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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
[deliverable/linux.git] / fs / xfs / libxfs / xfs_dir2_data.c
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_mount.h"
25 #include "xfs_da_format.h"
26 #include "xfs_da_btree.h"
27 #include "xfs_inode.h"
28 #include "xfs_dir2.h"
29 #include "xfs_dir2_priv.h"
30 #include "xfs_error.h"
31 #include "xfs_trans.h"
32 #include "xfs_buf_item.h"
33 #include "xfs_cksum.h"
34
35 /*
36 * Check the consistency of the data block.
37 * The input can also be a block-format directory.
38 * Return 0 is the buffer is good, otherwise an error.
39 */
40 int
41 __xfs_dir3_data_check(
42 struct xfs_inode *dp, /* incore inode pointer */
43 struct xfs_buf *bp) /* data block's buffer */
44 {
45 xfs_dir2_dataptr_t addr; /* addr for leaf lookup */
46 xfs_dir2_data_free_t *bf; /* bestfree table */
47 xfs_dir2_block_tail_t *btp=NULL; /* block tail */
48 int count; /* count of entries found */
49 xfs_dir2_data_hdr_t *hdr; /* data block header */
50 xfs_dir2_data_entry_t *dep; /* data entry */
51 xfs_dir2_data_free_t *dfp; /* bestfree entry */
52 xfs_dir2_data_unused_t *dup; /* unused entry */
53 char *endp; /* end of useful data */
54 int freeseen; /* mask of bestfrees seen */
55 xfs_dahash_t hash; /* hash of current name */
56 int i; /* leaf index */
57 int lastfree; /* last entry was unused */
58 xfs_dir2_leaf_entry_t *lep=NULL; /* block leaf entries */
59 xfs_mount_t *mp; /* filesystem mount point */
60 char *p; /* current data position */
61 int stale; /* count of stale leaves */
62 struct xfs_name name;
63 const struct xfs_dir_ops *ops;
64 struct xfs_da_geometry *geo;
65
66 mp = bp->b_target->bt_mount;
67 geo = mp->m_dir_geo;
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(geo, 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(mp, 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 + geo->blksize;
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(mp, !bf[0].offset);
111 freeseen |= 1 << 0;
112 }
113 if (!bf[1].length) {
114 XFS_WANT_CORRUPTED_RETURN(mp, !bf[1].offset);
115 freeseen |= 1 << 1;
116 }
117 if (!bf[2].length) {
118 XFS_WANT_CORRUPTED_RETURN(mp, !bf[2].offset);
119 freeseen |= 1 << 2;
120 }
121
122 XFS_WANT_CORRUPTED_RETURN(mp, be16_to_cpu(bf[0].length) >=
123 be16_to_cpu(bf[1].length));
124 XFS_WANT_CORRUPTED_RETURN(mp, 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(mp, lastfree == 0);
138 XFS_WANT_CORRUPTED_RETURN(mp,
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(mp,
145 (freeseen & (1 << i)) == 0);
146 freeseen |= 1 << i;
147 } else {
148 XFS_WANT_CORRUPTED_RETURN(mp,
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(mp, dep->namelen != 0);
164 XFS_WANT_CORRUPTED_RETURN(mp,
165 !xfs_dir_ino_validate(mp, be64_to_cpu(dep->inumber)));
166 XFS_WANT_CORRUPTED_RETURN(mp,
167 be16_to_cpu(*ops->data_entry_tag_p(dep)) ==
168 (char *)dep - (char *)hdr);
169 XFS_WANT_CORRUPTED_RETURN(mp,
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(geo, geo->datablk,
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(mp,
187 i < be32_to_cpu(btp->count));
188 }
189 p += ops->data_entsize(dep->namelen);
190 }
191 /*
192 * Need to have seen all the entries and all the bestfree slots.
