7536faaa61e7852175f7b7c20f1e4b0c566c24db
[~shefty/rdma-dev.git] / fs / xfs / xfs_dir2_block.c
1 /*
2  * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
3  * All Rights Reserved.
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU General Public License as
7  * published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it would be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * 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 the Free Software Foundation,
16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
17  */
18 #include "xfs.h"
19 #include "xfs_fs.h"
20 #include "xfs_types.h"
21 #include "xfs_log.h"
22 #include "xfs_trans.h"
23 #include "xfs_sb.h"
24 #include "xfs_ag.h"
25 #include "xfs_mount.h"
26 #include "xfs_da_btree.h"
27 #include "xfs_bmap_btree.h"
28 #include "xfs_dinode.h"
29 #include "xfs_inode.h"
30 #include "xfs_inode_item.h"
31 #include "xfs_dir2.h"
32 #include "xfs_dir2_format.h"
33 #include "xfs_dir2_priv.h"
34 #include "xfs_error.h"
35 #include "xfs_trace.h"
36
37 /*
38  * Local function prototypes.
39  */
40 static void xfs_dir2_block_log_leaf(xfs_trans_t *tp, struct xfs_buf *bp,
41                                     int first, int last);
42 static void xfs_dir2_block_log_tail(xfs_trans_t *tp, struct xfs_buf *bp);
43 static int xfs_dir2_block_lookup_int(xfs_da_args_t *args, struct xfs_buf **bpp,
44                                      int *entno);
45 static int xfs_dir2_block_sort(const void *a, const void *b);
46
47 static xfs_dahash_t xfs_dir_hash_dot, xfs_dir_hash_dotdot;
48
49 /*
50  * One-time startup routine called from xfs_init().
51  */
52 void
53 xfs_dir_startup(void)
54 {
55         xfs_dir_hash_dot = xfs_da_hashname((unsigned char *)".", 1);
56         xfs_dir_hash_dotdot = xfs_da_hashname((unsigned char *)"..", 2);
57 }
58
59 static void
60 xfs_dir2_block_verify(
61         struct xfs_buf          *bp)
62 {
63         struct xfs_mount        *mp = bp->b_target->bt_mount;
64         struct xfs_dir2_data_hdr *hdr = bp->b_addr;
65         int                     block_ok = 0;
66
67         block_ok = hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC);
68         block_ok = block_ok && __xfs_dir2_data_check(NULL, bp) == 0;
69
70         if (!block_ok) {
71                 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, hdr);
72                 xfs_buf_ioerror(bp, EFSCORRUPTED);
73         }
74 }
75
76 static void
77 xfs_dir2_block_read_verify(
78         struct xfs_buf  *bp)
79 {
80         xfs_dir2_block_verify(bp);
81 }
82
83 static void
84 xfs_dir2_block_write_verify(
85         struct xfs_buf  *bp)
86 {
87         xfs_dir2_block_verify(bp);
88 }
89
90 const struct xfs_buf_ops xfs_dir2_block_buf_ops = {
91         .verify_read = xfs_dir2_block_read_verify,
92         .verify_write = xfs_dir2_block_write_verify,
93 };
94
95 static int
96 xfs_dir2_block_read(
97         struct xfs_trans        *tp,
98         struct xfs_inode        *dp,
99         struct xfs_buf          **bpp)
100 {
101         struct xfs_mount        *mp = dp->i_mount;
102
103         return xfs_da_read_buf(tp, dp, mp->m_dirdatablk, -1, bpp,
104                                 XFS_DATA_FORK, &xfs_dir2_block_buf_ops);
105 }
106
107 static void
108 xfs_dir2_block_need_space(
109         struct xfs_dir2_data_hdr        *hdr,
110         struct xfs_dir2_block_tail      *btp,
111         struct xfs_dir2_leaf_entry      *blp,
112         __be16                          **tagpp,
113         struct xfs_dir2_data_unused     **dupp,
114         struct xfs_dir2_data_unused     **enddupp,
115         int                             *compact,
116         int                             len)
117 {
118         struct xfs_dir2_data_free       *bf;
119         __be16                          *tagp = NULL;
120         struct xfs_dir2_data_unused     *dup = NULL;
121         struct xfs_dir2_data_unused     *enddup = NULL;
122
123         *compact = 0;
124         bf = hdr->bestfree;
125
126         /*
127          * If there are stale entries we'll use one for the leaf.
128          */
129         if (btp->stale) {
130                 if (be16_to_cpu(bf[0].length) >= len) {
131                         /*
132                          * The biggest entry enough to avoid compaction.
133                          */
134                         dup = (xfs_dir2_data_unused_t *)
135                               ((char *)hdr + be16_to_cpu(bf[0].offset));
136                         goto out;
137                 }
138
139                 /*
140                  * Will need to compact to make this work.
141                  * Tag just before the first leaf entry.
142                  */
143                 *compact = 1;
144                 tagp = (__be16 *)blp - 1;
145
146                 /* Data object just before the first leaf entry.  */
147                 dup = (xfs_dir2_data_unused_t *)((char *)hdr + be16_to_cpu(*tagp));
148
149                 /*
150                  * If it's not free then the data will go where the
151                  * leaf data starts now, if it works at all.
152                  */
153                 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
154                         if (be16_to_cpu(dup->length) + (be32_to_cpu(btp->stale) - 1) *
155                             (uint)sizeof(*blp) < len)
156                                 dup = NULL;
157                 } else if ((be32_to_cpu(btp->stale) - 1) * (uint)sizeof(*blp) < len)
158                         dup = NULL;
159                 else
160                         dup = (xfs_dir2_data_unused_t *)blp;
161                 goto out;
162         }
163
164         /*
165          * no stale entries, so just use free space.
166          * Tag just before the first leaf entry.
167          */
168         tagp = (__be16 *)blp - 1;
169
170         /* Data object just before the first leaf entry.  */
171         enddup = (xfs_dir2_data_unused_t *)((char *)hdr + be16_to_cpu(*tagp));
172
173         /*
174          * If it's not free then can't do this add without cleaning up:
175          * the space before the first leaf entry needs to be free so it
176          * can be expanded to hold the pointer to the new entry.
177          */
178         if (be16_to_cpu(enddup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
179                 /*
180                  * Check out the biggest freespace and see if it's the same one.
181                  */
182                 dup = (xfs_dir2_data_unused_t *)
183                       ((char *)hdr + be16_to_cpu(bf[0].offset));
184                 if (dup != enddup) {
185                         /*
186                          * Not the same free entry, just check its length.
