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[CONNECTOR]: Initialize subsystem earlier.
[linux-2.6/verdex.git] / fs / ocfs2 / extent_map.c
blob1a5c69071df642afbe99a04ed348b33c955c9861
1 /* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
3 *
4 * extent_map.c
5 *
6 * In-memory extent map for OCFS2. Man, this code was prettier in
7 * the library.
8 *
9 * Copyright (C) 2004 Oracle. All rights reserved.
10 *
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public
13 * License, version 2, as published by the Free Software Foundation.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public
21 * License along with this program; if not, write to the
22 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23 * Boston, MA 021110-1307, USA.
24 */
25
26 #include <linux/fs.h>
27 #include <linux/init.h>
28 #include <linux/types.h>
29 #include <linux/slab.h>
30 #include <linux/rbtree.h>
31
32 #define MLOG_MASK_PREFIX ML_EXTENT_MAP
33 #include <cluster/masklog.h>
34
35 #include "ocfs2.h"
36
37 #include "extent_map.h"
38 #include "inode.h"
39 #include "super.h"
40
41 #include "buffer_head_io.h"
42
43
44 /*
45 * SUCK SUCK SUCK
46 * Our headers are so bad that struct ocfs2_extent_map is in ocfs.h
47 */
48
49 struct ocfs2_extent_map_entry {
50 struct rb_node e_node;
51 int e_tree_depth;
52 struct ocfs2_extent_rec e_rec;
53 };
54
55 struct ocfs2_em_insert_context {
56 int need_left;
57 int need_right;
58 struct ocfs2_extent_map_entry *new_ent;
59 struct ocfs2_extent_map_entry *old_ent;
60 struct ocfs2_extent_map_entry *left_ent;
61 struct ocfs2_extent_map_entry *right_ent;
62 };
63
64 static kmem_cache_t *ocfs2_em_ent_cachep = NULL;
65
66
67 static struct ocfs2_extent_map_entry *
68 ocfs2_extent_map_lookup(struct ocfs2_extent_map *em,
69 u32 cpos, u32 clusters,
70 struct rb_node ***ret_p,
71 struct rb_node **ret_parent);
72 static int ocfs2_extent_map_insert(struct inode *inode,
73 struct ocfs2_extent_rec *rec,
74 int tree_depth);
75 static int ocfs2_extent_map_insert_entry(struct ocfs2_extent_map *em,
76 struct ocfs2_extent_map_entry *ent);
77 static int ocfs2_extent_map_find_leaf(struct inode *inode,
78 u32 cpos, u32 clusters,
79 struct ocfs2_extent_list *el);
80 static int ocfs2_extent_map_lookup_read(struct inode *inode,
81 u32 cpos, u32 clusters,
82 struct ocfs2_extent_map_entry **ret_ent);
83 static int ocfs2_extent_map_try_insert(struct inode *inode,
84 struct ocfs2_extent_rec *rec,
85 int tree_depth,
86 struct ocfs2_em_insert_context *ctxt);
87
88 /* returns 1 only if the rec contains all the given clusters -- that is that
89 * rec's cpos is <= the cluster cpos and that the rec endpoint (cpos +
90 * clusters) is >= the argument's endpoint */
91 static int ocfs2_extent_rec_contains_clusters(struct ocfs2_extent_rec *rec,
92 u32 cpos, u32 clusters)
93 {
94 if (le32_to_cpu(rec->e_cpos) > cpos)
95 return 0;
96 if (cpos + clusters > le32_to_cpu(rec->e_cpos) +
97 le32_to_cpu(rec->e_clusters))
98 return 0;
99 return 1;
100 }
101
102
103 /*
104 * Find an entry in the tree that intersects the region passed in.
105 * Note that this will find straddled intervals, it is up to the
106 * callers to enforce any boundary conditions.
107 *
108 * Callers must hold ip_lock. This lookup is not guaranteed to return
109 * a tree_depth 0 match, and as such can race inserts if the lock
110 * were not held.
111 *
112 * The rb_node garbage lets insertion share the search. Trivial
113 * callers pass NULL.
