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1/*
2 * Copyright (c) 2000-2002,2005 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_inum.h"
23#include "xfs_trans.h"
24#include "xfs_sb.h"
25#include "xfs_ag.h"
26#include "xfs_mount.h"
27#include "xfs_da_btree.h"
28#include "xfs_bmap_btree.h"
29#include "xfs_dinode.h"
30#include "xfs_inode.h"
31#include "xfs_dir2_format.h"
32#include "xfs_dir2_priv.h"
33#include "xfs_error.h"
34
35STATIC xfs_dir2_data_free_t *
36xfs_dir2_data_freefind(xfs_dir2_data_hdr_t *hdr, xfs_dir2_data_unused_t *dup);
37
38#ifdef DEBUG
39/*
40 * Check the consistency of the data block.
41 * The input can also be a block-format directory.
42 * Pop an assert if we find anything bad.
43 */
44void
45xfs_dir2_data_check(
46 xfs_inode_t *dp, /* incore inode pointer */
47 xfs_dabuf_t *bp) /* data block's buffer */
48{
49 xfs_dir2_dataptr_t addr; /* addr for leaf lookup */
50 xfs_dir2_data_free_t *bf; /* bestfree table */
51 xfs_dir2_block_tail_t *btp=NULL; /* block tail */
52 int count; /* count of entries found */
53 xfs_dir2_data_hdr_t *hdr; /* data block header */
54 xfs_dir2_data_entry_t *dep; /* data entry */
55 xfs_dir2_data_free_t *dfp; /* bestfree entry */
56 xfs_dir2_data_unused_t *dup; /* unused entry */
57 char *endp; /* end of useful data */
58 int freeseen; /* mask of bestfrees seen */
59 xfs_dahash_t hash; /* hash of current name */
60 int i; /* leaf index */
61 int lastfree; /* last entry was unused */
62 xfs_dir2_leaf_entry_t *lep=NULL; /* block leaf entries */
63 xfs_mount_t *mp; /* filesystem mount point */
64 char *p; /* current data position */
65 int stale; /* count of stale leaves */
66 struct xfs_name name;
67
68 mp = dp->i_mount;
69 hdr = bp->data;
70 bf = hdr->bestfree;
71 p = (char *)(hdr + 1);
72
73 if (hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC)) {
74 btp = xfs_dir2_block_tail_p(mp, hdr);
75 lep = xfs_dir2_block_leaf_p(btp);
76 endp = (char *)lep;
77 } else {
78 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC));
79 endp = (char *)hdr + mp->m_dirblksize;
80 }
81
82 count = lastfree = freeseen = 0;
83 /*
84 * Account for zero bestfree entries.
85 */
86 if (!bf[0].length) {
87 ASSERT(!bf[0].offset);
88 freeseen |= 1 << 0;
89 }
90 if (!bf[1].length) {
91 ASSERT(!bf[1].offset);
92 freeseen |= 1 << 1;
93 }
94 if (!bf[2].length) {
95 ASSERT(!bf[2].offset);
96 freeseen |= 1 << 2;
97 }
98 ASSERT(be16_to_cpu(bf[0].length) >= be16_to_cpu(bf[1].length));
99 ASSERT(be16_to_cpu(bf[1].length) >= be16_to_cpu(bf[2].length));
100 /*
101 * Loop over the data/unused entries.
102 */
103 while (p < endp) {
104 dup = (xfs_dir2_data_unused_t *)p;
105 /*
106 * If it's unused, look for the space in the bestfree table.
107 * If we find it, account for that, else make sure it
108 * doesn't need to be there.
109 */
110 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
111 ASSERT(lastfree == 0);
112 ASSERT(be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)) ==
113 (char *)dup - (char *)hdr);
114 dfp = xfs_dir2_data_freefind(hdr, dup);
115 if (dfp) {
116 i = (int)(dfp - bf);
117 ASSERT((freeseen & (1 << i)) == 0);
118 freeseen |= 1 << i;
119 } else {
120 ASSERT(be16_to_cpu(dup->length) <=
121 be16_to_cpu(bf[2].length));
122 }
123 p += be16_to_cpu(dup->length);
124 lastfree = 1;
125 continue;
126 }
127 /*
128 * It's a real entry. Validate the fields.
129 * If this is a block directory then make sure it's
130 * in the leaf section of the block.
131 * The linear search is crude but this is DEBUG code.
132 */
133 dep = (xfs_dir2_data_entry_t *)p;
134 ASSERT(dep->namelen != 0);
135 ASSERT(xfs_dir_ino_validate(mp, be64_to_cpu(dep->inumber)) == 0);
136 ASSERT(be16_to_cpu(*xfs_dir2_data_entry_tag_p(dep)) ==
137 (char *)dep - (char *)hdr);
138 count++;
139 lastfree = 0;
140 if (hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC)) {
141 addr = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk,
142 (xfs_dir2_data_aoff_t)
143 ((char *)dep - (char *)hdr));
144 name.name = dep->name;
145 name.len = dep->namelen;
146 hash = mp->m_dirnameops->hashname(&name);
147 for (i = 0; i < be32_to_cpu(btp->count); i++) {
148 if (be32_to_cpu(lep[i].address) == addr &&
149 be32_to_cpu(lep[i].hashval) == hash)
150 break;
151 }
152 ASSERT(i < be32_to_cpu(btp->count));
153 }
154 p += xfs_dir2_data_entsize(dep->namelen);
155 }
156 /*
157 * Need to have seen all the entries and all the bestfree slots.
158 */
159 ASSERT(freeseen == 7);
160 if (hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC)) {
161 for (i = stale = 0; i < be32_to_cpu(btp->count); i++) {
162 if (lep[i].address ==
163 cpu_to_be32(XFS_DIR2_NULL_DATAPTR))
164 stale++;
165 if (i > 0)
166 ASSERT(be32_to_cpu(lep[i].hashval) >= be32_to_cpu(lep[i - 1].hashval));
167 }
168 ASSERT(count == be32_to_cpu(btp->count) - be32_to_cpu(btp->stale));
169 ASSERT(stale == be32_to_cpu(btp->stale));
170 }
171}
172#endif
173
174/*
175 * Given a data block and an unused entry from that block,
176 * return the bestfree entry if any that corresponds to it.
177 */
178STATIC xfs_dir2_data_free_t *
179xfs_dir2_data_freefind(
180 xfs_dir2_data_hdr_t *hdr, /* data block */
181 xfs_dir2_data_unused_t *dup) /* data unused entry */
182{
183 xfs_dir2_data_free_t *dfp; /* bestfree entry */
184 xfs_dir2_data_aoff_t off; /* offset value needed */
185#if defined(DEBUG) && defined(__KERNEL__)
186 int matched; /* matched the value */
187 int seenzero; /* saw a 0 bestfree entry */
188#endif
189
190 off = (xfs_dir2_data_aoff_t)((char *)dup - (char *)hdr);
191#if defined(DEBUG) && defined(__KERNEL__)
192 /*
193 * Validate some consistency in the bestfree table.
194 * Check order, non-overlapping entries, and if we find the
195 * one we're looking for it has to be exact.
196 */
197 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
198 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC));
199 for (dfp = &hdr->bestfree[0], seenzero = matched = 0;
200 dfp < &hdr->bestfree[XFS_DIR2_DATA_FD_COUNT];
201 dfp++) {
202 if (!dfp->offset) {
203 ASSERT(!dfp->length);
204 seenzero = 1;
205 continue;
206 }
207 ASSERT(seenzero == 0);
208 if (be16_to_cpu(dfp->offset) == off) {
209 matched = 1;
210 ASSERT(dfp->length == dup->length);
211 } else if (off < be16_to_cpu(dfp->offset))
212 ASSERT(off + be16_to_cpu(dup->length) <= be16_to_cpu(dfp->offset));
213 else
214 ASSERT(be16_to_cpu(dfp->offset) + be16_to_cpu(dfp->length) <= off);
215 ASSERT(matched || be16_to_cpu(dfp->length) >= be16_to_cpu(dup->length));
216 if (dfp > &hdr->bestfree[0])
217 ASSERT(be16_to_cpu(dfp[-1].length) >= be16_to_cpu(dfp[0].length));
218 }
219#endif
220 /*
221 * If this is smaller than the smallest bestfree entry,
222 * it can't be there since they're sorted.
223 */
224 if (be16_to_cpu(dup->length) <
225 be16_to_cpu(hdr->bestfree[XFS_DIR2_DATA_FD_COUNT - 1].length))
226 return NULL;
227 /*
228 * Look at the three bestfree entries for our guy.
229 */
230 for (dfp = &hdr->bestfree[0];
231 dfp < &hdr->bestfree[XFS_DIR2_DATA_FD_COUNT];
232 dfp++) {
233 if (!dfp->offset)
234 return NULL;
235 if (be16_to_cpu(dfp->offset) == off)
236 return dfp;
237 }
238 /*
239 * Didn't find it. This only happens if there are duplicate lengths.
