1 /*
2 * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18 #include "xfs.h"
19 #include "xfs_fs.h"
20 #include "xfs_types.h"
21 #include "xfs_log.h"
22 #include "xfs_inum.h"
23 #include "xfs_trans.h"
24 #include "xfs_sb.h"
25 #include "xfs_dir.h"
26 #include "xfs_dir2.h"
27 #include "xfs_dmapi.h"
28 #include "xfs_mount.h"
29 #include "xfs_da_btree.h"
30 #include "xfs_bmap_btree.h"
31 #include "xfs_dir_sf.h"
32 #include "xfs_dir2_sf.h"
33 #include "xfs_attr_sf.h"
34 #include "xfs_dinode.h"
35 #include "xfs_inode.h"
36 #include "xfs_dir_leaf.h"
37 #include "xfs_dir2_data.h"
38 #include "xfs_dir2_leaf.h"
39 #include "xfs_dir2_block.h"
40 #include "xfs_error.h"
41
42 #ifdef DEBUG
43 /*
44 * Check the consistency of the data block.
45 * The input can also be a block-format directory.
46 * Pop an assert if we find anything bad.
47 */
48 void
xfs_dir2_data_check(xfs_inode_t * dp,xfs_dabuf_t * bp)49 xfs_dir2_data_check(
50 xfs_inode_t *dp, /* incore inode pointer */
51 xfs_dabuf_t *bp) /* data block's buffer */
52 {
53 xfs_dir2_dataptr_t addr; /* addr for leaf lookup */
54 xfs_dir2_data_free_t *bf; /* bestfree table */
55 xfs_dir2_block_tail_t *btp=NULL; /* block tail */
56 int count; /* count of entries found */
57 xfs_dir2_data_t *d; /* data block pointer */
58 xfs_dir2_data_entry_t *dep; /* data entry */
59 xfs_dir2_data_free_t *dfp; /* bestfree entry */
60 xfs_dir2_data_unused_t *dup; /* unused entry */
61 char *endp; /* end of useful data */
62 int freeseen; /* mask of bestfrees seen */
63 xfs_dahash_t hash; /* hash of current name */
64 int i; /* leaf index */
65 int lastfree; /* last entry was unused */
66 xfs_dir2_leaf_entry_t *lep=NULL; /* block leaf entries */
67 xfs_mount_t *mp; /* filesystem mount point */
68 char *p; /* current data position */
69 int stale; /* count of stale leaves */
70
71 mp = dp->i_mount;
72 d = bp->data;
73 ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
74 be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
75 bf = d->hdr.bestfree;
76 p = (char *)d->u;
77 if (be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC) {
78 btp = XFS_DIR2_BLOCK_TAIL_P(mp, (xfs_dir2_block_t *)d);
79 lep = XFS_DIR2_BLOCK_LEAF_P(btp);
80 endp = (char *)lep;
81 } else
82 endp = (char *)d + mp->m_dirblksize;
83 count = lastfree = freeseen = 0;
84 /*
85 * Account for zero bestfree entries.
86 */
87 if (!bf[0].length) {
88 ASSERT(!bf[0].offset);
89 freeseen |= 1 << 0;
90 }
91 if (!bf[1].length) {
92 ASSERT(!bf[1].offset);
93 freeseen |= 1 << 1;
94 }
95 if (!bf[2].length) {
96 ASSERT(!bf[2].offset);
97 freeseen |= 1 << 2;
98 }
99 ASSERT(be16_to_cpu(bf[0].length) >= be16_to_cpu(bf[1].length));
100 ASSERT(be16_to_cpu(bf[1].length) >= be16_to_cpu(bf[2].length));
101 /*
102 * Loop over the data/unused entries.
103 */
104 while (p < endp) {
105 dup = (xfs_dir2_data_unused_t *)p;
106 /*
107 * If it's unused, look for the space in the bestfree table.
108 * If we find it, account for that, else make sure it
109 * doesn't need to be there.
