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TOMOYO Linux Cross Reference
Linux/fs/jfs/jfs_dtree.c

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

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