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c1d7c514 | 1 | // SPDX-License-Identifier: GPL-2.0 |
6cbd5570 | 2 | /* |
d352ac68 | 3 | * Copyright (C) 2007,2008 Oracle. All rights reserved. |
6cbd5570 CM |
4 | */ |
5 | ||
a6b6e75e | 6 | #include <linux/sched.h> |
5a0e3ad6 | 7 | #include <linux/slab.h> |
bd989ba3 | 8 | #include <linux/rbtree.h> |
adf02123 | 9 | #include <linux/mm.h> |
e41d12f5 | 10 | #include <linux/error-injection.h> |
9b569ea0 | 11 | #include "messages.h" |
eb60ceac CM |
12 | #include "ctree.h" |
13 | #include "disk-io.h" | |
7f5c1516 | 14 | #include "transaction.h" |
5f39d397 | 15 | #include "print-tree.h" |
925baedd | 16 | #include "locking.h" |
de37aa51 | 17 | #include "volumes.h" |
f616f5cd | 18 | #include "qgroup.h" |
f3a84ccd | 19 | #include "tree-mod-log.h" |
88c602ab | 20 | #include "tree-checker.h" |
ec8eb376 | 21 | #include "fs.h" |
ad1ac501 | 22 | #include "accessors.h" |
a0231804 | 23 | #include "extent-tree.h" |
67707479 | 24 | #include "relocation.h" |
6bfd0ffa | 25 | #include "file-item.h" |
9a8dd150 | 26 | |
226463d7 JB |
27 | static struct kmem_cache *btrfs_path_cachep; |
28 | ||
e089f05c CM |
29 | static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root |
30 | *root, struct btrfs_path *path, int level); | |
310712b2 OS |
31 | static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
32 | const struct btrfs_key *ins_key, struct btrfs_path *path, | |
33 | int data_size, int extend); | |
5f39d397 | 34 | static int push_node_left(struct btrfs_trans_handle *trans, |
2ff7e61e | 35 | struct extent_buffer *dst, |
971a1f66 | 36 | struct extent_buffer *src, int empty); |
5f39d397 | 37 | static int balance_node_right(struct btrfs_trans_handle *trans, |
5f39d397 CM |
38 | struct extent_buffer *dst_buf, |
39 | struct extent_buffer *src_buf); | |
d97e63b6 | 40 | |
af024ed2 JT |
41 | static const struct btrfs_csums { |
42 | u16 size; | |
59a0fcdb DS |
43 | const char name[10]; |
44 | const char driver[12]; | |
af024ed2 JT |
45 | } btrfs_csums[] = { |
46 | [BTRFS_CSUM_TYPE_CRC32] = { .size = 4, .name = "crc32c" }, | |
3951e7f0 | 47 | [BTRFS_CSUM_TYPE_XXHASH] = { .size = 8, .name = "xxhash64" }, |
3831bf00 | 48 | [BTRFS_CSUM_TYPE_SHA256] = { .size = 32, .name = "sha256" }, |
352ae07b DS |
49 | [BTRFS_CSUM_TYPE_BLAKE2] = { .size = 32, .name = "blake2b", |
50 | .driver = "blake2b-256" }, | |
af024ed2 JT |
51 | }; |
52 | ||
3a3178c7 JB |
53 | /* |
54 | * The leaf data grows from end-to-front in the node. this returns the address | |
55 | * of the start of the last item, which is the stop of the leaf data stack. | |
56 | */ | |
57 | static unsigned int leaf_data_end(const struct extent_buffer *leaf) | |
58 | { | |
59 | u32 nr = btrfs_header_nritems(leaf); | |
60 | ||
61 | if (nr == 0) | |
62 | return BTRFS_LEAF_DATA_SIZE(leaf->fs_info); | |
63 | return btrfs_item_offset(leaf, nr - 1); | |
64 | } | |
65 | ||
637e3b48 JB |
66 | /* |
67 | * Move data in a @leaf (using memmove, safe for overlapping ranges). | |
68 | * | |
69 | * @leaf: leaf that we're doing a memmove on | |
70 | * @dst_offset: item data offset we're moving to | |
71 | * @src_offset: item data offset were' moving from | |
72 | * @len: length of the data we're moving | |
73 | * | |
74 | * Wrapper around memmove_extent_buffer() that takes into account the header on | |
75 | * the leaf. The btrfs_item offset's start directly after the header, so we | |
76 | * have to adjust any offsets to account for the header in the leaf. This | |
77 | * handles that math to simplify the callers. | |
78 | */ | |
79 | static inline void memmove_leaf_data(const struct extent_buffer *leaf, | |
80 | unsigned long dst_offset, | |
81 | unsigned long src_offset, | |
82 | unsigned long len) | |
83 | { | |
8009adf3 JB |
84 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(leaf, 0) + dst_offset, |
85 | btrfs_item_nr_offset(leaf, 0) + src_offset, len); | |
637e3b48 JB |
86 | } |
87 | ||
88 | /* | |
89 | * Copy item data from @src into @dst at the given @offset. | |
90 | * | |
91 | * @dst: destination leaf that we're copying into | |
92 | * @src: source leaf that we're copying from | |
93 | * @dst_offset: item data offset we're copying to | |
94 | * @src_offset: item data offset were' copying from | |
95 | * @len: length of the data we're copying | |
96 | * | |
97 | * Wrapper around copy_extent_buffer() that takes into account the header on | |
98 | * the leaf. The btrfs_item offset's start directly after the header, so we | |
99 | * have to adjust any offsets to account for the header in the leaf. This | |
100 | * handles that math to simplify the callers. | |
101 | */ | |
102 | static inline void copy_leaf_data(const struct extent_buffer *dst, | |
103 | const struct extent_buffer *src, | |
104 | unsigned long dst_offset, | |
105 | unsigned long src_offset, unsigned long len) | |
106 | { | |
8009adf3 JB |
107 | copy_extent_buffer(dst, src, btrfs_item_nr_offset(dst, 0) + dst_offset, |
108 | btrfs_item_nr_offset(src, 0) + src_offset, len); | |
637e3b48 JB |
109 | } |
110 | ||
111 | /* | |
112 | * Move items in a @leaf (using memmove). | |
113 | * | |
114 | * @dst: destination leaf for the items | |
115 | * @dst_item: the item nr we're copying into | |
116 | * @src_item: the item nr we're copying from | |
117 | * @nr_items: the number of items to copy | |
118 | * | |
119 | * Wrapper around memmove_extent_buffer() that does the math to get the | |
120 | * appropriate offsets into the leaf from the item numbers. | |
121 | */ | |
122 | static inline void memmove_leaf_items(const struct extent_buffer *leaf, | |
123 | int dst_item, int src_item, int nr_items) | |
124 | { | |
125 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(leaf, dst_item), | |
126 | btrfs_item_nr_offset(leaf, src_item), | |
127 | nr_items * sizeof(struct btrfs_item)); | |
128 | } | |
129 | ||
130 | /* | |
131 | * Copy items from @src into @dst at the given @offset. | |
132 | * | |
133 | * @dst: destination leaf for the items | |
134 | * @src: source leaf for the items | |
135 | * @dst_item: the item nr we're copying into | |
136 | * @src_item: the item nr we're copying from | |
137 | * @nr_items: the number of items to copy | |
138 | * | |
139 | * Wrapper around copy_extent_buffer() that does the math to get the | |
140 | * appropriate offsets into the leaf from the item numbers. | |
141 | */ | |
142 | static inline void copy_leaf_items(const struct extent_buffer *dst, | |
143 | const struct extent_buffer *src, | |
144 | int dst_item, int src_item, int nr_items) | |
145 | { | |
146 | copy_extent_buffer(dst, src, btrfs_item_nr_offset(dst, dst_item), | |
147 | btrfs_item_nr_offset(src, src_item), | |
148 | nr_items * sizeof(struct btrfs_item)); | |
149 | } | |
150 | ||
b3cbfb0d JB |
151 | /* This exists for btrfs-progs usages. */ |
152 | u16 btrfs_csum_type_size(u16 type) | |
153 | { | |
154 | return btrfs_csums[type].size; | |
155 | } | |
156 | ||
af024ed2 JT |
157 | int btrfs_super_csum_size(const struct btrfs_super_block *s) |
158 | { | |
159 | u16 t = btrfs_super_csum_type(s); | |
160 | /* | |
161 | * csum type is validated at mount time | |
162 | */ | |
b3cbfb0d | 163 | return btrfs_csum_type_size(t); |
af024ed2 JT |
164 | } |
165 | ||
166 | const char *btrfs_super_csum_name(u16 csum_type) | |
167 | { | |
168 | /* csum type is validated at mount time */ | |
169 | return btrfs_csums[csum_type].name; | |
170 | } | |
171 | ||
b4e967be DS |
172 | /* |
173 | * Return driver name if defined, otherwise the name that's also a valid driver | |
174 | * name | |
175 | */ | |
176 | const char *btrfs_super_csum_driver(u16 csum_type) | |
177 | { | |
178 | /* csum type is validated at mount time */ | |
59a0fcdb DS |
179 | return btrfs_csums[csum_type].driver[0] ? |
180 | btrfs_csums[csum_type].driver : | |
b4e967be DS |
181 | btrfs_csums[csum_type].name; |
182 | } | |
183 | ||
604997b4 | 184 | size_t __attribute_const__ btrfs_get_num_csums(void) |
f7cea56c DS |
185 | { |
186 | return ARRAY_SIZE(btrfs_csums); | |
187 | } | |
188 | ||
df24a2b9 | 189 | struct btrfs_path *btrfs_alloc_path(void) |
2c90e5d6 | 190 | { |
a4c853af C |
191 | might_sleep(); |
192 | ||
e2c89907 | 193 | return kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS); |
2c90e5d6 CM |
194 | } |
195 | ||
d352ac68 | 196 | /* this also releases the path */ |
df24a2b9 | 197 | void btrfs_free_path(struct btrfs_path *p) |
be0e5c09 | 198 | { |
ff175d57 JJ |
199 | if (!p) |
200 | return; | |
b3b4aa74 | 201 | btrfs_release_path(p); |
df24a2b9 | 202 | kmem_cache_free(btrfs_path_cachep, p); |
be0e5c09 CM |
203 | } |
204 | ||
d352ac68 CM |
205 | /* |
206 | * path release drops references on the extent buffers in the path | |
207 | * and it drops any locks held by this path | |
208 | * | |
209 | * It is safe to call this on paths that no locks or extent buffers held. | |
210 | */ | |
b3b4aa74 | 211 | noinline void btrfs_release_path(struct btrfs_path *p) |
eb60ceac CM |
212 | { |
213 | int i; | |
a2135011 | 214 | |
234b63a0 | 215 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) { |
3f157a2f | 216 | p->slots[i] = 0; |
eb60ceac | 217 | if (!p->nodes[i]) |
925baedd CM |
218 | continue; |
219 | if (p->locks[i]) { | |
bd681513 | 220 | btrfs_tree_unlock_rw(p->nodes[i], p->locks[i]); |
925baedd CM |
221 | p->locks[i] = 0; |
222 | } | |
5f39d397 | 223 | free_extent_buffer(p->nodes[i]); |
3f157a2f | 224 | p->nodes[i] = NULL; |
eb60ceac CM |
225 | } |
226 | } | |
227 | ||
8bb808c6 DS |
228 | /* |
229 | * We want the transaction abort to print stack trace only for errors where the | |
230 | * cause could be a bug, eg. due to ENOSPC, and not for common errors that are | |
231 | * caused by external factors. | |
232 | */ | |
ed164802 | 233 | bool __cold abort_should_print_stack(int error) |
8bb808c6 | 234 | { |
ed164802 | 235 | switch (error) { |
8bb808c6 DS |
236 | case -EIO: |
237 | case -EROFS: | |
238 | case -ENOMEM: | |
239 | return false; | |
240 | } | |
241 | return true; | |
242 | } | |
243 | ||
d352ac68 CM |
244 | /* |
245 | * safely gets a reference on the root node of a tree. A lock | |
246 | * is not taken, so a concurrent writer may put a different node | |
247 | * at the root of the tree. See btrfs_lock_root_node for the | |
248 | * looping required. | |
249 | * | |
250 | * The extent buffer returned by this has a reference taken, so | |
251 | * it won't disappear. It may stop being the root of the tree | |
252 | * at any time because there are no locks held. | |
253 | */ | |
925baedd CM |
254 | struct extent_buffer *btrfs_root_node(struct btrfs_root *root) |
255 | { | |
256 | struct extent_buffer *eb; | |
240f62c8 | 257 | |
3083ee2e JB |
258 | while (1) { |
259 | rcu_read_lock(); | |
260 | eb = rcu_dereference(root->node); | |
261 | ||
262 | /* | |
263 | * RCU really hurts here, we could free up the root node because | |
01327610 | 264 | * it was COWed but we may not get the new root node yet so do |
3083ee2e JB |
265 | * the inc_not_zero dance and if it doesn't work then |
266 | * synchronize_rcu and try again. | |
267 | */ | |
268 | if (atomic_inc_not_zero(&eb->refs)) { | |
269 | rcu_read_unlock(); | |
270 | break; | |
271 | } | |
272 | rcu_read_unlock(); | |
273 | synchronize_rcu(); | |
274 | } | |
925baedd CM |
275 | return eb; |
276 | } | |
277 | ||
92a7cc42 QW |
278 | /* |
279 | * Cowonly root (not-shareable trees, everything not subvolume or reloc roots), | |
280 | * just get put onto a simple dirty list. Transaction walks this list to make | |
281 | * sure they get properly updated on disk. | |
d352ac68 | 282 | */ |
0b86a832 CM |
283 | static void add_root_to_dirty_list(struct btrfs_root *root) |
284 | { | |
0b246afa JM |
285 | struct btrfs_fs_info *fs_info = root->fs_info; |
286 | ||
e7070be1 JB |
287 | if (test_bit(BTRFS_ROOT_DIRTY, &root->state) || |
288 | !test_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state)) | |
289 | return; | |
290 | ||
0b246afa | 291 | spin_lock(&fs_info->trans_lock); |
e7070be1 JB |
292 | if (!test_and_set_bit(BTRFS_ROOT_DIRTY, &root->state)) { |
293 | /* Want the extent tree to be the last on the list */ | |
4fd786e6 | 294 | if (root->root_key.objectid == BTRFS_EXTENT_TREE_OBJECTID) |
e7070be1 | 295 | list_move_tail(&root->dirty_list, |
0b246afa | 296 | &fs_info->dirty_cowonly_roots); |
e7070be1 JB |
297 | else |
298 | list_move(&root->dirty_list, | |
0b246afa | 299 | &fs_info->dirty_cowonly_roots); |
0b86a832 | 300 | } |
0b246afa | 301 | spin_unlock(&fs_info->trans_lock); |
0b86a832 CM |
302 | } |
303 | ||
d352ac68 CM |
304 | /* |
305 | * used by snapshot creation to make a copy of a root for a tree with | |
306 | * a given objectid. The buffer with the new root node is returned in | |
307 | * cow_ret, and this func returns zero on success or a negative error code. | |
308 | */ | |
be20aa9d CM |
309 | int btrfs_copy_root(struct btrfs_trans_handle *trans, |
310 | struct btrfs_root *root, | |
311 | struct extent_buffer *buf, | |
312 | struct extent_buffer **cow_ret, u64 new_root_objectid) | |
313 | { | |
0b246afa | 314 | struct btrfs_fs_info *fs_info = root->fs_info; |
be20aa9d | 315 | struct extent_buffer *cow; |
be20aa9d CM |
316 | int ret = 0; |
317 | int level; | |
5d4f98a2 | 318 | struct btrfs_disk_key disk_key; |
60ea105a | 319 | u64 reloc_src_root = 0; |
be20aa9d | 320 | |
92a7cc42 | 321 | WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && |
0b246afa | 322 | trans->transid != fs_info->running_transaction->transid); |
92a7cc42 | 323 | WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && |
27cdeb70 | 324 | trans->transid != root->last_trans); |
be20aa9d CM |
325 | |
326 | level = btrfs_header_level(buf); | |
5d4f98a2 YZ |
327 | if (level == 0) |
328 | btrfs_item_key(buf, &disk_key, 0); | |
329 | else | |
330 | btrfs_node_key(buf, &disk_key, 0); | |
31840ae1 | 331 | |
60ea105a BB |
332 | if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) |
333 | reloc_src_root = btrfs_header_owner(buf); | |
4d75f8a9 | 334 | cow = btrfs_alloc_tree_block(trans, root, 0, new_root_objectid, |
cf6f34aa | 335 | &disk_key, level, buf->start, 0, |
60ea105a | 336 | reloc_src_root, BTRFS_NESTING_NEW_ROOT); |
5d4f98a2 | 337 | if (IS_ERR(cow)) |
be20aa9d CM |
338 | return PTR_ERR(cow); |
339 | ||
58e8012c | 340 | copy_extent_buffer_full(cow, buf); |
be20aa9d CM |
341 | btrfs_set_header_bytenr(cow, cow->start); |
342 | btrfs_set_header_generation(cow, trans->transid); | |
5d4f98a2 YZ |
343 | btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); |
344 | btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | | |
345 | BTRFS_HEADER_FLAG_RELOC); | |
346 | if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) | |
347 | btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); | |
348 | else | |
349 | btrfs_set_header_owner(cow, new_root_objectid); | |
be20aa9d | 350 | |
de37aa51 | 351 | write_extent_buffer_fsid(cow, fs_info->fs_devices->metadata_uuid); |
2b82032c | 352 | |
be20aa9d | 353 | WARN_ON(btrfs_header_generation(buf) > trans->transid); |
5d4f98a2 | 354 | if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) |
e339a6b0 | 355 | ret = btrfs_inc_ref(trans, root, cow, 1); |
5d4f98a2 | 356 | else |
e339a6b0 | 357 | ret = btrfs_inc_ref(trans, root, cow, 0); |
867ed321 | 358 | if (ret) { |
72c9925f FM |
359 | btrfs_tree_unlock(cow); |
360 | free_extent_buffer(cow); | |
867ed321 | 361 | btrfs_abort_transaction(trans, ret); |
be20aa9d | 362 | return ret; |
867ed321 | 363 | } |
be20aa9d | 364 | |
50564b65 | 365 | btrfs_mark_buffer_dirty(trans, cow); |
be20aa9d CM |
366 | *cow_ret = cow; |
367 | return 0; | |
368 | } | |
369 | ||
5d4f98a2 YZ |
370 | /* |
371 | * check if the tree block can be shared by multiple trees | |
372 | */ | |
eb96e221 FM |
373 | int btrfs_block_can_be_shared(struct btrfs_trans_handle *trans, |
374 | struct btrfs_root *root, | |
5d4f98a2 YZ |
375 | struct extent_buffer *buf) |
376 | { | |
377 | /* | |
92a7cc42 QW |
378 | * Tree blocks not in shareable trees and tree roots are never shared. |
379 | * If a block was allocated after the last snapshot and the block was | |
380 | * not allocated by tree relocation, we know the block is not shared. | |
5d4f98a2 | 381 | */ |
92a7cc42 | 382 | if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && |
eb96e221 | 383 | buf != root->node && |
5d4f98a2 YZ |
384 | (btrfs_header_generation(buf) <= |
385 | btrfs_root_last_snapshot(&root->root_item) || | |
eb96e221 FM |
386 | btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))) { |
387 | if (buf != root->commit_root) | |
388 | return 1; | |
389 | /* | |
390 | * An extent buffer that used to be the commit root may still be | |
391 | * shared because the tree height may have increased and it | |
392 | * became a child of a higher level root. This can happen when | |
393 | * snapshotting a subvolume created in the current transaction. | |
394 | */ | |
395 | if (btrfs_header_generation(buf) == trans->transid) | |
396 | return 1; | |
397 | } | |
a79865c6 | 398 | |
5d4f98a2 YZ |
399 | return 0; |
400 | } | |
401 | ||
402 | static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, | |
403 | struct btrfs_root *root, | |
404 | struct extent_buffer *buf, | |
f0486c68 YZ |
405 | struct extent_buffer *cow, |
406 | int *last_ref) | |
5d4f98a2 | 407 | { |
0b246afa | 408 | struct btrfs_fs_info *fs_info = root->fs_info; |
5d4f98a2 YZ |
409 | u64 refs; |
410 | u64 owner; | |
411 | u64 flags; | |
412 | u64 new_flags = 0; | |
413 | int ret; | |
414 | ||
415 | /* | |
416 | * Backrefs update rules: | |
417 | * | |
418 | * Always use full backrefs for extent pointers in tree block | |
419 | * allocated by tree relocation. | |
420 | * | |
421 | * If a shared tree block is no longer referenced by its owner | |
422 | * tree (btrfs_header_owner(buf) == root->root_key.objectid), | |
423 | * use full backrefs for extent pointers in tree block. | |
424 | * | |
425 | * If a tree block is been relocating | |
426 | * (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID), | |
427 | * use full backrefs for extent pointers in tree block. | |
428 | * The reason for this is some operations (such as drop tree) | |
429 | * are only allowed for blocks use full backrefs. | |
430 | */ | |
431 | ||
eb96e221 | 432 | if (btrfs_block_can_be_shared(trans, root, buf)) { |
2ff7e61e | 433 | ret = btrfs_lookup_extent_info(trans, fs_info, buf->start, |
3173a18f | 434 | btrfs_header_level(buf), 1, |
d8ba2a91 | 435 | &refs, &flags, NULL); |
be1a5564 MF |
436 | if (ret) |
437 | return ret; | |
eced687e FM |
438 | if (unlikely(refs == 0)) { |
439 | btrfs_crit(fs_info, | |
440 | "found 0 references for tree block at bytenr %llu level %d root %llu", | |
441 | buf->start, btrfs_header_level(buf), | |
442 | btrfs_root_id(root)); | |
443 | ret = -EUCLEAN; | |
444 | btrfs_abort_transaction(trans, ret); | |
e5df9573 MF |
445 | return ret; |
446 | } | |
5d4f98a2 YZ |
447 | } else { |
448 | refs = 1; | |
449 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || | |
450 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
451 | flags = BTRFS_BLOCK_FLAG_FULL_BACKREF; | |
452 | else | |
453 | flags = 0; | |
454 | } | |
455 | ||
456 | owner = btrfs_header_owner(buf); | |
457 | BUG_ON(owner == BTRFS_TREE_RELOC_OBJECTID && | |
458 | !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)); | |
459 | ||
460 | if (refs > 1) { | |
461 | if ((owner == root->root_key.objectid || | |
462 | root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && | |
463 | !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) { | |
e339a6b0 | 464 | ret = btrfs_inc_ref(trans, root, buf, 1); |
692826b2 JM |
465 | if (ret) |
466 | return ret; | |
5d4f98a2 YZ |
467 | |
468 | if (root->root_key.objectid == | |
469 | BTRFS_TREE_RELOC_OBJECTID) { | |
e339a6b0 | 470 | ret = btrfs_dec_ref(trans, root, buf, 0); |
692826b2 JM |
471 | if (ret) |
472 | return ret; | |
e339a6b0 | 473 | ret = btrfs_inc_ref(trans, root, cow, 1); |
692826b2 JM |
474 | if (ret) |
475 | return ret; | |
5d4f98a2 YZ |
476 | } |
477 | new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF; | |
478 | } else { | |
479 | ||
480 | if (root->root_key.objectid == | |
481 | BTRFS_TREE_RELOC_OBJECTID) | |
e339a6b0 | 482 | ret = btrfs_inc_ref(trans, root, cow, 1); |
5d4f98a2 | 483 | else |
e339a6b0 | 484 | ret = btrfs_inc_ref(trans, root, cow, 0); |
692826b2 JM |
485 | if (ret) |
486 | return ret; | |
5d4f98a2 YZ |
487 | } |
488 | if (new_flags != 0) { | |
4aec05fa | 489 | ret = btrfs_set_disk_extent_flags(trans, buf, new_flags); |
be1a5564 MF |
490 | if (ret) |
491 | return ret; | |
5d4f98a2 YZ |
492 | } |
493 | } else { | |
494 | if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) { | |
495 | if (root->root_key.objectid == | |
496 | BTRFS_TREE_RELOC_OBJECTID) | |
e339a6b0 | 497 | ret = btrfs_inc_ref(trans, root, cow, 1); |
5d4f98a2 | 498 | else |
e339a6b0 | 499 | ret = btrfs_inc_ref(trans, root, cow, 0); |
692826b2 JM |
500 | if (ret) |
501 | return ret; | |
e339a6b0 | 502 | ret = btrfs_dec_ref(trans, root, buf, 1); |
692826b2 JM |
503 | if (ret) |
504 | return ret; | |
5d4f98a2 | 505 | } |
190a8339 | 506 | btrfs_clear_buffer_dirty(trans, buf); |
f0486c68 | 507 | *last_ref = 1; |
5d4f98a2 YZ |
508 | } |
509 | return 0; | |
510 | } | |
511 | ||
d352ac68 | 512 | /* |
d397712b CM |
513 | * does the dirty work in cow of a single block. The parent block (if |
514 | * supplied) is updated to point to the new cow copy. The new buffer is marked | |
515 | * dirty and returned locked. If you modify the block it needs to be marked | |
516 | * dirty again. | |
d352ac68 CM |
517 | * |
518 | * search_start -- an allocation hint for the new block | |
519 | * | |
d397712b CM |
520 | * empty_size -- a hint that you plan on doing more cow. This is the size in |
521 | * bytes the allocator should try to find free next to the block it returns. | |
522 | * This is just a hint and may be ignored by the allocator. | |
d352ac68 | 523 | */ |
95f93bc4 FM |
524 | int btrfs_force_cow_block(struct btrfs_trans_handle *trans, |
525 | struct btrfs_root *root, | |
526 | struct extent_buffer *buf, | |
527 | struct extent_buffer *parent, int parent_slot, | |
528 | struct extent_buffer **cow_ret, | |
529 | u64 search_start, u64 empty_size, | |
530 | enum btrfs_lock_nesting nest) | |
02217ed2 | 531 | { |
0b246afa | 532 | struct btrfs_fs_info *fs_info = root->fs_info; |
5d4f98a2 | 533 | struct btrfs_disk_key disk_key; |
5f39d397 | 534 | struct extent_buffer *cow; |
be1a5564 | 535 | int level, ret; |
f0486c68 | 536 | int last_ref = 0; |
925baedd | 537 | int unlock_orig = 0; |
0f5053eb | 538 | u64 parent_start = 0; |
60ea105a | 539 | u64 reloc_src_root = 0; |
7bb86316 | 540 | |
925baedd CM |
541 | if (*cow_ret == buf) |
542 | unlock_orig = 1; | |
543 | ||
49d0c642 | 544 | btrfs_assert_tree_write_locked(buf); |
925baedd | 545 | |
92a7cc42 | 546 | WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && |
0b246afa | 547 | trans->transid != fs_info->running_transaction->transid); |
92a7cc42 | 548 | WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && |
27cdeb70 | 549 | trans->transid != root->last_trans); |
5f39d397 | 550 | |
7bb86316 | 551 | level = btrfs_header_level(buf); |
31840ae1 | 552 | |
5d4f98a2 YZ |
553 | if (level == 0) |
554 | btrfs_item_key(buf, &disk_key, 0); | |
555 | else | |
556 | btrfs_node_key(buf, &disk_key, 0); | |
557 | ||
60ea105a BB |
558 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) { |
559 | if (parent) | |
560 | parent_start = parent->start; | |
561 | reloc_src_root = btrfs_header_owner(buf); | |
562 | } | |
79bd3712 FM |
563 | cow = btrfs_alloc_tree_block(trans, root, parent_start, |
564 | root->root_key.objectid, &disk_key, level, | |
60ea105a | 565 | search_start, empty_size, reloc_src_root, nest); |
54aa1f4d CM |
566 | if (IS_ERR(cow)) |
567 | return PTR_ERR(cow); | |
6702ed49 | 568 | |
b4ce94de CM |
569 | /* cow is set to blocking by btrfs_init_new_buffer */ |
570 | ||
58e8012c | 571 | copy_extent_buffer_full(cow, buf); |
db94535d | 572 | btrfs_set_header_bytenr(cow, cow->start); |
5f39d397 | 573 | btrfs_set_header_generation(cow, trans->transid); |
5d4f98a2 YZ |
574 | btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); |
575 | btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | | |
576 | BTRFS_HEADER_FLAG_RELOC); | |
577 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) | |
578 | btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); | |
579 | else | |
580 | btrfs_set_header_owner(cow, root->root_key.objectid); | |
6702ed49 | 581 | |
de37aa51 | 582 | write_extent_buffer_fsid(cow, fs_info->fs_devices->metadata_uuid); |
2b82032c | 583 | |
be1a5564 | 584 | ret = update_ref_for_cow(trans, root, buf, cow, &last_ref); |
b68dc2a9 | 585 | if (ret) { |
572c83ac JB |
586 | btrfs_tree_unlock(cow); |
587 | free_extent_buffer(cow); | |
66642832 | 588 | btrfs_abort_transaction(trans, ret); |
b68dc2a9 MF |
589 | return ret; |
590 | } | |
1a40e23b | 591 | |
92a7cc42 | 592 | if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) { |
83d4cfd4 | 593 | ret = btrfs_reloc_cow_block(trans, root, buf, cow); |
93314e3b | 594 | if (ret) { |
572c83ac JB |
595 | btrfs_tree_unlock(cow); |
596 | free_extent_buffer(cow); | |
66642832 | 597 | btrfs_abort_transaction(trans, ret); |
83d4cfd4 | 598 | return ret; |
93314e3b | 599 | } |
83d4cfd4 | 600 | } |
3fd0a558 | 601 | |
02217ed2 | 602 | if (buf == root->node) { |
925baedd | 603 | WARN_ON(parent && parent != buf); |
5d4f98a2 YZ |