110 */
111 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
112 ASSERT(lastfree == 0);
113 ASSERT(be16_to_cpu(*XFS_DIR2_DATA_UNUSED_TAG_P(dup)) ==
114 (char *)dup - (char *)d);
115 dfp = xfs_dir2_data_freefind(d, dup);
116 if (dfp) {
117 i = (int)(dfp - bf);
118 ASSERT((freeseen & (1 << i)) == 0);
119 freeseen |= 1 << i;
120 } else {
121 ASSERT(be16_to_cpu(dup->length) <=
122 be16_to_cpu(bf[2].length));
123 }
124 p += be16_to_cpu(dup->length);
125 lastfree = 1;
126 continue;
127 }
128 /*
129 * It's a real entry. Validate the fields.
130 * If this is a block directory then make sure it's
131 * in the leaf section of the block.
132 * The linear search is crude but this is DEBUG code.
133 */
134 dep = (xfs_dir2_data_entry_t *)p;
135 ASSERT(dep->namelen != 0);
136 ASSERT(xfs_dir_ino_validate(mp, INT_GET(dep->inumber, ARCH_CONVERT)) == 0);
137 ASSERT(be16_to_cpu(*XFS_DIR2_DATA_ENTRY_TAG_P(dep)) ==
138 (char *)dep - (char *)d);
139 count++;
140 lastfree = 0;
141 if (be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC) {
142 addr = XFS_DIR2_DB_OFF_TO_DATAPTR(mp, mp->m_dirdatablk,
143 (xfs_dir2_data_aoff_t)
144 ((char *)dep - (char *)d));
145 hash = xfs_da_hashname((char *)dep->name, dep->namelen);
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 (be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC) {
160 for (i = stale = 0; i < be32_to_cpu(btp->count); i++) {
161 if (be32_to_cpu(lep[i].address) == XFS_DIR2_NULL_DATAPTR)
162 stale++;
163 if (i > 0)
164 ASSERT(be32_to_cpu(lep[i].hashval) >= be32_to_cpu(lep[i - 1].hashval));
165 }
166 ASSERT(count == be32_to_cpu(btp->count) - be32_to_cpu(btp->stale));
167 ASSERT(stale == be32_to_cpu(btp->stale));
168 }
169 }
170 #endif
171
172 /*
173 * Given a data block and an unused entry from that block,
174 * return the bestfree entry if any that corresponds to it.
175 */
176 xfs_dir2_data_free_t *
xfs_dir2_data_freefind(xfs_dir2_data_t * d,xfs_dir2_data_unused_t * dup)177 xfs_dir2_data_freefind(
178 xfs_dir2_data_t *d, /* data block */
179 xfs_dir2_data_unused_t *dup) /* data unused entry */
180 {
181 xfs_dir2_data_free_t *dfp; /* bestfree entry */
182 xfs_dir2_data_aoff_t off; /* offset value needed */
183 #if defined(DEBUG) && defined(__KERNEL__)
184 int matched; /* matched the value */
185 int seenzero; /* saw a 0 bestfree entry */
186 #endif
187
188 off = (xfs_dir2_data_aoff_t)((char *)dup - (char *)d);
189 #if defined(DEBUG) && defined(__KERNEL__)
190 /*
191 * Validate some consistency in the bestfree table.
192 * Check order, non-overlapping entries, and if we find the
193 * one we're looking for it has to be exact.
194 */
195 ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
196 be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
197 for (dfp = &d->hdr.bestfree[0], seenzero = matched = 0;
198 dfp < &d->hdr.bestfree[XFS_DIR2_DATA_FD_COUNT];
199 dfp++) {
200 if (!dfp->offset) {
201 ASSERT(!dfp->length);
202 seenzero = 1;
203 continue;
204 }
205 ASSERT(seenzero == 0);
206 if (be16_to_cpu(dfp->offset) == off) {
207 matched = 1;
208 ASSERT(dfp->length == dup->length);
209 } else if (off < be16_to_cpu(dfp->offset))
210 ASSERT(off + be16_to_cpu(dup->length) <= be16_to_cpu(dfp->offset));
211 else
212 ASSERT(be16_to_cpu(dfp->offset) + be16_to_cpu(dfp->length) <= off);
213 ASSERT(matched || be16_to_cpu(dfp->length) >= be16_to_cpu(dup->length));
214 if (dfp > &d->hdr.bestfree[0])
215 ASSERT(be16_to_cpu(dfp[-1].length) >= be16_to_cpu(dfp[0].length));
216 }
217 #endif
218 /*
219 * If this is smaller than the smallest bestfree entry,
220 * it can't be there since they're sorted.
