root/fs/jfs/jfs_dtree.c

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DEFINITIONS

This source file includes following definitions.
  1. read_index_page
  2. get_index_page
  3. find_index
  4. lock_index
  5. add_index
  6. free_index
  7. modify_index
  8. read_index
  9. dtSearch
  10. dtInsert
  11. dtSplitUp
  12. dtSplitPage
  13. dtExtendPage
  14. dtSplitRoot
  15. dtDelete
  16. dtDeleteUp
  17. dtRelocate
  18. dtSearchNode
  19. dtRelink
  20. dtInitRoot
  21. add_missing_indices
  22. next_jfs_dirent
  23. jfs_readdir
  24. dtReadFirst
  25. dtReadNext
  26. dtCompare
  27. ciCompare
  28. ciGetLeafPrefixKey
  29. dtGetKey
  30. dtInsertEntry
  31. dtMoveEntry
  32. dtDeleteEntry
  33. dtTruncateEntry
  34. dtLinelockFreelist
  35. dtModify

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *   Copyright (C) International Business Machines Corp., 2000-2004
   4  */
   5 
   6 /*
   7  *      jfs_dtree.c: directory B+-tree manager
   8  *
   9  * B+-tree with variable length key directory:
  10  *
  11  * each directory page is structured as an array of 32-byte
  12  * directory entry slots initialized as a freelist
  13  * to avoid search/compaction of free space at insertion.
  14  * when an entry is inserted, a number of slots are allocated
  15  * from the freelist as required to store variable length data
  16  * of the entry; when the entry is deleted, slots of the entry
  17  * are returned to freelist.
  18  *
  19  * leaf entry stores full name as key and file serial number
  20  * (aka inode number) as data.
  21  * internal/router entry stores sufffix compressed name
  22  * as key and simple extent descriptor as data.
  23  *
  24  * each directory page maintains a sorted entry index table
  25  * which stores the start slot index of sorted entries
  26  * to allow binary search on the table.
  27  *
  28  * directory starts as a root/leaf page in on-disk inode
  29  * inline data area.
  30  * when it becomes full, it starts a leaf of a external extent
  31  * of length of 1 block. each time the first leaf becomes full,
  32  * it is extended rather than split (its size is doubled),
  33  * until its length becoms 4 KBytes, from then the extent is split
  34  * with new 4 Kbyte extent when it becomes full
  35  * to reduce external fragmentation of small directories.
  36  *
  37  * blah, blah, blah, for linear scan of directory in pieces by
  38  * readdir().
  39  *
  40  *
  41  *      case-insensitive directory file system
  42  *
  43  * names are stored in case-sensitive way in leaf entry.
  44  * but stored, searched and compared in case-insensitive (uppercase) order
  45  * (i.e., both search key and entry key are folded for search/compare):
  46  * (note that case-sensitive order is BROKEN in storage, e.g.,
  47  *  sensitive: Ad, aB, aC, aD -> insensitive: aB, aC, aD, Ad
  48  *
  49  *  entries which folds to the same key makes up a equivalent class
  50  *  whose members are stored as contiguous cluster (may cross page boundary)
  51  *  but whose order is arbitrary and acts as duplicate, e.g.,
  52  *  abc, Abc, aBc, abC)
  53  *
  54  * once match is found at leaf, requires scan forward/backward
  55  * either for, in case-insensitive search, duplicate
  56  * or for, in case-sensitive search, for exact match
  57  *
  58  * router entry must be created/stored in case-insensitive way
  59  * in internal entry:
  60  * (right most key of left page and left most key of right page
  61  * are folded, and its suffix compression is propagated as router
  62  * key in parent)
  63  * (e.g., if split occurs <abc> and <aBd>, <ABD> trather than <aB>
  64  * should be made the router key for the split)
  65  *
  66  * case-insensitive search:
  67  *
  68  *      fold search key;
  69  *
  70  *      case-insensitive search of B-tree:
  71  *      for internal entry, router key is already folded;
  72  *      for leaf entry, fold the entry key before comparison.
  73  *
  74  *      if (leaf entry case-insensitive match found)
  75  *              if (next entry satisfies case-insensitive match)
  76  *                      return EDUPLICATE;
  77  *              if (prev entry satisfies case-insensitive match)
  78  *                      return EDUPLICATE;
  79  *              return match;
  80  *      else
  81  *              return no match;
  82  *
  83  *      serialization:
  84  * target directory inode lock is being held on entry/exit
  85  * of all main directory service routines.
  86  *
  87  *      log based recovery:
  88  */
  89 
  90 #include <linux/fs.h>
  91 #include <linux/quotaops.h>
  92 #include <linux/slab.h>
  93 #include "jfs_incore.h"
  94 #include "jfs_superblock.h"
  95 #include "jfs_filsys.h"
  96 #include "jfs_metapage.h"
  97 #include "jfs_dmap.h"
  98 #include "jfs_unicode.h"
  99 #include "jfs_debug.h"
 100 
 101 /* dtree split parameter */
 102 struct dtsplit {
 103         struct metapage *mp;
 104         s16 index;
 105         s16 nslot;
 106         struct component_name *key;
 107         ddata_t *data;
 108         struct pxdlist *pxdlist;
 109 };
 110 
 111 #define DT_PAGE(IP, MP) BT_PAGE(IP, MP, dtpage_t, i_dtroot)
 112 
 113 /* get page buffer for specified block address */
 114 #define DT_GETPAGE(IP, BN, MP, SIZE, P, RC)                             \
 115 do {                                                                    \
 116         BT_GETPAGE(IP, BN, MP, dtpage_t, SIZE, P, RC, i_dtroot);        \
 117         if (!(RC)) {                                                    \
 118                 if (((P)->header.nextindex >                            \
 119                      (((BN) == 0) ? DTROOTMAXSLOT : (P)->header.maxslot)) || \
 120                     ((BN) && ((P)->header.maxslot > DTPAGEMAXSLOT))) {  \
 121                         BT_PUTPAGE(MP);                                 \
 122                         jfs_error((IP)->i_sb,                           \
 123                                   "DT_GETPAGE: dtree page corrupt\n");  \
 124                         MP = NULL;                                      \
 125                         RC = -EIO;                                      \
 126                 }                                                       \
 127         }                                                               \
 128 } while (0)
 129 
 130 /* for consistency */
 131 #define DT_PUTPAGE(MP) BT_PUTPAGE(MP)
 132 
 133 #define DT_GETSEARCH(IP, LEAF, BN, MP, P, INDEX) \
 134         BT_GETSEARCH(IP, LEAF, BN, MP, dtpage_t, P, INDEX, i_dtroot)
 135 
 136 /*
 137  * forward references
 138  */
 139 static int dtSplitUp(tid_t tid, struct inode *ip,
 140                      struct dtsplit * split, struct btstack * btstack);
 141 
 142 static int dtSplitPage(tid_t tid, struct inode *ip, struct dtsplit * split,
 143                        struct metapage ** rmpp, dtpage_t ** rpp, pxd_t * rxdp);
 144 
 145 static int dtExtendPage(tid_t tid, struct inode *ip,
 146                         struct dtsplit * split, struct btstack * btstack);
 147 
 148 static int dtSplitRoot(tid_t tid, struct inode *ip,
 149                        struct dtsplit * split, struct metapage ** rmpp);
 150 
 151 static int dtDeleteUp(tid_t tid, struct inode *ip, struct metapage * fmp,
 152                       dtpage_t * fp, struct btstack * btstack);
 153 
 154 static int dtRelink(tid_t tid, struct inode *ip, dtpage_t * p);
 155 
 156 static int dtReadFirst(struct inode *ip, struct btstack * btstack);
 157 
 158 static int dtReadNext(struct inode *ip,
 159                       loff_t * offset, struct btstack * btstack);
 160 
 161 static int dtCompare(struct component_name * key, dtpage_t * p, int si);
 162 
 163 static int ciCompare(struct component_name * key, dtpage_t * p, int si,
 164                      int flag);
 165 
 166 static void dtGetKey(dtpage_t * p, int i, struct component_name * key,
 167                      int flag);
 168 
 169 static int ciGetLeafPrefixKey(dtpage_t * lp, int li, dtpage_t * rp,
 170                               int ri, struct component_name * key, int flag);
 171 
 172 static void dtInsertEntry(dtpage_t * p, int index, struct component_name * key,
 173                           ddata_t * data, struct dt_lock **);
 174 
 175 static void dtMoveEntry(dtpage_t * sp, int si, dtpage_t * dp,
 176                         struct dt_lock ** sdtlock, struct dt_lock ** ddtlock,
 177                         int do_index);
 178 
 179 static void dtDeleteEntry(dtpage_t * p, int fi, struct dt_lock ** dtlock);
 180 
 181 static void dtTruncateEntry(dtpage_t * p, int ti, struct dt_lock ** dtlock);
 182 
 183 static void dtLinelockFreelist(dtpage_t * p, int m, struct dt_lock ** dtlock);
 184 
 185 #define ciToUpper(c)    UniStrupr((c)->name)
 186 
 187 /*
 188  *      read_index_page()
 189  *
 190  *      Reads a page of a directory's index table.
 191  *      Having metadata mapped into the directory inode's address space
 192  *      presents a multitude of problems.  We avoid this by mapping to
 193  *      the absolute address space outside of the *_metapage routines
 194  */
 195 static struct metapage *read_index_page(struct inode *inode, s64 blkno)
 196 {
 197         int rc;
 198         s64 xaddr;
 199         int xflag;
 200         s32 xlen;
 201 
 202         rc = xtLookup(inode, blkno, 1, &xflag, &xaddr, &xlen, 1);
 203         if (rc || (xaddr == 0))
 204                 return NULL;
 205 
 206         return read_metapage(inode, xaddr, PSIZE, 1);
 207 }
 208 
 209 /*
 210  *      get_index_page()
 211  *
 212  *      Same as get_index_page(), but get's a new page without reading
 213  */
 214 static struct metapage *get_index_page(struct inode *inode, s64 blkno)
 215 {
 216         int rc;
 217         s64 xaddr;
 218         int xflag;
 219         s32 xlen;
 220 
 221         rc = xtLookup(inode, blkno, 1, &xflag, &xaddr, &xlen, 1);
 222         if (rc || (xaddr == 0))
 223                 return NULL;
 224 
 225         return get_metapage(inode, xaddr, PSIZE, 1);
 226 }
 227 
 228 /*
 229  *      find_index()
 230  *
 231  *      Returns dtree page containing directory table entry for specified
 232  *      index and pointer to its entry.
 233  *
 234  *      mp must be released by caller.
 235  */
 236 static struct dir_table_slot *find_index(struct inode *ip, u32 index,
 237                                          struct metapage ** mp, s64 *lblock)
 238 {
 239         struct jfs_inode_info *jfs_ip = JFS_IP(ip);
 240         s64 blkno;
 241         s64 offset;
 242         int page_offset;
 243         struct dir_table_slot *slot;
 244         static int maxWarnings = 10;
 245 
 246         if (index < 2) {
 247                 if (maxWarnings) {
 248                         jfs_warn("find_entry called with index = %d", index);
 249                         maxWarnings--;
 250                 }
 251                 return NULL;
 252         }
 253 
 254         if (index >= jfs_ip->next_index) {
 255                 jfs_warn("find_entry called with index >= next_index");
 256                 return NULL;
 257         }
 258 
 259         if (jfs_dirtable_inline(ip)) {
 260                 /*
 261                  * Inline directory table
 262                  */
 263                 *mp = NULL;
 264                 slot = &jfs_ip->i_dirtable[index - 2];
 265         } else {
 266                 offset = (index - 2) * sizeof(struct dir_table_slot);
 267                 page_offset = offset & (PSIZE - 1);
 268                 blkno = ((offset + 1) >> L2PSIZE) <<
 269                     JFS_SBI(ip->i_sb)->l2nbperpage;
 270 
 271                 if (*mp && (*lblock != blkno)) {
 272                         release_metapage(*mp);
 273                         *mp = NULL;
 274                 }
 275                 if (!(*mp)) {
 276                         *lblock = blkno;
 277                         *mp = read_index_page(ip, blkno);
 278                 }
 279                 if (!(*mp)) {
 280                         jfs_err("free_index: error reading directory table");
 281                         return NULL;
 282                 }
 283 
 284                 slot =
 285                     (struct dir_table_slot *) ((char *) (*mp)->data +
 286                                                page_offset);
 287         }
 288         return slot;
 289 }
 290 
 291 static inline void lock_index(tid_t tid, struct inode *ip, struct metapage * mp,
 292                               u32 index)
 293 {
 294         struct tlock *tlck;
 295         struct linelock *llck;
 296         struct lv *lv;
 297 
 298         tlck = txLock(tid, ip, mp, tlckDATA);
 299         llck = (struct linelock *) tlck->lock;
 300 
 301         if (llck->index >= llck->maxcnt)
 302                 llck = txLinelock(llck);
 303         lv = &llck->lv[llck->index];
 304 
 305         /*
 306          *      Linelock slot size is twice the size of directory table
 307          *      slot size.  512 entries per page.
 308          */
 309         lv->offset = ((index - 2) & 511) >> 1;
 310         lv->length = 1;
 311         llck->index++;
 312 }
 313 
 314 /*
 315  *      add_index()
 316  *
 317  *      Adds an entry to the directory index table.  This is used to provide
 318  *      each directory entry with a persistent index in which to resume
 319  *      directory traversals
 320  */
 321 static u32 add_index(tid_t tid, struct inode *ip, s64 bn, int slot)
 322 {
 323         struct super_block *sb = ip->i_sb;
 324         struct jfs_sb_info *sbi = JFS_SBI(sb);
 325         struct jfs_inode_info *jfs_ip = JFS_IP(ip);
 326         u64 blkno;
 327         struct dir_table_slot *dirtab_slot;
 328         u32 index;
 329         struct linelock *llck;
 330         struct lv *lv;
 331         struct metapage *mp;
 332         s64 offset;
 333         uint page_offset;
 334         struct tlock *tlck;
 335         s64 xaddr;
 336 
 337         ASSERT(DO_INDEX(ip));
 338 
 339         if (jfs_ip->next_index < 2) {
 340                 jfs_warn("add_index: next_index = %d.  Resetting!",
 341                            jfs_ip->next_index);
 342                 jfs_ip->next_index = 2;
 343         }
 344 
 345         index = jfs_ip->next_index++;
 346 
 347         if (index <= MAX_INLINE_DIRTABLE_ENTRY) {
 348                 /*
 349                  * i_size reflects size of index table, or 8 bytes per entry.
 350                  */
 351                 ip->i_size = (loff_t) (index - 1) << 3;
 352 
 353                 /*
 354                  * dir table fits inline within inode
 355                  */
 356                 dirtab_slot = &jfs_ip->i_dirtable[index-2];
 357                 dirtab_slot->flag = DIR_INDEX_VALID;
 358                 dirtab_slot->slot = slot;
 359                 DTSaddress(dirtab_slot, bn);
 360 
 361                 set_cflag(COMMIT_Dirtable, ip);
 362 
 363                 return index;
 364         }
 365         if (index == (MAX_INLINE_DIRTABLE_ENTRY + 1)) {
 366                 struct dir_table_slot temp_table[12];
 367 
 368                 /*
 369                  * It's time to move the inline table to an external
 370                  * page and begin to build the xtree
 371                  */
 372                 if (dquot_alloc_block(ip, sbi->nbperpage))
 373                         goto clean_up;
 374                 if (dbAlloc(ip, 0, sbi->nbperpage, &xaddr)) {
 375                         dquot_free_block(ip, sbi->nbperpage);
 376                         goto clean_up;
 377                 }
 378 
 379                 /*
 380                  * Save the table, we're going to overwrite it with the
 381                  * xtree root
 382                  */
 383                 memcpy(temp_table, &jfs_ip->i_dirtable, sizeof(temp_table));
 384 
 385                 /*
 386                  * Initialize empty x-tree
 387                  */
 388                 xtInitRoot(tid, ip);
 389 
 390                 /*
 391                  * Add the first block to the xtree
 392                  */
 393                 if (xtInsert(tid, ip, 0, 0, sbi->nbperpage, &xaddr, 0)) {
 394                         /* This really shouldn't fail */
 395                         jfs_warn("add_index: xtInsert failed!");
 396                         memcpy(&jfs_ip->i_dirtable, temp_table,
 397                                sizeof (temp_table));
 398                         dbFree(ip, xaddr, sbi->nbperpage);
 399                         dquot_free_block(ip, sbi->nbperpage);
 400                         goto clean_up;
 401                 }
 402                 ip->i_size = PSIZE;
 403 
 404                 mp = get_index_page(ip, 0);
 405                 if (!mp) {
 406                         jfs_err("add_index: get_metapage failed!");
 407                         xtTruncate(tid, ip, 0, COMMIT_PWMAP);
 408                         memcpy(&jfs_ip->i_dirtable, temp_table,
 409                                sizeof (temp_table));
 410                         goto clean_up;
 411                 }
 412                 tlck = txLock(tid, ip, mp, tlckDATA);
 413                 llck = (struct linelock *) & tlck->lock;
 414                 ASSERT(llck->index == 0);
 415                 lv = &llck->lv[0];
 416 
 417                 lv->offset = 0;
 418                 lv->length = 6; /* tlckDATA slot size is 16 bytes */
 419                 llck->index++;
 420 
 421                 memcpy(mp->data, temp_table, sizeof(temp_table));
 422 
 423                 mark_metapage_dirty(mp);
 424                 release_metapage(mp);
 425 
 426                 /*
 427                  * Logging is now directed by xtree tlocks
 428                  */
 429                 clear_cflag(COMMIT_Dirtable, ip);
 430         }
 431 
 432         offset = (index - 2) * sizeof(struct dir_table_slot);
 433         page_offset = offset & (PSIZE - 1);
 434         blkno = ((offset + 1) >> L2PSIZE) << sbi->l2nbperpage;
 435         if (page_offset == 0) {
 436                 /*
 437                  * This will be the beginning of a new page
 438                  */
 439                 xaddr = 0;
 440                 if (xtInsert(tid, ip, 0, blkno, sbi->nbperpage, &xaddr, 0)) {
 441                         jfs_warn("add_index: xtInsert failed!");
 442                         goto clean_up;
 443                 }
 444                 ip->i_size += PSIZE;
 445 
 446                 if ((mp = get_index_page(ip, blkno)))
 447                         memset(mp->data, 0, PSIZE);     /* Just looks better */
 448                 else
 449                         xtTruncate(tid, ip, offset, COMMIT_PWMAP);
 450         } else
 451                 mp = read_index_page(ip, blkno);
 452 
 453         if (!mp) {
 454                 jfs_err("add_index: get/read_metapage failed!");
 455                 goto clean_up;
 456         }
 457 
 458         lock_index(tid, ip, mp, index);
 459 
 460         dirtab_slot =
 461             (struct dir_table_slot *) ((char *) mp->data + page_offset);
 462         dirtab_slot->flag = DIR_INDEX_VALID;
 463         dirtab_slot->slot = slot;
 464         DTSaddress(dirtab_slot, bn);
 465 
 466         mark_metapage_dirty(mp);
 467         release_metapage(mp);
 468 
 469         return index;
 470 
 471       clean_up:
 472 
 473         jfs_ip->next_index--;
 474 
 475         return 0;
 476 }
 477 
 478 /*
 479  *      free_index()
 480  *
 481  *      Marks an entry to the directory index table as free.
