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Linux-2.6.12-rc2
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / xfs / xfs_dir2_data.c
blobdb9887a107deaab10addcc4e2cc96476ec1e4a03
1 /*
2 * Copyright (c) 2000-2002 Silicon Graphics, Inc. All Rights Reserved.
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of version 2 of the GNU General Public License as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it would be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
11 *
12 * Further, this software is distributed without any warranty that it is
13 * free of the rightful claim of any third person regarding infringement
14 * or the like. Any license provided herein, whether implied or
15 * otherwise, applies only to this software file. Patent licenses, if
16 * any, provided herein do not apply to combinations of this program with
17 * other software, or any other product whatsoever.
18 *
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write the Free Software Foundation, Inc., 59
21 * Temple Place - Suite 330, Boston MA 02111-1307, USA.
22 *
23 * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
24 * Mountain View, CA 94043, or:
25 *
26 * http://www.sgi.com
27 *
28 * For further information regarding this notice, see:
29 *
30 * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
31 */
32
33 /*
34 * xfs_dir2_data.c
35 * Core data block handling routines for XFS V2 directories.
36 * See xfs_dir2_data.h for data structures.
37 */
38
39 #include "xfs.h"
40
41 #include "xfs_macros.h"
42 #include "xfs_types.h"
43 #include "xfs_inum.h"
44 #include "xfs_log.h"
45 #include "xfs_trans.h"
46 #include "xfs_sb.h"
47 #include "xfs_dir.h"
48 #include "xfs_dir2.h"
49 #include "xfs_dmapi.h"
50 #include "xfs_mount.h"
51 #include "xfs_bmap_btree.h"
52 #include "xfs_attr_sf.h"
53 #include "xfs_dir_sf.h"
54 #include "xfs_dir2_sf.h"
55 #include "xfs_dinode.h"
56 #include "xfs_inode.h"
57 #include "xfs_da_btree.h"
58 #include "xfs_dir_leaf.h"
59 #include "xfs_dir2_data.h"
60 #include "xfs_dir2_leaf.h"
61 #include "xfs_dir2_block.h"
62 #include "xfs_error.h"
63
64 #ifdef DEBUG
65 /*
66 * Check the consistency of the data block.
67 * The input can also be a block-format directory.
68 * Pop an assert if we find anything bad.
69 */
70 void
71 xfs_dir2_data_check(
72 xfs_inode_t *dp, /* incore inode pointer */
73 xfs_dabuf_t *bp) /* data block's buffer */
74 {
75 xfs_dir2_dataptr_t addr; /* addr for leaf lookup */
76 xfs_dir2_data_free_t *bf; /* bestfree table */
77 xfs_dir2_block_tail_t *btp=NULL; /* block tail */
78 int count; /* count of entries found */
79 xfs_dir2_data_t *d; /* data block pointer */
80 xfs_dir2_data_entry_t *dep; /* data entry */
81 xfs_dir2_data_free_t *dfp; /* bestfree entry */
82 xfs_dir2_data_unused_t *dup; /* unused entry */
83 char *endp; /* end of useful data */
84 int freeseen; /* mask of bestfrees seen */
85 xfs_dahash_t hash; /* hash of current name */
86 int i; /* leaf index */
87 int lastfree; /* last entry was unused */
88 xfs_dir2_leaf_entry_t *lep=NULL; /* block leaf entries */
89 xfs_mount_t *mp; /* filesystem mount point */
90 char *p; /* current data position */
91 int stale; /* count of stale leaves */
92
93 mp = dp->i_mount;
94 d = bp->data;
95 ASSERT(INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_DATA_MAGIC ||
96 INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_BLOCK_MAGIC);
97 bf = d->hdr.bestfree;
98 p = (char *)d->u;
99 if (INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_BLOCK_MAGIC) {
100 btp = XFS_DIR2_BLOCK_TAIL_P(mp, (xfs_dir2_block_t *)d);
101 lep = XFS_DIR2_BLOCK_LEAF_P(btp);
102 endp = (char *)lep;
103 } else
104 endp = (char *)d + mp->m_dirblksize;
105 count = lastfree = freeseen = 0;
106 /*
107 * Account for zero bestfree entries.
108 */
109 if (!bf[0].length) {
110 ASSERT(!bf[0].offset);
111 freeseen |= 1 << 0;
112 }
113 if (!bf[1].length) {
114 ASSERT(!bf[1].offset);
115 freeseen |= 1 << 1;
116 }
117 if (!bf[2].length) {
118 ASSERT(!bf[2].offset);
119 freeseen |= 1 << 2;
120 }
121 ASSERT(INT_GET(bf[0].length, ARCH_CONVERT) >= INT_GET(bf[1].length, ARCH_CONVERT));
122 ASSERT(INT_GET(bf[1].length, ARCH_CONVERT) >= INT_GET(bf[2].length, ARCH_CONVERT));
123 /*
124 * Loop over the data/unused entries.