221 */
222 if (be16_to_cpu(dup->length) <
223 be16_to_cpu(d->hdr.bestfree[XFS_DIR2_DATA_FD_COUNT - 1].length))
224 return NULL;
225 /*
226 * Look at the three bestfree entries for our guy.
227 */
228 for (dfp = &d->hdr.bestfree[0];
229 dfp < &d->hdr.bestfree[XFS_DIR2_DATA_FD_COUNT];
230 dfp++) {
231 if (!dfp->offset)
232 return NULL;
233 if (be16_to_cpu(dfp->offset) == off)
234 return dfp;
235 }
236 /*
237 * Didn't find it. This only happens if there are duplicate lengths.
238 */
239 return NULL;
240 }
241
242 /*
243 * Insert an unused-space entry into the bestfree table.
244 */
245 xfs_dir2_data_free_t * /* entry inserted */
xfs_dir2_data_freeinsert(xfs_dir2_data_t * d,xfs_dir2_data_unused_t * dup,int * loghead)246 xfs_dir2_data_freeinsert(
247 xfs_dir2_data_t *d, /* data block pointer */
248 xfs_dir2_data_unused_t *dup, /* unused space */
249 int *loghead) /* log the data header (out) */
250 {
251 xfs_dir2_data_free_t *dfp; /* bestfree table pointer */
252 xfs_dir2_data_free_t new; /* new bestfree entry */
253
254 #ifdef __KERNEL__
255 ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
256 be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
257 #endif
258 dfp = d->hdr.bestfree;
259 new.length = dup->length;
260 new.offset = cpu_to_be16((char *)dup - (char *)d);
261 /*
262 * Insert at position 0, 1, or 2; or not at all.
263 */
264 if (be16_to_cpu(new.length) > be16_to_cpu(dfp[0].length)) {
265 dfp[2] = dfp[1];
266 dfp[1] = dfp[0];
267 dfp[0] = new;
268 *loghead = 1;
269 return &dfp[0];
270 }
271 if (be16_to_cpu(new.length) > be16_to_cpu(dfp[1].length)) {
272 dfp[2] = dfp[1];
273 dfp[1] = new;
274 *loghead = 1;
275 return &dfp[1];
276 }
277 if (be16_to_cpu(new.length) > be16_to_cpu(dfp[2].length)) {
278 dfp[2] = new;
279 *loghead = 1;
280 return &dfp[2];
281 }
282 return NULL;
283 }
284
285 /*
286 * Remove a bestfree entry from the table.
287 */
288 STATIC void
xfs_dir2_data_freeremove(xfs_dir2_data_t * d,xfs_dir2_data_free_t * dfp,int * loghead)289 xfs_dir2_data_freeremove(
290 xfs_dir2_data_t *d, /* data block pointer */
291 xfs_dir2_data_free_t *dfp, /* bestfree entry pointer */
292 int *loghead) /* out: log data header */
293 {
294 #ifdef __KERNEL__
295 ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
296 be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
297 #endif
298 /*
299 * It's the first entry, slide the next 2 up.
300 */
301 if (dfp == &d->hdr.bestfree[0]) {
302 d->hdr.bestfree[0] = d->hdr.bestfree[1];
303 d->hdr.bestfree[1] = d->hdr.bestfree[2];
304 }
305 /*
306 * It's the second entry, slide the 3rd entry up.
307 */
308 else if (dfp == &d->hdr.bestfree[1])
309 d->hdr.bestfree[1] = d->hdr.bestfree[2];
310 /*
311 * Must be the last entry.
312 */
313 else
314 ASSERT(dfp == &d->hdr.bestfree[2]);
315 /*
316 * Clear the 3rd entry, must be zero now.
317 */
318 d->hdr.bestfree[2].length = 0;
319 d->hdr.bestfree[2].offset = 0;
320 *loghead = 1;
321 }
322
323 /*
324 * Given a data block, reconstruct its bestfree map.
