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, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright 2005 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 30 /* 31 * This file contains the top half of the zfs directory structure 32 * implementation. The bottom half is in zap_leaf.c. 33 * 34 * The zdir is an extendable hash data structure. There is a table of 35 * pointers to buckets (zap_t->zd_data->zd_leafs). The buckets are 36 * each a constant size and hold a variable number of directory entries. 37 * The buckets (aka "leaf nodes") are implemented in zap_leaf.c. 38 * 39 * The pointer table holds a power of 2 number of pointers. 40 * (1<<zap_t->zd_data->zd_phys->zd_prefix_len). The bucket pointed to 41 * by the pointer at index i in the table holds entries whose hash value 42 * has a zd_prefix_len - bit prefix 43 */ 44 45 #include <sys/spa.h> 46 #include <sys/dmu.h> 47 #include <sys/zfs_context.h> 48 #include <sys/zap.h> 49 #include <sys/zap_impl.h> 50 #include <sys/zap_leaf.h> 51 52 #define MIN_FREE (ZAP_LEAF_NUMCHUNKS*9/10) 53 54 static void zap_grow_ptrtbl(zap_t *zap, dmu_tx_t *tx); 55 static int zap_tryupgradedir(zap_t *zap, dmu_tx_t *tx); 56 static zap_leaf_t *zap_get_leaf_byblk(zap_t *zap, uint64_t blkid, 57 dmu_tx_t *tx, krw_t lt); 58 static void zap_leaf_pageout(dmu_buf_t *db, void *vl); 59 60 61 void 62 fzap_byteswap(void *vbuf, size_t size) 63 { 64 uint64_t block_type; 65 66 ASSERT(size == (1<<ZAP_BLOCK_SHIFT)); 67 block_type = *(uint64_t *)vbuf; 68 69 switch (block_type) { 70 case ZBT_LEAF: 71 case BSWAP_64(ZBT_LEAF): 72 zap_leaf_byteswap(vbuf); 73 return; 74 case ZBT_HEADER: 75 case BSWAP_64(ZBT_HEADER): 76 default: 77 /* it's a ptrtbl block */ 78 byteswap_uint64_array(vbuf, 1<<ZAP_BLOCK_SHIFT); 79 return; 80 } 81 } 82 83 void 84 fzap_upgrade(zap_t *zap, dmu_tx_t *tx) 85 { 86 dmu_buf_t *db; 87 zap_leaf_t *l; 88 int i; 89 zap_phys_t *zp; 90 91 ASSERT(RW_WRITE_HELD(&zap->zap_rwlock)); 92 zap->zap_ismicro = FALSE; 93 94 (void) dmu_buf_update_user(zap->zap_dbuf, zap, zap, 95 &zap->zap_f.zap_phys, zap_pageout); 96 97 mutex_init(&zap->zap_f.zap_num_entries_mtx, 0, 0, 0); 98 99 zp = zap->zap_f.zap_phys; 100 /* 101 * explicitly zero it since it might be coming from an 102 * initialized microzap 103 */ 104 ASSERT3U(sizeof (zap_phys_t), ==, zap->zap_dbuf->db_size); 105 bzero(zp, sizeof (zap_phys_t)); 106 zp->zap_block_type = ZBT_HEADER; 107 zp->zap_magic = ZAP_MAGIC; 108 109 zp->zap_ptrtbl.zt_shift = ZAP_PTRTBL_MIN_SHIFT; 110 111 zp->zap_freeblk = 2; /* block 1 will be the first leaf */ 112 zp->zap_num_leafs = 1; 113 zp->zap_num_entries = 0; 114 zp->zap_salt = zap->zap_salt; 115 116 for (i = 0; i < (1<<ZAP_PTRTBL_MIN_SHIFT); i++) 117 zp->zap_leafs[i] = 1; /* block 1 will be the first leaf */ 118 119 /* 120 * set up block 1 - the first leaf 121 */ 122 db = dmu_buf_hold(zap->zap_objset, zap->zap_object, 123 1<<ZAP_BLOCK_SHIFT); 124 dmu_buf_will_dirty(db, tx); 125 126 l = kmem_zalloc(sizeof (zap_leaf_t), KM_SLEEP); 127 l->l_dbuf = db; 128 l->l_phys = db->db_data; 129 130 zap_leaf_init(l); 131 132 kmem_free(l, sizeof (zap_leaf_t)); 133 dmu_buf_rele(db); 134 } 135 136 static int 137 zap_tryupgradedir(zap_t *zap, dmu_tx_t *tx) 138 { 139 if (RW_WRITE_HELD(&zap->zap_rwlock)) 140 return (1); 141 if (rw_tryupgrade(&zap->zap_rwlock)) { 142 dmu_buf_will_dirty(zap->zap_dbuf, tx); 143 return (1); 144 } 145 return (0); 146 } 147 148 /* 149 * Generic routines for dealing with the pointer & cookie tables. 