604 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || |
605 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
606 | parent_start = buf->start; | |
925baedd | 607 | |
406808ab | 608 | ret = btrfs_tree_mod_log_insert_root(root->node, cow, true); |
40b0a749 FM |
609 | if (ret < 0) { |
610 | btrfs_tree_unlock(cow); | |
611 | free_extent_buffer(cow); | |
612 | btrfs_abort_transaction(trans, ret); | |
613 | return ret; | |
614 | } | |
615 | atomic_inc(&cow->refs); | |
240f62c8 | 616 | rcu_assign_pointer(root->node, cow); |
925baedd | 617 | |
7a163608 FM |
618 | btrfs_free_tree_block(trans, btrfs_root_id(root), buf, |
619 | parent_start, last_ref); | |
5f39d397 | 620 | free_extent_buffer(buf); |
0b86a832 | 621 | add_root_to_dirty_list(root); |
02217ed2 | 622 | } else { |
5d4f98a2 | 623 | WARN_ON(trans->transid != btrfs_header_generation(parent)); |
d09c5152 FM |
624 | ret = btrfs_tree_mod_log_insert_key(parent, parent_slot, |
625 | BTRFS_MOD_LOG_KEY_REPLACE); | |
626 | if (ret) { | |
627 | btrfs_tree_unlock(cow); | |
628 | free_extent_buffer(cow); | |
629 | btrfs_abort_transaction(trans, ret); | |
630 | return ret; | |
631 | } | |
5f39d397 | 632 | btrfs_set_node_blockptr(parent, parent_slot, |
db94535d | 633 | cow->start); |
74493f7a CM |
634 | btrfs_set_node_ptr_generation(parent, parent_slot, |
635 | trans->transid); | |
50564b65 | 636 | btrfs_mark_buffer_dirty(trans, parent); |
5de865ee | 637 | if (last_ref) { |
f3a84ccd | 638 | ret = btrfs_tree_mod_log_free_eb(buf); |
5de865ee | 639 | if (ret) { |
572c83ac JB |
640 | btrfs_tree_unlock(cow); |
641 | free_extent_buffer(cow); | |
66642832 | 642 | btrfs_abort_transaction(trans, ret); |
5de865ee FDBM |
643 | return ret; |
644 | } | |
645 | } | |
7a163608 FM |
646 | btrfs_free_tree_block(trans, btrfs_root_id(root), buf, |
647 | parent_start, last_ref); | |
02217ed2 | 648 | } |
925baedd CM |
649 | if (unlock_orig) |
650 | btrfs_tree_unlock(buf); | |
3083ee2e | 651 | free_extent_buffer_stale(buf); |
50564b65 | 652 | btrfs_mark_buffer_dirty(trans, cow); |
2c90e5d6 | 653 | *cow_ret = cow; |
02217ed2 CM |
654 | return 0; |
655 | } | |
656 | ||
5d4f98a2 YZ |
657 | static inline int should_cow_block(struct btrfs_trans_handle *trans, |
658 | struct btrfs_root *root, | |
659 | struct extent_buffer *buf) | |
660 | { | |
f5ee5c9a | 661 | if (btrfs_is_testing(root->fs_info)) |
faa2dbf0 | 662 | return 0; |
fccb84c9 | 663 | |
d1980131 DS |
664 | /* Ensure we can see the FORCE_COW bit */ |
665 | smp_mb__before_atomic(); | |
f1ebcc74 LB |
666 | |
667 | /* | |
668 | * We do not need to cow a block if | |
669 | * 1) this block is not created or changed in this transaction; | |
670 | * 2) this block does not belong to TREE_RELOC tree; | |
671 | * 3) the root is not forced COW. | |
672 | * | |
673 | * What is forced COW: | |
01327610 | 674 | * when we create snapshot during committing the transaction, |
52042d8e | 675 | * after we've finished copying src root, we must COW the shared |
f1ebcc74 LB |
676 | * block to ensure the metadata consistency. |
677 | */ | |
5d4f98a2 YZ |
678 | if (btrfs_header_generation(buf) == trans->transid && |
679 | !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) && | |
680 | !(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID && | |
f1ebcc74 | 681 | btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)) && |
27cdeb70 | 682 | !test_bit(BTRFS_ROOT_FORCE_COW, &root->state)) |
5d4f98a2 YZ |
683 | return 0; |
684 | return 1; | |
685 | } | |
686 | ||
d352ac68 | 687 | /* |
95f93bc4 | 688 | * COWs a single block, see btrfs_force_cow_block() for the real work. |
01327610 | 689 | * This version of it has extra checks so that a block isn't COWed more than |
d352ac68 CM |
690 | * once per transaction, as long as it hasn't been written yet |
691 | */ | |
7bff16e3 | 692 | int btrfs_cow_block(struct btrfs_trans_handle *trans, |
5f39d397 CM |
693 | struct btrfs_root *root, struct extent_buffer *buf, |
694 | struct extent_buffer *parent, int parent_slot, | |
9631e4cc JB |
695 | struct extent_buffer **cow_ret, |
696 | enum btrfs_lock_nesting nest) | |
6702ed49 | 697 | { |
0b246afa | 698 | struct btrfs_fs_info *fs_info = root->fs_info; |
6702ed49 | 699 | u64 search_start; |
f510cfec | 700 | int ret; |
dc17ff8f | 701 | |
a2caab29 FM |
702 | if (unlikely(test_bit(BTRFS_ROOT_DELETING, &root->state))) { |
703 | btrfs_abort_transaction(trans, -EUCLEAN); | |
704 | btrfs_crit(fs_info, | |
705 | "attempt to COW block %llu on root %llu that is being deleted", | |
706 | buf->start, btrfs_root_id(root)); | |
707 | return -EUCLEAN; | |
708 | } | |
83354f07 | 709 | |
48774f3b FM |
710 | /* |
711 | * COWing must happen through a running transaction, which always | |
712 | * matches the current fs generation (it's a transaction with a state | |
713 | * less than TRANS_STATE_UNBLOCKED). If it doesn't, then turn the fs | |
714 | * into error state to prevent the commit of any transaction. | |
715 | */ | |
716 | if (unlikely(trans->transaction != fs_info->running_transaction || | |
717 | trans->transid != fs_info->generation)) { | |
718 | btrfs_abort_transaction(trans, -EUCLEAN); | |
719 | btrfs_crit(fs_info, | |
720 | "unexpected transaction when attempting to COW block %llu on root %llu, transaction %llu running transaction %llu fs generation %llu", | |
721 | buf->start, btrfs_root_id(root), trans->transid, | |
722 | fs_info->running_transaction->transid, | |
723 | fs_info->generation); | |
724 | return -EUCLEAN; | |
725 | } | |
dc17ff8f | 726 | |
5d4f98a2 | 727 | if (!should_cow_block(trans, root, buf)) { |
6702ed49 CM |
728 | *cow_ret = buf; |
729 | return 0; | |
730 | } | |
c487685d | 731 | |
b8bf4e4d | 732 | search_start = round_down(buf->start, SZ_1G); |
b4ce94de | 733 | |
f616f5cd QW |
734 | /* |
735 | * Before CoWing this block for later modification, check if it's | |
736 | * the subtree root and do the delayed subtree trace if needed. | |
737 | * | |
738 | * Also We don't care about the error, as it's handled internally. | |
739 | */ | |
740 | btrfs_qgroup_trace_subtree_after_cow(trans, root, buf); | |
95f93bc4 FM |
741 | ret = btrfs_force_cow_block(trans, root, buf, parent, parent_slot, |
742 | cow_ret, search_start, 0, nest); | |
1abe9b8a | 743 | |
744 | trace_btrfs_cow_block(root, buf, *cow_ret); | |
745 | ||
f510cfec | 746 | return ret; |
6702ed49 | 747 | } |
f75e2b79 | 748 | ALLOW_ERROR_INJECTION(btrfs_cow_block, ERRNO); |
6702ed49 | 749 | |
f3465ca4 JB |
750 | /* |
751 | * same as comp_keys only with two btrfs_key's | |
752 | */ | |
e1f60a65 | 753 | int __pure btrfs_comp_cpu_keys(const struct btrfs_key *k1, const struct btrfs_key *k2) |
f3465ca4 JB |
754 | { |
755 | if (k1->objectid > k2->objectid) | |
756 | return 1; | |
757 | if (k1->objectid < k2->objectid) | |
758 | return -1; | |
759 | if (k1->type > k2->type) | |
760 | return 1; | |
761 | if (k1->type < k2->type) | |
762 | return -1; | |
763 | if (k1->offset > k2->offset) | |
764 | return 1; | |
765 | if (k1->offset < k2->offset) | |
766 | return -1; | |
767 | return 0; | |
768 | } | |
081e9573 | 769 | |
74123bd7 | 770 | /* |
fb81212c | 771 | * Search for a key in the given extent_buffer. |
5f39d397 | 772 | * |
a724f313 | 773 | * The lower boundary for the search is specified by the slot number @first_slot. |
fdf8d595 AJ |
774 | * Use a value of 0 to search over the whole extent buffer. Works for both |
775 | * leaves and nodes. | |
74123bd7 | 776 | * |
fb81212c FM |
777 | * The slot in the extent buffer is returned via @slot. If the key exists in the |
778 | * extent buffer, then @slot will point to the slot where the key is, otherwise | |
779 | * it points to the slot where you would insert the key. | |
780 | * | |
781 | * Slot may point to the total number of items (i.e. one position beyond the last | |
782 | * key) if the key is bigger than the last key in the extent buffer. | |
74123bd7 | 783 | */ |
fdf8d595 AJ |
784 | int btrfs_bin_search(struct extent_buffer *eb, int first_slot, |
785 | const struct btrfs_key *key, int *slot) | |
be0e5c09 | 786 | { |
fb81212c FM |
787 | unsigned long p; |
788 | int item_size; | |
a724f313 FM |
789 | /* |
790 | * Use unsigned types for the low and high slots, so that we get a more | |
791 | * efficient division in the search loop below. | |
792 | */ | |
793 | u32 low = first_slot; | |
794 | u32 high = btrfs_header_nritems(eb); | |
be0e5c09 | 795 | int ret; |
5cd17f34 | 796 | const int key_size = sizeof(struct btrfs_disk_key); |
be0e5c09 | 797 | |
a724f313 | 798 | if (unlikely(low > high)) { |
5e24e9af | 799 | btrfs_err(eb->fs_info, |
a724f313 | 800 | "%s: low (%u) > high (%u) eb %llu owner %llu level %d", |
5e24e9af LB |
801 | __func__, low, high, eb->start, |
802 | btrfs_header_owner(eb), btrfs_header_level(eb)); | |
803 | return -EINVAL; | |
804 | } | |
805 | ||
fb81212c FM |
806 | if (btrfs_header_level(eb) == 0) { |
807 | p = offsetof(struct btrfs_leaf, items); | |
808 | item_size = sizeof(struct btrfs_item); | |
809 | } else { | |
810 | p = offsetof(struct btrfs_node, ptrs); | |
811 | item_size = sizeof(struct btrfs_key_ptr); | |
812 | } | |
813 | ||
d397712b | 814 | while (low < high) { |
5cd17f34 DS |
815 | unsigned long oip; |
816 | unsigned long offset; | |
817 | struct btrfs_disk_key *tmp; | |
818 | struct btrfs_disk_key unaligned; | |
819 | int mid; | |
820 | ||
be0e5c09 | 821 | mid = (low + high) / 2; |
5f39d397 | 822 | offset = p + mid * item_size; |
5cd17f34 | 823 | oip = offset_in_page(offset); |
5f39d397 | 824 | |
5cd17f34 | 825 | if (oip + key_size <= PAGE_SIZE) { |
884b07d0 | 826 | const unsigned long idx = get_eb_page_index(offset); |
5cd17f34 | 827 | char *kaddr = page_address(eb->pages[idx]); |
5f39d397 | 828 | |
884b07d0 | 829 | oip = get_eb_offset_in_page(eb, offset); |
5cd17f34 | 830 | tmp = (struct btrfs_disk_key *)(kaddr + oip); |
5f39d397 | 831 | } else { |
5cd17f34 DS |
832 | read_extent_buffer(eb, &unaligned, offset, key_size); |
833 | tmp = &unaligned; | |
5f39d397 | 834 | } |
5cd17f34 | 835 | |
79d25df0 | 836 | ret = btrfs_comp_keys(tmp, key); |
be0e5c09 CM |
837 | |
838 | if (ret < 0) | |
839 | low = mid + 1; | |
840 | else if (ret > 0) | |
841 | high = mid; | |
842 | else { | |
843 | *slot = mid; | |
844 | return 0; | |
845 | } | |
846 | } | |
847 | *slot = low; | |
848 | return 1; | |
849 | } | |
850 | ||
02cd00fa | 851 | static void root_add_used_bytes(struct btrfs_root *root) |
f0486c68 YZ |
852 | { |
853 | spin_lock(&root->accounting_lock); | |
854 | btrfs_set_root_used(&root->root_item, | |
02cd00fa | 855 | btrfs_root_used(&root->root_item) + root->fs_info->nodesize); |
f0486c68 YZ |
856 | spin_unlock(&root->accounting_lock); |
857 | } | |
858 | ||
02cd00fa | 859 | static void root_sub_used_bytes(struct btrfs_root *root) |
f0486c68 YZ |
860 | { |
861 | spin_lock(&root->accounting_lock); | |
862 | btrfs_set_root_used(&root->root_item, | |
02cd00fa | 863 | btrfs_root_used(&root->root_item) - root->fs_info->nodesize); |
f0486c68 YZ |
864 | spin_unlock(&root->accounting_lock); |
865 | } | |
866 | ||
d352ac68 CM |
867 | /* given a node and slot number, this reads the blocks it points to. The |
868 | * extent buffer is returned with a reference taken (but unlocked). | |
d352ac68 | 869 | */ |
4b231ae4 DS |
870 | struct extent_buffer *btrfs_read_node_slot(struct extent_buffer *parent, |
871 | int slot) | |
bb803951 | 872 | { |
ca7a79ad | 873 | int level = btrfs_header_level(parent); |
789d6a3a | 874 | struct btrfs_tree_parent_check check = { 0 }; |
416bc658 JB |
875 | struct extent_buffer *eb; |
876 | ||
fb770ae4 LB |
877 | if (slot < 0 || slot >= btrfs_header_nritems(parent)) |
878 | return ERR_PTR(-ENOENT); | |
ca7a79ad | 879 | |
d4694728 | 880 | ASSERT(level); |
ca7a79ad | 881 | |
789d6a3a QW |
882 | check.level = level - 1; |
883 | check.transid = btrfs_node_ptr_generation(parent, slot); | |
884 | check.owner_root = btrfs_header_owner(parent); | |
885 | check.has_first_key = true; | |
886 | btrfs_node_key_to_cpu(parent, &check.first_key, slot); | |
887 | ||
d0d20b0f | 888 | eb = read_tree_block(parent->fs_info, btrfs_node_blockptr(parent, slot), |
789d6a3a | 889 | &check); |
4eb150d6 QW |
890 | if (IS_ERR(eb)) |
891 | return eb; | |
892 | if (!extent_buffer_uptodate(eb)) { | |
fb770ae4 | 893 | free_extent_buffer(eb); |
4eb150d6 | 894 | return ERR_PTR(-EIO); |
416bc658 JB |
895 | } |
896 | ||
897 | return eb; | |
bb803951 CM |
898 | } |
899 | ||
d352ac68 CM |
900 | /* |
901 | * node level balancing, used to make sure nodes are in proper order for | |
902 | * item deletion. We balance from the top down, so we have to make sure | |
903 | * that a deletion won't leave an node completely empty later on. | |
904 | */ | |
e02119d5 | 905 | static noinline int balance_level(struct btrfs_trans_handle *trans, |
98ed5174 CM |
906 | struct btrfs_root *root, |
907 | struct btrfs_path *path, int level) | |
bb803951 | 908 | { |
0b246afa | 909 | struct btrfs_fs_info *fs_info = root->fs_info; |
5f39d397 CM |
910 | struct extent_buffer *right = NULL; |
911 | struct extent_buffer *mid; | |
912 | struct extent_buffer *left = NULL; | |
913 | struct extent_buffer *parent = NULL; | |
bb803951 CM |
914 | int ret = 0; |
915 | int wret; | |
916 | int pslot; | |
bb803951 | 917 | int orig_slot = path->slots[level]; |
79f95c82 | 918 | u64 orig_ptr; |
bb803951 | 919 | |
98e6b1eb | 920 | ASSERT(level > 0); |
bb803951 | 921 | |
5f39d397 | 922 | mid = path->nodes[level]; |
b4ce94de | 923 | |
ac5887c8 | 924 | WARN_ON(path->locks[level] != BTRFS_WRITE_LOCK); |
7bb86316 CM |
925 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
926 | ||
1d4f8a0c | 927 | orig_ptr = btrfs_node_blockptr(mid, orig_slot); |
79f95c82 | 928 | |
a05a9bb1 | 929 | if (level < BTRFS_MAX_LEVEL - 1) { |
5f39d397 | 930 | parent = path->nodes[level + 1]; |
a05a9bb1 LZ |
931 | pslot = path->slots[level + 1]; |
932 | } | |
bb803951 | 933 | |
40689478 CM |
934 | /* |
935 | * deal with the case where there is only one pointer in the root | |
936 | * by promoting the node below to a root | |
937 | */ | |
5f39d397 CM |
938 | if (!parent) { |
939 | struct extent_buffer *child; | |
bb803951 | 940 | |
5f39d397 | 941 | if (btrfs_header_nritems(mid) != 1) |
bb803951 CM |
942 | return 0; |
943 | ||
944 | /* promote the child to a root */ | |
4b231ae4 | 945 | child = btrfs_read_node_slot(mid, 0); |
fb770ae4 LB |
946 | if (IS_ERR(child)) { |
947 | ret = PTR_ERR(child); | |
daefe4d4 | 948 | goto out; |
305a26af MF |
949 | } |
950 | ||
925baedd | 951 | btrfs_tree_lock(child); |
9631e4cc JB |
952 | ret = btrfs_cow_block(trans, root, child, mid, 0, &child, |
953 | BTRFS_NESTING_COW); | |
f0486c68 YZ |
954 | if (ret) { |
955 | btrfs_tree_unlock(child); | |
956 | free_extent_buffer(child); | |
daefe4d4 | 957 | goto out; |
f0486c68 | 958 | } |
2f375ab9 | 959 | |
406808ab | 960 | ret = btrfs_tree_mod_log_insert_root(root->node, child, true); |
39020d8a FM |
961 | if (ret < 0) { |
962 | btrfs_tree_unlock(child); | |
963 | free_extent_buffer(child); | |
964 | btrfs_abort_transaction(trans, ret); | |
daefe4d4 | 965 | goto out; |
39020d8a | 966 | } |
240f62c8 | 967 | rcu_assign_pointer(root->node, child); |
925baedd | 968 | |
0b86a832 | 969 | add_root_to_dirty_list(root); |
925baedd | 970 | btrfs_tree_unlock(child); |
b4ce94de | 971 | |
925baedd | 972 | path->locks[level] = 0; |
bb803951 | 973 | path->nodes[level] = NULL; |
190a8339 | 974 | btrfs_clear_buffer_dirty(trans, mid); |
925baedd | 975 | btrfs_tree_unlock(mid); |
bb803951 | 976 | /* once for the path */ |
5f39d397 | 977 | free_extent_buffer(mid); |
f0486c68 | 978 | |
02cd00fa | 979 | root_sub_used_bytes(root); |
7a163608 | 980 | btrfs_free_tree_block(trans, btrfs_root_id(root), mid, 0, 1); |
bb803951 | 981 | /* once for the root ptr */ |
3083ee2e | 982 | free_extent_buffer_stale(mid); |
f0486c68 | 983 | return 0; |
bb803951 | 984 | } |
5f39d397 | 985 | if (btrfs_header_nritems(mid) > |
0b246afa | 986 | BTRFS_NODEPTRS_PER_BLOCK(fs_info) / 4) |
bb803951 CM |
987 | return 0; |
988 | ||
9cf14029 JB |
989 | if (pslot) { |
990 | left = btrfs_read_node_slot(parent, pslot - 1); | |
991 | if (IS_ERR(left)) { | |
992 | ret = PTR_ERR(left); | |
993 | left = NULL; | |
daefe4d4 | 994 | goto out; |
9cf14029 | 995 | } |
fb770ae4 | 996 | |
bf77467a | 997 | __btrfs_tree_lock(left, BTRFS_NESTING_LEFT); |
5f39d397 | 998 | wret = btrfs_cow_block(trans, root, left, |
9631e4cc | 999 | parent, pslot - 1, &left, |
bf59a5a2 | 1000 | BTRFS_NESTING_LEFT_COW); |
54aa1f4d CM |
1001 | if (wret) { |
1002 | ret = wret; | |
daefe4d4 | 1003 | goto out; |
54aa1f4d | 1004 | } |
2cc58cf2 | 1005 | } |
fb770ae4 | 1006 | |
9cf14029 JB |
1007 | if (pslot + 1 < btrfs_header_nritems(parent)) { |
1008 | right = btrfs_read_node_slot(parent, pslot + 1); | |
1009 | if (IS_ERR(right)) { | |
1010 | ret = PTR_ERR(right); | |
1011 | right = NULL; | |
daefe4d4 | 1012 | goto out; |
9cf14029 | 1013 | } |
fb770ae4 | 1014 | |
bf77467a | 1015 | __btrfs_tree_lock(right, BTRFS_NESTING_RIGHT); |
5f39d397 | 1016 | wret = btrfs_cow_block(trans, root, right, |
9631e4cc | 1017 | parent, pslot + 1, &right, |
bf59a5a2 | 1018 | BTRFS_NESTING_RIGHT_COW); |
2cc58cf2 CM |
1019 | if (wret) { |
1020 | ret = wret; | |
daefe4d4 | 1021 | goto out; |
2cc58cf2 CM |
1022 | } |
1023 | } | |
1024 | ||
1025 | /* first, try to make some room in the middle buffer */ | |
5f39d397 CM |
1026 | if (left) { |
1027 | orig_slot += btrfs_header_nritems(left); | |
d30a668f | 1028 | wret = push_node_left(trans, left, mid, 1); |
79f95c82 CM |
1029 | if (wret < 0) |
1030 | ret = wret; | |
bb803951 | 1031 | } |
79f95c82 CM |
1032 | |
1033 | /* | |
1034 | * then try to empty the right most buffer into the middle | |
1035 | */ | |
5f39d397 | 1036 | if (right) { |
d30a668f | 1037 | wret = push_node_left(trans, mid, right, 1); |
54aa1f4d | 1038 | if (wret < 0 && wret != -ENOSPC) |
79f95c82 | 1039 | ret = wret; |
5f39d397 | 1040 | if (btrfs_header_nritems(right) == 0) { |
190a8339 | 1041 | btrfs_clear_buffer_dirty(trans, right); |
925baedd | 1042 | btrfs_tree_unlock(right); |
751a2761 FM |
1043 | ret = btrfs_del_ptr(trans, root, path, level + 1, pslot + 1); |
1044 | if (ret < 0) { | |
1045 | free_extent_buffer_stale(right); | |
1046 | right = NULL; | |
1047 | goto out; | |
1048 | } | |
02cd00fa | 1049 | root_sub_used_bytes(root); |
7a163608 FM |
1050 | btrfs_free_tree_block(trans, btrfs_root_id(root), right, |
1051 | 0, 1); | |
3083ee2e | 1052 | free_extent_buffer_stale(right); |
f0486c68 | 1053 | right = NULL; |
bb803951 | 1054 | } else { |
5f39d397 CM |
1055 | struct btrfs_disk_key right_key; |
1056 | btrfs_node_key(right, &right_key, 0); | |
f3a84ccd | 1057 | ret = btrfs_tree_mod_log_insert_key(parent, pslot + 1, |
33cff222 | 1058 | BTRFS_MOD_LOG_KEY_REPLACE); |
39020d8a FM |
1059 | if (ret < 0) { |
1060 | btrfs_abort_transaction(trans, ret); | |
daefe4d4 | 1061 | goto out; |
39020d8a | 1062 | } |
5f39d397 | 1063 | btrfs_set_node_key(parent, &right_key, pslot + 1); |
50564b65 | 1064 | btrfs_mark_buffer_dirty(trans, parent); |
bb803951 CM |
1065 | } |
1066 | } | |
5f39d397 | 1067 | if (btrfs_header_nritems(mid) == 1) { |
79f95c82 CM |
1068 | /* |
1069 | * we're not allowed to leave a node with one item in the | |
1070 | * tree during a delete. A deletion from lower in the tree | |
1071 | * could try to delete the only pointer in this node. | |
1072 | * So, pull some keys from the left. | |
1073 | * There has to be a left pointer at this point because | |
1074 | * otherwise we would have pulled some pointers from the | |
1075 | * right | |
1076 | */ | |
725026ed FM |
1077 | if (unlikely(!left)) { |
1078 | btrfs_crit(fs_info, | |
1079 | "missing left child when middle child only has 1 item, parent bytenr %llu level %d mid bytenr %llu root %llu", | |
1080 | parent->start, btrfs_header_level(parent), | |
1081 | mid->start, btrfs_root_id(root)); | |
1082 | ret = -EUCLEAN; | |
1083 | btrfs_abort_transaction(trans, ret); | |
daefe4d4 | 1084 | goto out; |
305a26af | 1085 | } |
55d32ed8 | 1086 | wret = balance_node_right(trans, mid, left); |
54aa1f4d | 1087 | if (wret < 0) { |
79f95c82 | 1088 | ret = wret; |
daefe4d4 | 1089 | goto out; |
54aa1f4d | 1090 | } |
bce4eae9 | 1091 | if (wret == 1) { |
d30a668f | 1092 | wret = push_node_left(trans, left, mid, 1); |
bce4eae9 CM |
1093 | if (wret < 0) |
1094 | ret = wret; | |
1095 | } | |
79f95c82 CM |
1096 | BUG_ON(wret == 1); |
1097 | } | |
5f39d397 | 1098 | if (btrfs_header_nritems(mid) == 0) { |
190a8339 | 1099 | btrfs_clear_buffer_dirty(trans, mid); |
925baedd | 1100 | btrfs_tree_unlock(mid); |
751a2761 FM |
1101 | ret = btrfs_del_ptr(trans, root, path, level + 1, pslot); |
1102 | if (ret < 0) { | |
1103 | free_extent_buffer_stale(mid); | |
1104 | mid = NULL; | |
1105 | goto out; | |
1106 | } | |
02cd00fa | 1107 | root_sub_used_bytes(root); |
7a163608 | 1108 | btrfs_free_tree_block(trans, btrfs_root_id(root), mid, 0, 1); |
3083ee2e | 1109 | free_extent_buffer_stale(mid); |
f0486c68 | 1110 | mid = NULL; |
79f95c82 CM |
1111 | } else { |
1112 | /* update the parent key to reflect our changes */ | |
5f39d397 CM |
1113 | struct btrfs_disk_key mid_key; |
1114 | btrfs_node_key(mid, &mid_key, 0); | |
f3a84ccd | 1115 | ret = btrfs_tree_mod_log_insert_key(parent, pslot, |
33cff222 | 1116 | BTRFS_MOD_LOG_KEY_REPLACE); |
39020d8a FM |
1117 | if (ret < 0) { |
1118 | btrfs_abort_transaction(trans, ret); | |
daefe4d4 | 1119 | goto out; |
39020d8a | 1120 | } |
5f39d397 | 1121 | btrfs_set_node_key(parent, &mid_key, pslot); |
50564b65 | 1122 | btrfs_mark_buffer_dirty(trans, parent); |
79f95c82 | 1123 | } |
bb803951 | 1124 | |
79f95c82 | 1125 | /* update the path */ |
5f39d397 CM |
1126 | if (left) { |
1127 | if (btrfs_header_nritems(left) > orig_slot) { | |
67439dad | 1128 | atomic_inc(&left->refs); |
925baedd | 1129 | /* left was locked after cow */ |
5f39d397 | 1130 | path->nodes[level] = left; |
bb803951 CM |
1131 | path->slots[level + 1] -= 1; |
1132 | path->slots[level] = orig_slot; | |
925baedd CM |
1133 | if (mid) { |
1134 | btrfs_tree_unlock(mid); | |
5f39d397 | 1135 | free_extent_buffer(mid); |
925baedd | 1136 | } |
bb803951 | 1137 | } else { |
5f39d397 | 1138 | orig_slot -= btrfs_header_nritems(left); |
bb803951 CM |
1139 | path->slots[level] = orig_slot; |
1140 | } | |
1141 | } | |
79f95c82 | 1142 | /* double check we haven't messed things up */ |
e20d96d6 | 1143 | if (orig_ptr != |
5f39d397 | 1144 | btrfs_node_blockptr(path->nodes[level], path->slots[level])) |
79f95c82 | 1145 | BUG(); |
daefe4d4 | 1146 | out: |
925baedd CM |
1147 | if (right) { |
1148 | btrfs_tree_unlock(right); | |
5f39d397 | 1149 | free_extent_buffer(right); |
925baedd CM |
1150 | } |
1151 | if (left) { | |
1152 | if (path->nodes[level] != left) | |
1153 | btrfs_tree_unlock(left); | |
5f39d397 | 1154 | free_extent_buffer(left); |
925baedd | 1155 | } |
bb803951 CM |
1156 | return ret; |
1157 | } | |
1158 | ||
d352ac68 CM |
1159 | /* Node balancing for insertion. Here we only split or push nodes around |
1160 | * when they are completely full. This is also done top down, so we | |
1161 | * have to be pessimistic. | |
1162 | */ | |
d397712b | 1163 | static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, |
98ed5174 CM |
1164 | struct btrfs_root *root, |
1165 | struct btrfs_path *path, int level) | |
e66f709b | 1166 | { |
0b246afa | 1167 | struct btrfs_fs_info *fs_info = root->fs_info; |
5f39d397 CM |
1168 | struct extent_buffer *right = NULL; |
1169 | struct extent_buffer *mid; | |
1170 | struct extent_buffer *left = NULL; | |
1171 | struct extent_buffer *parent = NULL; | |
e66f709b CM |
1172 | int ret = 0; |
1173 | int wret; | |
1174 | int pslot; | |
1175 | int orig_slot = path->slots[level]; | |
e66f709b CM |
1176 | |
1177 | if (level == 0) | |
1178 | return 1; | |
1179 | ||
5f39d397 | 1180 | mid = path->nodes[level]; |
7bb86316 | 1181 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
e66f709b | 1182 | |
a05a9bb1 | 1183 | if (level < BTRFS_MAX_LEVEL - 1) { |
5f39d397 | 1184 | parent = path->nodes[level + 1]; |
a05a9bb1 LZ |
1185 | pslot = path->slots[level + 1]; |
1186 | } | |
e66f709b | 1187 | |
5f39d397 | 1188 | if (!parent) |
e66f709b | 1189 | return 1; |
e66f709b | 1190 | |
e66f709b | 1191 | /* first, try to make some room in the middle buffer */ |
9cf14029 | 1192 | if (pslot) { |
e66f709b | 1193 | u32 left_nr; |
925baedd | 1194 | |
9cf14029 JB |
1195 | left = btrfs_read_node_slot(parent, pslot - 1); |
1196 | if (IS_ERR(left)) | |
1197 | return PTR_ERR(left); | |
1198 | ||
bf77467a | 1199 | __btrfs_tree_lock(left, BTRFS_NESTING_LEFT); |
b4ce94de | 1200 | |
5f39d397 | 1201 | left_nr = btrfs_header_nritems(left); |
0b246afa | 1202 | if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 1) { |
33ade1f8 CM |
1203 | wret = 1; |
1204 | } else { | |
5f39d397 | 1205 | ret = btrfs_cow_block(trans, root, left, parent, |
9631e4cc | 1206 | pslot - 1, &left, |
bf59a5a2 | 1207 | BTRFS_NESTING_LEFT_COW); |
54aa1f4d CM |
1208 | if (ret) |
1209 | wret = 1; | |
1210 | else { | |
d30a668f | 1211 | wret = push_node_left(trans, left, mid, 0); |
54aa1f4d | 1212 | } |
33ade1f8 | 1213 | } |
e66f709b CM |
1214 | if (wret < 0) |
1215 | ret = wret; | |
1216 | if (wret == 0) { | |
5f39d397 | 1217 | struct btrfs_disk_key disk_key; |
e66f709b | 1218 | orig_slot += left_nr; |
5f39d397 | 1219 | btrfs_node_key(mid, &disk_key, 0); |
f3a84ccd | 1220 | ret = btrfs_tree_mod_log_insert_key(parent, pslot, |
33cff222 | 1221 | BTRFS_MOD_LOG_KEY_REPLACE); |
11d6ae03 FM |
1222 | if (ret < 0) { |
1223 | btrfs_tree_unlock(left); | |