325 */
326 void
xfs_dir2_data_freescan(xfs_mount_t * mp,xfs_dir2_data_t * d,int * loghead,char * aendp)327 xfs_dir2_data_freescan(
328 xfs_mount_t *mp, /* filesystem mount point */
329 xfs_dir2_data_t *d, /* data block pointer */
330 int *loghead, /* out: log data header */
331 char *aendp) /* in: caller's endp */
332 {
333 xfs_dir2_block_tail_t *btp; /* block tail */
334 xfs_dir2_data_entry_t *dep; /* active data entry */
335 xfs_dir2_data_unused_t *dup; /* unused data entry */
336 char *endp; /* end of block's data */
337 char *p; /* current entry pointer */
338
339 #ifdef __KERNEL__
340 ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
341 be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
342 #endif
343 /*
344 * Start by clearing the table.
345 */
346 memset(d->hdr.bestfree, 0, sizeof(d->hdr.bestfree));
347 *loghead = 1;
348 /*
349 * Set up pointers.
350 */
351 p = (char *)d->u;
352 if (aendp)
353 endp = aendp;
354 else if (be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC) {
355 btp = XFS_DIR2_BLOCK_TAIL_P(mp, (xfs_dir2_block_t *)d);
356 endp = (char *)XFS_DIR2_BLOCK_LEAF_P(btp);
357 } else
358 endp = (char *)d + mp->m_dirblksize;
359 /*
360 * Loop over the block's entries.
361 */
362 while (p < endp) {
363 dup = (xfs_dir2_data_unused_t *)p;
364 /*
365 * If it's a free entry, insert it.
366 */
367 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
368 ASSERT((char *)dup - (char *)d ==
369 be16_to_cpu(*XFS_DIR2_DATA_UNUSED_TAG_P(dup)));
370 xfs_dir2_data_freeinsert(d, dup, loghead);
371 p += be16_to_cpu(dup->length);
372 }
373 /*
374 * For active entries, check their tags and skip them.
375 */
376 else {
377 dep = (xfs_dir2_data_entry_t *)p;
378 ASSERT((char *)dep - (char *)d ==
379 be16_to_cpu(*XFS_DIR2_DATA_ENTRY_TAG_P(dep)));
380 p += XFS_DIR2_DATA_ENTSIZE(dep->namelen);
381 }
382 }
383 }
384
385 /*
386 * Initialize a data block at the given block number in the directory.
387 * Give back the buffer for the created block.
388 */
389 int /* error */
xfs_dir2_data_init(xfs_da_args_t * args,xfs_dir2_db_t blkno,xfs_dabuf_t ** bpp)390 xfs_dir2_data_init(
391 xfs_da_args_t *args, /* directory operation args */
392 xfs_dir2_db_t blkno, /* logical dir block number */
393 xfs_dabuf_t **bpp) /* output block buffer */
394 {
395 xfs_dabuf_t *bp; /* block buffer */
396 xfs_dir2_data_t *d; /* pointer to block */
397 xfs_inode_t *dp; /* incore directory inode */
398 xfs_dir2_data_unused_t *dup; /* unused entry pointer */
399 int error; /* error return value */
400 int i; /* bestfree index */
401 xfs_mount_t *mp; /* filesystem mount point */
402 xfs_trans_t *tp; /* transaction pointer */
403 int t; /* temp */
404
405 dp = args->dp;
406 mp = dp->i_mount;
407 tp = args->trans;
408 /*
409 * Get the buffer set up for the block.
410 */
411 error = xfs_da_get_buf(tp, dp, XFS_DIR2_DB_TO_DA(mp, blkno), -1, &bp,
412 XFS_DATA_FORK);
413 if (error) {
414 return error;
415 }
416 ASSERT(bp != NULL);
417 /*
418 * Initialize the header.
