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