Loading...
Note: File does not exist in v6.13.7.
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_trans.h"
23#include "xfs_sb.h"
24#include "xfs_ag.h"
25#include "xfs_mount.h"
26#include "xfs_da_btree.h"
27#include "xfs_bmap_btree.h"
28#include "xfs_dinode.h"
29#include "xfs_inode.h"
30#include "xfs_dir2_format.h"
31#include "xfs_dir2_priv.h"
32#include "xfs_error.h"
33
34STATIC xfs_dir2_data_free_t *
35xfs_dir2_data_freefind(xfs_dir2_data_hdr_t *hdr, xfs_dir2_data_unused_t *dup);
36
37#ifdef DEBUG
38/*
39 * Check the consistency of the data block.
40 * The input can also be a block-format directory.
41 * Pop an assert if we find anything bad.
42 */
43void
44xfs_dir2_data_check(
45 xfs_inode_t *dp, /* incore inode pointer */
46 xfs_dabuf_t *bp) /* data block's buffer */
47{
48 xfs_dir2_dataptr_t addr; /* addr for leaf lookup */
49 xfs_dir2_data_free_t *bf; /* bestfree table */
50 xfs_dir2_block_tail_t *btp=NULL; /* block tail */
51 int count; /* count of entries found */
52 xfs_dir2_data_hdr_t *hdr; /* data block header */
53 xfs_dir2_data_entry_t *dep; /* data entry */
54 xfs_dir2_data_free_t *dfp; /* bestfree entry */
55 xfs_dir2_data_unused_t *dup; /* unused entry */
56 char *endp; /* end of useful data */
57 int freeseen; /* mask of bestfrees seen */
58 xfs_dahash_t hash; /* hash of current name */
59 int i; /* leaf index */
60 int lastfree; /* last entry was unused */
61 xfs_dir2_leaf_entry_t *lep=NULL; /* block leaf entries */
62 xfs_mount_t *mp; /* filesystem mount point */
63 char *p; /* current data position */
64 int stale; /* count of stale leaves */
65 struct xfs_name name;
66
67 mp = dp->i_mount;
68 hdr = bp->data;
69 bf = hdr->bestfree;
70 p = (char *)(hdr + 1);
71
72 if (hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC)) {
73 btp = xfs_dir2_block_tail_p(mp, hdr);
74 lep = xfs_dir2_block_leaf_p(btp);
75 endp = (char *)lep;
76 } else {
77 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC));
78 endp = (char *)hdr + mp->m_dirblksize;
79 }
80
81 count = lastfree = freeseen = 0;
82 /*
83 * Account for zero bestfree entries.
84 */
85 if (!bf[0].length) {
86 ASSERT(!bf[0].offset);
87 freeseen |= 1 << 0;
88 }
89 if (!bf[1].length) {
90 ASSERT(!bf[1].offset);
91 freeseen |= 1 << 1;
92 }
93 if (!bf[2].length) {
94 ASSERT(!bf[2].offset);
95 freeseen |= 1 << 2;
96 }
97 ASSERT(be16_to_cpu(bf[0].length) >= be16_to_cpu(bf[1].length));
98 ASSERT(be16_to_cpu(bf[1].length) >= be16_to_cpu(bf[2].length));
99 /*
100 * Loop over the data/unused entries.
101 */
102 while (p < endp) {
103 dup = (xfs_dir2_data_unused_t *)p;
104 /*
105 * If it's unused, look for the space in the bestfree table.
106 * If we find it, account for that, else make sure it
107 * doesn't need to be there.
108 */
109 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
110 ASSERT(lastfree == 0);
111 ASSERT(be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)) ==
112 (char *)dup - (char *)hdr);
113 dfp = xfs_dir2_data_freefind(hdr, dup);
114 if (dfp) {
115 i = (int)(dfp - bf);
116 ASSERT((freeseen & (1 << i)) == 0);
117 freeseen |= 1 << i;
118 } else {
119 ASSERT(be16_to_cpu(dup->length) <=
120 be16_to_cpu(bf[2].length));
121 }
122 p += be16_to_cpu(dup->length);
123 lastfree = 1;
124 continue;
125 }
126 /*
127 * It's a real entry. Validate the fields.
