?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
ALSA: seq: Fix missing NULL check at remove_events ioctl
[linux/fpc-iii.git] / fs / xfs / xfs_dir2_data.c
blobc2930238005c6605c1e69e4dc455b9ed7267f3da
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_types.h"
22 #include "xfs_log.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 #include "xfs_buf_item.h"
35 #include "xfs_cksum.h"
36
37 STATIC xfs_dir2_data_free_t *
38 xfs_dir2_data_freefind(xfs_dir2_data_hdr_t *hdr, xfs_dir2_data_unused_t *dup);
39
40 /*
41 * Check the consistency of the data block.
42 * The input can also be a block-format directory.
43 * Return 0 is the buffer is good, otherwise an error.
44 */
45 int
46 __xfs_dir3_data_check(
47 struct xfs_inode *dp, /* incore inode pointer */
48 struct xfs_buf *bp) /* data block's buffer */
49 {
50 xfs_dir2_dataptr_t addr; /* addr for leaf lookup */
51 xfs_dir2_data_free_t *bf; /* bestfree table */
52 xfs_dir2_block_tail_t *btp=NULL; /* block tail */
53 int count; /* count of entries found */
54 xfs_dir2_data_hdr_t *hdr; /* data block header */
55 xfs_dir2_data_entry_t *dep; /* data entry */
56 xfs_dir2_data_free_t *dfp; /* bestfree entry */
57 xfs_dir2_data_unused_t *dup; /* unused entry */
58 char *endp; /* end of useful data */
59 int freeseen; /* mask of bestfrees seen */
60 xfs_dahash_t hash; /* hash of current name */
61 int i; /* leaf index */
62 int lastfree; /* last entry was unused */
63 xfs_dir2_leaf_entry_t *lep=NULL; /* block leaf entries */
64 xfs_mount_t *mp; /* filesystem mount point */
65 char *p; /* current data position */
66 int stale; /* count of stale leaves */
67 struct xfs_name name;
68
69 mp = bp->b_target->bt_mount;
70 hdr = bp->b_addr;
71 bf = xfs_dir3_data_bestfree_p(hdr);
72 p = (char *)xfs_dir3_data_entry_p(hdr);
73
74 switch (hdr->magic) {
75 case cpu_to_be32(XFS_DIR3_BLOCK_MAGIC):
76 case cpu_to_be32(XFS_DIR2_BLOCK_MAGIC):
77 btp = xfs_dir2_block_tail_p(mp, hdr);
78 lep = xfs_dir2_block_leaf_p(btp);
79 endp = (char *)lep;
80 break;
81 case cpu_to_be32(XFS_DIR3_DATA_MAGIC):
82 case cpu_to_be32(XFS_DIR2_DATA_MAGIC):
83 endp = (char *)hdr + mp->m_dirblksize;
84 break;
85 default:
86 XFS_ERROR_REPORT("Bad Magic", XFS_ERRLEVEL_LOW, mp);
87 return EFSCORRUPTED;
88 }
89
90 count = lastfree = freeseen = 0;
91 /*
92 * Account for zero bestfree entries.
93 */
94 if (!bf[0].length) {
95 XFS_WANT_CORRUPTED_RETURN(!bf[0].offset);
96 freeseen |= 1 << 0;
97 }
98 if (!bf[1].length) {
99 XFS_WANT_CORRUPTED_RETURN(!bf[1].offset);
100 freeseen |= 1 << 1;
101 }
102 if (!bf[2].length) {
103 XFS_WANT_CORRUPTED_RETURN(!bf[2].offset);
104 freeseen |= 1 << 2;
105 }
106
107 XFS_WANT_CORRUPTED_RETURN(be16_to_cpu(bf[0].length) >=
108 be16_to_cpu(bf[1].length));
109 XFS_WANT_CORRUPTED_RETURN(be16_to_cpu(bf[1].length) >=
110 be16_to_cpu(bf[2].length));
111 /*
112 * Loop over the data/unused entries.
113 */
114 while (p < endp) {
115 dup = (xfs_dir2_data_unused_t *)p;
116 /*
117 * If it's unused, look for the space in the bestfree table.
118 * If we find it, account for that, else make sure it
119 * doesn't need to be there.
120 */
121 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
122 XFS_WANT_CORRUPTED_RETURN(lastfree == 0);
123 XFS_WANT_CORRUPTED_RETURN(
124 be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)) ==
125 (char *)dup - (char *)hdr);
126 dfp = xfs_dir2_data_freefind(hdr, dup);
127 if (dfp) {
128 i = (int)(dfp - bf);
129 XFS_WANT_CORRUPTED_RETURN(
130 (freeseen & (1 << i)) == 0);
131 freeseen |= 1 << i;
132 } else {
133 XFS_WANT_CORRUPTED_RETURN(
134 be16_to_cpu(dup->length) <=
135 be16_to_cpu(bf[2].length));
136 }
137 p += be16_to_cpu(dup->length);
138 lastfree = 1;
139 continue;
140 }
141 /*
142 * It's a real entry. Validate the fields.