187                          */
188                         if (be16_to_cpu(dup->length) < len)
189                                 dup = NULL;
190                         goto out;
191                 }
192
193                 /*
194                  * It is the biggest freespace, can it hold the leaf too?
195                  */
196                 if (be16_to_cpu(dup->length) < len + (uint)sizeof(*blp)) {
197                         /*
198                          * Yes, use the second-largest entry instead if it works.
199                          */
200                         if (be16_to_cpu(bf[1].length) >= len)
201                                 dup = (xfs_dir2_data_unused_t *)
202                                       ((char *)hdr + be16_to_cpu(bf[1].offset));
203                         else
204                                 dup = NULL;
205                 }
206         }
207 out:
208         *tagpp = tagp;
209         *dupp = dup;
210         *enddupp = enddup;
211 }
212
213 /*
214  * compact the leaf entries.
215  * Leave the highest-numbered stale entry stale.
216  * XXX should be the one closest to mid but mid is not yet computed.
217  */
218 static void
219 xfs_dir2_block_compact(
220         struct xfs_trans                *tp,
221         struct xfs_buf                  *bp,
222         struct xfs_dir2_data_hdr        *hdr,
223         struct xfs_dir2_block_tail      *btp,
224         struct xfs_dir2_leaf_entry      *blp,
225         int                             *needlog,
226         int                             *lfloghigh,
227         int                             *lfloglow)
228 {
229         int                     fromidx;        /* source leaf index */
230         int                     toidx;          /* target leaf index */
231         int                     needscan = 0;
232         int                     highstale;      /* high stale index */
233
234         fromidx = toidx = be32_to_cpu(btp->count) - 1;
235         highstale = *lfloghigh = -1;
236         for (; fromidx >= 0; fromidx--) {
237                 if (blp[fromidx].address == cpu_to_be32(XFS_DIR2_NULL_DATAPTR)) {
238                         if (highstale == -1)
239                                 highstale = toidx;
240                         else {
241                                 if (*lfloghigh == -1)
242                                         *lfloghigh = toidx;
243                                 continue;
244                         }
245                 }
246                 if (fromidx < toidx)
247                         blp[toidx] = blp[fromidx];
248                 toidx--;
249         }
250         *lfloglow = toidx + 1 - (be32_to_cpu(btp->stale) - 1);
251         *lfloghigh -= be32_to_cpu(btp->stale) - 1;
252         be32_add_cpu(&btp->count, -(be32_to_cpu(btp->stale) - 1));
253         xfs_dir2_data_make_free(tp, bp,
254                 (xfs_dir2_data_aoff_t)((char *)blp - (char *)hdr),
255                 (xfs_dir2_data_aoff_t)((be32_to_cpu(btp->stale) - 1) * sizeof(*blp)),
256                 needlog, &needscan);
257         blp += be32_to_cpu(btp->stale) - 1;
258         btp->stale = cpu_to_be32(1);
259         /*
260          * If we now need to rebuild the bestfree map, do so.
261          * This needs to happen before the next call to use_free.
262          */
263         if (needscan)
264                 xfs_dir2_data_freescan(tp->t_mountp, hdr, needlog);
265 }
266
267 /*
268  * Add an entry to a block directory.
269  */
270 int                                             /* error */
271 xfs_dir2_block_addname(
272         xfs_da_args_t           *args)          /* directory op arguments */
273 {
274         xfs_dir2_data_hdr_t     *hdr;           /* block header */
275         xfs_dir2_leaf_entry_t   *blp;           /* block leaf entries */
276         struct xfs_buf          *bp;            /* buffer for block */
277         xfs_dir2_block_tail_t   *btp;           /* block tail */
278         int                     compact;        /* need to compact leaf ents */
279         xfs_dir2_data_entry_t   *dep;           /* block data entry */
280         xfs_inode_t             *dp;            /* directory inode */
281         xfs_dir2_data_unused_t  *dup;           /* block unused entry */
282         int                     error;          /* error return value */
283         xfs_dir2_data_unused_t  *enddup=NULL;   /* unused at end of data */
284         xfs_dahash_t            hash;           /* hash value of found entry */
285         int                     high;           /* high index for binary srch */
286         int                     highstale;      /* high stale index */
287         int                     lfloghigh=0;    /* last final leaf to log */
288         int                     lfloglow=0;     /* first final leaf to log */
289         int                     len;            /* length of the new entry */
290         int                     low;            /* low index for binary srch */
291         int                     lowstale;       /* low stale index */
292         int                     mid=0;          /* midpoint for binary srch */
293         xfs_mount_t             *mp;            /* filesystem mount point */
294         int                     needlog;        /* need to log header */
295         int                     needscan;       /* need to rescan freespace */
296         __be16                  *tagp;          /* pointer to tag value */
297         xfs_trans_t             *tp;            /* transaction structure */
298
299         trace_xfs_dir2_block_addname(args);
300
301         dp = args->dp;
302         tp = args->trans;
303         mp = dp->i_mount;
304
305         /* Read the (one and only) directory block into bp. */
306         error = xfs_dir2_block_read(tp, dp, &bp);
307         if (error)
308                 return error;
309
310         len = xfs_dir2_data_entsize(args->namelen);
311
312         /*
313          * Set up pointers to parts of the block.
314          */
315         hdr = bp->b_addr;
316         btp = xfs_dir2_block_tail_p(mp, hdr);
317         blp = xfs_dir2_block_leaf_p(btp);
318
319         /*
320          * Find out if we can reuse stale entries or whether we need extra
321          * space for entry and new leaf.
322          */
323         xfs_dir2_block_need_space(hdr, btp, blp, &tagp, &dup,
324                                   &enddup, &compact, len);
325
326         /*
327          * Done everything we need for a space check now.
328          */
329         if (args->op_flags & XFS_DA_OP_JUSTCHECK) {
330                 xfs_trans_brelse(tp, bp);
331                 if (!dup)
332                         return XFS_ERROR(ENOSPC);
333                 return 0;
334         }
335
336         /*
337          * If we don't have space for the new entry & leaf ...
338          */
339         if (!dup) {
340                 /* Don't have a space reservation: return no-space.  */
341                 if (args->total == 0)
342                         return XFS_ERROR(ENOSPC);
343                 /*
344                  * Convert to the next larger format.
345                  * Then add the new entry in that format.
346                  */
347                 error = xfs_dir2_block_to_leaf(args, bp);
348                 if (error)
349                         return error;
350                 return xfs_dir2_leaf_addname(args);
351         }
352
353         needlog = needscan = 0;
354
355         /*
356          * If need to compact the leaf entries, do it now.