150 */ 151 152 static void 153 zap_table_grow(zap_t *zap, zap_table_phys_t *tbl, 154 void (*transfer_func)(const uint64_t *src, uint64_t *dst, int n), 155 dmu_tx_t *tx) 156 { 157 uint64_t b, newblk; 158 dmu_buf_t *db_old, *db_new; 159 int hepb = 1<<(ZAP_BLOCK_SHIFT-4); 160 /* hepb = half the number of entries in a block */ 161 162 ASSERT(RW_WRITE_HELD(&zap->zap_rwlock)); 163 ASSERT(tbl->zt_blk != 0); 164 ASSERT(tbl->zt_numblks > 0); 165 166 if (tbl->zt_nextblk != 0) { 167 newblk = tbl->zt_nextblk; 168 } else { 169 newblk = zap_allocate_blocks(zap, tbl->zt_numblks * 2, tx); 170 tbl->zt_nextblk = newblk; 171 ASSERT3U(tbl->zt_blks_copied, ==, 0); 172 dmu_prefetch(zap->zap_objset, zap->zap_object, 173 tbl->zt_blk << ZAP_BLOCK_SHIFT, tbl->zt_numblks << 174 ZAP_BLOCK_SHIFT); 175 } 176 177 /* 178 * Copy the ptrtbl from the old to new location, leaving the odd 179 * entries blank as we go. 180 */ 181 182 b = tbl->zt_blks_copied; 183 db_old = dmu_buf_hold(zap->zap_objset, zap->zap_object, 184 (tbl->zt_blk + b) << ZAP_BLOCK_SHIFT); 185 dmu_buf_read(db_old); 186 187 /* first half of entries in old[b] go to new[2*b+0] */ 188 db_new = dmu_buf_hold(zap->zap_objset, zap->zap_object, 189 (newblk + 2*b+0) << ZAP_BLOCK_SHIFT); 190 dmu_buf_will_dirty(db_new, tx); 191 transfer_func(db_old->db_data, db_new->db_data, hepb); 192 dmu_buf_rele(db_new); 193 194 /* second half of entries in old[b] go to new[2*b+1] */ 195 db_new = dmu_buf_hold(zap->zap_objset, zap->zap_object, 196 (newblk + 2*b+1) << ZAP_BLOCK_SHIFT); 197 dmu_buf_will_dirty(db_new, tx); 198 transfer_func((uint64_t *)db_old->db_data + hepb, 199 db_new->db_data, hepb); 200 dmu_buf_rele(db_new); 201 202 dmu_buf_rele(db_old); 203 204 tbl->zt_blks_copied++; 205 206 dprintf("copied block %llu of %llu\n", 207 tbl->zt_blks_copied, tbl->zt_numblks); 208 209 if (tbl->zt_blks_copied == tbl->zt_numblks) { 210 dmu_free_range(zap->zap_objset, zap->zap_object, 211 tbl->zt_blk << ZAP_BLOCK_SHIFT, 212 tbl->zt_numblks << ZAP_BLOCK_SHIFT, tx); 213 214 tbl->zt_blk = newblk; 215 tbl->zt_numblks *= 2; 216 tbl->zt_shift++; 217 tbl->zt_nextblk = 0; 218 tbl->zt_blks_copied = 0; 219 220 dprintf("finished; numblocks now %llu (%lluk entries)\n", 221 tbl->zt_numblks, 1<<(tbl->zt_shift-10)); 222 } 223 } 224 225 static uint64_t 226 zap_table_store(zap_t *zap, zap_table_phys_t *tbl, uint64_t idx, uint64_t val, 227 dmu_tx_t *tx) 228 { 229 uint64_t blk, off, oldval; 230 dmu_buf_t *db; 231 232 ASSERT(RW_LOCK_HELD(&zap->zap_rwlock)); 233 ASSERT(tbl->zt_blk != 0); 234 235 dprintf("storing %llx at index %llx\n", val, idx); 236 237 blk = idx >> (ZAP_BLOCK_SHIFT-3); 238 off = idx & ((1<<(ZAP_BLOCK_SHIFT-3))-1); 239 240 db = dmu_buf_hold(zap->zap_objset, zap->zap_object, 241 (tbl->zt_blk + blk) << ZAP_BLOCK_SHIFT); 242 dmu_buf_will_dirty(db, tx); 243 oldval = ((uint64_t *)db->db_data)[off]; 244 ((uint64_t *)db->db_data)[off] = val; 245 dmu_buf_rele(db); 246 247 if (tbl->zt_nextblk != 0) { 248 idx *= 2; 249 blk = idx >> (ZAP_BLOCK_SHIFT-3); 250 off = idx & ((1<<(ZAP_BLOCK_SHIFT-3))-1); 251 252 db = dmu_buf_hold(zap->zap_objset, zap->zap_object, 253 (tbl->zt_nextblk + blk) << ZAP_BLOCK_SHIFT); 254 dmu_buf_will_dirty(db, tx); 255 ((uint64_t *)db->db_data)[off] = val; 256 ((uint64_t *)db->db_data)[off+1] = val; 257 dmu_buf_rele(db); 258 } 259 260 return (oldval); 261 } 262 263 static uint64_t 264 zap_table_load(zap_t *zap, zap_table_phys_t *tbl, uint64_t idx) 265 { 266 uint64_t blk, off, val; 267 dmu_buf_t *db; 268 269 ASSERT(RW_LOCK_HELD(&zap->zap_rwlock)); 270 271 blk = idx >> (ZAP_BLOCK_SHIFT-3); 272 off = idx & ((1<<(ZAP_BLOCK_SHIFT-3))-1); 273 274 db = dmu_buf_hold(zap->zap_objset, zap->zap_object, 275 (tbl->zt_blk + blk) << ZAP_BLOCK_SHIFT); 276 dmu_buf_read(db); 277 val = ((uint64_t *)db->db_data)[off]; 278 dmu_buf_rele(db); 279 return (val); 280 } 281 282 /* 283 * Routines for growing the ptrtbl. 284 */ 285 286 static void 287 zap_ptrtbl_transfer(const uint64_t *src, uint64_t *dst, int n) 288 { 289 int i; 290 for (i = 0; i < n; i++) { 291 uint64_t lb = src[i]; 292 dst[2*i+0] = lb; 293 dst[2*i+1] = lb; 294 } 295 } 296 297 static void 298 zap_grow_ptrtbl(zap_t *zap, dmu_tx_t *tx) 299 { 300 if (zap->zap_f.zap_phys->zap_ptrtbl.zt_shift == 32) 301 return; 302 303 if (zap->zap_f.zap_phys->zap_ptrtbl.zt_numblks == 0) { 304 /* 305 * The ptrtbl can no longer be contained in the 306 * header block. Give it its own entire block, which 307 * will quadruple the size of the ptrtbl. 308 */ 309 uint64_t newblk; 310 dmu_buf_t *db_new; 311 312 ASSERT3U(zap->zap_f.zap_phys->zap_ptrtbl.zt_shift, ==, 313 ZAP_PTRTBL_MIN_SHIFT); 314 ASSERT3U(zap->zap_f.zap_phys->zap_ptrtbl.zt_blk, ==, 0); 315 316 newblk = zap_allocate_blocks(zap, 1, tx); 317 db_new = dmu_buf_hold(zap->zap_objset, zap->zap_object, 318 newblk << ZAP_BLOCK_SHIFT); 319 320 dmu_buf_will_dirty(db_new, tx); 321 zap_ptrtbl_transfer(zap->zap_f.zap_phys->zap_leafs, 322 db_new->db_data, 1 << ZAP_PTRTBL_MIN_SHIFT); 323 dmu_buf_rele(db_new); 324 325 zap->zap_f.zap_phys->zap_ptrtbl.zt_blk = newblk; 326 zap->zap_f.zap_phys->zap_ptrtbl.zt_numblks = 1; 327 zap->zap_f.zap_phys->zap_ptrtbl.zt_shift++; 328 329 ASSERT3U(1ULL << zap->zap_f.zap_phys->zap_ptrtbl.zt_shift, ==, 330 zap->zap_f.zap_phys->zap_ptrtbl.zt_numblks << 331 (ZAP_BLOCK_SHIFT-3)); 332 } else { 333 zap_table_grow(zap, &zap->zap_f.zap_phys->zap_ptrtbl, 334 zap_ptrtbl_transfer, tx); 335 } 336 } 337 338 static void 339 zap_increment_num_entries(zap_t *zap, int delta, dmu_tx_t *tx) 340 { 341 dmu_buf_will_dirty(zap->zap_dbuf, tx); 342 mutex_enter(&zap->zap_f.zap_num_entries_mtx); 343 344 ASSERT(delta > 0 || zap->zap_f.zap_phys->zap_num_entries >= -delta); 345 346 zap->zap_f.zap_phys->zap_num_entries += delta; 347 348 mutex_exit(&zap->zap_f.zap_num_entries_mtx); 349 } 350 351 uint64_t 352 zap_allocate_blocks(zap_t *zap, int nblocks, dmu_tx_t *tx) 353 { 354 uint64_t newblk; 355 ASSERT(tx != NULL); 356 if (!RW_WRITE_HELD(&zap->zap_rwlock)) { 357 dmu_buf_will_dirty(zap->zap_dbuf, tx); 358 } 359 newblk = atomic_add_64_nv(&zap->zap_f.zap_phys->zap_freeblk, nblocks) - 360 nblocks; 361 return (newblk); 362 } 363 364 365 /* 366 * This function doesn't increment zap_num_leafs because it's used to 367 * allocate a leaf chain, which doesn't count against zap_num_leafs. 