114 */
115 static struct ocfs2_extent_map_entry *
116 ocfs2_extent_map_lookup(struct ocfs2_extent_map *em,
117 u32 cpos, u32 clusters,
118 struct rb_node ***ret_p,
119 struct rb_node **ret_parent)
120 {
121 struct rb_node **p = &em->em_extents.rb_node;
122 struct rb_node *parent = NULL;
123 struct ocfs2_extent_map_entry *ent = NULL;
124
125 while (*p)
126 {
127 parent = *p;
128 ent = rb_entry(parent, struct ocfs2_extent_map_entry,
129 e_node);
130 if ((cpos + clusters) <= le32_to_cpu(ent->e_rec.e_cpos)) {
131 p = &(*p)->rb_left;
132 ent = NULL;
133 } else if (cpos >= (le32_to_cpu(ent->e_rec.e_cpos) +
134 le32_to_cpu(ent->e_rec.e_clusters))) {
135 p = &(*p)->rb_right;
136 ent = NULL;
137 } else
138 break;
139 }
140
141 if (ret_p != NULL)
142 *ret_p = p;
143 if (ret_parent != NULL)
144 *ret_parent = parent;
145 return ent;
146 }
147
148 /*
149 * Find the leaf containing the interval we want. While we're on our
150 * way down the tree, fill in every record we see at any depth, because
151 * we might want it later.
152 *
153 * Note that this code is run without ip_lock. That's because it
154 * sleeps while reading. If someone is also filling the extent list at
155 * the same time we are, we might have to restart.
156 */
157 static int ocfs2_extent_map_find_leaf(struct inode *inode,
158 u32 cpos, u32 clusters,
159 struct ocfs2_extent_list *el)
160 {
161 int i, ret;
162 struct buffer_head *eb_bh = NULL;
163 u64 blkno;
164 u32 rec_end;
165 struct ocfs2_extent_block *eb;
166 struct ocfs2_extent_rec *rec;
167
168 /*
169 * The bh data containing the el cannot change here, because
170 * we hold alloc_sem. So we can do this without other
171 * locks.
172 */
173 while (el->l_tree_depth)
174 {
175 blkno = 0;
176 for (i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
177 rec = &el->l_recs[i];
178 rec_end = (le32_to_cpu(rec->e_cpos) +
179 le32_to_cpu(rec->e_clusters));
180
181 ret = -EBADR;
182 if (rec_end > OCFS2_I(inode)->ip_clusters) {
183 mlog_errno(ret);
184 ocfs2_error(inode->i_sb,
185 "Extent %d at e_blkno %llu of inode %llu goes past ip_clusters of %u\n",
186 i,
187 (unsigned long long)le64_to_cpu(rec->e_blkno),
188 (unsigned long long)OCFS2_I(inode)->ip_blkno,
189 OCFS2_I(inode)->ip_clusters);
190 goto out_free;
191 }
192
193 if (rec_end <= cpos) {
194 ret = ocfs2_extent_map_insert(inode, rec,
195 le16_to_cpu(el->l_tree_depth));
196 if (ret && (ret != -EEXIST)) {
197 mlog_errno(ret);
198 goto out_free;
199 }
200 continue;
201 }
202 if ((cpos + clusters) <= le32_to_cpu(rec->e_cpos)) {
203 ret = ocfs2_extent_map_insert(inode, rec,
204 le16_to_cpu(el->l_tree_depth));
205 if (ret && (ret != -EEXIST)) {
206 mlog_errno(ret);
207 goto out_free;
208 }
209 continue;
210 }
211
212 /*
213 * We've found a record that matches our
214 * interval. We don't insert it because we're
215 * about to traverse it.
216 */
217
218 /* Check to see if we're stradling */
219 ret = -ESRCH;
220 if (!ocfs2_extent_rec_contains_clusters(rec,
221 cpos,
222 clusters)) {
223 mlog_errno(ret);
224 goto out_free;
225 }
226
227 /*
228 * If we've already found a record, the el has
229 * two records covering the same interval.
230 * EEEK!