240 */
241 return NULL;
242}
243
244/*
245 * Insert an unused-space entry into the bestfree table.
246 */
247xfs_dir2_data_free_t * /* entry inserted */
248xfs_dir2_data_freeinsert(
249 xfs_dir2_data_hdr_t *hdr, /* data block pointer */
250 xfs_dir2_data_unused_t *dup, /* unused space */
251 int *loghead) /* log the data header (out) */
252{
253 xfs_dir2_data_free_t *dfp; /* bestfree table pointer */
254 xfs_dir2_data_free_t new; /* new bestfree entry */
255
256#ifdef __KERNEL__
257 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
258 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC));
259#endif
260 dfp = hdr->bestfree;
261 new.length = dup->length;
262 new.offset = cpu_to_be16((char *)dup - (char *)hdr);
263
264 /*
265 * Insert at position 0, 1, or 2; or not at all.
266 */
267 if (be16_to_cpu(new.length) > be16_to_cpu(dfp[0].length)) {
268 dfp[2] = dfp[1];
269 dfp[1] = dfp[0];
270 dfp[0] = new;
271 *loghead = 1;
272 return &dfp[0];
273 }
274 if (be16_to_cpu(new.length) > be16_to_cpu(dfp[1].length)) {
275 dfp[2] = dfp[1];
276 dfp[1] = new;
277 *loghead = 1;
278 return &dfp[1];
279 }
280 if (be16_to_cpu(new.length) > be16_to_cpu(dfp[2].length)) {
281 dfp[2] = new;
282 *loghead = 1;
283 return &dfp[2];
284 }
285 return NULL;
286}
287
288/*
289 * Remove a bestfree entry from the table.
290 */
291STATIC void
292xfs_dir2_data_freeremove(
293 xfs_dir2_data_hdr_t *hdr, /* data block header */
294 xfs_dir2_data_free_t *dfp, /* bestfree entry pointer */
295 int *loghead) /* out: log data header */
296{
297#ifdef __KERNEL__
298 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
299 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC));
300#endif
301 /*
302 * It's the first entry, slide the next 2 up.
303 */
304 if (dfp == &hdr->bestfree[0]) {
305 hdr->bestfree[0] = hdr->bestfree[1];
306 hdr->bestfree[1] = hdr->bestfree[2];
307 }
308 /*
309 * It's the second entry, slide the 3rd entry up.
310 */
311 else if (dfp == &hdr->bestfree[1])
312 hdr->bestfree[1] = hdr->bestfree[2];
313 /*
314 * Must be the last entry.
315 */
316 else
317 ASSERT(dfp == &hdr->bestfree[2]);
318 /*
319 * Clear the 3rd entry, must be zero now.
320 */
321 hdr->bestfree[2].length = 0;
322 hdr->bestfree[2].offset = 0;
323 *loghead = 1;
324}
325
326/*
327 * Given a data block, reconstruct its bestfree map.
328 */
329void
330xfs_dir2_data_freescan(
331 xfs_mount_t *mp, /* filesystem mount point */
332 xfs_dir2_data_hdr_t *hdr, /* data block header */
333 int *loghead) /* out: log data header */
334{
335 xfs_dir2_block_tail_t *btp; /* block tail */
336 xfs_dir2_data_entry_t *dep; /* active data entry */
337 xfs_dir2_data_unused_t *dup; /* unused data entry */
338 char *endp; /* end of block's data */
339 char *p; /* current entry pointer */
340
341#ifdef __KERNEL__
342 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
343 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC));
344#endif
345 /*
346 * Start by clearing the table.
347 */
348 memset(hdr->bestfree, 0, sizeof(hdr->bestfree));
349 *loghead = 1;
350 /*
351 * Set up pointers.
352 */
353 p = (char *)(hdr + 1);
354 if (hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC)) {
355 btp = xfs_dir2_block_tail_p(mp, hdr);
356 endp = (char *)xfs_dir2_block_leaf_p(btp);
357 } else
358 endp = (char *)hdr + mp->m_dirblksize;
359 /*
360 * Loop over the block's entries.
361 */
362 while (p < endp) {
363 dup = (xfs_dir2_data_unused_t *)p;
364 /*
365 * If it's a free entry, insert it.
366 */
367 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
368 ASSERT((char *)dup - (char *)hdr ==
369 be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)));
370 xfs_dir2_data_freeinsert(hdr, dup, loghead);
371 p += be16_to_cpu(dup->length);
372 }
373 /*
374 * For active entries, check their tags and skip them.
375 */
376 else {
377 dep = (xfs_dir2_data_entry_t *)p;
378 ASSERT((char *)dep - (char *)hdr ==
379 be16_to_cpu(*xfs_dir2_data_entry_tag_p(dep)));
380 p += xfs_dir2_data_entsize(dep->namelen);
381 }
382 }
383}
384
385/*
386 * Initialize a data block at the given block number in the directory.
387 * Give back the buffer for the created block.
388 */
389int /* error */
390xfs_dir2_data_init(
391 xfs_da_args_t *args, /* directory operation args */
392 xfs_dir2_db_t blkno, /* logical dir block number */
393 xfs_dabuf_t **bpp) /* output block buffer */
394{
395 xfs_dabuf_t *bp; /* block buffer */
396 xfs_dir2_data_hdr_t *hdr; /* data block header */
397 xfs_inode_t *dp; /* incore directory inode */
398 xfs_dir2_data_unused_t *dup; /* unused entry pointer */
399 int error; /* error return value */
400 int i; /* bestfree index */
401 xfs_mount_t *mp; /* filesystem mount point */
402 xfs_trans_t *tp; /* transaction pointer */
403 int t; /* temp */
404
405 dp = args->dp;
406 mp = dp->i_mount;
407 tp = args->trans;
408 /*
409 * Get the buffer set up for the block.
410 */
411 error = xfs_da_get_buf(tp, dp, xfs_dir2_db_to_da(mp, blkno), -1, &bp,
412 XFS_DATA_FORK);
413 if (error) {
414 return error;
415 }
416 ASSERT(bp != NULL);
417
418 /*
419 * Initialize the header.
420 */
421 hdr = bp->data;
422 hdr->magic = cpu_to_be32(XFS_DIR2_DATA_MAGIC);
423 hdr->bestfree[0].offset = cpu_to_be16(sizeof(*hdr));
424 for (i = 1; i < XFS_DIR2_DATA_FD_COUNT; i++) {
425 hdr->bestfree[i].length = 0;
426 hdr->bestfree[i].offset = 0;
427 }
428
429 /*
430 * Set up an unused entry for the block's body.
431 */
432 dup = (xfs_dir2_data_unused_t *)(hdr + 1);
433 dup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
434
435 t = mp->m_dirblksize - (uint)sizeof(*hdr);
436 hdr->bestfree[0].length = cpu_to_be16(t);
437 dup->length = cpu_to_be16(t);
438 *xfs_dir2_data_unused_tag_p(dup) = cpu_to_be16((char *)dup - (char *)hdr);
439 /*
440 * Log it and return it.
441 */
442 xfs_dir2_data_log_header(tp, bp);
443 xfs_dir2_data_log_unused(tp, bp, dup);
444 *bpp = bp;
445 return 0;
446}
447
448/*
449 * Log an active data entry from the block.
450 */
451void
452xfs_dir2_data_log_entry(
453 xfs_trans_t *tp, /* transaction pointer */
454 xfs_dabuf_t *bp, /* block buffer */
455 xfs_dir2_data_entry_t *dep) /* data entry pointer */
456{
457 xfs_dir2_data_hdr_t *hdr = bp->data;
458
459 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
460 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC));
461
462 xfs_da_log_buf(tp, bp, (uint)((char *)dep - (char *)hdr),
463 (uint)((char *)(xfs_dir2_data_entry_tag_p(dep) + 1) -
464 (char *)hdr - 1));
465}
466
467/*
468 * Log a data block header.
469 */
470void
471xfs_dir2_data_log_header(
472 xfs_trans_t *tp, /* transaction pointer */
473 xfs_dabuf_t *bp) /* block buffer */
474{
475 xfs_dir2_data_hdr_t *hdr = bp->data;
476
477 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
478 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC));
479
480 xfs_da_log_buf(tp, bp, 0, sizeof(*hdr) - 1);
481}
482
483/*
484 * Log a data unused entry.
485 */
486void
487xfs_dir2_data_log_unused(
488 xfs_trans_t *tp, /* transaction pointer */
489 xfs_dabuf_t *bp, /* block buffer */
490 xfs_dir2_data_unused_t *dup) /* data unused pointer */
491{
492 xfs_dir2_data_hdr_t *hdr = bp->data;
493
494 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
495 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC));
496
497 /*
498 * Log the first part of the unused entry.
499 */
500 xfs_da_log_buf(tp, bp, (uint)((char *)dup - (char *)hdr),
501 (uint)((char *)&dup->length + sizeof(dup->length) -
502 1 - (char *)hdr));
503 /*
504 * Log the end (tag) of the unused entry.