125 */
126 while (p < endp) {
127 dup = (xfs_dir2_data_unused_t *)p;
128 /*
129 * If it's unused, look for the space in the bestfree table.
130 * If we find it, account for that, else make sure it
131 * doesn't need to be there.
132 */
133 if (INT_GET(dup->freetag, ARCH_CONVERT) == XFS_DIR2_DATA_FREE_TAG) {
134 ASSERT(lastfree == 0);
135 ASSERT(INT_GET(*XFS_DIR2_DATA_UNUSED_TAG_P(dup), ARCH_CONVERT) ==
136 (char *)dup - (char *)d);
137 dfp = xfs_dir2_data_freefind(d, dup);
138 if (dfp) {
139 i = (int)(dfp - bf);
140 ASSERT((freeseen & (1 << i)) == 0);
141 freeseen |= 1 << i;
142 } else
143 ASSERT(INT_GET(dup->length, ARCH_CONVERT) <= INT_GET(bf[2].length, ARCH_CONVERT));
144 p += INT_GET(dup->length, ARCH_CONVERT);
145 lastfree = 1;
146 continue;
147 }
148 /*
149 * It's a real entry. Validate the fields.
150 * If this is a block directory then make sure it's
151 * in the leaf section of the block.
152 * The linear search is crude but this is DEBUG code.
153 */
154 dep = (xfs_dir2_data_entry_t *)p;
155 ASSERT(dep->namelen != 0);
156 ASSERT(xfs_dir_ino_validate(mp, INT_GET(dep->inumber, ARCH_CONVERT)) == 0);
157 ASSERT(INT_GET(*XFS_DIR2_DATA_ENTRY_TAG_P(dep), ARCH_CONVERT) ==
158 (char *)dep - (char *)d);
159 count++;
160 lastfree = 0;
161 if (INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_BLOCK_MAGIC) {
162 addr = XFS_DIR2_DB_OFF_TO_DATAPTR(mp, mp->m_dirdatablk,
163 (xfs_dir2_data_aoff_t)
164 ((char *)dep - (char *)d));
165 hash = xfs_da_hashname((char *)dep->name, dep->namelen);
166 for (i = 0; i < INT_GET(btp->count, ARCH_CONVERT); i++) {
167 if (INT_GET(lep[i].address, ARCH_CONVERT) == addr &&
168 INT_GET(lep[i].hashval, ARCH_CONVERT) == hash)
169 break;
170 }
171 ASSERT(i < INT_GET(btp->count, ARCH_CONVERT));
172 }
173 p += XFS_DIR2_DATA_ENTSIZE(dep->namelen);
174 }
175 /*
176 * Need to have seen all the entries and all the bestfree slots.
177 */
178 ASSERT(freeseen == 7);
179 if (INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_BLOCK_MAGIC) {
180 for (i = stale = 0; i < INT_GET(btp->count, ARCH_CONVERT); i++) {
181 if (INT_GET(lep[i].address, ARCH_CONVERT) == XFS_DIR2_NULL_DATAPTR)
182 stale++;
183 if (i > 0)
184 ASSERT(INT_GET(lep[i].hashval, ARCH_CONVERT) >= INT_GET(lep[i - 1].hashval, ARCH_CONVERT));
185 }
186 ASSERT(count == INT_GET(btp->count, ARCH_CONVERT) - INT_GET(btp->stale, ARCH_CONVERT));
187 ASSERT(stale == INT_GET(btp->stale, ARCH_CONVERT));
188 }
189 }
190 #endif
191
192 /*
193 * Given a data block and an unused entry from that block,
194 * return the bestfree entry if any that corresponds to it.
195 */
196 xfs_dir2_data_free_t *
197 xfs_dir2_data_freefind(
198 xfs_dir2_data_t *d, /* data block */
199 xfs_dir2_data_unused_t *dup) /* data unused entry */
200 {
201 xfs_dir2_data_free_t *dfp; /* bestfree entry */
202 xfs_dir2_data_aoff_t off; /* offset value needed */
203 #if defined(DEBUG) && defined(__KERNEL__)
204 int matched; /* matched the value */
205 int seenzero; /* saw a 0 bestfree entry */
206 #endif
207
208 off = (xfs_dir2_data_aoff_t)((char *)dup - (char *)d);
209 #if defined(DEBUG) && defined(__KERNEL__)
210 /*
211 * Validate some consistency in the bestfree table.
212 * Check order, non-overlapping entries, and if we find the
213 * one we're looking for it has to be exact.