1224 | free_extent_buffer(left); | |
1225 | btrfs_abort_transaction(trans, ret); | |
1226 | return ret; | |
1227 | } | |
5f39d397 | 1228 | btrfs_set_node_key(parent, &disk_key, pslot); |
50564b65 | 1229 | btrfs_mark_buffer_dirty(trans, parent); |
5f39d397 CM |
1230 | if (btrfs_header_nritems(left) > orig_slot) { |
1231 | path->nodes[level] = left; | |
e66f709b CM |
1232 | path->slots[level + 1] -= 1; |
1233 | path->slots[level] = orig_slot; | |
925baedd | 1234 | btrfs_tree_unlock(mid); |
5f39d397 | 1235 | free_extent_buffer(mid); |
e66f709b CM |
1236 | } else { |
1237 | orig_slot -= | |
5f39d397 | 1238 | btrfs_header_nritems(left); |
e66f709b | 1239 | path->slots[level] = orig_slot; |
925baedd | 1240 | btrfs_tree_unlock(left); |
5f39d397 | 1241 | free_extent_buffer(left); |
e66f709b | 1242 | } |
e66f709b CM |
1243 | return 0; |
1244 | } | |
925baedd | 1245 | btrfs_tree_unlock(left); |
5f39d397 | 1246 | free_extent_buffer(left); |
e66f709b | 1247 | } |
e66f709b CM |
1248 | |
1249 | /* | |
1250 | * then try to empty the right most buffer into the middle | |
1251 | */ | |
9cf14029 | 1252 | if (pslot + 1 < btrfs_header_nritems(parent)) { |
33ade1f8 | 1253 | u32 right_nr; |
b4ce94de | 1254 | |
9cf14029 JB |
1255 | right = btrfs_read_node_slot(parent, pslot + 1); |
1256 | if (IS_ERR(right)) | |
1257 | return PTR_ERR(right); | |
1258 | ||
bf77467a | 1259 | __btrfs_tree_lock(right, BTRFS_NESTING_RIGHT); |
b4ce94de | 1260 | |
5f39d397 | 1261 | right_nr = btrfs_header_nritems(right); |
0b246afa | 1262 | if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 1) { |
33ade1f8 CM |
1263 | wret = 1; |
1264 | } else { | |
5f39d397 CM |
1265 | ret = btrfs_cow_block(trans, root, right, |
1266 | parent, pslot + 1, | |
bf59a5a2 | 1267 | &right, BTRFS_NESTING_RIGHT_COW); |
54aa1f4d CM |
1268 | if (ret) |
1269 | wret = 1; | |
1270 | else { | |
55d32ed8 | 1271 | wret = balance_node_right(trans, right, mid); |
54aa1f4d | 1272 | } |
33ade1f8 | 1273 | } |
e66f709b CM |
1274 | if (wret < 0) |
1275 | ret = wret; | |
1276 | if (wret == 0) { | |
5f39d397 CM |
1277 | struct btrfs_disk_key disk_key; |
1278 | ||
1279 | btrfs_node_key(right, &disk_key, 0); | |
f3a84ccd | 1280 | ret = btrfs_tree_mod_log_insert_key(parent, pslot + 1, |
33cff222 | 1281 | BTRFS_MOD_LOG_KEY_REPLACE); |
11d6ae03 FM |
1282 | if (ret < 0) { |
1283 | btrfs_tree_unlock(right); | |
1284 | free_extent_buffer(right); | |
1285 | btrfs_abort_transaction(trans, ret); | |
1286 | return ret; | |
1287 | } | |
5f39d397 | 1288 | btrfs_set_node_key(parent, &disk_key, pslot + 1); |
50564b65 | 1289 | btrfs_mark_buffer_dirty(trans, parent); |
5f39d397 CM |
1290 | |
1291 | if (btrfs_header_nritems(mid) <= orig_slot) { | |
1292 | path->nodes[level] = right; | |
e66f709b CM |
1293 | path->slots[level + 1] += 1; |
1294 | path->slots[level] = orig_slot - | |
5f39d397 | 1295 | btrfs_header_nritems(mid); |
925baedd | 1296 | btrfs_tree_unlock(mid); |
5f39d397 | 1297 | free_extent_buffer(mid); |
e66f709b | 1298 | } else { |
925baedd | 1299 | btrfs_tree_unlock(right); |
5f39d397 | 1300 | free_extent_buffer(right); |
e66f709b | 1301 | } |
e66f709b CM |
1302 | return 0; |
1303 | } | |
925baedd | 1304 | btrfs_tree_unlock(right); |
5f39d397 | 1305 | free_extent_buffer(right); |
e66f709b | 1306 | } |
e66f709b CM |
1307 | return 1; |
1308 | } | |
1309 | ||
3c69faec | 1310 | /* |
d352ac68 CM |
1311 | * readahead one full node of leaves, finding things that are close |
1312 | * to the block in 'slot', and triggering ra on them. | |
3c69faec | 1313 | */ |
2ff7e61e | 1314 | static void reada_for_search(struct btrfs_fs_info *fs_info, |
c8c42864 CM |
1315 | struct btrfs_path *path, |
1316 | int level, int slot, u64 objectid) | |
3c69faec | 1317 | { |
5f39d397 | 1318 | struct extent_buffer *node; |
01f46658 | 1319 | struct btrfs_disk_key disk_key; |
3c69faec | 1320 | u32 nritems; |
3c69faec | 1321 | u64 search; |
a7175319 | 1322 | u64 target; |
6b80053d | 1323 | u64 nread = 0; |
ace75066 | 1324 | u64 nread_max; |
6b80053d CM |
1325 | u32 nr; |
1326 | u32 blocksize; | |
1327 | u32 nscan = 0; | |
db94535d | 1328 | |
ace75066 | 1329 | if (level != 1 && path->reada != READA_FORWARD_ALWAYS) |
6702ed49 CM |
1330 | return; |
1331 | ||
1332 | if (!path->nodes[level]) | |
3c69faec CM |
1333 | return; |
1334 | ||
5f39d397 | 1335 | node = path->nodes[level]; |
925baedd | 1336 | |
ace75066 FM |
1337 | /* |
1338 | * Since the time between visiting leaves is much shorter than the time | |
1339 | * between visiting nodes, limit read ahead of nodes to 1, to avoid too | |
1340 | * much IO at once (possibly random). | |
1341 | */ | |
1342 | if (path->reada == READA_FORWARD_ALWAYS) { | |
1343 | if (level > 1) | |
1344 | nread_max = node->fs_info->nodesize; | |
1345 | else | |
1346 | nread_max = SZ_128K; | |
1347 | } else { | |
1348 | nread_max = SZ_64K; | |
1349 | } | |
1350 | ||
3c69faec | 1351 | search = btrfs_node_blockptr(node, slot); |
0b246afa | 1352 | blocksize = fs_info->nodesize; |
069a2e37 FM |
1353 | if (path->reada != READA_FORWARD_ALWAYS) { |
1354 | struct extent_buffer *eb; | |
1355 | ||
1356 | eb = find_extent_buffer(fs_info, search); | |
1357 | if (eb) { | |
1358 | free_extent_buffer(eb); | |
1359 | return; | |
1360 | } | |
3c69faec CM |
1361 | } |
1362 | ||
a7175319 | 1363 | target = search; |
6b80053d | 1364 | |
5f39d397 | 1365 | nritems = btrfs_header_nritems(node); |
6b80053d | 1366 | nr = slot; |
25b8b936 | 1367 | |
d397712b | 1368 | while (1) { |
e4058b54 | 1369 | if (path->reada == READA_BACK) { |
6b80053d CM |
1370 | if (nr == 0) |
1371 | break; | |
1372 | nr--; | |
ace75066 FM |
1373 | } else if (path->reada == READA_FORWARD || |
1374 | path->reada == READA_FORWARD_ALWAYS) { | |
6b80053d CM |
1375 | nr++; |
1376 | if (nr >= nritems) | |
1377 | break; | |
3c69faec | 1378 | } |
e4058b54 | 1379 | if (path->reada == READA_BACK && objectid) { |
01f46658 CM |
1380 | btrfs_node_key(node, &disk_key, nr); |
1381 | if (btrfs_disk_key_objectid(&disk_key) != objectid) | |
1382 | break; | |
1383 | } | |
6b80053d | 1384 | search = btrfs_node_blockptr(node, nr); |
ace75066 FM |
1385 | if (path->reada == READA_FORWARD_ALWAYS || |
1386 | (search <= target && target - search <= 65536) || | |
a7175319 | 1387 | (search > target && search - target <= 65536)) { |
bfb484d9 | 1388 | btrfs_readahead_node_child(node, nr); |
6b80053d CM |
1389 | nread += blocksize; |
1390 | } | |
1391 | nscan++; | |
ace75066 | 1392 | if (nread > nread_max || nscan > 32) |
6b80053d | 1393 | break; |
3c69faec CM |
1394 | } |
1395 | } | |
925baedd | 1396 | |
bfb484d9 | 1397 | static noinline void reada_for_balance(struct btrfs_path *path, int level) |
b4ce94de | 1398 | { |
bfb484d9 | 1399 | struct extent_buffer *parent; |
b4ce94de CM |
1400 | int slot; |
1401 | int nritems; | |
b4ce94de | 1402 | |
8c594ea8 | 1403 | parent = path->nodes[level + 1]; |
b4ce94de | 1404 | if (!parent) |
0b08851f | 1405 | return; |
b4ce94de CM |
1406 | |
1407 | nritems = btrfs_header_nritems(parent); | |
8c594ea8 | 1408 | slot = path->slots[level + 1]; |
b4ce94de | 1409 | |
bfb484d9 JB |
1410 | if (slot > 0) |
1411 | btrfs_readahead_node_child(parent, slot - 1); | |
1412 | if (slot + 1 < nritems) | |
1413 | btrfs_readahead_node_child(parent, slot + 1); | |
b4ce94de CM |
1414 | } |
1415 | ||
1416 | ||
d352ac68 | 1417 | /* |
d397712b CM |
1418 | * when we walk down the tree, it is usually safe to unlock the higher layers |
1419 | * in the tree. The exceptions are when our path goes through slot 0, because | |
1420 | * operations on the tree might require changing key pointers higher up in the | |
1421 | * tree. | |
d352ac68 | 1422 | * |
d397712b CM |
1423 | * callers might also have set path->keep_locks, which tells this code to keep |
1424 | * the lock if the path points to the last slot in the block. This is part of | |
1425 | * walking through the tree, and selecting the next slot in the higher block. | |
d352ac68 | 1426 | * |
d397712b CM |
1427 | * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so |
1428 | * if lowest_unlock is 1, level 0 won't be unlocked | |
d352ac68 | 1429 | */ |
e02119d5 | 1430 | static noinline void unlock_up(struct btrfs_path *path, int level, |
f7c79f30 CM |
1431 | int lowest_unlock, int min_write_lock_level, |
1432 | int *write_lock_level) | |
925baedd CM |
1433 | { |
1434 | int i; | |
1435 | int skip_level = level; | |
c1227996 | 1436 | bool check_skip = true; |
925baedd CM |
1437 | |
1438 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { | |
1439 | if (!path->nodes[i]) | |
1440 | break; | |
1441 | if (!path->locks[i]) | |
1442 | break; | |
c1227996 NB |
1443 | |
1444 | if (check_skip) { | |
1445 | if (path->slots[i] == 0) { | |
925baedd CM |
1446 | skip_level = i + 1; |
1447 | continue; | |
1448 | } | |
c1227996 NB |
1449 | |
1450 | if (path->keep_locks) { | |
1451 | u32 nritems; | |
1452 | ||
1453 | nritems = btrfs_header_nritems(path->nodes[i]); | |
1454 | if (nritems < 1 || path->slots[i] >= nritems - 1) { | |
1455 | skip_level = i + 1; | |
1456 | continue; | |
1457 | } | |
1458 | } | |
925baedd | 1459 | } |
051e1b9f | 1460 | |
d80bb3f9 | 1461 | if (i >= lowest_unlock && i > skip_level) { |
c1227996 NB |
1462 | check_skip = false; |
1463 | btrfs_tree_unlock_rw(path->nodes[i], path->locks[i]); | |
925baedd | 1464 | path->locks[i] = 0; |
f7c79f30 CM |
1465 | if (write_lock_level && |
1466 | i > min_write_lock_level && | |
1467 | i <= *write_lock_level) { | |
1468 | *write_lock_level = i - 1; | |
1469 | } | |
925baedd CM |
1470 | } |
1471 | } | |
1472 | } | |
1473 | ||
c8c42864 | 1474 | /* |
376a21d7 FM |
1475 | * Helper function for btrfs_search_slot() and other functions that do a search |
1476 | * on a btree. The goal is to find a tree block in the cache (the radix tree at | |
1477 | * fs_info->buffer_radix), but if we can't find it, or it's not up to date, read | |
1478 | * its pages from disk. | |
c8c42864 | 1479 | * |
376a21d7 FM |
1480 | * Returns -EAGAIN, with the path unlocked, if the caller needs to repeat the |
1481 | * whole btree search, starting again from the current root node. | |
c8c42864 CM |
1482 | */ |
1483 | static int | |
d07b8528 LB |
1484 | read_block_for_search(struct btrfs_root *root, struct btrfs_path *p, |
1485 | struct extent_buffer **eb_ret, int level, int slot, | |
cda79c54 | 1486 | const struct btrfs_key *key) |
c8c42864 | 1487 | { |
0b246afa | 1488 | struct btrfs_fs_info *fs_info = root->fs_info; |
789d6a3a | 1489 | struct btrfs_tree_parent_check check = { 0 }; |
c8c42864 CM |
1490 | u64 blocknr; |
1491 | u64 gen; | |
c8c42864 | 1492 | struct extent_buffer *tmp; |
76a05b35 | 1493 | int ret; |
581c1760 | 1494 | int parent_level; |
b246666e | 1495 | bool unlock_up; |
c8c42864 | 1496 | |
b246666e | 1497 | unlock_up = ((level + 1 < BTRFS_MAX_LEVEL) && p->locks[level + 1]); |
213ff4b7 NB |
1498 | blocknr = btrfs_node_blockptr(*eb_ret, slot); |
1499 | gen = btrfs_node_ptr_generation(*eb_ret, slot); | |
1500 | parent_level = btrfs_header_level(*eb_ret); | |
789d6a3a QW |
1501 | btrfs_node_key_to_cpu(*eb_ret, &check.first_key, slot); |
1502 | check.has_first_key = true; | |
1503 | check.level = parent_level - 1; | |
1504 | check.transid = gen; | |
1505 | check.owner_root = root->root_key.objectid; | |
c8c42864 | 1506 | |
b246666e FM |
1507 | /* |
1508 | * If we need to read an extent buffer from disk and we are holding locks | |
1509 | * on upper level nodes, we unlock all the upper nodes before reading the | |
1510 | * extent buffer, and then return -EAGAIN to the caller as it needs to | |
1511 | * restart the search. We don't release the lock on the current level | |
1512 | * because we need to walk this node to figure out which blocks to read. | |
1513 | */ | |
0b246afa | 1514 | tmp = find_extent_buffer(fs_info, blocknr); |
cb44921a | 1515 | if (tmp) { |
ace75066 FM |
1516 | if (p->reada == READA_FORWARD_ALWAYS) |
1517 | reada_for_search(fs_info, p, level, slot, key->objectid); | |
1518 | ||
b9fab919 | 1519 | /* first we do an atomic uptodate check */ |
bdf7c00e | 1520 | if (btrfs_buffer_uptodate(tmp, gen, 1) > 0) { |
448de471 QW |
1521 | /* |
1522 | * Do extra check for first_key, eb can be stale due to | |
1523 | * being cached, read from scrub, or have multiple | |
1524 | * parents (shared tree blocks). | |
1525 | */ | |
e064d5e9 | 1526 | if (btrfs_verify_level_key(tmp, |
789d6a3a | 1527 | parent_level - 1, &check.first_key, gen)) { |
448de471 QW |
1528 | free_extent_buffer(tmp); |
1529 | return -EUCLEAN; | |
1530 | } | |
bdf7c00e JB |
1531 | *eb_ret = tmp; |
1532 | return 0; | |
1533 | } | |
1534 | ||
857bc13f JB |
1535 | if (p->nowait) { |
1536 | free_extent_buffer(tmp); | |
1537 | return -EAGAIN; | |
1538 | } | |
1539 | ||
b246666e FM |
1540 | if (unlock_up) |
1541 | btrfs_unlock_up_safe(p, level + 1); | |
1542 | ||
bdf7c00e | 1543 | /* now we're allowed to do a blocking uptodate check */ |
789d6a3a | 1544 | ret = btrfs_read_extent_buffer(tmp, &check); |
9a4ffa1b QW |
1545 | if (ret) { |
1546 | free_extent_buffer(tmp); | |
1547 | btrfs_release_path(p); | |
1548 | return -EIO; | |
cb44921a | 1549 | } |
88c602ab QW |
1550 | if (btrfs_check_eb_owner(tmp, root->root_key.objectid)) { |
1551 | free_extent_buffer(tmp); | |
1552 | btrfs_release_path(p); | |
1553 | return -EUCLEAN; | |
1554 | } | |
b246666e FM |
1555 | |
1556 | if (unlock_up) | |
1557 | ret = -EAGAIN; | |
1558 | ||
1559 | goto out; | |
857bc13f JB |
1560 | } else if (p->nowait) { |
1561 | return -EAGAIN; | |
c8c42864 CM |
1562 | } |
1563 | ||
b246666e | 1564 | if (unlock_up) { |
4bb59055 FM |
1565 | btrfs_unlock_up_safe(p, level + 1); |
1566 | ret = -EAGAIN; | |
1567 | } else { | |
1568 | ret = 0; | |
1569 | } | |
8c594ea8 | 1570 | |
e4058b54 | 1571 | if (p->reada != READA_NONE) |
2ff7e61e | 1572 | reada_for_search(fs_info, p, level, slot, key->objectid); |
c8c42864 | 1573 | |
789d6a3a | 1574 | tmp = read_tree_block(fs_info, blocknr, &check); |
4eb150d6 QW |
1575 | if (IS_ERR(tmp)) { |
1576 | btrfs_release_path(p); | |
1577 | return PTR_ERR(tmp); | |
76a05b35 | 1578 | } |
4eb150d6 QW |
1579 | /* |
1580 | * If the read above didn't mark this buffer up to date, | |
1581 | * it will never end up being up to date. Set ret to EIO now | |
1582 | * and give up so that our caller doesn't loop forever | |
1583 | * on our EAGAINs. | |
1584 | */ | |
1585 | if (!extent_buffer_uptodate(tmp)) | |
1586 | ret = -EIO; | |
02a3307a | 1587 | |
b246666e | 1588 | out: |
4bb59055 FM |
1589 | if (ret == 0) { |
1590 | *eb_ret = tmp; | |
1591 | } else { | |
1592 | free_extent_buffer(tmp); | |
1593 | btrfs_release_path(p); | |
1594 | } | |
1595 | ||
76a05b35 | 1596 | return ret; |
c8c42864 CM |
1597 | } |
1598 | ||
1599 | /* | |
1600 | * helper function for btrfs_search_slot. This does all of the checks | |
1601 | * for node-level blocks and does any balancing required based on | |
1602 | * the ins_len. | |
1603 | * | |
1604 | * If no extra work was required, zero is returned. If we had to | |
1605 | * drop the path, -EAGAIN is returned and btrfs_search_slot must | |
1606 | * start over | |
1607 | */ | |
1608 | static int | |
1609 | setup_nodes_for_search(struct btrfs_trans_handle *trans, | |
1610 | struct btrfs_root *root, struct btrfs_path *p, | |
bd681513 CM |
1611 | struct extent_buffer *b, int level, int ins_len, |
1612 | int *write_lock_level) | |
c8c42864 | 1613 | { |
0b246afa | 1614 | struct btrfs_fs_info *fs_info = root->fs_info; |
95b982de | 1615 | int ret = 0; |
0b246afa | 1616 | |
c8c42864 | 1617 | if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >= |
0b246afa | 1618 | BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 3) { |
c8c42864 | 1619 | |
bd681513 CM |
1620 | if (*write_lock_level < level + 1) { |
1621 | *write_lock_level = level + 1; | |
1622 | btrfs_release_path(p); | |
95b982de | 1623 | return -EAGAIN; |
bd681513 CM |
1624 | } |
1625 | ||
bfb484d9 | 1626 | reada_for_balance(p, level); |
95b982de | 1627 | ret = split_node(trans, root, p, level); |
c8c42864 | 1628 | |
c8c42864 CM |
1629 | b = p->nodes[level]; |
1630 | } else if (ins_len < 0 && btrfs_header_nritems(b) < | |
0b246afa | 1631 | BTRFS_NODEPTRS_PER_BLOCK(fs_info) / 2) { |
c8c42864 | 1632 | |
bd681513 CM |
1633 | if (*write_lock_level < level + 1) { |
1634 | *write_lock_level = level + 1; | |
1635 | btrfs_release_path(p); | |
95b982de | 1636 | return -EAGAIN; |
bd681513 CM |
1637 | } |
1638 | ||
bfb484d9 | 1639 | reada_for_balance(p, level); |
95b982de NB |
1640 | ret = balance_level(trans, root, p, level); |
1641 | if (ret) | |
1642 | return ret; | |
c8c42864 | 1643 | |
c8c42864 CM |
1644 | b = p->nodes[level]; |
1645 | if (!b) { | |
b3b4aa74 | 1646 | btrfs_release_path(p); |
95b982de | 1647 | return -EAGAIN; |
c8c42864 CM |
1648 | } |
1649 | BUG_ON(btrfs_header_nritems(b) == 1); | |
1650 | } | |
c8c42864 CM |
1651 | return ret; |
1652 | } | |
1653 | ||
381cf658 | 1654 | int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *path, |
e33d5c3d KN |
1655 | u64 iobjectid, u64 ioff, u8 key_type, |
1656 | struct btrfs_key *found_key) | |
1657 | { | |
1658 | int ret; | |
1659 | struct btrfs_key key; | |
1660 | struct extent_buffer *eb; | |
381cf658 DS |
1661 | |
1662 | ASSERT(path); | |
1d4c08e0 | 1663 | ASSERT(found_key); |
e33d5c3d KN |
1664 | |
1665 | key.type = key_type; | |
1666 | key.objectid = iobjectid; | |
1667 | key.offset = ioff; | |
1668 | ||
1669 | ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0); | |
1d4c08e0 | 1670 | if (ret < 0) |
e33d5c3d KN |
1671 | return ret; |
1672 | ||
1673 | eb = path->nodes[0]; | |
1674 | if (ret && path->slots[0] >= btrfs_header_nritems(eb)) { | |
1675 | ret = btrfs_next_leaf(fs_root, path); | |
1676 | if (ret) | |
1677 | return ret; | |
1678 | eb = path->nodes[0]; | |
1679 | } | |
1680 | ||
1681 | btrfs_item_key_to_cpu(eb, found_key, path->slots[0]); | |
1682 | if (found_key->type != key.type || | |
1683 | found_key->objectid != key.objectid) | |
1684 | return 1; | |
1685 | ||
1686 | return 0; | |
1687 | } | |
1688 | ||
1fc28d8e LB |
1689 | static struct extent_buffer *btrfs_search_slot_get_root(struct btrfs_root *root, |
1690 | struct btrfs_path *p, | |
1691 | int write_lock_level) | |
1692 | { | |
1fc28d8e | 1693 | struct extent_buffer *b; |
120de408 | 1694 | int root_lock = 0; |
1fc28d8e LB |
1695 | int level = 0; |
1696 | ||
1fc28d8e | 1697 | if (p->search_commit_root) { |
d96b3424 FM |
1698 | b = root->commit_root; |
1699 | atomic_inc(&b->refs); | |
be6821f8 | 1700 | level = btrfs_header_level(b); |
f9ddfd05 LB |
1701 | /* |
1702 | * Ensure that all callers have set skip_locking when | |
1703 | * p->search_commit_root = 1. | |
1704 | */ | |
1705 | ASSERT(p->skip_locking == 1); | |
1fc28d8e LB |
1706 | |
1707 | goto out; | |
1708 | } | |
1709 | ||
1710 | if (p->skip_locking) { | |
1711 | b = btrfs_root_node(root); | |
1712 | level = btrfs_header_level(b); | |
1713 | goto out; | |
1714 | } | |
1715 | ||
120de408 JB |
1716 | /* We try very hard to do read locks on the root */ |
1717 | root_lock = BTRFS_READ_LOCK; | |
1718 | ||
1fc28d8e | 1719 | /* |
662c653b LB |
1720 | * If the level is set to maximum, we can skip trying to get the read |
1721 | * lock. | |
1fc28d8e | 1722 | */ |
662c653b LB |
1723 | if (write_lock_level < BTRFS_MAX_LEVEL) { |
1724 | /* | |
1725 | * We don't know the level of the root node until we actually | |
1726 | * have it read locked | |
1727 | */ | |
857bc13f JB |
1728 | if (p->nowait) { |
1729 | b = btrfs_try_read_lock_root_node(root); | |
1730 | if (IS_ERR(b)) | |
1731 | return b; | |
1732 | } else { | |
1733 | b = btrfs_read_lock_root_node(root); | |
1734 | } | |
662c653b LB |
1735 | level = btrfs_header_level(b); |
1736 | if (level > write_lock_level) | |
1737 | goto out; | |
1738 | ||
1739 | /* Whoops, must trade for write lock */ | |
1740 | btrfs_tree_read_unlock(b); | |
1741 | free_extent_buffer(b); | |
1742 | } | |
1fc28d8e | 1743 | |
1fc28d8e LB |
1744 | b = btrfs_lock_root_node(root); |
1745 | root_lock = BTRFS_WRITE_LOCK; | |
1746 | ||
1747 | /* The level might have changed, check again */ | |
1748 | level = btrfs_header_level(b); | |
1749 | ||
1750 | out: | |
120de408 JB |
1751 | /* |
1752 | * The root may have failed to write out at some point, and thus is no | |
1753 | * longer valid, return an error in this case. | |
1754 | */ | |
1755 | if (!extent_buffer_uptodate(b)) { | |
1756 | if (root_lock) | |
1757 | btrfs_tree_unlock_rw(b, root_lock); | |
1758 | free_extent_buffer(b); | |
1759 | return ERR_PTR(-EIO); | |
1760 | } | |
1761 | ||
1fc28d8e LB |
1762 | p->nodes[level] = b; |
1763 | if (!p->skip_locking) | |
1764 | p->locks[level] = root_lock; | |
1765 | /* | |
1766 | * Callers are responsible for dropping b's references. | |
1767 | */ | |
1768 | return b; | |
1769 | } | |
1770 | ||
d96b3424 FM |
1771 | /* |
1772 | * Replace the extent buffer at the lowest level of the path with a cloned | |
1773 | * version. The purpose is to be able to use it safely, after releasing the | |
1774 | * commit root semaphore, even if relocation is happening in parallel, the | |
1775 | * transaction used for relocation is committed and the extent buffer is | |
1776 | * reallocated in the next transaction. | |
1777 | * | |
1778 | * This is used in a context where the caller does not prevent transaction | |
1779 | * commits from happening, either by holding a transaction handle or holding | |
1780 | * some lock, while it's doing searches through a commit root. | |
1781 | * At the moment it's only used for send operations. | |
1782 | */ | |
1783 | static int finish_need_commit_sem_search(struct btrfs_path *path) | |
1784 | { | |
1785 | const int i = path->lowest_level; | |
1786 | const int slot = path->slots[i]; | |
1787 | struct extent_buffer *lowest = path->nodes[i]; | |
1788 | struct extent_buffer *clone; | |
1789 | ||
1790 | ASSERT(path->need_commit_sem); | |
1791 | ||
1792 | if (!lowest) | |
1793 | return 0; | |
1794 | ||
1795 | lockdep_assert_held_read(&lowest->fs_info->commit_root_sem); | |
1796 | ||
1797 | clone = btrfs_clone_extent_buffer(lowest); | |
1798 | if (!clone) | |
1799 | return -ENOMEM; | |
1800 | ||
1801 | btrfs_release_path(path); | |
1802 | path->nodes[i] = clone; | |
1803 | path->slots[i] = slot; | |
1804 | ||
1805 | return 0; | |
1806 | } | |
1fc28d8e | 1807 | |
e2e58d0f FM |
1808 | static inline int search_for_key_slot(struct extent_buffer *eb, |
1809 | int search_low_slot, | |
1810 | const struct btrfs_key *key, | |
1811 | int prev_cmp, | |
1812 | int *slot) | |
1813 | { | |
1814 | /* | |
1815 | * If a previous call to btrfs_bin_search() on a parent node returned an | |
1816 | * exact match (prev_cmp == 0), we can safely assume the target key will | |
1817 | * always be at slot 0 on lower levels, since each key pointer | |
1818 | * (struct btrfs_key_ptr) refers to the lowest key accessible from the | |
1819 | * subtree it points to. Thus we can skip searching lower levels. | |
1820 | */ | |
1821 | if (prev_cmp == 0) { | |
1822 | *slot = 0; | |
1823 | return 0; | |
1824 | } | |
1825 | ||
fdf8d595 | 1826 | return btrfs_bin_search(eb, search_low_slot, key, slot); |
e2e58d0f FM |
1827 | } |
1828 | ||
109324cf FM |
1829 | static int search_leaf(struct btrfs_trans_handle *trans, |
1830 | struct btrfs_root *root, | |
1831 | const struct btrfs_key *key, | |
1832 | struct btrfs_path *path, | |
1833 | int ins_len, | |
1834 | int prev_cmp) | |
1835 | { | |
1836 | struct extent_buffer *leaf = path->nodes[0]; | |
1837 | int leaf_free_space = -1; | |
1838 | int search_low_slot = 0; | |
1839 | int ret; | |
1840 | bool do_bin_search = true; | |
1841 | ||
1842 | /* | |
1843 | * If we are doing an insertion, the leaf has enough free space and the | |
1844 | * destination slot for the key is not slot 0, then we can unlock our | |
1845 | * write lock on the parent, and any other upper nodes, before doing the | |
1846 | * binary search on the leaf (with search_for_key_slot()), allowing other | |
1847 | * tasks to lock the parent and any other upper nodes. | |
1848 | */ | |
1849 | if (ins_len > 0) { | |
1850 | /* | |
1851 | * Cache the leaf free space, since we will need it later and it | |
1852 | * will not change until then. | |
1853 | */ | |
1854 | leaf_free_space = btrfs_leaf_free_space(leaf); | |
1855 | ||
1856 | /* | |
1857 | * !path->locks[1] means we have a single node tree, the leaf is | |
1858 | * the root of the tree. | |
1859 | */ | |
1860 | if (path->locks[1] && leaf_free_space >= ins_len) { | |
1861 | struct btrfs_disk_key first_key; | |
1862 | ||
1863 | ASSERT(btrfs_header_nritems(leaf) > 0); | |
1864 | btrfs_item_key(leaf, &first_key, 0); | |
1865 | ||
1866 | /* | |
1867 | * Doing the extra comparison with the first key is cheap, | |
1868 | * taking into account that the first key is very likely | |
1869 | * already in a cache line because it immediately follows | |
1870 | * the extent buffer's header and we have recently accessed | |
1871 | * the header's level field. | |
1872 | */ | |
79d25df0 | 1873 | ret = btrfs_comp_keys(&first_key, key); |
109324cf FM |
1874 | if (ret < 0) { |
1875 | /* | |
1876 | * The first key is smaller than the key we want | |
1877 | * to insert, so we are safe to unlock all upper | |
1878 | * nodes and we have to do the binary search. | |
1879 | * | |
1880 | * We do use btrfs_unlock_up_safe() and not | |
1881 | * unlock_up() because the later does not unlock | |
1882 | * nodes with a slot of 0 - we can safely unlock | |
1883 | * any node even if its slot is 0 since in this | |