419 */
420 d = bp->data;
421 d->hdr.magic = cpu_to_be32(XFS_DIR2_DATA_MAGIC);
422 d->hdr.bestfree[0].offset = cpu_to_be16(sizeof(d->hdr));
423 for (i = 1; i < XFS_DIR2_DATA_FD_COUNT; i++) {
424 d->hdr.bestfree[i].length = 0;
425 d->hdr.bestfree[i].offset = 0;
426 }
427 /*
428 * Set up an unused entry for the block's body.
429 */
430 dup = &d->u[0].unused;
431 dup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
432
433 t=mp->m_dirblksize - (uint)sizeof(d->hdr);
434 d->hdr.bestfree[0].length = cpu_to_be16(t);
435 dup->length = cpu_to_be16(t);
436 *XFS_DIR2_DATA_UNUSED_TAG_P(dup) = cpu_to_be16((char *)dup - (char *)d);
437 /*
438 * Log it and return it.
439 */
440 xfs_dir2_data_log_header(tp, bp);
441 xfs_dir2_data_log_unused(tp, bp, dup);
442 *bpp = bp;
443 return 0;
444 }
445
446 /*
447 * Log an active data entry from the block.
448 */
449 void
xfs_dir2_data_log_entry(xfs_trans_t * tp,xfs_dabuf_t * bp,xfs_dir2_data_entry_t * dep)450 xfs_dir2_data_log_entry(
451 xfs_trans_t *tp, /* transaction pointer */
452 xfs_dabuf_t *bp, /* block buffer */
453 xfs_dir2_data_entry_t *dep) /* data entry pointer */
454 {
455 xfs_dir2_data_t *d; /* data block pointer */
456
457 d = bp->data;
458 ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
459 be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
460 xfs_da_log_buf(tp, bp, (uint)((char *)dep - (char *)d),
461 (uint)((char *)(XFS_DIR2_DATA_ENTRY_TAG_P(dep) + 1) -
462 (char *)d - 1));
463 }
464
465 /*
466 * Log a data block header.
467 */
468 void
xfs_dir2_data_log_header(xfs_trans_t * tp,xfs_dabuf_t * bp)469 xfs_dir2_data_log_header(
470 xfs_trans_t *tp, /* transaction pointer */
471 xfs_dabuf_t *bp) /* block buffer */
472 {
473 xfs_dir2_data_t *d; /* data block pointer */
474
475 d = bp->data;
476 ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
477 be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
478 xfs_da_log_buf(tp, bp, (uint)((char *)&d->hdr - (char *)d),
479 (uint)(sizeof(d->hdr) - 1));
480 }
481
482 /*
483 * Log a data unused entry.
484 */
485 void
xfs_dir2_data_log_unused(xfs_trans_t * tp,xfs_dabuf_t * bp,xfs_dir2_data_unused_t * dup)486 xfs_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_t *d; /* data block pointer */
492
493 d = bp->data;
494 ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
495 be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
496 /*
497 * Log the first part of the unused entry.
498 */
499 xfs_da_log_buf(tp, bp, (uint)((char *)dup - (char *)d),
500 (uint)((char *)&dup->length + sizeof(dup->length) -
501 1 - (char *)d));
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 *)d),
507 (uint)((char *)XFS_DIR2_DATA_UNUSED_TAG_P(dup) - (char *)d +
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 */
515 void
xfs_dir2_data_make_free(xfs_trans_t * tp,xfs_dabuf_t * bp,xfs_dir2_data_aoff_t offset,xfs_dir2_data_aoff_t len,int * needlogp,int * needscanp)516 xfs_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_t *d; /* 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 d = bp->data;
535 /*
536 * Figure out where the end of the data area is.
537 */
538 if (be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC)
539 endptr = (char *)d + mp->m_dirblksize;
540 else {
541 xfs_dir2_block_tail_t *btp; /* block tail */
542
543 ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
544 btp = XFS_DIR2_BLOCK_TAIL_P(mp, (xfs_dir2_block_t *)d);
545 endptr = (char *)XFS_DIR2_BLOCK_LEAF_P(btp);
546 }
547 /*
548 * If this isn't the start of the block, then back up to
549 * the previous entry and see if it's free.
