linux/fs/jfs/jfs_dtree.c
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   1/*
   2 *   Copyright (C) International Business Machines Corp., 2000-2004
   3 *
   4 *   This program is free software;  you can redistribute it and/or modify
   5 *   it under the terms of the GNU General Public License as published by
   6 *   the Free Software Foundation; either version 2 of the License, or
   7 *   (at your option) any later version.
   8 *
   9 *   This program is distributed in the hope that it will be useful,
  10 *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
  11 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  12 *   the GNU General Public License for more details.
  13 *
  14 *   You should have received a copy of the GNU General Public License
  15 *   along with this program;  if not, write to the Free Software
  16 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  17 */
  18
  19/*
  20 *      jfs_dtree.c: directory B+-tree manager
  21 *
  22 * B+-tree with variable length key directory:
  23 *
  24 * each directory page is structured as an array of 32-byte
  25 * directory entry slots initialized as a freelist
  26 * to avoid search/compaction of free space at insertion.
  27 * when an entry is inserted, a number of slots are allocated
  28 * from the freelist as required to store variable length data
  29 * of the entry; when the entry is deleted, slots of the entry
  30 * are returned to freelist.
  31 *
  32 * leaf entry stores full name as key and file serial number
  33 * (aka inode number) as data.
  34 * internal/router entry stores sufffix compressed name
  35 * as key and simple extent descriptor as data.
  36 *
  37 * each directory page maintains a sorted entry index table
  38 * which stores the start slot index of sorted entries
  39 * to allow binary search on the table.
  40 *
  41 * directory starts as a root/leaf page in on-disk inode
  42 * inline data area.
  43 * when it becomes full, it starts a leaf of a external extent
  44 * of length of 1 block. each time the first leaf becomes full,
  45 * it is extended rather than split (its size is doubled),
  46 * until its length becoms 4 KBytes, from then the extent is split
  47 * with new 4 Kbyte extent when it becomes full
  48 * to reduce external fragmentation of small directories.
  49 *
  50 * blah, blah, blah, for linear scan of directory in pieces by
  51 * readdir().
  52 *
  53 *
  54 *      case-insensitive directory file system
  55 *
  56 * names are stored in case-sensitive way in leaf entry.
  57 * but stored, searched and compared in case-insensitive (uppercase) order
  58 * (i.e., both search key and entry key are folded for search/compare):
  59 * (note that case-sensitive order is BROKEN in storage, e.g.,
  60 *  sensitive: Ad, aB, aC, aD -> insensitive: aB, aC, aD, Ad
  61 *
  62 *  entries which folds to the same key makes up a equivalent class
  63 *  whose members are stored as contiguous cluster (may cross page boundary)
  64 *  but whose order is arbitrary and acts as duplicate, e.g.,
  65 *  abc, Abc, aBc, abC)
  66 *
  67 * once match is found at leaf, requires scan forward/backward
  68 * either for, in case-insensitive search, duplicate
  69 * or for, in case-sensitive search, for exact match
  70 *
  71 * router entry must be created/stored in case-insensitive way
  72 * in internal entry:
  73 * (right most key of left page and left most key of right page
  74 * are folded, and its suffix compression is propagated as router
  75 * key in parent)
  76 * (e.g., if split occurs <abc> and <aBd>, <ABD> trather than <aB>
  77 * should be made the router key for the split)
  78 *
  79 * case-insensitive search:
  80 *
  81 *      fold search key;
  82 *
  83 *      case-insensitive search of B-tree:
  84 *      for internal entry, router key is already folded;
  85 *      for leaf entry, fold the entry key before comparison.
  86 *
  87 *      if (leaf entry case-insensitive match found)
  88 *              if (next entry satisfies case-insensitive match)
  89 *                      return EDUPLICATE;
  90 *              if (prev entry satisfies case-insensitive match)
  91 *                      return EDUPLICATE;
  92 *              return match;
  93 *      else
  94 *              return no match;
  95 *
  96 *      serialization:
  97 * target directory inode lock is being held on entry/exit
  98 * of all main directory service routines.
  99 *
 100 *      log based recovery:
 101 */
 102
 103#include <linux/fs.h>
 104#include <linux/quotaops.h>
 105#include <linux/slab.h>
 106#include "jfs_incore.h"
 107#include "jfs_superblock.h"
 108#include "jfs_filsys.h"
 109#include "jfs_metapage.h"
 110#include "jfs_dmap.h"
 111#include "jfs_unicode.h"
 112#include "jfs_debug.h"
 113
 114/* dtree split parameter */
 115struct dtsplit {
 116        struct metapage *mp;
 117        s16 index;
 118        s16 nslot;
 119        struct component_name *key;
 120        ddata_t *data;
 121        struct pxdlist *pxdlist;
 122};
 123
 124#define DT_PAGE(IP, MP) BT_PAGE(IP, MP, dtpage_t, i_dtroot)
 125
 126/* get page buffer for specified block address */
 127#define DT_GETPAGE(IP, BN, MP, SIZE, P, RC)                             \
 128do {                                                                    \
 129        BT_GETPAGE(IP, BN, MP, dtpage_t, SIZE, P, RC, i_dtroot);        \
 130        if (!(RC)) {                                                    \
 131                if (((P)->header.nextindex >                            \
 132                     (((BN) == 0) ? DTROOTMAXSLOT : (P)->header.maxslot)) || \
 133                    ((BN) && ((P)->header.maxslot > DTPAGEMAXSLOT))) {  \
 134                        BT_PUTPAGE(MP);                                 \
 135                        jfs_error((IP)->i_sb,                           \
 136                                  "DT_GETPAGE: dtree page corrupt\n");  \
 137                        MP = NULL;                                      \
 138                        RC = -EIO;                                      \
 139                }                                                       \
 140        }                                                               \
 141} while (0)
 142
 143/* for consistency */
 144#define DT_PUTPAGE(MP) BT_PUTPAGE(MP)
 145
 146#define DT_GETSEARCH(IP, LEAF, BN, MP, P, INDEX) \
 147        BT_GETSEARCH(IP, LEAF, BN, MP, dtpage_t, P, INDEX, i_dtroot)
 148
 149/*
 150 * forward references
 151 */
 152static int dtSplitUp(tid_t tid, struct inode *ip,
 153                     struct dtsplit * split, struct btstack * btstack);
 154
 155static int dtSplitPage(tid_t tid, struct inode *ip, struct dtsplit * split,
 156                       struct metapage ** rmpp, dtpage_t ** rpp, pxd_t * rxdp);
 157
 158static int dtExtendPage(tid_t tid, struct inode *ip,
 159                        struct dtsplit * split, struct btstack * btstack);
 160
 161static int dtSplitRoot(tid_t tid, struct inode *ip,
 162                       struct dtsplit * split, struct metapage ** rmpp);
 163
 164static int dtDeleteUp(tid_t tid, struct inode *ip, struct metapage * fmp,
 165                      dtpage_t * fp, struct btstack * btstack);
 166
 167static int dtRelink(tid_t tid, struct inode *ip, dtpage_t * p);
 168
 169static int dtReadFirst(struct inode *ip, struct btstack * btstack);
 170
 171static int dtReadNext(struct inode *ip,
 172                      loff_t * offset, struct btstack * btstack);
 173
 174static int dtCompare(struct component_name * key, dtpage_t * p, int si);
 175
 176static int ciCompare(struct component_name * key, dtpage_t * p, int si,
 177                     int flag);
 178
 179static void dtGetKey(dtpage_t * p, int i, struct component_name * key,
 180                     int flag);
 181
 182static int ciGetLeafPrefixKey(dtpage_t * lp, int li, dtpage_t * rp,
 183                              int ri, struct component_name * key, int flag);
 184
 185static void dtInsertEntry(dtpage_t * p, int index, struct component_name * key,
 186                          ddata_t * data, struct dt_lock **);
 187
 188static void dtMoveEntry(dtpage_t * sp, int si, dtpage_t * dp,
 189                        struct dt_lock ** sdtlock, struct dt_lock ** ddtlock,
 190                        int do_index);
 191
 192static void dtDeleteEntry(dtpage_t * p, int fi, struct dt_lock ** dtlock);
 193
 194static void dtTruncateEntry(dtpage_t * p, int ti, struct dt_lock ** dtlock);
 195
 196static void dtLinelockFreelist(dtpage_t * p, int m, struct dt_lock ** dtlock);
 197
 198#define ciToUpper(c)    UniStrupr((c)->name)
 199
 200/*
 201 *      read_index_page()
 202 *
 203 *      Reads a page of a directory's index table.
 204 *      Having metadata mapped into the directory inode's address space
 205 *      presents a multitude of problems.  We avoid this by mapping to
 206 *      the absolute address space outside of the *_metapage routines
 207 */
 208static struct metapage *read_index_page(struct inode *inode, s64 blkno)
 209{
 210        int rc;
 211        s64 xaddr;
 212        int xflag;
 213        s32 xlen;
 214
 215        rc = xtLookup(inode, blkno, 1, &xflag, &xaddr, &xlen, 1);
 216        if (rc || (xaddr == 0))
 217                return NULL;
 218
 219        return read_metapage(inode, xaddr, PSIZE, 1);
 220}
 221
 222/*
 223 *      get_index_page()
 224 *
 225 *      Same as get_index_page(), but get's a new page without reading
 226 */
 227static struct metapage *get_index_page(struct inode *inode, s64 blkno)
 228{
 229        int rc;
 230        s64 xaddr;
 231        int xflag;
 232        s32 xlen;
 233
 234        rc = xtLookup(inode, blkno, 1, &xflag, &xaddr, &xlen, 1);
 235        if (rc || (xaddr == 0))
 236                return NULL;
 237
 238        return get_metapage(inode, xaddr, PSIZE, 1);
 239}
 240
 241/*
 242 *      find_index()
 243 *
 244 *      Returns dtree page containing directory table entry for specified
 245 *      index and pointer to its entry.
 246 *
 247 *      mp must be released by caller.
 248 */
 249static struct dir_table_slot *find_index(struct inode *ip, u32 index,
 250                                         struct metapage ** mp, s64 *lblock)
 251{
 252        struct jfs_inode_info *jfs_ip = JFS_IP(ip);
 253        s64 blkno;
 254        s64 offset;
 255        int page_offset;
 256        struct dir_table_slot *slot;
 257        static int maxWarnings = 10;
 258
 259        if (index < 2) {
 260                if (maxWarnings) {
 261                        jfs_warn("find_entry called with index = %d", index);
 262                        maxWarnings--;
 263                }
 264                return NULL;
 265        }
 266
 267        if (index >= jfs_ip->next_index) {
 268                jfs_warn("find_entry called with index >= next_index");
 269                return NULL;
 270        }
 271
 272        if (jfs_dirtable_inline(ip)) {
 273                /*
 274                 * Inline directory table
 275                 */
 276                *mp = NULL;
 277                slot = &jfs_ip->i_dirtable[index - 2];
 278        } else {
 279                offset = (index - 2) * sizeof(struct dir_table_slot);
 280                page_offset = offset & (PSIZE - 1);
 281                blkno = ((offset + 1) >> L2PSIZE) <<
 282                    JFS_SBI(ip->i_sb)->l2nbperpage;
 283
 284                if (*mp && (*lblock != blkno)) {
 285                        release_metapage(*mp);
 286                        *mp = NULL;
 287                }
 288                if (!(*mp)) {
 289                        *lblock = blkno;
 290                        *mp = read_index_page(ip, blkno);
 291                }
 292                if (!(*mp)) {
 293                        jfs_err("free_index: error reading directory table");
 294                        return NULL;
 295                }
 296
 297                slot =
 298                    (struct dir_table_slot *) ((char *) (*mp)->data +
 299                                               page_offset);
 300        }
 301        return slot;
 302}
 303
 304static inline void lock_index(tid_t tid, struct inode *ip, struct metapage * mp,
 305                              u32 index)
 306{
 307        struct tlock *tlck;
 308        struct linelock *llck;
 309        struct lv *lv;
 310
 311        tlck = txLock(tid, ip, mp, tlckDATA);
 312        llck = (struct linelock *) tlck->lock;
 313
 314        if (llck->index >= llck->maxcnt)
 315                llck = txLinelock(llck);
 316        lv = &llck->lv[llck->index];
 317
 318        /*
 319         *      Linelock slot size is twice the size of directory table
 320         *      slot size.  512 entries per page.
 321         */
 322        lv->offset = ((index - 2) & 511) >> 1;
 323        lv->length = 1;
 324        llck->index++;
 325}
 326
 327/*
 328 *      add_index()
 329 *
 330 *      Adds an entry to the directory index table.  This is used to provide
 331 *      each directory entry with a persistent index in which to resume
 332 *      directory traversals
 333 */
 334static u32 add_index(tid_t tid, struct inode *ip, s64 bn, int slot)
 335{
 336        struct super_block *sb = ip->i_sb;
 337        struct jfs_sb_info *sbi = JFS_SBI(sb);
 338        struct jfs_inode_info *jfs_ip = JFS_IP(ip);
 339        u64 blkno;
 340        struct dir_table_slot *dirtab_slot;
 341        u32 index;
 342        struct linelock *llck;
 343        struct lv *lv;
 344        struct metapage *mp;
 345        s64 offset;
 346        uint page_offset;
 347        struct tlock *tlck;
 348        s64 xaddr;
 349
 350        ASSERT(DO_INDEX(ip));
 351
 352        if (jfs_ip->next_index < 2) {
 353                jfs_warn("add_index: next_index = %d.  Resetting!",
 354                           jfs_ip->next_index);
 355                jfs_ip->next_index = 2;
 356        }
 357
 358        index = jfs_ip->next_index++;
 359
 360        if (index <= MAX_INLINE_DIRTABLE_ENTRY) {
 361                /*
 362                 * i_size reflects size of index table, or 8 bytes per entry.
 363                 */
 364                ip->i_size = (loff_t) (index - 1) << 3;
 365
 366                /*
 367                 * dir table fits inline within inode
 368                 */
 369                dirtab_slot = &jfs_ip->i_dirtable[index-2];
 370                dirtab_slot->flag = DIR_INDEX_VALID;
 371                dirtab_slot->slot = slot;
 372                DTSaddress(dirtab_slot, bn);
 373
 374                set_cflag(COMMIT_Dirtable, ip);
 375
 376                return index;
 377        }
 378        if (index == (MAX_INLINE_DIRTABLE_ENTRY + 1)) {
 379                struct dir_table_slot temp_table[12];
 380
 381                /*
 382                 * It's time to move the inline table to an external
 383                 * page and begin to build the xtree
 384                 */
 385                if (dquot_alloc_block(ip, sbi->nbperpage))
 386                        goto clean_up;
 387                if (dbAlloc(ip, 0, sbi->nbperpage, &xaddr)) {
 388                        dquot_free_block(ip, sbi->nbperpage);
 389                        goto clean_up;
 390                }
 391
 392                /*
 393                 * Save the table, we're going to overwrite it with the
 394                 * xtree root
 395                 */
 396                memcpy(temp_table, &jfs_ip->i_dirtable, sizeof(temp_table));
 397
 398                /*
 399                 * Initialize empty x-tree
 400                 */
 401                xtInitRoot(tid, ip);
 402
 403                /*
 404                 * Add the first block to the xtree
 405                 */
 406                if (xtInsert(tid, ip, 0, 0, sbi->nbperpage, &xaddr, 0)) {
 407                        /* This really shouldn't fail */
 408                        jfs_warn("add_index: xtInsert failed!");
 409                        memcpy(&jfs_ip->i_dirtable, temp_table,
 410                               sizeof (temp_table));
 411                        dbFree(ip, xaddr, sbi->nbperpage);
 412                        dquot_free_block(ip, sbi->nbperpage);
 413                        goto clean_up;
 414                }
 415                ip->i_size = PSIZE;
 416
 417                mp = get_index_page(ip, 0);
 418                if (!mp) {
 419                        jfs_err("add_index: get_metapage failed!");
 420                        xtTruncate(tid, ip, 0, COMMIT_PWMAP);
 421                        memcpy(&jfs_ip->i_dirtable, temp_table,
 422                               sizeof (temp_table));
 423                        goto clean_up;
 424                }
 425                tlck = txLock(tid, ip, mp, tlckDATA);
 426                llck = (struct linelock *) & tlck->lock;
 427                ASSERT(llck->index == 0);
 428                lv = &llck->lv[0];
 429
 430                lv->offset = 0;
 431                lv->length = 6; /* tlckDATA slot size is 16 bytes */
 432                llck->index++;
 433
 434                memcpy(mp->data, temp_table, sizeof(temp_table));
 435
 436                mark_metapage_dirty(mp);
 437                release_metapage(mp);
 438
 439                /*
 440                 * Logging is now directed by xtree tlocks
 441                 */
 442                clear_cflag(COMMIT_Dirtable, ip);
 443        }
 444
 445        offset = (index - 2) * sizeof(struct dir_table_slot);
 446        page_offset = offset & (PSIZE - 1);
 447        blkno = ((offset + 1) >> L2PSIZE) << sbi->l2nbperpage;
 448        if (page_offset == 0) {
 449                /*
 450                 * This will be the beginning of a new page
 451                 */
 452                xaddr = 0;
 453                if (xtInsert(tid, ip, 0, blkno, sbi->nbperpage, &xaddr, 0)) {
 454                        jfs_warn("add_index: xtInsert failed!");
 455                        goto clean_up;
 456                }
 457                ip->i_size += PSIZE;
 458
 459                if ((mp = get_index_page(ip, blkno)))
 460                        memset(mp->data, 0, PSIZE);     /* Just looks better */
 461                else
 462                        xtTruncate(tid, ip, offset, COMMIT_PWMAP);
 463        } else
 464                mp = read_index_page(ip, blkno);
 465
 466        if (!mp) {
 467                jfs_err("add_index: get/read_metapage failed!");
 468                goto clean_up;
 469        }
 470
 471        lock_index(tid, ip, mp, index);
 472
 473        dirtab_slot =
 474            (struct dir_table_slot *) ((char *) mp->data + page_offset);
 475        dirtab_slot->flag = DIR_INDEX_VALID;
 476        dirtab_slot->slot = slot;
 477        DTSaddress(dirtab_slot, bn);
 478
 479        mark_metapage_dirty(mp);
 480        release_metapage(mp);
 481
 482        return index;
 483
 484      clean_up:
 485
 486        jfs_ip->next_index--;
 487
 488        return 0;
 489}
 490
 491/*
 492 *      free_index()
 493 *
 494 *      Marks an entry to the directory index table as free.