214 */
215 ASSERT(INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_DATA_MAGIC ||
216 INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_BLOCK_MAGIC);
217 for (dfp = &d->hdr.bestfree[0], seenzero = matched = 0;
218 dfp < &d->hdr.bestfree[XFS_DIR2_DATA_FD_COUNT];
219 dfp++) {
220 if (!dfp->offset) {
221 ASSERT(!dfp->length);
222 seenzero = 1;
223 continue;
224 }
225 ASSERT(seenzero == 0);
226 if (INT_GET(dfp->offset, ARCH_CONVERT) == off) {
227 matched = 1;
228 ASSERT(INT_GET(dfp->length, ARCH_CONVERT) == INT_GET(dup->length, ARCH_CONVERT));
229 } else if (off < INT_GET(dfp->offset, ARCH_CONVERT))
230 ASSERT(off + INT_GET(dup->length, ARCH_CONVERT) <= INT_GET(dfp->offset, ARCH_CONVERT));
231 else
232 ASSERT(INT_GET(dfp->offset, ARCH_CONVERT) + INT_GET(dfp->length, ARCH_CONVERT) <= off);
233 ASSERT(matched || INT_GET(dfp->length, ARCH_CONVERT) >= INT_GET(dup->length, ARCH_CONVERT));
234 if (dfp > &d->hdr.bestfree[0])
235 ASSERT(INT_GET(dfp[-1].length, ARCH_CONVERT) >= INT_GET(dfp[0].length, ARCH_CONVERT));
236 }
237 #endif
238 /*
239 * If this is smaller than the smallest bestfree entry,
240 * it can't be there since they're sorted.
241 */
242 if (INT_GET(dup->length, ARCH_CONVERT) < INT_GET(d->hdr.bestfree[XFS_DIR2_DATA_FD_COUNT - 1].length, ARCH_CONVERT))
243 return NULL;
244 /*
245 * Look at the three bestfree entries for our guy.
246 */
247 for (dfp = &d->hdr.bestfree[0];
248 dfp < &d->hdr.bestfree[XFS_DIR2_DATA_FD_COUNT];
249 dfp++) {
250 if (!dfp->offset)
251 return NULL;
252 if (INT_GET(dfp->offset, ARCH_CONVERT) == off)
253 return dfp;
254 }
255 /*
256 * Didn't find it. This only happens if there are duplicate lengths.
257 */
258 return NULL;
259 }
260
261 /*
262 * Insert an unused-space entry into the bestfree table.
263 */
264 xfs_dir2_data_free_t * /* entry inserted */
265 xfs_dir2_data_freeinsert(
266 xfs_dir2_data_t *d, /* data block pointer */
267 xfs_dir2_data_unused_t *dup, /* unused space */
268 int *loghead) /* log the data header (out) */
269 {
270 xfs_dir2_data_free_t *dfp; /* bestfree table pointer */
271 xfs_dir2_data_free_t new; /* new bestfree entry */
272
273 #ifdef __KERNEL__
274 ASSERT(INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_DATA_MAGIC ||
275 INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_BLOCK_MAGIC);
276 #endif
277 dfp = d->hdr.bestfree;
278 INT_COPY(new.length, dup->length, ARCH_CONVERT);
279 INT_SET(new.offset, ARCH_CONVERT, (xfs_dir2_data_off_t)((char *)dup - (char *)d));
280 /*
281 * Insert at position 0, 1, or 2; or not at all.
282 */
283 if (INT_GET(new.length, ARCH_CONVERT) > INT_GET(dfp[0].length, ARCH_CONVERT)) {
284 dfp[2] = dfp[1];
285 dfp[1] = dfp[0];
286 dfp[0] = new;
287 *loghead = 1;
288 return &dfp[0];
289 }
290 if (INT_GET(new.length, ARCH_CONVERT) > INT_GET(dfp[1].length, ARCH_CONVERT)) {
291 dfp[2] = dfp[1];
292 dfp[1] = new;
293 *loghead = 1;
294 return &dfp[1];
295 }
296 if (INT_GET(new.length, ARCH_CONVERT) > INT_GET(dfp[2].length, ARCH_CONVERT)) {
297 dfp[2] = new;
298 *loghead = 1;
299 return &dfp[2];
300 }
301 return NULL;
302 }
303
304 /*
305 * Remove a bestfree entry from the table.
306 */
307 void
308 xfs_dir2_data_freeremove(
309 xfs_dir2_data_t *d, /* data block pointer */
310 xfs_dir2_data_free_t *dfp, /* bestfree entry pointer */
311 int *loghead) /* out: log data header */
312 {
313 #ifdef __KERNEL__
314 ASSERT(INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_DATA_MAGIC ||
315 INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_BLOCK_MAGIC);
316 #endif
317 /*
318 * It's the first entry, slide the next 2 up.
319 */
320 if (dfp == &d->hdr.bestfree[0]) {
321 d->hdr.bestfree[0] = d->hdr.bestfree[1];
322 d->hdr.bestfree[1] = d->hdr.bestfree[2];
323 }
324 /*
325 * It's the second entry, slide the 3rd entry up.
