1 /*
2 * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18 #include "xfs.h"
19 #include "xfs_fs.h"
20 #include "xfs_types.h"
21 #include "xfs_log.h"
22 #include "xfs_inum.h"
23 #include "xfs_trans.h"
24 #include "xfs_sb.h"
25 #include "xfs_ag.h"
26 #include "xfs_dir2.h"
27 #include "xfs_mount.h"
28 #include "xfs_da_btree.h"
29 #include "xfs_bmap_btree.h"
30 #include "xfs_dir2_sf.h"
31 #include "xfs_dinode.h"
32 #include "xfs_inode.h"
33 #include "xfs_dir2_data.h"
34 #include "xfs_dir2_leaf.h"
35 #include "xfs_dir2_block.h"
36 #include "xfs_error.h"
37
38 #ifdef DEBUG
39 /*
40 * Check the consistency of the data block.
41 * The input can also be a block-format directory.
42 * Pop an assert if we find anything bad.
43 */
44 void
xfs_dir2_data_check(xfs_inode_t * dp,xfs_dabuf_t * bp)45 xfs_dir2_data_check(
46 xfs_inode_t *dp, /* incore inode pointer */
47 xfs_dabuf_t *bp) /* data block's buffer */
48 {
49 xfs_dir2_dataptr_t addr; /* addr for leaf lookup */
50 xfs_dir2_data_free_t *bf; /* bestfree table */
51 xfs_dir2_block_tail_t *btp=NULL; /* block tail */
52 int count; /* count of entries found */
53 xfs_dir2_data_t *d; /* data block pointer */
54 xfs_dir2_data_entry_t *dep; /* data entry */
55 xfs_dir2_data_free_t *dfp; /* bestfree entry */
56 xfs_dir2_data_unused_t *dup; /* unused entry */
57 char *endp; /* end of useful data */
58 int freeseen; /* mask of bestfrees seen */
59 xfs_dahash_t hash; /* hash of current name */
60 int i; /* leaf index */
61 int lastfree; /* last entry was unused */
62 xfs_dir2_leaf_entry_t *lep=NULL; /* block leaf entries */
63 xfs_mount_t *mp; /* filesystem mount point */
64 char *p; /* current data position */
65 int stale; /* count of stale leaves */
66 struct xfs_name name;
67
68 mp = dp->i_mount;
69 d = bp->data;
70 ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
71 be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
72 bf = d->hdr.bestfree;
73 p = (char *)d->u;
74 if (be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC) {
75 btp = xfs_dir2_block_tail_p(mp, (xfs_dir2_block_t *)d);
76 lep = xfs_dir2_block_leaf_p(btp);
77 endp = (char *)lep;
78 } else
79 endp = (char *)d + mp->m_dirblksize;
80 count = lastfree = freeseen = 0;
81 /*
82 * Account for zero bestfree entries.
83 */
84 if (!bf[0].length) {
85 ASSERT(!bf[0].offset);
86 freeseen |= 1 << 0;
87 }
88 if (!bf[1].length) {
89 ASSERT(!bf[1].offset);
90 freeseen |= 1 << 1;
91 }
92 if (!bf[2].length) {
93 ASSERT(!bf[2].offset);
94 freeseen |= 1 << 2;
95 }
96 ASSERT(be16_to_cpu(bf[0].length) >= be16_to_cpu(bf[1].length));
97 ASSERT(be16_to_cpu(bf[1].length) >= be16_to_cpu(bf[2].length));
98 /*
99 * Loop over the data/unused entries.
100 */
101 while (p < endp) {
102 dup = (xfs_dir2_data_unused_t *)p;
103 /*
104 * If it's unused, look for the space in the bestfree table.
105 * If we find it, account for that, else make sure it
106 * doesn't need to be there.
107 */
108 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
109 ASSERT(lastfree == 0);
110 ASSERT(be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)) ==
111 (char *)dup - (char *)d);
112 dfp = xfs_dir2_data_freefind(d, dup);
113 if (dfp) {
114 i = (int)(dfp - bf);
115 ASSERT((freeseen & (1 << i)) == 0);
116 freeseen |= 1 << i;
117 } else {
118 ASSERT(be16_to_cpu(dup->length) <=
119 be16_to_cpu(bf[2].length));
120 }
121 p += be16_to_cpu(dup->length);
122 lastfree = 1;
123 continue;
124 }
125 /*
126 * It's a real entry. Validate the fields.