143 * If this is a block directory then make sure it's
144 * in the leaf section of the block.
145 * The linear search is crude but this is DEBUG code.
146 */
147 dep = (xfs_dir2_data_entry_t *)p;
148 XFS_WANT_CORRUPTED_RETURN(dep->namelen != 0);
149 XFS_WANT_CORRUPTED_RETURN(
150 !xfs_dir_ino_validate(mp, be64_to_cpu(dep->inumber)));
151 XFS_WANT_CORRUPTED_RETURN(
152 be16_to_cpu(*xfs_dir2_data_entry_tag_p(dep)) ==
153 (char *)dep - (char *)hdr);
154 count++;
155 lastfree = 0;
156 if (hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
157 hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC)) {
158 addr = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk,
159 (xfs_dir2_data_aoff_t)
160 ((char *)dep - (char *)hdr));
161 name.name = dep->name;
162 name.len = dep->namelen;
163 hash = mp->m_dirnameops->hashname(&name);
164 for (i = 0; i < be32_to_cpu(btp->count); i++) {
165 if (be32_to_cpu(lep[i].address) == addr &&
166 be32_to_cpu(lep[i].hashval) == hash)
167 break;
168 }
169 XFS_WANT_CORRUPTED_RETURN(i < be32_to_cpu(btp->count));
170 }
171 p += xfs_dir2_data_entsize(dep->namelen);
172 }
173 /*
174 * Need to have seen all the entries and all the bestfree slots.
175 */
176 XFS_WANT_CORRUPTED_RETURN(freeseen == 7);
177 if (hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
178 hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC)) {
179 for (i = stale = 0; i < be32_to_cpu(btp->count); i++) {
180 if (lep[i].address ==
181 cpu_to_be32(XFS_DIR2_NULL_DATAPTR))
182 stale++;
183 if (i > 0)
184 XFS_WANT_CORRUPTED_RETURN(
185 be32_to_cpu(lep[i].hashval) >=
186 be32_to_cpu(lep[i - 1].hashval));
187 }
188 XFS_WANT_CORRUPTED_RETURN(count ==
189 be32_to_cpu(btp->count) - be32_to_cpu(btp->stale));
190 XFS_WANT_CORRUPTED_RETURN(stale == be32_to_cpu(btp->stale));
191 }
192 return 0;
193 }
194
195 static bool
196 xfs_dir3_data_verify(
197 struct xfs_buf *bp)
198 {
199 struct xfs_mount *mp = bp->b_target->bt_mount;
200 struct xfs_dir3_blk_hdr *hdr3 = bp->b_addr;
201
202 if (xfs_sb_version_hascrc(&mp->m_sb)) {
203 if (hdr3->magic != cpu_to_be32(XFS_DIR3_DATA_MAGIC))
204 return false;
205 if (!uuid_equal(&hdr3->uuid, &mp->m_sb.sb_uuid))
206 return false;
207 if (be64_to_cpu(hdr3->blkno) != bp->b_bn)
208 return false;
209 } else {
210 if (hdr3->magic != cpu_to_be32(XFS_DIR2_DATA_MAGIC))
211 return false;
212 }
213 if (__xfs_dir3_data_check(NULL, bp))
214 return false;
215 return true;
216 }
217
218 /*
219 * Readahead of the first block of the directory when it is opened is completely
220 * oblivious to the format of the directory. Hence we can either get a block
221 * format buffer or a data format buffer on readahead.
