xfs: factor out xfs_dir2_leaf_find_entry
[linux-2.6.git] / fs / xfs / xfs_dir2_leaf.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_bit.h"
22 #include "xfs_log.h"
23 #include "xfs_inum.h"
24 #include "xfs_trans.h"
25 #include "xfs_sb.h"
26 #include "xfs_ag.h"
27 #include "xfs_dir2.h"
28 #include "xfs_mount.h"
29 #include "xfs_da_btree.h"
30 #include "xfs_bmap_btree.h"
31 #include "xfs_dir2_sf.h"
32 #include "xfs_dinode.h"
33 #include "xfs_inode.h"
34 #include "xfs_bmap.h"
35 #include "xfs_dir2_data.h"
36 #include "xfs_dir2_leaf.h"
37 #include "xfs_dir2_block.h"
38 #include "xfs_dir2_node.h"
39 #include "xfs_error.h"
40 #include "xfs_trace.h"
41
42 /*
43  * Local function declarations.
44  */
45 #ifdef DEBUG
46 static void xfs_dir2_leaf_check(xfs_inode_t *dp, xfs_dabuf_t *bp);
47 #else
48 #define xfs_dir2_leaf_check(dp, bp)
49 #endif
50 static int xfs_dir2_leaf_lookup_int(xfs_da_args_t *args, xfs_dabuf_t **lbpp,
51                                     int *indexp, xfs_dabuf_t **dbpp);
52 static void xfs_dir2_leaf_log_bests(struct xfs_trans *tp, struct xfs_dabuf *bp,
53                                     int first, int last);
54 static void xfs_dir2_leaf_log_tail(struct xfs_trans *tp, struct xfs_dabuf *bp);
55
56
57 /*
58  * Convert a block form directory to a leaf form directory.
59  */
60 int                                             /* error */
61 xfs_dir2_block_to_leaf(
62         xfs_da_args_t           *args,          /* operation arguments */
63         xfs_dabuf_t             *dbp)           /* input block's buffer */
64 {
65         __be16                  *bestsp;        /* leaf's bestsp entries */
66         xfs_dablk_t             blkno;          /* leaf block's bno */
67         xfs_dir2_block_t        *block;         /* block structure */
68         xfs_dir2_leaf_entry_t   *blp;           /* block's leaf entries */
69         xfs_dir2_block_tail_t   *btp;           /* block's tail */
70         xfs_inode_t             *dp;            /* incore directory inode */
71         int                     error;          /* error return code */
72         xfs_dabuf_t             *lbp;           /* leaf block's buffer */
73         xfs_dir2_db_t           ldb;            /* leaf block's bno */
74         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
75         xfs_dir2_leaf_tail_t    *ltp;           /* leaf's tail */
76         xfs_mount_t             *mp;            /* filesystem mount point */
77         int                     needlog;        /* need to log block header */
78         int                     needscan;       /* need to rescan bestfree */
79         xfs_trans_t             *tp;            /* transaction pointer */
80
81         trace_xfs_dir2_block_to_leaf(args);
82
83         dp = args->dp;
84         mp = dp->i_mount;
85         tp = args->trans;
86         /*
87          * Add the leaf block to the inode.
88          * This interface will only put blocks in the leaf/node range.
89          * Since that's empty now, we'll get the root (block 0 in range).
90          */
91         if ((error = xfs_da_grow_inode(args, &blkno))) {
92                 return error;
93         }
94         ldb = xfs_dir2_da_to_db(mp, blkno);
95         ASSERT(ldb == XFS_DIR2_LEAF_FIRSTDB(mp));
96         /*
97          * Initialize the leaf block, get a buffer for it.
98          */
99         if ((error = xfs_dir2_leaf_init(args, ldb, &lbp, XFS_DIR2_LEAF1_MAGIC))) {
100                 return error;
101         }
102         ASSERT(lbp != NULL);
103         leaf = lbp->data;
104         block = dbp->data;
105         xfs_dir2_data_check(dp, dbp);
106         btp = xfs_dir2_block_tail_p(mp, block);
107         blp = xfs_dir2_block_leaf_p(btp);
108         /*
109          * Set the counts in the leaf header.
110          */
111         leaf->hdr.count = cpu_to_be16(be32_to_cpu(btp->count));
112         leaf->hdr.stale = cpu_to_be16(be32_to_cpu(btp->stale));
113         /*
114          * Could compact these but I think we always do the conversion
115          * after squeezing out stale entries.
116          */
117         memcpy(leaf->ents, blp, be32_to_cpu(btp->count) * sizeof(xfs_dir2_leaf_entry_t));
118         xfs_dir2_leaf_log_ents(tp, lbp, 0, be16_to_cpu(leaf->hdr.count) - 1);
119         needscan = 0;
120         needlog = 1;
121         /*
122          * Make the space formerly occupied by the leaf entries and block
123          * tail be free.
124          */
125         xfs_dir2_data_make_free(tp, dbp,
126                 (xfs_dir2_data_aoff_t)((char *)blp - (char *)block),
127                 (xfs_dir2_data_aoff_t)((char *)block + mp->m_dirblksize -
128                                        (char *)blp),
129                 &needlog, &needscan);
130         /*
131          * Fix up the block header, make it a data block.
132          */
133         block->hdr.magic = cpu_to_be32(XFS_DIR2_DATA_MAGIC);
134         if (needscan)
135                 xfs_dir2_data_freescan(mp, (xfs_dir2_data_t *)block, &needlog);
136         /*
137          * Set up leaf tail and bests table.
138          */
139         ltp = xfs_dir2_leaf_tail_p(mp, leaf);
140         ltp->bestcount = cpu_to_be32(1);
141         bestsp = xfs_dir2_leaf_bests_p(ltp);
142         bestsp[0] =  block->hdr.bestfree[0].length;
143         /*
144          * Log the data header and leaf bests table.
145          */
146         if (needlog)
147                 xfs_dir2_data_log_header(tp, dbp);
148         xfs_dir2_leaf_check(dp, lbp);
149         xfs_dir2_data_check(dp, dbp);
150         xfs_dir2_leaf_log_bests(tp, lbp, 0, 0);
151         xfs_da_buf_done(lbp);
152         return 0;
153 }
154
155 struct xfs_dir2_leaf_entry *
156 xfs_dir2_leaf_find_entry(
157         xfs_dir2_leaf_t         *leaf,          /* leaf structure */
158         int                     index,          /* leaf table position */
159         int                     compact,        /* need to compact leaves */
160         int                     lowstale,       /* index of prev stale leaf */
161         int                     highstale,      /* index of next stale leaf */
162         int                     *lfloglow,      /* low leaf logging index */
163         int                     *lfloghigh)     /* high leaf logging index */
164 {
165         if (!leaf->hdr.stale) {
166                 xfs_dir2_leaf_entry_t   *lep;   /* leaf entry table pointer */
167
168                 /*
169                  * Now we need to make room to insert the leaf entry.
170                  *
171                  * If there are no stale entries, just insert a hole at index.
172                  */
173                 lep = &leaf->ents[index];
174                 if (index < be16_to_cpu(leaf->hdr.count))
175                         memmove(lep + 1, lep,
176                                 (be16_to_cpu(leaf->hdr.count) - index) *
177                                  sizeof(*lep));
178
179                 /*
180                  * Record low and high logging indices for the leaf.
181                  */
182                 *lfloglow = index;
183                 *lfloghigh = be16_to_cpu(leaf->hdr.count);
184                 be16_add_cpu(&leaf->hdr.count, 1);
185                 return lep;
186         }
187
188         /*
189          * There are stale entries.
190          *
191          * We will use one of them for the new entry.  It's probably not at
192          * the right location, so we'll have to shift some up or down first.
193          *
194          * If we didn't compact before, we need to find the nearest stale
195          * entries before and after our insertion point.
196          */
197         if (compact == 0) {
198                 /*
199                  * Find the first stale entry before the insertion point,
200                  * if any.
201                  */
202                 for (lowstale = index - 1;
203                      lowstale >= 0 &&
204                         be32_to_cpu(leaf->ents[lowstale].address) !=
205                         XFS_DIR2_NULL_DATAPTR;
206                      lowstale--)
207                         continue;
208
209                 /*
210                  * Find the next stale entry at or after the insertion point,
211                  * if any.   Stop if we go so far that the lowstale entry
212                  * would be better.
213                  */
214                 for (highstale = index;
215                      highstale < be16_to_cpu(leaf->hdr.count) &&
216                         be32_to_cpu(leaf->ents[highstale].address) !=
217                         XFS_DIR2_NULL_DATAPTR &&
218                         (lowstale < 0 ||
219                          index - lowstale - 1 >= highstale - index);
220                      highstale++)
221                         continue;
222         }
223
224         /*
225          * If the low one is better, use it.
226          */
227         if (lowstale >= 0 &&
228             (highstale == be16_to_cpu(leaf->hdr.count) ||
229              index - lowstale - 1 < highstale - index)) {
230                 ASSERT(index - lowstale - 1 >= 0);
231                 ASSERT(be32_to_cpu(leaf->ents[lowstale].address) ==
232                        XFS_DIR2_NULL_DATAPTR);
233
234                 /*
235                  * Copy entries up to cover the stale entry and make room
236                  * for the new entry.
237                  */
238                 if (index - lowstale - 1 > 0) {
239                         memmove(&leaf->ents[lowstale],
240                                 &leaf->ents[lowstale + 1],
241                                 (index - lowstale - 1) *
242                                 sizeof(xfs_dir2_leaf_entry_t));
243                 }
244                 *lfloglow = MIN(lowstale, *lfloglow);
245                 *lfloghigh = MAX(index - 1, *lfloghigh);
246                 be16_add_cpu(&leaf->hdr.stale, -1);
247                 return &leaf->ents[index - 1];
248         }
249
250         /*
251          * The high one is better, so use that one.
