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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> |
eb60ceac CM |
11 | #include "ctree.h" |
12 | #include "disk-io.h" | |
7f5c1516 | 13 | #include "transaction.h" |
5f39d397 | 14 | #include "print-tree.h" |
925baedd | 15 | #include "locking.h" |
de37aa51 | 16 | #include "volumes.h" |
f616f5cd | 17 | #include "qgroup.h" |
f3a84ccd | 18 | #include "tree-mod-log.h" |
9a8dd150 | 19 | |
e089f05c CM |
20 | static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root |
21 | *root, struct btrfs_path *path, int level); | |
310712b2 OS |
22 | static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
23 | const struct btrfs_key *ins_key, struct btrfs_path *path, | |
24 | int data_size, int extend); | |
5f39d397 | 25 | static int push_node_left(struct btrfs_trans_handle *trans, |
2ff7e61e | 26 | struct extent_buffer *dst, |
971a1f66 | 27 | struct extent_buffer *src, int empty); |
5f39d397 | 28 | static int balance_node_right(struct btrfs_trans_handle *trans, |
5f39d397 CM |
29 | struct extent_buffer *dst_buf, |
30 | struct extent_buffer *src_buf); | |
afe5fea7 TI |
31 | static void del_ptr(struct btrfs_root *root, struct btrfs_path *path, |
32 | int level, int slot); | |
d97e63b6 | 33 | |
af024ed2 JT |
34 | static const struct btrfs_csums { |
35 | u16 size; | |
59a0fcdb DS |
36 | const char name[10]; |
37 | const char driver[12]; | |
af024ed2 JT |
38 | } btrfs_csums[] = { |
39 | [BTRFS_CSUM_TYPE_CRC32] = { .size = 4, .name = "crc32c" }, | |
3951e7f0 | 40 | [BTRFS_CSUM_TYPE_XXHASH] = { .size = 8, .name = "xxhash64" }, |
3831bf00 | 41 | [BTRFS_CSUM_TYPE_SHA256] = { .size = 32, .name = "sha256" }, |
352ae07b DS |
42 | [BTRFS_CSUM_TYPE_BLAKE2] = { .size = 32, .name = "blake2b", |
43 | .driver = "blake2b-256" }, | |
af024ed2 JT |
44 | }; |
45 | ||
46 | int btrfs_super_csum_size(const struct btrfs_super_block *s) | |
47 | { | |
48 | u16 t = btrfs_super_csum_type(s); | |
49 | /* | |
50 | * csum type is validated at mount time | |
51 | */ | |
52 | return btrfs_csums[t].size; | |
53 | } | |
54 | ||
55 | const char *btrfs_super_csum_name(u16 csum_type) | |
56 | { | |
57 | /* csum type is validated at mount time */ | |
58 | return btrfs_csums[csum_type].name; | |
59 | } | |
60 | ||
b4e967be DS |
61 | /* |
62 | * Return driver name if defined, otherwise the name that's also a valid driver | |
63 | * name | |
64 | */ | |
65 | const char *btrfs_super_csum_driver(u16 csum_type) | |
66 | { | |
67 | /* csum type is validated at mount time */ | |
59a0fcdb DS |
68 | return btrfs_csums[csum_type].driver[0] ? |
69 | btrfs_csums[csum_type].driver : | |
b4e967be DS |
70 | btrfs_csums[csum_type].name; |
71 | } | |
72 | ||
604997b4 | 73 | size_t __attribute_const__ btrfs_get_num_csums(void) |
f7cea56c DS |
74 | { |
75 | return ARRAY_SIZE(btrfs_csums); | |
76 | } | |
77 | ||
df24a2b9 | 78 | struct btrfs_path *btrfs_alloc_path(void) |
2c90e5d6 | 79 | { |
e2c89907 | 80 | return kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS); |
2c90e5d6 CM |
81 | } |
82 | ||
d352ac68 | 83 | /* this also releases the path */ |
df24a2b9 | 84 | void btrfs_free_path(struct btrfs_path *p) |
be0e5c09 | 85 | { |
ff175d57 JJ |
86 | if (!p) |
87 | return; | |
b3b4aa74 | 88 | btrfs_release_path(p); |
df24a2b9 | 89 | kmem_cache_free(btrfs_path_cachep, p); |
be0e5c09 CM |
90 | } |
91 | ||
d352ac68 CM |
92 | /* |
93 | * path release drops references on the extent buffers in the path | |
94 | * and it drops any locks held by this path | |
95 | * | |
96 | * It is safe to call this on paths that no locks or extent buffers held. | |
97 | */ | |
b3b4aa74 | 98 | noinline void btrfs_release_path(struct btrfs_path *p) |
eb60ceac CM |
99 | { |
100 | int i; | |
a2135011 | 101 | |
234b63a0 | 102 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) { |
3f157a2f | 103 | p->slots[i] = 0; |
eb60ceac | 104 | if (!p->nodes[i]) |
925baedd CM |
105 | continue; |
106 | if (p->locks[i]) { | |
bd681513 | 107 | btrfs_tree_unlock_rw(p->nodes[i], p->locks[i]); |
925baedd CM |
108 | p->locks[i] = 0; |
109 | } | |
5f39d397 | 110 | free_extent_buffer(p->nodes[i]); |
3f157a2f | 111 | p->nodes[i] = NULL; |
eb60ceac CM |
112 | } |
113 | } | |
114 | ||
d352ac68 CM |
115 | /* |
116 | * safely gets a reference on the root node of a tree. A lock | |
117 | * is not taken, so a concurrent writer may put a different node | |
118 | * at the root of the tree. See btrfs_lock_root_node for the | |
119 | * looping required. | |
120 | * | |
121 | * The extent buffer returned by this has a reference taken, so | |
122 | * it won't disappear. It may stop being the root of the tree | |
123 | * at any time because there are no locks held. | |
124 | */ | |
925baedd CM |
125 | struct extent_buffer *btrfs_root_node(struct btrfs_root *root) |
126 | { | |
127 | struct extent_buffer *eb; | |
240f62c8 | 128 | |
3083ee2e JB |
129 | while (1) { |
130 | rcu_read_lock(); | |
131 | eb = rcu_dereference(root->node); | |
132 | ||
133 | /* | |
134 | * RCU really hurts here, we could free up the root node because | |
01327610 | 135 | * it was COWed but we may not get the new root node yet so do |
3083ee2e JB |
136 | * the inc_not_zero dance and if it doesn't work then |
137 | * synchronize_rcu and try again. | |
138 | */ | |
139 | if (atomic_inc_not_zero(&eb->refs)) { | |
140 | rcu_read_unlock(); | |
141 | break; | |
142 | } | |
143 | rcu_read_unlock(); | |
144 | synchronize_rcu(); | |
145 | } | |
925baedd CM |
146 | return eb; |
147 | } | |
148 | ||
92a7cc42 QW |
149 | /* |
150 | * Cowonly root (not-shareable trees, everything not subvolume or reloc roots), | |
151 | * just get put onto a simple dirty list. Transaction walks this list to make | |
152 | * sure they get properly updated on disk. | |
d352ac68 | 153 | */ |
0b86a832 CM |
154 | static void add_root_to_dirty_list(struct btrfs_root *root) |
155 | { | |
0b246afa JM |
156 | struct btrfs_fs_info *fs_info = root->fs_info; |
157 | ||
e7070be1 JB |
158 | if (test_bit(BTRFS_ROOT_DIRTY, &root->state) || |
159 | !test_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state)) | |
160 | return; | |
161 | ||
0b246afa | 162 | spin_lock(&fs_info->trans_lock); |
e7070be1 JB |
163 | if (!test_and_set_bit(BTRFS_ROOT_DIRTY, &root->state)) { |
164 | /* Want the extent tree to be the last on the list */ | |
4fd786e6 | 165 | if (root->root_key.objectid == BTRFS_EXTENT_TREE_OBJECTID) |
e7070be1 | 166 | list_move_tail(&root->dirty_list, |
0b246afa | 167 | &fs_info->dirty_cowonly_roots); |
e7070be1 JB |
168 | else |
169 | list_move(&root->dirty_list, | |
0b246afa | 170 | &fs_info->dirty_cowonly_roots); |
0b86a832 | 171 | } |
0b246afa | 172 | spin_unlock(&fs_info->trans_lock); |
0b86a832 CM |
173 | } |
174 | ||
d352ac68 CM |
175 | /* |
176 | * used by snapshot creation to make a copy of a root for a tree with | |
177 | * a given objectid. The buffer with the new root node is returned in | |
178 | * cow_ret, and this func returns zero on success or a negative error code. | |
179 | */ | |
be20aa9d CM |
180 | int btrfs_copy_root(struct btrfs_trans_handle *trans, |
181 | struct btrfs_root *root, | |
182 | struct extent_buffer *buf, | |
183 | struct extent_buffer **cow_ret, u64 new_root_objectid) | |
184 | { | |
0b246afa | 185 | struct btrfs_fs_info *fs_info = root->fs_info; |
be20aa9d | 186 | struct extent_buffer *cow; |
be20aa9d CM |
187 | int ret = 0; |
188 | int level; | |
5d4f98a2 | 189 | struct btrfs_disk_key disk_key; |
be20aa9d | 190 | |
92a7cc42 | 191 | WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && |
0b246afa | 192 | trans->transid != fs_info->running_transaction->transid); |
92a7cc42 | 193 | WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && |
27cdeb70 | 194 | trans->transid != root->last_trans); |
be20aa9d CM |
195 | |
196 | level = btrfs_header_level(buf); | |
5d4f98a2 YZ |
197 | if (level == 0) |
198 | btrfs_item_key(buf, &disk_key, 0); | |
199 | else | |
200 | btrfs_node_key(buf, &disk_key, 0); | |
31840ae1 | 201 | |
4d75f8a9 | 202 | cow = btrfs_alloc_tree_block(trans, root, 0, new_root_objectid, |
cf6f34aa JB |
203 | &disk_key, level, buf->start, 0, |