326 */
327 else if (dfp == &d->hdr.bestfree[1])
328 d->hdr.bestfree[1] = d->hdr.bestfree[2];
329 /*
330 * Must be the last entry.
331 */
332 else
333 ASSERT(dfp == &d->hdr.bestfree[2]);
334 /*
335 * Clear the 3rd entry, must be zero now.
336 */
337 d->hdr.bestfree[2].length = 0;
338 d->hdr.bestfree[2].offset = 0;
339 *loghead = 1;
340 }
341
342 /*
343 * Given a data block, reconstruct its bestfree map.
344 */
345 void
346 xfs_dir2_data_freescan(
347 xfs_mount_t *mp, /* filesystem mount point */
348 xfs_dir2_data_t *d, /* data block pointer */
349 int *loghead, /* out: log data header */
350 char *aendp) /* in: caller's endp */
351 {
352 xfs_dir2_block_tail_t *btp; /* block tail */
353 xfs_dir2_data_entry_t *dep; /* active data entry */
354 xfs_dir2_data_unused_t *dup; /* unused data entry */
355 char *endp; /* end of block's data */
356 char *p; /* current entry pointer */
357
358 #ifdef __KERNEL__
359 ASSERT(INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_DATA_MAGIC ||
360 INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_BLOCK_MAGIC);
361 #endif
362 /*
363 * Start by clearing the table.
364 */
365 memset(d->hdr.bestfree, 0, sizeof(d->hdr.bestfree));
366 *loghead = 1;
367 /*
368 * Set up pointers.
369 */
370 p = (char *)d->u;
371 if (aendp)
372 endp = aendp;
373 else if (INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_BLOCK_MAGIC) {
374 btp = XFS_DIR2_BLOCK_TAIL_P(mp, (xfs_dir2_block_t *)d);
375 endp = (char *)XFS_DIR2_BLOCK_LEAF_P(btp);
376 } else
377 endp = (char *)d + mp->m_dirblksize;
378 /*
379 * Loop over the block's entries.
380 */
381 while (p < endp) {
382 dup = (xfs_dir2_data_unused_t *)p;
383 /*
384 * If it's a free entry, insert it.
385 */
386 if (INT_GET(dup->freetag, ARCH_CONVERT) == XFS_DIR2_DATA_FREE_TAG) {
387 ASSERT((char *)dup - (char *)d ==
388 INT_GET(*XFS_DIR2_DATA_UNUSED_TAG_P(dup), ARCH_CONVERT));
389 xfs_dir2_data_freeinsert(d, dup, loghead);
390 p += INT_GET(dup->length, ARCH_CONVERT);
391 }
392 /*
393 * For active entries, check their tags and skip them.
394 */
395 else {
396 dep = (xfs_dir2_data_entry_t *)p;
397 ASSERT((char *)dep - (char *)d ==
398 INT_GET(*XFS_DIR2_DATA_ENTRY_TAG_P(dep), ARCH_CONVERT));
399 p += XFS_DIR2_DATA_ENTSIZE(dep->namelen);
400 }
401 }
402 }
403
404 /*
405 * Initialize a data block at the given block number in the directory.
406 * Give back the buffer for the created block.
407 */
408 int /* error */
409 xfs_dir2_data_init(
410 xfs_da_args_t *args, /* directory operation args */
411 xfs_dir2_db_t blkno, /* logical dir block number */
412 xfs_dabuf_t **bpp) /* output block buffer */
413 {
414 xfs_dabuf_t *bp; /* block buffer */
415 xfs_dir2_data_t *d; /* pointer to block */
416 xfs_inode_t *dp; /* incore directory inode */
417 xfs_dir2_data_unused_t *dup; /* unused entry pointer */
418 int error; /* error return value */
419 int i; /* bestfree index */
420 xfs_mount_t *mp; /* filesystem mount point */
421 xfs_trans_t *tp; /* transaction pointer */
422 int t; /* temp */
423
424 dp = args->dp;
425 mp = dp->i_mount;
426 tp = args->trans;
427 /*
428 * Get the buffer set up for the block.
429 */
430 error = xfs_da_get_buf(tp, dp, XFS_DIR2_DB_TO_DA(mp, blkno), -1, &bp,
431 XFS_DATA_FORK);
432 if (error) {
433 return error;
434 }
435 ASSERT(bp != NULL);
436 /*
437 * Initialize the header.
438 */
439 d = bp->data;
440 INT_SET(d->hdr.magic, ARCH_CONVERT, XFS_DIR2_DATA_MAGIC);
441 INT_SET(d->hdr.bestfree[0].offset, ARCH_CONVERT, (xfs_dir2_data_off_t)sizeof(d->hdr));
442 for (i = 1; i < XFS_DIR2_DATA_FD_COUNT; i++) {
443 d->hdr.bestfree[i].length = 0;
444 d->hdr.bestfree[i].offset = 0;
445 }
446 /*
447 * Set up an unused entry for the block's body.