252          */
253         ASSERT(highstale - index >= 0);
254         ASSERT(be32_to_cpu(leaf->ents[highstale].address) ==
255                XFS_DIR2_NULL_DATAPTR);
256
257         /*
258          * Copy entries down to cover the stale entry and make room for the
259          * new entry.
260          */
261         if (highstale - index > 0) {
262                 memmove(&leaf->ents[index + 1],
263                         &leaf->ents[index],
264                         (highstale - index) * sizeof(xfs_dir2_leaf_entry_t));
265         }
266         *lfloglow = MIN(index, *lfloglow);
267         *lfloghigh = MAX(highstale, *lfloghigh);
268         be16_add_cpu(&leaf->hdr.stale, -1);
269         return &leaf->ents[index];
270 }
271
272 /*
273  * Add an entry to a leaf form directory.
274  */
275 int                                             /* error */
276 xfs_dir2_leaf_addname(
277         xfs_da_args_t           *args)          /* operation arguments */
278 {
279         __be16                  *bestsp;        /* freespace table in leaf */
280         int                     compact;        /* need to compact leaves */
281         xfs_dir2_data_t         *data;          /* data block structure */
282         xfs_dabuf_t             *dbp;           /* data block buffer */
283         xfs_dir2_data_entry_t   *dep;           /* data block entry */
284         xfs_inode_t             *dp;            /* incore directory inode */
285         xfs_dir2_data_unused_t  *dup;           /* data unused entry */
286         int                     error;          /* error return value */
287         int                     grown;          /* allocated new data block */
288         int                     highstale;      /* index of next stale leaf */
289         int                     i;              /* temporary, index */
290         int                     index;          /* leaf table position */
291         xfs_dabuf_t             *lbp;           /* leaf's buffer */
292         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
293         int                     length;         /* length of new entry */
294         xfs_dir2_leaf_entry_t   *lep;           /* leaf entry table pointer */
295         int                     lfloglow;       /* low leaf logging index */
296         int                     lfloghigh;      /* high leaf logging index */
297         int                     lowstale;       /* index of prev stale leaf */
298         xfs_dir2_leaf_tail_t    *ltp;           /* leaf tail pointer */
299         xfs_mount_t             *mp;            /* filesystem mount point */
300         int                     needbytes;      /* leaf block bytes needed */
301         int                     needlog;        /* need to log data header */
302         int                     needscan;       /* need to rescan data free */
303         __be16                  *tagp;          /* end of data entry */
304         xfs_trans_t             *tp;            /* transaction pointer */
305         xfs_dir2_db_t           use_block;      /* data block number */
306
307         trace_xfs_dir2_leaf_addname(args);
308
309         dp = args->dp;
310         tp = args->trans;
311         mp = dp->i_mount;
312         /*
313          * Read the leaf block.
314          */
315         error = xfs_da_read_buf(tp, dp, mp->m_dirleafblk, -1, &lbp,
316                 XFS_DATA_FORK);
317         if (error) {
318                 return error;
319         }
320         ASSERT(lbp != NULL);
321         /*
322          * Look up the entry by hash value and name.
323          * We know it's not there, our caller has already done a lookup.
324          * So the index is of the entry to insert in front of.
325          * But if there are dup hash values the index is of the first of those.
326          */
327         index = xfs_dir2_leaf_search_hash(args, lbp);
328         leaf = lbp->data;
329         ltp = xfs_dir2_leaf_tail_p(mp, leaf);
330         bestsp = xfs_dir2_leaf_bests_p(ltp);
331         length = xfs_dir2_data_entsize(args->namelen);
332         /*
333          * See if there are any entries with the same hash value
334          * and space in their block for the new entry.
335          * This is good because it puts multiple same-hash value entries
336          * in a data block, improving the lookup of those entries.
337          */
338         for (use_block = -1, lep = &leaf->ents[index];
339              index < be16_to_cpu(leaf->hdr.count) && be32_to_cpu(lep->hashval) == args->hashval;
340              index++, lep++) {
341                 if (be32_to_cpu(lep->address) == XFS_DIR2_NULL_DATAPTR)
342                         continue;
343                 i = xfs_dir2_dataptr_to_db(mp, be32_to_cpu(lep->address));
344                 ASSERT(i < be32_to_cpu(ltp->bestcount));
345                 ASSERT(be16_to_cpu(bestsp[i]) != NULLDATAOFF);
346                 if (be16_to_cpu(bestsp[i]) >= length) {
347                         use_block = i;
348                         break;
349                 }
350         }
351         /*
352          * Didn't find a block yet, linear search all the data blocks.
353          */
354         if (use_block == -1) {
355                 for (i = 0; i < be32_to_cpu(ltp->bestcount); i++) {
356                         /*
357                          * Remember a block we see that's missing.
358                          */
359                         if (be16_to_cpu(bestsp[i]) == NULLDATAOFF && use_block == -1)
360                                 use_block = i;
361                         else if (be16_to_cpu(bestsp[i]) >= length) {
362                                 use_block = i;
363                                 break;
364                         }
365                 }
366         }
367         /*
368          * How many bytes do we need in the leaf block?
369          */
370         needbytes =
371                 (leaf->hdr.stale ? 0 : (uint)sizeof(leaf->ents[0])) +
372                 (use_block != -1 ? 0 : (uint)sizeof(leaf->bests[0]));
373         /*
374          * Now kill use_block if it refers to a missing block, so we
375          * can use it as an indication of allocation needed.
376          */
377         if (use_block != -1 && be16_to_cpu(bestsp[use_block]) == NULLDATAOFF)
378                 use_block = -1;
379         /*
380          * If we don't have enough free bytes but we can make enough
381          * by compacting out stale entries, we'll do that.
382          */
383         if ((char *)bestsp - (char *)&leaf->ents[be16_to_cpu(leaf->hdr.count)] <
384                                 needbytes && be16_to_cpu(leaf->hdr.stale) > 1) {
385                 compact = 1;
386         }
387         /*
388          * Otherwise if we don't have enough free bytes we need to
389          * convert to node form.
390          */
391         else if ((char *)bestsp - (char *)&leaf->ents[be16_to_cpu(
392                                                 leaf->hdr.count)] < needbytes) {
393                 /*
394                  * Just checking or no space reservation, give up.
395                  */
396                 if ((args->op_flags & XFS_DA_OP_JUSTCHECK) ||
397                                                         args->total == 0) {
398                         xfs_da_brelse(tp, lbp);
399                         return XFS_ERROR(ENOSPC);
400                 }
401                 /*
402                  * Convert to node form.
403                  */
404                 error = xfs_dir2_leaf_to_node(args, lbp);
405                 xfs_da_buf_done(lbp);
406                 if (error)
407                         return error;
408                 /*
409                  * Then add the new entry.
410                  */
411                 return xfs_dir2_node_addname(args);
412         }
413         /*
414          * Otherwise it will fit without compaction.
415          */
416         else
417                 compact = 0;
418         /*
419          * If just checking, then it will fit unless we needed to allocate
420          * a new data block.
421          */
422         if (args->op_flags & XFS_DA_OP_JUSTCHECK) {
423                 xfs_da_brelse(tp, lbp);
424                 return use_block == -1 ? XFS_ERROR(ENOSPC) : 0;
425         }
426         /*
427          * If no allocations are allowed, return now before we've
428          * changed anything.
429          */
430         if (args->total == 0 && use_block == -1) {
431                 xfs_da_brelse(tp, lbp);
432                 return XFS_ERROR(ENOSPC);
433         }
434         /*
435          * Need to compact the leaf entries, removing stale ones.
436          * Leave one stale entry behind - the one closest to our
437          * insertion index - and we'll shift that one to our insertion
438          * point later.
439          */
440         if (compact) {
441                 xfs_dir2_leaf_compact_x1(lbp, &index, &lowstale, &highstale,
442                         &lfloglow, &lfloghigh);
443         }
444         /*
445          * There are stale entries, so we'll need log-low and log-high
446          * impossibly bad values later.
447          */
448         else if (be16_to_cpu(leaf->hdr.stale)) {
449                 lfloglow = be16_to_cpu(leaf->hdr.count);
450                 lfloghigh = -1;
451         }
452         /*
453          * If there was no data block space found, we need to allocate
454          * a new one.
455          */
456         if (use_block == -1) {
457                 /*
458                  * Add the new data block.
459                  */
460                 if ((error = xfs_dir2_grow_inode(args, XFS_DIR2_DATA_SPACE,
461                                 &use_block))) {
462                         xfs_da_brelse(tp, lbp);
463                         return error;
464                 }
465                 /*
466                  * Initialize the block.
467                  */
468                 if ((error = xfs_dir2_data_init(args, use_block, &dbp))) {
469                         xfs_da_brelse(tp, lbp);
470                         return error;
471                 }
472                 /*
473                  * If we're adding a new data block on the end we need to
474                  * extend the bests table.  Copy it up one entry.
475                  */
476                 if (use_block >= be32_to_cpu(ltp->bestcount)) {
477                         bestsp--;
478                         memmove(&bestsp[0], &bestsp[1],
479                                 be32_to_cpu(ltp->bestcount) * sizeof(bestsp[0]));
480                         be32_add_cpu(&ltp->bestcount, 1);
481                         xfs_dir2_leaf_log_tail(tp, lbp);
482                         xfs_dir2_leaf_log_bests(tp, lbp, 0, be32_to_cpu(ltp->bestcount) - 1);
483                 }
484                 /*
485                  * If we're filling in a previously empty block just log it.
486                  */
487                 else
488                         xfs_dir2_leaf_log_bests(tp, lbp, use_block, use_block);
489                 data = dbp->data;
490                 bestsp[use_block] = data->hdr.bestfree[0].length;
491                 grown = 1;
492         }
493         /*
494          * Already had space in some data block.