550 */
551 if (offset > sizeof(d->hdr)) {
552 __be16 *tagp; /* tag just before us */
553
554 tagp = (__be16 *)((char *)d + offset) - 1;
555 prevdup = (xfs_dir2_data_unused_t *)((char *)d + be16_to_cpu(*tagp));
556 if (be16_to_cpu(prevdup->freetag) != XFS_DIR2_DATA_FREE_TAG)
557 prevdup = NULL;
558 } else
559 prevdup = NULL;
560 /*
561 * If this isn't the end of the block, see if the entry after
562 * us is free.
563 */
564 if ((char *)d + offset + len < endptr) {
565 postdup =
566 (xfs_dir2_data_unused_t *)((char *)d + offset + len);
567 if (be16_to_cpu(postdup->freetag) != XFS_DIR2_DATA_FREE_TAG)
568 postdup = NULL;
569 } else
570 postdup = NULL;
571 ASSERT(*needscanp == 0);
572 needscan = 0;
573 /*
574 * Previous and following entries are both free,
575 * merge everything into a single free entry.
576 */
577 if (prevdup && postdup) {
578 xfs_dir2_data_free_t *dfp2; /* another bestfree pointer */
579
580 /*
581 * See if prevdup and/or postdup are in bestfree table.
582 */
583 dfp = xfs_dir2_data_freefind(d, prevdup);
584 dfp2 = xfs_dir2_data_freefind(d, postdup);
585 /*
586 * We need a rescan unless there are exactly 2 free entries
587 * namely our two. Then we know what's happening, otherwise
588 * since the third bestfree is there, there might be more
589 * entries.
590 */
591 needscan = (d->hdr.bestfree[2].length != 0);
592 /*
593 * Fix up the new big freespace.
594 */
595 be16_add(&prevdup->length, len + be16_to_cpu(postdup->length));
596 *XFS_DIR2_DATA_UNUSED_TAG_P(prevdup) =
597 cpu_to_be16((char *)prevdup - (char *)d);
598 xfs_dir2_data_log_unused(tp, bp, prevdup);
599 if (!needscan) {
600 /*
601 * Has to be the case that entries 0 and 1 are
602 * dfp and dfp2 (don't know which is which), and
603 * entry 2 is empty.
604 * Remove entry 1 first then entry 0.
605 */
606 ASSERT(dfp && dfp2);
607 if (dfp == &d->hdr.bestfree[1]) {
608 dfp = &d->hdr.bestfree[0];
609 ASSERT(dfp2 == dfp);
610 dfp2 = &d->hdr.bestfree[1];
611 }
612 xfs_dir2_data_freeremove(d, dfp2, needlogp);
613 xfs_dir2_data_freeremove(d, dfp, needlogp);
614 /*
615 * Now insert the new entry.
616 */
617 dfp = xfs_dir2_data_freeinsert(d, prevdup, needlogp);
618 ASSERT(dfp == &d->hdr.bestfree[0]);
619 ASSERT(dfp->length == prevdup->length);
620 ASSERT(!dfp[1].length);
621 ASSERT(!dfp[2].length);
622 }
623 }
624 /*
625 * The entry before us is free, merge with it.
626 */
627 else if (prevdup) {
628 dfp = xfs_dir2_data_freefind(d, prevdup);
629 be16_add(&prevdup->length, len);
630 *XFS_DIR2_DATA_UNUSED_TAG_P(prevdup) =
631 cpu_to_be16((char *)prevdup - (char *)d);
632 xfs_dir2_data_log_unused(tp, bp, prevdup);
633 /*
634 * If the previous entry was in the table, the new entry
635 * is longer, so it will be in the table too. Remove
636 * the old one and add the new one.
637 */
638 if (dfp) {
639 xfs_dir2_data_freeremove(d, dfp, needlogp);
640 (void)xfs_dir2_data_freeinsert(d, prevdup, needlogp);
641 }
642 /*
643 * Otherwise we need a scan if the new entry is big enough.
644 */
645 else {
646 needscan = be16_to_cpu(prevdup->length) >
647 be16_to_cpu(d->hdr.bestfree[2].length);
648 }
649 }
650 /*
651 * The following entry is free, merge with it.