448 */
449 dup = &d->u[0].unused;
450 INT_SET(dup->freetag, ARCH_CONVERT, XFS_DIR2_DATA_FREE_TAG);
451
452 t=mp->m_dirblksize - (uint)sizeof(d->hdr);
453 INT_SET(d->hdr.bestfree[0].length, ARCH_CONVERT, t);
454 INT_SET(dup->length, ARCH_CONVERT, t);
455 INT_SET(*XFS_DIR2_DATA_UNUSED_TAG_P(dup), ARCH_CONVERT,
456 (xfs_dir2_data_off_t)((char *)dup - (char *)d));
457 /*
458 * Log it and return it.
459 */
460 xfs_dir2_data_log_header(tp, bp);
461 xfs_dir2_data_log_unused(tp, bp, dup);
462 *bpp = bp;
463 return 0;
464 }
465
466 /*
467 * Log an active data entry from the block.
468 */
469 void
470 xfs_dir2_data_log_entry(
471 xfs_trans_t *tp, /* transaction pointer */
472 xfs_dabuf_t *bp, /* block buffer */
473 xfs_dir2_data_entry_t *dep) /* data entry pointer */
474 {
475 xfs_dir2_data_t *d; /* data block pointer */
476
477 d = bp->data;
478 ASSERT(INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_DATA_MAGIC ||
479 INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_BLOCK_MAGIC);
480 xfs_da_log_buf(tp, bp, (uint)((char *)dep - (char *)d),
481 (uint)((char *)(XFS_DIR2_DATA_ENTRY_TAG_P(dep) + 1) -
482 (char *)d - 1));
483 }
484
485 /*
486 * Log a data block header.
487 */
488 void
489 xfs_dir2_data_log_header(
490 xfs_trans_t *tp, /* transaction pointer */
491 xfs_dabuf_t *bp) /* block buffer */
492 {
493 xfs_dir2_data_t *d; /* data block pointer */
494
495 d = bp->data;
496 ASSERT(INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_DATA_MAGIC ||
497 INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_BLOCK_MAGIC);
498 xfs_da_log_buf(tp, bp, (uint)((char *)&d->hdr - (char *)d),
499 (uint)(sizeof(d->hdr) - 1));
500 }
501
502 /*
503 * Log a data unused entry.
504 */
505 void
506 xfs_dir2_data_log_unused(
507 xfs_trans_t *tp, /* transaction pointer */
508 xfs_dabuf_t *bp, /* block buffer */
509 xfs_dir2_data_unused_t *dup) /* data unused pointer */
510 {
511 xfs_dir2_data_t *d; /* data block pointer */
512
513 d = bp->data;
514 ASSERT(INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_DATA_MAGIC ||
515 INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_BLOCK_MAGIC);
516 /*
517 * Log the first part of the unused entry.
518 */
519 xfs_da_log_buf(tp, bp, (uint)((char *)dup - (char *)d),
520 (uint)((char *)&dup->length + sizeof(dup->length) -
521 1 - (char *)d));
522 /*
523 * Log the end (tag) of the unused entry.
524 */
525 xfs_da_log_buf(tp, bp,
526 (uint)((char *)XFS_DIR2_DATA_UNUSED_TAG_P(dup) - (char *)d),
527 (uint)((char *)XFS_DIR2_DATA_UNUSED_TAG_P(dup) - (char *)d +
528 sizeof(xfs_dir2_data_off_t) - 1));
529 }
530
531 /*
532 * Make a byte range in the data block unused.
533 * Its current contents are unimportant.
534 */
535 void
536 xfs_dir2_data_make_free(
537 xfs_trans_t *tp, /* transaction pointer */
538 xfs_dabuf_t *bp, /* block buffer */
539 xfs_dir2_data_aoff_t offset, /* starting byte offset */
540 xfs_dir2_data_aoff_t len, /* length in bytes */
541 int *needlogp, /* out: log header */
542 int *needscanp) /* out: regen bestfree */
543 {
544 xfs_dir2_data_t *d; /* data block pointer */
545 xfs_dir2_data_free_t *dfp; /* bestfree pointer */
546 char *endptr; /* end of data area */
547 xfs_mount_t *mp; /* filesystem mount point */
548 int needscan; /* need to regen bestfree */
549 xfs_dir2_data_unused_t *newdup; /* new unused entry */
550 xfs_dir2_data_unused_t *postdup; /* unused entry after us */
551 xfs_dir2_data_unused_t *prevdup; /* unused entry before us */
552
553 mp = tp->t_mountp;
554 d = bp->data;
555 /*
556 * Figure out where the end of the data area is.