495          * Just read that one in.
496          */
497         else {
498                 if ((error =
499                     xfs_da_read_buf(tp, dp, xfs_dir2_db_to_da(mp, use_block),
500                             -1, &dbp, XFS_DATA_FORK))) {
501                         xfs_da_brelse(tp, lbp);
502                         return error;
503                 }
504                 data = dbp->data;
505                 grown = 0;
506         }
507         xfs_dir2_data_check(dp, dbp);
508         /*
509          * Point to the biggest freespace in our data block.
510          */
511         dup = (xfs_dir2_data_unused_t *)
512               ((char *)data + be16_to_cpu(data->hdr.bestfree[0].offset));
513         ASSERT(be16_to_cpu(dup->length) >= length);
514         needscan = needlog = 0;
515         /*
516          * Mark the initial part of our freespace in use for the new entry.
517          */
518         xfs_dir2_data_use_free(tp, dbp, dup,
519                 (xfs_dir2_data_aoff_t)((char *)dup - (char *)data), length,
520                 &needlog, &needscan);
521         /*
522          * Initialize our new entry (at last).
523          */
524         dep = (xfs_dir2_data_entry_t *)dup;
525         dep->inumber = cpu_to_be64(args->inumber);
526         dep->namelen = args->namelen;
527         memcpy(dep->name, args->name, dep->namelen);
528         tagp = xfs_dir2_data_entry_tag_p(dep);
529         *tagp = cpu_to_be16((char *)dep - (char *)data);
530         /*
531          * Need to scan fix up the bestfree table.
532          */
533         if (needscan)
534                 xfs_dir2_data_freescan(mp, data, &needlog);
535         /*
536          * Need to log the data block's header.
537          */
538         if (needlog)
539                 xfs_dir2_data_log_header(tp, dbp);
540         xfs_dir2_data_log_entry(tp, dbp, dep);
541         /*
542          * If the bests table needs to be changed, do it.
543          * Log the change unless we've already done that.
544          */
545         if (be16_to_cpu(bestsp[use_block]) != be16_to_cpu(data->hdr.bestfree[0].length)) {
546                 bestsp[use_block] = data->hdr.bestfree[0].length;
547                 if (!grown)
548                         xfs_dir2_leaf_log_bests(tp, lbp, use_block, use_block);
549         }
550
551         lep = xfs_dir2_leaf_find_entry(leaf, index, compact, lowstale,
552                                        highstale, &lfloglow, &lfloghigh);
553
554         /*
555          * Fill in the new leaf entry.
556          */
557         lep->hashval = cpu_to_be32(args->hashval);
558         lep->address = cpu_to_be32(xfs_dir2_db_off_to_dataptr(mp, use_block,
559                                 be16_to_cpu(*tagp)));
560         /*
561          * Log the leaf fields and give up the buffers.
562          */
563         xfs_dir2_leaf_log_header(tp, lbp);
564         xfs_dir2_leaf_log_ents(tp, lbp, lfloglow, lfloghigh);
565         xfs_dir2_leaf_check(dp, lbp);
566         xfs_da_buf_done(lbp);
567         xfs_dir2_data_check(dp, dbp);
568         xfs_da_buf_done(dbp);
569         return 0;
570 }
571
572 #ifdef DEBUG
573 /*
574  * Check the internal consistency of a leaf1 block.
575  * Pop an assert if something is wrong.
576  */
577 STATIC void
578 xfs_dir2_leaf_check(
579         xfs_inode_t             *dp,            /* incore directory inode */
580         xfs_dabuf_t             *bp)            /* leaf's buffer */
581 {
582         int                     i;              /* leaf index */
583         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
584         xfs_dir2_leaf_tail_t    *ltp;           /* leaf tail pointer */
585         xfs_mount_t             *mp;            /* filesystem mount point */
586         int                     stale;          /* count of stale leaves */
587
588         leaf = bp->data;
589         mp = dp->i_mount;
590         ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_DIR2_LEAF1_MAGIC);
591         /*
592          * This value is not restrictive enough.
593          * Should factor in the size of the bests table as well.
594          * We can deduce a value for that from di_size.
595          */
596         ASSERT(be16_to_cpu(leaf->hdr.count) <= xfs_dir2_max_leaf_ents(mp));
597         ltp = xfs_dir2_leaf_tail_p(mp, leaf);
598         /*
599          * Leaves and bests don't overlap.
600          */
601         ASSERT((char *)&leaf->ents[be16_to_cpu(leaf->hdr.count)] <=
602                (char *)xfs_dir2_leaf_bests_p(ltp));
603         /*
604          * Check hash value order, count stale entries.
605          */
606         for (i = stale = 0; i < be16_to_cpu(leaf->hdr.count); i++) {
607                 if (i + 1 < be16_to_cpu(leaf->hdr.count))
608                         ASSERT(be32_to_cpu(leaf->ents[i].hashval) <=
609                                be32_to_cpu(leaf->ents[i + 1].hashval));
610                 if (be32_to_cpu(leaf->ents[i].address) == XFS_DIR2_NULL_DATAPTR)
611                         stale++;
612         }
613         ASSERT(be16_to_cpu(leaf->hdr.stale) == stale);
614 }
615 #endif  /* DEBUG */
616
617 /*
618  * Compact out any stale entries in the leaf.
619  * Log the header and changed leaf entries, if any.
620  */
621 void
622 xfs_dir2_leaf_compact(
623         xfs_da_args_t   *args,          /* operation arguments */
624         xfs_dabuf_t     *bp)            /* leaf buffer */
625 {
626         int             from;           /* source leaf index */
627         xfs_dir2_leaf_t *leaf;          /* leaf structure */
628         int             loglow;         /* first leaf entry to log */
629         int             to;             /* target leaf index */
630
631         leaf = bp->data;
632         if (!leaf->hdr.stale) {
633                 return;
634         }
635         /*
636          * Compress out the stale entries in place.
637          */
638         for (from = to = 0, loglow = -1; from < be16_to_cpu(leaf->hdr.count); from++) {
639                 if (be32_to_cpu(leaf->ents[from].address) == XFS_DIR2_NULL_DATAPTR)
640                         continue;
641                 /*
642                  * Only actually copy the entries that are different.
643                  */
644                 if (from > to) {
645                         if (loglow == -1)
646                                 loglow = to;
647                         leaf->ents[to] = leaf->ents[from];
648                 }
649                 to++;
650         }
651         /*
652          * Update and log the header, log the leaf entries.
653          */
654         ASSERT(be16_to_cpu(leaf->hdr.stale) == from - to);
655         be16_add_cpu(&leaf->hdr.count, -(be16_to_cpu(leaf->hdr.stale)));
656         leaf->hdr.stale = 0;
657         xfs_dir2_leaf_log_header(args->trans, bp);
658         if (loglow != -1)
659                 xfs_dir2_leaf_log_ents(args->trans, bp, loglow, to - 1);
660 }
661
662 /*
663  * Compact the leaf entries, removing stale ones.
664  * Leave one stale entry behind - the one closest to our
665  * insertion index - and the caller will shift that one to our insertion
666  * point later.
667  * Return new insertion index, where the remaining stale entry is,
668  * and leaf logging indices.
669  */
670 void
671 xfs_dir2_leaf_compact_x1(
672         xfs_dabuf_t     *bp,            /* leaf buffer */
673         int             *indexp,        /* insertion index */
674         int             *lowstalep,     /* out: stale entry before us */
675         int             *highstalep,    /* out: stale entry after us */
676         int             *lowlogp,       /* out: low log index */
677         int             *highlogp)      /* out: high log index */
678 {
679         int             from;           /* source copy index */
680         int             highstale;      /* stale entry at/after index */
681         int             index;          /* insertion index */
682         int             keepstale;      /* source index of kept stale */
683         xfs_dir2_leaf_t *leaf;          /* leaf structure */
684         int             lowstale;       /* stale entry before index */
685         int             newindex=0;     /* new insertion index */
686         int             to;             /* destination copy index */
687
688         leaf = bp->data;
689         ASSERT(be16_to_cpu(leaf->hdr.stale) > 1);
690         index = *indexp;
691         /*
692          * Find the first stale entry before our index, if any.
693          */
694         for (lowstale = index - 1;
695              lowstale >= 0 &&
696                 be32_to_cpu(leaf->ents[lowstale].address) != XFS_DIR2_NULL_DATAPTR;
697              lowstale--)
698                 continue;
699         /*
700          * Find the first stale entry at or after our index, if any.
701          * Stop if the answer would be worse than lowstale.
702          */
703         for (highstale = index;
704              highstale < be16_to_cpu(leaf->hdr.count) &&
705                 be32_to_cpu(leaf->ents[highstale].address) != XFS_DIR2_NULL_DATAPTR &&
706                 (lowstale < 0 || index - lowstale > highstale - index);
707              highstale++)
708                 continue;
709         /*
710          * Pick the better of lowstale and highstale.
711          */
712         if (lowstale >= 0 &&
713             (highstale == be16_to_cpu(leaf->hdr.count) ||
714              index - lowstale <= highstale - index))
715                 keepstale = lowstale;
716         else
717                 keepstale = highstale;
718         /*
719          * Copy the entries in place, removing all the stale entries
720          * except keepstale.
721          */
722         for (from = to = 0; from < be16_to_cpu(leaf->hdr.count); from++) {
723                 /*
724                  * Notice the new value of index.
725                  */
726                 if (index == from)
727                         newindex = to;
728                 if (from != keepstale &&
729                     be32_to_cpu(leaf->ents[from].address) == XFS_DIR2_NULL_DATAPTR) {
730                         if (from == to)
731                                 *lowlogp = to;
732                         continue;
733                 }
734                 /*
735                  * Record the new keepstale value for the insertion.