1884 | * case the key does not end up at slot 0 of the | |
1885 | * leaf and there's no need to split the leaf. | |
1886 | */ | |
1887 | btrfs_unlock_up_safe(path, 1); | |
1888 | search_low_slot = 1; | |
1889 | } else { | |
1890 | /* | |
1891 | * The first key is >= then the key we want to | |
1892 | * insert, so we can skip the binary search as | |
1893 | * the target key will be at slot 0. | |
1894 | * | |
1895 | * We can not unlock upper nodes when the key is | |
1896 | * less than the first key, because we will need | |
1897 | * to update the key at slot 0 of the parent node | |
1898 | * and possibly of other upper nodes too. | |
1899 | * If the key matches the first key, then we can | |
1900 | * unlock all the upper nodes, using | |
1901 | * btrfs_unlock_up_safe() instead of unlock_up() | |
1902 | * as stated above. | |
1903 | */ | |
1904 | if (ret == 0) | |
1905 | btrfs_unlock_up_safe(path, 1); | |
1906 | /* | |
1907 | * ret is already 0 or 1, matching the result of | |
1908 | * a btrfs_bin_search() call, so there is no need | |
1909 | * to adjust it. | |
1910 | */ | |
1911 | do_bin_search = false; | |
1912 | path->slots[0] = 0; | |
1913 | } | |
1914 | } | |
1915 | } | |
1916 | ||
1917 | if (do_bin_search) { | |
1918 | ret = search_for_key_slot(leaf, search_low_slot, key, | |
1919 | prev_cmp, &path->slots[0]); | |
1920 | if (ret < 0) | |
1921 | return ret; | |
1922 | } | |
1923 | ||
1924 | if (ins_len > 0) { | |
1925 | /* | |
1926 | * Item key already exists. In this case, if we are allowed to | |
1927 | * insert the item (for example, in dir_item case, item key | |
1928 | * collision is allowed), it will be merged with the original | |
1929 | * item. Only the item size grows, no new btrfs item will be | |
1930 | * added. If search_for_extension is not set, ins_len already | |
1931 | * accounts the size btrfs_item, deduct it here so leaf space | |
1932 | * check will be correct. | |
1933 | */ | |
1934 | if (ret == 0 && !path->search_for_extension) { | |
1935 | ASSERT(ins_len >= sizeof(struct btrfs_item)); | |
1936 | ins_len -= sizeof(struct btrfs_item); | |
1937 | } | |
1938 | ||
1939 | ASSERT(leaf_free_space >= 0); | |
1940 | ||
1941 | if (leaf_free_space < ins_len) { | |
1942 | int err; | |
1943 | ||
1944 | err = split_leaf(trans, root, key, path, ins_len, | |
1945 | (ret == 0)); | |
bb8e9a60 FM |
1946 | ASSERT(err <= 0); |
1947 | if (WARN_ON(err > 0)) | |
1948 | err = -EUCLEAN; | |
109324cf FM |
1949 | if (err) |
1950 | ret = err; | |
1951 | } | |
1952 | } | |
1953 | ||
1954 | return ret; | |
1955 | } | |
1956 | ||
74123bd7 | 1957 | /* |
9580503b DS |
1958 | * Look for a key in a tree and perform necessary modifications to preserve |
1959 | * tree invariants. | |
74123bd7 | 1960 | * |
4271ecea NB |
1961 | * @trans: Handle of transaction, used when modifying the tree |
1962 | * @p: Holds all btree nodes along the search path | |
1963 | * @root: The root node of the tree | |
1964 | * @key: The key we are looking for | |
9a664971 | 1965 | * @ins_len: Indicates purpose of search: |
1966 | * >0 for inserts it's size of item inserted (*) | |
1967 | * <0 for deletions | |
1968 | * 0 for plain searches, not modifying the tree | |
1969 | * | |
1970 | * (*) If size of item inserted doesn't include | |
1971 | * sizeof(struct btrfs_item), then p->search_for_extension must | |
1972 | * be set. | |
4271ecea NB |
1973 | * @cow: boolean should CoW operations be performed. Must always be 1 |
1974 | * when modifying the tree. | |
97571fd0 | 1975 | * |
4271ecea NB |
1976 | * If @ins_len > 0, nodes and leaves will be split as we walk down the tree. |
1977 | * If @ins_len < 0, nodes will be merged as we walk down the tree (if possible) | |
1978 | * | |
1979 | * If @key is found, 0 is returned and you can find the item in the leaf level | |
1980 | * of the path (level 0) | |
1981 | * | |
1982 | * If @key isn't found, 1 is returned and the leaf level of the path (level 0) | |
1983 | * points to the slot where it should be inserted | |
1984 | * | |
1985 | * If an error is encountered while searching the tree a negative error number | |
1986 | * is returned | |
74123bd7 | 1987 | */ |
310712b2 OS |
1988 | int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
1989 | const struct btrfs_key *key, struct btrfs_path *p, | |
1990 | int ins_len, int cow) | |
be0e5c09 | 1991 | { |
d96b3424 | 1992 | struct btrfs_fs_info *fs_info = root->fs_info; |
5f39d397 | 1993 | struct extent_buffer *b; |
be0e5c09 CM |
1994 | int slot; |
1995 | int ret; | |
33c66f43 | 1996 | int err; |
be0e5c09 | 1997 | int level; |
925baedd | 1998 | int lowest_unlock = 1; |
bd681513 CM |
1999 | /* everything at write_lock_level or lower must be write locked */ |
2000 | int write_lock_level = 0; | |
9f3a7427 | 2001 | u8 lowest_level = 0; |
f7c79f30 | 2002 | int min_write_lock_level; |
d7396f07 | 2003 | int prev_cmp; |
9f3a7427 | 2004 | |
a4c853af C |
2005 | might_sleep(); |
2006 | ||
6702ed49 | 2007 | lowest_level = p->lowest_level; |
323ac95b | 2008 | WARN_ON(lowest_level && ins_len > 0); |
22b0ebda | 2009 | WARN_ON(p->nodes[0] != NULL); |
eb653de1 | 2010 | BUG_ON(!cow && ins_len); |
25179201 | 2011 | |
857bc13f JB |
2012 | /* |
2013 | * For now only allow nowait for read only operations. There's no | |
2014 | * strict reason why we can't, we just only need it for reads so it's | |
2015 | * only implemented for reads. | |
2016 | */ | |
2017 | ASSERT(!p->nowait || !cow); | |
2018 | ||
bd681513 | 2019 | if (ins_len < 0) { |
925baedd | 2020 | lowest_unlock = 2; |
65b51a00 | 2021 | |
bd681513 CM |
2022 | /* when we are removing items, we might have to go up to level |
2023 | * two as we update tree pointers Make sure we keep write | |
2024 | * for those levels as well | |
2025 | */ | |
2026 | write_lock_level = 2; | |
2027 | } else if (ins_len > 0) { | |
2028 | /* | |
2029 | * for inserting items, make sure we have a write lock on | |
2030 | * level 1 so we can update keys | |
2031 | */ | |
2032 | write_lock_level = 1; | |
2033 | } | |
2034 | ||
2035 | if (!cow) | |
2036 | write_lock_level = -1; | |
2037 | ||
09a2a8f9 | 2038 | if (cow && (p->keep_locks || p->lowest_level)) |
bd681513 CM |
2039 | write_lock_level = BTRFS_MAX_LEVEL; |
2040 | ||
f7c79f30 CM |
2041 | min_write_lock_level = write_lock_level; |
2042 | ||
d96b3424 FM |
2043 | if (p->need_commit_sem) { |
2044 | ASSERT(p->search_commit_root); | |
857bc13f JB |
2045 | if (p->nowait) { |
2046 | if (!down_read_trylock(&fs_info->commit_root_sem)) | |
2047 | return -EAGAIN; | |
2048 | } else { | |
2049 | down_read(&fs_info->commit_root_sem); | |
2050 | } | |
d96b3424 FM |
2051 | } |
2052 | ||
bb803951 | 2053 | again: |
d7396f07 | 2054 | prev_cmp = -1; |
1fc28d8e | 2055 | b = btrfs_search_slot_get_root(root, p, write_lock_level); |
be6821f8 FM |
2056 | if (IS_ERR(b)) { |
2057 | ret = PTR_ERR(b); | |
2058 | goto done; | |
2059 | } | |
925baedd | 2060 | |
eb60ceac | 2061 | while (b) { |
f624d976 QW |
2062 | int dec = 0; |
2063 | ||
5f39d397 | 2064 | level = btrfs_header_level(b); |
65b51a00 | 2065 | |
02217ed2 | 2066 | if (cow) { |
9ea2c7c9 NB |
2067 | bool last_level = (level == (BTRFS_MAX_LEVEL - 1)); |
2068 | ||
c8c42864 CM |
2069 | /* |
2070 | * if we don't really need to cow this block | |
2071 | * then we don't want to set the path blocking, | |
2072 | * so we test it here | |
2073 | */ | |
5963ffca | 2074 | if (!should_cow_block(trans, root, b)) |
65b51a00 | 2075 | goto cow_done; |
5d4f98a2 | 2076 | |
bd681513 CM |
2077 | /* |
2078 | * must have write locks on this node and the | |
2079 | * parent | |
2080 | */ | |
5124e00e JB |
2081 | if (level > write_lock_level || |
2082 | (level + 1 > write_lock_level && | |
2083 | level + 1 < BTRFS_MAX_LEVEL && | |
2084 | p->nodes[level + 1])) { | |
bd681513 CM |
2085 | write_lock_level = level + 1; |
2086 | btrfs_release_path(p); | |
2087 | goto again; | |
2088 | } | |
2089 | ||
9ea2c7c9 NB |
2090 | if (last_level) |
2091 | err = btrfs_cow_block(trans, root, b, NULL, 0, | |
9631e4cc JB |
2092 | &b, |
2093 | BTRFS_NESTING_COW); | |
9ea2c7c9 NB |
2094 | else |
2095 | err = btrfs_cow_block(trans, root, b, | |
2096 | p->nodes[level + 1], | |
9631e4cc JB |
2097 | p->slots[level + 1], &b, |
2098 | BTRFS_NESTING_COW); | |
33c66f43 | 2099 | if (err) { |
33c66f43 | 2100 | ret = err; |
65b51a00 | 2101 | goto done; |
54aa1f4d | 2102 | } |
02217ed2 | 2103 | } |
65b51a00 | 2104 | cow_done: |
eb60ceac | 2105 | p->nodes[level] = b; |
b4ce94de CM |
2106 | |
2107 | /* | |
2108 | * we have a lock on b and as long as we aren't changing | |
2109 | * the tree, there is no way to for the items in b to change. | |
2110 | * It is safe to drop the lock on our parent before we | |
2111 | * go through the expensive btree search on b. | |
2112 | * | |
eb653de1 FDBM |
2113 | * If we're inserting or deleting (ins_len != 0), then we might |
2114 | * be changing slot zero, which may require changing the parent. | |
2115 | * So, we can't drop the lock until after we know which slot | |
2116 | * we're operating on. | |
b4ce94de | 2117 | */ |
eb653de1 FDBM |
2118 | if (!ins_len && !p->keep_locks) { |
2119 | int u = level + 1; | |
2120 | ||
2121 | if (u < BTRFS_MAX_LEVEL && p->locks[u]) { | |
2122 | btrfs_tree_unlock_rw(p->nodes[u], p->locks[u]); | |
2123 | p->locks[u] = 0; | |
2124 | } | |
2125 | } | |
b4ce94de | 2126 | |
e2e58d0f | 2127 | if (level == 0) { |
109324cf | 2128 | if (ins_len > 0) |
e5e1c174 | 2129 | ASSERT(write_lock_level >= 1); |
bd681513 | 2130 | |
109324cf | 2131 | ret = search_leaf(trans, root, key, p, ins_len, prev_cmp); |
459931ec | 2132 | if (!p->search_for_split) |
f7c79f30 | 2133 | unlock_up(p, level, lowest_unlock, |
4b6f8e96 | 2134 | min_write_lock_level, NULL); |
65b51a00 | 2135 | goto done; |
be0e5c09 | 2136 | } |
e2e58d0f FM |
2137 | |
2138 | ret = search_for_key_slot(b, 0, key, prev_cmp, &slot); | |
2139 | if (ret < 0) | |
2140 | goto done; | |
2141 | prev_cmp = ret; | |
2142 | ||
f624d976 QW |
2143 | if (ret && slot > 0) { |
2144 | dec = 1; | |
2145 | slot--; | |
2146 | } | |
2147 | p->slots[level] = slot; | |
2148 | err = setup_nodes_for_search(trans, root, p, b, level, ins_len, | |
2149 | &write_lock_level); | |
2150 | if (err == -EAGAIN) | |
2151 | goto again; | |
2152 | if (err) { | |
2153 | ret = err; | |
2154 | goto done; | |
2155 | } | |
2156 | b = p->nodes[level]; | |
2157 | slot = p->slots[level]; | |
2158 | ||
2159 | /* | |
2160 | * Slot 0 is special, if we change the key we have to update | |
2161 | * the parent pointer which means we must have a write lock on | |
2162 | * the parent | |
2163 | */ | |
2164 | if (slot == 0 && ins_len && write_lock_level < level + 1) { | |
2165 | write_lock_level = level + 1; | |
2166 | btrfs_release_path(p); | |
2167 | goto again; | |
2168 | } | |
2169 | ||
2170 | unlock_up(p, level, lowest_unlock, min_write_lock_level, | |
2171 | &write_lock_level); | |
2172 | ||
2173 | if (level == lowest_level) { | |
2174 | if (dec) | |
2175 | p->slots[level]++; | |
2176 | goto done; | |
2177 | } | |
2178 | ||
2179 | err = read_block_for_search(root, p, &b, level, slot, key); | |
2180 | if (err == -EAGAIN) | |
2181 | goto again; | |
2182 | if (err) { | |
2183 | ret = err; | |
2184 | goto done; | |
2185 | } | |
2186 | ||
2187 | if (!p->skip_locking) { | |
2188 | level = btrfs_header_level(b); | |
b40130b2 JB |
2189 | |
2190 | btrfs_maybe_reset_lockdep_class(root, b); | |
2191 | ||
f624d976 | 2192 | if (level <= write_lock_level) { |
ac5887c8 | 2193 | btrfs_tree_lock(b); |
f624d976 QW |
2194 | p->locks[level] = BTRFS_WRITE_LOCK; |
2195 | } else { | |
857bc13f JB |
2196 | if (p->nowait) { |
2197 | if (!btrfs_try_tree_read_lock(b)) { | |
2198 | free_extent_buffer(b); | |
2199 | ret = -EAGAIN; | |
2200 | goto done; | |
2201 | } | |
2202 | } else { | |
2203 | btrfs_tree_read_lock(b); | |
2204 | } | |
f624d976 QW |
2205 | p->locks[level] = BTRFS_READ_LOCK; |
2206 | } | |
2207 | p->nodes[level] = b; | |
2208 | } | |
be0e5c09 | 2209 | } |
65b51a00 CM |
2210 | ret = 1; |
2211 | done: | |
5f5bc6b1 | 2212 | if (ret < 0 && !p->skip_release_on_error) |
b3b4aa74 | 2213 | btrfs_release_path(p); |
d96b3424 FM |
2214 | |
2215 | if (p->need_commit_sem) { | |
2216 | int ret2; | |
2217 | ||
2218 | ret2 = finish_need_commit_sem_search(p); | |
2219 | up_read(&fs_info->commit_root_sem); | |
2220 | if (ret2) | |
2221 | ret = ret2; | |
2222 | } | |
2223 | ||
65b51a00 | 2224 | return ret; |
be0e5c09 | 2225 | } |
f75e2b79 | 2226 | ALLOW_ERROR_INJECTION(btrfs_search_slot, ERRNO); |
be0e5c09 | 2227 | |
5d9e75c4 JS |
2228 | /* |
2229 | * Like btrfs_search_slot, this looks for a key in the given tree. It uses the | |
2230 | * current state of the tree together with the operations recorded in the tree | |
2231 | * modification log to search for the key in a previous version of this tree, as | |
2232 | * denoted by the time_seq parameter. | |
2233 | * | |
2234 | * Naturally, there is no support for insert, delete or cow operations. | |
2235 | * | |
2236 | * The resulting path and return value will be set up as if we called | |
2237 | * btrfs_search_slot at that point in time with ins_len and cow both set to 0. | |
2238 | */ | |
310712b2 | 2239 | int btrfs_search_old_slot(struct btrfs_root *root, const struct btrfs_key *key, |
5d9e75c4 JS |
2240 | struct btrfs_path *p, u64 time_seq) |
2241 | { | |
0b246afa | 2242 | struct btrfs_fs_info *fs_info = root->fs_info; |
5d9e75c4 JS |
2243 | struct extent_buffer *b; |
2244 | int slot; | |
2245 | int ret; | |
2246 | int err; | |
2247 | int level; | |
2248 | int lowest_unlock = 1; | |
2249 | u8 lowest_level = 0; | |
2250 | ||
2251 | lowest_level = p->lowest_level; | |
2252 | WARN_ON(p->nodes[0] != NULL); | |
c922b016 | 2253 | ASSERT(!p->nowait); |
5d9e75c4 JS |
2254 | |
2255 | if (p->search_commit_root) { | |
2256 | BUG_ON(time_seq); | |
2257 | return btrfs_search_slot(NULL, root, key, p, 0, 0); | |
2258 | } | |
2259 | ||
2260 | again: | |
f3a84ccd | 2261 | b = btrfs_get_old_root(root, time_seq); |
315bed43 NB |
2262 | if (!b) { |
2263 | ret = -EIO; | |
2264 | goto done; | |
2265 | } | |
5d9e75c4 | 2266 | level = btrfs_header_level(b); |
5d9e75c4 JS |
2267 | p->locks[level] = BTRFS_READ_LOCK; |
2268 | ||
2269 | while (b) { | |
abe9339d QW |
2270 | int dec = 0; |
2271 | ||
5d9e75c4 JS |
2272 | level = btrfs_header_level(b); |
2273 | p->nodes[level] = b; | |
5d9e75c4 JS |
2274 | |
2275 | /* | |
2276 | * we have a lock on b and as long as we aren't changing | |
2277 | * the tree, there is no way to for the items in b to change. | |
2278 | * It is safe to drop the lock on our parent before we | |
2279 | * go through the expensive btree search on b. | |
2280 | */ | |
2281 | btrfs_unlock_up_safe(p, level + 1); | |
2282 | ||
fdf8d595 | 2283 | ret = btrfs_bin_search(b, 0, key, &slot); |
cbca7d59 FM |
2284 | if (ret < 0) |
2285 | goto done; | |
5d9e75c4 | 2286 | |
abe9339d | 2287 | if (level == 0) { |
5d9e75c4 JS |
2288 | p->slots[level] = slot; |
2289 | unlock_up(p, level, lowest_unlock, 0, NULL); | |
abe9339d QW |
2290 | goto done; |
2291 | } | |
5d9e75c4 | 2292 | |
abe9339d QW |
2293 | if (ret && slot > 0) { |
2294 | dec = 1; | |
2295 | slot--; | |
2296 | } | |
2297 | p->slots[level] = slot; | |
2298 | unlock_up(p, level, lowest_unlock, 0, NULL); | |
5d9e75c4 | 2299 | |
abe9339d QW |
2300 | if (level == lowest_level) { |
2301 | if (dec) | |
2302 | p->slots[level]++; | |
2303 | goto done; | |
2304 | } | |
5d9e75c4 | 2305 | |
abe9339d QW |
2306 | err = read_block_for_search(root, p, &b, level, slot, key); |
2307 | if (err == -EAGAIN) | |
2308 | goto again; | |
2309 | if (err) { | |
2310 | ret = err; | |
5d9e75c4 JS |
2311 | goto done; |
2312 | } | |
abe9339d QW |
2313 | |
2314 | level = btrfs_header_level(b); | |
ac5887c8 | 2315 | btrfs_tree_read_lock(b); |
f3a84ccd | 2316 | b = btrfs_tree_mod_log_rewind(fs_info, p, b, time_seq); |
abe9339d QW |
2317 | if (!b) { |
2318 | ret = -ENOMEM; | |
2319 | goto done; | |
2320 | } | |
2321 | p->locks[level] = BTRFS_READ_LOCK; | |
2322 | p->nodes[level] = b; | |
5d9e75c4 JS |
2323 | } |
2324 | ret = 1; | |
2325 | done: | |
5d9e75c4 JS |
2326 | if (ret < 0) |
2327 | btrfs_release_path(p); | |
2328 | ||
2329 | return ret; | |
2330 | } | |
2331 | ||
f469c8bd FM |
2332 | /* |
2333 | * Search the tree again to find a leaf with smaller keys. | |
2334 | * Returns 0 if it found something. | |
2335 | * Returns 1 if there are no smaller keys. | |
2336 | * Returns < 0 on error. | |
2337 | * | |
2338 | * This may release the path, and so you may lose any locks held at the | |
2339 | * time you call it. | |
2340 | */ | |
2341 | static int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) | |
2342 | { | |
2343 | struct btrfs_key key; | |
2344 | struct btrfs_key orig_key; | |
2345 | struct btrfs_disk_key found_key; | |
2346 | int ret; | |
2347 | ||
2348 | btrfs_item_key_to_cpu(path->nodes[0], &key, 0); | |
2349 | orig_key = key; | |
2350 | ||
2351 | if (key.offset > 0) { | |
2352 | key.offset--; | |
2353 | } else if (key.type > 0) { | |
2354 | key.type--; | |
2355 | key.offset = (u64)-1; | |
2356 | } else if (key.objectid > 0) { | |
2357 | key.objectid--; | |
2358 | key.type = (u8)-1; | |
2359 | key.offset = (u64)-1; | |
2360 | } else { | |
2361 | return 1; | |
2362 | } | |
2363 | ||
2364 | btrfs_release_path(path); | |
2365 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); | |
2366 | if (ret <= 0) | |
2367 | return ret; | |
2368 | ||
2369 | /* | |
2370 | * Previous key not found. Even if we were at slot 0 of the leaf we had | |
2371 | * before releasing the path and calling btrfs_search_slot(), we now may | |
2372 | * be in a slot pointing to the same original key - this can happen if | |
2373 | * after we released the path, one of more items were moved from a | |
2374 | * sibling leaf into the front of the leaf we had due to an insertion | |
2375 | * (see push_leaf_right()). | |
2376 | * If we hit this case and our slot is > 0 and just decrement the slot | |
2377 | * so that the caller does not process the same key again, which may or | |
2378 | * may not break the caller, depending on its logic. | |
2379 | */ | |
2380 | if (path->slots[0] < btrfs_header_nritems(path->nodes[0])) { | |
2381 | btrfs_item_key(path->nodes[0], &found_key, path->slots[0]); | |
79d25df0 | 2382 | ret = btrfs_comp_keys(&found_key, &orig_key); |
f469c8bd FM |
2383 | if (ret == 0) { |
2384 | if (path->slots[0] > 0) { | |
2385 | path->slots[0]--; | |
2386 | return 0; | |
2387 | } | |
2388 | /* | |
2389 | * At slot 0, same key as before, it means orig_key is | |
2390 | * the lowest, leftmost, key in the tree. We're done. | |
2391 | */ | |
2392 | return 1; | |
2393 | } | |
2394 | } | |
2395 | ||
2396 | btrfs_item_key(path->nodes[0], &found_key, 0); | |
79d25df0 | 2397 | ret = btrfs_comp_keys(&found_key, &key); |
f469c8bd FM |
2398 | /* |
2399 | * We might have had an item with the previous key in the tree right | |
2400 | * before we released our path. And after we released our path, that | |
2401 | * item might have been pushed to the first slot (0) of the leaf we | |
2402 | * were holding due to a tree balance. Alternatively, an item with the | |
2403 | * previous key can exist as the only element of a leaf (big fat item). | |
2404 | * Therefore account for these 2 cases, so that our callers (like | |
2405 | * btrfs_previous_item) don't miss an existing item with a key matching | |
2406 | * the previous key we computed above. | |
2407 | */ | |
2408 | if (ret <= 0) | |
2409 | return 0; | |
2410 | return 1; | |
2411 | } | |
2412 | ||
2f38b3e1 AJ |
2413 | /* |
2414 | * helper to use instead of search slot if no exact match is needed but | |
2415 | * instead the next or previous item should be returned. | |
2416 | * When find_higher is true, the next higher item is returned, the next lower | |
2417 | * otherwise. | |
2418 | * When return_any and find_higher are both true, and no higher item is found, | |
2419 | * return the next lower instead. | |
2420 | * When return_any is true and find_higher is false, and no lower item is found, | |
2421 | * return the next higher instead. | |
2422 | * It returns 0 if any item is found, 1 if none is found (tree empty), and | |
2423 | * < 0 on error | |
2424 | */ | |
2425 | int btrfs_search_slot_for_read(struct btrfs_root *root, | |
310712b2 OS |
2426 | const struct btrfs_key *key, |
2427 | struct btrfs_path *p, int find_higher, | |
2428 | int return_any) | |
2f38b3e1 AJ |
2429 | { |
2430 | int ret; | |
2431 | struct extent_buffer *leaf; | |
2432 | ||
2433 | again: | |
2434 | ret = btrfs_search_slot(NULL, root, key, p, 0, 0); | |
2435 | if (ret <= 0) | |
2436 | return ret; | |
2437 | /* | |
2438 | * a return value of 1 means the path is at the position where the | |
2439 | * item should be inserted. Normally this is the next bigger item, | |
2440 | * but in case the previous item is the last in a leaf, path points | |
2441 | * to the first free slot in the previous leaf, i.e. at an invalid | |
2442 | * item. | |
2443 | */ | |
2444 | leaf = p->nodes[0]; | |
2445 | ||
2446 | if (find_higher) { | |
2447 | if (p->slots[0] >= btrfs_header_nritems(leaf)) { | |
2448 | ret = btrfs_next_leaf(root, p); | |
2449 | if (ret <= 0) | |
2450 | return ret; | |
2451 | if (!return_any) | |
2452 | return 1; | |
2453 | /* | |
2454 | * no higher item found, return the next | |
2455 | * lower instead | |
2456 | */ | |
2457 | return_any = 0; | |
2458 | find_higher = 0; | |
2459 | btrfs_release_path(p); | |
2460 | goto again; | |
2461 | } | |
2462 | } else { | |
e6793769 AJ |
2463 | if (p->slots[0] == 0) { |
2464 | ret = btrfs_prev_leaf(root, p); | |
2465 | if (ret < 0) | |
2466 | return ret; | |
2467 | if (!ret) { | |
23c6bf6a FDBM |
2468 | leaf = p->nodes[0]; |
2469 | if (p->slots[0] == btrfs_header_nritems(leaf)) | |
2470 | p->slots[0]--; | |
e6793769 | 2471 | return 0; |
2f38b3e1 | 2472 | } |
e6793769 AJ |
2473 | if (!return_any) |
2474 | return 1; | |
2475 | /* | |
2476 | * no lower item found, return the next | |
2477 | * higher instead | |
2478 | */ | |
2479 | return_any = 0; | |
2480 | find_higher = 1; | |
2481 | btrfs_release_path(p); | |
2482 | goto again; | |
2483 | } else { | |
2f38b3e1 AJ |
2484 | --p->slots[0]; |
2485 | } | |
2486 | } | |
2487 | return 0; | |
2488 | } | |
2489 | ||
0ff40a91 MPS |
2490 | /* |
2491 | * Execute search and call btrfs_previous_item to traverse backwards if the item | |
2492 | * was not found. | |
2493 | * | |
2494 | * Return 0 if found, 1 if not found and < 0 if error. | |
2495 | */ | |
2496 | int btrfs_search_backwards(struct btrfs_root *root, struct btrfs_key *key, | |
2497 | struct btrfs_path *path) | |
2498 | { | |
2499 | int ret; | |
2500 | ||
2501 | ret = btrfs_search_slot(NULL, root, key, path, 0, 0); | |
2502 | if (ret > 0) | |
2503 | ret = btrfs_previous_item(root, path, key->objectid, key->type); | |
2504 | ||
2505 | if (ret == 0) | |
2506 | btrfs_item_key_to_cpu(path->nodes[0], key, path->slots[0]); | |
2507 | ||
2508 | return ret; | |
2509 | } | |
2510 | ||
43dd529a | 2511 | /* |
62142be3 GN |
2512 | * Search for a valid slot for the given path. |
2513 | * | |
2514 | * @root: The root node of the tree. | |
2515 | * @key: Will contain a valid item if found. | |
2516 | * @path: The starting point to validate the slot. | |
2517 | * | |
2518 | * Return: 0 if the item is valid | |
2519 | * 1 if not found | |
2520 | * <0 if error. | |
2521 | */ | |
2522 | int btrfs_get_next_valid_item(struct btrfs_root *root, struct btrfs_key *key, | |
2523 | struct btrfs_path *path) | |
2524 | { | |
524f14bb | 2525 | if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) { |
62142be3 | 2526 | int ret; |
62142be3 | 2527 | |
524f14bb FM |
2528 | ret = btrfs_next_leaf(root, path); |
2529 | if (ret) | |
2530 | return ret; | |
62142be3 | 2531 | } |
524f14bb FM |
2532 | |
2533 | btrfs_item_key_to_cpu(path->nodes[0], key, path->slots[0]); | |
62142be3 GN |
2534 | return 0; |
2535 | } | |
2536 | ||
74123bd7 CM |
2537 | /* |
2538 | * adjust the pointers going up the tree, starting at level | |
2539 | * making sure the right key of each node is points to 'key'. | |
2540 | * This is used after shifting pointers to the left, so it stops | |
2541 | * fixing up pointers when a given leaf/node is not in slot 0 of the | |
2542 | * higher levels | |
aa5d6bed | 2543 | * |
74123bd7 | 2544 | */ |
50564b65 FM |
2545 | static void fixup_low_keys(struct btrfs_trans_handle *trans, |
2546 | struct btrfs_path *path, | |
143bede5 | 2547 | struct btrfs_disk_key *key, int level) |
be0e5c09 CM |
2548 | { |
2549 | int i; | |
5f39d397 | 2550 | struct extent_buffer *t; |
0e82bcfe | 2551 | int ret; |
5f39d397 | 2552 | |
234b63a0 | 2553 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { |
be0e5c09 | 2554 | int tslot = path->slots[i]; |
0e82bcfe | 2555 | |
eb60ceac | 2556 | if (!path->nodes[i]) |
be0e5c09 | 2557 | break; |
5f39d397 | 2558 | t = path->nodes[i]; |
f3a84ccd | 2559 | ret = btrfs_tree_mod_log_insert_key(t, tslot, |
33cff222 | 2560 | BTRFS_MOD_LOG_KEY_REPLACE); |
0e82bcfe | 2561 | BUG_ON(ret < 0); |
5f39d397 | 2562 | btrfs_set_node_key(t, key, tslot); |
50564b65 | 2563 | btrfs_mark_buffer_dirty(trans, path->nodes[i]); |
be0e5c09 CM |
2564 | if (tslot != 0) |
2565 | break; | |
2566 | } | |
2567 | } | |
2568 | ||
31840ae1 ZY |
2569 | /* |
2570 | * update item key. | |
2571 | * | |
2572 | * This function isn't completely safe. It's the caller's responsibility | |
2573 | * that the new key won't break the order | |
2574 | */ | |
