external/cddl/osnet/dist/uts/common/fs/zfs/space_map.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 #pragma ident   "%Z%%M% %I%     %E% SMI"
  27
  28 #include <sys/zfs_context.h>
  29 #include <sys/spa.h>
  30 #include <sys/dmu.h>
  31 #include <sys/zio.h>
  32 #include <sys/space_map.h>
  33
  34 /*
  35  * Space map routines.
  36  * NOTE: caller is responsible for all locking.
  37  */
  38 static int
  39 space_map_seg_compare(const void *x1, const void *x2)
  40 {
  41         const space_seg_t *s1 = x1;
  42         const space_seg_t *s2 = x2;
  43
  44         if (s1->ss_start < s2->ss_start) {
  45                 if (s1->ss_end > s2->ss_start)
  46                         return (0);
  47                 return (-1);
  48         }
  49         if (s1->ss_start > s2->ss_start) {
  50                 if (s1->ss_start < s2->ss_end)
  51                         return (0);
  52                 return (1);
  53         }
  54         return (0);
  55 }
  56
  57 void
  58 space_map_create(space_map_t *sm, uint64_t start, uint64_t size, uint8_t shift,
  59         kmutex_t *lp)
  60 {
  61         bzero(sm, sizeof (*sm));
  62
  63         avl_create(&sm->sm_root, space_map_seg_compare,
  64             sizeof (space_seg_t), offsetof(struct space_seg, ss_node));
  65
  66         cv_init(&sm->sm_load_cv, NULL, CV_DEFAULT, NULL);
  67
  68         sm->sm_start = start;
  69         sm->sm_size = size;
  70         sm->sm_shift = shift;
  71         sm->sm_lock = lp;
  72 }
  73
  74 void
  75 space_map_destroy(space_map_t *sm)
  76 {
  77         ASSERT(!sm->sm_loaded && !sm->sm_loading);
  78         VERIFY3U(sm->sm_space, ==, 0);
  79         avl_destroy(&sm->sm_root);
  80
  81         cv_destroy(&sm->sm_load_cv);
  82 }
  83
  84 void
  85 space_map_add(space_map_t *sm, uint64_t start, uint64_t size)
  86 {
  87         avl_index_t where;
  88         space_seg_t ssearch, *ss_before, *ss_after, *ss;
  89         uint64_t end = start + size;
  90         int merge_before, merge_after;
  91
  92         ASSERT(MUTEX_HELD(sm->sm_lock));
  93         VERIFY(size != 0);
  94         VERIFY3U(start, >=, sm->sm_start);
  95         VERIFY3U(end, <=, sm->sm_start + sm->sm_size);
  96         VERIFY(sm->sm_space + size <= sm->sm_size);
  97         VERIFY(P2PHASE(start, 1ULL << sm->sm_shift) == 0);
  98         VERIFY(P2PHASE(size, 1ULL << sm->sm_shift) == 0);
  99
 100         ssearch.ss_start = start;
 101         ssearch.ss_end = end;
 102         ss = avl_find(&sm->sm_root, &ssearch, &where);
 103
 104         if (ss != NULL && ss->ss_start <= start && ss->ss_end >= end) {
 105                 zfs_panic_recover("zfs: allocating allocated segment"
 106                     "(offset=%llu size=%llu)\n",
 107                     (longlong_t)start, (longlong_t)size);
 108                 return;
 109         }
 110
 111         /* Make sure we don't overlap with either of our neighbors */
 112         VERIFY(ss == NULL);
 113
 114         ss_before = avl_nearest(&sm->sm_root, where, AVL_BEFORE);
 115         ss_after = avl_nearest(&sm->sm_root, where, AVL_AFTER);
 116
 117         merge_before = (ss_before != NULL && ss_before->ss_end == start);
 118         merge_after = (ss_after != NULL && ss_after->ss_start == end);
 119
 120         if (merge_before && merge_after) {
 121                 avl_remove(&sm->sm_root, ss_before);
 122                 ss_after->ss_start = ss_before->ss_start;
 123                 kmem_free(ss_before, sizeof (*ss_before));
 124         } else if (merge_before) {
 125                 ss_before->ss_end = end;
 126         } else if (merge_after) {
 127                 ss_after->ss_start = start;
 128         } else {
 129                 ss = kmem_alloc(sizeof (*ss), KM_SLEEP);
 130                 ss->ss_start = start;
 131                 ss->ss_end = end;
 132                 avl_insert(&sm->sm_root, ss, where);
 133         }
 134
 135         sm->sm_space += size;
 136 }
 137
 138 void
 139 space_map_remove(space_map_t *sm, uint64_t start, uint64_t size)
 140 {
 141         avl_index_t where;
 142         space_seg_t ssearch, *ss, *newseg;
 143         uint64_t end = start + size;
 144         int left_over, right_over;
 145
 146         ASSERT(MUTEX_HELD(sm->sm_lock));
 147         VERIFY(size != 0);
 148         VERIFY(P2PHASE(start, 1ULL << sm->sm_shift) == 0);
 149         VERIFY(P2PHASE(size, 1ULL << sm->sm_shift) == 0);
 150
 151         ssearch.ss_start = start;
 152         ssearch.ss_end = end;
 153         ss = avl_find(&sm->sm_root, &ssearch, &where);
 154
 155         /* Make sure we completely overlap with someone */
 156         if (ss == NULL) {
 157                 zfs_panic_recover("zfs: freeing free segment "
 158                     "(offset=%llu size=%llu)",
 159                     (longlong_t)start, (longlong_t)size);
 160                 return;
 161         }
 162         VERIFY3U(ss->ss_start, <=, start);
 163         VERIFY3U(ss->ss_end, >=, end);
 164         VERIFY(sm->sm_space - size <= sm->sm_size);
 165
 166         left_over = (ss->ss_start != start);
 167         right_over = (ss->ss_end != end);
 168
 169         if (left_over && right_over) {
 170                 newseg = kmem_alloc(sizeof (*newseg), KM_SLEEP);
 171                 newseg->ss_start = end;
 172                 newseg->ss_end = ss->ss_end;
 173                 ss->ss_end = start;
 174                 avl_insert_here(&sm->sm_root, newseg, ss, AVL_AFTER);
 175         } else if (left_over) {
 176                 ss->ss_end = start;
 177         } else if (right_over) {
 178                 ss->ss_start = end;
 179         } else {
 180                 avl_remove(&sm->sm_root, ss);
 181                 kmem_free(ss, sizeof (*ss));
 182         }
 183
 184         sm->sm_space -= size;
 185 }
 186
 187 int
 188 space_map_contains(space_map_t *sm, uint64_t start, uint64_t size)
 189 {
 190         avl_index_t where;
 191         space_seg_t ssearch, *ss;
 192         uint64_t end = start + size;
 193
 194         ASSERT(MUTEX_HELD(sm->sm_lock));
 195         VERIFY(size != 0);
 196         VERIFY(P2PHASE(start, 1ULL << sm->sm_shift) == 0);
 197         VERIFY(P2PHASE(size, 1ULL << sm->sm_shift) == 0);
 198
 199         ssearch.ss_start = start;
 200         ssearch.ss_end = end;
 201         ss = avl_find(&sm->sm_root, &ssearch, &where);
 202
 203         return (ss != NULL && ss->ss_start <= start && ss->ss_end >= end);
 204 }
 205
 206 void
 207 space_map_vacate(space_map_t *sm, space_map_func_t *func, space_map_t *mdest)
 208 {
 209         space_seg_t *ss;
 210         void *cookie = NULL;
 211
 212         ASSERT(MUTEX_HELD(sm->sm_lock));
 213
 214         while ((ss = avl_destroy_nodes(&sm->sm_root, &cookie)) != NULL) {
 215                 if (func != NULL)
 216                         func(mdest, ss->ss_start, ss->ss_end - ss->ss_start);
 217                 kmem_free(ss, sizeof (*ss));
 218         }
 219         sm->sm_space = 0;
 220 }
 221
 222 void
 223 space_map_walk(space_map_t *sm, space_map_func_t *func, space_map_t *mdest)
 224 {
 225         space_seg_t *ss;
 226
 227         for (ss = avl_first(&sm->sm_root); ss; ss = AVL_NEXT(&sm->sm_root, ss))
 228                 func(mdest, ss->ss_start, ss->ss_end - ss->ss_start);
 229 }
 230
 231 void
 232 space_map_excise(space_map_t *sm, uint64_t start, uint64_t size)
 233 {
 234         avl_tree_t *t = &sm->sm_root;
 235         avl_index_t where;
 236         space_seg_t *ss, search;
 237         uint64_t end = start + size;
 238         uint64_t rm_start, rm_end;
 239
 240         ASSERT(MUTEX_HELD(sm->sm_lock));
 241
 242         search.ss_start = start;
 243         search.ss_end = start;
 244
 245         for (;;) {
 246                 ss = avl_find(t, &search, &where);
 247
 248                 if (ss == NULL)
 249                         ss = avl_nearest(t, where, AVL_AFTER);
 250
 251                 if (ss == NULL || ss->ss_start >= end)
 252                         break;
 253
 254                 rm_start = MAX(ss->ss_start, start);
 255                 rm_end = MIN(ss->ss_end, end);
 256
 257                 space_map_remove(sm, rm_start, rm_end - rm_start);
 258         }
 259 }
 260
 261 /*
 262  * Replace smd with the union of smd and sms.
 263  */
 264 void
 265 space_map_union(space_map_t *smd, space_map_t *sms)
 266 {
 267         avl_tree_t *t = &sms->sm_root;
 268         space_seg_t *ss;
 269
 270         ASSERT(MUTEX_HELD(smd->sm_lock));
 271
 272         /*
 273          * For each source segment, remove any intersections with the
 274          * destination, then add the source segment to the destination.
 275          */
 276         for (ss = avl_first(t); ss != NULL; ss = AVL_NEXT(t, ss)) {
 277                 space_map_excise(smd, ss->ss_start, ss->ss_end - ss->ss_start);
 278                 space_map_add(smd, ss->ss_start, ss->ss_end - ss->ss_start);
 279         }
 280 }
 281
 282 /*
 283  * Wait for any in-progress space_map_load() to complete.
 284  */
 285 void
 286 space_map_load_wait(space_map_t *sm)
 287 {
 288         ASSERT(MUTEX_HELD(sm->sm_lock));
 289
 290         while (sm->sm_loading)
 291                 cv_wait(&sm->sm_load_cv, sm->sm_lock);
 292 }
 293
 294 /*
 295  * Note: space_map_load() will drop sm_lock across dmu_read() calls.
 296  * The caller must be OK with this.
 297  */
 298 int
 299 space_map_load(space_map_t *sm, space_map_ops_t *ops, uint8_t maptype,
 300         space_map_obj_t *smo, objset_t *os)
 301 {
 302         uint64_t *entry, *entry_map, *entry_map_end;
 303         uint64_t bufsize, size, offset, end, space;
 304         uint64_t mapstart = sm->sm_start;
 305         int error = 0;
 306
 307         ASSERT(MUTEX_HELD(sm->sm_lock));
 308
 309         space_map_load_wait(sm);
 310
 311         if (sm->sm_loaded)
 312                 return (0);
 313
 314         sm->sm_loading = B_TRUE;
 315         end = smo->smo_objsize;
 316         space = smo->smo_alloc;
 317
 318         ASSERT(sm->sm_ops == NULL);
 319         VERIFY3U(sm->sm_space, ==, 0);
 320
 321         if (maptype == SM_FREE) {
 322                 space_map_add(sm, sm->sm_start, sm->sm_size);
 323                 space = sm->sm_size - space;
 324         }
 325
 326         bufsize = 1ULL << SPACE_MAP_BLOCKSHIFT;
 327         entry_map = zio_buf_alloc(bufsize);
 328
 329         mutex_exit(sm->sm_lock);
 330         if (end > bufsize)
 331                 dmu_prefetch(os, smo->smo_object, bufsize, end - bufsize);
 332         mutex_enter(sm->sm_lock);
 333
 334         for (offset = 0; offset < end; offset += bufsize) {
 335                 size = MIN(end - offset, bufsize);
 336                 VERIFY(P2PHASE(size, sizeof (uint64_t)) == 0);
 337                 VERIFY(size != 0);
 338
 339                 dprintf("object=%llu  offset=%llx  size=%llx\n",
 340                     smo->smo_object, offset, size);
 341
 342                 mutex_exit(sm->sm_lock);
 343                 error = dmu_read(os, smo->smo_object, offset, size, entry_map);
 344                 mutex_enter(sm->sm_lock);
 345                 if (error != 0)
 346                         break;
 347
 348                 entry_map_end = entry_map + (size / sizeof (uint64_t));
 349                 for (entry = entry_map; entry < entry_map_end; entry++) {
 350                         uint64_t e = *entry;
 351
 352                         if (SM_DEBUG_DECODE(e))         /* Skip debug entries */
 353                                 continue;
 354
 355                         (SM_TYPE_DECODE(e) == maptype ?
 356                             space_map_add : space_map_remove)(sm,
 357                             (SM_OFFSET_DECODE(e) << sm->sm_shift) + mapstart,
 358                             SM_RUN_DECODE(e) << sm->sm_shift);
 359                 }
 360         }
 361
 362         if (error == 0) {
 363                 VERIFY3U(sm->sm_space, ==, space);
 364
 365                 sm->sm_loaded = B_TRUE;
 366                 sm->sm_ops = ops;
 367                 if (ops != NULL)
 368                         ops->smop_load(sm);
 369         } else {
 370                 space_map_vacate(sm, NULL, NULL);
 371         }
 372
 373         zio_buf_free(entry_map, bufsize);
 374
 375         sm->sm_loading = B_FALSE;
 376
 377         cv_broadcast(&sm->sm_load_cv);
 378
 379         return (error);
 380 }
 381
 382 void
 383 space_map_unload(space_map_t *sm)
 384 {
 385         ASSERT(MUTEX_HELD(sm->sm_lock));
 386
 387         if (sm->sm_loaded && sm->sm_ops != NULL)
 388                 sm->sm_ops->smop_unload(sm);
 389
 390         sm->sm_loaded = B_FALSE;
 391         sm->sm_ops = NULL;
 392
 393         space_map_vacate(sm, NULL, NULL);
 394 }
 395
 396 uint64_t
 397 space_map_alloc(space_map_t *sm, uint64_t size)
 398 {
 399         uint64_t start;
 400
 401         start = sm->sm_ops->smop_alloc(sm, size);
 402         if (start != -1ULL)
 403                 space_map_remove(sm, start, size);
 404         return (start);
 405 }
 406
 407 void
 408 space_map_claim(space_map_t *sm, uint64_t start, uint64_t size)
 409 {
 410         sm->sm_ops->smop_claim(sm, start, size);
 411         space_map_remove(sm, start, size);
 412 }
 413
 414 void
 415 space_map_free(space_map_t *sm, uint64_t start, uint64_t size)
 416 {
 417         space_map_add(sm, start, size);
 418         sm->sm_ops->smop_free(sm, start, size);
 419 }
 420
 421 /*
 422  * Note: space_map_sync() will drop sm_lock across dmu_write() calls.
 423  */
 424 void
 425 space_map_sync(space_map_t *sm, uint8_t maptype,
 426         space_map_obj_t *smo, objset_t *os, dmu_tx_t *tx)
 427 {
 428         spa_t *spa = dmu_objset_spa(os);
 429         void *cookie = NULL;
 430         space_seg_t *ss;
 431         uint64_t bufsize, start, size, run_len;
 432         uint64_t *entry, *entry_map, *entry_map_end;
 433
 434         ASSERT(MUTEX_HELD(sm->sm_lock));
 435
 436         if (sm->sm_space == 0)
 437                 return;
 438
 439         dprintf("object %4llu, txg %llu, pass %d, %c, count %lu, space %llx\n",
 440             smo->smo_object, dmu_tx_get_txg(tx), spa_sync_pass(spa),
 441             maptype == SM_ALLOC ? 'A' : 'F', avl_numnodes(&sm->sm_root),
 442             sm->sm_space);
 443
 444         if (maptype == SM_ALLOC)
 445                 smo->smo_alloc += sm->sm_space;
 446         else
 447                 smo->smo_alloc -= sm->sm_space;
 448
 449         bufsize = (8 + avl_numnodes(&sm->sm_root)) * sizeof (uint64_t);
 450         bufsize = MIN(bufsize, 1ULL << SPACE_MAP_BLOCKSHIFT);
 451         entry_map = zio_buf_alloc(bufsize);
 452         entry_map_end = entry_map + (bufsize / sizeof (uint64_t));
 453         entry = entry_map;
 454
 455         *entry++ = SM_DEBUG_ENCODE(1) |
 456             SM_DEBUG_ACTION_ENCODE(maptype) |
 457             SM_DEBUG_SYNCPASS_ENCODE(spa_sync_pass(spa)) |
 458             SM_DEBUG_TXG_ENCODE(dmu_tx_get_txg(tx));
 459
 460         while ((ss = avl_destroy_nodes(&sm->sm_root, &cookie)) != NULL) {
 461                 size = ss->ss_end - ss->ss_start;
 462                 start = (ss->ss_start - sm->sm_start) >> sm->sm_shift;
 463
 464                 sm->sm_space -= size;
 465                 size >>= sm->sm_shift;
 466
 467                 while (size) {
 468                         run_len = MIN(size, SM_RUN_MAX);
 469
 470                         if (entry == entry_map_end) {
 471                                 mutex_exit(sm->sm_lock);
 472                                 dmu_write(os, smo->smo_object, smo->smo_objsize,
 473                                     bufsize, entry_map, tx);
 474                                 mutex_enter(sm->sm_lock);
 475                                 smo->smo_objsize += bufsize;
 476                                 entry = entry_map;
 477                         }
 478
 479                         *entry++ = SM_OFFSET_ENCODE(start) |
 480                             SM_TYPE_ENCODE(maptype) |
 481                             SM_RUN_ENCODE(run_len);
 482
 483                         start += run_len;
 484                         size -= run_len;
 485                 }
 486                 kmem_free(ss, sizeof (*ss));
 487         }
 488
 489         if (entry != entry_map) {
 490                 size = (entry - entry_map) * sizeof (uint64_t);
 491                 mutex_exit(sm->sm_lock);
 492                 dmu_write(os, smo->smo_object, smo->smo_objsize,
 493                     size, entry_map, tx);
 494                 mutex_enter(sm->sm_lock);
 495                 smo->smo_objsize += size;
 496         }
 497
 498         zio_buf_free(entry_map, bufsize);
 499
 500         VERIFY3U(sm->sm_space, ==, 0);
 501 }
 502
 503 void
 504 space_map_truncate(space_map_obj_t *smo, objset_t *os, dmu_tx_t *tx)
 505 {
 506         VERIFY(dmu_free_range(os, smo->smo_object, 0, -1ULL, tx) == 0);
 507
 508         smo->smo_objsize = 0;
 509         smo->smo_alloc = 0;
 510 }