557 */
558 if (INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_DATA_MAGIC)
559 endptr = (char *)d + mp->m_dirblksize;
560 else {
561 xfs_dir2_block_tail_t *btp; /* block tail */
562
563 ASSERT(INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_BLOCK_MAGIC);
564 btp = XFS_DIR2_BLOCK_TAIL_P(mp, (xfs_dir2_block_t *)d);
565 endptr = (char *)XFS_DIR2_BLOCK_LEAF_P(btp);
566 }
567 /*
568 * If this isn't the start of the block, then back up to
569 * the previous entry and see if it's free.
570 */
571 if (offset > sizeof(d->hdr)) {
572 xfs_dir2_data_off_t *tagp; /* tag just before us */
573
574 tagp = (xfs_dir2_data_off_t *)((char *)d + offset) - 1;
575 prevdup = (xfs_dir2_data_unused_t *)((char *)d + INT_GET(*tagp, ARCH_CONVERT));
576 if (INT_GET(prevdup->freetag, ARCH_CONVERT) != XFS_DIR2_DATA_FREE_TAG)
577 prevdup = NULL;
578 } else
579 prevdup = NULL;
580 /*
581 * If this isn't the end of the block, see if the entry after
582 * us is free.
583 */
584 if ((char *)d + offset + len < endptr) {
585 postdup =
586 (xfs_dir2_data_unused_t *)((char *)d + offset + len);
587 if (INT_GET(postdup->freetag, ARCH_CONVERT) != XFS_DIR2_DATA_FREE_TAG)
588 postdup = NULL;
589 } else
590 postdup = NULL;
591 ASSERT(*needscanp == 0);
592 needscan = 0;
593 /*
594 * Previous and following entries are both free,
595 * merge everything into a single free entry.
596 */
597 if (prevdup && postdup) {
598 xfs_dir2_data_free_t *dfp2; /* another bestfree pointer */
599
600 /*
601 * See if prevdup and/or postdup are in bestfree table.
602 */
603 dfp = xfs_dir2_data_freefind(d, prevdup);
604 dfp2 = xfs_dir2_data_freefind(d, postdup);
605 /*
606 * We need a rescan unless there are exactly 2 free entries
607 * namely our two. Then we know what's happening, otherwise
608 * since the third bestfree is there, there might be more
609 * entries.
610 */
611 needscan = d->hdr.bestfree[2].length;
612 /*
613 * Fix up the new big freespace.
614 */
615 INT_MOD(prevdup->length, ARCH_CONVERT, len + INT_GET(postdup->length, ARCH_CONVERT));
616 INT_SET(*XFS_DIR2_DATA_UNUSED_TAG_P(prevdup), ARCH_CONVERT,
617 (xfs_dir2_data_off_t)((char *)prevdup - (char *)d));
618 xfs_dir2_data_log_unused(tp, bp, prevdup);
619 if (!needscan) {
620 /*
621 * Has to be the case that entries 0 and 1 are
622 * dfp and dfp2 (don't know which is which), and
623 * entry 2 is empty.
624 * Remove entry 1 first then entry 0.
625 */
626 ASSERT(dfp && dfp2);
627 if (dfp == &d->hdr.bestfree[1]) {
628 dfp = &d->hdr.bestfree[0];
629 ASSERT(dfp2 == dfp);
630 dfp2 = &d->hdr.bestfree[1];
631 }
632 xfs_dir2_data_freeremove(d, dfp2, needlogp);
633 xfs_dir2_data_freeremove(d, dfp, needlogp);
634 /*
635 * Now insert the new entry.
636 */
637 dfp = xfs_dir2_data_freeinsert(d, prevdup, needlogp);
638 ASSERT(dfp == &d->hdr.bestfree[0]);
639 ASSERT(INT_GET(dfp->length, ARCH_CONVERT) == INT_GET(prevdup->length, ARCH_CONVERT));
640 ASSERT(!dfp[1].length);
641 ASSERT(!dfp[2].length);
642 }
643 }
644 /*
645 * The entry before us is free, merge with it.
646 */
647 else if (prevdup) {
648 dfp = xfs_dir2_data_freefind(d, prevdup);
649 INT_MOD(prevdup->length, ARCH_CONVERT, len);
650 INT_SET(*XFS_DIR2_DATA_UNUSED_TAG_P(prevdup), ARCH_CONVERT,
651 (xfs_dir2_data_off_t)((char *)prevdup - (char *)d));
652 xfs_dir2_data_log_unused(tp, bp, prevdup);
653 /*
654 * If the previous entry was in the table, the new entry
655 * is longer, so it will be in the table too. Remove
656 * the old one and add the new one.
657 */
658 if (dfp) {
659 xfs_dir2_data_freeremove(d, dfp, needlogp);
660 (void)xfs_dir2_data_freeinsert(d, prevdup, needlogp);
661 }
662 /*
663 * Otherwise we need a scan if the new entry is big enough.
664 */
665 else
666 needscan = INT_GET(prevdup->length, ARCH_CONVERT) > INT_GET(d->hdr.bestfree[2].length, ARCH_CONVERT);
667 }
668 /*
669 * The following entry is free, merge with it.
