sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zap_leaf.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) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  23  * Copyright (c) 2013, 2014 by Delphix. All rights reserved.
  24  */
  25
  26 /*
  27  * The 512-byte leaf is broken into 32 16-byte chunks.
  28  * chunk number n means l_chunk[n], even though the header precedes it.
  29  * the names are stored null-terminated.
  30  */
  31
  32 #include <sys/zio.h>
  33 #include <sys/spa.h>
  34 #include <sys/dmu.h>
  35 #include <sys/zfs_context.h>
  36 #include <sys/fs/zfs.h>
  37 #include <sys/zap.h>
  38 #include <sys/zap_impl.h>
  39 #include <sys/zap_leaf.h>
  40 #include <sys/arc.h>
  41
  42 static uint16_t *zap_leaf_rehash_entry(zap_leaf_t *l, uint16_t entry);
  43
  44 #define CHAIN_END 0xffff /* end of the chunk chain */
  45
  46 /* half the (current) minimum block size */
  47 #define MAX_ARRAY_BYTES (8<<10)
  48
  49 #define LEAF_HASH(l, h) \
  50         ((ZAP_LEAF_HASH_NUMENTRIES(l)-1) & \
  51         ((h) >> \
  52         (64 - ZAP_LEAF_HASH_SHIFT(l) - zap_leaf_phys(l)->l_hdr.lh_prefix_len)))
  53
  54 #define LEAF_HASH_ENTPTR(l, h) (&zap_leaf_phys(l)->l_hash[LEAF_HASH(l, h)])
  55
  56 extern inline zap_leaf_phys_t *zap_leaf_phys(zap_leaf_t *l);
  57
  58 static void
  59 zap_memset(void *a, int c, size_t n)
  60 {
  61         char *cp = a;
  62         char *cpend = cp + n;
  63
  64         while (cp < cpend)
  65                 *cp++ = c;
  66 }
  67
  68 static void
  69 stv(int len, void *addr, uint64_t value)
  70 {
  71         switch (len) {
  72         case 1:
  73                 *(uint8_t *)addr = value;
  74                 return;
  75         case 2:
  76                 *(uint16_t *)addr = value;
  77                 return;
  78         case 4:
  79                 *(uint32_t *)addr = value;
  80                 return;
  81         case 8:
  82                 *(uint64_t *)addr = value;
  83                 return;
  84         }
  85         ASSERT(!"bad int len");
  86 }
  87
  88 static uint64_t
  89 ldv(int len, const void *addr)
  90 {
  91         switch (len) {
  92         case 1:
  93                 return (*(uint8_t *)addr);
  94         case 2:
  95                 return (*(uint16_t *)addr);
  96         case 4:
  97                 return (*(uint32_t *)addr);
  98         case 8:
  99                 return (*(uint64_t *)addr);
 100         }
 101         ASSERT(!"bad int len");
 102         return (0xFEEDFACEDEADBEEFULL);
 103 }
 104
 105 void
 106 zap_leaf_byteswap(zap_leaf_phys_t *buf, int size)
 107 {
 108         int i;
 109         zap_leaf_t l;
 110         dmu_buf_t l_dbuf;
 111
 112         l_dbuf.db_data = buf;
 113         l.l_bs = highbit64(size) - 1;
 114         l.l_dbuf = &l_dbuf;
 115
 116         buf->l_hdr.lh_block_type =      BSWAP_64(buf->l_hdr.lh_block_type);
 117         buf->l_hdr.lh_prefix =          BSWAP_64(buf->l_hdr.lh_prefix);
 118         buf->l_hdr.lh_magic =           BSWAP_32(buf->l_hdr.lh_magic);
 119         buf->l_hdr.lh_nfree =           BSWAP_16(buf->l_hdr.lh_nfree);
 120         buf->l_hdr.lh_nentries =        BSWAP_16(buf->l_hdr.lh_nentries);
 121         buf->l_hdr.lh_prefix_len =      BSWAP_16(buf->l_hdr.lh_prefix_len);
 122         buf->l_hdr.lh_freelist =        BSWAP_16(buf->l_hdr.lh_freelist);
 123
 124         for (i = 0; i < ZAP_LEAF_HASH_NUMENTRIES(&l); i++)
 125                 buf->l_hash[i] = BSWAP_16(buf->l_hash[i]);
 126
 127         for (i = 0; i < ZAP_LEAF_NUMCHUNKS(&l); i++) {
 128                 zap_leaf_chunk_t *lc = &ZAP_LEAF_CHUNK(&l, i);
 129                 struct zap_leaf_entry *le;
 130
 131                 switch (lc->l_free.lf_type) {
 132                 case ZAP_CHUNK_ENTRY:
 133                         le = &lc->l_entry;
 134