222 */
223 static void
224 xfs_dir3_data_reada_verify(
225 struct xfs_buf *bp)
226 {
227 struct xfs_mount *mp = bp->b_target->bt_mount;
228 struct xfs_dir2_data_hdr *hdr = bp->b_addr;
229
230 switch (hdr->magic) {
231 case cpu_to_be32(XFS_DIR2_BLOCK_MAGIC):
232 case cpu_to_be32(XFS_DIR3_BLOCK_MAGIC):
233 bp->b_ops = &xfs_dir3_block_buf_ops;
234 bp->b_ops->verify_read(bp);
235 return;
236 case cpu_to_be32(XFS_DIR2_DATA_MAGIC):
237 case cpu_to_be32(XFS_DIR3_DATA_MAGIC):
238 xfs_dir3_data_verify(bp);
239 return;
240 default:
241 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, hdr);
242 xfs_buf_ioerror(bp, EFSCORRUPTED);
243 break;
244 }
245 }
246
247 static void
248 xfs_dir3_data_read_verify(
249 struct xfs_buf *bp)
250 {
251 struct xfs_mount *mp = bp->b_target->bt_mount;
252
253 if ((xfs_sb_version_hascrc(&mp->m_sb) &&
254 !xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
255 XFS_DIR3_DATA_CRC_OFF)) ||
256 !xfs_dir3_data_verify(bp)) {
257 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
258 xfs_buf_ioerror(bp, EFSCORRUPTED);
259 }
260 }
261
262 static void
263 xfs_dir3_data_write_verify(
264 struct xfs_buf *bp)
265 {
266 struct xfs_mount *mp = bp->b_target->bt_mount;
267 struct xfs_buf_log_item *bip = bp->b_fspriv;
268 struct xfs_dir3_blk_hdr *hdr3 = bp->b_addr;
269
270 if (!xfs_dir3_data_verify(bp)) {
271 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
272 xfs_buf_ioerror(bp, EFSCORRUPTED);
273 return;
274 }
275
276 if (!xfs_sb_version_hascrc(&mp->m_sb))
277 return;
278
279 if (bip)
280 hdr3->lsn = cpu_to_be64(bip->bli_item.li_lsn);
281
282 xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length), XFS_DIR3_DATA_CRC_OFF);
283 }
284
285 const struct xfs_buf_ops xfs_dir3_data_buf_ops = {
286 .verify_read = xfs_dir3_data_read_verify,
287 .verify_write = xfs_dir3_data_write_verify,
288 };
289
290 static const struct xfs_buf_ops xfs_dir3_data_reada_buf_ops = {
291 .verify_read = xfs_dir3_data_reada_verify,
292 .verify_write = xfs_dir3_data_write_verify,
293 };
294
295
296 int
297 xfs_dir3_data_read(
298 struct xfs_trans *tp,
299 struct xfs_inode *dp,
300 xfs_dablk_t bno,
301 xfs_daddr_t mapped_bno,
302 struct xfs_buf **bpp)
303 {
304 int err;
305
306 err = xfs_da_read_buf(tp, dp, bno, mapped_bno, bpp,
307 XFS_DATA_FORK, &xfs_dir3_data_buf_ops);
308 if (!err && tp)
309 xfs_trans_buf_set_type(tp, *bpp, XFS_BLFT_DIR_DATA_BUF);
310 return err;
311 }
312
313 int
314 xfs_dir3_data_readahead(
315 struct xfs_trans *tp,
316 struct xfs_inode *dp,
317 xfs_dablk_t bno,
318 xfs_daddr_t mapped_bno)
319 {
320 return xfs_da_reada_buf(tp, dp, bno, mapped_bno,
321 XFS_DATA_FORK, &xfs_dir3_data_reada_buf_ops);
322 }
323
324 /*
325 * Given a data block and an unused entry from that block,
326 * return the bestfree entry if any that corresponds to it.
327 */
328 STATIC xfs_dir2_data_free_t *
329 xfs_dir2_data_freefind(
330 xfs_dir2_data_hdr_t *hdr, /* data block */
331 xfs_dir2_data_unused_t *dup) /* data unused entry */
332 {
333 xfs_dir2_data_free_t *dfp; /* bestfree entry */
334 xfs_dir2_data_aoff_t off; /* offset value needed */
335 struct xfs_dir2_data_free *bf;
336 #if defined(DEBUG) && defined(__KERNEL__)
337 int matched; /* matched the value */
338 int seenzero; /* saw a 0 bestfree entry */
339 #endif
340
341 off = (xfs_dir2_data_aoff_t)((char *)dup - (char *)hdr);
342 bf = xfs_dir3_data_bestfree_p(hdr);
343
344 #if defined(DEBUG) && defined(__KERNEL__)
345 /*
346 * Validate some consistency in the bestfree table.
347 * Check order, non-overlapping entries, and if we find the
348 * one we're looking for it has to be exact.
349 */
350 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
351 hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
352 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
353 hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
354 for (dfp = &bf[0], seenzero = matched = 0;
355 dfp < &bf[XFS_DIR2_DATA_FD_COUNT];
356 dfp++) {
357 if (!dfp->offset) {
358 ASSERT(!dfp->length);
359 seenzero = 1;
360 continue;
361 }
362 ASSERT(seenzero == 0);
363 if (be16_to_cpu(dfp->offset) == off) {
364 matched = 1;
365 ASSERT(dfp->length == dup->length);
366 } else if (off < be16_to_cpu(dfp->offset))
367 ASSERT(off + be16_to_cpu(dup->length) <= be16_to_cpu(dfp->offset));
368 else
369 ASSERT(be16_to_cpu(dfp->offset) + be16_to_cpu(dfp->length) <= off);
370 ASSERT(matched || be16_to_cpu(dfp->length) >= be16_to_cpu(dup->length));
371 if (dfp > &bf[0])
372 ASSERT(be16_to_cpu(dfp[-1].length) >= be16_to_cpu(dfp[0].length));
373 }
374 #endif
375 /*
376 * If this is smaller than the smallest bestfree entry,
377 * it can't be there since they're sorted.
378 */
379 if (be16_to_cpu(dup->length) <
380 be16_to_cpu(bf[XFS_DIR2_DATA_FD_COUNT - 1].length))
381 return NULL;
382 /*
383 * Look at the three bestfree entries for our guy.
