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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); | |
afe5fea7 TI |
40 | static void del_ptr(struct btrfs_root *root, struct btrfs_path *path, |
41 | int level, int slot); | |
d97e63b6 | 42 | |
af024ed2 JT |
43 | static const struct btrfs_csums { |
44 | u16 size; | |
59a0fcdb DS |
45 | const char name[10]; |
46 | const char driver[12]; | |
af024ed2 JT |
47 | } btrfs_csums[] = { |
48 | [BTRFS_CSUM_TYPE_CRC32] = { .size = 4, .name = "crc32c" }, | |
3951e7f0 | 49 | [BTRFS_CSUM_TYPE_XXHASH] = { .size = 8, .name = "xxhash64" }, |
3831bf00 | 50 | [BTRFS_CSUM_TYPE_SHA256] = { .size = 32, .name = "sha256" }, |
352ae07b DS |
51 | [BTRFS_CSUM_TYPE_BLAKE2] = { .size = 32, .name = "blake2b", |
52 | .driver = "blake2b-256" }, | |
af024ed2 JT |
53 | }; |
54 | ||
3a3178c7 JB |
55 | /* |
56 | * The leaf data grows from end-to-front in the node. this returns the address | |
57 | * of the start of the last item, which is the stop of the leaf data stack. | |
58 | */ | |
59 | static unsigned int leaf_data_end(const struct extent_buffer *leaf) | |
60 | { | |
61 | u32 nr = btrfs_header_nritems(leaf); | |
62 | ||
63 | if (nr == 0) | |
64 | return BTRFS_LEAF_DATA_SIZE(leaf->fs_info); | |
65 | return btrfs_item_offset(leaf, nr - 1); | |
66 | } | |
67 | ||
637e3b48 JB |
68 | /* |
69 | * Move data in a @leaf (using memmove, safe for overlapping ranges). | |
70 | * | |
71 | * @leaf: leaf that we're doing a memmove on | |
72 | * @dst_offset: item data offset we're moving to | |
73 | * @src_offset: item data offset were' moving from | |
74 | * @len: length of the data we're moving | |
75 | * | |
76 | * Wrapper around memmove_extent_buffer() that takes into account the header on | |
77 | * the leaf. The btrfs_item offset's start directly after the header, so we | |
78 | * have to adjust any offsets to account for the header in the leaf. This | |
79 | * handles that math to simplify the callers. | |
80 | */ | |
81 | static inline void memmove_leaf_data(const struct extent_buffer *leaf, | |
82 | unsigned long dst_offset, | |
83 | unsigned long src_offset, | |
84 | unsigned long len) | |
85 | { | |
8009adf3 JB |
86 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(leaf, 0) + dst_offset, |
87 | btrfs_item_nr_offset(leaf, 0) + src_offset, len); | |
637e3b48 JB |
88 | } |
89 | ||
90 | /* | |
91 | * Copy item data from @src into @dst at the given @offset. | |
92 | * | |
93 | * @dst: destination leaf that we're copying into | |
94 | * @src: source leaf that we're copying from | |
95 | * @dst_offset: item data offset we're copying to | |
96 | * @src_offset: item data offset were' copying from | |
97 | * @len: length of the data we're copying | |
98 | * | |
99 | * Wrapper around copy_extent_buffer() that takes into account the header on | |
100 | * the leaf. The btrfs_item offset's start directly after the header, so we | |
101 | * have to adjust any offsets to account for the header in the leaf. This | |
102 | * handles that math to simplify the callers. | |
103 | */ | |
104 | static inline void copy_leaf_data(const struct extent_buffer *dst, | |
105 | const struct extent_buffer *src, | |
106 | unsigned long dst_offset, | |
107 | unsigned long src_offset, unsigned long len) | |
108 | { | |
8009adf3 JB |
109 | copy_extent_buffer(dst, src, btrfs_item_nr_offset(dst, 0) + dst_offset, |
110 | btrfs_item_nr_offset(src, 0) + src_offset, len); | |
637e3b48 JB |
111 | } |
112 | ||
113 | /* | |
114 | * Move items in a @leaf (using memmove). | |
115 | * | |
116 | * @dst: destination leaf for the items | |
117 | * @dst_item: the item nr we're copying into | |
118 | * @src_item: the item nr we're copying from | |
119 | * @nr_items: the number of items to copy | |
120 | * | |
121 | * Wrapper around memmove_extent_buffer() that does the math to get the | |
122 | * appropriate offsets into the leaf from the item numbers. | |
123 | */ | |
124 | static inline void memmove_leaf_items(const struct extent_buffer *leaf, | |
125 | int dst_item, int src_item, int nr_items) | |
126 | { | |
127 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(leaf, dst_item), | |
128 | btrfs_item_nr_offset(leaf, src_item), | |
129 | nr_items * sizeof(struct btrfs_item)); | |
130 | } | |
131 | ||
132 | /* | |
133 | * Copy items from @src into @dst at the given @offset. | |
134 | * | |
135 | * @dst: destination leaf for the items | |
136 | * @src: source leaf for the items | |
137 | * @dst_item: the item nr we're copying into | |
138 | * @src_item: the item nr we're copying from | |
139 | * @nr_items: the number of items to copy | |
140 | * | |
141 | * Wrapper around copy_extent_buffer() that does the math to get the | |
142 | * appropriate offsets into the leaf from the item numbers. | |
143 | */ | |
144 | static inline void copy_leaf_items(const struct extent_buffer *dst, | |
145 | const struct extent_buffer *src, | |
146 | int dst_item, int src_item, int nr_items) | |
147 | { | |
148 | copy_extent_buffer(dst, src, btrfs_item_nr_offset(dst, dst_item), | |
149 | btrfs_item_nr_offset(src, src_item), | |
150 | nr_items * sizeof(struct btrfs_item)); | |
151 | } | |
152 | ||
af024ed2 JT |
153 | int btrfs_super_csum_size(const struct btrfs_super_block *s) |
154 | { | |
155 | u16 t = btrfs_super_csum_type(s); | |
156 | /* | |
157 | * csum type is validated at mount time | |
158 | */ | |
159 | return btrfs_csums[t].size; | |
160 | } | |
161 | ||
162 | const char *btrfs_super_csum_name(u16 csum_type) | |
163 | { | |
164 | /* csum type is validated at mount time */ | |
165 | return btrfs_csums[csum_type].name; | |
166 | } | |
167 | ||
b4e967be DS |
168 | /* |
169 | * Return driver name if defined, otherwise the name that's also a valid driver | |
170 | * name | |
171 | */ | |
172 | const char *btrfs_super_csum_driver(u16 csum_type) | |
173 | { | |
174 | /* csum type is validated at mount time */ | |
59a0fcdb DS |
175 | return btrfs_csums[csum_type].driver[0] ? |
176 | btrfs_csums[csum_type].driver : | |
b4e967be DS |
177 | btrfs_csums[csum_type].name; |
178 | } | |
179 | ||
604997b4 | 180 | size_t __attribute_const__ btrfs_get_num_csums(void) |
f7cea56c DS |
181 | { |
182 | return ARRAY_SIZE(btrfs_csums); | |
183 | } | |
184 | ||
df24a2b9 | 185 | struct btrfs_path *btrfs_alloc_path(void) |
2c90e5d6 | 186 | { |
a4c853af C |
187 | might_sleep(); |
188 | ||
e2c89907 | 189 | return kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS); |
2c90e5d6 CM |
190 | } |
191 | ||
d352ac68 | 192 | /* this also releases the path */ |
df24a2b9 | 193 | void btrfs_free_path(struct btrfs_path *p) |
be0e5c09 | 194 | { |
ff175d57 JJ |
195 | if (!p) |
196 | return; | |
b3b4aa74 | 197 | btrfs_release_path(p); |
df24a2b9 | 198 | kmem_cache_free(btrfs_path_cachep, p); |
be0e5c09 CM |
199 | } |
200 | ||
d352ac68 CM |
201 | /* |
202 | * path release drops references on the extent buffers in the path | |
203 | * and it drops any locks held by this path | |
204 | * | |
205 | * It is safe to call this on paths that no locks or extent buffers held. | |
206 | */ | |
b3b4aa74 | 207 | noinline void btrfs_release_path(struct btrfs_path *p) |
eb60ceac CM |
208 | { |
209 | int i; | |
a2135011 | 210 | |
234b63a0 | 211 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) { |
3f157a2f | 212 | p->slots[i] = 0; |
eb60ceac | 213 | if (!p->nodes[i]) |
925baedd CM |
214 | continue; |
215 | if (p->locks[i]) { | |
bd681513 | 216 | btrfs_tree_unlock_rw(p->nodes[i], p->locks[i]); |
925baedd CM |
217 | p->locks[i] = 0; |
218 | } | |
5f39d397 | 219 | free_extent_buffer(p->nodes[i]); |
3f157a2f | 220 | p->nodes[i] = NULL; |
eb60ceac CM |
221 | } |
222 | } | |
223 | ||
8bb808c6 DS |
224 | /* |
225 | * We want the transaction abort to print stack trace only for errors where the | |
226 | * cause could be a bug, eg. due to ENOSPC, and not for common errors that are | |
227 | * caused by external factors. | |
228 | */ | |
229 | bool __cold abort_should_print_stack(int errno) | |
230 | { | |
231 | switch (errno) { | |
232 | case -EIO: | |
233 | case -EROFS: | |
234 | case -ENOMEM: | |
235 | return false; | |
236 | } | |
237 | return true; | |
238 | } | |
239 | ||
d352ac68 CM |
240 | /* |
241 | * safely gets a reference on the root node of a tree. A lock | |
242 | * is not taken, so a concurrent writer may put a different node | |
243 | * at the root of the tree. See btrfs_lock_root_node for the | |
244 | * looping required. | |
245 | * | |
246 | * The extent buffer returned by this has a reference taken, so | |
247 | * it won't disappear. It may stop being the root of the tree | |
248 | * at any time because there are no locks held. | |
249 | */ | |
925baedd CM |
250 | struct extent_buffer *btrfs_root_node(struct btrfs_root *root) |
251 | { | |
252 | struct extent_buffer *eb; | |
240f62c8 | 253 | |
3083ee2e JB |
254 | while (1) { |
255 | rcu_read_lock(); | |
256 | eb = rcu_dereference(root->node); | |
257 | ||
258 | /* | |
259 | * RCU really hurts here, we could free up the root node because | |
01327610 | 260 | * it was COWed but we may not get the new root node yet so do |
3083ee2e JB |
261 | * the inc_not_zero dance and if it doesn't work then |
262 | * synchronize_rcu and try again. | |
263 | */ | |
264 | if (atomic_inc_not_zero(&eb->refs)) { | |
265 | rcu_read_unlock(); | |
266 | break; | |
267 | } | |
268 | rcu_read_unlock(); | |
269 | synchronize_rcu(); | |
270 | } | |
925baedd CM |
271 | return eb; |
272 | } | |
273 | ||
92a7cc42 QW |
274 | /* |
275 | * Cowonly root (not-shareable trees, everything not subvolume or reloc roots), | |
276 | * just get put onto a simple dirty list. Transaction walks this list to make | |
277 | * sure they get properly updated on disk. | |
d352ac68 | 278 | */ |
0b86a832 CM |
279 | static void add_root_to_dirty_list(struct btrfs_root *root) |
280 | { | |
0b246afa JM |
281 | struct btrfs_fs_info *fs_info = root->fs_info; |
282 | ||
e7070be1 JB |
283 | if (test_bit(BTRFS_ROOT_DIRTY, &root->state) || |
284 | !test_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state)) | |
285 | return; | |
286 | ||
0b246afa | 287 | spin_lock(&fs_info->trans_lock); |
e7070be1 JB |
288 | if (!test_and_set_bit(BTRFS_ROOT_DIRTY, &root->state)) { |
289 | /* Want the extent tree to be the last on the list */ | |
4fd786e6 | 290 | if (root->root_key.objectid == BTRFS_EXTENT_TREE_OBJECTID) |
e7070be1 | 291 | list_move_tail(&root->dirty_list, |
0b246afa | 292 | &fs_info->dirty_cowonly_roots); |
e7070be1 JB |
293 | else |
294 | list_move(&root->dirty_list, | |
0b246afa | 295 | &fs_info->dirty_cowonly_roots); |
0b86a832 | 296 | } |
0b246afa | 297 | spin_unlock(&fs_info->trans_lock); |
0b86a832 CM |
298 | } |
299 | ||
d352ac68 CM |
300 | /* |
301 | * used by snapshot creation to make a copy of a root for a tree with | |
302 | * a given objectid. The buffer with the new root node is returned in | |
303 | * cow_ret, and this func returns zero on success or a negative error code. | |
304 | */ | |
be20aa9d CM |
305 | int btrfs_copy_root(struct btrfs_trans_handle *trans, |
306 | struct btrfs_root *root, | |
307 | struct extent_buffer *buf, | |
308 | struct extent_buffer **cow_ret, u64 new_root_objectid) | |
309 | { | |
0b246afa | 310 | struct btrfs_fs_info *fs_info = root->fs_info; |
be20aa9d | 311 | struct extent_buffer *cow; |
be20aa9d CM |
312 | int ret = 0; |
313 | int level; | |
5d4f98a2 | 314 | struct btrfs_disk_key disk_key; |
be20aa9d | 315 | |
92a7cc42 | 316 | WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && |
0b246afa | 317 | trans->transid != fs_info->running_transaction->transid); |
92a7cc42 | 318 | WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && |
27cdeb70 | 319 | trans->transid != root->last_trans); |
be20aa9d CM |
320 | |
321 | level = btrfs_header_level(buf); | |
5d4f98a2 YZ |
322 | if (level == 0) |
323 | btrfs_item_key(buf, &disk_key, 0); | |
324 | else | |
325 | btrfs_node_key(buf, &disk_key, 0); | |
31840ae1 | 326 | |
4d75f8a9 | 327 | cow = btrfs_alloc_tree_block(trans, root, 0, new_root_objectid, |
cf6f34aa JB |
328 | &disk_key, level, buf->start, 0, |
329 | BTRFS_NESTING_NEW_ROOT); | |
5d4f98a2 | 330 | if (IS_ERR(cow)) |
be20aa9d CM |
331 | return PTR_ERR(cow); |
332 | ||
58e8012c | 333 | copy_extent_buffer_full(cow, buf); |
be20aa9d CM |
334 | btrfs_set_header_bytenr(cow, cow->start); |
335 | btrfs_set_header_generation(cow, trans->transid); | |
5d4f98a2 YZ |
336 | btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); |
337 | btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | | |
338 | BTRFS_HEADER_FLAG_RELOC); | |
339 | if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) | |
340 | btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); | |
341 | else | |
342 | btrfs_set_header_owner(cow, new_root_objectid); | |
be20aa9d | 343 | |
de37aa51 | 344 | write_extent_buffer_fsid(cow, fs_info->fs_devices->metadata_uuid); |
2b82032c | 345 | |
be20aa9d | 346 | WARN_ON(btrfs_header_generation(buf) > trans->transid); |
5d4f98a2 | 347 | if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) |
e339a6b0 | 348 | ret = btrfs_inc_ref(trans, root, cow, 1); |
5d4f98a2 | 349 | else |
e339a6b0 | 350 | ret = btrfs_inc_ref(trans, root, cow, 0); |
867ed321 | 351 | if (ret) { |
72c9925f FM |
352 | btrfs_tree_unlock(cow); |
353 | free_extent_buffer(cow); | |
867ed321 | 354 | btrfs_abort_transaction(trans, ret); |
be20aa9d | 355 | return ret; |
867ed321 | 356 | } |
be20aa9d CM |
357 | |
358 | btrfs_mark_buffer_dirty(cow); | |
359 | *cow_ret = cow; | |
360 | return 0; | |
361 | } | |
362 | ||
5d4f98a2 YZ |
363 | /* |
364 | * check if the tree block can be shared by multiple trees | |
365 | */ | |
366 | int btrfs_block_can_be_shared(struct btrfs_root *root, | |
367 | struct extent_buffer *buf) | |
368 | { | |
369 | /* | |
92a7cc42 QW |
370 | * Tree blocks not in shareable trees and tree roots are never shared. |
371 | * If a block was allocated after the last snapshot and the block was | |
372 | * not allocated by tree relocation, we know the block is not shared. | |
5d4f98a2 | 373 | */ |
92a7cc42 | 374 | if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && |
5d4f98a2 YZ |
375 | buf != root->node && buf != root->commit_root && |
376 | (btrfs_header_generation(buf) <= | |
377 | btrfs_root_last_snapshot(&root->root_item) || | |
378 | btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))) | |
379 | return 1; | |
a79865c6 | 380 | |
5d4f98a2 YZ |
381 | return 0; |
382 | } | |
383 | ||
384 | static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, | |
385 | struct btrfs_root *root, | |
386 | struct extent_buffer *buf, | |
f0486c68 YZ |
387 | struct extent_buffer *cow, |
388 | int *last_ref) | |
5d4f98a2 | 389 | { |
0b246afa | 390 | struct btrfs_fs_info *fs_info = root->fs_info; |
5d4f98a2 YZ |
391 | u64 refs; |
392 | u64 owner; | |
393 | u64 flags; | |
394 | u64 new_flags = 0; | |
395 | int ret; | |
396 | ||
397 | /* | |
398 | * Backrefs update rules: | |
399 | * | |
400 | * Always use full backrefs for extent pointers in tree block | |
401 | * allocated by tree relocation. | |
402 | * | |
403 | * If a shared tree block is no longer referenced by its owner | |
404 | * tree (btrfs_header_owner(buf) == root->root_key.objectid), | |
405 | * use full backrefs for extent pointers in tree block. | |
406 | * | |
407 | * If a tree block is been relocating | |
408 | * (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID), | |
409 | * use full backrefs for extent pointers in tree block. | |
410 | * The reason for this is some operations (such as drop tree) | |
411 | * are only allowed for blocks use full backrefs. | |
412 | */ | |
413 | ||
414 | if (btrfs_block_can_be_shared(root, buf)) { | |
2ff7e61e | 415 | ret = btrfs_lookup_extent_info(trans, fs_info, buf->start, |
3173a18f JB |
416 | btrfs_header_level(buf), 1, |
417 | &refs, &flags); | |
be1a5564 MF |
418 | if (ret) |
419 | return ret; | |
e5df9573 MF |
420 | if (refs == 0) { |
421 | ret = -EROFS; | |
0b246afa | 422 | btrfs_handle_fs_error(fs_info, ret, NULL); |
e5df9573 MF |
423 | return ret; |
424 | } | |
5d4f98a2 YZ |
425 | } else { |
426 | refs = 1; | |
427 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || | |
428 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
429 | flags = BTRFS_BLOCK_FLAG_FULL_BACKREF; | |
430 | else | |
431 | flags = 0; | |
432 | } | |
433 | ||
434 | owner = btrfs_header_owner(buf); | |
435 | BUG_ON(owner == BTRFS_TREE_RELOC_OBJECTID && | |
436 | !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)); | |
437 | ||
438 | if (refs > 1) { | |
439 | if ((owner == root->root_key.objectid || | |
440 | root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && | |
441 | !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) { | |
e339a6b0 | 442 | ret = btrfs_inc_ref(trans, root, buf, 1); |
692826b2 JM |
443 | if (ret) |
444 | return ret; | |
5d4f98a2 YZ |
445 | |
446 | if (root->root_key.objectid == | |
447 | BTRFS_TREE_RELOC_OBJECTID) { | |
e339a6b0 | 448 | ret = btrfs_dec_ref(trans, root, buf, 0); |
692826b2 JM |
449 | if (ret) |
450 | return ret; | |
e339a6b0 | 451 | ret = btrfs_inc_ref(trans, root, cow, 1); |
692826b2 JM |
452 | if (ret) |
453 | return ret; | |
5d4f98a2 YZ |
454 | } |
455 | new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF; | |
456 | } else { | |
457 | ||
458 | if (root->root_key.objectid == | |
459 | BTRFS_TREE_RELOC_OBJECTID) | |
e339a6b0 | 460 | ret = btrfs_inc_ref(trans, root, cow, 1); |
5d4f98a2 | 461 | else |
e339a6b0 | 462 | ret = btrfs_inc_ref(trans, root, cow, 0); |
692826b2 JM |
463 | if (ret) |
464 | return ret; | |
5d4f98a2 YZ |
465 | } |
466 | if (new_flags != 0) { | |
b1c79e09 JB |
467 | int level = btrfs_header_level(buf); |
468 | ||
42c9d0b5 | 469 | ret = btrfs_set_disk_extent_flags(trans, buf, |
2fe6a5a1 | 470 | new_flags, level); |
be1a5564 MF |
471 | if (ret) |
472 | return ret; | |
5d4f98a2 YZ |
473 | } |
474 | } else { | |
475 | if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) { | |
476 | if (root->root_key.objectid == | |
477 | BTRFS_TREE_RELOC_OBJECTID) | |
e339a6b0 | 478 | ret = btrfs_inc_ref(trans, root, cow, 1); |
5d4f98a2 | 479 | else |
e339a6b0 | 480 | ret = btrfs_inc_ref(trans, root, cow, 0); |
692826b2 JM |
481 | if (ret) |
482 | return ret; | |
e339a6b0 | 483 | ret = btrfs_dec_ref(trans, root, buf, 1); |
692826b2 JM |
484 | if (ret) |
485 | return ret; | |
5d4f98a2 | 486 | } |
190a8339 | 487 | btrfs_clear_buffer_dirty(trans, buf); |
f0486c68 | 488 | *last_ref = 1; |
5d4f98a2 YZ |
489 | } |
490 | return 0; | |
491 | } | |
492 | ||
d352ac68 | 493 | /* |
d397712b CM |
494 | * does the dirty work in cow of a single block. The parent block (if |
495 | * supplied) is updated to point to the new cow copy. The new buffer is marked | |
496 | * dirty and returned locked. If you modify the block it needs to be marked | |
497 | * dirty again. | |
d352ac68 CM |
498 | * |
499 | * search_start -- an allocation hint for the new block | |
500 | * | |
d397712b CM |
501 | * empty_size -- a hint that you plan on doing more cow. This is the size in |
502 | * bytes the allocator should try to find free next to the block it returns. | |
503 | * This is just a hint and may be ignored by the allocator. | |
d352ac68 | 504 | */ |
d397712b | 505 | static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, |
5f39d397 CM |
506 | struct btrfs_root *root, |
507 | struct extent_buffer *buf, | |
508 | struct extent_buffer *parent, int parent_slot, | |
509 | struct extent_buffer **cow_ret, | |
9631e4cc JB |
510 | u64 search_start, u64 empty_size, |
511 | enum btrfs_lock_nesting nest) | |
02217ed2 | 512 | { |
0b246afa | 513 | struct btrfs_fs_info *fs_info = root->fs_info; |
5d4f98a2 | 514 | struct btrfs_disk_key disk_key; |
5f39d397 | 515 | struct extent_buffer *cow; |
be1a5564 | 516 | int level, ret; |
f0486c68 | 517 | int last_ref = 0; |
925baedd | 518 | int unlock_orig = 0; |
0f5053eb | 519 | u64 parent_start = 0; |
7bb86316 | 520 | |
925baedd CM |
521 | if (*cow_ret == buf) |
522 | unlock_orig = 1; | |
523 | ||
49d0c642 | 524 | btrfs_assert_tree_write_locked(buf); |
925baedd | 525 | |
92a7cc42 | 526 | WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && |
0b246afa | 527 | trans->transid != fs_info->running_transaction->transid); |
92a7cc42 | 528 | WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && |
27cdeb70 | 529 | trans->transid != root->last_trans); |
5f39d397 | 530 | |
7bb86316 | 531 | level = btrfs_header_level(buf); |
31840ae1 | 532 | |
5d4f98a2 YZ |
533 | if (level == 0) |
534 | btrfs_item_key(buf, &disk_key, 0); | |
535 | else | |
536 | btrfs_node_key(buf, &disk_key, 0); | |
537 | ||
0f5053eb GR |
538 | if ((root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && parent) |
539 | parent_start = parent->start; | |
5d4f98a2 | 540 | |
79bd3712 FM |
541 | cow = btrfs_alloc_tree_block(trans, root, parent_start, |
542 | root->root_key.objectid, &disk_key, level, | |
543 | search_start, empty_size, nest); | |
54aa1f4d CM |
544 | if (IS_ERR(cow)) |
545 | return PTR_ERR(cow); | |
6702ed49 | 546 | |
b4ce94de CM |
547 | /* cow is set to blocking by btrfs_init_new_buffer */ |
548 | ||
58e8012c | 549 | copy_extent_buffer_full(cow, buf); |
db94535d | 550 | btrfs_set_header_bytenr(cow, cow->start); |
5f39d397 | 551 | btrfs_set_header_generation(cow, trans->transid); |
5d4f98a2 YZ |
552 | btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); |
553 | btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | | |
554 | BTRFS_HEADER_FLAG_RELOC); | |
555 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) | |
556 | btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); | |
557 | else | |
558 | btrfs_set_header_owner(cow, root->root_key.objectid); | |
6702ed49 | 559 | |
de37aa51 | 560 | write_extent_buffer_fsid(cow, fs_info->fs_devices->metadata_uuid); |
2b82032c | 561 | |
be1a5564 | 562 | ret = update_ref_for_cow(trans, root, buf, cow, &last_ref); |
b68dc2a9 | 563 | if (ret) { |
572c83ac JB |
564 | btrfs_tree_unlock(cow); |
565 | free_extent_buffer(cow); | |
66642832 | 566 | btrfs_abort_transaction(trans, ret); |
b68dc2a9 MF |
567 | return ret; |
568 | } | |
1a40e23b | 569 | |
92a7cc42 | 570 | if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) { |
83d4cfd4 | 571 | ret = btrfs_reloc_cow_block(trans, root, buf, cow); |
93314e3b | 572 | if (ret) { |
572c83ac JB |
573 | btrfs_tree_unlock(cow); |
574 | free_extent_buffer(cow); | |
66642832 | 575 | btrfs_abort_transaction(trans, ret); |
83d4cfd4 | 576 | return ret; |
93314e3b | 577 | } |
83d4cfd4 | 578 | } |
3fd0a558 | 579 | |
02217ed2 | 580 | if (buf == root->node) { |
925baedd | 581 | WARN_ON(parent && parent != buf); |
5d4f98a2 YZ |
582 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || |
583 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
584 | parent_start = buf->start; | |
925baedd | 585 | |
67439dad | 586 | atomic_inc(&cow->refs); |
406808ab | 587 | ret = btrfs_tree_mod_log_insert_root(root->node, cow, true); |
d9d19a01 | 588 | BUG_ON(ret < 0); |
240f62c8 | 589 | rcu_assign_pointer(root->node, cow); |
925baedd | 590 | |
7a163608 FM |
591 | btrfs_free_tree_block(trans, btrfs_root_id(root), buf, |
592 | parent_start, last_ref); | |
5f39d397 | 593 | free_extent_buffer(buf); |
0b86a832 | 594 | add_root_to_dirty_list(root); |
02217ed2 | 595 | } else { |
5d4f98a2 | 596 | WARN_ON(trans->transid != btrfs_header_generation(parent)); |
f3a84ccd | 597 | btrfs_tree_mod_log_insert_key(parent, parent_slot, |
33cff222 | 598 | BTRFS_MOD_LOG_KEY_REPLACE); |
5f39d397 | 599 | btrfs_set_node_blockptr(parent, parent_slot, |
db94535d | 600 | cow->start); |
74493f7a CM |
601 | btrfs_set_node_ptr_generation(parent, parent_slot, |
602 | trans->transid); | |
d6025579 | 603 | btrfs_mark_buffer_dirty(parent); |
5de865ee | 604 | if (last_ref) { |
f3a84ccd | 605 | ret = btrfs_tree_mod_log_free_eb(buf); |
5de865ee | 606 | if (ret) { |
572c83ac JB |
607 | btrfs_tree_unlock(cow); |
608 | free_extent_buffer(cow); | |
66642832 | 609 | btrfs_abort_transaction(trans, ret); |
5de865ee FDBM |
610 | return ret; |
611 | } | |
612 | } | |
7a163608 FM |
613 | btrfs_free_tree_block(trans, btrfs_root_id(root), buf, |
614 | parent_start, last_ref); | |
02217ed2 | 615 | } |
925baedd CM |
616 | if (unlock_orig) |
617 | btrfs_tree_unlock(buf); | |
3083ee2e | 618 | free_extent_buffer_stale(buf); |
ccd467d6 | 619 | btrfs_mark_buffer_dirty(cow); |
2c90e5d6 | 620 | *cow_ret = cow; |
02217ed2 CM |
621 | return 0; |
622 | } | |
623 | ||
5d4f98a2 YZ |
624 | static inline int should_cow_block(struct btrfs_trans_handle *trans, |
625 | struct btrfs_root *root, | |
626 | struct extent_buffer *buf) | |
627 | { | |
f5ee5c9a | 628 | if (btrfs_is_testing(root->fs_info)) |
faa2dbf0 | 629 | return 0; |
fccb84c9 | 630 | |
d1980131 DS |
631 | /* Ensure we can see the FORCE_COW bit */ |
632 | smp_mb__before_atomic(); | |
f1ebcc74 LB |
633 | |
634 | /* | |
635 | * We do not need to cow a block if | |
636 | * 1) this block is not created or changed in this transaction; | |
637 | * 2) this block does not belong to TREE_RELOC tree; | |
638 | * 3) the root is not forced COW. | |
639 | * | |
640 | * What is forced COW: | |
01327610 | 641 | * when we create snapshot during committing the transaction, |
52042d8e | 642 | * after we've finished copying src root, we must COW the shared |
f1ebcc74 LB |
643 | * block to ensure the metadata consistency. |
644 | */ | |
5d4f98a2 YZ |
645 | if (btrfs_header_generation(buf) == trans->transid && |
646 | !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) && | |
647 | !(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID && | |
f1ebcc74 | 648 | btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)) && |
27cdeb70 | 649 | !test_bit(BTRFS_ROOT_FORCE_COW, &root->state)) |
5d4f98a2 YZ |
650 | return 0; |
651 | return 1; | |
652 | } | |
653 | ||
d352ac68 CM |
654 | /* |
655 | * cows a single block, see __btrfs_cow_block for the real work. | |
01327610 | 656 | * This version of it has extra checks so that a block isn't COWed more than |
d352ac68 CM |
657 | * once per transaction, as long as it hasn't been written yet |
658 | */ | |
d397712b | 659 | noinline int btrfs_cow_block(struct btrfs_trans_handle *trans, |
5f39d397 CM |
660 | struct btrfs_root *root, struct extent_buffer *buf, |
661 | struct extent_buffer *parent, int parent_slot, | |
9631e4cc JB |
662 | struct extent_buffer **cow_ret, |
663 | enum btrfs_lock_nesting nest) | |
6702ed49 | 664 | { |
0b246afa | 665 | struct btrfs_fs_info *fs_info = root->fs_info; |
6702ed49 | 666 | u64 search_start; |
f510cfec | 667 | int ret; |
dc17ff8f | 668 | |
83354f07 JB |
669 | if (test_bit(BTRFS_ROOT_DELETING, &root->state)) |
670 | btrfs_err(fs_info, | |
671 | "COW'ing blocks on a fs root that's being dropped"); | |
672 | ||
0b246afa | 673 | if (trans->transaction != fs_info->running_transaction) |
31b1a2bd | 674 | WARN(1, KERN_CRIT "trans %llu running %llu\n", |
c1c9ff7c | 675 | trans->transid, |
0b246afa | 676 | fs_info->running_transaction->transid); |
31b1a2bd | 677 | |
0b246afa | 678 | if (trans->transid != fs_info->generation) |
31b1a2bd | 679 | WARN(1, KERN_CRIT "trans %llu running %llu\n", |
0b246afa | 680 | trans->transid, fs_info->generation); |
dc17ff8f | 681 | |
5d4f98a2 | 682 | if (!should_cow_block(trans, root, buf)) { |
6702ed49 CM |
683 | *cow_ret = buf; |
684 | return 0; | |
685 | } | |
c487685d | 686 | |
ee22184b | 687 | search_start = buf->start & ~((u64)SZ_1G - 1); |
b4ce94de | 688 | |
f616f5cd QW |
689 | /* |
690 | * Before CoWing this block for later modification, check if it's | |
691 | * the subtree root and do the delayed subtree trace if needed. | |
692 | * | |
693 | * Also We don't care about the error, as it's handled internally. | |
694 | */ | |
695 | btrfs_qgroup_trace_subtree_after_cow(trans, root, buf); | |
f510cfec | 696 | ret = __btrfs_cow_block(trans, root, buf, parent, |
9631e4cc | 697 | parent_slot, cow_ret, search_start, 0, nest); |
1abe9b8a | 698 | |
699 | trace_btrfs_cow_block(root, buf, *cow_ret); | |
700 | ||
f510cfec | 701 | return ret; |
6702ed49 | 702 | } |
f75e2b79 | 703 | ALLOW_ERROR_INJECTION(btrfs_cow_block, ERRNO); |
6702ed49 | 704 | |
d352ac68 CM |
705 | /* |
706 | * helper function for defrag to decide if two blocks pointed to by a | |
707 | * node are actually close by | |
708 | */ | |
6b80053d | 709 | static int close_blocks(u64 blocknr, u64 other, u32 blocksize) |
6702ed49 | 710 | { |
6b80053d | 711 | if (blocknr < other && other - (blocknr + blocksize) < 32768) |
6702ed49 | 712 | return 1; |
6b80053d | 713 | if (blocknr > other && blocknr - (other + blocksize) < 32768) |
6702ed49 CM |
714 | return 1; |
715 | return 0; | |
716 | } | |
717 | ||
ce6ef5ab DS |
718 | #ifdef __LITTLE_ENDIAN |
719 | ||
720 | /* | |
721 | * Compare two keys, on little-endian the disk order is same as CPU order and | |
722 | * we can avoid the conversion. | |
723 | */ | |
724 | static int comp_keys(const struct btrfs_disk_key *disk_key, | |
725 | const struct btrfs_key *k2) | |
726 | { | |
727 | const struct btrfs_key *k1 = (const struct btrfs_key *)disk_key; | |
728 | ||
729 | return btrfs_comp_cpu_keys(k1, k2); | |
730 | } | |
731 | ||
732 | #else | |
733 | ||
081e9573 CM |
734 | /* |
735 | * compare two keys in a memcmp fashion | |
736 | */ | |
310712b2 OS |
737 | static int comp_keys(const struct btrfs_disk_key *disk, |
738 | const struct btrfs_key *k2) | |
081e9573 CM |
739 | { |
740 | struct btrfs_key k1; | |
741 | ||
742 | btrfs_disk_key_to_cpu(&k1, disk); | |
743 | ||
20736aba | 744 | return btrfs_comp_cpu_keys(&k1, k2); |
081e9573 | 745 | } |
ce6ef5ab | 746 | #endif |
081e9573 | 747 | |
f3465ca4 JB |
748 | /* |
749 | * same as comp_keys only with two btrfs_key's | |
750 | */ | |
e1f60a65 | 751 | int __pure btrfs_comp_cpu_keys(const struct btrfs_key *k1, const struct btrfs_key *k2) |
f3465ca4 JB |
752 | { |
753 | if (k1->objectid > k2->objectid) | |
754 | return 1; | |
755 | if (k1->objectid < k2->objectid) | |
756 | return -1; | |
757 | if (k1->type > k2->type) | |
758 | return 1; | |
759 | if (k1->type < k2->type) | |
760 | return -1; | |
761 | if (k1->offset > k2->offset) | |
762 | return 1; | |
763 | if (k1->offset < k2->offset) | |
764 | return -1; | |
765 | return 0; | |
766 | } | |
081e9573 | 767 | |
d352ac68 CM |
768 | /* |
769 | * this is used by the defrag code to go through all the | |
770 | * leaves pointed to by a node and reallocate them so that | |
771 | * disk order is close to key order | |
772 | */ | |
6702ed49 | 773 | int btrfs_realloc_node(struct btrfs_trans_handle *trans, |
5f39d397 | 774 | struct btrfs_root *root, struct extent_buffer *parent, |
de78b51a | 775 | int start_slot, u64 *last_ret, |
a6b6e75e | 776 | struct btrfs_key *progress) |
6702ed49 | 777 | { |
0b246afa | 778 | struct btrfs_fs_info *fs_info = root->fs_info; |
6b80053d | 779 | struct extent_buffer *cur; |
6702ed49 | 780 | u64 blocknr; |
e9d0b13b CM |
781 | u64 search_start = *last_ret; |
782 | u64 last_block = 0; | |
6702ed49 CM |
783 | u64 other; |
784 | u32 parent_nritems; | |
6702ed49 CM |
785 | int end_slot; |
786 | int i; | |
787 | int err = 0; | |
6b80053d | 788 | u32 blocksize; |
081e9573 CM |
789 | int progress_passed = 0; |
790 | struct btrfs_disk_key disk_key; | |
6702ed49 | 791 | |
0b246afa JM |
792 | WARN_ON(trans->transaction != fs_info->running_transaction); |
793 | WARN_ON(trans->transid != fs_info->generation); | |
86479a04 | 794 | |
6b80053d | 795 | parent_nritems = btrfs_header_nritems(parent); |
0b246afa | 796 | blocksize = fs_info->nodesize; |
5dfe2be7 | 797 | end_slot = parent_nritems - 1; |
6702ed49 | 798 | |
5dfe2be7 | 799 | if (parent_nritems <= 1) |
6702ed49 CM |
800 | return 0; |
801 | ||
5dfe2be7 | 802 | for (i = start_slot; i <= end_slot; i++) { |
6702ed49 | 803 | int close = 1; |
a6b6e75e | 804 | |
081e9573 CM |
805 | btrfs_node_key(parent, &disk_key, i); |
806 | if (!progress_passed && comp_keys(&disk_key, progress) < 0) | |
807 | continue; | |
808 | ||
809 | progress_passed = 1; | |
6b80053d | 810 | blocknr = btrfs_node_blockptr(parent, i); |
e9d0b13b CM |
811 | if (last_block == 0) |
812 | last_block = blocknr; | |
5708b959 | 813 | |
6702ed49 | 814 | if (i > 0) { |
6b80053d CM |
815 | other = btrfs_node_blockptr(parent, i - 1); |
816 | close = close_blocks(blocknr, other, blocksize); | |
6702ed49 | 817 | } |
5dfe2be7 | 818 | if (!close && i < end_slot) { |
6b80053d CM |
819 | other = btrfs_node_blockptr(parent, i + 1); |
820 | close = close_blocks(blocknr, other, blocksize); | |
6702ed49 | 821 | } |
e9d0b13b CM |
822 | if (close) { |
823 | last_block = blocknr; | |
6702ed49 | 824 | continue; |
e9d0b13b | 825 | } |
6702ed49 | 826 | |
206983b7 JB |
827 | cur = btrfs_read_node_slot(parent, i); |
828 | if (IS_ERR(cur)) | |
829 | return PTR_ERR(cur); | |
e9d0b13b | 830 | if (search_start == 0) |
6b80053d | 831 | search_start = last_block; |
e9d0b13b | 832 | |
e7a84565 | 833 | btrfs_tree_lock(cur); |
6b80053d | 834 | err = __btrfs_cow_block(trans, root, cur, parent, i, |
e7a84565 | 835 | &cur, search_start, |
6b80053d | 836 | min(16 * blocksize, |
9631e4cc JB |
837 | (end_slot - i) * blocksize), |
838 | BTRFS_NESTING_COW); | |
252c38f0 | 839 | if (err) { |
e7a84565 | 840 | btrfs_tree_unlock(cur); |
6b80053d | 841 | free_extent_buffer(cur); |
6702ed49 | 842 | break; |
252c38f0 | 843 | } |
e7a84565 CM |
844 | search_start = cur->start; |
845 | last_block = cur->start; | |
f2183bde | 846 | *last_ret = search_start; |
e7a84565 CM |
847 | btrfs_tree_unlock(cur); |
848 | free_extent_buffer(cur); | |
6702ed49 CM |
849 | } |
850 | return err; | |
851 | } | |
852 | ||
74123bd7 | 853 | /* |
fb81212c | 854 | * Search for a key in the given extent_buffer. |
5f39d397 | 855 | * |
a724f313 | 856 | * The lower boundary for the search is specified by the slot number @first_slot. |
fdf8d595 AJ |
857 | * Use a value of 0 to search over the whole extent buffer. Works for both |
858 | * leaves and nodes. | |
74123bd7 | 859 | * |
fb81212c FM |
860 | * The slot in the extent buffer is returned via @slot. If the key exists in the |
861 | * extent buffer, then @slot will point to the slot where the key is, otherwise | |
862 | * it points to the slot where you would insert the key. | |
863 | * | |
864 | * Slot may point to the total number of items (i.e. one position beyond the last | |
865 | * key) if the key is bigger than the last key in the extent buffer. | |
74123bd7 | 866 | */ |
fdf8d595 AJ |
867 | int btrfs_bin_search(struct extent_buffer *eb, int first_slot, |
868 | const struct btrfs_key *key, int *slot) | |
be0e5c09 | 869 | { |
fb81212c FM |
870 | unsigned long p; |
871 | int item_size; | |
a724f313 FM |
872 | /* |
873 | * Use unsigned types for the low and high slots, so that we get a more | |
874 | * efficient division in the search loop below. | |
875 | */ | |
876 | u32 low = first_slot; | |
877 | u32 high = btrfs_header_nritems(eb); | |
be0e5c09 | 878 | int ret; |
5cd17f34 | 879 | const int key_size = sizeof(struct btrfs_disk_key); |
be0e5c09 | 880 | |
a724f313 | 881 | if (unlikely(low > high)) { |
5e24e9af | 882 | btrfs_err(eb->fs_info, |
a724f313 | 883 | "%s: low (%u) > high (%u) eb %llu owner %llu level %d", |
5e24e9af LB |
884 | __func__, low, high, eb->start, |
885 | btrfs_header_owner(eb), btrfs_header_level(eb)); | |
886 | return -EINVAL; | |
887 | } | |
888 | ||
fb81212c FM |
889 | if (btrfs_header_level(eb) == 0) { |
890 | p = offsetof(struct btrfs_leaf, items); | |
891 | item_size = sizeof(struct btrfs_item); | |
892 | } else { | |
893 | p = offsetof(struct btrfs_node, ptrs); | |
894 | item_size = sizeof(struct btrfs_key_ptr); | |
895 | } | |
896 | ||
d397712b | 897 | while (low < high) { |
5cd17f34 DS |
898 | unsigned long oip; |
899 | unsigned long offset; | |
900 | struct btrfs_disk_key *tmp; | |
901 | struct btrfs_disk_key unaligned; | |
902 | int mid; | |
903 | ||
be0e5c09 | 904 | mid = (low + high) / 2; |
5f39d397 | 905 | offset = p + mid * item_size; |
5cd17f34 | 906 | oip = offset_in_page(offset); |
5f39d397 | 907 | |
5cd17f34 | 908 | if (oip + key_size <= PAGE_SIZE) { |
884b07d0 | 909 | const unsigned long idx = get_eb_page_index(offset); |
5cd17f34 | 910 | char *kaddr = page_address(eb->pages[idx]); |
5f39d397 | 911 | |
884b07d0 | 912 | oip = get_eb_offset_in_page(eb, offset); |
5cd17f34 | 913 | tmp = (struct btrfs_disk_key *)(kaddr + oip); |
5f39d397 | 914 | } else { |
5cd17f34 DS |
915 | read_extent_buffer(eb, &unaligned, offset, key_size); |
916 | tmp = &unaligned; | |
5f39d397 | 917 | } |
5cd17f34 | 918 | |
be0e5c09 CM |
919 | ret = comp_keys(tmp, key); |
920 | ||
921 | if (ret < 0) | |
922 | low = mid + 1; | |
923 | else if (ret > 0) | |
924 | high = mid; | |
925 | else { | |
926 | *slot = mid; | |
927 | return 0; | |
928 | } | |
929 | } | |
930 | *slot = low; | |
931 | return 1; | |
932 | } | |
933 | ||
f0486c68 YZ |
934 | static void root_add_used(struct btrfs_root *root, u32 size) |
935 | { | |
936 | spin_lock(&root->accounting_lock); | |
937 | btrfs_set_root_used(&root->root_item, | |
938 | btrfs_root_used(&root->root_item) + size); | |
939 | spin_unlock(&root->accounting_lock); | |
940 | } | |
941 | ||
942 | static void root_sub_used(struct btrfs_root *root, u32 size) | |
943 | { | |
944 | spin_lock(&root->accounting_lock); | |
945 | btrfs_set_root_used(&root->root_item, | |
946 | btrfs_root_used(&root->root_item) - size); | |
947 | spin_unlock(&root->accounting_lock); | |
948 | } | |
949 | ||
d352ac68 CM |
950 | /* given a node and slot number, this reads the blocks it points to. The |
951 | * extent buffer is returned with a reference taken (but unlocked). | |
d352ac68 | 952 | */ |
4b231ae4 DS |
953 | struct extent_buffer *btrfs_read_node_slot(struct extent_buffer *parent, |
954 | int slot) | |
bb803951 | 955 | { |
ca7a79ad | 956 | int level = btrfs_header_level(parent); |
789d6a3a | 957 | struct btrfs_tree_parent_check check = { 0 }; |
416bc658 JB |
958 | struct extent_buffer *eb; |
959 | ||
fb770ae4 LB |
960 | if (slot < 0 || slot >= btrfs_header_nritems(parent)) |
961 | return ERR_PTR(-ENOENT); | |
ca7a79ad | 962 | |
d4694728 | 963 | ASSERT(level); |
ca7a79ad | 964 | |
789d6a3a QW |
965 | check.level = level - 1; |
966 | check.transid = btrfs_node_ptr_generation(parent, slot); | |
967 | check.owner_root = btrfs_header_owner(parent); | |
968 | check.has_first_key = true; | |
969 | btrfs_node_key_to_cpu(parent, &check.first_key, slot); | |
970 | ||
d0d20b0f | 971 | eb = read_tree_block(parent->fs_info, btrfs_node_blockptr(parent, slot), |
789d6a3a | 972 | &check); |
4eb150d6 QW |
973 | if (IS_ERR(eb)) |
974 | return eb; | |
975 | if (!extent_buffer_uptodate(eb)) { | |
fb770ae4 | 976 | free_extent_buffer(eb); |
4eb150d6 | 977 | return ERR_PTR(-EIO); |
416bc658 JB |
978 | } |
979 | ||
980 | return eb; | |
bb803951 CM |
981 | } |
982 | ||
d352ac68 CM |
983 | /* |
984 | * node level balancing, used to make sure nodes are in proper order for | |
985 | * item deletion. We balance from the top down, so we have to make sure | |
986 | * that a deletion won't leave an node completely empty later on. | |
987 | */ | |
e02119d5 | 988 | static noinline int balance_level(struct btrfs_trans_handle *trans, |
98ed5174 CM |
989 | struct btrfs_root *root, |
990 | struct btrfs_path *path, int level) | |
bb803951 | 991 | { |
0b246afa | 992 | struct btrfs_fs_info *fs_info = root->fs_info; |
5f39d397 CM |
993 | struct extent_buffer *right = NULL; |
994 | struct extent_buffer *mid; | |
995 | struct extent_buffer *left = NULL; | |
996 | struct extent_buffer *parent = NULL; | |
bb803951 CM |
997 | int ret = 0; |
998 | int wret; | |
999 | int pslot; | |
bb803951 | 1000 | int orig_slot = path->slots[level]; |
79f95c82 | 1001 | u64 orig_ptr; |
bb803951 | 1002 | |
98e6b1eb | 1003 | ASSERT(level > 0); |
bb803951 | 1004 | |
5f39d397 | 1005 | mid = path->nodes[level]; |
b4ce94de | 1006 | |
ac5887c8 | 1007 | WARN_ON(path->locks[level] != BTRFS_WRITE_LOCK); |
7bb86316 CM |
1008 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
1009 | ||
1d4f8a0c | 1010 | orig_ptr = btrfs_node_blockptr(mid, orig_slot); |
79f95c82 | 1011 | |
a05a9bb1 | 1012 | if (level < BTRFS_MAX_LEVEL - 1) { |
5f39d397 | 1013 | parent = path->nodes[level + 1]; |
a05a9bb1 LZ |
1014 | pslot = path->slots[level + 1]; |
1015 | } | |
bb803951 | 1016 | |
40689478 CM |
1017 | /* |
1018 | * deal with the case where there is only one pointer in the root | |
1019 | * by promoting the node below to a root | |
1020 | */ | |
5f39d397 CM |
1021 | if (!parent) { |
1022 | struct extent_buffer *child; | |
bb803951 | 1023 | |
5f39d397 | 1024 | if (btrfs_header_nritems(mid) != 1) |
bb803951 CM |
1025 | return 0; |
1026 | ||
1027 | /* promote the child to a root */ | |
4b231ae4 | 1028 | child = btrfs_read_node_slot(mid, 0); |
fb770ae4 LB |
1029 | if (IS_ERR(child)) { |
1030 | ret = PTR_ERR(child); | |
0b246afa | 1031 | btrfs_handle_fs_error(fs_info, ret, NULL); |
305a26af MF |
1032 | goto enospc; |
1033 | } | |
1034 | ||
925baedd | 1035 | btrfs_tree_lock(child); |
9631e4cc JB |
1036 | ret = btrfs_cow_block(trans, root, child, mid, 0, &child, |
1037 | BTRFS_NESTING_COW); | |
f0486c68 YZ |
1038 | if (ret) { |
1039 | btrfs_tree_unlock(child); | |
1040 | free_extent_buffer(child); | |
1041 | goto enospc; | |
1042 | } | |
2f375ab9 | 1043 | |
406808ab | 1044 | ret = btrfs_tree_mod_log_insert_root(root->node, child, true); |
d9d19a01 | 1045 | BUG_ON(ret < 0); |
240f62c8 | 1046 | rcu_assign_pointer(root->node, child); |
925baedd | 1047 | |
0b86a832 | 1048 | add_root_to_dirty_list(root); |
925baedd | 1049 | btrfs_tree_unlock(child); |
b4ce94de | 1050 | |
925baedd | 1051 | path->locks[level] = 0; |
bb803951 | 1052 | path->nodes[level] = NULL; |
190a8339 | 1053 | btrfs_clear_buffer_dirty(trans, mid); |
925baedd | 1054 | btrfs_tree_unlock(mid); |
bb803951 | 1055 | /* once for the path */ |
5f39d397 | 1056 | free_extent_buffer(mid); |
f0486c68 YZ |
1057 | |
1058 | root_sub_used(root, mid->len); | |
7a163608 | 1059 | btrfs_free_tree_block(trans, btrfs_root_id(root), mid, 0, 1); |
bb803951 | 1060 | /* once for the root ptr */ |
3083ee2e | 1061 | free_extent_buffer_stale(mid); |
f0486c68 | 1062 | return 0; |
bb803951 | 1063 | } |
5f39d397 | 1064 | if (btrfs_header_nritems(mid) > |
0b246afa | 1065 | BTRFS_NODEPTRS_PER_BLOCK(fs_info) / 4) |
bb803951 CM |
1066 | return 0; |
1067 | ||
9cf14029 JB |
1068 | if (pslot) { |
1069 | left = btrfs_read_node_slot(parent, pslot - 1); | |
1070 | if (IS_ERR(left)) { | |
1071 | ret = PTR_ERR(left); | |
1072 | left = NULL; | |
1073 | goto enospc; | |
1074 | } | |
fb770ae4 | 1075 | |
bf77467a | 1076 | __btrfs_tree_lock(left, BTRFS_NESTING_LEFT); |
5f39d397 | 1077 | wret = btrfs_cow_block(trans, root, left, |
9631e4cc | 1078 | parent, pslot - 1, &left, |
bf59a5a2 | 1079 | BTRFS_NESTING_LEFT_COW); |
54aa1f4d CM |
1080 | if (wret) { |
1081 | ret = wret; | |
1082 | goto enospc; | |
1083 | } | |
2cc58cf2 | 1084 | } |
fb770ae4 | 1085 | |
9cf14029 JB |
1086 | if (pslot + 1 < btrfs_header_nritems(parent)) { |
1087 | right = btrfs_read_node_slot(parent, pslot + 1); | |
1088 | if (IS_ERR(right)) { | |
1089 | ret = PTR_ERR(right); | |
1090 | right = NULL; | |
1091 | goto enospc; | |
1092 | } | |
fb770ae4 | 1093 | |
bf77467a | 1094 | __btrfs_tree_lock(right, BTRFS_NESTING_RIGHT); |
5f39d397 | 1095 | wret = btrfs_cow_block(trans, root, right, |
9631e4cc | 1096 | parent, pslot + 1, &right, |
bf59a5a2 | 1097 | BTRFS_NESTING_RIGHT_COW); |
2cc58cf2 CM |
1098 | if (wret) { |
1099 | ret = wret; | |
1100 | goto enospc; | |
1101 | } | |
1102 | } | |
1103 | ||
1104 | /* first, try to make some room in the middle buffer */ | |
5f39d397 CM |
1105 | if (left) { |
1106 | orig_slot += btrfs_header_nritems(left); | |
d30a668f | 1107 | wret = push_node_left(trans, left, mid, 1); |
79f95c82 CM |
1108 | if (wret < 0) |
1109 | ret = wret; | |
bb803951 | 1110 | } |
79f95c82 CM |
1111 | |
1112 | /* | |
1113 | * then try to empty the right most buffer into the middle | |
1114 | */ | |
5f39d397 | 1115 | if (right) { |
d30a668f | 1116 | wret = push_node_left(trans, mid, right, 1); |
54aa1f4d | 1117 | if (wret < 0 && wret != -ENOSPC) |
79f95c82 | 1118 | ret = wret; |
5f39d397 | 1119 | if (btrfs_header_nritems(right) == 0) { |
190a8339 | 1120 | btrfs_clear_buffer_dirty(trans, right); |
925baedd | 1121 | btrfs_tree_unlock(right); |
afe5fea7 | 1122 | del_ptr(root, path, level + 1, pslot + 1); |
f0486c68 | 1123 | root_sub_used(root, right->len); |
7a163608 FM |
1124 | btrfs_free_tree_block(trans, btrfs_root_id(root), right, |
1125 | 0, 1); | |
3083ee2e | 1126 | free_extent_buffer_stale(right); |
f0486c68 | 1127 | right = NULL; |
bb803951 | 1128 | } else { |
5f39d397 CM |
1129 | struct btrfs_disk_key right_key; |
1130 | btrfs_node_key(right, &right_key, 0); | |
f3a84ccd | 1131 | ret = btrfs_tree_mod_log_insert_key(parent, pslot + 1, |
33cff222 | 1132 | BTRFS_MOD_LOG_KEY_REPLACE); |
0e82bcfe | 1133 | BUG_ON(ret < 0); |
5f39d397 CM |
1134 | btrfs_set_node_key(parent, &right_key, pslot + 1); |
1135 | btrfs_mark_buffer_dirty(parent); | |
bb803951 CM |
1136 | } |
1137 | } | |
5f39d397 | 1138 | if (btrfs_header_nritems(mid) == 1) { |
79f95c82 CM |
1139 | /* |
1140 | * we're not allowed to leave a node with one item in the | |
1141 | * tree during a delete. A deletion from lower in the tree | |
1142 | * could try to delete the only pointer in this node. | |
1143 | * So, pull some keys from the left. | |
1144 | * There has to be a left pointer at this point because | |
1145 | * otherwise we would have pulled some pointers from the | |
1146 | * right | |
1147 | */ | |
305a26af MF |
1148 | if (!left) { |
1149 | ret = -EROFS; | |
0b246afa | 1150 | btrfs_handle_fs_error(fs_info, ret, NULL); |
305a26af MF |
1151 | goto enospc; |
1152 | } | |
55d32ed8 | 1153 | wret = balance_node_right(trans, mid, left); |
54aa1f4d | 1154 | if (wret < 0) { |
79f95c82 | 1155 | ret = wret; |
54aa1f4d CM |
1156 | goto enospc; |
1157 | } | |
bce4eae9 | 1158 | if (wret == 1) { |
d30a668f | 1159 | wret = push_node_left(trans, left, mid, 1); |
bce4eae9 CM |
1160 | if (wret < 0) |
1161 | ret = wret; | |
1162 | } | |
79f95c82 CM |
1163 | BUG_ON(wret == 1); |
1164 | } | |
5f39d397 | 1165 | if (btrfs_header_nritems(mid) == 0) { |
190a8339 | 1166 | btrfs_clear_buffer_dirty(trans, mid); |
925baedd | 1167 | btrfs_tree_unlock(mid); |
afe5fea7 | 1168 | del_ptr(root, path, level + 1, pslot); |
f0486c68 | 1169 | root_sub_used(root, mid->len); |
7a163608 | 1170 | btrfs_free_tree_block(trans, btrfs_root_id(root), mid, 0, 1); |
3083ee2e | 1171 | free_extent_buffer_stale(mid); |
f0486c68 | 1172 | mid = NULL; |
79f95c82 CM |
1173 | } else { |
1174 | /* update the parent key to reflect our changes */ | |
5f39d397 CM |
1175 | struct btrfs_disk_key mid_key; |
1176 | btrfs_node_key(mid, &mid_key, 0); | |
f3a84ccd | 1177 | ret = btrfs_tree_mod_log_insert_key(parent, pslot, |
33cff222 | 1178 | BTRFS_MOD_LOG_KEY_REPLACE); |
0e82bcfe | 1179 | BUG_ON(ret < 0); |
5f39d397 CM |
1180 | btrfs_set_node_key(parent, &mid_key, pslot); |
1181 | btrfs_mark_buffer_dirty(parent); | |
79f95c82 | 1182 | } |
bb803951 | 1183 | |
79f95c82 | 1184 | /* update the path */ |
5f39d397 CM |
1185 | if (left) { |
1186 | if (btrfs_header_nritems(left) > orig_slot) { | |
67439dad | 1187 | atomic_inc(&left->refs); |
925baedd | 1188 | /* left was locked after cow */ |
5f39d397 | 1189 | path->nodes[level] = left; |
bb803951 CM |
1190 | path->slots[level + 1] -= 1; |
1191 | path->slots[level] = orig_slot; | |
925baedd CM |
1192 | if (mid) { |
1193 | btrfs_tree_unlock(mid); | |
5f39d397 | 1194 | free_extent_buffer(mid); |
925baedd | 1195 | } |
bb803951 | 1196 | } else { |
5f39d397 | 1197 | orig_slot -= btrfs_header_nritems(left); |
bb803951 CM |
1198 | path->slots[level] = orig_slot; |
1199 | } | |
1200 | } | |
79f95c82 | 1201 | /* double check we haven't messed things up */ |
e20d96d6 | 1202 | if (orig_ptr != |
5f39d397 | 1203 | btrfs_node_blockptr(path->nodes[level], path->slots[level])) |
79f95c82 | 1204 | BUG(); |
54aa1f4d | 1205 | enospc: |
925baedd CM |
1206 | if (right) { |
1207 | btrfs_tree_unlock(right); | |
5f39d397 | 1208 | free_extent_buffer(right); |
925baedd CM |
1209 | } |
1210 | if (left) { | |
1211 | if (path->nodes[level] != left) | |
1212 | btrfs_tree_unlock(left); | |
5f39d397 | 1213 | free_extent_buffer(left); |
925baedd | 1214 | } |
bb803951 CM |
1215 | return ret; |
1216 | } | |
1217 | ||
d352ac68 CM |
1218 | /* Node balancing for insertion. Here we only split or push nodes around |
1219 | * when they are completely full. This is also done top down, so we | |
1220 | * have to be pessimistic. | |
1221 | */ | |
d397712b | 1222 | static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, |
98ed5174 CM |
1223 | struct btrfs_root *root, |
1224 | struct btrfs_path *path, int level) | |
e66f709b | 1225 | { |
0b246afa | 1226 | struct btrfs_fs_info *fs_info = root->fs_info; |
5f39d397 CM |
1227 | struct extent_buffer *right = NULL; |
1228 | struct extent_buffer *mid; | |
1229 | struct extent_buffer *left = NULL; | |
1230 | struct extent_buffer *parent = NULL; | |
e66f709b CM |
1231 | int ret = 0; |
1232 | int wret; | |
1233 | int pslot; | |
1234 | int orig_slot = path->slots[level]; | |
e66f709b CM |
1235 | |
1236 | if (level == 0) | |
1237 | return 1; | |
1238 | ||
5f39d397 | 1239 | mid = path->nodes[level]; |
7bb86316 | 1240 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
e66f709b | 1241 | |
a05a9bb1 | 1242 | if (level < BTRFS_MAX_LEVEL - 1) { |
5f39d397 | 1243 | parent = path->nodes[level + 1]; |
a05a9bb1 LZ |
1244 | pslot = path->slots[level + 1]; |
1245 | } | |
e66f709b | 1246 | |
5f39d397 | 1247 | if (!parent) |
e66f709b | 1248 | return 1; |
e66f709b | 1249 | |
e66f709b | 1250 | /* first, try to make some room in the middle buffer */ |
9cf14029 | 1251 | if (pslot) { |
e66f709b | 1252 | u32 left_nr; |
925baedd | 1253 | |
9cf14029 JB |
1254 | left = btrfs_read_node_slot(parent, pslot - 1); |
1255 | if (IS_ERR(left)) | |
1256 | return PTR_ERR(left); | |
1257 | ||
bf77467a | 1258 | __btrfs_tree_lock(left, BTRFS_NESTING_LEFT); |
b4ce94de | 1259 | |
5f39d397 | 1260 | left_nr = btrfs_header_nritems(left); |
0b246afa | 1261 | if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 1) { |
33ade1f8 CM |
1262 | wret = 1; |
1263 | } else { | |
5f39d397 | 1264 | ret = btrfs_cow_block(trans, root, left, parent, |
9631e4cc | 1265 | pslot - 1, &left, |
bf59a5a2 | 1266 | BTRFS_NESTING_LEFT_COW); |
54aa1f4d CM |
1267 | if (ret) |
1268 | wret = 1; | |
1269 | else { | |
d30a668f | 1270 | wret = push_node_left(trans, left, mid, 0); |
54aa1f4d | 1271 | } |
33ade1f8 | 1272 | } |
e66f709b CM |
1273 | if (wret < 0) |
1274 | ret = wret; | |
1275 | if (wret == 0) { | |
5f39d397 | 1276 | struct btrfs_disk_key disk_key; |
e66f709b | 1277 | orig_slot += left_nr; |
5f39d397 | 1278 | btrfs_node_key(mid, &disk_key, 0); |
f3a84ccd | 1279 | ret = btrfs_tree_mod_log_insert_key(parent, pslot, |
33cff222 | 1280 | BTRFS_MOD_LOG_KEY_REPLACE); |
0e82bcfe | 1281 | BUG_ON(ret < 0); |
5f39d397 CM |
1282 | btrfs_set_node_key(parent, &disk_key, pslot); |
1283 | btrfs_mark_buffer_dirty(parent); | |
1284 | if (btrfs_header_nritems(left) > orig_slot) { | |
1285 | path->nodes[level] = left; | |
e66f709b CM |
1286 | path->slots[level + 1] -= 1; |
1287 | path->slots[level] = orig_slot; | |
925baedd | 1288 | btrfs_tree_unlock(mid); |
5f39d397 | 1289 | free_extent_buffer(mid); |
e66f709b CM |
1290 | } else { |
1291 | orig_slot -= | |
5f39d397 | 1292 | btrfs_header_nritems(left); |
e66f709b | 1293 | path->slots[level] = orig_slot; |
925baedd | 1294 | btrfs_tree_unlock(left); |
5f39d397 | 1295 | free_extent_buffer(left); |
e66f709b | 1296 | } |
e66f709b CM |
1297 | return 0; |
1298 | } | |
925baedd | 1299 | btrfs_tree_unlock(left); |
5f39d397 | 1300 | free_extent_buffer(left); |
e66f709b | 1301 | } |
e66f709b CM |
1302 | |
1303 | /* | |
1304 | * then try to empty the right most buffer into the middle | |
1305 | */ | |
9cf14029 | 1306 | if (pslot + 1 < btrfs_header_nritems(parent)) { |
33ade1f8 | 1307 | u32 right_nr; |
b4ce94de | 1308 | |
9cf14029 JB |
1309 | right = btrfs_read_node_slot(parent, pslot + 1); |
1310 | if (IS_ERR(right)) | |
1311 | return PTR_ERR(right); | |
1312 | ||
bf77467a | 1313 | __btrfs_tree_lock(right, BTRFS_NESTING_RIGHT); |
b4ce94de | 1314 | |
5f39d397 | 1315 | right_nr = btrfs_header_nritems(right); |
0b246afa | 1316 | if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 1) { |
33ade1f8 CM |
1317 | wret = 1; |
1318 | } else { | |
5f39d397 CM |
1319 | ret = btrfs_cow_block(trans, root, right, |
1320 | parent, pslot + 1, | |
bf59a5a2 | 1321 | &right, BTRFS_NESTING_RIGHT_COW); |
54aa1f4d CM |
1322 | if (ret) |
1323 | wret = 1; | |
1324 | else { | |
55d32ed8 | 1325 | wret = balance_node_right(trans, right, mid); |
54aa1f4d | 1326 | } |
33ade1f8 | 1327 | } |
e66f709b CM |
1328 | if (wret < 0) |
1329 | ret = wret; | |
1330 | if (wret == 0) { | |
5f39d397 CM |
1331 | struct btrfs_disk_key disk_key; |
1332 | ||
1333 | btrfs_node_key(right, &disk_key, 0); | |
f3a84ccd | 1334 | ret = btrfs_tree_mod_log_insert_key(parent, pslot + 1, |
33cff222 | 1335 | BTRFS_MOD_LOG_KEY_REPLACE); |
0e82bcfe | 1336 | BUG_ON(ret < 0); |
5f39d397 CM |
1337 | btrfs_set_node_key(parent, &disk_key, pslot + 1); |
1338 | btrfs_mark_buffer_dirty(parent); | |
1339 | ||
1340 | if (btrfs_header_nritems(mid) <= orig_slot) { | |
1341 | path->nodes[level] = right; | |
e66f709b CM |
1342 | path->slots[level + 1] += 1; |
1343 | path->slots[level] = orig_slot - | |
5f39d397 | 1344 | btrfs_header_nritems(mid); |
925baedd | 1345 | btrfs_tree_unlock(mid); |
5f39d397 | 1346 | free_extent_buffer(mid); |
e66f709b | 1347 | } else { |
925baedd | 1348 | btrfs_tree_unlock(right); |
5f39d397 | 1349 | free_extent_buffer(right); |
e66f709b | 1350 | } |
e66f709b CM |
1351 | return 0; |
1352 | } | |
925baedd | 1353 | btrfs_tree_unlock(right); |
5f39d397 | 1354 | free_extent_buffer(right); |
e66f709b | 1355 | } |
e66f709b CM |
1356 | return 1; |
1357 | } | |
1358 | ||
3c69faec | 1359 | /* |
d352ac68 CM |
1360 | * readahead one full node of leaves, finding things that are close |
1361 | * to the block in 'slot', and triggering ra on them. | |
3c69faec | 1362 | */ |
2ff7e61e | 1363 | static void reada_for_search(struct btrfs_fs_info *fs_info, |
c8c42864 CM |
1364 | struct btrfs_path *path, |
1365 | int level, int slot, u64 objectid) | |
3c69faec | 1366 | { |
5f39d397 | 1367 | struct extent_buffer *node; |
01f46658 | 1368 | struct btrfs_disk_key disk_key; |
3c69faec | 1369 | u32 nritems; |
3c69faec | 1370 | u64 search; |
a7175319 | 1371 | u64 target; |
6b80053d | 1372 | u64 nread = 0; |
ace75066 | 1373 | u64 nread_max; |
6b80053d CM |
1374 | u32 nr; |
1375 | u32 blocksize; | |
1376 | u32 nscan = 0; | |
db94535d | 1377 | |
ace75066 | 1378 | if (level != 1 && path->reada != READA_FORWARD_ALWAYS) |
6702ed49 CM |
1379 | return; |
1380 | ||
1381 | if (!path->nodes[level]) | |
3c69faec CM |
1382 | return; |
1383 | ||
5f39d397 | 1384 | node = path->nodes[level]; |
925baedd | 1385 | |
ace75066 FM |
1386 | /* |
1387 | * Since the time between visiting leaves is much shorter than the time | |
1388 | * between visiting nodes, limit read ahead of nodes to 1, to avoid too | |
1389 | * much IO at once (possibly random). | |
1390 | */ | |
1391 | if (path->reada == READA_FORWARD_ALWAYS) { | |
1392 | if (level > 1) | |
1393 | nread_max = node->fs_info->nodesize; | |
1394 | else | |
1395 | nread_max = SZ_128K; | |
1396 | } else { | |
1397 | nread_max = SZ_64K; | |
1398 | } | |
1399 | ||
3c69faec | 1400 | search = btrfs_node_blockptr(node, slot); |
0b246afa | 1401 | blocksize = fs_info->nodesize; |
069a2e37 FM |
1402 | if (path->reada != READA_FORWARD_ALWAYS) { |
1403 | struct extent_buffer *eb; | |
1404 | ||
1405 | eb = find_extent_buffer(fs_info, search); | |
1406 | if (eb) { | |
1407 | free_extent_buffer(eb); | |
1408 | return; | |
1409 | } | |
3c69faec CM |
1410 | } |
1411 | ||
a7175319 | 1412 | target = search; |
6b80053d | 1413 | |
5f39d397 | 1414 | nritems = btrfs_header_nritems(node); |
6b80053d | 1415 | nr = slot; |
25b8b936 | 1416 | |
d397712b | 1417 | while (1) { |
e4058b54 | 1418 | if (path->reada == READA_BACK) { |
6b80053d CM |
1419 | if (nr == 0) |
1420 | break; | |
1421 | nr--; | |
ace75066 FM |
1422 | } else if (path->reada == READA_FORWARD || |
1423 | path->reada == READA_FORWARD_ALWAYS) { | |
6b80053d CM |
1424 | nr++; |
1425 | if (nr >= nritems) | |
1426 | break; | |
3c69faec | 1427 | } |
e4058b54 | 1428 | if (path->reada == READA_BACK && objectid) { |
01f46658 CM |
1429 | btrfs_node_key(node, &disk_key, nr); |
1430 | if (btrfs_disk_key_objectid(&disk_key) != objectid) | |
1431 | break; | |
1432 | } | |
6b80053d | 1433 | search = btrfs_node_blockptr(node, nr); |
ace75066 FM |
1434 | if (path->reada == READA_FORWARD_ALWAYS || |
1435 | (search <= target && target - search <= 65536) || | |
a7175319 | 1436 | (search > target && search - target <= 65536)) { |
bfb484d9 | 1437 | btrfs_readahead_node_child(node, nr); |
6b80053d CM |
1438 | nread += blocksize; |
1439 | } | |
1440 | nscan++; | |
ace75066 | 1441 | if (nread > nread_max || nscan > 32) |
6b80053d | 1442 | break; |
3c69faec CM |
1443 | } |
1444 | } | |
925baedd | 1445 | |
bfb484d9 | 1446 | static noinline void reada_for_balance(struct btrfs_path *path, int level) |
b4ce94de | 1447 | { |
bfb484d9 | 1448 | struct extent_buffer *parent; |
b4ce94de CM |
1449 | int slot; |
1450 | int nritems; | |
b4ce94de | 1451 | |
8c594ea8 | 1452 | parent = path->nodes[level + 1]; |
b4ce94de | 1453 | if (!parent) |
0b08851f | 1454 | return; |
b4ce94de CM |
1455 | |
1456 | nritems = btrfs_header_nritems(parent); | |
8c594ea8 | 1457 | slot = path->slots[level + 1]; |
b4ce94de | 1458 | |
bfb484d9 JB |
1459 | if (slot > 0) |
1460 | btrfs_readahead_node_child(parent, slot - 1); | |
1461 | if (slot + 1 < nritems) | |
1462 | btrfs_readahead_node_child(parent, slot + 1); | |
b4ce94de CM |
1463 | } |
1464 | ||
1465 | ||
d352ac68 | 1466 | /* |
d397712b CM |
1467 | * when we walk down the tree, it is usually safe to unlock the higher layers |
1468 | * in the tree. The exceptions are when our path goes through slot 0, because | |
1469 | * operations on the tree might require changing key pointers higher up in the | |
1470 | * tree. | |
d352ac68 | 1471 | * |
d397712b CM |
1472 | * callers might also have set path->keep_locks, which tells this code to keep |
1473 | * the lock if the path points to the last slot in the block. This is part of | |
1474 | * walking through the tree, and selecting the next slot in the higher block. | |
d352ac68 | 1475 | * |
d397712b CM |
1476 | * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so |
1477 | * if lowest_unlock is 1, level 0 won't be unlocked | |
d352ac68 | 1478 | */ |
e02119d5 | 1479 | static noinline void unlock_up(struct btrfs_path *path, int level, |
f7c79f30 CM |
1480 | int lowest_unlock, int min_write_lock_level, |
1481 | int *write_lock_level) | |
925baedd CM |
1482 | { |
1483 | int i; | |
1484 | int skip_level = level; | |
c1227996 | 1485 | bool check_skip = true; |
925baedd CM |
1486 | |
1487 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { | |
1488 | if (!path->nodes[i]) | |
1489 | break; | |
1490 | if (!path->locks[i]) | |
1491 | break; | |
c1227996 NB |
1492 | |
1493 | if (check_skip) { | |
1494 | if (path->slots[i] == 0) { | |
925baedd CM |
1495 | skip_level = i + 1; |
1496 | continue; | |
1497 | } | |
c1227996 NB |
1498 | |
1499 | if (path->keep_locks) { | |
1500 | u32 nritems; | |
1501 | ||
1502 | nritems = btrfs_header_nritems(path->nodes[i]); | |
1503 | if (nritems < 1 || path->slots[i] >= nritems - 1) { | |
1504 | skip_level = i + 1; | |
1505 | continue; | |
1506 | } | |
1507 | } | |
925baedd | 1508 | } |
051e1b9f | 1509 | |
d80bb3f9 | 1510 | if (i >= lowest_unlock && i > skip_level) { |
c1227996 NB |
1511 | check_skip = false; |
1512 | btrfs_tree_unlock_rw(path->nodes[i], path->locks[i]); | |
925baedd | 1513 | path->locks[i] = 0; |
f7c79f30 CM |
1514 | if (write_lock_level && |
1515 | i > min_write_lock_level && | |
1516 | i <= *write_lock_level) { | |
1517 | *write_lock_level = i - 1; | |
1518 | } | |
925baedd CM |
1519 | } |
1520 | } | |
1521 | } | |
1522 | ||
c8c42864 | 1523 | /* |
376a21d7 FM |
1524 | * Helper function for btrfs_search_slot() and other functions that do a search |
1525 | * on a btree. The goal is to find a tree block in the cache (the radix tree at | |
1526 | * fs_info->buffer_radix), but if we can't find it, or it's not up to date, read | |
1527 | * its pages from disk. | |
c8c42864 | 1528 | * |
376a21d7 FM |
1529 | * Returns -EAGAIN, with the path unlocked, if the caller needs to repeat the |
1530 | * whole btree search, starting again from the current root node. | |
c8c42864 CM |
1531 | */ |
1532 | static int | |
d07b8528 LB |
1533 | read_block_for_search(struct btrfs_root *root, struct btrfs_path *p, |
1534 | struct extent_buffer **eb_ret, int level, int slot, | |
cda79c54 | 1535 | const struct btrfs_key *key) |
c8c42864 | 1536 | { |
0b246afa | 1537 | struct btrfs_fs_info *fs_info = root->fs_info; |
789d6a3a | 1538 | struct btrfs_tree_parent_check check = { 0 }; |
c8c42864 CM |
1539 | u64 blocknr; |
1540 | u64 gen; | |
c8c42864 | 1541 | struct extent_buffer *tmp; |
76a05b35 | 1542 | int ret; |
581c1760 | 1543 | int parent_level; |
b246666e | 1544 | bool unlock_up; |
c8c42864 | 1545 | |
b246666e | 1546 | unlock_up = ((level + 1 < BTRFS_MAX_LEVEL) && p->locks[level + 1]); |
213ff4b7 NB |
1547 | blocknr = btrfs_node_blockptr(*eb_ret, slot); |
1548 | gen = btrfs_node_ptr_generation(*eb_ret, slot); | |
1549 | parent_level = btrfs_header_level(*eb_ret); | |
789d6a3a QW |
1550 | btrfs_node_key_to_cpu(*eb_ret, &check.first_key, slot); |
1551 | check.has_first_key = true; | |
1552 | check.level = parent_level - 1; | |
1553 | check.transid = gen; | |
1554 | check.owner_root = root->root_key.objectid; | |
c8c42864 | 1555 | |
b246666e FM |
1556 | /* |
1557 | * If we need to read an extent buffer from disk and we are holding locks | |
1558 | * on upper level nodes, we unlock all the upper nodes before reading the | |
1559 | * extent buffer, and then return -EAGAIN to the caller as it needs to | |
1560 | * restart the search. We don't release the lock on the current level | |
1561 | * because we need to walk this node to figure out which blocks to read. | |
1562 | */ | |
0b246afa | 1563 | tmp = find_extent_buffer(fs_info, blocknr); |
cb44921a | 1564 | if (tmp) { |
ace75066 FM |
1565 | if (p->reada == READA_FORWARD_ALWAYS) |
1566 | reada_for_search(fs_info, p, level, slot, key->objectid); | |
1567 | ||
b9fab919 | 1568 | /* first we do an atomic uptodate check */ |
bdf7c00e | 1569 | if (btrfs_buffer_uptodate(tmp, gen, 1) > 0) { |
448de471 QW |
1570 | /* |
1571 | * Do extra check for first_key, eb can be stale due to | |
1572 | * being cached, read from scrub, or have multiple | |
1573 | * parents (shared tree blocks). | |
1574 | */ | |
e064d5e9 | 1575 | if (btrfs_verify_level_key(tmp, |
789d6a3a | 1576 | parent_level - 1, &check.first_key, gen)) { |
448de471 QW |
1577 | free_extent_buffer(tmp); |
1578 | return -EUCLEAN; | |
1579 | } | |
bdf7c00e JB |
1580 | *eb_ret = tmp; |
1581 | return 0; | |
1582 | } | |
1583 | ||
857bc13f JB |
1584 | if (p->nowait) { |
1585 | free_extent_buffer(tmp); | |
1586 | return -EAGAIN; | |
1587 | } | |
1588 | ||
b246666e FM |
1589 | if (unlock_up) |
1590 | btrfs_unlock_up_safe(p, level + 1); | |
1591 | ||
bdf7c00e | 1592 | /* now we're allowed to do a blocking uptodate check */ |
789d6a3a | 1593 | ret = btrfs_read_extent_buffer(tmp, &check); |
9a4ffa1b QW |
1594 | if (ret) { |
1595 | free_extent_buffer(tmp); | |
1596 | btrfs_release_path(p); | |
1597 | return -EIO; | |
cb44921a | 1598 | } |
88c602ab QW |
1599 | if (btrfs_check_eb_owner(tmp, root->root_key.objectid)) { |
1600 | free_extent_buffer(tmp); | |
1601 | btrfs_release_path(p); | |
1602 | return -EUCLEAN; | |
1603 | } | |
b246666e FM |
1604 | |
1605 | if (unlock_up) | |
1606 | ret = -EAGAIN; | |
1607 | ||
1608 | goto out; | |
857bc13f JB |
1609 | } else if (p->nowait) { |
1610 | return -EAGAIN; | |
c8c42864 CM |
1611 | } |
1612 | ||
b246666e | 1613 | if (unlock_up) { |
4bb59055 FM |
1614 | btrfs_unlock_up_safe(p, level + 1); |
1615 | ret = -EAGAIN; | |
1616 | } else { | |
1617 | ret = 0; | |
1618 | } | |
8c594ea8 | 1619 | |
e4058b54 | 1620 | if (p->reada != READA_NONE) |
2ff7e61e | 1621 | reada_for_search(fs_info, p, level, slot, key->objectid); |
c8c42864 | 1622 | |
789d6a3a | 1623 | tmp = read_tree_block(fs_info, blocknr, &check); |
4eb150d6 QW |
1624 | if (IS_ERR(tmp)) { |
1625 | btrfs_release_path(p); | |
1626 | return PTR_ERR(tmp); | |
76a05b35 | 1627 | } |
4eb150d6 QW |
1628 | /* |
1629 | * If the read above didn't mark this buffer up to date, | |
1630 | * it will never end up being up to date. Set ret to EIO now | |
1631 | * and give up so that our caller doesn't loop forever | |
1632 | * on our EAGAINs. | |
1633 | */ | |
1634 | if (!extent_buffer_uptodate(tmp)) | |
1635 | ret = -EIO; | |
02a3307a | 1636 | |
b246666e | 1637 | out: |
4bb59055 FM |
1638 | if (ret == 0) { |
1639 | *eb_ret = tmp; | |
1640 | } else { | |
1641 | free_extent_buffer(tmp); | |
1642 | btrfs_release_path(p); | |
1643 | } | |
1644 | ||
76a05b35 | 1645 | return ret; |
c8c42864 CM |
1646 | } |
1647 | ||
1648 | /* | |
1649 | * helper function for btrfs_search_slot. This does all of the checks | |
1650 | * for node-level blocks and does any balancing required based on | |
1651 | * the ins_len. | |
1652 | * | |
1653 | * If no extra work was required, zero is returned. If we had to | |
1654 | * drop the path, -EAGAIN is returned and btrfs_search_slot must | |
1655 | * start over | |
1656 | */ | |
1657 | static int | |
1658 | setup_nodes_for_search(struct btrfs_trans_handle *trans, | |
1659 | struct btrfs_root *root, struct btrfs_path *p, | |
bd681513 CM |
1660 | struct extent_buffer *b, int level, int ins_len, |
1661 | int *write_lock_level) | |
c8c42864 | 1662 | { |
0b246afa | 1663 | struct btrfs_fs_info *fs_info = root->fs_info; |
95b982de | 1664 | int ret = 0; |
0b246afa | 1665 | |
c8c42864 | 1666 | if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >= |
0b246afa | 1667 | BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 3) { |
c8c42864 | 1668 | |
bd681513 CM |
1669 | if (*write_lock_level < level + 1) { |
1670 | *write_lock_level = level + 1; | |
1671 | btrfs_release_path(p); | |
95b982de | 1672 | return -EAGAIN; |
bd681513 CM |
1673 | } |
1674 | ||
bfb484d9 | 1675 | reada_for_balance(p, level); |
95b982de | 1676 | ret = split_node(trans, root, p, level); |
c8c42864 | 1677 | |
c8c42864 CM |
1678 | b = p->nodes[level]; |
1679 | } else if (ins_len < 0 && btrfs_header_nritems(b) < | |
0b246afa | 1680 | BTRFS_NODEPTRS_PER_BLOCK(fs_info) / 2) { |
c8c42864 | 1681 | |
bd681513 CM |
1682 | if (*write_lock_level < level + 1) { |
1683 | *write_lock_level = level + 1; | |
1684 | btrfs_release_path(p); | |
95b982de | 1685 | return -EAGAIN; |
bd681513 CM |
1686 | } |
1687 | ||
bfb484d9 | 1688 | reada_for_balance(p, level); |
95b982de NB |
1689 | ret = balance_level(trans, root, p, level); |
1690 | if (ret) | |
1691 | return ret; | |
c8c42864 | 1692 | |
c8c42864 CM |
1693 | b = p->nodes[level]; |
1694 | if (!b) { | |
b3b4aa74 | 1695 | btrfs_release_path(p); |
95b982de | 1696 | return -EAGAIN; |
c8c42864 CM |
1697 | } |
1698 | BUG_ON(btrfs_header_nritems(b) == 1); | |
1699 | } | |
c8c42864 CM |
1700 | return ret; |
1701 | } | |
1702 | ||
381cf658 | 1703 | int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *path, |
e33d5c3d KN |
1704 | u64 iobjectid, u64 ioff, u8 key_type, |
1705 | struct btrfs_key *found_key) | |
1706 | { | |
1707 | int ret; | |
1708 | struct btrfs_key key; | |
1709 | struct extent_buffer *eb; | |
381cf658 DS |
1710 | |
1711 | ASSERT(path); | |
1d4c08e0 | 1712 | ASSERT(found_key); |
e33d5c3d KN |
1713 | |
1714 | key.type = key_type; | |
1715 | key.objectid = iobjectid; | |
1716 | key.offset = ioff; | |
1717 | ||
1718 | ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0); | |
1d4c08e0 | 1719 | if (ret < 0) |
e33d5c3d KN |
1720 | return ret; |
1721 | ||
1722 | eb = path->nodes[0]; | |
1723 | if (ret && path->slots[0] >= btrfs_header_nritems(eb)) { | |
1724 | ret = btrfs_next_leaf(fs_root, path); | |
1725 | if (ret) | |
1726 | return ret; | |
1727 | eb = path->nodes[0]; | |
1728 | } | |
1729 | ||
1730 | btrfs_item_key_to_cpu(eb, found_key, path->slots[0]); | |
1731 | if (found_key->type != key.type || | |
1732 | found_key->objectid != key.objectid) | |
1733 | return 1; | |
1734 | ||
1735 | return 0; | |
1736 | } | |
1737 | ||
1fc28d8e LB |
1738 | static struct extent_buffer *btrfs_search_slot_get_root(struct btrfs_root *root, |
1739 | struct btrfs_path *p, | |
1740 | int write_lock_level) | |
1741 | { | |
1fc28d8e | 1742 | struct extent_buffer *b; |
120de408 | 1743 | int root_lock = 0; |
1fc28d8e LB |
1744 | int level = 0; |
1745 | ||
1fc28d8e | 1746 | if (p->search_commit_root) { |
d96b3424 FM |
1747 | b = root->commit_root; |
1748 | atomic_inc(&b->refs); | |
be6821f8 | 1749 | level = btrfs_header_level(b); |
f9ddfd05 LB |
1750 | /* |
1751 | * Ensure that all callers have set skip_locking when | |
1752 | * p->search_commit_root = 1. | |
1753 | */ | |
1754 | ASSERT(p->skip_locking == 1); | |
1fc28d8e LB |
1755 | |
1756 | goto out; | |
1757 | } | |
1758 | ||
1759 | if (p->skip_locking) { | |
1760 | b = btrfs_root_node(root); | |
1761 | level = btrfs_header_level(b); | |
1762 | goto out; | |
1763 | } | |
1764 | ||
120de408 JB |
1765 | /* We try very hard to do read locks on the root */ |
1766 | root_lock = BTRFS_READ_LOCK; | |
1767 | ||
1fc28d8e | 1768 | /* |
662c653b LB |
1769 | * If the level is set to maximum, we can skip trying to get the read |
1770 | * lock. | |
1fc28d8e | 1771 | */ |
662c653b LB |
1772 | if (write_lock_level < BTRFS_MAX_LEVEL) { |
1773 | /* | |
1774 | * We don't know the level of the root node until we actually | |
1775 | * have it read locked | |
1776 | */ | |
857bc13f JB |
1777 | if (p->nowait) { |
1778 | b = btrfs_try_read_lock_root_node(root); | |
1779 | if (IS_ERR(b)) | |
1780 | return b; | |
1781 | } else { | |
1782 | b = btrfs_read_lock_root_node(root); | |
1783 | } | |
662c653b LB |
1784 | level = btrfs_header_level(b); |
1785 | if (level > write_lock_level) | |
1786 | goto out; | |
1787 | ||
1788 | /* Whoops, must trade for write lock */ | |
1789 | btrfs_tree_read_unlock(b); | |
1790 | free_extent_buffer(b); | |
1791 | } | |
1fc28d8e | 1792 | |
1fc28d8e LB |
1793 | b = btrfs_lock_root_node(root); |
1794 | root_lock = BTRFS_WRITE_LOCK; | |
1795 | ||
1796 | /* The level might have changed, check again */ | |
1797 | level = btrfs_header_level(b); | |
1798 | ||
1799 | out: | |
120de408 JB |
1800 | /* |
1801 | * The root may have failed to write out at some point, and thus is no | |
1802 | * longer valid, return an error in this case. | |
1803 | */ | |
1804 | if (!extent_buffer_uptodate(b)) { | |
1805 | if (root_lock) | |
1806 | btrfs_tree_unlock_rw(b, root_lock); | |
1807 | free_extent_buffer(b); | |
1808 | return ERR_PTR(-EIO); | |
1809 | } | |
1810 | ||
1fc28d8e LB |
1811 | p->nodes[level] = b; |
1812 | if (!p->skip_locking) | |
1813 | p->locks[level] = root_lock; | |
1814 | /* | |
1815 | * Callers are responsible for dropping b's references. | |
1816 | */ | |
1817 | return b; | |
1818 | } | |
1819 | ||
d96b3424 FM |
1820 | /* |
1821 | * Replace the extent buffer at the lowest level of the path with a cloned | |
1822 | * version. The purpose is to be able to use it safely, after releasing the | |
1823 | * commit root semaphore, even if relocation is happening in parallel, the | |
1824 | * transaction used for relocation is committed and the extent buffer is | |
1825 | * reallocated in the next transaction. | |
1826 | * | |
1827 | * This is used in a context where the caller does not prevent transaction | |
1828 | * commits from happening, either by holding a transaction handle or holding | |
1829 | * some lock, while it's doing searches through a commit root. | |
1830 | * At the moment it's only used for send operations. | |
1831 | */ | |
1832 | static int finish_need_commit_sem_search(struct btrfs_path *path) | |
1833 | { | |
1834 | const int i = path->lowest_level; | |
1835 | const int slot = path->slots[i]; | |
1836 | struct extent_buffer *lowest = path->nodes[i]; | |
1837 | struct extent_buffer *clone; | |
1838 | ||
1839 | ASSERT(path->need_commit_sem); | |
1840 | ||
1841 | if (!lowest) | |
1842 | return 0; | |
1843 | ||
1844 | lockdep_assert_held_read(&lowest->fs_info->commit_root_sem); | |
1845 | ||
1846 | clone = btrfs_clone_extent_buffer(lowest); | |
1847 | if (!clone) | |
1848 | return -ENOMEM; | |
1849 | ||
1850 | btrfs_release_path(path); | |
1851 | path->nodes[i] = clone; | |
1852 | path->slots[i] = slot; | |
1853 | ||
1854 | return 0; | |
1855 | } | |
1fc28d8e | 1856 | |
e2e58d0f FM |
1857 | static inline int search_for_key_slot(struct extent_buffer *eb, |
1858 | int search_low_slot, | |
1859 | const struct btrfs_key *key, | |
1860 | int prev_cmp, | |
1861 | int *slot) | |
1862 | { | |
1863 | /* | |
1864 | * If a previous call to btrfs_bin_search() on a parent node returned an | |
1865 | * exact match (prev_cmp == 0), we can safely assume the target key will | |
1866 | * always be at slot 0 on lower levels, since each key pointer | |
1867 | * (struct btrfs_key_ptr) refers to the lowest key accessible from the | |
1868 | * subtree it points to. Thus we can skip searching lower levels. | |
1869 | */ | |
1870 | if (prev_cmp == 0) { | |
1871 | *slot = 0; | |
1872 | return 0; | |
1873 | } | |
1874 | ||
fdf8d595 | 1875 | return btrfs_bin_search(eb, search_low_slot, key, slot); |
e2e58d0f FM |
1876 | } |
1877 | ||
109324cf FM |
1878 | static int search_leaf(struct btrfs_trans_handle *trans, |
1879 | struct btrfs_root *root, | |
1880 | const struct btrfs_key *key, | |
1881 | struct btrfs_path *path, | |
1882 | int ins_len, | |
1883 | int prev_cmp) | |
1884 | { | |
1885 | struct extent_buffer *leaf = path->nodes[0]; | |
1886 | int leaf_free_space = -1; | |
1887 | int search_low_slot = 0; | |
1888 | int ret; | |
1889 | bool do_bin_search = true; | |
1890 | ||
1891 | /* | |
1892 | * If we are doing an insertion, the leaf has enough free space and the | |
1893 | * destination slot for the key is not slot 0, then we can unlock our | |
1894 | * write lock on the parent, and any other upper nodes, before doing the | |
1895 | * binary search on the leaf (with search_for_key_slot()), allowing other | |
1896 | * tasks to lock the parent and any other upper nodes. | |
1897 | */ | |
1898 | if (ins_len > 0) { | |
1899 | /* | |
1900 | * Cache the leaf free space, since we will need it later and it | |
1901 | * will not change until then. | |
1902 | */ | |
1903 | leaf_free_space = btrfs_leaf_free_space(leaf); | |
1904 | ||
1905 | /* | |
1906 | * !path->locks[1] means we have a single node tree, the leaf is | |
1907 | * the root of the tree. | |
1908 | */ | |
1909 | if (path->locks[1] && leaf_free_space >= ins_len) { | |
1910 | struct btrfs_disk_key first_key; | |
1911 | ||
1912 | ASSERT(btrfs_header_nritems(leaf) > 0); | |
1913 | btrfs_item_key(leaf, &first_key, 0); | |
1914 | ||
1915 | /* | |
1916 | * Doing the extra comparison with the first key is cheap, | |
1917 | * taking into account that the first key is very likely | |
1918 | * already in a cache line because it immediately follows | |
1919 | * the extent buffer's header and we have recently accessed | |
1920 | * the header's level field. | |
1921 | */ | |
1922 | ret = comp_keys(&first_key, key); | |
1923 | if (ret < 0) { | |
1924 | /* | |
1925 | * The first key is smaller than the key we want | |
1926 | * to insert, so we are safe to unlock all upper | |
1927 | * nodes and we have to do the binary search. | |
1928 | * | |
1929 | * We do use btrfs_unlock_up_safe() and not | |
1930 | * unlock_up() because the later does not unlock | |
1931 | * nodes with a slot of 0 - we can safely unlock | |
1932 | * any node even if its slot is 0 since in this | |
1933 | * case the key does not end up at slot 0 of the | |
1934 | * leaf and there's no need to split the leaf. | |
1935 | */ | |
1936 | btrfs_unlock_up_safe(path, 1); | |
1937 | search_low_slot = 1; | |
1938 | } else { | |
1939 | /* | |
1940 | * The first key is >= then the key we want to | |
1941 | * insert, so we can skip the binary search as | |
1942 | * the target key will be at slot 0. | |
1943 | * | |
1944 | * We can not unlock upper nodes when the key is | |
1945 | * less than the first key, because we will need | |
1946 | * to update the key at slot 0 of the parent node | |
1947 | * and possibly of other upper nodes too. | |
1948 | * If the key matches the first key, then we can | |
1949 | * unlock all the upper nodes, using | |
1950 | * btrfs_unlock_up_safe() instead of unlock_up() | |
1951 | * as stated above. | |
1952 | */ | |
1953 | if (ret == 0) | |
1954 | btrfs_unlock_up_safe(path, 1); | |
1955 | /* | |
1956 | * ret is already 0 or 1, matching the result of | |
1957 | * a btrfs_bin_search() call, so there is no need | |
1958 | * to adjust it. | |
1959 | */ | |
1960 | do_bin_search = false; | |
1961 | path->slots[0] = 0; | |
1962 | } | |
1963 | } | |
1964 | } | |
1965 | ||
1966 | if (do_bin_search) { | |
1967 | ret = search_for_key_slot(leaf, search_low_slot, key, | |
1968 | prev_cmp, &path->slots[0]); | |
1969 | if (ret < 0) | |
1970 | return ret; | |
1971 | } | |
1972 | ||
1973 | if (ins_len > 0) { | |
1974 | /* | |
1975 | * Item key already exists. In this case, if we are allowed to | |
1976 | * insert the item (for example, in dir_item case, item key | |
1977 | * collision is allowed), it will be merged with the original | |
1978 | * item. Only the item size grows, no new btrfs item will be | |
1979 | * added. If search_for_extension is not set, ins_len already | |
1980 | * accounts the size btrfs_item, deduct it here so leaf space | |
1981 | * check will be correct. | |
1982 | */ | |
1983 | if (ret == 0 && !path->search_for_extension) { | |
1984 | ASSERT(ins_len >= sizeof(struct btrfs_item)); | |
1985 | ins_len -= sizeof(struct btrfs_item); | |
1986 | } | |
1987 | ||
1988 | ASSERT(leaf_free_space >= 0); | |
1989 | ||
1990 | if (leaf_free_space < ins_len) { | |
1991 | int err; | |
1992 | ||
1993 | err = split_leaf(trans, root, key, path, ins_len, | |
1994 | (ret == 0)); | |
bb8e9a60 FM |
1995 | ASSERT(err <= 0); |
1996 | if (WARN_ON(err > 0)) | |
1997 | err = -EUCLEAN; | |
109324cf FM |
1998 | if (err) |
1999 | ret = err; | |
2000 | } | |
2001 | } | |
2002 | ||
2003 | return ret; | |
2004 | } | |
2005 | ||
74123bd7 | 2006 | /* |
4271ecea NB |
2007 | * btrfs_search_slot - look for a key in a tree and perform necessary |
2008 | * modifications to preserve tree invariants. | |
74123bd7 | 2009 | * |
4271ecea NB |
2010 | * @trans: Handle of transaction, used when modifying the tree |
2011 | * @p: Holds all btree nodes along the search path | |
2012 | * @root: The root node of the tree | |
2013 | * @key: The key we are looking for | |
9a664971 | 2014 | * @ins_len: Indicates purpose of search: |
2015 | * >0 for inserts it's size of item inserted (*) | |
2016 | * <0 for deletions | |
2017 | * 0 for plain searches, not modifying the tree | |
2018 | * | |
2019 | * (*) If size of item inserted doesn't include | |
2020 | * sizeof(struct btrfs_item), then p->search_for_extension must | |
2021 | * be set. | |
4271ecea NB |
2022 | * @cow: boolean should CoW operations be performed. Must always be 1 |
2023 | * when modifying the tree. | |
97571fd0 | 2024 | * |
4271ecea NB |
2025 | * If @ins_len > 0, nodes and leaves will be split as we walk down the tree. |
2026 | * If @ins_len < 0, nodes will be merged as we walk down the tree (if possible) | |
2027 | * | |
2028 | * If @key is found, 0 is returned and you can find the item in the leaf level | |
2029 | * of the path (level 0) | |
2030 | * | |
2031 | * If @key isn't found, 1 is returned and the leaf level of the path (level 0) | |
2032 | * points to the slot where it should be inserted | |
2033 | * | |
2034 | * If an error is encountered while searching the tree a negative error number | |
2035 | * is returned | |
74123bd7 | 2036 | */ |
310712b2 OS |
2037 | int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
2038 | const struct btrfs_key *key, struct btrfs_path *p, | |
2039 | int ins_len, int cow) | |
be0e5c09 | 2040 | { |
d96b3424 | 2041 | struct btrfs_fs_info *fs_info = root->fs_info; |
5f39d397 | 2042 | struct extent_buffer *b; |
be0e5c09 CM |
2043 | int slot; |
2044 | int ret; | |
33c66f43 | 2045 | int err; |
be0e5c09 | 2046 | int level; |
925baedd | 2047 | int lowest_unlock = 1; |
bd681513 CM |
2048 | /* everything at write_lock_level or lower must be write locked */ |
2049 | int write_lock_level = 0; | |
9f3a7427 | 2050 | u8 lowest_level = 0; |
f7c79f30 | 2051 | int min_write_lock_level; |
d7396f07 | 2052 | int prev_cmp; |
9f3a7427 | 2053 | |
a4c853af C |
2054 | might_sleep(); |
2055 | ||
6702ed49 | 2056 | lowest_level = p->lowest_level; |
323ac95b | 2057 | WARN_ON(lowest_level && ins_len > 0); |
22b0ebda | 2058 | WARN_ON(p->nodes[0] != NULL); |
eb653de1 | 2059 | BUG_ON(!cow && ins_len); |
25179201 | 2060 | |
857bc13f JB |
2061 | /* |
2062 | * For now only allow nowait for read only operations. There's no | |
2063 | * strict reason why we can't, we just only need it for reads so it's | |
2064 | * only implemented for reads. | |
2065 | */ | |
2066 | ASSERT(!p->nowait || !cow); | |
2067 | ||
bd681513 | 2068 | if (ins_len < 0) { |
925baedd | 2069 | lowest_unlock = 2; |
65b51a00 | 2070 | |
bd681513 CM |
2071 | /* when we are removing items, we might have to go up to level |
2072 | * two as we update tree pointers Make sure we keep write | |
2073 | * for those levels as well | |
2074 | */ | |
2075 | write_lock_level = 2; | |
2076 | } else if (ins_len > 0) { | |
2077 | /* | |
2078 | * for inserting items, make sure we have a write lock on | |
2079 | * level 1 so we can update keys | |
2080 | */ | |
2081 | write_lock_level = 1; | |
2082 | } | |
2083 | ||
2084 | if (!cow) | |
2085 | write_lock_level = -1; | |
2086 | ||
09a2a8f9 | 2087 | if (cow && (p->keep_locks || p->lowest_level)) |
bd681513 CM |
2088 | write_lock_level = BTRFS_MAX_LEVEL; |
2089 | ||
f7c79f30 CM |
2090 | min_write_lock_level = write_lock_level; |
2091 | ||
d96b3424 FM |
2092 | if (p->need_commit_sem) { |
2093 | ASSERT(p->search_commit_root); | |
857bc13f JB |
2094 | if (p->nowait) { |
2095 | if (!down_read_trylock(&fs_info->commit_root_sem)) | |
2096 | return -EAGAIN; | |
2097 | } else { | |
2098 | down_read(&fs_info->commit_root_sem); | |
2099 | } | |
d96b3424 FM |
2100 | } |
2101 | ||
bb803951 | 2102 | again: |
d7396f07 | 2103 | prev_cmp = -1; |
1fc28d8e | 2104 | b = btrfs_search_slot_get_root(root, p, write_lock_level); |
be6821f8 FM |
2105 | if (IS_ERR(b)) { |
2106 | ret = PTR_ERR(b); | |
2107 | goto done; | |
2108 | } | |
925baedd | 2109 | |
eb60ceac | 2110 | while (b) { |
f624d976 QW |
2111 | int dec = 0; |
2112 | ||
5f39d397 | 2113 | level = btrfs_header_level(b); |
65b51a00 | 2114 | |
02217ed2 | 2115 | if (cow) { |
9ea2c7c9 NB |
2116 | bool last_level = (level == (BTRFS_MAX_LEVEL - 1)); |
2117 | ||
c8c42864 CM |
2118 | /* |
2119 | * if we don't really need to cow this block | |
2120 | * then we don't want to set the path blocking, | |
2121 | * so we test it here | |
2122 | */ | |
5963ffca | 2123 | if (!should_cow_block(trans, root, b)) |
65b51a00 | 2124 | goto cow_done; |
5d4f98a2 | 2125 | |
bd681513 CM |
2126 | /* |
2127 | * must have write locks on this node and the | |
2128 | * parent | |
2129 | */ | |
5124e00e JB |
2130 | if (level > write_lock_level || |
2131 | (level + 1 > write_lock_level && | |
2132 | level + 1 < BTRFS_MAX_LEVEL && | |
2133 | p->nodes[level + 1])) { | |
bd681513 CM |
2134 | write_lock_level = level + 1; |
2135 | btrfs_release_path(p); | |
2136 | goto again; | |
2137 | } | |
2138 | ||
9ea2c7c9 NB |
2139 | if (last_level) |
2140 | err = btrfs_cow_block(trans, root, b, NULL, 0, | |
9631e4cc JB |
2141 | &b, |
2142 | BTRFS_NESTING_COW); | |
9ea2c7c9 NB |
2143 | else |
2144 | err = btrfs_cow_block(trans, root, b, | |
2145 | p->nodes[level + 1], | |
9631e4cc JB |
2146 | p->slots[level + 1], &b, |
2147 | BTRFS_NESTING_COW); | |
33c66f43 | 2148 | if (err) { |
33c66f43 | 2149 | ret = err; |
65b51a00 | 2150 | goto done; |
54aa1f4d | 2151 | } |
02217ed2 | 2152 | } |
65b51a00 | 2153 | cow_done: |
eb60ceac | 2154 | p->nodes[level] = b; |
b4ce94de CM |
2155 | |
2156 | /* | |
2157 | * we have a lock on b and as long as we aren't changing | |
2158 | * the tree, there is no way to for the items in b to change. | |
2159 | * It is safe to drop the lock on our parent before we | |
2160 | * go through the expensive btree search on b. | |
2161 | * | |
eb653de1 FDBM |
2162 | * If we're inserting or deleting (ins_len != 0), then we might |
2163 | * be changing slot zero, which may require changing the parent. | |
2164 | * So, we can't drop the lock until after we know which slot | |
2165 | * we're operating on. | |
b4ce94de | 2166 | */ |
eb653de1 FDBM |
2167 | if (!ins_len && !p->keep_locks) { |
2168 | int u = level + 1; | |
2169 | ||
2170 | if (u < BTRFS_MAX_LEVEL && p->locks[u]) { | |
2171 | btrfs_tree_unlock_rw(p->nodes[u], p->locks[u]); | |
2172 | p->locks[u] = 0; | |
2173 | } | |
2174 | } | |
b4ce94de | 2175 | |
e2e58d0f | 2176 | if (level == 0) { |
109324cf | 2177 | if (ins_len > 0) |
e5e1c174 | 2178 | ASSERT(write_lock_level >= 1); |
bd681513 | 2179 | |
109324cf | 2180 | ret = search_leaf(trans, root, key, p, ins_len, prev_cmp); |
459931ec | 2181 | if (!p->search_for_split) |
f7c79f30 | 2182 | unlock_up(p, level, lowest_unlock, |
4b6f8e96 | 2183 | min_write_lock_level, NULL); |
65b51a00 | 2184 | goto done; |
be0e5c09 | 2185 | } |
e2e58d0f FM |
2186 | |
2187 | ret = search_for_key_slot(b, 0, key, prev_cmp, &slot); | |
2188 | if (ret < 0) | |
2189 | goto done; | |
2190 | prev_cmp = ret; | |
2191 | ||
f624d976 QW |
2192 | if (ret && slot > 0) { |
2193 | dec = 1; | |
2194 | slot--; | |
2195 | } | |
2196 | p->slots[level] = slot; | |
2197 | err = setup_nodes_for_search(trans, root, p, b, level, ins_len, | |
2198 | &write_lock_level); | |
2199 | if (err == -EAGAIN) | |
2200 | goto again; | |
2201 | if (err) { | |
2202 | ret = err; | |
2203 | goto done; | |
2204 | } | |
2205 | b = p->nodes[level]; | |
2206 | slot = p->slots[level]; | |
2207 | ||
2208 | /* | |
2209 | * Slot 0 is special, if we change the key we have to update | |
2210 | * the parent pointer which means we must have a write lock on | |
2211 | * the parent | |
2212 | */ | |
2213 | if (slot == 0 && ins_len && write_lock_level < level + 1) { | |
2214 | write_lock_level = level + 1; | |
2215 | btrfs_release_path(p); | |
2216 | goto again; | |
2217 | } | |
2218 | ||
2219 | unlock_up(p, level, lowest_unlock, min_write_lock_level, | |
2220 | &write_lock_level); | |
2221 | ||
2222 | if (level == lowest_level) { | |
2223 | if (dec) | |
2224 | p->slots[level]++; | |
2225 | goto done; | |
2226 | } | |
2227 | ||
2228 | err = read_block_for_search(root, p, &b, level, slot, key); | |
2229 | if (err == -EAGAIN) | |
2230 | goto again; | |
2231 | if (err) { | |
2232 | ret = err; | |
2233 | goto done; | |
2234 | } | |
2235 | ||
2236 | if (!p->skip_locking) { | |
2237 | level = btrfs_header_level(b); | |
b40130b2 JB |
2238 | |
2239 | btrfs_maybe_reset_lockdep_class(root, b); | |
2240 | ||
f624d976 | 2241 | if (level <= write_lock_level) { |
ac5887c8 | 2242 | btrfs_tree_lock(b); |
f624d976 QW |
2243 | p->locks[level] = BTRFS_WRITE_LOCK; |
2244 | } else { | |
857bc13f JB |
2245 | if (p->nowait) { |
2246 | if (!btrfs_try_tree_read_lock(b)) { | |
2247 | free_extent_buffer(b); | |
2248 | ret = -EAGAIN; | |
2249 | goto done; | |
2250 | } | |
2251 | } else { | |
2252 | btrfs_tree_read_lock(b); | |
2253 | } | |
f624d976 QW |
2254 | p->locks[level] = BTRFS_READ_LOCK; |
2255 | } | |
2256 | p->nodes[level] = b; | |
2257 | } | |
be0e5c09 | 2258 | } |
65b51a00 CM |
2259 | ret = 1; |
2260 | done: | |
5f5bc6b1 | 2261 | if (ret < 0 && !p->skip_release_on_error) |
b3b4aa74 | 2262 | btrfs_release_path(p); |
d96b3424 FM |
2263 | |
2264 | if (p->need_commit_sem) { | |
2265 | int ret2; | |
2266 | ||
2267 | ret2 = finish_need_commit_sem_search(p); | |
2268 | up_read(&fs_info->commit_root_sem); | |
2269 | if (ret2) | |
2270 | ret = ret2; | |
2271 | } | |
2272 | ||
65b51a00 | 2273 | return ret; |
be0e5c09 | 2274 | } |
f75e2b79 | 2275 | ALLOW_ERROR_INJECTION(btrfs_search_slot, ERRNO); |
be0e5c09 | 2276 | |
5d9e75c4 JS |
2277 | /* |
2278 | * Like btrfs_search_slot, this looks for a key in the given tree. It uses the | |
2279 | * current state of the tree together with the operations recorded in the tree | |
2280 | * modification log to search for the key in a previous version of this tree, as | |
2281 | * denoted by the time_seq parameter. | |
2282 | * | |
2283 | * Naturally, there is no support for insert, delete or cow operations. | |
2284 | * | |
2285 | * The resulting path and return value will be set up as if we called | |
2286 | * btrfs_search_slot at that point in time with ins_len and cow both set to 0. | |
2287 | */ | |
310712b2 | 2288 | int btrfs_search_old_slot(struct btrfs_root *root, const struct btrfs_key *key, |
5d9e75c4 JS |
2289 | struct btrfs_path *p, u64 time_seq) |
2290 | { | |
0b246afa | 2291 | struct btrfs_fs_info *fs_info = root->fs_info; |
5d9e75c4 JS |
2292 | struct extent_buffer *b; |
2293 | int slot; | |
2294 | int ret; | |
2295 | int err; | |
2296 | int level; | |
2297 | int lowest_unlock = 1; | |
2298 | u8 lowest_level = 0; | |
2299 | ||
2300 | lowest_level = p->lowest_level; | |
2301 | WARN_ON(p->nodes[0] != NULL); | |
c922b016 | 2302 | ASSERT(!p->nowait); |
5d9e75c4 JS |
2303 | |
2304 | if (p->search_commit_root) { | |
2305 | BUG_ON(time_seq); | |
2306 | return btrfs_search_slot(NULL, root, key, p, 0, 0); | |
2307 | } | |
2308 | ||
2309 | again: | |
f3a84ccd | 2310 | b = btrfs_get_old_root(root, time_seq); |
315bed43 NB |
2311 | if (!b) { |
2312 | ret = -EIO; | |
2313 | goto done; | |
2314 | } | |
5d9e75c4 | 2315 | level = btrfs_header_level(b); |
5d9e75c4 JS |
2316 | p->locks[level] = BTRFS_READ_LOCK; |
2317 | ||
2318 | while (b) { | |
abe9339d QW |
2319 | int dec = 0; |
2320 | ||
5d9e75c4 JS |
2321 | level = btrfs_header_level(b); |
2322 | p->nodes[level] = b; | |
5d9e75c4 JS |
2323 | |
2324 | /* | |
2325 | * we have a lock on b and as long as we aren't changing | |
2326 | * the tree, there is no way to for the items in b to change. | |
2327 | * It is safe to drop the lock on our parent before we | |
2328 | * go through the expensive btree search on b. | |
2329 | */ | |
2330 | btrfs_unlock_up_safe(p, level + 1); | |
2331 | ||
fdf8d595 | 2332 | ret = btrfs_bin_search(b, 0, key, &slot); |
cbca7d59 FM |
2333 | if (ret < 0) |
2334 | goto done; | |
5d9e75c4 | 2335 | |
abe9339d | 2336 | if (level == 0) { |
5d9e75c4 JS |
2337 | p->slots[level] = slot; |
2338 | unlock_up(p, level, lowest_unlock, 0, NULL); | |
abe9339d QW |
2339 | goto done; |
2340 | } | |
5d9e75c4 | 2341 | |
abe9339d QW |
2342 | if (ret && slot > 0) { |
2343 | dec = 1; | |
2344 | slot--; | |
2345 | } | |
2346 | p->slots[level] = slot; | |
2347 | unlock_up(p, level, lowest_unlock, 0, NULL); | |
5d9e75c4 | 2348 | |
abe9339d QW |
2349 | if (level == lowest_level) { |
2350 | if (dec) | |
2351 | p->slots[level]++; | |
2352 | goto done; | |
2353 | } | |
5d9e75c4 | 2354 | |
abe9339d QW |
2355 | err = read_block_for_search(root, p, &b, level, slot, key); |
2356 | if (err == -EAGAIN) | |
2357 | goto again; | |
2358 | if (err) { | |
2359 | ret = err; | |
5d9e75c4 JS |
2360 | goto done; |
2361 | } | |
abe9339d QW |
2362 | |
2363 | level = btrfs_header_level(b); | |
ac5887c8 | 2364 | btrfs_tree_read_lock(b); |
f3a84ccd | 2365 | b = btrfs_tree_mod_log_rewind(fs_info, p, b, time_seq); |
abe9339d QW |
2366 | if (!b) { |
2367 | ret = -ENOMEM; | |
2368 | goto done; | |
2369 | } | |
2370 | p->locks[level] = BTRFS_READ_LOCK; | |
2371 | p->nodes[level] = b; | |
5d9e75c4 JS |
2372 | } |
2373 | ret = 1; | |
2374 | done: | |
5d9e75c4 JS |
2375 | if (ret < 0) |
2376 | btrfs_release_path(p); | |
2377 | ||
2378 | return ret; | |
2379 | } | |
2380 | ||
2f38b3e1 AJ |
2381 | /* |
2382 | * helper to use instead of search slot if no exact match is needed but | |
2383 | * instead the next or previous item should be returned. | |
2384 | * When find_higher is true, the next higher item is returned, the next lower | |
2385 | * otherwise. | |
2386 | * When return_any and find_higher are both true, and no higher item is found, | |
2387 | * return the next lower instead. | |
2388 | * When return_any is true and find_higher is false, and no lower item is found, | |
2389 | * return the next higher instead. | |
2390 | * It returns 0 if any item is found, 1 if none is found (tree empty), and | |
2391 | * < 0 on error | |
2392 | */ | |
2393 | int btrfs_search_slot_for_read(struct btrfs_root *root, | |
310712b2 OS |
2394 | const struct btrfs_key *key, |
2395 | struct btrfs_path *p, int find_higher, | |
2396 | int return_any) | |
2f38b3e1 AJ |
2397 | { |
2398 | int ret; | |
2399 | struct extent_buffer *leaf; | |
2400 | ||
2401 | again: | |
2402 | ret = btrfs_search_slot(NULL, root, key, p, 0, 0); | |
2403 | if (ret <= 0) | |
2404 | return ret; | |
2405 | /* | |
2406 | * a return value of 1 means the path is at the position where the | |
2407 | * item should be inserted. Normally this is the next bigger item, | |
2408 | * but in case the previous item is the last in a leaf, path points | |
2409 | * to the first free slot in the previous leaf, i.e. at an invalid | |
2410 | * item. | |
2411 | */ | |
2412 | leaf = p->nodes[0]; | |
2413 | ||
2414 | if (find_higher) { | |
2415 | if (p->slots[0] >= btrfs_header_nritems(leaf)) { | |
2416 | ret = btrfs_next_leaf(root, p); | |
2417 | if (ret <= 0) | |
2418 | return ret; | |
2419 | if (!return_any) | |
2420 | return 1; | |
2421 | /* | |
2422 | * no higher item found, return the next | |
2423 | * lower instead | |
2424 | */ | |
2425 | return_any = 0; | |
2426 | find_higher = 0; | |
2427 | btrfs_release_path(p); | |
2428 | goto again; | |
2429 | } | |
2430 | } else { | |
e6793769 AJ |
2431 | if (p->slots[0] == 0) { |
2432 | ret = btrfs_prev_leaf(root, p); | |
2433 | if (ret < 0) | |
2434 | return ret; | |
2435 | if (!ret) { | |
23c6bf6a FDBM |
2436 | leaf = p->nodes[0]; |
2437 | if (p->slots[0] == btrfs_header_nritems(leaf)) | |
2438 | p->slots[0]--; | |
e6793769 | 2439 | return 0; |
2f38b3e1 | 2440 | } |
e6793769 AJ |
2441 | if (!return_any) |
2442 | return 1; | |
2443 | /* | |
2444 | * no lower item found, return the next | |
2445 | * higher instead | |
2446 | */ | |
2447 | return_any = 0; | |
2448 | find_higher = 1; | |
2449 | btrfs_release_path(p); | |
2450 | goto again; | |
2451 | } else { | |
2f38b3e1 AJ |
2452 | --p->slots[0]; |
2453 | } | |
2454 | } | |
2455 | return 0; | |
2456 | } | |
2457 | ||
0ff40a91 MPS |
2458 | /* |
2459 | * Execute search and call btrfs_previous_item to traverse backwards if the item | |
2460 | * was not found. | |
2461 | * | |
2462 | * Return 0 if found, 1 if not found and < 0 if error. | |
2463 | */ | |
2464 | int btrfs_search_backwards(struct btrfs_root *root, struct btrfs_key *key, | |
2465 | struct btrfs_path *path) | |
2466 | { | |
2467 | int ret; | |
2468 | ||
2469 | ret = btrfs_search_slot(NULL, root, key, path, 0, 0); | |
2470 | if (ret > 0) | |
2471 | ret = btrfs_previous_item(root, path, key->objectid, key->type); | |
2472 | ||
2473 | if (ret == 0) | |
2474 | btrfs_item_key_to_cpu(path->nodes[0], key, path->slots[0]); | |
2475 | ||
2476 | return ret; | |
2477 | } | |
2478 | ||
43dd529a | 2479 | /* |
62142be3 GN |
2480 | * Search for a valid slot for the given path. |
2481 | * | |
2482 | * @root: The root node of the tree. | |
2483 | * @key: Will contain a valid item if found. | |
2484 | * @path: The starting point to validate the slot. | |
2485 | * | |
2486 | * Return: 0 if the item is valid | |
2487 | * 1 if not found | |
2488 | * <0 if error. | |
2489 | */ | |
2490 | int btrfs_get_next_valid_item(struct btrfs_root *root, struct btrfs_key *key, | |
2491 | struct btrfs_path *path) | |
2492 | { | |
524f14bb | 2493 | if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) { |
62142be3 | 2494 | int ret; |
62142be3 | 2495 | |
524f14bb FM |
2496 | ret = btrfs_next_leaf(root, path); |
2497 | if (ret) | |
2498 | return ret; | |
62142be3 | 2499 | } |
524f14bb FM |
2500 | |
2501 | btrfs_item_key_to_cpu(path->nodes[0], key, path->slots[0]); | |
62142be3 GN |
2502 | return 0; |
2503 | } | |
2504 | ||
74123bd7 CM |
2505 | /* |
2506 | * adjust the pointers going up the tree, starting at level | |
2507 | * making sure the right key of each node is points to 'key'. | |
2508 | * This is used after shifting pointers to the left, so it stops | |
2509 | * fixing up pointers when a given leaf/node is not in slot 0 of the | |
2510 | * higher levels | |
aa5d6bed | 2511 | * |
74123bd7 | 2512 | */ |
b167fa91 | 2513 | static void fixup_low_keys(struct btrfs_path *path, |
143bede5 | 2514 | struct btrfs_disk_key *key, int level) |
be0e5c09 CM |
2515 | { |
2516 | int i; | |
5f39d397 | 2517 | struct extent_buffer *t; |
0e82bcfe | 2518 | int ret; |
5f39d397 | 2519 | |
234b63a0 | 2520 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { |
be0e5c09 | 2521 | int tslot = path->slots[i]; |
0e82bcfe | 2522 | |
eb60ceac | 2523 | if (!path->nodes[i]) |
be0e5c09 | 2524 | break; |
5f39d397 | 2525 | t = path->nodes[i]; |
f3a84ccd | 2526 | ret = btrfs_tree_mod_log_insert_key(t, tslot, |
33cff222 | 2527 | BTRFS_MOD_LOG_KEY_REPLACE); |
0e82bcfe | 2528 | BUG_ON(ret < 0); |
5f39d397 | 2529 | btrfs_set_node_key(t, key, tslot); |
d6025579 | 2530 | btrfs_mark_buffer_dirty(path->nodes[i]); |
be0e5c09 CM |
2531 | if (tslot != 0) |
2532 | break; | |
2533 | } | |
2534 | } | |
2535 | ||
31840ae1 ZY |
2536 | /* |
2537 | * update item key. | |
2538 | * | |
2539 | * This function isn't completely safe. It's the caller's responsibility | |
2540 | * that the new key won't break the order | |
2541 | */ | |
b7a0365e DD |
2542 | void btrfs_set_item_key_safe(struct btrfs_fs_info *fs_info, |
2543 | struct btrfs_path *path, | |
310712b2 | 2544 | const struct btrfs_key *new_key) |
31840ae1 ZY |
2545 | { |
2546 | struct btrfs_disk_key disk_key; | |
2547 | struct extent_buffer *eb; | |
2548 | int slot; | |
2549 | ||
2550 | eb = path->nodes[0]; | |
2551 | slot = path->slots[0]; | |
2552 | if (slot > 0) { | |
2553 | btrfs_item_key(eb, &disk_key, slot - 1); | |
7c15d410 QW |
2554 | if (unlikely(comp_keys(&disk_key, new_key) >= 0)) { |
2555 | btrfs_crit(fs_info, | |
2556 | "slot %u key (%llu %u %llu) new key (%llu %u %llu)", | |
2557 | slot, btrfs_disk_key_objectid(&disk_key), | |
2558 | btrfs_disk_key_type(&disk_key), | |
2559 | btrfs_disk_key_offset(&disk_key), | |
2560 | new_key->objectid, new_key->type, | |
2561 | new_key->offset); | |
2562 | btrfs_print_leaf(eb); | |
2563 | BUG(); | |
2564 | } | |
31840ae1 ZY |
2565 | } |
2566 | if (slot < btrfs_header_nritems(eb) - 1) { | |
2567 | btrfs_item_key(eb, &disk_key, slot + 1); | |
7c15d410 QW |
2568 | if (unlikely(comp_keys(&disk_key, new_key) <= 0)) { |
2569 | btrfs_crit(fs_info, | |
2570 | "slot %u key (%llu %u %llu) new key (%llu %u %llu)", | |
2571 | slot, btrfs_disk_key_objectid(&disk_key), | |
2572 | btrfs_disk_key_type(&disk_key), | |
2573 | btrfs_disk_key_offset(&disk_key), | |
2574 | new_key->objectid, new_key->type, | |
2575 | new_key->offset); | |
2576 | btrfs_print_leaf(eb); | |
2577 | BUG(); | |
2578 | } | |
31840ae1 ZY |
2579 | } |
2580 | ||
2581 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
2582 | btrfs_set_item_key(eb, &disk_key, slot); | |
2583 | btrfs_mark_buffer_dirty(eb); | |
2584 | if (slot == 0) | |
b167fa91 | 2585 | fixup_low_keys(path, &disk_key, 1); |
31840ae1 ZY |
2586 | } |
2587 | ||
d16c702f QW |
2588 | /* |
2589 | * Check key order of two sibling extent buffers. | |
2590 | * | |
2591 | * Return true if something is wrong. | |
2592 | * Return false if everything is fine. | |
2593 | * | |
2594 | * Tree-checker only works inside one tree block, thus the following | |
2595 | * corruption can not be detected by tree-checker: | |
2596 | * | |
2597 | * Leaf @left | Leaf @right | |
2598 | * -------------------------------------------------------------- | |
2599 | * | 1 | 2 | 3 | 4 | 5 | f6 | | 7 | 8 | | |
2600 | * | |
2601 | * Key f6 in leaf @left itself is valid, but not valid when the next | |
2602 | * key in leaf @right is 7. | |
2603 | * This can only be checked at tree block merge time. | |
2604 | * And since tree checker has ensured all key order in each tree block | |
2605 | * is correct, we only need to bother the last key of @left and the first | |
2606 | * key of @right. | |
2607 | */ | |
2608 | static bool check_sibling_keys(struct extent_buffer *left, | |
2609 | struct extent_buffer *right) | |
2610 | { | |
2611 | struct btrfs_key left_last; | |
2612 | struct btrfs_key right_first; | |
2613 | int level = btrfs_header_level(left); | |
2614 | int nr_left = btrfs_header_nritems(left); | |
2615 | int nr_right = btrfs_header_nritems(right); | |
2616 | ||
2617 | /* No key to check in one of the tree blocks */ | |
2618 | if (!nr_left || !nr_right) | |
2619 | return false; | |
2620 | ||
2621 | if (level) { | |
2622 | btrfs_node_key_to_cpu(left, &left_last, nr_left - 1); | |
2623 | btrfs_node_key_to_cpu(right, &right_first, 0); | |
2624 | } else { | |
2625 | btrfs_item_key_to_cpu(left, &left_last, nr_left - 1); | |
2626 | btrfs_item_key_to_cpu(right, &right_first, 0); | |
2627 | } | |
2628 | ||
2629 | if (btrfs_comp_cpu_keys(&left_last, &right_first) >= 0) { | |
2630 | btrfs_crit(left->fs_info, | |
2631 | "bad key order, sibling blocks, left last (%llu %u %llu) right first (%llu %u %llu)", | |
2632 | left_last.objectid, left_last.type, | |
2633 | left_last.offset, right_first.objectid, | |
2634 | right_first.type, right_first.offset); | |
2635 | return true; | |
2636 | } | |
2637 | return false; | |
2638 | } | |
2639 | ||
74123bd7 CM |
2640 | /* |
2641 | * try to push data from one node into the next node left in the | |
79f95c82 | 2642 | * tree. |
aa5d6bed CM |
2643 | * |
2644 | * returns 0 if some ptrs were pushed left, < 0 if there was some horrible | |
2645 | * error, and > 0 if there was no room in the left hand block. | |
74123bd7 | 2646 | */ |
98ed5174 | 2647 | static int push_node_left(struct btrfs_trans_handle *trans, |
2ff7e61e | 2648 | struct extent_buffer *dst, |
971a1f66 | 2649 | struct extent_buffer *src, int empty) |
be0e5c09 | 2650 | { |
d30a668f | 2651 | struct btrfs_fs_info *fs_info = trans->fs_info; |
be0e5c09 | 2652 | int push_items = 0; |
bb803951 CM |
2653 | int src_nritems; |
2654 | int dst_nritems; | |
aa5d6bed | 2655 | int ret = 0; |
be0e5c09 | 2656 | |
5f39d397 CM |
2657 | src_nritems = btrfs_header_nritems(src); |
2658 | dst_nritems = btrfs_header_nritems(dst); | |
0b246afa | 2659 | push_items = BTRFS_NODEPTRS_PER_BLOCK(fs_info) - dst_nritems; |
7bb86316 CM |
2660 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
2661 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
54aa1f4d | 2662 | |
bce4eae9 | 2663 | if (!empty && src_nritems <= 8) |
971a1f66 CM |
2664 | return 1; |
2665 | ||
d397712b | 2666 | if (push_items <= 0) |
be0e5c09 CM |
2667 | return 1; |
2668 | ||
bce4eae9 | 2669 | if (empty) { |
971a1f66 | 2670 | push_items = min(src_nritems, push_items); |
bce4eae9 CM |
2671 | if (push_items < src_nritems) { |
2672 | /* leave at least 8 pointers in the node if | |
2673 | * we aren't going to empty it | |
2674 | */ | |
2675 | if (src_nritems - push_items < 8) { | |
2676 | if (push_items <= 8) | |
2677 | return 1; | |
2678 | push_items -= 8; | |
2679 | } | |
2680 | } | |
2681 | } else | |
2682 | push_items = min(src_nritems - 8, push_items); | |
79f95c82 | 2683 | |
d16c702f QW |
2684 | /* dst is the left eb, src is the middle eb */ |
2685 | if (check_sibling_keys(dst, src)) { | |
2686 | ret = -EUCLEAN; | |
2687 | btrfs_abort_transaction(trans, ret); | |
2688 | return ret; | |
2689 | } | |
f3a84ccd | 2690 | ret = btrfs_tree_mod_log_eb_copy(dst, src, dst_nritems, 0, push_items); |
5de865ee | 2691 | if (ret) { |
66642832 | 2692 | btrfs_abort_transaction(trans, ret); |
5de865ee FDBM |
2693 | return ret; |
2694 | } | |
5f39d397 | 2695 | copy_extent_buffer(dst, src, |
e23efd8e JB |
2696 | btrfs_node_key_ptr_offset(dst, dst_nritems), |
2697 | btrfs_node_key_ptr_offset(src, 0), | |
d397712b | 2698 | push_items * sizeof(struct btrfs_key_ptr)); |
5f39d397 | 2699 | |
bb803951 | 2700 | if (push_items < src_nritems) { |
57911b8b | 2701 | /* |
f3a84ccd FM |
2702 | * Don't call btrfs_tree_mod_log_insert_move() here, key removal |
2703 | * was already fully logged by btrfs_tree_mod_log_eb_copy() above. | |
57911b8b | 2704 | */ |
e23efd8e JB |
2705 | memmove_extent_buffer(src, btrfs_node_key_ptr_offset(src, 0), |
2706 | btrfs_node_key_ptr_offset(src, push_items), | |
5f39d397 CM |
2707 | (src_nritems - push_items) * |
2708 | sizeof(struct btrfs_key_ptr)); | |
2709 | } | |
2710 | btrfs_set_header_nritems(src, src_nritems - push_items); | |
2711 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
2712 | btrfs_mark_buffer_dirty(src); | |
2713 | btrfs_mark_buffer_dirty(dst); | |
31840ae1 | 2714 | |
79f95c82 CM |
2715 | return ret; |
2716 | } | |
2717 | ||
2718 | /* | |
2719 | * try to push data from one node into the next node right in the | |
2720 | * tree. | |
2721 | * | |
2722 | * returns 0 if some ptrs were pushed, < 0 if there was some horrible | |
2723 | * error, and > 0 if there was no room in the right hand block. | |
2724 | * | |
2725 | * this will only push up to 1/2 the contents of the left node over | |
2726 | */ | |
5f39d397 | 2727 | static int balance_node_right(struct btrfs_trans_handle *trans, |
5f39d397 CM |
2728 | struct extent_buffer *dst, |
2729 | struct extent_buffer *src) | |
79f95c82 | 2730 | { |
55d32ed8 | 2731 | struct btrfs_fs_info *fs_info = trans->fs_info; |
79f95c82 CM |
2732 | int push_items = 0; |
2733 | int max_push; | |
2734 | int src_nritems; | |
2735 | int dst_nritems; | |
2736 | int ret = 0; | |
79f95c82 | 2737 | |
7bb86316 CM |
2738 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
2739 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
2740 | ||
5f39d397 CM |
2741 | src_nritems = btrfs_header_nritems(src); |
2742 | dst_nritems = btrfs_header_nritems(dst); | |
0b246afa | 2743 | push_items = BTRFS_NODEPTRS_PER_BLOCK(fs_info) - dst_nritems; |
d397712b | 2744 | if (push_items <= 0) |
79f95c82 | 2745 | return 1; |
bce4eae9 | 2746 | |
d397712b | 2747 | if (src_nritems < 4) |
bce4eae9 | 2748 | return 1; |
79f95c82 CM |
2749 | |
2750 | max_push = src_nritems / 2 + 1; | |
2751 | /* don't try to empty the node */ | |
d397712b | 2752 | if (max_push >= src_nritems) |
79f95c82 | 2753 | return 1; |
252c38f0 | 2754 | |
79f95c82 CM |
2755 | if (max_push < push_items) |
2756 | push_items = max_push; | |
2757 | ||
d16c702f QW |
2758 | /* dst is the right eb, src is the middle eb */ |
2759 | if (check_sibling_keys(src, dst)) { | |
2760 | ret = -EUCLEAN; | |
2761 | btrfs_abort_transaction(trans, ret); | |
2762 | return ret; | |
2763 | } | |
f3a84ccd | 2764 | ret = btrfs_tree_mod_log_insert_move(dst, push_items, 0, dst_nritems); |
bf1d3425 | 2765 | BUG_ON(ret < 0); |
e23efd8e JB |
2766 | memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(dst, push_items), |
2767 | btrfs_node_key_ptr_offset(dst, 0), | |
5f39d397 CM |
2768 | (dst_nritems) * |
2769 | sizeof(struct btrfs_key_ptr)); | |
d6025579 | 2770 | |
f3a84ccd FM |
2771 | ret = btrfs_tree_mod_log_eb_copy(dst, src, 0, src_nritems - push_items, |
2772 | push_items); | |
5de865ee | 2773 | if (ret) { |
66642832 | 2774 | btrfs_abort_transaction(trans, ret); |
5de865ee FDBM |
2775 | return ret; |
2776 | } | |
5f39d397 | 2777 | copy_extent_buffer(dst, src, |
e23efd8e JB |
2778 | btrfs_node_key_ptr_offset(dst, 0), |
2779 | btrfs_node_key_ptr_offset(src, src_nritems - push_items), | |
d397712b | 2780 | push_items * sizeof(struct btrfs_key_ptr)); |
79f95c82 | 2781 | |
5f39d397 CM |
2782 | btrfs_set_header_nritems(src, src_nritems - push_items); |
2783 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
79f95c82 | 2784 | |
5f39d397 CM |
2785 | btrfs_mark_buffer_dirty(src); |
2786 | btrfs_mark_buffer_dirty(dst); | |
31840ae1 | 2787 | |
aa5d6bed | 2788 | return ret; |
be0e5c09 CM |
2789 | } |
2790 | ||
97571fd0 CM |
2791 | /* |
2792 | * helper function to insert a new root level in the tree. | |
2793 | * A new node is allocated, and a single item is inserted to | |
2794 | * point to the existing root | |
aa5d6bed CM |
2795 | * |
2796 | * returns zero on success or < 0 on failure. | |
97571fd0 | 2797 | */ |
d397712b | 2798 | static noinline int insert_new_root(struct btrfs_trans_handle *trans, |
5f39d397 | 2799 | struct btrfs_root *root, |
fdd99c72 | 2800 | struct btrfs_path *path, int level) |
5c680ed6 | 2801 | { |
0b246afa | 2802 | struct btrfs_fs_info *fs_info = root->fs_info; |
7bb86316 | 2803 | u64 lower_gen; |
5f39d397 CM |
2804 | struct extent_buffer *lower; |
2805 | struct extent_buffer *c; | |
925baedd | 2806 | struct extent_buffer *old; |
5f39d397 | 2807 | struct btrfs_disk_key lower_key; |
d9d19a01 | 2808 | int ret; |
5c680ed6 CM |
2809 | |
2810 | BUG_ON(path->nodes[level]); | |
2811 | BUG_ON(path->nodes[level-1] != root->node); | |
2812 | ||
7bb86316 CM |
2813 | lower = path->nodes[level-1]; |
2814 | if (level == 1) | |
2815 | btrfs_item_key(lower, &lower_key, 0); | |
2816 | else | |
2817 | btrfs_node_key(lower, &lower_key, 0); | |
2818 | ||
79bd3712 FM |
2819 | c = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid, |
2820 | &lower_key, level, root->node->start, 0, | |
2821 | BTRFS_NESTING_NEW_ROOT); | |
5f39d397 CM |
2822 | if (IS_ERR(c)) |
2823 | return PTR_ERR(c); | |
925baedd | 2824 | |
0b246afa | 2825 | root_add_used(root, fs_info->nodesize); |
f0486c68 | 2826 | |
5f39d397 | 2827 | btrfs_set_header_nritems(c, 1); |
5f39d397 | 2828 | btrfs_set_node_key(c, &lower_key, 0); |
db94535d | 2829 | btrfs_set_node_blockptr(c, 0, lower->start); |
7bb86316 | 2830 | lower_gen = btrfs_header_generation(lower); |
31840ae1 | 2831 | WARN_ON(lower_gen != trans->transid); |
7bb86316 CM |
2832 | |
2833 | btrfs_set_node_ptr_generation(c, 0, lower_gen); | |
d5719762 | 2834 | |
5f39d397 | 2835 | btrfs_mark_buffer_dirty(c); |
d5719762 | 2836 | |
925baedd | 2837 | old = root->node; |
406808ab | 2838 | ret = btrfs_tree_mod_log_insert_root(root->node, c, false); |
d9d19a01 | 2839 | BUG_ON(ret < 0); |
240f62c8 | 2840 | rcu_assign_pointer(root->node, c); |
925baedd CM |
2841 | |
2842 | /* the super has an extra ref to root->node */ | |
2843 | free_extent_buffer(old); | |
2844 | ||
0b86a832 | 2845 | add_root_to_dirty_list(root); |
67439dad | 2846 | atomic_inc(&c->refs); |
5f39d397 | 2847 | path->nodes[level] = c; |
ac5887c8 | 2848 | path->locks[level] = BTRFS_WRITE_LOCK; |
5c680ed6 CM |
2849 | path->slots[level] = 0; |
2850 | return 0; | |
2851 | } | |
2852 | ||
74123bd7 CM |
2853 | /* |
2854 | * worker function to insert a single pointer in a node. | |
2855 | * the node should have enough room for the pointer already | |
97571fd0 | 2856 | * |
74123bd7 CM |
2857 | * slot and level indicate where you want the key to go, and |
2858 | * blocknr is the block the key points to. | |
2859 | */ | |
143bede5 | 2860 | static void insert_ptr(struct btrfs_trans_handle *trans, |
6ad3cf6d | 2861 | struct btrfs_path *path, |
143bede5 | 2862 | struct btrfs_disk_key *key, u64 bytenr, |
c3e06965 | 2863 | int slot, int level) |
74123bd7 | 2864 | { |
5f39d397 | 2865 | struct extent_buffer *lower; |
74123bd7 | 2866 | int nritems; |
f3ea38da | 2867 | int ret; |
5c680ed6 CM |
2868 | |
2869 | BUG_ON(!path->nodes[level]); | |
49d0c642 | 2870 | btrfs_assert_tree_write_locked(path->nodes[level]); |
5f39d397 CM |
2871 | lower = path->nodes[level]; |
2872 | nritems = btrfs_header_nritems(lower); | |
c293498b | 2873 | BUG_ON(slot > nritems); |
6ad3cf6d | 2874 | BUG_ON(nritems == BTRFS_NODEPTRS_PER_BLOCK(trans->fs_info)); |
74123bd7 | 2875 | if (slot != nritems) { |
bf1d3425 | 2876 | if (level) { |
f3a84ccd FM |
2877 | ret = btrfs_tree_mod_log_insert_move(lower, slot + 1, |
2878 | slot, nritems - slot); | |
bf1d3425 DS |
2879 | BUG_ON(ret < 0); |
2880 | } | |
5f39d397 | 2881 | memmove_extent_buffer(lower, |
e23efd8e JB |
2882 | btrfs_node_key_ptr_offset(lower, slot + 1), |
2883 | btrfs_node_key_ptr_offset(lower, slot), | |
d6025579 | 2884 | (nritems - slot) * sizeof(struct btrfs_key_ptr)); |
74123bd7 | 2885 | } |
c3e06965 | 2886 | if (level) { |
f3a84ccd | 2887 | ret = btrfs_tree_mod_log_insert_key(lower, slot, |
33cff222 | 2888 | BTRFS_MOD_LOG_KEY_ADD); |
f3ea38da JS |
2889 | BUG_ON(ret < 0); |
2890 | } | |
5f39d397 | 2891 | btrfs_set_node_key(lower, key, slot); |
db94535d | 2892 | btrfs_set_node_blockptr(lower, slot, bytenr); |
74493f7a CM |
2893 | WARN_ON(trans->transid == 0); |
2894 | btrfs_set_node_ptr_generation(lower, slot, trans->transid); | |
5f39d397 CM |
2895 | btrfs_set_header_nritems(lower, nritems + 1); |
2896 | btrfs_mark_buffer_dirty(lower); | |
74123bd7 CM |
2897 | } |
2898 | ||
97571fd0 CM |
2899 | /* |
2900 | * split the node at the specified level in path in two. | |
2901 | * The path is corrected to point to the appropriate node after the split | |
2902 | * | |
2903 | * Before splitting this tries to make some room in the node by pushing | |
2904 | * left and right, if either one works, it returns right away. | |
aa5d6bed CM |
2905 | * |
2906 | * returns 0 on success and < 0 on failure | |
97571fd0 | 2907 | */ |
e02119d5 CM |
2908 | static noinline int split_node(struct btrfs_trans_handle *trans, |
2909 | struct btrfs_root *root, | |
2910 | struct btrfs_path *path, int level) | |
be0e5c09 | 2911 | { |
0b246afa | 2912 | struct btrfs_fs_info *fs_info = root->fs_info; |
5f39d397 CM |
2913 | struct extent_buffer *c; |
2914 | struct extent_buffer *split; | |
2915 | struct btrfs_disk_key disk_key; | |
be0e5c09 | 2916 | int mid; |
5c680ed6 | 2917 | int ret; |
7518a238 | 2918 | u32 c_nritems; |
eb60ceac | 2919 | |
5f39d397 | 2920 | c = path->nodes[level]; |
7bb86316 | 2921 | WARN_ON(btrfs_header_generation(c) != trans->transid); |
5f39d397 | 2922 | if (c == root->node) { |
d9abbf1c | 2923 | /* |
90f8d62e JS |
2924 | * trying to split the root, lets make a new one |
2925 | * | |
fdd99c72 | 2926 | * tree mod log: We don't log_removal old root in |
90f8d62e JS |
2927 | * insert_new_root, because that root buffer will be kept as a |
2928 | * normal node. We are going to log removal of half of the | |
f3a84ccd FM |
2929 | * elements below with btrfs_tree_mod_log_eb_copy(). We're |
2930 | * holding a tree lock on the buffer, which is why we cannot | |
2931 | * race with other tree_mod_log users. | |
d9abbf1c | 2932 | */ |
fdd99c72 | 2933 | ret = insert_new_root(trans, root, path, level + 1); |
5c680ed6 CM |
2934 | if (ret) |
2935 | return ret; | |
b3612421 | 2936 | } else { |
e66f709b | 2937 | ret = push_nodes_for_insert(trans, root, path, level); |
5f39d397 CM |
2938 | c = path->nodes[level]; |
2939 | if (!ret && btrfs_header_nritems(c) < | |
0b246afa | 2940 | BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 3) |
e66f709b | 2941 | return 0; |
54aa1f4d CM |
2942 | if (ret < 0) |
2943 | return ret; | |
be0e5c09 | 2944 | } |
e66f709b | 2945 | |
5f39d397 | 2946 | c_nritems = btrfs_header_nritems(c); |
5d4f98a2 YZ |
2947 | mid = (c_nritems + 1) / 2; |
2948 | btrfs_node_key(c, &disk_key, mid); | |
7bb86316 | 2949 | |
79bd3712 FM |
2950 | split = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid, |
2951 | &disk_key, level, c->start, 0, | |
2952 | BTRFS_NESTING_SPLIT); | |
5f39d397 CM |
2953 | if (IS_ERR(split)) |
2954 | return PTR_ERR(split); | |
2955 | ||
0b246afa | 2956 | root_add_used(root, fs_info->nodesize); |
bc877d28 | 2957 | ASSERT(btrfs_header_level(c) == level); |
54aa1f4d | 2958 | |
f3a84ccd | 2959 | ret = btrfs_tree_mod_log_eb_copy(split, c, 0, mid, c_nritems - mid); |
5de865ee | 2960 | if (ret) { |
66642832 | 2961 | btrfs_abort_transaction(trans, ret); |
5de865ee FDBM |
2962 | return ret; |
2963 | } | |
5f39d397 | 2964 | copy_extent_buffer(split, c, |
e23efd8e JB |
2965 | btrfs_node_key_ptr_offset(split, 0), |
2966 | btrfs_node_key_ptr_offset(c, mid), | |
5f39d397 CM |
2967 | (c_nritems - mid) * sizeof(struct btrfs_key_ptr)); |
2968 | btrfs_set_header_nritems(split, c_nritems - mid); | |
2969 | btrfs_set_header_nritems(c, mid); | |
aa5d6bed | 2970 | |
5f39d397 CM |
2971 | btrfs_mark_buffer_dirty(c); |
2972 | btrfs_mark_buffer_dirty(split); | |
2973 | ||
6ad3cf6d | 2974 | insert_ptr(trans, path, &disk_key, split->start, |
c3e06965 | 2975 | path->slots[level + 1] + 1, level + 1); |
aa5d6bed | 2976 | |
5de08d7d | 2977 | if (path->slots[level] >= mid) { |
5c680ed6 | 2978 | path->slots[level] -= mid; |
925baedd | 2979 | btrfs_tree_unlock(c); |
5f39d397 CM |
2980 | free_extent_buffer(c); |
2981 | path->nodes[level] = split; | |
5c680ed6 CM |
2982 | path->slots[level + 1] += 1; |
2983 | } else { | |
925baedd | 2984 | btrfs_tree_unlock(split); |
5f39d397 | 2985 | free_extent_buffer(split); |
be0e5c09 | 2986 | } |
d5286a92 | 2987 | return 0; |
be0e5c09 CM |
2988 | } |
2989 | ||
74123bd7 CM |
2990 | /* |
2991 | * how many bytes are required to store the items in a leaf. start | |
2992 | * and nr indicate which items in the leaf to check. This totals up the | |
2993 | * space used both by the item structs and the item data | |
2994 | */ | |
5f39d397 | 2995 | static int leaf_space_used(struct extent_buffer *l, int start, int nr) |
be0e5c09 CM |
2996 | { |
2997 | int data_len; | |
5f39d397 | 2998 | int nritems = btrfs_header_nritems(l); |
d4dbff95 | 2999 | int end = min(nritems, start + nr) - 1; |
be0e5c09 CM |
3000 | |
3001 | if (!nr) | |
3002 | return 0; | |
3212fa14 JB |
3003 | data_len = btrfs_item_offset(l, start) + btrfs_item_size(l, start); |
3004 | data_len = data_len - btrfs_item_offset(l, end); | |
0783fcfc | 3005 | data_len += sizeof(struct btrfs_item) * nr; |
d4dbff95 | 3006 | WARN_ON(data_len < 0); |
be0e5c09 CM |
3007 | return data_len; |
3008 | } | |
3009 | ||
d4dbff95 CM |
3010 | /* |
3011 | * The space between the end of the leaf items and | |
3012 | * the start of the leaf data. IOW, how much room | |
3013 | * the leaf has left for both items and data | |
3014 | */ | |
e902baac | 3015 | noinline int btrfs_leaf_free_space(struct extent_buffer *leaf) |
d4dbff95 | 3016 | { |
e902baac | 3017 | struct btrfs_fs_info *fs_info = leaf->fs_info; |
5f39d397 CM |
3018 | int nritems = btrfs_header_nritems(leaf); |
3019 | int ret; | |
0b246afa JM |
3020 | |
3021 | ret = BTRFS_LEAF_DATA_SIZE(fs_info) - leaf_space_used(leaf, 0, nritems); | |
5f39d397 | 3022 | if (ret < 0) { |
0b246afa JM |
3023 | btrfs_crit(fs_info, |
3024 | "leaf free space ret %d, leaf data size %lu, used %d nritems %d", | |
3025 | ret, | |
3026 | (unsigned long) BTRFS_LEAF_DATA_SIZE(fs_info), | |
3027 | leaf_space_used(leaf, 0, nritems), nritems); | |
5f39d397 CM |
3028 | } |
3029 | return ret; | |
d4dbff95 CM |
3030 | } |
3031 | ||
99d8f83c CM |
3032 | /* |
3033 | * min slot controls the lowest index we're willing to push to the | |
3034 | * right. We'll push up to and including min_slot, but no lower | |
3035 | */ | |
ed25dab3 JB |
3036 | static noinline int __push_leaf_right(struct btrfs_trans_handle *trans, |
3037 | struct btrfs_path *path, | |
44871b1b CM |
3038 | int data_size, int empty, |
3039 | struct extent_buffer *right, | |
99d8f83c CM |
3040 | int free_space, u32 left_nritems, |
3041 | u32 min_slot) | |
00ec4c51 | 3042 | { |
f72f0010 | 3043 | struct btrfs_fs_info *fs_info = right->fs_info; |
5f39d397 | 3044 | struct extent_buffer *left = path->nodes[0]; |
44871b1b | 3045 | struct extent_buffer *upper = path->nodes[1]; |
cfed81a0 | 3046 | struct btrfs_map_token token; |
5f39d397 | 3047 | struct btrfs_disk_key disk_key; |
00ec4c51 | 3048 | int slot; |
34a38218 | 3049 | u32 i; |
00ec4c51 CM |
3050 | int push_space = 0; |
3051 | int push_items = 0; | |
34a38218 | 3052 | u32 nr; |
7518a238 | 3053 | u32 right_nritems; |
5f39d397 | 3054 | u32 data_end; |
db94535d | 3055 | u32 this_item_size; |
00ec4c51 | 3056 | |
34a38218 CM |
3057 | if (empty) |
3058 | nr = 0; | |
3059 | else | |
99d8f83c | 3060 | nr = max_t(u32, 1, min_slot); |
34a38218 | 3061 | |
31840ae1 | 3062 | if (path->slots[0] >= left_nritems) |
87b29b20 | 3063 | push_space += data_size; |
31840ae1 | 3064 | |
44871b1b | 3065 | slot = path->slots[1]; |
34a38218 CM |
3066 | i = left_nritems - 1; |
3067 | while (i >= nr) { | |
31840ae1 ZY |
3068 | if (!empty && push_items > 0) { |
3069 | if (path->slots[0] > i) | |
3070 | break; | |
3071 | if (path->slots[0] == i) { | |
e902baac DS |
3072 | int space = btrfs_leaf_free_space(left); |
3073 | ||
31840ae1 ZY |
3074 | if (space + push_space * 2 > free_space) |
3075 | break; | |
3076 | } | |
3077 | } | |
3078 | ||
00ec4c51 | 3079 | if (path->slots[0] == i) |
87b29b20 | 3080 | push_space += data_size; |
db94535d | 3081 | |
3212fa14 | 3082 | this_item_size = btrfs_item_size(left, i); |
74794207 JB |
3083 | if (this_item_size + sizeof(struct btrfs_item) + |
3084 | push_space > free_space) | |
00ec4c51 | 3085 | break; |
31840ae1 | 3086 | |
00ec4c51 | 3087 | push_items++; |
74794207 | 3088 | push_space += this_item_size + sizeof(struct btrfs_item); |
34a38218 CM |
3089 | if (i == 0) |
3090 | break; | |
3091 | i--; | |
db94535d | 3092 | } |
5f39d397 | 3093 | |
925baedd CM |
3094 | if (push_items == 0) |
3095 | goto out_unlock; | |
5f39d397 | 3096 | |
6c1500f2 | 3097 | WARN_ON(!empty && push_items == left_nritems); |
5f39d397 | 3098 | |
00ec4c51 | 3099 | /* push left to right */ |
5f39d397 | 3100 | right_nritems = btrfs_header_nritems(right); |
34a38218 | 3101 | |
dc2e724e | 3102 | push_space = btrfs_item_data_end(left, left_nritems - push_items); |
8f881e8c | 3103 | push_space -= leaf_data_end(left); |
5f39d397 | 3104 | |
00ec4c51 | 3105 | /* make room in the right data area */ |
8f881e8c | 3106 | data_end = leaf_data_end(right); |
637e3b48 JB |
3107 | memmove_leaf_data(right, data_end - push_space, data_end, |
3108 | BTRFS_LEAF_DATA_SIZE(fs_info) - data_end); | |
5f39d397 | 3109 | |
00ec4c51 | 3110 | /* copy from the left data area */ |
637e3b48 JB |
3111 | copy_leaf_data(right, left, BTRFS_LEAF_DATA_SIZE(fs_info) - push_space, |
3112 | leaf_data_end(left), push_space); | |
5f39d397 | 3113 | |
637e3b48 | 3114 | memmove_leaf_items(right, push_items, 0, right_nritems); |
5f39d397 | 3115 | |
00ec4c51 | 3116 | /* copy the items from left to right */ |
637e3b48 | 3117 | copy_leaf_items(right, left, 0, left_nritems - push_items, push_items); |
00ec4c51 CM |
3118 | |
3119 | /* update the item pointers */ | |
c82f823c | 3120 | btrfs_init_map_token(&token, right); |
7518a238 | 3121 | right_nritems += push_items; |
5f39d397 | 3122 | btrfs_set_header_nritems(right, right_nritems); |
0b246afa | 3123 | push_space = BTRFS_LEAF_DATA_SIZE(fs_info); |
7518a238 | 3124 | for (i = 0; i < right_nritems; i++) { |
3212fa14 JB |
3125 | push_space -= btrfs_token_item_size(&token, i); |
3126 | btrfs_set_token_item_offset(&token, i, push_space); | |
db94535d CM |
3127 | } |
3128 | ||
7518a238 | 3129 | left_nritems -= push_items; |
5f39d397 | 3130 | btrfs_set_header_nritems(left, left_nritems); |
00ec4c51 | 3131 | |
34a38218 CM |
3132 | if (left_nritems) |
3133 | btrfs_mark_buffer_dirty(left); | |
f0486c68 | 3134 | else |
190a8339 | 3135 | btrfs_clear_buffer_dirty(trans, left); |
f0486c68 | 3136 | |
5f39d397 | 3137 | btrfs_mark_buffer_dirty(right); |
a429e513 | 3138 | |
5f39d397 CM |
3139 | btrfs_item_key(right, &disk_key, 0); |
3140 | btrfs_set_node_key(upper, &disk_key, slot + 1); | |
d6025579 | 3141 | btrfs_mark_buffer_dirty(upper); |
02217ed2 | 3142 | |
00ec4c51 | 3143 | /* then fixup the leaf pointer in the path */ |
7518a238 CM |
3144 | if (path->slots[0] >= left_nritems) { |
3145 | path->slots[0] -= left_nritems; | |
925baedd | 3146 | if (btrfs_header_nritems(path->nodes[0]) == 0) |
190a8339 | 3147 | btrfs_clear_buffer_dirty(trans, path->nodes[0]); |
925baedd | 3148 | btrfs_tree_unlock(path->nodes[0]); |
5f39d397 CM |
3149 | free_extent_buffer(path->nodes[0]); |
3150 | path->nodes[0] = right; | |
00ec4c51 CM |
3151 | path->slots[1] += 1; |
3152 | } else { | |
925baedd | 3153 | btrfs_tree_unlock(right); |
5f39d397 | 3154 | free_extent_buffer(right); |
00ec4c51 CM |
3155 | } |
3156 | return 0; | |
925baedd CM |
3157 | |
3158 | out_unlock: | |
3159 | btrfs_tree_unlock(right); | |
3160 | free_extent_buffer(right); | |
3161 | return 1; | |
00ec4c51 | 3162 | } |
925baedd | 3163 | |
44871b1b CM |
3164 | /* |
3165 | * push some data in the path leaf to the right, trying to free up at | |
3166 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
3167 | * | |
3168 | * returns 1 if the push failed because the other node didn't have enough | |
3169 | * room, 0 if everything worked out and < 0 if there were major errors. | |
99d8f83c CM |
3170 | * |
3171 | * this will push starting from min_slot to the end of the leaf. It won't | |
3172 | * push any slot lower than min_slot | |
44871b1b CM |
3173 | */ |
3174 | static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root | |
99d8f83c CM |
3175 | *root, struct btrfs_path *path, |
3176 | int min_data_size, int data_size, | |
3177 | int empty, u32 min_slot) | |
44871b1b CM |
3178 | { |
3179 | struct extent_buffer *left = path->nodes[0]; | |
3180 | struct extent_buffer *right; | |
3181 | struct extent_buffer *upper; | |
3182 | int slot; | |
3183 | int free_space; | |
3184 | u32 left_nritems; | |
3185 | int ret; | |
3186 | ||
3187 | if (!path->nodes[1]) | |
3188 | return 1; | |
3189 | ||
3190 | slot = path->slots[1]; | |
3191 | upper = path->nodes[1]; | |
3192 | if (slot >= btrfs_header_nritems(upper) - 1) | |
3193 | return 1; | |
3194 | ||
49d0c642 | 3195 | btrfs_assert_tree_write_locked(path->nodes[1]); |
44871b1b | 3196 | |
4b231ae4 | 3197 | right = btrfs_read_node_slot(upper, slot + 1); |
fb770ae4 | 3198 | if (IS_ERR(right)) |
9cf14029 | 3199 | return PTR_ERR(right); |
91ca338d | 3200 | |
bf77467a | 3201 | __btrfs_tree_lock(right, BTRFS_NESTING_RIGHT); |
44871b1b | 3202 | |
e902baac | 3203 | free_space = btrfs_leaf_free_space(right); |
44871b1b CM |
3204 | if (free_space < data_size) |
3205 | goto out_unlock; | |
3206 | ||
44871b1b | 3207 | ret = btrfs_cow_block(trans, root, right, upper, |
bf59a5a2 | 3208 | slot + 1, &right, BTRFS_NESTING_RIGHT_COW); |
44871b1b CM |
3209 | if (ret) |
3210 | goto out_unlock; | |
3211 | ||
44871b1b CM |
3212 | left_nritems = btrfs_header_nritems(left); |
3213 | if (left_nritems == 0) | |
3214 | goto out_unlock; | |
3215 | ||
d16c702f QW |
3216 | if (check_sibling_keys(left, right)) { |
3217 | ret = -EUCLEAN; | |
3218 | btrfs_tree_unlock(right); | |
3219 | free_extent_buffer(right); | |
3220 | return ret; | |
3221 | } | |
2ef1fed2 FDBM |
3222 | if (path->slots[0] == left_nritems && !empty) { |
3223 | /* Key greater than all keys in the leaf, right neighbor has | |
3224 | * enough room for it and we're not emptying our leaf to delete | |
3225 | * it, therefore use right neighbor to insert the new item and | |
52042d8e | 3226 | * no need to touch/dirty our left leaf. */ |
2ef1fed2 FDBM |
3227 | btrfs_tree_unlock(left); |
3228 | free_extent_buffer(left); | |
3229 | path->nodes[0] = right; | |
3230 | path->slots[0] = 0; | |
3231 | path->slots[1]++; | |
3232 | return 0; | |
3233 | } | |
3234 | ||
ed25dab3 JB |
3235 | return __push_leaf_right(trans, path, min_data_size, empty, right, |
3236 | free_space, left_nritems, min_slot); | |
44871b1b CM |
3237 | out_unlock: |
3238 | btrfs_tree_unlock(right); | |
3239 | free_extent_buffer(right); | |
3240 | return 1; | |
3241 | } | |
3242 | ||
74123bd7 CM |
3243 | /* |
3244 | * push some data in the path leaf to the left, trying to free up at | |
3245 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
99d8f83c CM |
3246 | * |
3247 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
3248 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us do all the | |
3249 | * items | |
74123bd7 | 3250 | */ |
ed25dab3 JB |
3251 | static noinline int __push_leaf_left(struct btrfs_trans_handle *trans, |
3252 | struct btrfs_path *path, int data_size, | |
44871b1b | 3253 | int empty, struct extent_buffer *left, |
99d8f83c CM |
3254 | int free_space, u32 right_nritems, |
3255 | u32 max_slot) | |
be0e5c09 | 3256 | { |
8087c193 | 3257 | struct btrfs_fs_info *fs_info = left->fs_info; |
5f39d397 CM |
3258 | struct btrfs_disk_key disk_key; |
3259 | struct extent_buffer *right = path->nodes[0]; | |
be0e5c09 | 3260 | int i; |
be0e5c09 CM |
3261 | int push_space = 0; |
3262 | int push_items = 0; | |
7518a238 | 3263 | u32 old_left_nritems; |
34a38218 | 3264 | u32 nr; |
aa5d6bed | 3265 | int ret = 0; |
db94535d CM |
3266 | u32 this_item_size; |
3267 | u32 old_left_item_size; | |
cfed81a0 CM |
3268 | struct btrfs_map_token token; |
3269 | ||
34a38218 | 3270 | if (empty) |
99d8f83c | 3271 | nr = min(right_nritems, max_slot); |
34a38218 | 3272 | else |
99d8f83c | 3273 | nr = min(right_nritems - 1, max_slot); |
34a38218 CM |
3274 | |
3275 | for (i = 0; i < nr; i++) { | |
31840ae1 ZY |
3276 | if (!empty && push_items > 0) { |
3277 | if (path->slots[0] < i) | |
3278 | break; | |
3279 | if (path->slots[0] == i) { | |
e902baac DS |
3280 | int space = btrfs_leaf_free_space(right); |
3281 | ||
31840ae1 ZY |
3282 | if (space + push_space * 2 > free_space) |
3283 | break; | |
3284 | } | |
3285 | } | |
3286 | ||
be0e5c09 | 3287 | if (path->slots[0] == i) |
87b29b20 | 3288 | push_space += data_size; |
db94535d | 3289 | |
3212fa14 | 3290 | this_item_size = btrfs_item_size(right, i); |
74794207 JB |
3291 | if (this_item_size + sizeof(struct btrfs_item) + push_space > |
3292 | free_space) | |
be0e5c09 | 3293 | break; |
db94535d | 3294 | |
be0e5c09 | 3295 | push_items++; |
74794207 | 3296 | push_space += this_item_size + sizeof(struct btrfs_item); |
db94535d CM |
3297 | } |
3298 | ||
be0e5c09 | 3299 | if (push_items == 0) { |
925baedd CM |
3300 | ret = 1; |
3301 | goto out; | |
be0e5c09 | 3302 | } |
fae7f21c | 3303 | WARN_ON(!empty && push_items == btrfs_header_nritems(right)); |
5f39d397 | 3304 | |
be0e5c09 | 3305 | /* push data from right to left */ |
637e3b48 | 3306 | copy_leaf_items(left, right, btrfs_header_nritems(left), 0, push_items); |
5f39d397 | 3307 | |
0b246afa | 3308 | push_space = BTRFS_LEAF_DATA_SIZE(fs_info) - |
3212fa14 | 3309 | btrfs_item_offset(right, push_items - 1); |
5f39d397 | 3310 | |
637e3b48 JB |
3311 | copy_leaf_data(left, right, leaf_data_end(left) - push_space, |
3312 | btrfs_item_offset(right, push_items - 1), push_space); | |
5f39d397 | 3313 | old_left_nritems = btrfs_header_nritems(left); |
87b29b20 | 3314 | BUG_ON(old_left_nritems <= 0); |
eb60ceac | 3315 | |
c82f823c | 3316 | btrfs_init_map_token(&token, left); |
3212fa14 | 3317 | old_left_item_size = btrfs_item_offset(left, old_left_nritems - 1); |
0783fcfc | 3318 | for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { |
5f39d397 | 3319 | u32 ioff; |
db94535d | 3320 | |
3212fa14 JB |
3321 | ioff = btrfs_token_item_offset(&token, i); |
3322 | btrfs_set_token_item_offset(&token, i, | |
cc4c13d5 | 3323 | ioff - (BTRFS_LEAF_DATA_SIZE(fs_info) - old_left_item_size)); |
be0e5c09 | 3324 | } |
5f39d397 | 3325 | btrfs_set_header_nritems(left, old_left_nritems + push_items); |
be0e5c09 CM |
3326 | |
3327 | /* fixup right node */ | |
31b1a2bd JL |
3328 | if (push_items > right_nritems) |
3329 | WARN(1, KERN_CRIT "push items %d nr %u\n", push_items, | |
d397712b | 3330 | right_nritems); |
34a38218 CM |
3331 | |
3332 | if (push_items < right_nritems) { | |
3212fa14 | 3333 | push_space = btrfs_item_offset(right, push_items - 1) - |
8f881e8c | 3334 | leaf_data_end(right); |
637e3b48 JB |
3335 | memmove_leaf_data(right, |
3336 | BTRFS_LEAF_DATA_SIZE(fs_info) - push_space, | |
3337 | leaf_data_end(right), push_space); | |
3338 | ||
3339 | memmove_leaf_items(right, 0, push_items, | |
3340 | btrfs_header_nritems(right) - push_items); | |
34a38218 | 3341 | } |
c82f823c DS |
3342 | |
3343 | btrfs_init_map_token(&token, right); | |
eef1c494 Y |
3344 | right_nritems -= push_items; |
3345 | btrfs_set_header_nritems(right, right_nritems); | |
0b246afa | 3346 | push_space = BTRFS_LEAF_DATA_SIZE(fs_info); |
5f39d397 | 3347 | for (i = 0; i < right_nritems; i++) { |
3212fa14 JB |
3348 | push_space = push_space - btrfs_token_item_size(&token, i); |
3349 | btrfs_set_token_item_offset(&token, i, push_space); | |
db94535d | 3350 | } |
eb60ceac | 3351 | |
5f39d397 | 3352 | btrfs_mark_buffer_dirty(left); |
34a38218 CM |
3353 | if (right_nritems) |
3354 | btrfs_mark_buffer_dirty(right); | |
f0486c68 | 3355 | else |
190a8339 | 3356 | btrfs_clear_buffer_dirty(trans, right); |
098f59c2 | 3357 | |
5f39d397 | 3358 | btrfs_item_key(right, &disk_key, 0); |
b167fa91 | 3359 | fixup_low_keys(path, &disk_key, 1); |
be0e5c09 CM |
3360 | |
3361 | /* then fixup the leaf pointer in the path */ | |
3362 | if (path->slots[0] < push_items) { | |
3363 | path->slots[0] += old_left_nritems; | |
925baedd | 3364 | btrfs_tree_unlock(path->nodes[0]); |
5f39d397 CM |
3365 | free_extent_buffer(path->nodes[0]); |
3366 | path->nodes[0] = left; | |
be0e5c09 CM |
3367 | path->slots[1] -= 1; |
3368 | } else { | |
925baedd | 3369 | btrfs_tree_unlock(left); |
5f39d397 | 3370 | free_extent_buffer(left); |
be0e5c09 CM |
3371 | path->slots[0] -= push_items; |
3372 | } | |
eb60ceac | 3373 | BUG_ON(path->slots[0] < 0); |
aa5d6bed | 3374 | return ret; |
925baedd CM |
3375 | out: |
3376 | btrfs_tree_unlock(left); | |
3377 | free_extent_buffer(left); | |
3378 | return ret; | |
be0e5c09 CM |
3379 | } |
3380 | ||
44871b1b CM |
3381 | /* |
3382 | * push some data in the path leaf to the left, trying to free up at | |
3383 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
99d8f83c CM |
3384 | * |
3385 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
3386 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us push all the | |
3387 | * items | |
44871b1b CM |
3388 | */ |
3389 | static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root | |
99d8f83c CM |
3390 | *root, struct btrfs_path *path, int min_data_size, |
3391 | int data_size, int empty, u32 max_slot) | |
44871b1b CM |
3392 | { |
3393 | struct extent_buffer *right = path->nodes[0]; | |
3394 | struct extent_buffer *left; | |
3395 | int slot; | |
3396 | int free_space; | |
3397 | u32 right_nritems; | |
3398 | int ret = 0; | |
3399 | ||
3400 | slot = path->slots[1]; | |
3401 | if (slot == 0) | |
3402 | return 1; | |
3403 | if (!path->nodes[1]) | |
3404 | return 1; | |
3405 | ||
3406 | right_nritems = btrfs_header_nritems(right); | |
3407 | if (right_nritems == 0) | |
3408 | return 1; | |
3409 | ||
49d0c642 | 3410 | btrfs_assert_tree_write_locked(path->nodes[1]); |
44871b1b | 3411 | |
4b231ae4 | 3412 | left = btrfs_read_node_slot(path->nodes[1], slot - 1); |
fb770ae4 | 3413 | if (IS_ERR(left)) |
9cf14029 | 3414 | return PTR_ERR(left); |
91ca338d | 3415 | |
bf77467a | 3416 | __btrfs_tree_lock(left, BTRFS_NESTING_LEFT); |
44871b1b | 3417 | |
e902baac | 3418 | free_space = btrfs_leaf_free_space(left); |
44871b1b CM |
3419 | if (free_space < data_size) { |
3420 | ret = 1; | |
3421 | goto out; | |
3422 | } | |
3423 | ||
44871b1b | 3424 | ret = btrfs_cow_block(trans, root, left, |
9631e4cc | 3425 | path->nodes[1], slot - 1, &left, |
bf59a5a2 | 3426 | BTRFS_NESTING_LEFT_COW); |
44871b1b CM |
3427 | if (ret) { |
3428 | /* we hit -ENOSPC, but it isn't fatal here */ | |
79787eaa JM |
3429 | if (ret == -ENOSPC) |
3430 | ret = 1; | |
44871b1b CM |
3431 | goto out; |
3432 | } | |
3433 | ||
d16c702f QW |
3434 | if (check_sibling_keys(left, right)) { |
3435 | ret = -EUCLEAN; | |
3436 | goto out; | |
3437 | } | |
ed25dab3 JB |
3438 | return __push_leaf_left(trans, path, min_data_size, empty, left, |
3439 | free_space, right_nritems, max_slot); | |
44871b1b CM |
3440 | out: |
3441 | btrfs_tree_unlock(left); | |
3442 | free_extent_buffer(left); | |
3443 | return ret; | |
3444 | } | |
3445 | ||
3446 | /* | |
3447 | * split the path's leaf in two, making sure there is at least data_size | |
3448 | * available for the resulting leaf level of the path. | |
44871b1b | 3449 | */ |
143bede5 | 3450 | static noinline void copy_for_split(struct btrfs_trans_handle *trans, |
143bede5 JM |
3451 | struct btrfs_path *path, |
3452 | struct extent_buffer *l, | |
3453 | struct extent_buffer *right, | |
3454 | int slot, int mid, int nritems) | |
44871b1b | 3455 | { |
94f94ad9 | 3456 | struct btrfs_fs_info *fs_info = trans->fs_info; |
44871b1b CM |
3457 | int data_copy_size; |
3458 | int rt_data_off; | |
3459 | int i; | |
44871b1b | 3460 | struct btrfs_disk_key disk_key; |
cfed81a0 CM |
3461 | struct btrfs_map_token token; |
3462 | ||
44871b1b CM |
3463 | nritems = nritems - mid; |
3464 | btrfs_set_header_nritems(right, nritems); | |
dc2e724e | 3465 | data_copy_size = btrfs_item_data_end(l, mid) - leaf_data_end(l); |
44871b1b | 3466 | |
637e3b48 | 3467 | copy_leaf_items(right, l, 0, mid, nritems); |
44871b1b | 3468 | |
637e3b48 JB |
3469 | copy_leaf_data(right, l, BTRFS_LEAF_DATA_SIZE(fs_info) - data_copy_size, |
3470 | leaf_data_end(l), data_copy_size); | |
44871b1b | 3471 | |
dc2e724e | 3472 | rt_data_off = BTRFS_LEAF_DATA_SIZE(fs_info) - btrfs_item_data_end(l, mid); |
44871b1b | 3473 | |
c82f823c | 3474 | btrfs_init_map_token(&token, right); |
44871b1b | 3475 | for (i = 0; i < nritems; i++) { |
44871b1b CM |
3476 | u32 ioff; |
3477 | ||
3212fa14 JB |
3478 | ioff = btrfs_token_item_offset(&token, i); |
3479 | btrfs_set_token_item_offset(&token, i, ioff + rt_data_off); | |
44871b1b CM |
3480 | } |
3481 | ||
44871b1b | 3482 | btrfs_set_header_nritems(l, mid); |
44871b1b | 3483 | btrfs_item_key(right, &disk_key, 0); |
6ad3cf6d | 3484 | insert_ptr(trans, path, &disk_key, right->start, path->slots[1] + 1, 1); |
44871b1b CM |
3485 | |
3486 | btrfs_mark_buffer_dirty(right); | |
3487 | btrfs_mark_buffer_dirty(l); | |
3488 | BUG_ON(path->slots[0] != slot); | |
3489 | ||
44871b1b CM |
3490 | if (mid <= slot) { |
3491 | btrfs_tree_unlock(path->nodes[0]); | |
3492 | free_extent_buffer(path->nodes[0]); | |
3493 | path->nodes[0] = right; | |
3494 | path->slots[0] -= mid; | |
3495 | path->slots[1] += 1; | |
3496 | } else { | |
3497 | btrfs_tree_unlock(right); | |
3498 | free_extent_buffer(right); | |
3499 | } | |
3500 | ||
3501 | BUG_ON(path->slots[0] < 0); | |
44871b1b CM |
3502 | } |
3503 | ||
99d8f83c CM |
3504 | /* |
3505 | * double splits happen when we need to insert a big item in the middle | |
3506 | * of a leaf. A double split can leave us with 3 mostly empty leaves: | |
3507 | * leaf: [ slots 0 - N] [ our target ] [ N + 1 - total in leaf ] | |
3508 | * A B C | |
3509 | * | |
3510 | * We avoid this by trying to push the items on either side of our target | |
3511 | * into the adjacent leaves. If all goes well we can avoid the double split | |
3512 | * completely. | |
3513 | */ | |
3514 | static noinline int push_for_double_split(struct btrfs_trans_handle *trans, | |
3515 | struct btrfs_root *root, | |
3516 | struct btrfs_path *path, | |
3517 | int data_size) | |
3518 | { | |
3519 | int ret; | |
3520 | int progress = 0; | |
3521 | int slot; | |
3522 | u32 nritems; | |
5a4267ca | 3523 | int space_needed = data_size; |
99d8f83c CM |
3524 | |
3525 | slot = path->slots[0]; | |
5a4267ca | 3526 | if (slot < btrfs_header_nritems(path->nodes[0])) |
e902baac | 3527 | space_needed -= btrfs_leaf_free_space(path->nodes[0]); |
99d8f83c CM |
3528 | |
3529 | /* | |
3530 | * try to push all the items after our slot into the | |
3531 | * right leaf | |
3532 | */ | |
5a4267ca | 3533 | ret = push_leaf_right(trans, root, path, 1, space_needed, 0, slot); |
99d8f83c CM |
3534 | if (ret < 0) |
3535 | return ret; | |
3536 | ||
3537 | if (ret == 0) | |
3538 | progress++; | |
3539 | ||
3540 | nritems = btrfs_header_nritems(path->nodes[0]); | |
3541 | /* | |
3542 | * our goal is to get our slot at the start or end of a leaf. If | |
3543 | * we've done so we're done | |
3544 | */ | |
3545 | if (path->slots[0] == 0 || path->slots[0] == nritems) | |
3546 | return 0; | |
3547 | ||
e902baac | 3548 | if (btrfs_leaf_free_space(path->nodes[0]) >= data_size) |
99d8f83c CM |
3549 | return 0; |
3550 | ||
3551 | /* try to push all the items before our slot into the next leaf */ | |
3552 | slot = path->slots[0]; | |
263d3995 FM |
3553 | space_needed = data_size; |
3554 | if (slot > 0) | |
e902baac | 3555 | space_needed -= btrfs_leaf_free_space(path->nodes[0]); |
5a4267ca | 3556 | ret = push_leaf_left(trans, root, path, 1, space_needed, 0, slot); |
99d8f83c CM |
3557 | if (ret < 0) |
3558 | return ret; | |
3559 | ||
3560 | if (ret == 0) | |
3561 | progress++; | |
3562 | ||
3563 | if (progress) | |
3564 | return 0; | |
3565 | return 1; | |
3566 | } | |
3567 | ||
74123bd7 CM |
3568 | /* |
3569 | * split the path's leaf in two, making sure there is at least data_size | |
3570 | * available for the resulting leaf level of the path. | |
aa5d6bed CM |
3571 | * |
3572 | * returns 0 if all went well and < 0 on failure. | |
74123bd7 | 3573 | */ |
e02119d5 CM |
3574 | static noinline int split_leaf(struct btrfs_trans_handle *trans, |
3575 | struct btrfs_root *root, | |
310712b2 | 3576 | const struct btrfs_key *ins_key, |
e02119d5 CM |
3577 | struct btrfs_path *path, int data_size, |
3578 | int extend) | |
be0e5c09 | 3579 | { |
5d4f98a2 | 3580 | struct btrfs_disk_key disk_key; |
5f39d397 | 3581 | struct extent_buffer *l; |
7518a238 | 3582 | u32 nritems; |
eb60ceac CM |
3583 | int mid; |
3584 | int slot; | |
5f39d397 | 3585 | struct extent_buffer *right; |
b7a0365e | 3586 | struct btrfs_fs_info *fs_info = root->fs_info; |
d4dbff95 | 3587 | int ret = 0; |
aa5d6bed | 3588 | int wret; |
5d4f98a2 | 3589 | int split; |
cc0c5538 | 3590 | int num_doubles = 0; |
99d8f83c | 3591 | int tried_avoid_double = 0; |
aa5d6bed | 3592 | |
a5719521 YZ |
3593 | l = path->nodes[0]; |
3594 | slot = path->slots[0]; | |
3212fa14 | 3595 | if (extend && data_size + btrfs_item_size(l, slot) + |
0b246afa | 3596 | sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(fs_info)) |
a5719521 YZ |
3597 | return -EOVERFLOW; |
3598 | ||
40689478 | 3599 | /* first try to make some room by pushing left and right */ |
33157e05 | 3600 | if (data_size && path->nodes[1]) { |
5a4267ca FDBM |
3601 | int space_needed = data_size; |
3602 | ||
3603 | if (slot < btrfs_header_nritems(l)) | |
e902baac | 3604 | space_needed -= btrfs_leaf_free_space(l); |
5a4267ca FDBM |
3605 | |
3606 | wret = push_leaf_right(trans, root, path, space_needed, | |
3607 | space_needed, 0, 0); | |
d397712b | 3608 | if (wret < 0) |
eaee50e8 | 3609 | return wret; |
3685f791 | 3610 | if (wret) { |
263d3995 FM |
3611 | space_needed = data_size; |
3612 | if (slot > 0) | |
e902baac | 3613 | space_needed -= btrfs_leaf_free_space(l); |
5a4267ca FDBM |
3614 | wret = push_leaf_left(trans, root, path, space_needed, |
3615 | space_needed, 0, (u32)-1); | |
3685f791 CM |
3616 | if (wret < 0) |
3617 | return wret; | |
3618 | } | |
3619 | l = path->nodes[0]; | |
aa5d6bed | 3620 | |
3685f791 | 3621 | /* did the pushes work? */ |
e902baac | 3622 | if (btrfs_leaf_free_space(l) >= data_size) |
3685f791 | 3623 | return 0; |
3326d1b0 | 3624 | } |
aa5d6bed | 3625 | |
5c680ed6 | 3626 | if (!path->nodes[1]) { |
fdd99c72 | 3627 | ret = insert_new_root(trans, root, path, 1); |
5c680ed6 CM |
3628 | if (ret) |
3629 | return ret; | |
3630 | } | |
cc0c5538 | 3631 | again: |
5d4f98a2 | 3632 | split = 1; |
cc0c5538 | 3633 | l = path->nodes[0]; |
eb60ceac | 3634 | slot = path->slots[0]; |
5f39d397 | 3635 | nritems = btrfs_header_nritems(l); |
d397712b | 3636 | mid = (nritems + 1) / 2; |
54aa1f4d | 3637 | |
5d4f98a2 YZ |
3638 | if (mid <= slot) { |
3639 | if (nritems == 1 || | |
3640 | leaf_space_used(l, mid, nritems - mid) + data_size > | |
0b246afa | 3641 | BTRFS_LEAF_DATA_SIZE(fs_info)) { |
5d4f98a2 YZ |
3642 | if (slot >= nritems) { |
3643 | split = 0; | |
3644 | } else { | |
3645 | mid = slot; | |
3646 | if (mid != nritems && | |
3647 | leaf_space_used(l, mid, nritems - mid) + | |
0b246afa | 3648 | data_size > BTRFS_LEAF_DATA_SIZE(fs_info)) { |
99d8f83c CM |
3649 | if (data_size && !tried_avoid_double) |
3650 | goto push_for_double; | |
5d4f98a2 YZ |
3651 | split = 2; |
3652 | } | |
3653 | } | |
3654 | } | |
3655 | } else { | |
3656 | if (leaf_space_used(l, 0, mid) + data_size > | |
0b246afa | 3657 | BTRFS_LEAF_DATA_SIZE(fs_info)) { |
5d4f98a2 YZ |
3658 | if (!extend && data_size && slot == 0) { |
3659 | split = 0; | |
3660 | } else if ((extend || !data_size) && slot == 0) { | |
3661 | mid = 1; | |
3662 | } else { | |
3663 | mid = slot; | |
3664 | if (mid != nritems && | |
3665 | leaf_space_used(l, mid, nritems - mid) + | |
0b246afa | 3666 | data_size > BTRFS_LEAF_DATA_SIZE(fs_info)) { |
99d8f83c CM |
3667 | if (data_size && !tried_avoid_double) |
3668 | goto push_for_double; | |
67871254 | 3669 | split = 2; |
5d4f98a2 YZ |
3670 | } |
3671 | } | |
3672 | } | |
3673 | } | |
3674 | ||
3675 | if (split == 0) | |
3676 | btrfs_cpu_key_to_disk(&disk_key, ins_key); | |
3677 | else | |
3678 | btrfs_item_key(l, &disk_key, mid); | |
3679 | ||
ca9d473a JB |
3680 | /* |
3681 | * We have to about BTRFS_NESTING_NEW_ROOT here if we've done a double | |
3682 | * split, because we're only allowed to have MAX_LOCKDEP_SUBCLASSES | |
3683 | * subclasses, which is 8 at the time of this patch, and we've maxed it | |
3684 | * out. In the future we could add a | |
3685 | * BTRFS_NESTING_SPLIT_THE_SPLITTENING if we need to, but for now just | |
3686 | * use BTRFS_NESTING_NEW_ROOT. | |
3687 | */ | |
79bd3712 FM |
3688 | right = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid, |
3689 | &disk_key, 0, l->start, 0, | |
3690 | num_doubles ? BTRFS_NESTING_NEW_ROOT : | |
3691 | BTRFS_NESTING_SPLIT); | |
f0486c68 | 3692 | if (IS_ERR(right)) |
5f39d397 | 3693 | return PTR_ERR(right); |
f0486c68 | 3694 | |
0b246afa | 3695 | root_add_used(root, fs_info->nodesize); |
5f39d397 | 3696 | |
5d4f98a2 YZ |
3697 | if (split == 0) { |
3698 | if (mid <= slot) { | |
3699 | btrfs_set_header_nritems(right, 0); | |
6ad3cf6d | 3700 | insert_ptr(trans, path, &disk_key, |
2ff7e61e | 3701 | right->start, path->slots[1] + 1, 1); |
5d4f98a2 YZ |
3702 | btrfs_tree_unlock(path->nodes[0]); |
3703 | free_extent_buffer(path->nodes[0]); | |
3704 | path->nodes[0] = right; | |
3705 | path->slots[0] = 0; | |
3706 | path->slots[1] += 1; | |
3707 | } else { | |
3708 | btrfs_set_header_nritems(right, 0); | |
6ad3cf6d | 3709 | insert_ptr(trans, path, &disk_key, |
2ff7e61e | 3710 | right->start, path->slots[1], 1); |
5d4f98a2 YZ |
3711 | btrfs_tree_unlock(path->nodes[0]); |
3712 | free_extent_buffer(path->nodes[0]); | |
3713 | path->nodes[0] = right; | |
3714 | path->slots[0] = 0; | |
143bede5 | 3715 | if (path->slots[1] == 0) |
b167fa91 | 3716 | fixup_low_keys(path, &disk_key, 1); |
d4dbff95 | 3717 | } |
196e0249 LB |
3718 | /* |
3719 | * We create a new leaf 'right' for the required ins_len and | |
3720 | * we'll do btrfs_mark_buffer_dirty() on this leaf after copying | |
3721 | * the content of ins_len to 'right'. | |
3722 | */ | |
5d4f98a2 | 3723 | return ret; |
d4dbff95 | 3724 | } |
74123bd7 | 3725 | |
94f94ad9 | 3726 | copy_for_split(trans, path, l, right, slot, mid, nritems); |
31840ae1 | 3727 | |
5d4f98a2 | 3728 | if (split == 2) { |
cc0c5538 CM |
3729 | BUG_ON(num_doubles != 0); |
3730 | num_doubles++; | |
3731 | goto again; | |
a429e513 | 3732 | } |
44871b1b | 3733 | |
143bede5 | 3734 | return 0; |
99d8f83c CM |
3735 | |
3736 | push_for_double: | |
3737 | push_for_double_split(trans, root, path, data_size); | |
3738 | tried_avoid_double = 1; | |
e902baac | 3739 | if (btrfs_leaf_free_space(path->nodes[0]) >= data_size) |
99d8f83c CM |
3740 | return 0; |
3741 | goto again; | |
be0e5c09 CM |
3742 | } |
3743 | ||
ad48fd75 YZ |
3744 | static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans, |
3745 | struct btrfs_root *root, | |
3746 | struct btrfs_path *path, int ins_len) | |
459931ec | 3747 | { |
ad48fd75 | 3748 | struct btrfs_key key; |
459931ec | 3749 | struct extent_buffer *leaf; |
ad48fd75 YZ |
3750 | struct btrfs_file_extent_item *fi; |
3751 | u64 extent_len = 0; | |
3752 | u32 item_size; | |
3753 | int ret; | |
459931ec CM |
3754 | |
3755 | leaf = path->nodes[0]; | |
ad48fd75 YZ |
3756 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
3757 | ||
3758 | BUG_ON(key.type != BTRFS_EXTENT_DATA_KEY && | |
3759 | key.type != BTRFS_EXTENT_CSUM_KEY); | |
3760 | ||
e902baac | 3761 | if (btrfs_leaf_free_space(leaf) >= ins_len) |
ad48fd75 | 3762 | return 0; |
459931ec | 3763 | |
3212fa14 | 3764 | item_size = btrfs_item_size(leaf, path->slots[0]); |
ad48fd75 YZ |
3765 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
3766 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
3767 | struct btrfs_file_extent_item); | |
3768 | extent_len = btrfs_file_extent_num_bytes(leaf, fi); | |
3769 | } | |
b3b4aa74 | 3770 | btrfs_release_path(path); |
459931ec | 3771 | |
459931ec | 3772 | path->keep_locks = 1; |
ad48fd75 YZ |
3773 | path->search_for_split = 1; |
3774 | ret = btrfs_search_slot(trans, root, &key, path, 0, 1); | |
459931ec | 3775 | path->search_for_split = 0; |
a8df6fe6 FM |
3776 | if (ret > 0) |
3777 | ret = -EAGAIN; | |
ad48fd75 YZ |
3778 | if (ret < 0) |
3779 | goto err; | |
459931ec | 3780 | |
ad48fd75 YZ |
3781 | ret = -EAGAIN; |
3782 | leaf = path->nodes[0]; | |
a8df6fe6 | 3783 | /* if our item isn't there, return now */ |
3212fa14 | 3784 | if (item_size != btrfs_item_size(leaf, path->slots[0])) |
ad48fd75 YZ |
3785 | goto err; |
3786 | ||
109f6aef | 3787 | /* the leaf has changed, it now has room. return now */ |
e902baac | 3788 | if (btrfs_leaf_free_space(path->nodes[0]) >= ins_len) |
109f6aef CM |
3789 | goto err; |
3790 | ||
ad48fd75 YZ |
3791 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
3792 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
3793 | struct btrfs_file_extent_item); | |
3794 | if (extent_len != btrfs_file_extent_num_bytes(leaf, fi)) | |
3795 | goto err; | |
459931ec CM |
3796 | } |
3797 | ||
ad48fd75 | 3798 | ret = split_leaf(trans, root, &key, path, ins_len, 1); |
f0486c68 YZ |
3799 | if (ret) |
3800 | goto err; | |
459931ec | 3801 | |
ad48fd75 | 3802 | path->keep_locks = 0; |
b9473439 | 3803 | btrfs_unlock_up_safe(path, 1); |
ad48fd75 YZ |
3804 | return 0; |
3805 | err: | |
3806 | path->keep_locks = 0; | |
3807 | return ret; | |
3808 | } | |
3809 | ||
25263cd7 | 3810 | static noinline int split_item(struct btrfs_path *path, |
310712b2 | 3811 | const struct btrfs_key *new_key, |
ad48fd75 YZ |
3812 | unsigned long split_offset) |
3813 | { | |
3814 | struct extent_buffer *leaf; | |
c91666b1 | 3815 | int orig_slot, slot; |
ad48fd75 YZ |
3816 | char *buf; |
3817 | u32 nritems; | |
3818 | u32 item_size; | |
3819 | u32 orig_offset; | |
3820 | struct btrfs_disk_key disk_key; | |
3821 | ||
b9473439 | 3822 | leaf = path->nodes[0]; |
e902baac | 3823 | BUG_ON(btrfs_leaf_free_space(leaf) < sizeof(struct btrfs_item)); |
b9473439 | 3824 | |
c91666b1 | 3825 | orig_slot = path->slots[0]; |
3212fa14 JB |
3826 | orig_offset = btrfs_item_offset(leaf, path->slots[0]); |
3827 | item_size = btrfs_item_size(leaf, path->slots[0]); | |
459931ec | 3828 | |
459931ec | 3829 | buf = kmalloc(item_size, GFP_NOFS); |
ad48fd75 YZ |
3830 | if (!buf) |
3831 | return -ENOMEM; | |
3832 | ||
459931ec CM |
3833 | read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf, |
3834 | path->slots[0]), item_size); | |
459931ec | 3835 | |
ad48fd75 | 3836 | slot = path->slots[0] + 1; |
459931ec | 3837 | nritems = btrfs_header_nritems(leaf); |
459931ec CM |
3838 | if (slot != nritems) { |
3839 | /* shift the items */ | |
637e3b48 | 3840 | memmove_leaf_items(leaf, slot + 1, slot, nritems - slot); |
459931ec CM |
3841 | } |
3842 | ||
3843 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
3844 | btrfs_set_item_key(leaf, &disk_key, slot); | |
3845 | ||
3212fa14 JB |
3846 | btrfs_set_item_offset(leaf, slot, orig_offset); |
3847 | btrfs_set_item_size(leaf, slot, item_size - split_offset); | |
459931ec | 3848 | |
3212fa14 | 3849 | btrfs_set_item_offset(leaf, orig_slot, |
c91666b1 | 3850 | orig_offset + item_size - split_offset); |
3212fa14 | 3851 | btrfs_set_item_size(leaf, orig_slot, split_offset); |
459931ec CM |
3852 | |
3853 | btrfs_set_header_nritems(leaf, nritems + 1); | |
3854 | ||
3855 | /* write the data for the start of the original item */ | |
3856 | write_extent_buffer(leaf, buf, | |
3857 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
3858 | split_offset); | |
3859 | ||
3860 | /* write the data for the new item */ | |
3861 | write_extent_buffer(leaf, buf + split_offset, | |
3862 | btrfs_item_ptr_offset(leaf, slot), | |
3863 | item_size - split_offset); | |
3864 | btrfs_mark_buffer_dirty(leaf); | |
3865 | ||
e902baac | 3866 | BUG_ON(btrfs_leaf_free_space(leaf) < 0); |
459931ec | 3867 | kfree(buf); |
ad48fd75 YZ |
3868 | return 0; |
3869 | } | |
3870 | ||
3871 | /* | |
3872 | * This function splits a single item into two items, | |
3873 | * giving 'new_key' to the new item and splitting the | |
3874 | * old one at split_offset (from the start of the item). | |
3875 | * | |
3876 | * The path may be released by this operation. After | |
3877 | * the split, the path is pointing to the old item. The | |
3878 | * new item is going to be in the same node as the old one. | |
3879 | * | |
3880 | * Note, the item being split must be smaller enough to live alone on | |
3881 | * a tree block with room for one extra struct btrfs_item | |
3882 | * | |
3883 | * This allows us to split the item in place, keeping a lock on the | |
3884 | * leaf the entire time. | |
3885 | */ | |
3886 | int btrfs_split_item(struct btrfs_trans_handle *trans, | |
3887 | struct btrfs_root *root, | |
3888 | struct btrfs_path *path, | |
310712b2 | 3889 | const struct btrfs_key *new_key, |
ad48fd75 YZ |
3890 | unsigned long split_offset) |
3891 | { | |
3892 | int ret; | |
3893 | ret = setup_leaf_for_split(trans, root, path, | |
3894 | sizeof(struct btrfs_item)); | |
3895 | if (ret) | |
3896 | return ret; | |
3897 | ||
25263cd7 | 3898 | ret = split_item(path, new_key, split_offset); |
459931ec CM |
3899 | return ret; |
3900 | } | |
3901 | ||
d352ac68 CM |
3902 | /* |
3903 | * make the item pointed to by the path smaller. new_size indicates | |
3904 | * how small to make it, and from_end tells us if we just chop bytes | |
3905 | * off the end of the item or if we shift the item to chop bytes off | |
3906 | * the front. | |
3907 | */ | |
78ac4f9e | 3908 | void btrfs_truncate_item(struct btrfs_path *path, u32 new_size, int from_end) |
b18c6685 | 3909 | { |
b18c6685 | 3910 | int slot; |
5f39d397 | 3911 | struct extent_buffer *leaf; |
b18c6685 CM |
3912 | u32 nritems; |
3913 | unsigned int data_end; | |
3914 | unsigned int old_data_start; | |
3915 | unsigned int old_size; | |
3916 | unsigned int size_diff; | |
3917 | int i; | |
cfed81a0 CM |
3918 | struct btrfs_map_token token; |
3919 | ||
5f39d397 | 3920 | leaf = path->nodes[0]; |
179e29e4 CM |
3921 | slot = path->slots[0]; |
3922 | ||
3212fa14 | 3923 | old_size = btrfs_item_size(leaf, slot); |
179e29e4 | 3924 | if (old_size == new_size) |
143bede5 | 3925 | return; |
b18c6685 | 3926 | |
5f39d397 | 3927 | nritems = btrfs_header_nritems(leaf); |
8f881e8c | 3928 | data_end = leaf_data_end(leaf); |
b18c6685 | 3929 | |
3212fa14 | 3930 | old_data_start = btrfs_item_offset(leaf, slot); |
179e29e4 | 3931 | |
b18c6685 CM |
3932 | size_diff = old_size - new_size; |
3933 | ||
3934 | BUG_ON(slot < 0); | |
3935 | BUG_ON(slot >= nritems); | |
3936 | ||
3937 | /* | |
3938 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3939 | */ | |
3940 | /* first correct the data pointers */ | |
c82f823c | 3941 | btrfs_init_map_token(&token, leaf); |
b18c6685 | 3942 | for (i = slot; i < nritems; i++) { |
5f39d397 | 3943 | u32 ioff; |
db94535d | 3944 | |
3212fa14 JB |
3945 | ioff = btrfs_token_item_offset(&token, i); |
3946 | btrfs_set_token_item_offset(&token, i, ioff + size_diff); | |
b18c6685 | 3947 | } |
db94535d | 3948 | |
b18c6685 | 3949 | /* shift the data */ |
179e29e4 | 3950 | if (from_end) { |
637e3b48 JB |
3951 | memmove_leaf_data(leaf, data_end + size_diff, data_end, |
3952 | old_data_start + new_size - data_end); | |
179e29e4 CM |
3953 | } else { |
3954 | struct btrfs_disk_key disk_key; | |
3955 | u64 offset; | |
3956 | ||
3957 | btrfs_item_key(leaf, &disk_key, slot); | |
3958 | ||
3959 | if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) { | |
3960 | unsigned long ptr; | |
3961 | struct btrfs_file_extent_item *fi; | |
3962 | ||
3963 | fi = btrfs_item_ptr(leaf, slot, | |
3964 | struct btrfs_file_extent_item); | |
3965 | fi = (struct btrfs_file_extent_item *)( | |
3966 | (unsigned long)fi - size_diff); | |
3967 | ||
3968 | if (btrfs_file_extent_type(leaf, fi) == | |
3969 | BTRFS_FILE_EXTENT_INLINE) { | |
3970 | ptr = btrfs_item_ptr_offset(leaf, slot); | |
3971 | memmove_extent_buffer(leaf, ptr, | |
d397712b | 3972 | (unsigned long)fi, |
7ec20afb | 3973 | BTRFS_FILE_EXTENT_INLINE_DATA_START); |
179e29e4 CM |
3974 | } |
3975 | } | |
3976 | ||
637e3b48 JB |
3977 | memmove_leaf_data(leaf, data_end + size_diff, data_end, |
3978 | old_data_start - data_end); | |
179e29e4 CM |
3979 | |
3980 | offset = btrfs_disk_key_offset(&disk_key); | |
3981 | btrfs_set_disk_key_offset(&disk_key, offset + size_diff); | |
3982 | btrfs_set_item_key(leaf, &disk_key, slot); | |
3983 | if (slot == 0) | |
b167fa91 | 3984 | fixup_low_keys(path, &disk_key, 1); |
179e29e4 | 3985 | } |
5f39d397 | 3986 | |
3212fa14 | 3987 | btrfs_set_item_size(leaf, slot, new_size); |
5f39d397 | 3988 | btrfs_mark_buffer_dirty(leaf); |
b18c6685 | 3989 | |
e902baac | 3990 | if (btrfs_leaf_free_space(leaf) < 0) { |
a4f78750 | 3991 | btrfs_print_leaf(leaf); |
b18c6685 | 3992 | BUG(); |
5f39d397 | 3993 | } |
b18c6685 CM |
3994 | } |
3995 | ||
d352ac68 | 3996 | /* |
8f69dbd2 | 3997 | * make the item pointed to by the path bigger, data_size is the added size. |
d352ac68 | 3998 | */ |
c71dd880 | 3999 | void btrfs_extend_item(struct btrfs_path *path, u32 data_size) |
6567e837 | 4000 | { |
6567e837 | 4001 | int slot; |
5f39d397 | 4002 | struct extent_buffer *leaf; |
6567e837 CM |
4003 | u32 nritems; |
4004 | unsigned int data_end; | |
4005 | unsigned int old_data; | |
4006 | unsigned int old_size; | |
4007 | int i; | |
cfed81a0 CM |
4008 | struct btrfs_map_token token; |
4009 | ||
5f39d397 | 4010 | leaf = path->nodes[0]; |
6567e837 | 4011 | |
5f39d397 | 4012 | nritems = btrfs_header_nritems(leaf); |
8f881e8c | 4013 | data_end = leaf_data_end(leaf); |
6567e837 | 4014 | |
e902baac | 4015 | if (btrfs_leaf_free_space(leaf) < data_size) { |
a4f78750 | 4016 | btrfs_print_leaf(leaf); |
6567e837 | 4017 | BUG(); |
5f39d397 | 4018 | } |
6567e837 | 4019 | slot = path->slots[0]; |
dc2e724e | 4020 | old_data = btrfs_item_data_end(leaf, slot); |
6567e837 CM |
4021 | |
4022 | BUG_ON(slot < 0); | |
3326d1b0 | 4023 | if (slot >= nritems) { |
a4f78750 | 4024 | btrfs_print_leaf(leaf); |
c71dd880 | 4025 | btrfs_crit(leaf->fs_info, "slot %d too large, nritems %d", |
0b246afa | 4026 | slot, nritems); |
290342f6 | 4027 | BUG(); |
3326d1b0 | 4028 | } |
6567e837 CM |
4029 | |
4030 | /* | |
4031 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
4032 | */ | |
4033 | /* first correct the data pointers */ | |
c82f823c | 4034 | btrfs_init_map_token(&token, leaf); |
6567e837 | 4035 | for (i = slot; i < nritems; i++) { |
5f39d397 | 4036 | u32 ioff; |
db94535d | 4037 | |
3212fa14 JB |
4038 | ioff = btrfs_token_item_offset(&token, i); |
4039 | btrfs_set_token_item_offset(&token, i, ioff - data_size); | |
6567e837 | 4040 | } |
5f39d397 | 4041 | |
6567e837 | 4042 | /* shift the data */ |
637e3b48 JB |
4043 | memmove_leaf_data(leaf, data_end - data_size, data_end, |
4044 | old_data - data_end); | |
5f39d397 | 4045 | |
6567e837 | 4046 | data_end = old_data; |
3212fa14 JB |
4047 | old_size = btrfs_item_size(leaf, slot); |
4048 | btrfs_set_item_size(leaf, slot, old_size + data_size); | |
5f39d397 | 4049 | btrfs_mark_buffer_dirty(leaf); |
6567e837 | 4050 | |
e902baac | 4051 | if (btrfs_leaf_free_space(leaf) < 0) { |
a4f78750 | 4052 | btrfs_print_leaf(leaf); |
6567e837 | 4053 | BUG(); |
5f39d397 | 4054 | } |
6567e837 CM |
4055 | } |
4056 | ||
43dd529a DS |
4057 | /* |
4058 | * Make space in the node before inserting one or more items. | |
da9ffb24 NB |
4059 | * |
4060 | * @root: root we are inserting items to | |
4061 | * @path: points to the leaf/slot where we are going to insert new items | |
b7ef5f3a | 4062 | * @batch: information about the batch of items to insert |
43dd529a DS |
4063 | * |
4064 | * Main purpose is to save stack depth by doing the bulk of the work in a | |
4065 | * function that doesn't call btrfs_search_slot | |
74123bd7 | 4066 | */ |
f0641656 FM |
4067 | static void setup_items_for_insert(struct btrfs_root *root, struct btrfs_path *path, |
4068 | const struct btrfs_item_batch *batch) | |
be0e5c09 | 4069 | { |
0b246afa | 4070 | struct btrfs_fs_info *fs_info = root->fs_info; |
9c58309d | 4071 | int i; |
7518a238 | 4072 | u32 nritems; |
be0e5c09 | 4073 | unsigned int data_end; |
e2fa7227 | 4074 | struct btrfs_disk_key disk_key; |
44871b1b CM |
4075 | struct extent_buffer *leaf; |
4076 | int slot; | |
cfed81a0 | 4077 | struct btrfs_map_token token; |
fc0d82e1 | 4078 | u32 total_size; |
cfed81a0 | 4079 | |
b7ef5f3a FM |
4080 | /* |
4081 | * Before anything else, update keys in the parent and other ancestors | |
4082 | * if needed, then release the write locks on them, so that other tasks | |
4083 | * can use them while we modify the leaf. | |
4084 | */ | |
24cdc847 | 4085 | if (path->slots[0] == 0) { |
b7ef5f3a | 4086 | btrfs_cpu_key_to_disk(&disk_key, &batch->keys[0]); |
b167fa91 | 4087 | fixup_low_keys(path, &disk_key, 1); |
24cdc847 FM |
4088 | } |
4089 | btrfs_unlock_up_safe(path, 1); | |
4090 | ||
5f39d397 | 4091 | leaf = path->nodes[0]; |
44871b1b | 4092 | slot = path->slots[0]; |
74123bd7 | 4093 | |
5f39d397 | 4094 | nritems = btrfs_header_nritems(leaf); |
8f881e8c | 4095 | data_end = leaf_data_end(leaf); |
b7ef5f3a | 4096 | total_size = batch->total_data_size + (batch->nr * sizeof(struct btrfs_item)); |
eb60ceac | 4097 | |
e902baac | 4098 | if (btrfs_leaf_free_space(leaf) < total_size) { |
a4f78750 | 4099 | btrfs_print_leaf(leaf); |
0b246afa | 4100 | btrfs_crit(fs_info, "not enough freespace need %u have %d", |
e902baac | 4101 | total_size, btrfs_leaf_free_space(leaf)); |
be0e5c09 | 4102 | BUG(); |
d4dbff95 | 4103 | } |
5f39d397 | 4104 | |
c82f823c | 4105 | btrfs_init_map_token(&token, leaf); |
be0e5c09 | 4106 | if (slot != nritems) { |
dc2e724e | 4107 | unsigned int old_data = btrfs_item_data_end(leaf, slot); |
be0e5c09 | 4108 | |
5f39d397 | 4109 | if (old_data < data_end) { |
a4f78750 | 4110 | btrfs_print_leaf(leaf); |
7269ddd2 NB |
4111 | btrfs_crit(fs_info, |
4112 | "item at slot %d with data offset %u beyond data end of leaf %u", | |
5d163e0e | 4113 | slot, old_data, data_end); |
290342f6 | 4114 | BUG(); |
5f39d397 | 4115 | } |
be0e5c09 CM |
4116 | /* |
4117 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
4118 | */ | |
4119 | /* first correct the data pointers */ | |
0783fcfc | 4120 | for (i = slot; i < nritems; i++) { |
5f39d397 | 4121 | u32 ioff; |
db94535d | 4122 | |
3212fa14 JB |
4123 | ioff = btrfs_token_item_offset(&token, i); |
4124 | btrfs_set_token_item_offset(&token, i, | |
74794207 | 4125 | ioff - batch->total_data_size); |
0783fcfc | 4126 | } |
be0e5c09 | 4127 | /* shift the items */ |
637e3b48 | 4128 | memmove_leaf_items(leaf, slot + batch->nr, slot, nritems - slot); |
be0e5c09 CM |
4129 | |
4130 | /* shift the data */ | |
637e3b48 JB |
4131 | memmove_leaf_data(leaf, data_end - batch->total_data_size, |
4132 | data_end, old_data - data_end); | |
be0e5c09 CM |
4133 | data_end = old_data; |
4134 | } | |
5f39d397 | 4135 | |
62e2749e | 4136 | /* setup the item for the new data */ |
b7ef5f3a FM |
4137 | for (i = 0; i < batch->nr; i++) { |
4138 | btrfs_cpu_key_to_disk(&disk_key, &batch->keys[i]); | |
9c58309d | 4139 | btrfs_set_item_key(leaf, &disk_key, slot + i); |
b7ef5f3a | 4140 | data_end -= batch->data_sizes[i]; |
3212fa14 JB |
4141 | btrfs_set_token_item_offset(&token, slot + i, data_end); |
4142 | btrfs_set_token_item_size(&token, slot + i, batch->data_sizes[i]); | |
9c58309d | 4143 | } |
44871b1b | 4144 | |
b7ef5f3a | 4145 | btrfs_set_header_nritems(leaf, nritems + batch->nr); |
b9473439 | 4146 | btrfs_mark_buffer_dirty(leaf); |
aa5d6bed | 4147 | |
e902baac | 4148 | if (btrfs_leaf_free_space(leaf) < 0) { |
a4f78750 | 4149 | btrfs_print_leaf(leaf); |
be0e5c09 | 4150 | BUG(); |
5f39d397 | 4151 | } |
44871b1b CM |
4152 | } |
4153 | ||
f0641656 FM |
4154 | /* |
4155 | * Insert a new item into a leaf. | |
4156 | * | |
4157 | * @root: The root of the btree. | |
4158 | * @path: A path pointing to the target leaf and slot. | |
4159 | * @key: The key of the new item. | |
4160 | * @data_size: The size of the data associated with the new key. | |
4161 | */ | |
4162 | void btrfs_setup_item_for_insert(struct btrfs_root *root, | |
4163 | struct btrfs_path *path, | |
4164 | const struct btrfs_key *key, | |
4165 | u32 data_size) | |
4166 | { | |
4167 | struct btrfs_item_batch batch; | |
4168 | ||
4169 | batch.keys = key; | |
4170 | batch.data_sizes = &data_size; | |
4171 | batch.total_data_size = data_size; | |
4172 | batch.nr = 1; | |
4173 | ||
4174 | setup_items_for_insert(root, path, &batch); | |
4175 | } | |
4176 | ||
44871b1b CM |
4177 | /* |
4178 | * Given a key and some data, insert items into the tree. | |
4179 | * This does all the path init required, making room in the tree if needed. | |
4180 | */ | |
4181 | int btrfs_insert_empty_items(struct btrfs_trans_handle *trans, | |
4182 | struct btrfs_root *root, | |
4183 | struct btrfs_path *path, | |
b7ef5f3a | 4184 | const struct btrfs_item_batch *batch) |
44871b1b | 4185 | { |
44871b1b CM |
4186 | int ret = 0; |
4187 | int slot; | |
b7ef5f3a | 4188 | u32 total_size; |
44871b1b | 4189 | |
b7ef5f3a FM |
4190 | total_size = batch->total_data_size + (batch->nr * sizeof(struct btrfs_item)); |
4191 | ret = btrfs_search_slot(trans, root, &batch->keys[0], path, total_size, 1); | |
44871b1b CM |
4192 | if (ret == 0) |
4193 | return -EEXIST; | |
4194 | if (ret < 0) | |
143bede5 | 4195 | return ret; |
44871b1b | 4196 | |
44871b1b CM |
4197 | slot = path->slots[0]; |
4198 | BUG_ON(slot < 0); | |
4199 | ||
b7ef5f3a | 4200 | setup_items_for_insert(root, path, batch); |
143bede5 | 4201 | return 0; |
62e2749e CM |
4202 | } |
4203 | ||
4204 | /* | |
4205 | * Given a key and some data, insert an item into the tree. | |
4206 | * This does all the path init required, making room in the tree if needed. | |
4207 | */ | |
310712b2 OS |
4208 | int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
4209 | const struct btrfs_key *cpu_key, void *data, | |
4210 | u32 data_size) | |
62e2749e CM |
4211 | { |
4212 | int ret = 0; | |
2c90e5d6 | 4213 | struct btrfs_path *path; |
5f39d397 CM |
4214 | struct extent_buffer *leaf; |
4215 | unsigned long ptr; | |
62e2749e | 4216 | |
2c90e5d6 | 4217 | path = btrfs_alloc_path(); |
db5b493a TI |
4218 | if (!path) |
4219 | return -ENOMEM; | |
2c90e5d6 | 4220 | ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size); |
62e2749e | 4221 | if (!ret) { |
5f39d397 CM |
4222 | leaf = path->nodes[0]; |
4223 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
4224 | write_extent_buffer(leaf, data, ptr, data_size); | |
4225 | btrfs_mark_buffer_dirty(leaf); | |
62e2749e | 4226 | } |
2c90e5d6 | 4227 | btrfs_free_path(path); |
aa5d6bed | 4228 | return ret; |
be0e5c09 CM |
4229 | } |
4230 | ||
f0641656 FM |
4231 | /* |
4232 | * This function duplicates an item, giving 'new_key' to the new item. | |
4233 | * It guarantees both items live in the same tree leaf and the new item is | |
4234 | * contiguous with the original item. | |
4235 | * | |
4236 | * This allows us to split a file extent in place, keeping a lock on the leaf | |
4237 | * the entire time. | |
4238 | */ | |
4239 | int btrfs_duplicate_item(struct btrfs_trans_handle *trans, | |
4240 | struct btrfs_root *root, | |
4241 | struct btrfs_path *path, | |
4242 | const struct btrfs_key *new_key) | |
4243 | { | |
4244 | struct extent_buffer *leaf; | |
4245 | int ret; | |
4246 | u32 item_size; | |
4247 | ||
4248 | leaf = path->nodes[0]; | |
3212fa14 | 4249 | item_size = btrfs_item_size(leaf, path->slots[0]); |
f0641656 FM |
4250 | ret = setup_leaf_for_split(trans, root, path, |
4251 | item_size + sizeof(struct btrfs_item)); | |
4252 | if (ret) | |
4253 | return ret; | |
4254 | ||
4255 | path->slots[0]++; | |
4256 | btrfs_setup_item_for_insert(root, path, new_key, item_size); | |
4257 | leaf = path->nodes[0]; | |
4258 | memcpy_extent_buffer(leaf, | |
4259 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
4260 | btrfs_item_ptr_offset(leaf, path->slots[0] - 1), | |
4261 | item_size); | |
4262 | return 0; | |
4263 | } | |
4264 | ||
74123bd7 | 4265 | /* |
5de08d7d | 4266 | * delete the pointer from a given node. |
74123bd7 | 4267 | * |
d352ac68 CM |
4268 | * the tree should have been previously balanced so the deletion does not |
4269 | * empty a node. | |
74123bd7 | 4270 | */ |
afe5fea7 TI |
4271 | static void del_ptr(struct btrfs_root *root, struct btrfs_path *path, |
4272 | int level, int slot) | |
be0e5c09 | 4273 | { |
5f39d397 | 4274 | struct extent_buffer *parent = path->nodes[level]; |
7518a238 | 4275 | u32 nritems; |
f3ea38da | 4276 | int ret; |
be0e5c09 | 4277 | |
5f39d397 | 4278 | nritems = btrfs_header_nritems(parent); |
d397712b | 4279 | if (slot != nritems - 1) { |
bf1d3425 | 4280 | if (level) { |
f3a84ccd FM |
4281 | ret = btrfs_tree_mod_log_insert_move(parent, slot, |
4282 | slot + 1, nritems - slot - 1); | |
bf1d3425 DS |
4283 | BUG_ON(ret < 0); |
4284 | } | |
5f39d397 | 4285 | memmove_extent_buffer(parent, |
e23efd8e JB |
4286 | btrfs_node_key_ptr_offset(parent, slot), |
4287 | btrfs_node_key_ptr_offset(parent, slot + 1), | |
d6025579 CM |
4288 | sizeof(struct btrfs_key_ptr) * |
4289 | (nritems - slot - 1)); | |
57ba86c0 | 4290 | } else if (level) { |
f3a84ccd | 4291 | ret = btrfs_tree_mod_log_insert_key(parent, slot, |
33cff222 | 4292 | BTRFS_MOD_LOG_KEY_REMOVE); |
57ba86c0 | 4293 | BUG_ON(ret < 0); |
bb803951 | 4294 | } |
f3ea38da | 4295 | |
7518a238 | 4296 | nritems--; |
5f39d397 | 4297 | btrfs_set_header_nritems(parent, nritems); |
7518a238 | 4298 | if (nritems == 0 && parent == root->node) { |
5f39d397 | 4299 | BUG_ON(btrfs_header_level(root->node) != 1); |
bb803951 | 4300 | /* just turn the root into a leaf and break */ |
5f39d397 | 4301 | btrfs_set_header_level(root->node, 0); |
bb803951 | 4302 | } else if (slot == 0) { |
5f39d397 CM |
4303 | struct btrfs_disk_key disk_key; |
4304 | ||
4305 | btrfs_node_key(parent, &disk_key, 0); | |
b167fa91 | 4306 | fixup_low_keys(path, &disk_key, level + 1); |
be0e5c09 | 4307 | } |
d6025579 | 4308 | btrfs_mark_buffer_dirty(parent); |
be0e5c09 CM |
4309 | } |
4310 | ||
323ac95b CM |
4311 | /* |
4312 | * a helper function to delete the leaf pointed to by path->slots[1] and | |
5d4f98a2 | 4313 | * path->nodes[1]. |
323ac95b CM |
4314 | * |
4315 | * This deletes the pointer in path->nodes[1] and frees the leaf | |
4316 | * block extent. zero is returned if it all worked out, < 0 otherwise. | |
4317 | * | |
4318 | * The path must have already been setup for deleting the leaf, including | |
4319 | * all the proper balancing. path->nodes[1] must be locked. | |
4320 | */ | |
143bede5 JM |
4321 | static noinline void btrfs_del_leaf(struct btrfs_trans_handle *trans, |
4322 | struct btrfs_root *root, | |
4323 | struct btrfs_path *path, | |
4324 | struct extent_buffer *leaf) | |
323ac95b | 4325 | { |
5d4f98a2 | 4326 | WARN_ON(btrfs_header_generation(leaf) != trans->transid); |
afe5fea7 | 4327 | del_ptr(root, path, 1, path->slots[1]); |
323ac95b | 4328 | |
4d081c41 CM |
4329 | /* |
4330 | * btrfs_free_extent is expensive, we want to make sure we | |
4331 | * aren't holding any locks when we call it | |
4332 | */ | |
4333 | btrfs_unlock_up_safe(path, 0); | |
4334 | ||
f0486c68 YZ |
4335 | root_sub_used(root, leaf->len); |
4336 | ||
67439dad | 4337 | atomic_inc(&leaf->refs); |
7a163608 | 4338 | btrfs_free_tree_block(trans, btrfs_root_id(root), leaf, 0, 1); |
3083ee2e | 4339 | free_extent_buffer_stale(leaf); |
323ac95b | 4340 | } |
74123bd7 CM |
4341 | /* |
4342 | * delete the item at the leaf level in path. If that empties | |
4343 | * the leaf, remove it from the tree | |
4344 | */ | |
85e21bac CM |
4345 | int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
4346 | struct btrfs_path *path, int slot, int nr) | |
be0e5c09 | 4347 | { |
0b246afa | 4348 | struct btrfs_fs_info *fs_info = root->fs_info; |
5f39d397 | 4349 | struct extent_buffer *leaf; |
aa5d6bed CM |
4350 | int ret = 0; |
4351 | int wret; | |
7518a238 | 4352 | u32 nritems; |
be0e5c09 | 4353 | |
5f39d397 | 4354 | leaf = path->nodes[0]; |
5f39d397 | 4355 | nritems = btrfs_header_nritems(leaf); |
be0e5c09 | 4356 | |
85e21bac | 4357 | if (slot + nr != nritems) { |
0cae23b6 FM |
4358 | const u32 last_off = btrfs_item_offset(leaf, slot + nr - 1); |
4359 | const int data_end = leaf_data_end(leaf); | |
c82f823c | 4360 | struct btrfs_map_token token; |
0cae23b6 FM |
4361 | u32 dsize = 0; |
4362 | int i; | |
4363 | ||
4364 | for (i = 0; i < nr; i++) | |
4365 | dsize += btrfs_item_size(leaf, slot + i); | |
5f39d397 | 4366 | |
637e3b48 JB |
4367 | memmove_leaf_data(leaf, data_end + dsize, data_end, |
4368 | last_off - data_end); | |
5f39d397 | 4369 | |
c82f823c | 4370 | btrfs_init_map_token(&token, leaf); |
85e21bac | 4371 | for (i = slot + nr; i < nritems; i++) { |
5f39d397 | 4372 | u32 ioff; |
db94535d | 4373 | |
3212fa14 JB |
4374 | ioff = btrfs_token_item_offset(&token, i); |
4375 | btrfs_set_token_item_offset(&token, i, ioff + dsize); | |
0783fcfc | 4376 | } |
db94535d | 4377 | |
637e3b48 | 4378 | memmove_leaf_items(leaf, slot, slot + nr, nritems - slot - nr); |
be0e5c09 | 4379 | } |
85e21bac CM |
4380 | btrfs_set_header_nritems(leaf, nritems - nr); |
4381 | nritems -= nr; | |
5f39d397 | 4382 | |
74123bd7 | 4383 | /* delete the leaf if we've emptied it */ |
7518a238 | 4384 | if (nritems == 0) { |
5f39d397 CM |
4385 | if (leaf == root->node) { |
4386 | btrfs_set_header_level(leaf, 0); | |
9a8dd150 | 4387 | } else { |
190a8339 | 4388 | btrfs_clear_buffer_dirty(trans, leaf); |
143bede5 | 4389 | btrfs_del_leaf(trans, root, path, leaf); |
9a8dd150 | 4390 | } |
be0e5c09 | 4391 | } else { |
7518a238 | 4392 | int used = leaf_space_used(leaf, 0, nritems); |
aa5d6bed | 4393 | if (slot == 0) { |
5f39d397 CM |
4394 | struct btrfs_disk_key disk_key; |
4395 | ||
4396 | btrfs_item_key(leaf, &disk_key, 0); | |
b167fa91 | 4397 | fixup_low_keys(path, &disk_key, 1); |
aa5d6bed | 4398 | } |
aa5d6bed | 4399 | |
7c4063d1 FM |
4400 | /* |
4401 | * Try to delete the leaf if it is mostly empty. We do this by | |
4402 | * trying to move all its items into its left and right neighbours. | |
4403 | * If we can't move all the items, then we don't delete it - it's | |
4404 | * not ideal, but future insertions might fill the leaf with more | |
4405 | * items, or items from other leaves might be moved later into our | |
4406 | * leaf due to deletions on those leaves. | |
4407 | */ | |
0b246afa | 4408 | if (used < BTRFS_LEAF_DATA_SIZE(fs_info) / 3) { |
7c4063d1 FM |
4409 | u32 min_push_space; |
4410 | ||
be0e5c09 CM |
4411 | /* push_leaf_left fixes the path. |
4412 | * make sure the path still points to our leaf | |
4413 | * for possible call to del_ptr below | |
4414 | */ | |
4920c9ac | 4415 | slot = path->slots[1]; |
67439dad | 4416 | atomic_inc(&leaf->refs); |
7c4063d1 FM |
4417 | /* |
4418 | * We want to be able to at least push one item to the | |
4419 | * left neighbour leaf, and that's the first item. | |
4420 | */ | |
4421 | min_push_space = sizeof(struct btrfs_item) + | |
4422 | btrfs_item_size(leaf, 0); | |
4423 | wret = push_leaf_left(trans, root, path, 0, | |
4424 | min_push_space, 1, (u32)-1); | |
54aa1f4d | 4425 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed | 4426 | ret = wret; |
5f39d397 CM |
4427 | |
4428 | if (path->nodes[0] == leaf && | |
4429 | btrfs_header_nritems(leaf)) { | |
7c4063d1 FM |
4430 | /* |
4431 | * If we were not able to push all items from our | |
4432 | * leaf to its left neighbour, then attempt to | |
4433 | * either push all the remaining items to the | |
4434 | * right neighbour or none. There's no advantage | |
4435 | * in pushing only some items, instead of all, as | |
4436 | * it's pointless to end up with a leaf having | |
4437 | * too few items while the neighbours can be full | |
4438 | * or nearly full. | |
4439 | */ | |
4440 | nritems = btrfs_header_nritems(leaf); | |
4441 | min_push_space = leaf_space_used(leaf, 0, nritems); | |
4442 | wret = push_leaf_right(trans, root, path, 0, | |
4443 | min_push_space, 1, 0); | |
54aa1f4d | 4444 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed CM |
4445 | ret = wret; |
4446 | } | |
5f39d397 CM |
4447 | |
4448 | if (btrfs_header_nritems(leaf) == 0) { | |
323ac95b | 4449 | path->slots[1] = slot; |
143bede5 | 4450 | btrfs_del_leaf(trans, root, path, leaf); |
5f39d397 | 4451 | free_extent_buffer(leaf); |
143bede5 | 4452 | ret = 0; |
5de08d7d | 4453 | } else { |
925baedd CM |
4454 | /* if we're still in the path, make sure |
4455 | * we're dirty. Otherwise, one of the | |
4456 | * push_leaf functions must have already | |
4457 | * dirtied this buffer | |
4458 | */ | |
4459 | if (path->nodes[0] == leaf) | |
4460 | btrfs_mark_buffer_dirty(leaf); | |
5f39d397 | 4461 | free_extent_buffer(leaf); |
be0e5c09 | 4462 | } |
d5719762 | 4463 | } else { |
5f39d397 | 4464 | btrfs_mark_buffer_dirty(leaf); |
be0e5c09 CM |
4465 | } |
4466 | } | |
aa5d6bed | 4467 | return ret; |
be0e5c09 CM |
4468 | } |
4469 | ||
7bb86316 | 4470 | /* |
925baedd | 4471 | * search the tree again to find a leaf with lesser keys |
7bb86316 CM |
4472 | * returns 0 if it found something or 1 if there are no lesser leaves. |
4473 | * returns < 0 on io errors. | |
d352ac68 CM |
4474 | * |
4475 | * This may release the path, and so you may lose any locks held at the | |
4476 | * time you call it. | |
7bb86316 | 4477 | */ |
16e7549f | 4478 | int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) |
7bb86316 | 4479 | { |
925baedd CM |
4480 | struct btrfs_key key; |
4481 | struct btrfs_disk_key found_key; | |
4482 | int ret; | |
7bb86316 | 4483 | |
925baedd | 4484 | btrfs_item_key_to_cpu(path->nodes[0], &key, 0); |
7bb86316 | 4485 | |
e8b0d724 | 4486 | if (key.offset > 0) { |
925baedd | 4487 | key.offset--; |
e8b0d724 | 4488 | } else if (key.type > 0) { |
925baedd | 4489 | key.type--; |
e8b0d724 FDBM |
4490 | key.offset = (u64)-1; |
4491 | } else if (key.objectid > 0) { | |
925baedd | 4492 | key.objectid--; |
e8b0d724 FDBM |
4493 | key.type = (u8)-1; |
4494 | key.offset = (u64)-1; | |
4495 | } else { | |
925baedd | 4496 | return 1; |
e8b0d724 | 4497 | } |
7bb86316 | 4498 | |
b3b4aa74 | 4499 | btrfs_release_path(path); |
925baedd CM |
4500 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
4501 | if (ret < 0) | |
4502 | return ret; | |
4503 | btrfs_item_key(path->nodes[0], &found_key, 0); | |
4504 | ret = comp_keys(&found_key, &key); | |
337c6f68 FM |
4505 | /* |
4506 | * We might have had an item with the previous key in the tree right | |
4507 | * before we released our path. And after we released our path, that | |
4508 | * item might have been pushed to the first slot (0) of the leaf we | |
4509 | * were holding due to a tree balance. Alternatively, an item with the | |
4510 | * previous key can exist as the only element of a leaf (big fat item). | |
4511 | * Therefore account for these 2 cases, so that our callers (like | |
4512 | * btrfs_previous_item) don't miss an existing item with a key matching | |
4513 | * the previous key we computed above. | |
4514 | */ | |
4515 | if (ret <= 0) | |
925baedd CM |
4516 | return 0; |
4517 | return 1; | |
7bb86316 CM |
4518 | } |
4519 | ||
3f157a2f CM |
4520 | /* |
4521 | * A helper function to walk down the tree starting at min_key, and looking | |
de78b51a ES |
4522 | * for nodes or leaves that are have a minimum transaction id. |
4523 | * This is used by the btree defrag code, and tree logging | |
3f157a2f CM |
4524 | * |
4525 | * This does not cow, but it does stuff the starting key it finds back | |
4526 | * into min_key, so you can call btrfs_search_slot with cow=1 on the | |
4527 | * key and get a writable path. | |
4528 | * | |
3f157a2f CM |
4529 | * This honors path->lowest_level to prevent descent past a given level |
4530 | * of the tree. | |
4531 | * | |
d352ac68 CM |
4532 | * min_trans indicates the oldest transaction that you are interested |
4533 | * in walking through. Any nodes or leaves older than min_trans are | |
4534 | * skipped over (without reading them). | |
4535 | * | |
3f157a2f CM |
4536 | * returns zero if something useful was found, < 0 on error and 1 if there |
4537 | * was nothing in the tree that matched the search criteria. | |
4538 | */ | |
4539 | int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key, | |
de78b51a | 4540 | struct btrfs_path *path, |
3f157a2f CM |
4541 | u64 min_trans) |
4542 | { | |
4543 | struct extent_buffer *cur; | |
4544 | struct btrfs_key found_key; | |
4545 | int slot; | |
9652480b | 4546 | int sret; |
3f157a2f CM |
4547 | u32 nritems; |
4548 | int level; | |
4549 | int ret = 1; | |
f98de9b9 | 4550 | int keep_locks = path->keep_locks; |
3f157a2f | 4551 | |
c922b016 | 4552 | ASSERT(!path->nowait); |
f98de9b9 | 4553 | path->keep_locks = 1; |
3f157a2f | 4554 | again: |
bd681513 | 4555 | cur = btrfs_read_lock_root_node(root); |
3f157a2f | 4556 | level = btrfs_header_level(cur); |
e02119d5 | 4557 | WARN_ON(path->nodes[level]); |
3f157a2f | 4558 | path->nodes[level] = cur; |
bd681513 | 4559 | path->locks[level] = BTRFS_READ_LOCK; |
3f157a2f CM |
4560 | |
4561 | if (btrfs_header_generation(cur) < min_trans) { | |
4562 | ret = 1; | |
4563 | goto out; | |
4564 | } | |
d397712b | 4565 | while (1) { |
3f157a2f CM |
4566 | nritems = btrfs_header_nritems(cur); |
4567 | level = btrfs_header_level(cur); | |
fdf8d595 | 4568 | sret = btrfs_bin_search(cur, 0, min_key, &slot); |
cbca7d59 FM |
4569 | if (sret < 0) { |
4570 | ret = sret; | |
4571 | goto out; | |
4572 | } | |
3f157a2f | 4573 | |
323ac95b CM |
4574 | /* at the lowest level, we're done, setup the path and exit */ |
4575 | if (level == path->lowest_level) { | |
e02119d5 CM |
4576 | if (slot >= nritems) |
4577 | goto find_next_key; | |
3f157a2f CM |
4578 | ret = 0; |
4579 | path->slots[level] = slot; | |
4580 | btrfs_item_key_to_cpu(cur, &found_key, slot); | |
4581 | goto out; | |
4582 | } | |
9652480b Y |
4583 | if (sret && slot > 0) |
4584 | slot--; | |
3f157a2f | 4585 | /* |
de78b51a | 4586 | * check this node pointer against the min_trans parameters. |
260db43c | 4587 | * If it is too old, skip to the next one. |
3f157a2f | 4588 | */ |
d397712b | 4589 | while (slot < nritems) { |
3f157a2f | 4590 | u64 gen; |
e02119d5 | 4591 | |
3f157a2f CM |
4592 | gen = btrfs_node_ptr_generation(cur, slot); |
4593 | if (gen < min_trans) { | |
4594 | slot++; | |
4595 | continue; | |
4596 | } | |
de78b51a | 4597 | break; |
3f157a2f | 4598 | } |
e02119d5 | 4599 | find_next_key: |
3f157a2f CM |
4600 | /* |
4601 | * we didn't find a candidate key in this node, walk forward | |
4602 | * and find another one | |
4603 | */ | |
4604 | if (slot >= nritems) { | |
e02119d5 CM |
4605 | path->slots[level] = slot; |
4606 | sret = btrfs_find_next_key(root, path, min_key, level, | |
de78b51a | 4607 | min_trans); |
e02119d5 | 4608 | if (sret == 0) { |
b3b4aa74 | 4609 | btrfs_release_path(path); |
3f157a2f CM |
4610 | goto again; |
4611 | } else { | |
4612 | goto out; | |
4613 | } | |
4614 | } | |
4615 | /* save our key for returning back */ | |
4616 | btrfs_node_key_to_cpu(cur, &found_key, slot); | |
4617 | path->slots[level] = slot; | |
4618 | if (level == path->lowest_level) { | |
4619 | ret = 0; | |
3f157a2f CM |
4620 | goto out; |
4621 | } | |
4b231ae4 | 4622 | cur = btrfs_read_node_slot(cur, slot); |
fb770ae4 LB |
4623 | if (IS_ERR(cur)) { |
4624 | ret = PTR_ERR(cur); | |
4625 | goto out; | |
4626 | } | |
3f157a2f | 4627 | |
bd681513 | 4628 | btrfs_tree_read_lock(cur); |
b4ce94de | 4629 | |
bd681513 | 4630 | path->locks[level - 1] = BTRFS_READ_LOCK; |
3f157a2f | 4631 | path->nodes[level - 1] = cur; |
f7c79f30 | 4632 | unlock_up(path, level, 1, 0, NULL); |
3f157a2f CM |
4633 | } |
4634 | out: | |
f98de9b9 FM |
4635 | path->keep_locks = keep_locks; |
4636 | if (ret == 0) { | |
4637 | btrfs_unlock_up_safe(path, path->lowest_level + 1); | |
3f157a2f | 4638 | memcpy(min_key, &found_key, sizeof(found_key)); |
f98de9b9 | 4639 | } |
3f157a2f CM |
4640 | return ret; |
4641 | } | |
4642 | ||
4643 | /* | |
4644 | * this is similar to btrfs_next_leaf, but does not try to preserve | |
4645 | * and fixup the path. It looks for and returns the next key in the | |
de78b51a | 4646 | * tree based on the current path and the min_trans parameters. |
3f157a2f CM |
4647 | * |
4648 | * 0 is returned if another key is found, < 0 if there are any errors | |
4649 | * and 1 is returned if there are no higher keys in the tree | |
4650 | * | |
4651 | * path->keep_locks should be set to 1 on the search made before | |
4652 | * calling this function. | |
4653 | */ | |
e7a84565 | 4654 | int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path, |
de78b51a | 4655 | struct btrfs_key *key, int level, u64 min_trans) |
e7a84565 | 4656 | { |
e7a84565 CM |
4657 | int slot; |
4658 | struct extent_buffer *c; | |
4659 | ||
6a9fb468 | 4660 | WARN_ON(!path->keep_locks && !path->skip_locking); |
d397712b | 4661 | while (level < BTRFS_MAX_LEVEL) { |
e7a84565 CM |
4662 | if (!path->nodes[level]) |
4663 | return 1; | |
4664 | ||
4665 | slot = path->slots[level] + 1; | |
4666 | c = path->nodes[level]; | |
3f157a2f | 4667 | next: |
e7a84565 | 4668 | if (slot >= btrfs_header_nritems(c)) { |
33c66f43 YZ |
4669 | int ret; |
4670 | int orig_lowest; | |
4671 | struct btrfs_key cur_key; | |
4672 | if (level + 1 >= BTRFS_MAX_LEVEL || | |
4673 | !path->nodes[level + 1]) | |
e7a84565 | 4674 | return 1; |
33c66f43 | 4675 | |
6a9fb468 | 4676 | if (path->locks[level + 1] || path->skip_locking) { |
33c66f43 YZ |
4677 | level++; |
4678 | continue; | |
4679 | } | |
4680 | ||
4681 | slot = btrfs_header_nritems(c) - 1; | |
4682 | if (level == 0) | |
4683 | btrfs_item_key_to_cpu(c, &cur_key, slot); | |
4684 | else | |
4685 | btrfs_node_key_to_cpu(c, &cur_key, slot); | |
4686 | ||
4687 | orig_lowest = path->lowest_level; | |
b3b4aa74 | 4688 | btrfs_release_path(path); |
33c66f43 YZ |
4689 | path->lowest_level = level; |
4690 | ret = btrfs_search_slot(NULL, root, &cur_key, path, | |
4691 | 0, 0); | |
4692 | path->lowest_level = orig_lowest; | |
4693 | if (ret < 0) | |
4694 | return ret; | |
4695 | ||
4696 | c = path->nodes[level]; | |
4697 | slot = path->slots[level]; | |
4698 | if (ret == 0) | |
4699 | slot++; | |
4700 | goto next; | |
e7a84565 | 4701 | } |
33c66f43 | 4702 | |
e7a84565 CM |
4703 | if (level == 0) |
4704 | btrfs_item_key_to_cpu(c, key, slot); | |
3f157a2f | 4705 | else { |
3f157a2f CM |
4706 | u64 gen = btrfs_node_ptr_generation(c, slot); |
4707 | ||
3f157a2f CM |
4708 | if (gen < min_trans) { |
4709 | slot++; | |
4710 | goto next; | |
4711 | } | |
e7a84565 | 4712 | btrfs_node_key_to_cpu(c, key, slot); |
3f157a2f | 4713 | } |
e7a84565 CM |
4714 | return 0; |
4715 | } | |
4716 | return 1; | |
4717 | } | |
4718 | ||
3d7806ec JS |
4719 | int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path, |
4720 | u64 time_seq) | |
d97e63b6 CM |
4721 | { |
4722 | int slot; | |
8e73f275 | 4723 | int level; |
5f39d397 | 4724 | struct extent_buffer *c; |
8e73f275 | 4725 | struct extent_buffer *next; |
d96b3424 | 4726 | struct btrfs_fs_info *fs_info = root->fs_info; |
925baedd | 4727 | struct btrfs_key key; |
d96b3424 | 4728 | bool need_commit_sem = false; |
925baedd CM |
4729 | u32 nritems; |
4730 | int ret; | |
0e46318d | 4731 | int i; |
925baedd | 4732 | |
bdcdd86c FM |
4733 | /* |
4734 | * The nowait semantics are used only for write paths, where we don't | |
4735 | * use the tree mod log and sequence numbers. | |
4736 | */ | |
4737 | if (time_seq) | |
4738 | ASSERT(!path->nowait); | |
c922b016 | 4739 | |
925baedd | 4740 | nritems = btrfs_header_nritems(path->nodes[0]); |
d397712b | 4741 | if (nritems == 0) |
925baedd | 4742 | return 1; |
925baedd | 4743 | |
8e73f275 CM |
4744 | btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1); |
4745 | again: | |
4746 | level = 1; | |
4747 | next = NULL; | |
b3b4aa74 | 4748 | btrfs_release_path(path); |
8e73f275 | 4749 | |
a2135011 | 4750 | path->keep_locks = 1; |
8e73f275 | 4751 | |
d96b3424 | 4752 | if (time_seq) { |
3d7806ec | 4753 | ret = btrfs_search_old_slot(root, &key, path, time_seq); |
d96b3424 FM |
4754 | } else { |
4755 | if (path->need_commit_sem) { | |
4756 | path->need_commit_sem = 0; | |
4757 | need_commit_sem = true; | |
bdcdd86c FM |
4758 | if (path->nowait) { |
4759 | if (!down_read_trylock(&fs_info->commit_root_sem)) { | |
4760 | ret = -EAGAIN; | |
4761 | goto done; | |
4762 | } | |
4763 | } else { | |
4764 | down_read(&fs_info->commit_root_sem); | |
4765 | } | |
d96b3424 | 4766 | } |
3d7806ec | 4767 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
d96b3424 | 4768 | } |
925baedd CM |
4769 | path->keep_locks = 0; |
4770 | ||
4771 | if (ret < 0) | |
d96b3424 | 4772 | goto done; |
925baedd | 4773 | |
a2135011 | 4774 | nritems = btrfs_header_nritems(path->nodes[0]); |
168fd7d2 CM |
4775 | /* |
4776 | * by releasing the path above we dropped all our locks. A balance | |
4777 | * could have added more items next to the key that used to be | |
4778 | * at the very end of the block. So, check again here and | |
4779 | * advance the path if there are now more items available. | |
4780 | */ | |
a2135011 | 4781 | if (nritems > 0 && path->slots[0] < nritems - 1) { |
e457afec YZ |
4782 | if (ret == 0) |
4783 | path->slots[0]++; | |
8e73f275 | 4784 | ret = 0; |
925baedd CM |
4785 | goto done; |
4786 | } | |
0b43e04f LB |
4787 | /* |
4788 | * So the above check misses one case: | |
4789 | * - after releasing the path above, someone has removed the item that | |
4790 | * used to be at the very end of the block, and balance between leafs | |
4791 | * gets another one with bigger key.offset to replace it. | |
4792 | * | |
4793 | * This one should be returned as well, or we can get leaf corruption | |
4794 | * later(esp. in __btrfs_drop_extents()). | |
4795 | * | |
4796 | * And a bit more explanation about this check, | |
4797 | * with ret > 0, the key isn't found, the path points to the slot | |
4798 | * where it should be inserted, so the path->slots[0] item must be the | |
4799 | * bigger one. | |
4800 | */ | |
4801 | if (nritems > 0 && ret > 0 && path->slots[0] == nritems - 1) { | |
4802 | ret = 0; | |
4803 | goto done; | |
4804 | } | |
d97e63b6 | 4805 | |
d397712b | 4806 | while (level < BTRFS_MAX_LEVEL) { |
8e73f275 CM |
4807 | if (!path->nodes[level]) { |
4808 | ret = 1; | |
4809 | goto done; | |
4810 | } | |
5f39d397 | 4811 | |
d97e63b6 CM |
4812 | slot = path->slots[level] + 1; |
4813 | c = path->nodes[level]; | |
5f39d397 | 4814 | if (slot >= btrfs_header_nritems(c)) { |
d97e63b6 | 4815 | level++; |
8e73f275 CM |
4816 | if (level == BTRFS_MAX_LEVEL) { |
4817 | ret = 1; | |
4818 | goto done; | |
4819 | } | |
d97e63b6 CM |
4820 | continue; |
4821 | } | |
5f39d397 | 4822 | |
0e46318d JB |
4823 | |
4824 | /* | |
4825 | * Our current level is where we're going to start from, and to | |
4826 | * make sure lockdep doesn't complain we need to drop our locks | |
4827 | * and nodes from 0 to our current level. | |
4828 | */ | |
4829 | for (i = 0; i < level; i++) { | |
4830 | if (path->locks[level]) { | |
4831 | btrfs_tree_read_unlock(path->nodes[i]); | |
4832 | path->locks[i] = 0; | |
4833 | } | |
4834 | free_extent_buffer(path->nodes[i]); | |
4835 | path->nodes[i] = NULL; | |
925baedd | 4836 | } |
5f39d397 | 4837 | |
8e73f275 | 4838 | next = c; |
d07b8528 | 4839 | ret = read_block_for_search(root, path, &next, level, |
cda79c54 | 4840 | slot, &key); |
bdcdd86c | 4841 | if (ret == -EAGAIN && !path->nowait) |
8e73f275 | 4842 | goto again; |
5f39d397 | 4843 | |
76a05b35 | 4844 | if (ret < 0) { |
b3b4aa74 | 4845 | btrfs_release_path(path); |
76a05b35 CM |
4846 | goto done; |
4847 | } | |
4848 | ||
5cd57b2c | 4849 | if (!path->skip_locking) { |
bd681513 | 4850 | ret = btrfs_try_tree_read_lock(next); |
bdcdd86c FM |
4851 | if (!ret && path->nowait) { |
4852 | ret = -EAGAIN; | |
4853 | goto done; | |
4854 | } | |
d42244a0 JS |
4855 | if (!ret && time_seq) { |
4856 | /* | |
4857 | * If we don't get the lock, we may be racing | |
4858 | * with push_leaf_left, holding that lock while | |
4859 | * itself waiting for the leaf we've currently | |
4860 | * locked. To solve this situation, we give up | |
4861 | * on our lock and cycle. | |
4862 | */ | |
cf538830 | 4863 | free_extent_buffer(next); |
d42244a0 JS |
4864 | btrfs_release_path(path); |
4865 | cond_resched(); | |
4866 | goto again; | |
4867 | } | |
0e46318d JB |
4868 | if (!ret) |
4869 | btrfs_tree_read_lock(next); | |
5cd57b2c | 4870 | } |
d97e63b6 CM |
4871 | break; |
4872 | } | |
4873 | path->slots[level] = slot; | |
d397712b | 4874 | while (1) { |
d97e63b6 | 4875 | level--; |
d97e63b6 CM |
4876 | path->nodes[level] = next; |
4877 | path->slots[level] = 0; | |
a74a4b97 | 4878 | if (!path->skip_locking) |
ffeb03cf | 4879 | path->locks[level] = BTRFS_READ_LOCK; |
d97e63b6 CM |
4880 | if (!level) |
4881 | break; | |
b4ce94de | 4882 | |
d07b8528 | 4883 | ret = read_block_for_search(root, path, &next, level, |
cda79c54 | 4884 | 0, &key); |
bdcdd86c | 4885 | if (ret == -EAGAIN && !path->nowait) |
8e73f275 CM |
4886 | goto again; |
4887 | ||
76a05b35 | 4888 | if (ret < 0) { |
b3b4aa74 | 4889 | btrfs_release_path(path); |
76a05b35 CM |
4890 | goto done; |
4891 | } | |
4892 | ||
bdcdd86c FM |
4893 | if (!path->skip_locking) { |
4894 | if (path->nowait) { | |
4895 | if (!btrfs_try_tree_read_lock(next)) { | |
4896 | ret = -EAGAIN; | |
4897 | goto done; | |
4898 | } | |
4899 | } else { | |
4900 | btrfs_tree_read_lock(next); | |
4901 | } | |
4902 | } | |
d97e63b6 | 4903 | } |
8e73f275 | 4904 | ret = 0; |
925baedd | 4905 | done: |
f7c79f30 | 4906 | unlock_up(path, 0, 1, 0, NULL); |
d96b3424 FM |
4907 | if (need_commit_sem) { |
4908 | int ret2; | |
4909 | ||
4910 | path->need_commit_sem = 1; | |
4911 | ret2 = finish_need_commit_sem_search(path); | |
4912 | up_read(&fs_info->commit_root_sem); | |
4913 | if (ret2) | |
4914 | ret = ret2; | |
4915 | } | |
8e73f275 CM |
4916 | |
4917 | return ret; | |
d97e63b6 | 4918 | } |
0b86a832 | 4919 | |
890d2b1a JB |
4920 | int btrfs_next_old_item(struct btrfs_root *root, struct btrfs_path *path, u64 time_seq) |
4921 | { | |
4922 | path->slots[0]++; | |
4923 | if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) | |
4924 | return btrfs_next_old_leaf(root, path, time_seq); | |
4925 | return 0; | |
4926 | } | |
4927 | ||
3f157a2f CM |
4928 | /* |
4929 | * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps | |
4930 | * searching until it gets past min_objectid or finds an item of 'type' | |
4931 | * | |
4932 | * returns 0 if something is found, 1 if nothing was found and < 0 on error | |
4933 | */ | |
0b86a832 CM |
4934 | int btrfs_previous_item(struct btrfs_root *root, |
4935 | struct btrfs_path *path, u64 min_objectid, | |
4936 | int type) | |
4937 | { | |
4938 | struct btrfs_key found_key; | |
4939 | struct extent_buffer *leaf; | |
e02119d5 | 4940 | u32 nritems; |
0b86a832 CM |
4941 | int ret; |
4942 | ||
d397712b | 4943 | while (1) { |
0b86a832 CM |
4944 | if (path->slots[0] == 0) { |
4945 | ret = btrfs_prev_leaf(root, path); | |
4946 | if (ret != 0) | |
4947 | return ret; | |
4948 | } else { | |
4949 | path->slots[0]--; | |
4950 | } | |
4951 | leaf = path->nodes[0]; | |
e02119d5 CM |
4952 | nritems = btrfs_header_nritems(leaf); |
4953 | if (nritems == 0) | |
4954 | return 1; | |
4955 | if (path->slots[0] == nritems) | |
4956 | path->slots[0]--; | |
4957 | ||
0b86a832 | 4958 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
e02119d5 CM |
4959 | if (found_key.objectid < min_objectid) |
4960 | break; | |
0a4eefbb YZ |
4961 | if (found_key.type == type) |
4962 | return 0; | |
e02119d5 CM |
4963 | if (found_key.objectid == min_objectid && |
4964 | found_key.type < type) | |
4965 | break; | |
0b86a832 CM |
4966 | } |
4967 | return 1; | |
4968 | } | |
ade2e0b3 WS |
4969 | |
4970 | /* | |
4971 | * search in extent tree to find a previous Metadata/Data extent item with | |
4972 | * min objecitd. | |
4973 | * | |
4974 | * returns 0 if something is found, 1 if nothing was found and < 0 on error | |
4975 | */ | |
4976 | int btrfs_previous_extent_item(struct btrfs_root *root, | |
4977 | struct btrfs_path *path, u64 min_objectid) | |
4978 | { | |
4979 | struct btrfs_key found_key; | |
4980 | struct extent_buffer *leaf; | |
4981 | u32 nritems; | |
4982 | int ret; | |
4983 | ||
4984 | while (1) { | |
4985 | if (path->slots[0] == 0) { | |
ade2e0b3 WS |
4986 | ret = btrfs_prev_leaf(root, path); |
4987 | if (ret != 0) | |
4988 | return ret; | |
4989 | } else { | |
4990 | path->slots[0]--; | |
4991 | } | |
4992 | leaf = path->nodes[0]; | |
4993 | nritems = btrfs_header_nritems(leaf); | |
4994 | if (nritems == 0) | |
4995 | return 1; | |
4996 | if (path->slots[0] == nritems) | |
4997 | path->slots[0]--; | |
4998 | ||
4999 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); | |
5000 | if (found_key.objectid < min_objectid) | |
5001 | break; | |
5002 | if (found_key.type == BTRFS_EXTENT_ITEM_KEY || | |
5003 | found_key.type == BTRFS_METADATA_ITEM_KEY) | |
5004 | return 0; | |
5005 | if (found_key.objectid == min_objectid && | |
5006 | found_key.type < BTRFS_EXTENT_ITEM_KEY) | |
5007 | break; | |
5008 | } | |
5009 | return 1; | |
5010 | } | |
226463d7 JB |
5011 | |
5012 | int __init btrfs_ctree_init(void) | |
5013 | { | |
5014 | btrfs_path_cachep = kmem_cache_create("btrfs_path", | |
5015 | sizeof(struct btrfs_path), 0, | |
5016 | SLAB_MEM_SPREAD, NULL); | |
5017 | if (!btrfs_path_cachep) | |
5018 | return -ENOMEM; | |
5019 | return 0; | |
5020 | } | |
5021 | ||
5022 | void __cold btrfs_ctree_exit(void) | |
5023 | { | |
5024 | kmem_cache_destroy(btrfs_path_cachep); | |
5025 | } |