193 */
194 XFS_WANT_CORRUPTED_RETURN(mp, freeseen == 7);
195 if (hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
196 hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC)) {
197 for (i = stale = 0; i < be32_to_cpu(btp->count); i++) {
198 if (lep[i].address ==
199 cpu_to_be32(XFS_DIR2_NULL_DATAPTR))
200 stale++;
201 if (i > 0)
202 XFS_WANT_CORRUPTED_RETURN(mp,
203 be32_to_cpu(lep[i].hashval) >=
204 be32_to_cpu(lep[i - 1].hashval));
205 }
206 XFS_WANT_CORRUPTED_RETURN(mp, count ==
207 be32_to_cpu(btp->count) - be32_to_cpu(btp->stale));
208 XFS_WANT_CORRUPTED_RETURN(mp, stale == be32_to_cpu(btp->stale));
209 }
210 return 0;
211 }
212
213 static bool
214 xfs_dir3_data_verify(
215 struct xfs_buf *bp)
216 {
217 struct xfs_mount *mp = bp->b_target->bt_mount;
218 struct xfs_dir3_blk_hdr *hdr3 = bp->b_addr;
219
220 if (xfs_sb_version_hascrc(&mp->m_sb)) {
221 if (hdr3->magic != cpu_to_be32(XFS_DIR3_DATA_MAGIC))
222 return false;
223 if (!uuid_equal(&hdr3->uuid, &mp->m_sb.sb_uuid))
224 return false;
225 if (be64_to_cpu(hdr3->blkno) != bp->b_bn)
226 return false;
227 } else {
228 if (hdr3->magic != cpu_to_be32(XFS_DIR2_DATA_MAGIC))
229 return false;
230 }
231 if (__xfs_dir3_data_check(NULL, bp))
232 return false;
233 return true;
234 }
235
236 /*
237 * Readahead of the first block of the directory when it is opened is completely
238 * oblivious to the format of the directory. Hence we can either get a block
239 * format buffer or a data format buffer on readahead.
240 */
241 static void
242 xfs_dir3_data_reada_verify(
243 struct xfs_buf *bp)
244 {
245 struct xfs_dir2_data_hdr *hdr = bp->b_addr;
246
247 switch (hdr->magic) {
248 case cpu_to_be32(XFS_DIR2_BLOCK_MAGIC):
249 case cpu_to_be32(XFS_DIR3_BLOCK_MAGIC):
250 bp->b_ops = &xfs_dir3_block_buf_ops;
251 bp->b_ops->verify_read(bp);
252 return;
253 case cpu_to_be32(XFS_DIR2_DATA_MAGIC):
254 case cpu_to_be32(XFS_DIR3_DATA_MAGIC):
255 xfs_dir3_data_verify(bp);
256 return;
257 default:
258 xfs_buf_ioerror(bp, -EFSCORRUPTED);
259 xfs_verifier_error(bp);
260 break;
261 }
262 }
263
264 static void
265 xfs_dir3_data_read_verify(
266 struct xfs_buf *bp)
267 {
268 struct xfs_mount *mp = bp->b_target->bt_mount;
269
270 if (xfs_sb_version_hascrc(&mp->m_sb) &&
271 !xfs_buf_verify_cksum(bp, XFS_DIR3_DATA_CRC_OFF))
272 xfs_buf_ioerror(bp, -EFSBADCRC);
273 else if (!xfs_dir3_data_verify(bp))
274 xfs_buf_ioerror(bp, -EFSCORRUPTED);
275
276 if (bp->b_error)
277 xfs_verifier_error(bp);
278 }
279
280 static void
281 xfs_dir3_data_write_verify(
282 struct xfs_buf *bp)
283 {
284 struct xfs_mount *mp = bp->b_target->bt_mount;
285 struct xfs_buf_log_item *bip = bp->b_fspriv;
286 struct xfs_dir3_blk_hdr *hdr3 = bp->b_addr;
287
288 if (!xfs_dir3_data_verify(bp)) {
289 xfs_buf_ioerror(bp, -EFSCORRUPTED);
290 xfs_verifier_error(bp);
291 return;
292 }
293
294 if (!xfs_sb_version_hascrc(&mp->m_sb))
295 return;
296
297 if (bip)
298 hdr3->lsn = cpu_to_be64(bip->bli_item.li_lsn);
299
300 xfs_buf_update_cksum(bp, XFS_DIR3_DATA_CRC_OFF);
301 }
302
303 const struct xfs_buf_ops xfs_dir3_data_buf_ops = {
304 .verify_read = xfs_dir3_data_read_verify,
305 .verify_write = xfs_dir3_data_write_verify,
306 };
307
308 static const struct xfs_buf_ops xfs_dir3_data_reada_buf_ops = {
309 .verify_read = xfs_dir3_data_reada_verify,
310 .verify_write = xfs_dir3_data_write_verify,
311 };
312
313
314 int
315 xfs_dir3_data_read(
316 struct xfs_trans *tp,
317 struct xfs_inode *dp,
318 xfs_dablk_t bno,
319 xfs_daddr_t mapped_bno,
320 struct xfs_buf **bpp)