204 | BTRFS_NESTING_NEW_ROOT); | |
5d4f98a2 | 205 | if (IS_ERR(cow)) |
be20aa9d CM |
206 | return PTR_ERR(cow); |
207 | ||
58e8012c | 208 | copy_extent_buffer_full(cow, buf); |
be20aa9d CM |
209 | btrfs_set_header_bytenr(cow, cow->start); |
210 | btrfs_set_header_generation(cow, trans->transid); | |
5d4f98a2 YZ |
211 | btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); |
212 | btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | | |
213 | BTRFS_HEADER_FLAG_RELOC); | |
214 | if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) | |
215 | btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); | |
216 | else | |
217 | btrfs_set_header_owner(cow, new_root_objectid); | |
be20aa9d | 218 | |
de37aa51 | 219 | write_extent_buffer_fsid(cow, fs_info->fs_devices->metadata_uuid); |
2b82032c | 220 | |
be20aa9d | 221 | WARN_ON(btrfs_header_generation(buf) > trans->transid); |
5d4f98a2 | 222 | if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) |
e339a6b0 | 223 | ret = btrfs_inc_ref(trans, root, cow, 1); |
5d4f98a2 | 224 | else |
e339a6b0 | 225 | ret = btrfs_inc_ref(trans, root, cow, 0); |
867ed321 | 226 | if (ret) { |
72c9925f FM |
227 | btrfs_tree_unlock(cow); |
228 | free_extent_buffer(cow); | |
867ed321 | 229 | btrfs_abort_transaction(trans, ret); |
be20aa9d | 230 | return ret; |
867ed321 | 231 | } |
be20aa9d CM |
232 | |
233 | btrfs_mark_buffer_dirty(cow); | |
234 | *cow_ret = cow; | |
235 | return 0; | |
236 | } | |
237 | ||
5d4f98a2 YZ |
238 | /* |
239 | * check if the tree block can be shared by multiple trees | |
240 | */ | |
241 | int btrfs_block_can_be_shared(struct btrfs_root *root, | |
242 | struct extent_buffer *buf) | |
243 | { | |
244 | /* | |
92a7cc42 QW |
245 | * Tree blocks not in shareable trees and tree roots are never shared. |
246 | * If a block was allocated after the last snapshot and the block was | |
247 | * not allocated by tree relocation, we know the block is not shared. | |
5d4f98a2 | 248 | */ |
92a7cc42 | 249 | if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && |
5d4f98a2 YZ |
250 | buf != root->node && buf != root->commit_root && |
251 | (btrfs_header_generation(buf) <= | |
252 | btrfs_root_last_snapshot(&root->root_item) || | |
253 | btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))) | |
254 | return 1; | |
a79865c6 | 255 | |
5d4f98a2 YZ |
256 | return 0; |
257 | } | |
258 | ||
259 | static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, | |
260 | struct btrfs_root *root, | |
261 | struct extent_buffer *buf, | |
f0486c68 YZ |
262 | struct extent_buffer *cow, |
263 | int *last_ref) | |
5d4f98a2 | 264 | { |
0b246afa | 265 | struct btrfs_fs_info *fs_info = root->fs_info; |
5d4f98a2 YZ |
266 | u64 refs; |
267 | u64 owner; | |
268 | u64 flags; | |
269 | u64 new_flags = 0; | |
270 | int ret; | |
271 | ||
272 | /* | |
273 | * Backrefs update rules: | |
274 | * | |
275 | * Always use full backrefs for extent pointers in tree block | |
276 | * allocated by tree relocation. | |
277 | * | |
278 | * If a shared tree block is no longer referenced by its owner | |
279 | * tree (btrfs_header_owner(buf) == root->root_key.objectid), | |
280 | * use full backrefs for extent pointers in tree block. | |
281 | * | |
282 | * If a tree block is been relocating | |
283 | * (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID), | |
284 | * use full backrefs for extent pointers in tree block. | |
285 | * The reason for this is some operations (such as drop tree) | |
286 | * are only allowed for blocks use full backrefs. | |
287 | */ | |
288 | ||
289 | if (btrfs_block_can_be_shared(root, buf)) { | |
2ff7e61e | 290 | ret = btrfs_lookup_extent_info(trans, fs_info, buf->start, |
3173a18f JB |
291 | btrfs_header_level(buf), 1, |
292 | &refs, &flags); | |
be1a5564 MF |
293 | if (ret) |
294 | return ret; | |
e5df9573 MF |
295 | if (refs == 0) { |
296 | ret = -EROFS; | |
0b246afa | 297 | btrfs_handle_fs_error(fs_info, ret, NULL); |
e5df9573 MF |
298 | return ret; |
299 | } | |
5d4f98a2 YZ |
300 | } else { |
301 | refs = 1; | |
302 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || | |
303 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
304 | flags = BTRFS_BLOCK_FLAG_FULL_BACKREF; | |
305 | else | |
306 | flags = 0; | |
307 | } | |
308 | ||
309 | owner = btrfs_header_owner(buf); | |
310 | BUG_ON(owner == BTRFS_TREE_RELOC_OBJECTID && | |
311 | !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)); | |
312 | ||
313 | if (refs > 1) { | |
314 | if ((owner == root->root_key.objectid || | |
315 | root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && | |
316 | !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) { | |
e339a6b0 | 317 | ret = btrfs_inc_ref(trans, root, buf, 1); |
692826b2 JM |
318 | if (ret) |
319 | return ret; | |
5d4f98a2 YZ |
320 | |
321 | if (root->root_key.objectid == | |
322 | BTRFS_TREE_RELOC_OBJECTID) { | |
e339a6b0 | 323 | ret = btrfs_dec_ref(trans, root, buf, 0); |
692826b2 JM |
324 | if (ret) |
325 | return ret; | |
e339a6b0 | 326 | ret = btrfs_inc_ref(trans, root, cow, 1); |
692826b2 JM |
327 | if (ret) |
328 | return ret; | |
5d4f98a2 YZ |
329 | } |
330 | new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF; | |
331 | } else { | |
332 | ||
333 | if (root->root_key.objectid == | |
334 | BTRFS_TREE_RELOC_OBJECTID) | |
e339a6b0 | 335 | ret = btrfs_inc_ref(trans, root, cow, 1); |
5d4f98a2 | 336 | else |
e339a6b0 | 337 | ret = btrfs_inc_ref(trans, root, cow, 0); |
692826b2 JM |
338 | if (ret) |
339 | return ret; | |
5d4f98a2 YZ |
340 | } |
341 | if (new_flags != 0) { | |
b1c79e09 JB |
342 | int level = btrfs_header_level(buf); |
343 | ||
42c9d0b5 | 344 | ret = btrfs_set_disk_extent_flags(trans, buf, |
b1c79e09 | 345 | new_flags, level, 0); |
be1a5564 MF |
346 | if (ret) |
347 | return ret; | |
5d4f98a2 YZ |
348 | } |
349 | } else { | |
350 | if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) { | |
351 | if (root->root_key.objectid == | |
352 | BTRFS_TREE_RELOC_OBJECTID) | |
e339a6b0 | 353 | ret = btrfs_inc_ref(trans, root, cow, 1); |
5d4f98a2 | 354 | else |
e339a6b0 | 355 | ret = btrfs_inc_ref(trans, root, cow, 0); |
692826b2 JM |
356 | if (ret) |
357 | return ret; | |
e339a6b0 | 358 | ret = btrfs_dec_ref(trans, root, buf, 1); |
692826b2 JM |
359 | if (ret) |
360 | return ret; | |
5d4f98a2 | 361 | } |
6a884d7d | 362 | btrfs_clean_tree_block(buf); |
f0486c68 | 363 | *last_ref = 1; |
5d4f98a2 YZ |
364 | } |
365 | return 0; | |
366 | } | |
367 | ||
d352ac68 | 368 | /* |
d397712b CM |
369 | * does the dirty work in cow of a single block. The parent block (if |
370 | * supplied) is updated to point to the new cow copy. The new buffer is marked | |
371 | * dirty and returned locked. If you modify the block it needs to be marked | |
372 | * dirty again. | |
d352ac68 CM |
373 | * |
374 | * search_start -- an allocation hint for the new block | |
375 | * | |
d397712b CM |
376 | * empty_size -- a hint that you plan on doing more cow. This is the size in |
377 | * bytes the allocator should try to find free next to the block it returns. | |
378 | * This is just a hint and may be ignored by the allocator. | |
d352ac68 | 379 | */ |
d397712b | 380 | static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, |
5f39d397 CM |
381 | struct btrfs_root *root, |
382 | struct extent_buffer *buf, | |
383 | struct extent_buffer *parent, int parent_slot, | |
384 | struct extent_buffer **cow_ret, | |
9631e4cc JB |
385 | u64 search_start, u64 empty_size, |
386 | enum btrfs_lock_nesting nest) | |
02217ed2 | 387 | { |
0b246afa | 388 | struct btrfs_fs_info *fs_info = root->fs_info; |
5d4f98a2 | 389 | struct btrfs_disk_key disk_key; |
5f39d397 | 390 | struct extent_buffer *cow; |
be1a5564 | 391 | int level, ret; |
f0486c68 | 392 | int last_ref = 0; |
925baedd | 393 | int unlock_orig = 0; |
0f5053eb | 394 | u64 parent_start = 0; |
7bb86316 | 395 | |
925baedd CM |
396 | if (*cow_ret == buf) |
397 | unlock_orig = 1; | |
398 | ||
49d0c642 | 399 | btrfs_assert_tree_write_locked(buf); |
925baedd | 400 | |
92a7cc42 | 401 | WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && |
0b246afa | 402 | trans->transid != fs_info->running_transaction->transid); |
92a7cc42 | 403 | WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && |
27cdeb70 | 404 | trans->transid != root->last_trans); |
5f39d397 | 405 | |
7bb86316 | 406 | level = btrfs_header_level(buf); |
31840ae1 | 407 | |
5d4f98a2 YZ |
408 | if (level == 0) |
409 | btrfs_item_key(buf, &disk_key, 0); | |
410 | else | |
411 | btrfs_node_key(buf, &disk_key, 0); | |
412 | ||
0f5053eb GR |
413 | if ((root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && parent) |
414 | parent_start = parent->start; | |
5d4f98a2 | 415 | |
79bd3712 FM |
416 | cow = btrfs_alloc_tree_block(trans, root, parent_start, |
417 | root->root_key.objectid, &disk_key, level, | |
418 | search_start, empty_size, nest); | |
54aa1f4d CM |
419 | if (IS_ERR(cow)) |
420 | return PTR_ERR(cow); | |
6702ed49 | 421 | |
b4ce94de CM |
422 | /* cow is set to blocking by btrfs_init_new_buffer */ |
423 | ||
58e8012c | 424 | copy_extent_buffer_full(cow, buf); |
db94535d | 425 | btrfs_set_header_bytenr(cow, cow->start); |
5f39d397 | 426 | btrfs_set_header_generation(cow, trans->transid); |
5d4f98a2 YZ |
427 | btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); |
428 | btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | | |
429 | BTRFS_HEADER_FLAG_RELOC); | |
430 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) | |
431 | btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); | |
432 | else | |
433 | btrfs_set_header_owner(cow, root->root_key.objectid); | |
6702ed49 | 434 | |
de37aa51 | 435 | write_extent_buffer_fsid(cow, fs_info->fs_devices->metadata_uuid); |
2b82032c | 436 | |
be1a5564 | 437 | ret = update_ref_for_cow(trans, root, buf, cow, &last_ref); |
b68dc2a9 | 438 | if (ret) { |
572c83ac JB |
439 | btrfs_tree_unlock(cow); |
440 | free_extent_buffer(cow); | |
66642832 | 441 | btrfs_abort_transaction(trans, ret); |
b68dc2a9 MF |
442 | return ret; |
443 | } | |
1a40e23b | 444 | |
92a7cc42 | 445 | if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) { |
83d4cfd4 | 446 | ret = btrfs_reloc_cow_block(trans, root, buf, cow); |
93314e3b | 447 | if (ret) { |
572c83ac JB |
448 | btrfs_tree_unlock(cow); |
449 | free_extent_buffer(cow); | |
66642832 | 450 | btrfs_abort_transaction(trans, ret); |
83d4cfd4 | 451 | return ret; |
93314e3b | 452 | } |
83d4cfd4 | 453 | } |
3fd0a558 | 454 | |
02217ed2 | 455 | if (buf == root->node) { |
925baedd | 456 | WARN_ON(parent && parent != buf); |
5d4f98a2 YZ |
457 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || |
458 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
459 | parent_start = buf->start; | |
925baedd | 460 | |
67439dad | 461 | atomic_inc(&cow->refs); |
406808ab | 462 | ret = btrfs_tree_mod_log_insert_root(root->node, cow, true); |
d9d19a01 | 463 | BUG_ON(ret < 0); |
240f62c8 | 464 | rcu_assign_pointer(root->node, cow); |
925baedd | 465 | |
7a163608 FM |
466 | btrfs_free_tree_block(trans, btrfs_root_id(root), buf, |
467 | parent_start, last_ref); | |
5f39d397 | 468 | free_extent_buffer(buf); |
0b86a832 | 469 | add_root_to_dirty_list(root); |
02217ed2 | 470 | } else { |
5d4f98a2 | 471 | WARN_ON(trans->transid != btrfs_header_generation(parent)); |
f3a84ccd FM |
472 | btrfs_tree_mod_log_insert_key(parent, parent_slot, |
473 | BTRFS_MOD_LOG_KEY_REPLACE, GFP_NOFS); | |
5f39d397 | 474 | btrfs_set_node_blockptr(parent, parent_slot, |
db94535d | 475 | cow->start); |
74493f7a CM |
476 | btrfs_set_node_ptr_generation(parent, parent_slot, |
477 | trans->transid); | |
d6025579 | 478 | btrfs_mark_buffer_dirty(parent); |
5de865ee | 479 | if (last_ref) { |
f3a84ccd | 480 | ret = btrfs_tree_mod_log_free_eb(buf); |
5de865ee | 481 | if (ret) { |
572c83ac JB |
482 | btrfs_tree_unlock(cow); |
483 | free_extent_buffer(cow); | |
66642832 | 484 | btrfs_abort_transaction(trans, ret); |
5de865ee FDBM |
485 | return ret; |
486 | } | |
487 | } | |
7a163608 FM |
488 | btrfs_free_tree_block(trans, btrfs_root_id(root), buf, |
489 | parent_start, last_ref); | |
02217ed2 | 490 | } |
925baedd CM |
491 | if (unlock_orig) |
492 | btrfs_tree_unlock(buf); | |
3083ee2e | 493 | free_extent_buffer_stale(buf); |
ccd467d6 | 494 | btrfs_mark_buffer_dirty(cow); |
2c90e5d6 | 495 | *cow_ret = cow; |
02217ed2 CM |
496 | return 0; |
497 | } | |
498 | ||
5d4f98a2 YZ |
499 | static inline int should_cow_block(struct btrfs_trans_handle *trans, |
500 | struct btrfs_root *root, | |
501 | struct extent_buffer *buf) | |
502 | { | |
f5ee5c9a | 503 | if (btrfs_is_testing(root->fs_info)) |
faa2dbf0 | 504 | return 0; |
fccb84c9 | 505 | |
d1980131 DS |
506 | /* Ensure we can see the FORCE_COW bit */ |
507 | smp_mb__before_atomic(); | |
f1ebcc74 LB |
508 | |
509 | /* | |
510 | * We do not need to cow a block if | |
511 | * 1) this block is not created or changed in this transaction; | |
512 | * 2) this block does not belong to TREE_RELOC tree; | |
513 | * 3) the root is not forced COW. | |
514 | * | |
515 | * What is forced COW: | |
01327610 | 516 | * when we create snapshot during committing the transaction, |
52042d8e | 517 | * after we've finished copying src root, we must COW the shared |
f1ebcc74 LB |
518 | * block to ensure the metadata consistency. |
519 | */ | |
5d4f98a2 YZ |
520 | if (btrfs_header_generation(buf) == trans->transid && |
521 | !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) && | |
522 | !(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID && | |
f1ebcc74 | 523 | btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)) && |
27cdeb70 | 524 | !test_bit(BTRFS_ROOT_FORCE_COW, &root->state)) |
5d4f98a2 YZ |
525 | return 0; |
526 | return 1; | |
527 | } | |
528 | ||
d352ac68 CM |
529 | /* |
530 | * cows a single block, see __btrfs_cow_block for the real work. | |
01327610 | 531 | * This version of it has extra checks so that a block isn't COWed more than |
d352ac68 CM |
532 | * once per transaction, as long as it hasn't been written yet |
533 | */ | |
d397712b | 534 | noinline int btrfs_cow_block(struct btrfs_trans_handle *trans, |
5f39d397 CM |
535 | struct btrfs_root *root, struct extent_buffer *buf, |
536 | struct extent_buffer *parent, int parent_slot, | |
9631e4cc JB |
537 | struct extent_buffer **cow_ret, |
538 | enum btrfs_lock_nesting nest) | |
6702ed49 | 539 | { |
0b246afa | 540 | struct btrfs_fs_info *fs_info = root->fs_info; |
6702ed49 | 541 | u64 search_start; |
f510cfec | 542 | int ret; |
dc17ff8f | 543 | |
83354f07 JB |
544 | if (test_bit(BTRFS_ROOT_DELETING, &root->state)) |
545 | btrfs_err(fs_info, | |
546 | "COW'ing blocks on a fs root that's being dropped"); | |
547 | ||
0b246afa | 548 | if (trans->transaction != fs_info->running_transaction) |
31b1a2bd | 549 | WARN(1, KERN_CRIT "trans %llu running %llu\n", |
c1c9ff7c | 550 | trans->transid, |
0b246afa | 551 | fs_info->running_transaction->transid); |
31b1a2bd | 552 | |
0b246afa | 553 | if (trans->transid != fs_info->generation) |
31b1a2bd | 554 | WARN(1, KERN_CRIT "trans %llu running %llu\n", |
0b246afa | 555 | trans->transid, fs_info->generation); |
dc17ff8f | 556 | |
5d4f98a2 | 557 | if (!should_cow_block(trans, root, buf)) { |
6702ed49 CM |
558 | *cow_ret = buf; |
559 | return 0; | |
560 | } | |
c487685d | 561 | |
ee22184b | 562 | search_start = buf->start & ~((u64)SZ_1G - 1); |
b4ce94de | 563 | |
f616f5cd QW |
564 | /* |
565 | * Before CoWing this block for later modification, check if it's | |
566 | * the subtree root and do the delayed subtree trace if needed. | |
567 | * | |
568 | * Also We don't care about the error, as it's handled internally. | |
569 | */ | |
570 | btrfs_qgroup_trace_subtree_after_cow(trans, root, buf); | |
f510cfec | 571 | ret = __btrfs_cow_block(trans, root, buf, parent, |
9631e4cc | 572 | parent_slot, cow_ret, search_start, 0, nest); |
1abe9b8a | 573 | |
574 | trace_btrfs_cow_block(root, buf, *cow_ret); | |
575 | ||
f510cfec | 576 | return ret; |
6702ed49 | 577 | } |
f75e2b79 | 578 | ALLOW_ERROR_INJECTION(btrfs_cow_block, ERRNO); |
6702ed49 | 579 | |
d352ac68 CM |
580 | /* |
581 | * helper function for defrag to decide if two blocks pointed to by a | |