127 * If this is a block directory then make sure it's
128 * in the leaf section of the block.
129 * The linear search is crude but this is DEBUG code.
130 */
131 dep = (xfs_dir2_data_entry_t *)p;
132 ASSERT(dep->namelen != 0);
133 ASSERT(xfs_dir_ino_validate(mp, be64_to_cpu(dep->inumber)) == 0);
134 ASSERT(be16_to_cpu(*xfs_dir2_data_entry_tag_p(dep)) ==
135 (char *)dep - (char *)d);
136 count++;
137 lastfree = 0;
138 if (be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC) {
139 addr = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk,
140 (xfs_dir2_data_aoff_t)
141 ((char *)dep - (char *)d));
142 name.name = dep->name;
143 name.len = dep->namelen;
144 hash = mp->m_dirnameops->hashname(&name);
145 for (i = 0; i < be32_to_cpu(btp->count); i++) {
146 if (be32_to_cpu(lep[i].address) == addr &&
147 be32_to_cpu(lep[i].hashval) == hash)
148 break;
149 }
150 ASSERT(i < be32_to_cpu(btp->count));
151 }
152 p += xfs_dir2_data_entsize(dep->namelen);
153 }
154 /*
155 * Need to have seen all the entries and all the bestfree slots.
156 */
157 ASSERT(freeseen == 7);
158 if (be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC) {
159 for (i = stale = 0; i < be32_to_cpu(btp->count); i++) {
160 if (be32_to_cpu(lep[i].address) == XFS_DIR2_NULL_DATAPTR)
161 stale++;
162 if (i > 0)
163 ASSERT(be32_to_cpu(lep[i].hashval) >= be32_to_cpu(lep[i - 1].hashval));
164 }
165 ASSERT(count == be32_to_cpu(btp->count) - be32_to_cpu(btp->stale));
166 ASSERT(stale == be32_to_cpu(btp->stale));
167 }
168 }
169 #endif
170
171 /*
172 * Given a data block and an unused entry from that block,
173 * return the bestfree entry if any that corresponds to it.
174 */
175 xfs_dir2_data_free_t *
xfs_dir2_data_freefind(xfs_dir2_data_t * d,xfs_dir2_data_unused_t * dup)176 xfs_dir2_data_freefind(
177 xfs_dir2_data_t *d, /* data block */
178 xfs_dir2_data_unused_t *dup) /* data unused entry */
179 {
180 xfs_dir2_data_free_t *dfp; /* bestfree entry */
181 xfs_dir2_data_aoff_t off; /* offset value needed */
182 #if defined(DEBUG) && defined(__KERNEL__)
183 int matched; /* matched the value */
184 int seenzero; /* saw a 0 bestfree entry */
185 #endif
186
187 off = (xfs_dir2_data_aoff_t)((char *)dup - (char *)d);
188 #if defined(DEBUG) && defined(__KERNEL__)
189 /*
190 * Validate some consistency in the bestfree table.
191 * Check order, non-overlapping entries, and if we find the
192 * one we're looking for it has to be exact.
193 */
194 ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
195 be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
196 for (dfp = &d->hdr.bestfree[0], seenzero = matched = 0;
197 dfp < &d->hdr.bestfree[XFS_DIR2_DATA_FD_COUNT];
198 dfp++) {
199 if (!dfp->offset) {
200 ASSERT(!dfp->length);
201 seenzero = 1;
202 continue;
203 }
204 ASSERT(seenzero == 0);
205 if (be16_to_cpu(dfp->offset) == off) {
206 matched = 1;
207 ASSERT(dfp->length == dup->length);
208 } else if (off < be16_to_cpu(dfp->offset))
209 ASSERT(off + be16_to_cpu(dup->length) <= be16_to_cpu(dfp->offset));
210 else
211 ASSERT(be16_to_cpu(dfp->offset) + be16_to_cpu(dfp->length) <= off);
212 ASSERT(matched || be16_to_cpu(dfp->length) >= be16_to_cpu(dup->length));
213 if (dfp > &d->hdr.bestfree[0])
214 ASSERT(be16_to_cpu(dfp[-1].length) >= be16_to_cpu(dfp[0].length));
215 }
216 #endif
217 /*
218 * If this is smaller than the smallest bestfree entry,
219 * it can't be there since they're sorted.