 482  */
 483 static void free_index(tid_t tid, struct inode *ip, u32 index, u32 next)
 484 {
 485         struct dir_table_slot *dirtab_slot;
 486         s64 lblock;
 487         struct metapage *mp = NULL;
 488 
 489         dirtab_slot = find_index(ip, index, &mp, &lblock);
 490 
 491         if (!dirtab_slot)
 492                 return;
 493 
 494         dirtab_slot->flag = DIR_INDEX_FREE;
 495         dirtab_slot->slot = dirtab_slot->addr1 = 0;
 496         dirtab_slot->addr2 = cpu_to_le32(next);
 497 
 498         if (mp) {
 499                 lock_index(tid, ip, mp, index);
 500                 mark_metapage_dirty(mp);
 501                 release_metapage(mp);
 502         } else
 503                 set_cflag(COMMIT_Dirtable, ip);
 504 }
 505 
 506 /*
 507  *      modify_index()
 508  *
 509  *      Changes an entry in the directory index table
 510  */
 511 static void modify_index(tid_t tid, struct inode *ip, u32 index, s64 bn,
 512                          int slot, struct metapage ** mp, s64 *lblock)
 513 {
 514         struct dir_table_slot *dirtab_slot;
 515 
 516         dirtab_slot = find_index(ip, index, mp, lblock);
 517 
 518         if (!dirtab_slot)
 519                 return;
 520 
 521         DTSaddress(dirtab_slot, bn);
 522         dirtab_slot->slot = slot;
 523 
 524         if (*mp) {
 525                 lock_index(tid, ip, *mp, index);
 526                 mark_metapage_dirty(*mp);
 527         } else
 528                 set_cflag(COMMIT_Dirtable, ip);
 529 }
 530 
 531 /*
 532  *      read_index()
 533  *
 534  *      reads a directory table slot
 535  */
 536 static int read_index(struct inode *ip, u32 index,
 537                      struct dir_table_slot * dirtab_slot)
 538 {
 539         s64 lblock;
 540         struct metapage *mp = NULL;
 541         struct dir_table_slot *slot;
 542 
 543         slot = find_index(ip, index, &mp, &lblock);
 544         if (!slot) {
 545                 return -EIO;
 546         }
 547 
 548         memcpy(dirtab_slot, slot, sizeof(struct dir_table_slot));
 549 
 550         if (mp)
 551                 release_metapage(mp);
 552 
 553         return 0;
 554 }
 555 
 556 /*
 557  *      dtSearch()
 558  *
 559  * function:
 560  *      Search for the entry with specified key
 561  *
 562  * parameter:
 563  *
 564  * return: 0 - search result on stack, leaf page pinned;
 565  *         errno - I/O error
 566  */
 567 int dtSearch(struct inode *ip, struct component_name * key, ino_t * data,
 568              struct btstack * btstack, int flag)
 569 {
 570         int rc = 0;
 571         int cmp = 1;            /* init for empty page */
 572         s64 bn;
 573         struct metapage *mp;
 574         dtpage_t *p;
 575         s8 *stbl;
 576         int base, index, lim;
 577         struct btframe *btsp;
 578         pxd_t *pxd;
 579         int psize = 288;        /* initial in-line directory */
 580         ino_t inumber;
 581         struct component_name ciKey;
 582         struct super_block *sb = ip->i_sb;
 583 
 584         ciKey.name = kmalloc_array(JFS_NAME_MAX + 1, sizeof(wchar_t),
 585                                    GFP_NOFS);
 586         if (!ciKey.name) {
 587                 rc = -ENOMEM;
 588                 goto dtSearch_Exit2;
 589         }
 590 
 591 
 592         /* uppercase search key for c-i directory */
 593         UniStrcpy(ciKey.name, key->name);
 594         ciKey.namlen = key->namlen;
 595 
 596         /* only uppercase if case-insensitive support is on */
 597         if ((JFS_SBI(sb)->mntflag & JFS_OS2) == JFS_OS2) {
 598                 ciToUpper(&ciKey);
 599         }
 600         BT_CLR(btstack);        /* reset stack */
 601 
 602         /* init level count for max pages to split */
 603         btstack->nsplit = 1;
 604 
 605         /*
 606          *      search down tree from root:
 607          *
 608          * between two consecutive entries of <Ki, Pi> and <Kj, Pj> of
 609          * internal page, child page Pi contains entry with k, Ki <= K < Kj.
 610          *
 611          * if entry with search key K is not found
 612          * internal page search find the entry with largest key Ki
 613          * less than K which point to the child page to search;
 614          * leaf page search find the entry with smallest key Kj
 615          * greater than K so that the returned index is the position of
 616          * the entry to be shifted right for insertion of new entry.
 617          * for empty tree, search key is greater than any key of the tree.
 618          *
 619          * by convention, root bn = 0.
 620          */
 621         for (bn = 0;;) {
 622                 /* get/pin the page to search */
 623                 DT_GETPAGE(ip, bn, mp, psize, p, rc);
 624                 if (rc)
 625                         goto dtSearch_Exit1;
 626 
 627                 /* get sorted entry table of the page */
 628                 stbl = DT_GETSTBL(p);
 629 
 630                 /*
 631                  * binary search with search key K on the current page.
 632                  */
 633                 for (base = 0, lim = p->header.nextindex; lim; lim >>= 1) {
 634                         index = base + (lim >> 1);
 635 
 636                         if (p->header.flag & BT_LEAF) {
 637                                 /* uppercase leaf name to compare */
 638                                 cmp =
 639                                     ciCompare(&ciKey, p, stbl[index],
 640                                               JFS_SBI(sb)->mntflag);
 641                         } else {
 642                                 /* router key is in uppercase */
 643 
 644                                 cmp = dtCompare(&ciKey, p, stbl[index]);
 645 
 646 
 647                         }
 648                         if (cmp == 0) {
 649                                 /*
 650                                  *      search hit
 651                                  */
 652                                 /* search hit - leaf page:
 653                                  * return the entry found
 654                                  */
 655                                 if (p->header.flag & BT_LEAF) {
 656                                         inumber = le32_to_cpu(
 657                         ((struct ldtentry *) & p->slot[stbl[index]])->inumber);
 658 
 659                                         /*
 660                                          * search for JFS_LOOKUP
 661                                          */
 662                                         if (flag == JFS_LOOKUP) {
 663                                                 *data = inumber;
 664                                                 rc = 0;
 665                                                 goto out;
 666                                         }
 667 
 668                                         /*
 669                                          * search for JFS_CREATE
 670                                          */
 671                                         if (flag == JFS_CREATE) {
 672                                                 *data = inumber;
 673                                                 rc = -EEXIST;
 674                                                 goto out;
 675                                         }
 676 
 677                                         /*
 678                                          * search for JFS_REMOVE or JFS_RENAME
 679                                          */
 680                                         if ((flag == JFS_REMOVE ||
 681                                              flag == JFS_RENAME) &&
 682                                             *data != inumber) {
 683                                                 rc = -ESTALE;
 684                                                 goto out;
 685                                         }
 686 
 687                                         /*
 688                                          * JFS_REMOVE|JFS_FINDDIR|JFS_RENAME
 689                                          */
 690                                         /* save search result */
 691                                         *data = inumber;
 692                                         btsp = btstack->top;
 693                                         btsp->bn = bn;
 694                                         btsp->index = index;
 695                                         btsp->mp = mp;
 696 
 697                                         rc = 0;
 698                                         goto dtSearch_Exit1;
 699                                 }
 700 
 701                                 /* search hit - internal page:
 702                                  * descend/search its child page
 703                                  */
 704                                 goto getChild;
 705                         }
 706 
 707                         if (cmp > 0) {
 708                                 base = index + 1;
 709                                 --lim;
 710                         }
 711                 }
 712 
 713                 /*
 714                  *      search miss
 715                  *
 716                  * base is the smallest index with key (Kj) greater than
 717                  * search key (K) and may be zero or (maxindex + 1) index.
 718                  */
 719                 /*
 720                  * search miss - leaf page
 721                  *
 722                  * return location of entry (base) where new entry with
 723                  * search key K is to be inserted.
 724                  */
 725                 if (p->header.flag & BT_LEAF) {
 726                         /*
 727                          * search for JFS_LOOKUP, JFS_REMOVE, or JFS_RENAME
 728                          */
 729                         if (flag == JFS_LOOKUP || flag == JFS_REMOVE ||
 730                             flag == JFS_RENAME) {
 731                                 rc = -ENOENT;
 732                                 goto out;
 733                         }
 734 
 735                         /*
 736                          * search for JFS_CREATE|JFS_FINDDIR:
 737                          *
 738                          * save search result
 739                          */
 740                         *data = 0;
 741                         btsp = btstack->top;
 742                         btsp->bn = bn;
 743                         btsp->index = base;
 744                         btsp->mp = mp;
 745 
 746                         rc = 0;
 747                         goto dtSearch_Exit1;
 748                 }
 749 
 750                 /*
 751                  * search miss - internal page
 752                  *
 753                  * if base is non-zero, decrement base by one to get the parent
 754                  * entry of the child page to search.
 755                  */
 756                 index = base ? base - 1 : base;
 757 
 758                 /*
 759                  * go down to child page
 760                  */
 761               getChild:
 762                 /* update max. number of pages to split */
 763                 if (BT_STACK_FULL(btstack)) {
 764                         /* Something's corrupted, mark filesystem dirty so
 765                          * chkdsk will fix it.
 766                          */
 767                         jfs_error(sb, "stack overrun!\n");
 768                         BT_STACK_DUMP(btstack);
 769                         rc = -EIO;
 770                         goto out;
 771                 }
 772                 btstack->nsplit++;
 773 
 774                 /* push (bn, index) of the parent page/entry */
 775                 BT_PUSH(btstack, bn, index);
 776 
 777                 /* get the child page block number */
 778                 pxd = (pxd_t *) & p->slot[stbl[index]];
 779                 bn = addressPXD(pxd);
 780                 psize = lengthPXD(pxd) << JFS_SBI(ip->i_sb)->l2bsize;
 781 
 782                 /* unpin the parent page */
 783                 DT_PUTPAGE(mp);
 784         }
 785 
 786       out:
 787         DT_PUTPAGE(mp);
 788 
 789       dtSearch_Exit1:
 790 
 791         kfree(ciKey.name);
 792 
 793       dtSearch_Exit2:
 794 
 795         return rc;
 796 }
 797 
 798 
 799 /*
 800  *      dtInsert()
 801  *
 802  * function: insert an entry to directory tree
 803  *
 804  * parameter:
 805  *
 806  * return: 0 - success;
 807  *         errno - failure;
 808  */
 809 int dtInsert(tid_t tid, struct inode *ip,
 810          struct component_name * name, ino_t * fsn, struct btstack * btstack)
 811 {
 812         int rc = 0;
 813         struct metapage *mp;    /* meta-page buffer */
 814         dtpage_t *p;            /* base B+-tree index page */
 815         s64 bn;
 816         int index;
 817         struct dtsplit split;   /* split information */
 818         ddata_t data;
 819         struct dt_lock *dtlck;
 820         int n;
 821         struct tlock *tlck;
 822         struct lv *lv;
 823 
 824         /*
 825          *      retrieve search result
 826          *
 827          * dtSearch() returns (leaf page pinned, index at which to insert).
 828          * n.b. dtSearch() may return index of (maxindex + 1) of
 829          * the full page.
 830          */
 831         DT_GETSEARCH(ip, btstack->top, bn, mp, p, index);
 832 
 833         /*
 834          *      insert entry for new key
 835          */
 836         if (DO_INDEX(ip)) {
 837                 if (JFS_IP(ip)->next_index == DIREND) {
 838                         DT_PUTPAGE(mp);
 839                         return -EMLINK;
 840                 }
 841                 n = NDTLEAF(name->namlen);
 842                 data.leaf.tid = tid;
 843                 data.leaf.ip = ip;
 844         } else {
 845                 n = NDTLEAF_LEGACY(name->namlen);
 846                 data.leaf.ip = NULL;    /* signifies legacy directory format */
 847         }
 848         data.leaf.ino = *fsn;
 849 
 850         /*
 851          *      leaf page does not have enough room for new entry:
 852          *
 853          *      extend/split the leaf page;
 854          *
 855          * dtSplitUp() will insert the entry and unpin the leaf page.
 856          */
 857         if (n > p->header.freecnt) {
 858                 split.mp = mp;
 859                 split.index = index;
 860                 split.nslot = n;
 861                 split.key = name;
 862                 split.data = &data;
 863                 rc = dtSplitUp(tid, ip, &split, btstack);
 864                 return rc;
 865         }
 866 
 867         /*
 868          *      leaf page does have enough room for new entry:
 869          *
 870          *      insert the new data entry into the leaf page;
 871          */
 872         BT_MARK_DIRTY(mp, ip);
 873         /*
 874          * acquire a transaction lock on the leaf page
 875          */
 876         tlck = txLock(tid, ip, mp, tlckDTREE | tlckENTRY);
 877         dtlck = (struct dt_lock *) & tlck->lock;
 878         ASSERT(dtlck->index == 0);
 879         lv = & dtlck->lv[0];
 880 
 881         /* linelock header */
 882         lv->offset = 0;
 883         lv->length = 1;
 884         dtlck->index++;
 885 
 886         dtInsertEntry(p, index, name, &data, &dtlck);
 887 
 888         /* linelock stbl of non-root leaf page */
 889         if (!(p->header.flag & BT_ROOT)) {
 890                 if (dtlck->index >= dtlck->maxcnt)
 891                         dtlck = (struct dt_lock *) txLinelock(dtlck);
 892                 lv = & dtlck->lv[dtlck->index];
 893                 n = index >> L2DTSLOTSIZE;
 894                 lv->offset = p->header.stblindex + n;
 895                 lv->length =
 896                     ((p->header.nextindex - 1) >> L2DTSLOTSIZE) - n + 1;
 897                 dtlck->index++;
 898         }
 899 
 900         /* unpin the leaf page */
 901         DT_PUTPAGE(mp);
 902 
 903         return 0;
 904 }
 905 
 906 
 907 /*
 908  *      dtSplitUp()
 909  *
 910  * function: propagate insertion bottom up;
 911  *
 912  * parameter:
 913  *
 914  * return: 0 - success;
 915  *         errno - failure;
 916  *      leaf page unpinned;
 917  */
 918 static int dtSplitUp(tid_t tid,
 919           struct inode *ip, struct dtsplit * split, struct btstack * btstack)
 920 {
 921         struct jfs_sb_info *sbi = JFS_SBI(ip->i_sb);
 922         int rc = 0;
 923         struct metapage *smp;
 924         dtpage_t *sp;           /* split page */
 925         struct metapage *rmp;
 926         dtpage_t *rp;           /* new right page split from sp */
 927         pxd_t rpxd;             /* new right page extent descriptor */
 928         struct metapage *lmp;
 929         dtpage_t *lp;           /* left child page */
 930         int skip;               /* index of entry of insertion */
 931         struct btframe *parent; /* parent page entry on traverse stack */
 932         s64 xaddr, nxaddr;
 933         int xlen, xsize;
 934         struct pxdlist pxdlist;
 935         pxd_t *pxd;
 936         struct component_name key = { 0, NULL };
 937         ddata_t *data = split->data;
 938         int n;
 939         struct dt_lock *dtlck;
 940         struct tlock *tlck;
 941         struct lv *lv;
 942         int quota_allocation = 0;
 943 
 944         /* get split page */
 945         smp = split->mp;
 946         sp = DT_PAGE(ip, smp);
 947 
 948         key.name = kmalloc_array(JFS_NAME_MAX + 2, sizeof(wchar_t), GFP_NOFS);
 949         if (!key.name) {
 950                 DT_PUTPAGE(smp);
 951                 rc = -ENOMEM;
 952                 goto dtSplitUp_Exit;
 953         }
 954 
 955         /*
 956          *      split leaf page
 957          *
 958          * The split routines insert the new entry, and
 959          * acquire txLock as appropriate.
 960          */
 961         /*
 962          *      split root leaf page:
 963          */
 964         if (sp->header.flag & BT_ROOT) {
 965                 /*
 966                  * allocate a single extent child page
 967                  */
 968                 xlen = 1;
 969                 n = sbi->bsize >> L2DTSLOTSIZE;
 970                 n -= (n + 31) >> L2DTSLOTSIZE;  /* stbl size */
 971                 n -= DTROOTMAXSLOT - sp->header.freecnt; /* header + entries */
 972                 if (n <= split->nslot)
 973                         xlen++;
 974                 if ((rc = dbAlloc(ip, 0, (s64) xlen, &xaddr))) {
 975                         DT_PUTPAGE(smp);
 976                         goto freeKeyName;
 977                 }
 978 
 979                 pxdlist.maxnpxd = 1;
 980                 pxdlist.npxd = 0;
 981                 pxd = &pxdlist.pxd[0];
 982                 PXDaddress(pxd, xaddr);
 983                 PXDlength(pxd, xlen);
 984                 split->pxdlist = &pxdlist;
 985                 rc = dtSplitRoot(tid, ip, split, &rmp);
 986 
 987                 if (rc)
 988                         dbFree(ip, xaddr, xlen);
 989                 else
 990                         DT_PUTPAGE(rmp);
 991 
 992                 DT_PUTPAGE(smp);
 993 
 994                 if (!DO_INDEX(ip))
 995                         ip->i_size = xlen << sbi->l2bsize;
 996 
 997                 goto freeKeyName;
 998         }
 999 
1000         /*
1001          *      extend first leaf page
1002          *
1003          * extend the 1st extent if less than buffer page size
1004          * (dtExtendPage() reurns leaf page unpinned)
1005          */
1006         pxd = &sp->header.self;
1007         xlen = lengthPXD(pxd);
1008         xsize = xlen << sbi->l2bsize;
1009         if (xsize < PSIZE) {
1010                 xaddr = addressPXD(pxd);
1011                 n = xsize >> L2DTSLOTSIZE;
1012                 n -= (n + 31) >> L2DTSLOTSIZE;  /* stbl size */
1013                 if ((n + sp->header.freecnt) <= split->nslot)
1014                         n = xlen + (xlen << 1);
1015                 else
1016                         n = xlen;
1017 
1018                 /* Allocate blocks to quota. */
1019                 rc = dquot_alloc_block(ip, n);
1020                 if (rc)
1021                         goto extendOut;
1022                 quota_allocation += n;
1023 
1024                 if ((rc = dbReAlloc(sbi->ipbmap, xaddr, (s64) xlen,
1025                                     (s64) n, &nxaddr)))
1026                         goto extendOut;
1027 
1028                 pxdlist.maxnpxd = 1;
1029                 pxdlist.npxd = 0;
1030                 pxd = &pxdlist.pxd[0];
1031                 PXDaddress(pxd, nxaddr);
1032                 PXDlength(pxd, xlen + n);
1033                 split->pxdlist = &pxdlist;
1034                 if ((rc = dtExtendPage(tid, ip, split, btstack))) {
1035                         nxaddr = addressPXD(pxd);
1036                         if (xaddr != nxaddr) {
1037                                 /* free relocated extent */
1038                                 xlen = lengthPXD(pxd);
1039                                 dbFree(ip, nxaddr, (s64) xlen);
1040                         } else {
1041                                 /* free extended delta */
1042                                 xlen = lengthPXD(pxd) - n;
1043                                 xaddr = addressPXD(pxd) + xlen;
1044                                 dbFree(ip, xaddr, (s64) n);
1045                         }
1046                 } else if (!DO_INDEX(ip))
1047                         ip->i_size = lengthPXD(pxd) << sbi->l2bsize;
1048 
1049 
1050               extendOut:
1051                 DT_PUTPAGE(smp);
1052                 goto freeKeyName;
1053         }
1054 
1055         /*
1056          *      split leaf page <sp> into <sp> and a new right page <rp>.
1057          *
1058          * return <rp> pinned and its extent descriptor <rpxd>
1059          */
1060         /*
1061          * allocate new directory page extent and
1062          * new index page(s) to cover page split(s)
1063          *
1064          * allocation hint: ?