736                  */
737                 if (from == keepstale)
738                         lowstale = highstale = to;
739                 /*
740                  * Copy only the entries that have moved.
741                  */
742                 if (from > to)
743                         leaf->ents[to] = leaf->ents[from];
744                 to++;
745         }
746         ASSERT(from > to);
747         /*
748          * If the insertion point was past the last entry,
749          * set the new insertion point accordingly.
750          */
751         if (index == from)
752                 newindex = to;
753         *indexp = newindex;
754         /*
755          * Adjust the leaf header values.
756          */
757         be16_add_cpu(&leaf->hdr.count, -(from - to));
758         leaf->hdr.stale = cpu_to_be16(1);
759         /*
760          * Remember the low/high stale value only in the "right"
761          * direction.
762          */
763         if (lowstale >= newindex)
764                 lowstale = -1;
765         else
766                 highstale = be16_to_cpu(leaf->hdr.count);
767         *highlogp = be16_to_cpu(leaf->hdr.count) - 1;
768         *lowstalep = lowstale;
769         *highstalep = highstale;
770 }
771
772 /*
773  * Getdents (readdir) for leaf and node directories.
774  * This reads the data blocks only, so is the same for both forms.
775  */
776 int                                             /* error */
777 xfs_dir2_leaf_getdents(
778         xfs_inode_t             *dp,            /* incore directory inode */
779         void                    *dirent,
780         size_t                  bufsize,
781         xfs_off_t               *offset,
782         filldir_t               filldir)
783 {
784         xfs_dabuf_t             *bp;            /* data block buffer */
785         int                     byteoff;        /* offset in current block */
786         xfs_dir2_db_t           curdb;          /* db for current block */
787         xfs_dir2_off_t          curoff;         /* current overall offset */
788         xfs_dir2_data_t         *data;          /* data block structure */
789         xfs_dir2_data_entry_t   *dep;           /* data entry */
790         xfs_dir2_data_unused_t  *dup;           /* unused entry */
791         int                     error = 0;      /* error return value */
792         int                     i;              /* temporary loop index */
793         int                     j;              /* temporary loop index */
794         int                     length;         /* temporary length value */
795         xfs_bmbt_irec_t         *map;           /* map vector for blocks */
796         xfs_extlen_t            map_blocks;     /* number of fsbs in map */
797         xfs_dablk_t             map_off;        /* last mapped file offset */
798         int                     map_size;       /* total entries in *map */
799         int                     map_valid;      /* valid entries in *map */
800         xfs_mount_t             *mp;            /* filesystem mount point */
801         xfs_dir2_off_t          newoff;         /* new curoff after new blk */
802         int                     nmap;           /* mappings to ask xfs_bmapi */
803         char                    *ptr = NULL;    /* pointer to current data */
804         int                     ra_current;     /* number of read-ahead blks */
805         int                     ra_index;       /* *map index for read-ahead */
806         int                     ra_offset;      /* map entry offset for ra */
807         int                     ra_want;        /* readahead count wanted */
808
809         /*
810          * If the offset is at or past the largest allowed value,
811          * give up right away.
812          */
813         if (*offset >= XFS_DIR2_MAX_DATAPTR)
814                 return 0;
815
816         mp = dp->i_mount;
817
818         /*
819          * Set up to bmap a number of blocks based on the caller's
820          * buffer size, the directory block size, and the filesystem
821          * block size.
822          */
823         map_size = howmany(bufsize + mp->m_dirblksize, mp->m_sb.sb_blocksize);
824         map = kmem_alloc(map_size * sizeof(*map), KM_SLEEP);
825         map_valid = ra_index = ra_offset = ra_current = map_blocks = 0;
826         bp = NULL;
827
828         /*
829          * Inside the loop we keep the main offset value as a byte offset
830          * in the directory file.
831          */
832         curoff = xfs_dir2_dataptr_to_byte(mp, *offset);
833
834         /*
835          * Force this conversion through db so we truncate the offset
836          * down to get the start of the data block.
837          */
838         map_off = xfs_dir2_db_to_da(mp, xfs_dir2_byte_to_db(mp, curoff));
839         /*
840          * Loop over directory entries until we reach the end offset.
841          * Get more blocks and readahead as necessary.
842          */
843         while (curoff < XFS_DIR2_LEAF_OFFSET) {
844                 /*
845                  * If we have no buffer, or we're off the end of the
846                  * current buffer, need to get another one.
847                  */
848                 if (!bp || ptr >= (char *)bp->data + mp->m_dirblksize) {
849                         /*
850                          * If we have a buffer, we need to release it and
851                          * take it out of the mapping.
852                          */
853                         if (bp) {
854                                 xfs_da_brelse(NULL, bp);
855                                 bp = NULL;
856                                 map_blocks -= mp->m_dirblkfsbs;
857                                 /*
858                                  * Loop to get rid of the extents for the
859                                  * directory block.
860                                  */
861                                 for (i = mp->m_dirblkfsbs; i > 0; ) {
862                                         j = MIN((int)map->br_blockcount, i);
863                                         map->br_blockcount -= j;
864                                         map->br_startblock += j;
865                                         map->br_startoff += j;
866                                         /*
867                                          * If mapping is done, pitch it from
868                                          * the table.
869                                          */
870                                         if (!map->br_blockcount && --map_valid)
871                                                 memmove(&map[0], &map[1],
872                                                         sizeof(map[0]) *
873                                                         map_valid);
874                                         i -= j;
875                                 }
876                         }
877                         /*
878                          * Recalculate the readahead blocks wanted.
879                          */
880                         ra_want = howmany(bufsize + mp->m_dirblksize,
881                                           mp->m_sb.sb_blocksize) - 1;
882                         ASSERT(ra_want >= 0);
883
884                         /*
885                          * If we don't have as many as we want, and we haven't
886                          * run out of data blocks, get some more mappings.
887                          */
888                         if (1 + ra_want > map_blocks &&
889                             map_off <
890                             xfs_dir2_byte_to_da(mp, XFS_DIR2_LEAF_OFFSET)) {
891                                 /*
892                                  * Get more bmaps, fill in after the ones
893                                  * we already have in the table.
894                                  */
895                                 nmap = map_size - map_valid;
896                                 error = xfs_bmapi(NULL, dp,
897                                         map_off,
898                                         xfs_dir2_byte_to_da(mp,
899                                                 XFS_DIR2_LEAF_OFFSET) - map_off,
900                                         XFS_BMAPI_METADATA, NULL, 0,
901                                         &map[map_valid], &nmap, NULL);
902                                 /*
903                                  * Don't know if we should ignore this or
904                                  * try to return an error.
905                                  * The trouble with returning errors
906                                  * is that readdir will just stop without
907                                  * actually passing the error through.
908                                  */
909                                 if (error)
910                                         break;  /* XXX */
911                                 /*
912                                  * If we got all the mappings we asked for,
913                                  * set the final map offset based on the
914                                  * last bmap value received.
915                                  * Otherwise, we've reached the end.
916                                  */
917                                 if (nmap == map_size - map_valid)
918                                         map_off =
919                                         map[map_valid + nmap - 1].br_startoff +
920                                         map[map_valid + nmap - 1].br_blockcount;
921                                 else
922                                         map_off =
923                                                 xfs_dir2_byte_to_da(mp,
924                                                         XFS_DIR2_LEAF_OFFSET);
925                                 /*
926                                  * Look for holes in the mapping, and
927                                  * eliminate them.  Count up the valid blocks.
928                                  */
929                                 for (i = map_valid; i < map_valid + nmap; ) {
930                                         if (map[i].br_startblock ==
931                                             HOLESTARTBLOCK) {
932                                                 nmap--;
933                                                 length = map_valid + nmap - i;
934                                                 if (length)
935                                                         memmove(&map[i],
936                                                                 &map[i + 1],
937                                                                 sizeof(map[i]) *
938                                                                 length);
939                                         } else {
940                                                 map_blocks +=
941                                                         map[i].br_blockcount;
942                                                 i++;
943                                         }
944                                 }
945                                 map_valid += nmap;
946                         }
947                         /*
948                          * No valid mappings, so no more data blocks.
949                          */
950                         if (!map_valid) {
951                                 curoff = xfs_dir2_da_to_byte(mp, map_off);
952                                 break;
953                         }
954                         /*
955                          * Read the directory block starting at the first
956                          * mapping.
957                          */
958                         curdb = xfs_dir2_da_to_db(mp, map->br_startoff);
959                         error = xfs_da_read_buf(NULL, dp, map->br_startoff,
960                                 map->br_blockcount >= mp->m_dirblkfsbs ?
961                                     XFS_FSB_TO_DADDR(mp, map->br_startblock) :
962                                     -1,
963                                 &bp, XFS_DATA_FORK);
964                         /*
965                          * Should just skip over the data block instead
966                          * of giving up.
967                          */
968                         if (error)
969                                 break;  /* XXX */
970                         /*
971                          * Adjust the current amount of read-ahead: we just
972                          * read a block that was previously ra.
973                          */
974                         if (ra_current)
975                                 ra_current -= mp->m_dirblkfsbs;
976                         /*
977                          * Do we need more readahead?
978                          */
979                         for (ra_index = ra_offset = i = 0;
980                              ra_want > ra_current && i < map_blocks;
981                              i += mp->m_dirblkfsbs) {
982                                 ASSERT(ra_index < map_valid);
983                                 /*
984                                  * Read-ahead a contiguous directory block.
985                                  */
986                                 if (i > ra_current &&
987                                     map[ra_index].br_blockcount >=
988                                     mp->m_dirblkfsbs) {
989                                         xfs_buf_readahead(mp->m_ddev_targp,
990                                                 XFS_FSB_TO_DADDR(mp,
991                                                    map[ra_index].br_startblock +
992                                                    ra_offset),
993                                                 (int)BTOBB(mp->m_dirblksize));
994                                         ra_current = i;
995                                 }
996                                 /*
997                                  * Read-ahead a non-contiguous directory block.