357          */
358         if (compact)
359                 xfs_dir2_block_compact(tp, bp, hdr, btp, blp, &needlog,
360                                       &lfloghigh, &lfloglow);
361         else if (btp->stale) {
362                 /*
363                  * Set leaf logging boundaries to impossible state.
364                  * For the no-stale case they're set explicitly.
365                  */
366                 lfloglow = be32_to_cpu(btp->count);
367                 lfloghigh = -1;
368         }
369
370         /*
371          * Find the slot that's first lower than our hash value, -1 if none.
372          */
373         for (low = 0, high = be32_to_cpu(btp->count) - 1; low <= high; ) {
374                 mid = (low + high) >> 1;
375                 if ((hash = be32_to_cpu(blp[mid].hashval)) == args->hashval)
376                         break;
377                 if (hash < args->hashval)
378                         low = mid + 1;
379                 else
380                         high = mid - 1;
381         }
382         while (mid >= 0 && be32_to_cpu(blp[mid].hashval) >= args->hashval) {
383                 mid--;
384         }
385         /*
386          * No stale entries, will use enddup space to hold new leaf.
387          */
388         if (!btp->stale) {
389                 /*
390                  * Mark the space needed for the new leaf entry, now in use.
391                  */
392                 xfs_dir2_data_use_free(tp, bp, enddup,
393                         (xfs_dir2_data_aoff_t)
394                         ((char *)enddup - (char *)hdr + be16_to_cpu(enddup->length) -
395                          sizeof(*blp)),
396                         (xfs_dir2_data_aoff_t)sizeof(*blp),
397                         &needlog, &needscan);
398                 /*
399                  * Update the tail (entry count).
400                  */
401                 be32_add_cpu(&btp->count, 1);
402                 /*
403                  * If we now need to rebuild the bestfree map, do so.
404                  * This needs to happen before the next call to use_free.
405                  */
406                 if (needscan) {
407                         xfs_dir2_data_freescan(mp, hdr, &needlog);
408                         needscan = 0;
409                 }
410                 /*
411                  * Adjust pointer to the first leaf entry, we're about to move
412                  * the table up one to open up space for the new leaf entry.
413                  * Then adjust our index to match.
414                  */
415                 blp--;
416                 mid++;
417                 if (mid)
418                         memmove(blp, &blp[1], mid * sizeof(*blp));
419                 lfloglow = 0;
420                 lfloghigh = mid;
421         }
422         /*
423          * Use a stale leaf for our new entry.
424          */
425         else {
426                 for (lowstale = mid;
427                      lowstale >= 0 &&
428                         blp[lowstale].address !=
429                         cpu_to_be32(XFS_DIR2_NULL_DATAPTR);
430                      lowstale--)
431                         continue;
432                 for (highstale = mid + 1;
433                      highstale < be32_to_cpu(btp->count) &&
434                         blp[highstale].address !=
435                         cpu_to_be32(XFS_DIR2_NULL_DATAPTR) &&
436                         (lowstale < 0 || mid - lowstale > highstale - mid);
437                      highstale++)
438                         continue;
439                 /*
440                  * Move entries toward the low-numbered stale entry.
441                  */
442                 if (lowstale >= 0 &&
443                     (highstale == be32_to_cpu(btp->count) ||
444                      mid - lowstale <= highstale - mid)) {
445                         if (mid - lowstale)
446                                 memmove(&blp[lowstale], &blp[lowstale + 1],
447                                         (mid - lowstale) * sizeof(*blp));
448                         lfloglow = MIN(lowstale, lfloglow);
449                         lfloghigh = MAX(mid, lfloghigh);
450                 }
451                 /*
452                  * Move entries toward the high-numbered stale entry.
453                  */
454                 else {
455                         ASSERT(highstale < be32_to_cpu(btp->count));
456                         mid++;
457                         if (highstale - mid)
458                                 memmove(&blp[mid + 1], &blp[mid],
459                                         (highstale - mid) * sizeof(*blp));
460                         lfloglow = MIN(mid, lfloglow);
461                         lfloghigh = MAX(highstale, lfloghigh);
462                 }
463                 be32_add_cpu(&btp->stale, -1);
464         }
465         /*
466          * Point to the new data entry.
467          */
468         dep = (xfs_dir2_data_entry_t *)dup;
469         /*
470          * Fill in the leaf entry.
471          */
472         blp[mid].hashval = cpu_to_be32(args->hashval);
473         blp[mid].address = cpu_to_be32(xfs_dir2_byte_to_dataptr(mp,
474                                 (char *)dep - (char *)hdr));
475         xfs_dir2_block_log_leaf(tp, bp, lfloglow, lfloghigh);
476         /*
477          * Mark space for the data entry used.
478          */
479         xfs_dir2_data_use_free(tp, bp, dup,
480                 (xfs_dir2_data_aoff_t)((char *)dup - (char *)hdr),
481                 (xfs_dir2_data_aoff_t)len, &needlog, &needscan);
482         /*
483          * Create the new data entry.
484          */
485         dep->inumber = cpu_to_be64(args->inumber);
486         dep->namelen = args->namelen;
487         memcpy(dep->name, args->name, args->namelen);
488         tagp = xfs_dir2_data_entry_tag_p(dep);
489         *tagp = cpu_to_be16((char *)dep - (char *)hdr);
490         /*
491          * Clean up the bestfree array and log the header, tail, and entry.
492          */
493         if (needscan)
494                 xfs_dir2_data_freescan(mp, hdr, &needlog);
495         if (needlog)
496                 xfs_dir2_data_log_header(tp, bp);
497         xfs_dir2_block_log_tail(tp, bp);
498         xfs_dir2_data_log_entry(tp, bp, dep);
499         xfs_dir2_data_check(dp, bp);
500         return 0;
501 }
502
503 /*
504  * Readdir for block directories.
505  */
506 int                                             /* error */
507 xfs_dir2_block_getdents(
508         xfs_inode_t             *dp,            /* incore inode */
509         void                    *dirent,
510         xfs_off_t               *offset,
511         filldir_t               filldir)
512 {
513         xfs_dir2_data_hdr_t     *hdr;           /* block header */
514         struct xfs_buf          *bp;            /* buffer for block */
515         xfs_dir2_block_tail_t   *btp;           /* block tail */
516         xfs_dir2_data_entry_t   *dep;           /* block data entry */
517         xfs_dir2_data_unused_t  *dup;           /* block unused entry */
518         char                    *endptr;        /* end of the data entries */
519         int                     error;          /* error return value */
520         xfs_mount_t             *mp;            /* filesystem mount point */
521         char                    *ptr;           /* current data entry */
522         int                     wantoff;        /* starting block offset */
523         xfs_off_t               cook;
524
525         mp = dp->i_mount;
526         /*
527          * If the block number in the offset is out of range, we're done.
