module/zfs/dsl_deadlist.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 (c) 2010, Oracle and/or its affiliates. All rights reserved.
  23  * Copyright (c) 2011 by Delphix. All rights reserved.
  24  */
  25
  26 #include <sys/dsl_dataset.h>
  27 #include <sys/dmu.h>
  28 #include <sys/refcount.h>
  29 #include <sys/zap.h>
  30 #include <sys/zfs_context.h>
  31 #include <sys/dsl_pool.h>
  32
  33 /*
  34  * Deadlist concurrency:
  35  *
  36  * Deadlists can only be modified from the syncing thread.
  37  *
  38  * Except for dsl_deadlist_insert(), it can only be modified with the
  39  * dp_config_rwlock held with RW_WRITER.
  40  *
  41  * The accessors (dsl_deadlist_space() and dsl_deadlist_space_range()) can
  42  * be called concurrently, from open context, with the dl_config_rwlock held
  43  * with RW_READER.
  44  *
  45  * Therefore, we only need to provide locking between dsl_deadlist_insert() and
  46  * the accessors, protecting:
  47  *     dl_phys->dl_used,comp,uncomp
  48  *     and protecting the dl_tree from being loaded.
  49  * The locking is provided by dl_lock.  Note that locking on the bpobj_t
  50  * provides its own locking, and dl_oldfmt is immutable.
  51  */
  52
  53 static int
  54 dsl_deadlist_compare(const void *arg1, const void *arg2)
  55 {
  56         const dsl_deadlist_entry_t *dle1 = arg1;
  57         const dsl_deadlist_entry_t *dle2 = arg2;
  58
  59         if (dle1->dle_mintxg < dle2->dle_mintxg)
  60                 return (-1);
  61         else if (dle1->dle_mintxg > dle2->dle_mintxg)
  62                 return (+1);
  63         else
  64                 return (0);
  65 }
  66
  67 static void
  68 dsl_deadlist_load_tree(dsl_deadlist_t *dl)
  69 {
  70         zap_cursor_t zc;
  71         zap_attribute_t za;
  72
  73         ASSERT(!dl->dl_oldfmt);
  74         if (dl->dl_havetree)
  75                 return;
  76
  77         avl_create(&dl->dl_tree, dsl_deadlist_compare,
  78             sizeof (dsl_deadlist_entry_t),
  79             offsetof(dsl_deadlist_entry_t, dle_node));
  80         for (zap_cursor_init(&zc, dl->dl_os, dl->dl_object);
  81             zap_cursor_retrieve(&zc, &za) == 0;
  82             zap_cursor_advance(&zc)) {
  83                 dsl_deadlist_entry_t *dle;
  84
  85                 dle = kmem_alloc(sizeof (*dle), KM_PUSHPAGE);
  86                 dle->dle_mintxg = strtonum(za.za_name, NULL);
  87                 VERIFY3U(0, ==, bpobj_open(&dle->dle_bpobj, dl->dl_os,
  88                     za.za_first_integer));
  89                 avl_add(&dl->dl_tree, dle);
  90         }
  91         zap_cursor_fini(&zc);
  92         dl->dl_havetree = B_TRUE;
  93 }
  94
  95 void
  96 dsl_deadlist_open(dsl_deadlist_t *dl, objset_t *os, uint64_t object)
  97 {
  98         dmu_object_info_t doi;
  99
 100         mutex_init(&dl->dl_lock, NULL, MUTEX_DEFAULT, NULL);
 101         dl->dl_os = os;
 102         dl->dl_object = object;
 103         VERIFY3U(0, ==, dmu_bonus_hold(os, object, dl, &dl->dl_dbuf));
 104         dmu_object_info_from_db(dl->dl_dbuf, &doi);
 105         if (doi.doi_type == DMU_OT_BPOBJ) {
 106                 dmu_buf_rele(dl->dl_dbuf, dl);
 107                 dl->dl_dbuf = NULL;
 108                 dl->dl_oldfmt = B_TRUE;
 109                 VERIFY3U(0, ==, bpobj_open(&dl->dl_bpobj, os, object));
 110                 return;
 111         }
 112
 113         dl->dl_oldfmt = B_FALSE;
 114         dl->dl_phys = dl->dl_dbuf->db_data;
 115         dl->dl_havetree = B_FALSE;
 116 }
 117
 118 void
 119 dsl_deadlist_close(dsl_deadlist_t *dl)
 120 {
 121         void *cookie = NULL;
 122         dsl_deadlist_entry_t *dle;
 123
 124         if (dl->dl_oldfmt) {
 125                 dl->dl_oldfmt = B_FALSE;
 126                 bpobj_close(&dl->dl_bpobj);
 127                 return;
 128         }
 129
 130         if (dl->dl_havetree) {
 131                 while ((dle = avl_destroy_nodes(&dl->dl_tree, &cookie))
 132                     != NULL) {
 133                         bpobj_close(&dle->dle_bpobj);
 134                         kmem_free(dle, sizeof (*dle));
 135                 }
 136                 avl_destroy(&dl->dl_tree);
 137         }
 138         dmu_buf_rele(dl->dl_dbuf, dl);
 139         mutex_destroy(&dl->dl_lock);
 140         dl->dl_dbuf = NULL;
 141         dl->dl_phys = NULL;
 142 }
 143
 144 uint64_t
 145 dsl_deadlist_alloc(objset_t *os, dmu_tx_t *tx)
 146 {
 147         if (spa_version(dmu_objset_spa(os)) < SPA_VERSION_DEADLISTS)
 148                 return (bpobj_alloc(os, SPA_MAXBLOCKSIZE, tx));
 149         return (zap_create(os, DMU_OT_DEADLIST, DMU_OT_DEADLIST_HDR,
 150             sizeof (dsl_deadlist_phys_t), tx));
 151 }
 152
 153 void
 154 dsl_deadlist_free(objset_t *os, uint64_t dlobj, dmu_tx_t *tx)
 155 {
 156         dmu_object_info_t doi;
 157         zap_cursor_t zc;
 158         zap_attribute_t za;
 159
 160         VERIFY3U(0, ==, dmu_object_info(os, dlobj, &doi));
 161         if (doi.doi_type == DMU_OT_BPOBJ) {
 162                 bpobj_free(os, dlobj, tx);
 163                 return;
 164         }
 165
 166         for (zap_cursor_init(&zc, os, dlobj);
 167             zap_cursor_retrieve(&zc, &za) == 0;
 168             zap_cursor_advance(&zc))
 169                 bpobj_free(os, za.za_first_integer, tx);
 170         zap_cursor_fini(&zc);
 171         VERIFY3U(0, ==, dmu_object_free(os, dlobj, tx));
 172 }
 173
 174 void
 175 dsl_deadlist_insert(dsl_deadlist_t *dl, const blkptr_t *bp, dmu_tx_t *tx)
 176 {
 177         dsl_deadlist_entry_t dle_tofind;
 178         dsl_deadlist_entry_t *dle;
 179         avl_index_t where;
 180
 181         if (dl->dl_oldfmt) {
 182                 bpobj_enqueue(&dl->dl_bpobj, bp, tx);
 183                 return;
 184         }
 185
 186         dsl_deadlist_load_tree(dl);
 187
 188         dmu_buf_will_dirty(dl->dl_dbuf, tx);
 189         mutex_enter(&dl->dl_lock);
 190         dl->dl_phys->dl_used +=
 191             bp_get_dsize_sync(dmu_objset_spa(dl->dl_os), bp);
 192         dl->dl_phys->dl_comp += BP_GET_PSIZE(bp);
 193         dl->dl_phys->dl_uncomp += BP_GET_UCSIZE(bp);
 194         mutex_exit(&dl->dl_lock);
 195
 196         dle_tofind.dle_mintxg = bp->blk_birth;
 197         dle = avl_find(&dl->dl_tree, &dle_tofind, &where);
 198         if (dle == NULL)
 199                 dle = avl_nearest(&dl->dl_tree, where, AVL_BEFORE);
 200         else
 201                 dle = AVL_PREV(&dl->dl_tree, dle);
 202         bpobj_enqueue(&dle->dle_bpobj, bp, tx);
 203 }
 204
 205 /*
 206  * Insert new key in deadlist, which must be > all current entries.
 207  * mintxg is not inclusive.
 208  */
 209 void
 210 dsl_deadlist_add_key(dsl_deadlist_t *dl, uint64_t mintxg, dmu_tx_t *tx)
 211 {
 212         uint64_t obj;
 213         dsl_deadlist_entry_t *dle;
 214
 215         if (dl->dl_oldfmt)
 216                 return;
 217
 218         dsl_deadlist_load_tree(dl);
 219
 220         dle = kmem_alloc(sizeof (*dle), KM_PUSHPAGE);
 221         dle->dle_mintxg = mintxg;
 222         obj = bpobj_alloc(dl->dl_os, SPA_MAXBLOCKSIZE, tx);
 223         VERIFY3U(0, ==, bpobj_open(&dle->dle_bpobj, dl->dl_os, obj));
 224         avl_add(&dl->dl_tree, dle);
 225
 226         VERIFY3U(0, ==, zap_add_int_key(dl->dl_os, dl->dl_object,
 227             mintxg, obj, tx));
 228 }
 229
 230 /*
 231  * Remove this key, merging its entries into the previous key.
 232  */
 233 void
 234 dsl_deadlist_remove_key(dsl_deadlist_t *dl, uint64_t mintxg, dmu_tx_t *tx)
 235 {
 236         dsl_deadlist_entry_t dle_tofind;
 237         dsl_deadlist_entry_t *dle, *dle_prev;
 238
 239         if (dl->dl_oldfmt)
 240                 return;
 241
 242         dsl_deadlist_load_tree(dl);
 243
 244         dle_tofind.dle_mintxg = mintxg;
 245         dle = avl_find(&dl->dl_tree, &dle_tofind, NULL);
 246         dle_prev = AVL_PREV(&dl->dl_tree, dle);
 247
 248         bpobj_enqueue_subobj(&dle_prev->dle_bpobj,
 249             dle->dle_bpobj.bpo_object, tx);
 250
 251         avl_remove(&dl->dl_tree, dle);
 252         bpobj_close(&dle->dle_bpobj);
 253         kmem_free(dle, sizeof (*dle));
 254
 255         VERIFY3U(0, ==, zap_remove_int(dl->dl_os, dl->dl_object, mintxg, tx));
 256 }
 257
 258 /*
 259  * Walk ds's snapshots to regenerate generate ZAP & AVL.
 260  */
 261 static void
 262 dsl_deadlist_regenerate(objset_t *os, uint64_t dlobj,
 263     uint64_t mrs_obj, dmu_tx_t *tx)
 264 {
 265         dsl_deadlist_t dl;
 266         dsl_pool_t *dp = dmu_objset_pool(os);
 267
 268         dsl_deadlist_open(&dl, os, dlobj);
 269         if (dl.dl_oldfmt) {
 270                 dsl_deadlist_close(&dl);
 271                 return;
 272         }
 273
 274         while (mrs_obj != 0) {
 275                 dsl_dataset_t *ds;
 276                 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, mrs_obj, FTAG, &ds));
 277                 dsl_deadlist_add_key(&dl, ds->ds_phys->ds_prev_snap_txg, tx);
 278                 mrs_obj = ds->ds_phys->ds_prev_snap_obj;
 279                 dsl_dataset_rele(ds, FTAG);
 280         }
 281         dsl_deadlist_close(&dl);
 282 }
 283
 284 uint64_t
 285 dsl_deadlist_clone(dsl_deadlist_t *dl, uint64_t maxtxg,
 286     uint64_t mrs_obj, dmu_tx_t *tx)
 287 {
 288         dsl_deadlist_entry_t *dle;
 289         uint64_t newobj;
 290
 291         newobj = dsl_deadlist_alloc(dl->dl_os, tx);
 292
 293         if (dl->dl_oldfmt) {
 294                 dsl_deadlist_regenerate(dl->dl_os, newobj, mrs_obj, tx);
 295                 return (newobj);
 296         }
 297
 298         dsl_deadlist_load_tree(dl);
 299
 300         for (dle = avl_first(&dl->dl_tree); dle;
 301             dle = AVL_NEXT(&dl->dl_tree, dle)) {
 302                 uint64_t obj;
 303
 304                 if (dle->dle_mintxg >= maxtxg)
 305                         break;
 306
 307                 obj = bpobj_alloc(dl->dl_os, SPA_MAXBLOCKSIZE, tx);
 308                 VERIFY3U(0, ==, zap_add_int_key(dl->dl_os, newobj,
 309                     dle->dle_mintxg, obj, tx));
 310         }
 311         return (newobj);
 312 }
 313
 314 void
 315 dsl_deadlist_space(dsl_deadlist_t *dl,
 316     uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
 317 {
 318         if (dl->dl_oldfmt) {
 319                 VERIFY3U(0, ==, bpobj_space(&dl->dl_bpobj,
 320                     usedp, compp, uncompp));
 321                 return;
 322         }
 323
 324         mutex_enter(&dl->dl_lock);
 325         *usedp = dl->dl_phys->dl_used;
 326         *compp = dl->dl_phys->dl_comp;
 327         *uncompp = dl->dl_phys->dl_uncomp;
 328         mutex_exit(&dl->dl_lock);
 329 }
 330
 331 /*
 332  * return space used in the range (mintxg, maxtxg].
 333  * Includes maxtxg, does not include mintxg.
 334  * mintxg and maxtxg must both be keys in the deadlist (unless maxtxg is
 335  * larger than any bp in the deadlist (eg. UINT64_MAX)).
 336  */
 337 void
 338 dsl_deadlist_space_range(dsl_deadlist_t *dl, uint64_t mintxg, uint64_t maxtxg,
 339     uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
 340 {
 341         dsl_deadlist_entry_t *dle;
 342         dsl_deadlist_entry_t dle_tofind;
 343         avl_index_t where;
 344
 345         if (dl->dl_oldfmt) {
 346                 VERIFY3U(0, ==, bpobj_space_range(&dl->dl_bpobj,
 347                     mintxg, maxtxg, usedp, compp, uncompp));
 348                 return;
 349         }
 350
 351         *usedp = *compp = *uncompp = 0;
 352
 353         mutex_enter(&dl->dl_lock);
 354         dsl_deadlist_load_tree(dl);
 355         dle_tofind.dle_mintxg = mintxg;
 356         dle = avl_find(&dl->dl_tree, &dle_tofind, &where);
 357         /*
 358          * If we don't find this mintxg, there shouldn't be anything
 359          * after it either.
 360          */
 361         ASSERT(dle != NULL ||
 362             avl_nearest(&dl->dl_tree, where, AVL_AFTER) == NULL);
 363
 364         for (; dle && dle->dle_mintxg < maxtxg;
 365             dle = AVL_NEXT(&dl->dl_tree, dle)) {
 366                 uint64_t used, comp, uncomp;
 367
 368                 VERIFY3U(0, ==, bpobj_space(&dle->dle_bpobj,
 369                     &used, &comp, &uncomp));
 370
 371                 *usedp += used;
 372                 *compp += comp;
 373                 *uncompp += uncomp;
 374         }
 375         mutex_exit(&dl->dl_lock);
 376 }
 377
 378 static void
 379 dsl_deadlist_insert_bpobj(dsl_deadlist_t *dl, uint64_t obj, uint64_t birth,
 380     dmu_tx_t *tx)
 381 {
 382         dsl_deadlist_entry_t dle_tofind;
 383         dsl_deadlist_entry_t *dle;
 384         avl_index_t where;
 385         uint64_t used, comp, uncomp;
 386         bpobj_t bpo;
 387
 388         VERIFY3U(0, ==, bpobj_open(&bpo, dl->dl_os, obj));
 389         VERIFY3U(0, ==, bpobj_space(&bpo, &used, &comp, &uncomp));
 390         bpobj_close(&bpo);
 391
 392         dsl_deadlist_load_tree(dl);
 393
 394         dmu_buf_will_dirty(dl->dl_dbuf, tx);
 395         mutex_enter(&dl->dl_lock);
 396         dl->dl_phys->dl_used += used;
 397         dl->dl_phys->dl_comp += comp;
 398         dl->dl_phys->dl_uncomp += uncomp;
 399         mutex_exit(&dl->dl_lock);
 400
 401         dle_tofind.dle_mintxg = birth;
 402         dle = avl_find(&dl->dl_tree, &dle_tofind, &where);
 403         if (dle == NULL)
 404                 dle = avl_nearest(&dl->dl_tree, where, AVL_BEFORE);
 405         bpobj_enqueue_subobj(&dle->dle_bpobj, obj, tx);
 406 }
 407
 408 static int
 409 dsl_deadlist_insert_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
 410 {
 411         dsl_deadlist_t *dl = arg;
 412         dsl_deadlist_insert(dl, bp, tx);
 413         return (0);
 414 }
 415
 416 /*
 417  * Merge the deadlist pointed to by 'obj' into dl.  obj will be left as
 418  * an empty deadlist.
 419  */
 420 void
 421 dsl_deadlist_merge(dsl_deadlist_t *dl, uint64_t obj, dmu_tx_t *tx)
 422 {
 423         zap_cursor_t zc;
 424         zap_attribute_t za;
 425         dmu_buf_t *bonus;
 426         dsl_deadlist_phys_t *dlp;
 427         dmu_object_info_t doi;
 428
 429         VERIFY3U(0, ==, dmu_object_info(dl->dl_os, obj, &doi));
 430         if (doi.doi_type == DMU_OT_BPOBJ) {
 431                 bpobj_t bpo;
 432                 VERIFY3U(0, ==, bpobj_open(&bpo, dl->dl_os, obj));
 433                 VERIFY3U(0, ==, bpobj_iterate(&bpo,
 434                     dsl_deadlist_insert_cb, dl, tx));
 435                 bpobj_close(&bpo);
 436                 return;
 437         }
 438
 439         for (zap_cursor_init(&zc, dl->dl_os, obj);
 440             zap_cursor_retrieve(&zc, &za) == 0;
 441             zap_cursor_advance(&zc)) {
 442                 uint64_t mintxg = strtonum(za.za_name, NULL);
 443                 dsl_deadlist_insert_bpobj(dl, za.za_first_integer, mintxg, tx);
 444                 VERIFY3U(0, ==, zap_remove_int(dl->dl_os, obj, mintxg, tx));
 445         }
 446         zap_cursor_fini(&zc);
 447
 448         VERIFY3U(0, ==, dmu_bonus_hold(dl->dl_os, obj, FTAG, &bonus));
 449         dlp = bonus->db_data;
 450         dmu_buf_will_dirty(bonus, tx);
 451         bzero(dlp, sizeof (*dlp));
 452         dmu_buf_rele(bonus, FTAG);
 453 }
 454
 455 /*
 456  * Remove entries on dl that are >= mintxg, and put them on the bpobj.
 457  */
 458 void
 459 dsl_deadlist_move_bpobj(dsl_deadlist_t *dl, bpobj_t *bpo, uint64_t mintxg,
 460     dmu_tx_t *tx)
 461 {
 462         dsl_deadlist_entry_t dle_tofind;
 463         dsl_deadlist_entry_t *dle;
 464         avl_index_t where;
 465
 466         ASSERT(!dl->dl_oldfmt);
 467         dmu_buf_will_dirty(dl->dl_dbuf, tx);
 468         dsl_deadlist_load_tree(dl);
 469
 470         dle_tofind.dle_mintxg = mintxg;
 471         dle = avl_find(&dl->dl_tree, &dle_tofind, &where);
 472         if (dle == NULL)
 473                 dle = avl_nearest(&dl->dl_tree, where, AVL_AFTER);
 474         while (dle) {
 475                 uint64_t used, comp, uncomp;
 476                 dsl_deadlist_entry_t *dle_next;
 477
 478                 bpobj_enqueue_subobj(bpo, dle->dle_bpobj.bpo_object, tx);
 479
 480                 VERIFY3U(0, ==, bpobj_space(&dle->dle_bpobj,
 481                     &used, &comp, &uncomp));
 482                 mutex_enter(&dl->dl_lock);
 483                 ASSERT3U(dl->dl_phys->dl_used, >=, used);
 484                 ASSERT3U(dl->dl_phys->dl_comp, >=, comp);
 485                 ASSERT3U(dl->dl_phys->dl_uncomp, >=, uncomp);
 486                 dl->dl_phys->dl_used -= used;
 487                 dl->dl_phys->dl_comp -= comp;
 488                 dl->dl_phys->dl_uncomp -= uncomp;
 489                 mutex_exit(&dl->dl_lock);
 490
 491                 VERIFY3U(0, ==, zap_remove_int(dl->dl_os, dl->dl_object,
 492                     dle->dle_mintxg, tx));
 493
 494                 dle_next = AVL_NEXT(&dl->dl_tree, dle);
 495                 avl_remove(&dl->dl_tree, dle);
 496                 bpobj_close(&dle->dle_bpobj);
 497                 kmem_free(dle, sizeof (*dle));
 498                 dle = dle_next;
 499         }
 500 }