lustre/osd-ldiskfs/osd_iam_lvar.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.gnu.org/licenses/gpl-2.0.html
  19  *
  20  * GPL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Use is subject to license terms.
  25  *
  26  * Copyright (c) 2012, 2015, Intel Corporation.
  27  */
  28 /*
  29  * This file is part of Lustre, http://www.lustre.org/
  30  *
  31  * iam_lvar.c
  32  *
  33  * implementation of iam format for fixed size records, variable sized keys.
  34  *
  35  * Author: Nikita Danilov <nikita@clusterfs.com>
  36  */
  37
  38 #include <linux/types.h>
  39 #include "osd_internal.h"
  40
  41 /*
  42  * Leaf operations.
  43  */
  44
  45 enum {
  46         /* This is duplicated in lustre/utils/create_iam.c */
  47         IAM_LVAR_LEAF_MAGIC = 0x1973
  48 };
  49
  50 /* This is duplicated in lustre/utils/create_iam.c */
  51 struct lvar_leaf_header {
  52         __le16 vlh_magic; /* magic number IAM_LVAR_LEAF_MAGIC */
  53         __le16 vlh_used;  /* used bytes, including header */
  54 };
  55
  56 /*
  57  * Format of leaf entry:
  58  *
  59  * __le16 keysize
  60  *     u8 key[keysize]
  61  *     u8 record[rec_size]
  62  *
  63  * Entries are ordered in key order.
  64  */
  65
  66 /* This is duplicated in lustre/utils/create_iam.c */
  67 typedef u32 lvar_hash_t;
  68
  69 /* This is duplicated in lustre/utils/create_iam.c */
  70 struct lvar_leaf_entry {
  71         __le32 vle_hash;
  72         __le16 vle_keysize;
  73         u8 vle_key[0];
  74 };
  75
  76 #define PDIFF(ptr0, ptr1) (((char *)(ptr0)) - ((char *)(ptr1)))
  77
  78
  79 static inline int blocksize(const struct iam_leaf *leaf)
  80 {
  81         return iam_leaf_container(leaf)->ic_object->i_sb->s_blocksize;
  82 }
  83
  84 static inline const char *kchar(const struct iam_key *key)
  85 {
  86         return (void *)key;
  87 }
  88
  89 static inline struct iam_lentry *lvar_lentry(const struct lvar_leaf_entry *ent)
  90 {
  91         return (struct iam_lentry *)ent;
  92 }
  93
  94 static inline struct lvar_leaf_entry *lentry_lvar(const struct iam_lentry *lent)
  95 {
  96         return (struct lvar_leaf_entry *)lent;
  97 }
  98
  99
 100 static inline int e_keysize(const struct lvar_leaf_entry *ent)
 101 {
 102         return le16_to_cpu(ent->vle_keysize);
 103 }
 104
 105 /* This is duplicated in lustre/utils/create_iam.c */
 106 enum {
 107         LVAR_PAD   = 4,
 108         LVAR_ROUND = LVAR_PAD - 1
 109 };
 110
 111 static inline int getsize(const struct iam_leaf *leaf, int namelen, int recsize)
 112 {
 113         BUILD_BUG_ON((LVAR_PAD & (LVAR_PAD - 1)));
 114
 115         return (offsetof(struct lvar_leaf_entry, vle_key) +
 116                         namelen + recsize + LVAR_ROUND) & ~LVAR_ROUND;
 117 }
 118
 119 static inline int rec_size(const struct iam_rec *rec)
 120 {
 121         return *(const char *)rec;
 122 }
 123
 124 static inline struct iam_rec *e_rec(const struct lvar_leaf_entry *ent)
 125 {
 126         return ((void *)ent) +
 127                 offsetof(struct lvar_leaf_entry, vle_key) + e_keysize(ent);
 128 }
 129
 130 static inline int e_size(const struct iam_leaf *leaf,
 131                          const struct lvar_leaf_entry *ent)
 132 {
 133         return getsize(leaf, e_keysize(ent), rec_size(e_rec(ent)));
 134 }
 135
 136 static inline char *e_char(const struct lvar_leaf_entry *ent)
 137 {
 138         return (char *)&ent->vle_key;
 139 }
 140
 141 static inline struct iam_key *e_key(const struct lvar_leaf_entry *ent)
 142 {
 143         return (struct iam_key *)e_char(ent);
 144 }
 145
 146 static inline lvar_hash_t e_hash(const struct lvar_leaf_entry *ent)
 147 {
 148         return le32_to_cpu(ent->vle_hash);
 149 }
 150
 151 static void e_print(const struct lvar_leaf_entry *ent)
 152 {
 153         CERROR("        %p %8.8x \"%*.*s\"\n", ent, e_hash(ent),
 154                         e_keysize(ent), e_keysize(ent), e_char(ent));
 155 }
 156
 157 static inline struct lvar_leaf_entry *e_next(const struct iam_leaf *leaf,
 158                                              const struct lvar_leaf_entry *ent)
 159 {
 160         return ((void *)ent) + e_size(leaf, ent);
 161 }
 162
 163 #define LVAR_HASH_SANDWICH  (0)
 164 #define LVAR_HASH_TEA       (1)
 165 #define LVAR_HASH_R5        (0)
 166 #define LVAR_HASH_PREFIX    (0)
 167
 168 #ifdef HAVE_LDISKFSFS_DIRHASH_WITH_DIR
 169 #define e_ldiskfsfs_dirhash(dir, name, len, info) \
 170                 ldiskfsfs_dirhash((dir), (name), (len), (info))
 171 #else
 172 #define e_ldiskfsfs_dirhash(dir, name, len, info) \
 173                 ldiskfsfs_dirhash((name), (len), (info))
 174 #endif
 175
 176 static u32 hash_build0(const struct inode *dir, const char *name, int namelen)
 177 {
 178         u32 result;
 179
 180         if (namelen == 0)
 181                 return 0;
 182         if (strncmp(name, ".", 1) == 0 && namelen == 1)
