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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2007 Oracle. All rights reserved.
4 */
5
6#include "ctree.h"
7#include "fs.h"
8#include "messages.h"
9#include "inode-item.h"
10#include "disk-io.h"
11#include "transaction.h"
12#include "space-info.h"
13#include "accessors.h"
14#include "extent-tree.h"
15#include "file-item.h"
16
17struct btrfs_inode_ref *btrfs_find_name_in_backref(const struct extent_buffer *leaf,
18 int slot,
19 const struct fscrypt_str *name)
20{
21 struct btrfs_inode_ref *ref;
22 unsigned long ptr;
23 unsigned long name_ptr;
24 u32 item_size;
25 u32 cur_offset = 0;
26 int len;
27
28 item_size = btrfs_item_size(leaf, slot);
29 ptr = btrfs_item_ptr_offset(leaf, slot);
30 while (cur_offset < item_size) {
31 ref = (struct btrfs_inode_ref *)(ptr + cur_offset);
32 len = btrfs_inode_ref_name_len(leaf, ref);
33 name_ptr = (unsigned long)(ref + 1);
34 cur_offset += len + sizeof(*ref);
35 if (len != name->len)
36 continue;
37 if (memcmp_extent_buffer(leaf, name->name, name_ptr,
38 name->len) == 0)
39 return ref;
40 }
41 return NULL;
42}
43
44struct btrfs_inode_extref *btrfs_find_name_in_ext_backref(
45 const struct extent_buffer *leaf, int slot, u64 ref_objectid,
46 const struct fscrypt_str *name)
47{
48 struct btrfs_inode_extref *extref;
49 unsigned long ptr;
50 unsigned long name_ptr;
51 u32 item_size;
52 u32 cur_offset = 0;
53 int ref_name_len;
54
55 item_size = btrfs_item_size(leaf, slot);
56 ptr = btrfs_item_ptr_offset(leaf, slot);
57
58 /*
59 * Search all extended backrefs in this item. We're only
60 * looking through any collisions so most of the time this is
61 * just going to compare against one buffer. If all is well,
62 * we'll return success and the inode ref object.
63 */
64 while (cur_offset < item_size) {
65 extref = (struct btrfs_inode_extref *) (ptr + cur_offset);
66 name_ptr = (unsigned long)(&extref->name);
67 ref_name_len = btrfs_inode_extref_name_len(leaf, extref);
68
69 if (ref_name_len == name->len &&
70 btrfs_inode_extref_parent(leaf, extref) == ref_objectid &&
71 (memcmp_extent_buffer(leaf, name->name, name_ptr,
72 name->len) == 0))
73 return extref;
74
75 cur_offset += ref_name_len + sizeof(*extref);
76 }
77 return NULL;
78}
79
80/* Returns NULL if no extref found */
81struct btrfs_inode_extref *
82btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans,
83 struct btrfs_root *root,
84 struct btrfs_path *path,
85 const struct fscrypt_str *name,
86 u64 inode_objectid, u64 ref_objectid, int ins_len,
87 int cow)
88{
89 int ret;
90 struct btrfs_key key;
91
92 key.objectid = inode_objectid;
93 key.type = BTRFS_INODE_EXTREF_KEY;
94 key.offset = btrfs_extref_hash(ref_objectid, name->name, name->len);
95
96 ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
97 if (ret < 0)
98 return ERR_PTR(ret);
99 if (ret > 0)
100 return NULL;
101 return btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
102 ref_objectid, name);
103
104}
105
106static int btrfs_del_inode_extref(struct btrfs_trans_handle *trans,
107 struct btrfs_root *root,
108 const struct fscrypt_str *name,
109 u64 inode_objectid, u64 ref_objectid,
110 u64 *index)
111{
112 struct btrfs_path *path;
113 struct btrfs_key key;
114 struct btrfs_inode_extref *extref;
115 struct extent_buffer *leaf;
116 int ret;
117 int del_len = name->len + sizeof(*extref);
118 unsigned long ptr;
119 unsigned long item_start;
120 u32 item_size;
121
122 key.objectid = inode_objectid;
123 key.type = BTRFS_INODE_EXTREF_KEY;
124 key.offset = btrfs_extref_hash(ref_objectid, name->name, name->len);
125
126 path = btrfs_alloc_path();
127 if (!path)
128 return -ENOMEM;
129
130 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
131 if (ret > 0)
132 ret = -ENOENT;
133 if (ret < 0)
134 goto out;
135
136 /*
137 * Sanity check - did we find the right item for this name?
138 * This should always succeed so error here will make the FS
139 * readonly.
140 */
141 extref = btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
142 ref_objectid, name);
143 if (!extref) {
144 btrfs_abort_transaction(trans, -ENOENT);
145 ret = -ENOENT;
146 goto out;
147 }
148
149 leaf = path->nodes[0];
150 item_size = btrfs_item_size(leaf, path->slots[0]);
151 if (index)
152 *index = btrfs_inode_extref_index(leaf, extref);
153
154 if (del_len == item_size) {
155 /*
156 * Common case only one ref in the item, remove the
157 * whole item.
158 */
159 ret = btrfs_del_item(trans, root, path);
160 goto out;
161 }
162
163 ptr = (unsigned long)extref;
164 item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
165
166 memmove_extent_buffer(leaf, ptr, ptr + del_len,
167 item_size - (ptr + del_len - item_start));
168
169 btrfs_truncate_item(trans, path, item_size - del_len, 1);
170
171out:
172 btrfs_free_path(path);
173
174 return ret;
175}
176
177int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
178 struct btrfs_root *root, const struct fscrypt_str *name,
179 u64 inode_objectid, u64 ref_objectid, u64 *index)
180{
181 struct btrfs_path *path;
182 struct btrfs_key key;
183 struct btrfs_inode_ref *ref;
184 struct extent_buffer *leaf;
185 unsigned long ptr;
186 unsigned long item_start;
187 u32 item_size;
188 u32 sub_item_len;
189 int ret;
190 int search_ext_refs = 0;
191 int del_len = name->len + sizeof(*ref);
192
193 key.objectid = inode_objectid;
194 key.offset = ref_objectid;
195 key.type = BTRFS_INODE_REF_KEY;
196
197 path = btrfs_alloc_path();
198 if (!path)
199 return -ENOMEM;
200
201 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
202 if (ret > 0) {
203 ret = -ENOENT;
204 search_ext_refs = 1;
205 goto out;
206 } else if (ret < 0) {
207 goto out;
208 }
209
210 ref = btrfs_find_name_in_backref(path->nodes[0], path->slots[0], name);
211 if (!ref) {
212 ret = -ENOENT;
213 search_ext_refs = 1;
214 goto out;
215 }
216 leaf = path->nodes[0];
217 item_size = btrfs_item_size(leaf, path->slots[0]);
218
219 if (index)
220 *index = btrfs_inode_ref_index(leaf, ref);
221
222 if (del_len == item_size) {
223 ret = btrfs_del_item(trans, root, path);
224 goto out;
225 }
226 ptr = (unsigned long)ref;
227 sub_item_len = name->len + sizeof(*ref);
228 item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
229 memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
230 item_size - (ptr + sub_item_len - item_start));
231 btrfs_truncate_item(trans, path, item_size - sub_item_len, 1);
232out:
233 btrfs_free_path(path);
234
235 if (search_ext_refs) {
236 /*
237 * No refs were found, or we could not find the
238 * name in our ref array. Find and remove the extended
239 * inode ref then.
240 */
241 return btrfs_del_inode_extref(trans, root, name,
242 inode_objectid, ref_objectid, index);
243 }
244
245 return ret;
246}
247
248/*
249 * Insert an extended inode ref into a tree.
250 *
251 * The caller must have checked against BTRFS_LINK_MAX already.
252 */
253static int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans,
254 struct btrfs_root *root,
255 const struct fscrypt_str *name,
256 u64 inode_objectid, u64 ref_objectid,
257 u64 index)
258{
259 struct btrfs_inode_extref *extref;
260 int ret;
261 int ins_len = name->len + sizeof(*extref);
262 unsigned long ptr;
263 struct btrfs_path *path;
264 struct btrfs_key key;
265 struct extent_buffer *leaf;
266
267 key.objectid = inode_objectid;
268 key.type = BTRFS_INODE_EXTREF_KEY;
269 key.offset = btrfs_extref_hash(ref_objectid, name->name, name->len);
270
271 path = btrfs_alloc_path();
272 if (!path)
273 return -ENOMEM;
274
275 ret = btrfs_insert_empty_item(trans, root, path, &key,
276 ins_len);
277 if (ret == -EEXIST) {
278 if (btrfs_find_name_in_ext_backref(path->nodes[0],
279 path->slots[0],
280 ref_objectid,
281 name))
282 goto out;
283
284 btrfs_extend_item(trans, path, ins_len);
285 ret = 0;
286 }
287 if (ret < 0)
288 goto out;
289
290 leaf = path->nodes[0];
291 ptr = (unsigned long)btrfs_item_ptr(leaf, path->slots[0], char);
292 ptr += btrfs_item_size(leaf, path->slots[0]) - ins_len;
293 extref = (struct btrfs_inode_extref *)ptr;
294
295 btrfs_set_inode_extref_name_len(path->nodes[0], extref, name->len);
296 btrfs_set_inode_extref_index(path->nodes[0], extref, index);
297 btrfs_set_inode_extref_parent(path->nodes[0], extref, ref_objectid);