321 {
322 int err;
323
324 err = xfs_da_read_buf(tp, dp, bno, mapped_bno, bpp,
325 XFS_DATA_FORK, &xfs_dir3_data_buf_ops);
326 if (!err && tp)
327 xfs_trans_buf_set_type(tp, *bpp, XFS_BLFT_DIR_DATA_BUF);
328 return err;
329 }
330
331 int
332 xfs_dir3_data_readahead(
333 struct xfs_inode *dp,
334 xfs_dablk_t bno,
335 xfs_daddr_t mapped_bno)
336 {
337 return xfs_da_reada_buf(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 */
345 xfs_dir2_data_free_t *
346 xfs_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 */
416 xfs_dir2_data_free_t * /* entry inserted */
417 xfs_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 */
460 STATIC void
461 xfs_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 */
501 void
502 xfs_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 struct xfs_da_geometry *geo = dp->i_mount->m_dir_geo;
514
515 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
516 hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
517 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
518 hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
519
520 /*
521 * Start by clearing the table.
522 */
523 bf = dp->d_ops->data_bestfree_p(hdr);
524 memset(bf, 0, sizeof(*bf) * XFS_DIR2_DATA_FD_COUNT);
525 *loghead = 1;
526 /*
527 * Set up pointers.
528 */
529 p = (char *)dp->d_ops->data_entry_p(hdr);
530 if (hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
531 hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC)) {
532 btp = xfs_dir2_block_tail_p(geo, hdr);
533 endp = (char *)xfs_dir2_block_leaf_p(btp);
534 } else
535 endp = (char *)hdr + geo->blksize;
536 /*
537 * Loop over the block's entries.
538 */
539 while (p < endp) {
540 dup = (xfs_dir2_data_unused_t *)p;
541 /*
542 * If it's a free entry, insert it.
543 */
544 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
545 ASSERT((char *)dup - (char *)hdr ==
546 be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)));
547 xfs_dir2_data_freeinsert(hdr, bf, dup, loghead);
548 p += be16_to_cpu(dup->length);
549 }
550 /*
551 * For active entries, check their tags and skip them.
552 */
553 else {
554 dep = (xfs_dir2_data_entry_t *)p;
555 ASSERT((char *)dep - (char *)hdr ==
556 be16_to_cpu(*dp->d_ops->data_entry_tag_p(dep)));
557 p += dp->d_ops->data_entsize(dep->namelen);
558 }
559 }
560 }
561
562 /*
563 * Initialize a data block at the given block number in the directory.
564 * Give back the buffer for the created block.
565 */
566 int /* error */
567 xfs_dir3_data_init(
568 xfs_da_args_t *args, /* directory operation args */
569 xfs_dir2_db_t blkno, /* logical dir block number */
570 struct xfs_buf **bpp) /* output block buffer */
571 {
572 struct xfs_buf *bp; /* block buffer */
573 xfs_dir2_data_hdr_t *hdr; /* data block header */
574 xfs_inode_t *dp; /* incore directory inode */
575 xfs_dir2_data_unused_t *dup; /* unused entry pointer */
576 struct xfs_dir2_data_free *bf;
577 int error; /* error return value */
578 int i; /* bestfree index */
579 xfs_mount_t *mp; /* filesystem mount point */
580 xfs_trans_t *tp; /* transaction pointer */
581 int t; /* temp */
582
583 dp = args->dp;
584 mp = dp->i_mount;
585 tp = args->trans;
586 /*
587 * Get the buffer set up for the block.
588 */
589 error = xfs_da_get_buf(tp, dp, xfs_dir2_db_to_da(args->geo, blkno),
590 -1, &bp, XFS_DATA_FORK);
591 if (error)
592 return error;
593 bp->b_ops = &xfs_dir3_data_buf_ops;
594 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DIR_DATA_BUF);
595
596 /*
597 * Initialize the header.