652 */
653 else if (postdup) {
654 dfp = xfs_dir2_data_freefind(d, postdup);
655 newdup = (xfs_dir2_data_unused_t *)((char *)d + offset);
656 newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
657 newdup->length = cpu_to_be16(len + be16_to_cpu(postdup->length));
658 *XFS_DIR2_DATA_UNUSED_TAG_P(newdup) =
659 cpu_to_be16((char *)newdup - (char *)d);
660 xfs_dir2_data_log_unused(tp, bp, newdup);
661 /*
662 * If the following entry was in the table, the new entry
663 * is longer, so it will be in the table too. Remove
664 * the old one and add the new one.
665 */
666 if (dfp) {
667 xfs_dir2_data_freeremove(d, dfp, needlogp);
668 (void)xfs_dir2_data_freeinsert(d, newdup, needlogp);
669 }
670 /*
671 * Otherwise we need a scan if the new entry is big enough.
672 */
673 else {
674 needscan = be16_to_cpu(newdup->length) >
675 be16_to_cpu(d->hdr.bestfree[2].length);
676 }
677 }
678 /*
679 * Neither neighbor is free. Make a new entry.
680 */
681 else {
682 newdup = (xfs_dir2_data_unused_t *)((char *)d + offset);
683 newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
684 newdup->length = cpu_to_be16(len);
685 *XFS_DIR2_DATA_UNUSED_TAG_P(newdup) =
686 cpu_to_be16((char *)newdup - (char *)d);
687 xfs_dir2_data_log_unused(tp, bp, newdup);
688 (void)xfs_dir2_data_freeinsert(d, newdup, needlogp);
689 }
690 *needscanp = needscan;
691 }
692
693 /*
694 * Take a byte range out of an existing unused space and make it un-free.
695 */
696 void
xfs_dir2_data_use_free(xfs_trans_t * tp,xfs_dabuf_t * bp,xfs_dir2_data_unused_t * dup,xfs_dir2_data_aoff_t offset,xfs_dir2_data_aoff_t len,int * needlogp,int * needscanp)697 xfs_dir2_data_use_free(
698 xfs_trans_t *tp, /* transaction pointer */
699 xfs_dabuf_t *bp, /* data block buffer */
700 xfs_dir2_data_unused_t *dup, /* unused entry */
701 xfs_dir2_data_aoff_t offset, /* starting offset to use */
702 xfs_dir2_data_aoff_t len, /* length to use */
703 int *needlogp, /* out: need to log header */
704 int *needscanp) /* out: need regen bestfree */
705 {
706 xfs_dir2_data_t *d; /* data block */
707 xfs_dir2_data_free_t *dfp; /* bestfree pointer */
708 int matchback; /* matches end of freespace */
709 int matchfront; /* matches start of freespace */
710 int needscan; /* need to regen bestfree */
711 xfs_dir2_data_unused_t *newdup; /* new unused entry */
712 xfs_dir2_data_unused_t *newdup2; /* another new unused entry */
713 int oldlen; /* old unused entry's length */
714
715 d = bp->data;
716 ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
717 be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
718 ASSERT(be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG);
719 ASSERT(offset >= (char *)dup - (char *)d);
720 ASSERT(offset + len <= (char *)dup + be16_to_cpu(dup->length) - (char *)d);
721 ASSERT((char *)dup - (char *)d == be16_to_cpu(*XFS_DIR2_DATA_UNUSED_TAG_P(dup)));
722 /*
723 * Look up the entry in the bestfree table.
724 */
725 dfp = xfs_dir2_data_freefind(d, dup);
726 oldlen = be16_to_cpu(dup->length);
727 ASSERT(dfp || oldlen <= be16_to_cpu(d->hdr.bestfree[2].length));
728 /*
729 * Check for alignment with front and back of the entry.
730 */
731 matchfront = (char *)dup - (char *)d == offset;
732 matchback = (char *)dup + oldlen - (char *)d == offset + len;
733 ASSERT(*needscanp == 0);
734 needscan = 0;
735 /*
736 * If we matched it exactly we just need to get rid of it from
737 * the bestfree table.