384 */
385 for (dfp = &bf[0]; dfp < &bf[XFS_DIR2_DATA_FD_COUNT]; dfp++) {
386 if (!dfp->offset)
387 return NULL;
388 if (be16_to_cpu(dfp->offset) == off)
389 return dfp;
390 }
391 /*
392 * Didn't find it. This only happens if there are duplicate lengths.
393 */
394 return NULL;
395 }
396
397 /*
398 * Insert an unused-space entry into the bestfree table.
399 */
400 xfs_dir2_data_free_t * /* entry inserted */
401 xfs_dir2_data_freeinsert(
402 xfs_dir2_data_hdr_t *hdr, /* data block pointer */
403 xfs_dir2_data_unused_t *dup, /* unused space */
404 int *loghead) /* log the data header (out) */
405 {
406 xfs_dir2_data_free_t *dfp; /* bestfree table pointer */
407 xfs_dir2_data_free_t new; /* new bestfree entry */
408
409 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
410 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
411 hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
412 hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
413
414 dfp = xfs_dir3_data_bestfree_p(hdr);
415 new.length = dup->length;
416 new.offset = cpu_to_be16((char *)dup - (char *)hdr);
417
418 /*
419 * Insert at position 0, 1, or 2; or not at all.
420 */
421 if (be16_to_cpu(new.length) > be16_to_cpu(dfp[0].length)) {
422 dfp[2] = dfp[1];
423 dfp[1] = dfp[0];
424 dfp[0] = new;
425 *loghead = 1;
426 return &dfp[0];
427 }
428 if (be16_to_cpu(new.length) > be16_to_cpu(dfp[1].length)) {
429 dfp[2] = dfp[1];
430 dfp[1] = new;
431 *loghead = 1;
432 return &dfp[1];
433 }
434 if (be16_to_cpu(new.length) > be16_to_cpu(dfp[2].length)) {
435 dfp[2] = new;
436 *loghead = 1;
437 return &dfp[2];
438 }
439 return NULL;
440 }
441
442 /*
443 * Remove a bestfree entry from the table.
444 */
445 STATIC void
446 xfs_dir2_data_freeremove(
447 xfs_dir2_data_hdr_t *hdr, /* data block header */
448 xfs_dir2_data_free_t *dfp, /* bestfree entry pointer */
449 int *loghead) /* out: log data header */
450 {
451 struct xfs_dir2_data_free *bf;
452
453 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
454 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
455 hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
456 hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
457
458 /*
459 * It's the first entry, slide the next 2 up.
460 */
461 bf = xfs_dir3_data_bestfree_p(hdr);
462 if (dfp == &bf[0]) {
463 bf[0] = bf[1];
464 bf[1] = bf[2];
465 }
466 /*
467 * It's the second entry, slide the 3rd entry up.
468 */
469 else if (dfp == &bf[1])
470 bf[1] = bf[2];
471 /*
472 * Must be the last entry.
473 */
474 else
475 ASSERT(dfp == &bf[2]);
476 /*
477 * Clear the 3rd entry, must be zero now.
478 */
479 bf[2].length = 0;
480 bf[2].offset = 0;
481 *loghead = 1;
482 }
483
484 /*
485 * Given a data block, reconstruct its bestfree map.
486 */
487 void
488 xfs_dir2_data_freescan(
489 xfs_mount_t *mp, /* filesystem mount point */
490 xfs_dir2_data_hdr_t *hdr, /* data block header */
491 int *loghead) /* out: log data header */
492 {
493 xfs_dir2_block_tail_t *btp; /* block tail */
494 xfs_dir2_data_entry_t *dep; /* active data entry */
495 xfs_dir2_data_unused_t *dup; /* unused data entry */
496 struct xfs_dir2_data_free *bf;
497 char *endp; /* end of block's data */
498 char *p; /* current entry pointer */
499
500 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
501 hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
502 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
503 hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
504
505 /*
506 * Start by clearing the table.
507 */
508 bf = xfs_dir3_data_bestfree_p(hdr);
509 memset(bf, 0, sizeof(*bf) * XFS_DIR2_DATA_FD_COUNT);
510 *loghead = 1;
511 /*
512 * Set up pointers.
513 */
514 p = (char *)xfs_dir3_data_entry_p(hdr);
515 if (hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
516 hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC)) {
517 btp = xfs_dir2_block_tail_p(mp, hdr);
518 endp = (char *)xfs_dir2_block_leaf_p(btp);
519 } else
520 endp = (char *)hdr + mp->m_dirblksize;
521 /*
522 * Loop over the block's entries.
523 */
524 while (p < endp) {
525 dup = (xfs_dir2_data_unused_t *)p;
526 /*
527 * If it's a free entry, insert it.
528 */
529 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
530 ASSERT((char *)dup - (char *)hdr ==
531 be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)));
532 xfs_dir2_data_freeinsert(hdr, dup, loghead);
533 p += be16_to_cpu(dup->length);
534 }
535 /*
536 * For active entries, check their tags and skip them.