598 */
599 hdr = bp->b_addr;
600 if (xfs_sb_version_hascrc(&mp->m_sb)) {
601 struct xfs_dir3_blk_hdr *hdr3 = bp->b_addr;
602
603 memset(hdr3, 0, sizeof(*hdr3));
604 hdr3->magic = cpu_to_be32(XFS_DIR3_DATA_MAGIC);
605 hdr3->blkno = cpu_to_be64(bp->b_bn);
606 hdr3->owner = cpu_to_be64(dp->i_ino);
607 uuid_copy(&hdr3->uuid, &mp->m_sb.sb_uuid);
608
609 } else
610 hdr->magic = cpu_to_be32(XFS_DIR2_DATA_MAGIC);
611
612 bf = dp->d_ops->data_bestfree_p(hdr);
613 bf[0].offset = cpu_to_be16(dp->d_ops->data_entry_offset);
614 for (i = 1; i < XFS_DIR2_DATA_FD_COUNT; i++) {
615 bf[i].length = 0;
616 bf[i].offset = 0;
617 }
618
619 /*
620 * Set up an unused entry for the block's body.
621 */
622 dup = dp->d_ops->data_unused_p(hdr);
623 dup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
624
625 t = args->geo->blksize - (uint)dp->d_ops->data_entry_offset;
626 bf[0].length = cpu_to_be16(t);
627 dup->length = cpu_to_be16(t);
628 *xfs_dir2_data_unused_tag_p(dup) = cpu_to_be16((char *)dup - (char *)hdr);
629 /*
630 * Log it and return it.
631 */
632 xfs_dir2_data_log_header(args, bp);
633 xfs_dir2_data_log_unused(args, bp, dup);
634 *bpp = bp;
635 return 0;
636 }
637
638 /*
639 * Log an active data entry from the block.
640 */
641 void
642 xfs_dir2_data_log_entry(
643 struct xfs_da_args *args,
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(args->trans, bp, (uint)((char *)dep - (char *)hdr),
655 (uint)((char *)(args->dp->d_ops->data_entry_tag_p(dep) + 1) -
656 (char *)hdr - 1));
657 }
658
659 /*
660 * Log a data block header.
661 */
662 void
663 xfs_dir2_data_log_header(
664 struct xfs_da_args *args,
665 struct xfs_buf *bp)
666 {
667 #ifdef DEBUG
668 struct xfs_dir2_data_hdr *hdr = bp->b_addr;
669
670 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
671 hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
672 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
673 hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
674 #endif
675
676 xfs_trans_log_buf(args->trans, bp, 0,
677 args->dp->d_ops->data_entry_offset - 1);
678 }
679
680 /*
681 * Log a data unused entry.
682 */
683 void
684 xfs_dir2_data_log_unused(
685 struct xfs_da_args *args,
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(args->trans, 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(args->trans, 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 */
715 void
716 xfs_dir2_data_make_free(
717 struct xfs_da_args *args,
718 struct xfs_buf *bp,
719 xfs_dir2_data_aoff_t offset, /* starting byte offset */
720 xfs_dir2_data_aoff_t len, /* length in bytes */
721 int *needlogp, /* out: log header */
722 int *needscanp) /* out: regen bestfree */
723 {
724 xfs_dir2_data_hdr_t *hdr; /* data block pointer */
725 xfs_dir2_data_free_t *dfp; /* bestfree pointer */
726 char *endptr; /* end of data area */
727 int needscan; /* need to regen bestfree */
728 xfs_dir2_data_unused_t *newdup; /* new unused entry */
729 xfs_dir2_data_unused_t *postdup; /* unused entry after us */
730 xfs_dir2_data_unused_t *prevdup; /* unused entry before us */
731 struct xfs_dir2_data_free *bf;
732
733 hdr = bp->b_addr;
734
735 /*
736 * Figure out where the end of the data area is.
737 */
738 if (hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
739 hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC))
740 endptr = (char *)hdr + args->geo->blksize;
741 else {
742 xfs_dir2_block_tail_t *btp; /* block tail */
743
744 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
745 hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
746 btp = xfs_dir2_block_tail_p(args->geo, hdr);
747 endptr = (char *)xfs_dir2_block_leaf_p(btp);
748 }
749 /*
750 * If this isn't the start of the block, then back up to
751 * the previous entry and see if it's free.