368 * The directory must be held exclusively for this tx. 369 */ 370 zap_leaf_t * 371 zap_create_leaf(zap_t *zap, dmu_tx_t *tx) 372 { 373 void *winner; 374 zap_leaf_t *l = kmem_alloc(sizeof (zap_leaf_t), KM_SLEEP); 375 376 ASSERT(tx != NULL); 377 ASSERT(RW_WRITE_HELD(&zap->zap_rwlock)); 378 /* hence we already dirtied zap->zap_dbuf */ 379 380 rw_init(&l->l_rwlock, 0, 0, 0); 381 rw_enter(&l->l_rwlock, RW_WRITER); 382 l->l_blkid = zap_allocate_blocks(zap, 1, tx); 383 l->l_next = NULL; 384 l->l_dbuf = NULL; 385 l->l_phys = NULL; 386 387 l->l_dbuf = dmu_buf_hold(zap->zap_objset, zap->zap_object, 388 l->l_blkid << ZAP_BLOCK_SHIFT); 389 winner = dmu_buf_set_user(l->l_dbuf, l, &l->l_phys, zap_leaf_pageout); 390 ASSERT(winner == NULL); 391 dmu_buf_will_dirty(l->l_dbuf, tx); 392 393 zap_leaf_init(l); 394 395 return (l); 396 } 397 398 /* ARGSUSED */ 399 void 400 zap_destroy_leaf(zap_t *zap, zap_leaf_t *l, dmu_tx_t *tx) 401 { 402 /* uint64_t offset = l->l_blkid << ZAP_BLOCK_SHIFT; */ 403 rw_exit(&l->l_rwlock); 404 dmu_buf_rele(l->l_dbuf); 405 /* XXX there are still holds on this block, so we can't free it? */ 406 /* dmu_free_range(zap->zap_objset, zap->zap_object, */ 407 /* offset, 1<<ZAP_BLOCK_SHIFT, tx); */ 408 } 409 410 int 411 fzap_count(zap_t *zap, uint64_t *count) 412 { 413 ASSERT(!zap->zap_ismicro); 414 mutex_enter(&zap->zap_f.zap_num_entries_mtx); /* unnecessary */ 415 *count = zap->zap_f.zap_phys->zap_num_entries; 416 mutex_exit(&zap->zap_f.zap_num_entries_mtx); 417 return (0); 418 } 419 420 /* 421 * Routines for obtaining zap_leaf_t's 422 */ 423 424 void 425 zap_put_leaf(zap_leaf_t *l) 426 { 427 zap_leaf_t *nl = l->l_next; 428 while (nl) { 429 zap_leaf_t *nnl = nl->l_next; 430 rw_exit(&nl->l_rwlock); 431 dmu_buf_rele(nl->l_dbuf); 432 nl = nnl; 433 } 434 rw_exit(&l->l_rwlock); 435 dmu_buf_rele(l->l_dbuf); 436 } 437 438 _NOTE(ARGSUSED(0)) 439 static void 440 zap_leaf_pageout(dmu_buf_t *db, void *vl) 441 { 442 zap_leaf_t *l = vl; 443 444 rw_destroy(&l->l_rwlock); 445 kmem_free(l, sizeof (zap_leaf_t)); 446 } 447 448 static zap_leaf_t * 449 zap_open_leaf(uint64_t blkid, dmu_buf_t *db) 450 { 451 zap_leaf_t *l, *winner; 452 453 ASSERT(blkid != 0); 454 455 l = kmem_alloc(sizeof (zap_leaf_t), KM_SLEEP); 456 rw_init(&l->l_rwlock, 0, 0, 0); 457 rw_enter(&l->l_rwlock, RW_WRITER); 458 l->l_blkid = blkid; 459 l->l_next = NULL; 460 l->l_dbuf = db; 461 l->l_phys = NULL; 462 463 winner = dmu_buf_set_user(db, l, &l->l_phys, zap_leaf_pageout); 464 465 rw_exit(&l->l_rwlock); 466 if (winner != NULL) { 467 /* someone else set it first */ 468 zap_leaf_pageout(NULL, l); 469 l = winner; 470 } 471 472 return (l); 473 } 474 475 static zap_leaf_t * 476 zap_get_leaf_byblk_impl(zap_t *zap, uint64_t blkid, dmu_tx_t *tx, krw_t lt) 477 { 478 dmu_buf_t *db; 479 zap_leaf_t *l; 480 481 ASSERT(RW_LOCK_HELD(&zap->zap_rwlock)); 482 483 db = dmu_buf_hold(zap->zap_objset, zap->zap_object, 484 blkid << ZAP_BLOCK_SHIFT); 485 486 ASSERT3U(db->db_object, ==, zap->zap_object); 487 ASSERT3U(db->db_offset, ==, blkid << ZAP_BLOCK_SHIFT); 488 ASSERT3U(db->db_size, ==, 1 << ZAP_BLOCK_SHIFT); 489 ASSERT(blkid != 0); 490 491 dmu_buf_read(db); 492 l = dmu_buf_get_user(db); 493 494 if (l == NULL) 495 l = zap_open_leaf(blkid, db); 496 497 rw_enter(&l->l_rwlock, lt); 498 /* 499 * Must lock before dirtying, otherwise l->l_phys could change, 500 * causing ASSERT below to fail. 501 */ 502 if (lt == RW_WRITER) 503 dmu_buf_will_dirty(db, tx); 504 ASSERT3U(l->l_blkid, ==, blkid); 505 ASSERT3P(l->l_dbuf, ==, db); 506 ASSERT3P(l->l_phys, ==, l->l_dbuf->db_data); 507 ASSERT3U(l->lh_block_type, ==, ZBT_LEAF); 508 ASSERT3U(l->lh_magic, ==, ZAP_LEAF_MAGIC); 509 510 return (l); 511 } 512 513 