528          */
529         if (xfs_dir2_dataptr_to_db(mp, *offset) > mp->m_dirdatablk)
530                 return 0;
531
532         error = xfs_dir2_block_read(NULL, dp, &bp);
533         if (error)
534                 return error;
535
536         /*
537          * Extract the byte offset we start at from the seek pointer.
538          * We'll skip entries before this.
539          */
540         wantoff = xfs_dir2_dataptr_to_off(mp, *offset);
541         hdr = bp->b_addr;
542         xfs_dir2_data_check(dp, bp);
543         /*
544          * Set up values for the loop.
545          */
546         btp = xfs_dir2_block_tail_p(mp, hdr);
547         ptr = (char *)(hdr + 1);
548         endptr = (char *)xfs_dir2_block_leaf_p(btp);
549
550         /*
551          * Loop over the data portion of the block.
552          * Each object is a real entry (dep) or an unused one (dup).
553          */
554         while (ptr < endptr) {
555                 dup = (xfs_dir2_data_unused_t *)ptr;
556                 /*
557                  * Unused, skip it.
558                  */
559                 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
560                         ptr += be16_to_cpu(dup->length);
561                         continue;
562                 }
563
564                 dep = (xfs_dir2_data_entry_t *)ptr;
565
566                 /*
567                  * Bump pointer for the next iteration.
568                  */
569                 ptr += xfs_dir2_data_entsize(dep->namelen);
570                 /*
571                  * The entry is before the desired starting point, skip it.
572                  */
573                 if ((char *)dep - (char *)hdr < wantoff)
574                         continue;
575
576                 cook = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk,
577                                             (char *)dep - (char *)hdr);
578
579                 /*
580                  * If it didn't fit, set the final offset to here & return.
581                  */
582                 if (filldir(dirent, (char *)dep->name, dep->namelen,
583                             cook & 0x7fffffff, be64_to_cpu(dep->inumber),
584                             DT_UNKNOWN)) {
585                         *offset = cook & 0x7fffffff;
586                         xfs_trans_brelse(NULL, bp);
587                         return 0;
588                 }
589         }
590
591         /*
592          * Reached the end of the block.
593          * Set the offset to a non-existent block 1 and return.
594          */
595         *offset = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk + 1, 0) &
596                         0x7fffffff;
597         xfs_trans_brelse(NULL, bp);
598         return 0;
599 }
600
601 /*
602  * Log leaf entries from the block.
603  */
604 static void
605 xfs_dir2_block_log_leaf(
606         xfs_trans_t             *tp,            /* transaction structure */
607         struct xfs_buf          *bp,            /* block buffer */
608         int                     first,          /* index of first logged leaf */
609         int                     last)           /* index of last logged leaf */
610 {
611         xfs_dir2_data_hdr_t     *hdr = bp->b_addr;
612         xfs_dir2_leaf_entry_t   *blp;
613         xfs_dir2_block_tail_t   *btp;
614
615         btp = xfs_dir2_block_tail_p(tp->t_mountp, hdr);
616         blp = xfs_dir2_block_leaf_p(btp);
617         xfs_trans_log_buf(tp, bp, (uint)((char *)&blp[first] - (char *)hdr),
618                 (uint)((char *)&blp[last + 1] - (char *)hdr - 1));
619 }
620
621 /*
622  * Log the block tail.
623  */
624 static void
625 xfs_dir2_block_log_tail(
626         xfs_trans_t             *tp,            /* transaction structure */
627         struct xfs_buf          *bp)            /* block buffer */
628 {
629         xfs_dir2_data_hdr_t     *hdr = bp->b_addr;
630         xfs_dir2_block_tail_t   *btp;
631
632         btp = xfs_dir2_block_tail_p(tp->t_mountp, hdr);
633         xfs_trans_log_buf(tp, bp, (uint)((char *)btp - (char *)hdr),
634                 (uint)((char *)(btp + 1) - (char *)hdr - 1));
635 }
636
637 /*
638  * Look up an entry in the block.  This is the external routine,
639  * xfs_dir2_block_lookup_int does the real work.
640  */
641 int                                             /* error */
642 xfs_dir2_block_lookup(
643         xfs_da_args_t           *args)          /* dir lookup arguments */
644 {
645         xfs_dir2_data_hdr_t     *hdr;           /* block header */
646         xfs_dir2_leaf_entry_t   *blp;           /* block leaf entries */
647         struct xfs_buf          *bp;            /* block buffer */
648         xfs_dir2_block_tail_t   *btp;           /* block tail */
649         xfs_dir2_data_entry_t   *dep;           /* block data entry */
650         xfs_inode_t             *dp;            /* incore inode */
651         int                     ent;            /* entry index */
652         int                     error;          /* error return value */
653         xfs_mount_t             *mp;            /* filesystem mount point */
654
655         trace_xfs_dir2_block_lookup(args);
656
657         /*
658          * Get the buffer, look up the entry.
659          * If not found (ENOENT) then return, have no buffer.
660          */
661         if ((error = xfs_dir2_block_lookup_int(args, &bp, &ent)))
662                 return error;
663         dp = args->dp;
664         mp = dp->i_mount;
665         hdr = bp->b_addr;
666         xfs_dir2_data_check(dp, bp);
667         btp = xfs_dir2_block_tail_p(mp, hdr);
668         blp = xfs_dir2_block_leaf_p(btp);
669         /*
670          * Get the offset from the leaf entry, to point to the data.
671          */
672         dep = (xfs_dir2_data_entry_t *)((char *)hdr +
673                 xfs_dir2_dataptr_to_off(mp, be32_to_cpu(blp[ent].address)));
674         /*
675          * Fill in inode number, CI name if appropriate, release the block.
676          */
677         args->inumber = be64_to_cpu(dep->inumber);
678         error = xfs_dir_cilookup_result(args, dep->name, dep->namelen);
679         xfs_trans_brelse(args->trans, bp);
680         return XFS_ERROR(error);
681 }
682
683 /*
684  * Internal block lookup routine.
685  */
686 static int                                      /* error */
687 xfs_dir2_block_lookup_int(
688         xfs_da_args_t           *args,          /* dir lookup arguments */
689         struct xfs_buf          **bpp,          /* returned block buffer */
690         int                     *entno)         /* returned entry number */
691 {
692         xfs_dir2_dataptr_t      addr;           /* data entry address */
693         xfs_dir2_data_hdr_t     *hdr;           /* block header */
694         xfs_dir2_leaf_entry_t   *blp;           /* block leaf entries */
695         struct xfs_buf          *bp;            /* block buffer */
696         xfs_dir2_block_tail_t   *btp;           /* block tail */
697         xfs_dir2_data_entry_t   *dep;           /* block data entry */
698         xfs_inode_t             *dp;            /* incore inode */
699         int                     error;          /* error return value */
700         xfs_dahash_t            hash;           /* found hash value */
701         int                     high;           /* binary search high index */
702         int                     low;            /* binary search low index */
703         int                     mid;            /* binary search current idx */
704         xfs_mount_t             *mp;            /* filesystem mount point */
705         xfs_trans_t             *tp;            /* transaction pointer */
706         enum xfs_dacmp          cmp;            /* comparison result */
707
708         dp = args->dp;
709         tp = args->trans;
710         mp = dp->i_mount;
711
712         error = xfs_dir2_block_read(tp, dp, &bp);
713         if (error)
714                 return error;
715
716         hdr = bp->b_addr;
717         xfs_dir2_data_check(dp, bp);
718         btp = xfs_dir2_block_tail_p(mp, hdr);
719         blp = xfs_dir2_block_leaf_p(btp);
720         /*
721          * Loop doing a binary search for our hash value.
722          * Find our entry, ENOENT if it's not there.
723          */
724         for (low = 0, high = be32_to_cpu(btp->count) - 1; ; ) {
725                 ASSERT(low <= high);
726                 mid = (low + high) >> 1;
727                 if ((hash = be32_to_cpu(blp[mid].hashval)) == args->hashval)
728                         break;
729                 if (hash < args->hashval)
730                         low = mid + 1;
731                 else
732                         high = mid - 1;
733                 if (low > high) {
734                         ASSERT(args->op_flags & XFS_DA_OP_OKNOENT);
735                         xfs_trans_brelse(tp, bp);
736                         return XFS_ERROR(ENOENT);
737                 }
738         }
739         /*
740          * Back up to the first one with the right hash value.
741          */
742         while (mid > 0 && be32_to_cpu(blp[mid - 1].hashval) == args->hashval) {
743                 mid--;
744         }
745         /*
746          * Now loop forward through all the entries with the
747          * right hash value looking for our name.
748          */
749         do {
750                 if ((addr = be32_to_cpu(blp[mid].address)) == XFS_DIR2_NULL_DATAPTR)
751                         continue;
752                 /*
753                  * Get pointer to the entry from the leaf.
754                  */
755                 dep = (xfs_dir2_data_entry_t *)
756                         ((char *)hdr + xfs_dir2_dataptr_to_off(mp, addr));
757                 /*
758                  * Compare name and if it's an exact match, return the index
759                  * and buffer. If it's the first case-insensitive match, store
760                  * the index and buffer and continue looking for an exact match.
761                  */
762                 cmp = mp->m_dirnameops->compname(args, dep->name, dep->namelen);
763                 if (cmp != XFS_CMP_DIFFERENT && cmp != args->cmpresult) {
764                         args->cmpresult = cmp;
765                         *bpp = bp;
766                         *entno = mid;
767                         if (cmp == XFS_CMP_EXACT)
768                                 return 0;
769                 }
770         } while (++mid < be32_to_cpu(btp->count) &&
771                         be32_to_cpu(blp[mid].hashval) == hash);
772
773         ASSERT(args->op_flags & XFS_DA_OP_OKNOENT);
774         /*
775          * Here, we can only be doing a lookup (not a rename or replace).
776          * If a case-insensitive match was found earlier, return success.
777          */
778         if (args->cmpresult == XFS_CMP_CASE)
779                 return 0;
780         /*
781          * No match, release the buffer and return ENOENT.
782          */
783         xfs_trans_brelse(tp, bp);
784         return XFS_ERROR(ENOENT);
785 }
786
787 /*
788  * Remove an entry from a block format directory.
789  * If that makes the block small enough to fit in shortform, transform it.
790  */
791 int                                             /* error */
792 xfs_dir2_block_removename(
793         xfs_da_args_t           *args)          /* directory operation args */
794 {
795         xfs_dir2_data_hdr_t     *hdr;           /* block header */
796         xfs_dir2_leaf_entry_t   *blp;           /* block leaf pointer */
797         struct xfs_buf          *bp;            /* block buffer */
798         xfs_dir2_block_tail_t   *btp;           /* block tail */
799         xfs_dir2_data_entry_t   *dep;           /* block data entry */
800         xfs_inode_t             *dp;            /* incore inode */
801         int                     ent;            /* block leaf entry index */
802         int                     error;          /* error return value */
803         xfs_mount_t             *mp;            /* filesystem mount point */
804         int                     needlog;        /* need to log block header */
805         int                     needscan;       /* need to fixup bestfree */
806         xfs_dir2_sf_hdr_t       sfh;            /* shortform header */
807         int                     size;           /* shortform size */
808         xfs_trans_t             *tp;            /* transaction pointer */
809
810         trace_xfs_dir2_block_removename(args);
811
812         /*
813          * Look up the entry in the block.  Gets the buffer and entry index.
814          * It will always be there, the vnodeops level does a lookup first.
815          */
816         if ((error = xfs_dir2_block_lookup_int(args, &bp, &ent))) {
817                 return error;
818         }
819         dp = args->dp;
820         tp = args->trans;
821         mp = dp->i_mount;
822         hdr = bp->b_addr;
823         btp = xfs_dir2_block_tail_p(mp, hdr);
824         blp = xfs_dir2_block_leaf_p(btp);
825         /*
826          * Point to the data entry using the leaf entry.
827          */
828         dep = (xfs_dir2_data_entry_t *)
829               ((char *)hdr + xfs_dir2_dataptr_to_off(mp, be32_to_cpu(blp[ent].address)));
830         /*
831          * Mark the data entry's space free.
832          */
833         needlog = needscan = 0;
834         xfs_dir2_data_make_free(tp, bp,
835                 (xfs_dir2_data_aoff_t)((char *)dep - (char *)hdr),
836                 xfs_dir2_data_entsize(dep->namelen), &needlog, &needscan);
837         /*
838          * Fix up the block tail.
839          */
840         be32_add_cpu(&btp->stale, 1);
841         xfs_dir2_block_log_tail(tp, bp);
842         /*
843          * Remove the leaf entry by marking it stale.
844          */
845         blp[ent].address = cpu_to_be32(XFS_DIR2_NULL_DATAPTR);
846         xfs_dir2_block_log_leaf(tp, bp, ent, ent);
847         /*
848          * Fix up bestfree, log the header if necessary.