 135                         le->le_type =           BSWAP_8(le->le_type);
 136                         le->le_value_intlen =   BSWAP_8(le->le_value_intlen);
 137                         le->le_next =           BSWAP_16(le->le_next);
 138                         le->le_name_chunk =     BSWAP_16(le->le_name_chunk);
 139                         le->le_name_numints =   BSWAP_16(le->le_name_numints);
 140                         le->le_value_chunk =    BSWAP_16(le->le_value_chunk);
 141                         le->le_value_numints =  BSWAP_16(le->le_value_numints);
 142                         le->le_cd =             BSWAP_32(le->le_cd);
 143                         le->le_hash =           BSWAP_64(le->le_hash);
 144                         break;
 145                 case ZAP_CHUNK_FREE:
 146                         lc->l_free.lf_type =    BSWAP_8(lc->l_free.lf_type);
 147                         lc->l_free.lf_next =    BSWAP_16(lc->l_free.lf_next);
 148                         break;
 149                 case ZAP_CHUNK_ARRAY:
 150                         lc->l_array.la_type =   BSWAP_8(lc->l_array.la_type);
 151                         lc->l_array.la_next =   BSWAP_16(lc->l_array.la_next);
 152                         /* la_array doesn't need swapping */
 153                         break;
 154                 default:
 155                         ASSERT(!"bad leaf type");
 156                 }
 157         }
 158 }
 159
 160 void
 161 zap_leaf_init(zap_leaf_t *l, boolean_t sort)
 162 {
 163         int i;
 164
 165         l->l_bs = highbit64(l->l_dbuf->db_size) - 1;
 166         zap_memset(&zap_leaf_phys(l)->l_hdr, 0,
 167             sizeof (struct zap_leaf_header));
 168         zap_memset(zap_leaf_phys(l)->l_hash, CHAIN_END,
 169             2*ZAP_LEAF_HASH_NUMENTRIES(l));
 170         for (i = 0; i < ZAP_LEAF_NUMCHUNKS(l); i++) {
 171                 ZAP_LEAF_CHUNK(l, i).l_free.lf_type = ZAP_CHUNK_FREE;
 172                 ZAP_LEAF_CHUNK(l, i).l_free.lf_next = i+1;
 173         }
 174         ZAP_LEAF_CHUNK(l, ZAP_LEAF_NUMCHUNKS(l)-1).l_free.lf_next = CHAIN_END;
 175         zap_leaf_phys(l)->l_hdr.lh_block_type = ZBT_LEAF;
 176         zap_leaf_phys(l)->l_hdr.lh_magic = ZAP_LEAF_MAGIC;
 177         zap_leaf_phys(l)->l_hdr.lh_nfree = ZAP_LEAF_NUMCHUNKS(l);
 178         if (sort)
 179                 zap_leaf_phys(l)->l_hdr.lh_flags |= ZLF_ENTRIES_CDSORTED;
 180 }
 181
 182 /*
 183  * Routines which manipulate leaf chunks (l_chunk[]).
 184  */
 185
 186 static uint16_t
 187 zap_leaf_chunk_alloc(zap_leaf_t *l)
 188 {
 189         int chunk;
 190
 191         ASSERT(zap_leaf_phys(l)->l_hdr.lh_nfree > 0);
 192
 193         chunk = zap_leaf_phys(l)->l_hdr.lh_freelist;
 194         ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
 195         ASSERT3U(ZAP_LEAF_CHUNK(l, chunk).l_free.lf_type, ==, ZAP_CHUNK_FREE);
 196
 197         zap_leaf_phys(l)->l_hdr.lh_freelist =
 198             ZAP_LEAF_CHUNK(l, chunk).l_free.lf_next;
 199
 200         zap_leaf_phys(l)->l_hdr.lh_nfree--;
 201
 202         return (chunk);
 203 }
 204
 205 static void
 206 zap_leaf_chunk_free(zap_leaf_t *l, uint16_t chunk)
 207 {
 208         struct zap_leaf_free *zlf = &ZAP_LEAF_CHUNK(l, chunk).l_free;
 209         ASSERT3U(zap_leaf_phys(l)->l_hdr.lh_nfree, <, ZAP_LEAF_NUMCHUNKS(l));
 210         ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
 211         ASSERT(zlf->lf_type != ZAP_CHUNK_FREE);
 212
 213         zlf->lf_type = ZAP_CHUNK_FREE;
 214         zlf->lf_next = zap_leaf_phys(l)->l_hdr.lh_freelist;
 215         bzero(zlf->lf_pad, sizeof (zlf->lf_pad)); /* help it to compress */
 216         zap_leaf_phys(l)->l_hdr.lh_freelist = chunk;
 217
 218         zap_leaf_phys(l)->l_hdr.lh_nfree++;
 219 }
 220
 221 /*
 222  * Routines which manipulate leaf arrays (zap_leaf_array type chunks).