998                                  * This doesn't use our mapping, but this
999                                  * is a very rare case.
1000                                  */
1001                                 else if (i > ra_current) {
1002                                         (void)xfs_da_reada_buf(NULL, dp,
1003                                                 map[ra_index].br_startoff +
1004                                                 ra_offset, XFS_DATA_FORK);
1005                                         ra_current = i;
1006                                 }
1007                                 /*
1008                                  * Advance offset through the mapping table.
1009                                  */
1010                                 for (j = 0; j < mp->m_dirblkfsbs; j++) {
1011                                         /*
1012                                          * The rest of this extent but not
1013                                          * more than a dir block.
1014                                          */
1015                                         length = MIN(mp->m_dirblkfsbs,
1016                                                 (int)(map[ra_index].br_blockcount -
1017                                                 ra_offset));
1018                                         j += length;
1019                                         ra_offset += length;
1020                                         /*
1021                                          * Advance to the next mapping if
1022                                          * this one is used up.
1023                                          */
1024                                         if (ra_offset ==
1025                                             map[ra_index].br_blockcount) {
1026                                                 ra_offset = 0;
1027                                                 ra_index++;
1028                                         }
1029                                 }
1030                         }
1031                         /*
1032                          * Having done a read, we need to set a new offset.
1033                          */
1034                         newoff = xfs_dir2_db_off_to_byte(mp, curdb, 0);
1035                         /*
1036                          * Start of the current block.
1037                          */
1038                         if (curoff < newoff)
1039                                 curoff = newoff;
1040                         /*
1041                          * Make sure we're in the right block.
1042                          */
1043                         else if (curoff > newoff)
1044                                 ASSERT(xfs_dir2_byte_to_db(mp, curoff) ==
1045                                        curdb);
1046                         data = bp->data;
1047                         xfs_dir2_data_check(dp, bp);
1048                         /*
1049                          * Find our position in the block.
1050                          */
1051                         ptr = (char *)&data->u;
1052                         byteoff = xfs_dir2_byte_to_off(mp, curoff);
1053                         /*
1054                          * Skip past the header.
1055                          */
1056                         if (byteoff == 0)
1057                                 curoff += (uint)sizeof(data->hdr);
1058                         /*
1059                          * Skip past entries until we reach our offset.
1060                          */
1061                         else {
1062                                 while ((char *)ptr - (char *)data < byteoff) {
1063                                         dup = (xfs_dir2_data_unused_t *)ptr;
1064
1065                                         if (be16_to_cpu(dup->freetag)
1066                                                   == XFS_DIR2_DATA_FREE_TAG) {
1067
1068                                                 length = be16_to_cpu(dup->length);
1069                                                 ptr += length;
1070                                                 continue;
1071                                         }
1072                                         dep = (xfs_dir2_data_entry_t *)ptr;
1073                                         length =
1074                                            xfs_dir2_data_entsize(dep->namelen);
1075                                         ptr += length;
1076                                 }
1077                                 /*
1078                                  * Now set our real offset.
1079                                  */
1080                                 curoff =
1081                                         xfs_dir2_db_off_to_byte(mp,
1082                                             xfs_dir2_byte_to_db(mp, curoff),
1083                                             (char *)ptr - (char *)data);
1084                                 if (ptr >= (char *)data + mp->m_dirblksize) {
1085                                         continue;
1086                                 }
1087                         }
1088                 }
1089                 /*
1090                  * We have a pointer to an entry.
1091                  * Is it a live one?
1092                  */
1093                 dup = (xfs_dir2_data_unused_t *)ptr;
1094                 /*
1095                  * No, it's unused, skip over it.
1096                  */
1097                 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
1098                         length = be16_to_cpu(dup->length);
1099                         ptr += length;
1100                         curoff += length;
1101                         continue;
1102                 }
1103
1104                 dep = (xfs_dir2_data_entry_t *)ptr;
1105                 length = xfs_dir2_data_entsize(dep->namelen);
1106
1107                 if (filldir(dirent, (char *)dep->name, dep->namelen,
1108                             xfs_dir2_byte_to_dataptr(mp, curoff) & 0x7fffffff,
1109                             be64_to_cpu(dep->inumber), DT_UNKNOWN))
1110                         break;
1111
1112                 /*
1113                  * Advance to next entry in the block.
1114                  */
1115                 ptr += length;
1116                 curoff += length;
1117                 /* bufsize may have just been a guess; don't go negative */
1118                 bufsize = bufsize > length ? bufsize - length : 0;
1119         }
1120
1121         /*
1122          * All done.  Set output offset value to current offset.
1123          */
1124         if (curoff > xfs_dir2_dataptr_to_byte(mp, XFS_DIR2_MAX_DATAPTR))
1125                 *offset = XFS_DIR2_MAX_DATAPTR & 0x7fffffff;
1126         else
1127                 *offset = xfs_dir2_byte_to_dataptr(mp, curoff) & 0x7fffffff;
1128         kmem_free(map);
1129         if (bp)
1130                 xfs_da_brelse(NULL, bp);
1131         return error;
1132 }
1133
1134 /*
1135  * Initialize a new leaf block, leaf1 or leafn magic accepted.
1136  */
1137 int
1138 xfs_dir2_leaf_init(
1139         xfs_da_args_t           *args,          /* operation arguments */
1140         xfs_dir2_db_t           bno,            /* directory block number */
1141         xfs_dabuf_t             **bpp,          /* out: leaf buffer */
1142         int                     magic)          /* magic number for block */
1143 {
1144         xfs_dabuf_t             *bp;            /* leaf buffer */
1145         xfs_inode_t             *dp;            /* incore directory inode */
1146         int                     error;          /* error return code */
1147         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
1148         xfs_dir2_leaf_tail_t    *ltp;           /* leaf tail structure */
1149         xfs_mount_t             *mp;            /* filesystem mount point */
1150         xfs_trans_t             *tp;            /* transaction pointer */
1151
1152         dp = args->dp;
1153         ASSERT(dp != NULL);
1154         tp = args->trans;
1155         mp = dp->i_mount;
1156         ASSERT(bno >= XFS_DIR2_LEAF_FIRSTDB(mp) &&
1157                bno < XFS_DIR2_FREE_FIRSTDB(mp));
1158         /*
1159          * Get the buffer for the block.
1160          */
1161         error = xfs_da_get_buf(tp, dp, xfs_dir2_db_to_da(mp, bno), -1, &bp,
1162                 XFS_DATA_FORK);
1163         if (error) {
1164                 return error;
1165         }
1166         ASSERT(bp != NULL);
1167         leaf = bp->data;
1168         /*
1169          * Initialize the header.
1170          */
1171         leaf->hdr.info.magic = cpu_to_be16(magic);
1172         leaf->hdr.info.forw = 0;
1173         leaf->hdr.info.back = 0;
1174         leaf->hdr.count = 0;
1175         leaf->hdr.stale = 0;
1176         xfs_dir2_leaf_log_header(tp, bp);
1177         /*
1178          * If it's a leaf-format directory initialize the tail.
1179          * In this case our caller has the real bests table to copy into
1180          * the block.
1181          */
1182         if (magic == XFS_DIR2_LEAF1_MAGIC) {
1183                 ltp = xfs_dir2_leaf_tail_p(mp, leaf);
1184                 ltp->bestcount = 0;
1185                 xfs_dir2_leaf_log_tail(tp, bp);
1186         }
1187         *bpp = bp;
1188         return 0;
1189 }
1190
1191 /*
1192  * Log the bests entries indicated from a leaf1 block.
1193  */
1194 static void
1195 xfs_dir2_leaf_log_bests(
1196         xfs_trans_t             *tp,            /* transaction pointer */
1197         xfs_dabuf_t             *bp,            /* leaf buffer */
1198         int                     first,          /* first entry to log */
1199         int                     last)           /* last entry to log */
1200 {
1201         __be16                  *firstb;        /* pointer to first entry */
1202         __be16                  *lastb;         /* pointer to last entry */
1203         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
1204         xfs_dir2_leaf_tail_t    *ltp;           /* leaf tail structure */
1205
1206         leaf = bp->data;
1207         ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_DIR2_LEAF1_MAGIC);
1208         ltp = xfs_dir2_leaf_tail_p(tp->t_mountp, leaf);
1209         firstb = xfs_dir2_leaf_bests_p(ltp) + first;
1210         lastb = xfs_dir2_leaf_bests_p(ltp) + last;
1211         xfs_da_log_buf(tp, bp, (uint)((char *)firstb - (char *)leaf),
1212                 (uint)((char *)lastb - (char *)leaf + sizeof(*lastb) - 1));
1213 }
1214
1215 /*
1216  * Log the leaf entries indicated from a leaf1 or leafn block.
1217  */
1218 void
1219 xfs_dir2_leaf_log_ents(
1220         xfs_trans_t             *tp,            /* transaction pointer */
1221         xfs_dabuf_t             *bp,            /* leaf buffer */
1222         int                     first,          /* first entry to log */
1223         int                     last)           /* last entry to log */
1224 {
1225         xfs_dir2_leaf_entry_t   *firstlep;      /* pointer to first entry */
1226         xfs_dir2_leaf_entry_t   *lastlep;       /* pointer to last entry */
1227         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
1228
1229         leaf = bp->data;
1230         ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_DIR2_LEAF1_MAGIC ||
1231                be16_to_cpu(leaf->hdr.info.magic) == XFS_DIR2_LEAFN_MAGIC);
1232         firstlep = &leaf->ents[first];
1233         lastlep = &leaf->ents[last];
1234         xfs_da_log_buf(tp, bp, (uint)((char *)firstlep - (char *)leaf),
1235                 (uint)((char *)lastlep - (char *)leaf + sizeof(*lastlep) - 1));
1236 }
1237
1238 /*
1239  * Log the header of the leaf1 or leafn block.