1065          */
1066         n = btstack->nsplit;
1067         pxdlist.maxnpxd = pxdlist.npxd = 0;
1068         xlen = sbi->nbperpage;
1069         for (pxd = pxdlist.pxd; n > 0; n--, pxd++) {
1070                 if ((rc = dbAlloc(ip, 0, (s64) xlen, &xaddr)) == 0) {
1071                         PXDaddress(pxd, xaddr);
1072                         PXDlength(pxd, xlen);
1073                         pxdlist.maxnpxd++;
1074                         continue;
1075                 }
1076 
1077                 DT_PUTPAGE(smp);
1078 
1079                 /* undo allocation */
1080                 goto splitOut;
1081         }
1082 
1083         split->pxdlist = &pxdlist;
1084         if ((rc = dtSplitPage(tid, ip, split, &rmp, &rp, &rpxd))) {
1085                 DT_PUTPAGE(smp);
1086 
1087                 /* undo allocation */
1088                 goto splitOut;
1089         }
1090 
1091         if (!DO_INDEX(ip))
1092                 ip->i_size += PSIZE;
1093 
1094         /*
1095          * propagate up the router entry for the leaf page just split
1096          *
1097          * insert a router entry for the new page into the parent page,
1098          * propagate the insert/split up the tree by walking back the stack
1099          * of (bn of parent page, index of child page entry in parent page)
1100          * that were traversed during the search for the page that split.
1101          *
1102          * the propagation of insert/split up the tree stops if the root
1103          * splits or the page inserted into doesn't have to split to hold
1104          * the new entry.
1105          *
1106          * the parent entry for the split page remains the same, and
1107          * a new entry is inserted at its right with the first key and
1108          * block number of the new right page.
1109          *
1110          * There are a maximum of 4 pages pinned at any time:
1111          * two children, left parent and right parent (when the parent splits).
1112          * keep the child pages pinned while working on the parent.
1113          * make sure that all pins are released at exit.
1114          */
1115         while ((parent = BT_POP(btstack)) != NULL) {
1116                 /* parent page specified by stack frame <parent> */
1117 
1118                 /* keep current child pages (<lp>, <rp>) pinned */
1119                 lmp = smp;
1120                 lp = sp;
1121 
1122                 /*
1123                  * insert router entry in parent for new right child page <rp>
1124                  */
1125                 /* get the parent page <sp> */
1126                 DT_GETPAGE(ip, parent->bn, smp, PSIZE, sp, rc);
1127                 if (rc) {
1128                         DT_PUTPAGE(lmp);
1129                         DT_PUTPAGE(rmp);
1130                         goto splitOut;
1131                 }
1132 
1133                 /*
1134                  * The new key entry goes ONE AFTER the index of parent entry,
1135                  * because the split was to the right.
1136                  */
1137                 skip = parent->index + 1;
1138 
1139                 /*
1140                  * compute the key for the router entry
1141                  *
1142                  * key suffix compression:
1143                  * for internal pages that have leaf pages as children,
1144                  * retain only what's needed to distinguish between
1145                  * the new entry and the entry on the page to its left.
1146                  * If the keys compare equal, retain the entire key.
1147                  *
1148                  * note that compression is performed only at computing
1149                  * router key at the lowest internal level.
1150                  * further compression of the key between pairs of higher
1151                  * level internal pages loses too much information and
1152                  * the search may fail.
1153                  * (e.g., two adjacent leaf pages of {a, ..., x} {xx, ...,}
1154                  * results in two adjacent parent entries (a)(xx).
1155                  * if split occurs between these two entries, and
1156                  * if compression is applied, the router key of parent entry
1157                  * of right page (x) will divert search for x into right
1158                  * subtree and miss x in the left subtree.)
1159                  *
1160                  * the entire key must be retained for the next-to-leftmost
1161                  * internal key at any level of the tree, or search may fail
1162                  * (e.g., ?)
1163                  */
1164                 switch (rp->header.flag & BT_TYPE) {
1165                 case BT_LEAF:
1166                         /*
1167                          * compute the length of prefix for suffix compression
1168                          * between last entry of left page and first entry
1169                          * of right page
1170                          */
1171                         if ((sp->header.flag & BT_ROOT && skip > 1) ||
1172                             sp->header.prev != 0 || skip > 1) {
1173                                 /* compute uppercase router prefix key */
1174                                 rc = ciGetLeafPrefixKey(lp,
1175                                                         lp->header.nextindex-1,
1176                                                         rp, 0, &key,
1177                                                         sbi->mntflag);
1178                                 if (rc) {
1179                                         DT_PUTPAGE(lmp);
1180                                         DT_PUTPAGE(rmp);
1181                                         DT_PUTPAGE(smp);
1182                                         goto splitOut;
1183                                 }
1184                         } else {
1185                                 /* next to leftmost entry of
1186                                    lowest internal level */
1187 
1188                                 /* compute uppercase router key */
1189                                 dtGetKey(rp, 0, &key, sbi->mntflag);
1190                                 key.name[key.namlen] = 0;
1191 
1192                                 if ((sbi->mntflag & JFS_OS2) == JFS_OS2)
1193                                         ciToUpper(&key);
1194                         }
1195 
1196                         n = NDTINTERNAL(key.namlen);
1197                         break;
1198 
1199                 case BT_INTERNAL:
1200                         dtGetKey(rp, 0, &key, sbi->mntflag);
1201                         n = NDTINTERNAL(key.namlen);
1202                         break;
1203 
1204                 default:
1205                         jfs_err("dtSplitUp(): UFO!");
1206                         break;
1207                 }
1208 
1209                 /* unpin left child page */
1210                 DT_PUTPAGE(lmp);
1211 
1212                 /*
1213                  * compute the data for the router entry
1214                  */
1215                 data->xd = rpxd;        /* child page xd */
1216 
1217                 /*
1218                  * parent page is full - split the parent page
1219                  */
1220                 if (n > sp->header.freecnt) {
1221                         /* init for parent page split */
1222                         split->mp = smp;
1223                         split->index = skip;    /* index at insert */
1224                         split->nslot = n;
1225                         split->key = &key;
1226                         /* split->data = data; */
1227 
1228                         /* unpin right child page */
1229                         DT_PUTPAGE(rmp);
1230 
1231                         /* The split routines insert the new entry,
1232                          * acquire txLock as appropriate.
1233                          * return <rp> pinned and its block number <rbn>.
1234                          */
1235                         rc = (sp->header.flag & BT_ROOT) ?
1236                             dtSplitRoot(tid, ip, split, &rmp) :
1237                             dtSplitPage(tid, ip, split, &rmp, &rp, &rpxd);
1238                         if (rc) {
1239                                 DT_PUTPAGE(smp);
1240                                 goto splitOut;
1241                         }
1242 
1243                         /* smp and rmp are pinned */
1244                 }
1245                 /*
1246                  * parent page is not full - insert router entry in parent page
1247                  */
1248                 else {
1249                         BT_MARK_DIRTY(smp, ip);
1250                         /*
1251                          * acquire a transaction lock on the parent page
1252                          */
1253                         tlck = txLock(tid, ip, smp, tlckDTREE | tlckENTRY);
1254                         dtlck = (struct dt_lock *) & tlck->lock;
1255                         ASSERT(dtlck->index == 0);
1256                         lv = & dtlck->lv[0];
1257 
1258                         /* linelock header */
1259                         lv->offset = 0;
1260                         lv->length = 1;
1261                         dtlck->index++;
1262 
1263                         /* linelock stbl of non-root parent page */
1264                         if (!(sp->header.flag & BT_ROOT)) {
1265                                 lv++;
1266                                 n = skip >> L2DTSLOTSIZE;
1267                                 lv->offset = sp->header.stblindex + n;
1268                                 lv->length =
1269                                     ((sp->header.nextindex -
1270                                       1) >> L2DTSLOTSIZE) - n + 1;
1271                                 dtlck->index++;
1272                         }
1273 
1274                         dtInsertEntry(sp, skip, &key, data, &dtlck);
1275 
1276                         /* exit propagate up */
1277                         break;
1278                 }
1279         }
1280 
1281         /* unpin current split and its right page */
1282         DT_PUTPAGE(smp);
1283         DT_PUTPAGE(rmp);
1284 
1285         /*
1286          * free remaining extents allocated for split
1287          */
1288       splitOut:
1289         n = pxdlist.npxd;
1290         pxd = &pxdlist.pxd[n];
1291         for (; n < pxdlist.maxnpxd; n++, pxd++)
1292                 dbFree(ip, addressPXD(pxd), (s64) lengthPXD(pxd));
1293 
1294       freeKeyName:
1295         kfree(key.name);
1296 
1297         /* Rollback quota allocation */
1298         if (rc && quota_allocation)
1299                 dquot_free_block(ip, quota_allocation);
1300 
1301       dtSplitUp_Exit:
1302 
1303         return rc;
1304 }
1305 
1306 
1307 /*
1308  *      dtSplitPage()
1309  *
1310  * function: Split a non-root page of a btree.
1311  *
1312  * parameter:
1313  *
1314  * return: 0 - success;
1315  *         errno - failure;
1316  *      return split and new page pinned;
1317  */
1318 static int dtSplitPage(tid_t tid, struct inode *ip, struct dtsplit * split,
1319             struct metapage ** rmpp, dtpage_t ** rpp, pxd_t * rpxdp)
1320 {
1321         int rc = 0;
1322         struct metapage *smp;
1323         dtpage_t *sp;
1324         struct metapage *rmp;
1325         dtpage_t *rp;           /* new right page allocated */
1326         s64 rbn;                /* new right page block number */
1327         struct metapage *mp;
1328         dtpage_t *p;
1329         s64 nextbn;
1330         struct pxdlist *pxdlist;
1331         pxd_t *pxd;
1332         int skip, nextindex, half, left, nxt, off, si;
1333         struct ldtentry *ldtentry;
1334         struct idtentry *idtentry;
1335         u8 *stbl;
1336         struct dtslot *f;
1337         int fsi, stblsize;
1338         int n;
1339         struct dt_lock *sdtlck, *rdtlck;
1340         struct tlock *tlck;
1341         struct dt_lock *dtlck;
1342         struct lv *slv, *rlv, *lv;
1343 
1344         /* get split page */
1345         smp = split->mp;
1346         sp = DT_PAGE(ip, smp);
1347 
1348         /*
1349          * allocate the new right page for the split
1350          */
1351         pxdlist = split->pxdlist;
1352         pxd = &pxdlist->pxd[pxdlist->npxd];
1353         pxdlist->npxd++;
1354         rbn = addressPXD(pxd);
1355         rmp = get_metapage(ip, rbn, PSIZE, 1);
1356         if (rmp == NULL)
1357                 return -EIO;
1358 
1359         /* Allocate blocks to quota. */
1360         rc = dquot_alloc_block(ip, lengthPXD(pxd));
1361         if (rc) {
1362                 release_metapage(rmp);
1363                 return rc;
1364         }
1365 
1366         jfs_info("dtSplitPage: ip:0x%p smp:0x%p rmp:0x%p", ip, smp, rmp);
1367 
1368         BT_MARK_DIRTY(rmp, ip);
1369         /*
1370          * acquire a transaction lock on the new right page
1371          */
1372         tlck = txLock(tid, ip, rmp, tlckDTREE | tlckNEW);
1373         rdtlck = (struct dt_lock *) & tlck->lock;
1374 
1375         rp = (dtpage_t *) rmp->data;
1376         *rpp = rp;
1377         rp->header.self = *pxd;
1378 
1379         BT_MARK_DIRTY(smp, ip);
1380         /*
1381          * acquire a transaction lock on the split page
1382          *
1383          * action:
1384          */
1385         tlck = txLock(tid, ip, smp, tlckDTREE | tlckENTRY);
1386         sdtlck = (struct dt_lock *) & tlck->lock;
1387 
1388         /* linelock header of split page */
1389         ASSERT(sdtlck->index == 0);
1390         slv = & sdtlck->lv[0];
1391         slv->offset = 0;
1392         slv->length = 1;
1393         sdtlck->index++;
1394 
1395         /*
1396          * initialize/update sibling pointers between sp and rp
1397          */
1398         nextbn = le64_to_cpu(sp->header.next);
1399         rp->header.next = cpu_to_le64(nextbn);
1400         rp->header.prev = cpu_to_le64(addressPXD(&sp->header.self));
1401         sp->header.next = cpu_to_le64(rbn);
1402 
1403         /*
1404          * initialize new right page
1405          */
1406         rp->header.flag = sp->header.flag;
1407 
1408         /* compute sorted entry table at start of extent data area */
1409         rp->header.nextindex = 0;
1410         rp->header.stblindex = 1;
1411 
1412         n = PSIZE >> L2DTSLOTSIZE;
1413         rp->header.maxslot = n;
1414         stblsize = (n + 31) >> L2DTSLOTSIZE;    /* in unit of slot */
1415 
1416         /* init freelist */
1417         fsi = rp->header.stblindex + stblsize;
1418         rp->header.freelist = fsi;
1419         rp->header.freecnt = rp->header.maxslot - fsi;
1420 
1421         /*
1422          *      sequential append at tail: append without split
1423          *
1424          * If splitting the last page on a level because of appending
1425          * a entry to it (skip is maxentry), it's likely that the access is
1426          * sequential. Adding an empty page on the side of the level is less
1427          * work and can push the fill factor much higher than normal.
1428          * If we're wrong it's no big deal, we'll just do the split the right
1429          * way next time.
1430          * (It may look like it's equally easy to do a similar hack for
1431          * reverse sorted data, that is, split the tree left,
1432          * but it's not. Be my guest.)
1433          */
1434         if (nextbn == 0 && split->index == sp->header.nextindex) {
1435                 /* linelock header + stbl (first slot) of new page */
1436                 rlv = & rdtlck->lv[rdtlck->index];
1437                 rlv->offset = 0;
1438                 rlv->length = 2;
1439                 rdtlck->index++;
1440 
1441                 /*
1442                  * initialize freelist of new right page
1443                  */
1444                 f = &rp->slot[fsi];
1445                 for (fsi++; fsi < rp->header.maxslot; f++, fsi++)
1446                         f->next = fsi;
1447                 f->next = -1;
1448 
1449                 /* insert entry at the first entry of the new right page */
1450                 dtInsertEntry(rp, 0, split->key, split->data, &rdtlck);
1451 
1452                 goto out;
1453         }
1454 
1455         /*
1456          *      non-sequential insert (at possibly middle page)
1457          */
1458 
1459         /*
1460          * update prev pointer of previous right sibling page;
1461          */
1462         if (nextbn != 0) {
1463                 DT_GETPAGE(ip, nextbn, mp, PSIZE, p, rc);
1464                 if (rc) {
1465                         discard_metapage(rmp);
1466                         return rc;
1467                 }
1468 
1469                 BT_MARK_DIRTY(mp, ip);
1470                 /*
1471                  * acquire a transaction lock on the next page
1472                  */
1473                 tlck = txLock(tid, ip, mp, tlckDTREE | tlckRELINK);
1474                 jfs_info("dtSplitPage: tlck = 0x%p, ip = 0x%p, mp=0x%p",
1475                         tlck, ip, mp);
1476                 dtlck = (struct dt_lock *) & tlck->lock;
1477 
1478                 /* linelock header of previous right sibling page */
1479                 lv = & dtlck->lv[dtlck->index];
1480                 lv->offset = 0;
1481                 lv->length = 1;
1482                 dtlck->index++;
1483 
1484                 p->header.prev = cpu_to_le64(rbn);
1485 
1486                 DT_PUTPAGE(mp);
1487         }
1488 
1489         /*
1490          * split the data between the split and right pages.