 223  */
 224
 225 static uint16_t
 226 zap_leaf_array_create(zap_leaf_t *l, const char *buf,
 227     int integer_size, int num_integers)
 228 {
 229         uint16_t chunk_head;
 230         uint16_t *chunkp = &chunk_head;
 231         int byten = 0;
 232         uint64_t value = 0;
 233         int shift = (integer_size-1)*8;
 234         int len = num_integers;
 235
 236         ASSERT3U(num_integers * integer_size, <, MAX_ARRAY_BYTES);
 237
 238         while (len > 0) {
 239                 uint16_t chunk = zap_leaf_chunk_alloc(l);
 240                 struct zap_leaf_array *la = &ZAP_LEAF_CHUNK(l, chunk).l_array;
 241                 int i;
 242
 243                 la->la_type = ZAP_CHUNK_ARRAY;
 244                 for (i = 0; i < ZAP_LEAF_ARRAY_BYTES; i++) {
 245                         if (byten == 0)
 246                                 value = ldv(integer_size, buf);
 247                         la->la_array[i] = value >> shift;
 248                         value <<= 8;
 249                         if (++byten == integer_size) {
 250                                 byten = 0;
 251                                 buf += integer_size;
 252                                 if (--len == 0)
 253                                         break;
 254                         }
 255                 }
 256
 257                 *chunkp = chunk;
 258                 chunkp = &la->la_next;
 259         }
 260         *chunkp = CHAIN_END;
 261
 262         return (chunk_head);
 263 }
 264
 265 static void
 266 zap_leaf_array_free(zap_leaf_t *l, uint16_t *chunkp)
 267 {
 268         uint16_t chunk = *chunkp;
 269
 270         *chunkp = CHAIN_END;
 271
 272         while (chunk != CHAIN_END) {
 273                 int nextchunk = ZAP_LEAF_CHUNK(l, chunk).l_array.la_next;
 274                 ASSERT3U(ZAP_LEAF_CHUNK(l, chunk).l_array.la_type, ==,
 275                     ZAP_CHUNK_ARRAY);
 276                 zap_leaf_chunk_free(l, chunk);
 277                 chunk = nextchunk;
 278         }
 279 }
 280
 281 /* array_len and buf_len are in integers, not bytes */
 282 static void
 283 zap_leaf_array_read(zap_leaf_t *l, uint16_t chunk,
 284     int array_int_len, int array_len, int buf_int_len, uint64_t buf_len,
 285     void *buf)
 286 {
 287         int len = MIN(array_len, buf_len);
 288         int byten = 0;
 289         uint64_t value = 0;
 290         char *p = buf;
 291
 292         ASSERT3U(array_int_len, <=, buf_int_len);
 293
 294         /* Fast path for one 8-byte integer */
 295         if (array_int_len == 8 && buf_int_len == 8 && len == 1) {
 296                 struct zap_leaf_array *la = &ZAP_LEAF_CHUNK(l, chunk).l_array;
 297                 uint8_t *ip = la->la_array;
 298                 uint64_t *buf64 = buf;
 299
 300                 *buf64 = (uint64_t)ip[0] << 56 | (uint64_t)ip[1] << 48 |
 301                     (uint64_t)ip[2] << 40 | (uint64_t)ip[3] << 32 |
 302                     (uint64_t)ip[4] << 24 | (uint64_t)ip[5] << 16 |
 303                     (uint64_t)ip[6] << 8 | (uint64_t)ip[7];
 304                 return;
 305         }
 306
 307         /* Fast path for an array of 1-byte integers (eg. the entry name) */
 308         if (array_int_len == 1 && buf_int_len == 1 &&
 309             buf_len > array_len + ZAP_LEAF_ARRAY_BYTES) {
 310                 while (chunk != CHAIN_END) {
 311                         struct zap_leaf_array *la =
 312                             &ZAP_LEAF_CHUNK(l, chunk).l_array;
 313                         bcopy(la->la_array, p, ZAP_LEAF_ARRAY_BYTES);
 314                         p += ZAP_LEAF_ARRAY_BYTES;
 315                         chunk = la->la_next;
 316                 }
 317                 return;
 318         }
 319
 320         while (len > 0) {
 321                 struct zap_leaf_array *la = &ZAP_LEAF_CHUNK(l, chunk).l_array;
 322                 int i;
 323
 324                 ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
 325                 for (i = 0; i < ZAP_LEAF_ARRAY_BYTES && len > 0; i++) {
 326                         value = (value << 8) | la->la_array[i];
 327                         byten++;
 328                         if (byten == array_int_len) {
 329                                 stv(buf_int_len, p, value);
 330                                 byten = 0;
 331                                 len--;
 332                                 if (len == 0)
 333                                         return;
 334                                 p += buf_int_len;
 335                         }
 336                 }
 337                 chunk = la->la_next;
 338         }
 339 }
 340
 341 static boolean_t
 342 zap_leaf_array_match(zap_leaf_t *l, zap_name_t *zn,
 343     int chunk, int array_numints)
 344 {
 345         int bseen = 0;
 346
 347         if (zap_getflags(zn->zn_zap) & ZAP_FLAG_UINT64_KEY) {
 348                 uint64_t *thiskey;
 349                 boolean_t match;
 350
 351                 ASSERT(zn->zn_key_intlen == sizeof (*thiskey));
 352                 thiskey = kmem_alloc(array_numints * sizeof (*thiskey),
 353                     KM_SLEEP);
 354
 355                 zap_leaf_array_read(l, chunk, sizeof (*thiskey), array_numints,
 356                     sizeof (*thiskey), array_numints, thiskey);
 357                 match = bcmp(thiskey, zn->zn_key_orig,
 358                     array_numints * sizeof (*thiskey)) == 0;
 359                 kmem_free(thiskey, array_numints * sizeof (*thiskey));
 360                 return (match);
 361         }
 362
 363         ASSERT(zn->zn_key_intlen == 1);
 364         if (zn->zn_matchtype == MT_FIRST) {
 365                 char *thisname = kmem_alloc(array_numints, KM_SLEEP);
 366                 boolean_t match;
 367
 368                 zap_leaf_array_read(l, chunk, sizeof (char), array_numints,
 369                     sizeof (char), array_numints, thisname);
 370                 match = zap_match(zn, thisname);
 371                 kmem_free(thisname, array_numints);
 372                 return (match);
 373         }
 374
 375         /*
 376          * Fast path for exact matching.