 183                 return 1;
 184         if (strncmp(name, "..", 2) == 0 && namelen == 2)
 185                 return 2;
 186
 187         if (LVAR_HASH_PREFIX) {
 188                 result = 0;
 189                 strncpy((void *)&result,
 190                         name, min_t(int, namelen, sizeof(result)));
 191         } else {
 192                 struct ldiskfs_dx_hash_info hinfo;
 193
 194                 hinfo.hash_version = LDISKFS_DX_HASH_TEA;
 195                 hinfo.seed = NULL;
 196                 e_ldiskfsfs_dirhash(dir, name, namelen, &hinfo);
 197                 result = hinfo.hash;
 198                 if (LVAR_HASH_SANDWICH) {
 199                         u32 result2;
 200
 201                         hinfo.hash_version = LDISKFS_DX_HASH_TEA;
 202                         hinfo.seed = NULL;
 203                         e_ldiskfsfs_dirhash(dir, name, namelen, &hinfo);
 204                         result2 = hinfo.hash;
 205                         result = (0xfc000000 & result2) | (0x03ffffff & result);
 206                 }
 207         }
 208         return result;
 209 }
 210
 211 enum {
 212         HASH_GRAY_AREA = 1024,
 213         HASH_MAX_SIZE  = 0x7fffffffUL
 214 };
 215
 216 static u32 hash_build(const struct inode *dir, const char *name, int namelen)
 217 {
 218         u32 hash;
 219
 220         hash = (hash_build0(dir, name, namelen) << 1) & HASH_MAX_SIZE;
 221         if (hash > HASH_MAX_SIZE - HASH_GRAY_AREA)
 222                 hash &= HASH_GRAY_AREA - 1;
 223         return hash;
 224 }
 225
 226 static inline lvar_hash_t get_hash(const struct inode *dir,
 227                                    const char *name, int namelen)
 228 {
 229         return hash_build(dir, name, namelen);
 230 }
 231
 232 static inline lvar_hash_t iam_get_hash(const struct iam_leaf *leaf,
 233                                        const char *name, int namelen)
 234 {
 235         struct iam_path *iam_path = iam_leaf_path(leaf);
 236
 237         return get_hash(iam_path_obj(iam_path), name, namelen);
 238 }
 239
 240 static inline int e_eq(const struct lvar_leaf_entry *ent,
 241                        const char *name, int namelen)
 242 {
 243         return namelen == e_keysize(ent) && !memcmp(e_char(ent), name, namelen);
 244 }
 245
 246 static inline int e_cmp(const struct iam_leaf *leaf,
 247                         const struct lvar_leaf_entry *ent, lvar_hash_t hash)
 248 {
 249         lvar_hash_t ehash;
 250
 251         ehash = e_hash(ent);
 252         return ehash == hash ? 0 : (ehash < hash ? -1 : 1);
 253 }
 254
 255 static struct lvar_leaf_header *n_head(const struct iam_leaf *l)
 256 {
 257         return (struct lvar_leaf_header *)l->il_bh->b_data;
 258 }
 259
 260 static int h_used(const struct lvar_leaf_header *hdr)
 261 {
 262         return le16_to_cpu(hdr->vlh_used);
 263 }
 264
 265 static void h_used_adj(const struct iam_leaf *leaf,
 266                        struct lvar_leaf_header *hdr, int adj)
 267 {
 268         int used;
 269
 270         used = h_used(hdr) + adj;
 271         assert_corr(sizeof(*hdr) <= used && used <= blocksize(leaf));
 272         hdr->vlh_used = cpu_to_le16(used);
 273 }
 274
 275 static struct lvar_leaf_entry *n_start(const struct iam_leaf *leaf)
 276 {
 277         return (void *)leaf->il_bh->b_data + sizeof(struct lvar_leaf_header);
 278 }
 279
 280 static struct lvar_leaf_entry *n_end(const struct iam_leaf *l)
 281 {
 282         return (void *)l->il_bh->b_data + h_used(n_head(l));
 283 }
 284
 285 static struct lvar_leaf_entry *n_cur(const struct iam_leaf *l)
 286 {
 287         return lentry_lvar(l->il_at);
 288 }
 289
 290 void n_print(const struct iam_leaf *l)
 291 {
 292         struct lvar_leaf_entry *scan;
 293
 294         CERROR("used: %d\n", h_used(n_head(l)));
 295         for (scan = n_start(l); scan < n_end(l); scan = e_next(l, scan))
 296                 e_print(scan);
 297 }
 298
 299 #if LDISKFS_CORRECTNESS_ON
 300 static int n_at_rec(const struct iam_leaf *folio)
 301 {
 302         return n_start(folio) <= lentry_lvar(folio->il_at) &&
 303                 lentry_lvar(folio->il_at) < n_end(folio);
 304 }
 305
 306 #if LDISKFS_INVARIANT_ON
 307 static int n_invariant(const struct iam_leaf *leaf)
 308 {
 309         struct iam_path *path;
 310         struct inode *dir;
 311         struct lvar_leaf_entry *scan;
 312         struct lvar_leaf_entry *end;
 313         lvar_hash_t hash;
 314         lvar_hash_t nexthash;
 315         lvar_hash_t starthash;
 316
 317         end  = n_end(leaf);
 318         hash = 0;
 319         path = leaf->il_path;
 320
 321         if (h_used(n_head(leaf)) > blocksize(leaf))
 322                 return 0;
 323
 324         dir = iam_path_obj(iam_path);
 325         /*
 326          * Delimiting key in the parent index node. Clear least bit to account
 327          * for hash collision marker.
 328          */
 329         starthash = *(lvar_hash_t *)iam_ikey_at(path, path->ip_frame->at) & ~1;
 330         for (scan = n_start(leaf); scan < end; scan = e_next(leaf, scan)) {
 331                 nexthash = e_hash(scan);
 332                 if (nexthash != get_hash(dir, e_char(scan), e_keysize(scan))) {
 333                         BREAKPOINT();
 334                         return 0;
 335                 }
 336                 if (0 && nexthash < starthash) {
 337                         /*
 338                          * Unfortunately this useful invariant cannot be
 339                          * reliably checked as parent node is not necessarily
 340                          * locked.
 341                          */
 342                         n_print(leaf);
 343                         CERROR("invalid hash value less than start hash: %#x < %#x\n",
 344                                 nexthash, starthash);
 345                         dump_stack();
 346                         return 0;
 347                 }
 348                 if (nexthash < hash) {
 349                         BREAKPOINT();
 350                         return 0;
 351                 }
 352                 hash = nexthash;
 353         }
 354         if (scan != end) {
 355                 BREAKPOINT();
 356                 return 0;
 357         }
 358         return 1;
 359 }
 360 /* LDISKFS_INVARIANT_ON */
 361 #endif
 362
 363 /* LDISKFS_CORRECTNESS_ON */
 364 #endif
 365
 366 static struct iam_ikey *lvar_ikey(const struct iam_leaf *l,
 367                                   struct iam_ikey *key)
 368 {
 369         lvar_hash_t *hash;
 370
 371         assert_corr(n_at_rec(l));
 372
 373         hash = (void *)key;
 374         *hash = e_hash(n_cur(l));
 375         return key;
 376 }
 377
 378 static struct iam_key *lvar_key(const struct iam_leaf *l)
 379 {
 380         return e_key(n_cur(l));
 381 }
 382
 383 static int lvar_key_size(const struct iam_leaf *l)
 384 {
 385         return e_keysize(n_cur(l));
 386 }
 387
 388 static void lvar_start(struct iam_leaf *l)
 389 {
 390         l->il_at = lvar_lentry(n_start(l));
 391 }
 392
 393 static int lvar_init(struct iam_leaf *l)
 394 {
 395         int result;
 396         int used;
 397         struct lvar_leaf_header *head;
 398
 399         assert_corr(l->il_bh != NULL);
 400
 401         head = n_head(l);
 402         used = h_used(head);
 403         if (le16_to_cpu(head->vlh_magic) == IAM_LVAR_LEAF_MAGIC &&
 404                         used <= blocksize(l)) {
 405                 l->il_at = l->il_entries = lvar_lentry(n_start(l));
 406                 result = 0;
 407         } else {
 408                 struct inode *obj;
 409
 410                 obj = iam_leaf_container(l)->ic_object;
 411                 CERROR(
 412                 "Bad magic in node %llu (#%lu): %#x != %#x or wrong used: %d\n",
 413                 (unsigned long long)l->il_bh->b_blocknr, obj->i_ino,
 414                 le16_to_cpu(head->vlh_magic), IAM_LVAR_LEAF_MAGIC,
 415                 used);
 416                 result = -EIO;
 417         }
 418         return result;
 419 }
 420
 421 static void lvar_fini(struct iam_leaf *l)
 422 {
 423         l->il_entries = l->il_at = NULL;
 424 }
 425
 426 static struct iam_rec *lvar_rec(const struct iam_leaf *l)
 427 {
 428         assert_corr(n_at_rec(l));
 429         return e_rec(n_cur(l));
 430 }
 431
 432 static void lvar_next(struct iam_leaf *l)
 433 {
 434         assert_corr(n_at_rec(l));
 435         assert_corr(iam_leaf_is_locked(l));
 436         l->il_at = lvar_lentry(e_next(l, n_cur(l)));
 437 }
 438
 439 static int lvar_lookup(struct iam_leaf *leaf, const struct iam_key *k)
 440 {
 441         struct lvar_leaf_entry *found;
 442         struct lvar_leaf_entry *scan;
 443         struct lvar_leaf_entry *end;
 444         int result;
 445         const char *name;
 446         int namelen;
 447         int found_equal;
 448         lvar_hash_t hash;
 449         int last;
 450
 451         assert_inv(n_invariant(leaf));
 452         end = n_end(leaf);
 453
 454         name = kchar(k);
 455         namelen = strlen(name);
 456         hash = iam_get_hash(leaf, name, namelen);
 457         found = NULL;
 458         found_equal = 0;
 459         last = 1;
 460
 461         for (scan = n_start(leaf); scan < end; scan = e_next(leaf, scan)) {
 462                 lvar_hash_t scan_hash;
 463
 464                 scan_hash = e_hash(scan);
 465                 if (scan_hash < hash)
 466                         found = scan;
 467                 else if (scan_hash == hash) {
 468                         if (e_eq(scan, name, namelen)) {
 469                                 /*
 470                                  * perfect match
 471                                  */
 472                                 leaf->il_at = lvar_lentry(scan);
 473                                 return IAM_LOOKUP_EXACT;
 474                         } else if (!found_equal) {
 475                                 found = scan;
 476                                 found_equal = 1;
 477                         }
 478                 } else {
 479                         last = 0;
 480                         break;
 481                 }
 482         }
 483         if (found == NULL) {
 484                 /*
 485                  * @k is less than all hashes in the leaf.
 486                  */
 487                 lvar_start(leaf);
 488                 result = IAM_LOOKUP_BEFORE;
 489         } else {
 490                 leaf->il_at = lvar_lentry(found);
 491                 result = IAM_LOOKUP_OK;
 492                 assert_corr(n_at_rec(leaf));
 493         }
 494         if (last)
 495                 result |= IAM_LOOKUP_LAST;
 496         assert_inv(n_invariant(leaf));
 497
 498         return result;
 499 }
 500
 501 static int lvar_ilookup(struct iam_leaf *leaf, const struct iam_ikey *ik)
 502 {
 503         struct lvar_leaf_entry *scan;
 504         struct lvar_leaf_entry *end;
 505         lvar_hash_t hash;
 506
 507         assert_inv(n_invariant(leaf));
 508         end  = n_end(leaf);
 509         hash = *(const lvar_hash_t *)ik;
 510
 511         lvar_start(leaf);
 512         for (scan = n_start(leaf); scan < end; scan = e_next(leaf, scan)) {
 513                 lvar_hash_t scan_hash;
 514
 515                 scan_hash = e_hash(scan);
 516                 if (scan_hash > hash)
 517                         return scan == n_start(leaf) ?
 518                                 IAM_LOOKUP_BEFORE : IAM_LOOKUP_OK;
 519                 leaf->il_at = lvar_lentry(scan);
 520                 if (scan_hash == hash)
 521                         return IAM_LOOKUP_EXACT;
 522         }
 523         assert_inv(n_invariant(leaf));
 524         /*
 525          * @ik is greater than any key in the node. Return last record in the
 526          * node.
 527          */
 528         return IAM_LOOKUP_OK;
 529 }
 530
 531 static void __lvar_key_set(struct iam_leaf *l, const struct iam_key *k)
 532 {
 533         memcpy(e_key(n_cur(l)), k, e_keysize(n_cur(l)));
 534 }
 535
 536 static void lvar_key_set(struct iam_leaf *l, const struct iam_key *k)
 537 {
 538         assert_corr(n_at_rec(l));
 539         assert_corr(strlen(kchar(k)) == e_keysize(n_cur(l)));
 540         assert_corr(iam_leaf_is_locked(l));
 541         __lvar_key_set(l, k);
 542         assert_inv(n_invariant(l));
 543 }
 544
 545 static int lvar_key_cmp(const struct iam_leaf *l, const struct iam_key *k)
 546 {
 547         lvar_hash_t hash;
 548         const char *name;
 549
 550         name = kchar(k);
 551
 552         hash = iam_get_hash(l, name, strlen(name));
 553         return e_cmp(l, n_cur(l), hash);
 554 }
 555
 556 static int lvar_key_eq(const struct iam_leaf *l, const struct iam_key *k)
 557 {
 558         const char *name;
 559
 560         name = kchar(k);
 561         return e_eq(n_cur(l), name, strlen(name));
 562 }
 563
 564 static void __lvar_rec_set(struct iam_leaf *l, const struct iam_rec *r)
 565 {
 566         memcpy(e_rec(n_cur(l)), r, rec_size(r));
 567 }
 568
 569 static void lvar_rec_set(struct iam_leaf *l, const struct iam_rec *r)
 570 {
 571         assert_corr(n_at_rec(l));
 572         assert_corr(iam_leaf_is_locked(l));
 573         __lvar_rec_set(l, r);
 574         assert_inv(n_invariant(l));
 575 }
 576
 577 static int lvar_rec_eq(const struct iam_leaf *l, const struct iam_rec *r)
 578 {
 579         struct iam_rec *rec = e_rec(n_cur(l));
 580
 581         if (rec_size(rec) != rec_size(r))
 582                 return 0;
 583         return !memcmp(rec, r, rec_size(r));
 584 }
 585
 586 static void lvar_rec_get(const struct iam_leaf *l, struct iam_rec *r)
 587 {
 588         struct iam_rec *rec;
 589
 590         rec = e_rec(n_cur(l));
 591         assert_corr(n_at_rec(l));
 592         assert_corr(iam_leaf_is_locked(l));
 593         memcpy(r, rec, rec_size(rec));
 594         assert_inv(n_invariant(l));
 595 }
 596
 597 static int lvar_can_add(const struct iam_leaf *l,