1491          */
1492         skip = split->index;
1493         half = (PSIZE >> L2DTSLOTSIZE) >> 1;    /* swag */
1494         left = 0;
1495 
1496         /*
1497          *      compute fill factor for split pages
1498          *
1499          * <nxt> traces the next entry to move to rp
1500          * <off> traces the next entry to stay in sp
1501          */
1502         stbl = (u8 *) & sp->slot[sp->header.stblindex];
1503         nextindex = sp->header.nextindex;
1504         for (nxt = off = 0; nxt < nextindex; ++off) {
1505                 if (off == skip)
1506                         /* check for fill factor with new entry size */
1507                         n = split->nslot;
1508                 else {
1509                         si = stbl[nxt];
1510                         switch (sp->header.flag & BT_TYPE) {
1511                         case BT_LEAF:
1512                                 ldtentry = (struct ldtentry *) & sp->slot[si];
1513                                 if (DO_INDEX(ip))
1514                                         n = NDTLEAF(ldtentry->namlen);
1515                                 else
1516                                         n = NDTLEAF_LEGACY(ldtentry->
1517                                                            namlen);
1518                                 break;
1519 
1520                         case BT_INTERNAL:
1521                                 idtentry = (struct idtentry *) & sp->slot[si];
1522                                 n = NDTINTERNAL(idtentry->namlen);
1523                                 break;
1524 
1525                         default:
1526                                 break;
1527                         }
1528 
1529                         ++nxt;  /* advance to next entry to move in sp */
1530                 }
1531 
1532                 left += n;
1533                 if (left >= half)
1534                         break;
1535         }
1536 
1537         /* <nxt> poins to the 1st entry to move */
1538 
1539         /*
1540          *      move entries to right page
1541          *
1542          * dtMoveEntry() initializes rp and reserves entry for insertion
1543          *
1544          * split page moved out entries are linelocked;
1545          * new/right page moved in entries are linelocked;
1546          */
1547         /* linelock header + stbl of new right page */
1548         rlv = & rdtlck->lv[rdtlck->index];
1549         rlv->offset = 0;
1550         rlv->length = 5;
1551         rdtlck->index++;
1552 
1553         dtMoveEntry(sp, nxt, rp, &sdtlck, &rdtlck, DO_INDEX(ip));
1554 
1555         sp->header.nextindex = nxt;
1556 
1557         /*
1558          * finalize freelist of new right page
1559          */
1560         fsi = rp->header.freelist;
1561         f = &rp->slot[fsi];
1562         for (fsi++; fsi < rp->header.maxslot; f++, fsi++)
1563                 f->next = fsi;
1564         f->next = -1;
1565 
1566         /*
1567          * Update directory index table for entries now in right page
1568          */
1569         if ((rp->header.flag & BT_LEAF) && DO_INDEX(ip)) {
1570                 s64 lblock;
1571 
1572                 mp = NULL;
1573                 stbl = DT_GETSTBL(rp);
1574                 for (n = 0; n < rp->header.nextindex; n++) {
1575                         ldtentry = (struct ldtentry *) & rp->slot[stbl[n]];
1576                         modify_index(tid, ip, le32_to_cpu(ldtentry->index),
1577                                      rbn, n, &mp, &lblock);
1578                 }
1579                 if (mp)
1580                         release_metapage(mp);
1581         }
1582 
1583         /*
1584          * the skipped index was on the left page,
1585          */
1586         if (skip <= off) {
1587                 /* insert the new entry in the split page */
1588                 dtInsertEntry(sp, skip, split->key, split->data, &sdtlck);
1589 
1590                 /* linelock stbl of split page */
1591                 if (sdtlck->index >= sdtlck->maxcnt)
1592                         sdtlck = (struct dt_lock *) txLinelock(sdtlck);
1593                 slv = & sdtlck->lv[sdtlck->index];
1594                 n = skip >> L2DTSLOTSIZE;
1595                 slv->offset = sp->header.stblindex + n;
1596                 slv->length =
1597                     ((sp->header.nextindex - 1) >> L2DTSLOTSIZE) - n + 1;
1598                 sdtlck->index++;
1599         }
1600         /*
1601          * the skipped index was on the right page,
1602          */
1603         else {
1604                 /* adjust the skip index to reflect the new position */
1605                 skip -= nxt;
1606 
1607                 /* insert the new entry in the right page */
1608                 dtInsertEntry(rp, skip, split->key, split->data, &rdtlck);
1609         }
1610 
1611       out:
1612         *rmpp = rmp;
1613         *rpxdp = *pxd;
1614 
1615         return rc;
1616 }
1617 
1618 
1619 /*
1620  *      dtExtendPage()
1621  *
1622  * function: extend 1st/only directory leaf page
1623  *
1624  * parameter:
1625  *
1626  * return: 0 - success;
1627  *         errno - failure;
1628  *      return extended page pinned;
1629  */
1630 static int dtExtendPage(tid_t tid,
1631              struct inode *ip, struct dtsplit * split, struct btstack * btstack)
1632 {
1633         struct super_block *sb = ip->i_sb;
1634         int rc;
1635         struct metapage *smp, *pmp, *mp;
1636         dtpage_t *sp, *pp;
1637         struct pxdlist *pxdlist;
1638         pxd_t *pxd, *tpxd;
1639         int xlen, xsize;
1640         int newstblindex, newstblsize;
1641         int oldstblindex, oldstblsize;
1642         int fsi, last;
1643         struct dtslot *f;
1644         struct btframe *parent;
1645         int n;
1646         struct dt_lock *dtlck;
1647         s64 xaddr, txaddr;
1648         struct tlock *tlck;
1649         struct pxd_lock *pxdlock;
1650         struct lv *lv;
1651         uint type;
1652         struct ldtentry *ldtentry;
1653         u8 *stbl;
1654 
1655         /* get page to extend */
1656         smp = split->mp;
1657         sp = DT_PAGE(ip, smp);
1658 
1659         /* get parent/root page */
1660         parent = BT_POP(btstack);
1661         DT_GETPAGE(ip, parent->bn, pmp, PSIZE, pp, rc);
1662         if (rc)
1663                 return (rc);
1664 
1665         /*
1666          *      extend the extent
1667          */
1668         pxdlist = split->pxdlist;
1669         pxd = &pxdlist->pxd[pxdlist->npxd];
1670         pxdlist->npxd++;
1671 
1672         xaddr = addressPXD(pxd);
1673         tpxd = &sp->header.self;
1674         txaddr = addressPXD(tpxd);
1675         /* in-place extension */
1676         if (xaddr == txaddr) {
1677                 type = tlckEXTEND;
1678         }
1679         /* relocation */
1680         else {
1681                 type = tlckNEW;
1682 
1683                 /* save moved extent descriptor for later free */
1684                 tlck = txMaplock(tid, ip, tlckDTREE | tlckRELOCATE);
1685                 pxdlock = (struct pxd_lock *) & tlck->lock;
1686                 pxdlock->flag = mlckFREEPXD;
1687                 pxdlock->pxd = sp->header.self;
1688                 pxdlock->index = 1;
1689 
1690                 /*
1691                  * Update directory index table to reflect new page address
1692                  */
1693                 if (DO_INDEX(ip)) {
1694                         s64 lblock;
1695 
1696                         mp = NULL;
1697                         stbl = DT_GETSTBL(sp);
1698                         for (n = 0; n < sp->header.nextindex; n++) {
1699                                 ldtentry =
1700                                     (struct ldtentry *) & sp->slot[stbl[n]];
1701                                 modify_index(tid, ip,
1702                                              le32_to_cpu(ldtentry->index),
1703                                              xaddr, n, &mp, &lblock);
1704                         }
1705                         if (mp)
1706                                 release_metapage(mp);
1707                 }
1708         }
1709 
1710         /*
1711          *      extend the page
1712          */
1713         sp->header.self = *pxd;
1714 
1715         jfs_info("dtExtendPage: ip:0x%p smp:0x%p sp:0x%p", ip, smp, sp);
1716 
1717         BT_MARK_DIRTY(smp, ip);
1718         /*
1719          * acquire a transaction lock on the extended/leaf page
1720          */
1721         tlck = txLock(tid, ip, smp, tlckDTREE | type);
1722         dtlck = (struct dt_lock *) & tlck->lock;
1723         lv = & dtlck->lv[0];
1724 
1725         /* update buffer extent descriptor of extended page */
1726         xlen = lengthPXD(pxd);
1727         xsize = xlen << JFS_SBI(sb)->l2bsize;
1728 
1729         /*
1730          * copy old stbl to new stbl at start of extended area
1731          */
1732         oldstblindex = sp->header.stblindex;
1733         oldstblsize = (sp->header.maxslot + 31) >> L2DTSLOTSIZE;
1734         newstblindex = sp->header.maxslot;
1735         n = xsize >> L2DTSLOTSIZE;
1736         newstblsize = (n + 31) >> L2DTSLOTSIZE;
1737         memcpy(&sp->slot[newstblindex], &sp->slot[oldstblindex],
1738                sp->header.nextindex);
1739 
1740         /*
1741          * in-line extension: linelock old area of extended page
1742          */
1743         if (type == tlckEXTEND) {
1744                 /* linelock header */
1745                 lv->offset = 0;
1746                 lv->length = 1;
1747                 dtlck->index++;
1748                 lv++;
1749 
1750                 /* linelock new stbl of extended page */
1751                 lv->offset = newstblindex;
1752                 lv->length = newstblsize;
1753         }
1754         /*
1755          * relocation: linelock whole relocated area
1756          */
1757         else {
1758                 lv->offset = 0;
1759                 lv->length = sp->header.maxslot + newstblsize;
1760         }
1761 
1762         dtlck->index++;
1763 
1764         sp->header.maxslot = n;
1765         sp->header.stblindex = newstblindex;
1766         /* sp->header.nextindex remains the same */
1767 
1768         /*
1769          * add old stbl region at head of freelist
1770          */
1771         fsi = oldstblindex;
1772         f = &sp->slot[fsi];
1773         last = sp->header.freelist;
1774         for (n = 0; n < oldstblsize; n++, fsi++, f++) {
1775                 f->next = last;
1776                 last = fsi;
1777         }
1778         sp->header.freelist = last;
1779         sp->header.freecnt += oldstblsize;
1780 
1781         /*
1782          * append free region of newly extended area at tail of freelist
1783          */
1784         /* init free region of newly extended area */
1785         fsi = n = newstblindex + newstblsize;
1786         f = &sp->slot[fsi];
1787         for (fsi++; fsi < sp->header.maxslot; f++, fsi++)
1788                 f->next = fsi;
1789         f->next = -1;
1790 
1791         /* append new free region at tail of old freelist */
1792         fsi = sp->header.freelist;
1793         if (fsi == -1)
1794                 sp->header.freelist = n;
1795         else {
1796                 do {
1797                         f = &sp->slot[fsi];
1798                         fsi = f->next;
1799                 } while (fsi != -1);
1800 
1801                 f->next = n;
1802         }
1803 
1804         sp->header.freecnt += sp->header.maxslot - n;
1805 
1806         /*
1807          * insert the new entry
1808          */
1809         dtInsertEntry(sp, split->index, split->key, split->data, &dtlck);
1810 
1811         BT_MARK_DIRTY(pmp, ip);
1812         /*
1813          * linelock any freeslots residing in old extent
1814          */
1815         if (type == tlckEXTEND) {
1816                 n = sp->header.maxslot >> 2;
1817                 if (sp->header.freelist < n)
1818                         dtLinelockFreelist(sp, n, &dtlck);
1819         }
1820 
1821         /*
1822          *      update parent entry on the parent/root page
1823          */
1824         /*
1825          * acquire a transaction lock on the parent/root page
1826          */
1827         tlck = txLock(tid, ip, pmp, tlckDTREE | tlckENTRY);
1828         dtlck = (struct dt_lock *) & tlck->lock;
1829         lv = & dtlck->lv[dtlck->index];
1830 
1831         /* linelock parent entry - 1st slot */
1832         lv->offset = 1;
1833         lv->length = 1;
1834         dtlck->index++;
1835 
1836         /* update the parent pxd for page extension */
1837         tpxd = (pxd_t *) & pp->slot[1];
1838         *tpxd = *pxd;
1839 
1840         DT_PUTPAGE(pmp);
1841         return 0;
1842 }
1843 
1844 
1845 /*
1846  *      dtSplitRoot()
1847  *
1848  * function:
1849  *      split the full root page into
1850  *      original/root/split page and new right page
1851  *      i.e., root remains fixed in tree anchor (inode) and
1852  *      the root is copied to a single new right child page
1853  *      since root page << non-root page, and
1854  *      the split root page contains a single entry for the
1855  *      new right child page.
1856  *
1857  * parameter:
1858  *
1859  * return: 0 - success;
1860  *         errno - failure;
1861  *      return new page pinned;
1862  */
1863 static int dtSplitRoot(tid_t tid,
1864             struct inode *ip, struct dtsplit * split, struct metapage ** rmpp)
1865 {
1866         struct super_block *sb = ip->i_sb;
1867         struct metapage *smp;
1868         dtroot_t *sp;
1869         struct metapage *rmp;
1870         dtpage_t *rp;
1871         s64 rbn;
1872         int xlen;
1873         int xsize;
1874         struct dtslot *f;
1875         s8 *stbl;
1876         int fsi, stblsize, n;
1877         struct idtentry *s;
1878         pxd_t *ppxd;
1879         struct pxdlist *pxdlist;
1880         pxd_t *pxd;
1881         struct dt_lock *dtlck;
1882         struct tlock *tlck;
1883         struct lv *lv;
1884         int rc;
1885 
1886         /* get split root page */
1887         smp = split->mp;
1888         sp = &JFS_IP(ip)->i_dtroot;
1889 
1890         /*
1891          *      allocate/initialize a single (right) child page
1892          *
1893          * N.B. at first split, a one (or two) block to fit new entry
1894          * is allocated; at subsequent split, a full page is allocated;
1895          */
1896         pxdlist = split->pxdlist;
1897         pxd = &pxdlist->pxd[pxdlist->npxd];
1898         pxdlist->npxd++;
1899         rbn = addressPXD(pxd);
1900         xlen = lengthPXD(pxd);
1901         xsize = xlen << JFS_SBI(sb)->l2bsize;
1902         rmp = get_metapage(ip, rbn, xsize, 1);
1903         if (!rmp)
1904                 return -EIO;
1905 
1906         rp = rmp->data;
1907 
1908         /* Allocate blocks to quota. */
1909         rc = dquot_alloc_block(ip, lengthPXD(pxd));
1910         if (rc) {
1911                 release_metapage(rmp);
1912                 return rc;
1913         }
1914 
1915         BT_MARK_DIRTY(rmp, ip);
1916         /*
1917          * acquire a transaction lock on the new right page
1918          */
1919         tlck = txLock(tid, ip, rmp, tlckDTREE | tlckNEW);
1920         dtlck = (struct dt_lock *) & tlck->lock;
1921 
1922         rp->header.flag =
1923             (sp->header.flag & BT_LEAF) ? BT_LEAF : BT_INTERNAL;
1924         rp->header.self = *pxd;
1925 
1926         /* initialize sibling pointers */
1927         rp->header.next = 0;
1928         rp->header.prev = 0;
1929 
1930         /*
1931          *      move in-line root page into new right page extent
1932          */
1933         /* linelock header + copied entries + new stbl (1st slot) in new page */
1934         ASSERT(dtlck->index == 0);
1935         lv = & dtlck->lv[0];
1936         lv->offset = 0;
1937         lv->length = 10;        /* 1 + 8 + 1 */
1938         dtlck->index++;
1939 
1940         n = xsize >> L2DTSLOTSIZE;
1941         rp->header.maxslot = n;
1942         stblsize = (n + 31) >> L2DTSLOTSIZE;
1943 
1944         /* copy old stbl to new stbl at start of extended area */
1945         rp->header.stblindex = DTROOTMAXSLOT;
1946         stbl = (s8 *) & rp->slot[DTROOTMAXSLOT];
1947         memcpy(stbl, sp->header.stbl, sp->header.nextindex);
1948         rp->header.nextindex = sp->header.nextindex;
1949 
1950         /* copy old data area to start of new data area */
1951         memcpy(&rp->slot[1], &sp->slot[1], IDATASIZE);
1952 
1953         /*
1954          * append free region of newly extended area at tail of freelist
1955          */
1956         /* init free region of newly extended area */
1957         fsi = n = DTROOTMAXSLOT + stblsize;
1958         f = &rp->slot[fsi];
1959         for (fsi++; fsi < rp->header.maxslot; f++, fsi++)
1960                 f->next = fsi;
1961         f->next = -1;
1962 
1963         /* append new free region at tail of old freelist */
1964         fsi = sp->header.freelist;
1965         if (fsi == -1)
1966                 rp->header.freelist = n;
1967         else {
1968                 rp->header.freelist = fsi;
1969 
1970                 do {
1971                         f = &rp->slot[fsi];
1972                         fsi = f->next;
1973                 } while (fsi != -1);
1974 
1975                 f->next = n;
1976         }
1977 
1978         rp->header.freecnt = sp->header.freecnt + rp->header.maxslot - n;
1979 
1980         /*
1981          * Update directory index table for entries now in right page
1982          */
1983         if ((rp->header.flag & BT_LEAF) && DO_INDEX(ip)) {
1984                 s64 lblock;
1985                 struct metapage *mp = NULL;
1986                 struct ldtentry *ldtentry;
1987 
1988                 stbl = DT_GETSTBL(rp);
1989                 for (n = 0; n < rp->header.nextindex; n++) {
1990                         ldtentry = (struct ldtentry *) & rp->slot[stbl[n]];
1991                         modify_index(tid, ip, le32_to_cpu(ldtentry->index),
1992                                      rbn, n, &mp, &lblock);
1993                 }
1994                 if (mp)
1995                         release_metapage(mp);
1996         }
1997         /*
1998          * insert the new entry into the new right/child page
1999          * (skip index in the new right page will not change)
2000          */
2001         dtInsertEntry(rp, split->index, split->key, split->data, &dtlck);
2002 
2003         /*
2004          *      reset parent/root page
2005          *
2006          * set the 1st entry offset to 0, which force the left-most key
2007          * at any level of the tree to be less than any search key.
2008          *
2009          * The btree comparison code guarantees that the left-most key on any
2010          * level of the tree is never used, so it doesn't need to be filled in.
2011          */
2012         BT_MARK_DIRTY(smp, ip);
2013         /*
2014          * acquire a transaction lock on the root page (in-memory inode)
2015          */
2016         tlck = txLock(tid, ip, smp, tlckDTREE | tlckNEW | tlckBTROOT);
2017         dtlck = (struct dt_lock *) & tlck->lock;
2018 
2019         /* linelock root */
2020         ASSERT(dtlck->index == 0);
2021         lv = & dtlck->lv[0];
2022         lv->offset = 0;
2023         lv->length = DTROOTMAXSLOT;
2024         dtlck->index++;
2025 
2026         /* update page header of root */
2027         if (sp->header.flag & BT_LEAF) {
2028                 sp->header.flag &= ~BT_LEAF;
2029                 sp->header.flag |= BT_INTERNAL;
2030         }
2031 
2032         /* init the first entry */
2033         s = (struct idtentry *) & sp->slot[DTENTRYSTART];
2034         ppxd = (pxd_t *) s;
2035         *ppxd = *pxd;
2036         s->next = -1;
2037         s->namlen = 0;
2038 
2039         stbl = sp->header.stbl;
2040         stbl[0] = DTENTRYSTART;
2041         sp->header.nextindex = 1;
2042 
2043         /* init freelist */
2044         fsi = DTENTRYSTART + 1;
2045         f = &sp->slot[fsi];
2046 
2047         /* init free region of remaining area */
2048         for (fsi++; fsi < DTROOTMAXSLOT; f++, fsi++)
2049                 f->next = fsi;
2050         f->next = -1;
2051 
2052         sp->header.freelist = DTENTRYSTART + 1;
2053         sp->header.freecnt = DTROOTMAXSLOT - (DTENTRYSTART + 1);
2054 
2055         *rmpp = rmp;
2056 
2057         return 0;
2058 }
2059 
2060 
2061 /*
2062  *      dtDelete()
2063  *
2064  * function: delete the entry(s) referenced by a key.
2065  *
2066  * parameter:
2067  *
2068  * return:
2069  */
2070 int dtDelete(tid_t tid,
2071          struct inode *ip, struct component_name * key, ino_t * ino, int flag)
2072 {
2073         int rc = 0;
2074         s64 bn;
2075         struct metapage *mp, *imp;
2076         dtpage_t *p;
2077         int index;
2078         struct btstack btstack;
2079         struct dt_lock *dtlck;
2080         struct tlock *tlck;
2081         struct lv *lv;
2082         int i;
2083         struct ldtentry *ldtentry;
2084         u8 *stbl;
2085         u32 table_index, next_index;
2086         struct metapage *nmp;
2087         dtpage_t *np;
2088 
2089         /*
2090          *      search for the entry to delete:
2091          *
2092          * dtSearch() returns (leaf page pinned, index at which to delete).
2093          */
2094         if ((rc = dtSearch(ip, key, ino, &btstack, flag)))
2095                 return rc;
2096 
2097         /* retrieve search result */
2098         DT_GETSEARCH(ip, btstack.top, bn, mp, p, index);
2099 
2100         /*
2101          * We need to find put the index of the next entry into the
2102          * directory index table in order to resume a readdir from this
2103          * entry.
2104          */
2105         if (DO_INDEX(ip)) {
2106                 stbl = DT_GETSTBL(p);
2107                 ldtentry = (struct ldtentry *) & p->slot[stbl[index]];
2108                 table_index = le32_to_cpu(ldtentry->index);
2109                 if (index == (p->header.nextindex - 1)) {
2110                         /*
2111                          * Last entry in this leaf page
2112                          */
2113                         if ((p->header.flag & BT_ROOT)
2114                             || (p->header.next == 0))
2115                                 next_index = -1;
2116                         else {
2117                                 /* Read next leaf page */
2118                                 DT_GETPAGE(ip, le64_to_cpu(p->header.next),
2119                                            nmp, PSIZE, np, rc);
2120                                 if (rc)
2121                                         next_index = -1;
2122                                 else {
2123                                         stbl = DT_GETSTBL(np);
2124                                         ldtentry =
2125                                             (struct ldtentry *) & np->
2126                                             slot[stbl[0]];
2127                                         next_index =
2128                                             le32_to_cpu(ldtentry->index);
2129                                         DT_PUTPAGE(nmp);
2130                                 }
2131                         }
2132                 } else {
2133                         ldtentry =
2134                             (struct ldtentry *) & p->slot[stbl[index + 1]];
2135                         next_index = le32_to_cpu(ldtentry->index);
2136                 }
2137                 free_index(tid, ip, table_index, next_index);
2138         }
2139         /*
2140          * the leaf page becomes empty, delete the page
2141          */
2142         if (p->header.nextindex == 1) {
2143                 /* delete empty page */
2144                 rc = dtDeleteUp(tid, ip, mp, p, &btstack);
2145         }
2146         /*
2147          * the leaf page has other entries remaining:
2148          *
2149          * delete the entry from the leaf page.
2150          */
2151         else {
2152                 BT_MARK_DIRTY(mp, ip);
2153                 /*
2154                  * acquire a transaction lock on the leaf page
2155                  */
2156                 tlck = txLock(tid, ip, mp, tlckDTREE | tlckENTRY);
2157                 dtlck = (struct dt_lock *) & tlck->lock;
2158 
2159                 /*
2160                  * Do not assume that dtlck->index will be zero.  During a
2161                  * rename within a directory, this transaction may have
2162                  * modified this page already when adding the new entry.