505 */
506 xfs_da_log_buf(tp, bp,
507 (uint)((char *)xfs_dir2_data_unused_tag_p(dup) - (char *)hdr),
508 (uint)((char *)xfs_dir2_data_unused_tag_p(dup) - (char *)hdr +
509 sizeof(xfs_dir2_data_off_t) - 1));
510}
511
512/*
513 * Make a byte range in the data block unused.
514 * Its current contents are unimportant.
515 */
516void
517xfs_dir2_data_make_free(
518 xfs_trans_t *tp, /* transaction pointer */
519 xfs_dabuf_t *bp, /* block buffer */
520 xfs_dir2_data_aoff_t offset, /* starting byte offset */
521 xfs_dir2_data_aoff_t len, /* length in bytes */
522 int *needlogp, /* out: log header */
523 int *needscanp) /* out: regen bestfree */
524{
525 xfs_dir2_data_hdr_t *hdr; /* data block pointer */
526 xfs_dir2_data_free_t *dfp; /* bestfree pointer */
527 char *endptr; /* end of data area */
528 xfs_mount_t *mp; /* filesystem mount point */
529 int needscan; /* need to regen bestfree */
530 xfs_dir2_data_unused_t *newdup; /* new unused entry */
531 xfs_dir2_data_unused_t *postdup; /* unused entry after us */
532 xfs_dir2_data_unused_t *prevdup; /* unused entry before us */
533
534 mp = tp->t_mountp;
535 hdr = bp->data;
536
537 /*
538 * Figure out where the end of the data area is.
539 */
540 if (hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC))
541 endptr = (char *)hdr + mp->m_dirblksize;
542 else {
543 xfs_dir2_block_tail_t *btp; /* block tail */
544
545 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC));
546 btp = xfs_dir2_block_tail_p(mp, hdr);
547 endptr = (char *)xfs_dir2_block_leaf_p(btp);
548 }
549 /*
550 * If this isn't the start of the block, then back up to
551 * the previous entry and see if it's free.
552 */
553 if (offset > sizeof(*hdr)) {
554 __be16 *tagp; /* tag just before us */
555
556 tagp = (__be16 *)((char *)hdr + offset) - 1;
557 prevdup = (xfs_dir2_data_unused_t *)((char *)hdr + be16_to_cpu(*tagp));
558 if (be16_to_cpu(prevdup->freetag) != XFS_DIR2_DATA_FREE_TAG)
559 prevdup = NULL;
560 } else
561 prevdup = NULL;
562 /*
563 * If this isn't the end of the block, see if the entry after
564 * us is free.
565 */
566 if ((char *)hdr + offset + len < endptr) {
567 postdup =
568 (xfs_dir2_data_unused_t *)((char *)hdr + offset + len);
569 if (be16_to_cpu(postdup->freetag) != XFS_DIR2_DATA_FREE_TAG)
570 postdup = NULL;
571 } else
572 postdup = NULL;
573 ASSERT(*needscanp == 0);
574 needscan = 0;
575 /*
576 * Previous and following entries are both free,
577 * merge everything into a single free entry.
578 */
579 if (prevdup && postdup) {
580 xfs_dir2_data_free_t *dfp2; /* another bestfree pointer */
581
582 /*
583 * See if prevdup and/or postdup are in bestfree table.
584 */
585 dfp = xfs_dir2_data_freefind(hdr, prevdup);
586 dfp2 = xfs_dir2_data_freefind(hdr, postdup);
587 /*
588 * We need a rescan unless there are exactly 2 free entries
589 * namely our two. Then we know what's happening, otherwise
590 * since the third bestfree is there, there might be more
591 * entries.
592 */
593 needscan = (hdr->bestfree[2].length != 0);
594 /*
595 * Fix up the new big freespace.
596 */
597 be16_add_cpu(&prevdup->length, len + be16_to_cpu(postdup->length));
598 *xfs_dir2_data_unused_tag_p(prevdup) =
599 cpu_to_be16((char *)prevdup - (char *)hdr);
600 xfs_dir2_data_log_unused(tp, bp, prevdup);
601 if (!needscan) {
602 /*
603 * Has to be the case that entries 0 and 1 are
604 * dfp and dfp2 (don't know which is which), and
605 * entry 2 is empty.
606 * Remove entry 1 first then entry 0.
607 */
608 ASSERT(dfp && dfp2);
609 if (dfp == &hdr->bestfree[1]) {
610 dfp = &hdr->bestfree[0];
611 ASSERT(dfp2 == dfp);
612 dfp2 = &hdr->bestfree[1];
613 }
614 xfs_dir2_data_freeremove(hdr, dfp2, needlogp);
615 xfs_dir2_data_freeremove(hdr, dfp, needlogp);
616 /*
617 * Now insert the new entry.
618 */
619 dfp = xfs_dir2_data_freeinsert(hdr, prevdup, needlogp);
620 ASSERT(dfp == &hdr->bestfree[0]);
621 ASSERT(dfp->length == prevdup->length);
622 ASSERT(!dfp[1].length);
623 ASSERT(!dfp[2].length);
624 }
625 }
626 /*
627 * The entry before us is free, merge with it.
628 */
629 else if (prevdup) {
630 dfp = xfs_dir2_data_freefind(hdr, prevdup);
631 be16_add_cpu(&prevdup->length, len);
632 *xfs_dir2_data_unused_tag_p(prevdup) =
633 cpu_to_be16((char *)prevdup - (char *)hdr);
634 xfs_dir2_data_log_unused(tp, bp, prevdup);
635 /*
636 * If the previous entry was in the table, the new entry
637 * is longer, so it will be in the table too. Remove
638 * the old one and add the new one.
639 */
640 if (dfp) {
641 xfs_dir2_data_freeremove(hdr, dfp, needlogp);
642 xfs_dir2_data_freeinsert(hdr, prevdup, needlogp);
643 }
644 /*
645 * Otherwise we need a scan if the new entry is big enough.
646 */
647 else {
648 needscan = be16_to_cpu(prevdup->length) >
649 be16_to_cpu(hdr->bestfree[2].length);
650 }
651 }
652 /*
653 * The following entry is free, merge with it.
654 */
655 else if (postdup) {
656 dfp = xfs_dir2_data_freefind(hdr, postdup);
657 newdup = (xfs_dir2_data_unused_t *)((char *)hdr + offset);
658 newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
659 newdup->length = cpu_to_be16(len + be16_to_cpu(postdup->length));
660 *xfs_dir2_data_unused_tag_p(newdup) =
661 cpu_to_be16((char *)newdup - (char *)hdr);
662 xfs_dir2_data_log_unused(tp, bp, newdup);
663 /*
664 * If the following entry was in the table, the new entry
665 * is longer, so it will be in the table too. Remove
666 * the old one and add the new one.
667 */
668 if (dfp) {
669 xfs_dir2_data_freeremove(hdr, dfp, needlogp);
670 xfs_dir2_data_freeinsert(hdr, newdup, needlogp);
671 }
672 /*
673 * Otherwise we need a scan if the new entry is big enough.
674 */
675 else {
676 needscan = be16_to_cpu(newdup->length) >
677 be16_to_cpu(hdr->bestfree[2].length);
678 }
679 }
680 /*
681 * Neither neighbor is free. Make a new entry.
682 */
683 else {
684 newdup = (xfs_dir2_data_unused_t *)((char *)hdr + offset);
685 newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
686 newdup->length = cpu_to_be16(len);
687 *xfs_dir2_data_unused_tag_p(newdup) =
688 cpu_to_be16((char *)newdup - (char *)hdr);
689 xfs_dir2_data_log_unused(tp, bp, newdup);
690 xfs_dir2_data_freeinsert(hdr, newdup, needlogp);
691 }
692 *needscanp = needscan;
693}
694
695/*
696 * Take a byte range out of an existing unused space and make it un-free.
697 */
698void
699xfs_dir2_data_use_free(
700 xfs_trans_t *tp, /* transaction pointer */
701 xfs_dabuf_t *bp, /* data block buffer */
702 xfs_dir2_data_unused_t *dup, /* unused entry */
703 xfs_dir2_data_aoff_t offset, /* starting offset to use */
704 xfs_dir2_data_aoff_t len, /* length to use */
705 int *needlogp, /* out: need to log header */
706 int *needscanp) /* out: need regen bestfree */
707{
708 xfs_dir2_data_hdr_t *hdr; /* data block header */
709 xfs_dir2_data_free_t *dfp; /* bestfree pointer */
710 int matchback; /* matches end of freespace */
711 int matchfront; /* matches start of freespace */
712 int needscan; /* need to regen bestfree */
713 xfs_dir2_data_unused_t *newdup; /* new unused entry */
714 xfs_dir2_data_unused_t *newdup2; /* another new unused entry */
715 int oldlen; /* old unused entry's length */
716
717 hdr = bp->data;
718 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
719 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC));
720 ASSERT(be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG);
721 ASSERT(offset >= (char *)dup - (char *)hdr);
722 ASSERT(offset + len <= (char *)dup + be16_to_cpu(dup->length) - (char *)hdr);
723 ASSERT((char *)dup - (char *)hdr == be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)));
724 /*
725 * Look up the entry in the bestfree table.