582 | * node are actually close by | |
583 | */ | |
6b80053d | 584 | static int close_blocks(u64 blocknr, u64 other, u32 blocksize) |
6702ed49 | 585 | { |
6b80053d | 586 | if (blocknr < other && other - (blocknr + blocksize) < 32768) |
6702ed49 | 587 | return 1; |
6b80053d | 588 | if (blocknr > other && blocknr - (other + blocksize) < 32768) |
6702ed49 CM |
589 | return 1; |
590 | return 0; | |
591 | } | |
592 | ||
ce6ef5ab DS |
593 | #ifdef __LITTLE_ENDIAN |
594 | ||
595 | /* | |
596 | * Compare two keys, on little-endian the disk order is same as CPU order and | |
597 | * we can avoid the conversion. | |
598 | */ | |
599 | static int comp_keys(const struct btrfs_disk_key *disk_key, | |
600 | const struct btrfs_key *k2) | |
601 | { | |
602 | const struct btrfs_key *k1 = (const struct btrfs_key *)disk_key; | |
603 | ||
604 | return btrfs_comp_cpu_keys(k1, k2); | |
605 | } | |
606 | ||
607 | #else | |
608 | ||
081e9573 CM |
609 | /* |
610 | * compare two keys in a memcmp fashion | |
611 | */ | |
310712b2 OS |
612 | static int comp_keys(const struct btrfs_disk_key *disk, |
613 | const struct btrfs_key *k2) | |
081e9573 CM |
614 | { |
615 | struct btrfs_key k1; | |
616 | ||
617 | btrfs_disk_key_to_cpu(&k1, disk); | |
618 | ||
20736aba | 619 | return btrfs_comp_cpu_keys(&k1, k2); |
081e9573 | 620 | } |
ce6ef5ab | 621 | #endif |
081e9573 | 622 | |
f3465ca4 JB |
623 | /* |
624 | * same as comp_keys only with two btrfs_key's | |
625 | */ | |
e1f60a65 | 626 | int __pure btrfs_comp_cpu_keys(const struct btrfs_key *k1, const struct btrfs_key *k2) |
f3465ca4 JB |
627 | { |
628 | if (k1->objectid > k2->objectid) | |
629 | return 1; | |
630 | if (k1->objectid < k2->objectid) | |
631 | return -1; | |
632 | if (k1->type > k2->type) | |
633 | return 1; | |
634 | if (k1->type < k2->type) | |
635 | return -1; | |
636 | if (k1->offset > k2->offset) | |
637 | return 1; | |
638 | if (k1->offset < k2->offset) | |
639 | return -1; | |
640 | return 0; | |
641 | } | |
081e9573 | 642 | |
d352ac68 CM |
643 | /* |
644 | * this is used by the defrag code to go through all the | |
645 | * leaves pointed to by a node and reallocate them so that | |
646 | * disk order is close to key order | |
647 | */ | |
6702ed49 | 648 | int btrfs_realloc_node(struct btrfs_trans_handle *trans, |
5f39d397 | 649 | struct btrfs_root *root, struct extent_buffer *parent, |
de78b51a | 650 | int start_slot, u64 *last_ret, |
a6b6e75e | 651 | struct btrfs_key *progress) |
6702ed49 | 652 | { |
0b246afa | 653 | struct btrfs_fs_info *fs_info = root->fs_info; |
6b80053d | 654 | struct extent_buffer *cur; |
6702ed49 | 655 | u64 blocknr; |
e9d0b13b CM |
656 | u64 search_start = *last_ret; |
657 | u64 last_block = 0; | |
6702ed49 CM |
658 | u64 other; |
659 | u32 parent_nritems; | |
6702ed49 CM |
660 | int end_slot; |
661 | int i; | |
662 | int err = 0; | |
6b80053d | 663 | u32 blocksize; |
081e9573 CM |
664 | int progress_passed = 0; |
665 | struct btrfs_disk_key disk_key; | |
6702ed49 | 666 | |
0b246afa JM |
667 | WARN_ON(trans->transaction != fs_info->running_transaction); |
668 | WARN_ON(trans->transid != fs_info->generation); | |
86479a04 | 669 | |
6b80053d | 670 | parent_nritems = btrfs_header_nritems(parent); |
0b246afa | 671 | blocksize = fs_info->nodesize; |
5dfe2be7 | 672 | end_slot = parent_nritems - 1; |
6702ed49 | 673 | |
5dfe2be7 | 674 | if (parent_nritems <= 1) |
6702ed49 CM |
675 | return 0; |
676 | ||
5dfe2be7 | 677 | for (i = start_slot; i <= end_slot; i++) { |
6702ed49 | 678 | int close = 1; |
a6b6e75e | 679 | |
081e9573 CM |
680 | btrfs_node_key(parent, &disk_key, i); |
681 | if (!progress_passed && comp_keys(&disk_key, progress) < 0) | |
682 | continue; | |
683 | ||
684 | progress_passed = 1; | |
6b80053d | 685 | blocknr = btrfs_node_blockptr(parent, i); |
e9d0b13b CM |
686 | if (last_block == 0) |
687 | last_block = blocknr; | |
5708b959 | 688 | |
6702ed49 | 689 | if (i > 0) { |
6b80053d CM |
690 | other = btrfs_node_blockptr(parent, i - 1); |
691 | close = close_blocks(blocknr, other, blocksize); | |
6702ed49 | 692 | } |
5dfe2be7 | 693 | if (!close && i < end_slot) { |
6b80053d CM |
694 | other = btrfs_node_blockptr(parent, i + 1); |
695 | close = close_blocks(blocknr, other, blocksize); | |
6702ed49 | 696 | } |
e9d0b13b CM |
697 | if (close) { |
698 | last_block = blocknr; | |
6702ed49 | 699 | continue; |
e9d0b13b | 700 | } |
6702ed49 | 701 | |
206983b7 JB |
702 | cur = btrfs_read_node_slot(parent, i); |
703 | if (IS_ERR(cur)) | |
704 | return PTR_ERR(cur); | |
e9d0b13b | 705 | if (search_start == 0) |
6b80053d | 706 | search_start = last_block; |
e9d0b13b | 707 | |
e7a84565 | 708 | btrfs_tree_lock(cur); |
6b80053d | 709 | err = __btrfs_cow_block(trans, root, cur, parent, i, |
e7a84565 | 710 | &cur, search_start, |
6b80053d | 711 | min(16 * blocksize, |
9631e4cc JB |
712 | (end_slot - i) * blocksize), |
713 | BTRFS_NESTING_COW); | |
252c38f0 | 714 | if (err) { |
e7a84565 | 715 | btrfs_tree_unlock(cur); |
6b80053d | 716 | free_extent_buffer(cur); |
6702ed49 | 717 | break; |
252c38f0 | 718 | } |
e7a84565 CM |
719 | search_start = cur->start; |
720 | last_block = cur->start; | |
f2183bde | 721 | *last_ret = search_start; |
e7a84565 CM |
722 | btrfs_tree_unlock(cur); |
723 | free_extent_buffer(cur); | |
6702ed49 CM |
724 | } |
725 | return err; | |
726 | } | |
727 | ||
74123bd7 | 728 | /* |
fb81212c | 729 | * Search for a key in the given extent_buffer. |
5f39d397 | 730 | * |
fb81212c FM |
731 | * The lower boundary for the search is specified by the slot number @low. Use a |
732 | * value of 0 to search over the whole extent buffer. | |
74123bd7 | 733 | * |
fb81212c FM |
734 | * The slot in the extent buffer is returned via @slot. If the key exists in the |
735 | * extent buffer, then @slot will point to the slot where the key is, otherwise | |
736 | * it points to the slot where you would insert the key. | |
737 | * | |
738 | * Slot may point to the total number of items (i.e. one position beyond the last | |
739 | * key) if the key is bigger than the last key in the extent buffer. | |
74123bd7 | 740 | */ |
fb81212c | 741 | static noinline int generic_bin_search(struct extent_buffer *eb, int low, |
67d5e289 | 742 | const struct btrfs_key *key, int *slot) |
be0e5c09 | 743 | { |
fb81212c FM |
744 | unsigned long p; |
745 | int item_size; | |
67d5e289 | 746 | int high = btrfs_header_nritems(eb); |
be0e5c09 | 747 | int ret; |
5cd17f34 | 748 | const int key_size = sizeof(struct btrfs_disk_key); |
be0e5c09 | 749 | |
5e24e9af LB |
750 | if (low > high) { |
751 | btrfs_err(eb->fs_info, | |
752 | "%s: low (%d) > high (%d) eb %llu owner %llu level %d", | |
753 | __func__, low, high, eb->start, | |
754 | btrfs_header_owner(eb), btrfs_header_level(eb)); | |
755 | return -EINVAL; | |
756 | } | |
757 | ||
fb81212c FM |
758 | if (btrfs_header_level(eb) == 0) { |
759 | p = offsetof(struct btrfs_leaf, items); | |
760 | item_size = sizeof(struct btrfs_item); | |
761 | } else { | |
762 | p = offsetof(struct btrfs_node, ptrs); | |
763 | item_size = sizeof(struct btrfs_key_ptr); | |
764 | } | |
765 | ||
d397712b | 766 | while (low < high) { |
5cd17f34 DS |
767 | unsigned long oip; |
768 | unsigned long offset; | |
769 | struct btrfs_disk_key *tmp; | |
770 | struct btrfs_disk_key unaligned; | |
771 | int mid; | |
772 | ||
be0e5c09 | 773 | mid = (low + high) / 2; |
5f39d397 | 774 | offset = p + mid * item_size; |
5cd17f34 | 775 | oip = offset_in_page(offset); |
5f39d397 | 776 | |
5cd17f34 | 777 | if (oip + key_size <= PAGE_SIZE) { |
884b07d0 | 778 | const unsigned long idx = get_eb_page_index(offset); |
5cd17f34 | 779 | char *kaddr = page_address(eb->pages[idx]); |
5f39d397 | 780 | |
884b07d0 | 781 | oip = get_eb_offset_in_page(eb, offset); |
5cd17f34 | 782 | tmp = (struct btrfs_disk_key *)(kaddr + oip); |
5f39d397 | 783 | } else { |
5cd17f34 DS |
784 | read_extent_buffer(eb, &unaligned, offset, key_size); |
785 | tmp = &unaligned; | |
5f39d397 | 786 | } |
5cd17f34 | 787 | |
be0e5c09 CM |
788 | ret = comp_keys(tmp, key); |
789 | ||
790 | if (ret < 0) | |
791 | low = mid + 1; | |
792 | else if (ret > 0) | |
793 | high = mid; | |
794 | else { | |
795 | *slot = mid; | |
796 | return 0; | |
797 | } | |
798 | } | |
799 | *slot = low; | |
800 | return 1; | |
801 | } | |
802 | ||
97571fd0 | 803 | /* |
fb81212c FM |
804 | * Simple binary search on an extent buffer. Works for both leaves and nodes, and |
805 | * always searches over the whole range of keys (slot 0 to slot 'nritems - 1'). | |
97571fd0 | 806 | */ |
a74b35ec | 807 | int btrfs_bin_search(struct extent_buffer *eb, const struct btrfs_key *key, |
e3b83361 | 808 | int *slot) |
be0e5c09 | 809 | { |
fb81212c | 810 | return generic_bin_search(eb, 0, key, slot); |
be0e5c09 CM |
811 | } |
812 | ||
f0486c68 YZ |
813 | static void root_add_used(struct btrfs_root *root, u32 size) |
814 | { | |
815 | spin_lock(&root->accounting_lock); | |
816 | btrfs_set_root_used(&root->root_item, | |
817 | btrfs_root_used(&root->root_item) + size); | |
818 | spin_unlock(&root->accounting_lock); | |
819 | } | |
820 | ||
821 | static void root_sub_used(struct btrfs_root *root, u32 size) | |
822 | { | |
823 | spin_lock(&root->accounting_lock); | |
824 | btrfs_set_root_used(&root->root_item, | |
825 | btrfs_root_used(&root->root_item) - size); | |
826 | spin_unlock(&root->accounting_lock); | |
827 | } | |
828 | ||
d352ac68 CM |
829 | /* given a node and slot number, this reads the blocks it points to. The |
830 | * extent buffer is returned with a reference taken (but unlocked). | |
d352ac68 | 831 | */ |
4b231ae4 DS |
832 | struct extent_buffer *btrfs_read_node_slot(struct extent_buffer *parent, |
833 | int slot) | |
bb803951 | 834 | { |
ca7a79ad | 835 | int level = btrfs_header_level(parent); |
416bc658 | 836 | struct extent_buffer *eb; |
581c1760 | 837 | struct btrfs_key first_key; |
416bc658 | 838 | |
fb770ae4 LB |
839 | if (slot < 0 || slot >= btrfs_header_nritems(parent)) |
840 | return ERR_PTR(-ENOENT); | |
ca7a79ad CM |
841 | |
842 | BUG_ON(level == 0); | |
843 | ||
581c1760 | 844 | btrfs_node_key_to_cpu(parent, &first_key, slot); |
d0d20b0f | 845 | eb = read_tree_block(parent->fs_info, btrfs_node_blockptr(parent, slot), |
1b7ec85e | 846 | btrfs_header_owner(parent), |
581c1760 QW |
847 | btrfs_node_ptr_generation(parent, slot), |
848 | level - 1, &first_key); | |
4eb150d6 QW |
849 | if (IS_ERR(eb)) |
850 | return eb; | |
851 | if (!extent_buffer_uptodate(eb)) { | |
fb770ae4 | 852 | free_extent_buffer(eb); |
4eb150d6 | 853 | return ERR_PTR(-EIO); |
416bc658 JB |
854 | } |
855 | ||
856 | return eb; | |
bb803951 CM |
857 | } |
858 | ||
d352ac68 CM |
859 | /* |
860 | * node level balancing, used to make sure nodes are in proper order for | |
861 | * item deletion. We balance from the top down, so we have to make sure | |
862 | * that a deletion won't leave an node completely empty later on. | |
863 | */ | |
e02119d5 | 864 | static noinline int balance_level(struct btrfs_trans_handle *trans, |
98ed5174 CM |
865 | struct btrfs_root *root, |
866 | struct btrfs_path *path, int level) | |
bb803951 | 867 | { |
0b246afa | 868 | struct btrfs_fs_info *fs_info = root->fs_info; |
5f39d397 CM |
869 | struct extent_buffer *right = NULL; |
870 | struct extent_buffer *mid; | |
871 | struct extent_buffer *left = NULL; | |
872 | struct extent_buffer *parent = NULL; | |
bb803951 CM |
873 | int ret = 0; |
874 | int wret; | |
875 | int pslot; | |
bb803951 | 876 | int orig_slot = path->slots[level]; |
79f95c82 | 877 | u64 orig_ptr; |
bb803951 | 878 | |
98e6b1eb | 879 | ASSERT(level > 0); |
bb803951 | 880 | |
5f39d397 | 881 | mid = path->nodes[level]; |
b4ce94de | 882 | |
ac5887c8 | 883 | WARN_ON(path->locks[level] != BTRFS_WRITE_LOCK); |
7bb86316 CM |
884 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
885 | ||
1d4f8a0c | 886 | orig_ptr = btrfs_node_blockptr(mid, orig_slot); |
79f95c82 | 887 | |
a05a9bb1 | 888 | if (level < BTRFS_MAX_LEVEL - 1) { |
5f39d397 | 889 | parent = path->nodes[level + 1]; |
a05a9bb1 LZ |
890 | pslot = path->slots[level + 1]; |
891 | } | |
bb803951 | 892 | |
40689478 CM |
893 | /* |
894 | * deal with the case where there is only one pointer in the root | |
895 | * by promoting the node below to a root | |
896 | */ | |
5f39d397 CM |
897 | if (!parent) { |
898 | struct extent_buffer *child; | |
bb803951 | 899 | |
5f39d397 | 900 | if (btrfs_header_nritems(mid) != 1) |
bb803951 CM |
901 | return 0; |
902 | ||
903 | /* promote the child to a root */ | |
4b231ae4 | 904 | child = btrfs_read_node_slot(mid, 0); |
fb770ae4 LB |
905 | if (IS_ERR(child)) { |
906 | ret = PTR_ERR(child); | |
0b246afa | 907 | btrfs_handle_fs_error(fs_info, ret, NULL); |
305a26af MF |
908 | goto enospc; |
909 | } | |
910 | ||
925baedd | 911 | btrfs_tree_lock(child); |
9631e4cc JB |
912 | ret = btrfs_cow_block(trans, root, child, mid, 0, &child, |
913 | BTRFS_NESTING_COW); | |
f0486c68 YZ |
914 | if (ret) { |
915 | btrfs_tree_unlock(child); | |
916 | free_extent_buffer(child); | |
917 | goto enospc; | |
918 | } | |
2f375ab9 | 919 | |
406808ab | 920 | ret = btrfs_tree_mod_log_insert_root(root->node, child, true); |
d9d19a01 | 921 | BUG_ON(ret < 0); |
240f62c8 | 922 | rcu_assign_pointer(root->node, child); |
925baedd | 923 | |
0b86a832 | 924 | add_root_to_dirty_list(root); |
925baedd | 925 | btrfs_tree_unlock(child); |
b4ce94de | 926 | |
925baedd | 927 | path->locks[level] = 0; |
bb803951 | 928 | path->nodes[level] = NULL; |
6a884d7d | 929 | btrfs_clean_tree_block(mid); |
925baedd | 930 | btrfs_tree_unlock(mid); |
bb803951 | 931 | /* once for the path */ |
5f39d397 | 932 | free_extent_buffer(mid); |
f0486c68 YZ |
933 | |
934 | root_sub_used(root, mid->len); | |
7a163608 | 935 | btrfs_free_tree_block(trans, btrfs_root_id(root), mid, 0, 1); |
bb803951 | 936 | /* once for the root ptr */ |
3083ee2e | 937 | free_extent_buffer_stale(mid); |
f0486c68 | 938 | return 0; |
bb803951 | 939 | } |
5f39d397 | 940 | if (btrfs_header_nritems(mid) > |
0b246afa | 941 | BTRFS_NODEPTRS_PER_BLOCK(fs_info) / 4) |
bb803951 CM |
942 | return 0; |
943 | ||
4b231ae4 | 944 | left = btrfs_read_node_slot(parent, pslot - 1); |
fb770ae4 LB |
945 | if (IS_ERR(left)) |
946 | left = NULL; | |
947 | ||
5f39d397 | 948 | if (left) { |
bf77467a | 949 | __btrfs_tree_lock(left, BTRFS_NESTING_LEFT); |
5f39d397 | 950 | wret = btrfs_cow_block(trans, root, left, |
9631e4cc | 951 | parent, pslot - 1, &left, |
bf59a5a2 | 952 | BTRFS_NESTING_LEFT_COW); |
54aa1f4d CM |
953 | if (wret) { |
954 | ret = wret; | |
955 | goto enospc; | |
956 | } | |
2cc58cf2 | 957 | } |
fb770ae4 | 958 | |
4b231ae4 | 959 | right = btrfs_read_node_slot(parent, pslot + 1); |
fb770ae4 LB |
960 | if (IS_ERR(right)) |
961 | right = NULL; | |
962 | ||
5f39d397 | 963 | if (right) { |
bf77467a | 964 | __btrfs_tree_lock(right, BTRFS_NESTING_RIGHT); |
5f39d397 | 965 | wret = btrfs_cow_block(trans, root, right, |
9631e4cc | 966 | parent, pslot + 1, &right, |
bf59a5a2 | 967 | BTRFS_NESTING_RIGHT_COW); |
2cc58cf2 CM |
968 | if (wret) { |
969 | ret = wret; | |
970 | goto enospc; | |
971 | } | |
972 | } | |
973 | ||
974 | /* first, try to make some room in the middle buffer */ | |
5f39d397 CM |
975 | if (left) { |
976 | orig_slot += btrfs_header_nritems(left); | |
d30a668f | 977 | wret = push_node_left(trans, left, mid, 1); |
79f95c82 CM |
978 | if (wret < 0) |
979 | ret = wret; | |
bb803951 | 980 | } |
79f95c82 CM |
981 | |
982 | /* | |
983 | * then try to empty the right most buffer into the middle | |
984 | */ | |
5f39d397 | 985 | if (right) { |
d30a668f | 986 | wret = push_node_left(trans, mid, right, 1); |
54aa1f4d | 987 | if (wret < 0 && wret != -ENOSPC) |
79f95c82 | 988 | ret = wret; |
5f39d397 | 989 | if (btrfs_header_nritems(right) == 0) { |
6a884d7d | 990 | btrfs_clean_tree_block(right); |
925baedd | 991 | btrfs_tree_unlock(right); |
afe5fea7 | 992 | del_ptr(root, path, level + 1, pslot + 1); |
f0486c68 | 993 | root_sub_used(root, right->len); |
7a163608 FM |
994 | btrfs_free_tree_block(trans, btrfs_root_id(root), right, |
995 | 0, 1); | |
3083ee2e | 996 | free_extent_buffer_stale(right); |
f0486c68 | 997 | right = NULL; |
bb803951 | 998 | } else { |
5f39d397 CM |
999 | struct btrfs_disk_key right_key; |