298
299 ptr = (unsigned long)&extref->name;
300 write_extent_buffer(path->nodes[0], name->name, ptr, name->len);
301 btrfs_mark_buffer_dirty(trans, path->nodes[0]);
302
303out:
304 btrfs_free_path(path);
305 return ret;
306}
307
308/* Will return 0, -ENOMEM, -EMLINK, or -EEXIST or anything from the CoW path */
309int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
310 struct btrfs_root *root, const struct fscrypt_str *name,
311 u64 inode_objectid, u64 ref_objectid, u64 index)
312{
313 struct btrfs_fs_info *fs_info = root->fs_info;
314 struct btrfs_path *path;
315 struct btrfs_key key;
316 struct btrfs_inode_ref *ref;
317 unsigned long ptr;
318 int ret;
319 int ins_len = name->len + sizeof(*ref);
320
321 key.objectid = inode_objectid;
322 key.offset = ref_objectid;
323 key.type = BTRFS_INODE_REF_KEY;
324
325 path = btrfs_alloc_path();
326 if (!path)
327 return -ENOMEM;
328
329 path->skip_release_on_error = 1;
330 ret = btrfs_insert_empty_item(trans, root, path, &key,
331 ins_len);
332 if (ret == -EEXIST) {
333 u32 old_size;
334 ref = btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
335 name);
336 if (ref)
337 goto out;
338
339 old_size = btrfs_item_size(path->nodes[0], path->slots[0]);
340 btrfs_extend_item(trans, path, ins_len);
341 ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
342 struct btrfs_inode_ref);
343 ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size);
344 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name->len);
345 btrfs_set_inode_ref_index(path->nodes[0], ref, index);
346 ptr = (unsigned long)(ref + 1);
347 ret = 0;
348 } else if (ret < 0) {
349 if (ret == -EOVERFLOW) {
350 if (btrfs_find_name_in_backref(path->nodes[0],
351 path->slots[0],
352 name))
353 ret = -EEXIST;
354 else
355 ret = -EMLINK;
356 }
357 goto out;
358 } else {
359 ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
360 struct btrfs_inode_ref);
361 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name->len);
362 btrfs_set_inode_ref_index(path->nodes[0], ref, index);
363 ptr = (unsigned long)(ref + 1);
364 }
365 write_extent_buffer(path->nodes[0], name->name, ptr, name->len);
366 btrfs_mark_buffer_dirty(trans, path->nodes[0]);
367
368out:
369 btrfs_free_path(path);
370
371 if (ret == -EMLINK) {
372 struct btrfs_super_block *disk_super = fs_info->super_copy;
373 /* We ran out of space in the ref array. Need to
374 * add an extended ref. */
375 if (btrfs_super_incompat_flags(disk_super)
376 & BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
377 ret = btrfs_insert_inode_extref(trans, root, name,
378 inode_objectid,
379 ref_objectid, index);
380 }
381
382 return ret;
383}
384
385int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans,
386 struct btrfs_root *root,
387 struct btrfs_path *path, u64 objectid)
388{
389 struct btrfs_key key;
390 int ret;
391 key.objectid = objectid;
392 key.type = BTRFS_INODE_ITEM_KEY;
393 key.offset = 0;
394
395 ret = btrfs_insert_empty_item(trans, root, path, &key,
396 sizeof(struct btrfs_inode_item));
397 return ret;
398}
399
400int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
401 *root, struct btrfs_path *path,
402 struct btrfs_key *location, int mod)
403{
404 int ins_len = mod < 0 ? -1 : 0;
405 int cow = mod != 0;
406 int ret;
407 int slot;
408 struct extent_buffer *leaf;
409 struct btrfs_key found_key;
410
411 ret = btrfs_search_slot(trans, root, location, path, ins_len, cow);
412 if (ret > 0 && location->type == BTRFS_ROOT_ITEM_KEY &&
413 location->offset == (u64)-1 && path->slots[0] != 0) {
414 slot = path->slots[0] - 1;
415 leaf = path->nodes[0];
416 btrfs_item_key_to_cpu(leaf, &found_key, slot);
417 if (found_key.objectid == location->objectid &&
418 found_key.type == location->type) {
419 path->slots[0]--;
420 return 0;
421 }
422 }
423 return ret;
424}
425
426static inline void btrfs_trace_truncate(const struct btrfs_inode *inode,
427 const struct extent_buffer *leaf,
428 const struct btrfs_file_extent_item *fi,
429 u64 offset, int extent_type, int slot)
430{
431 if (!inode)
432 return;
433 if (extent_type == BTRFS_FILE_EXTENT_INLINE)
434 trace_btrfs_truncate_show_fi_inline(inode, leaf, fi, slot,
435 offset);
436 else
437 trace_btrfs_truncate_show_fi_regular(inode, leaf, fi, offset);
438}
439
440/*
441 * Remove inode items from a given root.
442 *
443 * @trans: A transaction handle.
444 * @root: The root from which to remove items.
445 * @inode: The inode whose items we want to remove.
446 * @control: The btrfs_truncate_control to control how and what we
447 * are truncating.
448 *
449 * Remove all keys associated with the inode from the given root that have a key
450 * with a type greater than or equals to @min_type. When @min_type has a value of
451 * BTRFS_EXTENT_DATA_KEY, only remove file extent items that have an offset value
452 * greater than or equals to @new_size. If a file extent item that starts before
453 * @new_size and ends after it is found, its length is adjusted.
454 *
455 * Returns: 0 on success, < 0 on error and NEED_TRUNCATE_BLOCK when @min_type is
456 * BTRFS_EXTENT_DATA_KEY and the caller must truncate the last block.
457 */
458int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
459 struct btrfs_root *root,
460 struct btrfs_truncate_control *control)
461{
462 struct btrfs_fs_info *fs_info = root->fs_info;
463 struct btrfs_path *path;
464 struct extent_buffer *leaf;
465 struct btrfs_file_extent_item *fi;
466 struct btrfs_key key;
467 struct btrfs_key found_key;
468 u64 new_size = control->new_size;
469 u64 extent_num_bytes = 0;
470 u64 extent_offset = 0;
471 u64 item_end = 0;
472 u32 found_type = (u8)-1;
473 int del_item;
474 int pending_del_nr = 0;
475 int pending_del_slot = 0;
476 int extent_type = -1;
477 int ret;
478 u64 bytes_deleted = 0;
479 bool be_nice = false;
480
481 ASSERT(control->inode || !control->clear_extent_range);
482 ASSERT(new_size == 0 || control->min_type == BTRFS_EXTENT_DATA_KEY);
483
484 control->last_size = new_size;
485 control->sub_bytes = 0;
486
487 /*
488 * For shareable roots we want to back off from time to time, this turns
489 * out to be subvolume roots, reloc roots, and data reloc roots.
490 */
491 if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state))
492 be_nice = true;
493
494 path = btrfs_alloc_path();
495 if (!path)
496 return -ENOMEM;
497 path->reada = READA_BACK;
498
499 key.objectid = control->ino;
500 key.offset = (u64)-1;
501 key.type = (u8)-1;
502
503search_again:
504 /*
505 * With a 16K leaf size and 128MiB extents, you can actually queue up a
506 * huge file in a single leaf. Most of the time that bytes_deleted is
507 * > 0, it will be huge by the time we get here
508 */
509 if (be_nice && bytes_deleted > SZ_32M &&
510 btrfs_should_end_transaction(trans)) {
511 ret = -EAGAIN;
512 goto out;
513 }
514
515 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
516 if (ret < 0)
517 goto out;
518
519 if (ret > 0) {
520 ret = 0;
521 /* There are no items in the tree for us to truncate, we're done */
522 if (path->slots[0] == 0)
523 goto out;
524 path->slots[0]--;
525 }
526
527 while (1) {
528 u64 clear_start = 0, clear_len = 0, extent_start = 0;
529 bool refill_delayed_refs_rsv = false;
530
531 fi = NULL;
532 leaf = path->nodes[0];
533 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
534 found_type = found_key.type;
535
536 if (found_key.objectid != control->ino)
537 break;
538
539 if (found_type < control->min_type)
540 break;
541
542 item_end = found_key.offset;
543 if (found_type == BTRFS_EXTENT_DATA_KEY) {
544 fi = btrfs_item_ptr(leaf, path->slots[0],
545 struct btrfs_file_extent_item);
546 extent_type = btrfs_file_extent_type(leaf, fi);
547 if (extent_type != BTRFS_FILE_EXTENT_INLINE)
548 item_end +=
549 btrfs_file_extent_num_bytes(leaf, fi);
550 else if (extent_type == BTRFS_FILE_EXTENT_INLINE)
551 item_end += btrfs_file_extent_ram_bytes(leaf, fi);
552
553 btrfs_trace_truncate(control->inode, leaf, fi,
554 found_key.offset, extent_type,
555 path->slots[0]);
556 item_end--;
557 }
558 if (found_type > control->min_type) {
559 del_item = 1;
560 } else {
561 if (item_end < new_size)
562 break;
563 if (found_key.offset >= new_size)
564 del_item = 1;
565 else
566 del_item = 0;
567 }
568
569 /* FIXME, shrink the extent if the ref count is only 1 */
570 if (found_type != BTRFS_EXTENT_DATA_KEY)
571 goto delete;
572
573 control->extents_found++;
574
575 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
576 u64 num_dec;
577
578 clear_start = found_key.offset;
579 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
580 if (!del_item) {
581 u64 orig_num_bytes =
582 btrfs_file_extent_num_bytes(leaf, fi);
583 extent_num_bytes = ALIGN(new_size -
584 found_key.offset,
585 fs_info->sectorsize);
586 clear_start = ALIGN(new_size, fs_info->sectorsize);
587
588 btrfs_set_file_extent_num_bytes(leaf, fi,
589 extent_num_bytes);
590 num_dec = (orig_num_bytes - extent_num_bytes);
591 if (extent_start != 0)
592 control->sub_bytes += num_dec;
593 btrfs_mark_buffer_dirty(trans, leaf);
594 } else {
595 extent_num_bytes =
596 btrfs_file_extent_disk_num_bytes(leaf, fi);
597 extent_offset = found_key.offset -
598 btrfs_file_extent_offset(leaf, fi);
599
600 /* FIXME blocksize != 4096 */
601 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
602 if (extent_start != 0)
603 control->sub_bytes += num_dec;
604 }
605 clear_len = num_dec;
606 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
607 /*
608 * We can't truncate inline items that have had
609 * special encodings
610 */
611 if (!del_item &&
612 btrfs_file_extent_encryption(leaf, fi) == 0 &&
613 btrfs_file_extent_other_encoding(leaf, fi) == 0 &&
614 btrfs_file_extent_compression(leaf, fi) == 0) {
615 u32 size = (u32)(new_size - found_key.offset);
616
617 btrfs_set_file_extent_ram_bytes(leaf, fi, size);
618 size = btrfs_file_extent_calc_inline_size(size);
619 btrfs_truncate_item(trans, path, size, 1);
620 } else if (!del_item) {
621 /*
622 * We have to bail so the last_size is set to
623 * just before this extent.
624 */
625 ret = BTRFS_NEED_TRUNCATE_BLOCK;
626 break;
627 } else {
628 /*
629 * Inline extents are special, we just treat
630 * them as a full sector worth in the file
631 * extent tree just for simplicity sake.
632 */
633 clear_len = fs_info->sectorsize;
634 }
635
636 control->sub_bytes += item_end + 1 - new_size;
637 }
638delete:
639 /*
640 * We only want to clear the file extent range if we're
641 * modifying the actual inode's mapping, which is just the
642 * normal truncate path.
643 */
644 if (control->clear_extent_range) {
645 ret = btrfs_inode_clear_file_extent_range(control->inode,
646 clear_start, clear_len);
647 if (ret) {
648 btrfs_abort_transaction(trans, ret);
649 break;
650 }
651 }
652
653 if (del_item) {
654 ASSERT(!pending_del_nr ||
655 ((path->slots[0] + 1) == pending_del_slot));
656
657 control->last_size = found_key.offset;
658 if (!pending_del_nr) {
659 /* No pending yet, add ourselves */
660 pending_del_slot = path->slots[0];
661 pending_del_nr = 1;
662 } else if (path->slots[0] + 1 == pending_del_slot) {
663 /* Hop on the pending chunk */
664 pending_del_nr++;
665 pending_del_slot = path->slots[0];
666 }
667 } else {
668 control->last_size = new_size;
669 break;
670 }
671
672 if (del_item && extent_start != 0 && !control->skip_ref_updates) {
673 struct btrfs_ref ref = {
674 .action = BTRFS_DROP_DELAYED_REF,
675 .bytenr = extent_start,
676 .num_bytes = extent_num_bytes,
677 .owning_root = btrfs_root_id(root),
678 .ref_root = btrfs_header_owner(leaf),
679 };
680
681 bytes_deleted += extent_num_bytes;
682
683 btrfs_init_data_ref(&ref, control->ino, extent_offset,
684 btrfs_root_id(root), false);
685 ret = btrfs_free_extent(trans, &ref);
686 if (ret) {
687 btrfs_abort_transaction(trans, ret);
688 break;
689 }
690 if (be_nice && btrfs_check_space_for_delayed_refs(fs_info))
691 refill_delayed_refs_rsv = true;
692 }
693
694 if (found_type == BTRFS_INODE_ITEM_KEY)
695 break;
696
697 if (path->slots[0] == 0 ||
698 path->slots[0] != pending_del_slot ||
699 refill_delayed_refs_rsv) {
700 if (pending_del_nr) {
701 ret = btrfs_del_items(trans, root, path,
702 pending_del_slot,
703 pending_del_nr);
704 if (ret) {
705 btrfs_abort_transaction(trans, ret);
706 break;
707 }
708 pending_del_nr = 0;
709 }
710 btrfs_release_path(path);
711
712 /*
713 * We can generate a lot of delayed refs, so we need to
714 * throttle every once and a while and make sure we're
715 * adding enough space to keep up with the work we are
716 * generating. Since we hold a transaction here we
717 * can't flush, and we don't want to FLUSH_LIMIT because
718 * we could have generated too many delayed refs to
719 * actually allocate, so just bail if we're short and
720 * let the normal reservation dance happen higher up.
721 */
722 if (refill_delayed_refs_rsv) {
723 ret = btrfs_delayed_refs_rsv_refill(fs_info,
724 BTRFS_RESERVE_NO_FLUSH);
725 if (ret) {
726 ret = -EAGAIN;
727 break;
728 }
729 }
730 goto search_again;
731 } else {
732 path->slots[0]--;
733 }
734 }
735out:
736 if (ret >= 0 && pending_del_nr) {
737 int err;
738
739 err = btrfs_del_items(trans, root, path, pending_del_slot,
740 pending_del_nr);
741 if (err) {
742 btrfs_abort_transaction(trans, err);
743 ret = err;
744 }
745 }
746
747 ASSERT(control->last_size >= new_size);
748 if (!ret && control->last_size > new_size)
749 control->last_size = new_size;
750
751 btrfs_free_path(path);
752 return ret;
753}
1/*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19#include "ctree.h"
20#include "disk-io.h"
21#include "hash.h"
22#include "transaction.h"
23#include "print-tree.h"
24
25static int find_name_in_backref(struct btrfs_path *path, const char *name,
26 int name_len, struct btrfs_inode_ref **ref_ret)
27{
28 struct extent_buffer *leaf;
29 struct btrfs_inode_ref *ref;
30 unsigned long ptr;
31 unsigned long name_ptr;
32 u32 item_size;
33 u32 cur_offset = 0;
34 int len;
35
36 leaf = path->nodes[0];
37 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
38 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
39 while (cur_offset < item_size) {
40 ref = (struct btrfs_inode_ref *)(ptr + cur_offset);
41 len = btrfs_inode_ref_name_len(leaf, ref);
42 name_ptr = (unsigned long)(ref + 1);
43 cur_offset += len + sizeof(*ref);
44 if (len != name_len)
45 continue;
46 if (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0) {
47 *ref_ret = ref;
48 return 1;
49 }
50 }
51 return 0;
52}
53
54int btrfs_find_name_in_ext_backref(struct btrfs_path *path, u64 ref_objectid,
55 const char *name, int name_len,
56 struct btrfs_inode_extref **extref_ret)
57{
58 struct extent_buffer *leaf;
59 struct btrfs_inode_extref *extref;
60 unsigned long ptr;
61 unsigned long name_ptr;
62 u32 item_size;
63 u32 cur_offset = 0;
64 int ref_name_len;
65
66 leaf = path->nodes[0];
67 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
68 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
69
70 /*
71 * Search all extended backrefs in this item. We're only
72 * looking through any collisions so most of the time this is
73 * just going to compare against one buffer. If all is well,
74 * we'll return success and the inode ref object.
75 */
76 while (cur_offset < item_size) {
77 extref = (struct btrfs_inode_extref *) (ptr + cur_offset);
78 name_ptr = (unsigned long)(&extref->name);
79 ref_name_len = btrfs_inode_extref_name_len(leaf, extref);
80
81 if (ref_name_len == name_len &&
82 btrfs_inode_extref_parent(leaf, extref) == ref_objectid &&
83 (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)) {
84 if (extref_ret)
85 *extref_ret = extref;
86 return 1;
87 }
88
89 cur_offset += ref_name_len + sizeof(*extref);
90 }
91 return 0;
92}
93
94/* Returns NULL if no extref found */
95struct btrfs_inode_extref *
96btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans,
97 struct btrfs_root *root,
98 struct btrfs_path *path,
99 const char *name, int name_len,
100 u64 inode_objectid, u64 ref_objectid, int ins_len,
101 int cow)
102{
103 int ret;
104 struct btrfs_key key;
105 struct btrfs_inode_extref *extref;
106
107 key.objectid = inode_objectid;
108 key.type = BTRFS_INODE_EXTREF_KEY;
109 key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
110
111 ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
112 if (ret < 0)
113 return ERR_PTR(ret);
114 if (ret > 0)
115 return NULL;
116 if (!btrfs_find_name_in_ext_backref(path, ref_objectid, name, name_len, &extref))
117 return NULL;
118 return extref;
119}
120
121static int btrfs_del_inode_extref(struct btrfs_trans_handle *trans,
122 struct btrfs_root *root,
123 const char *name, int name_len,
124 u64 inode_objectid, u64 ref_objectid,
125 u64 *index)
126{
127 struct btrfs_path *path;
128 struct btrfs_key key;
129 struct btrfs_inode_extref *extref;
130 struct extent_buffer *leaf;
131 int ret;
132 int del_len = name_len + sizeof(*extref);
133 unsigned long ptr;
134 unsigned long item_start;
135 u32 item_size;
136
137 key.objectid = inode_objectid;
138 btrfs_set_key_type(&key, BTRFS_INODE_EXTREF_KEY);
139 key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
140
141 path = btrfs_alloc_path();
142 if (!path)
143 return -ENOMEM;
144
145 path->leave_spinning = 1;
146
147 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
148 if (ret > 0)
149 ret = -ENOENT;
150 if (ret < 0)
151 goto out;
152
153 /*
154 * Sanity check - did we find the right item for this name?
155 * This should always succeed so error here will make the FS
156 * readonly.
157 */
158 if (!btrfs_find_name_in_ext_backref(path, ref_objectid,
159 name, name_len, &extref)) {
160 btrfs_std_error(root->fs_info, -ENOENT);
161 ret = -EROFS;
162 goto out;
163 }
164
165 leaf = path->nodes[0];
166 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
167 if (index)
168 *index = btrfs_inode_extref_index(leaf, extref);
169
170 if (del_len == item_size) {
171 /*
172 * Common case only one ref in the item, remove the
173 * whole item.
174 */
175 ret = btrfs_del_item(trans, root, path);
176 goto out;
177 }
178
179 ptr = (unsigned long)extref;
180 item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
181
182 memmove_extent_buffer(leaf, ptr, ptr + del_len,
183 item_size - (ptr + del_len - item_start));
184
185 btrfs_truncate_item(root, path, item_size - del_len, 1);
186
187out:
188 btrfs_free_path(path);
189
190 return ret;
191}
192
193int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
194 struct btrfs_root *root,
195 const char *name, int name_len,
196 u64 inode_objectid, u64 ref_objectid, u64 *index)
197{
198 struct btrfs_path *path;
199 struct btrfs_key key;
200 struct btrfs_inode_ref *ref;
201 struct extent_buffer *leaf;
202 unsigned long ptr;
203 unsigned long item_start;
204 u32 item_size;
205 u32 sub_item_len;
206 int ret;
207 int search_ext_refs = 0;
208 int del_len = name_len + sizeof(*ref);
209
210 key.objectid = inode_objectid;
211 key.offset = ref_objectid;
212 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
213
214 path = btrfs_alloc_path();
215 if (!path)
216 return -ENOMEM;
217
218 path->leave_spinning = 1;
219
220 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
221 if (ret > 0) {
222 ret = -ENOENT;
223 search_ext_refs = 1;
224 goto out;
225 } else if (ret < 0) {
226 goto out;
227 }
228 if (!find_name_in_backref(path, name, name_len, &ref)) {
229 ret = -ENOENT;
230 search_ext_refs = 1;
231 goto out;
232 }
233 leaf = path->nodes[0];
234 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
235
236 if (index)
237 *index = btrfs_inode_ref_index(leaf, ref);
238
239 if (del_len == item_size) {
240 ret = btrfs_del_item(trans, root, path);
241 goto out;
242 }
243 ptr = (unsigned long)ref;
244 sub_item_len = name_len + sizeof(*ref);
245 item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
246 memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
247 item_size - (ptr + sub_item_len - item_start));
248 btrfs_truncate_item(root, path, item_size - sub_item_len, 1);
249out:
250 btrfs_free_path(path);
251
252 if (search_ext_refs) {
253 /*
254 * No refs were found, or we could not find the
255 * name in our ref array. Find and remove the extended
256 * inode ref then.
257 */
258 return btrfs_del_inode_extref(trans, root, name, name_len,
259 inode_objectid, ref_objectid, index);
260 }
261
262 return ret;
263}
264
265/*
266 * btrfs_insert_inode_extref() - Inserts an extended inode ref into a tree.
267 *
268 * The caller must have checked against BTRFS_LINK_MAX already.