752 */
753 if (offset > args->dp->d_ops->data_entry_offset) {
754 __be16 *tagp; /* tag just before us */
755
756 tagp = (__be16 *)((char *)hdr + offset) - 1;
757 prevdup = (xfs_dir2_data_unused_t *)((char *)hdr + be16_to_cpu(*tagp));
758 if (be16_to_cpu(prevdup->freetag) != XFS_DIR2_DATA_FREE_TAG)
759 prevdup = NULL;
760 } else
761 prevdup = NULL;
762 /*
763 * If this isn't the end of the block, see if the entry after
764 * us is free.
765 */
766 if ((char *)hdr + offset + len < endptr) {
767 postdup =
768 (xfs_dir2_data_unused_t *)((char *)hdr + offset + len);
769 if (be16_to_cpu(postdup->freetag) != XFS_DIR2_DATA_FREE_TAG)
770 postdup = NULL;
771 } else
772 postdup = NULL;
773 ASSERT(*needscanp == 0);
774 needscan = 0;
775 /*
776 * Previous and following entries are both free,
777 * merge everything into a single free entry.
778 */
779 bf = args->dp->d_ops->data_bestfree_p(hdr);
780 if (prevdup && postdup) {
781 xfs_dir2_data_free_t *dfp2; /* another bestfree pointer */
782
783 /*
784 * See if prevdup and/or postdup are in bestfree table.
785 */
786 dfp = xfs_dir2_data_freefind(hdr, bf, prevdup);
787 dfp2 = xfs_dir2_data_freefind(hdr, bf, postdup);
788 /*
789 * We need a rescan unless there are exactly 2 free entries
790 * namely our two. Then we know what's happening, otherwise
791 * since the third bestfree is there, there might be more
792 * entries.
793 */
794 needscan = (bf[2].length != 0);
795 /*
796 * Fix up the new big freespace.
797 */
798 be16_add_cpu(&prevdup->length, len + be16_to_cpu(postdup->length));
799 *xfs_dir2_data_unused_tag_p(prevdup) =
800 cpu_to_be16((char *)prevdup - (char *)hdr);
801 xfs_dir2_data_log_unused(args, bp, prevdup);
802 if (!needscan) {
803 /*
804 * Has to be the case that entries 0 and 1 are
805 * dfp and dfp2 (don't know which is which), and
806 * entry 2 is empty.
807 * Remove entry 1 first then entry 0.
808 */
809 ASSERT(dfp && dfp2);
810 if (dfp == &bf[1]) {
811 dfp = &bf[0];
812 ASSERT(dfp2 == dfp);
813 dfp2 = &bf[1];
814 }
815 xfs_dir2_data_freeremove(hdr, bf, dfp2, needlogp);
816 xfs_dir2_data_freeremove(hdr, bf, dfp, needlogp);
817 /*
818 * Now insert the new entry.
819 */
820 dfp = xfs_dir2_data_freeinsert(hdr, bf, prevdup,
821 needlogp);
822 ASSERT(dfp == &bf[0]);
823 ASSERT(dfp->length == prevdup->length);
824 ASSERT(!dfp[1].length);
825 ASSERT(!dfp[2].length);
826 }
827 }
828 /*
829 * The entry before us is free, merge with it.
830 */
831 else if (prevdup) {
832 dfp = xfs_dir2_data_freefind(hdr, bf, prevdup);
833 be16_add_cpu(&prevdup->length, len);
834 *xfs_dir2_data_unused_tag_p(prevdup) =
835 cpu_to_be16((char *)prevdup - (char *)hdr);
836 xfs_dir2_data_log_unused(args, bp, prevdup);
837 /*
838 * If the previous entry was in the table, the new entry
839 * is longer, so it will be in the table too. Remove
840 * the old one and add the new one.
841 */
842 if (dfp) {
843 xfs_dir2_data_freeremove(hdr, bf, dfp, needlogp);
844 xfs_dir2_data_freeinsert(hdr, bf, prevdup, needlogp);
845 }
846 /*
847 * Otherwise we need a scan if the new entry is big enough.