1240  */
1241 void
1242 xfs_dir2_leaf_log_header(
1243         xfs_trans_t             *tp,            /* transaction pointer */
1244         xfs_dabuf_t             *bp)            /* leaf buffer */
1245 {
1246         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
1247
1248         leaf = bp->data;
1249         ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_DIR2_LEAF1_MAGIC ||
1250                be16_to_cpu(leaf->hdr.info.magic) == XFS_DIR2_LEAFN_MAGIC);
1251         xfs_da_log_buf(tp, bp, (uint)((char *)&leaf->hdr - (char *)leaf),
1252                 (uint)(sizeof(leaf->hdr) - 1));
1253 }
1254
1255 /*
1256  * Log the tail of the leaf1 block.
1257  */
1258 STATIC void
1259 xfs_dir2_leaf_log_tail(
1260         xfs_trans_t             *tp,            /* transaction pointer */
1261         xfs_dabuf_t             *bp)            /* leaf buffer */
1262 {
1263         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
1264         xfs_dir2_leaf_tail_t    *ltp;           /* leaf tail structure */
1265         xfs_mount_t             *mp;            /* filesystem mount point */
1266
1267         mp = tp->t_mountp;
1268         leaf = bp->data;
1269         ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_DIR2_LEAF1_MAGIC);
1270         ltp = xfs_dir2_leaf_tail_p(mp, leaf);
1271         xfs_da_log_buf(tp, bp, (uint)((char *)ltp - (char *)leaf),
1272                 (uint)(mp->m_dirblksize - 1));
1273 }
1274
1275 /*
1276  * Look up the entry referred to by args in the leaf format directory.
1277  * Most of the work is done by the xfs_dir2_leaf_lookup_int routine which
1278  * is also used by the node-format code.
1279  */
1280 int
1281 xfs_dir2_leaf_lookup(
1282         xfs_da_args_t           *args)          /* operation arguments */
1283 {
1284         xfs_dabuf_t             *dbp;           /* data block buffer */
1285         xfs_dir2_data_entry_t   *dep;           /* data block entry */
1286         xfs_inode_t             *dp;            /* incore directory inode */
1287         int                     error;          /* error return code */
1288         int                     index;          /* found entry index */
1289         xfs_dabuf_t             *lbp;           /* leaf buffer */
1290         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
1291         xfs_dir2_leaf_entry_t   *lep;           /* leaf entry */
1292         xfs_trans_t             *tp;            /* transaction pointer */
1293
1294         trace_xfs_dir2_leaf_lookup(args);
1295
1296         /*
1297          * Look up name in the leaf block, returning both buffers and index.
1298          */
1299         if ((error = xfs_dir2_leaf_lookup_int(args, &lbp, &index, &dbp))) {
1300                 return error;
1301         }
1302         tp = args->trans;
1303         dp = args->dp;
1304         xfs_dir2_leaf_check(dp, lbp);
1305         leaf = lbp->data;
1306         /*
1307          * Get to the leaf entry and contained data entry address.
1308          */
1309         lep = &leaf->ents[index];
1310         /*
1311          * Point to the data entry.
1312          */
1313         dep = (xfs_dir2_data_entry_t *)
1314               ((char *)dbp->data +
1315                xfs_dir2_dataptr_to_off(dp->i_mount, be32_to_cpu(lep->address)));
1316         /*
1317          * Return the found inode number & CI name if appropriate
1318          */
1319         args->inumber = be64_to_cpu(dep->inumber);
1320         error = xfs_dir_cilookup_result(args, dep->name, dep->namelen);
1321         xfs_da_brelse(tp, dbp);
1322         xfs_da_brelse(tp, lbp);
1323         return XFS_ERROR(error);
1324 }
1325
1326 /*
1327  * Look up name/hash in the leaf block.
1328  * Fill in indexp with the found index, and dbpp with the data buffer.
1329  * If not found dbpp will be NULL, and ENOENT comes back.
1330  * lbpp will always be filled in with the leaf buffer unless there's an error.
1331  */
1332 static int                                      /* error */
1333 xfs_dir2_leaf_lookup_int(
1334         xfs_da_args_t           *args,          /* operation arguments */
1335         xfs_dabuf_t             **lbpp,         /* out: leaf buffer */
1336         int                     *indexp,        /* out: index in leaf block */
1337         xfs_dabuf_t             **dbpp)         /* out: data buffer */
1338 {
1339         xfs_dir2_db_t           curdb = -1;     /* current data block number */
1340         xfs_dabuf_t             *dbp = NULL;    /* data buffer */
1341         xfs_dir2_data_entry_t   *dep;           /* data entry */
1342         xfs_inode_t             *dp;            /* incore directory inode */
1343         int                     error;          /* error return code */
1344         int                     index;          /* index in leaf block */
1345         xfs_dabuf_t             *lbp;           /* leaf buffer */
1346         xfs_dir2_leaf_entry_t   *lep;           /* leaf entry */
1347         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
1348         xfs_mount_t             *mp;            /* filesystem mount point */
1349         xfs_dir2_db_t           newdb;          /* new data block number */
1350         xfs_trans_t             *tp;            /* transaction pointer */
1351         xfs_dir2_db_t           cidb = -1;      /* case match data block no. */
1352         enum xfs_dacmp          cmp;            /* name compare result */
1353
1354         dp = args->dp;
1355         tp = args->trans;
1356         mp = dp->i_mount;
1357         /*
1358          * Read the leaf block into the buffer.
1359          */
1360         error = xfs_da_read_buf(tp, dp, mp->m_dirleafblk, -1, &lbp,
1361                                                         XFS_DATA_FORK);
1362         if (error)
1363                 return error;
1364         *lbpp = lbp;
1365         leaf = lbp->data;
1366         xfs_dir2_leaf_check(dp, lbp);
1367         /*
1368          * Look for the first leaf entry with our hash value.
1369          */
1370         index = xfs_dir2_leaf_search_hash(args, lbp);
1371         /*
1372          * Loop over all the entries with the right hash value
1373          * looking to match the name.
1374          */
1375         for (lep = &leaf->ents[index]; index < be16_to_cpu(leaf->hdr.count) &&
1376                                 be32_to_cpu(lep->hashval) == args->hashval;
1377                                 lep++, index++) {
1378                 /*
1379                  * Skip over stale leaf entries.
1380                  */
1381                 if (be32_to_cpu(lep->address) == XFS_DIR2_NULL_DATAPTR)
1382                         continue;
1383                 /*
1384                  * Get the new data block number.
1385                  */
1386                 newdb = xfs_dir2_dataptr_to_db(mp, be32_to_cpu(lep->address));
1387                 /*
1388                  * If it's not the same as the old data block number,
1389                  * need to pitch the old one and read the new one.
1390                  */
1391                 if (newdb != curdb) {
1392                         if (dbp)
1393                                 xfs_da_brelse(tp, dbp);
1394                         error = xfs_da_read_buf(tp, dp,
1395                                                 xfs_dir2_db_to_da(mp, newdb),
1396                                                 -1, &dbp, XFS_DATA_FORK);
1397                         if (error) {
1398                                 xfs_da_brelse(tp, lbp);
1399                                 return error;
1400                         }
1401                         xfs_dir2_data_check(dp, dbp);
1402                         curdb = newdb;
1403                 }
1404                 /*
1405                  * Point to the data entry.
1406                  */
1407                 dep = (xfs_dir2_data_entry_t *)((char *)dbp->data +
1408                         xfs_dir2_dataptr_to_off(mp, be32_to_cpu(lep->address)));
1409                 /*
1410                  * Compare name and if it's an exact match, return the index
1411                  * and buffer. If it's the first case-insensitive match, store
1412                  * the index and buffer and continue looking for an exact match.
1413                  */
1414                 cmp = mp->m_dirnameops->compname(args, dep->name, dep->namelen);
1415                 if (cmp != XFS_CMP_DIFFERENT && cmp != args->cmpresult) {
1416                         args->cmpresult = cmp;
1417                         *indexp = index;
1418                         /* case exact match: return the current buffer. */
1419                         if (cmp == XFS_CMP_EXACT) {
1420                                 *dbpp = dbp;
1421                                 return 0;
1422                         }
1423                         cidb = curdb;
1424                 }
1425         }
1426         ASSERT(args->op_flags & XFS_DA_OP_OKNOENT);
1427         /*
1428          * Here, we can only be doing a lookup (not a rename or remove).
1429          * If a case-insensitive match was found earlier, re-read the
1430          * appropriate data block if required and return it.
1431          */
1432         if (args->cmpresult == XFS_CMP_CASE) {
1433                 ASSERT(cidb != -1);
1434                 if (cidb != curdb) {
1435                         xfs_da_brelse(tp, dbp);
1436                         error = xfs_da_read_buf(tp, dp,
1437                                                 xfs_dir2_db_to_da(mp, cidb),
1438                                                 -1, &dbp, XFS_DATA_FORK);
1439                         if (error) {
1440                                 xfs_da_brelse(tp, lbp);
1441                                 return error;
1442                         }
1443                 }
1444                 *dbpp = dbp;
1445                 return 0;
1446         }
1447         /*
1448          * No match found, return ENOENT.
1449          */
1450         ASSERT(cidb == -1);
1451         if (dbp)
1452                 xfs_da_brelse(tp, dbp);
1453         xfs_da_brelse(tp, lbp);
1454         return XFS_ERROR(ENOENT);
1455 }
1456
1457 /*
1458  * Remove an entry from a leaf format directory.
