wait);
1046         }
1047
1048         spin_unlock_irqrestore(&mdev->al_lock, flags);
1049 }
1050
1051 /**
1052  * drbd_rs_cancel_all() - Removes all extents from the resync LRU (even BME_LOCKED)
1053  * @mdev:       DRBD device.
1054  */
1055 void drbd_rs_cancel_all(struct drbd_conf *mdev)
1056 {
1057         spin_lock_irq(&mdev->al_lock);
1058
1059         if (get_ldev_if_state(mdev, D_FAILED)) { /* Makes sure ->resync is there. */
1060                 lc_reset(mdev->resync);
1061                 put_ldev(mdev);
1062         }
1063         mdev->resync_locked = 0;
1064         mdev->resync_wenr = LC_FREE;
1065         spin_unlock_irq(&mdev->al_lock);
1066         wake_up(&mdev->al_wait);
1067 }
1068
1069 /**
1070  * drbd_rs_del_all() - Gracefully remove all extents from the resync LRU
1071  * @mdev:       DRBD device.
1072  *
1073  * Returns 0 upon success, -EAGAIN if at least one reference count was
1074  * not zero.
1075  */
1076 int drbd_rs_del_all(struct drbd_conf *mdev)
1077 {
1078         struct lc_element *e;
1079         struct bm_extent *bm_ext;
1080         int i;
1081
1082         spin_lock_irq(&mdev->al_lock);
1083
1084         if (get_ldev_if_state(mdev, D_FAILED)) {
1085                 /* ok, ->resync is there. */
1086                 for (i = 0; i < mdev->resync->nr_elements; i++) {
1087                         e = lc_element_by_index(mdev->resync, i);
1088                         bm_ext = lc_entry(e, struct bm_extent, lce);
1089                         if (bm_ext->lce.lc_number == LC_FREE)
1090                                 continue;
1091                         if (bm_ext->lce.lc_number == mdev->resync_wenr) {
1092                                 dev_info(DEV, "dropping %u in drbd_rs_del_all, apparently"
1093                                      " got 'synced' by application io\n",
1094                                      mdev->resync_wenr);
1095                                 D_ASSERT(!test_bit(BME_LOCKED, &bm_ext->flags));
1096                                 D_ASSERT(test_bit(BME_NO_WRITES, &bm_ext->flags));
1097                                 clear_bit(BME_NO_WRITES, &bm_ext->flags);
1098                                 mdev->resync_wenr = LC_FREE;
1099                                 lc_put(mdev->resync, &bm_ext->lce);
1100                         }
1101                         if (bm_ext->lce.refcnt != 0) {
1102                                 dev_info(DEV, "Retrying drbd_rs_del_all() later. "
1103                                      "refcnt=%d\n", bm_ext->lce.refcnt);
1104                                 put_ldev(mdev);
1105                                 spin_unlock_irq(&mdev->al_lock);
1106                                 return -EAGAIN;
1107                         }
1108                         D_ASSERT(!test_bit(BME_LOCKED, &bm_ext->flags));
1109                         D_ASSERT(!test_bit(BME_NO_WRITES, &bm_ext->flags));
1110                         lc_del(mdev->resync, &bm_ext->lce);
1111                 }
1112                 D_ASSERT(mdev->resync->used == 0);
1113                 put_ldev(mdev);
1114         }
1115         spin_unlock_irq(&mdev->al_lock);
1116         wake_up(&mdev->al_wait);
1117
1118         return 0;
1119 }
1120
1121 /**
1122  * drbd_rs_failed_io() - Record information on a failure to resync the specified blocks
1123  * @mdev:       DRBD device.
1124  * @sector:     The sector number.
1125  * @size:       Size of failed IO operation, in byte.
1126  */
1127 void drbd_rs_failed_io(struct drbd_conf *mdev, sector_t sector, int size)
1128 {
1129         /* Is called from worker and receiver context _only_ */
1130         unsigned long sbnr, ebnr, lbnr;
1131         unsigned long count;
1132         sector_t esector, nr_sectors;
1133         int wake_up = 0;
1134
1135         if (size <= 0 || !IS_ALIGNED(size, 512) || size > DRBD_MAX_BIO_SIZE) {
1136                 dev_err(DEV, "drbd_rs_failed_io: sector=%llus size=%d nonsense!\n",
1137                                 (unsigned long long)sector, size);
1138                 return;
1139         }
1140         nr_sectors = drbd_get_capacity(mdev->this_bdev);
1141         esector = sector + (size >> 9) - 1;
1142
1143         if (!expect(sector < nr_sectors))
1144                 return;
1145         if (!expect(esector < nr_sectors))
1146                 esector = nr_sectors - 1;
1147
1148         lbnr = BM_SECT_TO_BIT(nr_sectors-1);
1149
1150         /*
1151          * round up start sector, round down end sector.  we make sure we only
1152          * handle full, aligned, BM_BLOCK_SIZE (4K) blocks */
1153         if (unlikely(esector < BM_SECT_PER_BIT-1))
1154                 return;
1155         if (unlikely(esector == (nr_sectors-1)))
1156                 ebnr = lbnr;
1157         else
1158                 ebnr = BM_SECT_TO_BIT(esector - (BM_SECT_PER_BIT-1));
1159         sbnr = BM_SECT_TO_BIT(sector + BM_SECT_PER_BIT-1);
1160
1161         if (sbnr > ebnr)
1162                 return;
1163
1164         /*
1165          * ok, (capacity & 7) != 0 sometimes, but who cares...
1166          * we count rs_{total,left} in bits, not sectors.
1167          */
1168         spin_lock_irq(&mdev->al_lock);
1169         count = drbd_bm_count_bits(mdev, sbnr, ebnr);
1170         if (count) {
1171                 mdev->rs_failed += count;
1172
1173                 if (get_ldev(mdev)) {
1174                         drbd_try_clear_on_disk_bm(mdev, sector, count, false);
1175                         put_ldev(mdev);
1176                 }
1177
1178                 /* just wake_up unconditional now, various lc_chaged(),
1179                  * lc_put() in drbd_try_clear_on_disk_bm(). */
1180                 wake_up = 1;
1181         }
1182         spin_unlock_irq(&mdev->al_lock);
1183         if (wake_up)
1184                 wake_up(&mdev->al_wait);
1185 }