670 */
671 else if (postdup) {
672 dfp = xfs_dir2_data_freefind(d, postdup);
673 newdup = (xfs_dir2_data_unused_t *)((char *)d + offset);
674 INT_SET(newdup->freetag, ARCH_CONVERT, XFS_DIR2_DATA_FREE_TAG);
675 INT_SET(newdup->length, ARCH_CONVERT, len + INT_GET(postdup->length, ARCH_CONVERT));
676 INT_SET(*XFS_DIR2_DATA_UNUSED_TAG_P(newdup), ARCH_CONVERT,
677 (xfs_dir2_data_off_t)((char *)newdup - (char *)d));
678 xfs_dir2_data_log_unused(tp, bp, newdup);
679 /*
680 * If the following entry was in the table, the new entry
681 * is longer, so it will be in the table too. Remove
682 * the old one and add the new one.
683 */
684 if (dfp) {
685 xfs_dir2_data_freeremove(d, dfp, needlogp);
686 (void)xfs_dir2_data_freeinsert(d, newdup, needlogp);
687 }
688 /*
689 * Otherwise we need a scan if the new entry is big enough.
690 */
691 else
692 needscan = INT_GET(newdup->length, ARCH_CONVERT) > INT_GET(d->hdr.bestfree[2].length, ARCH_CONVERT);
693 }
694 /*
695 * Neither neighbor is free. Make a new entry.
696 */
697 else {
698 newdup = (xfs_dir2_data_unused_t *)((char *)d + offset);
699 INT_SET(newdup->freetag, ARCH_CONVERT, XFS_DIR2_DATA_FREE_TAG);
700 INT_SET(newdup->length, ARCH_CONVERT, len);
701 INT_SET(*XFS_DIR2_DATA_UNUSED_TAG_P(newdup), ARCH_CONVERT,
702 (xfs_dir2_data_off_t)((char *)newdup - (char *)d));
703 xfs_dir2_data_log_unused(tp, bp, newdup);
704 (void)xfs_dir2_data_freeinsert(d, newdup, needlogp);
705 }
706 *needscanp = needscan;
707 }
708
709 /*
710 * Take a byte range out of an existing unused space and make it un-free.
711 */
712 void
713 xfs_dir2_data_use_free(
714 xfs_trans_t *tp, /* transaction pointer */
715 xfs_dabuf_t *bp, /* data block buffer */
716 xfs_dir2_data_unused_t *dup, /* unused entry */
717 xfs_dir2_data_aoff_t offset, /* starting offset to use */
718 xfs_dir2_data_aoff_t len, /* length to use */
719 int *needlogp, /* out: need to log header */
720 int *needscanp) /* out: need regen bestfree */
721 {
722 xfs_dir2_data_t *d; /* data block */
723 xfs_dir2_data_free_t *dfp; /* bestfree pointer */
724 int matchback; /* matches end of freespace */
725 int matchfront; /* matches start of freespace */
726 int needscan; /* need to regen bestfree */
727 xfs_dir2_data_unused_t *newdup; /* new unused entry */
728 xfs_dir2_data_unused_t *newdup2; /* another new unused entry */
729 int oldlen; /* old unused entry's length */
730
731 d = bp->data;
732 ASSERT(INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_DATA_MAGIC ||
733 INT_GET(d->hdr.magic, ARCH_CONVERT) == XFS_DIR2_BLOCK_MAGIC);
734 ASSERT(INT_GET(dup->freetag, ARCH_CONVERT) == XFS_DIR2_DATA_FREE_TAG);
735 ASSERT(offset >= (char *)dup - (char *)d);
736 ASSERT(offset + len <= (char *)dup + INT_GET(dup->length, ARCH_CONVERT) - (char *)d);
737 ASSERT((char *)dup - (char *)d == INT_GET(*XFS_DIR2_DATA_UNUSED_TAG_P(dup), ARCH_CONVERT));
738 /*
739 * Look up the entry in the bestfree table.
740 */
741 dfp = xfs_dir2_data_freefind(d, dup);
742 oldlen = INT_GET(dup->length, ARCH_CONVERT);
743 ASSERT(dfp || oldlen <= INT_GET(d->hdr.bestfree[2].length, ARCH_CONVERT));
744 /*
745 * Check for alignment with front and back of the entry.
746 */
747 matchfront = (char *)dup - (char *)d == offset;
748 matchback = (char *)dup + oldlen - (char *)d == offset + len;
749 ASSERT(*needscanp == 0);
750 needscan = 0;
751 /*
752 * If we matched it exactly we just need to get rid of it from
753 * the bestfree table.
754 */
755 if (matchfront && matchback) {
756 if (dfp) {
757 needscan = d->hdr.bestfree[2].offset;
758 if (!needscan)
759 xfs_dir2_data_freeremove(d, dfp, needlogp);
760 }
761 }
762 /*
763 * We match the first part of the entry.