static zap_leaf_t * 514 zap_get_leaf_byblk(zap_t *zap, uint64_t blkid, dmu_tx_t *tx, krw_t lt) 515 { 516 zap_leaf_t *l, *nl; 517 518 l = zap_get_leaf_byblk_impl(zap, blkid, tx, lt); 519 520 nl = l; 521 while (nl->lh_next != 0) { 522 zap_leaf_t *nnl; 523 nnl = zap_get_leaf_byblk_impl(zap, nl->lh_next, tx, lt); 524 nl->l_next = nnl; 525 nl = nnl; 526 } 527 528 return (l); 529 } 530 531 static uint64_t 532 zap_idx_to_blk(zap_t *zap, uint64_t idx) 533 { 534 ASSERT(RW_LOCK_HELD(&zap->zap_rwlock)); 535 536 if (zap->zap_f.zap_phys->zap_ptrtbl.zt_numblks == 0) { 537 ASSERT3U(idx, <, 538 (1ULL << zap->zap_f.zap_phys->zap_ptrtbl.zt_shift)); 539 return (zap->zap_f.zap_phys->zap_leafs[idx]); 540 } else { 541 return (zap_table_load(zap, &zap->zap_f.zap_phys->zap_ptrtbl, 542 idx)); 543 } 544 } 545 546 static void 547 zap_set_idx_to_blk(zap_t *zap, uint64_t idx, uint64_t blk, dmu_tx_t *tx) 548 { 549 ASSERT(tx != NULL); 550 ASSERT(RW_WRITE_HELD(&zap->zap_rwlock)); 551 552 if (zap->zap_f.zap_phys->zap_ptrtbl.zt_blk == 0) { 553 zap->zap_f.zap_phys->zap_leafs[idx] = blk; 554 } else { 555 (void) zap_table_store(zap, &zap->zap_f.zap_phys->zap_ptrtbl, 556 idx, blk, tx); 557 } 558 } 559 560 static zap_leaf_t * 561 zap_deref_leaf(zap_t *zap, uint64_t h, dmu_tx_t *tx, krw_t lt) 562 { 563 uint64_t idx; 564 zap_leaf_t *l; 565 566 ASSERT(zap->zap_dbuf == NULL || 567 zap->zap_f.zap_phys == zap->zap_dbuf->db_data); 568 ASSERT3U(zap->zap_f.zap_phys->zap_magic, ==, ZAP_MAGIC); 569 idx = ZAP_HASH_IDX(h, zap->zap_f.zap_phys->zap_ptrtbl.zt_shift); 570 l = zap_get_leaf_byblk(zap, zap_idx_to_blk(zap, idx), tx, lt); 571 572 ASSERT3U(ZAP_HASH_IDX(h, l->lh_prefix_len), ==, l->lh_prefix); 573 574 return (l); 575 } 576 577 578 static zap_leaf_t * 579 zap_expand_leaf(zap_t *zap, zap_leaf_t *l, uint64_t hash, dmu_tx_t *tx) 580 { 581 zap_leaf_t *nl; 582 int prefix_diff, i, err; 583 uint64_t sibling; 584 585 ASSERT3U(l->lh_prefix_len, <=, 586 zap->zap_f.zap_phys->zap_ptrtbl.zt_shift); 587 ASSERT(RW_LOCK_HELD(&zap->zap_rwlock)); 588 589 ASSERT3U(ZAP_HASH_IDX(hash, l->lh_prefix_len), ==, l->lh_prefix); 590 591 if (zap_tryupgradedir(zap, tx) == 0) { 592 /* failed to upgrade */ 593 int old_prefix_len = l->lh_prefix_len; 594 objset_t *os = zap->zap_objset; 595 uint64_t object = zap->zap_object; 596 597 zap_put_leaf(l); 598 zap_unlockdir(zap); 599 err = zap_lockdir(os, object, tx, RW_WRITER, FALSE, &zap); 600 ASSERT3U(err, ==, 0); 601 ASSERT(!zap->zap_ismicro); 602 l = zap_deref_leaf(zap, hash, tx, RW_WRITER); 603 604 if (l->lh_prefix_len != old_prefix_len) 605 /* it split while our locks were down */ 606 return (l); 607 } 608 ASSERT(RW_WRITE_HELD(&zap->zap_rwlock)); 609 610 if (l->lh_prefix_len == zap->zap_f.zap_phys->zap_ptrtbl.zt_shift) { 611 /* There's only one pointer to us. Chain on another leaf blk. */ 612 (void) zap_leaf_chainmore(l, zap_create_leaf(zap, tx)); 613 dprintf("chaining leaf %x/%d\n", l->lh_prefix, 614 l->lh_prefix_len); 615 return (l); 616 } 617 618 ASSERT3U(ZAP_HASH_IDX(hash, l->lh_prefix_len), ==, l->lh_prefix); 619 620 /* There's more than one pointer to us. Split this leaf. */ 621 nl = zap_leaf_split(zap, l, tx); 622 623 /* set sibling pointers */ 624 prefix_diff = 625 zap->zap_f.zap_phys->zap_ptrtbl.zt_shift - l->lh_prefix_len; 626 sibling = (ZAP_HASH_IDX(hash, l->lh_prefix_len) | 1) << prefix_diff; 627 for (i = 0; i < (1ULL<<prefix_diff); i++) { 628 ASSERT3U(zap_idx_to_blk(zap, sibling+i), ==, l->l_blkid); 629 zap_set_idx_to_blk(zap, sibling+i, nl->l_blkid, tx); 630 /* dprintf("set %d to %u %x\n", sibling+i, nl->l_blkid, nl); */ 631 } 632 633 zap->zap_f.zap_phys->zap_num_leafs++; 634 635 if (hash & (1ULL << (64 - l->lh_prefix_len))) { 636 /* we want the sibling */ 637 zap_put_leaf(l); 638 l = nl; 639 } else { 640 zap_put_leaf(nl); 641 } 642 643 return (l); 644 } 645 646 static void 647 zap_put_leaf_maybe_grow_ptrtbl(zap_t *zap, 648 zap_leaf_t *l, dmu_tx_t *tx) 649 { 650 int shift, err; 651 652 again: 653 shift = zap->zap_f.zap_phys->zap_ptrtbl.zt_shift; 654 655 if (l->lh_prefix_len == shift && 656 (l->l_next != NULL || l->lh_nfree < MIN_FREE)) { 657 /* this leaf will soon make us grow the pointer table */ 658 659 if (zap_tryupgradedir(zap, tx) == 0) { 660 objset_t *os = zap->zap_objset; 661 uint64_t zapobj = zap->zap_object; 662 uint64_t blkid = l->l_blkid; 663 664 zap_put_leaf(l); 665 zap_unlockdir(zap); 666 err = zap_lockdir(os, zapobj, tx, 667 RW_WRITER, FALSE, &zap); 668 ASSERT3U(err, ==, 0); 669 l = zap_get_leaf_byblk(zap, blkid, tx, RW_READER); 670 goto again; 671 } 672 673 zap_put_leaf(l); 674 zap_grow_ptrtbl(zap, tx); 675 } else { 676 zap_put_leaf(l); 677 } 678 } 679 680 681 static int 682 fzap_checksize(uint64_t integer_size, uint64_t num_integers) 683 { 684 /* Only integer sizes supported by C */ 685 switch (integer_size) { 686 case 1: 687 case 2: 688 case 4: 689 case 8: 690 break; 691 default: 692 return (EINVAL); 693 } 694 695 /* Make sure we won't overflow */ 696 if (integer_size * num_integers < num_integers) 697 return (EINVAL); 698 if (integer_size * num_integers > DMU_MAX_ACCESS) 699 return (EINVAL); 700 701 return (0); 702 } 703 704 /* 705 * Routines for maniplulating attributes. 706 */ 707 int 708 fzap_lookup(zap_t *zap, const char *name, 709 uint64_t integer_size, uint64_t num_integers, void *buf) 710 { 711 zap_leaf_t *l; 712 int err; 713 uint64_t hash; 714 zap_entry_handle_t zeh; 715 716 err = fzap_checksize(integer_size, num_integers); 717 if (err != 0) 718 return (err); 719 720 hash = zap_hash(zap, name); 721 l = zap_deref_leaf(zap, hash, NULL, RW_READER); 722 err = zap_leaf_lookup(l, name, hash, &zeh); 723 if (err != 0) 724 goto out; 725 err = zap_entry_read(&zeh, integer_size, num_integers, buf); 726 out: 727 zap_put_leaf(l); 728 return (err); 729 } 730 731 int 732 fzap_add_cd(zap_t *zap, const char *name, 733 uint64_t integer_size, uint64_t num_integers, 734 const void *val, uint32_t cd, dmu_tx_t *tx, zap_leaf_t **lp) 735 { 736 zap_leaf_t *l; 737 uint64_t hash; 738 int err; 739 zap_entry_handle_t zeh; 740 741 ASSERT(RW_LOCK_HELD(&zap->zap_rwlock)); 742 ASSERT(!zap->zap_ismicro); 743 ASSERT(fzap_checksize(integer_size, num_integers) == 0); 744 745 hash = zap_hash(zap, name); 746 l = zap_deref_leaf(zap, hash, tx, RW_WRITER); 747 retry: 748 err = zap_leaf_lookup(l, name, hash, &zeh); 749 if (err == 0) { 750 err = EEXIST; 751 goto out; 752 } 753 ASSERT(err == ENOENT); 754 755 /* XXX If this leaf is chained, split it if we can. */ 756 err = zap_entry_create(l, name, hash, cd, 757 integer_size, num_integers, val, &zeh); 758 759 if (err == 0) { 760 zap_increment_num_entries(zap, 1, tx); 761 } else if (err == EAGAIN) { 762 l = zap_expand_leaf(zap, l, hash, tx); 763 goto retry; 764 } 765 766 out: 