848 */
849 else {
850 needscan = be16_to_cpu(prevdup->length) >
851 be16_to_cpu(bf[2].length);
852 }
853 }
854 /*
855 * The following entry is free, merge with it.
856 */
857 else if (postdup) {
858 dfp = xfs_dir2_data_freefind(hdr, bf, postdup);
859 newdup = (xfs_dir2_data_unused_t *)((char *)hdr + offset);
860 newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
861 newdup->length = cpu_to_be16(len + be16_to_cpu(postdup->length));
862 *xfs_dir2_data_unused_tag_p(newdup) =
863 cpu_to_be16((char *)newdup - (char *)hdr);
864 xfs_dir2_data_log_unused(args, bp, newdup);
865 /*
866 * If the following entry was in the table, the new entry
867 * is longer, so it will be in the table too. Remove
868 * the old one and add the new one.
869 */
870 if (dfp) {
871 xfs_dir2_data_freeremove(hdr, bf, dfp, needlogp);
872 xfs_dir2_data_freeinsert(hdr, bf, newdup, needlogp);
873 }
874 /*
875 * Otherwise we need a scan if the new entry is big enough.
876 */
877 else {
878 needscan = be16_to_cpu(newdup->length) >
879 be16_to_cpu(bf[2].length);
880 }
881 }
882 /*
883 * Neither neighbor is free. Make a new entry.
884 */
885 else {
886 newdup = (xfs_dir2_data_unused_t *)((char *)hdr + offset);
887 newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
888 newdup->length = cpu_to_be16(len);
889 *xfs_dir2_data_unused_tag_p(newdup) =
890 cpu_to_be16((char *)newdup - (char *)hdr);
891 xfs_dir2_data_log_unused(args, bp, newdup);
892 xfs_dir2_data_freeinsert(hdr, bf, newdup, needlogp);
893 }
894 *needscanp = needscan;
895 }
896
897 /*
898 * Take a byte range out of an existing unused space and make it un-free.
899 */
900 void
901 xfs_dir2_data_use_free(
902 struct xfs_da_args *args,
903 struct xfs_buf *bp,
904 xfs_dir2_data_unused_t *dup, /* unused entry */
905 xfs_dir2_data_aoff_t offset, /* starting offset to use */
906 xfs_dir2_data_aoff_t len, /* length to use */
907 int *needlogp, /* out: need to log header */
908 int *needscanp) /* out: need regen bestfree */
909 {
910 xfs_dir2_data_hdr_t *hdr; /* data block header */
911 xfs_dir2_data_free_t *dfp; /* bestfree pointer */
912 int matchback; /* matches end of freespace */
913 int matchfront; /* matches start of freespace */
914 int needscan; /* need to regen bestfree */
915 xfs_dir2_data_unused_t *newdup; /* new unused entry */
916 xfs_dir2_data_unused_t *newdup2; /* another new unused entry */
917 int oldlen; /* old unused entry's length */
918 struct xfs_dir2_data_free *bf;
919
920 hdr = bp->b_addr;
921 ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
922 hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
923 hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
924 hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
925 ASSERT(be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG);
926 ASSERT(offset >= (char *)dup - (char *)hdr);
927 ASSERT(offset + len <= (char *)dup + be16_to_cpu(dup->length) - (char *)hdr);
928 ASSERT((char *)dup - (char *)hdr == be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)));
929 /*
930 * Look up the entry in the bestfree table.
931 */
932 oldlen = be16_to_cpu(dup->length);
933 bf = args->dp->d_ops->data_bestfree_p(hdr);
934 dfp = xfs_dir2_data_freefind(hdr, bf, dup);
935 ASSERT(dfp || oldlen <= be16_to_cpu(bf[2].length));
936 /*
937 * Check for alignment with front and back of the entry.
938 */
939 matchfront = (char *)dup - (char *)hdr == offset;
940 matchback = (char *)dup + oldlen - (char *)hdr == offset + len;
941 ASSERT(*needscanp == 0);
942 needscan = 0;
943 /*
944 * If we matched it exactly we just need to get rid of it from
945 * the bestfree table.
946 */
947 if (matchfront && matchback) {
948 if (dfp) {
949 needscan = (bf[2].offset != 0);
950 if (!needscan)
951 xfs_dir2_data_freeremove(hdr, bf, dfp,
952 needlogp);
953 }
954 }
955 /*
956 * We match the first part of the entry.