849          */
850         if (needscan)
851                 xfs_dir2_data_freescan(mp, hdr, &needlog);
852         if (needlog)
853                 xfs_dir2_data_log_header(tp, bp);
854         xfs_dir2_data_check(dp, bp);
855         /*
856          * See if the size as a shortform is good enough.
857          */
858         size = xfs_dir2_block_sfsize(dp, hdr, &sfh);
859         if (size > XFS_IFORK_DSIZE(dp))
860                 return 0;
861
862         /*
863          * If it works, do the conversion.
864          */
865         return xfs_dir2_block_to_sf(args, bp, size, &sfh);
866 }
867
868 /*
869  * Replace an entry in a V2 block directory.
870  * Change the inode number to the new value.
871  */
872 int                                             /* error */
873 xfs_dir2_block_replace(
874         xfs_da_args_t           *args)          /* directory operation args */
875 {
876         xfs_dir2_data_hdr_t     *hdr;           /* block header */
877         xfs_dir2_leaf_entry_t   *blp;           /* block leaf entries */
878         struct xfs_buf          *bp;            /* block buffer */
879         xfs_dir2_block_tail_t   *btp;           /* block tail */
880         xfs_dir2_data_entry_t   *dep;           /* block data entry */
881         xfs_inode_t             *dp;            /* incore inode */
882         int                     ent;            /* leaf entry index */
883         int                     error;          /* error return value */
884         xfs_mount_t             *mp;            /* filesystem mount point */
885
886         trace_xfs_dir2_block_replace(args);
887
888         /*
889          * Lookup the entry in the directory.  Get buffer and entry index.
890          * This will always succeed since the caller has already done a lookup.
891          */
892         if ((error = xfs_dir2_block_lookup_int(args, &bp, &ent))) {
893                 return error;
894         }
895         dp = args->dp;
896         mp = dp->i_mount;
897         hdr = bp->b_addr;
898         btp = xfs_dir2_block_tail_p(mp, hdr);
899         blp = xfs_dir2_block_leaf_p(btp);
900         /*
901          * Point to the data entry we need to change.
902          */
903         dep = (xfs_dir2_data_entry_t *)
904               ((char *)hdr + xfs_dir2_dataptr_to_off(mp, be32_to_cpu(blp[ent].address)));
905         ASSERT(be64_to_cpu(dep->inumber) != args->inumber);
906         /*
907          * Change the inode number to the new value.
908          */
909         dep->inumber = cpu_to_be64(args->inumber);
910         xfs_dir2_data_log_entry(args->trans, bp, dep);
911         xfs_dir2_data_check(dp, bp);
912         return 0;
913 }
914
915 /*
916  * Qsort comparison routine for the block leaf entries.
917  */
918 static int                                      /* sort order */
919 xfs_dir2_block_sort(
920         const void                      *a,     /* first leaf entry */
921         const void                      *b)     /* second leaf entry */
922 {
923         const xfs_dir2_leaf_entry_t     *la;    /* first leaf entry */
924         const xfs_dir2_leaf_entry_t     *lb;    /* second leaf entry */
925
926         la = a;
927         lb = b;
928         return be32_to_cpu(la->hashval) < be32_to_cpu(lb->hashval) ? -1 :
929                 (be32_to_cpu(la->hashval) > be32_to_cpu(lb->hashval) ? 1 : 0);
930 }
931
932 /*
933  * Convert a V2 leaf directory to a V2 block directory if possible.
934  */
935 int                                             /* error */
936 xfs_dir2_leaf_to_block(
937         xfs_da_args_t           *args,          /* operation arguments */
938         struct xfs_buf          *lbp,           /* leaf buffer */
939         struct xfs_buf          *dbp)           /* data buffer */
940 {
941         __be16                  *bestsp;        /* leaf bests table */
942         xfs_dir2_data_hdr_t     *hdr;           /* block header */
943         xfs_dir2_block_tail_t   *btp;           /* block tail */
944         xfs_inode_t             *dp;            /* incore directory inode */
945         xfs_dir2_data_unused_t  *dup;           /* unused data entry */
946         int                     error;          /* error return value */
947         int                     from;           /* leaf from index */
948         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
949         xfs_dir2_leaf_entry_t   *lep;           /* leaf entry */
950         xfs_dir2_leaf_tail_t    *ltp;           /* leaf tail structure */
951         xfs_mount_t             *mp;            /* file system mount point */
952         int                     needlog;        /* need to log data header */
953         int                     needscan;       /* need to scan for bestfree */
954         xfs_dir2_sf_hdr_t       sfh;            /* shortform header */
955         int                     size;           /* bytes used */
956         __be16                  *tagp;          /* end of entry (tag) */
957         int                     to;             /* block/leaf to index */
958         xfs_trans_t             *tp;            /* transaction pointer */
959
960         trace_xfs_dir2_leaf_to_block(args);
961
962         dp = args->dp;
963         tp = args->trans;
964         mp = dp->i_mount;
965         leaf = lbp->b_addr;
966         ASSERT(leaf->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAF1_MAGIC));
967         ltp = xfs_dir2_leaf_tail_p(mp, leaf);
968         /*
969          * If there are data blocks other than the first one, take this
970          * opportunity to remove trailing empty data blocks that may have
971          * been left behind during no-space-reservation operations.
972          * These will show up in the leaf bests table.
973          */
974         while (dp->i_d.di_size > mp->m_dirblksize) {
975                 bestsp = xfs_dir2_leaf_bests_p(ltp);
976                 if (be16_to_cpu(bestsp[be32_to_cpu(ltp->bestcount) - 1]) ==
977                     mp->m_dirblksize - (uint)sizeof(*hdr)) {
978                         if ((error =
979                             xfs_dir2_leaf_trim_data(args, lbp,
980                                     (xfs_dir2_db_t)(be32_to_cpu(ltp->bestcount) - 1))))
981                                 return error;
982                 } else
983                         return 0;
984         }
985         /*
986          * Read the data block if we don't already have it, give up if it fails.
987          */
988         if (!dbp) {
989                 error = xfs_dir2_data_read(tp, dp, mp->m_dirdatablk, -1, &dbp);
990                 if (error)
991                         return error;
992         }
993         hdr = dbp->b_addr;
994         ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC));
995         /*
996          * Size of the "leaf" area in the block.
997          */
998         size = (uint)sizeof(xfs_dir2_block_tail_t) +
999                (uint)sizeof(*lep) * (be16_to_cpu(leaf->hdr.count) - be16_to_cpu(leaf->hdr.stale));
1000         /*
1001          * Look at the last data entry.