50564b65 | 2575 | void btrfs_set_item_key_safe(struct btrfs_trans_handle *trans, |
b7a0365e | 2576 | struct btrfs_path *path, |
310712b2 | 2577 | const struct btrfs_key *new_key) |
31840ae1 | 2578 | { |
50564b65 | 2579 | struct btrfs_fs_info *fs_info = trans->fs_info; |
31840ae1 ZY |
2580 | struct btrfs_disk_key disk_key; |
2581 | struct extent_buffer *eb; | |
2582 | int slot; | |
2583 | ||
2584 | eb = path->nodes[0]; | |
2585 | slot = path->slots[0]; | |
2586 | if (slot > 0) { | |
2587 | btrfs_item_key(eb, &disk_key, slot - 1); | |
79d25df0 | 2588 | if (unlikely(btrfs_comp_keys(&disk_key, new_key) >= 0)) { |
eee3b811 | 2589 | btrfs_print_leaf(eb); |
7c15d410 QW |
2590 | btrfs_crit(fs_info, |
2591 | "slot %u key (%llu %u %llu) new key (%llu %u %llu)", | |
2592 | slot, btrfs_disk_key_objectid(&disk_key), | |
2593 | btrfs_disk_key_type(&disk_key), | |
2594 | btrfs_disk_key_offset(&disk_key), | |
2595 | new_key->objectid, new_key->type, | |
2596 | new_key->offset); | |
7c15d410 QW |
2597 | BUG(); |
2598 | } | |
31840ae1 ZY |
2599 | } |
2600 | if (slot < btrfs_header_nritems(eb) - 1) { | |
2601 | btrfs_item_key(eb, &disk_key, slot + 1); | |
79d25df0 | 2602 | if (unlikely(btrfs_comp_keys(&disk_key, new_key) <= 0)) { |
eee3b811 | 2603 | btrfs_print_leaf(eb); |
7c15d410 QW |
2604 | btrfs_crit(fs_info, |
2605 | "slot %u key (%llu %u %llu) new key (%llu %u %llu)", | |
2606 | slot, btrfs_disk_key_objectid(&disk_key), | |
2607 | btrfs_disk_key_type(&disk_key), | |
2608 | btrfs_disk_key_offset(&disk_key), | |
2609 | new_key->objectid, new_key->type, | |
2610 | new_key->offset); | |
7c15d410 QW |
2611 | BUG(); |
2612 | } | |
31840ae1 ZY |
2613 | } |
2614 | ||
2615 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
2616 | btrfs_set_item_key(eb, &disk_key, slot); | |
50564b65 | 2617 | btrfs_mark_buffer_dirty(trans, eb); |
31840ae1 | 2618 | if (slot == 0) |
50564b65 | 2619 | fixup_low_keys(trans, path, &disk_key, 1); |
31840ae1 ZY |
2620 | } |
2621 | ||
d16c702f QW |
2622 | /* |
2623 | * Check key order of two sibling extent buffers. | |
2624 | * | |
2625 | * Return true if something is wrong. | |
2626 | * Return false if everything is fine. | |
2627 | * | |
2628 | * Tree-checker only works inside one tree block, thus the following | |
2629 | * corruption can not be detected by tree-checker: | |
2630 | * | |
2631 | * Leaf @left | Leaf @right | |
2632 | * -------------------------------------------------------------- | |
2633 | * | 1 | 2 | 3 | 4 | 5 | f6 | | 7 | 8 | | |
2634 | * | |
2635 | * Key f6 in leaf @left itself is valid, but not valid when the next | |
2636 | * key in leaf @right is 7. | |
2637 | * This can only be checked at tree block merge time. | |
2638 | * And since tree checker has ensured all key order in each tree block | |
2639 | * is correct, we only need to bother the last key of @left and the first | |
2640 | * key of @right. | |
2641 | */ | |
2642 | static bool check_sibling_keys(struct extent_buffer *left, | |
2643 | struct extent_buffer *right) | |
2644 | { | |
2645 | struct btrfs_key left_last; | |
2646 | struct btrfs_key right_first; | |
2647 | int level = btrfs_header_level(left); | |
2648 | int nr_left = btrfs_header_nritems(left); | |
2649 | int nr_right = btrfs_header_nritems(right); | |
2650 | ||
2651 | /* No key to check in one of the tree blocks */ | |
2652 | if (!nr_left || !nr_right) | |
2653 | return false; | |
2654 | ||
2655 | if (level) { | |
2656 | btrfs_node_key_to_cpu(left, &left_last, nr_left - 1); | |
2657 | btrfs_node_key_to_cpu(right, &right_first, 0); | |
2658 | } else { | |
2659 | btrfs_item_key_to_cpu(left, &left_last, nr_left - 1); | |
2660 | btrfs_item_key_to_cpu(right, &right_first, 0); | |
2661 | } | |
2662 | ||
88ad95b0 | 2663 | if (unlikely(btrfs_comp_cpu_keys(&left_last, &right_first) >= 0)) { |
a2cea677 FM |
2664 | btrfs_crit(left->fs_info, "left extent buffer:"); |
2665 | btrfs_print_tree(left, false); | |
2666 | btrfs_crit(left->fs_info, "right extent buffer:"); | |
2667 | btrfs_print_tree(right, false); | |
d16c702f QW |
2668 | btrfs_crit(left->fs_info, |
2669 | "bad key order, sibling blocks, left last (%llu %u %llu) right first (%llu %u %llu)", | |
2670 | left_last.objectid, left_last.type, | |
2671 | left_last.offset, right_first.objectid, | |
2672 | right_first.type, right_first.offset); | |
2673 | return true; | |
2674 | } | |
2675 | return false; | |
2676 | } | |
2677 | ||
74123bd7 CM |
2678 | /* |
2679 | * try to push data from one node into the next node left in the | |
79f95c82 | 2680 | * tree. |
aa5d6bed CM |
2681 | * |
2682 | * returns 0 if some ptrs were pushed left, < 0 if there was some horrible | |
2683 | * error, and > 0 if there was no room in the left hand block. | |
74123bd7 | 2684 | */ |
98ed5174 | 2685 | static int push_node_left(struct btrfs_trans_handle *trans, |
2ff7e61e | 2686 | struct extent_buffer *dst, |
971a1f66 | 2687 | struct extent_buffer *src, int empty) |
be0e5c09 | 2688 | { |
d30a668f | 2689 | struct btrfs_fs_info *fs_info = trans->fs_info; |
be0e5c09 | 2690 | int push_items = 0; |
bb803951 CM |
2691 | int src_nritems; |
2692 | int dst_nritems; | |
aa5d6bed | 2693 | int ret = 0; |
be0e5c09 | 2694 | |
5f39d397 CM |
2695 | src_nritems = btrfs_header_nritems(src); |
2696 | dst_nritems = btrfs_header_nritems(dst); | |
0b246afa | 2697 | push_items = BTRFS_NODEPTRS_PER_BLOCK(fs_info) - dst_nritems; |
7bb86316 CM |
2698 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
2699 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
54aa1f4d | 2700 | |
bce4eae9 | 2701 | if (!empty && src_nritems <= 8) |
971a1f66 CM |
2702 | return 1; |
2703 | ||
d397712b | 2704 | if (push_items <= 0) |
be0e5c09 CM |
2705 | return 1; |
2706 | ||
bce4eae9 | 2707 | if (empty) { |
971a1f66 | 2708 | push_items = min(src_nritems, push_items); |
bce4eae9 CM |
2709 | if (push_items < src_nritems) { |
2710 | /* leave at least 8 pointers in the node if | |
2711 | * we aren't going to empty it | |
2712 | */ | |
2713 | if (src_nritems - push_items < 8) { | |
2714 | if (push_items <= 8) | |
2715 | return 1; | |
2716 | push_items -= 8; | |
2717 | } | |
2718 | } | |
2719 | } else | |
2720 | push_items = min(src_nritems - 8, push_items); | |
79f95c82 | 2721 | |
d16c702f QW |
2722 | /* dst is the left eb, src is the middle eb */ |
2723 | if (check_sibling_keys(dst, src)) { | |
2724 | ret = -EUCLEAN; | |
2725 | btrfs_abort_transaction(trans, ret); | |
2726 | return ret; | |
2727 | } | |
f3a84ccd | 2728 | ret = btrfs_tree_mod_log_eb_copy(dst, src, dst_nritems, 0, push_items); |
5de865ee | 2729 | if (ret) { |
66642832 | 2730 | btrfs_abort_transaction(trans, ret); |
5de865ee FDBM |
2731 | return ret; |
2732 | } | |
5f39d397 | 2733 | copy_extent_buffer(dst, src, |
e23efd8e JB |
2734 | btrfs_node_key_ptr_offset(dst, dst_nritems), |
2735 | btrfs_node_key_ptr_offset(src, 0), | |
d397712b | 2736 | push_items * sizeof(struct btrfs_key_ptr)); |
5f39d397 | 2737 | |
bb803951 | 2738 | if (push_items < src_nritems) { |
57911b8b | 2739 | /* |
5cead542 BB |
2740 | * btrfs_tree_mod_log_eb_copy handles logging the move, so we |
2741 | * don't need to do an explicit tree mod log operation for it. | |
57911b8b | 2742 | */ |
e23efd8e JB |
2743 | memmove_extent_buffer(src, btrfs_node_key_ptr_offset(src, 0), |
2744 | btrfs_node_key_ptr_offset(src, push_items), | |
5f39d397 CM |
2745 | (src_nritems - push_items) * |
2746 | sizeof(struct btrfs_key_ptr)); | |
2747 | } | |
2748 | btrfs_set_header_nritems(src, src_nritems - push_items); | |
2749 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
50564b65 FM |
2750 | btrfs_mark_buffer_dirty(trans, src); |
2751 | btrfs_mark_buffer_dirty(trans, dst); | |
31840ae1 | 2752 | |
79f95c82 CM |
2753 | return ret; |
2754 | } | |
2755 | ||
2756 | /* | |
2757 | * try to push data from one node into the next node right in the | |
2758 | * tree. | |
2759 | * | |
2760 | * returns 0 if some ptrs were pushed, < 0 if there was some horrible | |
2761 | * error, and > 0 if there was no room in the right hand block. | |
2762 | * | |
2763 | * this will only push up to 1/2 the contents of the left node over | |
2764 | */ | |
5f39d397 | 2765 | static int balance_node_right(struct btrfs_trans_handle *trans, |
5f39d397 CM |
2766 | struct extent_buffer *dst, |
2767 | struct extent_buffer *src) | |
79f95c82 | 2768 | { |
55d32ed8 | 2769 | struct btrfs_fs_info *fs_info = trans->fs_info; |
79f95c82 CM |
2770 | int push_items = 0; |
2771 | int max_push; | |
2772 | int src_nritems; | |
2773 | int dst_nritems; | |
2774 | int ret = 0; | |
79f95c82 | 2775 | |
7bb86316 CM |
2776 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
2777 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
2778 | ||
5f39d397 CM |
2779 | src_nritems = btrfs_header_nritems(src); |
2780 | dst_nritems = btrfs_header_nritems(dst); | |
0b246afa | 2781 | push_items = BTRFS_NODEPTRS_PER_BLOCK(fs_info) - dst_nritems; |
d397712b | 2782 | if (push_items <= 0) |
79f95c82 | 2783 | return 1; |
bce4eae9 | 2784 | |
d397712b | 2785 | if (src_nritems < 4) |
bce4eae9 | 2786 | return 1; |
79f95c82 CM |
2787 | |
2788 | max_push = src_nritems / 2 + 1; | |
2789 | /* don't try to empty the node */ | |
d397712b | 2790 | if (max_push >= src_nritems) |
79f95c82 | 2791 | return 1; |
252c38f0 | 2792 | |
79f95c82 CM |
2793 | if (max_push < push_items) |
2794 | push_items = max_push; | |
2795 | ||
d16c702f QW |
2796 | /* dst is the right eb, src is the middle eb */ |
2797 | if (check_sibling_keys(src, dst)) { | |
2798 | ret = -EUCLEAN; | |
2799 | btrfs_abort_transaction(trans, ret); | |
2800 | return ret; | |
2801 | } | |
5cead542 BB |
2802 | |
2803 | /* | |
2804 | * btrfs_tree_mod_log_eb_copy handles logging the move, so we don't | |
2805 | * need to do an explicit tree mod log operation for it. | |
2806 | */ | |
e23efd8e JB |
2807 | memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(dst, push_items), |
2808 | btrfs_node_key_ptr_offset(dst, 0), | |
5f39d397 CM |
2809 | (dst_nritems) * |
2810 | sizeof(struct btrfs_key_ptr)); | |
d6025579 | 2811 | |
f3a84ccd FM |
2812 | ret = btrfs_tree_mod_log_eb_copy(dst, src, 0, src_nritems - push_items, |
2813 | push_items); | |
5de865ee | 2814 | if (ret) { |
66642832 | 2815 | btrfs_abort_transaction(trans, ret); |
5de865ee FDBM |
2816 | return ret; |
2817 | } | |
5f39d397 | 2818 | copy_extent_buffer(dst, src, |
e23efd8e JB |
2819 | btrfs_node_key_ptr_offset(dst, 0), |
2820 | btrfs_node_key_ptr_offset(src, src_nritems - push_items), | |
d397712b | 2821 | push_items * sizeof(struct btrfs_key_ptr)); |
79f95c82 | 2822 | |
5f39d397 CM |
2823 | btrfs_set_header_nritems(src, src_nritems - push_items); |
2824 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
79f95c82 | 2825 | |
50564b65 FM |
2826 | btrfs_mark_buffer_dirty(trans, src); |
2827 | btrfs_mark_buffer_dirty(trans, dst); | |
31840ae1 | 2828 | |
aa5d6bed | 2829 | return ret; |
be0e5c09 CM |
2830 | } |
2831 | ||
97571fd0 CM |
2832 | /* |
2833 | * helper function to insert a new root level in the tree. | |
2834 | * A new node is allocated, and a single item is inserted to | |
2835 | * point to the existing root | |
aa5d6bed CM |
2836 | * |
2837 | * returns zero on success or < 0 on failure. | |
97571fd0 | 2838 | */ |
d397712b | 2839 | static noinline int insert_new_root(struct btrfs_trans_handle *trans, |
5f39d397 | 2840 | struct btrfs_root *root, |
fdd99c72 | 2841 | struct btrfs_path *path, int level) |
5c680ed6 | 2842 | { |
7bb86316 | 2843 | u64 lower_gen; |
5f39d397 CM |
2844 | struct extent_buffer *lower; |
2845 | struct extent_buffer *c; | |
925baedd | 2846 | struct extent_buffer *old; |
5f39d397 | 2847 | struct btrfs_disk_key lower_key; |
d9d19a01 | 2848 | int ret; |
5c680ed6 CM |
2849 | |
2850 | BUG_ON(path->nodes[level]); | |
2851 | BUG_ON(path->nodes[level-1] != root->node); | |
2852 | ||
7bb86316 CM |
2853 | lower = path->nodes[level-1]; |
2854 | if (level == 1) | |
2855 | btrfs_item_key(lower, &lower_key, 0); | |
2856 | else | |
2857 | btrfs_node_key(lower, &lower_key, 0); | |
2858 | ||
79bd3712 FM |
2859 | c = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid, |
2860 | &lower_key, level, root->node->start, 0, | |
60ea105a | 2861 | 0, BTRFS_NESTING_NEW_ROOT); |
5f39d397 CM |
2862 | if (IS_ERR(c)) |
2863 | return PTR_ERR(c); | |
925baedd | 2864 | |
02cd00fa | 2865 | root_add_used_bytes(root); |
f0486c68 | 2866 | |
5f39d397 | 2867 | btrfs_set_header_nritems(c, 1); |
5f39d397 | 2868 | btrfs_set_node_key(c, &lower_key, 0); |
db94535d | 2869 | btrfs_set_node_blockptr(c, 0, lower->start); |
7bb86316 | 2870 | lower_gen = btrfs_header_generation(lower); |
31840ae1 | 2871 | WARN_ON(lower_gen != trans->transid); |
7bb86316 CM |
2872 | |
2873 | btrfs_set_node_ptr_generation(c, 0, lower_gen); | |
d5719762 | 2874 | |
50564b65 | 2875 | btrfs_mark_buffer_dirty(trans, c); |
d5719762 | 2876 | |
925baedd | 2877 | old = root->node; |
406808ab | 2878 | ret = btrfs_tree_mod_log_insert_root(root->node, c, false); |
f61aa7ba FM |
2879 | if (ret < 0) { |
2880 | btrfs_free_tree_block(trans, btrfs_root_id(root), c, 0, 1); | |
2881 | btrfs_tree_unlock(c); | |
2882 | free_extent_buffer(c); | |
2883 | return ret; | |
2884 | } | |
240f62c8 | 2885 | rcu_assign_pointer(root->node, c); |
925baedd CM |
2886 | |
2887 | /* the super has an extra ref to root->node */ | |
2888 | free_extent_buffer(old); | |
2889 | ||
0b86a832 | 2890 | add_root_to_dirty_list(root); |
67439dad | 2891 | atomic_inc(&c->refs); |
5f39d397 | 2892 | path->nodes[level] = c; |
ac5887c8 | 2893 | path->locks[level] = BTRFS_WRITE_LOCK; |
5c680ed6 CM |
2894 | path->slots[level] = 0; |
2895 | return 0; | |
2896 | } | |
2897 | ||
74123bd7 CM |
2898 | /* |
2899 | * worker function to insert a single pointer in a node. | |
2900 | * the node should have enough room for the pointer already | |
97571fd0 | 2901 | * |
74123bd7 CM |
2902 | * slot and level indicate where you want the key to go, and |
2903 | * blocknr is the block the key points to. | |
2904 | */ | |
50b5d1fc FM |
2905 | static int insert_ptr(struct btrfs_trans_handle *trans, |
2906 | struct btrfs_path *path, | |
2907 | struct btrfs_disk_key *key, u64 bytenr, | |
2908 | int slot, int level) | |
74123bd7 | 2909 | { |
5f39d397 | 2910 | struct extent_buffer *lower; |
74123bd7 | 2911 | int nritems; |
f3ea38da | 2912 | int ret; |
5c680ed6 CM |
2913 | |
2914 | BUG_ON(!path->nodes[level]); | |
49d0c642 | 2915 | btrfs_assert_tree_write_locked(path->nodes[level]); |
5f39d397 CM |
2916 | lower = path->nodes[level]; |
2917 | nritems = btrfs_header_nritems(lower); | |
c293498b | 2918 | BUG_ON(slot > nritems); |
6ad3cf6d | 2919 | BUG_ON(nritems == BTRFS_NODEPTRS_PER_BLOCK(trans->fs_info)); |
74123bd7 | 2920 | if (slot != nritems) { |
bf1d3425 | 2921 | if (level) { |
f3a84ccd FM |
2922 | ret = btrfs_tree_mod_log_insert_move(lower, slot + 1, |
2923 | slot, nritems - slot); | |
50b5d1fc FM |
2924 | if (ret < 0) { |
2925 | btrfs_abort_transaction(trans, ret); | |
2926 | return ret; | |
2927 | } | |
bf1d3425 | 2928 | } |
5f39d397 | 2929 | memmove_extent_buffer(lower, |
e23efd8e JB |
2930 | btrfs_node_key_ptr_offset(lower, slot + 1), |
2931 | btrfs_node_key_ptr_offset(lower, slot), | |
d6025579 | 2932 | (nritems - slot) * sizeof(struct btrfs_key_ptr)); |
74123bd7 | 2933 | } |
c3e06965 | 2934 | if (level) { |
f3a84ccd | 2935 | ret = btrfs_tree_mod_log_insert_key(lower, slot, |
33cff222 | 2936 | BTRFS_MOD_LOG_KEY_ADD); |
50b5d1fc FM |
2937 | if (ret < 0) { |
2938 | btrfs_abort_transaction(trans, ret); | |
2939 | return ret; | |
2940 | } | |
f3ea38da | 2941 | } |
5f39d397 | 2942 | btrfs_set_node_key(lower, key, slot); |
db94535d | 2943 | btrfs_set_node_blockptr(lower, slot, bytenr); |
74493f7a CM |
2944 | WARN_ON(trans->transid == 0); |
2945 | btrfs_set_node_ptr_generation(lower, slot, trans->transid); | |
5f39d397 | 2946 | btrfs_set_header_nritems(lower, nritems + 1); |
50564b65 | 2947 | btrfs_mark_buffer_dirty(trans, lower); |
50b5d1fc FM |
2948 | |
2949 | return 0; | |
74123bd7 CM |
2950 | } |
2951 | ||
97571fd0 CM |
2952 | /* |
2953 | * split the node at the specified level in path in two. | |
2954 | * The path is corrected to point to the appropriate node after the split | |
2955 | * | |
2956 | * Before splitting this tries to make some room in the node by pushing | |
2957 | * left and right, if either one works, it returns right away. | |
aa5d6bed CM |
2958 | * |
2959 | * returns 0 on success and < 0 on failure | |
97571fd0 | 2960 | */ |
e02119d5 CM |
2961 | static noinline int split_node(struct btrfs_trans_handle *trans, |
2962 | struct btrfs_root *root, | |
2963 | struct btrfs_path *path, int level) | |
be0e5c09 | 2964 | { |
0b246afa | 2965 | struct btrfs_fs_info *fs_info = root->fs_info; |
5f39d397 CM |
2966 | struct extent_buffer *c; |
2967 | struct extent_buffer *split; | |
2968 | struct btrfs_disk_key disk_key; | |
be0e5c09 | 2969 | int mid; |
5c680ed6 | 2970 | int ret; |
7518a238 | 2971 | u32 c_nritems; |
eb60ceac | 2972 | |
5f39d397 | 2973 | c = path->nodes[level]; |
7bb86316 | 2974 | WARN_ON(btrfs_header_generation(c) != trans->transid); |
5f39d397 | 2975 | if (c == root->node) { |
d9abbf1c | 2976 | /* |
90f8d62e JS |
2977 | * trying to split the root, lets make a new one |
2978 | * | |
fdd99c72 | 2979 | * tree mod log: We don't log_removal old root in |
90f8d62e JS |
2980 | * insert_new_root, because that root buffer will be kept as a |
2981 | * normal node. We are going to log removal of half of the | |
f3a84ccd FM |
2982 | * elements below with btrfs_tree_mod_log_eb_copy(). We're |
2983 | * holding a tree lock on the buffer, which is why we cannot | |
2984 | * race with other tree_mod_log users. | |
d9abbf1c | 2985 | */ |
fdd99c72 | 2986 | ret = insert_new_root(trans, root, path, level + 1); |
5c680ed6 CM |
2987 | if (ret) |
2988 | return ret; | |
b3612421 | 2989 | } else { |
e66f709b | 2990 | ret = push_nodes_for_insert(trans, root, path, level); |
5f39d397 CM |
2991 | c = path->nodes[level]; |
2992 | if (!ret && btrfs_header_nritems(c) < | |
0b246afa | 2993 | BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 3) |
e66f709b | 2994 | return 0; |
54aa1f4d CM |
2995 | if (ret < 0) |
2996 | return ret; | |
be0e5c09 | 2997 | } |
e66f709b | 2998 | |
5f39d397 | 2999 | c_nritems = btrfs_header_nritems(c); |
5d4f98a2 YZ |
3000 | mid = (c_nritems + 1) / 2; |
3001 | btrfs_node_key(c, &disk_key, mid); | |
7bb86316 | 3002 | |
79bd3712 FM |
3003 | split = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid, |
3004 | &disk_key, level, c->start, 0, | |
60ea105a | 3005 | 0, BTRFS_NESTING_SPLIT); |
5f39d397 CM |
3006 | if (IS_ERR(split)) |
3007 | return PTR_ERR(split); | |
3008 | ||
02cd00fa | 3009 | root_add_used_bytes(root); |
bc877d28 | 3010 | ASSERT(btrfs_header_level(c) == level); |
54aa1f4d | 3011 | |
f3a84ccd | 3012 | ret = btrfs_tree_mod_log_eb_copy(split, c, 0, mid, c_nritems - mid); |
5de865ee | 3013 | if (ret) { |
ede600e4 FM |
3014 | btrfs_tree_unlock(split); |
3015 | free_extent_buffer(split); | |
66642832 | 3016 | btrfs_abort_transaction(trans, ret); |
5de865ee FDBM |
3017 | return ret; |
3018 | } | |
5f39d397 | 3019 | copy_extent_buffer(split, c, |
e23efd8e JB |
3020 | btrfs_node_key_ptr_offset(split, 0), |
3021 | btrfs_node_key_ptr_offset(c, mid), | |
5f39d397 CM |
3022 | (c_nritems - mid) * sizeof(struct btrfs_key_ptr)); |
3023 | btrfs_set_header_nritems(split, c_nritems - mid); | |
3024 | btrfs_set_header_nritems(c, mid); | |
aa5d6bed | 3025 | |
50564b65 FM |
3026 | btrfs_mark_buffer_dirty(trans, c); |
3027 | btrfs_mark_buffer_dirty(trans, split); | |
5f39d397 | 3028 | |
50b5d1fc FM |
3029 | ret = insert_ptr(trans, path, &disk_key, split->start, |
3030 | path->slots[level + 1] + 1, level + 1); | |
3031 | if (ret < 0) { | |
3032 | btrfs_tree_unlock(split); | |
3033 | free_extent_buffer(split); | |
3034 | return ret; | |
3035 | } | |
aa5d6bed | 3036 | |
5de08d7d | 3037 | if (path->slots[level] >= mid) { |
5c680ed6 | 3038 | path->slots[level] -= mid; |
925baedd | 3039 | btrfs_tree_unlock(c); |
5f39d397 CM |
3040 | free_extent_buffer(c); |
3041 | path->nodes[level] = split; | |
5c680ed6 CM |
3042 | path->slots[level + 1] += 1; |
3043 | } else { | |
925baedd | 3044 | btrfs_tree_unlock(split); |
5f39d397 | 3045 | free_extent_buffer(split); |
be0e5c09 | 3046 | } |
d5286a92 | 3047 | return 0; |
be0e5c09 CM |
3048 | } |
3049 | ||
74123bd7 CM |
3050 | /* |
3051 | * how many bytes are required to store the items in a leaf. start | |
3052 | * and nr indicate which items in the leaf to check. This totals up the | |
3053 | * space used both by the item structs and the item data | |
3054 | */ | |
6c75a589 | 3055 | static int leaf_space_used(const struct extent_buffer *l, int start, int nr) |
be0e5c09 CM |
3056 | { |
3057 | int data_len; | |
5f39d397 | 3058 | int nritems = btrfs_header_nritems(l); |
d4dbff95 | 3059 | int end = min(nritems, start + nr) - 1; |
be0e5c09 CM |
3060 | |
3061 | if (!nr) | |
3062 | return 0; | |
3212fa14 JB |
3063 | data_len = btrfs_item_offset(l, start) + btrfs_item_size(l, start); |
3064 | data_len = data_len - btrfs_item_offset(l, end); | |
0783fcfc | 3065 | data_len += sizeof(struct btrfs_item) * nr; |
d4dbff95 | 3066 | WARN_ON(data_len < 0); |
be0e5c09 CM |
3067 | return data_len; |
3068 | } | |
3069 | ||
d4dbff95 CM |
3070 | /* |
3071 | * The space between the end of the leaf items and | |
3072 | * the start of the leaf data. IOW, how much room | |
3073 | * the leaf has left for both items and data | |
3074 | */ | |
6c75a589 | 3075 | int btrfs_leaf_free_space(const struct extent_buffer *leaf) |
d4dbff95 | 3076 | { |
e902baac | 3077 | struct btrfs_fs_info *fs_info = leaf->fs_info; |
5f39d397 CM |
3078 | int nritems = btrfs_header_nritems(leaf); |
3079 | int ret; | |
0b246afa JM |
3080 | |
3081 | ret = BTRFS_LEAF_DATA_SIZE(fs_info) - leaf_space_used(leaf, 0, nritems); | |
5f39d397 | 3082 | if (ret < 0) { |
0b246afa JM |
3083 | btrfs_crit(fs_info, |
3084 | "leaf free space ret %d, leaf data size %lu, used %d nritems %d", | |
3085 | ret, | |
3086 | (unsigned long) BTRFS_LEAF_DATA_SIZE(fs_info), | |
3087 | leaf_space_used(leaf, 0, nritems), nritems); | |
5f39d397 CM |
3088 | } |
3089 | return ret; | |
d4dbff95 CM |
3090 | } |
3091 | ||
99d8f83c CM |
3092 | /* |
3093 | * min slot controls the lowest index we're willing to push to the | |
3094 | * right. We'll push up to and including min_slot, but no lower | |
3095 | */ | |
ed25dab3 JB |
3096 | static noinline int __push_leaf_right(struct btrfs_trans_handle *trans, |
3097 | struct btrfs_path *path, | |
44871b1b CM |
3098 | int data_size, int empty, |
3099 | struct extent_buffer *right, | |
99d8f83c CM |
3100 | int free_space, u32 left_nritems, |
3101 | u32 min_slot) | |
00ec4c51 | 3102 | { |
f72f0010 | 3103 | struct btrfs_fs_info *fs_info = right->fs_info; |
5f39d397 | 3104 | struct extent_buffer *left = path->nodes[0]; |
44871b1b | 3105 | struct extent_buffer *upper = path->nodes[1]; |
cfed81a0 | 3106 | struct btrfs_map_token token; |
5f39d397 | 3107 | struct btrfs_disk_key disk_key; |
00ec4c51 | 3108 | int slot; |
34a38218 | 3109 | u32 i; |
00ec4c51 CM |
3110 | int push_space = 0; |
3111 | int push_items = 0; | |
34a38218 | 3112 | u32 nr; |
7518a238 | 3113 | u32 right_nritems; |
5f39d397 | 3114 | u32 data_end; |
db94535d | 3115 | u32 this_item_size; |
00ec4c51 | 3116 | |
34a38218 CM |
3117 | if (empty) |
3118 | nr = 0; | |
3119 | else | |
99d8f83c | 3120 | nr = max_t(u32, 1, min_slot); |
34a38218 | 3121 | |
31840ae1 | 3122 | if (path->slots[0] >= left_nritems) |
87b29b20 | 3123 | push_space += data_size; |
31840ae1 | 3124 | |
44871b1b | 3125 | slot = path->slots[1]; |
34a38218 CM |
3126 | i = left_nritems - 1; |
3127 | while (i >= nr) { | |
31840ae1 ZY |
3128 | if (!empty && push_items > 0) { |
3129 | if (path->slots[0] > i) | |
3130 | break; | |
3131 | if (path->slots[0] == i) { | |
e902baac DS |
3132 | int space = btrfs_leaf_free_space(left); |
3133 | ||
31840ae1 ZY |
3134 | if (space + push_space * 2 > free_space) |
3135 | break; | |
3136 | } | |
3137 | } | |
3138 | ||
00ec4c51 | 3139 | if (path->slots[0] == i) |
87b29b20 | 3140 | push_space += data_size; |
db94535d | 3141 | |
3212fa14 | 3142 | this_item_size = btrfs_item_size(left, i); |
74794207 JB |
3143 | if (this_item_size + sizeof(struct btrfs_item) + |
3144 | push_space > free_space) | |
00ec4c51 | 3145 | break; |
31840ae1 | 3146 | |
00ec4c51 | 3147 | push_items++; |
74794207 | 3148 | push_space += this_item_size + sizeof(struct btrfs_item); |
34a38218 CM |
3149 | if (i == 0) |
3150 | break; | |
3151 | i--; | |
db94535d | 3152 | } |
5f39d397 | 3153 | |
925baedd CM |
3154 | if (push_items == 0) |
3155 | goto out_unlock; | |
5f39d397 | 3156 | |
6c1500f2 | 3157 | WARN_ON(!empty && push_items == left_nritems); |
5f39d397 | 3158 | |
00ec4c51 | 3159 | /* push left to right */ |
5f39d397 | 3160 | right_nritems = btrfs_header_nritems(right); |
34a38218 | 3161 | |
dc2e724e | 3162 | push_space = btrfs_item_data_end(left, left_nritems - push_items); |
8f881e8c | 3163 | push_space -= leaf_data_end(left); |
5f39d397 | 3164 | |
00ec4c51 | 3165 | /* make room in the right data area */ |
8f881e8c | 3166 | data_end = leaf_data_end(right); |
637e3b48 JB |
3167 | memmove_leaf_data(right, data_end - push_space, data_end, |
3168 | BTRFS_LEAF_DATA_SIZE(fs_info) - data_end); | |
5f39d397 | 3169 | |
00ec4c51 | 3170 | /* copy from the left data area */ |
637e3b48 JB |
3171 | copy_leaf_data(right, left, BTRFS_LEAF_DATA_SIZE(fs_info) - push_space, |