231 */
232 ret = -EBADR;
233 if (blkno) {
234 mlog_errno(ret);
235 ocfs2_error(inode->i_sb,
236 "Multiple extents for (cpos = %u, clusters = %u) on inode %llu; e_blkno %llu and rec %d at e_blkno %llu\n",
237 cpos, clusters,
238 (unsigned long long)OCFS2_I(inode)->ip_blkno,
239 (unsigned long long)blkno, i,
240 (unsigned long long)le64_to_cpu(rec->e_blkno));
241 goto out_free;
242 }
243
244 blkno = le64_to_cpu(rec->e_blkno);
245 }
246
247 /*
248 * We don't support holes, and we're still up
249 * in the branches, so we'd better have found someone
250 */
251 ret = -EBADR;
252 if (!blkno) {
253 ocfs2_error(inode->i_sb,
254 "No record found for (cpos = %u, clusters = %u) on inode %llu\n",
255 cpos, clusters,
256 (unsigned long long)OCFS2_I(inode)->ip_blkno);
257 mlog_errno(ret);
258 goto out_free;
259 }
260
261 if (eb_bh) {
262 brelse(eb_bh);
263 eb_bh = NULL;
264 }
265 ret = ocfs2_read_block(OCFS2_SB(inode->i_sb),
266 blkno, &eb_bh, OCFS2_BH_CACHED,
267 inode);
268 if (ret) {
269 mlog_errno(ret);
270 goto out_free;
271 }
272 eb = (struct ocfs2_extent_block *)eb_bh->b_data;
273 if (!OCFS2_IS_VALID_EXTENT_BLOCK(eb)) {
274 OCFS2_RO_ON_INVALID_EXTENT_BLOCK(inode->i_sb, eb);
275 ret = -EIO;
276 goto out_free;
277 }
278 el = &eb->h_list;
279 }
280
281 BUG_ON(el->l_tree_depth);
282
283 for (i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
284 rec = &el->l_recs[i];
285
286 if ((le32_to_cpu(rec->e_cpos) + le32_to_cpu(rec->e_clusters)) >
287 OCFS2_I(inode)->ip_clusters) {
288 ret = -EBADR;
289 mlog_errno(ret);
290 ocfs2_error(inode->i_sb,
291 "Extent %d at e_blkno %llu of inode %llu goes past ip_clusters of %u\n",
292 i,
293 (unsigned long long)le64_to_cpu(rec->e_blkno),
294 (unsigned long long)OCFS2_I(inode)->ip_blkno,
295 OCFS2_I(inode)->ip_clusters);
296 return ret;
297 }
298
299 ret = ocfs2_extent_map_insert(inode, rec,
300 le16_to_cpu(el->l_tree_depth));
301 if (ret) {
302 mlog_errno(ret);
303 goto out_free;
304 }
305 }
306
307 ret = 0;
308
309 out_free:
310 if (eb_bh)
311 brelse(eb_bh);
312
313 return ret;
314 }
315
316 /*
317 * This lookup actually will read from disk. It has one invariant:
318 * It will never re-traverse blocks. This means that all inserts should
319 * be new regions or more granular regions (both allowed by insert).
320 */
321 static int ocfs2_extent_map_lookup_read(struct inode *inode,
322 u32 cpos,
323 u32 clusters,
324 struct ocfs2_extent_map_entry **ret_ent)
325 {
326 int ret;
327 u64 blkno;
328 struct ocfs2_extent_map *em = &OCFS2_I(inode)->ip_map;
329 struct ocfs2_extent_map_entry *ent;
330 struct buffer_head *bh = NULL;
331 struct ocfs2_extent_block *eb;
332 struct ocfs2_dinode *di;
333 struct ocfs2_extent_list *el;
334
335 spin_lock(&OCFS2_I(inode)->ip_lock);
336 ent = ocfs2_extent_map_lookup(em, cpos, clusters, NULL, NULL);
337 if (ent) {
338 if (!ent->e_tree_depth) {
339 spin_unlock(&OCFS2_I(inode)->ip_lock);
340 *ret_ent = ent;
341 return 0;
342 }
343 blkno = le64_to_cpu(ent->e_rec.e_blkno);
344 spin_unlock(&OCFS2_I(inode)->ip_lock);
345
346 ret = ocfs2_read_block(OCFS2_SB(inode->i_sb), blkno, &bh,
347 OCFS2_BH_CACHED, inode);
348 if (ret) {
349 mlog_errno(ret);
350 if (bh)
351 brelse(bh);
352 return ret;
353 }
354 eb = (struct ocfs2_extent_block *)bh->b_data;
355 if (!OCFS2_IS_VALID_EXTENT_BLOCK(eb)) {
356 OCFS2_RO_ON_INVALID_EXTENT_BLOCK(inode->i_sb, eb);
357 brelse(bh);
358 return -EIO;
359 }
360 el = &eb->h_list;
361 } else {
362 spin_unlock(&OCFS2_I(inode)->ip_lock);
363
364 ret = ocfs2_read_block(OCFS2_SB(inode->i_sb),
365 OCFS2_I(inode)->ip_blkno, &bh,
366 OCFS2_BH_CACHED, inode);
367 if (ret) {
368 mlog_errno(ret);
369 if (bh)
370 brelse(bh);
371 return ret;
372 }
373 di = (struct ocfs2_dinode *)bh->b_data;
374 if (!OCFS2_IS_VALID_DINODE(di)) {
375 brelse(bh);
376 OCFS2_RO_ON_INVALID_DINODE(inode->i_sb, di);
377 return -EIO;
378 }
379 el = &di->id2.i_list;
380 }
381
382 ret = ocfs2_extent_map_find_leaf(inode, cpos, clusters, el);
383 brelse(bh);
384 if (ret) {
385 mlog_errno(ret);
386 return ret;
387 }
388
389 ent = ocfs2_extent_map_lookup(em, cpos, clusters, NULL, NULL);
390 if (!ent) {
391 ret = -ESRCH;
392 mlog_errno(ret);
393 return ret;
394 }
395
396 /* FIXME: Make sure this isn't a corruption */
397 BUG_ON(ent->e_tree_depth);
398
399 *ret_ent = ent;
400
401 return 0;
402 }
403
404 /*
405 * Callers must hold ip_lock. This can insert pieces of the tree,
406 * thus racing lookup if the lock weren't held.
