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NEX-4582 update wrc test cases for allow to use write back cache per tree of datasets
Reviewed by: Steve Peng <steve.peng@nexenta.com>
Reviewed by: Alex Aizman <alex.aizman@nexenta.com>
5960 zfs recv should prefetch indirect blocks
5925 zfs receive -o origin=
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>


  29 #include <sys/zfs_context.h>
  30 #include <sys/spa.h>
  31 #include <sys/dmu.h>
  32 #include <sys/dmu_tx.h>
  33 #include <sys/dnode.h>
  34 #include <sys/dsl_pool.h>
  35 #include <sys/zio.h>
  36 #include <sys/space_map.h>
  37 #include <sys/refcount.h>
  38 #include <sys/zfeature.h>
  39 
  40 /*
  41  * The data for a given space map can be kept on blocks of any size.
  42  * Larger blocks entail fewer i/o operations, but they also cause the
  43  * DMU to keep more data in-core, and also to waste more i/o bandwidth
  44  * when only a few blocks have changed since the last transaction group.
  45  */
  46 int space_map_blksz = (1 << 12);
  47 
  48 /*
  49  * Iterate through the space map, invoking the callback on each (non-debug)
  50  * space map entry.



  51  */
  52 int
  53 space_map_iterate(space_map_t *sm, sm_cb_t callback, void *arg)
  54 {
  55         uint64_t *entry, *entry_map, *entry_map_end;
  56         uint64_t bufsize, size, offset, end;
  57         int error = 0;
  58 


  59         end = space_map_length(sm);

  60 







  61         bufsize = MAX(sm->sm_blksz, SPA_MINBLOCKSIZE);
  62         entry_map = zio_buf_alloc(bufsize);
  63 

  64         if (end > bufsize) {
  65                 dmu_prefetch(sm->sm_os, space_map_object(sm), 0, bufsize,
  66                     end - bufsize, ZIO_PRIORITY_SYNC_READ);
  67         }

  68 
  69         for (offset = 0; offset < end && error == 0; offset += bufsize) {
  70                 size = MIN(end - offset, bufsize);
  71                 VERIFY(P2PHASE(size, sizeof (uint64_t)) == 0);
  72                 VERIFY(size != 0);
  73                 ASSERT3U(sm->sm_blksz, !=, 0);
  74 
  75                 dprintf("object=%llu  offset=%llx  size=%llx\n",
  76                     space_map_object(sm), offset, size);
  77 

  78                 error = dmu_read(sm->sm_os, space_map_object(sm), offset, size,
  79                     entry_map, DMU_READ_PREFETCH);

  80                 if (error != 0)
  81                         break;
  82 
  83                 entry_map_end = entry_map + (size / sizeof (uint64_t));
  84                 for (entry = entry_map; entry < entry_map_end && error == 0;
  85                     entry++) {
  86                         uint64_t e = *entry;
  87                         uint64_t offset, size;
  88 
  89                         if (SM_DEBUG_DECODE(e)) /* Skip debug entries */
  90                                 continue;
  91 
  92                         offset = (SM_OFFSET_DECODE(e) << sm->sm_shift) +
  93                             sm->sm_start;
  94                         size = SM_RUN_DECODE(e) << sm->sm_shift;
  95 
  96                         VERIFY0(P2PHASE(offset, 1ULL << sm->sm_shift));
  97                         VERIFY0(P2PHASE(size, 1ULL << sm->sm_shift));
  98                         VERIFY3U(offset, >=, sm->sm_start);
  99                         VERIFY3U(offset + size, <=, sm->sm_start + sm->sm_size);
 100                         error = callback(SM_TYPE_DECODE(e), offset, size, arg);