3172 | leaf_data_end(left), push_space); | |
5f39d397 | 3173 | |
637e3b48 | 3174 | memmove_leaf_items(right, push_items, 0, right_nritems); |
5f39d397 | 3175 | |
00ec4c51 | 3176 | /* copy the items from left to right */ |
637e3b48 | 3177 | copy_leaf_items(right, left, 0, left_nritems - push_items, push_items); |
00ec4c51 CM |
3178 | |
3179 | /* update the item pointers */ | |
c82f823c | 3180 | btrfs_init_map_token(&token, right); |
7518a238 | 3181 | right_nritems += push_items; |
5f39d397 | 3182 | btrfs_set_header_nritems(right, right_nritems); |
0b246afa | 3183 | push_space = BTRFS_LEAF_DATA_SIZE(fs_info); |
7518a238 | 3184 | for (i = 0; i < right_nritems; i++) { |
3212fa14 JB |
3185 | push_space -= btrfs_token_item_size(&token, i); |
3186 | btrfs_set_token_item_offset(&token, i, push_space); | |
db94535d CM |
3187 | } |
3188 | ||
7518a238 | 3189 | left_nritems -= push_items; |
5f39d397 | 3190 | btrfs_set_header_nritems(left, left_nritems); |
00ec4c51 | 3191 | |
34a38218 | 3192 | if (left_nritems) |
50564b65 | 3193 | btrfs_mark_buffer_dirty(trans, left); |
f0486c68 | 3194 | else |
190a8339 | 3195 | btrfs_clear_buffer_dirty(trans, left); |
f0486c68 | 3196 | |
50564b65 | 3197 | btrfs_mark_buffer_dirty(trans, right); |
a429e513 | 3198 | |
5f39d397 CM |
3199 | btrfs_item_key(right, &disk_key, 0); |
3200 | btrfs_set_node_key(upper, &disk_key, slot + 1); | |
50564b65 | 3201 | btrfs_mark_buffer_dirty(trans, upper); |
02217ed2 | 3202 | |
00ec4c51 | 3203 | /* then fixup the leaf pointer in the path */ |
7518a238 CM |
3204 | if (path->slots[0] >= left_nritems) { |
3205 | path->slots[0] -= left_nritems; | |
925baedd | 3206 | if (btrfs_header_nritems(path->nodes[0]) == 0) |
190a8339 | 3207 | btrfs_clear_buffer_dirty(trans, path->nodes[0]); |
925baedd | 3208 | btrfs_tree_unlock(path->nodes[0]); |
5f39d397 CM |
3209 | free_extent_buffer(path->nodes[0]); |
3210 | path->nodes[0] = right; | |
00ec4c51 CM |
3211 | path->slots[1] += 1; |
3212 | } else { | |
925baedd | 3213 | btrfs_tree_unlock(right); |
5f39d397 | 3214 | free_extent_buffer(right); |
00ec4c51 CM |
3215 | } |
3216 | return 0; | |
925baedd CM |
3217 | |
3218 | out_unlock: | |
3219 | btrfs_tree_unlock(right); | |
3220 | free_extent_buffer(right); | |
3221 | return 1; | |
00ec4c51 | 3222 | } |
925baedd | 3223 | |
44871b1b CM |
3224 | /* |
3225 | * push some data in the path leaf to the right, trying to free up at | |
3226 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
3227 | * | |
3228 | * returns 1 if the push failed because the other node didn't have enough | |
3229 | * room, 0 if everything worked out and < 0 if there were major errors. | |
99d8f83c CM |
3230 | * |
3231 | * this will push starting from min_slot to the end of the leaf. It won't | |
3232 | * push any slot lower than min_slot | |
44871b1b CM |
3233 | */ |
3234 | static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root | |
99d8f83c CM |
3235 | *root, struct btrfs_path *path, |
3236 | int min_data_size, int data_size, | |
3237 | int empty, u32 min_slot) | |
44871b1b CM |
3238 | { |
3239 | struct extent_buffer *left = path->nodes[0]; | |
3240 | struct extent_buffer *right; | |
3241 | struct extent_buffer *upper; | |
3242 | int slot; | |
3243 | int free_space; | |
3244 | u32 left_nritems; | |
3245 | int ret; | |
3246 | ||
3247 | if (!path->nodes[1]) | |
3248 | return 1; | |
3249 | ||
3250 | slot = path->slots[1]; | |
3251 | upper = path->nodes[1]; | |
3252 | if (slot >= btrfs_header_nritems(upper) - 1) | |
3253 | return 1; | |
3254 | ||
49d0c642 | 3255 | btrfs_assert_tree_write_locked(path->nodes[1]); |
44871b1b | 3256 | |
4b231ae4 | 3257 | right = btrfs_read_node_slot(upper, slot + 1); |
fb770ae4 | 3258 | if (IS_ERR(right)) |
9cf14029 | 3259 | return PTR_ERR(right); |
91ca338d | 3260 | |
bf77467a | 3261 | __btrfs_tree_lock(right, BTRFS_NESTING_RIGHT); |
44871b1b | 3262 | |
e902baac | 3263 | free_space = btrfs_leaf_free_space(right); |
44871b1b CM |
3264 | if (free_space < data_size) |
3265 | goto out_unlock; | |
3266 | ||
44871b1b | 3267 | ret = btrfs_cow_block(trans, root, right, upper, |
bf59a5a2 | 3268 | slot + 1, &right, BTRFS_NESTING_RIGHT_COW); |
44871b1b CM |
3269 | if (ret) |
3270 | goto out_unlock; | |
3271 | ||
44871b1b CM |
3272 | left_nritems = btrfs_header_nritems(left); |
3273 | if (left_nritems == 0) | |
3274 | goto out_unlock; | |
3275 | ||
d16c702f QW |
3276 | if (check_sibling_keys(left, right)) { |
3277 | ret = -EUCLEAN; | |
9ae5afd0 | 3278 | btrfs_abort_transaction(trans, ret); |
d16c702f QW |
3279 | btrfs_tree_unlock(right); |
3280 | free_extent_buffer(right); | |
3281 | return ret; | |
3282 | } | |
2ef1fed2 FDBM |
3283 | if (path->slots[0] == left_nritems && !empty) { |
3284 | /* Key greater than all keys in the leaf, right neighbor has | |
3285 | * enough room for it and we're not emptying our leaf to delete | |
3286 | * it, therefore use right neighbor to insert the new item and | |
52042d8e | 3287 | * no need to touch/dirty our left leaf. */ |
2ef1fed2 FDBM |
3288 | btrfs_tree_unlock(left); |
3289 | free_extent_buffer(left); | |
3290 | path->nodes[0] = right; | |
3291 | path->slots[0] = 0; | |
3292 | path->slots[1]++; | |
3293 | return 0; | |
3294 | } | |
3295 | ||
ed25dab3 JB |
3296 | return __push_leaf_right(trans, path, min_data_size, empty, right, |
3297 | free_space, left_nritems, min_slot); | |
44871b1b CM |
3298 | out_unlock: |
3299 | btrfs_tree_unlock(right); | |
3300 | free_extent_buffer(right); | |
3301 | return 1; | |
3302 | } | |
3303 | ||
74123bd7 CM |
3304 | /* |
3305 | * push some data in the path leaf to the left, trying to free up at | |
3306 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
99d8f83c CM |
3307 | * |
3308 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
3309 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us do all the | |
3310 | * items | |
74123bd7 | 3311 | */ |
ed25dab3 JB |
3312 | static noinline int __push_leaf_left(struct btrfs_trans_handle *trans, |
3313 | struct btrfs_path *path, int data_size, | |
44871b1b | 3314 | int empty, struct extent_buffer *left, |
99d8f83c CM |
3315 | int free_space, u32 right_nritems, |
3316 | u32 max_slot) | |
be0e5c09 | 3317 | { |
8087c193 | 3318 | struct btrfs_fs_info *fs_info = left->fs_info; |
5f39d397 CM |
3319 | struct btrfs_disk_key disk_key; |
3320 | struct extent_buffer *right = path->nodes[0]; | |
be0e5c09 | 3321 | int i; |
be0e5c09 CM |
3322 | int push_space = 0; |
3323 | int push_items = 0; | |
7518a238 | 3324 | u32 old_left_nritems; |
34a38218 | 3325 | u32 nr; |
aa5d6bed | 3326 | int ret = 0; |
db94535d CM |
3327 | u32 this_item_size; |
3328 | u32 old_left_item_size; | |
cfed81a0 CM |
3329 | struct btrfs_map_token token; |
3330 | ||
34a38218 | 3331 | if (empty) |
99d8f83c | 3332 | nr = min(right_nritems, max_slot); |
34a38218 | 3333 | else |
99d8f83c | 3334 | nr = min(right_nritems - 1, max_slot); |
34a38218 CM |
3335 | |
3336 | for (i = 0; i < nr; i++) { | |
31840ae1 ZY |
3337 | if (!empty && push_items > 0) { |
3338 | if (path->slots[0] < i) | |
3339 | break; | |
3340 | if (path->slots[0] == i) { | |
e902baac DS |
3341 | int space = btrfs_leaf_free_space(right); |
3342 | ||
31840ae1 ZY |
3343 | if (space + push_space * 2 > free_space) |
3344 | break; | |
3345 | } | |
3346 | } | |
3347 | ||
be0e5c09 | 3348 | if (path->slots[0] == i) |
87b29b20 | 3349 | push_space += data_size; |
db94535d | 3350 | |
3212fa14 | 3351 | this_item_size = btrfs_item_size(right, i); |
74794207 JB |
3352 | if (this_item_size + sizeof(struct btrfs_item) + push_space > |
3353 | free_space) | |
be0e5c09 | 3354 | break; |
db94535d | 3355 | |
be0e5c09 | 3356 | push_items++; |
74794207 | 3357 | push_space += this_item_size + sizeof(struct btrfs_item); |
db94535d CM |
3358 | } |
3359 | ||
be0e5c09 | 3360 | if (push_items == 0) { |
925baedd CM |
3361 | ret = 1; |
3362 | goto out; | |
be0e5c09 | 3363 | } |
fae7f21c | 3364 | WARN_ON(!empty && push_items == btrfs_header_nritems(right)); |
5f39d397 | 3365 | |
be0e5c09 | 3366 | /* push data from right to left */ |
637e3b48 | 3367 | copy_leaf_items(left, right, btrfs_header_nritems(left), 0, push_items); |
5f39d397 | 3368 | |
0b246afa | 3369 | push_space = BTRFS_LEAF_DATA_SIZE(fs_info) - |
3212fa14 | 3370 | btrfs_item_offset(right, push_items - 1); |
5f39d397 | 3371 | |
637e3b48 JB |
3372 | copy_leaf_data(left, right, leaf_data_end(left) - push_space, |
3373 | btrfs_item_offset(right, push_items - 1), push_space); | |
5f39d397 | 3374 | old_left_nritems = btrfs_header_nritems(left); |
87b29b20 | 3375 | BUG_ON(old_left_nritems <= 0); |
eb60ceac | 3376 | |
c82f823c | 3377 | btrfs_init_map_token(&token, left); |
3212fa14 | 3378 | old_left_item_size = btrfs_item_offset(left, old_left_nritems - 1); |
0783fcfc | 3379 | for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { |
5f39d397 | 3380 | u32 ioff; |
db94535d | 3381 | |
3212fa14 JB |
3382 | ioff = btrfs_token_item_offset(&token, i); |
3383 | btrfs_set_token_item_offset(&token, i, | |
cc4c13d5 | 3384 | ioff - (BTRFS_LEAF_DATA_SIZE(fs_info) - old_left_item_size)); |
be0e5c09 | 3385 | } |
5f39d397 | 3386 | btrfs_set_header_nritems(left, old_left_nritems + push_items); |
be0e5c09 CM |
3387 | |
3388 | /* fixup right node */ | |
31b1a2bd JL |
3389 | if (push_items > right_nritems) |
3390 | WARN(1, KERN_CRIT "push items %d nr %u\n", push_items, | |
d397712b | 3391 | right_nritems); |
34a38218 CM |
3392 | |
3393 | if (push_items < right_nritems) { | |
3212fa14 | 3394 | push_space = btrfs_item_offset(right, push_items - 1) - |
8f881e8c | 3395 | leaf_data_end(right); |
637e3b48 JB |
3396 | memmove_leaf_data(right, |
3397 | BTRFS_LEAF_DATA_SIZE(fs_info) - push_space, | |
3398 | leaf_data_end(right), push_space); | |
3399 | ||
3400 | memmove_leaf_items(right, 0, push_items, | |
3401 | btrfs_header_nritems(right) - push_items); | |
34a38218 | 3402 | } |
c82f823c DS |
3403 | |
3404 | btrfs_init_map_token(&token, right); | |
eef1c494 Y |
3405 | right_nritems -= push_items; |
3406 | btrfs_set_header_nritems(right, right_nritems); | |
0b246afa | 3407 | push_space = BTRFS_LEAF_DATA_SIZE(fs_info); |
5f39d397 | 3408 | for (i = 0; i < right_nritems; i++) { |
3212fa14 JB |
3409 | push_space = push_space - btrfs_token_item_size(&token, i); |
3410 | btrfs_set_token_item_offset(&token, i, push_space); | |
db94535d | 3411 | } |
eb60ceac | 3412 | |
50564b65 | 3413 | btrfs_mark_buffer_dirty(trans, left); |
34a38218 | 3414 | if (right_nritems) |
50564b65 | 3415 | btrfs_mark_buffer_dirty(trans, right); |
f0486c68 | 3416 | else |
190a8339 | 3417 | btrfs_clear_buffer_dirty(trans, right); |
098f59c2 | 3418 | |
5f39d397 | 3419 | btrfs_item_key(right, &disk_key, 0); |
50564b65 | 3420 | fixup_low_keys(trans, path, &disk_key, 1); |
be0e5c09 CM |
3421 | |
3422 | /* then fixup the leaf pointer in the path */ | |
3423 | if (path->slots[0] < push_items) { | |
3424 | path->slots[0] += old_left_nritems; | |
925baedd | 3425 | btrfs_tree_unlock(path->nodes[0]); |
5f39d397 CM |
3426 | free_extent_buffer(path->nodes[0]); |
3427 | path->nodes[0] = left; | |
be0e5c09 CM |
3428 | path->slots[1] -= 1; |
3429 | } else { | |
925baedd | 3430 | btrfs_tree_unlock(left); |
5f39d397 | 3431 | free_extent_buffer(left); |
be0e5c09 CM |
3432 | path->slots[0] -= push_items; |
3433 | } | |
eb60ceac | 3434 | BUG_ON(path->slots[0] < 0); |
aa5d6bed | 3435 | return ret; |
925baedd CM |
3436 | out: |
3437 | btrfs_tree_unlock(left); | |
3438 | free_extent_buffer(left); | |
3439 | return ret; | |
be0e5c09 CM |
3440 | } |
3441 | ||
44871b1b CM |
3442 | /* |
3443 | * push some data in the path leaf to the left, trying to free up at | |
3444 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
99d8f83c CM |
3445 | * |
3446 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
3447 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us push all the | |
3448 | * items | |
44871b1b CM |
3449 | */ |
3450 | static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root | |
99d8f83c CM |
3451 | *root, struct btrfs_path *path, int min_data_size, |
3452 | int data_size, int empty, u32 max_slot) | |
44871b1b CM |
3453 | { |
3454 | struct extent_buffer *right = path->nodes[0]; | |
3455 | struct extent_buffer *left; | |
3456 | int slot; | |
3457 | int free_space; | |
3458 | u32 right_nritems; | |
3459 | int ret = 0; | |
3460 | ||
3461 | slot = path->slots[1]; | |
3462 | if (slot == 0) | |
3463 | return 1; | |
3464 | if (!path->nodes[1]) | |
3465 | return 1; | |
3466 | ||
3467 | right_nritems = btrfs_header_nritems(right); | |
3468 | if (right_nritems == 0) | |
3469 | return 1; | |
3470 | ||
49d0c642 | 3471 | btrfs_assert_tree_write_locked(path->nodes[1]); |
44871b1b | 3472 | |
4b231ae4 | 3473 | left = btrfs_read_node_slot(path->nodes[1], slot - 1); |
fb770ae4 | 3474 | if (IS_ERR(left)) |
9cf14029 | 3475 | return PTR_ERR(left); |
91ca338d | 3476 | |
bf77467a | 3477 | __btrfs_tree_lock(left, BTRFS_NESTING_LEFT); |
44871b1b | 3478 | |
e902baac | 3479 | free_space = btrfs_leaf_free_space(left); |
44871b1b CM |
3480 | if (free_space < data_size) { |
3481 | ret = 1; | |
3482 | goto out; | |
3483 | } | |
3484 | ||
44871b1b | 3485 | ret = btrfs_cow_block(trans, root, left, |
9631e4cc | 3486 | path->nodes[1], slot - 1, &left, |
bf59a5a2 | 3487 | BTRFS_NESTING_LEFT_COW); |
44871b1b CM |
3488 | if (ret) { |
3489 | /* we hit -ENOSPC, but it isn't fatal here */ | |
79787eaa JM |
3490 | if (ret == -ENOSPC) |
3491 | ret = 1; | |
44871b1b CM |
3492 | goto out; |
3493 | } | |
3494 | ||
d16c702f QW |
3495 | if (check_sibling_keys(left, right)) { |
3496 | ret = -EUCLEAN; | |
9ae5afd0 | 3497 | btrfs_abort_transaction(trans, ret); |
d16c702f QW |
3498 | goto out; |
3499 | } | |
ed25dab3 JB |
3500 | return __push_leaf_left(trans, path, min_data_size, empty, left, |
3501 | free_space, right_nritems, max_slot); | |
44871b1b CM |
3502 | out: |
3503 | btrfs_tree_unlock(left); | |
3504 | free_extent_buffer(left); | |
3505 | return ret; | |
3506 | } | |
3507 | ||
3508 | /* | |
3509 | * split the path's leaf in two, making sure there is at least data_size | |
3510 | * available for the resulting leaf level of the path. | |
44871b1b | 3511 | */ |
50b5d1fc FM |
3512 | static noinline int copy_for_split(struct btrfs_trans_handle *trans, |
3513 | struct btrfs_path *path, | |
3514 | struct extent_buffer *l, | |
3515 | struct extent_buffer *right, | |
3516 | int slot, int mid, int nritems) | |
44871b1b | 3517 | { |
94f94ad9 | 3518 | struct btrfs_fs_info *fs_info = trans->fs_info; |
44871b1b CM |
3519 | int data_copy_size; |
3520 | int rt_data_off; | |
3521 | int i; | |
50b5d1fc | 3522 | int ret; |
44871b1b | 3523 | struct btrfs_disk_key disk_key; |
cfed81a0 CM |
3524 | struct btrfs_map_token token; |
3525 | ||
44871b1b CM |
3526 | nritems = nritems - mid; |
3527 | btrfs_set_header_nritems(right, nritems); | |
dc2e724e | 3528 | data_copy_size = btrfs_item_data_end(l, mid) - leaf_data_end(l); |
44871b1b | 3529 | |
637e3b48 | 3530 | copy_leaf_items(right, l, 0, mid, nritems); |
44871b1b | 3531 | |
637e3b48 JB |
3532 | copy_leaf_data(right, l, BTRFS_LEAF_DATA_SIZE(fs_info) - data_copy_size, |
3533 | leaf_data_end(l), data_copy_size); | |
44871b1b | 3534 | |
dc2e724e | 3535 | rt_data_off = BTRFS_LEAF_DATA_SIZE(fs_info) - btrfs_item_data_end(l, mid); |
44871b1b | 3536 | |
c82f823c | 3537 | btrfs_init_map_token(&token, right); |
44871b1b | 3538 | for (i = 0; i < nritems; i++) { |
44871b1b CM |
3539 | u32 ioff; |
3540 | ||
3212fa14 JB |
3541 | ioff = btrfs_token_item_offset(&token, i); |
3542 | btrfs_set_token_item_offset(&token, i, ioff + rt_data_off); | |
44871b1b CM |
3543 | } |
3544 | ||
44871b1b | 3545 | btrfs_set_header_nritems(l, mid); |
44871b1b | 3546 | btrfs_item_key(right, &disk_key, 0); |
50b5d1fc FM |
3547 | ret = insert_ptr(trans, path, &disk_key, right->start, path->slots[1] + 1, 1); |
3548 | if (ret < 0) | |
3549 | return ret; | |
44871b1b | 3550 | |
50564b65 FM |
3551 | btrfs_mark_buffer_dirty(trans, right); |
3552 | btrfs_mark_buffer_dirty(trans, l); | |
44871b1b CM |
3553 | BUG_ON(path->slots[0] != slot); |
3554 | ||
44871b1b CM |
3555 | if (mid <= slot) { |
3556 | btrfs_tree_unlock(path->nodes[0]); | |
3557 | free_extent_buffer(path->nodes[0]); | |
3558 | path->nodes[0] = right; | |
3559 | path->slots[0] -= mid; | |
3560 | path->slots[1] += 1; | |
3561 | } else { | |
3562 | btrfs_tree_unlock(right); | |
3563 | free_extent_buffer(right); | |
3564 | } | |
3565 | ||
3566 | BUG_ON(path->slots[0] < 0); | |
50b5d1fc FM |
3567 | |
3568 | return 0; | |
44871b1b CM |
3569 | } |
3570 | ||
99d8f83c CM |
3571 | /* |
3572 | * double splits happen when we need to insert a big item in the middle | |
3573 | * of a leaf. A double split can leave us with 3 mostly empty leaves: | |
3574 | * leaf: [ slots 0 - N] [ our target ] [ N + 1 - total in leaf ] | |
3575 | * A B C | |
3576 | * | |
3577 | * We avoid this by trying to push the items on either side of our target | |
3578 | * into the adjacent leaves. If all goes well we can avoid the double split | |
3579 | * completely. | |
3580 | */ | |
3581 | static noinline int push_for_double_split(struct btrfs_trans_handle *trans, | |
3582 | struct btrfs_root *root, | |
3583 | struct btrfs_path *path, | |
3584 | int data_size) | |
3585 | { | |
3586 | int ret; | |
3587 | int progress = 0; | |
3588 | int slot; | |
3589 | u32 nritems; | |
5a4267ca | 3590 | int space_needed = data_size; |
99d8f83c CM |
3591 | |
3592 | slot = path->slots[0]; | |
5a4267ca | 3593 | if (slot < btrfs_header_nritems(path->nodes[0])) |
e902baac | 3594 | space_needed -= btrfs_leaf_free_space(path->nodes[0]); |
99d8f83c CM |
3595 | |
3596 | /* | |
3597 | * try to push all the items after our slot into the | |
3598 | * right leaf | |
3599 | */ | |
5a4267ca | 3600 | ret = push_leaf_right(trans, root, path, 1, space_needed, 0, slot); |
99d8f83c CM |
3601 | if (ret < 0) |
3602 | return ret; | |
3603 | ||
3604 | if (ret == 0) | |
3605 | progress++; | |
3606 | ||
3607 | nritems = btrfs_header_nritems(path->nodes[0]); | |
3608 | /* | |
3609 | * our goal is to get our slot at the start or end of a leaf. If | |
3610 | * we've done so we're done | |
3611 | */ | |
3612 | if (path->slots[0] == 0 || path->slots[0] == nritems) | |
3613 | return 0; | |
3614 | ||
e902baac | 3615 | if (btrfs_leaf_free_space(path->nodes[0]) >= data_size) |
99d8f83c CM |
3616 | return 0; |
3617 | ||
3618 | /* try to push all the items before our slot into the next leaf */ | |
3619 | slot = path->slots[0]; | |
263d3995 FM |
3620 | space_needed = data_size; |
3621 | if (slot > 0) | |
e902baac | 3622 | space_needed -= btrfs_leaf_free_space(path->nodes[0]); |
5a4267ca | 3623 | ret = push_leaf_left(trans, root, path, 1, space_needed, 0, slot); |
99d8f83c CM |
3624 | if (ret < 0) |
3625 | return ret; | |
3626 | ||
3627 | if (ret == 0) | |
3628 | progress++; | |
3629 | ||
3630 | if (progress) | |
3631 | return 0; | |
3632 | return 1; | |
3633 | } | |
3634 | ||
74123bd7 CM |
3635 | /* |
3636 | * split the path's leaf in two, making sure there is at least data_size | |
3637 | * available for the resulting leaf level of the path. | |
aa5d6bed CM |
3638 | * |
3639 | * returns 0 if all went well and < 0 on failure. | |
74123bd7 | 3640 | */ |
e02119d5 CM |
3641 | static noinline int split_leaf(struct btrfs_trans_handle *trans, |
3642 | struct btrfs_root *root, | |
310712b2 | 3643 | const struct btrfs_key *ins_key, |
e02119d5 CM |
3644 | struct btrfs_path *path, int data_size, |
3645 | int extend) | |
be0e5c09 | 3646 | { |
5d4f98a2 | 3647 | struct btrfs_disk_key disk_key; |
5f39d397 | 3648 | struct extent_buffer *l; |
7518a238 | 3649 | u32 nritems; |
eb60ceac CM |
3650 | int mid; |
3651 | int slot; | |
5f39d397 | 3652 | struct extent_buffer *right; |
b7a0365e | 3653 | struct btrfs_fs_info *fs_info = root->fs_info; |
d4dbff95 | 3654 | int ret = 0; |
aa5d6bed | 3655 | int wret; |
5d4f98a2 | 3656 | int split; |
cc0c5538 | 3657 | int num_doubles = 0; |
99d8f83c | 3658 | int tried_avoid_double = 0; |
aa5d6bed | 3659 | |
a5719521 YZ |
3660 | l = path->nodes[0]; |
3661 | slot = path->slots[0]; | |
3212fa14 | 3662 | if (extend && data_size + btrfs_item_size(l, slot) + |
0b246afa | 3663 | sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(fs_info)) |
a5719521 YZ |
3664 | return -EOVERFLOW; |
3665 | ||
40689478 | 3666 | /* first try to make some room by pushing left and right */ |
33157e05 | 3667 | if (data_size && path->nodes[1]) { |
5a4267ca FDBM |
3668 | int space_needed = data_size; |
3669 | ||
3670 | if (slot < btrfs_header_nritems(l)) | |
e902baac | 3671 | space_needed -= btrfs_leaf_free_space(l); |
5a4267ca FDBM |
3672 | |
3673 | wret = push_leaf_right(trans, root, path, space_needed, | |
3674 | space_needed, 0, 0); | |
d397712b | 3675 | if (wret < 0) |
eaee50e8 | 3676 | return wret; |
3685f791 | 3677 | if (wret) { |
263d3995 FM |
3678 | space_needed = data_size; |
3679 | if (slot > 0) | |
e902baac | 3680 | space_needed -= btrfs_leaf_free_space(l); |
5a4267ca FDBM |
3681 | wret = push_leaf_left(trans, root, path, space_needed, |
3682 | space_needed, 0, (u32)-1); | |
3685f791 CM |
3683 | if (wret < 0) |
3684 | return wret; | |
3685 | } | |
3686 | l = path->nodes[0]; | |
aa5d6bed | 3687 | |
3685f791 | 3688 | /* did the pushes work? */ |
e902baac | 3689 | if (btrfs_leaf_free_space(l) >= data_size) |
3685f791 | 3690 | return 0; |
3326d1b0 | 3691 | } |
aa5d6bed | 3692 | |
5c680ed6 | 3693 | if (!path->nodes[1]) { |
fdd99c72 | 3694 | ret = insert_new_root(trans, root, path, 1); |
5c680ed6 CM |
3695 | if (ret) |
3696 | return ret; | |
3697 | } | |
cc0c5538 | 3698 | again: |
5d4f98a2 | 3699 | split = 1; |
cc0c5538 | 3700 | l = path->nodes[0]; |
eb60ceac | 3701 | slot = path->slots[0]; |
5f39d397 | 3702 | nritems = btrfs_header_nritems(l); |
d397712b | 3703 | mid = (nritems + 1) / 2; |
54aa1f4d | 3704 | |
5d4f98a2 YZ |
3705 | if (mid <= slot) { |
3706 | if (nritems == 1 || | |
3707 | leaf_space_used(l, mid, nritems - mid) + data_size > | |
0b246afa | 3708 | BTRFS_LEAF_DATA_SIZE(fs_info)) { |
5d4f98a2 YZ |
3709 | if (slot >= nritems) { |
3710 | split = 0; | |
3711 | } else { | |
3712 | mid = slot; | |
3713 | if (mid != nritems && | |
3714 | leaf_space_used(l, mid, nritems - mid) + | |
0b246afa | 3715 | data_size > BTRFS_LEAF_DATA_SIZE(fs_info)) { |
99d8f83c CM |
3716 | if (data_size && !tried_avoid_double) |
3717 | goto push_for_double; | |
5d4f98a2 YZ |
3718 | split = 2; |
3719 | } | |
3720 | } | |
3721 | } | |
3722 | } else { | |
3723 | if (leaf_space_used(l, 0, mid) + data_size > | |
0b246afa | 3724 | BTRFS_LEAF_DATA_SIZE(fs_info)) { |
5d4f98a2 YZ |
3725 | if (!extend && data_size && slot == 0) { |
3726 | split = 0; | |
3727 | } else if ((extend || !data_size) && slot == 0) { | |
3728 | mid = 1; | |
3729 | } else { | |
3730 | mid = slot; | |
3731 | if (mid != nritems && | |
3732 | leaf_space_used(l, mid, nritems - mid) + | |
0b246afa | 3733 | data_size > BTRFS_LEAF_DATA_SIZE(fs_info)) { |
99d8f83c CM |
3734 | if (data_size && !tried_avoid_double) |
3735 | goto push_for_double; | |
67871254 | 3736 | split = 2; |
5d4f98a2 YZ |
3737 | } |
3738 | } | |
3739 | } | |
3740 | } | |
3741 | ||
3742 | if (split == 0) | |
3743 | btrfs_cpu_key_to_disk(&disk_key, ins_key); | |
3744 | else | |
3745 | btrfs_item_key(l, &disk_key, mid); | |
3746 | ||
ca9d473a JB |
3747 | /* |
3748 | * We have to about BTRFS_NESTING_NEW_ROOT here if we've done a double | |
3749 | * split, because we're only allowed to have MAX_LOCKDEP_SUBCLASSES | |
3750 | * subclasses, which is 8 at the time of this patch, and we've maxed it | |
3751 | * out. In the future we could add a | |
3752 | * BTRFS_NESTING_SPLIT_THE_SPLITTENING if we need to, but for now just | |
3753 | * use BTRFS_NESTING_NEW_ROOT. | |
3754 | */ | |
79bd3712 | 3755 | right = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid, |
60ea105a | 3756 | &disk_key, 0, l->start, 0, 0, |
79bd3712 FM |
3757 | num_doubles ? BTRFS_NESTING_NEW_ROOT : |
3758 | BTRFS_NESTING_SPLIT); | |
f0486c68 | 3759 | if (IS_ERR(right)) |
5f39d397 | 3760 | return PTR_ERR(right); |
f0486c68 | 3761 | |
02cd00fa | 3762 | root_add_used_bytes(root); |
5f39d397 | 3763 | |
5d4f98a2 YZ |
3764 | if (split == 0) { |
3765 | if (mid <= slot) { | |
3766 | btrfs_set_header_nritems(right, 0); | |
50b5d1fc FM |
3767 | ret = insert_ptr(trans, path, &disk_key, |
3768 | right->start, path->slots[1] + 1, 1); | |
3769 | if (ret < 0) { | |
3770 | btrfs_tree_unlock(right); | |
3771 | free_extent_buffer(right); | |
3772 | return ret; | |
3773 | } | |
5d4f98a2 YZ |
3774 | btrfs_tree_unlock(path->nodes[0]); |
3775 | free_extent_buffer(path->nodes[0]); | |
3776 | path->nodes[0] = right; | |
3777 | path->slots[0] = 0; | |
3778 | path->slots[1] += 1; | |
3779 | } else { | |
3780 | btrfs_set_header_nritems(right, 0); | |
50b5d1fc FM |
3781 | ret = insert_ptr(trans, path, &disk_key, |
3782 | right->start, path->slots[1], 1); | |
3783 | if (ret < 0) { | |
3784 | btrfs_tree_unlock(right); | |
3785 | free_extent_buffer(right); | |
3786 | return ret; | |
3787 | } | |
5d4f98a2 YZ |
3788 | btrfs_tree_unlock(path->nodes[0]); |
3789 | free_extent_buffer(path->nodes[0]); | |
3790 | path->nodes[0] = right; | |
3791 | path->slots[0] = 0; | |
143bede5 | 3792 | if (path->slots[1] == 0) |
50564b65 | 3793 | fixup_low_keys(trans, path, &disk_key, 1); |
d4dbff95 | 3794 | } |
196e0249 LB |
3795 | /* |
3796 | * We create a new leaf 'right' for the required ins_len and | |
3797 | * we'll do btrfs_mark_buffer_dirty() on this leaf after copying | |
3798 | * the content of ins_len to 'right'. | |
3799 | */ | |
5d4f98a2 | 3800 | return ret; |
d4dbff95 | 3801 | } |
74123bd7 | 3802 | |
50b5d1fc FM |
3803 | ret = copy_for_split(trans, path, l, right, slot, mid, nritems); |
3804 | if (ret < 0) { | |
3805 | btrfs_tree_unlock(right); | |
3806 | free_extent_buffer(right); | |
3807 | return ret; | |
3808 | } | |
31840ae1 | 3809 | |
5d4f98a2 | 3810 | if (split == 2) { |
cc0c5538 CM |
3811 | BUG_ON(num_doubles != 0); |
3812 | num_doubles++; | |
3813 | goto again; | |
a429e513 | 3814 | } |
44871b1b | 3815 | |
143bede5 | 3816 | return 0; |
99d8f83c CM |
3817 | |
3818 | push_for_double: | |
3819 | push_for_double_split(trans, root, path, data_size); | |
3820 | tried_avoid_double = 1; | |
e902baac | 3821 | if (btrfs_leaf_free_space(path->nodes[0]) >= data_size) |
99d8f83c CM |
3822 | return 0; |
3823 | goto again; | |
be0e5c09 CM |
3824 | } |
3825 | ||
ad48fd75 YZ |
3826 | static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans, |
3827 | struct btrfs_root *root, | |
3828 | struct btrfs_path *path, int ins_len) | |
459931ec | 3829 | { |
ad48fd75 | 3830 | struct btrfs_key key; |
459931ec | 3831 | struct extent_buffer *leaf; |
ad48fd75 YZ |
3832 | struct btrfs_file_extent_item *fi; |
3833 | u64 extent_len = 0; | |
3834 | u32 item_size; | |
3835 | int ret; | |
459931ec CM |
3836 | |
3837 | leaf = path->nodes[0]; | |
ad48fd75 YZ |
3838 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
3839 | ||
3840 | BUG_ON(key.type != BTRFS_EXTENT_DATA_KEY && | |
3841 | key.type != BTRFS_EXTENT_CSUM_KEY); | |
3842 | ||
e902baac | 3843 | if (btrfs_leaf_free_space(leaf) >= ins_len) |
ad48fd75 | 3844 | return 0; |
459931ec | 3845 | |
3212fa14 | 3846 | item_size = btrfs_item_size(leaf, path->slots[0]); |
ad48fd75 YZ |
3847 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
3848 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
3849 | struct btrfs_file_extent_item); | |
3850 | extent_len = btrfs_file_extent_num_bytes(leaf, fi); | |
3851 | } | |
b3b4aa74 | 3852 | btrfs_release_path(path); |
459931ec | 3853 | |
459931ec | 3854 | path->keep_locks = 1; |
ad48fd75 YZ |
3855 | path->search_for_split = 1; |
3856 | ret = btrfs_search_slot(trans, root, &key, path, 0, 1); | |
459931ec | 3857 | path->search_for_split = 0; |
a8df6fe6 FM |
3858 | if (ret > 0) |
3859 | ret = -EAGAIN; | |
ad48fd75 YZ |
3860 | if (ret < 0) |
3861 | goto err; | |
459931ec | 3862 | |
ad48fd75 YZ |
3863 | ret = -EAGAIN; |
3864 | leaf = path->nodes[0]; | |
a8df6fe6 | 3865 | /* if our item isn't there, return now */ |
3212fa14 | 3866 | if (item_size != btrfs_item_size(leaf, path->slots[0])) |
ad48fd75 YZ |
3867 | goto err; |
3868 | ||
109f6aef | 3869 | /* the leaf has changed, it now has room. return now */ |
e902baac | 3870 | if (btrfs_leaf_free_space(path->nodes[0]) >= ins_len) |
109f6aef CM |
3871 | goto err; |
3872 | ||
ad48fd75 YZ |
3873 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
3874 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
3875 | struct btrfs_file_extent_item); | |
3876 | if (extent_len != btrfs_file_extent_num_bytes(leaf, fi)) | |
3877 | goto err; | |
459931ec CM |
3878 | } |
3879 | ||
ad48fd75 | 3880 | ret = split_leaf(trans, root, &key, path, ins_len, 1); |
f0486c68 YZ |
3881 | if (ret) |
3882 | goto err; | |
459931ec | 3883 | |
ad48fd75 | 3884 | path->keep_locks = 0; |
b9473439 | 3885 | btrfs_unlock_up_safe(path, 1); |
ad48fd75 YZ |
3886 | return 0; |
3887 | err: | |
3888 | path->keep_locks = 0; | |
3889 | return ret; | |
3890 | } | |
3891 | ||
50564b65 FM |
3892 | static noinline int split_item(struct btrfs_trans_handle *trans, |
3893 | struct btrfs_path *path, | |
310712b2 | 3894 | const struct btrfs_key *new_key, |
ad48fd75 YZ |
3895 | unsigned long split_offset) |
3896 | { | |
3897 | struct extent_buffer *leaf; | |
c91666b1 | 3898 | int orig_slot, slot; |
ad48fd75 YZ |
3899 | char *buf; |
3900 | u32 nritems; | |
3901 | u32 item_size; | |
3902 | u32 orig_offset; | |
3903 | struct btrfs_disk_key disk_key; | |
3904 | ||
b9473439 | 3905 | leaf = path->nodes[0]; |
7569141e FM |
3906 | /* |
3907 | * Shouldn't happen because the caller must have previously called | |
3908 | * setup_leaf_for_split() to make room for the new item in the leaf. | |
3909 | */ | |
3910 | if (WARN_ON(btrfs_leaf_free_space(leaf) < sizeof(struct btrfs_item))) | |
3911 | return -ENOSPC; | |
b9473439 | 3912 | |
c91666b1 | 3913 | orig_slot = path->slots[0]; |
3212fa14 JB |
3914 | orig_offset = btrfs_item_offset(leaf, path->slots[0]); |
3915 | item_size = btrfs_item_size(leaf, path->slots[0]); | |
459931ec | 3916 | |
459931ec | 3917 | buf = kmalloc(item_size, GFP_NOFS); |
ad48fd75 YZ |
3918 | if (!buf) |
3919 | return -ENOMEM; | |
3920 | ||
459931ec CM |
3921 | read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf, |
3922 | path->slots[0]), item_size); | |
459931ec | 3923 | |
ad48fd75 | 3924 | slot = path->slots[0] + 1; |
459931ec | 3925 | nritems = btrfs_header_nritems(leaf); |
459931ec CM |
3926 | if (slot != nritems) { |
3927 | /* shift the items */ | |
637e3b48 | 3928 | memmove_leaf_items(leaf, slot + 1, slot, nritems - slot); |
459931ec CM |
3929 | } |
3930 | ||
3931 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
3932 | btrfs_set_item_key(leaf, &disk_key, slot); | |
3933 | ||
3212fa14 JB |
3934 | btrfs_set_item_offset(leaf, slot, orig_offset); |
3935 | btrfs_set_item_size(leaf, slot, item_size - split_offset); | |
459931ec | 3936 | |
3212fa14 | 3937 | btrfs_set_item_offset(leaf, orig_slot, |
c91666b1 | 3938 | orig_offset + item_size - split_offset); |
3212fa14 | 3939 | btrfs_set_item_size(leaf, orig_slot, split_offset); |
459931ec CM |
3940 | |
3941 | btrfs_set_header_nritems(leaf, nritems + 1); | |
3942 | ||
3943 | /* write the data for the start of the original item */ | |
3944 | write_extent_buffer(leaf, buf, | |
3945 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
3946 | split_offset); | |
3947 | ||
3948 | /* write the data for the new item */ | |
3949 | write_extent_buffer(leaf, buf + split_offset, | |
3950 | btrfs_item_ptr_offset(leaf, slot), | |
3951 | item_size - split_offset); | |
50564b65 | 3952 | btrfs_mark_buffer_dirty(trans, leaf); |
459931ec | 3953 | |
e902baac | 3954 | BUG_ON(btrfs_leaf_free_space(leaf) < 0); |
459931ec | 3955 | kfree(buf); |
ad48fd75 YZ |
3956 | return 0; |
3957 | } | |
3958 | ||
3959 | /* | |
3960 | * This function splits a single item into two items, | |
3961 | * giving 'new_key' to the new item and splitting the | |
3962 | * old one at split_offset (from the start of the item). | |
3963 | * | |
3964 | * The path may be released by this operation. After | |
3965 | * the split, the path is pointing to the old item. The | |
3966 | * new item is going to be in the same node as the old one. | |
3967 | * | |
3968 | * Note, the item being split must be smaller enough to live alone on | |
3969 | * a tree block with room for one extra struct btrfs_item | |
3970 | * | |
3971 | * This allows us to split the item in place, keeping a lock on the | |
3972 | * leaf the entire time. | |
3973 | */ | |
3974 | int btrfs_split_item(struct btrfs_trans_handle *trans, | |
3975 | struct btrfs_root *root, | |
3976 | struct btrfs_path *path, | |
310712b2 | 3977 | const struct btrfs_key *new_key, |
ad48fd75 YZ |
3978 | unsigned long split_offset) |
3979 | { | |
3980 | int ret; | |
3981 | ret = setup_leaf_for_split(trans, root, path, | |
3982 | sizeof(struct btrfs_item)); | |
3983 | if (ret) | |
3984 | return ret; | |
3985 | ||
50564b65 | 3986 | ret = split_item(trans, path, new_key, split_offset); |
459931ec CM |
3987 | return ret; |
3988 | } | |
3989 | ||
d352ac68 CM |
3990 | /* |
3991 | * make the item pointed to by the path smaller. new_size indicates | |
3992 | * how small to make it, and from_end tells us if we just chop bytes | |
3993 | * off the end of the item or if we shift the item to chop bytes off | |
3994 | * the front. | |
3995 | */ | |
50564b65 FM |
3996 | void btrfs_truncate_item(struct btrfs_trans_handle *trans, |
3997 | struct btrfs_path *path, u32 new_size, int from_end) | |
b18c6685 | 3998 | { |
b18c6685 | 3999 | int slot; |
5f39d397 | 4000 | struct extent_buffer *leaf; |
b18c6685 CM |
4001 | u32 nritems; |
4002 | unsigned int data_end; | |
4003 | unsigned int old_data_start; | |
4004 | unsigned int old_size; | |
4005 | unsigned int size_diff; | |
4006 | int i; | |
cfed81a0 CM |
4007 | struct btrfs_map_token token; |
4008 | ||
5f39d397 | 4009 | leaf = path->nodes[0]; |
179e29e4 CM |
4010 | slot = path->slots[0]; |
4011 | ||
3212fa14 | 4012 | old_size = btrfs_item_size(leaf, slot); |
179e29e4 | 4013 | if (old_size == new_size) |
143bede5 | 4014 | return; |
b18c6685 | 4015 | |
5f39d397 | 4016 | nritems = btrfs_header_nritems(leaf); |
8f881e8c | 4017 | data_end = leaf_data_end(leaf); |
b18c6685 | 4018 | |
3212fa14 | 4019 | old_data_start = btrfs_item_offset(leaf, slot); |
179e29e4 | 4020 | |
b18c6685 CM |
4021 | size_diff = old_size - new_size; |
4022 | ||
4023 | BUG_ON(slot < 0); | |
4024 | BUG_ON(slot >= nritems); | |
4025 | ||
4026 | /* | |
4027 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
4028 | */ | |
4029 | /* first correct the data pointers */ | |
c82f823c | 4030 | btrfs_init_map_token(&token, leaf); |
b18c6685 | 4031 | for (i = slot; i < nritems; i++) { |
5f39d397 | 4032 | u32 ioff; |
db94535d | 4033 | |
3212fa14 JB |
4034 | ioff = btrfs_token_item_offset(&token, i); |
4035 | btrfs_set_token_item_offset(&token, i, ioff + size_diff); | |
b18c6685 | 4036 | } |
db94535d | 4037 | |
b18c6685 | 4038 | /* shift the data */ |
179e29e4 | 4039 | if (from_end) { |
637e3b48 JB |
4040 | memmove_leaf_data(leaf, data_end + size_diff, data_end, |
4041 | old_data_start + new_size - data_end); | |
179e29e4 CM |
4042 | } else { |
4043 | struct btrfs_disk_key disk_key; | |
4044 | u64 offset; | |
4045 | ||
4046 | btrfs_item_key(leaf, &disk_key, slot); | |
4047 | ||
4048 | if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) { | |
4049 | unsigned long ptr; | |
4050 | struct btrfs_file_extent_item *fi; | |
4051 | ||
4052 | fi = btrfs_item_ptr(leaf, slot, | |
4053 | struct btrfs_file_extent_item); | |
4054 | fi = (struct btrfs_file_extent_item *)( | |
4055 | (unsigned long)fi - size_diff); | |
4056 | ||
4057 | if (btrfs_file_extent_type(leaf, fi) == | |
4058 | BTRFS_FILE_EXTENT_INLINE) { | |
4059 | ptr = btrfs_item_ptr_offset(leaf, slot); | |
4060 | memmove_extent_buffer(leaf, ptr, | |
d397712b | 4061 | (unsigned long)fi, |
7ec20afb | 4062 | BTRFS_FILE_EXTENT_INLINE_DATA_START); |
179e29e4 CM |
4063 | } |
4064 | } | |
4065 | ||
637e3b48 JB |
4066 | memmove_leaf_data(leaf, data_end + size_diff, data_end, |
4067 | old_data_start - data_end); | |
179e29e4 CM |
4068 | |
4069 | offset = btrfs_disk_key_offset(&disk_key); | |
4070 | btrfs_set_disk_key_offset(&disk_key, offset + size_diff); | |
4071 | btrfs_set_item_key(leaf, &disk_key, slot); | |
4072 | if (slot == 0) | |
50564b65 | 4073 | fixup_low_keys(trans, path, &disk_key, 1); |
179e29e4 | 4074 | } |
5f39d397 | 4075 | |
3212fa14 | 4076 | btrfs_set_item_size(leaf, slot, new_size); |
50564b65 | 4077 | btrfs_mark_buffer_dirty(trans, leaf); |
b18c6685 | 4078 | |
e902baac | 4079 | if (btrfs_leaf_free_space(leaf) < 0) { |
a4f78750 | 4080 | btrfs_print_leaf(leaf); |
b18c6685 | 4081 | BUG(); |
5f39d397 | 4082 | } |
b18c6685 CM |
4083 | } |
4084 | ||
d352ac68 | 4085 | /* |
8f69dbd2 | 4086 | * make the item pointed to by the path bigger, data_size is the added size. |
d352ac68 | 4087 | */ |
50564b65 FM |
4088 | void btrfs_extend_item(struct btrfs_trans_handle *trans, |
4089 | struct btrfs_path *path, u32 data_size) | |
6567e837 | 4090 | { |
6567e837 | 4091 | int slot; |
5f39d397 | 4092 | struct extent_buffer *leaf; |
6567e837 CM |
4093 | u32 nritems; |
4094 | unsigned int data_end; | |
4095 | unsigned int old_data; | |
4096 | unsigned int old_size; | |
4097 | int i; | |
cfed81a0 CM |
4098 | struct btrfs_map_token token; |
4099 | ||
5f39d397 | 4100 | leaf = path->nodes[0]; |
6567e837 | 4101 | |
5f39d397 | 4102 | nritems = btrfs_header_nritems(leaf); |
8f881e8c | 4103 | data_end = leaf_data_end(leaf); |
6567e837 | 4104 | |
e902baac | 4105 | if (btrfs_leaf_free_space(leaf) < data_size) { |
a4f78750 | 4106 | btrfs_print_leaf(leaf); |
6567e837 | 4107 | BUG(); |
5f39d397 | 4108 | } |
6567e837 | 4109 | slot = path->slots[0]; |
dc2e724e | 4110 | old_data = btrfs_item_data_end(leaf, slot); |
6567e837 CM |
4111 | |
4112 | BUG_ON(slot < 0); | |
3326d1b0 | 4113 | if (slot >= nritems) { |
a4f78750 | 4114 | btrfs_print_leaf(leaf); |
c71dd880 | 4115 | btrfs_crit(leaf->fs_info, "slot %d too large, nritems %d", |
0b246afa | 4116 | slot, nritems); |
290342f6 | 4117 | BUG(); |
3326d1b0 | 4118 | } |
6567e837 CM |
4119 | |
4120 | /* | |
4121 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
4122 | */ | |
4123 | /* first correct the data pointers */ | |
c82f823c | 4124 | btrfs_init_map_token(&token, leaf); |
6567e837 | 4125 | for (i = slot; i < nritems; i++) { |
5f39d397 | 4126 | u32 ioff; |
db94535d | 4127 | |
3212fa14 JB |
4128 | ioff = btrfs_token_item_offset(&token, i); |
4129 | btrfs_set_token_item_offset(&token, i, ioff - data_size); | |
6567e837 | 4130 | } |
5f39d397 | 4131 | |
6567e837 | 4132 | /* shift the data */ |
637e3b48 JB |
4133 | memmove_leaf_data(leaf, data_end - data_size, data_end, |
4134 | old_data - data_end); | |
5f39d397 | 4135 | |
6567e837 | 4136 | data_end = old_data; |
3212fa14 JB |
4137 | old_size = btrfs_item_size(leaf, slot); |
4138 | btrfs_set_item_size(leaf, slot, old_size + data_size); | |
50564b65 | 4139 | btrfs_mark_buffer_dirty(trans, leaf); |
6567e837 | 4140 | |
e902baac | 4141 | if (btrfs_leaf_free_space(leaf) < 0) { |
a4f78750 | 4142 | btrfs_print_leaf(leaf); |
6567e837 | 4143 | BUG(); |
5f39d397 | 4144 | } |
6567e837 CM |
4145 | } |
4146 | ||
43dd529a DS |
4147 | /* |
4148 | * Make space in the node before inserting one or more items. | |
da9ffb24 | 4149 | * |
50564b65 | 4150 | * @trans: transaction handle |
da9ffb24 NB |
4151 | * @root: root we are inserting items to |
4152 | * @path: points to the leaf/slot where we are going to insert new items | |
b7ef5f3a | 4153 | * @batch: information about the batch of items to insert |
43dd529a DS |
4154 | * |
4155 | * Main purpose is to save stack depth by doing the bulk of the work in a | |
4156 | * function that doesn't call btrfs_search_slot | |
74123bd7 | 4157 | */ |
50564b65 FM |
4158 | static void setup_items_for_insert(struct btrfs_trans_handle *trans, |
4159 | struct btrfs_root *root, struct btrfs_path *path, | |
f0641656 | 4160 | const struct btrfs_item_batch *batch) |
be0e5c09 | 4161 | { |
0b246afa | 4162 | struct btrfs_fs_info *fs_info = root->fs_info; |
9c58309d | 4163 | int i; |
7518a238 | 4164 | u32 nritems; |
be0e5c09 | 4165 | unsigned int data_end; |
e2fa7227 | 4166 | struct btrfs_disk_key disk_key; |
44871b1b CM |
4167 | struct extent_buffer *leaf; |
4168 | int slot; | |
cfed81a0 | 4169 | struct btrfs_map_token token; |
fc0d82e1 | 4170 | u32 total_size; |
cfed81a0 | 4171 | |
b7ef5f3a FM |
4172 | /* |
4173 | * Before anything else, update keys in the parent and other ancestors | |
4174 | * if needed, then release the write locks on them, so that other tasks | |
4175 | * can use them while we modify the leaf. | |
4176 | */ | |
24cdc847 | 4177 | if (path->slots[0] == 0) { |
b7ef5f3a | 4178 | btrfs_cpu_key_to_disk(&disk_key, &batch->keys[0]); |
50564b65 | 4179 | fixup_low_keys(trans, path, &disk_key, 1); |
24cdc847 FM |
4180 | } |
4181 | btrfs_unlock_up_safe(path, 1); | |
4182 | ||
5f39d397 | 4183 | leaf = path->nodes[0]; |
44871b1b | 4184 | slot = path->slots[0]; |
74123bd7 | 4185 | |
5f39d397 | 4186 | nritems = btrfs_header_nritems(leaf); |
8f881e8c | 4187 | data_end = leaf_data_end(leaf); |
b7ef5f3a | 4188 | total_size = batch->total_data_size + (batch->nr * sizeof(struct btrfs_item)); |
eb60ceac | 4189 | |
e902baac | 4190 | if (btrfs_leaf_free_space(leaf) < total_size) { |
a4f78750 | 4191 | btrfs_print_leaf(leaf); |
0b246afa | 4192 | btrfs_crit(fs_info, "not enough freespace need %u have %d", |
e902baac | 4193 | total_size, btrfs_leaf_free_space(leaf)); |
be0e5c09 | 4194 | BUG(); |
d4dbff95 | 4195 | } |
5f39d397 | 4196 | |
c82f823c | 4197 | btrfs_init_map_token(&token, leaf); |
be0e5c09 | 4198 | if (slot != nritems) { |
dc2e724e | 4199 | unsigned int old_data = btrfs_item_data_end(leaf, slot); |
be0e5c09 | 4200 | |
5f39d397 | 4201 | if (old_data < data_end) { |
a4f78750 | 4202 | btrfs_print_leaf(leaf); |
7269ddd2 NB |
4203 | btrfs_crit(fs_info, |
4204 | "item at slot %d with data offset %u beyond data end of leaf %u", | |
5d163e0e | 4205 | slot, old_data, data_end); |
290342f6 | 4206 | BUG(); |
5f39d397 | 4207 | } |
be0e5c09 CM |
4208 | /* |
4209 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
4210 | */ | |
4211 | /* first correct the data pointers */ | |
0783fcfc | 4212 | for (i = slot; i < nritems; i++) { |
5f39d397 | 4213 | u32 ioff; |
db94535d | 4214 | |
3212fa14 JB |
4215 | ioff = btrfs_token_item_offset(&token, i); |
4216 | btrfs_set_token_item_offset(&token, i, | |
74794207 | 4217 | ioff - batch->total_data_size); |
0783fcfc | 4218 | } |
be0e5c09 | 4219 | /* shift the items */ |
637e3b48 | 4220 | memmove_leaf_items(leaf, slot + batch->nr, slot, nritems - slot); |
be0e5c09 CM |
4221 | |
4222 | /* shift the data */ | |
637e3b48 JB |
4223 | memmove_leaf_data(leaf, data_end - batch->total_data_size, |
4224 | data_end, old_data - data_end); | |
be0e5c09 CM |
4225 | data_end = old_data; |
4226 | } | |
5f39d397 | 4227 | |
62e2749e | 4228 | /* setup the item for the new data */ |
b7ef5f3a FM |
4229 | for (i = 0; i < batch->nr; i++) { |
4230 | btrfs_cpu_key_to_disk(&disk_key, &batch->keys[i]); | |
9c58309d | 4231 | btrfs_set_item_key(leaf, &disk_key, slot + i); |
b7ef5f3a | 4232 | data_end -= batch->data_sizes[i]; |
3212fa14 JB |
4233 | btrfs_set_token_item_offset(&token, slot + i, data_end); |
4234 | btrfs_set_token_item_size(&token, slot + i, batch->data_sizes[i]); | |
9c58309d | 4235 | } |
44871b1b | 4236 | |
b7ef5f3a | 4237 | btrfs_set_header_nritems(leaf, nritems + batch->nr); |
50564b65 | 4238 | btrfs_mark_buffer_dirty(trans, leaf); |
aa5d6bed | 4239 | |
e902baac | 4240 | if (btrfs_leaf_free_space(leaf) < 0) { |
a4f78750 | 4241 | btrfs_print_leaf(leaf); |
be0e5c09 | 4242 | BUG(); |
5f39d397 | 4243 | } |
44871b1b CM |
4244 | } |
4245 | ||
f0641656 FM |
4246 | /* |
4247 | * Insert a new item into a leaf. | |
4248 | * | |
50564b65 | 4249 | * @trans: Transaction handle. |
f0641656 FM |
4250 | * @root: The root of the btree. |
4251 | * @path: A path pointing to the target leaf and slot. | |
4252 | * @key: The key of the new item. | |
4253 | * @data_size: The size of the data associated with the new key. | |
4254 | */ | |
50564b65 FM |
4255 | void btrfs_setup_item_for_insert(struct btrfs_trans_handle *trans, |
4256 | struct btrfs_root *root, | |
f0641656 FM |
4257 | struct btrfs_path *path, |
4258 | const struct btrfs_key *key, | |
4259 | u32 data_size) | |
4260 | { | |
4261 | struct btrfs_item_batch batch; | |
4262 | ||
4263 | batch.keys = key; | |
4264 | batch.data_sizes = &data_size; | |
4265 | batch.total_data_size = data_size; | |
4266 | batch.nr = 1; | |
4267 | ||
50564b65 | 4268 | setup_items_for_insert(trans, root, path, &batch); |
f0641656 FM |
4269 | } |
4270 | ||
44871b1b CM |
4271 | /* |
4272 | * Given a key and some data, insert items into the tree. | |
4273 | * This does all the path init required, making room in the tree if needed. | |
4274 | */ | |
4275 | int btrfs_insert_empty_items(struct btrfs_trans_handle *trans, | |
4276 | struct btrfs_root *root, | |
4277 | struct btrfs_path *path, | |
b7ef5f3a | 4278 | const struct btrfs_item_batch *batch) |
44871b1b | 4279 | { |
44871b1b CM |
4280 | int ret = 0; |
4281 | int slot; | |
b7ef5f3a | 4282 | u32 total_size; |
44871b1b | 4283 | |
b7ef5f3a FM |
4284 | total_size = batch->total_data_size + (batch->nr * sizeof(struct btrfs_item)); |
4285 | ret = btrfs_search_slot(trans, root, &batch->keys[0], path, total_size, 1); | |
44871b1b CM |
4286 | if (ret == 0) |
4287 | return -EEXIST; | |
4288 | if (ret < 0) | |
143bede5 | 4289 | return ret; |
44871b1b | 4290 | |
44871b1b CM |
4291 | slot = path->slots[0]; |
4292 | BUG_ON(slot < 0); | |
4293 | ||
50564b65 | 4294 | setup_items_for_insert(trans, root, path, batch); |
143bede5 | 4295 | return 0; |
62e2749e CM |
4296 | } |
4297 | ||
4298 | /* | |
4299 | * Given a key and some data, insert an item into the tree. | |
4300 | * This does all the path init required, making room in the tree if needed. | |
4301 | */ | |
310712b2 OS |
4302 | int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
4303 | const struct btrfs_key *cpu_key, void *data, | |
4304 | u32 data_size) | |
62e2749e CM |
4305 | { |
4306 | int ret = 0; | |
2c90e5d6 | 4307 | struct btrfs_path *path; |
5f39d397 CM |
4308 | struct extent_buffer *leaf; |
4309 | unsigned long ptr; | |
62e2749e | 4310 | |
2c90e5d6 | 4311 | path = btrfs_alloc_path(); |
db5b493a TI |
4312 | if (!path) |
4313 | return -ENOMEM; | |
2c90e5d6 | 4314 | ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size); |
62e2749e | 4315 | if (!ret) { |
5f39d397 CM |
4316 | leaf = path->nodes[0]; |
4317 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
4318 | write_extent_buffer(leaf, data, ptr, data_size); | |
50564b65 | 4319 | btrfs_mark_buffer_dirty(trans, leaf); |
62e2749e | 4320 | } |
2c90e5d6 | 4321 | btrfs_free_path(path); |
aa5d6bed | 4322 | return ret; |
be0e5c09 CM |
4323 | } |
4324 | ||
f0641656 FM |
4325 | /* |
4326 | * This function duplicates an item, giving 'new_key' to the new item. | |
4327 | * It guarantees both items live in the same tree leaf and the new item is | |
4328 | * contiguous with the original item. | |
4329 | * | |
4330 | * This allows us to split a file extent in place, keeping a lock on the leaf | |
4331 | * the entire time. | |
4332 | */ | |
4333 | int btrfs_duplicate_item(struct btrfs_trans_handle *trans, | |
4334 | struct btrfs_root *root, | |
4335 | struct btrfs_path *path, | |
4336 | const struct btrfs_key *new_key) | |
4337 | { | |
4338 | struct extent_buffer *leaf; | |
4339 | int ret; | |
4340 | u32 item_size; | |
4341 | ||
4342 | leaf = path->nodes[0]; | |
3212fa14 | 4343 | item_size = btrfs_item_size(leaf, path->slots[0]); |
f0641656 FM |
4344 | ret = setup_leaf_for_split(trans, root, path, |
4345 | item_size + sizeof(struct btrfs_item)); | |
4346 | if (ret) | |
4347 | return ret; | |
4348 | ||
4349 | path->slots[0]++; | |
50564b65 | 4350 | btrfs_setup_item_for_insert(trans, root, path, new_key, item_size); |
f0641656 FM |
4351 | leaf = path->nodes[0]; |
4352 | memcpy_extent_buffer(leaf, | |
4353 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
4354 | btrfs_item_ptr_offset(leaf, path->slots[0] - 1), | |
4355 | item_size); | |
4356 | return 0; | |
4357 | } | |
4358 | ||
74123bd7 | 4359 | /* |
5de08d7d | 4360 | * delete the pointer from a given node. |
74123bd7 | 4361 | * |
d352ac68 CM |
4362 | * the tree should have been previously balanced so the deletion does not |
4363 | * empty a node. | |
016f9d0b JB |
4364 | * |
4365 | * This is exported for use inside btrfs-progs, don't un-export it. | |
74123bd7 | 4366 | */ |
751a2761 FM |
4367 | int btrfs_del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
4368 | struct btrfs_path *path, int level, int slot) | |
be0e5c09 | 4369 | { |
5f39d397 | 4370 | struct extent_buffer *parent = path->nodes[level]; |
7518a238 | 4371 | u32 nritems; |
f3ea38da | 4372 | int ret; |
be0e5c09 | 4373 | |
5f39d397 | 4374 | nritems = btrfs_header_nritems(parent); |
d397712b | 4375 | if (slot != nritems - 1) { |
bf1d3425 | 4376 | if (level) { |
f3a84ccd FM |
4377 | ret = btrfs_tree_mod_log_insert_move(parent, slot, |
4378 | slot + 1, nritems - slot - 1); | |
751a2761 FM |
4379 | if (ret < 0) { |
4380 | btrfs_abort_transaction(trans, ret); | |
4381 | return ret; | |
4382 | } | |
bf1d3425 | 4383 | } |
5f39d397 | 4384 | memmove_extent_buffer(parent, |
e23efd8e JB |
4385 | btrfs_node_key_ptr_offset(parent, slot), |
4386 | btrfs_node_key_ptr_offset(parent, slot + 1), | |
d6025579 CM |
4387 | sizeof(struct btrfs_key_ptr) * |
4388 | (nritems - slot - 1)); | |
57ba86c0 | 4389 | } else if (level) { |
f3a84ccd | 4390 | ret = btrfs_tree_mod_log_insert_key(parent, slot, |
33cff222 | 4391 | BTRFS_MOD_LOG_KEY_REMOVE); |
751a2761 FM |
4392 | if (ret < 0) { |
4393 | btrfs_abort_transaction(trans, ret); | |
4394 | return ret; | |
4395 | } | |
bb803951 | 4396 | } |
f3ea38da | 4397 | |
7518a238 | 4398 | nritems--; |
5f39d397 | 4399 | btrfs_set_header_nritems(parent, nritems); |
7518a238 | 4400 | if (nritems == 0 && parent == root->node) { |
5f39d397 | 4401 | BUG_ON(btrfs_header_level(root->node) != 1); |
bb803951 | 4402 | /* just turn the root into a leaf and break */ |
5f39d397 | 4403 | btrfs_set_header_level(root->node, 0); |
bb803951 | 4404 | } else if (slot == 0) { |
5f39d397 CM |
4405 | struct btrfs_disk_key disk_key; |
4406 | ||
4407 | btrfs_node_key(parent, &disk_key, 0); | |
50564b65 | 4408 | fixup_low_keys(trans, path, &disk_key, level + 1); |
be0e5c09 | 4409 | } |
50564b65 | 4410 | btrfs_mark_buffer_dirty(trans, parent); |
751a2761 | 4411 | return 0; |
be0e5c09 CM |
4412 | } |
4413 | ||
323ac95b CM |
4414 | /* |
4415 | * a helper function to delete the leaf pointed to by path->slots[1] and | |
5d4f98a2 | 4416 | * path->nodes[1]. |
323ac95b CM |
4417 | * |
4418 | * This deletes the pointer in path->nodes[1] and frees the leaf | |
4419 | * block extent. zero is returned if it all worked out, < 0 otherwise. | |
4420 | * | |
4421 | * The path must have already been setup for deleting the leaf, including | |
4422 | * all the proper balancing. path->nodes[1] must be locked. | |
4423 | */ | |
751a2761 FM |
4424 | static noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans, |
4425 | struct btrfs_root *root, | |
4426 | struct btrfs_path *path, | |
4427 | struct extent_buffer *leaf) | |
323ac95b | 4428 | { |
751a2761 FM |
4429 | int ret; |
4430 | ||
5d4f98a2 | 4431 | WARN_ON(btrfs_header_generation(leaf) != trans->transid); |
751a2761 FM |
4432 | ret = btrfs_del_ptr(trans, root, path, 1, path->slots[1]); |
4433 | if (ret < 0) | |
4434 | return ret; | |
323ac95b | 4435 | |
4d081c41 CM |
4436 | /* |
4437 | * btrfs_free_extent is expensive, we want to make sure we | |
4438 | * aren't holding any locks when we call it | |
4439 | */ | |
4440 | btrfs_unlock_up_safe(path, 0); | |
4441 | ||
02cd00fa | 4442 | root_sub_used_bytes(root); |
f0486c68 | 4443 | |
67439dad | 4444 | atomic_inc(&leaf->refs); |
7a163608 | 4445 | btrfs_free_tree_block(trans, btrfs_root_id(root), leaf, 0, 1); |
3083ee2e | 4446 | free_extent_buffer_stale(leaf); |
751a2761 | 4447 | return 0; |
323ac95b | 4448 | } |
74123bd7 CM |
4449 | /* |
4450 | * delete the item at the leaf level in path. If that empties | |
4451 | * the leaf, remove it from the tree | |
4452 | */ | |
85e21bac CM |
4453 | int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
4454 | struct btrfs_path *path, int slot, int nr) | |
be0e5c09 | 4455 | { |
0b246afa | 4456 | struct btrfs_fs_info *fs_info = root->fs_info; |
5f39d397 | 4457 | struct extent_buffer *leaf; |
aa5d6bed CM |
4458 | int ret = 0; |
4459 | int wret; | |
7518a238 | 4460 | u32 nritems; |
be0e5c09 | 4461 | |
5f39d397 | 4462 | leaf = path->nodes[0]; |
5f39d397 | 4463 | nritems = btrfs_header_nritems(leaf); |
be0e5c09 | 4464 | |
85e21bac | 4465 | if (slot + nr != nritems) { |
0cae23b6 FM |
4466 | const u32 last_off = btrfs_item_offset(leaf, slot + nr - 1); |
4467 | const int data_end = leaf_data_end(leaf); | |
c82f823c | 4468 | struct btrfs_map_token token; |
0cae23b6 FM |
4469 | u32 dsize = 0; |
4470 | int i; | |
4471 | ||
4472 | for (i = 0; i < nr; i++) | |
4473 | dsize += btrfs_item_size(leaf, slot + i); | |
5f39d397 | 4474 | |
637e3b48 JB |
4475 | memmove_leaf_data(leaf, data_end + dsize, data_end, |
4476 | last_off - data_end); | |
5f39d397 | 4477 | |
c82f823c | 4478 | btrfs_init_map_token(&token, leaf); |
85e21bac | 4479 | for (i = slot + nr; i < nritems; i++) { |
5f39d397 | 4480 | u32 ioff; |
db94535d | 4481 | |
3212fa14 JB |
4482 | ioff = btrfs_token_item_offset(&token, i); |
4483 | btrfs_set_token_item_offset(&token, i, ioff + dsize); | |
0783fcfc | 4484 | } |
db94535d | 4485 | |
637e3b48 | 4486 | memmove_leaf_items(leaf, slot, slot + nr, nritems - slot - nr); |
be0e5c09 | 4487 | } |
85e21bac CM |
4488 | btrfs_set_header_nritems(leaf, nritems - nr); |
4489 | nritems -= nr; | |
5f39d397 | 4490 | |
74123bd7 | 4491 | /* delete the leaf if we've emptied it */ |
7518a238 | 4492 | if (nritems == 0) { |
5f39d397 CM |
4493 | if (leaf == root->node) { |
4494 | btrfs_set_header_level(leaf, 0); | |
9a8dd150 | 4495 | } else { |
190a8339 | 4496 | btrfs_clear_buffer_dirty(trans, leaf); |
751a2761 FM |
4497 | ret = btrfs_del_leaf(trans, root, path, leaf); |
4498 | if (ret < 0) | |
4499 | return ret; | |
9a8dd150 | 4500 | } |
be0e5c09 | 4501 | } else { |
7518a238 | 4502 | int used = leaf_space_used(leaf, 0, nritems); |
aa5d6bed | 4503 | if (slot == 0) { |
5f39d397 CM |
4504 | struct btrfs_disk_key disk_key; |
4505 | ||
4506 | btrfs_item_key(leaf, &disk_key, 0); | |
50564b65 | 4507 | fixup_low_keys(trans, path, &disk_key, 1); |
aa5d6bed | 4508 | } |
aa5d6bed | 4509 | |
7c4063d1 FM |
4510 | /* |
4511 | * Try to delete the leaf if it is mostly empty. We do this by | |
4512 | * trying to move all its items into its left and right neighbours. | |
4513 | * If we can't move all the items, then we don't delete it - it's | |
4514 | * not ideal, but future insertions might fill the leaf with more | |
4515 | * items, or items from other leaves might be moved later into our | |
4516 | * leaf due to deletions on those leaves. | |
4517 | */ | |
0b246afa | 4518 | if (used < BTRFS_LEAF_DATA_SIZE(fs_info) / 3) { |
7c4063d1 FM |
4519 | u32 min_push_space; |
4520 | ||
be0e5c09 CM |
4521 | /* push_leaf_left fixes the path. |
4522 | * make sure the path still points to our leaf | |
016f9d0b | 4523 | * for possible call to btrfs_del_ptr below |
be0e5c09 | 4524 | */ |
4920c9ac | 4525 | slot = path->slots[1]; |
67439dad | 4526 | atomic_inc(&leaf->refs); |
7c4063d1 FM |
4527 | /* |
4528 | * We want to be able to at least push one item to the | |
4529 | * left neighbour leaf, and that's the first item. | |
4530 | */ | |
4531 | min_push_space = sizeof(struct btrfs_item) + | |
4532 | btrfs_item_size(leaf, 0); | |
4533 | wret = push_leaf_left(trans, root, path, 0, | |
4534 | min_push_space, 1, (u32)-1); | |
54aa1f4d | 4535 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed | 4536 | ret = wret; |
5f39d397 CM |
4537 | |
4538 | if (path->nodes[0] == leaf && | |
4539 | btrfs_header_nritems(leaf)) { | |
7c4063d1 FM |
4540 | /* |
4541 | * If we were not able to push all items from our | |
4542 | * leaf to its left neighbour, then attempt to | |
4543 | * either push all the remaining items to the | |
4544 | * right neighbour or none. There's no advantage | |
4545 | * in pushing only some items, instead of all, as | |
4546 | * it's pointless to end up with a leaf having | |
4547 | * too few items while the neighbours can be full | |
4548 | * or nearly full. | |
4549 | */ | |
4550 | nritems = btrfs_header_nritems(leaf); | |
4551 | min_push_space = leaf_space_used(leaf, 0, nritems); | |
4552 | wret = push_leaf_right(trans, root, path, 0, | |
4553 | min_push_space, 1, 0); | |
54aa1f4d | 4554 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed CM |
4555 | ret = wret; |
4556 | } | |
5f39d397 CM |
4557 | |
4558 | if (btrfs_header_nritems(leaf) == 0) { | |
323ac95b | 4559 | path->slots[1] = slot; |
751a2761 FM |
4560 | ret = btrfs_del_leaf(trans, root, path, leaf); |
4561 | if (ret < 0) | |
4562 | return ret; | |
5f39d397 | 4563 | free_extent_buffer(leaf); |
143bede5 | 4564 | ret = 0; |
5de08d7d | 4565 | } else { |
925baedd CM |
4566 | /* if we're still in the path, make sure |
4567 | * we're dirty. Otherwise, one of the | |
4568 | * push_leaf functions must have already | |
4569 | * dirtied this buffer | |
4570 | */ | |
4571 | if (path->nodes[0] == leaf) | |
50564b65 | 4572 | btrfs_mark_buffer_dirty(trans, leaf); |
5f39d397 | 4573 | free_extent_buffer(leaf); |
be0e5c09 | 4574 | } |
d5719762 | 4575 | } else { |
50564b65 | 4576 | btrfs_mark_buffer_dirty(trans, leaf); |
be0e5c09 CM |
4577 | } |
4578 | } | |
aa5d6bed | 4579 | return ret; |
be0e5c09 CM |
4580 | } |
4581 | ||
3f157a2f CM |
4582 | /* |
4583 | * A helper function to walk down the tree starting at min_key, and looking | |
de78b51a ES |
4584 | * for nodes or leaves that are have a minimum transaction id. |
4585 | * This is used by the btree defrag code, and tree logging | |
3f157a2f CM |
4586 | * |
4587 | * This does not cow, but it does stuff the starting key it finds back | |
4588 | * into min_key, so you can call btrfs_search_slot with cow=1 on the | |
4589 | * key and get a writable path. | |
4590 | * | |
3f157a2f CM |
4591 | * This honors path->lowest_level to prevent descent past a given level |
4592 | * of the tree. | |
4593 | * | |
d352ac68 CM |
4594 | * min_trans indicates the oldest transaction that you are interested |
4595 | * in walking through. Any nodes or leaves older than min_trans are | |
4596 | * skipped over (without reading them). | |
4597 | * | |
3f157a2f CM |
4598 | * returns zero if something useful was found, < 0 on error and 1 if there |
4599 | * was nothing in the tree that matched the search criteria. | |
4600 | */ | |
4601 | int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key, | |
de78b51a | 4602 | struct btrfs_path *path, |
3f157a2f CM |
4603 | u64 min_trans) |
4604 | { | |
4605 | struct extent_buffer *cur; | |
4606 | struct btrfs_key found_key; | |
4607 | int slot; | |
9652480b | 4608 | int sret; |
3f157a2f CM |
4609 | u32 nritems; |
4610 | int level; | |
4611 | int ret = 1; | |
f98de9b9 | 4612 | int keep_locks = path->keep_locks; |
3f157a2f | 4613 | |
c922b016 | 4614 | ASSERT(!path->nowait); |
f98de9b9 | 4615 | path->keep_locks = 1; |
3f157a2f | 4616 | again: |
bd681513 | 4617 | cur = btrfs_read_lock_root_node(root); |
3f157a2f | 4618 | level = btrfs_header_level(cur); |
e02119d5 | 4619 | WARN_ON(path->nodes[level]); |
3f157a2f | 4620 | path->nodes[level] = cur; |
bd681513 | 4621 | path->locks[level] = BTRFS_READ_LOCK; |
3f157a2f CM |
4622 | |
4623 | if (btrfs_header_generation(cur) < min_trans) { | |
4624 | ret = 1; | |
4625 | goto out; | |
4626 | } | |
d397712b | 4627 | while (1) { |
3f157a2f CM |
4628 | nritems = btrfs_header_nritems(cur); |
4629 | level = btrfs_header_level(cur); | |
fdf8d595 | 4630 | sret = btrfs_bin_search(cur, 0, min_key, &slot); |
cbca7d59 FM |
4631 | if (sret < 0) { |
4632 | ret = sret; | |
4633 | goto out; | |
4634 | } | |
3f157a2f | 4635 | |
323ac95b CM |
4636 | /* at the lowest level, we're done, setup the path and exit */ |
4637 | if (level == path->lowest_level) { | |
e02119d5 CM |
4638 | if (slot >= nritems) |
4639 | goto find_next_key; | |
3f157a2f CM |
4640 | ret = 0; |
4641 | path->slots[level] = slot; | |
4642 | btrfs_item_key_to_cpu(cur, &found_key, slot); | |
4643 | goto out; | |
4644 | } | |
9652480b Y |
4645 | if (sret && slot > 0) |
4646 | slot--; | |
3f157a2f | 4647 | /* |
de78b51a | 4648 | * check this node pointer against the min_trans parameters. |
260db43c | 4649 | * If it is too old, skip to the next one. |
3f157a2f | 4650 | */ |
d397712b | 4651 | while (slot < nritems) { |
3f157a2f | 4652 | u64 gen; |
e02119d5 | 4653 | |
3f157a2f CM |
4654 | gen = btrfs_node_ptr_generation(cur, slot); |
4655 | if (gen < min_trans) { | |
4656 | slot++; | |
4657 | continue; | |
4658 | } | |
de78b51a | 4659 | break; |
3f157a2f | 4660 | } |
e02119d5 | 4661 | find_next_key: |
3f157a2f CM |
4662 | /* |
4663 | * we didn't find a candidate key in this node, walk forward | |
4664 | * and find another one | |
4665 | */ | |
4666 | if (slot >= nritems) { | |
e02119d5 CM |
4667 | path->slots[level] = slot; |
4668 | sret = btrfs_find_next_key(root, path, min_key, level, | |
de78b51a | 4669 | min_trans); |
e02119d5 | 4670 | if (sret == 0) { |
b3b4aa74 | 4671 | btrfs_release_path(path); |
3f157a2f CM |
4672 | goto again; |
4673 | } else { | |
4674 | goto out; | |
4675 | } | |
4676 | } | |
4677 | /* save our key for returning back */ | |
4678 | btrfs_node_key_to_cpu(cur, &found_key, slot); | |
4679 | path->slots[level] = slot; | |
4680 | if (level == path->lowest_level) { | |
4681 | ret = 0; | |
3f157a2f CM |
4682 | goto out; |
4683 | } | |
4b231ae4 | 4684 | cur = btrfs_read_node_slot(cur, slot); |
fb770ae4 LB |
4685 | if (IS_ERR(cur)) { |
4686 | ret = PTR_ERR(cur); | |
4687 | goto out; | |
4688 | } | |
3f157a2f | 4689 | |
bd681513 | 4690 | btrfs_tree_read_lock(cur); |
b4ce94de | 4691 | |
bd681513 | 4692 | path->locks[level - 1] = BTRFS_READ_LOCK; |
3f157a2f | 4693 | path->nodes[level - 1] = cur; |
f7c79f30 | 4694 | unlock_up(path, level, 1, 0, NULL); |
3f157a2f CM |
4695 | } |
4696 | out: | |
f98de9b9 FM |
4697 | path->keep_locks = keep_locks; |
4698 | if (ret == 0) { | |
4699 | btrfs_unlock_up_safe(path, path->lowest_level + 1); | |
3f157a2f | 4700 | memcpy(min_key, &found_key, sizeof(found_key)); |
f98de9b9 | 4701 | } |
3f157a2f CM |
4702 | return ret; |
4703 | } | |
4704 | ||
4705 | /* | |
4706 | * this is similar to btrfs_next_leaf, but does not try to preserve | |
4707 | * and fixup the path. It looks for and returns the next key in the | |
de78b51a | 4708 | * tree based on the current path and the min_trans parameters. |
3f157a2f CM |
4709 | * |
4710 | * 0 is returned if another key is found, < 0 if there are any errors | |
4711 | * and 1 is returned if there are no higher keys in the tree | |
4712 | * | |
4713 | * path->keep_locks should be set to 1 on the search made before | |
4714 | * calling this function. | |
4715 | */ | |
e7a84565 | 4716 | int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path, |
de78b51a | 4717 | struct btrfs_key *key, int level, u64 min_trans) |
e7a84565 | 4718 | { |
e7a84565 CM |
4719 | int slot; |
4720 | struct extent_buffer *c; | |
4721 | ||
6a9fb468 | 4722 | WARN_ON(!path->keep_locks && !path->skip_locking); |
d397712b | 4723 | while (level < BTRFS_MAX_LEVEL) { |
e7a84565 CM |
4724 | if (!path->nodes[level]) |
4725 | return 1; | |
4726 | ||
4727 | slot = path->slots[level] + 1; | |
4728 | c = path->nodes[level]; | |
3f157a2f | 4729 | next: |
e7a84565 | 4730 | if (slot >= btrfs_header_nritems(c)) { |
33c66f43 YZ |
4731 | int ret; |
4732 | int orig_lowest; | |
4733 | struct btrfs_key cur_key; | |
4734 | if (level + 1 >= BTRFS_MAX_LEVEL || | |
4735 | !path->nodes[level + 1]) | |
e7a84565 | 4736 | return 1; |
33c66f43 | 4737 | |
6a9fb468 | 4738 | if (path->locks[level + 1] || path->skip_locking) { |
33c66f43 YZ |
4739 | level++; |
4740 | continue; | |
4741 | } | |
4742 | ||
4743 | slot = btrfs_header_nritems(c) - 1; | |
4744 | if (level == 0) | |
4745 | btrfs_item_key_to_cpu(c, &cur_key, slot); | |
4746 | else | |
4747 | btrfs_node_key_to_cpu(c, &cur_key, slot); | |
4748 | ||
4749 | orig_lowest = path->lowest_level; | |
b3b4aa74 | 4750 | btrfs_release_path(path); |
33c66f43 YZ |
4751 | path->lowest_level = level; |
4752 | ret = btrfs_search_slot(NULL, root, &cur_key, path, | |
4753 | 0, 0); | |
4754 | path->lowest_level = orig_lowest; | |
4755 | if (ret < 0) | |
4756 | return ret; | |
4757 | ||
4758 | c = path->nodes[level]; | |
4759 | slot = path->slots[level]; | |
4760 | if (ret == 0) | |
4761 | slot++; | |
4762 | goto next; | |
e7a84565 | 4763 | } |
33c66f43 | 4764 | |
e7a84565 CM |
4765 | if (level == 0) |
4766 | btrfs_item_key_to_cpu(c, key, slot); | |
3f157a2f | 4767 | else { |
3f157a2f CM |
4768 | u64 gen = btrfs_node_ptr_generation(c, slot); |
4769 | ||
3f157a2f CM |
4770 | if (gen < min_trans) { |
4771 | slot++; | |
4772 | goto next; | |
4773 | } | |
e7a84565 | 4774 | btrfs_node_key_to_cpu(c, key, slot); |
3f157a2f | 4775 | } |
e7a84565 CM |
4776 | return 0; |
4777 | } | |
4778 | return 1; | |
4779 | } | |
4780 | ||
3d7806ec JS |
4781 | int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path, |
4782 | u64 time_seq) | |
d97e63b6 CM |
4783 | { |
4784 | int slot; | |
8e73f275 | 4785 | int level; |
5f39d397 | 4786 | struct extent_buffer *c; |
8e73f275 | 4787 | struct extent_buffer *next; |
d96b3424 | 4788 | struct btrfs_fs_info *fs_info = root->fs_info; |
925baedd | 4789 | struct btrfs_key key; |
d96b3424 | 4790 | bool need_commit_sem = false; |
925baedd CM |
4791 | u32 nritems; |
4792 | int ret; | |
0e46318d | 4793 | int i; |
925baedd | 4794 | |
bdcdd86c FM |
4795 | /* |
4796 | * The nowait semantics are used only for write paths, where we don't | |
4797 | * use the tree mod log and sequence numbers. | |
4798 | */ | |
4799 | if (time_seq) | |
4800 | ASSERT(!path->nowait); | |
c922b016 | 4801 | |
925baedd | 4802 | nritems = btrfs_header_nritems(path->nodes[0]); |
d397712b | 4803 | if (nritems == 0) |
925baedd | 4804 | return 1; |
925baedd | 4805 | |
8e73f275 CM |
4806 | btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1); |
4807 | again: | |
4808 | level = 1; | |
4809 | next = NULL; | |
b3b4aa74 | 4810 | btrfs_release_path(path); |
8e73f275 | 4811 | |
a2135011 | 4812 | path->keep_locks = 1; |
8e73f275 | 4813 | |
d96b3424 | 4814 | if (time_seq) { |
3d7806ec | 4815 | ret = btrfs_search_old_slot(root, &key, path, time_seq); |
d96b3424 FM |
4816 | } else { |
4817 | if (path->need_commit_sem) { | |
4818 | path->need_commit_sem = 0; | |
4819 | need_commit_sem = true; | |
bdcdd86c FM |
4820 | if (path->nowait) { |
4821 | if (!down_read_trylock(&fs_info->commit_root_sem)) { | |
4822 | ret = -EAGAIN; | |
4823 | goto done; | |
4824 | } | |
4825 | } else { | |
4826 | down_read(&fs_info->commit_root_sem); | |
4827 | } | |
d96b3424 | 4828 | } |
3d7806ec | 4829 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
d96b3424 | 4830 | } |
925baedd CM |
4831 | path->keep_locks = 0; |
4832 | ||
4833 | if (ret < 0) | |
d96b3424 | 4834 | goto done; |
925baedd | 4835 | |
a2135011 | 4836 | nritems = btrfs_header_nritems(path->nodes[0]); |
168fd7d2 CM |
4837 | /* |
4838 | * by releasing the path above we dropped all our locks. A balance | |
4839 | * could have added more items next to the key that used to be | |
4840 | * at the very end of the block. So, check again here and | |
4841 | * advance the path if there are now more items available. | |
4842 | */ | |
a2135011 | 4843 | if (nritems > 0 && path->slots[0] < nritems - 1) { |
e457afec YZ |
4844 | if (ret == 0) |
4845 | path->slots[0]++; | |
8e73f275 | 4846 | ret = 0; |
925baedd CM |
4847 | goto done; |
4848 | } | |
0b43e04f LB |
4849 | /* |
4850 | * So the above check misses one case: | |
4851 | * - after releasing the path above, someone has removed the item that | |
4852 | * used to be at the very end of the block, and balance between leafs | |
4853 | * gets another one with bigger key.offset to replace it. | |
4854 | * | |
4855 | * This one should be returned as well, or we can get leaf corruption | |
4856 | * later(esp. in __btrfs_drop_extents()). | |
4857 | * | |
4858 | * And a bit more explanation about this check, | |
4859 | * with ret > 0, the key isn't found, the path points to the slot | |
4860 | * where it should be inserted, so the path->slots[0] item must be the | |
4861 | * bigger one. | |
4862 | */ | |
4863 | if (nritems > 0 && ret > 0 && path->slots[0] == nritems - 1) { | |
4864 | ret = 0; | |
4865 | goto done; | |
4866 | } | |
d97e63b6 | 4867 | |
d397712b | 4868 | while (level < BTRFS_MAX_LEVEL) { |
8e73f275 CM |
4869 | if (!path->nodes[level]) { |
4870 | ret = 1; | |
4871 | goto done; | |
4872 | } | |
5f39d397 | 4873 | |
d97e63b6 CM |
4874 | slot = path->slots[level] + 1; |
4875 | c = path->nodes[level]; | |
5f39d397 | 4876 | if (slot >= btrfs_header_nritems(c)) { |
d97e63b6 | 4877 | level++; |
8e73f275 CM |
4878 | if (level == BTRFS_MAX_LEVEL) { |
4879 | ret = 1; | |
4880 | goto done; | |
4881 | } | |
d97e63b6 CM |
4882 | continue; |
4883 | } | |
5f39d397 | 4884 | |
0e46318d JB |
4885 | |
4886 | /* | |
4887 | * Our current level is where we're going to start from, and to | |
4888 | * make sure lockdep doesn't complain we need to drop our locks | |
4889 | * and nodes from 0 to our current level. | |
4890 | */ | |
4891 | for (i = 0; i < level; i++) { | |
4892 | if (path->locks[level]) { | |
4893 | btrfs_tree_read_unlock(path->nodes[i]); | |
4894 | path->locks[i] = 0; | |
4895 | } | |
4896 | free_extent_buffer(path->nodes[i]); | |
4897 | path->nodes[i] = NULL; | |
925baedd | 4898 | } |
5f39d397 | 4899 | |
8e73f275 | 4900 | next = c; |
d07b8528 | 4901 | ret = read_block_for_search(root, path, &next, level, |
cda79c54 | 4902 | slot, &key); |
bdcdd86c | 4903 | if (ret == -EAGAIN && !path->nowait) |
8e73f275 | 4904 | goto again; |
5f39d397 | 4905 | |
76a05b35 | 4906 | if (ret < 0) { |
b3b4aa74 | 4907 | btrfs_release_path(path); |
76a05b35 CM |
4908 | goto done; |
4909 | } | |
4910 | ||
5cd57b2c | 4911 | if (!path->skip_locking) { |
bd681513 | 4912 | ret = btrfs_try_tree_read_lock(next); |
bdcdd86c FM |
4913 | if (!ret && path->nowait) { |
4914 | ret = -EAGAIN; | |
4915 | goto done; | |
4916 | } | |
d42244a0 JS |
4917 | if (!ret && time_seq) { |
4918 | /* | |
4919 | * If we don't get the lock, we may be racing | |
4920 | * with push_leaf_left, holding that lock while | |
4921 | * itself waiting for the leaf we've currently | |
4922 | * locked. To solve this situation, we give up | |
4923 | * on our lock and cycle. | |
4924 | */ | |
cf538830 | 4925 | free_extent_buffer(next); |
d42244a0 JS |
4926 | btrfs_release_path(path); |
4927 | cond_resched(); | |
4928 | goto again; | |
4929 | } | |
0e46318d JB |
4930 | if (!ret) |
4931 | btrfs_tree_read_lock(next); | |
5cd57b2c | 4932 | } |
d97e63b6 CM |
4933 | break; |
4934 | } | |
4935 | path->slots[level] = slot; | |
d397712b | 4936 | while (1) { |
d97e63b6 | 4937 | level--; |
d97e63b6 CM |
4938 | path->nodes[level] = next; |
4939 | path->slots[level] = 0; | |
a74a4b97 | 4940 | if (!path->skip_locking) |
ffeb03cf | 4941 | path->locks[level] = BTRFS_READ_LOCK; |
d97e63b6 CM |
4942 | if (!level) |
4943 | break; | |
b4ce94de | 4944 | |
d07b8528 | 4945 | ret = read_block_for_search(root, path, &next, level, |
cda79c54 | 4946 | 0, &key); |
bdcdd86c | 4947 | if (ret == -EAGAIN && !path->nowait) |
8e73f275 CM |
4948 | goto again; |
4949 | ||
76a05b35 | 4950 | if (ret < 0) { |
b3b4aa74 | 4951 | btrfs_release_path(path); |
76a05b35 CM |
4952 | goto done; |
4953 | } | |
4954 | ||
bdcdd86c FM |
4955 | if (!path->skip_locking) { |
4956 | if (path->nowait) { | |
4957 | if (!btrfs_try_tree_read_lock(next)) { | |
4958 | ret = -EAGAIN; | |
4959 | goto done; | |
4960 | } | |
4961 | } else { | |
4962 | btrfs_tree_read_lock(next); | |
4963 | } | |
4964 | } | |
d97e63b6 | 4965 | } |
8e73f275 | 4966 | ret = 0; |
925baedd | 4967 | done: |
f7c79f30 | 4968 | unlock_up(path, 0, 1, 0, NULL); |
d96b3424 FM |
4969 | if (need_commit_sem) { |
4970 | int ret2; | |
4971 | ||
4972 | path->need_commit_sem = 1; | |
4973 | ret2 = finish_need_commit_sem_search(path); | |
4974 | up_read(&fs_info->commit_root_sem); | |
4975 | if (ret2) | |
4976 | ret = ret2; | |
4977 | } | |
8e73f275 CM |
4978 | |
4979 | return ret; | |
d97e63b6 | 4980 | } |
0b86a832 | 4981 | |
890d2b1a JB |
4982 | int btrfs_next_old_item(struct btrfs_root *root, struct btrfs_path *path, u64 time_seq) |
4983 | { | |
4984 | path->slots[0]++; | |
4985 | if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) | |
4986 | return btrfs_next_old_leaf(root, path, time_seq); | |
4987 | return 0; | |
4988 | } | |
4989 | ||
3f157a2f CM |
4990 | /* |
4991 | * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps | |
4992 | * searching until it gets past min_objectid or finds an item of 'type' | |
4993 | * | |
4994 | * returns 0 if something is found, 1 if nothing was found and < 0 on error | |
4995 | */ | |
0b86a832 CM |
4996 | int btrfs_previous_item(struct btrfs_root *root, |
4997 | struct btrfs_path *path, u64 min_objectid, | |
4998 | int type) | |
4999 | { | |
5000 | struct btrfs_key found_key; | |
5001 | struct extent_buffer *leaf; | |
e02119d5 | 5002 | u32 nritems; |
0b86a832 CM |
5003 | int ret; |
5004 | ||
d397712b | 5005 | while (1) { |
0b86a832 CM |
5006 | if (path->slots[0] == 0) { |
5007 | ret = btrfs_prev_leaf(root, path); | |
5008 | if (ret != 0) | |
5009 | return ret; | |
5010 | } else { | |
5011 | path->slots[0]--; | |
5012 | } | |
5013 | leaf = path->nodes[0]; | |
e02119d5 CM |
5014 | nritems = btrfs_header_nritems(leaf); |
5015 | if (nritems == 0) | |
5016 | return 1; | |
5017 | if (path->slots[0] == nritems) | |
5018 | path->slots[0]--; | |
5019 | ||
0b86a832 | 5020 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
e02119d5 CM |
5021 | if (found_key.objectid < min_objectid) |
5022 | break; | |
0a4eefbb YZ |
5023 | if (found_key.type == type) |
5024 | return 0; | |
e02119d5 CM |
5025 | if (found_key.objectid == min_objectid && |
5026 | found_key.type < type) | |
5027 | break; | |
0b86a832 CM |
5028 | } |
5029 | return 1; | |
5030 | } | |
ade2e0b3 WS |
5031 | |
5032 | /* | |
5033 | * search in extent tree to find a previous Metadata/Data extent item with | |
5034 | * min objecitd. | |
5035 | * | |
5036 | * returns 0 if something is found, 1 if nothing was found and < 0 on error | |
5037 | */ | |
5038 | int btrfs_previous_extent_item(struct btrfs_root *root, | |
5039 | struct btrfs_path *path, u64 min_objectid) | |
5040 | { | |
5041 | struct btrfs_key found_key; | |
5042 | struct extent_buffer *leaf; | |
5043 | u32 nritems; | |
5044 | int ret; | |
5045 | ||
5046 | while (1) { | |
5047 | if (path->slots[0] == 0) { | |
ade2e0b3 WS |
5048 | ret = btrfs_prev_leaf(root, path); |
5049 | if (ret != 0) | |
5050 | return ret; | |
5051 | } else { | |
5052 | path->slots[0]--; | |
5053 | } | |
5054 | leaf = path->nodes[0]; | |
5055 | nritems = btrfs_header_nritems(leaf); | |
5056 | if (nritems == 0) | |
5057 | return 1; | |
5058 | if (path->slots[0] == nritems) | |
5059 | path->slots[0]--; | |
5060 | ||
5061 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); | |
5062 | if (found_key.objectid < min_objectid) | |
5063 | break; | |
5064 | if (found_key.type == BTRFS_EXTENT_ITEM_KEY || | |
5065 | found_key.type == BTRFS_METADATA_ITEM_KEY) | |
5066 | return 0; | |
5067 | if (found_key.objectid == min_objectid && | |
5068 | found_key.type < BTRFS_EXTENT_ITEM_KEY) | |
5069 | break; | |
5070 | } | |
5071 | return 1; | |
5072 | } | |
226463d7 JB |
5073 | |
5074 | int __init btrfs_ctree_init(void) | |
5075 | { | |
5076 | btrfs_path_cachep = kmem_cache_create("btrfs_path", | |
5077 | sizeof(struct btrfs_path), 0, | |
5078 | SLAB_MEM_SPREAD, NULL); | |
5079 | if (!btrfs_path_cachep) | |
5080 | return -ENOMEM; | |
5081 | return 0; | |
5082 | } | |
5083 | ||
5084 | void __cold btrfs_ctree_exit(void) | |
5085 | { | |
5086 | kmem_cache_destroy(btrfs_path_cachep); | |
5087 | } |