220 */
221 if (be16_to_cpu(dup->length) <
222 be16_to_cpu(d->hdr.bestfree[XFS_DIR2_DATA_FD_COUNT - 1].length))
223 return NULL;
224 /*
225 * Look at the three bestfree entries for our guy.
226 */
227 for (dfp = &d->hdr.bestfree[0];
228 dfp < &d->hdr.bestfree[XFS_DIR2_DATA_FD_COUNT];
229 dfp++) {
230 if (!dfp->offset)
231 return NULL;
232 if (be16_to_cpu(dfp->offset) == off)
233 return dfp;
234 }
235 /*
236 * Didn't find it. This only happens if there are duplicate lengths.
237 */
238 return NULL;
239 }
240
241 /*
242 * Insert an unused-space entry into the bestfree table.
243 */
244 xfs_dir2_data_free_t * /* entry inserted */
xfs_dir2_data_freeinsert(xfs_dir2_data_t * d,xfs_dir2_data_unused_t * dup,int * loghead)245 xfs_dir2_data_freeinsert(
246 xfs_dir2_data_t *d, /* data block pointer */
247 xfs_dir2_data_unused_t *dup, /* unused space */
248 int *loghead) /* log the data header (out) */
249 {
250 xfs_dir2_data_free_t *dfp; /* bestfree table pointer */
251 xfs_dir2_data_free_t new; /* new bestfree entry */
252
253 #ifdef __KERNEL__
254 ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
255 be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
256 #endif
257 dfp = d->hdr.bestfree;
258 new.length = dup->length;
259 new.offset = cpu_to_be16((char *)dup - (char *)d);
260 /*
261 * Insert at position 0, 1, or 2; or not at all.
262 */
263 if (be16_to_cpu(new.length) > be16_to_cpu(dfp[0].length)) {
264 dfp[2] = dfp[1];
265 dfp[1] = dfp[0];
266 dfp[0] = new;
267 *loghead = 1;
268 return &dfp[0];
269 }
270 if (be16_to_cpu(new.length) > be16_to_cpu(dfp[1].length)) {
271 dfp[2] = dfp[1];
272 dfp[1] = new;
273 *loghead = 1;
274 return &dfp[1];
275 }
276 if (be16_to_cpu(new.length) > be16_to_cpu(dfp[2].length)) {
277 dfp[2] = new;
278 *loghead = 1;
279 return &dfp[2];
280 }
281 return NULL;
282 }
283
284 /*
285 * Remove a bestfree entry from the table.
286 */
287 STATIC void
xfs_dir2_data_freeremove(xfs_dir2_data_t * d,xfs_dir2_data_free_t * dfp,int * loghead)288 xfs_dir2_data_freeremove(
289 xfs_dir2_data_t *d, /* data block pointer */
290 xfs_dir2_data_free_t *dfp, /* bestfree entry pointer */
291 int *loghead) /* out: log data header */
292 {
293 #ifdef __KERNEL__
294 ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
295 be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
296 #endif
297 /*
298 * It's the first entry, slide the next 2 up.
299 */
300 if (dfp == &d->hdr.bestfree[0]) {
301 d->hdr.bestfree[0] = d->hdr.bestfree[1];
302 d->hdr.bestfree[1] = d->hdr.bestfree[2];
303 }
304 /*
305 * It's the second entry, slide the 3rd entry up.
306 */
307 else if (dfp == &d->hdr.bestfree[1])
308 d->hdr.bestfree[1] = d->hdr.bestfree[2];
309 /*
310 * Must be the last entry.
311 */
312 else
313 ASSERT(dfp == &d->hdr.bestfree[2]);
314 /*
315 * Clear the 3rd entry, must be zero now.
316 */
317 d->hdr.bestfree[2].length = 0;
318 d->hdr.bestfree[2].offset = 0;
319 *loghead = 1;
320 }
321
322 /*
323 * Given a data block, reconstruct its bestfree map.
324 */
325 void
xfs_dir2_data_freescan(xfs_mount_t * mp,xfs_dir2_data_t * d,int * loghead)326 xfs_dir2_data_freescan(
327 xfs_mount_t *mp, /* filesystem mount point */
328 xfs_dir2_data_t *d, /* data block pointer */
329 int *loghead) /* out: log data header */
330 {
331 xfs_dir2_block_tail_t *btp; /* block tail */
332 xfs_dir2_data_entry_t *dep; /* active data entry */
333 xfs_dir2_data_unused_t *dup; /* unused data entry */
334 char *endp; /* end of block's data */
335 char *p; /* current entry pointer */
336
337 #ifdef __KERNEL__
338 ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
339 be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
340 #endif
341 /*
342 * Start by clearing the table.
343 */
344 memset(d->hdr.bestfree, 0, sizeof(d->hdr.bestfree));
345 *loghead = 1;
346 /*
347 * Set up pointers.
348 */
349 p = (char *)d->u;
350 if (be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC) {
351 btp = xfs_dir2_block_tail_p(mp, (xfs_dir2_block_t *)d);
352 endp = (char *)xfs_dir2_block_leaf_p(btp);
353 } else
354 endp = (char *)d + mp->m_dirblksize;
355 /*
356 * Loop over the block's entries.
357 */
358 while (p < endp) {
359 dup = (xfs_dir2_data_unused_t *)p;
360 /*
361 * If it's a free entry, insert it.
362 */
363 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
364 ASSERT((char *)dup - (char *)d ==
365 be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)));
366 xfs_dir2_data_freeinsert(d, dup, loghead);
367 p += be16_to_cpu(dup->length);
368 }
369 /*
370 * For active entries, check their tags and skip them.
371 */
372 else {
373 dep = (xfs_dir2_data_entry_t *)p;
374 ASSERT((char *)dep - (char *)d ==
375 be16_to_cpu(*xfs_dir2_data_entry_tag_p(dep)));
376 p += xfs_dir2_data_entsize(dep->namelen);
377 }
378 }
379 }
380
381 /*
382 * Initialize a data block at the given block number in the directory.
383 * Give back the buffer for the created block.
384 */
385 int /* error */
xfs_dir2_data_init(xfs_da_args_t * args,xfs_dir2_db_t blkno,xfs_dabuf_t ** bpp)386 xfs_dir2_data_init(
387 xfs_da_args_t *args, /* directory operation args */
388 xfs_dir2_db_t blkno, /* logical dir block number */
389 xfs_dabuf_t **bpp) /* output block buffer */
390 {
391 xfs_dabuf_t *bp; /* block buffer */
392 xfs_dir2_data_t *d; /* pointer to block */
393 xfs_inode_t *dp; /* incore directory inode */
394 xfs_dir2_data_unused_t *dup; /* unused entry pointer */
395 int error; /* error return value */
396 int i; /* bestfree index */
397 xfs_mount_t *mp; /* filesystem mount point */
398 xfs_trans_t *tp; /* transaction pointer */
399 int t; /* temp */
400
401 dp = args->dp;
402 mp = dp->i_mount;
403 tp = args->trans;
404 /*
405 * Get the buffer set up for the block.
406 */
407 error = xfs_da_get_buf(tp, dp, xfs_dir2_db_to_da(mp, blkno), -1, &bp,
408 XFS_DATA_FORK);
409 if (error) {
410 return error;
411 }
412 ASSERT(bp != NULL);
413 /*
414 * Initialize the header.
415 */
416 d = bp->data;
417 d->hdr.magic = cpu_to_be32(XFS_DIR2_DATA_MAGIC);
418 d->hdr.bestfree[0].offset = cpu_to_be16(sizeof(d->hdr));
419 for (i = 1; i < XFS_DIR2_DATA_FD_COUNT; i++) {
420 d->hdr.bestfree[i].length = 0;
421 d->hdr.bestfree[i].offset = 0;
422 }
423 /*
424 * Set up an unused entry for the block's body.
425 */
426 dup = &d->u[0].unused;
427 dup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
428
429 t=mp->m_dirblksize - (uint)sizeof(d->hdr);
430 d->hdr.bestfree[0].length = cpu_to_be16(t);
431 dup->length = cpu_to_be16(t);
432 *xfs_dir2_data_unused_tag_p(dup) = cpu_to_be16((char *)dup - (char *)d);
433 /*
434 * Log it and return it.
435 */
436 xfs_dir2_data_log_header(tp, bp);
437 xfs_dir2_data_log_unused(tp, bp, dup);
438 *bpp = bp;
439 return 0;
440 }
441
442 /*
443 * Log an active data entry from the block.
444 */
445 void
xfs_dir2_data_log_entry(xfs_trans_t * tp,xfs_dabuf_t * bp,xfs_dir2_data_entry_t * dep)446 xfs_dir2_data_log_entry(
447 xfs_trans_t *tp, /* transaction pointer */
448 xfs_dabuf_t *bp, /* block buffer */
449 xfs_dir2_data_entry_t *dep) /* data entry pointer */
450 {
451 xfs_dir2_data_t *d; /* data block pointer */
452
453 d = bp->data;
454 ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
455 be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
456 xfs_da_log_buf(tp, bp, (uint)((char *)dep - (char *)d),
457 (uint)((char *)(xfs_dir2_data_entry_tag_p(dep) + 1) -
458 (char *)d - 1));
459 }
460
461 /*
462 * Log a data block header.
463 */
464 void
xfs_dir2_data_log_header(xfs_trans_t * tp,xfs_dabuf_t * bp)465 xfs_dir2_data_log_header(
466 xfs_trans_t *tp, /* transaction pointer */
467 xfs_dabuf_t *bp) /* block buffer */
468 {
469 xfs_dir2_data_t *d; /* data block pointer */
470
471 d = bp->data;
472 ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
473 be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
474 xfs_da_log_buf(tp, bp, (uint)((char *)&d->hdr - (char *)d),
475 (uint)(sizeof(d->hdr) - 1));
476 }
477
478 /*
479 * Log a data unused entry.
480 */
481 void
xfs_dir2_data_log_unused(xfs_trans_t * tp,xfs_dabuf_t * bp,xfs_dir2_data_unused_t * dup)482 xfs_dir2_data_log_unused(
483 xfs_trans_t *tp, /* transaction pointer */
484 xfs_dabuf_t *bp, /* block buffer */
485 xfs_dir2_data_unused_t *dup) /* data unused pointer */
486 {
487 xfs_dir2_data_t *d; /* data block pointer */
488
489 d = bp->data;
490 ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
491 be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
492 /*
493 * Log the first part of the unused entry.
494 */
495 xfs_da_log_buf(tp, bp, (uint)((char *)dup - (char *)d),
496 (uint)((char *)&dup->length + sizeof(dup->length) -
497 1 - (char *)d));
498 /*
499 * Log the end (tag) of the unused entry.
500 */
501 xfs_da_log_buf(tp, bp,
502 (uint)((char *)xfs_dir2_data_unused_tag_p(dup) - (char *)d),
503 (uint)((char *)xfs_dir2_data_unused_tag_p(dup) - (char *)d +
504 sizeof(xfs_dir2_data_off_t) - 1));
505 }
506
507 /*
508 * Make a byte range in the data block unused.
509 * Its current contents are unimportant.
510 */
511 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)512 xfs_dir2_data_make_free(
513 xfs_trans_t *tp, /* transaction pointer */
514 xfs_dabuf_t *bp, /* block buffer */
515 xfs_dir2_data_aoff_t offset, /* starting byte offset */
516 xfs_dir2_data_aoff_t len, /* length in bytes */
517 int *needlogp, /* out: log header */
518 int *needscanp) /* out: regen bestfree */
519 {
520 xfs_dir2_data_t *d; /* data block pointer */
521 xfs_dir2_data_free_t *dfp; /* bestfree pointer */
522 char *endptr; /* end of data area */
523 xfs_mount_t *mp; /* filesystem mount point */
524 int needscan; /* need to regen bestfree */
525 xfs_dir2_data_unused_t *newdup; /* new unused entry */
526 xfs_dir2_data_unused_t *postdup; /* unused entry after us */
527 xfs_dir2_data_unused_t *prevdup; /* unused entry before us */
528
529 mp = tp->t_mountp;
530 d = bp->data;
531 /*
532 * Figure out where the end of the data area is.
533 */
534 if (be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC)
535 endptr = (char *)d + mp->m_dirblksize;
536 else {
537 xfs_dir2_block_tail_t *btp; /* block tail */
538
539 ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
540 btp = xfs_dir2_block_tail_p(mp, (xfs_dir2_block_t *)d);
541 endptr = (char *)xfs_dir2_block_leaf_p(btp);
542 }
543 /*
544 * If this isn't the start of the block, then back up to
545 * the previous entry and see if it's free.
546 */
547 if (offset > sizeof(d->hdr)) {
548 __be16 *tagp; /* tag just before us */
549
550 tagp = (__be16 *)((char *)d + offset) - 1;
551 prevdup = (xfs_dir2_data_unused_t *)((char *)d + be16_to_cpu(*tagp));
552 if (be16_to_cpu(prevdup->freetag) != XFS_DIR2_DATA_FREE_TAG)
553 prevdup = NULL;
554 } else
555 prevdup = NULL;
556 /*
557 * If this isn't the end of the block, see if the entry after
558 * us is free.
559 */
560 if ((char *)d + offset + len < endptr) {
561 postdup =
562 (xfs_dir2_data_unused_t *)((char *)d + offset + len);
563 if (be16_to_cpu(postdup->freetag) != XFS_DIR2_DATA_FREE_TAG)
564 postdup = NULL;
565 } else
566 postdup = NULL;
567 ASSERT(*needscanp == 0);
568 needscan = 0;
569 /*
570 * Previous and following entries are both free,
571 * merge everything into a single free entry.
572 */
573 if (prevdup && postdup) {
574 xfs_dir2_data_free_t *dfp2; /* another bestfree pointer */
575
576 /*
577 * See if prevdup and/or postdup are in bestfree table.
578 */
579 dfp = xfs_dir2_data_freefind(d, prevdup);
580 dfp2 = xfs_dir2_data_freefind(d, postdup);
581 /*
582 * We need a rescan unless there are exactly 2 free entries
583 * namely our two. Then we know what's happening, otherwise
584 * since the third bestfree is there, there might be more
585 * entries.
586 */
587 needscan = (d->hdr.bestfree[2].length != 0);
588 /*
589 * Fix up the new big freespace.
590 */
591 be16_add_cpu(&prevdup->length, len + be16_to_cpu(postdup->length));
592 *xfs_dir2_data_unused_tag_p(prevdup) =
593 cpu_to_be16((char *)prevdup - (char *)d);
594 xfs_dir2_data_log_unused(tp, bp, prevdup);
595 if (!needscan) {
596 /*
597 * Has to be the case that entries 0 and 1 are
598 * dfp and dfp2 (don't know which is which), and
599 * entry 2 is empty.
600 * Remove entry 1 first then entry 0.
601 */
602 ASSERT(dfp && dfp2);
603 if (dfp == &d->hdr.bestfree[1]) {
604 dfp = &d->hdr.bestfree[0];
605 ASSERT(dfp2 == dfp);
606 dfp2 = &d->hdr.bestfree[1];
607 }
608 xfs_dir2_data_freeremove(d, dfp2, needlogp);
609 xfs_dir2_data_freeremove(d, dfp, needlogp);
610 /*
611 * Now insert the new entry.
612 */
613 dfp = xfs_dir2_data_freeinsert(d, prevdup, needlogp);
614 ASSERT(dfp == &d->hdr.bestfree[0]);
615 ASSERT(dfp->length == prevdup->length);
616 ASSERT(!dfp[1].length);
617 ASSERT(!dfp[2].length);
618 }
619 }
620 /*
621 * The entry before us is free, merge with it.
622 */
623 else if (prevdup) {
624 dfp = xfs_dir2_data_freefind(d, prevdup);
625 be16_add_cpu(&prevdup->length, len);
626 *xfs_dir2_data_unused_tag_p(prevdup) =
627 cpu_to_be16((char *)prevdup - (char *)d);
628 xfs_dir2_data_log_unused(tp, bp, prevdup);
629 /*
630 * If the previous entry was in the table, the new entry
631 * is longer, so it will be in the table too. Remove
632 * the old one and add the new one.
633 */
634 if (dfp) {
635 xfs_dir2_data_freeremove(d, dfp, needlogp);
636 (void)xfs_dir2_data_freeinsert(d, prevdup, needlogp);
637 }
638 /*
639 * Otherwise we need a scan if the new entry is big enough.
640 */
641 else {
642 needscan = be16_to_cpu(prevdup->length) >
643 be16_to_cpu(d->hdr.bestfree[2].length);
644 }
645 }
646 /*
647 * The following entry is free, merge with it.
648 */
649 else if (postdup) {
650 dfp = xfs_dir2_data_freefind(d, postdup);
651 newdup = (xfs_dir2_data_unused_t *)((char *)d + offset);
652 newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
653 newdup->length = cpu_to_be16(len + be16_to_cpu(postdup->length));
654 *xfs_dir2_data_unused_tag_p(newdup) =
655 cpu_to_be16((char *)newdup - (char *)d);
656 xfs_dir2_data_log_unused(tp, bp, newdup);
657 /*
658 * If the following entry was in the table, the new entry
659 * is longer, so it will be in the table too. Remove
660 * the old one and add the new one.
661 */
662 if (dfp) {
663 xfs_dir2_data_freeremove(d, dfp, needlogp);
664 (void)xfs_dir2_data_freeinsert(d, newdup, needlogp);
665 }
666 /*
667 * Otherwise we need a scan if the new entry is big enough.
668 */
669 else {
670 needscan = be16_to_cpu(newdup->length) >
671 be16_to_cpu(d->hdr.bestfree[2].length);
672 }
673 }
674 /*
675 * Neither neighbor is free. Make a new entry.
676 */
677 else {
678 newdup = (xfs_dir2_data_unused_t *)((char *)d + offset);
679 newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
680 newdup->length = cpu_to_be16(len);
681 *xfs_dir2_data_unused_tag_p(newdup) =
682 cpu_to_be16((char *)newdup - (char *)d);
683 xfs_dir2_data_log_unused(tp, bp, newdup);
684 (void)xfs_dir2_data_freeinsert(d, newdup, needlogp);
685 }
686 *needscanp = needscan;
687 }
688
689 /*
690 * Take a byte range out of an existing unused space and make it un-free.
691 */
692 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)693 xfs_dir2_data_use_free(
694 xfs_trans_t *tp, /* transaction pointer */
695 xfs_dabuf_t *bp, /* data block buffer */
696 xfs_dir2_data_unused_t *dup, /* unused entry */
697 xfs_dir2_data_aoff_t offset, /* starting offset to use */
698 xfs_dir2_data_aoff_t len, /* length to use */
699 int *needlogp, /* out: need to log header */
700 int *needscanp) /* out: need regen bestfree */
701 {
702 xfs_dir2_data_t *d; /* data block */
703 xfs_dir2_data_free_t *dfp; /* bestfree pointer */
704 int matchback; /* matches end of freespace */
705 int matchfront; /* matches start of freespace */
706 int needscan; /* need to regen bestfree */
707 xfs_dir2_data_unused_t *newdup; /* new unused entry */
708 xfs_dir2_data_unused_t *newdup2; /* another new unused entry */
709 int oldlen; /* old unused entry's length */
710
711 d = bp->data;
712 ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
713 be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
714 ASSERT(be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG);
715 ASSERT(offset >= (char *)dup - (char *)d);
716 ASSERT(offset + len <= (char *)dup + be16_to_cpu(dup->length) - (char *)d);
717 ASSERT((char *)dup - (char *)d == be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)));
718 /*
719 * Look up the entry in the bestfree table.
720 */
721 dfp = xfs_dir2_data_freefind(d, dup);
722 oldlen = be16_to_cpu(dup->length);
723 ASSERT(dfp || oldlen <= be16_to_cpu(d->hdr.bestfree[2].length));
724 /*
725 * Check for alignment with front and back of the entry.
726 */
727 matchfront = (char *)dup - (char *)d == offset;
728 matchback = (char *)dup + oldlen - (char *)d == offset + len;
729 ASSERT(*needscanp == 0);
730 needscan = 0;
731 /*
732 * If we matched it exactly we just need to get rid of it from
733 * the bestfree table.
734 */
735 if (matchfront && matchback) {
736 if (dfp) {
737 needscan = (d->hdr.bestfree[2].offset != 0);
738 if (!needscan)
739 xfs_dir2_data_freeremove(d, dfp, needlogp);
740 }
741 }
742 /*
743 * We match the first part of the entry.
744 * Make a new entry with the remaining freespace.
745 */
746 else if (matchfront) {
747 newdup = (xfs_dir2_data_unused_t *)((char *)d + offset + len);
748 newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
749 newdup->length = cpu_to_be16(oldlen - len);
750 *xfs_dir2_data_unused_tag_p(newdup) =
751 cpu_to_be16((char *)newdup - (char *)d);
752 xfs_dir2_data_log_unused(tp, bp, newdup);
753 /*
754 * If it was in the table, remove it and add the new one.
755 */
756 if (dfp) {
757 xfs_dir2_data_freeremove(d, dfp, needlogp);
758 dfp = xfs_dir2_data_freeinsert(d, newdup, needlogp);
759 ASSERT(dfp != NULL);
760 ASSERT(dfp->length == newdup->length);
761 ASSERT(be16_to_cpu(dfp->offset) == (char *)newdup - (char *)d);
762 /*
763 * If we got inserted at the last slot,
764 * that means we don't know if there was a better
765 * choice for the last slot, or not. Rescan.
766 */
767 needscan = dfp == &d->hdr.bestfree[2];
768 }
769 }
770 /*
771 * We match the last part of the entry.
772 * Trim the allocated space off the tail of the entry.
773 */
774 else if (matchback) {
775 newdup = dup;
776 newdup->length = cpu_to_be16(((char *)d + offset) - (char *)newdup);
777 *xfs_dir2_data_unused_tag_p(newdup) =
778 cpu_to_be16((char *)newdup - (char *)d);
779 xfs_dir2_data_log_unused(tp, bp, newdup);
780 /*
781 * If it was in the table, remove it and add the new one.
782 */
783 if (dfp) {
784 xfs_dir2_data_freeremove(d, dfp, needlogp);
785 dfp = xfs_dir2_data_freeinsert(d, newdup, needlogp);
786 ASSERT(dfp != NULL);
787 ASSERT(dfp->length == newdup->length);
788 ASSERT(be16_to_cpu(dfp->offset) == (char *)newdup - (char *)d);
789 /*
790 * If we got inserted at the last slot,
791 * that means we don't know if there was a better
792 * choice for the last slot, or not. Rescan.
793 */
794 needscan = dfp == &d->hdr.bestfree[2];
795 }
796 }
797 /*
798 * Poking out the middle of an entry.
799 * Make two new entries.
800 */
801 else {
802 newdup = dup;
803 newdup->length = cpu_to_be16(((char *)d + offset) - (char *)newdup);
804 *xfs_dir2_data_unused_tag_p(newdup) =
805 cpu_to_be16((char *)newdup - (char *)d);
806 xfs_dir2_data_log_unused(tp, bp, newdup);
807 newdup2 = (xfs_dir2_data_unused_t *)((char *)d + offset + len);
808 newdup2->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
809 newdup2->length = cpu_to_be16(oldlen - len - be16_to_cpu(newdup->length));
810 *xfs_dir2_data_unused_tag_p(newdup2) =
811 cpu_to_be16((char *)newdup2 - (char *)d);
812 xfs_dir2_data_log_unused(tp, bp, newdup2);
813 /*
814 * If the old entry was in the table, we need to scan
815 * if the 3rd entry was valid, since these entries
816 * are smaller than the old one.
817 * If we don't need to scan that means there were 1 or 2
818 * entries in the table, and removing the old and adding
819 * the 2 new will work.
820 */
821 if (dfp) {
822 needscan = (d->hdr.bestfree[2].length != 0);
823 if (!needscan) {
824 xfs_dir2_data_freeremove(d, dfp, needlogp);
825 (void)xfs_dir2_data_freeinsert(d, newdup,
826 needlogp);
827 (void)xfs_dir2_data_freeinsert(d, newdup2,
828 needlogp);
829 }
830 }
831 }
832 *needscanp = needscan;
833 }
834