738 */
739 if (matchfront && matchback) {
740 if (dfp) {
741 needscan = (d->hdr.bestfree[2].offset != 0);
742 if (!needscan)
743 xfs_dir2_data_freeremove(d, dfp, needlogp);
744 }
745 }
746 /*
747 * We match the first part of the entry.
748 * Make a new entry with the remaining freespace.
749 */
750 else if (matchfront) {
751 newdup = (xfs_dir2_data_unused_t *)((char *)d + offset + len);
752 newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
753 newdup->length = cpu_to_be16(oldlen - len);
754 *XFS_DIR2_DATA_UNUSED_TAG_P(newdup) =
755 cpu_to_be16((char *)newdup - (char *)d);
756 xfs_dir2_data_log_unused(tp, bp, newdup);
757 /*
758 * If it was in the table, remove it and add the new one.
759 */
760 if (dfp) {
761 xfs_dir2_data_freeremove(d, dfp, needlogp);
762 dfp = xfs_dir2_data_freeinsert(d, newdup, needlogp);
763 ASSERT(dfp != NULL);
764 ASSERT(dfp->length == newdup->length);
765 ASSERT(be16_to_cpu(dfp->offset) == (char *)newdup - (char *)d);
766 /*
767 * If we got inserted at the last slot,
768 * that means we don't know if there was a better
769 * choice for the last slot, or not. Rescan.
770 */
771 needscan = dfp == &d->hdr.bestfree[2];
772 }
773 }
774 /*
775 * We match the last part of the entry.
776 * Trim the allocated space off the tail of the entry.
777 */
778 else if (matchback) {
779 newdup = dup;
780 newdup->length = cpu_to_be16(((char *)d + offset) - (char *)newdup);
781 *XFS_DIR2_DATA_UNUSED_TAG_P(newdup) =
782 cpu_to_be16((char *)newdup - (char *)d);
783 xfs_dir2_data_log_unused(tp, bp, newdup);
784 /*
785 * If it was in the table, remove it and add the new one.
786 */
787 if (dfp) {
788 xfs_dir2_data_freeremove(d, dfp, needlogp);
789 dfp = xfs_dir2_data_freeinsert(d, newdup, needlogp);
790 ASSERT(dfp != NULL);
791 ASSERT(dfp->length == newdup->length);
792 ASSERT(be16_to_cpu(dfp->offset) == (char *)newdup - (char *)d);
793 /*
794 * If we got inserted at the last slot,
795 * that means we don't know if there was a better
796 * choice for the last slot, or not. Rescan.
797 */
798 needscan = dfp == &d->hdr.bestfree[2];
799 }
800 }
801 /*
802 * Poking out the middle of an entry.
803 * Make two new entries.
804 */
805 else {
806 newdup = dup;
807 newdup->length = cpu_to_be16(((char *)d + offset) - (char *)newdup);
808 *XFS_DIR2_DATA_UNUSED_TAG_P(newdup) =
809 cpu_to_be16((char *)newdup - (char *)d);
810 xfs_dir2_data_log_unused(tp, bp, newdup);
811 newdup2 = (xfs_dir2_data_unused_t *)((char *)d + offset + len);
812 newdup2->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
813 newdup2->length = cpu_to_be16(oldlen - len - be16_to_cpu(newdup->length));
814 *XFS_DIR2_DATA_UNUSED_TAG_P(newdup2) =
815 cpu_to_be16((char *)newdup2 - (char *)d);
816 xfs_dir2_data_log_unused(tp, bp, newdup2);
817 /*
818 * If the old entry was in the table, we need to scan
819 * if the 3rd entry was valid, since these entries
820 * are smaller than the old one.
821 * If we don't need to scan that means there were 1 or 2
822 * entries in the table, and removing the old and adding
823 * the 2 new will work.
824 */
825 if (dfp) {
826 needscan = (d->hdr.bestfree[2].length != 0);
827 if (!needscan) {
828 xfs_dir2_data_freeremove(d, dfp, needlogp);
829 (void)xfs_dir2_data_freeinsert(d, newdup,
830 needlogp);
831 (void)xfs_dir2_data_freeinsert(d, newdup2,
832 needlogp);
833 }
834 }
835 }
836 *needscanp = needscan;
837 }
838