269 */
270static int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans,
271 struct btrfs_root *root,
272 const char *name, int name_len,
273 u64 inode_objectid, u64 ref_objectid, u64 index)
274{
275 struct btrfs_inode_extref *extref;
276 int ret;
277 int ins_len = name_len + sizeof(*extref);
278 unsigned long ptr;
279 struct btrfs_path *path;
280 struct btrfs_key key;
281 struct extent_buffer *leaf;
282 struct btrfs_item *item;
283
284 key.objectid = inode_objectid;
285 key.type = BTRFS_INODE_EXTREF_KEY;
286 key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
287
288 path = btrfs_alloc_path();
289 if (!path)
290 return -ENOMEM;
291
292 path->leave_spinning = 1;
293 ret = btrfs_insert_empty_item(trans, root, path, &key,
294 ins_len);
295 if (ret == -EEXIST) {
296 if (btrfs_find_name_in_ext_backref(path, ref_objectid,
297 name, name_len, NULL))
298 goto out;
299
300 btrfs_extend_item(root, path, ins_len);
301 ret = 0;
302 }
303 if (ret < 0)
304 goto out;
305
306 leaf = path->nodes[0];
307 item = btrfs_item_nr(path->slots[0]);
308 ptr = (unsigned long)btrfs_item_ptr(leaf, path->slots[0], char);
309 ptr += btrfs_item_size(leaf, item) - ins_len;
310 extref = (struct btrfs_inode_extref *)ptr;
311
312 btrfs_set_inode_extref_name_len(path->nodes[0], extref, name_len);
313 btrfs_set_inode_extref_index(path->nodes[0], extref, index);
314 btrfs_set_inode_extref_parent(path->nodes[0], extref, ref_objectid);
315
316 ptr = (unsigned long)&extref->name;
317 write_extent_buffer(path->nodes[0], name, ptr, name_len);
318 btrfs_mark_buffer_dirty(path->nodes[0]);
319
320out:
321 btrfs_free_path(path);
322 return ret;
323}
324
325/* Will return 0, -ENOMEM, -EMLINK, or -EEXIST or anything from the CoW path */
326int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
327 struct btrfs_root *root,
328 const char *name, int name_len,
329 u64 inode_objectid, u64 ref_objectid, u64 index)
330{
331 struct btrfs_path *path;
332 struct btrfs_key key;
333 struct btrfs_inode_ref *ref;
334 unsigned long ptr;
335 int ret;
336 int ins_len = name_len + sizeof(*ref);
337
338 key.objectid = inode_objectid;
339 key.offset = ref_objectid;
340 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
341
342 path = btrfs_alloc_path();
343 if (!path)
344 return -ENOMEM;
345
346 path->leave_spinning = 1;
347 ret = btrfs_insert_empty_item(trans, root, path, &key,
348 ins_len);
349 if (ret == -EEXIST) {
350 u32 old_size;
351
352 if (find_name_in_backref(path, name, name_len, &ref))
353 goto out;
354
355 old_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
356 btrfs_extend_item(root, path, ins_len);
357 ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
358 struct btrfs_inode_ref);
359 ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size);
360 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
361 btrfs_set_inode_ref_index(path->nodes[0], ref, index);
362 ptr = (unsigned long)(ref + 1);
363 ret = 0;
364 } else if (ret < 0) {
365 if (ret == -EOVERFLOW)
366 ret = -EMLINK;
367 goto out;
368 } else {
369 ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
370 struct btrfs_inode_ref);
371 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
372 btrfs_set_inode_ref_index(path->nodes[0], ref, index);
373 ptr = (unsigned long)(ref + 1);
374 }
375 write_extent_buffer(path->nodes[0], name, ptr, name_len);
376 btrfs_mark_buffer_dirty(path->nodes[0]);
377
378out:
379 btrfs_free_path(path);
380
381 if (ret == -EMLINK) {
382 struct btrfs_super_block *disk_super = root->fs_info->super_copy;
383 /* We ran out of space in the ref array. Need to
384 * add an extended ref. */
385 if (btrfs_super_incompat_flags(disk_super)
386 & BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
387 ret = btrfs_insert_inode_extref(trans, root, name,
388 name_len,
389 inode_objectid,
390 ref_objectid, index);
391 }
392
393 return ret;
394}
395
396int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans,
397 struct btrfs_root *root,
398 struct btrfs_path *path, u64 objectid)
399{
400 struct btrfs_key key;
401 int ret;
402 key.objectid = objectid;
403 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
404 key.offset = 0;
405
406 ret = btrfs_insert_empty_item(trans, root, path, &key,
407 sizeof(struct btrfs_inode_item));
408 return ret;
409}
410
411int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
412 *root, struct btrfs_path *path,
413 struct btrfs_key *location, int mod)
414{
415 int ins_len = mod < 0 ? -1 : 0;
416 int cow = mod != 0;
417 int ret;
418 int slot;
419 struct extent_buffer *leaf;
420 struct btrfs_key found_key;
421
422 ret = btrfs_search_slot(trans, root, location, path, ins_len, cow);
423 if (ret > 0 && btrfs_key_type(location) == BTRFS_ROOT_ITEM_KEY &&
424 location->offset == (u64)-1 && path->slots[0] != 0) {
425 slot = path->slots[0] - 1;
426 leaf = path->nodes[0];
427 btrfs_item_key_to_cpu(leaf, &found_key, slot);
428 if (found_key.objectid == location->objectid &&
429 btrfs_key_type(&found_key) == btrfs_key_type(location)) {
430 path->slots[0]--;
431 return 0;
432 }
433 }
434 return ret;
435}