537 */
538 else {
539 dep = (xfs_dir2_data_entry_t *)p;
540 ASSERT((char *)dep - (char *)hdr ==
541 be16_to_cpu(*xfs_dir2_data_entry_tag_p(dep)));
542 p += xfs_dir2_data_entsize(dep->namelen);
543 }
544 }
545 }
546
547 /*
548 * Initialize a data block at the given block number in the directory.
549 * Give back the buffer for the created block.
550 */
551 int /* error */
552 xfs_dir3_data_init(
553 xfs_da_args_t *args, /* directory operation args */
554 xfs_dir2_db_t blkno, /* logical dir block number */
555 struct xfs_buf **bpp) /* output block buffer */
556 {
557 struct xfs_buf *bp; /* block buffer */
558 xfs_dir2_data_hdr_t *hdr; /* data block header */
559 xfs_inode_t *dp; /* incore directory inode */
560 xfs_dir2_data_unused_t *dup; /* unused entry pointer */
561 struct xfs_dir2_data_free *bf;
562 int error; /* error return value */
563 int i; /* bestfree index */
564 xfs_mount_t *mp; /* filesystem mount point */
565 xfs_trans_t *tp; /* transaction pointer */
566 int t; /* temp */
567
568 dp = args->dp;
569 mp = dp->i_mount;
570 tp = args->trans;
571 /*
572 * Get the buffer set up for the block.
573 */
574 error = xfs_da_get_buf(tp, dp, xfs_dir2_db_to_da(mp, blkno), -1, &bp,
575 XFS_DATA_FORK);
576 if (error)
577 return error;
578 bp->b_ops = &xfs_dir3_data_buf_ops;
579 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DIR_DATA_BUF);
580
581 /*
582 * Initialize the header.
583 */
584 hdr = bp->b_addr;
585 if (xfs_sb_version_hascrc(&mp->m_sb)) {
586 struct xfs_dir3_blk_hdr *hdr3 = bp->b_addr;
587
588 memset(hdr3, 0, sizeof(*hdr3));
589 hdr3->magic = cpu_to_be32(XFS_DIR3_DATA_MAGIC);
590 hdr3->blkno = cpu_to_be64(bp->b_bn);
591 hdr3->owner = cpu_to_be64(dp->i_ino);
592 uuid_copy(&hdr3->uuid, &mp->m_sb.sb_uuid);
593
594 } else
595 hdr->magic = cpu_to_be32(XFS_DIR2_DATA_MAGIC);
596
597 bf = xfs_dir3_data_bestfree_p(hdr);
598 bf[0].offset = cpu_to_be16(xfs_dir3_data_entry_offset(hdr));
599 for (i = 1; i < XFS_DIR2_DATA_FD_COUNT; i++) {
600 bf[i].length = 0;
601 bf[i].offset = 0;
602 }
603
604 /*
605 * Set up an unused entry for the block's body.
606 */
607 dup = xfs_dir3_data_unused_p(hdr);
608 dup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
609
610 t = mp->m_dirblksize - (uint)xfs_dir3_data_entry_offset(hdr);
611 bf[0].length = cpu_to_be16(t);
612 dup->length = cpu_to_be16(t);
613 *xfs_dir2_data_unused_tag_p(dup) = cpu_to_be16((char *)dup - (char *)hdr);
614 /*
615 * Log it and return it.
616 */
617 xfs_dir2_data_log_header(tp, bp);
618 xfs_dir2_data_log_unused(tp, bp, dup);
619 *bpp = bp;
620 return 0;
621 }
622
623 /*
624 * Log an active data entry from the block.
625 */
626 void
627 xfs_dir2_data_log_entry(
628 struct xfs_trans *tp,
629 struct xfs_buf *bp,
630 xfs_dir2_data_entry_t *dep) /* data entry pointer */
631 {
632 xfs_dir2_data_hdr_t *hdr = bp->b_addr;
633
634 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
635 hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
636 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
637 hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
638
639 xfs_trans_log_buf(tp, bp, (uint)((char *)dep - (char *)hdr),
640 (uint)((char *)(xfs_dir2_data_entry_tag_p(dep) + 1) -
641 (char *)hdr - 1));
642 }
643
644 /*
645 * Log a data block header.
646 */
647 void
648 xfs_dir2_data_log_header(
649 struct xfs_trans *tp,
650 struct xfs_buf *bp)
651 {
652 xfs_dir2_data_hdr_t *hdr = bp->b_addr;
653
654 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
655 hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
656 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
657 hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
658
659 xfs_trans_log_buf(tp, bp, 0, xfs_dir3_data_entry_offset(hdr) - 1);
660 }
661
662 /*
663 * Log a data unused entry.