957 * Make a new entry with the remaining freespace.
958 */
959 else if (matchfront) {
960 newdup = (xfs_dir2_data_unused_t *)((char *)hdr + offset + len);
961 newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
962 newdup->length = cpu_to_be16(oldlen - len);
963 *xfs_dir2_data_unused_tag_p(newdup) =
964 cpu_to_be16((char *)newdup - (char *)hdr);
965 xfs_dir2_data_log_unused(args, bp, newdup);
966 /*
967 * If it was in the table, remove it and add the new one.
968 */
969 if (dfp) {
970 xfs_dir2_data_freeremove(hdr, bf, dfp, needlogp);
971 dfp = xfs_dir2_data_freeinsert(hdr, bf, newdup,
972 needlogp);
973 ASSERT(dfp != NULL);
974 ASSERT(dfp->length == newdup->length);
975 ASSERT(be16_to_cpu(dfp->offset) == (char *)newdup - (char *)hdr);
976 /*
977 * If we got inserted at the last slot,
978 * that means we don't know if there was a better
979 * choice for the last slot, or not. Rescan.
980 */
981 needscan = dfp == &bf[2];
982 }
983 }
984 /*
985 * We match the last part of the entry.
986 * Trim the allocated space off the tail of the entry.
987 */
988 else if (matchback) {
989 newdup = dup;
990 newdup->length = cpu_to_be16(((char *)hdr + offset) - (char *)newdup);
991 *xfs_dir2_data_unused_tag_p(newdup) =
992 cpu_to_be16((char *)newdup - (char *)hdr);
993 xfs_dir2_data_log_unused(args, bp, newdup);
994 /*
995 * If it was in the table, remove it and add the new one.
996 */
997 if (dfp) {
998 xfs_dir2_data_freeremove(hdr, bf, dfp, needlogp);
999 dfp = xfs_dir2_data_freeinsert(hdr, bf, newdup,
1000 needlogp);
1001 ASSERT(dfp != NULL);
1002 ASSERT(dfp->length == newdup->length);
1003 ASSERT(be16_to_cpu(dfp->offset) == (char *)newdup - (char *)hdr);
1004 /*
1005 * If we got inserted at the last slot,
1006 * that means we don't know if there was a better
1007 * choice for the last slot, or not. Rescan.
1008 */
1009 needscan = dfp == &bf[2];
1010 }
1011 }
1012 /*
1013 * Poking out the middle of an entry.
1014 * Make two new entries.
1015 */
1016 else {
1017 newdup = dup;
1018 newdup->length = cpu_to_be16(((char *)hdr + offset) - (char *)newdup);
1019 *xfs_dir2_data_unused_tag_p(newdup) =
1020 cpu_to_be16((char *)newdup - (char *)hdr);
1021 xfs_dir2_data_log_unused(args, bp, newdup);
1022 newdup2 = (xfs_dir2_data_unused_t *)((char *)hdr + offset + len);
1023 newdup2->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
1024 newdup2->length = cpu_to_be16(oldlen - len - be16_to_cpu(newdup->length));
1025 *xfs_dir2_data_unused_tag_p(newdup2) =
1026 cpu_to_be16((char *)newdup2 - (char *)hdr);
1027 xfs_dir2_data_log_unused(args, bp, newdup2);
1028 /*
1029 * If the old entry was in the table, we need to scan
1030 * if the 3rd entry was valid, since these entries
1031 * are smaller than the old one.
1032 * If we don't need to scan that means there were 1 or 2
1033 * entries in the table, and removing the old and adding
1034 * the 2 new will work.
1035 */
1036 if (dfp) {
1037 needscan = (bf[2].length != 0);
1038 if (!needscan) {
1039 xfs_dir2_data_freeremove(hdr, bf, dfp,
1040 needlogp);
1041 xfs_dir2_data_freeinsert(hdr, bf, newdup,
1042 needlogp);
1043 xfs_dir2_data_freeinsert(hdr, bf, newdup2,
1044 needlogp);
1045 }
1046 }
1047 }
1048 *needscanp = needscan;
1049 }
Linux kernel - Deliverables
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