 101                 }
 102         }
 103 
 104         zio_buf_free(entry_map, bufsize);
 105         return (error);
 106 }
 107 
 108 typedef struct space_map_load_arg {
 109         space_map_t     *smla_sm;
 110         range_tree_t    *smla_rt;
 111         maptype_t       smla_type;
 112 } space_map_load_arg_t;
 113 
 114 static int
 115 space_map_load_callback(maptype_t type, uint64_t offset, uint64_t size,
 116     void *arg)
 117 {
 118         space_map_load_arg_t *smla = arg;
 119         if (type == smla->smla_type) {
 120                 VERIFY3U(range_tree_space(smla->smla_rt) + size, <=,
 121                     smla->smla_sm->sm_size);
 122                 range_tree_add(smla->smla_rt, offset, size);
 123         } else {
 124                 range_tree_remove(smla->smla_rt, offset, size);
 125         }
 126 
 127         return (0);
 128 }
 129 
 130 /*
 131  * Load the space map disk into the specified range tree. Segments of maptype
 132  * are added to the range tree, other segment types are removed.
 133  */
 134 int
 135 space_map_load(space_map_t *sm, range_tree_t *rt, maptype_t maptype)
 136 {
 137         uint64_t space;
 138         int err;
 139         space_map_load_arg_t smla;
 140 
 141         VERIFY0(range_tree_space(rt));
 142         space = space_map_allocated(sm);
 143 
 144         if (maptype == SM_FREE) {
 145                 range_tree_add(rt, sm->sm_start, sm->sm_size);
 146                 space = sm->sm_size - space;
 147         }
 148 
 149         smla.smla_rt = rt;
 150         smla.smla_sm = sm;
 151         smla.smla_type = maptype;
 152         err = space_map_iterate(sm, space_map_load_callback, &smla);
 153 
 154         if (err == 0) {
 155                 VERIFY3U(range_tree_space(rt), ==, space);
 156         } else {
 157                 range_tree_vacate(rt, NULL, NULL);
 158         }
 159 
 160         return (err);

 161 }
 162 
 163 void
 164 space_map_histogram_clear(space_map_t *sm)
 165 {
 166         if (sm->sm_dbuf->db_size != sizeof (space_map_phys_t))
 167                 return;
 168 
 169         bzero(sm->sm_phys->smp_histogram, sizeof (sm->sm_phys->smp_histogram));
 170 }
 171 
 172 boolean_t
 173 space_map_histogram_verify(space_map_t *sm, range_tree_t *rt)
 174 {
 175         /*
 176          * Verify that the in-core range tree does not have any
 177          * ranges smaller than our sm_shift size.
 178          */
 179         for (int i = 0; i < sm->sm_shift; i++) {
 180                 if (rt->rt_histogram[i] != 0)
 181                         return (B_FALSE);
 182         }
 183         return (B_TRUE);
 184 }
 185 
 186 void
 187 space_map_histogram_add(space_map_t *sm, range_tree_t *rt, dmu_tx_t *tx)
 188 {
 189         int idx = 0;
 190 

 191         ASSERT(dmu_tx_is_syncing(tx));
 192         VERIFY3U(space_map_object(sm), !=, 0);
 193 
 194         if (sm->sm_dbuf->db_size != sizeof (space_map_phys_t))
 195                 return;
 196 
 197         dmu_buf_will_dirty(sm->sm_dbuf, tx);
 198 
 199         ASSERT(space_map_histogram_verify(sm, rt));
 200         /*
 201          * Transfer the content of the range tree histogram to the space
 202          * map histogram. The space map histogram contains 32 buckets ranging
 203          * between 2^sm_shift to 2^(32+sm_shift-1). The range tree,
 204          * however, can represent ranges from 2^0 to 2^63. Since the space
 205          * map only cares about allocatable blocks (minimum of sm_shift) we
 206          * can safely ignore all ranges in the range tree smaller than sm_shift.
 207          */
 208         for (int i = sm->sm_shift; i < RANGE_TREE_HISTOGRAM_SIZE; i++) {
 209 
 210                 /*


 239         avl_tree_t *t = &rt->rt_root;
 240         range_seg_t *rs;
 241         uint64_t size, entries;
 242 
 243         /*
 244          * All space_maps always have a debug entry so account for it here.
 245          */
 246         entries = 1;
 247 
 248         /*
 249          * Traverse the range tree and calculate the number of space map
 250          * entries that would be required to write out the range tree.
 251          */
 252         for (rs = avl_first(t); rs != NULL; rs = AVL_NEXT(t, rs)) {
 253                 size = (rs->rs_end - rs->rs_start) >> sm->sm_shift;
 254                 entries += howmany(size, SM_RUN_MAX);
 255         }
 256         return (entries);
 257 }
 258 