128 * If this is a block directory then make sure it's
129 * in the leaf section of the block.
130 * The linear search is crude but this is DEBUG code.
131 */
132 dep = (xfs_dir2_data_entry_t *)p;
133 ASSERT(dep->namelen != 0);
134 ASSERT(xfs_dir_ino_validate(mp, be64_to_cpu(dep->inumber)) == 0);
135 ASSERT(be16_to_cpu(*xfs_dir2_data_entry_tag_p(dep)) ==
136 (char *)dep - (char *)hdr);
137 count++;
138 lastfree = 0;
139 if (hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC)) {
140 addr = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk,
141 (xfs_dir2_data_aoff_t)
142 ((char *)dep - (char *)hdr));
143 name.name = dep->name;
144 name.len = dep->namelen;
145 hash = mp->m_dirnameops->hashname(&name);
146 for (i = 0; i < be32_to_cpu(btp->count); i++) {
147 if (be32_to_cpu(lep[i].address) == addr &&
148 be32_to_cpu(lep[i].hashval) == hash)
149 break;
150 }
151 ASSERT(i < be32_to_cpu(btp->count));
152 }
153 p += xfs_dir2_data_entsize(dep->namelen);
154 }
155 /*
156 * Need to have seen all the entries and all the bestfree slots.
157 */
158 ASSERT(freeseen == 7);
159 if (hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC)) {
160 for (i = stale = 0; i < be32_to_cpu(btp->count); i++) {
161 if (lep[i].address ==
162 cpu_to_be32(XFS_DIR2_NULL_DATAPTR))
163 stale++;
164 if (i > 0)
165 ASSERT(be32_to_cpu(lep[i].hashval) >= be32_to_cpu(lep[i - 1].hashval));
166 }
167 ASSERT(count == be32_to_cpu(btp->count) - be32_to_cpu(btp->stale));
168 ASSERT(stale == be32_to_cpu(btp->stale));
169 }
170}
171#endif
172
173/*
174 * Given a data block and an unused entry from that block,
175 * return the bestfree entry if any that corresponds to it.
176 */
177STATIC xfs_dir2_data_free_t *
178xfs_dir2_data_freefind(
179 xfs_dir2_data_hdr_t *hdr, /* data block */
180 xfs_dir2_data_unused_t *dup) /* data unused entry */
181{
182 xfs_dir2_data_free_t *dfp; /* bestfree entry */
183 xfs_dir2_data_aoff_t off; /* offset value needed */
184#if defined(DEBUG) && defined(__KERNEL__)
185 int matched; /* matched the value */
186 int seenzero; /* saw a 0 bestfree entry */
187#endif
188
189 off = (xfs_dir2_data_aoff_t)((char *)dup - (char *)hdr);
190#if defined(DEBUG) && defined(__KERNEL__)
191 /*
192 * Validate some consistency in the bestfree table.
193 * Check order, non-overlapping entries, and if we find the
194 * one we're looking for it has to be exact.
195 */
196 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
197 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC));
198 for (dfp = &hdr->bestfree[0], seenzero = matched = 0;
199 dfp < &hdr->bestfree[XFS_DIR2_DATA_FD_COUNT];
200 dfp++) {
201 if (!dfp->offset) {
202 ASSERT(!dfp->length);
203 seenzero = 1;
204 continue;
205 }
206 ASSERT(seenzero == 0);
207 if (be16_to_cpu(dfp->offset) == off) {
208 matched = 1;
209 ASSERT(dfp->length == dup->length);
210 } else if (off < be16_to_cpu(dfp->offset))
211 ASSERT(off + be16_to_cpu(dup->length) <= be16_to_cpu(dfp->offset));
212 else
213 ASSERT(be16_to_cpu(dfp->offset) + be16_to_cpu(dfp->length) <= off);
214 ASSERT(matched || be16_to_cpu(dfp->length) >= be16_to_cpu(dup->length));
215 if (dfp > &hdr->bestfree[0])
216 ASSERT(be16_to_cpu(dfp[-1].length) >= be16_to_cpu(dfp[0].length));
217 }
218#endif
219 /*
220 * If this is smaller than the smallest bestfree entry,
221 * it can't be there since they're sorted.
222 */
223 if (be16_to_cpu(dup->length) <
224 be16_to_cpu(hdr->bestfree[XFS_DIR2_DATA_FD_COUNT - 1].length))
225 return NULL;
226 /*
227 * Look at the three bestfree entries for our guy.
228 */
229 for (dfp = &hdr->bestfree[0];
230 dfp < &hdr->bestfree[XFS_DIR2_DATA_FD_COUNT];
231 dfp++) {
232 if (!dfp->offset)
233 return NULL;
234 if (be16_to_cpu(dfp->offset) == off)
235 return dfp;
236 }
237 /*
238 * Didn't find it. This only happens if there are duplicate lengths.
239 */
240 return NULL;
241}
242
243/*
244 * Insert an unused-space entry into the bestfree table.
245 */
246xfs_dir2_data_free_t * /* entry inserted */
247xfs_dir2_data_freeinsert(
248 xfs_dir2_data_hdr_t *hdr, /* data block pointer */
249 xfs_dir2_data_unused_t *dup, /* unused space */
250 int *loghead) /* log the data header (out) */
251{
252 xfs_dir2_data_free_t *dfp; /* bestfree table pointer */
253 xfs_dir2_data_free_t new; /* new bestfree entry */
254
255#ifdef __KERNEL__
256 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
257 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC));
258#endif
259 dfp = hdr->bestfree;
260 new.length = dup->length;
261 new.offset = cpu_to_be16((char *)dup - (char *)hdr);
262
263 /*
264 * Insert at position 0, 1, or 2; or not at all.
265 */
266 if (be16_to_cpu(new.length) > be16_to_cpu(dfp[0].length)) {
267 dfp[2] = dfp[1];
268 dfp[1] = dfp[0];
269 dfp[0] = new;
270 *loghead = 1;
271 return &dfp[0];
272 }
273 if (be16_to_cpu(new.length) > be16_to_cpu(dfp[1].length)) {
274 dfp[2] = dfp[1];
275 dfp[1] = new;
276 *loghead = 1;
277 return &dfp[1];
278 }
279 if (be16_to_cpu(new.length) > be16_to_cpu(dfp[2].length)) {
280 dfp[2] = new;
281 *loghead = 1;
282 return &dfp[2];
283 }
284 return NULL;
285}
286
287/*
288 * Remove a bestfree entry from the table.
289 */
290STATIC void
291xfs_dir2_data_freeremove(
292 xfs_dir2_data_hdr_t *hdr, /* data block header */
293 xfs_dir2_data_free_t *dfp, /* bestfree entry pointer */
294 int *loghead) /* out: log data header */
295{
296#ifdef __KERNEL__
297 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
298 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC));
299#endif
300 /*
301 * It's the first entry, slide the next 2 up.
302 */
303 if (dfp == &hdr->bestfree[0]) {
304 hdr->bestfree[0] = hdr->bestfree[1];
305 hdr->bestfree[1] = hdr->bestfree[2];
306 }
307 /*
308 * It's the second entry, slide the 3rd entry up.
309 */
310 else if (dfp == &hdr->bestfree[1])
311 hdr->bestfree[1] = hdr->bestfree[2];
312 /*
313 * Must be the last entry.
314 */
315 else
316 ASSERT(dfp == &hdr->bestfree[2]);
317 /*
318 * Clear the 3rd entry, must be zero now.
319 */
320 hdr->bestfree[2].length = 0;
321 hdr->bestfree[2].offset = 0;
322 *loghead = 1;
323}
324
325/*
326 * Given a data block, reconstruct its bestfree map.
327 */
328void
329xfs_dir2_data_freescan(
330 xfs_mount_t *mp, /* filesystem mount point */
331 xfs_dir2_data_hdr_t *hdr, /* data block header */
332 int *loghead) /* out: log data header */
333{
334 xfs_dir2_block_tail_t *btp; /* block tail */
335 xfs_dir2_data_entry_t *dep; /* active data entry */
336 xfs_dir2_data_unused_t *dup; /* unused data entry */
337 char *endp; /* end of block's data */
338 char *p; /* current entry pointer */
339
340#ifdef __KERNEL__
341 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
342 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC));
343#endif
344 /*
345 * Start by clearing the table.
346 */
347 memset(hdr->bestfree, 0, sizeof(hdr->bestfree));
348 *loghead = 1;
349 /*
350 * Set up pointers.
351 */
352 p = (char *)(hdr + 1);
353 if (hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC)) {
354 btp = xfs_dir2_block_tail_p(mp, hdr);
355 endp = (char *)xfs_dir2_block_leaf_p(btp);
356 } else
357 endp = (char *)hdr + mp->m_dirblksize;
358 /*
359 * Loop over the block's entries.
360 */
361 while (p < endp) {
362 dup = (xfs_dir2_data_unused_t *)p;
363 /*
364 * If it's a free entry, insert it.
365 */
366 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
367 ASSERT((char *)dup - (char *)hdr ==
368 be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)));
369 xfs_dir2_data_freeinsert(hdr, dup, loghead);
370 p += be16_to_cpu(dup->length);
371 }
372 /*
373 * For active entries, check their tags and skip them.
374 */
375 else {
376 dep = (xfs_dir2_data_entry_t *)p;
377 ASSERT((char *)dep - (char *)hdr ==
378 be16_to_cpu(*xfs_dir2_data_entry_tag_p(dep)));
379 p += xfs_dir2_data_entsize(dep->namelen);
380 }
381 }
382}
383
384/*
385 * Initialize a data block at the given block number in the directory.
386 * Give back the buffer for the created block.
387 */
388int /* error */
389xfs_dir2_data_init(
390 xfs_da_args_t *args, /* directory operation args */
391 xfs_dir2_db_t blkno, /* logical dir block number */
392 xfs_dabuf_t **bpp) /* output block buffer */
393{
394 xfs_dabuf_t *bp; /* block buffer */
395 xfs_dir2_data_hdr_t *hdr; /* data block header */
396 xfs_inode_t *dp; /* incore directory inode */
397 xfs_dir2_data_unused_t *dup; /* unused entry pointer */
398 int error; /* error return value */
399 int i; /* bestfree index */
400 xfs_mount_t *mp; /* filesystem mount point */
401 xfs_trans_t *tp; /* transaction pointer */
402 int t; /* temp */
403
404 dp = args->dp;
405 mp = dp->i_mount;
406 tp = args->trans;
407 /*
408 * Get the buffer set up for the block.
409 */
410 error = xfs_da_get_buf(tp, dp, xfs_dir2_db_to_da(mp, blkno), -1, &bp,
411 XFS_DATA_FORK);
412 if (error) {
413 return error;
414 }
415 ASSERT(bp != NULL);
416
417 /*
418 * Initialize the header.
419 */
420 hdr = bp->data;
421 hdr->magic = cpu_to_be32(XFS_DIR2_DATA_MAGIC);
422 hdr->bestfree[0].offset = cpu_to_be16(sizeof(*hdr));
423 for (i = 1; i < XFS_DIR2_DATA_FD_COUNT; i++) {
424 hdr->bestfree[i].length = 0;
425 hdr->bestfree[i].offset = 0;
426 }
427
428 /*
429 * Set up an unused entry for the block's body.
430 */
431 dup = (xfs_dir2_data_unused_t *)(hdr + 1);
432 dup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
433
434 t = mp->m_dirblksize - (uint)sizeof(*hdr);
435 hdr->bestfree[0].length = cpu_to_be16(t);
436 dup->length = cpu_to_be16(t);
437 *xfs_dir2_data_unused_tag_p(dup) = cpu_to_be16((char *)dup - (char *)hdr);
438 /*
439 * Log it and return it.
440 */
441 xfs_dir2_data_log_header(tp, bp);
442 xfs_dir2_data_log_unused(tp, bp, dup);
443 *bpp = bp;
444 return 0;
445}
446
447/*
448 * Log an active data entry from the block.
449 */
450void
451xfs_dir2_data_log_entry(
452 xfs_trans_t *tp, /* transaction pointer */
453 xfs_dabuf_t *bp, /* block buffer */
454 xfs_dir2_data_entry_t *dep) /* data entry pointer */
455{
456 xfs_dir2_data_hdr_t *hdr = bp->data;
457
458 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
459 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC));
460
461 xfs_da_log_buf(tp, bp, (uint)((char *)dep - (char *)hdr),
462 (uint)((char *)(xfs_dir2_data_entry_tag_p(dep) + 1) -
463 (char *)hdr - 1));
464}
465
466/*
467 * Log a data block header.
468 */
469void
470xfs_dir2_data_log_header(
471 xfs_trans_t *tp, /* transaction pointer */
472 xfs_dabuf_t *bp) /* block buffer */
473{
474 xfs_dir2_data_hdr_t *hdr = bp->data;
475
476 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
477 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC));
478
479 xfs_da_log_buf(tp, bp, 0, sizeof(*hdr) - 1);
480}
481
482/*
483 * Log a data unused entry.
484 */
485void
486xfs_dir2_data_log_unused(
487 xfs_trans_t *tp, /* transaction pointer */
488 xfs_dabuf_t *bp, /* block buffer */
489 xfs_dir2_data_unused_t *dup) /* data unused pointer */
490{
491 xfs_dir2_data_hdr_t *hdr = bp->data;
492
493 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
494 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC));
495
496 /*
497 * Log the first part of the unused entry.
498 */
499 xfs_da_log_buf(tp, bp, (uint)((char *)dup - (char *)hdr),
500 (uint)((char *)&dup->length + sizeof(dup->length) -
501 1 - (char *)hdr));
502 /*
503 * Log the end (tag) of the unused entry.
504 */
505 xfs_da_log_buf(tp, bp,
506 (uint)((char *)xfs_dir2_data_unused_tag_p(dup) - (char *)hdr),
507 (uint)((char *)xfs_dir2_data_unused_tag_p(dup) - (char *)hdr +
508 sizeof(xfs_dir2_data_off_t) - 1));
509}
510
511/*
512 * Make a byte range in the data block unused.
513 * Its current contents are unimportant.
514 */
515void
516xfs_dir2_data_make_free(
517 xfs_trans_t *tp, /* transaction pointer */
518 xfs_dabuf_t *bp, /* block buffer */
519 xfs_dir2_data_aoff_t offset, /* starting byte offset */
520 xfs_dir2_data_aoff_t len, /* length in bytes */
521 int *needlogp, /* out: log header */
522 int *needscanp) /* out: regen bestfree */
523{
524 xfs_dir2_data_hdr_t *hdr; /* data block pointer */
525 xfs_dir2_data_free_t *dfp; /* bestfree pointer */
526 char *endptr; /* end of data area */
527 xfs_mount_t *mp; /* filesystem mount point */
528 int needscan; /* need to regen bestfree */
529 xfs_dir2_data_unused_t *newdup; /* new unused entry */
530 xfs_dir2_data_unused_t *postdup; /* unused entry after us */
531 xfs_dir2_data_unused_t *prevdup; /* unused entry before us */
532
533 mp = tp->t_mountp;
534 hdr = bp->data;
535
536 /*
537 * Figure out where the end of the data area is.
538 */
539 if (hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC))
540 endptr = (char *)hdr + mp->m_dirblksize;
541 else {
542 xfs_dir2_block_tail_t *btp; /* block tail */
543
544 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC));
545 btp = xfs_dir2_block_tail_p(mp, hdr);
546 endptr = (char *)xfs_dir2_block_leaf_p(btp);
547 }
548 /*
549 * If this isn't the start of the block, then back up to
550 * the previous entry and see if it's free.
551 */
552 if (offset > sizeof(*hdr)) {
553 __be16 *tagp; /* tag just before us */
554
555 tagp = (__be16 *)((char *)hdr + offset) - 1;
556 prevdup = (xfs_dir2_data_unused_t *)((char *)hdr + be16_to_cpu(*tagp));
557 if (be16_to_cpu(prevdup->freetag) != XFS_DIR2_DATA_FREE_TAG)
558 prevdup = NULL;
559 } else
560 prevdup = NULL;
561 /*
562 * If this isn't the end of the block, see if the entry after
563 * us is free.
564 */
565 if ((char *)hdr + offset + len < endptr) {
566 postdup =
567 (xfs_dir2_data_unused_t *)((char *)hdr + offset + len);
568 if (be16_to_cpu(postdup->freetag) != XFS_DIR2_DATA_FREE_TAG)
569 postdup = NULL;
570 } else
571 postdup = NULL;
572 ASSERT(*needscanp == 0);
573 needscan = 0;
574 /*
575 * Previous and following entries are both free,
576 * merge everything into a single free entry.
577 */
578 if (prevdup && postdup) {
579 xfs_dir2_data_free_t *dfp2; /* another bestfree pointer */
580
581 /*
582 * See if prevdup and/or postdup are in bestfree table.
583 */
584 dfp = xfs_dir2_data_freefind(hdr, prevdup);
585 dfp2 = xfs_dir2_data_freefind(hdr, postdup);
586 /*
587 * We need a rescan unless there are exactly 2 free entries
588 * namely our two. Then we know what's happening, otherwise
589 * since the third bestfree is there, there might be more
590 * entries.
591 */
592 needscan = (hdr->bestfree[2].length != 0);
593 /*
594 * Fix up the new big freespace.
595 */
596 be16_add_cpu(&prevdup->length, len + be16_to_cpu(postdup->length));
597 *xfs_dir2_data_unused_tag_p(prevdup) =
598 cpu_to_be16((char *)prevdup - (char *)hdr);
599 xfs_dir2_data_log_unused(tp, bp, prevdup);
600 if (!needscan) {
601 /*
602 * Has to be the case that entries 0 and 1 are
603 * dfp and dfp2 (don't know which is which), and
604 * entry 2 is empty.
605 * Remove entry 1 first then entry 0.
606 */
607 ASSERT(dfp && dfp2);
608 if (dfp == &hdr->bestfree[1]) {
609 dfp = &hdr->bestfree[0];
610 ASSERT(dfp2 == dfp);
611 dfp2 = &hdr->bestfree[1];
612 }
613 xfs_dir2_data_freeremove(hdr, dfp2, needlogp);
614 xfs_dir2_data_freeremove(hdr, dfp, needlogp);
615 /*
616 * Now insert the new entry.
617 */
618 dfp = xfs_dir2_data_freeinsert(hdr, prevdup, needlogp);
619 ASSERT(dfp == &hdr->bestfree[0]);
620 ASSERT(dfp->length == prevdup->length);
621 ASSERT(!dfp[1].length);
622 ASSERT(!dfp[2].length);
623 }
624 }
625 /*
626 * The entry before us is free, merge with it.
627 */
628 else if (prevdup) {
629 dfp = xfs_dir2_data_freefind(hdr, prevdup);
630 be16_add_cpu(&prevdup->length, len);
631 *xfs_dir2_data_unused_tag_p(prevdup) =
632 cpu_to_be16((char *)prevdup - (char *)hdr);
633 xfs_dir2_data_log_unused(tp, bp, prevdup);
634 /*
635 * If the previous entry was in the table, the new entry
636 * is longer, so it will be in the table too. Remove
637 * the old one and add the new one.
638 */
639 if (dfp) {
640 xfs_dir2_data_freeremove(hdr, dfp, needlogp);
641 xfs_dir2_data_freeinsert(hdr, prevdup, needlogp);
642 }
643 /*
644 * Otherwise we need a scan if the new entry is big enough.
645 */
646 else {
647 needscan = be16_to_cpu(prevdup->length) >
648 be16_to_cpu(hdr->bestfree[2].length);
649 }
650 }
651 /*
652 * The following entry is free, merge with it.
653 */
654 else if (postdup) {
655 dfp = xfs_dir2_data_freefind(hdr, postdup);
656 newdup = (xfs_dir2_data_unused_t *)((char *)hdr + offset);
657 newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
658 newdup->length = cpu_to_be16(len + be16_to_cpu(postdup->length));
659 *xfs_dir2_data_unused_tag_p(newdup) =
660 cpu_to_be16((char *)newdup - (char *)hdr);
661 xfs_dir2_data_log_unused(tp, bp, newdup);
662 /*
663 * If the following entry was in the table, the new entry
664 * is longer, so it will be in the table too. Remove
665 * the old one and add the new one.
666 */
667 if (dfp) {
668 xfs_dir2_data_freeremove(hdr, dfp, needlogp);
669 xfs_dir2_data_freeinsert(hdr, newdup, needlogp);
670 }
671 /*
672 * Otherwise we need a scan if the new entry is big enough.
673 */
674 else {
675 needscan = be16_to_cpu(newdup->length) >
676 be16_to_cpu(hdr->bestfree[2].length);
677 }
678 }
679 /*
680 * Neither neighbor is free. Make a new entry.
681 */
682 else {
683 newdup = (xfs_dir2_data_unused_t *)((char *)hdr + offset);
684 newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
685 newdup->length = cpu_to_be16(len);
686 *xfs_dir2_data_unused_tag_p(newdup) =
687 cpu_to_be16((char *)newdup - (char *)hdr);
688 xfs_dir2_data_log_unused(tp, bp, newdup);
689 xfs_dir2_data_freeinsert(hdr, newdup, needlogp);
690 }
691 *needscanp = needscan;
692}
693
694/*
695 * Take a byte range out of an existing unused space and make it un-free.
696 */
697void
698xfs_dir2_data_use_free(
699 xfs_trans_t *tp, /* transaction pointer */
700 xfs_dabuf_t *bp, /* data block buffer */
701 xfs_dir2_data_unused_t *dup, /* unused entry */
702 xfs_dir2_data_aoff_t offset, /* starting offset to use */
703 xfs_dir2_data_aoff_t len, /* length to use */
704 int *needlogp, /* out: need to log header */
705 int *needscanp) /* out: need regen bestfree */
706{
707 xfs_dir2_data_hdr_t *hdr; /* data block header */
708 xfs_dir2_data_free_t *dfp; /* bestfree pointer */
709 int matchback; /* matches end of freespace */
710 int matchfront; /* matches start of freespace */
711 int needscan; /* need to regen bestfree */
712 xfs_dir2_data_unused_t *newdup; /* new unused entry */
713 xfs_dir2_data_unused_t *newdup2; /* another new unused entry */
714 int oldlen; /* old unused entry's length */
715
716 hdr = bp->data;
717 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
718 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC));
719 ASSERT(be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG);
720 ASSERT(offset >= (char *)dup - (char *)hdr);
721 ASSERT(offset + len <= (char *)dup + be16_to_cpu(dup->length) - (char *)hdr);
722 ASSERT((char *)dup - (char *)hdr == be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)));
723 /*
724 * Look up the entry in the bestfree table.
725 */
726 dfp = xfs_dir2_data_freefind(hdr, dup);
727 oldlen = be16_to_cpu(dup->length);
728 ASSERT(dfp || oldlen <= be16_to_cpu(hdr->bestfree[2].length));
729 /*
730 * Check for alignment with front and back of the entry.
731 */
732 matchfront = (char *)dup - (char *)hdr == offset;
733 matchback = (char *)dup + oldlen - (char *)hdr == offset + len;
734 ASSERT(*needscanp == 0);
735 needscan = 0;
736 /*
737 * If we matched it exactly we just need to get rid of it from
738 * the bestfree table.
739 */
740 if (matchfront && matchback) {
741 if (dfp) {
742 needscan = (hdr->bestfree[2].offset != 0);
743 if (!needscan)
744 xfs_dir2_data_freeremove(hdr, dfp, needlogp);
745 }
746 }
747 /*
748 * We match the first part of the entry.
749 * Make a new entry with the remaining freespace.
750 */
751 else if (matchfront) {
752 newdup = (xfs_dir2_data_unused_t *)((char *)hdr + offset + len);
753 newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
754 newdup->length = cpu_to_be16(oldlen - len);
755 *xfs_dir2_data_unused_tag_p(newdup) =
756 cpu_to_be16((char *)newdup - (char *)hdr);
757 xfs_dir2_data_log_unused(tp, bp, newdup);
758 /*
759 * If it was in the table, remove it and add the new one.
760 */
761 if (dfp) {
762 xfs_dir2_data_freeremove(hdr, dfp, needlogp);
763 dfp = xfs_dir2_data_freeinsert(hdr, newdup, needlogp);
764 ASSERT(dfp != NULL);
765 ASSERT(dfp->length == newdup->length);
766 ASSERT(be16_to_cpu(dfp->offset) == (char *)newdup - (char *)hdr);
767 /*
768 * If we got inserted at the last slot,
769 * that means we don't know if there was a better
770 * choice for the last slot, or not. Rescan.
771 */
772 needscan = dfp == &hdr->bestfree[2];
773 }
774 }
775 /*
776 * We match the last part of the entry.
777 * Trim the allocated space off the tail of the entry.
778 */
779 else if (matchback) {
780 newdup = dup;
781 newdup->length = cpu_to_be16(((char *)hdr + offset) - (char *)newdup);
782 *xfs_dir2_data_unused_tag_p(newdup) =
783 cpu_to_be16((char *)newdup - (char *)hdr);
784 xfs_dir2_data_log_unused(tp, bp, newdup);
785 /*
786 * If it was in the table, remove it and add the new one.
787 */
788 if (dfp) {
789 xfs_dir2_data_freeremove(hdr, dfp, needlogp);
790 dfp = xfs_dir2_data_freeinsert(hdr, newdup, needlogp);
791 ASSERT(dfp != NULL);
792 ASSERT(dfp->length == newdup->length);
793 ASSERT(be16_to_cpu(dfp->offset) == (char *)newdup - (char *)hdr);
794 /*
795 * If we got inserted at the last slot,
796 * that means we don't know if there was a better
797 * choice for the last slot, or not. Rescan.
798 */
799 needscan = dfp == &hdr->bestfree[2];
800 }
801 }
802 /*
803 * Poking out the middle of an entry.
804 * Make two new entries.
805 */
806 else {
807 newdup = dup;
808 newdup->length = cpu_to_be16(((char *)hdr + offset) - (char *)newdup);
809 *xfs_dir2_data_unused_tag_p(newdup) =
810 cpu_to_be16((char *)newdup - (char *)hdr);
811 xfs_dir2_data_log_unused(tp, bp, newdup);
812 newdup2 = (xfs_dir2_data_unused_t *)((char *)hdr + offset + len);
813 newdup2->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
814 newdup2->length = cpu_to_be16(oldlen - len - be16_to_cpu(newdup->length));
815 *xfs_dir2_data_unused_tag_p(newdup2) =
816 cpu_to_be16((char *)newdup2 - (char *)hdr);
817 xfs_dir2_data_log_unused(tp, bp, newdup2);
818 /*
819 * If the old entry was in the table, we need to scan
820 * if the 3rd entry was valid, since these entries
821 * are smaller than the old one.
822 * If we don't need to scan that means there were 1 or 2
823 * entries in the table, and removing the old and adding
824 * the 2 new will work.
825 */
826 if (dfp) {
827 needscan = (hdr->bestfree[2].length != 0);
828 if (!needscan) {
829 xfs_dir2_data_freeremove(hdr, dfp, needlogp);
830 xfs_dir2_data_freeinsert(hdr, newdup, needlogp);
831 xfs_dir2_data_freeinsert(hdr, newdup2,
832 needlogp);
833 }
834 }
835 }
836 *needscanp = needscan;
837}