726 */
727 dfp = xfs_dir2_data_freefind(hdr, dup);
728 oldlen = be16_to_cpu(dup->length);
729 ASSERT(dfp || oldlen <= be16_to_cpu(hdr->bestfree[2].length));
730 /*
731 * Check for alignment with front and back of the entry.
732 */
733 matchfront = (char *)dup - (char *)hdr == offset;
734 matchback = (char *)dup + oldlen - (char *)hdr == offset + len;
735 ASSERT(*needscanp == 0);
736 needscan = 0;
737 /*
738 * If we matched it exactly we just need to get rid of it from
739 * the bestfree table.
740 */
741 if (matchfront && matchback) {
742 if (dfp) {
743 needscan = (hdr->bestfree[2].offset != 0);
744 if (!needscan)
745 xfs_dir2_data_freeremove(hdr, dfp, needlogp);
746 }
747 }
748 /*
749 * We match the first part of the entry.
750 * Make a new entry with the remaining freespace.
751 */
752 else if (matchfront) {
753 newdup = (xfs_dir2_data_unused_t *)((char *)hdr + offset + len);
754 newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
755 newdup->length = cpu_to_be16(oldlen - len);
756 *xfs_dir2_data_unused_tag_p(newdup) =
757 cpu_to_be16((char *)newdup - (char *)hdr);
758 xfs_dir2_data_log_unused(tp, bp, newdup);
759 /*
760 * If it was in the table, remove it and add the new one.
761 */
762 if (dfp) {
763 xfs_dir2_data_freeremove(hdr, dfp, needlogp);
764 dfp = xfs_dir2_data_freeinsert(hdr, newdup, needlogp);
765 ASSERT(dfp != NULL);
766 ASSERT(dfp->length == newdup->length);
767 ASSERT(be16_to_cpu(dfp->offset) == (char *)newdup - (char *)hdr);
768 /*
769 * If we got inserted at the last slot,
770 * that means we don't know if there was a better
771 * choice for the last slot, or not. Rescan.
772 */
773 needscan = dfp == &hdr->bestfree[2];
774 }
775 }
776 /*
777 * We match the last part of the entry.
778 * Trim the allocated space off the tail of the entry.
779 */
780 else if (matchback) {
781 newdup = dup;
782 newdup->length = cpu_to_be16(((char *)hdr + offset) - (char *)newdup);
783 *xfs_dir2_data_unused_tag_p(newdup) =
784 cpu_to_be16((char *)newdup - (char *)hdr);
785 xfs_dir2_data_log_unused(tp, bp, newdup);
786 /*
787 * If it was in the table, remove it and add the new one.
788 */
789 if (dfp) {
790 xfs_dir2_data_freeremove(hdr, dfp, needlogp);
791 dfp = xfs_dir2_data_freeinsert(hdr, newdup, needlogp);
792 ASSERT(dfp != NULL);
793 ASSERT(dfp->length == newdup->length);
794 ASSERT(be16_to_cpu(dfp->offset) == (char *)newdup - (char *)hdr);
795 /*
796 * If we got inserted at the last slot,
797 * that means we don't know if there was a better
798 * choice for the last slot, or not. Rescan.
799 */
800 needscan = dfp == &hdr->bestfree[2];
801 }
802 }
803 /*
804 * Poking out the middle of an entry.
805 * Make two new entries.
806 */
807 else {
808 newdup = dup;
809 newdup->length = cpu_to_be16(((char *)hdr + offset) - (char *)newdup);
810 *xfs_dir2_data_unused_tag_p(newdup) =
811 cpu_to_be16((char *)newdup - (char *)hdr);
812 xfs_dir2_data_log_unused(tp, bp, newdup);
813 newdup2 = (xfs_dir2_data_unused_t *)((char *)hdr + offset + len);
814 newdup2->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
815 newdup2->length = cpu_to_be16(oldlen - len - be16_to_cpu(newdup->length));
816 *xfs_dir2_data_unused_tag_p(newdup2) =
817 cpu_to_be16((char *)newdup2 - (char *)hdr);
818 xfs_dir2_data_log_unused(tp, bp, newdup2);
819 /*
820 * If the old entry was in the table, we need to scan
821 * if the 3rd entry was valid, since these entries
822 * are smaller than the old one.
823 * If we don't need to scan that means there were 1 or 2
824 * entries in the table, and removing the old and adding
825 * the 2 new will work.
826 */
827 if (dfp) {
828 needscan = (hdr->bestfree[2].length != 0);
829 if (!needscan) {
830 xfs_dir2_data_freeremove(hdr, dfp, needlogp);
831 xfs_dir2_data_freeinsert(hdr, newdup, needlogp);
832 xfs_dir2_data_freeinsert(hdr, newdup2,
833 needlogp);
834 }
835 }
836 }
837 *needscanp = needscan;
838}
1/*
2 * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
3 * Copyright (c) 2013 Red Hat, Inc.
4 * All Rights Reserved.
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it would be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18 */
19#include "xfs.h"
20#include "xfs_fs.h"
21#include "xfs_format.h"
22#include "xfs_log_format.h"
23#include "xfs_trans_resv.h"
24#include "xfs_sb.h"
25#include "xfs_ag.h"
26#include "xfs_mount.h"
27#include "xfs_da_format.h"
28#include "xfs_da_btree.h"
29#include "xfs_inode.h"
30#include "xfs_dir2.h"
31#include "xfs_dir2_priv.h"
32#include "xfs_error.h"
33#include "xfs_trans.h"
34#include "xfs_buf_item.h"
35#include "xfs_cksum.h"
36
37/*
38 * Check the consistency of the data block.
39 * The input can also be a block-format directory.
40 * Return 0 is the buffer is good, otherwise an error.
41 */
42int
43__xfs_dir3_data_check(
44 struct xfs_inode *dp, /* incore inode pointer */
45 struct xfs_buf *bp) /* data block's buffer */
46{
47 xfs_dir2_dataptr_t addr; /* addr for leaf lookup */
48 xfs_dir2_data_free_t *bf; /* bestfree table */
49 xfs_dir2_block_tail_t *btp=NULL; /* block tail */
50 int count; /* count of entries found */
51 xfs_dir2_data_hdr_t *hdr; /* data block header */
52 xfs_dir2_data_entry_t *dep; /* data entry */
53 xfs_dir2_data_free_t *dfp; /* bestfree entry */
54 xfs_dir2_data_unused_t *dup; /* unused entry */
55 char *endp; /* end of useful data */
56 int freeseen; /* mask of bestfrees seen */
57 xfs_dahash_t hash; /* hash of current name */
58 int i; /* leaf index */
59 int lastfree; /* last entry was unused */
60 xfs_dir2_leaf_entry_t *lep=NULL; /* block leaf entries */
61 xfs_mount_t *mp; /* filesystem mount point */
62 char *p; /* current data position */
63 int stale; /* count of stale leaves */
64 struct xfs_name name;
65 const struct xfs_dir_ops *ops;
66
67 mp = bp->b_target->bt_mount;
68
69 /*
70 * We can be passed a null dp here from a verifier, so we need to go the
71 * hard way to get them.
72 */
73 ops = xfs_dir_get_ops(mp, dp);
74
75 hdr = bp->b_addr;
76 p = (char *)ops->data_entry_p(hdr);
77
78 switch (hdr->magic) {
79 case cpu_to_be32(XFS_DIR3_BLOCK_MAGIC):
80 case cpu_to_be32(XFS_DIR2_BLOCK_MAGIC):
81 btp = xfs_dir2_block_tail_p(mp, hdr);
82 lep = xfs_dir2_block_leaf_p(btp);
83 endp = (char *)lep;
84
85 /*
86 * The number of leaf entries is limited by the size of the
87 * block and the amount of space used by the data entries.
88 * We don't know how much space is used by the data entries yet,
89 * so just ensure that the count falls somewhere inside the
90 * block right now.
91 */
92 XFS_WANT_CORRUPTED_RETURN(be32_to_cpu(btp->count) <
93 ((char *)btp - p) / sizeof(struct xfs_dir2_leaf_entry));
94 break;
95 case cpu_to_be32(XFS_DIR3_DATA_MAGIC):
96 case cpu_to_be32(XFS_DIR2_DATA_MAGIC):
97 endp = (char *)hdr + mp->m_dirblksize;
98 break;
99 default:
100 XFS_ERROR_REPORT("Bad Magic", XFS_ERRLEVEL_LOW, mp);
101 return EFSCORRUPTED;
102 }
103
104 /*
105 * Account for zero bestfree entries.
106 */
107 bf = ops->data_bestfree_p(hdr);
108 count = lastfree = freeseen = 0;
109 if (!bf[0].length) {
110 XFS_WANT_CORRUPTED_RETURN(!bf[0].offset);
111 freeseen |= 1 << 0;
112 }
113 if (!bf[1].length) {
114 XFS_WANT_CORRUPTED_RETURN(!bf[1].offset);
115 freeseen |= 1 << 1;
116 }
117 if (!bf[2].length) {
118 XFS_WANT_CORRUPTED_RETURN(!bf[2].offset);
119 freeseen |= 1 << 2;
120 }
121
122 XFS_WANT_CORRUPTED_RETURN(be16_to_cpu(bf[0].length) >=
123 be16_to_cpu(bf[1].length));
124 XFS_WANT_CORRUPTED_RETURN(be16_to_cpu(bf[1].length) >=
125 be16_to_cpu(bf[2].length));
126 /*
127 * Loop over the data/unused entries.
128 */
129 while (p < endp) {
130 dup = (xfs_dir2_data_unused_t *)p;
131 /*
132 * If it's unused, look for the space in the bestfree table.
133 * If we find it, account for that, else make sure it
134 * doesn't need to be there.
135 */
136 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
137 XFS_WANT_CORRUPTED_RETURN(lastfree == 0);
138 XFS_WANT_CORRUPTED_RETURN(
139 be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)) ==
140 (char *)dup - (char *)hdr);
141 dfp = xfs_dir2_data_freefind(hdr, bf, dup);
142 if (dfp) {
143 i = (int)(dfp - bf);
144 XFS_WANT_CORRUPTED_RETURN(
145 (freeseen & (1 << i)) == 0);
146 freeseen |= 1 << i;
147 } else {
148 XFS_WANT_CORRUPTED_RETURN(
149 be16_to_cpu(dup->length) <=
150 be16_to_cpu(bf[2].length));
151 }
152 p += be16_to_cpu(dup->length);
153 lastfree = 1;
154 continue;
155 }
156 /*
157 * It's a real entry. Validate the fields.
158 * If this is a block directory then make sure it's
159 * in the leaf section of the block.
160 * The linear search is crude but this is DEBUG code.
161 */
162 dep = (xfs_dir2_data_entry_t *)p;
163 XFS_WANT_CORRUPTED_RETURN(dep->namelen != 0);
164 XFS_WANT_CORRUPTED_RETURN(
165 !xfs_dir_ino_validate(mp, be64_to_cpu(dep->inumber)));
166 XFS_WANT_CORRUPTED_RETURN(
167 be16_to_cpu(*ops->data_entry_tag_p(dep)) ==
168 (char *)dep - (char *)hdr);
169 XFS_WANT_CORRUPTED_RETURN(
170 ops->data_get_ftype(dep) < XFS_DIR3_FT_MAX);
171 count++;
172 lastfree = 0;
173 if (hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
174 hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC)) {
175 addr = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk,
176 (xfs_dir2_data_aoff_t)
177 ((char *)dep - (char *)hdr));
178 name.name = dep->name;
179 name.len = dep->namelen;
180 hash = mp->m_dirnameops->hashname(&name);
181 for (i = 0; i < be32_to_cpu(btp->count); i++) {
182 if (be32_to_cpu(lep[i].address) == addr &&
183 be32_to_cpu(lep[i].hashval) == hash)
184 break;
185 }
186 XFS_WANT_CORRUPTED_RETURN(i < be32_to_cpu(btp->count));
187 }
188 p += ops->data_entsize(dep->namelen);
189 }
190 /*
191 * Need to have seen all the entries and all the bestfree slots.
192 */
193 XFS_WANT_CORRUPTED_RETURN(freeseen == 7);
194 if (hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
195 hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC)) {
196 for (i = stale = 0; i < be32_to_cpu(btp->count); i++) {
197 if (lep[i].address ==
198 cpu_to_be32(XFS_DIR2_NULL_DATAPTR))
199 stale++;
200 if (i > 0)
201 XFS_WANT_CORRUPTED_RETURN(
202 be32_to_cpu(lep[i].hashval) >=
203 be32_to_cpu(lep[i - 1].hashval));
204 }
205 XFS_WANT_CORRUPTED_RETURN(count ==
206 be32_to_cpu(btp->count) - be32_to_cpu(btp->stale));
207 XFS_WANT_CORRUPTED_RETURN(stale == be32_to_cpu(btp->stale));
208 }
209 return 0;
210}
211
212static bool
213xfs_dir3_data_verify(
214 struct xfs_buf *bp)
215{
216 struct xfs_mount *mp = bp->b_target->bt_mount;
217 struct xfs_dir3_blk_hdr *hdr3 = bp->b_addr;
218
219 if (xfs_sb_version_hascrc(&mp->m_sb)) {
220 if (hdr3->magic != cpu_to_be32(XFS_DIR3_DATA_MAGIC))
221 return false;
222 if (!uuid_equal(&hdr3->uuid, &mp->m_sb.sb_uuid))
223 return false;
224 if (be64_to_cpu(hdr3->blkno) != bp->b_bn)
225 return false;
226 } else {
227 if (hdr3->magic != cpu_to_be32(XFS_DIR2_DATA_MAGIC))
228 return false;
229 }
230 if (__xfs_dir3_data_check(NULL, bp))
231 return false;
232 return true;
233}
234
235/*
236 * Readahead of the first block of the directory when it is opened is completely
237 * oblivious to the format of the directory. Hence we can either get a block
238 * format buffer or a data format buffer on readahead.
239 */
240static void
241xfs_dir3_data_reada_verify(
242 struct xfs_buf *bp)
243{
244 struct xfs_dir2_data_hdr *hdr = bp->b_addr;
245
246 switch (hdr->magic) {
247 case cpu_to_be32(XFS_DIR2_BLOCK_MAGIC):
248 case cpu_to_be32(XFS_DIR3_BLOCK_MAGIC):
249 bp->b_ops = &xfs_dir3_block_buf_ops;
250 bp->b_ops->verify_read(bp);
251 return;
252 case cpu_to_be32(XFS_DIR2_DATA_MAGIC):
253 case cpu_to_be32(XFS_DIR3_DATA_MAGIC):
254 xfs_dir3_data_verify(bp);
255 return;
256 default:
257 xfs_buf_ioerror(bp, EFSCORRUPTED);
258 xfs_verifier_error(bp);
259 break;
260 }
261}
262
263static void
264xfs_dir3_data_read_verify(
265 struct xfs_buf *bp)
266{
267 struct xfs_mount *mp = bp->b_target->bt_mount;
268
269 if (xfs_sb_version_hascrc(&mp->m_sb) &&
270 !xfs_buf_verify_cksum(bp, XFS_DIR3_DATA_CRC_OFF))
271 xfs_buf_ioerror(bp, EFSBADCRC);
272 else if (!xfs_dir3_data_verify(bp))
273 xfs_buf_ioerror(bp, EFSCORRUPTED);
274
275 if (bp->b_error)
276 xfs_verifier_error(bp);
277}
278
279static void
280xfs_dir3_data_write_verify(
281 struct xfs_buf *bp)
282{
283 struct xfs_mount *mp = bp->b_target->bt_mount;
284 struct xfs_buf_log_item *bip = bp->b_fspriv;
285 struct xfs_dir3_blk_hdr *hdr3 = bp->b_addr;
286
287 if (!xfs_dir3_data_verify(bp)) {
288 xfs_buf_ioerror(bp, EFSCORRUPTED);
289 xfs_verifier_error(bp);
290 return;
291 }
292
293 if (!xfs_sb_version_hascrc(&mp->m_sb))
294 return;
295
296 if (bip)
297 hdr3->lsn = cpu_to_be64(bip->bli_item.li_lsn);
298
299 xfs_buf_update_cksum(bp, XFS_DIR3_DATA_CRC_OFF);
300}
301
302const struct xfs_buf_ops xfs_dir3_data_buf_ops = {
303 .verify_read = xfs_dir3_data_read_verify,
304 .verify_write = xfs_dir3_data_write_verify,
305};
306
307static const struct xfs_buf_ops xfs_dir3_data_reada_buf_ops = {
308 .verify_read = xfs_dir3_data_reada_verify,
309 .verify_write = xfs_dir3_data_write_verify,
310};
311
312
313int
314xfs_dir3_data_read(
315 struct xfs_trans *tp,
316 struct xfs_inode *dp,
317 xfs_dablk_t bno,
318 xfs_daddr_t mapped_bno,
319 struct xfs_buf **bpp)
320{
321 int err;
322
323 err = xfs_da_read_buf(tp, dp, bno, mapped_bno, bpp,
324 XFS_DATA_FORK, &xfs_dir3_data_buf_ops);
325 if (!err && tp)
326 xfs_trans_buf_set_type(tp, *bpp, XFS_BLFT_DIR_DATA_BUF);
327 return err;
328}
329
330int
331xfs_dir3_data_readahead(
332 struct xfs_trans *tp,
333 struct xfs_inode *dp,
334 xfs_dablk_t bno,
335 xfs_daddr_t mapped_bno)
336{
337 return xfs_da_reada_buf(tp, dp, bno, mapped_bno,
338 XFS_DATA_FORK, &xfs_dir3_data_reada_buf_ops);
339}
340
341/*
342 * Given a data block and an unused entry from that block,
343 * return the bestfree entry if any that corresponds to it.