767 if (lp) 768 *lp = l; 769 else 770 zap_put_leaf(l); 771 return (err); 772 } 773 774 int 775 fzap_add(zap_t *zap, const char *name, 776 uint64_t integer_size, uint64_t num_integers, 777 const void *val, dmu_tx_t *tx) 778 { 779 int err; 780 zap_leaf_t *l; 781 782 err = fzap_checksize(integer_size, num_integers); 783 if (err != 0) 784 return (err); 785 786 err = fzap_add_cd(zap, name, integer_size, num_integers, 787 val, ZAP_MAXCD, tx, &l); 788 789 zap_put_leaf_maybe_grow_ptrtbl(zap, l, tx); 790 return (err); 791 } 792 793 int 794 fzap_update(zap_t *zap, const char *name, 795 int integer_size, uint64_t num_integers, const void *val, dmu_tx_t *tx) 796 { 797 zap_leaf_t *l; 798 uint64_t hash; 799 int err, create; 800 zap_entry_handle_t zeh; 801 802 ASSERT(RW_LOCK_HELD(&zap->zap_rwlock)); 803 err = fzap_checksize(integer_size, num_integers); 804 if (err != 0) 805 return (err); 806 807 hash = zap_hash(zap, name); 808 l = zap_deref_leaf(zap, hash, tx, RW_WRITER); 809 retry: 810 err = zap_leaf_lookup(l, name, hash, &zeh); 811 create = (err == ENOENT); 812 ASSERT(err == 0 || err == ENOENT); 813 814 /* XXX If this leaf is chained, split it if we can. */ 815 816 if (create) { 817 err = zap_entry_create(l, name, hash, ZAP_MAXCD, 818 integer_size, num_integers, val, &zeh); 819 if (err == 0) 820 zap_increment_num_entries(zap, 1, tx); 821 } else { 822 err = zap_entry_update(&zeh, integer_size, num_integers, val); 823 } 824 825 if (err == EAGAIN) { 826 l = zap_expand_leaf(zap, l, hash, tx); 827 goto retry; 828 } 829 830 zap_put_leaf_maybe_grow_ptrtbl(zap, l, tx); 831 return (err); 832 } 833 834 int 835 fzap_length(zap_t *zap, const char *name, 836 uint64_t *integer_size, uint64_t *num_integers) 837 { 838 zap_leaf_t *l; 839 int err; 840 uint64_t hash; 841 zap_entry_handle_t zeh; 842 843 hash = zap_hash(zap, name); 844 l = zap_deref_leaf(zap, hash, NULL, RW_READER); 845 err = zap_leaf_lookup(l, name, hash, &zeh); 846 if (err != 0) 847 goto out; 848 849 if (integer_size) 850 *integer_size = zeh.zeh_integer_size; 851 if (num_integers) 852 *num_integers = zeh.zeh_num_integers; 853 out: 854 zap_put_leaf(l); 855 return (err); 856 } 857 858 int 859 fzap_remove(zap_t *zap, const char *name, dmu_tx_t *tx) 860 { 861 zap_leaf_t *l; 862 uint64_t hash; 863 int err; 864 zap_entry_handle_t zeh; 865 866 hash = zap_hash(zap, name); 867 l = zap_deref_leaf(zap, hash, tx, RW_WRITER); 868 err = zap_leaf_lookup(l, name, hash, &zeh); 869 if (err == 0) { 870 zap_entry_remove(&zeh); 871 zap_increment_num_entries(zap, -1, tx); 872 } 873 zap_put_leaf(l); 874 dprintf("fzap_remove: ds=%p obj=%llu name=%s err=%d\n", 875 zap->zap_objset, zap->zap_object, name, err); 876 return (err); 877 } 878 879 int 880 zap_value_search(objset_t *os, uint64_t zapobj, uint64_t value, char *name) 881 { 882 zap_cursor_t zc; 883 zap_attribute_t *za; 884 int err; 885 886 za = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP); 887 for (zap_cursor_init(&zc, os, zapobj); 888 (err = zap_cursor_retrieve(&zc, za)) == 0; 889 zap_cursor_advance(&zc)) { 890 if (za->za_first_integer == value) { 891 (void) strcpy(name, za->za_name); 892 break; 893 } 894 } 895 zap_cursor_fini(&zc); 896 kmem_free(za, sizeof (zap_attribute_t)); 897 return (err); 898 } 899 900 901 /* 902 * Routines for iterating over the attributes. 903 */ 904 905 int 906 fzap_cursor_retrieve(zap_t *zap, zap_cursor_t *zc, zap_attribute_t *za) 907 { 908 int err = ENOENT; 909 zap_entry_handle_t zeh; 910 zap_leaf_t *l; 911 912 /* retrieve the next entry at or after zc_hash/zc_cd */ 913 /* if no entry, return ENOENT */ 914 915 if (zc->zc_leaf && 916 (ZAP_HASH_IDX(zc->zc_hash, zc->zc_leaf->lh_prefix_len) != 917 zc->zc_leaf->lh_prefix)) { 918 rw_enter(&zc->zc_leaf->l_rwlock, RW_READER); 919 zap_put_leaf(zc->zc_leaf); 920 zc->zc_leaf = NULL; 921 } 922 923 again: 924 if (zc->zc_leaf == NULL) { 925 zc->zc_leaf = zap_deref_leaf(zap, zc->zc_hash, NULL, RW_READER); 926 } else { 927 rw_enter(&zc->zc_leaf->l_rwlock, RW_READER); 928 } 929 l = zc->zc_leaf; 930 931 err = zap_leaf_lookup_closest(l, zc->zc_hash, zc->zc_cd, &zeh); 932 933 if (err == ENOENT) { 934 uint64_t nocare = (1ULL << (64 - l->lh_prefix_len)) - 1; 935 zc->zc_hash = (zc->zc_hash & ~nocare) + nocare + 1; 936 zc->zc_cd = 0; 937 if (l->lh_prefix_len == 0 || zc->zc_hash == 0) { 938 zc->zc_hash = -1ULL; 939 } else { 940 zap_put_leaf(zc->zc_leaf); 941 zc->zc_leaf = NULL; 942 goto again; 943 } 944 } 945 946 if (err == 0) { 947 zc->zc_hash = zeh.zeh_hash; 948 zc->zc_cd = zeh.zeh_cd; 949 za->za_integer_length = zeh.zeh_integer_size; 950 za->za_num_integers = zeh.zeh_num_integers; 951 if (zeh.zeh_num_integers == 0) { 952 za->za_first_integer = 0; 953 } else { 954 err = zap_entry_read(&zeh, 8, 1, &za->za_first_integer); 955 ASSERT(err == 0 || err == EOVERFLOW); 956 } 957 err = zap_entry_read_name(&zeh, 958 sizeof (za->za_name), za->za_name); 959 ASSERT(err == 0); 960 } 961 rw_exit(&zc->zc_leaf->l_rwlock); 962 return (err); 963 } 964 965 966 static void 967 zap_stats_ptrtbl(zap_t *zap, uint64_t *tbl, int len, zap_stats_t *zs) 968 { 969 int i; 970 uint64_t lastblk = 0; 971 972 /* 973 * NB: if a leaf has more pointers than an entire ptrtbl block 974 * can hold, then it'll be accounted for more than once, since 975 * we won't have lastblk. 976 */ 977 for (i = 0; i < len; i++) { 978 zap_leaf_t *l; 979 980 if (tbl[i] == lastblk) 981 continue; 982 lastblk = tbl[i]; 983 984 l = zap_get_leaf_byblk(zap, tbl[i], NULL, RW_READER); 985 986 zap_stats_leaf(zap, l, zs); 987 zap_put_leaf(l); 988 } 989 } 990 991 void 992 fzap_get_stats(zap_t *zap, zap_stats_t *zs) 993 { 994 zs->zs_ptrtbl_len = 1ULL << zap->zap_f.zap_phys->zap_ptrtbl.zt_shift; 995 zs->zs_blocksize = 1ULL << ZAP_BLOCK_SHIFT; 996 zs->zs_num_leafs = zap->zap_f.zap_phys->zap_num_leafs; 997 zs->zs_num_entries = zap->zap_f.zap_phys->zap_num_entries; 998 zs->zs_num_blocks = zap->zap_f.zap_phys->zap_freeblk; 999 1000 if (zap->zap_f.zap_phys->zap_ptrtbl.zt_numblks == 0) { 1001 /* the ptrtbl is entirely in the header block. */ 1002 zap_stats_ptrtbl(zap, zap->zap_f.zap_phys->zap_leafs, 1003 1 << ZAP_PTRTBL_MIN_SHIFT, zs); 1004 } else { 1005 int b; 1006 1007 dmu_prefetch(zap->zap_objset, zap->zap_object, 1008 zap->zap_f.zap_phys->zap_ptrtbl.zt_blk << ZAP_BLOCK_SHIFT, 1009 zap->zap_f.zap_phys->zap_ptrtbl.zt_numblks << 1010 ZAP_BLOCK_SHIFT); 1011 1012 for (b = 0; b < zap->zap_f.zap_phys->zap_ptrtbl.zt_numblks; 1013 b++) { 1014 dmu_buf_t *db; 1015 1016 db = dmu_buf_hold(zap->zap_objset, zap->zap_object, 1017 (zap->zap_f.zap_phys->zap_ptrtbl.zt_blk + b) << 1018 ZAP_BLOCK_SHIFT); 1019 dmu_buf_read(db); 1020 zap_stats_ptrtbl(zap, db->db_data, 1021 1<<(ZAP_BLOCK_SHIFT-3), zs); 1022 dmu_buf_rele(db); 1023 } 1024 } 1025 } 1026