 495 */
 496static void free_index(tid_t tid, struct inode *ip, u32 index, u32 next)
 497{
 498        struct dir_table_slot *dirtab_slot;
 499        s64 lblock;
 500        struct metapage *mp = NULL;
 501
 502        dirtab_slot = find_index(ip, index, &mp, &lblock);
 503
 504        if (!dirtab_slot)
 505                return;
 506
 507        dirtab_slot->flag = DIR_INDEX_FREE;
 508        dirtab_slot->slot = dirtab_slot->addr1 = 0;
 509        dirtab_slot->addr2 = cpu_to_le32(next);
 510
 511        if (mp) {
 512                lock_index(tid, ip, mp, index);
 513                mark_metapage_dirty(mp);
 514                release_metapage(mp);
 515        } else
 516                set_cflag(COMMIT_Dirtable, ip);
 517}
 518
 519/*
 520 *      modify_index()
 521 *
 522 *      Changes an entry in the directory index table
 523 */
 524static void modify_index(tid_t tid, struct inode *ip, u32 index, s64 bn,
 525                         int slot, struct metapage ** mp, s64 *lblock)
 526{
 527        struct dir_table_slot *dirtab_slot;
 528
 529        dirtab_slot = find_index(ip, index, mp, lblock);
 530
 531        if (!dirtab_slot)
 532                return;
 533
 534        DTSaddress(dirtab_slot, bn);
 535        dirtab_slot->slot = slot;
 536
 537        if (*mp) {
 538                lock_index(tid, ip, *mp, index);
 539                mark_metapage_dirty(*mp);
 540        } else
 541                set_cflag(COMMIT_Dirtable, ip);
 542}
 543
 544/*
 545 *      read_index()
 546 *
 547 *      reads a directory table slot
 548 */
 549static int read_index(struct inode *ip, u32 index,
 550                     struct dir_table_slot * dirtab_slot)
 551{
 552        s64 lblock;
 553        struct metapage *mp = NULL;
 554        struct dir_table_slot *slot;
 555
 556        slot = find_index(ip, index, &mp, &lblock);
 557        if (!slot) {
 558                return -EIO;
 559        }
 560
 561        memcpy(dirtab_slot, slot, sizeof(struct dir_table_slot));
 562
 563        if (mp)
 564                release_metapage(mp);
 565
 566        return 0;
 567}
 568
 569/*
 570 *      dtSearch()
 571 *
 572 * function:
 573 *      Search for the entry with specified key
 574 *
 575 * parameter:
 576 *
 577 * return: 0 - search result on stack, leaf page pinned;
 578 *         errno - I/O error
 579 */
 580int dtSearch(struct inode *ip, struct component_name * key, ino_t * data,
 581             struct btstack * btstack, int flag)
 582{
 583        int rc = 0;
 584        int cmp = 1;            /* init for empty page */
 585        s64 bn;
 586        struct metapage *mp;
 587        dtpage_t *p;
 588        s8 *stbl;
 589        int base, index, lim;
 590        struct btframe *btsp;
 591        pxd_t *pxd;
 592        int psize = 288;        /* initial in-line directory */
 593        ino_t inumber;
 594        struct component_name ciKey;
 595        struct super_block *sb = ip->i_sb;
 596
 597        ciKey.name = kmalloc_array(JFS_NAME_MAX + 1, sizeof(wchar_t),
 598                                   GFP_NOFS);
 599        if (!ciKey.name) {
 600                rc = -ENOMEM;
 601                goto dtSearch_Exit2;
 602        }
 603
 604
 605        /* uppercase search key for c-i directory */
 606        UniStrcpy(ciKey.name, key->name);
 607        ciKey.namlen = key->namlen;
 608
 609        /* only uppercase if case-insensitive support is on */
 610        if ((JFS_SBI(sb)->mntflag & JFS_OS2) == JFS_OS2) {
 611                ciToUpper(&ciKey);
 612        }
 613        BT_CLR(btstack);        /* reset stack */
 614
 615        /* init level count for max pages to split */
 616        btstack->nsplit = 1;
 617
 618        /*
 619         *      search down tree from root:
 620         *
 621         * between two consecutive entries of <Ki, Pi> and <Kj, Pj> of
 622         * internal page, child page Pi contains entry with k, Ki <= K < Kj.
 623         *
 624         * if entry with search key K is not found
 625         * internal page search find the entry with largest key Ki
 626         * less than K which point to the child page to search;
 627         * leaf page search find the entry with smallest key Kj
 628         * greater than K so that the returned index is the position of
 629         * the entry to be shifted right for insertion of new entry.
 630         * for empty tree, search key is greater than any key of the tree.
 631         *
 632         * by convention, root bn = 0.
 633         */
 634        for (bn = 0;;) {
 635                /* get/pin the page to search */
 636                DT_GETPAGE(ip, bn, mp, psize, p, rc);
 637                if (rc)
 638                        goto dtSearch_Exit1;
 639
 640                /* get sorted entry table of the page */
 641                stbl = DT_GETSTBL(p);
 642
 643                /*
 644                 * binary search with search key K on the current page.
 645                 */
 646                for (base = 0, lim = p->header.nextindex; lim; lim >>= 1) {
 647                        index = base + (lim >> 1);
 648
 649                        if (p->header.flag & BT_LEAF) {
 650                                /* uppercase leaf name to compare */
 651                                cmp =
 652                                    ciCompare(&ciKey, p, stbl[index],
 653                                              JFS_SBI(sb)->mntflag);
 654                        } else {
 655                                /* router key is in uppercase */
 656
 657                                cmp = dtCompare(&ciKey, p, stbl[index]);
 658
 659
 660                        }
 661                        if (cmp == 0) {
 662                                /*
 663                                 *      search hit
 664                                 */
 665                                /* search hit - leaf page:
 666                                 * return the entry found
 667                                 */
 668                                if (p->header.flag & BT_LEAF) {
 669                                        inumber = le32_to_cpu(
 670                        ((struct ldtentry *) & p->slot[stbl[index]])->inumber);
 671
 672                                        /*
 673                                         * search for JFS_LOOKUP
 674                                         */
 675                                        if (flag == JFS_LOOKUP) {
 676                                                *data = inumber;
 677                                                rc = 0;
 678                                                goto out;
 679                                        }
 680
 681                                        /*
 682                                         * search for JFS_CREATE
 683                                         */
 684                                        if (flag == JFS_CREATE) {
 685                                                *data = inumber;
 686                                                rc = -EEXIST;
 687                                                goto out;
 688                                        }
 689
 690                                        /*
 691                                         * search for JFS_REMOVE or JFS_RENAME
 692                                         */
 693                                        if ((flag == JFS_REMOVE ||
 694                                             flag == JFS_RENAME) &&
 695                                            *data != inumber) {
 696                                                rc = -ESTALE;
 697                                                goto out;
 698                                        }
 699
 700                                        /*
 701                                         * JFS_REMOVE|JFS_FINDDIR|JFS_RENAME
 702                                         */
 703                                        /* save search result */
 704                                        *data = inumber;
 705                                        btsp = btstack->top;
 706                                        btsp->bn = bn;
 707                                        btsp->index = index;
 708                                        btsp->mp = mp;
 709
 710                                        rc = 0;
 711                                        goto dtSearch_Exit1;
 712                                }
 713
 714                                /* search hit - internal page:
 715                                 * descend/search its child page
 716                                 */
 717                                goto getChild;
 718                        }
 719
 720                        if (cmp > 0) {
 721                                base = index + 1;
 722                                --lim;
 723                        }
 724                }
 725
 726                /*
 727                 *      search miss
 728                 *
 729                 * base is the smallest index with key (Kj) greater than
 730                 * search key (K) and may be zero or (maxindex + 1) index.
 731                 */
 732                /*
 733                 * search miss - leaf page
 734                 *
 735                 * return location of entry (base) where new entry with
 736                 * search key K is to be inserted.
 737                 */
 738                if (p->header.flag & BT_LEAF) {
 739                        /*
 740                         * search for JFS_LOOKUP, JFS_REMOVE, or JFS_RENAME
 741                         */
 742                        if (flag == JFS_LOOKUP || flag == JFS_REMOVE ||
 743                            flag == JFS_RENAME) {
 744                                rc = -ENOENT;
 745                                goto out;
 746                        }
 747
 748                        /*
 749                         * search for JFS_CREATE|JFS_FINDDIR:
 750                         *
 751                         * save search result
 752                         */
 753                        *data = 0;
 754                        btsp = btstack->top;
 755                        btsp->bn = bn;
 756                        btsp->index = base;
 757                        btsp->mp = mp;
 758
 759                        rc = 0;
 760                        goto dtSearch_Exit1;
 761                }
 762
 763                /*
 764                 * search miss - internal page
 765                 *
 766                 * if base is non-zero, decrement base by one to get the parent
 767                 * entry of the child page to search.
 768                 */
 769                index = base ? base - 1 : base;
 770
 771                /*
 772                 * go down to child page
 773                 */
 774              getChild:
 775                /* update max. number of pages to split */
 776                if (BT_STACK_FULL(btstack)) {
 777                        /* Something's corrupted, mark filesystem dirty so
 778                         * chkdsk will fix it.
 779                         */
 780                        jfs_error(sb, "stack overrun!\n");
 781                        BT_STACK_DUMP(btstack);
 782                        rc = -EIO;
 783                        goto out;
 784                }
 785                btstack->nsplit++;
 786
 787                /* push (bn, index) of the parent page/entry */
 788                BT_PUSH(btstack, bn, index);
 789
 790                /* get the child page block number */
 791                pxd = (pxd_t *) & p->slot[stbl[index]];
 792                bn = addressPXD(pxd);
 793                psize = lengthPXD(pxd) << JFS_SBI(ip->i_sb)->l2bsize;
 794
 795                /* unpin the parent page */
 796                DT_PUTPAGE(mp);
 797        }
 798
 799      out:
 800        DT_PUTPAGE(mp);
 801
 802      dtSearch_Exit1:
 803
 804        kfree(ciKey.name);
 805
 806      dtSearch_Exit2:
 807
 808        return rc;
 809}
 810
 811
 812/*
 813 *      dtInsert()
 814 *
 815 * function: insert an entry to directory tree
 816 *
 817 * parameter:
 818 *
 819 * return: 0 - success;
 820 *         errno - failure;
 821 */
 822int dtInsert(tid_t tid, struct inode *ip,
 823         struct component_name * name, ino_t * fsn, struct btstack * btstack)
 824{
 825        int rc = 0;
 826        struct metapage *mp;    /* meta-page buffer */
 827        dtpage_t *p;            /* base B+-tree index page */
 828        s64 bn;
 829        int index;
 830        struct dtsplit split;   /* split information */
 831        ddata_t data;
 832        struct dt_lock *dtlck;
 833        int n;
 834        struct tlock *tlck;
 835        struct lv *lv;
 836
 837        /*
 838         *      retrieve search result
 839         *
 840         * dtSearch() returns (leaf page pinned, index at which to insert).
 841         * n.b. dtSearch() may return index of (maxindex + 1) of
 842         * the full page.
 843         */
 844        DT_GETSEARCH(ip, btstack->top, bn, mp, p, index);
 845
 846        /*
 847         *      insert entry for new key
 848         */
 849        if (DO_INDEX(ip)) {
 850                if (JFS_IP(ip)->next_index == DIREND) {
 851                        DT_PUTPAGE(mp);
 852                        return -EMLINK;
 853                }
 854                n = NDTLEAF(name->namlen);
 855                data.leaf.tid = tid;
 856                data.leaf.ip = ip;
 857        } else {
 858                n = NDTLEAF_LEGACY(name->namlen);
 859                data.leaf.ip = NULL;    /* signifies legacy directory format */
 860        }
 861        data.leaf.ino = *fsn;
 862
 863        /*
 864         *      leaf page does not have enough room for new entry:
 865         *
 866         *      extend/split the leaf page;
 867         *
 868         * dtSplitUp() will insert the entry and unpin the leaf page.
 869         */
 870        if (n > p->header.freecnt) {
 871                split.mp = mp;
 872                split.index = index;
 873                split.nslot = n;
 874                split.key = name;
 875                split.data = &data;
 876                rc = dtSplitUp(tid, ip, &split, btstack);
 877                return rc;
 878        }
 879
 880        /*
 881         *      leaf page does have enough room for new entry:
 882         *
 883         *      insert the new data entry into the leaf page;
 884         */
 885        BT_MARK_DIRTY(mp, ip);
 886        /*
 887         * acquire a transaction lock on the leaf page
 888         */
 889        tlck = txLock(tid, ip, mp, tlckDTREE | tlckENTRY);
 890        dtlck = (struct dt_lock *) & tlck->lock;
 891        ASSERT(dtlck->index == 0);
 892        lv = & dtlck->lv[0];
 893
 894        /* linelock header */
 895        lv->offset = 0;
 896        lv->length = 1;
 897        dtlck->index++;
 898
 899        dtInsertEntry(p, index, name, &data, &dtlck);
 900
 901        /* linelock stbl of non-root leaf page */
 902        if (!(p->header.flag & BT_ROOT)) {
 903                if (dtlck->index >= dtlck->maxcnt)
 904                        dtlck = (struct dt_lock *) txLinelock(dtlck);
 905                lv = & dtlck->lv[dtlck->index];
 906                n = index >> L2DTSLOTSIZE;
 907                lv->offset = p->header.stblindex + n;
 908                lv->length =
 909                    ((p->header.nextindex - 1) >> L2DTSLOTSIZE) - n + 1;
 910                dtlck->index++;
 911        }
 912
 913        /* unpin the leaf page */
 914        DT_PUTPAGE(mp);
 915
 916        return 0;
 917}
 918
 919
 920/*
 921 *      dtSplitUp()
 922 *
 923 * function: propagate insertion bottom up;
 924 *
 925 * parameter:
 926 *
 927 * return: 0 - success;
 928 *         errno - failure;
 929 *      leaf page unpinned;
 930 */
 931static int dtSplitUp(tid_t tid,
 932          struct inode *ip, struct dtsplit * split, struct btstack * btstack)
 933{
 934        struct jfs_sb_info *sbi = JFS_SBI(ip->i_sb);
 935        int rc = 0;
 936        struct metapage *smp;
 937        dtpage_t *sp;           /* split page */
 938        struct metapage *rmp;
 939        dtpage_t *rp;           /* new right page split from sp */
 940        pxd_t rpxd;             /* new right page extent descriptor */
 941        struct metapage *lmp;
 942        dtpage_t *lp;           /* left child page */
 943        int skip;               /* index of entry of insertion */
 944        struct btframe *parent; /* parent page entry on traverse stack */
 945        s64 xaddr, nxaddr;
 946        int xlen, xsize;
 947        struct pxdlist pxdlist;
 948        pxd_t *pxd;
 949        struct component_name key = { 0, NULL };
 950        ddata_t *data = split->data;
 951        int n;
 952        struct dt_lock *dtlck;
 953        struct tlock *tlck;
 954        struct lv *lv;
 955        int quota_allocation = 0;
 956
 957        /* get split page */
 958        smp = split->mp;
 959        sp = DT_PAGE(ip, smp);
 960
 961        key.name = kmalloc_array(JFS_NAME_MAX + 2, sizeof(wchar_t), GFP_NOFS);
 962        if (!key.name) {
 963                DT_PUTPAGE(smp);
 964                rc = -ENOMEM;
 965                goto dtSplitUp_Exit;
 966        }
 967
 968        /*
 969         *      split leaf page
 970         *
 971         * The split routines insert the new entry, and
 972         * acquire txLock as appropriate.
 973         */
 974        /*
 975         *      split root leaf page:
 976         */
 977        if (sp->header.flag & BT_ROOT) {
 978                /*
 979                 * allocate a single extent child page
 980                 */
 981                xlen = 1;
 982                n = sbi->bsize >> L2DTSLOTSIZE;
 983                n -= (n + 31) >> L2DTSLOTSIZE;  /* stbl size */
 984                n -= DTROOTMAXSLOT - sp->header.freecnt; /* header + entries */
 985                if (n <= split->nslot)
 986                        xlen++;
 987                if ((rc = dbAlloc(ip, 0, (s64) xlen, &xaddr))) {
 988                        DT_PUTPAGE(smp);
 989                        goto freeKeyName;
 990                }
 991
 992                pxdlist.maxnpxd = 1;
 993                pxdlist.npxd = 0;
 994                pxd = &pxdlist.pxd[0];
 995                PXDaddress(pxd, xaddr);
 996                PXDlength(pxd, xlen);
 997                split->pxdlist = &pxdlist;
 998                rc = dtSplitRoot(tid, ip, split, &rmp);
 999
1000                if (rc)
1001                        dbFree(ip, xaddr, xlen);
1002                else
1003                        DT_PUTPAGE(rmp);
1004
1005                DT_PUTPAGE(smp);
1006
1007                if (!DO_INDEX(ip))
1008                        ip->i_size = xlen << sbi->l2bsize;
1009
1010                goto freeKeyName;
1011        }
1012
1013        /*
1014         *      extend first leaf page
1015         *
1016         * extend the 1st extent if less than buffer page size
1017         * (dtExtendPage() reurns leaf page unpinned)
1018         */
1019        pxd = &sp->header.self;
1020        xlen = lengthPXD(pxd);
1021        xsize = xlen << sbi->l2bsize;
1022        if (xsize < PSIZE) {
1023                xaddr = addressPXD(pxd);
1024                n = xsize >> L2DTSLOTSIZE;
1025                n -= (n + 31) >> L2DTSLOTSIZE;  /* stbl size */
1026                if ((n + sp->header.freecnt) <= split->nslot)
1027                        n = xlen + (xlen << 1);
1028                else
1029                        n = xlen;
1030
1031                /* Allocate blocks to quota. */
1032                rc = dquot_alloc_block(ip, n);
1033                if (rc)
1034                        goto extendOut;
1035                quota_allocation += n;
1036
1037                if ((rc = dbReAlloc(sbi->ipbmap, xaddr, (s64) xlen,
1038                                    (s64) n, &nxaddr)))
1039                        goto extendOut;
1040
1041                pxdlist.maxnpxd = 1;
1042                pxdlist.npxd = 0;
1043                pxd = &pxdlist.pxd[0];
1044                PXDaddress(pxd, nxaddr);
1045                PXDlength(pxd, xlen + n);
1046                split->pxdlist = &pxdlist;
1047                if ((rc = dtExtendPage(tid, ip, split, btstack))) {
1048                        nxaddr = addressPXD(pxd);
1049                        if (xaddr != nxaddr) {
1050                                /* free relocated extent */
1051                                xlen = lengthPXD(pxd);
1052                                dbFree(ip, nxaddr, (s64) xlen);
1053                        } else {
1054                                /* free extended delta */
1055                                xlen = lengthPXD(pxd) - n;
1056                                xaddr = addressPXD(pxd) + xlen;
1057                                dbFree(ip, xaddr, (s64) n);
1058                        }
1059                } else if (!DO_INDEX(ip))
1060                        ip->i_size = lengthPXD(pxd) << sbi->l2bsize;
1061
1062
1063              extendOut:
1064                DT_PUTPAGE(smp);
1065                goto freeKeyName;
1066        }
1067
1068        /*
1069         *      split leaf page <sp> into <sp> and a new right page <rp>.
1070         *
1071         * return <rp> pinned and its extent descriptor <rpxd>
1072         */
1073        /*
1074         * allocate new directory page extent and
1075         * new index page(s) to cover page split(s)
1076         *
1077         * allocation hint: ?
1078         */
1079        n = btstack->nsplit;
1080        pxdlist.maxnpxd = pxdlist.npxd = 0;
1081        xlen = sbi->nbperpage;
1082        for (pxd = pxdlist.pxd; n > 0; n--, pxd++) {
1083                if ((rc = dbAlloc(ip, 0, (s64) xlen, &xaddr)) == 0) {
1084                        PXDaddress(pxd, xaddr);
1085                        PXDlength(pxd, xlen);
1086                        pxdlist.maxnpxd++;
1087                        continue;
1088                }
1089
1090                DT_PUTPAGE(smp);
1091
1092                /* undo allocation */
1093                goto splitOut;
1094        }
1095
1096        split->pxdlist = &pxdlist;
1097        if ((rc = dtSplitPage(tid, ip, split, &rmp, &rp, &rpxd))) {
1098                DT_PUTPAGE(smp);
1099
1100                /* undo allocation */
1101                goto splitOut;
1102        }
1103
1104        if (!DO_INDEX(ip))
1105                ip->i_size += PSIZE;
1106
1107        /*
1108         * propagate up the router entry for the leaf page just split
1109         *
1110         * insert a router entry for the new page into the parent page,
1111         * propagate the insert/split up the tree by walking back the stack
1112         * of (bn of parent page, index of child page entry in parent page)
1113         * that were traversed during the search for the page that split.
1114         *
1115         * the propagation of insert/split up the tree stops if the root
1116         * splits or the page inserted into doesn't have to split to hold
1117         * the new entry.
1118         *
1119         * the parent entry for the split page remains the same, and
1120         * a new entry is inserted at its right with the first key and
1121         * block number of the new right page.
1122         *
1123         * There are a maximum of 4 pages pinned at any time:
1124         * two children, left parent and right parent (when the parent splits).
1125         * keep the child pages pinned while working on the parent.
1126         * make sure that all pins are released at exit.
1127         */
1128        while ((parent = BT_POP(btstack)) != NULL) {
1129                /* parent page specified by stack frame <parent> */
1130
1131                /* keep current child pages (<lp>, <rp>) pinned */
1132                lmp = smp;
1133                lp = sp;
1134
1135                /*
1136                 * insert router entry in parent for new right child page <rp>
1137                 */
1138                /* get the parent page <sp> */
1139                DT_GETPAGE(ip, parent->bn, smp, PSIZE, sp, rc);
1140                if (rc) {
1141                        DT_PUTPAGE(lmp);
1142                        DT_PUTPAGE(rmp);
1143                        goto splitOut;
1144                }
1145
1146                /*
1147                 * The new key entry goes ONE AFTER the index of parent entry,
1148                 * because the split was to the right.
1149                 */
1150                skip = parent->index + 1;
1151
1152                /*
1153                 * compute the key for the router entry
1154                 *
1155                 * key suffix compression:
1156                 * for internal pages that have leaf pages as children,
1157                 * retain only what's needed to distinguish between
1158                 * the new entry and the entry on the page to its left.
1159                 * If the keys compare equal, retain the entire key.
1160                 *
1161                 * note that compression is performed only at computing
1162                 * router key at the lowest internal level.
1163                 * further compression of the key between pairs of higher
1164                 * level internal pages loses too much information and
1165                 * the search may fail.
1166                 * (e.g., two adjacent leaf pages of {a, ..., x} {xx, ...,}
1167                 * results in two adjacent parent entries (a)(xx).
1168                 * if split occurs between these two entries, and
1169                 * if compression is applied, the router key of parent entry
1170                 * of right page (x) will divert search for x into right
1171                 * subtree and miss x in the left subtree.)
1172                 *
1173                 * the entire key must be retained for the next-to-leftmost
1174                 * internal key at any level of the tree, or search may fail
1175                 * (e.g., ?)
1176                 */
1177                switch (rp->header.flag & BT_TYPE) {
1178                case BT_LEAF:
1179                        /*
1180                         * compute the length of prefix for suffix compression
1181                         * between last entry of left page and first entry
1182                         * of right page
1183                         */
1184                        if ((sp->header.flag & BT_ROOT && skip > 1) ||
1185                            sp->header.prev != 0 || skip > 1) {
1186                                /* compute uppercase router prefix key */
1187                                rc = ciGetLeafPrefixKey(lp,
1188                                                        lp->header.nextindex-1,
1189                                                        rp, 0, &key,
1190                                                        sbi->mntflag);
1191                                if (rc) {
1192                                        DT_PUTPAGE(lmp);
1193                                        DT_PUTPAGE(rmp);
1194                                        DT_PUTPAGE(smp);
1195                                        goto splitOut;
1196                                }
1197                        } else {
1198                                /* next to leftmost entry of
1199                                   lowest internal level */
1200
1201                                /* compute uppercase router key */
1202                                dtGetKey(rp, 0, &key, sbi->mntflag);
1203                                key.name[key.namlen] = 0;
1204
1205                                if ((sbi->mntflag & JFS_OS2) == JFS_OS2)
1206                                        ciToUpper(&key);
1207                        }
1208
1209                        n = NDTINTERNAL(key.namlen);
1210                        break;
1211
1212                case BT_INTERNAL:
1213                        dtGetKey(rp, 0, &key, sbi->mntflag);
1214                        n = NDTINTERNAL(key.namlen);
1215                        break;
1216
1217                default:
1218                        jfs_err("dtSplitUp(): UFO!");
1219                        break;
1220                }
1221
1222                /* unpin left child page */
1223                DT_PUTPAGE(lmp);
1224
1225                /*
1226                 * compute the data for the router entry
1227                 */
1228                data->xd = rpxd;        /* child page xd */
1229
1230                /*
1231                 * parent page is full - split the parent page
1232                 */
1233                if (n > sp->header.freecnt) {
1234                        /* init for parent page split */
1235                        split->mp = smp;
1236                        split->index = skip;    /* index at insert */
1237                        split->nslot = n;
1238                        split->key = &key;
1239                        /* split->data = data; */
1240
1241                        /* unpin right child page */
1242                        DT_PUTPAGE(rmp);
1243
1244                        /* The split routines insert the new entry,
1245                         * acquire txLock as appropriate.
1246                         * return <rp> pinned and its block number <rbn>.
1247                         */
1248                        rc = (sp->header.flag & BT_ROOT) ?
1249                            dtSplitRoot(tid, ip, split, &rmp) :
1250                            dtSplitPage(tid, ip, split, &rmp, &rp, &rpxd);
1251                        if (rc) {
1252                                DT_PUTPAGE(smp);
1253                                goto splitOut;
1254                        }
1255
1256                        /* smp and rmp are pinned */
1257                }
1258                /*
1259                 * parent page is not full - insert router entry in parent page
1260                 */
1261                else {
1262                        BT_MARK_DIRTY(smp, ip);
1263                        /*
1264                         * acquire a transaction lock on the parent page
1265                         */
1266                        tlck = txLock(tid, ip, smp, tlckDTREE | tlckENTRY);
1267                        dtlck = (struct dt_lock *) & tlck->lock;
1268                        ASSERT(dtlck->index == 0);
1269                        lv = & dtlck->lv[0];
1270
1271                        /* linelock header */
1272                        lv->offset = 0;
1273                        lv->length = 1;
1274                        dtlck->index++;
1275
1276                        /* linelock stbl of non-root parent page */
1277                        if (!(sp->header.flag & BT_ROOT)) {
1278                                lv++;
1279                                n = skip >> L2DTSLOTSIZE;
1280                                lv->offset = sp->header.stblindex + n;
1281                                lv->length =
1282                                    ((sp->header.nextindex -
1283                                      1) >> L2DTSLOTSIZE) - n + 1;
1284                                dtlck->index++;
1285                        }
1286
1287                        dtInsertEntry(sp, skip, &key, data, &dtlck);
1288
1289                        /* exit propagate up */
1290                        break;
1291                }
1292        }
1293
1294        /* unpin current split and its right page */
1295        DT_PUTPAGE(smp);
1296        DT_PUTPAGE(rmp);
1297
1298        /*
1299         * free remaining extents allocated for split
1300         */
1301      splitOut:
1302        n = pxdlist.npxd;
1303        pxd = &pxdlist.pxd[n];
1304        for (; n < pxdlist.maxnpxd; n++, pxd++)
1305                dbFree(ip, addressPXD(pxd), (s64) lengthPXD(pxd));
1306
1307      freeKeyName:
1308        kfree(key.name);
1309
1310        /* Rollback quota allocation */
1311        if (rc && quota_allocation)
1312                dquot_free_block(ip, quota_allocation);
1313
1314      dtSplitUp_Exit:
1315
1316        return rc;
1317}
1318
1319
1320/*
1321 *      dtSplitPage()
1322 *
1323 * function: Split a non-root page of a btree.
1324 *
1325 * parameter:
1326 *
1327 * return: 0 - success;
1328 *         errno - failure;
1329 *      return split and new page pinned;
1330 */
1331static int dtSplitPage(tid_t tid, struct inode *ip, struct dtsplit * split,
1332            struct metapage ** rmpp, dtpage_t ** rpp, pxd_t * rpxdp)
1333{
1334        int rc = 0;
1335        struct metapage *smp;
1336        dtpage_t *sp;
1337        struct metapage *rmp;
1338        dtpage_t *rp;           /* new right page allocated */
1339        s64 rbn;                /* new right page block number */
1340        struct metapage *mp;
1341        dtpage_t *p;
1342        s64 nextbn;
1343        struct pxdlist *pxdlist;
1344        pxd_t *pxd;
1345        int skip, nextindex, half, left, nxt, off, si;
1346        struct ldtentry *ldtentry;
1347        struct idtentry *idtentry;
1348        u8 *stbl;
1349        struct dtslot *f;
1350        int fsi, stblsize;
1351        int n;
1352        struct dt_lock *sdtlck, *rdtlck;
1353        struct tlock *tlck;
1354        struct dt_lock *dtlck;
1355        struct lv *slv, *rlv, *lv;
1356
1357        /* get split page */
1358        smp = split->mp;
1359        sp = DT_PAGE(ip, smp);
1360
1361        /*
1362         * allocate the new right page for the split
1363         */
1364        pxdlist = split->pxdlist;
1365        pxd = &pxdlist->pxd[pxdlist->npxd];
1366        pxdlist->npxd++;
1367        rbn = addressPXD(pxd);
1368        rmp = get_metapage(ip, rbn, PSIZE, 1);
1369        if (rmp == NULL)
1370                return -EIO;
1371
1372        /* Allocate blocks to quota. */
1373        rc = dquot_alloc_block(ip, lengthPXD(pxd));
1374        if (rc) {
1375                release_metapage(rmp);
1376                return rc;
1377        }
1378
1379        jfs_info("dtSplitPage: ip:0x%p smp:0x%p rmp:0x%p", ip, smp, rmp);
1380
1381        BT_MARK_DIRTY(rmp, ip);
1382        /*
1383         * acquire a transaction lock on the new right page
1384         */
1385        tlck = txLock(tid, ip, rmp, tlckDTREE | tlckNEW);
1386        rdtlck = (struct dt_lock *) & tlck->lock;
1387
1388        rp = (dtpage_t *) rmp->data;
1389        *rpp = rp;
1390        rp->header.self = *pxd;
1391
1392        BT_MARK_DIRTY(smp, ip);
1393        /*
1394         * acquire a transaction lock on the split page
1395         *
1396         * action:
1397         */
1398        tlck = txLock(tid, ip, smp, tlckDTREE | tlckENTRY);
1399        sdtlck = (struct dt_lock *) & tlck->lock;
1400
1401        /* linelock header of split page */
1402        ASSERT(sdtlck->index == 0);
1403        slv = & sdtlck->lv[0];
1404        slv->offset = 0;
1405        slv->length = 1;
1406        sdtlck->index++;
1407
1408        /*
1409         * initialize/update sibling pointers between sp and rp
1410         */
1411        nextbn = le64_to_cpu(sp->header.next);
1412        rp->header.next = cpu_to_le64(nextbn);
1413        rp->header.prev = cpu_to_le64(addressPXD(&sp->header.self));
1414        sp->header.next = cpu_to_le64(rbn);
1415
1416        /*
1417         * initialize new right page
1418         */
1419        rp->header.flag = sp->header.flag;
1420
1421        /* compute sorted entry table at start of extent data area */
1422        rp->header.nextindex = 0;
1423        rp->header.stblindex = 1;
1424
1425        n = PSIZE >> L2DTSLOTSIZE;
1426        rp->header.maxslot = n;
1427        stblsize = (n + 31) >> L2DTSLOTSIZE;    /* in unit of slot */
1428
1429        /* init freelist */
1430        fsi = rp->header.stblindex + stblsize;
1431        rp->header.freelist = fsi;
1432        rp->header.freecnt = rp->header.maxslot - fsi;
1433
1434        /*
1435         *      sequential append at tail: append without split
1436         *
1437         * If splitting the last page on a level because of appending
1438         * a entry to it (skip is maxentry), it's likely that the access is
1439         * sequential. Adding an empty page on the side of the level is less
1440         * work and can push the fill factor much higher than normal.
1441         * If we're wrong it's no big deal, we'll just do the split the right
1442         * way next time.
1443         * (It may look like it's equally easy to do a similar hack for
1444         * reverse sorted data, that is, split the tree left,
1445         * but it's not. Be my guest.)
1446         */
1447        if (nextbn == 0 && split->index == sp->header.nextindex) {
1448                /* linelock header + stbl (first slot) of new page */
1449                rlv = & rdtlck->lv[rdtlck->index];
1450                rlv->offset = 0;
1451                rlv->length = 2;
1452                rdtlck->index++;
1453
1454                /*
1455                 * initialize freelist of new right page
1456                 */
1457                f = &rp->slot[fsi];
1458                for (fsi++; fsi < rp->header.maxslot; f++, fsi++)
1459                        f->next = fsi;
1460                f->next = -1;
1461
1462                /* insert entry at the first entry of the new right page */
1463                dtInsertEntry(rp, 0, split->key, split->data, &rdtlck);
1464
1465                goto out;
1466        }
1467
1468        /*
1469         *      non-sequential insert (at possibly middle page)
1470         */
1471
1472        /*
1473         * update prev pointer of previous right sibling page;
1474         */
1475        if (nextbn != 0) {
1476                DT_GETPAGE(ip, nextbn, mp, PSIZE, p, rc);
1477                if (rc) {
1478                        discard_metapage(rmp);
1479                        return rc;
1480                }
1481
1482                BT_MARK_DIRTY(mp, ip);
1483                /*
1484                 * acquire a transaction lock on the next page
1485                 */
1486                tlck = txLock(tid, ip, mp, tlckDTREE | tlckRELINK);
1487                jfs_info("dtSplitPage: tlck = 0x%p, ip = 0x%p, mp=0x%p",
1488                        tlck, ip, mp);
1489                dtlck = (struct dt_lock *) & tlck->lock;
1490
1491                /* linelock header of previous right sibling page */
1492                lv = & dtlck->lv[dtlck->index];
1493                lv->offset = 0;
1494                lv->length = 1;
1495                dtlck->index++;
1496
1497                p->header.prev = cpu_to_le64(rbn);
1498
1499                DT_PUTPAGE(mp);
1500        }
1501
1502        /*
1503         * split the data between the split and right pages.
1504         */
1505        skip = split->index;
1506        half = (PSIZE >> L2DTSLOTSIZE) >> 1;    /* swag */
1507        left = 0;
1508
1509        /*
1510         *      compute fill factor for split pages
1511         *
1512         * <nxt> traces the next entry to move to rp
1513         * <off> traces the next entry to stay in sp
1514         */
1515        stbl = (u8 *) & sp->slot[sp->header.stblindex];
1516        nextindex = sp->header.nextindex;
1517        for (nxt = off = 0; nxt < nextindex; ++off) {
1518                if (off == skip)
1519                        /* check for fill factor with new entry size */
1520                        n = split->nslot;
1521                else {
1522                        si = stbl[nxt];
1523                        switch (sp->header.flag & BT_TYPE) {
1524                        case BT_LEAF:
1525                                ldtentry = (struct ldtentry *) & sp->slot[si];
1526                                if (DO_INDEX(ip))
1527                                        n = NDTLEAF(ldtentry->namlen);
1528                                else
1529                                        n = NDTLEAF_LEGACY(ldtentry->
1530                                                           namlen);
1531                                break;
1532
1533                        case BT_INTERNAL:
1534                                idtentry = (struct idtentry *) & sp->slot[si];
1535                                n = NDTINTERNAL(idtentry->namlen);
1536                                break;
1537
1538                        default:
1539                                break;
1540                        }
1541
1542                        ++nxt;  /* advance to next entry to move in sp */
1543                }
1544
1545                left += n;
1546                if (left >= half)
1547                        break;
1548        }
1549
1550        /* <nxt> poins to the 1st entry to move */
1551
1552        /*
1553         *      move entries to right page
1554         *
1555         * dtMoveEntry() initializes rp and reserves entry for insertion
1556         *
1557         * split page moved out entries are linelocked;
1558         * new/right page moved in entries are linelocked;
1559         */
1560        /* linelock header + stbl of new right page */
1561        rlv = & rdtlck->lv[rdtlck->index];
1562        rlv->offset = 0;
1563        rlv->length = 5;
1564        rdtlck->index++;
1565
1566        dtMoveEntry(sp, nxt, rp, &sdtlck, &rdtlck, DO_INDEX(ip));
1567
1568        sp->header.nextindex = nxt;
1569
1570        /*
1571         * finalize freelist of new right page
1572         */
1573        fsi = rp->header.freelist;
1574        f = &rp->slot[fsi];
1575        for (fsi++; fsi < rp->header.maxslot; f++, fsi++)
1576                f->next = fsi;
1577        f->next = -1;
1578
1579        /*
1580         * Update directory index table for entries now in right page
1581         */
1582        if ((rp->header.flag & BT_LEAF) && DO_INDEX(ip)) {
1583                s64 lblock;
1584
1585                mp = NULL;
1586                stbl = DT_GETSTBL(rp);
1587                for (n = 0; n < rp->header.nextindex; n++) {
1588                        ldtentry = (struct ldtentry *) & rp->slot[stbl[n]];
1589                        modify_index(tid, ip, le32_to_cpu(ldtentry->index),
1590                                     rbn, n, &mp, &lblock);
1591                }
1592                if (mp)
1593                        release_metapage(mp);
1594        }
1595
1596        /*
1597         * the skipped index was on the left page,
1598         */
1599        if (skip <= off) {
1600                /* insert the new entry in the split page */
1601                dtInsertEntry(sp, skip, split->key, split->data, &sdtlck);
1602
1603                /* linelock stbl of split page */
1604                if (sdtlck->index >= sdtlck->maxcnt)
1605                        sdtlck = (struct dt_lock *) txLinelock(sdtlck);
1606                slv = & sdtlck->lv[sdtlck->index];
1607                n = skip >> L2DTSLOTSIZE;
1608                slv->offset = sp->header.stblindex + n;
1609                slv->length =
1610                    ((sp->header.nextindex - 1) >> L2DTSLOTSIZE) - n + 1;
1611                sdtlck->index++;
1612        }
1613        /*
1614         * the skipped index was on the right page,
1615         */
1616        else {
1617                /* adjust the skip index to reflect the new position */
1618                skip -= nxt;
1619
1620                /* insert the new entry in the right page */
1621                dtInsertEntry(rp, skip, split->key, split->data, &rdtlck);
1622        }
1623
1624      out:
1625        *rmpp = rmp;
1626        *rpxdp = *pxd;
1627
1628        return rc;
1629}
1630
1631
1632/*
1633 *      dtExtendPage()
1634 *
1635 * function: extend 1st/only directory leaf page
1636 *
1637 * parameter:
1638 *
1639 * return: 0 - success;
1640 *         errno - failure;
1641 *      return extended page pinned;
1642 */
1643static int dtExtendPage(tid_t tid,
1644             struct inode *ip, struct dtsplit * split, struct btstack * btstack)
1645{
1646        struct super_block *sb = ip->i_sb;
1647        int rc;
1648        struct metapage *smp, *pmp, *mp;
1649        dtpage_t *sp, *pp;
1650        struct pxdlist *pxdlist;
1651        pxd_t *pxd, *tpxd;
1652        int xlen, xsize;
1653        int newstblindex, newstblsize;
1654        int oldstblindex, oldstblsize;
1655        int fsi, last;
1656        struct dtslot *f;
1657        struct btframe *parent;
1658        int n;
1659        struct dt_lock *dtlck;
1660        s64 xaddr, txaddr;
1661        struct tlock *tlck;
1662        struct pxd_lock *pxdlock;
1663        struct lv *lv;
1664        uint type;
1665        struct ldtentry *ldtentry;
1666        u8 *stbl;
1667
1668        /* get page to extend */
1669        smp = split->mp;
1670        sp = DT_PAGE(ip, smp);
1671
1672        /* get parent/root page */
1673        parent = BT_POP(btstack);
1674        DT_GETPAGE(ip, parent->bn, pmp, PSIZE, pp, rc);
1675        if (rc)
1676                return (rc);
1677
1678        /*
1679         *      extend the extent
1680         */
1681        pxdlist = split->pxdlist;
1682        pxd = &pxdlist->pxd[pxdlist->npxd];
1683        pxdlist->npxd++;
1684
1685        xaddr = addressPXD(pxd);
1686        tpxd = &sp->header.self;
1687        txaddr = addressPXD(tpxd);
1688        /* in-place extension */
1689        if (xaddr == txaddr) {
1690                type = tlckEXTEND;
1691        }
1692        /* relocation */
1693        else {
1694                type = tlckNEW;
1695
1696                /* save moved extent descriptor for later free */
1697                tlck = txMaplock(tid, ip, tlckDTREE | tlckRELOCATE);
1698                pxdlock = (struct pxd_lock *) & tlck->lock;
1699                pxdlock->flag = mlckFREEPXD;
1700                pxdlock->pxd = sp->header.self;
1701                pxdlock->index = 1;
1702
1703                /*
1704                 * Update directory index table to reflect new page address
1705                 */
1706                if (DO_INDEX(ip)) {
1707                        s64 lblock;
1708
1709                        mp = NULL;
1710                        stbl = DT_GETSTBL(sp);
1711                        for (n = 0; n < sp->header.nextindex; n++) {
1712                                ldtentry =
1713                                    (struct ldtentry *) & sp->slot[stbl[n]];
1714                                modify_index(tid, ip,
1715                                             le32_to_cpu(ldtentry->index),
1716                                             xaddr, n, &mp, &lblock);
1717                        }
1718                        if (mp)
1719                                release_metapage(mp);
1720                }
1721        }
1722
1723        /*
1724         *      extend the page
1725         */
1726        sp->header.self = *pxd;
1727
1728        jfs_info("dtExtendPage: ip:0x%p smp:0x%p sp:0x%p", ip, smp, sp);
1729
1730        BT_MARK_DIRTY(smp, ip);
1731        /*
1732         * acquire a transaction lock on the extended/leaf page
1733         */
1734        tlck = txLock(tid, ip, smp, tlckDTREE | type);
1735        dtlck = (struct dt_lock *) & tlck->lock;
1736        lv = & dtlck->lv[0];
1737
1738        /* update buffer extent descriptor of extended page */
1739        xlen = lengthPXD(pxd);
1740        xsize = xlen << JFS_SBI(sb)->l2bsize;
1741
1742        /*
1743         * copy old stbl to new stbl at start of extended area
1744         */
1745        oldstblindex = sp->header.stblindex;
1746        oldstblsize = (sp->header.maxslot + 31) >> L2DTSLOTSIZE;
1747        newstblindex = sp->header.maxslot;
1748        n = xsize >> L2DTSLOTSIZE;
1749        newstblsize = (n + 31) >> L2DTSLOTSIZE;
1750        memcpy(&sp->slot[newstblindex], &sp->slot[oldstblindex],
1751               sp->header.nextindex);
1752
1753        /*
1754         * in-line extension: linelock old area of extended page
1755         */
1756        if (type == tlckEXTEND) {
1757                /* linelock header */
1758                lv->offset = 0;
1759                lv->length = 1;
1760                dtlck->index++;
1761                lv++;
1762
1763                /* linelock new stbl of extended page */
1764                lv->offset = newstblindex;
1765                lv->length = newstblsize;
1766        }
1767        /*
1768         * relocation: linelock whole relocated area
1769         */
1770        else {
1771                lv->offset = 0;
1772                lv->length = sp->header.maxslot + newstblsize;
1773        }
1774
1775        dtlck->index++;
1776
1777        sp->header.maxslot = n;
1778        sp->header.stblindex = newstblindex;
1779        /* sp->header.nextindex remains the same */
1780
1781        /*
1782         * add old stbl region at head of freelist
1783         */
1784        fsi = oldstblindex;
1785        f = &sp->slot[fsi];
1786        last = sp->header.freelist;
1787        for (n = 0; n < oldstblsize; n++, fsi++, f++) {
1788                f->next = last;
1789                last = fsi;
1790        }
1791        sp->header.freelist = last;
1792        sp->header.freecnt += oldstblsize;
1793
1794        /*
1795         * append free region of newly extended area at tail of freelist
1796         */
1797        /* init free region of newly extended area */
1798        fsi = n = newstblindex + newstblsize;
1799        f = &sp->slot[fsi];
1800        for (fsi++; fsi < sp->header.maxslot; f++, fsi++)
1801                f->next = fsi;
1802        f->next = -1;
1803
1804        /* append new free region at tail of old freelist */
1805        fsi = sp->header.freelist;
1806        if (fsi == -1)
1807                sp->header.freelist = n;
1808        else {
1809                do {
1810                        f = &sp->slot[fsi];
1811                        fsi = f->next;
1812                } while (fsi != -1);
1813
1814                f->next = n;
1815        }
1816
1817        sp->header.freecnt += sp->header.maxslot - n;
1818
1819        /*
1820         * insert the new entry
1821         */
1822        dtInsertEntry(sp, split->index, split->key, split->data, &dtlck);
1823
1824        BT_MARK_DIRTY(pmp, ip);
1825        /*
1826         * linelock any freeslots residing in old extent
1827         */
1828        if (type == tlckEXTEND) {
1829                n = sp->header.maxslot >> 2;
1830                if (sp->header.freelist < n)
1831                        dtLinelockFreelist(sp, n, &dtlck);
1832        }
1833
1834        /*
1835         *      update parent entry on the parent/root page
1836         */
1837        /*
1838         * acquire a transaction lock on the parent/root page
1839         */
1840        tlck = txLock(tid, ip, pmp, tlckDTREE | tlckENTRY);
1841        dtlck = (struct dt_lock *) & tlck->lock;
1842        lv = & dtlck->lv[dtlck->index];
1843
1844        /* linelock parent entry - 1st slot */
1845        lv->offset = 1;
1846        lv->length = 1;
1847        dtlck->index++;
1848
1849        /* update the parent pxd for page extension */
1850        tpxd = (pxd_t *) & pp->slot[1];
1851        *tpxd = *pxd;
1852
1853        DT_PUTPAGE(pmp);
1854        return 0;
1855}
1856
1857
1858/*
1859 *      dtSplitRoot()
1860 *
1861 * function:
1862 *      split the full root page into
1863 *      original/root/split page and new right page
1864 *      i.e., root remains fixed in tree anchor (inode) and
1865 *      the root is copied to a single new right child page
1866 *      since root page << non-root page, and
1867 *      the split root page contains a single entry for the
1868 *      new right child page.
1869 *
1870 * parameter:
1871 *
1872 * return: 0 - success;
1873 *         errno - failure;
1874 *      return new page pinned;
1875 */
1876static int dtSplitRoot(tid_t tid,
1877            struct inode *ip, struct dtsplit * split, struct metapage ** rmpp)
1878{
1879        struct super_block *sb = ip->i_sb;
1880        struct metapage *smp;
1881        dtroot_t *sp;
1882        struct metapage *rmp;
1883        dtpage_t *rp;
1884        s64 rbn;
1885        int xlen;
1886        int xsize;
1887        struct dtslot *f;
1888        s8 *stbl;
1889        int fsi, stblsize, n;
1890        struct idtentry *s;
1891        pxd_t *ppxd;
1892        struct pxdlist *pxdlist;
1893        pxd_t *pxd;
1894        struct dt_lock *dtlck;
1895        struct tlock *tlck;
1896        struct lv *lv;
1897        int rc;
1898
1899        /* get split root page */
1900        smp = split->mp;
1901        sp = &JFS_IP(ip)->i_dtroot;
1902
1903        /*
1904         *      allocate/initialize a single (right) child page
1905         *
1906         * N.B. at first split, a one (or two) block to fit new entry
1907         * is allocated; at subsequent split, a full page is allocated;
1908         */
1909        pxdlist = split->pxdlist;
1910        pxd = &pxdlist->pxd[pxdlist->npxd];
1911        pxdlist->npxd++;
1912        rbn = addressPXD(pxd);
1913        xlen = lengthPXD(pxd);
1914        xsize = xlen << JFS_SBI(sb)->l2bsize;
1915        rmp = get_metapage(ip, rbn, xsize, 1);
1916        if (!rmp)
1917                return -EIO;
1918
1919        rp = rmp->data;
1920
1921        /* Allocate blocks to quota. */
1922        rc = dquot_alloc_block(ip, lengthPXD(pxd));
1923        if (rc) {
1924                release_metapage(rmp);
1925                return rc;
1926        }
1927
1928        BT_MARK_DIRTY(rmp, ip);
1929        /*
1930         * acquire a transaction lock on the new right page
1931         */
1932        tlck = txLock(tid, ip, rmp, tlckDTREE | tlckNEW);
1933        dtlck = (struct dt_lock *) & tlck->lock;
1934
1935        rp->header.flag =
1936            (sp->header.flag & BT_LEAF) ? BT_LEAF : BT_INTERNAL;
1937        rp->header.self = *pxd;
1938
1939        /* initialize sibling pointers */
1940        rp->header.next = 0;
1941        rp->header.prev = 0;
1942
1943        /*
1944         *      move in-line root page into new right page extent
1945         */
1946        /* linelock header + copied entries + new stbl (1st slot) in new page */
1947        ASSERT(dtlck->index == 0);
1948        lv = & dtlck->lv[0];
1949        lv->offset = 0;
1950        lv->length = 10;        /* 1 + 8 + 1 */
1951        dtlck->index++;
1952
1953        n = xsize >> L2DTSLOTSIZE;
1954        rp->header.maxslot = n;
1955        stblsize = (n + 31) >> L2DTSLOTSIZE;
1956
1957        /* copy old stbl to new stbl at start of extended area */
1958        rp->header.stblindex = DTROOTMAXSLOT;
1959        stbl = (s8 *) & rp->slot[DTROOTMAXSLOT];
1960        memcpy(stbl, sp->header.stbl, sp->header.nextindex);
1961        rp->header.nextindex = sp->header.nextindex;
1962
1963        /* copy old data area to start of new data area */
1964        memcpy(&rp->slot[1], &sp->slot[1], IDATASIZE);
1965
1966        /*
1967         * append free region of newly extended area at tail of freelist
1968         */
1969        /* init free region of newly extended area */
1970        fsi = n = DTROOTMAXSLOT + stblsize;
1971        f = &rp->slot[fsi];
1972        for (fsi++; fsi < rp->header.maxslot; f++, fsi++)
1973                f->next = fsi;
1974        f->next = -1;
1975
1976        /* append new free region at tail of old freelist */
1977        fsi = sp->header.freelist;
1978        if (fsi == -1)
1979                rp->header.freelist = n;
1980        else {
1981                rp->header.freelist = fsi;
1982
1983                do {
1984                        f = &rp->slot[fsi];
1985                        fsi = f->next;
1986                } while (fsi != -1);
1987
1988                f->next = n;
1989        }
1990
1991        rp->header.freecnt = sp->header.freecnt + rp->header.maxslot - n;
1992
1993        /*
1994         * Update directory index table for entries now in right page
1995         */
1996        if ((rp->header.flag & BT_LEAF) && DO_INDEX(ip)) {
1997                s64 lblock;
1998                struct metapage *mp = NULL;
1999                struct ldtentry *ldtentry;
2000
2001                stbl = DT_GETSTBL(rp);
2002                for (n = 0; n < rp->header.nextindex; n++) {
2003                        ldtentry = (struct ldtentry *) & rp->slot[stbl[n]];
2004                        modify_index(tid, ip, le32_to_cpu(ldtentry->index),
2005                                     rbn, n, &mp, &lblock);
2006                }
2007                if (mp)
2008                        release_metapage(mp);
2009        }
2010        /*
2011         * insert the new entry into the new right/child page
2012         * (skip index in the new right page will not change)
2013         */
2014        dtInsertEntry(rp, split->index, split->key, split->data, &dtlck);
2015
2016        /*
2017         *      reset parent/root page
2018         *
2019         * set the 1st entry offset to 0, which force the left-most key
2020         * at any level of the tree to be less than any search key.
2021         *
2022         * The btree comparison code guarantees that the left-most key on any
2023         * level of the tree is never used, so it doesn't need to be filled in.
2024         */
2025        BT_MARK_DIRTY(smp, ip);
2026        /*
2027         * acquire a transaction lock on the root page (in-memory inode)
2028         */
2029        tlck = txLock(tid, ip, smp, tlckDTREE | tlckNEW | tlckBTROOT);
2030        dtlck = (struct dt_lock *) & tlck->lock;
2031
2032        /* linelock root */
2033        ASSERT(dtlck->index == 0);
2034        lv = & dtlck->lv[0];
2035        lv->offset = 0;
2036        lv->length = DTROOTMAXSLOT;
2037        dtlck->index++;
2038
2039        /* update page header of root */
2040        if (sp->header.flag & BT_LEAF) {
2041                sp->header.flag &= ~BT_LEAF;
2042                sp->header.flag |= BT_INTERNAL;
2043        }
2044
2045        /* init the first entry */
2046        s = (struct idtentry *) & sp->slot[DTENTRYSTART];
2047        ppxd = (pxd_t *) s;
2048        *ppxd = *pxd;
2049        s->next = -1;
2050        s->namlen = 0;
2051
2052        stbl = sp->header.stbl;
2053        stbl[0] = DTENTRYSTART;
2054        sp->header.nextindex = 1;
2055
2056        /* init freelist */
2057        fsi = DTENTRYSTART + 1;
2058        f = &sp->slot[fsi];
2059
2060        /* init free region of remaining area */
2061        for (fsi++; fsi < DTROOTMAXSLOT; f++, fsi++)
2062                f->next = fsi;
2063        f->next = -1;
2064
2065        sp->header.freelist = DTENTRYSTART + 1;
2066        sp->header.freecnt = DTROOTMAXSLOT - (DTENTRYSTART + 1);
2067
2068        *rmpp = rmp;
2069
2070        return 0;
2071}
2072
2073
2074/*
2075 *      dtDelete()
2076 *
2077 * function: delete the entry(s) referenced by a key.
2078 *
2079 * parameter:
2080 *
2081 * return:
2082 */
2083int dtDelete(tid_t tid,
2084         struct inode *ip, struct component_name * key, ino_t * ino, int flag)
2085{
2086        int rc = 0;
2087        s64 bn;
2088        struct metapage *mp, *imp;
2089        dtpage_t *p;
2090        int index;
2091        struct btstack btstack;
2092        struct dt_lock *dtlck;
2093        struct tlock *tlck;
2094        struct lv *lv;
2095        int i;
2096        struct ldtentry *ldtentry;
2097        u8 *stbl;
2098        u32 table_index, next_index;
2099        struct metapage *nmp;
2100        dtpage_t *np;
2101
2102        /*
2103         *      search for the entry to delete:
2104         *
2105         * dtSearch() returns (leaf page pinned, index at which to delete).
2106         */
2107        if ((rc = dtSearch(ip, key, ino, &btstack, flag)))
2108                return rc;
2109
2110        /* retrieve search result */
2111        DT_GETSEARCH(ip, btstack.top, bn, mp, p, index);
2112
2113        /*
2114         * We need to find put the index of the next entry into the
2115         * directory index table in order to resume a readdir from this
2116         * entry.
2117         */
2118        if (DO_INDEX(ip)) {
2119                stbl = DT_GETSTBL(p);
2120                ldtentry = (struct ldtentry *) & p->slot[stbl[index]];
2121                table_index = le32_to_cpu(ldtentry->index);
2122                if (index == (p->header.nextindex - 1)) {
2123                        /*
2124                         * Last entry in this leaf page
2125                         */
2126                        if ((p->header.flag & BT_ROOT)
2127                            || (p->header.next == 0))
2128                                next_index = -1;
2129                        else {
2130                                /* Read next leaf page */
2131                                DT_GETPAGE(ip, le64_to_cpu(p->header.next),
2132                                           nmp, PSIZE, np, rc);
2133                                if (rc)
2134                                        next_index = -1;
2135                                else {
2136                                        stbl = DT_GETSTBL(np);
2137                                        ldtentry =
2138                                            (struct ldtentry *) & np->
2139                                            slot[stbl[0]];
2140                                        next_index =
2141                                            le32_to_cpu(ldtentry->index);
2142                                        DT_PUTPAGE(nmp);
2143                                }
2144                        }
2145                } else {
2146                        ldtentry =
2147                            (struct ldtentry *) & p->slot[stbl[index + 1]];
2148                        next_index = le32_to_cpu(ldtentry->index);
2149                }
2150                free_index(tid, ip, table_index, next_index);
2151        }
2152        /*
2153         * the leaf page becomes empty, delete the page
2154         */
2155        if (p->header.nextindex == 1) {
2156                /* delete empty page */
2157                rc = dtDeleteUp(tid, ip, mp, p, &btstack);
2158        }
2159        /*
2160         * the leaf page has other entries remaining:
2161         *
2162         * delete the entry from the leaf page.
2163         */
2164        else {
2165                BT_MARK_DIRTY(mp, ip);
2166                /*
2167                 * acquire a transaction lock on the leaf page
2168                 */
2169                tlck = txLock(tid, ip, mp, tlckDTREE | tlckENTRY);
2170                dtlck = (struct dt_lock *) & tlck->lock;
2171
2172                /*
2173                 * Do not assume that dtlck->index will be zero.  During a
2174                 * rename within a directory, this transaction may have
2175                 * modified this page already when adding the new entry.
2176                 */
2177
2178                /* linelock header */
2179                if (dtlck->index >= dtlck->maxcnt)
2180                        dtlck = (struct dt_lock *) txLinelock(dtlck);
2181                lv = & dtlck->lv[dtlck->index];
2182                lv->offset = 0;
2183                lv->length = 1;
2184                dtlck->index++;
2185
2186                /* linelock stbl of non-root leaf page */
2187                if (!(p->header.flag & BT_ROOT)) {
2188                        if (dtlck->index >= dtlck->maxcnt)
2189                                dtlck = (struct dt_lock *) txLinelock(dtlck);
2190                        lv = & dtlck->lv[dtlck->index];
2191                        i = index >> L2DTSLOTSIZE;
2192                        lv->offset = p->header.stblindex + i;
2193                        lv->length =
2194                            ((p->header.nextindex - 1) >> L2DTSLOTSIZE) -
2195                            i + 1;
2196                        dtlck->index++;
2197                }
2198
2199                /* free the leaf entry */
2200                dtDeleteEntry(p, index, &dtlck);
2201
2202                /*
2203                 * Update directory index table for entries moved in stbl
2204                 */
2205                if (DO_INDEX(ip) && index < p->header.nextindex) {
2206                        s64 lblock;
2207
2208                        imp = NULL;
2209                        stbl = DT_GETSTBL(p);
2210                        for (i = index; i < p->header.nextindex; i++) {
2211                                ldtentry =
2212                                    (struct ldtentry *) & p->slot[stbl[i]];
2213                                modify_index(tid, ip,
2214                                             le32_to_cpu(ldtentry->index),
2215                                             bn, i, &imp, &lblock);
2216                        }
2217                        if (imp)
2218                                release_metapage(imp);
2219                }
2220
2221                DT_PUTPAGE(mp);
2222        }
2223
2224        return rc;
2225}
2226
2227
2228/*
2229 *      dtDeleteUp()
2230 *
2231 * function:
2232 *      free empty pages as propagating deletion up the tree
2233 *
2234 * parameter:
2235 *
2236 * return:
2237 */
2238static int dtDeleteUp(tid_t tid, struct inode *ip,
2239           struct metapage * fmp, dtpage_t * fp, struct btstack * btstack)
2240{
2241        int rc = 0;
2242        struct metapage *mp;
2243        dtpage_t *p;
2244        int index, nextindex;
2245        int xlen;
2246        struct btframe *parent;
2247        struct dt_lock *dtlck;
2248        struct tlock *tlck;
2249        struct lv *lv;
2250        struct pxd_lock *pxdlock;
2251        int i;
2252
2253        /*
2254         *      keep the root leaf page which has become empty
2255         */
2256        if (BT_IS_ROOT(fmp)) {
2257                /*
2258                 * reset the root
2259                 *
2260                 * dtInitRoot() acquires txlock on the root
2261                 */
2262                dtInitRoot(tid, ip, PARENT(ip));
2263
2264                DT_PUTPAGE(fmp);
2265
2266                return 0;
2267        }
2268
2269        /*
2270         *      free the non-root leaf page
2271         */
2272        /*
2273         * acquire a transaction lock on the page
2274         *
2275         * write FREEXTENT|NOREDOPAGE log record
2276         * N.B. linelock is overlaid as freed extent descriptor, and
2277         * the buffer page is freed;
2278         */
2279        tlck = txMaplock(tid, ip, tlckDTREE | tlckFREE);
2280        pxdlock = (struct pxd_lock *) & tlck->lock;
2281        pxdlock->flag = mlckFREEPXD;
2282        pxdlock->pxd = fp->header.self;
2283        pxdlock->index = 1;
2284
2285        /* update sibling pointers */
2286        if ((rc = dtRelink(tid, ip, fp))) {
2287                BT_PUTPAGE(fmp);
2288                return rc;
2289        }
2290
2291        xlen = lengthPXD(&fp->header.self);
2292
2293        /* Free quota allocation. */
2294        dquot_free_block(ip, xlen);
2295
2296        /* free/invalidate its buffer page */
2297        discard_metapage(fmp);
2298
2299        /*
2300         *      propagate page deletion up the directory tree
2301         *
2302         * If the delete from the parent page makes it empty,
2303         * continue all the way up the tree.
2304         * stop if the root page is reached (which is never deleted) or
2305         * if the entry deletion does not empty the page.
2306         */
2307        while ((parent = BT_POP(btstack)) != NULL) {
2308                /* pin the parent page <sp> */
2309                DT_GETPAGE(ip, parent->bn, mp, PSIZE, p, rc);
2310                if (rc)
2311                        return rc;
2312
2313                /*
2314                 * free the extent of the child page deleted
2315                 */
2316                index = parent->index;
2317
2318                /*
2319                 * delete the entry for the child page from parent
2320                 */
2321                nextindex = p->header.nextindex;
2322
2323                /*
2324                 * the parent has the single entry being deleted:
2325                 *
2326                 * free the parent page which has become empty.
2327                 */
2328                if (nextindex == 1) {
2329                        /*
2330                         * keep the root internal page which has become empty
2331                         */
2332                        if (p->header.flag & BT_ROOT) {
2333                                /*
2334                                 * reset the root
2335                                 *
2336                                 * dtInitRoot() acquires txlock on the root
2337                                 */
2338                                dtInitRoot(tid, ip, PARENT(ip));
2339
2340                                DT_PUTPAGE(mp);
2341
2342                                return 0;
2343                        }
2344                        /*
2345                         * free the parent page
2346                         */
2347                        else {
2348                                /*
2349                                 * acquire a transaction lock on the page
2350                                 *
2351                                 * write FREEXTENT|NOREDOPAGE log record
2352                                 */
2353                                tlck =
2354                                    txMaplock(tid, ip,
2355                                              tlckDTREE | tlckFREE);
2356                                pxdlock = (struct pxd_lock *) & tlck->lock;
2357                                pxdlock->flag = mlckFREEPXD;
2358                                pxdlock->pxd = p->header.self;
2359                                pxdlock->index = 1;
2360
2361                                /* update sibling pointers */
2362                                if ((rc = dtRelink(tid, ip, p))) {
2363                                        DT_PUTPAGE(mp);
2364                                        return rc;
2365                                }
2366
2367                                xlen = lengthPXD(&p->header.self);
2368
2369                                /* Free quota allocation */
2370                                dquot_free_block(ip, xlen);
2371
2372                                /* free/invalidate its buffer page */
2373                                discard_metapage(mp);
2374
2375                                /* propagate up */
2376                                continue;
2377                        }
2378                }
2379
2380                /*
2381                 * the parent has other entries remaining:
2382                 *
2383                 * delete the router entry from the parent page.
2384                 */
2385                BT_MARK_DIRTY(mp, ip);
2386                /*
2387                 * acquire a transaction lock on the page
2388                 *
2389                 * action: router entry deletion
2390                 */
2391                tlck = txLock(tid, ip, mp, tlckDTREE | tlckENTRY);
2392                dtlck = (struct dt_lock *) & tlck->lock;
2393
2394                /* linelock header */
2395                if (dtlck->index >= dtlck->maxcnt)
2396                        dtlck = (struct dt_lock *) txLinelock(dtlck);
2397                lv = & dtlck->lv[dtlck->index];
2398                lv->offset = 0;
2399                lv->length = 1;
2400                dtlck->index++;
2401
2402                /* linelock stbl of non-root leaf page */
2403                if (!(p->header.flag & BT_ROOT)) {
2404                        if (dtlck->index < dtlck->maxcnt)
2405                                lv++;
2406                        else {
2407                                dtlck = (struct dt_lock *) txLinelock(dtlck);
2408                                lv = & dtlck->lv[0];
2409                        }
2410                        i = index >> L2DTSLOTSIZE;
2411                        lv->offset = p->header.stblindex + i;
2412                        lv->length =
2413                            ((p->header.nextindex - 1) >> L2DTSLOTSIZE) -
2414                            i + 1;
2415                        dtlck->index++;
2416                }
2417
2418                /* free the router entry */
2419                dtDeleteEntry(p, index, &dtlck);
2420
2421                /* reset key of new leftmost entry of level (for consistency) */
2422                if (index == 0 &&
2423                    ((p->header.flag & BT_ROOT) || p->header.prev == 0))
2424                        dtTruncateEntry(p, 0, &dtlck);
2425
2426                /* unpin the parent page */
2427                DT_PUTPAGE(mp);
2428
2429                /* exit propagation up */
2430                break;
2431        }
2432
2433        if (!DO_INDEX(ip))
2434                ip->i_size -= PSIZE;
2435
2436        return 0;
2437}
2438
2439#ifdef _NOTYET
2440/*
2441 * NAME:        dtRelocate()
2442 *
2443 * FUNCTION:    relocate dtpage (internal or leaf) of directory;
2444 *              This function is mainly used by defragfs utility.
2445 */
2446int dtRelocate(tid_t tid, struct inode *ip, s64 lmxaddr, pxd_t * opxd,
2447               s64 nxaddr)
2448{
2449        int rc = 0;
2450        struct metapage *mp, *pmp, *lmp, *rmp;
2451        dtpage_t *p, *pp, *rp = 0, *lp= 0;
2452        s64 bn;
2453        int index;
2454        struct btstack btstack;
2455        pxd_t *pxd;
2456        s64 oxaddr, nextbn, prevbn;
2457        int xlen, xsize;
2458        struct tlock *tlck;
2459        struct dt_lock *dtlck;
2460        struct pxd_lock *pxdlock;
2461        s8 *stbl;
2462        struct lv *lv;
2463
2464        oxaddr = addressPXD(opxd);
2465        xlen = lengthPXD(opxd);
2466
2467        jfs_info("dtRelocate: lmxaddr:%Ld xaddr:%Ld:%Ld xlen:%d",
2468                   (long long)lmxaddr, (long long)oxaddr, (long long)nxaddr,
2469                   xlen);
2470
2471        /*
2472         *      1. get the internal parent dtpage covering
2473         *      router entry for the tartget page to be relocated;
2474         */
2475        rc = dtSearchNode(ip, lmxaddr, opxd, &btstack);
2476        if (rc)
2477                return rc;
2478
2479        /* retrieve search result */
2480        DT_GETSEARCH(ip, btstack.top, bn, pmp, pp, index);
2481        jfs_info("dtRelocate: parent router entry validated.");
2482
2483        /*
2484         *      2. relocate the target dtpage
2485         */
2486        /* read in the target page from src extent */
2487        DT_GETPAGE(ip, oxaddr, mp, PSIZE, p, rc);
2488        if (rc) {
2489                /* release the pinned parent page */
2490                DT_PUTPAGE(pmp);
2491                return rc;
2492        }
2493
2494        /*
2495         * read in sibling pages if any to update sibling pointers;
2496         */
2497        rmp = NULL;
2498        if (p->header.next) {
2499                nextbn = le64_to_cpu(p->header.next);
2500                DT_GETPAGE(ip, nextbn, rmp, PSIZE, rp, rc);
2501                if (rc) {
2502                        DT_PUTPAGE(mp);
2503                        DT_PUTPAGE(pmp);
2504                        return (rc);
2505                }
2506        }
2507
2508        lmp = NULL;
2509        if (p->header.prev) {
2510                prevbn = le64_to_cpu(p->header.prev);
2511                DT_GETPAGE(ip, prevbn, lmp, PSIZE, lp, rc);
2512                if (rc) {
2513                        DT_PUTPAGE(mp);
2514                        DT_PUTPAGE(pmp);
2515                        if (rmp)
2516                                DT_PUTPAGE(rmp);
2517                        return (rc);
2518                }
2519        }
2520
2521        /* at this point, all xtpages to be updated are in memory */
2522
2523        /*
2524         * update sibling pointers of sibling dtpages if any;
2525         */
2526        if (lmp) {
2527                tlck = txLock(tid, ip, lmp, tlckDTREE | tlckRELINK);
2528                dtlck = (struct dt_lock *) & tlck->lock;
2529                /* linelock header */
2530                ASSERT(dtlck->index == 0);
2531                lv = & dtlck->lv[0];
2532                lv->offset = 0;
2533                lv->length = 1;
2534                dtlck->index++;
2535
2536                lp->header.next = cpu_to_le64(nxaddr);
2537                DT_PUTPAGE(lmp);
2538        }
2539
2540        if (rmp) {
2541                tlck = txLock(tid, ip, rmp, tlckDTREE | tlckRELINK);
2542                dtlck = (struct dt_lock *) & tlck->lock;
2543                /* linelock header */
2544                ASSERT(dtlck->index == 0);
2545                lv = & dtlck->lv[0];
2546                lv->offset = 0;
2547                lv->length = 1;
2548                dtlck->index++;
2549
2550                rp->header.prev = cpu_to_le64(nxaddr);
2551                DT_PUTPAGE(rmp);
2552        }
2553
2554        /*
2555         * update the target dtpage to be relocated
2556         *
2557         * write LOG_REDOPAGE of LOG_NEW type for dst page
2558         * for the whole target page (logredo() will apply
2559         * after image and update bmap for allocation of the
2560         * dst extent), and update bmap for allocation of
2561         * the dst extent;
2562         */
2563        tlck = txLock(tid, ip, mp, tlckDTREE | tlckNEW);
2564        dtlck = (struct dt_lock *) & tlck->lock;
2565        /* linelock header */
2566        ASSERT(dtlck->index == 0);
2567        lv = & dtlck->lv[0];
2568
2569        /* update the self address in the dtpage header */
2570        pxd = &p->header.self;
2571        PXDaddress(pxd, nxaddr);
2572
2573        /* the dst page is the same as the src page, i.e.,
2574         * linelock for afterimage of the whole page;
2575         */
2576        lv->offset = 0;
2577        lv->length = p->header.maxslot;
2578        dtlck->index++;
2579
2580        /* update the buffer extent descriptor of the dtpage */
2581        xsize = xlen << JFS_SBI(ip->i_sb)->l2bsize;
2582
2583        /* unpin the relocated page */
2584        DT_PUTPAGE(mp);
2585        jfs_info("dtRelocate: target dtpage relocated.");
2586
2587        /* the moved extent is dtpage, then a LOG_NOREDOPAGE log rec
2588         * needs to be written (in logredo(), the LOG_NOREDOPAGE log rec
2589         * will also force a bmap update ).
2590         */
2591
2592        /*
2593         *      3. acquire maplock for the source extent to be freed;
2594         */
2595        /* for dtpage relocation, write a LOG_NOREDOPAGE record
2596         * for the source dtpage (logredo() will init NoRedoPage
2597         * filter and will also update bmap for free of the source
2598         * dtpage), and upadte bmap for free of the source dtpage;
2599         */
2600        tlck = txMaplock(tid, ip, tlckDTREE | tlckFREE);
2601        pxdlock = (struct pxd_lock *) & tlck->lock;
2602        pxdlock->flag = mlckFREEPXD;
2603        PXDaddress(&pxdlock->pxd, oxaddr);
2604        PXDlength(&pxdlock->pxd, xlen);
2605        pxdlock->index = 1;
2606
2607        /*
2608         *      4. update the parent router entry for relocation;
2609         *
2610         * acquire tlck for the parent entry covering the target dtpage;
2611         * write LOG_REDOPAGE to apply after image only;
2612         */
2613        jfs_info("dtRelocate: update parent router entry.");
2614        tlck = txLock(tid, ip, pmp, tlckDTREE | tlckENTRY);
2615        dtlck = (struct dt_lock *) & tlck->lock;
2616        lv = & dtlck->lv[dtlck->index];
2617
2618        /* update the PXD with the new address */
2619        stbl = DT_GETSTBL(pp);
2620        pxd = (pxd_t *) & pp->slot[stbl[index]];
2621        PXDaddress(pxd, nxaddr);
2622        lv->offset = stbl[index];
2623        lv->length = 1;
2624        dtlck->index++;
2625
2626        /* unpin the parent dtpage */
2627        DT_PUTPAGE(pmp);
2628
2629        return rc;
2630}
2631
2632/*
2633 * NAME:        dtSearchNode()
2634 *
2635 * FUNCTION:    Search for an dtpage containing a specified address
2636 *              This function is mainly used by defragfs utility.
2637 *
2638 * NOTE:        Search result on stack, the found page is pinned at exit.
2639 *              The result page must be an internal dtpage.
2640 *              lmxaddr give the address of the left most page of the
2641 *              dtree level, in which the required dtpage resides.
2642 */
2643static int dtSearchNode(struct inode *ip, s64 lmxaddr, pxd_t * kpxd,
2644                        struct btstack * btstack)
2645{
2646        int rc = 0;
2647        s64 bn;
2648        struct metapage *mp;
2649        dtpage_t *p;
2650        int psize = 288;        /* initial in-line directory */
2651        s8 *stbl;
2652        int i;
2653        pxd_t *pxd;
2654        struct btframe *btsp;
2655
2656        BT_CLR(btstack);        /* reset stack */
2657
2658        /*
2659         *      descend tree to the level with specified leftmost page
2660         *
2661         *  by convention, root bn = 0.
2662         */
2663        for (bn = 0;;) {
2664                /* get/pin the page to search */
2665                DT_GETPAGE(ip, bn, mp, psize, p, rc);
2666                if (rc)
2667                        return rc;
2668
2669                /* does the xaddr of leftmost page of the levevl
2670                 * matches levevl search key ?
2671                 */
2672                if (p->header.flag & BT_ROOT) {
2673                        if (lmxaddr == 0)
2674                                break;
2675                } else if (addressPXD(&p->header.self) == lmxaddr)
2676                        break;
2677
2678                /*
2679                 * descend down to leftmost child page
2680                 */
2681                if (p->header.flag & BT_LEAF) {
2682                        DT_PUTPAGE(mp);
2683                        return -ESTALE;
2684                }
2685
2686                /* get the leftmost entry */
2687                stbl = DT_GETSTBL(p);
2688                pxd = (pxd_t *) & p->slot[stbl[0]];
2689
2690                /* get the child page block address */
2691                bn = addressPXD(pxd);
2692                psize = lengthPXD(pxd) << JFS_SBI(ip->i_sb)->l2bsize;
2693                /* unpin the parent page */
2694                DT_PUTPAGE(mp);
2695        }
2696
2697        /*
2698         *      search each page at the current levevl
2699         */
2700      loop:
2701        stbl = DT_GETSTBL(p);
2702        for (i = 0; i < p->header.nextindex; i++) {
2703                pxd = (pxd_t *) & p->slot[stbl[i]];
2704
2705                /* found the specified router entry */
2706                if (addressPXD(pxd) == addressPXD(kpxd) &&
2707                    lengthPXD(pxd) == lengthPXD(kpxd)) {
2708                        btsp = btstack->top;
2709                        btsp->bn = bn;
2710                        btsp->index = i;
2711                        btsp->mp = mp;
2712
2713                        return 0;
2714                }
2715        }
2716
2717        /* get the right sibling page if any */
2718        if (p->header.next)
2719                bn = le64_to_cpu(p->header.next);
2720        else {
2721                DT_PUTPAGE(mp);
2722                return -ESTALE;
2723        }
2724
2725        /* unpin current page */
2726        DT_PUTPAGE(mp);
2727
2728        /* get the right sibling page */
2729        DT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
2730        if (rc)
2731                return rc;
2732
2733        goto loop;
2734}
2735#endif /* _NOTYET */
2736
2737/*
2738 *      dtRelink()
2739 *
2740 * function:
2741 *      link around a freed page.
2742 *
2743 * parameter:
2744 *      fp:     page to be freed
2745 *
2746 * return:
2747 */
2748static int dtRelink(tid_t tid, struct inode *ip, dtpage_t * p)
2749{
2750        int rc;
2751        struct metapage *mp;
2752        s64 nextbn, prevbn;
2753        struct tlock *tlck;
2754        struct dt_lock *dtlck;
2755        struct lv *lv;
2756
2757        nextbn = le64_to_cpu(p->header.next);
2758        prevbn = le64_to_cpu(p->header.prev);
2759
2760        /* update prev pointer of the next page */
2761        if (nextbn != 0) {
2762                DT_GETPAGE(ip, nextbn, mp, PSIZE, p, rc);
2763                if (rc)
2764                        return rc;
2765
2766                BT_MARK_DIRTY(mp, ip);
2767                /*
2768                 * acquire a transaction lock on the next page
2769                 *
2770                 * action: update prev pointer;
2771                 */
2772                tlck = txLock(tid, ip, mp, tlckDTREE | tlckRELINK);
2773                jfs_info("dtRelink nextbn: tlck = 0x%p, ip = 0x%p, mp=0x%p",
2774                        tlck, ip, mp);
2775                dtlck = (struct dt_lock *) & tlck->lock;
2776
2777                /* linelock header */
2778                if (dtlck->index >= dtlck->maxcnt)
2779                        dtlck = (struct dt_lock *) txLinelock(dtlck);
2780                lv = & dtlck->lv[dtlck->index];
2781                lv->offset = 0;
2782                lv->length = 1;
2783                dtlck->index++;
2784
2785                p->header.prev = cpu_to_le64(prevbn);
2786                DT_PUTPAGE(mp);
2787        }
2788
2789        /* update next pointer of the previous page */
2790        if (prevbn != 0) {
2791                DT_GETPAGE(ip, prevbn, mp, PSIZE, p, rc);
2792                if (rc)
2793                        return rc;
2794
2795                BT_MARK_DIRTY(mp, ip);
2796                /*
2797                 * acquire a transaction lock on the prev page
2798                 *
2799                 * action: update next pointer;
2800                 */
2801                tlck = txLock(tid, ip, mp, tlckDTREE | tlckRELINK);
2802                jfs_info("dtRelink prevbn: tlck = 0x%p, ip = 0x%p, mp=0x%p",
2803                        tlck, ip, mp);
2804                dtlck = (struct dt_lock *) & tlck->lock;
2805
2806                /* linelock header */
2807                if (dtlck->index >= dtlck->maxcnt)
2808                        dtlck = (struct dt_lock *) txLinelock(dtlck);
2809                lv = & dtlck->lv[dtlck->index];
2810                lv->offset = 0;
2811                lv->length = 1;
2812                dtlck->index++;
2813
2814                p->header.next = cpu_to_le64(nextbn);
2815                DT_PUTPAGE(mp);
2816        }
2817
2818        return 0;
2819}
2820
2821
2822/*
2823 *      dtInitRoot()
2824 *
2825 * initialize directory root (inline in inode)
2826 */
2827void dtInitRoot(tid_t tid, struct inode *ip, u32 idotdot)
2828{
2829        struct jfs_inode_info *jfs_ip = JFS_IP(ip);
2830        dtroot_t *p;
2831        int fsi;
2832        struct dtslot *f;
2833        struct tlock *tlck;
2834        struct dt_lock *dtlck;
2835        struct lv *lv;
2836        u16 xflag_save;
2837
2838        /*
2839         * If this was previously an non-empty directory, we need to remove
2840         * the old directory table.
2841         */
2842        if (DO_INDEX(ip)) {
2843                if (!jfs_dirtable_inline(ip)) {
2844                        struct tblock *tblk = tid_to_tblock(tid);
2845                        /*
2846                         * We're playing games with the tid's xflag.  If
2847                         * we're removing a regular file, the file's xtree
2848                         * is committed with COMMIT_PMAP, but we always
2849                         * commit the directories xtree with COMMIT_PWMAP.
2850                         */
2851                        xflag_save = tblk->xflag;
2852                        tblk->xflag = 0;
2853                        /*
2854                         * xtTruncate isn't guaranteed to fully truncate
2855                         * the xtree.  The caller needs to check i_size
2856                         * after committing the transaction to see if
2857                         * additional truncation is needed.  The
2858                         * COMMIT_Stale flag tells caller that we
2859                         * initiated the truncation.
2860                         */
2861                        xtTruncate(tid, ip, 0, COMMIT_PWMAP);
2862                        set_cflag(COMMIT_Stale, ip);
2863
2864                        tblk->xflag = xflag_save;
2865                } else
2866                        ip->i_size = 1;
2867
2868                jfs_ip->next_index = 2;
2869        } else
2870                ip->i_size = IDATASIZE;
2871
2872        /*
2873         * acquire a transaction lock on the root
2874         *
2875         * action: directory initialization;
2876         */
2877        tlck = txLock(tid, ip, (struct metapage *) & jfs_ip->bxflag,
2878                      tlckDTREE | tlckENTRY | tlckBTROOT);
2879        dtlck = (struct dt_lock *) & tlck->lock;
2880
2881        /* linelock root */
2882        ASSERT(dtlck->index == 0);
2883        lv = & dtlck->lv[0];
2884        lv->offset = 0;
2885        lv->length = DTROOTMAXSLOT;
2886        dtlck->index++;
2887
2888        p = &jfs_ip->i_dtroot;
2889
2890        p->header.flag = DXD_INDEX | BT_ROOT | BT_LEAF;
2891
2892        p->header.nextindex = 0;
2893
2894        /* init freelist */
2895        fsi = 1;
2896        f = &p->slot[fsi];
2897
2898        /* init data area of root */
2899        for (fsi++; fsi < DTROOTMAXSLOT; f++, fsi++)
2900                f->next = fsi;
2901        f->next = -1;
2902
2903        p->header.freelist = 1;
2904        p->header.freecnt = 8;
2905
2906        /* init '..' entry */
2907        p->header.idotdot = cpu_to_le32(idotdot);
2908
2909        return;
2910}
2911
2912/*
2913 *      add_missing_indices()
2914 *
2915 * function: Fix dtree page in which one or more entries has an invalid index.
2916 *           fsck.jfs should really fix this, but it currently does not.
2917 *           Called from jfs_readdir when bad index is detected.
2918 */
2919static void add_missing_indices(struct inode *inode, s64 bn)
2920{
2921        struct ldtentry *d;
2922        struct dt_lock *dtlck;
2923        int i;
2924        uint index;
2925        struct lv *lv;
2926        struct metapage *mp;
2927        dtpage_t *p;
2928        int rc;
2929        s8 *stbl;
2930        tid_t tid;
2931        struct tlock *tlck;
2932
2933        tid = txBegin(inode->i_sb, 0);
2934
2935        DT_GETPAGE(inode, bn, mp, PSIZE, p, rc);
2936
2937        if (rc) {
2938                printk(KERN_ERR "DT_GETPAGE failed!\n");
2939                goto end;
2940        }
2941        BT_MARK_DIRTY(mp, inode);
2942
2943        ASSERT(p->header.flag & BT_LEAF);
2944
2945        tlck = txLock(tid, inode, mp, tlckDTREE | tlckENTRY);
2946        if (BT_IS_ROOT(mp))
2947                tlck->type |= tlckBTROOT;
2948
2949        dtlck = (struct dt_lock *) &tlck->lock;
2950
2951        stbl = DT_GETSTBL(p);
2952        for (i = 0; i < p->header.nextindex; i++) {
2953                d = (struct ldtentry *) &p->slot[stbl[i]];
2954                index = le32_to_cpu(d->index);
2955                if ((index < 2) || (index >= JFS_IP(inode)->next_index)) {
2956                        d->index = cpu_to_le32(add_index(tid, inode, bn, i));
2957                        if (dtlck->index >= dtlck->maxcnt)
2958                                dtlck = (struct dt_lock *) txLinelock(dtlck);
2959                        lv = &dtlck->lv[dtlck->index];
2960                        lv->offset = stbl[i];
2961                        lv->length = 1;
2962                        dtlck->index++;
2963                }
2964        }
2965
2966        DT_PUTPAGE(mp);
2967        (void) txCommit(tid, 1, &inode, 0);
2968end:
2969        txEnd(tid);
2970}
2971
2972/*
2973 * Buffer to hold directory entry info while traversing a dtree page
2974 * before being fed to the filldir function
2975 */
2976struct jfs_dirent {
2977        loff_t position;
2978        int ino;
2979        u16 name_len;
2980        char name[0];
2981};
2982
2983/*
2984 * function to determine next variable-sized jfs_dirent in buffer
2985 */
2986static inline struct jfs_dirent *next_jfs_dirent(struct jfs_dirent *dirent)
2987{
2988        return (struct jfs_dirent *)
2989                ((char *)dirent +
2990                 ((sizeof (struct jfs_dirent) + dirent->name_len + 1 +
2991                   sizeof (loff_t) - 1) &
2992                  ~(sizeof (loff_t) - 1)));
2993}
2994
2995/*
2996 *      jfs_readdir()
2997 *
2998 * function: read directory entries sequentially
2999 *      from the specified entry offset
3000 *
3001 * parameter:
3002 *
3003 * return: offset = (pn, index) of start entry
3004 *      of next jfs_readdir()/dtRead()
3005 */
3006int jfs_readdir(struct file *file, struct dir_context *ctx)
3007{
3008        struct inode *ip = file_inode(file);
3009        struct nls_table *codepage = JFS_SBI(ip->i_sb)->nls_tab;
3010        int rc = 0;
3011        loff_t dtpos;   /* legacy OS/2 style position */
3012        struct dtoffset {
3013                s16 pn;
3014                s16 index;
3015                s32 unused;
3016        } *dtoffset = (struct dtoffset *) &dtpos;
3017        s64 bn;
3018        struct metapage *mp;
3019        dtpage_t *p;
3020        int index;
3021        s8 *stbl;
3022        struct btstack btstack;
3023        int i, next;
3024        struct ldtentry *d;
3025        struct dtslot *t;
3026        int d_namleft, len, outlen;
3027        unsigned long dirent_buf;
3028        char *name_ptr;
3029        u32 dir_index;
3030        int do_index = 0;
3031        uint loop_count = 0;
3032        struct jfs_dirent *jfs_dirent;
3033        int jfs_dirents;
3034        int overflow, fix_page, page_fixed = 0;
3035        static int unique_pos = 2;      /* If we can't fix broken index */
3036
3037        if (ctx->pos == DIREND)
3038                return 0;
3039
3040        if (DO_INDEX(ip)) {
3041                /*
3042                 * persistent index is stored in directory entries.
3043                 * Special cases:        0 = .
3044                 *                       1 = ..
3045                 *                      -1 = End of directory
3046                 */
3047                do_index = 1;
3048
3049                dir_index = (u32) ctx->pos;
3050
3051                /*
3052                 * NFSv4 reserves cookies 1 and 2 for . and .. so the value
3053                 * we return to the vfs is one greater than the one we use
3054                 * internally.
3055                 */
3056                if (dir_index)
3057                        dir_index--;
3058
3059                if (dir_index > 1) {
3060                        struct dir_table_slot dirtab_slot;
3061
3062                        if (dtEmpty(ip) ||
3063                            (dir_index >= JFS_IP(ip)->next_index)) {
3064                                /* Stale position.  Directory has shrunk */
3065                                ctx->pos = DIREND;
3066                                return 0;
3067                        }
3068                      repeat:
3069                        rc = read_index(ip, dir_index, &dirtab_slot);
3070                        if (rc) {
3071                                ctx->pos = DIREND;
3072                                return rc;
3073                        }
3074                        if (dirtab_slot.flag == DIR_INDEX_FREE) {
3075                                if (loop_count++ > JFS_IP(ip)->next_index) {
3076                                        jfs_err("jfs_readdir detected infinite loop!");
3077                                        ctx->pos = DIREND;
3078                                        return 0;
3079                                }
3080                                dir_index = le32_to_cpu(dirtab_slot.addr2);
3081                                if (dir_index == -1) {
3082                                        ctx->pos = DIREND;
3083                                        return 0;
3084                                }
3085                                goto repeat;
3086                        }
3087                        bn = addressDTS(&dirtab_slot);
3088                        index = dirtab_slot.slot;
3089                        DT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
3090                        if (rc) {
3091                                ctx->pos = DIREND;
3092                                return 0;
3093                        }
3094                        if (p->header.flag & BT_INTERNAL) {
3095                                jfs_err("jfs_readdir: bad index table");
3096                                DT_PUTPAGE(mp);
3097                                ctx->pos = DIREND;
3098                                return 0;
3099                        }
3100                } else {
3101                        if (dir_index == 0) {
3102                                /*
3103                                 * self "."
3104                                 */
3105                                ctx->pos = 1;
3106                                if (!dir_emit(ctx, ".", 1, ip->i_ino, DT_DIR))
3107                                        return 0;
3108                        }
3109                        /*
3110                         * parent ".."
3111                         */
3112                        ctx->pos = 2;
3113                        if (!dir_emit(ctx, "..", 2, PARENT(ip), DT_DIR))
3114                                return 0;
3115
3116                        /*
3117                         * Find first entry of left-most leaf
3118                         */
3119                        if (dtEmpty(ip)) {
3120                                ctx->pos = DIREND;
3121                                return 0;
3122                        }
3123
3124                        if ((rc = dtReadFirst(ip, &btstack)))
3125                                return rc;
3126
3127                        DT_GETSEARCH(ip, btstack.top, bn, mp, p, index);
3128                }
3129        } else {
3130                /*
3131                 * Legacy filesystem - OS/2 & Linux JFS < 0.3.6
3132                 *
3133                 * pn = 0; index = 1:   First entry "."
3134                 * pn = 0; index = 2:   Second entry ".."
3135                 * pn > 0:              Real entries, pn=1 -> leftmost page
3136                 * pn = index = -1:     No more entries
3137                 */
3138                dtpos = ctx->pos;
3139                if (dtpos < 2) {
3140                        /* build "." entry */
3141                        ctx->pos = 1;
3142                        if (!dir_emit(ctx, ".", 1, ip->i_ino, DT_DIR))
3143                                return 0;
3144                        dtoffset->index = 2;
3145                        ctx->pos = dtpos;
3146                }
3147
3148                if (dtoffset->pn == 0) {
3149                        if (dtoffset->index == 2) {
3150                                /* build ".." entry */
3151                                if (!dir_emit(ctx, "..", 2, PARENT(ip), DT_DIR))
3152                                        return 0;
3153                        } else {
3154                                jfs_err("jfs_readdir called with invalid offset!");
3155                        }
3156                        dtoffset->pn = 1;
3157                        dtoffset->index = 0;
3158                        ctx->pos = dtpos;
3159                }
3160
3161                if (dtEmpty(ip)) {
3162                        ctx->pos = DIREND;
3163                        return 0;
3164                }
3165
3166                if ((rc = dtReadNext(ip, &ctx->pos, &btstack))) {
3167                        jfs_err("jfs_readdir: unexpected rc = %d from dtReadNext",
3168                                rc);
3169                        ctx->pos = DIREND;
3170                        return 0;
3171                }
3172                /* get start leaf page and index */
3173                DT_GETSEARCH(ip, btstack.top, bn, mp, p, index);
3174
3175                /* offset beyond directory eof ? */
3176                if (bn < 0) {
3177                        ctx->pos = DIREND;
3178                        return 0;
3179                }
3180        }
3181
3182        dirent_buf = __get_free_page(GFP_KERNEL);
3183        if (dirent_buf == 0) {
3184                DT_PUTPAGE(mp);
3185                jfs_warn("jfs_readdir: __get_free_page failed!");
3186                ctx->pos = DIREND;
3187                return -ENOMEM;
3188        }
3189
3190        while (1) {
3191                jfs_dirent = (struct jfs_dirent *) dirent_buf;
3192                jfs_dirents = 0;
3193                overflow = fix_page = 0;
3194
3195                stbl = DT_GETSTBL(p);
3196
3197                for (i = index; i < p->header.nextindex; i++) {
3198                        d = (struct ldtentry *) & p->slot[stbl[i]];
3199
3200                        if (((long) jfs_dirent + d->namlen + 1) >
3201                            (dirent_buf + PAGE_SIZE)) {
3202                                /* DBCS codepages could overrun dirent_buf */
3203                                index = i;
3204                                overflow = 1;
3205                                break;
3206                        }
3207
3208                        d_namleft = d->namlen;
3209                        name_ptr = jfs_dirent->name;
3210                        jfs_dirent->ino = le32_to_cpu(d->inumber);
3211
3212                        if (do_index) {
3213                                len = min(d_namleft, DTLHDRDATALEN);
3214                                jfs_dirent->position = le32_to_cpu(d->index);
3215                                /*
3216                                 * d->index should always be valid, but it
3217                                 * isn't.  fsck.jfs doesn't create the
3218                                 * directory index for the lost+found
3219                                 * directory.  Rather than let it go,
3220                                 * we can try to fix it.
3221                                 */
3222                                if ((jfs_dirent->position < 2) ||
3223                                    (jfs_dirent->position >=
3224                                     JFS_IP(ip)->next_index)) {
3225                                        if (!page_fixed && !isReadOnly(ip)) {
3226                                                fix_page = 1;
3227                                                /*
3228                                                 * setting overflow and setting
3229                                                 * index to i will cause the
3230                                                 * same page to be processed
3231                                                 * again starting here
3232                                                 */
3233                                                overflow = 1;
3234                                                index = i;
3235                                                break;
3236                                        }
3237                                        jfs_dirent->position = unique_pos++;
3238                                }
3239                                /*
3240                                 * We add 1 to the index because we may
3241                                 * use a value of 2 internally, and NFSv4
3242                                 * doesn't like that.
3243                                 */
3244                                jfs_dirent->position++;
3245                        } else {
3246                                jfs_dirent->position = dtpos;
3247                                len = min(d_namleft, DTLHDRDATALEN_LEGACY);
3248                        }
3249
3250                        /* copy the name of head/only segment */
3251                        outlen = jfs_strfromUCS_le(name_ptr, d->name, len,
3252                                                   codepage);
3253                        jfs_dirent->name_len = outlen;
3254
3255                        /* copy name in the additional segment(s) */
3256                        next = d->next;
3257                        while (next >= 0) {
3258                                t = (struct dtslot *) & p->slot[next];
3259                                name_ptr += outlen;
3260                                d_namleft -= len;
3261                                /* Sanity Check */
3262                                if (d_namleft == 0) {
3263                                        jfs_error(ip->i_sb,
3264                                                  "JFS:Dtree error: ino = %ld, bn=%lld, index = %d\n",
3265                                                  (long)ip->i_ino,
3266                                                  (long long)bn,
3267                                                  i);
3268                                        goto skip_one;
3269                                }
3270                                len = min(d_namleft, DTSLOTDATALEN);
3271                                outlen = jfs_strfromUCS_le(name_ptr, t->name,
3272                                                           len, codepage);
3273                                jfs_dirent->name_len += outlen;
3274
3275                                next = t->next;
3276                        }
3277
3278                        jfs_dirents++;
3279                        jfs_dirent = next_jfs_dirent(jfs_dirent);
3280skip_one:
3281                        if (!do_index)
3282                                dtoffset->index++;
3283                }
3284
3285                if (!overflow) {
3286                        /* Point to next leaf page */
3287                        if (p->header.flag & BT_ROOT)
3288                                bn = 0;
3289                        else {
3290                                bn = le64_to_cpu(p->header.next);
3291                                index = 0;
3292                                /* update offset (pn:index) for new page */
3293                                if (!do_index) {
3294                                        dtoffset->pn++;
3295                                        dtoffset->index = 0;
3296                                }
3297                        }
3298                        page_fixed = 0;
3299                }
3300
3301                /* unpin previous leaf page */
3302                DT_PUTPAGE(mp);
3303
3304                jfs_dirent = (struct jfs_dirent *) dirent_buf;
3305                while (jfs_dirents--) {
3306                        ctx->pos = jfs_dirent->position;
3307                        if (!dir_emit(ctx, jfs_dirent->name,
3308                                    jfs_dirent->name_len,
3309                                    jfs_dirent->ino, DT_UNKNOWN))
3310                                goto out;
3311                        jfs_dirent = next_jfs_dirent(jfs_dirent);
3312                }
3313
3314                if (fix_page) {
3315                        add_missing_indices(ip, bn);
3316                        page_fixed = 1;
3317                }
3318
3319                if (!overflow && (bn == 0)) {
3320                        ctx->pos = DIREND;
3321                        break;
3322                }
3323
3324                DT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
3325                if (rc) {
3326                        free_page(dirent_buf);
3327                        return rc;
3328                }
3329        }
3330
3331      out:
3332        free_page(dirent_buf);
3333
3334        return rc;
3335}
3336
3337
3338/*
3339 *      dtReadFirst()
3340 *
3341 * function: get the leftmost page of the directory
3342 */
3343static int dtReadFirst(struct inode *ip, struct btstack * btstack)
3344{
3345        int rc = 0;
3346        s64 bn;
3347        int psize = 288;        /* initial in-line directory */
3348        struct metapage *mp;
3349        dtpage_t *p;
3350        s8 *stbl;
3351        struct btframe *btsp;
3352        pxd_t *xd;
3353
3354        BT_CLR(btstack);        /* reset stack */
3355
3356        /*
3357         *      descend leftmost path of the tree
3358         *
3359         * by convention, root bn = 0.
3360         */
3361        for (bn = 0;;) {
3362                DT_GETPAGE(ip, bn, mp, psize, p, rc);
3363                if (rc)
3364                        return rc;
3365
3366                /*
3367                 * leftmost leaf page
3368                 */
3369                if (p->header.flag & BT_LEAF) {
3370                        /* return leftmost entry */
3371                        btsp = btstack->top;
3372                        btsp->bn = bn;
3373                        btsp->index = 0;
3374                        btsp->mp = mp;
3375
3376                        return 0;
3377                }
3378
3379                /*
3380                 * descend down to leftmost child page
3381                 */
3382                if (BT_STACK_FULL(btstack)) {
3383                        DT_PUTPAGE(mp);
3384                        jfs_error(ip->i_sb, "btstack overrun\n");
3385                        BT_STACK_DUMP(btstack);
3386                        return -EIO;
3387                }
3388                /* push (bn, index) of the parent page/entry */
3389                BT_PUSH(btstack, bn, 0);
3390
3391                /* get the leftmost entry */
3392                stbl = DT_GETSTBL(p);
3393                xd = (pxd_t *) & p->slot[stbl[0]];
3394
3395                /* get the child page block address */
3396                bn = addressPXD(xd);
3397                psize = lengthPXD(xd) << JFS_SBI(ip->i_sb)->l2bsize;
3398
3399                /* unpin the parent page */
3400                DT_PUTPAGE(mp);
3401        }
3402}
3403
3404
3405/*
3406 *      dtReadNext()
3407 *
3408 * function: get the page of the specified offset (pn:index)
3409 *
3410 * return: if (offset > eof), bn = -1;
3411 *
3412 * note: if index > nextindex of the target leaf page,
3413 * start with 1st entry of next leaf page;
3414 */
3415static int dtReadNext(struct inode *ip, loff_t * offset,
3416                      struct btstack * btstack)
3417{
3418        int rc = 0;
3419        struct dtoffset {
3420                s16 pn;
3421                s16 index;
3422                s32 unused;
3423        } *dtoffset = (struct dtoffset *) offset;
3424        s64 bn;
3425        struct metapage *mp;
3426        dtpage_t *p;
3427        int index;
3428        int pn;
3429        s8 *stbl;
3430        struct btframe *btsp, *parent;
3431        pxd_t *xd;
3432
3433        /*
3434         * get leftmost leaf page pinned
3435         */
3436        if ((rc = dtReadFirst(ip, btstack)))
3437                return rc;
3438
3439        /* get leaf page */
3440        DT_GETSEARCH(ip, btstack->top, bn, mp, p, index);
3441
3442        /* get the start offset (pn:index) */
3443        pn = dtoffset->pn - 1;  /* Now pn = 0 represents leftmost leaf */
3444        index = dtoffset->index;
3445
3446        /* start at leftmost page ? */
3447        if (pn == 0) {
3448                /* offset beyond eof ? */
3449                if (index < p->header.nextindex)
3450                        goto out;
3451
3452                if (p->header.flag & BT_ROOT) {
3453                        bn = -1;
3454                        goto out;
3455                }
3456
3457                /* start with 1st entry of next leaf page */
3458                dtoffset->pn++;
3459                dtoffset->index = index = 0;
3460                goto a;
3461        }
3462
3463        /* start at non-leftmost page: scan parent pages for large pn */
3464        if (p->header.flag & BT_ROOT) {
3465                bn = -1;
3466                goto out;
3467        }
3468
3469        /* start after next leaf page ? */
3470        if (pn > 1)
3471                goto b;
3472
3473        /* get leaf page pn = 1 */
3474      a:
3475        bn = le64_to_cpu(p->header.next);
3476
3477        /* unpin leaf page */
3478        DT_PUTPAGE(mp);
3479
3480        /* offset beyond eof ? */
3481        if (bn == 0) {
3482                bn = -1;
3483                goto out;
3484        }
3485
3486        goto c;
3487
3488        /*
3489         * scan last internal page level to get target leaf page
3490         */
3491      b:
3492        /* unpin leftmost leaf page */
3493        DT_PUTPAGE(mp);
3494
3495        /* get left most parent page */
3496        btsp = btstack->top;
3497        parent = btsp - 1;
3498        bn = parent->bn;
3499        DT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
3500        if (rc)
3501                return rc;
3502
3503        /* scan parent pages at last internal page level */
3504        while (pn >= p->header.nextindex) {
3505                pn -= p->header.nextindex;
3506
3507                /* get next parent page address */
3508                bn = le64_to_cpu(p->header.next);
3509
3510                /* unpin current parent page */
3511                DT_PUTPAGE(mp);
3512
3513                /* offset beyond eof ? */
3514                if (bn == 0) {
3515                        bn = -1;
3516                        goto out;
3517                }
3518
3519                /* get next parent page */
3520                DT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
3521                if (rc)
3522                        return rc;
3523
3524                /* update parent page stack frame */
3525                parent->bn = bn;
3526        }
3527
3528        /* get leaf page address */
3529        stbl = DT_GETSTBL(p);
3530        xd = (pxd_t *) & p->slot[stbl[pn]];
3531        bn = addressPXD(xd);
3532
3533        /* unpin parent page */
3534        DT_PUTPAGE(mp);
3535
3536        /*
3537         * get target leaf page
3538         */
3539      c:
3540        DT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
3541        if (rc)
3542                return rc;
3543
3544        /*
3545         * leaf page has been completed:
3546         * start with 1st entry of next leaf page
3547         */
3548        if (index >= p->header.nextindex) {
3549                bn = le64_to_cpu(p->header.next);
3550
3551                /* unpin leaf page */
3552                DT_PUTPAGE(mp);
3553
3554                /* offset beyond eof ? */
3555                if (bn == 0) {
3556                        bn = -1;
3557                        goto out;
3558                }
3559
3560                /* get next leaf page */
3561                DT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
3562                if (rc)
3563                        return rc;
3564
3565                /* start with 1st entry of next leaf page */
3566                dtoffset->pn++;
3567                dtoffset->index = 0;
3568        }
3569
3570      out:
3571        /* return target leaf page pinned */
3572        btsp = btstack->top;
3573        btsp->bn = bn;
3574        btsp->index = dtoffset->index;
3575        btsp->mp = mp;
3576
3577        return 0;
3578}
3579
3580
3581/*
3582 *      dtCompare()
3583 *
3584 * function: compare search key with an internal entry
3585 *
3586 * return:
3587 *      < 0 if k is < record
3588 *      = 0 if k is = record
3589 *      > 0 if k is > record
3590 */
3591static int dtCompare(struct component_name * key,       /* search key */
3592                     dtpage_t * p,      /* directory page */
3593                     int si)
3594{                               /* entry slot index */
3595        wchar_t *kname;
3596        __le16 *name;
3597        int klen, namlen, len, rc;
3598        struct idtentry *ih;
3599        struct dtslot *t;
3600
3601        /*
3602         * force the left-most key on internal pages, at any level of
3603         * the tree, to be less than any search key.
3604         * this obviates having to update the leftmost key on an internal
3605         * page when the user inserts a new key in the tree smaller than
3606         * anything that has been stored.
3607         *
3608         * (? if/when dtSearch() narrows down to 1st entry (index = 0),
3609         * at any internal page at any level of the tree,
3610         * it descends to child of the entry anyway -
3611         * ? make the entry as min size dummy entry)
3612         *
3613         * if (e->index == 0 && h->prevpg == P_INVALID && !(h->flags & BT_LEAF))
3614         * return (1);
3615         */
3616
3617        kname = key->name;
3618        klen = key->namlen;
3619
3620        ih = (struct idtentry *) & p->slot[si];
3621        si = ih->next;
3622        name = ih->name;
3623        namlen = ih->namlen;
3624        len = min(namlen, DTIHDRDATALEN);
3625
3626        /* compare with head/only segment */
3627        len = min(klen, len);
3628        if ((rc = UniStrncmp_le(kname, name, len)))
3629                return rc;
3630
3631        klen -= len;
3632        namlen -= len;
3633
3634        /* compare with additional segment(s) */
3635        kname += len;
3636        while (klen > 0 && namlen > 0) {
3637                /* compare with next name segment */
3638                t = (struct dtslot *) & p->slot[si];
3639                len = min(namlen, DTSLOTDATALEN);
3640                len = min(klen, len);
3641                name = t->name;
3642                if ((rc = UniStrncmp_le(kname, name, len)))
3643                        return rc;
3644
3645                klen -= len;
3646                namlen -= len;
3647                kname += len;
3648                si = t->next;
3649        }
3650
3651        return (klen - namlen);
3652}
3653
3654
3655
3656
3657/*
3658 *      ciCompare()
3659 *
3660 * function: compare search key with an (leaf/internal) entry
3661 *
3662 * return:
3663 *      < 0 if k is < record
3664 *      = 0 if k is = record
3665 *      > 0 if k is > record
3666 */
3667static int ciCompare(struct component_name * key,       /* search key */
3668                     dtpage_t * p,      /* directory page */
3669                     int si,    /* entry slot index */
3670                     int flag)
3671{
3672        wchar_t *kname, x;
3673        __le16 *name;
3674        int klen, namlen, len, rc;
3675        struct ldtentry *lh;
3676        struct idtentry *ih;
3677        struct dtslot *t;
3678        int i;
3679
3680        /*
3681         * force the left-most key on internal pages, at any level of
3682         * the tree, to be less than any search key.
3683         * this obviates having to update the leftmost key on an internal
3684         * page when the user inserts a new key in the tree smaller than
3685         * anything that has been stored.
3686         *
3687         * (? if/when dtSearch() narrows down to 1st entry (index = 0),
3688         * at any internal page at any level of the tree,
3689         * it descends to child of the entry anyway -
3690         * ? make the entry as min size dummy entry)
3691         *
3692         * if (e->index == 0 && h->prevpg == P_INVALID && !(h->flags & BT_LEAF))
3693         * return (1);
3694         */
3695
3696        kname = key->name;
3697        klen = key->namlen;
3698
3699        /*
3700         * leaf page entry
3701         */
3702        if (p->header.flag & BT_LEAF) {
3703                lh = (struct ldtentry *) & p->slot[si];
3704                si = lh->next;
3705                name = lh->name;
3706                namlen = lh->namlen;
3707                if (flag & JFS_DIR_INDEX)
3708                        len = min(namlen, DTLHDRDATALEN);
3709                else
3710                        len = min(namlen, DTLHDRDATALEN_LEGACY);
3711        }
3712        /*
3713         * internal page entry
3714         */
3715        else {
3716                ih = (struct idtentry *) & p->slot[si];
3717                si = ih->next;
3718                name = ih->name;
3719                namlen = ih->namlen;
3720                len = min(namlen, DTIHDRDATALEN);
3721        }
3722
3723        /* compare with head/only segment */
3724        len = min(klen, len);
3725        for (i = 0; i < len; i++, kname++, name++) {
3726                /* only uppercase if case-insensitive support is on */
3727                if ((flag & JFS_OS2) == JFS_OS2)
3728                        x = UniToupper(le16_to_cpu(*name));
3729                else
3730                        x = le16_to_cpu(*name);
3731                if ((rc = *kname - x))
3732                        return rc;
3733        }
3734
3735        klen -= len;
3736        namlen -= len;
3737
3738        /* compare with additional segment(s) */
3739        while (klen > 0 && namlen > 0) {
3740                /* compare with next name segment */
3741                t = (struct dtslot *) & p->slot[si];
3742                len = min(namlen, DTSLOTDATALEN);
3743                len = min(klen, len);
3744                name = t->name;
3745                for (i = 0; i < len; i++, kname++, name++) {
3746                        /* only uppercase if case-insensitive support is on */
3747                        if ((flag & JFS_OS2) == JFS_OS2)
3748                                x = UniToupper(le16_to_cpu(*name));
3749                        else
3750                                x = le16_to_cpu(*name);
3751
3752                        if ((rc = *kname - x))
3753                                return rc;
3754                }
3755
3756                klen -= len;
3757                namlen -= len;
3758                si = t->next;
3759        }
3760
3761        return (klen - namlen);
3762}
3763
3764
3765/*
3766 *      ciGetLeafPrefixKey()
3767 *
3768 * function: compute prefix of suffix compression
3769 *           from two adjacent leaf entries
3770 *           across page boundary
3771 *
3772 * return: non-zero on error
3773 *
3774 */
3775static int ciGetLeafPrefixKey(dtpage_t * lp, int li, dtpage_t * rp,
3776                               int ri, struct component_name * key, int flag)
3777{
3778        int klen, namlen;
3779        wchar_t *pl, *pr, *kname;
3780        struct component_name lkey;
3781        struct component_name rkey;
3782
3783        lkey.name = kmalloc_array(JFS_NAME_MAX + 1, sizeof(wchar_t),
3784                                        GFP_KERNEL);
3785        if (lkey.name == NULL)
3786                return -ENOMEM;
3787
3788        rkey.name = kmalloc_array(JFS_NAME_MAX + 1, sizeof(wchar_t),
3789                                        GFP_KERNEL);
3790        if (rkey.name == NULL) {
3791                kfree(lkey.name);
3792                return -ENOMEM;
3793        }
3794
3795        /* get left and right key */
3796        dtGetKey(lp, li, &lkey, flag);
3797        lkey.name[lkey.namlen] = 0;
3798
3799        if ((flag & JFS_OS2) == JFS_OS2)
3800                ciToUpper(&lkey);
3801
3802        dtGetKey(rp, ri, &rkey, flag);
3803        rkey.name[rkey.namlen] = 0;
3804
3805
3806        if ((flag & JFS_OS2) == JFS_OS2)
3807                ciToUpper(&rkey);
3808
3809        /* compute prefix */
3810        klen = 0;
3811        kname = key->name;
3812        namlen = min(lkey.namlen, rkey.namlen);
3813        for (pl = lkey.name, pr = rkey.name;
3814             namlen; pl++, pr++, namlen--, klen++, kname++) {
3815                *kname = *pr;
3816                if (*pl != *pr) {
3817                        key->namlen = klen + 1;
3818                        goto free_names;
3819                }
3820        }
3821
3822        /* l->namlen <= r->namlen since l <= r */
3823        if (lkey.namlen < rkey.namlen) {
3824                *kname = *pr;
3825                key->namlen = klen + 1;
3826        } else                  /* l->namelen == r->namelen */
3827                key->namlen = klen;
3828
3829free_names:
3830        kfree(lkey.name);
3831        kfree(rkey.name);
3832        return 0;
3833}
3834
3835
3836
3837/*
3838 *      dtGetKey()
3839 *
3840 * function: get key of the entry
3841 */
3842static void dtGetKey(dtpage_t * p, int i,       /* entry index */
3843                     struct component_name * key, int flag)
3844{
3845        int si;
3846        s8 *stbl;
3847        struct ldtentry *lh;
3848        struct idtentry *ih;
3849        struct dtslot *t;
3850        int namlen, len;
3851        wchar_t *kname;
3852        __le16 *name;
3853
3854        /* get entry */
3855        stbl = DT_GETSTBL(p);
3856        si = stbl[i];
3857        if (p->header.flag & BT_LEAF) {
3858                lh = (struct ldtentry *) & p->slot[si];
3859                si = lh->next;
3860                namlen = lh->namlen;
3861                name = lh->name;
3862                if (flag & JFS_DIR_INDEX)
3863                        len = min(namlen, DTLHDRDATALEN);
3864                else
3865                        len = min(namlen, DTLHDRDATALEN_LEGACY);
3866        } else {
3867                ih = (struct idtentry *) & p->slot[si];
3868                si = ih->next;
3869                namlen = ih->namlen;
3870                name = ih->name;
3871                len = min(namlen, DTIHDRDATALEN);
3872        }
3873
3874        key->namlen = namlen;
3875        kname = key->name;
3876
3877        /*
3878         * move head/only segment
3879         */
3880        UniStrncpy_from_le(kname, name, len);
3881
3882        /*
3883         * move additional segment(s)
3884         */
3885        while (si >= 0) {
3886                /* get next segment */
3887                t = &p->slot[si];
3888                kname += len;
3889                namlen -= len;
3890                len = min(namlen, DTSLOTDATALEN);
3891                UniStrncpy_from_le(kname, t->name, len);
3892
3893                si = t->next;
3894        }
3895}
3896
3897
3898/*
3899 *      dtInsertEntry()
3900 *
3901 * function: allocate free slot(s) and
3902 *           write a leaf/internal entry
3903 *
3904 * return: entry slot index
3905 */
3906static void dtInsertEntry(dtpage_t * p, int index, struct component_name * key,
3907                          ddata_t * data, struct dt_lock ** dtlock)
3908{
3909        struct dtslot *h, *t;
3910        struct ldtentry *lh = NULL;
3911        struct idtentry *ih = NULL;
3912        int hsi, fsi, klen, len, nextindex;
3913        wchar_t *kname;
3914        __le16 *name;
3915        s8 *stbl;
3916        pxd_t *xd;
3917        struct dt_lock *dtlck = *dtlock;
3918        struct lv *lv;
3919        int xsi, n;
3920        s64 bn = 0;
3921        struct metapage *mp = NULL;
3922
3923        klen = key->namlen;
3924        kname = key->name;
3925
3926        /* allocate a free slot */
3927        hsi = fsi = p->header.freelist;
3928        h = &p->slot[fsi];
3929        p->header.freelist = h->next;
3930        --p->header.freecnt;
3931
3932        /* open new linelock */
3933        if (dtlck->index >= dtlck->maxcnt)
3934                dtlck = (struct dt_lock *) txLinelock(dtlck);
3935
3936        lv = & dtlck->lv[dtlck->index];
3937        lv->offset = hsi;
3938
3939        /* write head/only segment */
3940        if (p->header.flag & BT_LEAF) {
3941                lh = (struct ldtentry *) h;
3942                lh->next = h->next;
3943                lh->inumber = cpu_to_le32(data->leaf.ino);
3944                lh->namlen = klen;
3945                name = lh->name;
3946                if (data->leaf.ip) {
3947                        len = min(klen, DTLHDRDATALEN);
3948                        if (!(p->header.flag & BT_ROOT))
3949                                bn = addressPXD(&p->header.self);
3950                        lh->index = cpu_to_le32(add_index(data->leaf.tid,
3951                                                          data->leaf.ip,
3952                                                          bn, index));
3953                } else
3954                        len = min(klen, DTLHDRDATALEN_LEGACY);
3955        } else {
3956                ih = (struct idtentry *) h;
3957                ih->next = h->next;
3958                xd = (pxd_t *) ih;
3959                *xd = data->xd;
3960                ih->namlen = klen;
3961                name = ih->name;
3962                len = min(klen, DTIHDRDATALEN);
3963        }
3964
3965        UniStrncpy_to_le(name, kname, len);
3966
3967        n = 1;
3968        xsi = hsi;
3969
3970        /* write additional segment(s) */
3971        t = h;
3972        klen -= len;
3973        while (klen) {
3974                /* get free slot */
3975                fsi = p->header.freelist;
3976                t = &p->slot[fsi];
3977                p->header.freelist = t->next;
3978                --p->header.freecnt;
3979
3980                /* is next slot contiguous ? */
3981                if (fsi != xsi + 1) {
3982                        /* close current linelock */
3983                        lv->length = n;
3984                        dtlck->index++;
3985
3986                        /* open new linelock */
3987                        if (dtlck->index < dtlck->maxcnt)
3988                                lv++;
3989                        else {
3990                                dtlck = (struct dt_lock *) txLinelock(dtlck);
3991                                lv = & dtlck->lv[0];
3992                        }
3993
3994                        lv->offset = fsi;
3995                        n = 0;
3996                }
3997
3998                kname += len;
3999                len = min(klen, DTSLOTDATALEN);
4000                UniStrncpy_to_le(t->name, kname, len);
4001
4002                n++;
4003                xsi = fsi;
4004                klen -= len;
4005        }
4006
4007        /* close current linelock */
4008        lv->length = n;
4009        dtlck->index++;
4010
4011        *dtlock = dtlck;
4012
4013        /* terminate last/only segment */
4014        if (h == t) {
4015                /* single segment entry */
4016                if (p->header.flag & BT_LEAF)
4017                        lh->next = -1;
4018                else
4019                        ih->next = -1;
4020        } else
4021                /* multi-segment entry */
4022                t->next = -1;
4023
4024        /* if insert into middle, shift right succeeding entries in stbl */
4025        stbl = DT_GETSTBL(p);
4026        nextindex = p->header.nextindex;
4027        if (index < nextindex) {
4028                memmove(stbl + index + 1, stbl + index, nextindex - index);
4029
4030                if ((p->header.flag & BT_LEAF) && data->leaf.ip) {
4031                        s64 lblock;
4032
4033                        /*
4034                         * Need to update slot number for entries that moved
4035                         * in the stbl
4036                         */
4037                        mp = NULL;
4038                        for (n = index + 1; n <= nextindex; n++) {
4039                                lh = (struct ldtentry *) & (p->slot[stbl[n]]);
4040                                modify_index(data->leaf.tid, data->leaf.ip,
4041                                             le32_to_cpu(lh->index), bn, n,
4042                                             &mp, &lblock);
4043                        }
4044                        if (mp)
4045                                release_metapage(mp);
4046                }
4047        }
4048
4049        stbl[index] = hsi;
4050
4051        /* advance next available entry index of stbl */
4052        ++p->header.nextindex;
4053}
4054
4055
4056/*
4057 *      dtMoveEntry()
4058 *
4059 * function: move entries from split/left page to new/right page
4060 *
4061 *      nextindex of dst page and freelist/freecnt of both pages
4062 *      are updated.
4063 */
4064static void dtMoveEntry(dtpage_t * sp, int si, dtpage_t * dp,
4065                        struct dt_lock ** sdtlock, struct dt_lock ** ddtlock,
4066                        int do_index)
4067{
4068        int ssi, next;          /* src slot index */
4069        int di;                 /* dst entry index */
4070        int dsi;                /* dst slot index */
4071        s8 *sstbl, *dstbl;      /* sorted entry table */
4072        int snamlen, len;
4073        struct ldtentry *slh, *dlh = NULL;
4074        struct idtentry *sih, *dih = NULL;
4075        struct dtslot *h, *s, *d;
4076        struct dt_lock *sdtlck = *sdtlock, *ddtlck = *ddtlock;
4077        struct lv *slv, *dlv;
4078        int xssi, ns, nd;
4079        int sfsi;
4080
4081        sstbl = (s8 *) & sp->slot[sp->header.stblindex];
4082        dstbl = (s8 *) & dp->slot[dp->header.stblindex];
4083
4084        dsi = dp->header.freelist;      /* first (whole page) free slot */
4085        sfsi = sp->header.freelist;
4086
4087        /* linelock destination entry slot */
4088        dlv = & ddtlck->lv[ddtlck->index];
4089        dlv->offset = dsi;
4090
4091        /* linelock source entry slot */
4092        slv = & sdtlck->lv[sdtlck->index];
4093        slv->offset = sstbl[si];
4094        xssi = slv->offset - 1;
4095
4096        /*
4097         * move entries
4098         */
4099        ns = nd = 0;
4100        for (di = 0; si < sp->header.nextindex; si++, di++) {
4101                ssi = sstbl[si];
4102                dstbl[di] = dsi;
4103
4104                /* is next slot contiguous ? */
4105                if (ssi != xssi + 1) {
4106                        /* close current linelock */
4107                        slv->length = ns;
4108                        sdtlck->index++;
4109
4110                        /* open new linelock */
4111                        if (sdtlck->index < sdtlck->maxcnt)
4112                                slv++;
4113                        else {
4114                                sdtlck = (struct dt_lock *) txLinelock(sdtlck);
4115                                slv = & sdtlck->lv[0];
4116                        }
4117
4118                        slv->offset = ssi;
4119                        ns = 0;
4120                }
4121
4122                /*
4123                 * move head/only segment of an entry
4124                 */
4125                /* get dst slot */
4126                h = d = &dp->slot[dsi];
4127
4128                /* get src slot and move */
4129                s = &sp->slot[ssi];
4130                if (sp->header.flag & BT_LEAF) {
4131                        /* get source entry */
4132                        slh = (struct ldtentry *) s;
4133                        dlh = (struct ldtentry *) h;
4134                        snamlen = slh->namlen;
4135
4136                        if (do_index) {
4137                                len = min(snamlen, DTLHDRDATALEN);
4138                                dlh->index = slh->index; /* little-endian */
4139                        } else
4140                                len = min(snamlen, DTLHDRDATALEN_LEGACY);
4141
4142                        memcpy(dlh, slh, 6 + len * 2);
4143
4144                        next = slh->next;
4145
4146                        /* update dst head/only segment next field */
4147                        dsi++;
4148                        dlh->next = dsi;
4149                } else {
4150                        sih = (struct idtentry *) s;
4151                        snamlen = sih->namlen;
4152
4153                        len = min(snamlen, DTIHDRDATALEN);
4154                        dih = (struct idtentry *) h;
4155                        memcpy(dih, sih, 10 + len * 2);
4156                        next = sih->next;
4157
4158                        dsi++;
4159                        dih->next = dsi;
4160                }
4161
4162                /* free src head/only segment */
4163                s->next = sfsi;
4164                s->cnt = 1;
4165                sfsi = ssi;
4166
4167                ns++;
4168                nd++;
4169                xssi = ssi;
4170
4171                /*
4172                 * move additional segment(s) of the entry
4173                 */
4174                snamlen -= len;
4175                while ((ssi = next) >= 0) {
4176                        /* is next slot contiguous ? */
4177                        if (ssi != xssi + 1) {
4178                                /* close current linelock */
4179                                slv->length = ns;
4180                                sdtlck->index++;
4181
4182                                /* open new linelock */
4183                                if (sdtlck->index < sdtlck->maxcnt)
4184                                        slv++;
4185                                else {
4186                                        sdtlck =
4187                                            (struct dt_lock *)
4188                                            txLinelock(sdtlck);
4189                                        slv = & sdtlck->lv[0];
4190                                }
4191
4192                                slv->offset = ssi;
4193                                ns = 0;
4194                        }
4195
4196                        /* get next source segment */
4197                        s = &sp->slot[ssi];
4198
4199                        /* get next destination free slot */
4200                        d++;
4201
4202                        len = min(snamlen, DTSLOTDATALEN);
4203                        UniStrncpy_le(d->name, s->name, len);
4204
4205                        ns++;
4206                        nd++;
4207                        xssi = ssi;
4208
4209                        dsi++;
4210                        d->next = dsi;
4211
4212                        /* free source segment */
4213                        next = s->next;
4214                        s->next = sfsi;
4215                        s->cnt = 1;
4216                        sfsi = ssi;
4217
4218                        snamlen -= len;
4219                }               /* end while */
4220
4221                /* terminate dst last/only segment */
4222                if (h == d) {
4223                        /* single segment entry */
4224                        if (dp->header.flag & BT_LEAF)
4225                                dlh->next = -1;
4226                        else
4227                                dih->next = -1;
4228                } else
4229                        /* multi-segment entry */
4230                        d->next = -1;
4231        }                       /* end for */
4232
4233        /* close current linelock */
4234        slv->length = ns;
4235        sdtlck->index++;
4236        *sdtlock = sdtlck;
4237
4238        dlv->length = nd;
4239        ddtlck->index++;
4240        *ddtlock = ddtlck;
4241
4242        /* update source header */
4243        sp->header.freelist = sfsi;
4244        sp->header.freecnt += nd;
4245
4246        /* update destination header */
4247        dp->header.nextindex = di;
4248
4249        dp->header.freelist = dsi;
4250        dp->header.freecnt -= nd;
4251}
4252
4253
4254/*
4255 *      dtDeleteEntry()
4256 *
4257 * function: free a (leaf/internal) entry
4258 *
4259 * log freelist header, stbl, and each segment slot of entry
4260 * (even though last/only segment next field is modified,
4261 * physical image logging requires all segment slots of
4262 * the entry logged to avoid applying previous updates
4263 * to the same slots)
4264 */
4265static void dtDeleteEntry(dtpage_t * p, int fi, struct dt_lock ** dtlock)
4266{
4267        int fsi;                /* free entry slot index */
4268        s8 *stbl;
4269        struct dtslot *t;
4270        int si, freecnt;
4271        struct dt_lock *dtlck = *dtlock;
4272        struct lv *lv;
4273        int xsi, n;
4274
4275        /* get free entry slot index */
4276        stbl = DT_GETSTBL(p);
4277        fsi = stbl[fi];
4278
4279        /* open new linelock */
4280        if (dtlck->index >= dtlck->maxcnt)
4281                dtlck = (struct dt_lock *) txLinelock(dtlck);
4282        lv = & dtlck->lv[dtlck->index];
4283
4284        lv->offset = fsi;
4285
4286        /* get the head/only segment */
4287        t = &p->slot[fsi];
4288        if (p->header.flag & BT_LEAF)
4289                si = ((struct ldtentry *) t)->next;
4290        else
4291                si = ((struct idtentry *) t)->next;
4292        t->next = si;
4293        t->cnt = 1;
4294
4295        n = freecnt = 1;
4296        xsi = fsi;
4297
4298        /* find the last/only segment */
4299        while (si >= 0) {
4300                /* is next slot contiguous ? */
4301                if (si != xsi + 1) {
4302                        /* close current linelock */
4303                        lv->length = n;
4304                        dtlck->index++;
4305
4306                        /* open new linelock */
4307                        if (dtlck->index < dtlck->maxcnt)
4308                                lv++;
4309                        else {
4310                                dtlck = (struct dt_lock *) txLinelock(dtlck);
4311                                lv = & dtlck->lv[0];
4312                        }
4313
4314                        lv->offset = si;
4315                        n = 0;
4316                }
4317
4318                n++;
4319                xsi = si;
4320                freecnt++;
4321
4322                t = &p->slot[si];
4323                t->cnt = 1;
4324                si = t->next;
4325        }
4326
4327        /* close current linelock */
4328        lv->length = n;
4329        dtlck->index++;
4330
4331        *dtlock = dtlck;
4332
4333        /* update freelist */
4334        t->next = p->header.freelist;
4335        p->header.freelist = fsi;
4336        p->header.freecnt += freecnt;
4337
4338        /* if delete from middle,
4339         * shift left the succedding entries in the stbl
4340         */
4341        si = p->header.nextindex;
4342        if (fi < si - 1)
4343                memmove(&stbl[fi], &stbl[fi + 1], si - fi - 1);
4344
4345        p->header.nextindex--;
4346}
4347
4348
4349/*
4350 *      dtTruncateEntry()
4351 *
4352 * function: truncate a (leaf/internal) entry
4353 *
4354 * log freelist header, stbl, and each segment slot of entry
4355 * (even though last/only segment next field is modified,
4356 * physical image logging requires all segment slots of
4357 * the entry logged to avoid applying previous updates
4358 * to the same slots)
4359 */
4360static void dtTruncateEntry(dtpage_t * p, int ti, struct dt_lock ** dtlock)
4361{
4362        int tsi;                /* truncate entry slot index */
4363        s8 *stbl;
4364        struct dtslot *t;
4365        int si, freecnt;
4366        struct dt_lock *dtlck = *dtlock;
4367        struct lv *lv;
4368        int fsi, xsi, n;
4369
4370        /* get free entry slot index */
4371        stbl = DT_GETSTBL(p);
4372        tsi = stbl[ti];
4373
4374        /* open new linelock */
4375        if (dtlck->index >= dtlck->maxcnt)
4376                dtlck = (struct dt_lock *) txLinelock(dtlck);
4377        lv = & dtlck->lv[dtlck->index];
4378
4379        lv->offset = tsi;
4380
4381        /* get the head/only segment */
4382        t = &p->slot[tsi];
4383        ASSERT(p->header.flag & BT_INTERNAL);
4384        ((struct idtentry *) t)->namlen = 0;
4385        si = ((struct idtentry *) t)->next;
4386        ((struct idtentry *) t)->next = -1;
4387
4388        n = 1;
4389        freecnt = 0;
4390        fsi = si;
4391        xsi = tsi;
4392
4393        /* find the last/only segment */
4394        while (si >= 0) {
4395                /* is next slot contiguous ? */
4396                if (si != xsi + 1) {
4397                        /* close current linelock */
4398                        lv->length = n;
4399                        dtlck->index++;
4400
4401                        /* open new linelock */
4402                        if (dtlck->index < dtlck->maxcnt)
4403                                lv++;
4404                        else {
4405                                dtlck = (struct dt_lock *) txLinelock(dtlck);
4406                                lv = & dtlck->lv[0];
4407                        }
4408
4409                        lv->offset = si;
4410                        n = 0;
4411                }
4412
4413                n++;
4414                xsi = si;
4415                freecnt++;
4416
4417                t = &p->slot[si];
4418                t->cnt = 1;
4419                si = t->next;
4420        }
4421
4422        /* close current linelock */
4423        lv->length = n;
4424        dtlck->index++;
4425
4426        *dtlock = dtlck;
4427
4428        /* update freelist */
4429        if (freecnt == 0)
4430                return;
4431        t->next = p->header.freelist;
4432        p->header.freelist = fsi;
4433        p->header.freecnt += freecnt;
4434}
4435
4436
4437/*
4438 *      dtLinelockFreelist()
4439 */
4440static void dtLinelockFreelist(dtpage_t * p,    /* directory page */
4441                               int m,   /* max slot index */
4442                               struct dt_lock ** dtlock)
4443{
4444        int fsi;                /* free entry slot index */
4445        struct dtslot *t;
4446        int si;
4447        struct dt_lock *dtlck = *dtlock;
4448        struct lv *lv;
4449        int xsi, n;
4450
4451        /* get free entry slot index */
4452        fsi = p->header.freelist;
4453
4454        /* open new linelock */
4455        if (dtlck->index >= dtlck->maxcnt)
4456                dtlck = (struct dt_lock *) txLinelock(dtlck);
4457        lv = & dtlck->lv[dtlck->index];
4458
4459        lv->offset = fsi;
4460
4461        n = 1;
4462        xsi = fsi;
4463
4464        t = &p->slot[fsi];
4465        si = t->next;
4466
4467        /* find the last/only segment */
4468        while (si < m && si >= 0) {
4469                /* is next slot contiguous ? */
4470                if (si != xsi + 1) {
4471                        /* close current linelock */
4472                        lv->length = n;
4473                        dtlck->index++;
4474
4475                        /* open new linelock */
4476                        if (dtlck->index < dtlck->maxcnt)
4477                                lv++;
4478                        else {
4479                                dtlck = (struct dt_lock *) txLinelock(dtlck);
4480                                lv = & dtlck->lv[0];
4481                        }
4482
4483                        lv->offset = si;
4484                        n = 0;
4485                }
4486
4487                n++;
4488                xsi = si;
4489
4490                t = &p->slot[si];
4491                si = t->next;
4492        }
4493
4494        /* close current linelock */
4495        lv->length = n;
4496        dtlck->index++;
4497
4498        *dtlock = dtlck;
4499}
4500
4501
4502/*
4503 * NAME: dtModify
4504 *
4505 * FUNCTION: Modify the inode number part of a directory entry
4506 *
4507 * PARAMETERS:
4508 *      tid     - Transaction id
4509 *      ip      - Inode of parent directory
4510 *      key     - Name of entry to be modified
4511 *      orig_ino        - Original inode number expected in entry
4512 *      new_ino - New inode number to put into entry
4513 *      flag    - JFS_RENAME
4514 *
4515 * RETURNS:
4516 *      -ESTALE - If entry found does not match orig_ino passed in
4517 *      -ENOENT - If no entry can be found to match key
4518 *      0       - If successfully modified entry
4519 */
4520int dtModify(tid_t tid, struct inode *ip,
4521         struct component_name * key, ino_t * orig_ino, ino_t new_ino, int flag)
4522{
4523        int rc;
4524        s64 bn;
4525        struct metapage *mp;
4526        dtpage_t *p;
4527        int index;
4528        struct btstack btstack;
4529        struct tlock *tlck;
4530        struct dt_lock *dtlck;
4531        struct lv *lv;
4532        s8 *stbl;
4533        int entry_si;           /* entry slot index */
4534        struct ldtentry *entry;
4535
4536        /*
4537         *      search for the entry to modify:
4538         *
4539         * dtSearch() returns (leaf page pinned, index at which to modify).
4540         */
4541        if ((rc = dtSearch(ip, key, orig_ino, &btstack, flag)))
4542                return rc;
4543
4544        /* retrieve search result */
4545        DT_GETSEARCH(ip, btstack.top, bn, mp, p, index);
4546
4547        BT_MARK_DIRTY(mp, ip);
4548        /*
4549         * acquire a transaction lock on the leaf page of named entry
4550         */
4551        tlck = txLock(tid, ip, mp, tlckDTREE | tlckENTRY);
4552        dtlck = (struct dt_lock *) & tlck->lock;
4553
4554        /* get slot index of the entry */
4555        stbl = DT_GETSTBL(p);
4556        entry_si = stbl[index];
4557
4558        /* linelock entry */
4559        ASSERT(dtlck->index == 0);
4560        lv = & dtlck->lv[0];
4561        lv->offset = entry_si;
4562        lv->length = 1;
4563        dtlck->index++;
4564
4565        /* get the head/only segment */
4566        entry = (struct ldtentry *) & p->slot[entry_si];
4567
4568        /* substitute the inode number of the entry */
4569        entry->inumber = cpu_to_le32(new_ino);
4570
4571        /* unpin the leaf page */
4572        DT_PUTPAGE(mp);
4573
4574        return 0;
4575}
4576