407 */
408 static int ocfs2_extent_map_insert_entry(struct ocfs2_extent_map *em,
409 struct ocfs2_extent_map_entry *ent)
410 {
411 struct rb_node **p, *parent;
412 struct ocfs2_extent_map_entry *old_ent;
413
414 old_ent = ocfs2_extent_map_lookup(em, le32_to_cpu(ent->e_rec.e_cpos),
415 le32_to_cpu(ent->e_rec.e_clusters),
416 &p, &parent);
417 if (old_ent)
418 return -EEXIST;
419
420 rb_link_node(&ent->e_node, parent, p);
421 rb_insert_color(&ent->e_node, &em->em_extents);
422
423 return 0;
424 }
425
426
427 /*
428 * Simple rule: on any return code other than -EAGAIN, anything left
429 * in the insert_context will be freed.
430 */
431 static int ocfs2_extent_map_try_insert(struct inode *inode,
432 struct ocfs2_extent_rec *rec,
433 int tree_depth,
434 struct ocfs2_em_insert_context *ctxt)
435 {
436 int ret;
437 struct ocfs2_extent_map *em = &OCFS2_I(inode)->ip_map;
438 struct ocfs2_extent_map_entry *old_ent;
439
440 ctxt->need_left = 0;
441 ctxt->need_right = 0;
442 ctxt->old_ent = NULL;
443
444 spin_lock(&OCFS2_I(inode)->ip_lock);
445 ret = ocfs2_extent_map_insert_entry(em, ctxt->new_ent);
446 if (!ret) {
447 ctxt->new_ent = NULL;
448 goto out_unlock;
449 }
450
451 old_ent = ocfs2_extent_map_lookup(em, le32_to_cpu(rec->e_cpos),
452 le32_to_cpu(rec->e_clusters), NULL,
453 NULL);
454
455 BUG_ON(!old_ent);
456
457 ret = -EEXIST;
458 if (old_ent->e_tree_depth < tree_depth)
459 goto out_unlock;
460
461 if (old_ent->e_tree_depth == tree_depth) {
462 if (!memcmp(rec, &old_ent->e_rec,
463 sizeof(struct ocfs2_extent_rec)))
464 ret = 0;
465
466 /* FIXME: Should this be ESRCH/EBADR??? */
467 goto out_unlock;
468 }
469
470 /*
471 * We do it in this order specifically so that no actual tree
472 * changes occur until we have all the pieces we need. We
473 * don't want malloc failures to leave an inconsistent tree.
474 * Whenever we drop the lock, another process could be
475 * inserting. Also note that, if another process just beat us
476 * to an insert, we might not need the same pieces we needed
477 * the first go round. In the end, the pieces we need will
478 * be used, and the pieces we don't will be freed.
479 */
480 ctxt->need_left = !!(le32_to_cpu(rec->e_cpos) >
481 le32_to_cpu(old_ent->e_rec.e_cpos));
482 ctxt->need_right = !!((le32_to_cpu(old_ent->e_rec.e_cpos) +
483 le32_to_cpu(old_ent->e_rec.e_clusters)) >
484 (le32_to_cpu(rec->e_cpos) + le32_to_cpu(rec->e_clusters)));
485 ret = -EAGAIN;
486 if (ctxt->need_left) {
487 if (!ctxt->left_ent)
488 goto out_unlock;
489 *(ctxt->left_ent) = *old_ent;
490 ctxt->left_ent->e_rec.e_clusters =
491 cpu_to_le32(le32_to_cpu(rec->e_cpos) -
492 le32_to_cpu(ctxt->left_ent->e_rec.e_cpos));
493 }
494 if (ctxt->need_right) {
495 if (!ctxt->right_ent)
496 goto out_unlock;
497 *(ctxt->right_ent) = *old_ent;
498 ctxt->right_ent->e_rec.e_cpos =
499 cpu_to_le32(le32_to_cpu(rec->e_cpos) +
500 le32_to_cpu(rec->e_clusters));
501 ctxt->right_ent->e_rec.e_clusters =
502 cpu_to_le32((le32_to_cpu(old_ent->e_rec.e_cpos) +
503 le32_to_cpu(old_ent->e_rec.e_clusters)) -
504 le32_to_cpu(ctxt->right_ent->e_rec.e_cpos));
505 }
506
507 rb_erase(&old_ent->e_node, &em->em_extents);
508 /* Now that he's erased, set him up for deletion */
509 ctxt->old_ent = old_ent;
510