 377          * First check that the lengths match, so that we don't read
 378          * past the end of the zn_key_orig array.
 379          */
 380         if (array_numints != zn->zn_key_orig_numints)
 381                 return (B_FALSE);
 382         while (bseen < array_numints) {
 383                 struct zap_leaf_array *la = &ZAP_LEAF_CHUNK(l, chunk).l_array;
 384                 int toread = MIN(array_numints - bseen, ZAP_LEAF_ARRAY_BYTES);
 385                 ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
 386                 if (bcmp(la->la_array, (char *)zn->zn_key_orig + bseen, toread))
 387                         break;
 388                 chunk = la->la_next;
 389                 bseen += toread;
 390         }
 391         return (bseen == array_numints);
 392 }
 393
 394 /*
 395  * Routines which manipulate leaf entries.
 396  */
 397
 398 int
 399 zap_leaf_lookup(zap_leaf_t *l, zap_name_t *zn, zap_entry_handle_t *zeh)
 400 {
 401         uint16_t *chunkp;
 402         struct zap_leaf_entry *le;
 403
 404         ASSERT3U(zap_leaf_phys(l)->l_hdr.lh_magic, ==, ZAP_LEAF_MAGIC);
 405
 406 again:
 407         for (chunkp = LEAF_HASH_ENTPTR(l, zn->zn_hash);
 408             *chunkp != CHAIN_END; chunkp = &le->le_next) {
 409                 uint16_t chunk = *chunkp;
 410                 le = ZAP_LEAF_ENTRY(l, chunk);
 411
 412                 ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
 413                 ASSERT3U(le->le_type, ==, ZAP_CHUNK_ENTRY);
 414
 415                 if (le->le_hash != zn->zn_hash)
 416                         continue;
 417
 418                 /*
 419                  * NB: the entry chain is always sorted by cd on
 420                  * normalized zap objects, so this will find the
 421                  * lowest-cd match for MT_FIRST.
 422                  */
 423                 ASSERT(zn->zn_matchtype == MT_EXACT ||
 424                     (zap_leaf_phys(l)->l_hdr.lh_flags & ZLF_ENTRIES_CDSORTED));
 425                 if (zap_leaf_array_match(l, zn, le->le_name_chunk,
 426                     le->le_name_numints)) {
 427                         zeh->zeh_num_integers = le->le_value_numints;
 428                         zeh->zeh_integer_size = le->le_value_intlen;
 429                         zeh->zeh_cd = le->le_cd;
 430                         zeh->zeh_hash = le->le_hash;
 431                         zeh->zeh_chunkp = chunkp;
 432                         zeh->zeh_leaf = l;
 433                         return (0);
 434                 }
 435         }
 436
 437         /*
 438          * NB: we could of course do this in one pass, but that would be
 439          * a pain.  We'll see if MT_BEST is even used much.