1002          */
1003         tagp = (__be16 *)((char *)hdr + mp->m_dirblksize) - 1;
1004         dup = (xfs_dir2_data_unused_t *)((char *)hdr + be16_to_cpu(*tagp));
1005         /*
1006          * If it's not free or is too short we can't do it.
1007          */
1008         if (be16_to_cpu(dup->freetag) != XFS_DIR2_DATA_FREE_TAG ||
1009             be16_to_cpu(dup->length) < size)
1010                 return 0;
1011
1012         /*
1013          * Start converting it to block form.
1014          */
1015         dbp->b_ops = &xfs_dir2_block_buf_ops;
1016         hdr->magic = cpu_to_be32(XFS_DIR2_BLOCK_MAGIC);
1017         needlog = 1;
1018         needscan = 0;
1019         /*
1020          * Use up the space at the end of the block (blp/btp).
1021          */
1022         xfs_dir2_data_use_free(tp, dbp, dup, mp->m_dirblksize - size, size,
1023                 &needlog, &needscan);
1024         /*
1025          * Initialize the block tail.
1026          */
1027         btp = xfs_dir2_block_tail_p(mp, hdr);
1028         btp->count = cpu_to_be32(be16_to_cpu(leaf->hdr.count) - be16_to_cpu(leaf->hdr.stale));
1029         btp->stale = 0;
1030         xfs_dir2_block_log_tail(tp, dbp);
1031         /*
1032          * Initialize the block leaf area.  We compact out stale entries.
1033          */
1034         lep = xfs_dir2_block_leaf_p(btp);
1035         for (from = to = 0; from < be16_to_cpu(leaf->hdr.count); from++) {
1036                 if (leaf->ents[from].address ==
1037                     cpu_to_be32(XFS_DIR2_NULL_DATAPTR))
1038                         continue;
1039                 lep[to++] = leaf->ents[from];
1040         }
1041         ASSERT(to == be32_to_cpu(btp->count));
1042         xfs_dir2_block_log_leaf(tp, dbp, 0, be32_to_cpu(btp->count) - 1);
1043         /*
1044          * Scan the bestfree if we need it and log the data block header.
1045          */
1046         if (needscan)
1047                 xfs_dir2_data_freescan(mp, hdr, &needlog);
1048         if (needlog)
1049                 xfs_dir2_data_log_header(tp, dbp);
1050         /*
1051          * Pitch the old leaf block.
1052          */
1053         error = xfs_da_shrink_inode(args, mp->m_dirleafblk, lbp);
1054         if (error)
1055                 return error;
1056
1057         /*
1058          * Now see if the resulting block can be shrunken to shortform.
1059          */
1060         size = xfs_dir2_block_sfsize(dp, hdr, &sfh);
1061         if (size > XFS_IFORK_DSIZE(dp))
1062                 return 0;
1063
1064         return xfs_dir2_block_to_sf(args, dbp, size, &sfh);
1065 }
1066
1067 /*
1068  * Convert the shortform directory to block form.
1069  */
1070 int                                             /* error */
1071 xfs_dir2_sf_to_block(
1072         xfs_da_args_t           *args)          /* operation arguments */
1073 {
1074         xfs_dir2_db_t           blkno;          /* dir-relative block # (0) */
1075         xfs_dir2_data_hdr_t     *hdr;           /* block header */
1076         xfs_dir2_leaf_entry_t   *blp;           /* block leaf entries */
1077         struct xfs_buf          *bp;            /* block buffer */
1078         xfs_dir2_block_tail_t   *btp;           /* block tail pointer */
1079         xfs_dir2_data_entry_t   *dep;           /* data entry pointer */
1080         xfs_inode_t             *dp;            /* incore directory inode */
1081         int                     dummy;          /* trash */
1082         xfs_dir2_data_unused_t  *dup;           /* unused entry pointer */
1083         int                     endoffset;      /* end of data objects */
1084         int                     error;          /* error return value */
1085         int                     i;              /* index */
1086         xfs_mount_t             *mp;            /* filesystem mount point */
1087         int                     needlog;        /* need to log block header */
1088         int                     needscan;       /* need to scan block freespc */
1089         int                     newoffset;      /* offset from current entry */
1090         int                     offset;         /* target block offset */
1091         xfs_dir2_sf_entry_t     *sfep;          /* sf entry pointer */
1092         xfs_dir2_sf_hdr_t       *oldsfp;        /* old shortform header  */
1093         xfs_dir2_sf_hdr_t       *sfp;           /* shortform header  */
1094         __be16                  *tagp;          /* end of data entry */
1095         xfs_trans_t             *tp;            /* transaction pointer */
1096         struct xfs_name         name;
1097
1098         trace_xfs_dir2_sf_to_block(args);
1099
1100         dp = args->dp;
1101         tp = args->trans;
1102         mp = dp->i_mount;
1103         ASSERT(dp->i_df.if_flags & XFS_IFINLINE);
1104         /*
1105          * Bomb out if the shortform directory is way too short.
1106          */
1107         if (dp->i_d.di_size < offsetof(xfs_dir2_sf_hdr_t, parent)) {
1108                 ASSERT(XFS_FORCED_SHUTDOWN(mp));
1109                 return XFS_ERROR(EIO);
1110         }
1111
1112         oldsfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
1113
1114         ASSERT(dp->i_df.if_bytes == dp->i_d.di_size);
1115         ASSERT(dp->i_df.if_u1.if_data != NULL);
1116         ASSERT(dp->i_d.di_size >= xfs_dir2_sf_hdr_size(oldsfp->i8count));
1117
1118         /*
1119          * Copy the directory into a temporary buffer.
1120          * Then pitch the incore inode data so we can make extents.
1121          */
1122         sfp = kmem_alloc(dp->i_df.if_bytes, KM_SLEEP);
1123         memcpy(sfp, oldsfp, dp->i_df.if_bytes);
1124
1125         xfs_idata_realloc(dp, -dp->i_df.if_bytes, XFS_DATA_FORK);
1126         dp->i_d.di_size = 0;
1127         xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
1128
1129         /*
1130          * Add block 0 to the inode.
1131          */
1132         error = xfs_dir2_grow_inode(args, XFS_DIR2_DATA_SPACE, &blkno);
1133         if (error) {
1134                 kmem_free(sfp);
1135                 return error;
1136         }
1137         /*
1138          * Initialize the data block.
1139          */
1140         error = xfs_dir2_data_init(args, blkno, &bp);
1141         if (error) {
1142                 kmem_free(sfp);
1143                 return error;
1144         }
1145         bp->b_ops = &xfs_dir2_block_buf_ops;
1146         hdr = bp->b_addr;
1147         hdr->magic = cpu_to_be32(XFS_DIR2_BLOCK_MAGIC);
1148         /*
1149          * Compute size of block "tail" area.