1000 | btrfs_node_key(right, &right_key, 0); | |
f3a84ccd FM |
1001 | ret = btrfs_tree_mod_log_insert_key(parent, pslot + 1, |
1002 | BTRFS_MOD_LOG_KEY_REPLACE, GFP_NOFS); | |
0e82bcfe | 1003 | BUG_ON(ret < 0); |
5f39d397 CM |
1004 | btrfs_set_node_key(parent, &right_key, pslot + 1); |
1005 | btrfs_mark_buffer_dirty(parent); | |
bb803951 CM |
1006 | } |
1007 | } | |
5f39d397 | 1008 | if (btrfs_header_nritems(mid) == 1) { |
79f95c82 CM |
1009 | /* |
1010 | * we're not allowed to leave a node with one item in the | |
1011 | * tree during a delete. A deletion from lower in the tree | |
1012 | * could try to delete the only pointer in this node. | |
1013 | * So, pull some keys from the left. | |
1014 | * There has to be a left pointer at this point because | |
1015 | * otherwise we would have pulled some pointers from the | |
1016 | * right | |
1017 | */ | |
305a26af MF |
1018 | if (!left) { |
1019 | ret = -EROFS; | |
0b246afa | 1020 | btrfs_handle_fs_error(fs_info, ret, NULL); |
305a26af MF |
1021 | goto enospc; |
1022 | } | |
55d32ed8 | 1023 | wret = balance_node_right(trans, mid, left); |
54aa1f4d | 1024 | if (wret < 0) { |
79f95c82 | 1025 | ret = wret; |
54aa1f4d CM |
1026 | goto enospc; |
1027 | } | |
bce4eae9 | 1028 | if (wret == 1) { |
d30a668f | 1029 | wret = push_node_left(trans, left, mid, 1); |
bce4eae9 CM |
1030 | if (wret < 0) |
1031 | ret = wret; | |
1032 | } | |
79f95c82 CM |
1033 | BUG_ON(wret == 1); |
1034 | } | |
5f39d397 | 1035 | if (btrfs_header_nritems(mid) == 0) { |
6a884d7d | 1036 | btrfs_clean_tree_block(mid); |
925baedd | 1037 | btrfs_tree_unlock(mid); |
afe5fea7 | 1038 | del_ptr(root, path, level + 1, pslot); |
f0486c68 | 1039 | root_sub_used(root, mid->len); |
7a163608 | 1040 | btrfs_free_tree_block(trans, btrfs_root_id(root), mid, 0, 1); |
3083ee2e | 1041 | free_extent_buffer_stale(mid); |
f0486c68 | 1042 | mid = NULL; |
79f95c82 CM |
1043 | } else { |
1044 | /* update the parent key to reflect our changes */ | |
5f39d397 CM |
1045 | struct btrfs_disk_key mid_key; |
1046 | btrfs_node_key(mid, &mid_key, 0); | |
f3a84ccd FM |
1047 | ret = btrfs_tree_mod_log_insert_key(parent, pslot, |
1048 | BTRFS_MOD_LOG_KEY_REPLACE, GFP_NOFS); | |
0e82bcfe | 1049 | BUG_ON(ret < 0); |
5f39d397 CM |
1050 | btrfs_set_node_key(parent, &mid_key, pslot); |
1051 | btrfs_mark_buffer_dirty(parent); | |
79f95c82 | 1052 | } |
bb803951 | 1053 | |
79f95c82 | 1054 | /* update the path */ |
5f39d397 CM |
1055 | if (left) { |
1056 | if (btrfs_header_nritems(left) > orig_slot) { | |
67439dad | 1057 | atomic_inc(&left->refs); |
925baedd | 1058 | /* left was locked after cow */ |
5f39d397 | 1059 | path->nodes[level] = left; |
bb803951 CM |
1060 | path->slots[level + 1] -= 1; |
1061 | path->slots[level] = orig_slot; | |
925baedd CM |
1062 | if (mid) { |
1063 | btrfs_tree_unlock(mid); | |
5f39d397 | 1064 | free_extent_buffer(mid); |
925baedd | 1065 | } |
bb803951 | 1066 | } else { |
5f39d397 | 1067 | orig_slot -= btrfs_header_nritems(left); |
bb803951 CM |
1068 | path->slots[level] = orig_slot; |
1069 | } | |
1070 | } | |
79f95c82 | 1071 | /* double check we haven't messed things up */ |
e20d96d6 | 1072 | if (orig_ptr != |
5f39d397 | 1073 | btrfs_node_blockptr(path->nodes[level], path->slots[level])) |
79f95c82 | 1074 | BUG(); |
54aa1f4d | 1075 | enospc: |
925baedd CM |
1076 | if (right) { |
1077 | btrfs_tree_unlock(right); | |
5f39d397 | 1078 | free_extent_buffer(right); |
925baedd CM |
1079 | } |
1080 | if (left) { | |
1081 | if (path->nodes[level] != left) | |
1082 | btrfs_tree_unlock(left); | |
5f39d397 | 1083 | free_extent_buffer(left); |
925baedd | 1084 | } |
bb803951 CM |
1085 | return ret; |
1086 | } | |
1087 | ||
d352ac68 CM |
1088 | /* Node balancing for insertion. Here we only split or push nodes around |
1089 | * when they are completely full. This is also done top down, so we | |
1090 | * have to be pessimistic. | |
1091 | */ | |
d397712b | 1092 | static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, |
98ed5174 CM |
1093 | struct btrfs_root *root, |
1094 | struct btrfs_path *path, int level) | |
e66f709b | 1095 | { |
0b246afa | 1096 | struct btrfs_fs_info *fs_info = root->fs_info; |
5f39d397 CM |
1097 | struct extent_buffer *right = NULL; |
1098 | struct extent_buffer *mid; | |
1099 | struct extent_buffer *left = NULL; | |
1100 | struct extent_buffer *parent = NULL; | |
e66f709b CM |
1101 | int ret = 0; |
1102 | int wret; | |
1103 | int pslot; | |
1104 | int orig_slot = path->slots[level]; | |
e66f709b CM |
1105 | |
1106 | if (level == 0) | |
1107 | return 1; | |
1108 | ||
5f39d397 | 1109 | mid = path->nodes[level]; |
7bb86316 | 1110 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
e66f709b | 1111 | |
a05a9bb1 | 1112 | if (level < BTRFS_MAX_LEVEL - 1) { |
5f39d397 | 1113 | parent = path->nodes[level + 1]; |
a05a9bb1 LZ |
1114 | pslot = path->slots[level + 1]; |
1115 | } | |
e66f709b | 1116 | |
5f39d397 | 1117 | if (!parent) |
e66f709b | 1118 | return 1; |
e66f709b | 1119 | |
4b231ae4 | 1120 | left = btrfs_read_node_slot(parent, pslot - 1); |
fb770ae4 LB |
1121 | if (IS_ERR(left)) |
1122 | left = NULL; | |
e66f709b CM |
1123 | |
1124 | /* first, try to make some room in the middle buffer */ | |
5f39d397 | 1125 | if (left) { |
e66f709b | 1126 | u32 left_nr; |
925baedd | 1127 | |
bf77467a | 1128 | __btrfs_tree_lock(left, BTRFS_NESTING_LEFT); |
b4ce94de | 1129 | |
5f39d397 | 1130 | left_nr = btrfs_header_nritems(left); |
0b246afa | 1131 | if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 1) { |
33ade1f8 CM |
1132 | wret = 1; |
1133 | } else { | |
5f39d397 | 1134 | ret = btrfs_cow_block(trans, root, left, parent, |
9631e4cc | 1135 | pslot - 1, &left, |
bf59a5a2 | 1136 | BTRFS_NESTING_LEFT_COW); |
54aa1f4d CM |
1137 | if (ret) |
1138 | wret = 1; | |
1139 | else { | |
d30a668f | 1140 | wret = push_node_left(trans, left, mid, 0); |
54aa1f4d | 1141 | } |
33ade1f8 | 1142 | } |
e66f709b CM |
1143 | if (wret < 0) |
1144 | ret = wret; | |
1145 | if (wret == 0) { | |
5f39d397 | 1146 | struct btrfs_disk_key disk_key; |
e66f709b | 1147 | orig_slot += left_nr; |
5f39d397 | 1148 | btrfs_node_key(mid, &disk_key, 0); |
f3a84ccd FM |
1149 | ret = btrfs_tree_mod_log_insert_key(parent, pslot, |
1150 | BTRFS_MOD_LOG_KEY_REPLACE, GFP_NOFS); | |
0e82bcfe | 1151 | BUG_ON(ret < 0); |
5f39d397 CM |
1152 | btrfs_set_node_key(parent, &disk_key, pslot); |
1153 | btrfs_mark_buffer_dirty(parent); | |
1154 | if (btrfs_header_nritems(left) > orig_slot) { | |
1155 | path->nodes[level] = left; | |
e66f709b CM |
1156 | path->slots[level + 1] -= 1; |
1157 | path->slots[level] = orig_slot; | |
925baedd | 1158 | btrfs_tree_unlock(mid); |
5f39d397 | 1159 | free_extent_buffer(mid); |
e66f709b CM |
1160 | } else { |
1161 | orig_slot -= | |
5f39d397 | 1162 | btrfs_header_nritems(left); |
e66f709b | 1163 | path->slots[level] = orig_slot; |
925baedd | 1164 | btrfs_tree_unlock(left); |
5f39d397 | 1165 | free_extent_buffer(left); |
e66f709b | 1166 | } |
e66f709b CM |
1167 | return 0; |
1168 | } | |
925baedd | 1169 | btrfs_tree_unlock(left); |
5f39d397 | 1170 | free_extent_buffer(left); |
e66f709b | 1171 | } |
4b231ae4 | 1172 | right = btrfs_read_node_slot(parent, pslot + 1); |
fb770ae4 LB |
1173 | if (IS_ERR(right)) |
1174 | right = NULL; | |
e66f709b CM |
1175 | |
1176 | /* | |
1177 | * then try to empty the right most buffer into the middle | |
1178 | */ | |
5f39d397 | 1179 | if (right) { |
33ade1f8 | 1180 | u32 right_nr; |
b4ce94de | 1181 | |
bf77467a | 1182 | __btrfs_tree_lock(right, BTRFS_NESTING_RIGHT); |
b4ce94de | 1183 | |
5f39d397 | 1184 | right_nr = btrfs_header_nritems(right); |
0b246afa | 1185 | if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 1) { |
33ade1f8 CM |
1186 | wret = 1; |
1187 | } else { | |
5f39d397 CM |
1188 | ret = btrfs_cow_block(trans, root, right, |
1189 | parent, pslot + 1, | |
bf59a5a2 | 1190 | &right, BTRFS_NESTING_RIGHT_COW); |
54aa1f4d CM |
1191 | if (ret) |
1192 | wret = 1; | |
1193 | else { | |
55d32ed8 | 1194 | wret = balance_node_right(trans, right, mid); |
54aa1f4d | 1195 | } |
33ade1f8 | 1196 | } |
e66f709b CM |
1197 | if (wret < 0) |