 598                         const struct iam_key *k, const struct iam_rec *r)
 599 {
 600         assert_corr(iam_leaf_is_locked(l));
 601         return h_used(n_head(l)) +
 602                 getsize(l, strlen(kchar(k)), rec_size(r)) <= blocksize(l);
 603 }
 604
 605 static int lvar_at_end(const struct iam_leaf *folio)
 606 {
 607         assert_corr(iam_leaf_is_locked(folio));
 608         return n_cur(folio) == n_end(folio);
 609 }
 610
 611 static void lvar_rec_add(struct iam_leaf *leaf,
 612                          const struct iam_key *k, const struct iam_rec *r)
 613 {
 614         const char *key;
 615         int ksize;
 616         int shift;
 617         void *end;
 618         void *start;
 619         ptrdiff_t diff;
 620
 621         assert_corr(lvar_can_add(leaf, k, r));
 622         assert_inv(n_invariant(leaf));
 623         assert_corr(iam_leaf_is_locked(leaf));
 624
 625         key   = kchar(k);
 626         ksize = strlen(key);
 627         shift = getsize(leaf, ksize, rec_size(r));
 628
 629         if (!lvar_at_end(leaf)) {
 630                 assert_corr(n_cur(leaf) < n_end(leaf));
 631                 end = n_end(leaf);
 632                 if (lvar_key_cmp(leaf, k) <= 0)
 633                         lvar_next(leaf);
 634                 else
 635                         /*
 636                          * Another exceptional case: insertion with the key
 637                          * less than least key in the leaf.
 638                          */
 639                         assert_corr(leaf->il_at == leaf->il_entries);
 640
 641                 start = leaf->il_at;
 642                 diff  = PDIFF(end, start);
 643                 assert_corr(diff >= 0);
 644                 memmove(start + shift, start, diff);
 645         }
 646         h_used_adj(leaf, n_head(leaf), shift);
 647         n_cur(leaf)->vle_keysize = cpu_to_le16(ksize);
 648         n_cur(leaf)->vle_hash = cpu_to_le32(iam_get_hash(leaf, key, ksize));
 649         __lvar_key_set(leaf, k);
 650         __lvar_rec_set(leaf, r);
 651         assert_corr(n_at_rec(leaf));
 652         assert_inv(n_invariant(leaf));
 653 }
 654
 655 static void lvar_rec_del(struct iam_leaf *leaf, int shift)
 656 {
 657         void *next;
 658         void *end;
 659         int nob;
 660
 661         assert_corr(n_at_rec(leaf));
 662         assert_inv(n_invariant(leaf));
 663         assert_corr(iam_leaf_is_locked(leaf));
 664
 665         end  = n_end(leaf);
 666         next = e_next(leaf, n_cur(leaf));
 667         nob  = e_size(leaf, n_cur(leaf));
 668         memmove(leaf->il_at, next, end - next);
 669         h_used_adj(leaf, n_head(leaf), -nob);
 670         assert_inv(n_invariant(leaf));
 671 }
 672
 673 static void lvar_init_new(struct iam_container *c, struct buffer_head *bh)
 674 {
 675         struct lvar_leaf_header *hdr;
 676
 677         hdr = (struct lvar_leaf_header *)bh->b_data;
 678         hdr->vlh_magic = cpu_to_le16(IAM_LVAR_LEAF_MAGIC);
 679         hdr->vlh_used  = sizeof(*hdr);
 680 }
 681
 682 static struct lvar_leaf_entry *find_pivot(const struct iam_leaf *leaf,
 683                                           struct lvar_leaf_entry **prev)
 684 {
 685         void *scan;
 686         void *start;
 687         int threshold;
 688
 689         *prev = NULL;
 690         threshold = blocksize(leaf) / 2;
 691         for (scan = start = n_start(leaf); scan - start <= threshold;
 692                         *prev = scan, scan = e_next(leaf, scan)) {
 693                 ;
 694         }
 695         return scan;
 696 }
 697
 698 static void lvar_split(struct iam_leaf *leaf, struct buffer_head **bh,
 699                        iam_ptr_t new_blknr)
 700 {
 701         struct lvar_leaf_entry *first_to_move;
 702         struct lvar_leaf_entry *last_to_stay;
 703         struct iam_path *path;
 704         struct lvar_leaf_header *hdr;
 705         struct buffer_head *new_leaf;
 706         ptrdiff_t tomove;
 707         lvar_hash_t hash;
 708
 709         assert_inv(n_invariant(leaf));
 710         assert_corr(iam_leaf_is_locked(leaf));
 711
 712         new_leaf = *bh;
 713         path = iam_leaf_path(leaf);
 714
 715         hdr = (void *)new_leaf->b_data;
 716
 717         first_to_move = find_pivot(leaf, &last_to_stay);
 718         assert_corr(last_to_stay != NULL);
 719         assert_corr(e_next(leaf, last_to_stay) == first_to_move);
 720
 721         hash = e_hash(first_to_move);
 722         if (hash == e_hash(last_to_stay))
 723                 /*
 724                  * Duplicate hash.