1150          */
1151         i = (uint)sizeof(*btp) +
1152             (sfp->count + 2) * (uint)sizeof(xfs_dir2_leaf_entry_t);
1153         /*
1154          * The whole thing is initialized to free by the init routine.
1155          * Say we're using the leaf and tail area.
1156          */
1157         dup = (xfs_dir2_data_unused_t *)(hdr + 1);
1158         needlog = needscan = 0;
1159         xfs_dir2_data_use_free(tp, bp, dup, mp->m_dirblksize - i, i, &needlog,
1160                 &needscan);
1161         ASSERT(needscan == 0);
1162         /*
1163          * Fill in the tail.
1164          */
1165         btp = xfs_dir2_block_tail_p(mp, hdr);
1166         btp->count = cpu_to_be32(sfp->count + 2);       /* ., .. */
1167         btp->stale = 0;
1168         blp = xfs_dir2_block_leaf_p(btp);
1169         endoffset = (uint)((char *)blp - (char *)hdr);
1170         /*
1171          * Remove the freespace, we'll manage it.
1172          */
1173         xfs_dir2_data_use_free(tp, bp, dup,
1174                 (xfs_dir2_data_aoff_t)((char *)dup - (char *)hdr),
1175                 be16_to_cpu(dup->length), &needlog, &needscan);
1176         /*
1177          * Create entry for .
1178          */
1179         dep = (xfs_dir2_data_entry_t *)
1180               ((char *)hdr + XFS_DIR2_DATA_DOT_OFFSET);
1181         dep->inumber = cpu_to_be64(dp->i_ino);
1182         dep->namelen = 1;
1183         dep->name[0] = '.';
1184         tagp = xfs_dir2_data_entry_tag_p(dep);
1185         *tagp = cpu_to_be16((char *)dep - (char *)hdr);
1186         xfs_dir2_data_log_entry(tp, bp, dep);
1187         blp[0].hashval = cpu_to_be32(xfs_dir_hash_dot);
1188         blp[0].address = cpu_to_be32(xfs_dir2_byte_to_dataptr(mp,
1189                                 (char *)dep - (char *)hdr));
1190         /*
1191          * Create entry for ..
1192          */
1193         dep = (xfs_dir2_data_entry_t *)
1194                 ((char *)hdr + XFS_DIR2_DATA_DOTDOT_OFFSET);
1195         dep->inumber = cpu_to_be64(xfs_dir2_sf_get_parent_ino(sfp));
1196         dep->namelen = 2;
1197         dep->name[0] = dep->name[1] = '.';
1198         tagp = xfs_dir2_data_entry_tag_p(dep);
1199         *tagp = cpu_to_be16((char *)dep - (char *)hdr);
1200         xfs_dir2_data_log_entry(tp, bp, dep);
1201         blp[1].hashval = cpu_to_be32(xfs_dir_hash_dotdot);
1202         blp[1].address = cpu_to_be32(xfs_dir2_byte_to_dataptr(mp,
1203                                 (char *)dep - (char *)hdr));
1204         offset = XFS_DIR2_DATA_FIRST_OFFSET;
1205         /*
1206          * Loop over existing entries, stuff them in.
1207          */
1208         i = 0;
1209         if (!sfp->count)
1210                 sfep = NULL;
1211         else
1212                 sfep = xfs_dir2_sf_firstentry(sfp);
1213         /*
1214          * Need to preserve the existing offset values in the sf directory.
1215          * Insert holes (unused entries) where necessary.
1216          */
1217         while (offset < endoffset) {
1218                 /*
1219                  * sfep is null when we reach the end of the list.
1220                  */
1221                 if (sfep == NULL)
1222                         newoffset = endoffset;
1223                 else
1224                         newoffset = xfs_dir2_sf_get_offset(sfep);
1225                 /*
1226                  * There should be a hole here, make one.
1227                  */
1228                 if (offset < newoffset) {
1229                         dup = (xfs_dir2_data_unused_t *)((char *)hdr + offset);
1230                         dup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
1231                         dup->length = cpu_to_be16(newoffset - offset);
1232                         *xfs_dir2_data_unused_tag_p(dup) = cpu_to_be16(
1233                                 ((char *)dup - (char *)hdr));
1234                         xfs_dir2_data_log_unused(tp, bp, dup);
1235                         xfs_dir2_data_freeinsert(hdr, dup, &dummy);
1236                         offset += be16_to_cpu(dup->length);
1237                         continue;
1238                 }
1239                 /*
1240                  * Copy a real entry.
1241                  */
1242                 dep = (xfs_dir2_data_entry_t *)((char *)hdr + newoffset);
1243                 dep->inumber = cpu_to_be64(xfs_dir2_sfe_get_ino(sfp, sfep));
1244                 dep->namelen = sfep->namelen;
1245                 memcpy(dep->name, sfep->name, dep->namelen);
1246                 tagp = xfs_dir2_data_entry_tag_p(dep);
1247                 *tagp = cpu_to_be16((char *)dep - (char *)hdr);
1248                 xfs_dir2_data_log_entry(tp, bp, dep);
1249                 name.name = sfep->name;
1250                 name.len = sfep->namelen;
1251                 blp[2 + i].hashval = cpu_to_be32(mp->m_dirnameops->
1252                                                         hashname(&name));
1253                 blp[2 + i].address = cpu_to_be32(xfs_dir2_byte_to_dataptr(mp,
1254                                                  (char *)dep - (char *)hdr));
1255                 offset = (int)((char *)(tagp + 1) - (char *)hdr);
1256                 if (++i == sfp->count)
1257                         sfep = NULL;
1258                 else
1259                         sfep = xfs_dir2_sf_nextentry(sfp, sfep);
1260         }
1261         /* Done with the temporary buffer */
1262         kmem_free(sfp);
1263         /*
1264          * Sort the leaf entries by hash value.
1265          */
1266         xfs_sort(blp, be32_to_cpu(btp->count), sizeof(*blp), xfs_dir2_block_sort);
1267         /*
1268          * Log the leaf entry area and tail.
1269          * Already logged the header in data_init, ignore needlog.
1270          */
1271         ASSERT(needscan == 0);
1272         xfs_dir2_block_log_leaf(tp, bp, 0, be32_to_cpu(btp->count) - 1);
1273         xfs_dir2_block_log_tail(tp, bp);
1274         xfs_dir2_data_check(dp, bp);
1275         return 0;
1276 }