1198 | ret = wret; | |
1199 | if (wret == 0) { | |
5f39d397 CM |
1200 | struct btrfs_disk_key disk_key; |
1201 | ||
1202 | btrfs_node_key(right, &disk_key, 0); | |
f3a84ccd FM |
1203 | ret = btrfs_tree_mod_log_insert_key(parent, pslot + 1, |
1204 | BTRFS_MOD_LOG_KEY_REPLACE, GFP_NOFS); | |
0e82bcfe | 1205 | BUG_ON(ret < 0); |
5f39d397 CM |
1206 | btrfs_set_node_key(parent, &disk_key, pslot + 1); |
1207 | btrfs_mark_buffer_dirty(parent); | |
1208 | ||
1209 | if (btrfs_header_nritems(mid) <= orig_slot) { | |
1210 | path->nodes[level] = right; | |
e66f709b CM |
1211 | path->slots[level + 1] += 1; |
1212 | path->slots[level] = orig_slot - | |
5f39d397 | 1213 | btrfs_header_nritems(mid); |
925baedd | 1214 | btrfs_tree_unlock(mid); |
5f39d397 | 1215 | free_extent_buffer(mid); |
e66f709b | 1216 | } else { |
925baedd | 1217 | btrfs_tree_unlock(right); |
5f39d397 | 1218 | free_extent_buffer(right); |
e66f709b | 1219 | } |
e66f709b CM |
1220 | return 0; |
1221 | } | |
925baedd | 1222 | btrfs_tree_unlock(right); |
5f39d397 | 1223 | free_extent_buffer(right); |
e66f709b | 1224 | } |
e66f709b CM |
1225 | return 1; |
1226 | } | |
1227 | ||
3c69faec | 1228 | /* |
d352ac68 CM |
1229 | * readahead one full node of leaves, finding things that are close |
1230 | * to the block in 'slot', and triggering ra on them. | |
3c69faec | 1231 | */ |
2ff7e61e | 1232 | static void reada_for_search(struct btrfs_fs_info *fs_info, |
c8c42864 CM |
1233 | struct btrfs_path *path, |
1234 | int level, int slot, u64 objectid) | |
3c69faec | 1235 | { |
5f39d397 | 1236 | struct extent_buffer *node; |
01f46658 | 1237 | struct btrfs_disk_key disk_key; |
3c69faec | 1238 | u32 nritems; |
3c69faec | 1239 | u64 search; |
a7175319 | 1240 | u64 target; |
6b80053d | 1241 | u64 nread = 0; |
ace75066 | 1242 | u64 nread_max; |
6b80053d CM |
1243 | u32 nr; |
1244 | u32 blocksize; | |
1245 | u32 nscan = 0; | |
db94535d | 1246 | |
ace75066 | 1247 | if (level != 1 && path->reada != READA_FORWARD_ALWAYS) |
6702ed49 CM |
1248 | return; |
1249 | ||
1250 | if (!path->nodes[level]) | |
3c69faec CM |
1251 | return; |
1252 | ||
5f39d397 | 1253 | node = path->nodes[level]; |
925baedd | 1254 | |
ace75066 FM |
1255 | /* |
1256 | * Since the time between visiting leaves is much shorter than the time | |
1257 | * between visiting nodes, limit read ahead of nodes to 1, to avoid too | |
1258 | * much IO at once (possibly random). | |
1259 | */ | |
1260 | if (path->reada == READA_FORWARD_ALWAYS) { | |
1261 | if (level > 1) | |
1262 | nread_max = node->fs_info->nodesize; | |
1263 | else | |
1264 | nread_max = SZ_128K; | |
1265 | } else { | |
1266 | nread_max = SZ_64K; | |
1267 | } | |
1268 | ||
3c69faec | 1269 | search = btrfs_node_blockptr(node, slot); |
0b246afa | 1270 | blocksize = fs_info->nodesize; |
069a2e37 FM |
1271 | if (path->reada != READA_FORWARD_ALWAYS) { |
1272 | struct extent_buffer *eb; | |
1273 | ||
1274 | eb = find_extent_buffer(fs_info, search); | |
1275 | if (eb) { | |
1276 | free_extent_buffer(eb); | |
1277 | return; | |
1278 | } | |
3c69faec CM |
1279 | } |
1280 | ||
a7175319 | 1281 | target = search; |
6b80053d | 1282 | |
5f39d397 | 1283 | nritems = btrfs_header_nritems(node); |
6b80053d | 1284 | nr = slot; |
25b8b936 | 1285 | |
d397712b | 1286 | while (1) { |
e4058b54 | 1287 | if (path->reada == READA_BACK) { |
6b80053d CM |
1288 | if (nr == 0) |
1289 | break; | |
1290 | nr--; | |
ace75066 FM |
1291 | } else if (path->reada == READA_FORWARD || |
1292 | path->reada == READA_FORWARD_ALWAYS) { | |
6b80053d CM |
1293 | nr++; |
1294 | if (nr >= nritems) | |
1295 | break; | |
3c69faec | 1296 | } |
e4058b54 | 1297 | if (path->reada == READA_BACK && objectid) { |
01f46658 CM |
1298 | btrfs_node_key(node, &disk_key, nr); |
1299 | if (btrfs_disk_key_objectid(&disk_key) != objectid) | |
1300 | break; | |
1301 | } | |
6b80053d | 1302 | search = btrfs_node_blockptr(node, nr); |
ace75066 FM |
1303 | if (path->reada == READA_FORWARD_ALWAYS || |
1304 | (search <= target && target - search <= 65536) || | |
a7175319 | 1305 | (search > target && search - target <= 65536)) { |
bfb484d9 | 1306 | btrfs_readahead_node_child(node, nr); |
6b80053d CM |
1307 | nread += blocksize; |
1308 | } | |
1309 | nscan++; | |
ace75066 | 1310 | if (nread > nread_max || nscan > 32) |
6b80053d | 1311 | break; |
3c69faec CM |
1312 | } |
1313 | } | |
925baedd | 1314 | |
bfb484d9 | 1315 | static noinline void reada_for_balance(struct btrfs_path *path, int level) |
b4ce94de | 1316 | { |
bfb484d9 | 1317 | struct extent_buffer *parent; |
b4ce94de CM |
1318 | int slot; |
1319 | int nritems; | |
b4ce94de | 1320 | |
8c594ea8 | 1321 | parent = path->nodes[level + 1]; |
b4ce94de | 1322 | if (!parent) |
0b08851f | 1323 | return; |
b4ce94de CM |
1324 | |
1325 | nritems = btrfs_header_nritems(parent); | |
8c594ea8 | 1326 | slot = path->slots[level + 1]; |
b4ce94de | 1327 | |
bfb484d9 JB |
1328 | if (slot > 0) |
1329 | btrfs_readahead_node_child(parent, slot - 1); | |
1330 | if (slot + 1 < nritems) | |
1331 | btrfs_readahead_node_child(parent, slot + 1); | |
b4ce94de CM |
1332 | } |
1333 | ||
1334 | ||
d352ac68 | 1335 | /* |
d397712b CM |
1336 | * when we walk down the tree, it is usually safe to unlock the higher layers |
1337 | * in the tree. The exceptions are when our path goes through slot 0, because | |
1338 | * operations on the tree might require changing key pointers higher up in the | |
1339 | * tree. | |
d352ac68 | 1340 | * |
d397712b CM |
1341 | * callers might also have set path->keep_locks, which tells this code to keep |
1342 | * the lock if the path points to the last slot in the block. This is part of | |
1343 | * walking through the tree, and selecting the next slot in the higher block. | |
d352ac68 | 1344 | * |
d397712b CM |
1345 | * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so |
1346 | * if lowest_unlock is 1, level 0 won't be unlocked | |
d352ac68 | 1347 | */ |
e02119d5 | 1348 | static noinline void unlock_up(struct btrfs_path *path, int level, |
f7c79f30 CM |
1349 | int lowest_unlock, int min_write_lock_level, |
1350 | int *write_lock_level) | |
925baedd CM |
1351 | { |
1352 | int i; | |
1353 | int skip_level = level; | |
c1227996 | 1354 | bool check_skip = true; |
925baedd CM |
1355 | |
1356 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { | |
1357 | if (!path->nodes[i]) | |
1358 | break; | |
1359 | if (!path->locks[i]) | |
1360 | break; | |
c1227996 NB |
1361 | |
1362 | if (check_skip) { | |
1363 | if (path->slots[i] == 0) { | |
925baedd CM |
1364 | skip_level = i + 1; |
1365 | continue; | |
1366 | } | |
c1227996 NB |
1367 | |
1368 | if (path->keep_locks) { | |
1369 | u32 nritems; | |
1370 | ||
1371 | nritems = btrfs_header_nritems(path->nodes[i]); | |
1372 | if (nritems < 1 || path->slots[i] >= nritems - 1) { | |
1373 | skip_level = i + 1; | |
1374 | continue; | |
1375 | } | |
1376 | } | |
925baedd | 1377 | } |
051e1b9f | 1378 | |
d80bb3f9 | 1379 | if (i >= lowest_unlock && i > skip_level) { |
c1227996 NB |
1380 | check_skip = false; |
1381 | btrfs_tree_unlock_rw(path->nodes[i], path->locks[i]); | |
925baedd | 1382 | path->locks[i] = 0; |
f7c79f30 CM |
1383 | if (write_lock_level && |
1384 | i > min_write_lock_level && | |
1385 | i <= *write_lock_level) { | |
1386 | *write_lock_level = i - 1; | |
1387 | } | |
925baedd CM |
1388 | } |
1389 | } | |
1390 | } | |
1391 | ||
c8c42864 CM |
1392 | /* |
1393 | * helper function for btrfs_search_slot. The goal is to find a block | |
1394 | * in cache without setting the path to blocking. If we find the block | |
1395 | * we return zero and the path is unchanged. | |
1396 | * | |
1397 | * If we can't find the block, we set the path blocking and do some | |
1398 | * reada. -EAGAIN is returned and the search must be repeated. | |
1399 | */ | |
1400 | static int | |
d07b8528 LB |
1401 | read_block_for_search(struct btrfs_root *root, struct btrfs_path *p, |
1402 | struct extent_buffer **eb_ret, int level, int slot, | |
cda79c54 | 1403 | const struct btrfs_key *key) |
c8c42864 | 1404 | { |
0b246afa | 1405 | struct btrfs_fs_info *fs_info = root->fs_info; |
c8c42864 CM |