2163                  */
2164 
2165                 /* linelock header */
2166                 if (dtlck->index >= dtlck->maxcnt)
2167                         dtlck = (struct dt_lock *) txLinelock(dtlck);
2168                 lv = & dtlck->lv[dtlck->index];
2169                 lv->offset = 0;
2170                 lv->length = 1;
2171                 dtlck->index++;
2172 
2173                 /* linelock stbl of non-root leaf page */
2174                 if (!(p->header.flag & BT_ROOT)) {
2175                         if (dtlck->index >= dtlck->maxcnt)
2176                                 dtlck = (struct dt_lock *) txLinelock(dtlck);
2177                         lv = & dtlck->lv[dtlck->index];
2178                         i = index >> L2DTSLOTSIZE;
2179                         lv->offset = p->header.stblindex + i;
2180                         lv->length =
2181                             ((p->header.nextindex - 1) >> L2DTSLOTSIZE) -
2182                             i + 1;
2183                         dtlck->index++;
2184                 }
2185 
2186                 /* free the leaf entry */
2187                 dtDeleteEntry(p, index, &dtlck);
2188 
2189                 /*
2190                  * Update directory index table for entries moved in stbl
2191                  */
2192                 if (DO_INDEX(ip) && index < p->header.nextindex) {
2193                         s64 lblock;
2194 
2195                         imp = NULL;
2196                         stbl = DT_GETSTBL(p);
2197                         for (i = index; i < p->header.nextindex; i++) {
2198                                 ldtentry =
2199                                     (struct ldtentry *) & p->slot[stbl[i]];
2200                                 modify_index(tid, ip,
2201                                              le32_to_cpu(ldtentry->index),
2202                                              bn, i, &imp, &lblock);
2203                         }
2204                         if (imp)
2205                                 release_metapage(imp);
2206                 }
2207 
2208                 DT_PUTPAGE(mp);
2209         }
2210 
2211         return rc;
2212 }
2213 
2214 
2215 /*
2216  *      dtDeleteUp()
2217  *
2218  * function:
2219  *      free empty pages as propagating deletion up the tree
2220  *
2221  * parameter:
2222  *
2223  * return:
2224  */
2225 static int dtDeleteUp(tid_t tid, struct inode *ip,
2226            struct metapage * fmp, dtpage_t * fp, struct btstack * btstack)
2227 {
2228         int rc = 0;
2229         struct metapage *mp;
2230         dtpage_t *p;
2231         int index, nextindex;
2232         int xlen;
2233         struct btframe *parent;
2234         struct dt_lock *dtlck;
2235         struct tlock *tlck;
2236         struct lv *lv;
2237         struct pxd_lock *pxdlock;
2238         int i;
2239 
2240         /*
2241          *      keep the root leaf page which has become empty
2242          */
2243         if (BT_IS_ROOT(fmp)) {
2244                 /*
2245                  * reset the root
2246                  *
2247                  * dtInitRoot() acquires txlock on the root
2248                  */
2249                 dtInitRoot(tid, ip, PARENT(ip));
2250 
2251                 DT_PUTPAGE(fmp);
2252 
2253                 return 0;
2254         }
2255 
2256         /*
2257          *      free the non-root leaf page
2258          */
2259         /*
2260          * acquire a transaction lock on the page
2261          *
2262          * write FREEXTENT|NOREDOPAGE log record
2263          * N.B. linelock is overlaid as freed extent descriptor, and
2264          * the buffer page is freed;
2265          */
2266         tlck = txMaplock(tid, ip, tlckDTREE | tlckFREE);
2267         pxdlock = (struct pxd_lock *) & tlck->lock;
2268         pxdlock->flag = mlckFREEPXD;
2269         pxdlock->pxd = fp->header.self;
2270         pxdlock->index = 1;
2271 
2272         /* update sibling pointers */
2273         if ((rc = dtRelink(tid, ip, fp))) {
2274                 BT_PUTPAGE(fmp);
2275                 return rc;
2276         }
2277 
2278         xlen = lengthPXD(&fp->header.self);
2279 
2280         /* Free quota allocation. */
2281         dquot_free_block(ip, xlen);
2282 
2283         /* free/invalidate its buffer page */
2284         discard_metapage(fmp);
2285 
2286         /*
2287          *      propagate page deletion up the directory tree
2288          *
2289          * If the delete from the parent page makes it empty,
2290          * continue all the way up the tree.
2291          * stop if the root page is reached (which is never deleted) or
2292          * if the entry deletion does not empty the page.
2293          */
2294         while ((parent = BT_POP(btstack)) != NULL) {
2295                 /* pin the parent page <sp> */
2296                 DT_GETPAGE(ip, parent->bn, mp, PSIZE, p, rc);
2297                 if (rc)
2298                         return rc;
2299 
2300                 /*
2301                  * free the extent of the child page deleted
2302                  */
2303                 index = parent->index;
2304 
2305                 /*
2306                  * delete the entry for the child page from parent
2307                  */
2308                 nextindex = p->header.nextindex;
2309 
2310                 /*
2311                  * the parent has the single entry being deleted:
2312                  *
2313                  * free the parent page which has become empty.
2314                  */
2315                 if (nextindex == 1) {
2316                         /*
2317                          * keep the root internal page which has become empty
2318                          */
2319                         if (p->header.flag & BT_ROOT) {
2320                                 /*
2321                                  * reset the root
2322                                  *
2323                                  * dtInitRoot() acquires txlock on the root
2324                                  */
2325                                 dtInitRoot(tid, ip, PARENT(ip));
2326 
2327                                 DT_PUTPAGE(mp);
2328 
2329                                 return 0;
2330                         }
2331                         /*
2332                          * free the parent page
2333                          */
2334                         else {
2335                                 /*
2336                                  * acquire a transaction lock on the page
2337                                  *
2338                                  * write FREEXTENT|NOREDOPAGE log record
2339                                  */
2340                                 tlck =
2341                                     txMaplock(tid, ip,
2342                                               tlckDTREE | tlckFREE);
2343                                 pxdlock = (struct pxd_lock *) & tlck->lock;
2344                                 pxdlock->flag = mlckFREEPXD;
2345                                 pxdlock->pxd = p->header.self;
2346                                 pxdlock->index = 1;
2347 
2348                                 /* update sibling pointers */
2349                                 if ((rc = dtRelink(tid, ip, p))) {
2350                                         DT_PUTPAGE(mp);
2351                                         return rc;
2352                                 }
2353 
2354                                 xlen = lengthPXD(&p->header.self);
2355 
2356                                 /* Free quota allocation */
2357                                 dquot_free_block(ip, xlen);
2358 
2359                                 /* free/invalidate its buffer page */
2360                                 discard_metapage(mp);
2361 
2362                                 /* propagate up */
2363                                 continue;
2364                         }
2365                 }
2366 
2367                 /*
2368                  * the parent has other entries remaining:
2369                  *
2370                  * delete the router entry from the parent page.
2371                  */
2372                 BT_MARK_DIRTY(mp, ip);
2373                 /*
2374                  * acquire a transaction lock on the page
2375                  *
2376                  * action: router entry deletion
2377                  */
2378                 tlck = txLock(tid, ip, mp, tlckDTREE | tlckENTRY);
2379                 dtlck = (struct dt_lock *) & tlck->lock;
2380 
2381                 /* linelock header */
2382                 if (dtlck->index >= dtlck->maxcnt)
2383                         dtlck = (struct dt_lock *) txLinelock(dtlck);
2384                 lv = & dtlck->lv[dtlck->index];
2385                 lv->offset = 0;
2386                 lv->length = 1;
2387                 dtlck->index++;
2388 
2389                 /* linelock stbl of non-root leaf page */
2390                 if (!(p->header.flag & BT_ROOT)) {
2391                         if (dtlck->index < dtlck->maxcnt)
2392                                 lv++;
2393                         else {
2394                                 dtlck = (struct dt_lock *) txLinelock(dtlck);
2395                                 lv = & dtlck->lv[0];
2396                         }
2397                         i = index >> L2DTSLOTSIZE;
2398                         lv->offset = p->header.stblindex + i;
2399                         lv->length =
2400                             ((p->header.nextindex - 1) >> L2DTSLOTSIZE) -
2401                             i + 1;
2402                         dtlck->index++;
2403                 }
2404 
2405                 /* free the router entry */
2406                 dtDeleteEntry(p, index, &dtlck);
2407 
2408                 /* reset key of new leftmost entry of level (for consistency) */
2409                 if (index == 0 &&
2410                     ((p->header.flag & BT_ROOT) || p->header.prev == 0))
2411                         dtTruncateEntry(p, 0, &dtlck);
2412 
2413                 /* unpin the parent page */
2414                 DT_PUTPAGE(mp);
2415 
2416                 /* exit propagation up */
2417                 break;
2418         }
2419 
2420         if (!DO_INDEX(ip))
2421                 ip->i_size -= PSIZE;
2422 
2423         return 0;
2424 }
2425 
2426 #ifdef _NOTYET
2427 /*
2428  * NAME:        dtRelocate()
2429  *
2430  * FUNCTION:    relocate dtpage (internal or leaf) of directory;
2431  *              This function is mainly used by defragfs utility.
2432  */
2433 int dtRelocate(tid_t tid, struct inode *ip, s64 lmxaddr, pxd_t * opxd,
2434                s64 nxaddr)
2435 {
2436         int rc = 0;
2437         struct metapage *mp, *pmp, *lmp, *rmp;
2438         dtpage_t *p, *pp, *rp = 0, *lp= 0;
2439         s64 bn;
2440         int index;
2441         struct btstack btstack;
2442         pxd_t *pxd;
2443         s64 oxaddr, nextbn, prevbn;
2444         int xlen, xsize;
2445         struct tlock *tlck;
2446         struct dt_lock *dtlck;
2447         struct pxd_lock *pxdlock;
2448         s8 *stbl;
2449         struct lv *lv;
2450 
2451         oxaddr = addressPXD(opxd);
2452         xlen = lengthPXD(opxd);
2453 
2454         jfs_info("dtRelocate: lmxaddr:%Ld xaddr:%Ld:%Ld xlen:%d",
2455                    (long long)lmxaddr, (long long)oxaddr, (long long)nxaddr,
2456                    xlen);
2457 
2458         /*
2459          *      1. get the internal parent dtpage covering
2460          *      router entry for the tartget page to be relocated;
2461          */
2462         rc = dtSearchNode(ip, lmxaddr, opxd, &btstack);
2463         if (rc)
2464                 return rc;
2465 
2466         /* retrieve search result */
2467         DT_GETSEARCH(ip, btstack.top, bn, pmp, pp, index);
2468         jfs_info("dtRelocate: parent router entry validated.");
2469 
2470         /*
2471          *      2. relocate the target dtpage
2472          */
2473         /* read in the target page from src extent */
2474         DT_GETPAGE(ip, oxaddr, mp, PSIZE, p, rc);
2475         if (rc) {
2476                 /* release the pinned parent page */
2477                 DT_PUTPAGE(pmp);
2478                 return rc;
2479         }
2480 
2481         /*
2482          * read in sibling pages if any to update sibling pointers;
2483          */
2484         rmp = NULL;
2485         if (p->header.next) {
2486                 nextbn = le64_to_cpu(p->header.next);
2487                 DT_GETPAGE(ip, nextbn, rmp, PSIZE, rp, rc);
2488                 if (rc) {
2489                         DT_PUTPAGE(mp);
2490                         DT_PUTPAGE(pmp);
2491                         return (rc);
2492                 }
2493         }
2494 
2495         lmp = NULL;
2496         if (p->header.prev) {
2497                 prevbn = le64_to_cpu(p->header.prev);
2498                 DT_GETPAGE(ip, prevbn, lmp, PSIZE, lp, rc);
2499                 if (rc) {
2500                         DT_PUTPAGE(mp);
2501                         DT_PUTPAGE(pmp);
2502                         if (rmp)
2503                                 DT_PUTPAGE(rmp);
2504                         return (rc);
2505                 }
2506         }
2507 
2508         /* at this point, all xtpages to be updated are in memory */
2509 
2510         /*
2511          * update sibling pointers of sibling dtpages if any;
2512          */
2513         if (lmp) {
2514                 tlck = txLock(tid, ip, lmp, tlckDTREE | tlckRELINK);
2515                 dtlck = (struct dt_lock *) & tlck->lock;
2516                 /* linelock header */
2517                 ASSERT(dtlck->index == 0);
2518                 lv = & dtlck->lv[0];
2519                 lv->offset = 0;
2520                 lv->length = 1;
2521                 dtlck->index++;
2522 
2523                 lp->header.next = cpu_to_le64(nxaddr);
2524                 DT_PUTPAGE(lmp);
2525         }
2526 
2527         if (rmp) {
2528                 tlck = txLock(tid, ip, rmp, tlckDTREE | tlckRELINK);
2529                 dtlck = (struct dt_lock *) & tlck->lock;
2530                 /* linelock header */
2531                 ASSERT(dtlck->index == 0);
2532                 lv = & dtlck->lv[0];
2533                 lv->offset = 0;
2534                 lv->length = 1;
2535                 dtlck->index++;
2536 
2537                 rp->header.prev = cpu_to_le64(nxaddr);
2538                 DT_PUTPAGE(rmp);
2539         }
2540 
2541         /*
2542          * update the target dtpage to be relocated
2543          *
2544          * write LOG_REDOPAGE of LOG_NEW type for dst page
2545          * for the whole target page (logredo() will apply
2546          * after image and update bmap for allocation of the
2547          * dst extent), and update bmap for allocation of
2548          * the dst extent;
2549          */
2550         tlck = txLock(tid, ip, mp, tlckDTREE | tlckNEW);
2551         dtlck = (struct dt_lock *) & tlck->lock;
2552         /* linelock header */
2553         ASSERT(dtlck->index == 0);
2554         lv = & dtlck->lv[0];
2555 
2556         /* update the self address in the dtpage header */
2557         pxd = &p->header.self;
2558         PXDaddress(pxd, nxaddr);
2559 
2560         /* the dst page is the same as the src page, i.e.,
2561          * linelock for afterimage of the whole page;
2562          */
2563         lv->offset = 0;
2564         lv->length = p->header.maxslot;
2565         dtlck->index++;
2566 
2567         /* update the buffer extent descriptor of the dtpage */
2568         xsize = xlen << JFS_SBI(ip->i_sb)->l2bsize;
2569 
2570         /* unpin the relocated page */
2571         DT_PUTPAGE(mp);
2572         jfs_info("dtRelocate: target dtpage relocated.");
2573 
2574         /* the moved extent is dtpage, then a LOG_NOREDOPAGE log rec
2575          * needs to be written (in logredo(), the LOG_NOREDOPAGE log rec
2576          * will also force a bmap update ).
2577          */
2578 
2579         /*
2580          *      3. acquire maplock for the source extent to be freed;
2581          */
2582         /* for dtpage relocation, write a LOG_NOREDOPAGE record
2583          * for the source dtpage (logredo() will init NoRedoPage
2584          * filter and will also update bmap for free of the source
2585          * dtpage), and upadte bmap for free of the source dtpage;
2586          */
2587         tlck = txMaplock(tid, ip, tlckDTREE | tlckFREE);
2588         pxdlock = (struct pxd_lock *) & tlck->lock;
2589         pxdlock->flag = mlckFREEPXD;
2590         PXDaddress(&pxdlock->pxd, oxaddr);
2591         PXDlength(&pxdlock->pxd, xlen);
2592         pxdlock->index = 1;
2593 
2594         /*
2595          *      4. update the parent router entry for relocation;
2596          *
2597          * acquire tlck for the parent entry covering the target dtpage;
2598          * write LOG_REDOPAGE to apply after image only;
2599          */
2600         jfs_info("dtRelocate: update parent router entry.");
2601         tlck = txLock(tid, ip, pmp, tlckDTREE | tlckENTRY);
2602         dtlck = (struct dt_lock *) & tlck->lock;
2603         lv = & dtlck->lv[dtlck->index];
2604 
2605         /* update the PXD with the new address */
2606         stbl = DT_GETSTBL(pp);
2607         pxd = (pxd_t *) & pp->slot[stbl[index]];
2608         PXDaddress(pxd, nxaddr);
2609         lv->offset = stbl[index];
2610         lv->length = 1;
2611         dtlck->index++;
2612 
2613         /* unpin the parent dtpage */
2614         DT_PUTPAGE(pmp);
2615 
2616         return rc;
2617 }
2618 
2619 /*
2620  * NAME:        dtSearchNode()
2621  *
2622  * FUNCTION:    Search for an dtpage containing a specified address
2623  *              This function is mainly used by defragfs utility.
2624  *
2625  * NOTE:        Search result on stack, the found page is pinned at exit.
2626  *              The result page must be an internal dtpage.
2627  *              lmxaddr give the address of the left most page of the
2628  *              dtree level, in which the required dtpage resides.
2629  */
2630 static int dtSearchNode(struct inode *ip, s64 lmxaddr, pxd_t * kpxd,
2631                         struct btstack * btstack)
2632 {
2633         int rc = 0;
2634         s64 bn;
2635         struct metapage *mp;
2636         dtpage_t *p;
2637         int psize = 288;        /* initial in-line directory */
2638         s8 *stbl;
2639         int i;
2640         pxd_t *pxd;
2641         struct btframe *btsp;
2642 
2643         BT_CLR(btstack);        /* reset stack */
2644 
2645         /*
2646          *      descend tree to the level with specified leftmost page
2647          *
2648          *  by convention, root bn = 0.
2649          */
2650         for (bn = 0;;) {
2651                 /* get/pin the page to search */
2652                 DT_GETPAGE(ip, bn, mp, psize, p, rc);
2653                 if (rc)
2654                         return rc;
2655 
2656                 /* does the xaddr of leftmost page of the levevl
2657                  * matches levevl search key ?
2658                  */
2659                 if (p->header.flag & BT_ROOT) {
2660                         if (lmxaddr == 0)
2661                                 break;
2662                 } else if (addressPXD(&p->header.self) == lmxaddr)
2663                         break;
2664 
2665                 /*
2666                  * descend down to leftmost child page
2667                  */
2668                 if (p->header.flag & BT_LEAF) {
2669                         DT_PUTPAGE(mp);
2670                         return -ESTALE;
2671                 }
2672 
2673                 /* get the leftmost entry */
2674                 stbl = DT_GETSTBL(p);
2675                 pxd = (pxd_t *) & p->slot[stbl[0]];
2676 
2677                 /* get the child page block address */
2678                 bn = addressPXD(pxd);
2679                 psize = lengthPXD(pxd) << JFS_SBI(ip->i_sb)->l2bsize;
2680                 /* unpin the parent page */
2681                 DT_PUTPAGE(mp);
2682         }
2683 
2684         /*
2685          *      search each page at the current levevl
2686          */
2687       loop:
2688         stbl = DT_GETSTBL(p);
2689         for (i = 0; i < p->header.nextindex; i++) {
2690                 pxd = (pxd_t *) & p->slot[stbl[i]];
2691 
2692                 /* found the specified router entry */
2693                 if (addressPXD(pxd) == addressPXD(kpxd) &&
2694                     lengthPXD(pxd) == lengthPXD(kpxd)) {
2695                         btsp = btstack->top;
2696                         btsp->bn = bn;
2697                         btsp->index = i;
2698                         btsp->mp = mp;
2699 
2700                         return 0;
2701                 }
2702         }
2703 
2704         /* get the right sibling page if any */
2705         if (p->header.next)
2706                 bn = le64_to_cpu(p->header.next);
2707         else {
2708                 DT_PUTPAGE(mp);
2709                 return -ESTALE;
2710         }
2711 
2712         /* unpin current page */
2713         DT_PUTPAGE(mp);
2714 
2715         /* get the right sibling page */
2716         DT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
2717         if (rc)
2718                 return rc;
2719 
2720         goto loop;
2721 }
2722 #endif /* _NOTYET */
2723 
2724 /*
2725  *      dtRelink()
2726  *
2727  * function:
2728  *      link around a freed page.