344 */
345xfs_dir2_data_free_t *
346xfs_dir2_data_freefind(
347 struct xfs_dir2_data_hdr *hdr, /* data block header */
348 struct xfs_dir2_data_free *bf, /* bestfree table pointer */
349 struct xfs_dir2_data_unused *dup) /* unused space */
350{
351 xfs_dir2_data_free_t *dfp; /* bestfree entry */
352 xfs_dir2_data_aoff_t off; /* offset value needed */
353#ifdef DEBUG
354 int matched; /* matched the value */
355 int seenzero; /* saw a 0 bestfree entry */
356#endif
357
358 off = (xfs_dir2_data_aoff_t)((char *)dup - (char *)hdr);
359
360#ifdef DEBUG
361 /*
362 * Validate some consistency in the bestfree table.
363 * Check order, non-overlapping entries, and if we find the
364 * one we're looking for it has to be exact.
365 */
366 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
367 hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
368 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
369 hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
370 for (dfp = &bf[0], seenzero = matched = 0;
371 dfp < &bf[XFS_DIR2_DATA_FD_COUNT];
372 dfp++) {
373 if (!dfp->offset) {
374 ASSERT(!dfp->length);
375 seenzero = 1;
376 continue;
377 }
378 ASSERT(seenzero == 0);
379 if (be16_to_cpu(dfp->offset) == off) {
380 matched = 1;
381 ASSERT(dfp->length == dup->length);
382 } else if (off < be16_to_cpu(dfp->offset))
383 ASSERT(off + be16_to_cpu(dup->length) <= be16_to_cpu(dfp->offset));
384 else
385 ASSERT(be16_to_cpu(dfp->offset) + be16_to_cpu(dfp->length) <= off);
386 ASSERT(matched || be16_to_cpu(dfp->length) >= be16_to_cpu(dup->length));
387 if (dfp > &bf[0])
388 ASSERT(be16_to_cpu(dfp[-1].length) >= be16_to_cpu(dfp[0].length));
389 }
390#endif
391 /*
392 * If this is smaller than the smallest bestfree entry,
393 * it can't be there since they're sorted.
394 */
395 if (be16_to_cpu(dup->length) <
396 be16_to_cpu(bf[XFS_DIR2_DATA_FD_COUNT - 1].length))
397 return NULL;
398 /*
399 * Look at the three bestfree entries for our guy.
400 */
401 for (dfp = &bf[0]; dfp < &bf[XFS_DIR2_DATA_FD_COUNT]; dfp++) {
402 if (!dfp->offset)
403 return NULL;
404 if (be16_to_cpu(dfp->offset) == off)
405 return dfp;
406 }
407 /*
408 * Didn't find it. This only happens if there are duplicate lengths.
409 */
410 return NULL;
411}
412
413/*
414 * Insert an unused-space entry into the bestfree table.
415 */
416xfs_dir2_data_free_t * /* entry inserted */
417xfs_dir2_data_freeinsert(
418 struct xfs_dir2_data_hdr *hdr, /* data block pointer */
419 struct xfs_dir2_data_free *dfp, /* bestfree table pointer */
420 struct xfs_dir2_data_unused *dup, /* unused space */
421 int *loghead) /* log the data header (out) */
422{
423 xfs_dir2_data_free_t new; /* new bestfree entry */
424
425 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
426 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
427 hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
428 hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
429
430 new.length = dup->length;
431 new.offset = cpu_to_be16((char *)dup - (char *)hdr);
432
433 /*
434 * Insert at position 0, 1, or 2; or not at all.
435 */
436 if (be16_to_cpu(new.length) > be16_to_cpu(dfp[0].length)) {
437 dfp[2] = dfp[1];
438 dfp[1] = dfp[0];
439 dfp[0] = new;
440 *loghead = 1;
441 return &dfp[0];
442 }
443 if (be16_to_cpu(new.length) > be16_to_cpu(dfp[1].length)) {
444 dfp[2] = dfp[1];
445 dfp[1] = new;
446 *loghead = 1;
447 return &dfp[1];
448 }
449 if (be16_to_cpu(new.length) > be16_to_cpu(dfp[2].length)) {
450 dfp[2] = new;
451 *loghead = 1;
452 return &dfp[2];
453 }
454 return NULL;
455}
456
457/*
458 * Remove a bestfree entry from the table.
459 */
460STATIC void
461xfs_dir2_data_freeremove(
462 struct xfs_dir2_data_hdr *hdr, /* data block header */
463 struct xfs_dir2_data_free *bf, /* bestfree table pointer */
464 struct xfs_dir2_data_free *dfp, /* bestfree entry pointer */
465 int *loghead) /* out: log data header */
466{
467
468 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
469 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
470 hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
471 hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
472
473 /*
474 * It's the first entry, slide the next 2 up.
475 */
476 if (dfp == &bf[0]) {
477 bf[0] = bf[1];
478 bf[1] = bf[2];
479 }
480 /*
481 * It's the second entry, slide the 3rd entry up.
482 */
483 else if (dfp == &bf[1])
484 bf[1] = bf[2];
485 /*
486 * Must be the last entry.
487 */
488 else
489 ASSERT(dfp == &bf[2]);
490 /*
491 * Clear the 3rd entry, must be zero now.
492 */
493 bf[2].length = 0;
494 bf[2].offset = 0;
495 *loghead = 1;
496}
497
498/*
499 * Given a data block, reconstruct its bestfree map.
500 */
501void
502xfs_dir2_data_freescan(
503 struct xfs_inode *dp,
504 struct xfs_dir2_data_hdr *hdr,
505 int *loghead)
506{
507 xfs_dir2_block_tail_t *btp; /* block tail */
508 xfs_dir2_data_entry_t *dep; /* active data entry */
509 xfs_dir2_data_unused_t *dup; /* unused data entry */
510 struct xfs_dir2_data_free *bf;
511 char *endp; /* end of block's data */
512 char *p; /* current entry pointer */
513
514 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
515 hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
516 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
517 hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
518
519 /*
520 * Start by clearing the table.
521 */
522 bf = dp->d_ops->data_bestfree_p(hdr);
523 memset(bf, 0, sizeof(*bf) * XFS_DIR2_DATA_FD_COUNT);
524 *loghead = 1;
525 /*
526 * Set up pointers.
527 */
528 p = (char *)dp->d_ops->data_entry_p(hdr);
529 if (hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
530 hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC)) {
531 btp = xfs_dir2_block_tail_p(dp->i_mount, hdr);
532 endp = (char *)xfs_dir2_block_leaf_p(btp);
533 } else
534 endp = (char *)hdr + dp->i_mount->m_dirblksize;
535 /*
536 * Loop over the block's entries.
537 */
538 while (p < endp) {
539 dup = (xfs_dir2_data_unused_t *)p;
540 /*
541 * If it's a free entry, insert it.
542 */
543 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
544 ASSERT((char *)dup - (char *)hdr ==
545 be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)));
546 xfs_dir2_data_freeinsert(hdr, bf, dup, loghead);
547 p += be16_to_cpu(dup->length);
548 }
549 /*
550 * For active entries, check their tags and skip them.
551 */
552 else {
553 dep = (xfs_dir2_data_entry_t *)p;
554 ASSERT((char *)dep - (char *)hdr ==
555 be16_to_cpu(*dp->d_ops->data_entry_tag_p(dep)));
556 p += dp->d_ops->data_entsize(dep->namelen);
557 }
558 }
559}
560
561/*
562 * Initialize a data block at the given block number in the directory.
563 * Give back the buffer for the created block.
564 */
565int /* error */
566xfs_dir3_data_init(
567 xfs_da_args_t *args, /* directory operation args */
568 xfs_dir2_db_t blkno, /* logical dir block number */
569 struct xfs_buf **bpp) /* output block buffer */
570{
571 struct xfs_buf *bp; /* block buffer */
572 xfs_dir2_data_hdr_t *hdr; /* data block header */
573 xfs_inode_t *dp; /* incore directory inode */
574 xfs_dir2_data_unused_t *dup; /* unused entry pointer */
575 struct xfs_dir2_data_free *bf;
576 int error; /* error return value */
577 int i; /* bestfree index */
578 xfs_mount_t *mp; /* filesystem mount point */
579 xfs_trans_t *tp; /* transaction pointer */
580 int t; /* temp */
581
582 dp = args->dp;
583 mp = dp->i_mount;
584 tp = args->trans;
585 /*
586 * Get the buffer set up for the block.
587 */
588 error = xfs_da_get_buf(tp, dp, xfs_dir2_db_to_da(mp, blkno), -1, &bp,
589 XFS_DATA_FORK);
590 if (error)
591 return error;
592 bp->b_ops = &xfs_dir3_data_buf_ops;
593 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DIR_DATA_BUF);
594
595 /*
596 * Initialize the header.
597 */
598 hdr = bp->b_addr;
599 if (xfs_sb_version_hascrc(&mp->m_sb)) {
600 struct xfs_dir3_blk_hdr *hdr3 = bp->b_addr;
601
602 memset(hdr3, 0, sizeof(*hdr3));
603 hdr3->magic = cpu_to_be32(XFS_DIR3_DATA_MAGIC);
604 hdr3->blkno = cpu_to_be64(bp->b_bn);
605 hdr3->owner = cpu_to_be64(dp->i_ino);
606 uuid_copy(&hdr3->uuid, &mp->m_sb.sb_uuid);
607
608 } else
609 hdr->magic = cpu_to_be32(XFS_DIR2_DATA_MAGIC);
610
611 bf = dp->d_ops->data_bestfree_p(hdr);
612 bf[0].offset = cpu_to_be16(dp->d_ops->data_entry_offset);
613 for (i = 1; i < XFS_DIR2_DATA_FD_COUNT; i++) {
614 bf[i].length = 0;
615 bf[i].offset = 0;
616 }
617
618 /*
619 * Set up an unused entry for the block's body.
620 */
621 dup = dp->d_ops->data_unused_p(hdr);
622 dup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
623
624 t = mp->m_dirblksize - (uint)dp->d_ops->data_entry_offset;
625 bf[0].length = cpu_to_be16(t);
626 dup->length = cpu_to_be16(t);
627 *xfs_dir2_data_unused_tag_p(dup) = cpu_to_be16((char *)dup - (char *)hdr);
628 /*
629 * Log it and return it.
630 */
631 xfs_dir2_data_log_header(tp, dp, bp);
632 xfs_dir2_data_log_unused(tp, bp, dup);
633 *bpp = bp;
634 return 0;
635}
636
637/*
638 * Log an active data entry from the block.
639 */
640void
641xfs_dir2_data_log_entry(
642 struct xfs_trans *tp,
643 struct xfs_inode *dp,
644 struct xfs_buf *bp,
645 xfs_dir2_data_entry_t *dep) /* data entry pointer */
646{
647 struct xfs_dir2_data_hdr *hdr = bp->b_addr;
648
649 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
650 hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
651 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
652 hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
653
654 xfs_trans_log_buf(tp, bp, (uint)((char *)dep - (char *)hdr),
655 (uint)((char *)(dp->d_ops->data_entry_tag_p(dep) + 1) -
656 (char *)hdr - 1));
657}
658
659/*
660 * Log a data block header.
661 */
662void
663xfs_dir2_data_log_header(
664 struct xfs_trans *tp,
665 struct xfs_inode *dp,
666 struct xfs_buf *bp)
667{
668#ifdef DEBUG
669 struct xfs_dir2_data_hdr *hdr = bp->b_addr;
670
671 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
672 hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
673 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
674 hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
675#endif
676
677 xfs_trans_log_buf(tp, bp, 0, dp->d_ops->data_entry_offset - 1);
678}
679
680/*
681 * Log a data unused entry.
682 */
683void
684xfs_dir2_data_log_unused(
685 struct xfs_trans *tp,
686 struct xfs_buf *bp,
687 xfs_dir2_data_unused_t *dup) /* data unused pointer */
688{
689 xfs_dir2_data_hdr_t *hdr = bp->b_addr;
690
691 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
692 hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
693 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
694 hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
695
696 /*
697 * Log the first part of the unused entry.
698 */
699 xfs_trans_log_buf(tp, bp, (uint)((char *)dup - (char *)hdr),
700 (uint)((char *)&dup->length + sizeof(dup->length) -
701 1 - (char *)hdr));
702 /*
703 * Log the end (tag) of the unused entry.
704 */
705 xfs_trans_log_buf(tp, bp,
706 (uint)((char *)xfs_dir2_data_unused_tag_p(dup) - (char *)hdr),
707 (uint)((char *)xfs_dir2_data_unused_tag_p(dup) - (char *)hdr +
708 sizeof(xfs_dir2_data_off_t) - 1));
709}
710
711/*
712 * Make a byte range in the data block unused.
713 * Its current contents are unimportant.
714 */
715void
716xfs_dir2_data_make_free(
717 struct xfs_trans *tp,
718 struct xfs_inode *dp,
719 struct xfs_buf *bp,
720 xfs_dir2_data_aoff_t offset, /* starting byte offset */
721 xfs_dir2_data_aoff_t len, /* length in bytes */
722 int *needlogp, /* out: log header */
723 int *needscanp) /* out: regen bestfree */
724{
725 xfs_dir2_data_hdr_t *hdr; /* data block pointer */
726 xfs_dir2_data_free_t *dfp; /* bestfree pointer */
727 char *endptr; /* end of data area */
728 xfs_mount_t *mp; /* filesystem mount point */
729 int needscan; /* need to regen bestfree */
730 xfs_dir2_data_unused_t *newdup; /* new unused entry */
731 xfs_dir2_data_unused_t *postdup; /* unused entry after us */
732 xfs_dir2_data_unused_t *prevdup; /* unused entry before us */
733 struct xfs_dir2_data_free *bf;
734
735 mp = tp->t_mountp;
736 hdr = bp->b_addr;
737
738 /*
739 * Figure out where the end of the data area is.
740 */
741 if (hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
742 hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC))
743 endptr = (char *)hdr + mp->m_dirblksize;
744 else {
745 xfs_dir2_block_tail_t *btp; /* block tail */
746
747 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
748 hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
749 btp = xfs_dir2_block_tail_p(mp, hdr);
750 endptr = (char *)xfs_dir2_block_leaf_p(btp);
751 }
752 /*
753 * If this isn't the start of the block, then back up to
754 * the previous entry and see if it's free.
755 */
756 if (offset > dp->d_ops->data_entry_offset) {
757 __be16 *tagp; /* tag just before us */
758
759 tagp = (__be16 *)((char *)hdr + offset) - 1;
760 prevdup = (xfs_dir2_data_unused_t *)((char *)hdr + be16_to_cpu(*tagp));
761 if (be16_to_cpu(prevdup->freetag) != XFS_DIR2_DATA_FREE_TAG)
762 prevdup = NULL;
763 } else
764 prevdup = NULL;
765 /*
766 * If this isn't the end of the block, see if the entry after
767 * us is free.
768 */
769 if ((char *)hdr + offset + len < endptr) {
770 postdup =
771 (xfs_dir2_data_unused_t *)((char *)hdr + offset + len);
772 if (be16_to_cpu(postdup->freetag) != XFS_DIR2_DATA_FREE_TAG)
773 postdup = NULL;
774 } else
775 postdup = NULL;
776 ASSERT(*needscanp == 0);
777 needscan = 0;
778 /*
779 * Previous and following entries are both free,
780 * merge everything into a single free entry.
781 */
782 bf = dp->d_ops->data_bestfree_p(hdr);
783 if (prevdup && postdup) {
784 xfs_dir2_data_free_t *dfp2; /* another bestfree pointer */
785
786 /*
787 * See if prevdup and/or postdup are in bestfree table.
788 */
789 dfp = xfs_dir2_data_freefind(hdr, bf, prevdup);
790 dfp2 = xfs_dir2_data_freefind(hdr, bf, postdup);
791 /*
792 * We need a rescan unless there are exactly 2 free entries
793 * namely our two. Then we know what's happening, otherwise
794 * since the third bestfree is there, there might be more
795 * entries.
796 */
797 needscan = (bf[2].length != 0);
798 /*
799 * Fix up the new big freespace.
800 */
801 be16_add_cpu(&prevdup->length, len + be16_to_cpu(postdup->length));
802 *xfs_dir2_data_unused_tag_p(prevdup) =
803 cpu_to_be16((char *)prevdup - (char *)hdr);
804 xfs_dir2_data_log_unused(tp, bp, prevdup);
805 if (!needscan) {
806 /*
807 * Has to be the case that entries 0 and 1 are
808 * dfp and dfp2 (don't know which is which), and
809 * entry 2 is empty.
810 * Remove entry 1 first then entry 0.
811 */
812 ASSERT(dfp && dfp2);
813 if (dfp == &bf[1]) {
814 dfp = &bf[0];
815 ASSERT(dfp2 == dfp);
816 dfp2 = &bf[1];
817 }
818 xfs_dir2_data_freeremove(hdr, bf, dfp2, needlogp);
819 xfs_dir2_data_freeremove(hdr, bf, dfp, needlogp);
820 /*
821 * Now insert the new entry.
822 */
823 dfp = xfs_dir2_data_freeinsert(hdr, bf, prevdup,
824 needlogp);
825 ASSERT(dfp == &bf[0]);
826 ASSERT(dfp->length == prevdup->length);
827 ASSERT(!dfp[1].length);
828 ASSERT(!dfp[2].length);
829 }
830 }
831 /*
832 * The entry before us is free, merge with it.
833 */
834 else if (prevdup) {
835 dfp = xfs_dir2_data_freefind(hdr, bf, prevdup);
836 be16_add_cpu(&prevdup->length, len);
837 *xfs_dir2_data_unused_tag_p(prevdup) =
838 cpu_to_be16((char *)prevdup - (char *)hdr);
839 xfs_dir2_data_log_unused(tp, bp, prevdup);
840 /*
841 * If the previous entry was in the table, the new entry
842 * is longer, so it will be in the table too. Remove
843 * the old one and add the new one.
844 */
845 if (dfp) {
846 xfs_dir2_data_freeremove(hdr, bf, dfp, needlogp);
847 xfs_dir2_data_freeinsert(hdr, bf, prevdup, needlogp);
848 }
849 /*
850 * Otherwise we need a scan if the new entry is big enough.
851 */
852 else {
853 needscan = be16_to_cpu(prevdup->length) >
854 be16_to_cpu(bf[2].length);
855 }
856 }
857 /*
858 * The following entry is free, merge with it.
859 */
860 else if (postdup) {
861 dfp = xfs_dir2_data_freefind(hdr, bf, postdup);
862 newdup = (xfs_dir2_data_unused_t *)((char *)hdr + offset);
863 newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
864 newdup->length = cpu_to_be16(len + be16_to_cpu(postdup->length));
865 *xfs_dir2_data_unused_tag_p(newdup) =
866 cpu_to_be16((char *)newdup - (char *)hdr);
867 xfs_dir2_data_log_unused(tp, bp, newdup);
868 /*
869 * If the following entry was in the table, the new entry
870 * is longer, so it will be in the table too. Remove
871 * the old one and add the new one.
872 */
873 if (dfp) {
874 xfs_dir2_data_freeremove(hdr, bf, dfp, needlogp);
875 xfs_dir2_data_freeinsert(hdr, bf, newdup, needlogp);
876 }
877 /*
878 * Otherwise we need a scan if the new entry is big enough.
879 */
880 else {
881 needscan = be16_to_cpu(newdup->length) >
882 be16_to_cpu(bf[2].length);
883 }
884 }
885 /*
886 * Neither neighbor is free. Make a new entry.
887 */
888 else {
889 newdup = (xfs_dir2_data_unused_t *)((char *)hdr + offset);
890 newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
891 newdup->length = cpu_to_be16(len);
892 *xfs_dir2_data_unused_tag_p(newdup) =
893 cpu_to_be16((char *)newdup - (char *)hdr);
894 xfs_dir2_data_log_unused(tp, bp, newdup);
895 xfs_dir2_data_freeinsert(hdr, bf, newdup, needlogp);
896 }
897 *needscanp = needscan;
898}
899
900/*
901 * Take a byte range out of an existing unused space and make it un-free.
902 */
903void
904xfs_dir2_data_use_free(
905 struct xfs_trans *tp,
906 struct xfs_inode *dp,
907 struct xfs_buf *bp,
908 xfs_dir2_data_unused_t *dup, /* unused entry */
909 xfs_dir2_data_aoff_t offset, /* starting offset to use */
910 xfs_dir2_data_aoff_t len, /* length to use */
911 int *needlogp, /* out: need to log header */
912 int *needscanp) /* out: need regen bestfree */
913{
914 xfs_dir2_data_hdr_t *hdr; /* data block header */
915 xfs_dir2_data_free_t *dfp; /* bestfree pointer */
916 int matchback; /* matches end of freespace */
917 int matchfront; /* matches start of freespace */
918 int needscan; /* need to regen bestfree */
919 xfs_dir2_data_unused_t *newdup; /* new unused entry */
920 xfs_dir2_data_unused_t *newdup2; /* another new unused entry */
921 int oldlen; /* old unused entry's length */
922 struct xfs_dir2_data_free *bf;
923
924 hdr = bp->b_addr;
925 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
926 hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
927 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
928 hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
929 ASSERT(be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG);
930 ASSERT(offset >= (char *)dup - (char *)hdr);
931 ASSERT(offset + len <= (char *)dup + be16_to_cpu(dup->length) - (char *)hdr);
932 ASSERT((char *)dup - (char *)hdr == be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)));
933 /*
934 * Look up the entry in the bestfree table.
935 */
936 oldlen = be16_to_cpu(dup->length);
937 bf = dp->d_ops->data_bestfree_p(hdr);
938 dfp = xfs_dir2_data_freefind(hdr, bf, dup);
939 ASSERT(dfp || oldlen <= be16_to_cpu(bf[2].length));
940 /*
941 * Check for alignment with front and back of the entry.
942 */
943 matchfront = (char *)dup - (char *)hdr == offset;
944 matchback = (char *)dup + oldlen - (char *)hdr == offset + len;
945 ASSERT(*needscanp == 0);
946 needscan = 0;
947 /*
948 * If we matched it exactly we just need to get rid of it from
949 * the bestfree table.
950 */
951 if (matchfront && matchback) {
952 if (dfp) {
953 needscan = (bf[2].offset != 0);
954 if (!needscan)
955 xfs_dir2_data_freeremove(hdr, bf, dfp,
956 needlogp);
957 }
958 }
959 /*
960 * We match the first part of the entry.
961 * Make a new entry with the remaining freespace.
962 */
963 else if (matchfront) {
964 newdup = (xfs_dir2_data_unused_t *)((char *)hdr + offset + len);
965 newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
966 newdup->length = cpu_to_be16(oldlen - len);
967 *xfs_dir2_data_unused_tag_p(newdup) =
968 cpu_to_be16((char *)newdup - (char *)hdr);
969 xfs_dir2_data_log_unused(tp, bp, newdup);
970 /*
971 * If it was in the table, remove it and add the new one.
972 */
973 if (dfp) {
974 xfs_dir2_data_freeremove(hdr, bf, dfp, needlogp);
975 dfp = xfs_dir2_data_freeinsert(hdr, bf, newdup,
976 needlogp);
977 ASSERT(dfp != NULL);
978 ASSERT(dfp->length == newdup->length);
979 ASSERT(be16_to_cpu(dfp->offset) == (char *)newdup - (char *)hdr);
980 /*
981 * If we got inserted at the last slot,
982 * that means we don't know if there was a better
983 * choice for the last slot, or not. Rescan.
984 */
985 needscan = dfp == &bf[2];
986 }
987 }
988 /*
989 * We match the last part of the entry.
990 * Trim the allocated space off the tail of the entry.
991 */
992 else if (matchback) {
993 newdup = dup;
994 newdup->length = cpu_to_be16(((char *)hdr + offset) - (char *)newdup);
995 *xfs_dir2_data_unused_tag_p(newdup) =
996 cpu_to_be16((char *)newdup - (char *)hdr);
997 xfs_dir2_data_log_unused(tp, bp, newdup);
998 /*
999 * If it was in the table, remove it and add the new one.
1000 */
1001 if (dfp) {
1002 xfs_dir2_data_freeremove(hdr, bf, dfp, needlogp);
1003 dfp = xfs_dir2_data_freeinsert(hdr, bf, newdup,
1004 needlogp);
1005 ASSERT(dfp != NULL);
1006 ASSERT(dfp->length == newdup->length);
1007 ASSERT(be16_to_cpu(dfp->offset) == (char *)newdup - (char *)hdr);
1008 /*
1009 * If we got inserted at the last slot,
1010 * that means we don't know if there was a better
1011 * choice for the last slot, or not. Rescan.
1012 */
1013 needscan = dfp == &bf[2];
1014 }
1015 }
1016 /*
1017 * Poking out the middle of an entry.
1018 * Make two new entries.
1019 */
1020 else {
1021 newdup = dup;
1022 newdup->length = cpu_to_be16(((char *)hdr + offset) - (char *)newdup);
1023 *xfs_dir2_data_unused_tag_p(newdup) =
1024 cpu_to_be16((char *)newdup - (char *)hdr);
1025 xfs_dir2_data_log_unused(tp, bp, newdup);
1026 newdup2 = (xfs_dir2_data_unused_t *)((char *)hdr + offset + len);
1027 newdup2->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
1028 newdup2->length = cpu_to_be16(oldlen - len - be16_to_cpu(newdup->length));
1029 *xfs_dir2_data_unused_tag_p(newdup2) =
1030 cpu_to_be16((char *)newdup2 - (char *)hdr);
1031 xfs_dir2_data_log_unused(tp, bp, newdup2);
1032 /*
1033 * If the old entry was in the table, we need to scan
1034 * if the 3rd entry was valid, since these entries
1035 * are smaller than the old one.
1036 * If we don't need to scan that means there were 1 or 2
1037 * entries in the table, and removing the old and adding
1038 * the 2 new will work.
1039 */
1040 if (dfp) {
1041 needscan = (bf[2].length != 0);
1042 if (!needscan) {
1043 xfs_dir2_data_freeremove(hdr, bf, dfp,
1044 needlogp);
1045 xfs_dir2_data_freeinsert(hdr, bf, newdup,
1046 needlogp);
1047 xfs_dir2_data_freeinsert(hdr, bf, newdup2,
1048 needlogp);
1049 }
1050 }
1051 }
1052 *needscanp = needscan;
1053}