fs/jfs/jfs_dtree.c

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