2729  *
2730  * parameter:
2731  *      fp:     page to be freed
2732  *
2733  * return:
2734  */
2735 static int dtRelink(tid_t tid, struct inode *ip, dtpage_t * p)
2736 {
2737         int rc;
2738         struct metapage *mp;
2739         s64 nextbn, prevbn;
2740         struct tlock *tlck;
2741         struct dt_lock *dtlck;
2742         struct lv *lv;
2743 
2744         nextbn = le64_to_cpu(p->header.next);
2745         prevbn = le64_to_cpu(p->header.prev);
2746 
2747         /* update prev pointer of the next page */
2748         if (nextbn != 0) {
2749                 DT_GETPAGE(ip, nextbn, mp, PSIZE, p, rc);
2750                 if (rc)
2751                         return rc;
2752 
2753                 BT_MARK_DIRTY(mp, ip);
2754                 /*
2755                  * acquire a transaction lock on the next page
2756                  *
2757                  * action: update prev pointer;
2758                  */
2759                 tlck = txLock(tid, ip, mp, tlckDTREE | tlckRELINK);
2760                 jfs_info("dtRelink nextbn: tlck = 0x%p, ip = 0x%p, mp=0x%p",
2761                         tlck, ip, mp);
2762                 dtlck = (struct dt_lock *) & tlck->lock;
2763 
2764                 /* linelock header */
2765                 if (dtlck->index >= dtlck->maxcnt)
2766                         dtlck = (struct dt_lock *) txLinelock(dtlck);
2767                 lv = & dtlck->lv[dtlck->index];
2768                 lv->offset = 0;
2769                 lv->length = 1;
2770                 dtlck->index++;
2771 
2772                 p->header.prev = cpu_to_le64(prevbn);
2773                 DT_PUTPAGE(mp);
2774         }
2775 
2776         /* update next pointer of the previous page */
2777         if (prevbn != 0) {
2778                 DT_GETPAGE(ip, prevbn, mp, PSIZE, p, rc);
2779                 if (rc)
2780                         return rc;
2781 
2782                 BT_MARK_DIRTY(mp, ip);
2783                 /*
2784                  * acquire a transaction lock on the prev page
2785                  *
2786                  * action: update next pointer;
2787                  */
2788                 tlck = txLock(tid, ip, mp, tlckDTREE | tlckRELINK);
2789                 jfs_info("dtRelink prevbn: tlck = 0x%p, ip = 0x%p, mp=0x%p",
2790                         tlck, ip, mp);
2791                 dtlck = (struct dt_lock *) & tlck->lock;
2792 
2793                 /* linelock header */
2794                 if (dtlck->index >= dtlck->maxcnt)
2795                         dtlck = (struct dt_lock *) txLinelock(dtlck);
2796                 lv = & dtlck->lv[dtlck->index];
2797                 lv->offset = 0;
2798                 lv->length = 1;
2799                 dtlck->index++;
2800 
2801                 p->header.next = cpu_to_le64(nextbn);
2802                 DT_PUTPAGE(mp);
2803         }
2804 
2805         return 0;
2806 }
2807 
2808 
2809 /*
2810  *      dtInitRoot()
2811  *
2812  * initialize directory root (inline in inode)
2813  */
2814 void dtInitRoot(tid_t tid, struct inode *ip, u32 idotdot)
2815 {
2816         struct jfs_inode_info *jfs_ip = JFS_IP(ip);
2817         dtroot_t *p;
2818         int fsi;
2819         struct dtslot *f;
2820         struct tlock *tlck;
2821         struct dt_lock *dtlck;
2822         struct lv *lv;
2823         u16 xflag_save;
2824 
2825         /*
2826          * If this was previously an non-empty directory, we need to remove
2827          * the old directory table.
2828          */
2829         if (DO_INDEX(ip)) {
2830                 if (!jfs_dirtable_inline(ip)) {
2831                         struct tblock *tblk = tid_to_tblock(tid);
2832                         /*
2833                          * We're playing games with the tid's xflag.  If
2834                          * we're removing a regular file, the file's xtree
2835                          * is committed with COMMIT_PMAP, but we always
2836                          * commit the directories xtree with COMMIT_PWMAP.
2837                          */
2838                         xflag_save = tblk->xflag;
2839                         tblk->xflag = 0;
2840                         /*
2841                          * xtTruncate isn't guaranteed to fully truncate
2842                          * the xtree.  The caller needs to check i_size
2843                          * after committing the transaction to see if
2844                          * additional truncation is needed.  The
2845                          * COMMIT_Stale flag tells caller that we
2846                          * initiated the truncation.
2847                          */
2848                         xtTruncate(tid, ip, 0, COMMIT_PWMAP);
2849                         set_cflag(COMMIT_Stale, ip);
2850 
2851                         tblk->xflag = xflag_save;
2852                 } else
2853                         ip->i_size = 1;
2854 
2855                 jfs_ip->next_index = 2;
2856         } else
2857                 ip->i_size = IDATASIZE;
2858 
2859         /*
2860          * acquire a transaction lock on the root
2861          *
2862          * action: directory initialization;
2863          */
2864         tlck = txLock(tid, ip, (struct metapage *) & jfs_ip->bxflag,
2865                       tlckDTREE | tlckENTRY | tlckBTROOT);
2866         dtlck = (struct dt_lock *) & tlck->lock;
2867 
2868         /* linelock root */
2869         ASSERT(dtlck->index == 0);
2870         lv = & dtlck->lv[0];
2871         lv->offset = 0;
2872         lv->length = DTROOTMAXSLOT;
2873         dtlck->index++;
2874 
2875         p = &jfs_ip->i_dtroot;
2876 
2877         p->header.flag = DXD_INDEX | BT_ROOT | BT_LEAF;
2878 
2879         p->header.nextindex = 0;
2880 
2881         /* init freelist */
2882         fsi = 1;
2883         f = &p->slot[fsi];
2884 
2885         /* init data area of root */
2886         for (fsi++; fsi < DTROOTMAXSLOT; f++, fsi++)
2887                 f->next = fsi;
2888         f->next = -1;
2889 
2890         p->header.freelist = 1;
2891         p->header.freecnt = 8;
2892 
2893         /* init '..' entry */
2894         p->header.idotdot = cpu_to_le32(idotdot);
2895 
2896         return;
2897 }
2898 
2899 /*
2900  *      add_missing_indices()
2901  *
2902  * function: Fix dtree page in which one or more entries has an invalid index.
2903  *           fsck.jfs should really fix this, but it currently does not.
2904  *           Called from jfs_readdir when bad index is detected.
2905  */
2906 static void add_missing_indices(struct inode *inode, s64 bn)
2907 {
2908         struct ldtentry *d;
2909         struct dt_lock *dtlck;
2910         int i;
2911         uint index;
2912         struct lv *lv;
2913         struct metapage *mp;
2914         dtpage_t *p;
2915         int rc;
2916         s8 *stbl;
2917         tid_t tid;
2918         struct tlock *tlck;
2919 
2920         tid = txBegin(inode->i_sb, 0);
2921 
2922         DT_GETPAGE(inode, bn, mp, PSIZE, p, rc);
2923 
2924         if (rc) {
2925                 printk(KERN_ERR "DT_GETPAGE failed!\n");
2926                 goto end;
2927         }
2928         BT_MARK_DIRTY(mp, inode);
2929 
2930         ASSERT(p->header.flag & BT_LEAF);
2931 
2932         tlck = txLock(tid, inode, mp, tlckDTREE | tlckENTRY);
2933         if (BT_IS_ROOT(mp))
2934                 tlck->type |= tlckBTROOT;
2935 
2936         dtlck = (struct dt_lock *) &tlck->lock;
2937 
2938         stbl = DT_GETSTBL(p);
2939         for (i = 0; i < p->header.nextindex; i++) {
2940                 d = (struct ldtentry *) &p->slot[stbl[i]];
2941                 index = le32_to_cpu(d->index);
2942                 if ((index < 2) || (index >= JFS_IP(inode)->next_index)) {
2943                         d->index = cpu_to_le32(add_index(tid, inode, bn, i));
2944                         if (dtlck->index >= dtlck->maxcnt)
2945                                 dtlck = (struct dt_lock *) txLinelock(dtlck);
2946                         lv = &dtlck->lv[dtlck->index];
2947                         lv->offset = stbl[i];
2948                         lv->length = 1;
2949                         dtlck->index++;
2950                 }
2951         }
2952 
2953         DT_PUTPAGE(mp);
2954         (void) txCommit(tid, 1, &inode, 0);
2955 end:
2956         txEnd(tid);
2957 }
2958 
2959 /*
2960  * Buffer to hold directory entry info while traversing a dtree page
2961  * before being fed to the filldir function
2962  */
2963 struct jfs_dirent {
2964         loff_t position;
2965         int ino;
2966         u16 name_len;
2967         char name[0];
2968 };
2969 
2970 /*
2971  * function to determine next variable-sized jfs_dirent in buffer
2972  */
2973 static inline struct jfs_dirent *next_jfs_dirent(struct jfs_dirent *dirent)
2974 {
2975         return (struct jfs_dirent *)
2976                 ((char *)dirent +
2977                  ((sizeof (struct jfs_dirent) + dirent->name_len + 1 +
2978                    sizeof (loff_t) - 1) &
2979                   ~(sizeof (loff_t) - 1)));
2980 }
2981 
2982 /*
2983  *      jfs_readdir()
2984  *
2985  * function: read directory entries sequentially
2986  *      from the specified entry offset
2987  *
2988  * parameter:
2989  *
2990  * return: offset = (pn, index) of start entry
2991  *      of next jfs_readdir()/dtRead()
2992  */
2993 int jfs_readdir(struct file *file, struct dir_context *ctx)
2994 {
2995         struct inode *ip = file_inode(file);
2996         struct nls_table *codepage = JFS_SBI(ip->i_sb)->nls_tab;
2997         int rc = 0;
2998         loff_t dtpos;   /* legacy OS/2 style position */
2999         struct dtoffset {
3000                 s16 pn;
3001                 s16 index;
3002                 s32 unused;
3003         } *dtoffset = (struct dtoffset *) &dtpos;
3004         s64 bn;
3005         struct metapage *mp;
3006         dtpage_t *p;
3007         int index;
3008         s8 *stbl;
3009         struct btstack btstack;
3010         int i, next;
3011         struct ldtentry *d;
3012         struct dtslot *t;
3013         int d_namleft, len, outlen;
3014         unsigned long dirent_buf;
3015         char *name_ptr;
3016         u32 dir_index;
3017         int do_index = 0;
3018         uint loop_count = 0;
3019         struct jfs_dirent *jfs_dirent;
3020         int jfs_dirents;
3021         int overflow, fix_page, page_fixed = 0;
3022         static int unique_pos = 2;      /* If we can't fix broken index */
3023 
3024         if (ctx->pos == DIREND)
3025                 return 0;
3026 
3027         if (DO_INDEX(ip)) {
3028                 /*
3029                  * persistent index is stored in directory entries.
3030                  * Special cases:        0 = .
3031                  *                       1 = ..
3032                  *                      -1 = End of directory
3033                  */
3034                 do_index = 1;
3035 
3036                 dir_index = (u32) ctx->pos;
3037 
3038                 /*
3039                  * NFSv4 reserves cookies 1 and 2 for . and .. so the value
3040                  * we return to the vfs is one greater than the one we use
3041                  * internally.
3042                  */
3043                 if (dir_index)
3044                         dir_index--;
3045 
3046                 if (dir_index > 1) {
3047                         struct dir_table_slot dirtab_slot;
3048 
3049                         if (dtEmpty(ip) ||
3050                             (dir_index >= JFS_IP(ip)->next_index)) {
3051                                 /* Stale position.  Directory has shrunk */
3052                                 ctx->pos = DIREND;
3053                                 return 0;
3054                         }
3055                       repeat:
3056                         rc = read_index(ip, dir_index, &dirtab_slot);
3057                         if (rc) {
3058                                 ctx->pos = DIREND;
3059                                 return rc;
3060                         }
3061                         if (dirtab_slot.flag == DIR_INDEX_FREE) {
3062                                 if (loop_count++ > JFS_IP(ip)->next_index) {
3063                                         jfs_err("jfs_readdir detected infinite loop!");
3064                                         ctx->pos = DIREND;
3065                                         return 0;
3066                                 }
3067                                 dir_index = le32_to_cpu(dirtab_slot.addr2);
3068                                 if (dir_index == -1) {
3069                                         ctx->pos = DIREND;
3070                                         return 0;
3071                                 }
3072                                 goto repeat;
3073                         }
3074                         bn = addressDTS(&dirtab_slot);
3075                         index = dirtab_slot.slot;
3076                         DT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
3077                         if (rc) {
3078                                 ctx->pos = DIREND;
3079                                 return 0;
3080                         }
3081                         if (p->header.flag & BT_INTERNAL) {
3082                                 jfs_err("jfs_readdir: bad index table");
3083                                 DT_PUTPAGE(mp);
3084                                 ctx->pos = DIREND;
3085                                 return 0;
3086                         }
3087                 } else {
3088                         if (dir_index == 0) {
3089                                 /*
3090                                  * self "."
3091                                  */
3092                                 ctx->pos = 1;
3093                                 if (!dir_emit(ctx, ".", 1, ip->i_ino, DT_DIR))
3094                                         return 0;
3095                         }
3096                         /*
3097                          * parent ".."
3098                          */
3099                         ctx->pos = 2;
3100                         if (!dir_emit(ctx, "..", 2, PARENT(ip), DT_DIR))
3101                                 return 0;
3102 
3103                         /*
3104                          * Find first entry of left-most leaf
3105                          */
3106                         if (dtEmpty(ip)) {
3107                                 ctx->pos = DIREND;
3108                                 return 0;
3109                         }
3110 
3111                         if ((rc = dtReadFirst(ip, &btstack)))
3112                                 return rc;
3113 
3114                         DT_GETSEARCH(ip, btstack.top, bn, mp, p, index);
3115                 }
3116         } else {
3117                 /*
3118                  * Legacy filesystem - OS/2 & Linux JFS < 0.3.6
3119                  *
3120                  * pn = 0; index = 1:   First entry "."
3121                  * pn = 0; index = 2:   Second entry ".."
3122                  * pn > 0:              Real entries, pn=1 -> leftmost page
3123                  * pn = index = -1:     No more entries
3124                  */
3125                 dtpos = ctx->pos;
3126                 if (dtpos < 2) {
3127                         /* build "." entry */
3128                         ctx->pos = 1;
3129                         if (!dir_emit(ctx, ".", 1, ip->i_ino, DT_DIR))
3130                                 return 0;
3131                         dtoffset->index = 2;
3132                         ctx->pos = dtpos;
3133                 }
3134 
3135                 if (dtoffset->pn == 0) {
3136                         if (dtoffset->index == 2) {
3137                                 /* build ".." entry */
3138                                 if (!dir_emit(ctx, "..", 2, PARENT(ip), DT_DIR))
3139                                         return 0;
3140                         } else {
3141                                 jfs_err("jfs_readdir called with invalid offset!");
3142                         }
3143                         dtoffset->pn = 1;
3144                         dtoffset->index = 0;
3145                         ctx->pos = dtpos;
3146                 }
3147 
3148                 if (dtEmpty(ip)) {
3149                         ctx->pos = DIREND;
3150                         return 0;
3151                 }
3152 
3153                 if ((rc = dtReadNext(ip, &ctx->pos, &btstack))) {
3154                         jfs_err("jfs_readdir: unexpected rc = %d from dtReadNext",
3155                                 rc);
3156                         ctx->pos = DIREND;
3157                         return 0;
3158                 }
3159                 /* get start leaf page and index */
3160                 DT_GETSEARCH(ip, btstack.top, bn, mp, p, index);
3161 
3162                 /* offset beyond directory eof ? */
3163                 if (bn < 0) {
3164                         ctx->pos = DIREND;
3165                         return 0;
3166                 }
3167         }
3168 
3169         dirent_buf = __get_free_page(GFP_KERNEL);
3170         if (dirent_buf == 0) {
3171                 DT_PUTPAGE(mp);
3172                 jfs_warn("jfs_readdir: __get_free_page failed!");
3173                 ctx->pos = DIREND;
3174                 return -ENOMEM;
3175         }
3176 
3177         while (1) {
3178                 jfs_dirent = (struct jfs_dirent *) dirent_buf;
3179                 jfs_dirents = 0;
3180                 overflow = fix_page = 0;
3181 
3182                 stbl = DT_GETSTBL(p);
3183 
3184                 for (i = index; i < p->header.nextindex; i++) {
3185                         d = (struct ldtentry *) & p->slot[stbl[i]];
3186 
3187                         if (((long) jfs_dirent + d->namlen + 1) >
3188                             (dirent_buf + PAGE_SIZE)) {
3189                                 /* DBCS codepages could overrun dirent_buf */
3190                                 index = i;
3191                                 overflow = 1;
3192                                 break;
3193                         }
3194 
3195                         d_namleft = d->namlen;
3196                         name_ptr = jfs_dirent->name;
3197                         jfs_dirent->ino = le32_to_cpu(d->inumber);
3198 
3199                         if (do_index) {
3200                                 len = min(d_namleft, DTLHDRDATALEN);
3201                                 jfs_dirent->position = le32_to_cpu(d->index);
3202                                 /*
3203                                  * d->index should always be valid, but it
3204                                  * isn't.  fsck.jfs doesn't create the
3205                                  * directory index for the lost+found
3206                                  * directory.  Rather than let it go,
3207                                  * we can try to fix it.
3208                                  */
3209                                 if ((jfs_dirent->position < 2) ||
3210                                     (jfs_dirent->position >=
3211                                      JFS_IP(ip)->next_index)) {
3212                                         if (!page_fixed && !isReadOnly(ip)) {
3213                                                 fix_page = 1;
3214                                                 /*
3215                                                  * setting overflow and setting
3216                                                  * index to i will cause the
3217                                                  * same page to be processed
3218                                                  * again starting here
3219                                                  */
3220                                                 overflow = 1;
3221                                                 index = i;
3222                                                 break;
3223                                         }
3224                                         jfs_dirent->position = unique_pos++;
3225                                 }
3226                                 /*
3227                                  * We add 1 to the index because we may
3228                                  * use a value of 2 internally, and NFSv4
3229                                  * doesn't like that.
3230                                  */
3231                                 jfs_dirent->position++;
3232                         } else {
3233                                 jfs_dirent->position = dtpos;
3234                                 len = min(d_namleft, DTLHDRDATALEN_LEGACY);
3235                         }
3236 
3237                         /* copy the name of head/only segment */
3238                         outlen = jfs_strfromUCS_le(name_ptr, d->name, len,
3239                                                    codepage);
3240                         jfs_dirent->name_len = outlen;
3241 
3242                         /* copy name in the additional segment(s) */
3243                         next = d->next;
3244                         while (next >= 0) {
3245                                 t = (struct dtslot *) & p->slot[next];
3246                                 name_ptr += outlen;
3247                                 d_namleft -= len;
3248                                 /* Sanity Check */
3249                                 if (d_namleft == 0) {
3250                                         jfs_error(ip->i_sb,
3251                                                   "JFS:Dtree error: ino = %ld, bn=%lld, index = %d\n",
3252                                                   (long)ip->i_ino,
3253                                                   (long long)bn,
3254                                                   i);
3255                                         goto skip_one;
3256                                 }
3257                                 len = min(d_namleft, DTSLOTDATALEN);
3258                                 outlen = jfs_strfromUCS_le(name_ptr, t->name,
3259                                                            len, codepage);
3260                                 jfs_dirent->name_len += outlen;
3261 
3262                                 next = t->next;
3263                         }
3264 
3265                         jfs_dirents++;
3266                         jfs_dirent = next_jfs_dirent(jfs_dirent);
3267 skip_one:
3268                         if (!do_index)
3269                                 dtoffset->index++;
3270                 }
3271 
3272                 if (!overflow) {
3273                         /* Point to next leaf page */
3274                         if (p->header.flag & BT_ROOT)
3275                                 bn = 0;
3276                         else {
3277                                 bn = le64_to_cpu(p->header.next);
3278                                 index = 0;
3279                                 /* update offset (pn:index) for new page */
3280                                 if (!do_index) {
3281                                         dtoffset->pn++;
3282                                         dtoffset->index = 0;
3283                                 }
3284                         }
3285                         page_fixed = 0;
3286                 }
3287 
3288                 /* unpin previous leaf page */
3289                 DT_PUTPAGE(mp);
3290 
3291                 jfs_dirent = (struct jfs_dirent *) dirent_buf;
3292                 while (jfs_dirents--) {
3293                         ctx->pos = jfs_dirent->position;
3294                         if (!dir_emit(ctx, jfs_dirent->name,
3295                                     jfs_dirent->name_len,
3296                                     jfs_dirent->ino, DT_UNKNOWN))
3297                                 goto out;
3298                         jfs_dirent = next_jfs_dirent(jfs_dirent);
3299                 }
3300 
3301                 if (fix_page) {
3302                         add_missing_indices(ip, bn);
3303                         page_fixed = 1;
3304                 }
3305 
3306                 if (!overflow && (bn == 0)) {
3307                         ctx->pos = DIREND;
3308                         break;
3309                 }
3310 
3311                 DT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
3312                 if (rc) {
3313                         free_page(dirent_buf);
3314                         return rc;
3315                 }
3316         }
3317 
3318       out:
3319         free_page(dirent_buf);
3320 
3321         return rc;
3322 }
3323 
3324 
3325 /*
3326  *      dtReadFirst()
3327  *
3328  * function: get the leftmost page of the directory
3329  */
3330 static int dtReadFirst(struct inode *ip, struct btstack * btstack)
3331 {
3332         int rc = 0;
3333         s64 bn;
3334         int psize = 288;        /* initial in-line directory */
3335         struct metapage *mp;
3336         dtpage_t *p;
3337         s8 *stbl;
3338         struct btframe *btsp;
3339         pxd_t *xd;
3340 
3341         BT_CLR(btstack);        /* reset stack */
3342 
3343         /*
3344          *      descend leftmost path of the tree
3345          *
3346          * by convention, root bn = 0.
3347          */
3348         for (bn = 0;;) {
3349                 DT_GETPAGE(ip, bn, mp, psize, p, rc);
3350                 if (rc)
3351                         return rc;
3352 
3353                 /*
3354                  * leftmost leaf page
3355                  */
3356                 if (p->header.flag & BT_LEAF) {
3357                         /* return leftmost entry */
3358                         btsp = btstack->top;
3359                         btsp->bn = bn;
3360                         btsp->index = 0;
3361                         btsp->mp = mp;
3362 
3363                         return 0;
3364                 }
3365 
3366                 /*
3367                  * descend down to leftmost child page
3368                  */
3369                 if (BT_STACK_FULL(btstack)) {
3370                         DT_PUTPAGE(mp);
3371                         jfs_error(ip->i_sb, "btstack overrun\n");
3372                         BT_STACK_DUMP(btstack);
3373                         return -EIO;
3374                 }
3375                 /* push (bn, index) of the parent page/entry */
3376                 BT_PUSH(btstack, bn, 0);
3377 
3378                 /* get the leftmost entry */
3379                 stbl = DT_GETSTBL(p);
3380                 xd = (pxd_t *) & p->slot[stbl[0]];
3381 
3382                 /* get the child page block address */
3383                 bn = addressPXD(xd);
3384                 psize = lengthPXD(xd) << JFS_SBI(ip->i_sb)->l2bsize;
3385 
3386                 /* unpin the parent page */
3387                 DT_PUTPAGE(mp);
3388         }
3389 }
3390 
3391 
3392 /*
3393  *      dtReadNext()
3394  *
3395  * function: get the page of the specified offset (pn:index)
3396  *
3397  * return: if (offset > eof), bn = -1;
3398  *
3399  * note: if index > nextindex of the target leaf page,
3400  * start with 1st entry of next leaf page;
3401  */
3402 static int dtReadNext(struct inode *ip, loff_t * offset,
3403                       struct btstack * btstack)
3404 {
3405         int rc = 0;
3406         struct dtoffset {
3407                 s16 pn;
3408                 s16 index;
3409                 s32 unused;
3410         } *dtoffset = (struct dtoffset *) offset;
3411         s64 bn;
3412         struct metapage *mp;
3413         dtpage_t *p;
3414         int index;
3415         int pn;
3416         s8 *stbl;
3417         struct btframe *btsp, *parent;
3418         pxd_t *xd;
3419 
3420         /*
3421          * get leftmost leaf page pinned
3422          */
3423         if ((rc = dtReadFirst(ip, btstack)))
3424                 return rc;
3425 
3426         /* get leaf page */
3427         DT_GETSEARCH(ip, btstack->top, bn, mp, p, index);
3428 
3429         /* get the start offset (pn:index) */
3430         pn = dtoffset->pn - 1;  /* Now pn = 0 represents leftmost leaf */
3431         index = dtoffset->index;
3432 
3433         /* start at leftmost page ? */
3434         if (pn == 0) {
3435                 /* offset beyond eof ? */
3436                 if (index < p->header.nextindex)
3437                         goto out;
3438 
3439                 if (p->header.flag & BT_ROOT) {
3440                         bn = -1;
3441                         goto out;
3442                 }
3443 
3444                 /* start with 1st entry of next leaf page */
3445                 dtoffset->pn++;
3446                 dtoffset->index = index = 0;
3447                 goto a;
3448         }
3449 
3450         /* start at non-leftmost page: scan parent pages for large pn */
3451         if (p->header.flag & BT_ROOT) {
3452                 bn = -1;
3453                 goto out;
3454         }
3455 
3456         /* start after next leaf page ? */
3457         if (pn > 1)
3458                 goto b;
3459 
3460         /* get leaf page pn = 1 */
3461       a:
3462         bn = le64_to_cpu(p->header.next);
3463 
3464         /* unpin leaf page */
3465         DT_PUTPAGE(mp);
3466 
3467         /* offset beyond eof ? */
3468         if (bn == 0) {
3469                 bn = -1;
3470                 goto out;
3471         }
3472 
3473         goto c;
3474 
3475         /*
3476          * scan last internal page level to get target leaf page
3477          */
3478       b:
3479         /* unpin leftmost leaf page */
3480         DT_PUTPAGE(mp);
3481 
3482         /* get left most parent page */
3483         btsp = btstack->top;
3484         parent = btsp - 1;
3485         bn = parent->bn;
3486         DT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
3487         if (rc)
3488                 return rc;
3489 
3490         /* scan parent pages at last internal page level */
3491         while (pn >= p->header.nextindex) {
3492                 pn -= p->header.nextindex;
3493 
3494                 /* get next parent page address */
3495                 bn = le64_to_cpu(p->header.next);
3496 
3497                 /* unpin current parent page */
3498                 DT_PUTPAGE(mp);
3499 
3500                 /* offset beyond eof ? */
3501                 if (bn == 0) {
3502                         bn = -1;
3503                         goto out;
3504                 }
3505 
3506                 /* get next parent page */
3507                 DT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
3508                 if (rc)
3509                         return rc;
3510 
3511                 /* update parent page stack frame */
3512                 parent->bn = bn;
3513         }
3514 
3515         /* get leaf page address */
3516         stbl = DT_GETSTBL(p);
3517         xd = (pxd_t *) & p->slot[stbl[pn]];
3518         bn = addressPXD(xd);
3519 
3520         /* unpin parent page */
3521         DT_PUTPAGE(mp);
3522 
3523         /*
3524          * get target leaf page
3525          */
3526       c:
3527         DT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
3528         if (rc)
3529                 return rc;
3530 
3531         /*
3532          * leaf page has been completed:
3533          * start with 1st entry of next leaf page
3534          */
3535         if (index >= p->header.nextindex) {
3536                 bn = le64_to_cpu(p->header.next);
3537 
3538                 /* unpin leaf page */
3539                 DT_PUTPAGE(mp);
3540 
3541                 /* offset beyond eof ? */
3542                 if (bn == 0) {
3543                         bn = -1;
3544                         goto out;
3545                 }
3546 
3547                 /* get next leaf page */
3548                 DT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
3549                 if (rc)
3550                         return rc;
3551 
3552                 /* start with 1st entry of next leaf page */
3553                 dtoffset->pn++;
3554                 dtoffset->index = 0;
3555         }
3556 
3557       out:
3558         /* return target leaf page pinned */
3559         btsp = btstack->top;
3560         btsp->bn = bn;
3561         btsp->index = dtoffset->index;
3562         btsp->mp = mp;
3563 
3564         return 0;
3565 }
3566 
3567 
3568 /*
3569  *      dtCompare()
3570  *
3571  * function: compare search key with an internal entry
3572  *
3573  * return:
3574  *      < 0 if k is < record
3575  *      = 0 if k is = record
3576  *      > 0 if k is > record
3577  */
3578 static int dtCompare(struct component_name * key,       /* search key */
3579                      dtpage_t * p,      /* directory page */
3580                      int si)
3581 {                               /* entry slot index */
3582         wchar_t *kname;
3583         __le16 *name;
3584         int klen, namlen, len, rc;
3585         struct idtentry *ih;
3586         struct dtslot *t;
3587 
3588         /*
3589          * force the left-most key on internal pages, at any level of
3590          * the tree, to be less than any search key.
3591          * this obviates having to update the leftmost key on an internal
3592          * page when the user inserts a new key in the tree smaller than
3593          * anything that has been stored.
3594          *
3595          * (? if/when dtSearch() narrows down to 1st entry (index = 0),
3596          * at any internal page at any level of the tree,
3597          * it descends to child of the entry anyway -
3598          * ? make the entry as min size dummy entry)
3599          *
3600          * if (e->index == 0 && h->prevpg == P_INVALID && !(h->flags & BT_LEAF))
3601          * return (1);
3602          */
3603 
3604         kname = key->name;
3605         klen = key->namlen;
3606 
3607         ih = (struct idtentry *) & p->slot[si];
3608         si = ih->next;
3609         name = ih->name;
3610         namlen = ih->namlen;
3611         len = min(namlen, DTIHDRDATALEN);
3612 
3613         /* compare with head/only segment */
3614         len = min(klen, len);
3615         if ((rc = UniStrncmp_le(kname, name, len)))
3616                 return rc;
3617 
3618         klen -= len;
3619         namlen -= len;
3620 
3621         /* compare with additional segment(s) */
3622         kname += len;
3623         while (klen > 0 && namlen > 0) {
3624                 /* compare with next name segment */
3625                 t = (struct dtslot *) & p->slot[si];
3626                 len = min(namlen, DTSLOTDATALEN);
3627                 len = min(klen, len);
3628                 name = t->name;
3629                 if ((rc = UniStrncmp_le(kname, name, len)))
3630                         return rc;
3631 
3632                 klen -= len;
3633                 namlen -= len;
3634                 kname += len;
3635                 si = t->next;
3636         }
3637 
3638         return (klen - namlen);
3639 }
3640 
3641 
3642 
3643 
3644 /*
3645  *      ciCompare()
3646  *
3647  * function: compare search key with an (leaf/internal) entry
3648  *
3649  * return:
3650  *      < 0 if k is < record
3651  *      = 0 if k is = record
3652  *      > 0 if k is > record
3653  */
3654 static int ciCompare(struct component_name * key,       /* search key */
3655                      dtpage_t * p,      /* directory page */
3656                      int si,    /* entry slot index */
3657                      int flag)
3658 {
3659         wchar_t *kname, x;
3660         __le16 *name;
3661         int klen, namlen, len, rc;
3662         struct ldtentry *lh;
3663         struct idtentry *ih;
3664         struct dtslot *t;
3665         int i;
3666 
3667         /*
3668          * force the left-most key on internal pages, at any level of
3669          * the tree, to be less than any search key.
3670          * this obviates having to update the leftmost key on an internal
3671          * page when the user inserts a new key in the tree smaller than
3672          * anything that has been stored.
3673          *
3674          * (? if/when dtSearch() narrows down to 1st entry (index = 0),
3675          * at any internal page at any level of the tree,
3676          * it descends to child of the entry anyway -
3677          * ? make the entry as min size dummy entry)
3678          *
3679          * if (e->index == 0 && h->prevpg == P_INVALID && !(h->flags & BT_LEAF))
3680          * return (1);
3681          */
3682 
3683         kname = key->name;
3684         klen = key->namlen;
3685 
3686         /*
3687          * leaf page entry
3688          */
3689         if (p->header.flag & BT_LEAF) {
3690                 lh = (struct ldtentry *) & p->slot[si];
3691                 si = lh->next;
3692                 name = lh->name;
3693                 namlen = lh->namlen;
3694                 if (flag & JFS_DIR_INDEX)
3695                         len = min(namlen, DTLHDRDATALEN);
3696                 else
3697                         len = min(namlen, DTLHDRDATALEN_LEGACY);
3698         }
3699         /*
3700          * internal page entry
3701          */
3702         else {
3703                 ih = (struct idtentry *) & p->slot[si];
3704                 si = ih->next;
3705                 name = ih->name;
3706                 namlen = ih->namlen;
3707                 len = min(namlen, DTIHDRDATALEN);
3708         }
3709 
3710         /* compare with head/only segment */
3711         len = min(klen, len);
3712         for (i = 0; i < len; i++, kname++, name++) {
3713                 /* only uppercase if case-insensitive support is on */
3714                 if ((flag & JFS_OS2) == JFS_OS2)
3715                         x = UniToupper(le16_to_cpu(*name));
3716                 else
3717                         x = le16_to_cpu(*name);
3718                 if ((rc = *kname - x))
3719                         return rc;
3720         }
3721 
3722         klen -= len;
3723         namlen -= len;
3724 
3725         /* compare with additional segment(s) */
3726         while (klen > 0 && namlen > 0) {
3727                 /* compare with next name segment */
3728                 t = (struct dtslot *) & p->slot[si];
3729                 len = min(namlen, DTSLOTDATALEN);
3730                 len = min(klen, len);
3731                 name = t->name;
3732                 for (i = 0; i < len; i++, kname++, name++) {
3733                         /* only uppercase if case-insensitive support is on */
3734                         if ((flag & JFS_OS2) == JFS_OS2)
3735                                 x = UniToupper(le16_to_cpu(*name));
3736                         else
3737                                 x = le16_to_cpu(*name);
3738 
3739                         if ((rc = *kname - x))
3740                                 return rc;
3741                 }
3742 
3743                 klen -= len;
3744                 namlen -= len;
3745                 si = t->next;
3746         }
3747 
3748         return (klen - namlen);
3749 }
3750 
3751 
3752 /*
3753  *      ciGetLeafPrefixKey()
3754  *
3755  * function: compute prefix of suffix compression
3756  *           from two adjacent leaf entries
3757  *           across page boundary
3758  *
3759  * return: non-zero on error
3760  *
3761  */
3762 static int ciGetLeafPrefixKey(dtpage_t * lp, int li, dtpage_t * rp,
3763                                int ri, struct component_name * key, int flag)
3764 {
3765         int klen, namlen;
3766         wchar_t *pl, *pr, *kname;
3767         struct component_name lkey;
3768         struct component_name rkey;
3769 
3770         lkey.name = kmalloc_array(JFS_NAME_MAX + 1, sizeof(wchar_t),
3771                                         GFP_KERNEL);
3772         if (lkey.name == NULL)
3773                 return -ENOMEM;
3774 
3775         rkey.name = kmalloc_array(JFS_NAME_MAX + 1, sizeof(wchar_t),
3776                                         GFP_KERNEL);
3777         if (rkey.name == NULL) {
3778                 kfree(lkey.name);
3779                 return -ENOMEM;
3780         }
3781 
3782         /* get left and right key */
3783         dtGetKey(lp, li, &lkey, flag);
3784         lkey.name[lkey.namlen] = 0;
3785 
3786         if ((flag & JFS_OS2) == JFS_OS2)
3787                 ciToUpper(&lkey);
3788 
3789         dtGetKey(rp, ri, &rkey, flag);
3790         rkey.name[rkey.namlen] = 0;
3791 
3792 
3793         if ((flag & JFS_OS2) == JFS_OS2)
3794                 ciToUpper(&rkey);
3795 
3796         /* compute prefix */
3797         klen = 0;
3798         kname = key->name;
3799         namlen = min(lkey.namlen, rkey.namlen);
3800         for (pl = lkey.name, pr = rkey.name;
3801              namlen; pl++, pr++, namlen--, klen++, kname++) {
3802                 *kname = *pr;
3803                 if (*pl != *pr) {
3804                         key->namlen = klen + 1;
3805                         goto free_names;
3806                 }
3807         }
3808 
3809         /* l->namlen <= r->namlen since l <= r */
3810         if (lkey.namlen < rkey.namlen) {
3811                 *kname = *pr;
3812                 key->namlen = klen + 1;
3813         } else                  /* l->namelen == r->namelen */
3814                 key->namlen = klen;
3815 
3816 free_names:
3817         kfree(lkey.name);
3818         kfree(rkey.name);
3819         return 0;
3820 }
3821 
3822 
3823 
3824 /*
3825  *      dtGetKey()
3826  *
3827  * function: get key of the entry
3828  */
3829 static void dtGetKey(dtpage_t * p, int i,       /* entry index */
3830                      struct component_name * key, int flag)
3831 {
3832         int si;
3833         s8 *stbl;
3834         struct ldtentry *lh;
3835         struct idtentry *ih;
3836         struct dtslot *t;
3837         int namlen, len;
3838         wchar_t *kname;
3839         __le16 *name;
3840 
3841         /* get entry */
3842         stbl = DT_GETSTBL(p);
3843         si = stbl[i];
3844         if (p->header.flag & BT_LEAF) {
3845                 lh = (struct ldtentry *) & p->slot[si];
3846                 si = lh->next;
3847                 namlen = lh->namlen;
3848                 name = lh->name;
3849                 if (flag & JFS_DIR_INDEX)
3850                         len = min(namlen, DTLHDRDATALEN);
3851                 else
3852                         len = min(namlen, DTLHDRDATALEN_LEGACY);
3853         } else {
3854                 ih = (struct idtentry *) & p->slot[si];
3855                 si = ih->next;
3856                 namlen = ih->namlen;
3857                 name = ih->name;
3858                 len = min(namlen, DTIHDRDATALEN);
3859         }
3860 
3861         key->namlen = namlen;
3862         kname = key->name;
3863 
3864         /*
3865          * move head/only segment
3866          */
3867         UniStrncpy_from_le(kname, name, len);
3868 
3869         /*
3870          * move additional segment(s)
3871          */
3872         while (si >= 0) {
3873                 /* get next segment */
3874                 t = &p->slot[si];
3875                 kname += len;
3876                 namlen -= len;
3877                 len = min(namlen, DTSLOTDATALEN);
3878                 UniStrncpy_from_le(kname, t->name, len);
3879 
3880                 si = t->next;
3881         }
3882 }
3883 
3884 
3885 /*
3886  *      dtInsertEntry()
3887  *
3888  * function: allocate free slot(s) and
3889  *           write a leaf/internal entry
3890  *
3891  * return: entry slot index
3892  */
3893 static void dtInsertEntry(dtpage_t * p, int index, struct component_name * key,
3894                           ddata_t * data, struct dt_lock ** dtlock)
3895 {
3896         struct dtslot *h, *t;
3897         struct ldtentry *lh = NULL;
3898         struct idtentry *ih = NULL;
3899         int hsi, fsi, klen, len, nextindex;
3900         wchar_t *kname;
3901         __le16 *name;
3902         s8 *stbl;
3903         pxd_t *xd;
3904         struct dt_lock *dtlck = *dtlock;
3905         struct lv *lv;
3906         int xsi, n;
3907         s64 bn = 0;
3908         struct metapage *mp = NULL;
3909 
3910         klen = key->namlen;
3911         kname = key->name;
3912 
3913         /* allocate a free slot */
3914         hsi = fsi = p->header.freelist;
3915         h = &p->slot[fsi];
3916         p->header.freelist = h->next;
3917         --p->header.freecnt;
3918 
3919         /* open new linelock */
3920         if (dtlck->index >= dtlck->maxcnt)
3921                 dtlck = (struct dt_lock *) txLinelock(dtlck);
3922 
3923         lv = & dtlck->lv[dtlck->index];
3924         lv->offset = hsi;
3925 
3926         /* write head/only segment */
3927         if (p->header.flag & BT_LEAF) {
3928                 lh = (struct ldtentry *) h;
3929                 lh->next = h->next;
3930                 lh->inumber = cpu_to_le32(data->leaf.ino);
3931                 lh->namlen = klen;
3932                 name = lh->name;
3933                 if (data->leaf.ip) {
3934                         len = min(klen, DTLHDRDATALEN);
3935                         if (!(p->header.flag & BT_ROOT))
3936                                 bn = addressPXD(&p->header.self);
3937                         lh->index = cpu_to_le32(add_index(data->leaf.tid,
3938                                                           data->leaf.ip,
3939                                                           bn, index));
3940                 } else
3941                         len = min(klen, DTLHDRDATALEN_LEGACY);
3942         } else {
3943                 ih = (struct idtentry *) h;
3944                 ih->next = h->next;
3945                 xd = (pxd_t *) ih;
3946                 *xd = data->xd;
3947                 ih->namlen = klen;
3948                 name = ih->name;
3949                 len = min(klen, DTIHDRDATALEN);
3950         }
3951 
3952         UniStrncpy_to_le(name, kname, len);
3953 
3954         n = 1;
3955         xsi = hsi;
3956 
3957         /* write additional segment(s) */
3958         t = h;
3959         klen -= len;
3960         while (klen) {
3961                 /* get free slot */
3962                 fsi = p->header.freelist;
3963                 t = &p->slot[fsi];
3964                 p->header.freelist = t->next;
3965                 --p->header.freecnt;
3966 
3967                 /* is next slot contiguous ? */
3968                 if (fsi != xsi + 1) {
3969                         /* close current linelock */
3970                         lv->length = n;
3971                         dtlck->index++;
3972 
3973                         /* open new linelock */
3974                         if (dtlck->index < dtlck->maxcnt)
3975                                 lv++;
3976                         else {
3977                                 dtlck = (struct dt_lock *) txLinelock(dtlck);
3978                                 lv = & dtlck->lv[0];
3979                         }
3980 
3981                         lv->offset = fsi;
3982                         n = 0;
3983                 }
3984 
3985                 kname += len;
3986                 len = min(klen, DTSLOTDATALEN);
3987                 UniStrncpy_to_le(t->name, kname, len);
3988 
3989                 n++;
3990                 xsi = fsi;
3991                 klen -= len;
3992         }
3993 
3994         /* close current linelock */
3995         lv->length = n;
3996         dtlck->index++;
3997 
3998         *dtlock = dtlck;
3999 
4000         /* terminate last/only segment */
4001         if (h == t) {
4002                 /* single segment entry */
4003                 if (p->header.flag & BT_LEAF)
4004                         lh->next = -1;
4005                 else
4006                         ih->next = -1;
4007         } else
4008                 /* multi-segment entry */
4009                 t->next = -1;
4010 
4011         /* if insert into middle, shift right succeeding entries in stbl */
4012         stbl = DT_GETSTBL(p);
4013         nextindex = p->header.nextindex;
4014         if (index < nextindex) {
4015                 memmove(stbl + index + 1, stbl + index, nextindex - index);
4016 
4017                 if ((p->header.flag & BT_LEAF) && data->leaf.ip) {
4018                         s64 lblock;
4019 
4020                         /*
4021                          * Need to update slot number for entries that moved
4022                          * in the stbl
4023                          */
4024                         mp = NULL;
4025                         for (n = index + 1; n <= nextindex; n++) {
4026                                 lh = (struct ldtentry *) & (p->slot[stbl[n]]);
4027                                 modify_index(data->leaf.tid, data->leaf.ip,
4028                                              le32_to_cpu(lh->index), bn, n,
4029                                              &mp, &lblock);
4030                         }
4031                         if (mp)
4032                                 release_metapage(mp);
4033                 }
4034         }
4035 
4036         stbl[index] = hsi;
4037 
4038         /* advance next available entry index of stbl */
4039         ++p->header.nextindex;
4040 }
4041 
4042 
4043 /*
4044  *      dtMoveEntry()
4045  *
4046  * function: move entries from split/left page to new/right page
4047  *
4048  *      nextindex of dst page and freelist/freecnt of both pages
4049  *      are updated.
4050  */
4051 static void dtMoveEntry(dtpage_t * sp, int si, dtpage_t * dp,
4052                         struct dt_lock ** sdtlock, struct dt_lock ** ddtlock,
4053                         int do_index)
4054 {
4055         int ssi, next;          /* src slot index */
4056         int di;                 /* dst entry index */
4057         int dsi;                /* dst slot index */
4058         s8 *sstbl, *dstbl;      /* sorted entry table */
4059         int snamlen, len;
4060         struct ldtentry *slh, *dlh = NULL;
4061         struct idtentry *sih, *dih = NULL;
4062         struct dtslot *h, *s, *d;
4063         struct dt_lock *sdtlck = *sdtlock, *ddtlck = *ddtlock;
4064         struct lv *slv, *dlv;
4065         int xssi, ns, nd;
4066         int sfsi;
4067 
4068         sstbl = (s8 *) & sp->slot[sp->header.stblindex];
4069         dstbl = (s8 *) & dp->slot[dp->header.stblindex];
4070 
4071         dsi = dp->header.freelist;      /* first (whole page) free slot */
4072         sfsi = sp->header.freelist;
4073 
4074         /* linelock destination entry slot */
4075         dlv = & ddtlck->lv[ddtlck->index];
4076         dlv->offset = dsi;
4077 
4078         /* linelock source entry slot */
4079         slv = & sdtlck->lv[sdtlck->index];
4080         slv->offset = sstbl[si];
4081         xssi = slv->offset - 1;
4082 
4083         /*
4084          * move entries
4085          */
4086         ns = nd = 0;
4087         for (di = 0; si < sp->header.nextindex; si++, di++) {
4088                 ssi = sstbl[si];
4089                 dstbl[di] = dsi;
4090 
4091                 /* is next slot contiguous ? */
4092                 if (ssi != xssi + 1) {
4093                         /* close current linelock */
4094                         slv->length = ns;
4095                         sdtlck->index++;
4096 
4097                         /* open new linelock */
4098                         if (sdtlck->index < sdtlck->maxcnt)
4099                                 slv++;
4100                         else {
4101                                 sdtlck = (struct dt_lock *) txLinelock(sdtlck);
4102                                 slv = & sdtlck->lv[0];
4103                         }
4104 
4105                         slv->offset = ssi;
4106                         ns = 0;
4107                 }
4108 
4109                 /*
4110                  * move head/only segment of an entry
4111                  */
4112                 /* get dst slot */
4113                 h = d = &dp->slot[dsi];
4114 
4115                 /* get src slot and move */
4116                 s = &sp->slot[ssi];
4117                 if (sp->header.flag & BT_LEAF) {
4118                         /* get source entry */
4119                         slh = (struct ldtentry *) s;
4120                         dlh = (struct ldtentry *) h;
4121                         snamlen = slh->namlen;
4122 
4123                         if (do_index) {
4124                                 len = min(snamlen, DTLHDRDATALEN);
4125                                 dlh->index = slh->index; /* little-endian */
4126                         } else
4127                                 len = min(snamlen, DTLHDRDATALEN_LEGACY);
4128 
4129                         memcpy(dlh, slh, 6 + len * 2);
4130 
4131                         next = slh->next;
4132 
4133                         /* update dst head/only segment next field */
4134                         dsi++;
4135                         dlh->next = dsi;
4136                 } else {
4137                         sih = (struct idtentry *) s;
4138                         snamlen = sih->namlen;
4139 
4140                         len = min(snamlen, DTIHDRDATALEN);
4141                         dih = (struct idtentry *) h;
4142                         memcpy(dih, sih, 10 + len * 2);
4143                         next = sih->next;
4144 
4145                         dsi++;
4146                         dih->next = dsi;
4147                 }
4148 
4149                 /* free src head/only segment */
4150                 s->next = sfsi;
4151                 s->cnt = 1;
4152                 sfsi = ssi;
4153 
4154                 ns++;
4155                 nd++;
4156                 xssi = ssi;
4157 
4158                 /*
4159                  * move additional segment(s) of the entry
4160                  */
4161                 snamlen -= len;
4162                 while ((ssi = next) >= 0) {
4163                         /* is next slot contiguous ? */
4164                         if (ssi != xssi + 1) {
4165                                 /* close current linelock */
4166                                 slv->length = ns;
4167                                 sdtlck->index++;
4168 
4169                                 /* open new linelock */
4170                                 if (sdtlck->index < sdtlck->maxcnt)
4171                                         slv++;
4172                                 else {
4173                                         sdtlck =
4174                                             (struct dt_lock *)
4175                                             txLinelock(sdtlck);
4176                                         slv = & sdtlck->lv[0];
4177                                 }
4178 
4179                                 slv->offset = ssi;
4180                                 ns = 0;
4181                         }
4182 
4183                         /* get next source segment */
4184                         s = &sp->slot[ssi];
4185 
4186                         /* get next destination free slot */
4187                         d++;
4188 
4189                         len = min(snamlen, DTSLOTDATALEN);
4190                         UniStrncpy_le(d->name, s->name, len);
4191 
4192                         ns++;
4193                         nd++;
4194                         xssi = ssi;
4195 
4196                         dsi++;
4197                         d->next = dsi;
4198 
4199                         /* free source segment */
4200                         next = s->next;
4201                         s->next = sfsi;
4202                         s->cnt = 1;
4203                         sfsi = ssi;
4204 
4205                         snamlen -= len;
4206                 }               /* end while */
4207 
4208                 /* terminate dst last/only segment */
4209                 if (h == d) {
4210                         /* single segment entry */
4211                         if (dp->header.flag & BT_LEAF)
4212                                 dlh->next = -1;
4213                         else
4214                                 dih->next = -1;
4215                 } else
4216                         /* multi-segment entry */
4217                         d->next = -1;
4218         }                       /* end for */
4219 
4220         /* close current linelock */
4221         slv->length = ns;
4222         sdtlck->index++;
4223         *sdtlock = sdtlck;
4224 
4225         dlv->length = nd;
4226         ddtlck->index++;
4227         *ddtlock = ddtlck;
4228 
4229         /* update source header */
4230         sp->header.freelist = sfsi;
4231         sp->header.freecnt += nd;
4232 
4233         /* update destination header */
4234         dp->header.nextindex = di;
4235 
4236         dp->header.freelist = dsi;
4237         dp->header.freecnt -= nd;
4238 }
4239 
4240 
4241 /*
4242  *      dtDeleteEntry()
4243  *
4244  * function: free a (leaf/internal) entry
4245  *
4246  * log freelist header, stbl, and each segment slot of entry
4247  * (even though last/only segment next field is modified,
4248  * physical image logging requires all segment slots of
4249  * the entry logged to avoid applying previous updates
4250  * to the same slots)
4251  */
4252 static void dtDeleteEntry(dtpage_t * p, int fi, struct dt_lock ** dtlock)
4253 {
4254         int fsi;                /* free entry slot index */
4255         s8 *stbl;
4256         struct dtslot *t;
4257         int si, freecnt;
4258         struct dt_lock *dtlck = *dtlock;
4259         struct lv *lv;
4260         int xsi, n;
4261 
4262         /* get free entry slot index */
4263         stbl = DT_GETSTBL(p);
4264         fsi = stbl[fi];
4265 
4266         /* open new linelock */
4267         if (dtlck->index >= dtlck->maxcnt)
4268                 dtlck = (struct dt_lock *) txLinelock(dtlck);
4269         lv = & dtlck->lv[dtlck->index];
4270 
4271         lv->offset = fsi;
4272 
4273         /* get the head/only segment */
4274         t = &p->slot[fsi];
4275         if (p->header.flag & BT_LEAF)
4276                 si = ((struct ldtentry *) t)->next;
4277         else
4278                 si = ((struct idtentry *) t)->next;
4279         t->next = si;
4280         t->cnt = 1;
4281 
4282         n = freecnt = 1;
4283         xsi = fsi;
4284 
4285         /* find the last/only segment */
4286         while (si >= 0) {
4287                 /* is next slot contiguous ? */
4288                 if (si != xsi + 1) {
4289                         /* close current linelock */
4290                         lv->length = n;
4291                         dtlck->index++;
4292 
4293                         /* open new linelock */
4294                         if (dtlck->index < dtlck->maxcnt)
4295                                 lv++;
4296                         else {
4297                                 dtlck = (struct dt_lock *) txLinelock(dtlck);
4298                                 lv = & dtlck->lv[0];
4299                         }
4300 
4301                         lv->offset = si;
4302                         n = 0;
4303                 }
4304 
4305                 n++;
4306                 xsi = si;
4307                 freecnt++;
4308 
4309                 t = &p->slot[si];
4310                 t->cnt = 1;
4311                 si = t->next;
4312         }
4313 
4314         /* close current linelock */
4315         lv->length = n;
4316         dtlck->index++;
4317 
4318         *dtlock = dtlck;
4319 
4320         /* update freelist */
4321         t->next = p->header.freelist;
4322         p->header.freelist = fsi;
4323         p->header.freecnt += freecnt;
4324 
4325         /* if delete from middle,
4326          * shift left the succedding entries in the stbl
4327          */
4328         si = p->header.nextindex;
4329         if (fi < si - 1)
4330                 memmove(&stbl[fi], &stbl[fi + 1], si - fi - 1);
4331 
4332         p->header.nextindex--;
4333 }
4334 
4335 
4336 /*
4337  *      dtTruncateEntry()
4338  *
4339  * function: truncate a (leaf/internal) entry
4340  *
4341  * log freelist header, stbl, and each segment slot of entry
4342  * (even though last/only segment next field is modified,
4343  * physical image logging requires all segment slots of
4344  * the entry logged to avoid applying previous updates
4345  * to the same slots)
4346  */
4347 static void dtTruncateEntry(dtpage_t * p, int ti, struct dt_lock ** dtlock)
4348 {
4349         int tsi;                /* truncate entry slot index */
4350         s8 *stbl;
4351         struct dtslot *t;
4352         int si, freecnt;
4353         struct dt_lock *dtlck = *dtlock;
4354         struct lv *lv;
4355         int fsi, xsi, n;
4356 
4357         /* get free entry slot index */
4358         stbl = DT_GETSTBL(p);
4359         tsi = stbl[ti];
4360 
4361         /* open new linelock */
4362         if (dtlck->index >= dtlck->maxcnt)
4363                 dtlck = (struct dt_lock *) txLinelock(dtlck);
4364         lv = & dtlck->lv[dtlck->index];
4365 
4366         lv->offset = tsi;
4367 
4368         /* get the head/only segment */
4369         t = &p->slot[tsi];
4370         ASSERT(p->header.flag & BT_INTERNAL);
4371         ((struct idtentry *) t)->namlen = 0;
4372         si = ((struct idtentry *) t)->next;
4373         ((struct idtentry *) t)->next = -1;
4374 
4375         n = 1;
4376         freecnt = 0;
4377         fsi = si;
4378         xsi = tsi;
4379 
4380         /* find the last/only segment */
4381         while (si >= 0) {
4382                 /* is next slot contiguous ? */
4383                 if (si != xsi + 1) {
4384                         /* close current linelock */
4385                         lv->length = n;
4386                         dtlck->index++;
4387 
4388                         /* open new linelock */
4389                         if (dtlck->index < dtlck->maxcnt)
4390                                 lv++;
4391                         else {
4392                                 dtlck = (struct dt_lock *) txLinelock(dtlck);
4393                                 lv = & dtlck->lv[0];
4394                         }
4395 
4396                         lv->offset = si;
4397                         n = 0;
4398                 }
4399 
4400                 n++;
4401                 xsi = si;
4402                 freecnt++;
4403 
4404                 t = &p->slot[si];
4405                 t->cnt = 1;
4406                 si = t->next;
4407         }
4408 
4409         /* close current linelock */
4410         lv->length = n;
4411         dtlck->index++;
4412 
4413         *dtlock = dtlck;
4414 
4415         /* update freelist */
4416         if (freecnt == 0)
4417                 return;
4418         t->next = p->header.freelist;
4419         p->header.freelist = fsi;
4420         p->header.freecnt += freecnt;
4421 }
4422 
4423 
4424 /*
4425  *      dtLinelockFreelist()
4426  */
4427 static void dtLinelockFreelist(dtpage_t * p,    /* directory page */
4428                                int m,   /* max slot index */
4429                                struct dt_lock ** dtlock)
4430 {
4431         int fsi;                /* free entry slot index */
4432         struct dtslot *t;
4433         int si;
4434         struct dt_lock *dtlck = *dtlock;
4435         struct lv *lv;
4436         int xsi, n;
4437 
4438         /* get free entry slot index */
4439         fsi = p->header.freelist;
4440 
4441         /* open new linelock */
4442         if (dtlck->index >= dtlck->maxcnt)
4443                 dtlck = (struct dt_lock *) txLinelock(dtlck);
4444         lv = & dtlck->lv[dtlck->index];
4445 
4446         lv->offset = fsi;
4447 
4448         n = 1;
4449         xsi = fsi;
4450 
4451         t = &p->slot[fsi];
4452         si = t->next;
4453 
4454         /* find the last/only segment */
4455         while (si < m && si >= 0) {
4456                 /* is next slot contiguous ? */
4457                 if (si != xsi + 1) {
4458                         /* close current linelock */
4459                         lv->length = n;
4460                         dtlck->index++;
4461 
4462                         /* open new linelock */
4463                         if (dtlck->index < dtlck->maxcnt)
4464                                 lv++;
4465                         else {
4466                                 dtlck = (struct dt_lock *) txLinelock(dtlck);
4467                                 lv = & dtlck->lv[0];
4468                         }
4469 
4470                         lv->offset = si;
4471                         n = 0;
4472                 }
4473 
4474                 n++;
4475                 xsi = si;
4476 
4477                 t = &p->slot[si];
4478                 si = t->next;
4479         }
4480 
4481         /* close current linelock */
4482         lv->length = n;
4483         dtlck->index++;
4484 
4485         *dtlock = dtlck;
4486 }
4487 
4488 
4489 /*
4490  * NAME: dtModify
4491  *
4492  * FUNCTION: Modify the inode number part of a directory entry
4493  *
4494  * PARAMETERS:
4495  *      tid     - Transaction id
4496  *      ip      - Inode of parent directory
4497  *      key     - Name of entry to be modified
4498  *      orig_ino        - Original inode number expected in entry
4499  *      new_ino - New inode number to put into entry
4500  *      flag    - JFS_RENAME
4501  *
4502  * RETURNS:
4503  *      -ESTALE - If entry found does not match orig_ino passed in
4504  *      -ENOENT - If no entry can be found to match key
4505  *      0       - If successfully modified entry
4506  */
4507 int dtModify(tid_t tid, struct inode *ip,
4508          struct component_name * key, ino_t * orig_ino, ino_t new_ino, int flag)
4509 {
4510         int rc;
4511         s64 bn;
4512         struct metapage *mp;
4513         dtpage_t *p;
4514         int index;
4515         struct btstack btstack;
4516         struct tlock *tlck;
4517         struct dt_lock *dtlck;
4518         struct lv *lv;
4519         s8 *stbl;
4520         int entry_si;           /* entry slot index */
4521         struct ldtentry *entry;
4522 
4523         /*
4524          *      search for the entry to modify:
4525          *
4526          * dtSearch() returns (leaf page pinned, index at which to modify).
4527          */
4528         if ((rc = dtSearch(ip, key, orig_ino, &btstack, flag)))
4529                 return rc;
4530 
4531         /* retrieve search result */
4532         DT_GETSEARCH(ip, btstack.top, bn, mp, p, index);
4533 
4534         BT_MARK_DIRTY(mp, ip);
4535         /*
4536          * acquire a transaction lock on the leaf page of named entry
4537          */
4538         tlck = txLock(tid, ip, mp, tlckDTREE | tlckENTRY);
4539         dtlck = (struct dt_lock *) & tlck->lock;
4540 
4541         /* get slot index of the entry */
4542         stbl = DT_GETSTBL(p);
4543         entry_si = stbl[index];
4544 
4545         /* linelock entry */
4546         ASSERT(dtlck->index == 0);
4547         lv = & dtlck->lv[0];
4548         lv->offset = entry_si;
4549         lv->length = 1;
4550         dtlck->index++;
4551 
4552         /* get the head/only segment */
4553         entry = (struct ldtentry *) & p->slot[entry_si];
4554 
4555         /* substitute the inode number of the entry */
4556         entry->inumber = cpu_to_le32(new_ino);
4557 
4558         /* unpin the leaf page */
4559         DT_PUTPAGE(mp);
4560 
4561         return 0;
4562 }

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