1459  */
1460 int                                             /* error */
1461 xfs_dir2_leaf_removename(
1462         xfs_da_args_t           *args)          /* operation arguments */
1463 {
1464         __be16                  *bestsp;        /* leaf block best freespace */
1465         xfs_dir2_data_t         *data;          /* data block structure */
1466         xfs_dir2_db_t           db;             /* data block number */
1467         xfs_dabuf_t             *dbp;           /* data block buffer */
1468         xfs_dir2_data_entry_t   *dep;           /* data entry structure */
1469         xfs_inode_t             *dp;            /* incore directory inode */
1470         int                     error;          /* error return code */
1471         xfs_dir2_db_t           i;              /* temporary data block # */
1472         int                     index;          /* index into leaf entries */
1473         xfs_dabuf_t             *lbp;           /* leaf buffer */
1474         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
1475         xfs_dir2_leaf_entry_t   *lep;           /* leaf entry */
1476         xfs_dir2_leaf_tail_t    *ltp;           /* leaf tail structure */
1477         xfs_mount_t             *mp;            /* filesystem mount point */
1478         int                     needlog;        /* need to log data header */
1479         int                     needscan;       /* need to rescan data frees */
1480         xfs_dir2_data_off_t     oldbest;        /* old value of best free */
1481         xfs_trans_t             *tp;            /* transaction pointer */
1482
1483         trace_xfs_dir2_leaf_removename(args);
1484
1485         /*
1486          * Lookup the leaf entry, get the leaf and data blocks read in.
1487          */
1488         if ((error = xfs_dir2_leaf_lookup_int(args, &lbp, &index, &dbp))) {
1489                 return error;
1490         }
1491         dp = args->dp;
1492         tp = args->trans;
1493         mp = dp->i_mount;
1494         leaf = lbp->data;
1495         data = dbp->data;
1496         xfs_dir2_data_check(dp, dbp);
1497         /*
1498          * Point to the leaf entry, use that to point to the data entry.
1499          */
1500         lep = &leaf->ents[index];
1501         db = xfs_dir2_dataptr_to_db(mp, be32_to_cpu(lep->address));
1502         dep = (xfs_dir2_data_entry_t *)
1503               ((char *)data + xfs_dir2_dataptr_to_off(mp, be32_to_cpu(lep->address)));
1504         needscan = needlog = 0;
1505         oldbest = be16_to_cpu(data->hdr.bestfree[0].length);
1506         ltp = xfs_dir2_leaf_tail_p(mp, leaf);
1507         bestsp = xfs_dir2_leaf_bests_p(ltp);
1508         ASSERT(be16_to_cpu(bestsp[db]) == oldbest);
1509         /*
1510          * Mark the former data entry unused.
1511          */
1512         xfs_dir2_data_make_free(tp, dbp,
1513                 (xfs_dir2_data_aoff_t)((char *)dep - (char *)data),
1514                 xfs_dir2_data_entsize(dep->namelen), &needlog, &needscan);
1515         /*
1516          * We just mark the leaf entry stale by putting a null in it.
1517          */
1518         be16_add_cpu(&leaf->hdr.stale, 1);
1519         xfs_dir2_leaf_log_header(tp, lbp);
1520         lep->address = cpu_to_be32(XFS_DIR2_NULL_DATAPTR);
1521         xfs_dir2_leaf_log_ents(tp, lbp, index, index);
1522         /*
1523          * Scan the freespace in the data block again if necessary,
1524          * log the data block header if necessary.
1525          */
1526         if (needscan)
1527                 xfs_dir2_data_freescan(mp, data, &needlog);
1528         if (needlog)
1529                 xfs_dir2_data_log_header(tp, dbp);
1530         /*
1531          * If the longest freespace in the data block has changed,
1532          * put the new value in the bests table and log that.
1533          */
1534         if (be16_to_cpu(data->hdr.bestfree[0].length) != oldbest) {
1535                 bestsp[db] = data->hdr.bestfree[0].length;
1536                 xfs_dir2_leaf_log_bests(tp, lbp, db, db);
1537         }
1538         xfs_dir2_data_check(dp, dbp);
1539         /*
1540          * If the data block is now empty then get rid of the data block.
1541          */
1542         if (be16_to_cpu(data->hdr.bestfree[0].length) ==
1543             mp->m_dirblksize - (uint)sizeof(data->hdr)) {
1544                 ASSERT(db != mp->m_dirdatablk);
1545                 if ((error = xfs_dir2_shrink_inode(args, db, dbp))) {
1546                         /*
1547                          * Nope, can't get rid of it because it caused
1548                          * allocation of a bmap btree block to do so.
1549                          * Just go on, returning success, leaving the
1550                          * empty block in place.
1551                          */
1552                         if (error == ENOSPC && args->total == 0) {
1553                                 xfs_da_buf_done(dbp);
1554                                 error = 0;
1555                         }
1556                         xfs_dir2_leaf_check(dp, lbp);
1557                         xfs_da_buf_done(lbp);
1558                         return error;
1559                 }
1560                 dbp = NULL;
1561                 /*
1562                  * If this is the last data block then compact the
1563                  * bests table by getting rid of entries.
1564                  */
1565                 if (db == be32_to_cpu(ltp->bestcount) - 1) {
1566                         /*
1567                          * Look for the last active entry (i).
1568                          */
1569                         for (i = db - 1; i > 0; i--) {
1570                                 if (be16_to_cpu(bestsp[i]) != NULLDATAOFF)
1571                                         break;
1572                         }
1573                         /*
1574                          * Copy the table down so inactive entries at the
1575                          * end are removed.
1576                          */
1577                         memmove(&bestsp[db - i], bestsp,
1578                                 (be32_to_cpu(ltp->bestcount) - (db - i)) * sizeof(*bestsp));
1579                         be32_add_cpu(&ltp->bestcount, -(db - i));
1580                         xfs_dir2_leaf_log_tail(tp, lbp);
1581                         xfs_dir2_leaf_log_bests(tp, lbp, 0, be32_to_cpu(ltp->bestcount) - 1);
1582                 } else
1583                         bestsp[db] = cpu_to_be16(NULLDATAOFF);
1584         }
1585         /*
1586          * If the data block was not the first one, drop it.
1587          */
1588         else if (db != mp->m_dirdatablk && dbp != NULL) {
1589                 xfs_da_buf_done(dbp);
1590                 dbp = NULL;
1591         }
1592         xfs_dir2_leaf_check(dp, lbp);
1593         /*
1594          * See if we can convert to block form.
1595          */
1596         return xfs_dir2_leaf_to_block(args, lbp, dbp);
1597 }
1598
1599 /*
1600  * Replace the inode number in a leaf format directory entry.
1601  */
1602 int                                             /* error */
1603 xfs_dir2_leaf_replace(
1604         xfs_da_args_t           *args)          /* operation arguments */
1605 {
1606         xfs_dabuf_t             *dbp;           /* data block buffer */
1607         xfs_dir2_data_entry_t   *dep;           /* data block entry */
1608         xfs_inode_t             *dp;            /* incore directory inode */
1609         int                     error;          /* error return code */
1610         int                     index;          /* index of leaf entry */
1611         xfs_dabuf_t             *lbp;           /* leaf buffer */
1612         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
1613         xfs_dir2_leaf_entry_t   *lep;           /* leaf entry */
1614         xfs_trans_t             *tp;            /* transaction pointer */
1615
1616         trace_xfs_dir2_leaf_replace(args);
1617
1618         /*
1619          * Look up the entry.
1620          */
1621         if ((error = xfs_dir2_leaf_lookup_int(args, &lbp, &index, &dbp))) {
1622                 return error;
1623         }
1624         dp = args->dp;
1625         leaf = lbp->data;
1626         /*
1627          * Point to the leaf entry, get data address from it.
1628          */
1629         lep = &leaf->ents[index];
1630         /*
1631          * Point to the data entry.
1632          */
1633         dep = (xfs_dir2_data_entry_t *)
1634               ((char *)dbp->data +
1635                xfs_dir2_dataptr_to_off(dp->i_mount, be32_to_cpu(lep->address)));
1636         ASSERT(args->inumber != be64_to_cpu(dep->inumber));
1637         /*
1638          * Put the new inode number in, log it.
1639          */
1640         dep->inumber = cpu_to_be64(args->inumber);
1641         tp = args->trans;
1642         xfs_dir2_data_log_entry(tp, dbp, dep);
1643         xfs_da_buf_done(dbp);
1644         xfs_dir2_leaf_check(dp, lbp);
1645         xfs_da_brelse(tp, lbp);
1646         return 0;
1647 }
1648
1649 /*
1650  * Return index in the leaf block (lbp) which is either the first
1651  * one with this hash value, or if there are none, the insert point
1652  * for that hash value.
1653  */
1654 int                                             /* index value */
1655 xfs_dir2_leaf_search_hash(
1656         xfs_da_args_t           *args,          /* operation arguments */
1657         xfs_dabuf_t             *lbp)           /* leaf buffer */
1658 {
1659         xfs_dahash_t            hash=0;         /* hash from this entry */
1660         xfs_dahash_t            hashwant;       /* hash value looking for */
1661         int                     high;           /* high leaf index */
1662         int                     low;            /* low leaf index */
1663         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
1664         xfs_dir2_leaf_entry_t   *lep;           /* leaf entry */
1665         int                     mid=0;          /* current leaf index */
1666
1667         leaf = lbp->data;
1668 #ifndef __KERNEL__
1669         if (!leaf->hdr.count)
1670                 return 0;
1671 #endif
1672         /*
1673          * Note, the table cannot be empty, so we have to go through the loop.
1674          * Binary search the leaf entries looking for our hash value.