 440          */
 441         if (zn->zn_matchtype == MT_BEST) {
 442                 zn->zn_matchtype = MT_FIRST;
 443                 goto again;
 444         }
 445
 446         return (SET_ERROR(ENOENT));
 447 }
 448
 449 /* Return (h1,cd1 >= h2,cd2) */
 450 #define HCD_GTEQ(h1, cd1, h2, cd2) \
 451         ((h1 > h2) ? TRUE : ((h1 == h2 && cd1 >= cd2) ? TRUE : FALSE))
 452
 453 int
 454 zap_leaf_lookup_closest(zap_leaf_t *l,
 455     uint64_t h, uint32_t cd, zap_entry_handle_t *zeh)
 456 {
 457         uint16_t chunk;
 458         uint64_t besth = -1ULL;
 459         uint32_t bestcd = -1U;
 460         uint16_t bestlh = ZAP_LEAF_HASH_NUMENTRIES(l)-1;
 461         uint16_t lh;
 462         struct zap_leaf_entry *le;
 463
 464         ASSERT3U(zap_leaf_phys(l)->l_hdr.lh_magic, ==, ZAP_LEAF_MAGIC);
 465
 466         for (lh = LEAF_HASH(l, h); lh <= bestlh; lh++) {
 467                 for (chunk = zap_leaf_phys(l)->l_hash[lh];
 468                     chunk != CHAIN_END; chunk = le->le_next) {
 469                         le = ZAP_LEAF_ENTRY(l, chunk);
 470
 471                         ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
 472                         ASSERT3U(le->le_type, ==, ZAP_CHUNK_ENTRY);
 473
 474                         if (HCD_GTEQ(le->le_hash, le->le_cd, h, cd) &&
 475                             HCD_GTEQ(besth, bestcd, le->le_hash, le->le_cd)) {
 476                                 ASSERT3U(bestlh, >=, lh);
 477                                 bestlh = lh;
 478                                 besth = le->le_hash;
 479                                 bestcd = le->le_cd;
 480
 481                                 zeh->zeh_num_integers = le->le_value_numints;
 482                                 zeh->zeh_integer_size = le->le_value_intlen;
 483                                 zeh->zeh_cd = le->le_cd;
 484                                 zeh->zeh_hash = le->le_hash;
 485                                 zeh->zeh_fakechunk = chunk;
 486                                 zeh->zeh_chunkp = &zeh->zeh_fakechunk;
 487                                 zeh->zeh_leaf = l;
 488                         }
 489                 }
 490         }
 491
 492         return (bestcd == -1U ? ENOENT : 0);
 493 }
 494
 495 int
 496 zap_entry_read(const zap_entry_handle_t *zeh,
 497     uint8_t integer_size, uint64_t num_integers, void *buf)
 498 {
 499         struct zap_leaf_entry *le =
 500             ZAP_LEAF_ENTRY(zeh->zeh_leaf, *zeh->zeh_chunkp);
 501         ASSERT3U(le->le_type, ==, ZAP_CHUNK_ENTRY);
 502
 503         if (le->le_value_intlen > integer_size)
 504                 return (SET_ERROR(EINVAL));
 505
 506         zap_leaf_array_read(zeh->zeh_leaf, le->le_value_chunk,
 507             le->le_value_intlen, le->le_value_numints,
 508             integer_size, num_integers, buf);
 509
 510         if (zeh->zeh_num_integers > num_integers)
 511                 return (SET_ERROR(EOVERFLOW));
 512         return (0);
 513
 514 }
 515
 516 int
 517 zap_entry_read_name(zap_t *zap, const zap_entry_handle_t *zeh, uint16_t buflen,
 518     char *buf)
 519 {
 520         struct zap_leaf_entry *le =
 521             ZAP_LEAF_ENTRY(zeh->zeh_leaf, *zeh->zeh_chunkp);
 522         ASSERT3U(le->le_type, ==, ZAP_CHUNK_ENTRY);
 523
 524         if (zap_getflags(zap) & ZAP_FLAG_UINT64_KEY) {
 525                 zap_leaf_array_read(zeh->zeh_leaf, le->le_name_chunk, 8,
 526                     le->le_name_numints, 8, buflen / 8, buf);
 527         } else {
 528                 zap_leaf_array_read(zeh->zeh_leaf, le->le_name_chunk, 1,
 529                     le->le_name_numints, 1, buflen, buf);
 530         }
 531         if (le->le_name_numints > buflen)
 532                 return (SET_ERROR(EOVERFLOW));
 533         return (0);
 534 }
 535
 536 int
 537 zap_entry_update(zap_entry_handle_t *zeh,
 538         uint8_t integer_size, uint64_t num_integers, const void *buf)
 539 {
 540         int delta_chunks;
 541         zap_leaf_t *l = zeh->zeh_leaf;
 542         struct zap_leaf_entry *le = ZAP_LEAF_ENTRY(l, *zeh->zeh_chunkp);
 543
 544         delta_chunks = ZAP_LEAF_ARRAY_NCHUNKS(num_integers * integer_size) -
 545             ZAP_LEAF_ARRAY_NCHUNKS(le->le_value_numints * le->le_value_intlen);
 546
 547         if ((int)zap_leaf_phys(l)->l_hdr.lh_nfree < delta_chunks)
 548                 return (SET_ERROR(EAGAIN));
 549
 550         zap_leaf_array_free(l, &le->le_value_chunk);
 551         le->le_value_chunk =
 552             zap_leaf_array_create(l, buf, integer_size, num_integers);
 553         le->le_value_numints = num_integers;
 554         le->le_value_intlen = integer_size;
 555         return (0);
 556 }
 557
 558 void