 259 void
 260 space_map_write(space_map_t *sm, range_tree_t *rt, maptype_t maptype,
 261     dmu_tx_t *tx)
 262 {
 263         objset_t *os = sm->sm_os;
 264         spa_t *spa = dmu_objset_spa(os);
 265         avl_tree_t *t = &rt->rt_root;
 266         range_seg_t *rs;
 267         uint64_t size, total, rt_space, nodes;
 268         uint64_t *entry, *entry_map, *entry_map_end;
 269         uint64_t expected_entries, actual_entries = 1;
 270 

 271         ASSERT(dsl_pool_sync_context(dmu_objset_pool(os)));
 272         VERIFY3U(space_map_object(sm), !=, 0);
 273         dmu_buf_will_dirty(sm->sm_dbuf, tx);
 274 
 275         /*
 276          * This field is no longer necessary since the in-core space map
 277          * now contains the object number but is maintained for backwards
 278          * compatibility.
 279          */
 280         sm->sm_phys->smp_object = sm->sm_object;
 281 
 282         if (range_tree_space(rt) == 0) {
 283                 VERIFY3U(sm->sm_object, ==, sm->sm_phys->smp_object);
 284                 return;
 285         }
 286 
 287         if (maptype == SM_ALLOC)
 288                 sm->sm_phys->smp_alloc += range_tree_space(rt);
 289         else
 290                 sm->sm_phys->smp_alloc -= range_tree_space(rt);


 300             SM_DEBUG_SYNCPASS_ENCODE(spa_sync_pass(spa)) |
 301             SM_DEBUG_TXG_ENCODE(dmu_tx_get_txg(tx));
 302 
 303         total = 0;
 304         nodes = avl_numnodes(&rt->rt_root);
 305         rt_space = range_tree_space(rt);
 306         for (rs = avl_first(t); rs != NULL; rs = AVL_NEXT(t, rs)) {
 307                 uint64_t start;
 308 
 309                 size = (rs->rs_end - rs->rs_start) >> sm->sm_shift;
 310                 start = (rs->rs_start - sm->sm_start) >> sm->sm_shift;
 311 
 312                 total += size << sm->sm_shift;
 313 
 314                 while (size != 0) {
 315                         uint64_t run_len;
 316 
 317                         run_len = MIN(size, SM_RUN_MAX);
 318 
 319                         if (entry == entry_map_end) {

 320                                 dmu_write(os, space_map_object(sm),
 321                                     sm->sm_phys->smp_objsize, sm->sm_blksz,
 322                                     entry_map, tx);

 323                                 sm->sm_phys->smp_objsize += sm->sm_blksz;
 324                                 entry = entry_map;
 325                         }
 326 
 327                         *entry++ = SM_OFFSET_ENCODE(start) |
 328                             SM_TYPE_ENCODE(maptype) |
 329                             SM_RUN_ENCODE(run_len);
 330 
 331                         start += run_len;
 332                         size -= run_len;
 333                         actual_entries++;
 334                 }
 335         }
 336 
 337         if (entry != entry_map) {
 338                 size = (entry - entry_map) * sizeof (uint64_t);

 339                 dmu_write(os, space_map_object(sm), sm->sm_phys->smp_objsize,
 340                     size, entry_map, tx);

 341                 sm->sm_phys->smp_objsize += size;
 342         }
 343         ASSERT3U(expected_entries, ==, actual_entries);
 344 
 345         /*
 346          * Ensure that the space_map's accounting wasn't changed
 347          * while we were in the middle of writing it out.
 348          */
 349         VERIFY3U(nodes, ==, avl_numnodes(&rt->rt_root));
 350         VERIFY3U(range_tree_space(rt), ==, rt_space);
 351         VERIFY3U(range_tree_space(rt), ==, total);
 352 
 353         zio_buf_free(entry_map, sm->sm_blksz);
 354 }
 355 
 356 static int
 357 space_map_open_impl(space_map_t *sm)
 358 {
 359         int error;
 360         u_longlong_t blocks;
 361 
 362         error = dmu_bonus_hold(sm->sm_os, sm->sm_object, sm, &sm->sm_dbuf);
 363         if (error)
 364                 return (error);
 365 
 366         dmu_object_size_from_db(sm->sm_dbuf, &sm->sm_blksz, &blocks);
 367         sm->sm_phys = sm->sm_dbuf->db_data;
 368         return (0);
 369 }
 370 
 371 int
 372 space_map_open(space_map_t **smp, objset_t *os, uint64_t object,
 373     uint64_t start, uint64_t size, uint8_t shift)
 374 {
 375         space_map_t *sm;
 376         int error;
 377 
 378         ASSERT(*smp == NULL);
 379         ASSERT(os != NULL);
 380         ASSERT(object != 0);
 381 
 382         sm = kmem_zalloc(sizeof (space_map_t), KM_SLEEP);
 383 
 384         sm->sm_start = start;
 385         sm->sm_size = size;
 386         sm->sm_shift = shift;

 387         sm->sm_os = os;
 388         sm->sm_object = object;
 389 
 390         error = space_map_open_impl(sm);
 391         if (error != 0) {
 392                 space_map_close(sm);
 393                 return (error);
 394         }
 395 
 396         *smp = sm;
 397 
 398         return (0);
 399 }
 400 
 401 void
 402 space_map_close(space_map_t *sm)
 403 {
 404         if (sm == NULL)
 405                 return;
 406 


 455                  * bugs related to the uncommon case do not go unnoticed.
 456                  */
 457                 bzero(sm->sm_phys->smp_histogram,
 458                     sizeof (sm->sm_phys->smp_histogram));
 459         }
 460 
 461         dmu_buf_will_dirty(sm->sm_dbuf, tx);
 462         sm->sm_phys->smp_objsize = 0;
 463         sm->sm_phys->smp_alloc = 0;
 464 }
 465 
 466 /*
 467  * Update the in-core space_map allocation and length values.
 468  */
 469 void
 470 space_map_update(space_map_t *sm)
 471 {
 472         if (sm == NULL)
 473                 return;
 474 


 475         sm->sm_alloc = sm->sm_phys->smp_alloc;
 476         sm->sm_length = sm->sm_phys->smp_objsize;
 477 }
 478 
 479 uint64_t
 480 space_map_alloc(objset_t *os, dmu_tx_t *tx)
 481 {
 482         spa_t *spa = dmu_objset_spa(os);
 483         uint64_t object;
 484         int bonuslen;
 485 
 486         if (spa_feature_is_enabled(spa, SPA_FEATURE_SPACEMAP_HISTOGRAM)) {
 487                 spa_feature_incr(spa, SPA_FEATURE_SPACEMAP_HISTOGRAM, tx);
 488                 bonuslen = sizeof (space_map_phys_t);
 489                 ASSERT3U(bonuslen, <=, dmu_bonus_max());
 490         } else {
 491                 bonuslen = SPACE_MAP_SIZE_V0;
 492         }
 493 
 494         object = dmu_object_alloc(os,
 495             DMU_OT_SPACE_MAP, space_map_blksz,
 496             DMU_OT_SPACE_MAP_HEADER, bonuslen, tx);
 497 
 498         return (object);
 499 }
 500 
 501 void
 502 space_map_free_obj(objset_t *os, uint64_t smobj, dmu_tx_t *tx)
 503 {
 504         spa_t *spa = dmu_objset_spa(os);





 505         if (spa_feature_is_enabled(spa, SPA_FEATURE_SPACEMAP_HISTOGRAM)) {
 506                 dmu_object_info_t doi;
 507 
 508                 VERIFY0(dmu_object_info(os, smobj, &doi));
 509                 if (doi.doi_bonus_size != SPACE_MAP_SIZE_V0) {


 510                         spa_feature_decr(spa,
 511                             SPA_FEATURE_SPACEMAP_HISTOGRAM, tx);
 512                 }
 513         }
 514 
 515         VERIFY0(dmu_object_free(os, smobj, tx));
 516 }
 517 
 518 void
 519 space_map_free(space_map_t *sm, dmu_tx_t *tx)
 520 {
 521         if (sm == NULL)
 522                 return;
 523 
 524         space_map_free_obj(sm->sm_os, space_map_object(sm), tx);
 525         sm->sm_object = 0;
 526 }
 527 
 528 uint64_t
 529 space_map_object(space_map_t *sm)
 530 {
 531         return (sm != NULL ? sm->sm_object : 0);
 532 }
 533 
 534 /*
 535  * Returns the already synced, on-disk allocated space.
 536  */
 537 uint64_t
 538 space_map_allocated(space_map_t *sm)
 539 {
 540         return (sm != NULL ? sm->sm_alloc : 0);
 541 }
 542 
 543 /*
 544  * Returns the already synced, on-disk length;


  29 #include <sys/zfs_context.h>
  30 #include <sys/spa.h>
  31 #include <sys/dmu.h>
  32 #include <sys/dmu_tx.h>
  33 #include <sys/dnode.h>
  34 #include <sys/dsl_pool.h>
  35 #include <sys/zio.h>
  36 #include <sys/space_map.h>
  37 #include <sys/refcount.h>
  38 #include <sys/zfeature.h>
  39 
  40 /*
  41  * The data for a given space map can be kept on blocks of any size.
  42  * Larger blocks entail fewer i/o operations, but they also cause the
  43  * DMU to keep more data in-core, and also to waste more i/o bandwidth
  44  * when only a few blocks have changed since the last transaction group.
  45  */
  46 int space_map_blksz = (1 << 12);
  47 
  48 /*
  49  * Load the space map disk into the specified range tree. Segments of maptype
  50  * are added to the range tree, other segment types are removed.
  51  *
  52  * Note: space_map_load() will drop sm_lock across dmu_read() calls.
  53  * The caller must be OK with this.
  54  */
  55 int
  56 space_map_load(space_map_t *sm, range_tree_t *rt, maptype_t maptype)
  57 {
  58         uint64_t *entry, *entry_map, *entry_map_end;
  59         uint64_t bufsize, size, offset, end, space;
  60         int error = 0;
  61 
  62         ASSERT(MUTEX_HELD(sm->sm_lock));
  63 
  64         end = space_map_length(sm);
  65         space = space_map_allocated(sm);
  66 
  67         VERIFY0(range_tree_space(rt));
  68 
  69         if (maptype == SM_FREE) {
  70                 range_tree_add(rt, sm->sm_start, sm->sm_size);
  71                 space = sm->sm_size - space;
  72         }
  73 
  74         bufsize = MAX(sm->sm_blksz, SPA_MINBLOCKSIZE);
  75         entry_map = zio_buf_alloc(bufsize);
  76 
  77         mutex_exit(sm->sm_lock);
  78         if (end > bufsize) {
  79                 dmu_prefetch(sm->sm_os, space_map_object(sm), 0, bufsize,
  80                     end - bufsize, ZIO_PRIORITY_SYNC_READ);
  81         }
  82         mutex_enter(sm->sm_lock);
  83 
  84         for (offset = 0; offset < end; offset += bufsize) {
  85                 size = MIN(end - offset, bufsize);
  86                 VERIFY(P2PHASE(size, sizeof (uint64_t)) == 0);
  87                 VERIFY(size != 0);
  88                 ASSERT3U(sm->sm_blksz, !=, 0);
  89 
  90                 dprintf("object=%llu  offset=%llx  size=%llx\n",
  91                     space_map_object(sm), offset, size);
  92 
  93                 mutex_exit(sm->sm_lock);
  94                 error = dmu_read(sm->sm_os, space_map_object(sm), offset, size,
  95                     entry_map, DMU_READ_PREFETCH);
  96                 mutex_enter(sm->sm_lock);
  97                 if (error != 0)
  98                         break;
  99 
 100                 entry_map_end = entry_map + (size / sizeof (uint64_t));
 101                 for (entry = entry_map; entry < entry_map_end; entry++) {

 102                         uint64_t e = *entry;
 103                         uint64_t offset, size;
 104 
 105                         if (SM_DEBUG_DECODE(e))         /* Skip debug entries */
 106                                 continue;
 107 
 108                         offset = (SM_OFFSET_DECODE(e) << sm->sm_shift) +
 109                             sm->sm_start;
 110                         size = SM_RUN_DECODE(e) << sm->sm_shift;
 111 
 112                         VERIFY0(P2PHASE(offset, 1ULL << sm->sm_shift));
 113                         VERIFY0(P2PHASE(size, 1ULL << sm->sm_shift));
 114                         VERIFY3U(offset, >=, sm->sm_start);
 115                         VERIFY3U(offset + size, <=, sm->sm_start + sm->sm_size);
 116                         if (SM_TYPE_DECODE(e) == maptype) {
 117                                 VERIFY3U(range_tree_space(rt) + size, <=,
 118                                     sm->sm_size);
 119                                 range_tree_add(rt, offset, size);
 120                         } else {
 121                                 range_tree_remove(rt, offset, size);
 122                         }
 123                 }






















 124         }
 125 
 126         if (error == 0)



























 127                 VERIFY3U(range_tree_space(rt), ==, space);
 128         else
 129                 range_tree_vacate(rt, NULL, NULL);

 130 
 131         zio_buf_free(entry_map, bufsize);
 132         return (error);
 133 }
 134 
 135 void
 136 space_map_histogram_clear(space_map_t *sm)
 137 {
 138         if (sm->sm_dbuf->db_size != sizeof (space_map_phys_t))
 139                 return;
 140 
 141         bzero(sm->sm_phys->smp_histogram, sizeof (sm->sm_phys->smp_histogram));
 142 }
 143 
 144 boolean_t
 145 space_map_histogram_verify(space_map_t *sm, range_tree_t *rt)
 146 {
 147         /*
 148          * Verify that the in-core range tree does not have any
 149          * ranges smaller than our sm_shift size.
 150          */
 151         for (int i = 0; i < sm->sm_shift; i++) {
 152                 if (rt->rt_histogram[i] != 0)
 153                         return (B_FALSE);
 154         }
 155         return (B_TRUE);
 156 }
 157 
 158 void
 159 space_map_histogram_add(space_map_t *sm, range_tree_t *rt, dmu_tx_t *tx)
 160 {
 161         int idx = 0;
 162 
 163         ASSERT(MUTEX_HELD(rt->rt_lock));
 164         ASSERT(dmu_tx_is_syncing(tx));
 165         VERIFY3U(space_map_object(sm), !=, 0);
 166 
 167         if (sm->sm_dbuf->db_size != sizeof (space_map_phys_t))
 168                 return;
 169 
 170         dmu_buf_will_dirty(sm->sm_dbuf, tx);
 171 
 172         ASSERT(space_map_histogram_verify(sm, rt));
 173         /*
 174          * Transfer the content of the range tree histogram to the space
 175          * map histogram. The space map histogram contains 32 buckets ranging
 176          * between 2^sm_shift to 2^(32+sm_shift-1). The range tree,
 177          * however, can represent ranges from 2^0 to 2^63. Since the space
 178          * map only cares about allocatable blocks (minimum of sm_shift) we
 179          * can safely ignore all ranges in the range tree smaller than sm_shift.
 180          */
 181         for (int i = sm->sm_shift; i < RANGE_TREE_HISTOGRAM_SIZE; i++) {
 182 
 183                 /*


 212         avl_tree_t *t = &rt->rt_root;
 213         range_seg_t *rs;
 214         uint64_t size, entries;
 215 
 216         /*
 217          * All space_maps always have a debug entry so account for it here.
 218          */
 219         entries = 1;
 220 
 221         /*
 222          * Traverse the range tree and calculate the number of space map
 223          * entries that would be required to write out the range tree.
 224          */
 225         for (rs = avl_first(t); rs != NULL; rs = AVL_NEXT(t, rs)) {
 226                 size = (rs->rs_end - rs->rs_start) >> sm->sm_shift;
 227                 entries += howmany(size, SM_RUN_MAX);
 228         }
 229         return (entries);
 230 }
 231 
 232 /*
 233  * Note: space_map_write() will drop sm_lock across dmu_write() calls.
 234  */
 235 void
 236 space_map_write(space_map_t *sm, range_tree_t *rt, maptype_t maptype,
 237     dmu_tx_t *tx)
 238 {
 239         objset_t *os = sm->sm_os;
 240         spa_t *spa = dmu_objset_spa(os);
 241         avl_tree_t *t = &rt->rt_root;
 242         range_seg_t *rs;
 243         uint64_t size, total, rt_space, nodes;
 244         uint64_t *entry, *entry_map, *entry_map_end;
 245         uint64_t expected_entries, actual_entries = 1;
 246 
 247         ASSERT(MUTEX_HELD(rt->rt_lock));
 248         ASSERT(dsl_pool_sync_context(dmu_objset_pool(os)));
 249         VERIFY3U(space_map_object(sm), !=, 0);
 250         dmu_buf_will_dirty(sm->sm_dbuf, tx);
 251 
 252         /*
 253          * This field is no longer necessary since the in-core space map
 254          * now contains the object number but is maintained for backwards
 255          * compatibility.
 256          */
 257         sm->sm_phys->smp_object = sm->sm_object;
 258 
 259         if (range_tree_space(rt) == 0) {
 260                 VERIFY3U(sm->sm_object, ==, sm->sm_phys->smp_object);
 261                 return;
 262         }
 263 
 264         if (maptype == SM_ALLOC)
 265                 sm->sm_phys->smp_alloc += range_tree_space(rt);
 266         else
 267                 sm->sm_phys->smp_alloc -= range_tree_space(rt);


 277             SM_DEBUG_SYNCPASS_ENCODE(spa_sync_pass(spa)) |
 278             SM_DEBUG_TXG_ENCODE(dmu_tx_get_txg(tx));
 279 
 280         total = 0;
 281         nodes = avl_numnodes(&rt->rt_root);
 282         rt_space = range_tree_space(rt);
 283         for (rs = avl_first(t); rs != NULL; rs = AVL_NEXT(t, rs)) {
 284                 uint64_t start;
 285 
 286                 size = (rs->rs_end - rs->rs_start) >> sm->sm_shift;
 287                 start = (rs->rs_start - sm->sm_start) >> sm->sm_shift;
 288 
 289                 total += size << sm->sm_shift;
 290 
 291                 while (size != 0) {
 292                         uint64_t run_len;
 293 
 294                         run_len = MIN(size, SM_RUN_MAX);
 295 
 296                         if (entry == entry_map_end) {
 297                                 mutex_exit(rt->rt_lock);
 298                                 dmu_write(os, space_map_object(sm),
 299                                     sm->sm_phys->smp_objsize, sm->sm_blksz,
 300                                     entry_map, tx);
 301                                 mutex_enter(rt->rt_lock);
 302                                 sm->sm_phys->smp_objsize += sm->sm_blksz;
 303                                 entry = entry_map;
 304                         }
 305 
 306                         *entry++ = SM_OFFSET_ENCODE(start) |
 307                             SM_TYPE_ENCODE(maptype) |
 308                             SM_RUN_ENCODE(run_len);
 309 
 310                         start += run_len;
 311                         size -= run_len;
 312                         actual_entries++;
 313                 }
 314         }
 315 
 316         if (entry != entry_map) {
 317                 size = (entry - entry_map) * sizeof (uint64_t);
 318                 mutex_exit(rt->rt_lock);
 319                 dmu_write(os, space_map_object(sm), sm->sm_phys->smp_objsize,
 320                     size, entry_map, tx);
 321                 mutex_enter(rt->rt_lock);
 322                 sm->sm_phys->smp_objsize += size;
 323         }
 324         ASSERT3U(expected_entries, ==, actual_entries);
 325 
 326         /*
 327          * Ensure that the space_map's accounting wasn't changed
 328          * while we were in the middle of writing it out.
 329          */
 330         VERIFY3U(nodes, ==, avl_numnodes(&rt->rt_root));
 331         VERIFY3U(range_tree_space(rt), ==, rt_space);
 332         VERIFY3U(range_tree_space(rt), ==, total);
 333 
 334         zio_buf_free(entry_map, sm->sm_blksz);
 335 }
 336 
 337 static int
 338 space_map_open_impl(space_map_t *sm)
 339 {
 340         int error;
 341         u_longlong_t blocks;
 342 
 343         error = dmu_bonus_hold(sm->sm_os, sm->sm_object, sm, &sm->sm_dbuf);
 344         if (error)
 345                 return (error);
 346 
 347         dmu_object_size_from_db(sm->sm_dbuf, &sm->sm_blksz, &blocks);
 348         sm->sm_phys = sm->sm_dbuf->db_data;
 349         return (0);
 350 }
 351 
 352 int
 353 space_map_open(space_map_t **smp, objset_t *os, uint64_t object,
 354     uint64_t start, uint64_t size, uint8_t shift, kmutex_t *lp)
 355 {
 356         space_map_t *sm;
 357         int error;
 358 
 359         ASSERT(*smp == NULL);
 360         ASSERT(os != NULL);
 361         ASSERT(object != 0);
 362 
 363         sm = kmem_zalloc(sizeof (space_map_t), KM_SLEEP);
 364 
 365         sm->sm_start = start;
 366         sm->sm_size = size;
 367         sm->sm_shift = shift;
 368         sm->sm_lock = lp;
 369         sm->sm_os = os;
 370         sm->sm_object = object;
 371 
 372         error = space_map_open_impl(sm);
 373         if (error != 0) {
 374                 space_map_close(sm);
 375                 return (error);
 376         }
 377 
 378         *smp = sm;
 379 
 380         return (0);
 381 }
 382 
 383 void
 384 space_map_close(space_map_t *sm)
 385 {
 386         if (sm == NULL)
 387                 return;
 388 


 437                  * bugs related to the uncommon case do not go unnoticed.
 438                  */
 439                 bzero(sm->sm_phys->smp_histogram,
 440                     sizeof (sm->sm_phys->smp_histogram));
 441         }
 442 
 443         dmu_buf_will_dirty(sm->sm_dbuf, tx);
 444         sm->sm_phys->smp_objsize = 0;
 445         sm->sm_phys->smp_alloc = 0;
 446 }
 447 
 448 /*
 449  * Update the in-core space_map allocation and length values.
 450  */
 451 void
 452 space_map_update(space_map_t *sm)
 453 {
 454         if (sm == NULL)
 455                 return;
 456 
 457         ASSERT(MUTEX_HELD(sm->sm_lock));
 458 
 459         sm->sm_alloc = sm->sm_phys->smp_alloc;
 460         sm->sm_length = sm->sm_phys->smp_objsize;
 461 }
 462 
 463 uint64_t
 464 space_map_alloc(objset_t *os, dmu_tx_t *tx)
 465 {
 466         spa_t *spa = dmu_objset_spa(os);
 467         uint64_t object;
 468         int bonuslen;
 469 
 470         if (spa_feature_is_enabled(spa, SPA_FEATURE_SPACEMAP_HISTOGRAM)) {
 471                 spa_feature_incr(spa, SPA_FEATURE_SPACEMAP_HISTOGRAM, tx);
 472                 bonuslen = sizeof (space_map_phys_t);
 473                 ASSERT3U(bonuslen, <=, dmu_bonus_max());
 474         } else {
 475                 bonuslen = SPACE_MAP_SIZE_V0;
 476         }
 477 
 478         object = dmu_object_alloc(os,
 479             DMU_OT_SPACE_MAP, space_map_blksz,
 480             DMU_OT_SPACE_MAP_HEADER, bonuslen, tx);
 481 
 482         return (object);
 483 }
 484 
 485 void
 486 space_map_free(space_map_t *sm, dmu_tx_t *tx)
 487 {
 488         spa_t *spa;
 489 
 490         if (sm == NULL)
 491                 return;
 492 
 493         spa = dmu_objset_spa(sm->sm_os);
 494         if (spa_feature_is_enabled(spa, SPA_FEATURE_SPACEMAP_HISTOGRAM)) {
 495                 dmu_object_info_t doi;
 496 
 497                 dmu_object_info_from_db(sm->sm_dbuf, &doi);
 498                 if (doi.doi_bonus_size != SPACE_MAP_SIZE_V0) {
 499                         VERIFY(spa_feature_is_active(spa,
 500                             SPA_FEATURE_SPACEMAP_HISTOGRAM));
 501                         spa_feature_decr(spa,
 502                             SPA_FEATURE_SPACEMAP_HISTOGRAM, tx);
 503                 }
 504         }
 505 
 506         VERIFY3U(dmu_object_free(sm->sm_os, space_map_object(sm), tx), ==, 0);









 507         sm->sm_object = 0;
 508 }
 509 
 510 uint64_t
 511 space_map_object(space_map_t *sm)
 512 {
 513         return (sm != NULL ? sm->sm_object : 0);
 514 }
 515 
 516 /*
 517  * Returns the already synced, on-disk allocated space.
 518  */
 519 uint64_t
 520 space_map_allocated(space_map_t *sm)
 521 {
 522         return (sm != NULL ? sm->sm_alloc : 0);
 523 }
 524 
 525 /*
 526  * Returns the already synced, on-disk length;