1675          */
1676         for (lep = leaf->ents, low = 0, high = be16_to_cpu(leaf->hdr.count) - 1,
1677                 hashwant = args->hashval;
1678              low <= high; ) {
1679                 mid = (low + high) >> 1;
1680                 if ((hash = be32_to_cpu(lep[mid].hashval)) == hashwant)
1681                         break;
1682                 if (hash < hashwant)
1683                         low = mid + 1;
1684                 else
1685                         high = mid - 1;
1686         }
1687         /*
1688          * Found one, back up through all the equal hash values.
1689          */
1690         if (hash == hashwant) {
1691                 while (mid > 0 && be32_to_cpu(lep[mid - 1].hashval) == hashwant) {
1692                         mid--;
1693                 }
1694         }
1695         /*
1696          * Need to point to an entry higher than ours.
1697          */
1698         else if (hash < hashwant)
1699                 mid++;
1700         return mid;
1701 }
1702
1703 /*
1704  * Trim off a trailing data block.  We know it's empty since the leaf
1705  * freespace table says so.
1706  */
1707 int                                             /* error */
1708 xfs_dir2_leaf_trim_data(
1709         xfs_da_args_t           *args,          /* operation arguments */
1710         xfs_dabuf_t             *lbp,           /* leaf buffer */
1711         xfs_dir2_db_t           db)             /* data block number */
1712 {
1713         __be16                  *bestsp;        /* leaf bests table */
1714 #ifdef DEBUG
1715         xfs_dir2_data_t         *data;          /* data block structure */
1716 #endif
1717         xfs_dabuf_t             *dbp;           /* data block buffer */
1718         xfs_inode_t             *dp;            /* incore directory inode */
1719         int                     error;          /* error return value */
1720         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
1721         xfs_dir2_leaf_tail_t    *ltp;           /* leaf tail structure */
1722         xfs_mount_t             *mp;            /* filesystem mount point */
1723         xfs_trans_t             *tp;            /* transaction pointer */
1724
1725         dp = args->dp;
1726         mp = dp->i_mount;
1727         tp = args->trans;
1728         /*
1729          * Read the offending data block.  We need its buffer.
1730          */
1731         if ((error = xfs_da_read_buf(tp, dp, xfs_dir2_db_to_da(mp, db), -1, &dbp,
1732                         XFS_DATA_FORK))) {
1733                 return error;
1734         }
1735 #ifdef DEBUG
1736         data = dbp->data;
1737         ASSERT(be32_to_cpu(data->hdr.magic) == XFS_DIR2_DATA_MAGIC);
1738 #endif
1739         /* this seems to be an error
1740          * data is only valid if DEBUG is defined?
1741          * RMC 09/08/1999
1742          */
1743
1744         leaf = lbp->data;
1745         ltp = xfs_dir2_leaf_tail_p(mp, leaf);
1746         ASSERT(be16_to_cpu(data->hdr.bestfree[0].length) ==
1747                mp->m_dirblksize - (uint)sizeof(data->hdr));
1748         ASSERT(db == be32_to_cpu(ltp->bestcount) - 1);
1749         /*
1750          * Get rid of the data block.
1751          */
1752         if ((error = xfs_dir2_shrink_inode(args, db, dbp))) {
1753                 ASSERT(error != ENOSPC);
1754                 xfs_da_brelse(tp, dbp);
1755                 return error;
1756         }
1757         /*
1758          * Eliminate the last bests entry from the table.
1759          */
1760         bestsp = xfs_dir2_leaf_bests_p(ltp);
1761         be32_add_cpu(&ltp->bestcount, -1);
1762         memmove(&bestsp[1], &bestsp[0], be32_to_cpu(ltp->bestcount) * sizeof(*bestsp));
1763         xfs_dir2_leaf_log_tail(tp, lbp);
1764         xfs_dir2_leaf_log_bests(tp, lbp, 0, be32_to_cpu(ltp->bestcount) - 1);
1765         return 0;
1766 }
1767
1768 /*
1769  * Convert node form directory to leaf form directory.
1770  * The root of the node form dir needs to already be a LEAFN block.
1771  * Just return if we can't do anything.
1772  */
1773 int                                             /* error */
1774 xfs_dir2_node_to_leaf(
1775         xfs_da_state_t          *state)         /* directory operation state */
1776 {
1777         xfs_da_args_t           *args;          /* operation arguments */
1778         xfs_inode_t             *dp;            /* incore directory inode */
1779         int                     error;          /* error return code */
1780         xfs_dabuf_t             *fbp;           /* buffer for freespace block */
1781         xfs_fileoff_t           fo;             /* freespace file offset */
1782         xfs_dir2_free_t         *free;          /* freespace structure */
1783         xfs_dabuf_t             *lbp;           /* buffer for leaf block */
1784         xfs_dir2_leaf_tail_t    *ltp;           /* tail of leaf structure */
1785         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
1786         xfs_mount_t             *mp;            /* filesystem mount point */
1787         int                     rval;           /* successful free trim? */
1788         xfs_trans_t             *tp;            /* transaction pointer */
1789
1790         /*
1791          * There's more than a leaf level in the btree, so there must
1792          * be multiple leafn blocks.  Give up.
1793          */
1794         if (state->path.active > 1)
1795                 return 0;
1796         args = state->args;
1797
1798         trace_xfs_dir2_node_to_leaf(args);
1799
1800         mp = state->mp;
1801         dp = args->dp;
1802         tp = args->trans;
1803         /*
1804          * Get the last offset in the file.
1805          */
1806         if ((error = xfs_bmap_last_offset(tp, dp, &fo, XFS_DATA_FORK))) {
1807                 return error;
1808         }
1809         fo -= mp->m_dirblkfsbs;
1810         /*
1811          * If there are freespace blocks other than the first one,
1812          * take this opportunity to remove trailing empty freespace blocks
1813          * that may have been left behind during no-space-reservation
1814          * operations.
1815          */
1816         while (fo > mp->m_dirfreeblk) {
1817                 if ((error = xfs_dir2_node_trim_free(args, fo, &rval))) {
1818                         return error;
1819                 }
1820                 if (rval)
1821                         fo -= mp->m_dirblkfsbs;
1822                 else
1823                         return 0;
1824         }
1825         /*
1826          * Now find the block just before the freespace block.
1827          */
1828         if ((error = xfs_bmap_last_before(tp, dp, &fo, XFS_DATA_FORK))) {
1829                 return error;
1830         }
1831         /*
1832          * If it's not the single leaf block, give up.
1833          */
1834         if (XFS_FSB_TO_B(mp, fo) > XFS_DIR2_LEAF_OFFSET + mp->m_dirblksize)
1835                 return 0;
1836         lbp = state->path.blk[0].bp;
1837         leaf = lbp->data;
1838         ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_DIR2_LEAFN_MAGIC);
1839         /*
1840          * Read the freespace block.
1841          */
1842         if ((error = xfs_da_read_buf(tp, dp, mp->m_dirfreeblk, -1, &fbp,
1843                         XFS_DATA_FORK))) {
1844                 return error;
1845         }
1846         free = fbp->data;
1847         ASSERT(be32_to_cpu(free->hdr.magic) == XFS_DIR2_FREE_MAGIC);
1848         ASSERT(!free->hdr.firstdb);
1849         /*
1850          * Now see if the leafn and free data will fit in a leaf1.
1851          * If not, release the buffer and give up.
1852          */
1853         if ((uint)sizeof(leaf->hdr) +
1854             (be16_to_cpu(leaf->hdr.count) - be16_to_cpu(leaf->hdr.stale)) * (uint)sizeof(leaf->ents[0]) +
1855             be32_to_cpu(free->hdr.nvalid) * (uint)sizeof(leaf->bests[0]) +
1856             (uint)sizeof(leaf->tail) >
1857             mp->m_dirblksize) {
1858                 xfs_da_brelse(tp, fbp);
1859                 return 0;
1860         }
1861         /*
1862          * If the leaf has any stale entries in it, compress them out.
1863          * The compact routine will log the header.
1864          */
1865         if (be16_to_cpu(leaf->hdr.stale))
1866                 xfs_dir2_leaf_compact(args, lbp);
1867         else
1868                 xfs_dir2_leaf_log_header(tp, lbp);
1869         leaf->hdr.info.magic = cpu_to_be16(XFS_DIR2_LEAF1_MAGIC);
1870         /*
1871          * Set up the leaf tail from the freespace block.
1872          */
1873         ltp = xfs_dir2_leaf_tail_p(mp, leaf);
1874         ltp->bestcount = free->hdr.nvalid;
1875         /*
1876          * Set up the leaf bests table.
1877          */
1878         memcpy(xfs_dir2_leaf_bests_p(ltp), free->bests,
1879                 be32_to_cpu(ltp->bestcount) * sizeof(leaf->bests[0]));
1880         xfs_dir2_leaf_log_bests(tp, lbp, 0, be32_to_cpu(ltp->bestcount) - 1);
1881         xfs_dir2_leaf_log_tail(tp, lbp);
1882         xfs_dir2_leaf_check(dp, lbp);
1883         /*
1884          * Get rid of the freespace block.
1885          */
1886         error = xfs_dir2_shrink_inode(args, XFS_DIR2_FREE_FIRSTDB(mp), fbp);
1887         if (error) {
1888                 /*
1889                  * This can't fail here because it can only happen when
1890                  * punching out the middle of an extent, and this is an
1891                  * isolated block.
1892                  */
1893                 ASSERT(error != ENOSPC);
1894                 return error;
1895         }
1896         fbp = NULL;
1897         /*
1898          * Now see if we can convert the single-leaf directory
1899          * down to a block form directory.
1900          * This routine always kills the dabuf for the leaf, so
1901          * eliminate it from the path.
1902          */
1903         error = xfs_dir2_leaf_to_block(args, lbp, NULL);
1904         state->path.blk[0].bp = NULL;
1905         return error;
1906 }