 559 zap_entry_remove(zap_entry_handle_t *zeh)
 560 {
 561         uint16_t entry_chunk;
 562         struct zap_leaf_entry *le;
 563         zap_leaf_t *l = zeh->zeh_leaf;
 564
 565         ASSERT3P(zeh->zeh_chunkp, !=, &zeh->zeh_fakechunk);
 566
 567         entry_chunk = *zeh->zeh_chunkp;
 568         le = ZAP_LEAF_ENTRY(l, entry_chunk);
 569         ASSERT3U(le->le_type, ==, ZAP_CHUNK_ENTRY);
 570
 571         zap_leaf_array_free(l, &le->le_name_chunk);
 572         zap_leaf_array_free(l, &le->le_value_chunk);
 573
 574         *zeh->zeh_chunkp = le->le_next;
 575         zap_leaf_chunk_free(l, entry_chunk);
 576
 577         zap_leaf_phys(l)->l_hdr.lh_nentries--;
 578 }
 579
 580 int
 581 zap_entry_create(zap_leaf_t *l, zap_name_t *zn, uint32_t cd,
 582     uint8_t integer_size, uint64_t num_integers, const void *buf,
 583     zap_entry_handle_t *zeh)
 584 {
 585         uint16_t chunk;
 586         uint16_t *chunkp;
 587         struct zap_leaf_entry *le;
 588         uint64_t valuelen;
 589         int numchunks;
 590         uint64_t h = zn->zn_hash;
 591
 592         valuelen = integer_size * num_integers;
 593
 594         numchunks = 1 + ZAP_LEAF_ARRAY_NCHUNKS(zn->zn_key_orig_numints *
 595             zn->zn_key_intlen) + ZAP_LEAF_ARRAY_NCHUNKS(valuelen);
 596         if (numchunks > ZAP_LEAF_NUMCHUNKS(l))
 597                 return (E2BIG);
 598
 599         if (cd == ZAP_NEED_CD) {
 600                 /* find the lowest unused cd */
 601                 if (zap_leaf_phys(l)->l_hdr.lh_flags & ZLF_ENTRIES_CDSORTED) {
 602                         cd = 0;
 603
 604                         for (chunk = *LEAF_HASH_ENTPTR(l, h);
 605                             chunk != CHAIN_END; chunk = le->le_next) {
 606                                 le = ZAP_LEAF_ENTRY(l, chunk);
 607                                 if (le->le_cd > cd)
 608                                         break;
 609                                 if (le->le_hash == h) {
 610                                         ASSERT3U(cd, ==, le->le_cd);
 611                                         cd++;
 612                                 }
 613                         }
 614                 } else {
 615                         /* old unsorted format; do it the O(n^2) way */
 616                         for (cd = 0; ; cd++) {
 617                                 for (chunk = *LEAF_HASH_ENTPTR(l, h);
 618                                     chunk != CHAIN_END; chunk = le->le_next) {
 619                                         le = ZAP_LEAF_ENTRY(l, chunk);
 620                                         if (le->le_hash == h &&
 621                                             le->le_cd == cd) {
 622                                                 break;
 623                                         }
 624                                 }
 625                                 /* If this cd is not in use, we are good. */
 626                                 if (chunk == CHAIN_END)
 627                                         break;
 628                         }
 629                 }
 630                 /*
 631                  * We would run out of space in a block before we could
 632                  * store enough entries to run out of CD values.
 633                  */
 634                 ASSERT3U(cd, <, zap_maxcd(zn->zn_zap));
 635         }
 636
 637         if (zap_leaf_phys(l)->l_hdr.lh_nfree < numchunks)
 638                 return (SET_ERROR(EAGAIN));
 639
 640         /* make the entry */
 641         chunk = zap_leaf_chunk_alloc(l);
 642         le = ZAP_LEAF_ENTRY(l, chunk);
 643         le->le_type = ZAP_CHUNK_ENTRY;
 644         le->le_name_chunk = zap_leaf_array_create(l, zn->zn_key_orig,
 645             zn->zn_key_intlen, zn->zn_key_orig_numints);
 646         le->le_name_numints = zn->zn_key_orig_numints;
 647         le->le_value_chunk =
 648             zap_leaf_array_create(l, buf, integer_size, num_integers);
 649         le->le_value_numints = num_integers;
 650         le->le_value_intlen = integer_size;
 651         le->le_hash = h;
 652         le->le_cd = cd;
 653
 654         /* link it into the hash chain */
 655         /* XXX if we did the search above, we could just use that */
 656         chunkp = zap_leaf_rehash_entry(l, chunk);
 657
 658         zap_leaf_phys(l)->l_hdr.lh_nentries++;
 659
 660         zeh->zeh_leaf = l;
 661         zeh->zeh_num_integers = num_integers;
 662         zeh->zeh_integer_size = le->le_value_intlen;
 663         zeh->zeh_cd = le->le_cd;
 664         zeh->zeh_hash = le->le_hash;
 665         zeh->zeh_chunkp = chunkp;
 666
 667         return (0);
 668 }
 669
 670 /*
 671  * Determine if there is another entry with the same normalized form.
 672  * For performance purposes, either zn or name must be provided (the
 673  * other can be NULL).  Note, there usually won't be any hash
 674  * conflicts, in which case we don't need the concatenated/normalized
 675  * form of the name.  But all callers have one of these on hand anyway,
 676  * so might as well take advantage.  A cleaner but slower interface
 677  * would accept neither argument, and compute the normalized name as
 678  * needed (using zap_name_alloc(zap_entry_read_name(zeh))).
 679  */
 680 boolean_t
 681 zap_entry_normalization_conflict(zap_entry_handle_t *zeh, zap_name_t *zn,
 682     const char *name, zap_t *zap)
 683 {
 684         uint64_t chunk;
 685         struct zap_leaf_entry *le;
 686         boolean_t allocdzn = B_FALSE;
 687
 688         if (zap->zap_normflags == 0)
 689                 return (B_FALSE);
 690
 691         for (chunk = *LEAF_HASH_ENTPTR(zeh->zeh_leaf, zeh->zeh_hash);
 692             chunk != CHAIN_END; chunk = le->le_next) {
 693                 le = ZAP_LEAF_ENTRY(zeh->zeh_leaf, chunk);
 694                 if (le->le_hash != zeh->zeh_hash)
 695                         continue;
 696                 if (le->le_cd == zeh->zeh_cd)
 697                         continue;
 698
 699                 if (zn == NULL) {
 700                         zn = zap_name_alloc(zap, name, MT_FIRST);
 701                         allocdzn = B_TRUE;
 702                 }
 703                 if (zap_leaf_array_match(zeh->zeh_leaf, zn,
 704                     le->le_name_chunk, le->le_name_numints)) {
 705                         if (allocdzn)
 706                                 zap_name_free(zn);
 707                         return (B_TRUE);
 708                 }
 709         }
 710         if (allocdzn)
 711                 zap_name_free(zn);
 712         return (B_FALSE);
 713 }
 714
 715 /*
 716  * Routines for transferring entries between leafs.
 717  */
 718
 719 static uint16_t *
 720 zap_leaf_rehash_entry(zap_leaf_t *l, uint16_t entry)
 721 {
 722         struct zap_leaf_entry *le = ZAP_LEAF_ENTRY(l, entry);
 723         struct zap_leaf_entry *le2;
 724         uint16_t *chunkp;
 725
 726         /*
 727          * keep the entry chain sorted by cd
 728          * NB: this will not cause problems for unsorted leafs, though
 729          * it is unnecessary there.
 730          */
 731         for (chunkp = LEAF_HASH_ENTPTR(l, le->le_hash);
 732             *chunkp != CHAIN_END; chunkp = &le2->le_next) {
 733                 le2 = ZAP_LEAF_ENTRY(l, *chunkp);
 734                 if (le2->le_cd > le->le_cd)
 735                         break;
 736         }
 737
 738         le->le_next = *chunkp;
 739         *chunkp = entry;
 740         return (chunkp);
 741 }
 742
 743 static uint16_t
 744 zap_leaf_transfer_array(zap_leaf_t *l, uint16_t chunk, zap_leaf_t *nl)
 745 {
 746         uint16_t new_chunk;
 747         uint16_t *nchunkp = &new_chunk;
 748
 749         while (chunk != CHAIN_END) {
 750                 uint16_t nchunk = zap_leaf_chunk_alloc(nl);
 751                 struct zap_leaf_array *nla =
 752                     &ZAP_LEAF_CHUNK(nl, nchunk).l_array;
 753                 struct zap_leaf_array *la =
 754                     &ZAP_LEAF_CHUNK(l, chunk).l_array;
 755                 int nextchunk = la->la_next;
 756
 757                 ASSERT3U(chunk, <, ZAP_LEAF_NUMCHUNKS(l));
 758                 ASSERT3U(nchunk, <, ZAP_LEAF_NUMCHUNKS(l));
 759
 760                 *nla = *la; /* structure assignment */
 761
 762                 zap_leaf_chunk_free(l, chunk);
 763                 chunk = nextchunk;
 764                 *nchunkp = nchunk;
 765                 nchunkp = &nla->la_next;
 766         }
 767         *nchunkp = CHAIN_END;
 768         return (new_chunk);
 769 }
 770
 771 static void
 772 zap_leaf_transfer_entry(zap_leaf_t *l, int entry, zap_leaf_t *nl)
 773 {
 774         struct zap_leaf_entry *le, *nle;
 775         uint16_t chunk;
 776
 777         le = ZAP_LEAF_ENTRY(l, entry);
 778         ASSERT3U(le->le_type, ==, ZAP_CHUNK_ENTRY);
 779
 780         chunk = zap_leaf_chunk_alloc(nl);
 781         nle = ZAP_LEAF_ENTRY(nl, chunk);
 782         *nle = *le; /* structure assignment */
 783
 784         (void) zap_leaf_rehash_entry(nl, chunk);
 785
 786         nle->le_name_chunk = zap_leaf_transfer_array(l, le->le_name_chunk, nl);
 787         nle->le_value_chunk =
 788             zap_leaf_transfer_array(l, le->le_value_chunk, nl);
 789
 790         zap_leaf_chunk_free(l, entry);
 791
 792         zap_leaf_phys(l)->l_hdr.lh_nentries--;
 793         zap_leaf_phys(nl)->l_hdr.lh_nentries++;
 794 }
 795
 796 /*
 797  * Transfer the entries whose hash prefix ends in 1 to the new leaf.
 798  */
 799 void
 800 zap_leaf_split(zap_leaf_t *l, zap_leaf_t *nl, boolean_t sort)
 801 {
 802         int i;
 803         int bit = 64 - 1 - zap_leaf_phys(l)->l_hdr.lh_prefix_len;
 804
 805         /* set new prefix and prefix_len */
 806         zap_leaf_phys(l)->l_hdr.lh_prefix <<= 1;
 807         zap_leaf_phys(l)->l_hdr.lh_prefix_len++;
 808         zap_leaf_phys(nl)->l_hdr.lh_prefix =
 809             zap_leaf_phys(l)->l_hdr.lh_prefix | 1;
 810         zap_leaf_phys(nl)->l_hdr.lh_prefix_len =
 811             zap_leaf_phys(l)->l_hdr.lh_prefix_len;
 812
 813         /* break existing hash chains */
 814         zap_memset(zap_leaf_phys(l)->l_hash, CHAIN_END,
 815             2*ZAP_LEAF_HASH_NUMENTRIES(l));
 816
 817         if (sort)
 818                 zap_leaf_phys(l)->l_hdr.lh_flags |= ZLF_ENTRIES_CDSORTED;
 819
 820         /*
 821          * Transfer entries whose hash bit 'bit' is set to nl; rehash
 822          * the remaining entries
 823          *
 824          * NB: We could find entries via the hashtable instead. That
 825          * would be O(hashents+numents) rather than O(numblks+numents),
 826          * but this accesses memory more sequentially, and when we're
 827          * called, the block is usually pretty full.
 828          */
 829         for (i = 0; i < ZAP_LEAF_NUMCHUNKS(l); i++) {
 830                 struct zap_leaf_entry *le = ZAP_LEAF_ENTRY(l, i);
 831                 if (le->le_type != ZAP_CHUNK_ENTRY)
 832                         continue;
 833
 834                 if (le->le_hash & (1ULL << bit))
 835                         zap_leaf_transfer_entry(l, i, nl);
 836                 else
 837                         (void) zap_leaf_rehash_entry(l, i);
 838         }
 839 }
 840
 841 void
 842 zap_leaf_stats(zap_t *zap, zap_leaf_t *l, zap_stats_t *zs)
 843 {
 844         int i, n;
 845
 846         n = zap_f_phys(zap)->zap_ptrtbl.zt_shift -
 847             zap_leaf_phys(l)->l_hdr.lh_prefix_len;
 848         n = MIN(n, ZAP_HISTOGRAM_SIZE-1);
 849         zs->zs_leafs_with_2n_pointers[n]++;
 850
 851
 852         n = zap_leaf_phys(l)->l_hdr.lh_nentries/5;
 853         n = MIN(n, ZAP_HISTOGRAM_SIZE-1);
 854         zs->zs_blocks_with_n5_entries[n]++;
 855
 856         n = ((1<<FZAP_BLOCK_SHIFT(zap)) -
 857             zap_leaf_phys(l)->l_hdr.lh_nfree * (ZAP_LEAF_ARRAY_BYTES+1))*10 /
 858             (1<<FZAP_BLOCK_SHIFT(zap));
 859         n = MIN(n, ZAP_HISTOGRAM_SIZE-1);
 860         zs->zs_blocks_n_tenths_full[n]++;
 861
 862         for (i = 0; i < ZAP_LEAF_HASH_NUMENTRIES(l); i++) {
 863                 int nentries = 0;
 864                 int chunk = zap_leaf_phys(l)->l_hash[i];
 865
 866                 while (chunk != CHAIN_END) {
 867                         struct zap_leaf_entry *le =
 868                             ZAP_LEAF_ENTRY(l, chunk);
 869
 870                         n = 1 + ZAP_LEAF_ARRAY_NCHUNKS(le->le_name_numints) +
 871                             ZAP_LEAF_ARRAY_NCHUNKS(le->le_value_numints *
 872                             le->le_value_intlen);
 873                         n = MIN(n, ZAP_HISTOGRAM_SIZE-1);
 874                         zs->zs_entries_using_n_chunks[n]++;
 875
 876                         chunk = le->le_next;
 877                         nentries++;
 878                 }
 879
 880                 n = nentries;
 881                 n = MIN(n, ZAP_HISTOGRAM_SIZE-1);
 882                 zs->zs_buckets_with_n_entries[n]++;
 883         }
 884 }