664 */
665 void
666 xfs_dir2_data_log_unused(
667 struct xfs_trans *tp,
668 struct xfs_buf *bp,
669 xfs_dir2_data_unused_t *dup) /* data unused pointer */
670 {
671 xfs_dir2_data_hdr_t *hdr = bp->b_addr;
672
673 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
674 hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
675 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
676 hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
677
678 /*
679 * Log the first part of the unused entry.
680 */
681 xfs_trans_log_buf(tp, bp, (uint)((char *)dup - (char *)hdr),
682 (uint)((char *)&dup->length + sizeof(dup->length) -
683 1 - (char *)hdr));
684 /*
685 * Log the end (tag) of the unused entry.
686 */
687 xfs_trans_log_buf(tp, bp,
688 (uint)((char *)xfs_dir2_data_unused_tag_p(dup) - (char *)hdr),
689 (uint)((char *)xfs_dir2_data_unused_tag_p(dup) - (char *)hdr +
690 sizeof(xfs_dir2_data_off_t) - 1));
691 }
692
693 /*
694 * Make a byte range in the data block unused.
695 * Its current contents are unimportant.
696 */
697 void
698 xfs_dir2_data_make_free(
699 struct xfs_trans *tp,
700 struct xfs_buf *bp,
701 xfs_dir2_data_aoff_t offset, /* starting byte offset */
702 xfs_dir2_data_aoff_t len, /* length in bytes */
703 int *needlogp, /* out: log header */
704 int *needscanp) /* out: regen bestfree */
705 {
706 xfs_dir2_data_hdr_t *hdr; /* data block pointer */
707 xfs_dir2_data_free_t *dfp; /* bestfree pointer */
708 char *endptr; /* end of data area */
709 xfs_mount_t *mp; /* filesystem mount point */
710 int needscan; /* need to regen bestfree */
711 xfs_dir2_data_unused_t *newdup; /* new unused entry */
712 xfs_dir2_data_unused_t *postdup; /* unused entry after us */
713 xfs_dir2_data_unused_t *prevdup; /* unused entry before us */
714 struct xfs_dir2_data_free *bf;
715
716 mp = tp->t_mountp;
717 hdr = bp->b_addr;
718
719 /*
720 * Figure out where the end of the data area is.
721 */
722 if (hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
723 hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC))
724 endptr = (char *)hdr + mp->m_dirblksize;
725 else {
726 xfs_dir2_block_tail_t *btp; /* block tail */
727
728 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
729 hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
730 btp = xfs_dir2_block_tail_p(mp, hdr);
731 endptr = (char *)xfs_dir2_block_leaf_p(btp);
732 }
733 /*
734 * If this isn't the start of the block, then back up to
735 * the previous entry and see if it's free.
736 */
737 if (offset > xfs_dir3_data_entry_offset(hdr)) {
738 __be16 *tagp; /* tag just before us */
739
740 tagp = (__be16 *)((char *)hdr + offset) - 1;
741 prevdup = (xfs_dir2_data_unused_t *)((char *)hdr + be16_to_cpu(*tagp));
742 if (be16_to_cpu(prevdup->freetag) != XFS_DIR2_DATA_FREE_TAG)
743 prevdup = NULL;
744 } else
745 prevdup = NULL;
746 /*
747 * If this isn't the end of the block, see if the entry after
748 * us is free.
749 */
750 if ((char *)hdr + offset + len < endptr) {
751 postdup =
752 (xfs_dir2_data_unused_t *)((char *)hdr + offset + len);
753 if (be16_to_cpu(postdup->freetag) != XFS_DIR2_DATA_FREE_TAG)
754 postdup = NULL;
755 } else
756 postdup = NULL;
757 ASSERT(*needscanp == 0);
758 needscan = 0;
759 /*
760 * Previous and following entries are both free,
761 * merge everything into a single free entry.
762 */
763 bf = xfs_dir3_data_bestfree_p(hdr);
764 if (prevdup && postdup) {
765 xfs_dir2_data_free_t *dfp2; /* another bestfree pointer */
766
767 /*
768 * See if prevdup and/or postdup are in bestfree table.
769 */
770 dfp = xfs_dir2_data_freefind(hdr, prevdup);
771 dfp2 = xfs_dir2_data_freefind(hdr, postdup);
772 /*
773 * We need a rescan unless there are exactly 2 free entries
774 * namely our two. Then we know what's happening, otherwise
775 * since the third bestfree is there, there might be more
776 * entries.
777 */
778 needscan = (bf[2].length != 0);
779 /*
780 * Fix up the new big freespace.
781 */
782 be16_add_cpu(&prevdup->length, len + be16_to_cpu(postdup->length));
783 *xfs_dir2_data_unused_tag_p(prevdup) =
784 cpu_to_be16((char *)prevdup - (char *)hdr);
785 xfs_dir2_data_log_unused(tp, bp, prevdup);
786 if (!needscan) {
787 /*
788 * Has to be the case that entries 0 and 1 are
789 * dfp and dfp2 (don't know which is which), and
790 * entry 2 is empty.
791 * Remove entry 1 first then entry 0.
