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