511 if (ctxt->need_left) {
512 ret = ocfs2_extent_map_insert_entry(em,
513 ctxt->left_ent);
514 if (ret)
515 goto out_unlock;
516 ctxt->left_ent = NULL;
517 }
518
519 if (ctxt->need_right) {
520 ret = ocfs2_extent_map_insert_entry(em,
521 ctxt->right_ent);
522 if (ret)
523 goto out_unlock;
524 ctxt->right_ent = NULL;
525 }
526
527 ret = ocfs2_extent_map_insert_entry(em, ctxt->new_ent);
528
529 if (!ret)
530 ctxt->new_ent = NULL;
531
532 out_unlock:
533 spin_unlock(&OCFS2_I(inode)->ip_lock);
534
535 return ret;
536 }
537
538
539 static int ocfs2_extent_map_insert(struct inode *inode,
540 struct ocfs2_extent_rec *rec,
541 int tree_depth)
542 {
543 int ret;
544 struct ocfs2_em_insert_context ctxt = {0, };
545
546 if ((le32_to_cpu(rec->e_cpos) + le32_to_cpu(rec->e_clusters)) >
547 OCFS2_I(inode)->ip_map.em_clusters) {
548 ret = -EBADR;
549 mlog_errno(ret);
550 return ret;
551 }
552
553 /* Zero e_clusters means a truncated tail record. It better be EOF */
554 if (!rec->e_clusters) {
555 if ((le32_to_cpu(rec->e_cpos) + le32_to_cpu(rec->e_clusters)) !=
556 OCFS2_I(inode)->ip_map.em_clusters) {
557 ret = -EBADR;
558 mlog_errno(ret);
559 ocfs2_error(inode->i_sb,
560 "Zero e_clusters on non-tail extent record at e_blkno %llu on inode %llu\n",
561 (unsigned long long)le64_to_cpu(rec->e_blkno),
562 (unsigned long long)OCFS2_I(inode)->ip_blkno);
563 return ret;
564 }
565
566 /* Ignore the truncated tail */
567 return 0;
568 }
569
570 ret = -ENOMEM;
571 ctxt.new_ent = kmem_cache_alloc(ocfs2_em_ent_cachep,
572 GFP_NOFS);
573 if (!ctxt.new_ent) {
574 mlog_errno(ret);
575 return ret;
576 }
577
578 ctxt.new_ent->e_rec = *rec;
579 ctxt.new_ent->e_tree_depth = tree_depth;
580
581 do {
582 ret = -ENOMEM;
583 if (ctxt.need_left && !ctxt.left_ent) {
584 ctxt.left_ent =
585 kmem_cache_alloc(ocfs2_em_ent_cachep,
586 GFP_NOFS);
587 if (!ctxt.left_ent)
588 break;
589 }
590 if (ctxt.need_right && !ctxt.right_ent) {
591 ctxt.right_ent =
592 kmem_cache_alloc(ocfs2_em_ent_cachep,
593 GFP_NOFS);
594 if (!ctxt.right_ent)
595 break;
596 }
597
598 ret = ocfs2_extent_map_try_insert(inode, rec,
599 tree_depth, &ctxt);
600 } while (ret == -EAGAIN);
601
602 if (ret < 0)
603 mlog_errno(ret);
604
605 if (ctxt.left_ent)
606 kmem_cache_free(ocfs2_em_ent_cachep, ctxt.left_ent);
607 if (ctxt.right_ent)
608 kmem_cache_free(ocfs2_em_ent_cachep, ctxt.right_ent);
609 if (ctxt.old_ent)
610 kmem_cache_free(ocfs2_em_ent_cachep, ctxt.old_ent);
611 if (ctxt.new_ent)
612 kmem_cache_free(ocfs2_em_ent_cachep, ctxt.new_ent);
613
614 return ret;
615 }
616
617 /*
618 * Append this record to the tail of the extent map. It must be
619 * tree_depth 0. The record might be an extension of an existing
620 * record, and as such that needs to be handled. eg:
621 *
622 * Existing record in the extent map:
623 *
624 * cpos = 10, len = 10
625 * |---------|
626 *
627 * New Record:
628 *
629 * cpos = 10, len = 20
630 * |------------------|
631 *
632 * The passed record is the new on-disk record. The new_clusters value
633 * is how many clusters were added to the file. If the append is a
634 * contiguous append, the new_clusters has been added to
635 * rec->e_clusters. If the append is an entirely new extent, then
636 * rec->e_clusters is == new_clusters.
637 */
638 int ocfs2_extent_map_append(struct inode *inode,
639 struct ocfs2_extent_rec *rec,
640 u32 new_clusters)
641 {
642 int ret;
643 struct ocfs2_extent_map *em = &OCFS2_I(inode)->ip_map;
644 struct ocfs2_extent_map_entry *ent;
645 struct ocfs2_extent_rec *old;
646
647 BUG_ON(!new_clusters);
648 BUG_ON(le32_to_cpu(rec->e_clusters) < new_clusters);
649
650 if (em->em_clusters < OCFS2_I(inode)->ip_clusters) {
651 /*
652 * Size changed underneath us on disk. Drop any
653 * straddling records and update our idea of
654 * i_clusters
655 */
656 ocfs2_extent_map_drop(inode, em->em_clusters - 1);
657 em->em_clusters = OCFS2_I(inode)->ip_clusters;
658 }
659
660 mlog_bug_on_msg((le32_to_cpu(rec->e_cpos) +
661 le32_to_cpu(rec->e_clusters)) !=
662 (em->em_clusters + new_clusters),
663 "Inode %llu:\n"
664 "rec->e_cpos = %u + rec->e_clusters = %u = %u\n"
665 "em->em_clusters = %u + new_clusters = %u = %u\n",
666 (unsigned long long)OCFS2_I(inode)->ip_blkno,
667 le32_to_cpu(rec->e_cpos), le32_to_cpu(rec->e_clusters),
668 le32_to_cpu(rec->e_cpos) + le32_to_cpu(rec->e_clusters),
669 em->em_clusters, new_clusters,
670 em->em_clusters + new_clusters);
671
672 em->em_clusters += new_clusters;
673
674 ret = -ENOENT;
675 if (le32_to_cpu(rec->e_clusters) > new_clusters) {
676 /* This is a contiguous append */
677 ent = ocfs2_extent_map_lookup(em, le32_to_cpu(rec->e_cpos), 1,
678 NULL, NULL);
679 if (ent) {
680 old = &ent->e_rec;
681 BUG_ON((le32_to_cpu(rec->e_cpos) +
682 le32_to_cpu(rec->e_clusters)) !=
683 (le32_to_cpu(old->e_cpos) +
684 le32_to_cpu(old->e_clusters) +
685 new_clusters));
686 if (ent->e_tree_depth == 0) {
687 BUG_ON(le32_to_cpu(old->e_cpos) !=
688 le32_to_cpu(rec->e_cpos));
689 BUG_ON(le64_to_cpu(old->e_blkno) !=
690 le64_to_cpu(rec->e_blkno));
691 ret = 0;
692 }
693 /*
694 * Let non-leafs fall through as -ENOENT to
695 * force insertion of the new leaf.
696 */
697 le32_add_cpu(&old->e_clusters, new_clusters);
698 }
699 }
700
701 if (ret == -ENOENT)
702 ret = ocfs2_extent_map_insert(inode, rec, 0);
703 if (ret < 0)
704 mlog_errno(ret);
705 return ret;
706 }
707
708 #if 0
709 /* Code here is included but defined out as it completes the extent
710 * map api and may be used in the future. */
711
712 /*
713 * Look up the record containing this cluster offset. This record is
714 * part of the extent map. Do not free it. Any changes you make to
715 * it will reflect in the extent map. So, if your last extent
716 * is (cpos = 10, clusters = 10) and you truncate the file by 5
717 * clusters, you can do:
718 *
719 * ret = ocfs2_extent_map_get_rec(em, orig_size - 5, &rec);
720 * rec->e_clusters -= 5;
721 *
722 * The lookup does not read from disk. If the map isn't filled in for
723 * an entry, you won't find it.
724 *
725 * Also note that the returned record is valid until alloc_sem is
726 * dropped. After that, truncate and extend can happen. Caveat Emptor.
727 */
728 int ocfs2_extent_map_get_rec(struct inode *inode, u32 cpos,
729 struct ocfs2_extent_rec **rec,
730 int *tree_depth)
731 {
732 int ret = -ENOENT;
733 struct ocfs2_extent_map *em = &OCFS2_I(inode)->ip_map;
734 struct ocfs2_extent_map_entry *ent;
735
736 *rec = NULL;
737
738 if (cpos >= OCFS2_I(inode)->ip_clusters)
739 return -EINVAL;
740
741 if (cpos >= em->em_clusters) {
742 /*
743 * Size changed underneath us on disk. Drop any
744 * straddling records and update our idea of
745 * i_clusters
746 */
747 ocfs2_extent_map_drop(inode, em->em_clusters - 1);
748 em->em_clusters = OCFS2_I(inode)->ip_clusters ;
749 }
750
751 ent = ocfs2_extent_map_lookup(&OCFS2_I(inode)->ip_map, cpos, 1,
752 NULL, NULL);
753
754 if (ent) {
755 *rec = &ent->e_rec;
756 if (tree_depth)
757 *tree_depth = ent->e_tree_depth;
758 ret = 0;
759 }
760
761 return ret;
762 }
763
764 int ocfs2_extent_map_get_clusters(struct inode *inode,
765 u32 v_cpos, int count,
766 u32 *p_cpos, int *ret_count)
767 {
768 int ret;
769 u32 coff, ccount;
770 struct ocfs2_extent_map *em = &OCFS2_I(inode)->ip_map;
771 struct ocfs2_extent_map_entry *ent = NULL;
772
773 *p_cpos = ccount = 0;
774
775 if ((v_cpos + count) > OCFS2_I(inode)->ip_clusters)
776 return -EINVAL;
777
778 if ((v_cpos + count) > em->em_clusters) {
779 /*
780 * Size changed underneath us on disk. Drop any
781 * straddling records and update our idea of
782 * i_clusters
783 */
784 ocfs2_extent_map_drop(inode, em->em_clusters - 1);
785 em->em_clusters = OCFS2_I(inode)->ip_clusters;
786 }
787
788
789 ret = ocfs2_extent_map_lookup_read(inode, v_cpos, count, &ent);
790 if (ret)
791 return ret;
792
793 if (ent) {
794 /* We should never find ourselves straddling an interval */
795 if (!ocfs2_extent_rec_contains_clusters(&ent->e_rec,
796 v_cpos,
797 count))
798 return -ESRCH;
799
800 coff = v_cpos - le32_to_cpu(ent->e_rec.e_cpos);
801 *p_cpos = ocfs2_blocks_to_clusters(inode->i_sb,
802 le64_to_cpu(ent->e_rec.e_blkno)) +
803 coff;
804
805 if (ret_count)
806 *ret_count = le32_to_cpu(ent->e_rec.e_clusters) - coff;
807
808 return 0;
809 }
810
811
812 return -ENOENT;
813 }
814
815 #endif /* 0 */
816
817 int ocfs2_extent_map_get_blocks(struct inode *inode,
818 u64 v_blkno, int count,
819 u64 *p_blkno, int *ret_count)
820 {
821 int ret;
822 u64 boff;
823 u32 cpos, clusters;
824 int bpc = ocfs2_clusters_to_blocks(inode->i_sb, 1);
825 struct ocfs2_extent_map_entry *ent = NULL;
826 struct ocfs2_extent_map *em = &OCFS2_I(inode)->ip_map;
827 struct ocfs2_extent_rec *rec;
828
829 *p_blkno = 0;
830
831 cpos = ocfs2_blocks_to_clusters(inode->i_sb, v_blkno);
832 clusters = ocfs2_blocks_to_clusters(inode->i_sb,
833 (u64)count + bpc - 1);
834 if ((cpos + clusters) > OCFS2_I(inode)->ip_clusters) {
835 ret = -EINVAL;
836 mlog_errno(ret);
837 return ret;
838 }
839
840 if ((cpos + clusters) > em->em_clusters) {
841 /*
842 * Size changed underneath us on disk. Drop any
843 * straddling records and update our idea of
844 * i_clusters
845 */
846 ocfs2_extent_map_drop(inode, em->em_clusters - 1);
847 em->em_clusters = OCFS2_I(inode)->ip_clusters;
848 }
849
850 ret = ocfs2_extent_map_lookup_read(inode, cpos, clusters, &ent);
851 if (ret) {
852 mlog_errno(ret);
853 return ret;
854 }
855
856 if (ent)
857 {
858 rec = &ent->e_rec;
859
860 /* We should never find ourselves straddling an interval */
861 if (!ocfs2_extent_rec_contains_clusters(rec, cpos, clusters)) {
862 ret = -ESRCH;
863 mlog_errno(ret);
864 return ret;
865 }
866
867 boff = ocfs2_clusters_to_blocks(inode->i_sb, cpos -
868 le32_to_cpu(rec->e_cpos));
869 boff += (v_blkno & (u64)(bpc - 1));
870 *p_blkno = le64_to_cpu(rec->e_blkno) + boff;
871
872 if (ret_count) {
873 *ret_count = ocfs2_clusters_to_blocks(inode->i_sb,
874 le32_to_cpu(rec->e_clusters)) - boff;
875 }
876
877 return 0;
878 }
879
880 return -ENOENT;
881 }
882
883 int ocfs2_extent_map_init(struct inode *inode)
884 {
885 struct ocfs2_extent_map *em = &OCFS2_I(inode)->ip_map;
886
887 em->em_extents = RB_ROOT;
888 em->em_clusters = 0;
889
890 return 0;
891 }
892
893 /* Needs the lock */
894 static void __ocfs2_extent_map_drop(struct inode *inode,
895 u32 new_clusters,
896 struct rb_node **free_head,
897 struct ocfs2_extent_map_entry **tail_ent)
898 {
899 struct rb_node *node, *next;
900 struct ocfs2_extent_map *em = &OCFS2_I(inode)->ip_map;
901 struct ocfs2_extent_map_entry *ent;
902
903 *free_head = NULL;
904
905 ent = NULL;
906 node = rb_last(&em->em_extents);
907 while (node)
908 {
909 next = rb_prev(node);
910
911 ent = rb_entry(node, struct ocfs2_extent_map_entry,
912 e_node);
913 if (le32_to_cpu(ent->e_rec.e_cpos) < new_clusters)
914 break;
915
916 rb_erase(&ent->e_node, &em->em_extents);
917
918 node->rb_right = *free_head;
919 *free_head = node;
920
921 ent = NULL;
922 node = next;
923 }
924
925 /* Do we have an entry straddling new_clusters? */
926 if (tail_ent) {
927 if (ent &&
928 ((le32_to_cpu(ent->e_rec.e_cpos) +
929 le32_to_cpu(ent->e_rec.e_clusters)) > new_clusters))
930 *tail_ent = ent;
931 else
932 *tail_ent = NULL;
933 }
934 }
935
936 static void __ocfs2_extent_map_drop_cleanup(struct rb_node *free_head)
937 {
938 struct rb_node *node;
939 struct ocfs2_extent_map_entry *ent;
940
941 while (free_head) {
942 node = free_head;
943 free_head = node->rb_right;
944
945 ent = rb_entry(node, struct ocfs2_extent_map_entry,
946 e_node);
947 kmem_cache_free(ocfs2_em_ent_cachep, ent);
948 }
949 }
950
951 /*
952 * Remove all entries past new_clusters, inclusive of an entry that
953 * contains new_clusters. This is effectively a cache forget.
954 *
955 * If you want to also clip the last extent by some number of clusters,
956 * you need to call ocfs2_extent_map_trunc().
957 * This code does not check or modify ip_clusters.
958 */
959 int ocfs2_extent_map_drop(struct inode *inode, u32 new_clusters)
960 {
961 struct rb_node *free_head = NULL;
962 struct ocfs2_extent_map *em = &OCFS2_I(inode)->ip_map;
963 struct ocfs2_extent_map_entry *ent;
964
965 spin_lock(&OCFS2_I(inode)->ip_lock);
966
967 __ocfs2_extent_map_drop(inode, new_clusters, &free_head, &ent);
968
969 if (ent) {
970 rb_erase(&ent->e_node, &em->em_extents);
971 ent->e_node.rb_right = free_head;
972 free_head = &ent->e_node;
973 }
974
975 spin_unlock(&OCFS2_I(inode)->ip_lock);
976
977 if (free_head)
978 __ocfs2_extent_map_drop_cleanup(free_head);
979
980 return 0;
981 }
982
983 /*
984 * Remove all entries past new_clusters and also clip any extent
985 * straddling new_clusters, if there is one. This does not check
986 * or modify ip_clusters
987 */
988 int ocfs2_extent_map_trunc(struct inode *inode, u32 new_clusters)
989 {
990 struct rb_node *free_head = NULL;
991 struct ocfs2_extent_map_entry *ent = NULL;
992
993 spin_lock(&OCFS2_I(inode)->ip_lock);
994
995 __ocfs2_extent_map_drop(inode, new_clusters, &free_head, &ent);
996
997 if (ent)
998 ent->e_rec.e_clusters = cpu_to_le32(new_clusters -
999 le32_to_cpu(ent->e_rec.e_cpos));
1000
1001 OCFS2_I(inode)->ip_map.em_clusters = new_clusters;
1002
1003 spin_unlock(&OCFS2_I(inode)->ip_lock);
1004
1005 if (free_head)
1006 __ocfs2_extent_map_drop_cleanup(free_head);
1007
1008 return 0;
1009 }
1010
1011 int __init init_ocfs2_extent_maps(void)
1012 {
1013 ocfs2_em_ent_cachep =
1014 kmem_cache_create("ocfs2_em_ent",
1015 sizeof(struct ocfs2_extent_map_entry),
1016 0, SLAB_HWCACHE_ALIGN, NULL, NULL);
1017 if (!ocfs2_em_ent_cachep)
1018 return -ENOMEM;
1019
1020 return 0;
1021 }
1022
1023 void exit_ocfs2_extent_maps(void)
1024 {
1025 kmem_cache_destroy(ocfs2_em_ent_cachep);
1026 }
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