792 */
793 ASSERT(dfp && dfp2);
794 if (dfp == &bf[1]) {
795 dfp = &bf[0];
796 ASSERT(dfp2 == dfp);
797 dfp2 = &bf[1];
798 }
799 xfs_dir2_data_freeremove(hdr, dfp2, needlogp);
800 xfs_dir2_data_freeremove(hdr, dfp, needlogp);
801 /*
802 * Now insert the new entry.
803 */
804 dfp = xfs_dir2_data_freeinsert(hdr, prevdup, needlogp);
805 ASSERT(dfp == &bf[0]);
806 ASSERT(dfp->length == prevdup->length);
807 ASSERT(!dfp[1].length);
808 ASSERT(!dfp[2].length);
809 }
810 }
811 /*
812 * The entry before us is free, merge with it.
813 */
814 else if (prevdup) {
815 dfp = xfs_dir2_data_freefind(hdr, prevdup);
816 be16_add_cpu(&prevdup->length, len);
817 *xfs_dir2_data_unused_tag_p(prevdup) =
818 cpu_to_be16((char *)prevdup - (char *)hdr);
819 xfs_dir2_data_log_unused(tp, bp, prevdup);
820 /*
821 * If the previous entry was in the table, the new entry
822 * is longer, so it will be in the table too. Remove
823 * the old one and add the new one.
824 */
825 if (dfp) {
826 xfs_dir2_data_freeremove(hdr, dfp, needlogp);
827 xfs_dir2_data_freeinsert(hdr, prevdup, needlogp);
828 }
829 /*
830 * Otherwise we need a scan if the new entry is big enough.
831 */
832 else {
833 needscan = be16_to_cpu(prevdup->length) >
834 be16_to_cpu(bf[2].length);
835 }
836 }
837 /*
838 * The following entry is free, merge with it.
839 */
840 else if (postdup) {
841 dfp = xfs_dir2_data_freefind(hdr, postdup);
842 newdup = (xfs_dir2_data_unused_t *)((char *)hdr + offset);
843 newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
844 newdup->length = cpu_to_be16(len + be16_to_cpu(postdup->length));
845 *xfs_dir2_data_unused_tag_p(newdup) =
846 cpu_to_be16((char *)newdup - (char *)hdr);
847 xfs_dir2_data_log_unused(tp, bp, newdup);
848 /*
849 * If the following entry was in the table, the new entry
850 * is longer, so it will be in the table too. Remove
851 * the old one and add the new one.
852 */
853 if (dfp) {
854 xfs_dir2_data_freeremove(hdr, dfp, needlogp);
855 xfs_dir2_data_freeinsert(hdr, newdup, needlogp);
856 }
857 /*
858 * Otherwise we need a scan if the new entry is big enough.
859 */
860 else {
861 needscan = be16_to_cpu(newdup->length) >
862 be16_to_cpu(bf[2].length);
863 }
864 }
865 /*
866 * Neither neighbor is free. Make a new entry.
867 */
868 else {
869 newdup = (xfs_dir2_data_unused_t *)((char *)hdr + offset);
870 newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
871 newdup->length = cpu_to_be16(len);
872 *xfs_dir2_data_unused_tag_p(newdup) =
873 cpu_to_be16((char *)newdup - (char *)hdr);
874 xfs_dir2_data_log_unused(tp, bp, newdup);
875 xfs_dir2_data_freeinsert(hdr, newdup, needlogp);
876 }
877 *needscanp = needscan;
878 }
879
880 /*
881 * Take a byte range out of an existing unused space and make it un-free.
882 */
883 void
884 xfs_dir2_data_use_free(
885 struct xfs_trans *tp,
886 struct xfs_buf *bp,
887 xfs_dir2_data_unused_t *dup, /* unused entry */
888 xfs_dir2_data_aoff_t offset, /* starting offset to use */
889 xfs_dir2_data_aoff_t len, /* length to use */
890 int *needlogp, /* out: need to log header */
891 int *needscanp) /* out: need regen bestfree */
892 {
893 xfs_dir2_data_hdr_t *hdr; /* data block header */
894 xfs_dir2_data_free_t *dfp; /* bestfree pointer */
895 int matchback; /* matches end of freespace */
896 int matchfront; /* matches start of freespace */
897 int needscan; /* need to regen bestfree */
898 xfs_dir2_data_unused_t *newdup; /* new unused entry */
899 xfs_dir2_data_unused_t *newdup2; /* another new unused entry */
900 int oldlen; /* old unused entry's length */
901 struct xfs_dir2_data_free *bf;
902
903 hdr = bp->b_addr;
904 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
905 hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
906 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
907 hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
908 ASSERT(be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG);
909 ASSERT(offset >= (char *)dup - (char *)hdr);
910 ASSERT(offset + len <= (char *)dup + be16_to_cpu(dup->length) - (char *)hdr);
911 ASSERT((char *)dup - (char *)hdr == be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)));
912 /*
913 * Look up the entry in the bestfree table.
914 */
915 dfp = xfs_dir2_data_freefind(hdr, dup);
916 oldlen = be16_to_cpu(dup->length);
917 bf = xfs_dir3_data_bestfree_p(hdr);
918 ASSERT(dfp || oldlen <= be16_to_cpu(bf[2].length));
919 /*
920 * Check for alignment with front and back of the entry.
921 */
922 matchfront = (char *)dup - (char *)hdr == offset;
923 matchback = (char *)dup + oldlen - (char *)hdr == offset + len;
924 ASSERT(*needscanp == 0);
925 needscan = 0;
926 /*
927 * If we matched it exactly we just need to get rid of it from
928 * the bestfree table.
929 */
930 if (matchfront && matchback) {
931 if (dfp) {
932 needscan = (bf[2].offset != 0);
933 if (!needscan)
934 xfs_dir2_data_freeremove(hdr, dfp, needlogp);
935 }
936 }
937 /*
938 * We match the first part of the entry.
939 * Make a new entry with the remaining freespace.
940 */
941 else if (matchfront) {
942 newdup = (xfs_dir2_data_unused_t *)((char *)hdr + offset + len);
943 newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
944 newdup->length = cpu_to_be16(oldlen - len);
945 *xfs_dir2_data_unused_tag_p(newdup) =
946 cpu_to_be16((char *)newdup - (char *)hdr);
947 xfs_dir2_data_log_unused(tp, bp, newdup);
948 /*
949 * If it was in the table, remove it and add the new one.
950 */
951 if (dfp) {
952 xfs_dir2_data_freeremove(hdr, dfp, needlogp);
953 dfp = xfs_dir2_data_freeinsert(hdr, newdup, needlogp);
954 ASSERT(dfp != NULL);
955 ASSERT(dfp->length == newdup->length);
956 ASSERT(be16_to_cpu(dfp->offset) == (char *)newdup - (char *)hdr);
957 /*
958 * If we got inserted at the last slot,
959 * that means we don't know if there was a better
960 * choice for the last slot, or not. Rescan.
961 */
962 needscan = dfp == &bf[2];
963 }
964 }
965 /*
966 * We match the last part of the entry.
967 * Trim the allocated space off the tail of the entry.
968 */
969 else if (matchback) {
970 newdup = dup;
971 newdup->length = cpu_to_be16(((char *)hdr + offset) - (char *)newdup);
972 *xfs_dir2_data_unused_tag_p(newdup) =
973 cpu_to_be16((char *)newdup - (char *)hdr);
974 xfs_dir2_data_log_unused(tp, bp, newdup);
975 /*
976 * If it was in the table, remove it and add the new one.
977 */
978 if (dfp) {
979 xfs_dir2_data_freeremove(hdr, dfp, needlogp);
980 dfp = xfs_dir2_data_freeinsert(hdr, newdup, needlogp);
981 ASSERT(dfp != NULL);
982 ASSERT(dfp->length == newdup->length);
983 ASSERT(be16_to_cpu(dfp->offset) == (char *)newdup - (char *)hdr);
984 /*
985 * If we got inserted at the last slot,
986 * that means we don't know if there was a better
987 * choice for the last slot, or not. Rescan.
988 */
989 needscan = dfp == &bf[2];
990 }
991 }
992 /*
993 * Poking out the middle of an entry.
994 * Make two new entries.
995 */
996 else {
997 newdup = dup;
998 newdup->length = cpu_to_be16(((char *)hdr + offset) - (char *)newdup);
999 *xfs_dir2_data_unused_tag_p(newdup) =
1000 cpu_to_be16((char *)newdup - (char *)hdr);
1001 xfs_dir2_data_log_unused(tp, bp, newdup);
1002 newdup2 = (xfs_dir2_data_unused_t *)((char *)hdr + offset + len);
1003 newdup2->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
1004 newdup2->length = cpu_to_be16(oldlen - len - be16_to_cpu(newdup->length));
1005 *xfs_dir2_data_unused_tag_p(newdup2) =
1006 cpu_to_be16((char *)newdup2 - (char *)hdr);
1007 xfs_dir2_data_log_unused(tp, bp, newdup2);
1008 /*
1009 * If the old entry was in the table, we need to scan
1010 * if the 3rd entry was valid, since these entries
1011 * are smaller than the old one.
1012 * If we don't need to scan that means there were 1 or 2
1013 * entries in the table, and removing the old and adding
1014 * the 2 new will work.
1015 */
1016 if (dfp) {
1017 needscan = (bf[2].length != 0);
1018 if (!needscan) {
1019 xfs_dir2_data_freeremove(hdr, dfp, needlogp);
1020 xfs_dir2_data_freeinsert(hdr, newdup, needlogp);
1021 xfs_dir2_data_freeinsert(hdr, newdup2,
1022 needlogp);
1023 }
1024 }
1025 }
1026 *needscanp = needscan;
1027 }
Linux with added FPC-III support