764 * Make a new entry with the remaining freespace.
765 */
766 else if (matchfront) {
767 newdup = (xfs_dir2_data_unused_t *)((char *)d + offset + len);
768 INT_SET(newdup->freetag, ARCH_CONVERT, XFS_DIR2_DATA_FREE_TAG);
769 INT_SET(newdup->length, ARCH_CONVERT, oldlen - len);
770 INT_SET(*XFS_DIR2_DATA_UNUSED_TAG_P(newdup), ARCH_CONVERT,
771 (xfs_dir2_data_off_t)((char *)newdup - (char *)d));
772 xfs_dir2_data_log_unused(tp, bp, newdup);
773 /*
774 * If it was in the table, remove it and add the new one.
775 */
776 if (dfp) {
777 xfs_dir2_data_freeremove(d, dfp, needlogp);
778 dfp = xfs_dir2_data_freeinsert(d, newdup, needlogp);
779 ASSERT(dfp != NULL);
780 ASSERT(INT_GET(dfp->length, ARCH_CONVERT) == INT_GET(newdup->length, ARCH_CONVERT));
781 ASSERT(INT_GET(dfp->offset, ARCH_CONVERT) == (char *)newdup - (char *)d);
782 /*
783 * If we got inserted at the last slot,
784 * that means we don't know if there was a better
785 * choice for the last slot, or not. Rescan.
786 */
787 needscan = dfp == &d->hdr.bestfree[2];
788 }
789 }
790 /*
791 * We match the last part of the entry.
792 * Trim the allocated space off the tail of the entry.
793 */
794 else if (matchback) {
795 newdup = dup;
796 INT_SET(newdup->length, ARCH_CONVERT, (xfs_dir2_data_off_t)
797 (((char *)d + offset) - (char *)newdup));
798 INT_SET(*XFS_DIR2_DATA_UNUSED_TAG_P(newdup), ARCH_CONVERT,
799 (xfs_dir2_data_off_t)((char *)newdup - (char *)d));
800 xfs_dir2_data_log_unused(tp, bp, newdup);
801 /*
802 * If it was in the table, remove it and add the new one.
803 */
804 if (dfp) {
805 xfs_dir2_data_freeremove(d, dfp, needlogp);
806 dfp = xfs_dir2_data_freeinsert(d, newdup, needlogp);
807 ASSERT(dfp != NULL);
808 ASSERT(INT_GET(dfp->length, ARCH_CONVERT) == INT_GET(newdup->length, ARCH_CONVERT));
809 ASSERT(INT_GET(dfp->offset, ARCH_CONVERT) == (char *)newdup - (char *)d);
810 /*
811 * If we got inserted at the last slot,
812 * that means we don't know if there was a better
813 * choice for the last slot, or not. Rescan.
814 */
815 needscan = dfp == &d->hdr.bestfree[2];
816 }
817 }
818 /*
819 * Poking out the middle of an entry.
820 * Make two new entries.
821 */
822 else {
823 newdup = dup;
824 INT_SET(newdup->length, ARCH_CONVERT, (xfs_dir2_data_off_t)
825 (((char *)d + offset) - (char *)newdup));
826 INT_SET(*XFS_DIR2_DATA_UNUSED_TAG_P(newdup), ARCH_CONVERT,
827 (xfs_dir2_data_off_t)((char *)newdup - (char *)d));
828 xfs_dir2_data_log_unused(tp, bp, newdup);
829 newdup2 = (xfs_dir2_data_unused_t *)((char *)d + offset + len);
830 INT_SET(newdup2->freetag, ARCH_CONVERT, XFS_DIR2_DATA_FREE_TAG);
831 INT_SET(newdup2->length, ARCH_CONVERT, oldlen - len - INT_GET(newdup->length, ARCH_CONVERT));
832 INT_SET(*XFS_DIR2_DATA_UNUSED_TAG_P(newdup2), ARCH_CONVERT,
833 (xfs_dir2_data_off_t)((char *)newdup2 - (char *)d));
834 xfs_dir2_data_log_unused(tp, bp, newdup2);
835 /*
836 * If the old entry was in the table, we need to scan
837 * if the 3rd entry was valid, since these entries
838 * are smaller than the old one.
839 * If we don't need to scan that means there were 1 or 2
840 * entries in the table, and removing the old and adding
841 * the 2 new will work.
842 */
843 if (dfp) {
844 needscan = d->hdr.bestfree[2].length;
845 if (!needscan) {
846 xfs_dir2_data_freeremove(d, dfp, needlogp);
847 (void)xfs_dir2_data_freeinsert(d, newdup,
848 needlogp);
849 (void)xfs_dir2_data_freeinsert(d, newdup2,
850 needlogp);
851 }
852 }
853 }
854 *needscanp = needscan;
855 }
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree