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[PATCH] lockdep: fix printk recursion logic
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / xfs / xfs_dir2_data.c
blobf7c799217072066518a560965c907cc8f428ef35
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_dir2.h"
26 #include "xfs_dmapi.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_attr_sf.h"
32 #include "xfs_dinode.h"
33 #include "xfs_inode.h"
34 #include "xfs_dir2_data.h"
35 #include "xfs_dir2_leaf.h"
36 #include "xfs_dir2_block.h"
37 #include "xfs_error.h"
38
39 #ifdef DEBUG
40 /*
41 * Check the consistency of the data block.
42 * The input can also be a block-format directory.
43 * Pop an assert if we find anything bad.
44 */
45 void
46 xfs_dir2_data_check(
47 xfs_inode_t *dp, /* incore inode pointer */
48 xfs_dabuf_t *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_t *d; /* data block pointer */
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
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 hash = xfs_da_hashname((char *)dep->name, dep->namelen);
143 for (i = 0; i < be32_to_cpu(btp->count); i++) {
144 if (be32_to_cpu(lep[i].address) == addr &&
145 be32_to_cpu(lep[i].hashval) == hash)
146 break;
147 }
148 ASSERT(i < be32_to_cpu(btp->count));
149 }
150 p += XFS_DIR2_DATA_ENTSIZE(dep->namelen);
151 }
152 /*
153 * Need to have seen all the entries and all the bestfree slots.
154 */
155 ASSERT(freeseen == 7);
156 if (be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC) {
157 for (i = stale = 0; i < be32_to_cpu(btp->count); i++) {
158 if (be32_to_cpu(lep[i].address) == XFS_DIR2_NULL_DATAPTR)
159 stale++;
160 if (i > 0)
161 ASSERT(be32_to_cpu(lep[i].hashval) >= be32_to_cpu(lep[i - 1].hashval));
162 }
163 ASSERT(count == be32_to_cpu(btp->count) - be32_to_cpu(btp->stale));
164 ASSERT(stale == be32_to_cpu(btp->stale));
165 }
166 }
167 #endif
168
169 /*
170 * Given a data block and an unused entry from that block,
171 * return the bestfree entry if any that corresponds to it.
172 */
173 xfs_dir2_data_free_t *
174 xfs_dir2_data_freefind(
175 xfs_dir2_data_t *d, /* data block */
176 xfs_dir2_data_unused_t *dup) /* data unused entry */
177 {
178 xfs_dir2_data_free_t *dfp; /* bestfree entry */
179 xfs_dir2_data_aoff_t off; /* offset value needed */
180 #if defined(DEBUG) && defined(__KERNEL__)
181 int matched; /* matched the value */
182 int seenzero; /* saw a 0 bestfree entry */
183 #endif
184
185 off = (xfs_dir2_data_aoff_t)((char *)dup - (char *)d);
186 #if defined(DEBUG) && defined(__KERNEL__)
187 /*
188 * Validate some consistency in the bestfree table.
189 * Check order, non-overlapping entries, and if we find the
190 * one we're looking for it has to be exact.
191 */
192 ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
193 be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
194 for (dfp = &d->hdr.bestfree[0], seenzero = matched = 0;
195 dfp < &d->hdr.bestfree[XFS_DIR2_DATA_FD_COUNT];
196 dfp++) {
197 if (!dfp->offset) {
198 ASSERT(!dfp->length);
199 seenzero = 1;
200 continue;
201 }
202 ASSERT(seenzero == 0);
203 if (be16_to_cpu(dfp->offset) == off) {
204 matched = 1;
205 ASSERT(dfp->length == dup->length);
206 } else if (off < be16_to_cpu(dfp->offset))
207 ASSERT(off + be16_to_cpu(dup->length) <= be16_to_cpu(dfp->offset));
208 else
209 ASSERT(be16_to_cpu(dfp->offset) + be16_to_cpu(dfp->length) <= off);
210 ASSERT(matched || be16_to_cpu(dfp->length) >= be16_to_cpu(dup->length));
211 if (dfp > &d->hdr.bestfree[0])
212 ASSERT(be16_to_cpu(dfp[-1].length) >= be16_to_cpu(dfp[0].length));
213 }
214 #endif
215 /*
216 * If this is smaller than the smallest bestfree entry,
217 * it can't be there since they're sorted.
218 */
219 if (be16_to_cpu(dup->length) <
220 be16_to_cpu(d->hdr.bestfree[XFS_DIR2_DATA_FD_COUNT - 1].length))
221 return NULL;
222 /*
223 * Look at the three bestfree entries for our guy.
224 */
225 for (dfp = &d->hdr.bestfree[0];
226 dfp < &d->hdr.bestfree[XFS_DIR2_DATA_FD_COUNT];
227 dfp++) {
228 if (!dfp->offset)
229 return NULL;
230 if (be16_to_cpu(dfp->offset) == off)
231 return dfp;
232 }
233 /*
234 * Didn't find it. This only happens if there are duplicate lengths.
235 */
236 return NULL;
237 }
238
239 /*
240 * Insert an unused-space entry into the bestfree table.
241 */
242 xfs_dir2_data_free_t * /* entry inserted */
243 xfs_dir2_data_freeinsert(
244 xfs_dir2_data_t *d, /* data block pointer */
245 xfs_dir2_data_unused_t *dup, /* unused space */
246 int *loghead) /* log the data header (out) */
247 {
248 xfs_dir2_data_free_t *dfp; /* bestfree table pointer */
249 xfs_dir2_data_free_t new; /* new bestfree entry */
250
251 #ifdef __KERNEL__
252 ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
253 be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
254 #endif
255 dfp = d->hdr.bestfree;
256 new.length = dup->length;
257 new.offset = cpu_to_be16((char *)dup - (char *)d);
258 /*
259 * Insert at position 0, 1, or 2; or not at all.
260 */
261 if (be16_to_cpu(new.length) > be16_to_cpu(dfp[0].length)) {
262 dfp[2] = dfp[1];
263 dfp[1] = dfp[0];
264 dfp[0] = new;
265 *loghead = 1;
266 return &dfp[0];
267 }
268 if (be16_to_cpu(new.length) > be16_to_cpu(dfp[1].length)) {
269 dfp[2] = dfp[1];
270 dfp[1] = new;
271 *loghead = 1;
272 return &dfp[1];
273 }
274 if (be16_to_cpu(new.length) > be16_to_cpu(dfp[2].length)) {
275 dfp[2] = new;
276 *loghead = 1;
277 return &dfp[2];
278 }
279 return NULL;
280 }
281
282 /*
283 * Remove a bestfree entry from the table.
284 */
285 STATIC void
286 xfs_dir2_data_freeremove(
287 xfs_dir2_data_t *d, /* data block pointer */
288 xfs_dir2_data_free_t *dfp, /* bestfree entry pointer */
289 int *loghead) /* out: log data header */
290 {
291 #ifdef __KERNEL__
292 ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
293 be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
294 #endif
295 /*
296 * It's the first entry, slide the next 2 up.
297 */
298 if (dfp == &d->hdr.bestfree[0]) {
299 d->hdr.bestfree[0] = d->hdr.bestfree[1];
300 d->hdr.bestfree[1] = d->hdr.bestfree[2];
301 }
302 /*
303 * It's the second entry, slide the 3rd entry up.
304 */
305 else if (dfp == &d->hdr.bestfree[1])
306 d->hdr.bestfree[1] = d->hdr.bestfree[2];
307 /*
308 * Must be the last entry.
309 */
310 else
311 ASSERT(dfp == &d->hdr.bestfree[2]);
312 /*
313 * Clear the 3rd entry, must be zero now.
314 */
315 d->hdr.bestfree[2].length = 0;
316 d->hdr.bestfree[2].offset = 0;
317 *loghead = 1;
318 }
319
320 /*
321 * Given a data block, reconstruct its bestfree map.
322 */
323 void
324 xfs_dir2_data_freescan(
325 xfs_mount_t *mp, /* filesystem mount point */
326 xfs_dir2_data_t *d, /* data block pointer */
327 int *loghead, /* out: log data header */
328 char *aendp) /* in: caller's endp */
329 {
330 xfs_dir2_block_tail_t *btp; /* block tail */
331 xfs_dir2_data_entry_t *dep; /* active data entry */
332 xfs_dir2_data_unused_t *dup; /* unused data entry */
333 char *endp; /* end of block's data */
334 char *p; /* current entry pointer */
335
336 #ifdef __KERNEL__
337 ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
338 be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
339 #endif
340 /*
341 * Start by clearing the table.
342 */
343 memset(d->hdr.bestfree, 0, sizeof(d->hdr.bestfree));
344 *loghead = 1;
345 /*
346 * Set up pointers.
347 */
348 p = (char *)d->u;
349 if (aendp)
350 endp = aendp;
351 else if (be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC) {
352 btp = XFS_DIR2_BLOCK_TAIL_P(mp, (xfs_dir2_block_t *)d);
353 endp = (char *)XFS_DIR2_BLOCK_LEAF_P(btp);
354 } else
355 endp = (char *)d + mp->m_dirblksize;
356 /*
357 * Loop over the block's entries.
358 */
359 while (p < endp) {
360 dup = (xfs_dir2_data_unused_t *)p;
361 /*
362 * If it's a free entry, insert it.
363 */
364 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
365 ASSERT((char *)dup - (char *)d ==
366 be16_to_cpu(*XFS_DIR2_DATA_UNUSED_TAG_P(dup)));
367 xfs_dir2_data_freeinsert(d, dup, loghead);
368 p += be16_to_cpu(dup->length);
369 }
370 /*
371 * For active entries, check their tags and skip them.
372 */
373 else {
374 dep = (xfs_dir2_data_entry_t *)p;
375 ASSERT((char *)dep - (char *)d ==
376 be16_to_cpu(*XFS_DIR2_DATA_ENTRY_TAG_P(dep)));
377 p += XFS_DIR2_DATA_ENTSIZE(dep->namelen);
378 }
379 }
380 }
381
382 /*
383 * Initialize a data block at the given block number in the directory.
384 * Give back the buffer for the created block.
385 */
386 int /* error */
387 xfs_dir2_data_init(
388 xfs_da_args_t *args, /* directory operation args */
389 xfs_dir2_db_t blkno, /* logical dir block number */
390 xfs_dabuf_t **bpp) /* output block buffer */
391 {
392 xfs_dabuf_t *bp; /* block buffer */
393 xfs_dir2_data_t *d; /* pointer to block */
394 xfs_inode_t *dp; /* incore directory inode */
395 xfs_dir2_data_unused_t *dup; /* unused entry pointer */
396 int error; /* error return value */
397 int i; /* bestfree index */
398 xfs_mount_t *mp; /* filesystem mount point */
399 xfs_trans_t *tp; /* transaction pointer */
400 int t; /* temp */
401
402 dp = args->dp;
403 mp = dp->i_mount;
404 tp = args->trans;
405 /*
406 * Get the buffer set up for the block.
407 */
408 error = xfs_da_get_buf(tp, dp, XFS_DIR2_DB_TO_DA(mp, blkno), -1, &bp,
409 XFS_DATA_FORK);
410 if (error) {
411 return error;
412 }
413 ASSERT(bp != NULL);
414 /*
415 * Initialize the header.
416 */
417 d = bp->data;
418 d->hdr.magic = cpu_to_be32(XFS_DIR2_DATA_MAGIC);
419 d->hdr.bestfree[0].offset = cpu_to_be16(sizeof(d->hdr));
420 for (i = 1; i < XFS_DIR2_DATA_FD_COUNT; i++) {
421 d->hdr.bestfree[i].length = 0;
422 d->hdr.bestfree[i].offset = 0;
423 }
424 /*
425 * Set up an unused entry for the block's body.
426 */
427 dup = &d->u[0].unused;
428 dup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
429
430 t=mp->m_dirblksize - (uint)sizeof(d->hdr);
431 d->hdr.bestfree[0].length = cpu_to_be16(t);
432 dup->length = cpu_to_be16(t);
433 *XFS_DIR2_DATA_UNUSED_TAG_P(dup) = cpu_to_be16((char *)dup - (char *)d);
434 /*
435 * Log it and return it.
436 */
437 xfs_dir2_data_log_header(tp, bp);
438 xfs_dir2_data_log_unused(tp, bp, dup);
439 *bpp = bp;
440 return 0;
441 }
442
443 /*
444 * Log an active data entry from the block.
445 */
446 void
447 xfs_dir2_data_log_entry(
448 xfs_trans_t *tp, /* transaction pointer */
449 xfs_dabuf_t *bp, /* block buffer */
450 xfs_dir2_data_entry_t *dep) /* data entry pointer */
451 {
452 xfs_dir2_data_t *d; /* data block pointer */
453
454 d = bp->data;
455 ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
456 be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
457 xfs_da_log_buf(tp, bp, (uint)((char *)dep - (char *)d),
458 (uint)((char *)(XFS_DIR2_DATA_ENTRY_TAG_P(dep) + 1) -
459 (char *)d - 1));
460 }
461
462 /*
463 * Log a data block header.
464 */
465 void
466 xfs_dir2_data_log_header(
467 xfs_trans_t *tp, /* transaction pointer */
468 xfs_dabuf_t *bp) /* block buffer */
469 {
470 xfs_dir2_data_t *d; /* data block pointer */
471
472 d = bp->data;
473 ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
474 be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
475 xfs_da_log_buf(tp, bp, (uint)((char *)&d->hdr - (char *)d),
476 (uint)(sizeof(d->hdr) - 1));
477 }
478
479 /*
480 * Log a data unused entry.
481 */
482 void
483 xfs_dir2_data_log_unused(
484 xfs_trans_t *tp, /* transaction pointer */
485 xfs_dabuf_t *bp, /* block buffer */
486 xfs_dir2_data_unused_t *dup) /* data unused pointer */
487 {
488 xfs_dir2_data_t *d; /* data block pointer */
489
490 d = bp->data;
491 ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
492 be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
493 /*
494 * Log the first part of the unused entry.
495 */
496 xfs_da_log_buf(tp, bp, (uint)((char *)dup - (char *)d),
497 (uint)((char *)&dup->length + sizeof(dup->length) -
498 1 - (char *)d));
499 /*
500 * Log the end (tag) of the unused entry.
501 */
502 xfs_da_log_buf(tp, bp,
503 (uint)((char *)XFS_DIR2_DATA_UNUSED_TAG_P(dup) - (char *)d),
504 (uint)((char *)XFS_DIR2_DATA_UNUSED_TAG_P(dup) - (char *)d +
505 sizeof(xfs_dir2_data_off_t) - 1));
506 }
507
508 /*
509 * Make a byte range in the data block unused.
510 * Its current contents are unimportant.
511 */
512 void
513 xfs_dir2_data_make_free(
514 xfs_trans_t *tp, /* transaction pointer */
515 xfs_dabuf_t *bp, /* block buffer */
516 xfs_dir2_data_aoff_t offset, /* starting byte offset */
517 xfs_dir2_data_aoff_t len, /* length in bytes */
518 int *needlogp, /* out: log header */
519 int *needscanp) /* out: regen bestfree */
520 {
521 xfs_dir2_data_t *d; /* data block pointer */
522 xfs_dir2_data_free_t *dfp; /* bestfree pointer */
523 char *endptr; /* end of data area */
524 xfs_mount_t *mp; /* filesystem mount point */
525 int needscan; /* need to regen bestfree */
526 xfs_dir2_data_unused_t *newdup; /* new unused entry */
527 xfs_dir2_data_unused_t *postdup; /* unused entry after us */
528 xfs_dir2_data_unused_t *prevdup; /* unused entry before us */
529
530 mp = tp->t_mountp;
531 d = bp->data;
532 /*
533 * Figure out where the end of the data area is.
534 */
535 if (be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC)
536 endptr = (char *)d + mp->m_dirblksize;
537 else {
538 xfs_dir2_block_tail_t *btp; /* block tail */
539
540 ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
541 btp = XFS_DIR2_BLOCK_TAIL_P(mp, (xfs_dir2_block_t *)d);
542 endptr = (char *)XFS_DIR2_BLOCK_LEAF_P(btp);
543 }
544 /*
545 * If this isn't the start of the block, then back up to
546 * the previous entry and see if it's free.
547 */
548 if (offset > sizeof(d->hdr)) {
549 __be16 *tagp; /* tag just before us */
550
551 tagp = (__be16 *)((char *)d + offset) - 1;
552 prevdup = (xfs_dir2_data_unused_t *)((char *)d + be16_to_cpu(*tagp));
553 if (be16_to_cpu(prevdup->freetag) != XFS_DIR2_DATA_FREE_TAG)
554 prevdup = NULL;
555 } else
556 prevdup = NULL;
557 /*
558 * If this isn't the end of the block, see if the entry after
559 * us is free.
560 */
561 if ((char *)d + offset + len < endptr) {
562 postdup =
563 (xfs_dir2_data_unused_t *)((char *)d + offset + len);
564 if (be16_to_cpu(postdup->freetag) != XFS_DIR2_DATA_FREE_TAG)
565 postdup = NULL;
566 } else
567 postdup = NULL;
568 ASSERT(*needscanp == 0);
569 needscan = 0;
570 /*
571 * Previous and following entries are both free,
572 * merge everything into a single free entry.
573 */
574 if (prevdup && postdup) {
575 xfs_dir2_data_free_t *dfp2; /* another bestfree pointer */
576
577 /*
578 * See if prevdup and/or postdup are in bestfree table.
579 */
580 dfp = xfs_dir2_data_freefind(d, prevdup);
581 dfp2 = xfs_dir2_data_freefind(d, postdup);
582 /*
583 * We need a rescan unless there are exactly 2 free entries
584 * namely our two. Then we know what's happening, otherwise
585 * since the third bestfree is there, there might be more
586 * entries.
587 */
588 needscan = (d->hdr.bestfree[2].length != 0);
589 /*
590 * Fix up the new big freespace.
591 */
592 be16_add(&prevdup->length, len + be16_to_cpu(postdup->length));
593 *XFS_DIR2_DATA_UNUSED_TAG_P(prevdup) =
594 cpu_to_be16((char *)prevdup - (char *)d);
595 xfs_dir2_data_log_unused(tp, bp, prevdup);
596 if (!needscan) {
597 /*
598 * Has to be the case that entries 0 and 1 are
599 * dfp and dfp2 (don't know which is which), and
600 * entry 2 is empty.
601 * Remove entry 1 first then entry 0.
602 */
603 ASSERT(dfp && dfp2);
604 if (dfp == &d->hdr.bestfree[1]) {
605 dfp = &d->hdr.bestfree[0];
606 ASSERT(dfp2 == dfp);
607 dfp2 = &d->hdr.bestfree[1];
608 }
609 xfs_dir2_data_freeremove(d, dfp2, needlogp);
610 xfs_dir2_data_freeremove(d, dfp, needlogp);
611 /*
612 * Now insert the new entry.
613 */
614 dfp = xfs_dir2_data_freeinsert(d, prevdup, needlogp);
615 ASSERT(dfp == &d->hdr.bestfree[0]);
616 ASSERT(dfp->length == prevdup->length);
617 ASSERT(!dfp[1].length);
618 ASSERT(!dfp[2].length);
619 }
620 }
621 /*
622 * The entry before us is free, merge with it.
623 */
624 else if (prevdup) {
625 dfp = xfs_dir2_data_freefind(d, prevdup);
626 be16_add(&prevdup->length, len);
627 *XFS_DIR2_DATA_UNUSED_TAG_P(prevdup) =
628 cpu_to_be16((char *)prevdup - (char *)d);
629 xfs_dir2_data_log_unused(tp, bp, prevdup);
630 /*
631 * If the previous entry was in the table, the new entry
632 * is longer, so it will be in the table too. Remove
633 * the old one and add the new one.
634 */
635 if (dfp) {
636 xfs_dir2_data_freeremove(d, dfp, needlogp);
637 (void)xfs_dir2_data_freeinsert(d, prevdup, needlogp);
638 }
639 /*
640 * Otherwise we need a scan if the new entry is big enough.
641 */
642 else {
643 needscan = be16_to_cpu(prevdup->length) >
644 be16_to_cpu(d->hdr.bestfree[2].length);
645 }
646 }
647 /*
648 * The following entry is free, merge with it.
649 */
650 else if (postdup) {
651 dfp = xfs_dir2_data_freefind(d, postdup);
652 newdup = (xfs_dir2_data_unused_t *)((char *)d + offset);
653 newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
654 newdup->length = cpu_to_be16(len + be16_to_cpu(postdup->length));
655 *XFS_DIR2_DATA_UNUSED_TAG_P(newdup) =
656 cpu_to_be16((char *)newdup - (char *)d);
657 xfs_dir2_data_log_unused(tp, bp, newdup);
658 /*
659 * If the following entry was in the table, the new entry
660 * is longer, so it will be in the table too. Remove
661 * the old one and add the new one.
662 */
663 if (dfp) {
664 xfs_dir2_data_freeremove(d, dfp, needlogp);
665 (void)xfs_dir2_data_freeinsert(d, newdup, needlogp);
666 }
667 /*
668 * Otherwise we need a scan if the new entry is big enough.
669 */
670 else {
671 needscan = be16_to_cpu(newdup->length) >
672 be16_to_cpu(d->hdr.bestfree[2].length);
673 }
674 }
675 /*
676 * Neither neighbor is free. Make a new entry.
677 */
678 else {
679 newdup = (xfs_dir2_data_unused_t *)((char *)d + offset);
680 newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
681 newdup->length = cpu_to_be16(len);
682 *XFS_DIR2_DATA_UNUSED_TAG_P(newdup) =
683 cpu_to_be16((char *)newdup - (char *)d);
684 xfs_dir2_data_log_unused(tp, bp, newdup);
685 (void)xfs_dir2_data_freeinsert(d, newdup, needlogp);
686 }
687 *needscanp = needscan;
688 }
689
690 /*
691 * Take a byte range out of an existing unused space and make it un-free.
692 */
693 void
694 xfs_dir2_data_use_free(
695 xfs_trans_t *tp, /* transaction pointer */
696 xfs_dabuf_t *bp, /* data block buffer */
697 xfs_dir2_data_unused_t *dup, /* unused entry */
698 xfs_dir2_data_aoff_t offset, /* starting offset to use */
699 xfs_dir2_data_aoff_t len, /* length to use */
700 int *needlogp, /* out: need to log header */
701 int *needscanp) /* out: need regen bestfree */
702 {
703 xfs_dir2_data_t *d; /* data block */
704 xfs_dir2_data_free_t *dfp; /* bestfree pointer */
705 int matchback; /* matches end of freespace */
706 int matchfront; /* matches start of freespace */
707 int needscan; /* need to regen bestfree */
708 xfs_dir2_data_unused_t *newdup; /* new unused entry */
709 xfs_dir2_data_unused_t *newdup2; /* another new unused entry */
710 int oldlen; /* old unused entry's length */
711
712 d = bp->data;
713 ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
714 be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
715 ASSERT(be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG);
716 ASSERT(offset >= (char *)dup - (char *)d);
717 ASSERT(offset + len <= (char *)dup + be16_to_cpu(dup->length) - (char *)d);
718 ASSERT((char *)dup - (char *)d == be16_to_cpu(*XFS_DIR2_DATA_UNUSED_TAG_P(dup)));
719 /*
720 * Look up the entry in the bestfree table.
721 */
722 dfp = xfs_dir2_data_freefind(d, dup);
723 oldlen = be16_to_cpu(dup->length);
724 ASSERT(dfp || oldlen <= be16_to_cpu(d->hdr.bestfree[2].length));
725 /*
726 * Check for alignment with front and back of the entry.
727 */
728 matchfront = (char *)dup - (char *)d == offset;
729 matchback = (char *)dup + oldlen - (char *)d == offset + len;
730 ASSERT(*needscanp == 0);
731 needscan = 0;
732 /*
733 * If we matched it exactly we just need to get rid of it from
734 * the bestfree table.
735 */
736 if (matchfront && matchback) {
737 if (dfp) {
738 needscan = (d->hdr.bestfree[2].offset != 0);
739 if (!needscan)
740 xfs_dir2_data_freeremove(d, dfp, needlogp);
741 }
742 }
743 /*
744 * We match the first part of the entry.
745 * Make a new entry with the remaining freespace.
746 */
747 else if (matchfront) {
748 newdup = (xfs_dir2_data_unused_t *)((char *)d + offset + len);
749 newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
750 newdup->length = cpu_to_be16(oldlen - len);
751 *XFS_DIR2_DATA_UNUSED_TAG_P(newdup) =
752 cpu_to_be16((char *)newdup - (char *)d);
753 xfs_dir2_data_log_unused(tp, bp, newdup);
754 /*
755 * If it was in the table, remove it and add the new one.
756 */
757 if (dfp) {
758 xfs_dir2_data_freeremove(d, dfp, needlogp);
759 dfp = xfs_dir2_data_freeinsert(d, newdup, needlogp);
760 ASSERT(dfp != NULL);
761 ASSERT(dfp->length == newdup->length);
762 ASSERT(be16_to_cpu(dfp->offset) == (char *)newdup - (char *)d);
763 /*
764 * If we got inserted at the last slot,
765 * that means we don't know if there was a better
766 * choice for the last slot, or not. Rescan.
767 */
768 needscan = dfp == &d->hdr.bestfree[2];
769 }
770 }
771 /*
772 * We match the last part of the entry.
773 * Trim the allocated space off the tail of the entry.
774 */
775 else if (matchback) {
776 newdup = dup;
777 newdup->length = cpu_to_be16(((char *)d + offset) - (char *)newdup);
778 *XFS_DIR2_DATA_UNUSED_TAG_P(newdup) =
779 cpu_to_be16((char *)newdup - (char *)d);
780 xfs_dir2_data_log_unused(tp, bp, newdup);
781 /*
782 * If it was in the table, remove it and add the new one.
783 */
784 if (dfp) {
785 xfs_dir2_data_freeremove(d, dfp, needlogp);
786 dfp = xfs_dir2_data_freeinsert(d, newdup, needlogp);
787 ASSERT(dfp != NULL);
788 ASSERT(dfp->length == newdup->length);
789 ASSERT(be16_to_cpu(dfp->offset) == (char *)newdup - (char *)d);
790 /*
791 * If we got inserted at the last slot,
792 * that means we don't know if there was a better
793 * choice for the last slot, or not. Rescan.
794 */
795 needscan = dfp == &d->hdr.bestfree[2];
796 }
797 }
798 /*
799 * Poking out the middle of an entry.
800 * Make two new entries.
801 */
802 else {
803 newdup = dup;
804 newdup->length = cpu_to_be16(((char *)d + offset) - (char *)newdup);
805 *XFS_DIR2_DATA_UNUSED_TAG_P(newdup) =
806 cpu_to_be16((char *)newdup - (char *)d);
807 xfs_dir2_data_log_unused(tp, bp, newdup);
808 newdup2 = (xfs_dir2_data_unused_t *)((char *)d + offset + len);
809 newdup2->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
810 newdup2->length = cpu_to_be16(oldlen - len - be16_to_cpu(newdup->length));
811 *XFS_DIR2_DATA_UNUSED_TAG_P(newdup2) =
812 cpu_to_be16((char *)newdup2 - (char *)d);
813 xfs_dir2_data_log_unused(tp, bp, newdup2);
814 /*
815 * If the old entry was in the table, we need to scan
816 * if the 3rd entry was valid, since these entries
817 * are smaller than the old one.
818 * If we don't need to scan that means there were 1 or 2
819 * entries in the table, and removing the old and adding
820 * the 2 new will work.
821 */
822 if (dfp) {
823 needscan = (d->hdr.bestfree[2].length != 0);
824 if (!needscan) {
825 xfs_dir2_data_freeremove(d, dfp, needlogp);
826 (void)xfs_dir2_data_freeinsert(d, newdup,
827 needlogp);
828 (void)xfs_dir2_data_freeinsert(d, newdup2,
829 needlogp);
830 }
831 }
832 }
833 *needscanp = needscan;
834 }
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree