1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * extent_map.c
4 *
5 * Block/Cluster mapping functions
6 *
7 * Copyright (C) 2004 Oracle. All rights reserved.
8 */
9
10 #include <linux/fs.h>
11 #include <linux/init.h>
12 #include <linux/slab.h>
13 #include <linux/types.h>
14 #include <linux/fiemap.h>
15
16 #include <cluster/masklog.h>
17
18 #include "ocfs2.h"
19
20 #include "alloc.h"
21 #include "dlmglue.h"
22 #include "extent_map.h"
23 #include "inode.h"
24 #include "super.h"
25 #include "symlink.h"
26 #include "aops.h"
27 #include "ocfs2_trace.h"
28
29 #include "buffer_head_io.h"
30
31 /*
32 * The extent caching implementation is intentionally trivial.
33 *
34 * We only cache a small number of extents stored directly on the
35 * inode, so linear order operations are acceptable. If we ever want
36 * to increase the size of the extent map, then these algorithms must
37 * get smarter.
38 */
39
40 void ocfs2_extent_map_init(struct inode *inode)
41 {
42 struct ocfs2_inode_info *oi = OCFS2_I(inode);
43
44 oi->ip_extent_map.em_num_items = 0;
45 INIT_LIST_HEAD(&oi->ip_extent_map.em_list);
46 }
47
48 static void __ocfs2_extent_map_lookup(struct ocfs2_extent_map *em,
49 unsigned int cpos,
50 struct ocfs2_extent_map_item **ret_emi)
51 {
52 unsigned int range;
53 struct ocfs2_extent_map_item *emi;
54
55 *ret_emi = NULL;
56
57 list_for_each_entry(emi, &em->em_list, ei_list) {
58 range = emi->ei_cpos + emi->ei_clusters;
59
60 if (cpos >= emi->ei_cpos && cpos < range) {
61 list_move(&emi->ei_list, &em->em_list);
62
63 *ret_emi = emi;
64 break;
65 }
66 }
67 }
68
69 static int ocfs2_extent_map_lookup(struct inode *inode, unsigned int cpos,
70 unsigned int *phys, unsigned int *len,
71 unsigned int *flags)
72 {
73 unsigned int coff;
74 struct ocfs2_inode_info *oi = OCFS2_I(inode);
75 struct ocfs2_extent_map_item *emi;
76
77 spin_lock(&oi->ip_lock);
78
79 __ocfs2_extent_map_lookup(&oi->ip_extent_map, cpos, &emi);
80 if (emi) {
81 coff = cpos - emi->ei_cpos;
82 *phys = emi->ei_phys + coff;
83 if (len)
84 *len = emi->ei_clusters - coff;
85 if (flags)
86 *flags = emi->ei_flags;
87 }
88
89 spin_unlock(&oi->ip_lock);
90
91 if (emi == NULL)
92 return -ENOENT;
93
94 return 0;
95 }
96
97 /*
98 * Forget about all clusters equal to or greater than cpos.
99 */
100 void ocfs2_extent_map_trunc(struct inode *inode, unsigned int cpos)
101 {
102 struct ocfs2_extent_map_item *emi, *n;
103 struct ocfs2_inode_info *oi = OCFS2_I(inode);
104 struct ocfs2_extent_map *em = &oi->ip_extent_map;
105 LIST_HEAD(tmp_list);
106 unsigned int range;
107
108 spin_lock(&oi->ip_lock);
109 list_for_each_entry_safe(emi, n, &em->em_list, ei_list) {
110 if (emi->ei_cpos >= cpos) {
111 /* Full truncate of this record. */
112 list_move(&emi->ei_list, &tmp_list);
113 BUG_ON(em->em_num_items == 0);
114 em->em_num_items--;
115 continue;
116 }
117
118 range = emi->ei_cpos + emi->ei_clusters;
119 if (range > cpos) {
120 /* Partial truncate */
121 emi->ei_clusters = cpos - emi->ei_cpos;
122 }
123 }
124 spin_unlock(&oi->ip_lock);
125
126 list_for_each_entry_safe(emi, n, &tmp_list, ei_list) {
127 list_del(&emi->ei_list);
128 kfree(emi);
129 }
130 }
131
132 /*
133 * Is any part of emi2 contained within emi1
134 */
135 static int ocfs2_ei_is_contained(struct ocfs2_extent_map_item *emi1,
136 struct ocfs2_extent_map_item *emi2)
137 {
138 unsigned int range1, range2;
139
140 /*
141 * Check if logical start of emi2 is inside emi1
142 */
143 range1 = emi1->ei_cpos + emi1->ei_clusters;
144 if (emi2->ei_cpos >= emi1->ei_cpos && emi2->ei_cpos < range1)
145 return 1;
146
147 /*
148 * Check if logical end of emi2 is inside emi1
149 */
150 range2 = emi2->ei_cpos + emi2->ei_clusters;
151 if (range2 > emi1->ei_cpos && range2 <= range1)
152 return 1;
153
154 return 0;
155 }
156
157 static void ocfs2_copy_emi_fields(struct ocfs2_extent_map_item *dest,
158 struct ocfs2_extent_map_item *src)
159 {
160 dest->ei_cpos = src->ei_cpos;
161 dest->ei_phys = src->ei_phys;
162 dest->ei_clusters = src->ei_clusters;
163 dest->ei_flags = src->ei_flags;
164 }
165
166 /*
167 * Try to merge emi with ins. Returns 1 if merge succeeds, zero
168 * otherwise.
169 */
170 static int ocfs2_try_to_merge_extent_map(struct ocfs2_extent_map_item *emi,
171 struct ocfs2_extent_map_item *ins)
172 {
173 /*
174 * Handle contiguousness
175 */
176 if (ins->ei_phys == (emi->ei_phys + emi->ei_clusters) &&
177 ins->ei_cpos == (emi->ei_cpos + emi->ei_clusters) &&
178 ins->ei_flags == emi->ei_flags) {
179 emi->ei_clusters += ins->ei_clusters;
180 return 1;
181 } else if ((ins->ei_phys + ins->ei_clusters) == emi->ei_phys &&
182 (ins->ei_cpos + ins->ei_clusters) == emi->ei_cpos &&
183 ins->ei_flags == emi->ei_flags) {
184 emi->ei_phys = ins->ei_phys;
185 emi->ei_cpos = ins->ei_cpos;
186 emi->ei_clusters += ins->ei_clusters;
187 return 1;
188 }
189
190 /*
191 * Overlapping extents - this shouldn't happen unless we've
192 * split an extent to change it's flags. That is exceedingly
193 * rare, so there's no sense in trying to optimize it yet.
194 */
195 if (ocfs2_ei_is_contained(emi, ins) ||
196 ocfs2_ei_is_contained(ins, emi)) {
197 ocfs2_copy_emi_fields(emi, ins);
198 return 1;
199 }
200
201 /* No merge was possible. */
202 return 0;
203 }
204
205 /*
206 * In order to reduce complexity on the caller, this insert function
207 * is intentionally liberal in what it will accept.
208 *
209 * The only rule is that the truncate call *must* be used whenever
210 * records have been deleted. This avoids inserting overlapping
211 * records with different physical mappings.
212 */
213 void ocfs2_extent_map_insert_rec(struct inode *inode,
214 struct ocfs2_extent_rec *rec)
215 {
216 struct ocfs2_inode_info *oi = OCFS2_I(inode);
217 struct ocfs2_extent_map *em = &oi->ip_extent_map;
218 struct ocfs2_extent_map_item *emi, *new_emi = NULL;
219 struct ocfs2_extent_map_item ins;
220
221 ins.ei_cpos = le32_to_cpu(rec->e_cpos);
222 ins.ei_phys = ocfs2_blocks_to_clusters(inode->i_sb,
223 le64_to_cpu(rec->e_blkno));
224 ins.ei_clusters = le16_to_cpu(rec->e_leaf_clusters);
225 ins.ei_flags = rec->e_flags;
226
227 search:
228 spin_lock(&oi->ip_lock);
229
230 list_for_each_entry(emi, &em->em_list, ei_list) {
231 if (ocfs2_try_to_merge_extent_map(emi, &ins)) {
232 list_move(&emi->ei_list, &em->em_list);
233 spin_unlock(&oi->ip_lock);
234 goto out;
235 }
236 }
237
238 /*
239 * No item could be merged.
240 *
241 * Either allocate and add a new item, or overwrite the last recently
242 * inserted.
243 */
244
245 if (em->em_num_items < OCFS2_MAX_EXTENT_MAP_ITEMS) {
246 if (new_emi == NULL) {
247 spin_unlock(&oi->ip_lock);
248
249 new_emi = kmalloc(sizeof(*new_emi), GFP_NOFS);
250 if (new_emi == NULL)
251 goto out;
252
253 goto search;
254 }
255
256 ocfs2_copy_emi_fields(new_emi, &ins);
257 list_add(&new_emi->ei_list, &em->em_list);
258 em->em_num_items++;
259 new_emi = NULL;
260 } else {
261 BUG_ON(list_empty(&em->em_list) || em->em_num_items == 0);
262 emi = list_entry(em->em_list.prev,
263 struct ocfs2_extent_map_item, ei_list);
264 list_move(&emi->ei_list, &em->em_list);
265 ocfs2_copy_emi_fields(emi, &ins);
266 }
267
268 spin_unlock(&oi->ip_lock);
269
270 out:
271 kfree(new_emi);
272 }
273
274 static int ocfs2_last_eb_is_empty(struct inode *inode,
275 struct ocfs2_dinode *di)
276 {
277 int ret, next_free;
278 u64 last_eb_blk = le64_to_cpu(di->i_last_eb_blk);
279 struct buffer_head *eb_bh = NULL;
280 struct ocfs2_extent_block *eb;
281 struct ocfs2_extent_list *el;
282
283 ret = ocfs2_read_extent_block(INODE_CACHE(inode), last_eb_blk, &eb_bh);
284 if (ret) {
285 mlog_errno(ret);
286 goto out;
287 }
288
289 eb = (struct ocfs2_extent_block *) eb_bh->b_data;
290 el = &eb->h_list;
291
292 if (el->l_tree_depth) {
293 ocfs2_error(inode->i_sb,
294 "Inode %lu has non zero tree depth in leaf block %llu\n",
295 inode->i_ino,
296 (unsigned long long)eb_bh->b_blocknr);
297 ret = -EROFS;
298 goto out;
299 }
300
301 next_free = le16_to_cpu(el->l_next_free_rec);
302
303 if (next_free == 0 ||
304 (next_free == 1 && ocfs2_is_empty_extent(&el->l_recs[0])))
305 ret = 1;
306
307 out:
308 brelse(eb_bh);
309 return ret;
310 }
311
312 /*
313 * Return the 1st index within el which contains an extent start
314 * larger than v_cluster.
315 */
316 static int ocfs2_search_for_hole_index(struct ocfs2_extent_list *el,
317 u32 v_cluster)
318 {
319 int i;
320 struct ocfs2_extent_rec *rec;
321
322 for(i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
323 rec = &el->l_recs[i];
324
325 if (v_cluster < le32_to_cpu(rec->e_cpos))
326 break;
327 }
328
329 return i;
330 }
331
332 /*
333 * Figure out the size of a hole which starts at v_cluster within the given
334 * extent list.
335 *
336 * If there is no more allocation past v_cluster, we return the maximum
337 * cluster size minus v_cluster.
338 *
339 * If we have in-inode extents, then el points to the dinode list and
340 * eb_bh is NULL. Otherwise, eb_bh should point to the extent block
341 * containing el.
342 */
343 int ocfs2_figure_hole_clusters(struct ocfs2_caching_info *ci,
344 struct ocfs2_extent_list *el,
345 struct buffer_head *eb_bh,
346 u32 v_cluster,
347 u32 *num_clusters)
348 {
349 int ret, i;
350 struct buffer_head *next_eb_bh = NULL;
351 struct ocfs2_extent_block *eb, *next_eb;
352
353 i = ocfs2_search_for_hole_index(el, v_cluster);
354
355 if (i == le16_to_cpu(el->l_next_free_rec) && eb_bh) {
356 eb = (struct ocfs2_extent_block *)eb_bh->b_data;
357
358 /*
359 * Check the next leaf for any extents.
360 */
361
362 if (le64_to_cpu(eb->h_next_leaf_blk) == 0ULL)
363 goto no_more_extents;
364
365 ret = ocfs2_read_extent_block(ci,
366 le64_to_cpu(eb->h_next_leaf_blk),
367 &next_eb_bh);
368 if (ret) {
369 mlog_errno(ret);
370 goto out;
371 }
372
373 next_eb = (struct ocfs2_extent_block *)next_eb_bh->b_data;
374 el = &next_eb->h_list;
375 i = ocfs2_search_for_hole_index(el, v_cluster);
376 }
377
378 no_more_extents:
379 if (i == le16_to_cpu(el->l_next_free_rec)) {
380 /*
381 * We're at the end of our existing allocation. Just
382 * return the maximum number of clusters we could
383 * possibly allocate.
384 */
385 *num_clusters = UINT_MAX - v_cluster;
386 } else {
387 *num_clusters = le32_to_cpu(el->l_recs[i].e_cpos) - v_cluster;
388 }
389
390 ret = 0;
391 out:
392 brelse(next_eb_bh);
393 return ret;
394 }
395
396 static int ocfs2_get_clusters_nocache(struct inode *inode,
397 struct buffer_head *di_bh,
398 u32 v_cluster, unsigned int *hole_len,
399 struct ocfs2_extent_rec *ret_rec,
400 unsigned int *is_last)
401 {
402 int i, ret, tree_height, len;
403 struct ocfs2_dinode *di;
404 struct ocfs2_extent_block *eb;
405 struct ocfs2_extent_list *el;
406 struct ocfs2_extent_rec *rec;
407 struct buffer_head *eb_bh = NULL;
408
409 memset(ret_rec, 0, sizeof(*ret_rec));
410 if (is_last)
411 *is_last = 0;
412
413 di = (struct ocfs2_dinode *) di_bh->b_data;
414 el = &di->id2.i_list;
415 tree_height = le16_to_cpu(el->l_tree_depth);
416
417 if (tree_height > 0) {
418 ret = ocfs2_find_leaf(INODE_CACHE(inode), el, v_cluster,
419 &eb_bh);
420 if (ret) {
421 mlog_errno(ret);
422 goto out;
423 }
424
425 eb = (struct ocfs2_extent_block *) eb_bh->b_data;
426 el = &eb->h_list;
427
428 if (el->l_tree_depth) {
429 ocfs2_error(inode->i_sb,
430 "Inode %lu has non zero tree depth in leaf block %llu\n",
431 inode->i_ino,
432 (unsigned long long)eb_bh->b_blocknr);
433 ret = -EROFS;
434 goto out;
435 }
436 }
437
438 i = ocfs2_search_extent_list(el, v_cluster);
439 if (i == -1) {
440 /*
441 * Holes can be larger than the maximum size of an
442 * extent, so we return their lengths in a separate
443 * field.
444 */
445 if (hole_len) {
446 ret = ocfs2_figure_hole_clusters(INODE_CACHE(inode),
447 el, eb_bh,
448 v_cluster, &len);
449 if (ret) {
450 mlog_errno(ret);
451 goto out;
452 }
453
454 *hole_len = len;
455 }
456 goto out_hole;
457 }
458
459 rec = &el->l_recs[i];
460
461 BUG_ON(v_cluster < le32_to_cpu(rec->e_cpos));
462
463 if (!rec->e_blkno) {
464 ocfs2_error(inode->i_sb,
465 "Inode %lu has bad extent record (%u, %u, 0)\n",
466 inode->i_ino,
467 le32_to_cpu(rec->e_cpos),
468 ocfs2_rec_clusters(el, rec));
469 ret = -EROFS;
470 goto out;
471 }
472
473 *ret_rec = *rec;
474
475 /*
476 * Checking for last extent is potentially expensive - we
477 * might have to look at the next leaf over to see if it's
478 * empty.
479 *
480 * The first two checks are to see whether the caller even
481 * cares for this information, and if the extent is at least
482 * the last in it's list.
483 *
484 * If those hold true, then the extent is last if any of the
485 * additional conditions hold true:
486 * - Extent list is in-inode
487 * - Extent list is right-most
488 * - Extent list is 2nd to rightmost, with empty right-most
489 */
490 if (is_last) {
491 if (i == (le16_to_cpu(el->l_next_free_rec) - 1)) {
492 if (tree_height == 0)
493 *is_last = 1;
494 else if (eb->h_blkno == di->i_last_eb_blk)
495 *is_last = 1;
496 else if (eb->h_next_leaf_blk == di->i_last_eb_blk) {
497 ret = ocfs2_last_eb_is_empty(inode, di);
498 if (ret < 0) {
499 mlog_errno(ret);
500 goto out;
501 }
502 if (ret == 1)
503 *is_last = 1;
504 }
505 }
506 }
507
508 out_hole:
509 ret = 0;
510 out:
511 brelse(eb_bh);
512 return ret;
513 }
514
515 static void ocfs2_relative_extent_offsets(struct super_block *sb,
516 u32 v_cluster,
517 struct ocfs2_extent_rec *rec,
518 u32 *p_cluster, u32 *num_clusters)
519
520 {
521 u32 coff = v_cluster - le32_to_cpu(rec->e_cpos);
522
523 *p_cluster = ocfs2_blocks_to_clusters(sb, le64_to_cpu(rec->e_blkno));
524 *p_cluster = *p_cluster + coff;
525
526 if (num_clusters)
527 *num_clusters = le16_to_cpu(rec->e_leaf_clusters) - coff;
528 }
529
530 int ocfs2_xattr_get_clusters(struct inode *inode, u32 v_cluster,
531 u32 *p_cluster, u32 *num_clusters,
532 struct ocfs2_extent_list *el,
533 unsigned int *extent_flags)
534 {
535 int ret = 0, i;
536 struct buffer_head *eb_bh = NULL;
537 struct ocfs2_extent_block *eb;
538 struct ocfs2_extent_rec *rec;
539 u32 coff;
540
541 if (el->l_tree_depth) {
542 ret = ocfs2_find_leaf(INODE_CACHE(inode), el, v_cluster,
543 &eb_bh);
544 if (ret) {
545 mlog_errno(ret);
546 goto out;
547 }
548
549 eb = (struct ocfs2_extent_block *) eb_bh->b_data;
550 el = &eb->h_list;
551
552 if (el->l_tree_depth) {
553 ocfs2_error(inode->i_sb,
554 "Inode %lu has non zero tree depth in xattr leaf block %llu\n",
555 inode->i_ino,
556 (unsigned long long)eb_bh->b_blocknr);
557 ret = -EROFS;
558 goto out;
559 }
560 }
561
562 i = ocfs2_search_extent_list(el, v_cluster);
563 if (i == -1) {
564 ret = -EROFS;
565 mlog_errno(ret);
566 goto out;
567 } else {
568 rec = &el->l_recs[i];
569 BUG_ON(v_cluster < le32_to_cpu(rec->e_cpos));
570
571 if (!rec->e_blkno) {
572 ocfs2_error(inode->i_sb,
573 "Inode %lu has bad extent record (%u, %u, 0) in xattr\n",
574 inode->i_ino,
575 le32_to_cpu(rec->e_cpos),
576 ocfs2_rec_clusters(el, rec));
577 ret = -EROFS;
578 goto out;
579 }
580 coff = v_cluster - le32_to_cpu(rec->e_cpos);
581 *p_cluster = ocfs2_blocks_to_clusters(inode->i_sb,
582 le64_to_cpu(rec->e_blkno));
583 *p_cluster = *p_cluster + coff;
584 if (num_clusters)
585 *num_clusters = ocfs2_rec_clusters(el, rec) - coff;
586
587 if (extent_flags)
588 *extent_flags = rec->e_flags;
589 }
590 out:
591 brelse(eb_bh);
592 return ret;
593 }
594
595 int ocfs2_get_clusters(struct inode *inode, u32 v_cluster,
596 u32 *p_cluster, u32 *num_clusters,
597 unsigned int *extent_flags)
598 {
599 int ret;
600 unsigned int hole_len, flags = 0;
601 struct buffer_head *di_bh = NULL;
602 struct ocfs2_extent_rec rec;
603
604 if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
605 ret = -ERANGE;
606 mlog_errno(ret);
607 goto out;
608 }
609
610 ret = ocfs2_extent_map_lookup(inode, v_cluster, p_cluster,
611 num_clusters, extent_flags);
612 if (ret == 0)
613 goto out;
614
615 ret = ocfs2_read_inode_block(inode, &di_bh);
616 if (ret) {
617 mlog_errno(ret);
618 goto out;
619 }
620
621 ret = ocfs2_get_clusters_nocache(inode, di_bh, v_cluster, &hole_len,
622 &rec, NULL);
623 if (ret) {
624 mlog_errno(ret);
625 goto out;
626 }
627
628 if (rec.e_blkno == 0ULL) {
629 /*
630 * A hole was found. Return some canned values that
631 * callers can key on. If asked for, num_clusters will
632 * be populated with the size of the hole.
633 */
634 *p_cluster = 0;
635 if (num_clusters) {
636 *num_clusters = hole_len;
637 }
638 } else {
639 ocfs2_relative_extent_offsets(inode->i_sb, v_cluster, &rec,
640 p_cluster, num_clusters);
641 flags = rec.e_flags;
642
643 ocfs2_extent_map_insert_rec(inode, &rec);
644 }
645
646 if (extent_flags)
647 *extent_flags = flags;
648
649 out:
650 brelse(di_bh);
651 return ret;
652 }
653
654 /*
655 * This expects alloc_sem to be held. The allocation cannot change at
656 * all while the map is in the process of being updated.
657 */
658 int ocfs2_extent_map_get_blocks(struct inode *inode, u64 v_blkno, u64 *p_blkno,
659 u64 *ret_count, unsigned int *extent_flags)
660 {
661 int ret;
662 int bpc = ocfs2_clusters_to_blocks(inode->i_sb, 1);
663 u32 cpos, num_clusters, p_cluster;
664 u64 boff = 0;
665
666 cpos = ocfs2_blocks_to_clusters(inode->i_sb, v_blkno);
667
668 ret = ocfs2_get_clusters(inode, cpos, &p_cluster, &num_clusters,
669 extent_flags);
670 if (ret) {
671 mlog_errno(ret);
672 goto out;
673 }
674
675 /*
676 * p_cluster == 0 indicates a hole.
677 */
678 if (p_cluster) {
679 boff = ocfs2_clusters_to_blocks(inode->i_sb, p_cluster);
680 boff += (v_blkno & (u64)(bpc - 1));
681 }
682
683 *p_blkno = boff;
684
685 if (ret_count) {
686 *ret_count = ocfs2_clusters_to_blocks(inode->i_sb, num_clusters);
687 *ret_count -= v_blkno & (u64)(bpc - 1);
688 }
689
690 out:
691 return ret;
692 }
693
694 /*
695 * The ocfs2_fiemap_inline() may be a little bit misleading, since
696 * it not only handles the fiemap for inlined files, but also deals
697 * with the fast symlink, cause they have no difference for extent
698 * mapping per se.
699 */
700 static int ocfs2_fiemap_inline(struct inode *inode, struct buffer_head *di_bh,
701 struct fiemap_extent_info *fieinfo,
702 u64 map_start)
703 {
704 int ret;
705 unsigned int id_count;
706 struct ocfs2_dinode *di;
707 u64 phys;
708 u32 flags = FIEMAP_EXTENT_DATA_INLINE|FIEMAP_EXTENT_LAST;
709 struct ocfs2_inode_info *oi = OCFS2_I(inode);
710
711 di = (struct ocfs2_dinode *)di_bh->b_data;
712 if (ocfs2_inode_is_fast_symlink(inode))
713 id_count = ocfs2_fast_symlink_chars(inode->i_sb);
714 else
715 id_count = le16_to_cpu(di->id2.i_data.id_count);
716
717 if (map_start < id_count) {
718 phys = oi->ip_blkno << inode->i_sb->s_blocksize_bits;
719 if (ocfs2_inode_is_fast_symlink(inode))
720 phys += offsetof(struct ocfs2_dinode, id2.i_symlink);
721 else
722 phys += offsetof(struct ocfs2_dinode,
723 id2.i_data.id_data);
724
725 ret = fiemap_fill_next_extent(fieinfo, 0, phys, id_count,
726 flags);
727 if (ret < 0)
728 return ret;
729 }
730
731 return 0;
732 }
733
734 int ocfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
735 u64 map_start, u64 map_len)
736 {
737 int ret, is_last;
738 u32 mapping_end, cpos;
739 unsigned int hole_size;
740 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
741 u64 len_bytes, phys_bytes, virt_bytes;
742 struct buffer_head *di_bh = NULL;
743 struct ocfs2_extent_rec rec;
744
745 ret = fiemap_prep(inode, fieinfo, map_start, &map_len, 0);
746 if (ret)
747 return ret;
748
749 ret = ocfs2_inode_lock(inode, &di_bh, 0);
750 if (ret) {
751 mlog_errno(ret);
752 goto out;
753 }
754
755 down_read(&OCFS2_I(inode)->ip_alloc_sem);
756
757 /*
758 * Handle inline-data and fast symlink separately.
759 */
760 if ((OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) ||
761 ocfs2_inode_is_fast_symlink(inode)) {
762 ret = ocfs2_fiemap_inline(inode, di_bh, fieinfo, map_start);
763 goto out_unlock;
764 }
765
766 cpos = map_start >> osb->s_clustersize_bits;
767 mapping_end = ocfs2_clusters_for_bytes(inode->i_sb,
768 map_start + map_len);
769 is_last = 0;
770 while (cpos < mapping_end && !is_last) {
771 u32 fe_flags;
772
773 ret = ocfs2_get_clusters_nocache(inode, di_bh, cpos,
774 &hole_size, &rec, &is_last);
775 if (ret) {
776 mlog_errno(ret);
777 goto out_unlock;
778 }
779
780 if (rec.e_blkno == 0ULL) {
781 cpos += hole_size;
782 continue;
783 }
784
785 fe_flags = 0;
786 if (rec.e_flags & OCFS2_EXT_UNWRITTEN)
787 fe_flags |= FIEMAP_EXTENT_UNWRITTEN;
788 if (rec.e_flags & OCFS2_EXT_REFCOUNTED)
789 fe_flags |= FIEMAP_EXTENT_SHARED;
790 if (is_last)
791 fe_flags |= FIEMAP_EXTENT_LAST;
792 len_bytes = (u64)le16_to_cpu(rec.e_leaf_clusters) << osb->s_clustersize_bits;
793 phys_bytes = le64_to_cpu(rec.e_blkno) << osb->sb->s_blocksize_bits;
794 virt_bytes = (u64)le32_to_cpu(rec.e_cpos) << osb->s_clustersize_bits;
795
796 ret = fiemap_fill_next_extent(fieinfo, virt_bytes, phys_bytes,
797 len_bytes, fe_flags);
798 if (ret)
799 break;
800
801 cpos = le32_to_cpu(rec.e_cpos)+ le16_to_cpu(rec.e_leaf_clusters);
802 }
803
804 if (ret > 0)
805 ret = 0;
806
807 out_unlock:
808 brelse(di_bh);
809
810 up_read(&OCFS2_I(inode)->ip_alloc_sem);
811
812 ocfs2_inode_unlock(inode, 0);
813 out:
814
815 return ret;
816 }
817
818 /* Is IO overwriting allocated blocks? */
819 int ocfs2_overwrite_io(struct inode *inode, struct buffer_head *di_bh,
820 u64 map_start, u64 map_len)
821 {
822 int ret = 0, is_last;
823 u32 mapping_end, cpos;
824 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
825 struct ocfs2_extent_rec rec;
826
827 if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
828 if (ocfs2_size_fits_inline_data(di_bh, map_start + map_len))
829 return ret;
830 else
831 return -EAGAIN;
832 }
833
834 cpos = map_start >> osb->s_clustersize_bits;
835 mapping_end = ocfs2_clusters_for_bytes(inode->i_sb,
836 map_start + map_len);
837 is_last = 0;
838 while (cpos < mapping_end && !is_last) {
839 ret = ocfs2_get_clusters_nocache(inode, di_bh, cpos,
840 NULL, &rec, &is_last);
841 if (ret) {
842 mlog_errno(ret);
843 goto out;
844 }
845
846 if (rec.e_blkno == 0ULL)
847 break;
848
849 if (rec.e_flags & OCFS2_EXT_REFCOUNTED)
850 break;
851
852 cpos = le32_to_cpu(rec.e_cpos) +
853 le16_to_cpu(rec.e_leaf_clusters);
854 }
855
856 if (cpos < mapping_end)
857 ret = -EAGAIN;
858 out:
859 return ret;
860 }
861
862 int ocfs2_seek_data_hole_offset(struct file *file, loff_t *offset, int whence)
863 {
864 struct inode *inode = file->f_mapping->host;
865 int ret;
866 unsigned int is_last = 0, is_data = 0;
867 u16 cs_bits = OCFS2_SB(inode->i_sb)->s_clustersize_bits;
868 u32 cpos, cend, clen, hole_size;
869 u64 extoff, extlen;
870 struct buffer_head *di_bh = NULL;
871 struct ocfs2_extent_rec rec;
872
873 BUG_ON(whence != SEEK_DATA && whence != SEEK_HOLE);
874
875 ret = ocfs2_inode_lock(inode, &di_bh, 0);
876 if (ret) {
877 mlog_errno(ret);
878 goto out;
879 }
880
881 down_read(&OCFS2_I(inode)->ip_alloc_sem);
882
883 if (*offset >= i_size_read(inode)) {
884 ret = -ENXIO;
885 goto out_unlock;
886 }
887
888 if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
889 if (whence == SEEK_HOLE)
890 *offset = i_size_read(inode);
891 goto out_unlock;
892 }
893
894 clen = 0;
895 cpos = *offset >> cs_bits;
896 cend = ocfs2_clusters_for_bytes(inode->i_sb, i_size_read(inode));
897
898 while (cpos < cend && !is_last) {
899 ret = ocfs2_get_clusters_nocache(inode, di_bh, cpos, &hole_size,
900 &rec, &is_last);
901 if (ret) {
902 mlog_errno(ret);
903 goto out_unlock;
904 }
905
906 extoff = cpos;
907 extoff <<= cs_bits;
908
909 if (rec.e_blkno == 0ULL) {
910 clen = hole_size;
911 is_data = 0;
912 } else {
913 clen = le16_to_cpu(rec.e_leaf_clusters) -
914 (cpos - le32_to_cpu(rec.e_cpos));
915 is_data = (rec.e_flags & OCFS2_EXT_UNWRITTEN) ? 0 : 1;
916 }
917
918 if ((!is_data && whence == SEEK_HOLE) ||
919 (is_data && whence == SEEK_DATA)) {
920 if (extoff > *offset)
921 *offset = extoff;
922 goto out_unlock;
923 }
924
925 if (!is_last)
926 cpos += clen;
927 }
928
929 if (whence == SEEK_HOLE) {
930 extoff = cpos;
931 extoff <<= cs_bits;
932 extlen = clen;
933 extlen <<= cs_bits;
934
935 if ((extoff + extlen) > i_size_read(inode))
936 extlen = i_size_read(inode) - extoff;
937 extoff += extlen;
938 if (extoff > *offset)
939 *offset = extoff;
940 goto out_unlock;
941 }
942
943 ret = -ENXIO;
944
945 out_unlock:
946
947 brelse(di_bh);
948
949 up_read(&OCFS2_I(inode)->ip_alloc_sem);
950
951 ocfs2_inode_unlock(inode, 0);
952 out:
953 return ret;
954 }
955
956 int ocfs2_read_virt_blocks(struct inode *inode, u64 v_block, int nr,
957 struct buffer_head *bhs[], int flags,
958 int (*validate)(struct super_block *sb,
959 struct buffer_head *bh))
960 {
961 int rc = 0;
962 u64 p_block, p_count;
963 int i, count, done = 0;
964
965 trace_ocfs2_read_virt_blocks(
966 inode, (unsigned long long)v_block, nr, bhs, flags,
967 validate);
968
969 if (((v_block + nr - 1) << inode->i_sb->s_blocksize_bits) >=
970 i_size_read(inode)) {
971 BUG_ON(!(flags & OCFS2_BH_READAHEAD));
972 goto out;
973 }
974
975 while (done < nr) {
976 down_read(&OCFS2_I(inode)->ip_alloc_sem);
977 rc = ocfs2_extent_map_get_blocks(inode, v_block + done,
978 &p_block, &p_count, NULL);
979 up_read(&OCFS2_I(inode)->ip_alloc_sem);
980 if (rc) {
981 mlog_errno(rc);
982 break;
983 }
984
985 if (!p_block) {
986 rc = -EIO;
987 mlog(ML_ERROR,
988 "Inode #%llu contains a hole at offset %llu\n",
989 (unsigned long long)OCFS2_I(inode)->ip_blkno,
990 (unsigned long long)(v_block + done) <<
991 inode->i_sb->s_blocksize_bits);
992 break;
993 }
994
995 count = nr - done;
996 if (p_count < count)
997 count = p_count;
998
999 /*
1000 * If the caller passed us bhs, they should have come
1001 * from a previous readahead call to this function. Thus,
1002 * they should have the right b_blocknr.
1003 */
1004 for (i = 0; i < count; i++) {
1005 if (!bhs[done + i])
1006 continue;
1007 BUG_ON(bhs[done + i]->b_blocknr != (p_block + i));
1008 }
1009
1010 rc = ocfs2_read_blocks(INODE_CACHE(inode), p_block, count,
1011 bhs + done, flags, validate);
1012 if (rc) {
1013 mlog_errno(rc);
1014 break;
1015 }
1016 done += count;
1017 }
1018
1019 out:
1020 return rc;
1021 }
1022
1023
1024
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