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