 725                  */
 726                 hash |= 1;
 727
 728         tomove = PDIFF(n_end(leaf), first_to_move);
 729         memmove(hdr + 1, first_to_move, tomove);
 730
 731         h_used_adj(leaf, hdr, tomove);
 732         h_used_adj(leaf, n_head(leaf), -tomove);
 733
 734         assert_corr(n_end(leaf) == first_to_move);
 735
 736         if (n_cur(leaf) >= first_to_move) {
 737                 /*
 738                  * insertion point moves into new leaf.
 739                  */
 740                 ptrdiff_t shift;
 741
 742                 shift = PDIFF(leaf->il_at, first_to_move);
 743                 *bh = leaf->il_bh;
 744                 leaf->il_bh = new_leaf;
 745                 leaf->il_curidx = new_blknr;
 746
 747                 assert_corr(iam_leaf_is_locked(leaf));
 748                 lvar_init(leaf);
 749                 /*
 750                  * init cannot fail, as node was just initialized.
 751                  */
 752                 assert_corr(result == 0);
 753                 leaf->il_at = ((void *)leaf->il_at) + shift;
 754         }
 755         /*
 756          * Insert pointer to the new node (together with the least key in
 757          * the node) into index node.
 758          */
 759         iam_insert_key_lock(path, path->ip_frame, (struct iam_ikey *)&hash,
 760                             new_blknr);
 761         assert_corr(n_cur(leaf) < n_end(leaf));
 762         assert_inv(n_invariant(leaf));
 763 }
 764
 765 static int lvar_leaf_empty(struct iam_leaf *leaf)
 766 {
 767         return h_used(n_head(leaf)) == sizeof(struct lvar_leaf_header);
 768 }
 769
 770 static const struct iam_leaf_operations lvar_leaf_ops = {
 771         .init           = lvar_init,
 772         .init_new       = lvar_init_new,
 773         .fini           = lvar_fini,
 774         .start          = lvar_start,
 775         .next           = lvar_next,
 776         .key            = lvar_key,
 777         .ikey           = lvar_ikey,
 778         .rec            = lvar_rec,
 779         .key_set        = lvar_key_set,
 780         .key_cmp        = lvar_key_cmp,
 781         .key_eq         = lvar_key_eq,
 782         .key_size       = lvar_key_size,
 783         .rec_set        = lvar_rec_set,
 784         .rec_eq         = lvar_rec_eq,
 785         .rec_get        = lvar_rec_get,
 786         .lookup         = lvar_lookup,
 787         .ilookup        = lvar_ilookup,
 788         .at_end         = lvar_at_end,
 789         .rec_add        = lvar_rec_add,
 790         .rec_del        = lvar_rec_del,
 791         .can_add        = lvar_can_add,
 792         .split          = lvar_split,
 793         .leaf_empty     = lvar_leaf_empty,
 794 };
 795
 796 /*
 797  * Index operations.
 798  */
 799
 800 enum {
 801         /* This is duplicated in lustre/utils/create_iam.c */
 802         /* egrep -i '^o?x?[olabcdef]*$' /usr/share/dict/words */
 803         IAM_LVAR_ROOT_MAGIC = 0xb01dface
 804 };
 805
 806 /* This is duplicated in lustre/utils/create_iam.c */
 807 struct lvar_root {
 808         __le32 vr_magic;
 809         __le16 vr_recsize;
 810         __le16 vr_ptrsize;
 811         u8 vr_indirect_levels;
 812         u8 vr_padding0;
 813         __le16 vr_padding1;
 814 };
 815
 816 static u32 lvar_root_ptr(struct iam_container *c)
 817 {
 818         return 0;
 819 }
 820
 821 static int lvar_node_init(struct iam_container *c, struct buffer_head *bh,
 822                           int root)
 823 {
 824         return 0;
 825 }
 826
 827 static struct iam_entry *lvar_root_inc(struct iam_container *c,
 828                                        struct iam_path *path,
 829                                        struct iam_frame *frame)
 830 {
 831         struct lvar_root *root;
 832         struct iam_entry *entries;
 833
 834         assert_corr(iam_frame_is_locked(path, frame));
 835         entries = frame->entries;
 836
 837         dx_set_count(entries, 2);
 838         assert_corr(dx_get_limit(entries) == dx_root_limit(path));
 839
 840         root = (void *)frame->bh->b_data;
 841         assert_corr(le64_to_cpu(root->vr_magic) == IAM_LVAR_ROOT_MAGIC);
 842         root->vr_indirect_levels++;
 843         frame->at = entries = iam_entry_shift(path, entries, 1);
 844         memset(iam_ikey_at(path, entries), 0,
 845                iam_path_descr(path)->id_ikey_size);
 846         return entries;
 847 }
 848
 849 static int lvar_node_check(struct iam_path *path, struct iam_frame *frame)
 850 {
 851         unsigned int count;
 852         unsigned int limit;
 853         unsigned int limit_correct;
 854         struct iam_entry *entries;
 855
 856         entries = dx_node_get_entries(path, frame);
 857
 858         if (frame == path->ip_frames) {
 859                 struct lvar_root *root;
 860
 861                 root = (void *)frame->bh->b_data;
 862                 if (le32_to_cpu(root->vr_magic) != IAM_LVAR_ROOT_MAGIC)
 863                         return -EIO;
 864                 limit_correct = dx_root_limit(path);
 865         } else
 866                 limit_correct = dx_node_limit(path);
 867         count = dx_get_count(entries);
 868         limit = dx_get_limit(entries);
 869         if (count > limit)
 870                 return -EIO;
 871         if (limit != limit_correct)
 872                 return -EIO;
 873         return 0;
 874 }
 875
 876 static int lvar_node_load(struct iam_path *path, struct iam_frame *frame)
 877 {
 878         struct iam_entry *entries;
 879         void *data;
 880
 881         entries = dx_node_get_entries(path, frame);
 882         data = frame->bh->b_data;
 883
 884         if (frame == path->ip_frames) {
 885                 struct lvar_root *root;
 886                 const char *name;
 887
 888                 root = data;
 889                 name = kchar(path->ip_key_target);
 890                 path->ip_indirect = root->vr_indirect_levels;
 891                 if (path->ip_ikey_target == NULL) {
 892                         path->ip_ikey_target = iam_path_ikey(path, 4);
 893                         *(lvar_hash_t *)path->ip_ikey_target =
 894                                 get_hash(iam_path_obj(path), name,
 895                                          strlen(name));
 896                 }
 897         }
 898         frame->entries = frame->at = entries;
 899         return 0;
 900 }
 901
 902 static int lvar_ikeycmp(const struct iam_container *c,
 903                         const struct iam_ikey *k1, const struct iam_ikey *k2)
 904 {
 905         lvar_hash_t p1 = le32_to_cpu(*(lvar_hash_t *)k1);
 906         lvar_hash_t p2 = le32_to_cpu(*(lvar_hash_t *)k2);
 907
 908         return p1 > p2 ? 1 : (p1 < p2 ? -1 : 0);
 909 }
 910
 911 static struct iam_path_descr *lvar_ipd_alloc(const struct iam_container *c,
 912                                              void *area)
 913 {
 914         return iam_ipd_alloc(area, c->ic_descr->id_ikey_size);
 915 }
 916
 917 static void lvar_root(void *buf,
 918                       int blocksize, int keysize, int ptrsize, int recsize)
 919 {
 920         struct lvar_root *root;
 921         struct dx_countlimit *limit;
 922         void *entry;
 923         int isize;
 924
 925         isize = sizeof(lvar_hash_t) + ptrsize;
 926         root = buf;
 927         *root = (typeof(*root)) {
 928                 .vr_magic            = cpu_to_le32(IAM_LVAR_ROOT_MAGIC),
 929                 .vr_recsize          = cpu_to_le16(recsize),
 930                 .vr_ptrsize          = cpu_to_le16(ptrsize),
 931                 .vr_indirect_levels  = 0
 932         };
 933
 934         limit = (void *)(root + 1);
 935         *limit = (typeof(*limit)){
 936                 /*
 937                  * limit itself + one pointer to the leaf.
 938                  */
 939                 .count = cpu_to_le16(2),
 940                 .limit = iam_root_limit(sizeof(struct lvar_root), blocksize,
 941                                         sizeof(lvar_hash_t) + ptrsize)
 942         };
 943
 944         /* To guarantee that the padding "keysize + ptrsize"
 945          * covers the "dx_countlimit" and the "idle_blocks". */
 946         LASSERT((keysize + ptrsize) >=
 947                 (sizeof(struct dx_countlimit) + sizeof(u32)));
 948
 949         entry = (void *)(limit + 1);
 950         /* Put "idle_blocks" just after the limit. There was padding after
 951          * the limit, the "idle_blocks" re-uses part of the padding, so no
 952          * compatibility issues with old layout.
 953          */
 954         *(u32 *)entry = 0;
 955
 956         /*
 957          * Skip over @limit.
 958          */
 959         entry = (void *)(root + 1) + isize;
 960
 961         /*
 962          * Entry format is <key> followed by <ptr>. In the minimal tree
 963          * consisting of a root and single node, <key> is a minimal possible
 964          * key.
 965          */
 966         *(lvar_hash_t *)entry = 0;
 967         entry += sizeof(lvar_hash_t);
 968         /* now @entry points to <ptr> */
 969         if (ptrsize == 4)
 970                 *(u_int32_t *)entry = cpu_to_le32(1);
 971         else
 972                 *(u_int64_t *)entry = cpu_to_le64(1);
 973 }
 974
 975 static int lvar_esize(int namelen, int recsize)
 976 {
 977         return (offsetof(struct lvar_leaf_entry, vle_key) +
 978                         namelen + recsize + LVAR_ROUND) & ~LVAR_ROUND;
 979 }
 980
 981 static void lvar_leaf(void *buf,
 982                       int blocksize, int keysize, int ptrsize, int recsize)
 983 {
 984         struct lvar_leaf_header *head;
 985         struct lvar_leaf_entry *entry;
 986
 987         /* form leaf */
 988         head = buf;
 989         *head = (typeof(*head)) {
 990                 .vlh_magic = cpu_to_le16(IAM_LVAR_LEAF_MAGIC),
 991                 .vlh_used  = cpu_to_le16(sizeof(*head) + lvar_esize(0, recsize))
 992         };
 993         entry = (void *)(head + 1);
 994         *entry = (typeof(*entry)) {
 995                 .vle_hash    = 0,
 996                 .vle_keysize = 0
 997         };
 998         memset(e_rec(entry), 0, recsize);
 999         *(char *)e_rec(entry) = recsize;
1000 }
1001
1002 int iam_lvar_create(struct inode *obj,
1003                     int keysize, int ptrsize, int recsize, handle_t *handle)
1004 {
1005         struct buffer_head *root_node;
1006         struct buffer_head *leaf_node;
1007         struct super_block *sb;
1008
1009         u32 blknr;
1010         int result = 0;
1011         unsigned long bsize;
1012
1013         assert_corr(obj->i_size == 0);
1014
1015         sb = obj->i_sb;
1016         bsize = sb->s_blocksize;
1017         root_node = osd_ldiskfs_append(handle, obj, &blknr);
1018         if (IS_ERR(root_node))
1019                 GOTO(out, result = PTR_ERR(root_node));
1020
1021         leaf_node = osd_ldiskfs_append(handle, obj, &blknr);
1022         if (IS_ERR(leaf_node))
1023                 GOTO(out_root, result = PTR_ERR(leaf_node));
1024
1025         lvar_root(root_node->b_data, bsize, keysize, ptrsize, recsize);
1026         lvar_leaf(leaf_node->b_data, bsize, keysize, ptrsize, recsize);
1027         ldiskfs_mark_inode_dirty(handle, obj);
1028         result = ldiskfs_handle_dirty_metadata(handle, NULL, root_node);
1029         if (result == 0)
1030                 result = ldiskfs_handle_dirty_metadata(handle, NULL, leaf_node);
1031         if (result != 0)
1032                 ldiskfs_std_error(sb, result);
1033
1034         brelse(leaf_node);
1035
1036         GOTO(out_root, result);
1037
1038 out_root:
1039         brelse(root_node);
1040 out:
1041         return result;
1042 }
1043
1044 static const struct iam_operations lvar_ops = {
1045         .id_root_ptr    = lvar_root_ptr,
1046         .id_node_read   = iam_node_read,
1047         .id_node_init   = lvar_node_init,
1048         .id_node_check  = lvar_node_check,
1049         .id_node_load   = lvar_node_load,
1050         .id_ikeycmp     = lvar_ikeycmp,
1051         .id_root_inc    = lvar_root_inc,
1052         .id_ipd_alloc   = lvar_ipd_alloc,
1053         .id_ipd_free    = iam_ipd_free,
1054         .id_name        = "lvar"
1055 };
1056
1057 int iam_lvar_guess(struct iam_container *c)
1058 {
1059         int result;
1060         struct buffer_head *bh;
1061         const struct lvar_root *root;
1062
1063         assert_corr(c->ic_object != NULL);
1064
1065         result = iam_node_read(c, lvar_root_ptr(c), NULL, &bh);
1066         if (result == 0) {
1067                 root = (void *)bh->b_data;
1068
1069                 if (le32_to_cpu(root->vr_magic) == IAM_LVAR_ROOT_MAGIC) {
1070                         struct iam_descr *descr;
1071
1072                         descr = c->ic_descr;
1073                         descr->id_key_size  = LDISKFS_NAME_LEN;
1074                         descr->id_ikey_size = sizeof(lvar_hash_t);
1075                         descr->id_rec_size  = le16_to_cpu(root->vr_recsize);
1076                         descr->id_ptr_size  = le16_to_cpu(root->vr_ptrsize);
1077                         descr->id_root_gap  = sizeof(*root);
1078                         descr->id_node_gap  = 0;
1079                         descr->id_ops       = &lvar_ops;
1080                         descr->id_leaf_ops  = &lvar_leaf_ops;
1081                         c->ic_root_bh = bh;
1082                 } else {
1083                         result = -EBADF;
1084                         brelse(bh);
1085                 }
1086         }
1087         return result;
1088 }