1406 | u64 blocknr; |
1407 | u64 gen; | |
c8c42864 | 1408 | struct extent_buffer *tmp; |
581c1760 | 1409 | struct btrfs_key first_key; |
76a05b35 | 1410 | int ret; |
581c1760 | 1411 | int parent_level; |
c8c42864 | 1412 | |
213ff4b7 NB |
1413 | blocknr = btrfs_node_blockptr(*eb_ret, slot); |
1414 | gen = btrfs_node_ptr_generation(*eb_ret, slot); | |
1415 | parent_level = btrfs_header_level(*eb_ret); | |
1416 | btrfs_node_key_to_cpu(*eb_ret, &first_key, slot); | |
c8c42864 | 1417 | |
0b246afa | 1418 | tmp = find_extent_buffer(fs_info, blocknr); |
cb44921a | 1419 | if (tmp) { |
ace75066 FM |
1420 | if (p->reada == READA_FORWARD_ALWAYS) |
1421 | reada_for_search(fs_info, p, level, slot, key->objectid); | |
1422 | ||
b9fab919 | 1423 | /* first we do an atomic uptodate check */ |
bdf7c00e | 1424 | if (btrfs_buffer_uptodate(tmp, gen, 1) > 0) { |
448de471 QW |
1425 | /* |
1426 | * Do extra check for first_key, eb can be stale due to | |
1427 | * being cached, read from scrub, or have multiple | |
1428 | * parents (shared tree blocks). | |
1429 | */ | |
e064d5e9 | 1430 | if (btrfs_verify_level_key(tmp, |
448de471 QW |
1431 | parent_level - 1, &first_key, gen)) { |
1432 | free_extent_buffer(tmp); | |
1433 | return -EUCLEAN; | |
1434 | } | |
bdf7c00e JB |
1435 | *eb_ret = tmp; |
1436 | return 0; | |
1437 | } | |
1438 | ||
bdf7c00e | 1439 | /* now we're allowed to do a blocking uptodate check */ |
581c1760 | 1440 | ret = btrfs_read_buffer(tmp, gen, parent_level - 1, &first_key); |
9a4ffa1b QW |
1441 | if (ret) { |
1442 | free_extent_buffer(tmp); | |
1443 | btrfs_release_path(p); | |
1444 | return -EIO; | |
cb44921a | 1445 | } |
9a4ffa1b QW |
1446 | *eb_ret = tmp; |
1447 | return 0; | |
c8c42864 CM |
1448 | } |
1449 | ||
1450 | /* | |
1451 | * reduce lock contention at high levels | |
1452 | * of the btree by dropping locks before | |
76a05b35 CM |
1453 | * we read. Don't release the lock on the current |
1454 | * level because we need to walk this node to figure | |
1455 | * out which blocks to read. | |
c8c42864 | 1456 | */ |
8c594ea8 | 1457 | btrfs_unlock_up_safe(p, level + 1); |
8c594ea8 | 1458 | |
e4058b54 | 1459 | if (p->reada != READA_NONE) |
2ff7e61e | 1460 | reada_for_search(fs_info, p, level, slot, key->objectid); |
c8c42864 | 1461 | |
76a05b35 | 1462 | ret = -EAGAIN; |
1b7ec85e JB |
1463 | tmp = read_tree_block(fs_info, blocknr, root->root_key.objectid, |
1464 | gen, parent_level - 1, &first_key); | |
4eb150d6 QW |
1465 | if (IS_ERR(tmp)) { |
1466 | btrfs_release_path(p); | |
1467 | return PTR_ERR(tmp); | |
76a05b35 | 1468 | } |
4eb150d6 QW |
1469 | /* |
1470 | * If the read above didn't mark this buffer up to date, | |
1471 | * it will never end up being up to date. Set ret to EIO now | |
1472 | * and give up so that our caller doesn't loop forever | |
1473 | * on our EAGAINs. | |
1474 | */ | |
1475 | if (!extent_buffer_uptodate(tmp)) | |
1476 | ret = -EIO; | |
1477 | free_extent_buffer(tmp); | |
02a3307a LB |
1478 | |
1479 | btrfs_release_path(p); | |
76a05b35 | 1480 | return ret; |
c8c42864 CM |
1481 | } |
1482 | ||
1483 | /* | |
1484 | * helper function for btrfs_search_slot. This does all of the checks | |
1485 | * for node-level blocks and does any balancing required based on | |
1486 | * the ins_len. | |
1487 | * | |
1488 | * If no extra work was required, zero is returned. If we had to | |
1489 | * drop the path, -EAGAIN is returned and btrfs_search_slot must | |
1490 | * start over | |
1491 | */ | |
1492 | static int | |
1493 | setup_nodes_for_search(struct btrfs_trans_handle *trans, | |
1494 | struct btrfs_root *root, struct btrfs_path *p, | |
bd681513 CM |
1495 | struct extent_buffer *b, int level, int ins_len, |
1496 | int *write_lock_level) | |
c8c42864 | 1497 | { |
0b246afa | 1498 | struct btrfs_fs_info *fs_info = root->fs_info; |
95b982de | 1499 | int ret = 0; |
0b246afa | 1500 | |
c8c42864 | 1501 | if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >= |
0b246afa | 1502 | BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 3) { |
c8c42864 | 1503 | |
bd681513 CM |
1504 | if (*write_lock_level < level + 1) { |
1505 | *write_lock_level = level + 1; | |
1506 | btrfs_release_path(p); | |
95b982de | 1507 | return -EAGAIN; |
bd681513 CM |
1508 | } |
1509 | ||
bfb484d9 | 1510 | reada_for_balance(p, level); |
95b982de | 1511 | ret = split_node(trans, root, p, level); |
c8c42864 | 1512 | |
c8c42864 CM |
1513 | b = p->nodes[level]; |
1514 | } else if (ins_len < 0 && btrfs_header_nritems(b) < | |
0b246afa | 1515 | BTRFS_NODEPTRS_PER_BLOCK(fs_info) / 2) { |
c8c42864 | 1516 | |
bd681513 CM |
1517 | if (*write_lock_level < level + 1) { |
1518 | *write_lock_level = level + 1; | |
1519 | btrfs_release_path(p); | |
95b982de | 1520 | return -EAGAIN; |
bd681513 CM |
1521 | } |
1522 | ||
bfb484d9 | 1523 | reada_for_balance(p, level); |
95b982de NB |
1524 | ret = balance_level(trans, root, p, level); |
1525 | if (ret) | |
1526 | return ret; | |
c8c42864 | 1527 | |
c8c42864 CM |
1528 | b = p->nodes[level]; |
1529 | if (!b) { | |
b3b4aa74 | 1530 | btrfs_release_path(p); |
95b982de | 1531 | return -EAGAIN; |
c8c42864 CM |
1532 | } |
1533 | BUG_ON(btrfs_header_nritems(b) == 1); | |
1534 | } | |
c8c42864 CM |
1535 | return ret; |
1536 | } | |
1537 | ||
381cf658 | 1538 | int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *path, |
e33d5c3d KN |
1539 | u64 iobjectid, u64 ioff, u8 key_type, |
1540 | struct btrfs_key *found_key) | |
1541 | { | |
1542 | int ret; | |
1543 | struct btrfs_key key; | |
1544 | struct extent_buffer *eb; | |
381cf658 DS |
1545 | |
1546 | ASSERT(path); | |
1d4c08e0 | 1547 | ASSERT(found_key); |
e33d5c3d KN |
1548 | |
1549 | key.type = key_type; | |
1550 | key.objectid = iobjectid; | |
1551 | key.offset = ioff; | |
1552 | ||
1553 | ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0); | |
1d4c08e0 | 1554 | if (ret < 0) |
e33d5c3d KN |
1555 | return ret; |
1556 | ||
1557 | eb = path->nodes[0]; | |
1558 | if (ret && path->slots[0] >= btrfs_header_nritems(eb)) { | |
1559 | ret = btrfs_next_leaf(fs_root, path); | |
1560 | if (ret) | |
1561 | return ret; | |
1562 | eb = path->nodes[0]; | |
1563 | } | |
1564 | ||
1565 | btrfs_item_key_to_cpu(eb, found_key, path->slots[0]); | |
1566 | if (found_key->type != key.type || | |
1567 | found_key->objectid != key.objectid) | |
1568 | return 1; | |
1569 | ||
1570 | return 0; | |
1571 | } | |
1572 | ||
1fc28d8e LB |
1573 | static struct extent_buffer *btrfs_search_slot_get_root(struct btrfs_root *root, |
1574 | struct btrfs_path *p, | |
1575 | int write_lock_level) | |
1576 | { | |
1fc28d8e | 1577 | struct extent_buffer *b; |
120de408 | 1578 | int root_lock = 0; |
1fc28d8e LB |
1579 | int level = 0; |
1580 | ||
1fc28d8e | 1581 | if (p->search_commit_root) { |
d96b3424 FM |
1582 | b = root->commit_root; |
1583 | atomic_inc(&b->refs); | |
be6821f8 | 1584 | level = btrfs_header_level(b); |
f9ddfd05 LB |
1585 | /* |
1586 | * Ensure that all callers have set skip_locking when | |
1587 | * p->search_commit_root = 1. | |
1588 | */ | |
1589 | ASSERT(p->skip_locking == 1); | |
1fc28d8e LB |
1590 | |
1591 | goto out; | |
1592 | } | |
1593 | ||
1594 | if (p->skip_locking) { | |
1595 | b = btrfs_root_node(root); | |
1596 | level = btrfs_header_level(b); | |
1597 | goto out; | |
1598 | } | |
1599 | ||
120de408 JB |
1600 | /* We try very hard to do read locks on the root */ |
1601 | root_lock = BTRFS_READ_LOCK; | |
1602 | ||
1fc28d8e | 1603 | /* |
662c653b LB |
1604 | * If the level is set to maximum, we can skip trying to get the read |
1605 | * lock. | |
1fc28d8e | 1606 | */ |
662c653b LB |
1607 | if (write_lock_level < BTRFS_MAX_LEVEL) { |
1608 | /* | |
1609 | * We don't know the level of the root node until we actually | |
1610 | * have it read locked | |
1611 | */ | |
1bb96598 | 1612 | b = btrfs_read_lock_root_node(root); |
662c653b LB |
1613 | level = btrfs_header_level(b); |
1614 | if (level > write_lock_level) | |
1615 | goto out; | |
1616 | ||
1617 | /* Whoops, must trade for write lock */ | |
1618 | btrfs_tree_read_unlock(b); | |
1619 | free_extent_buffer(b); | |
1620 | } | |
1fc28d8e | 1621 | |
1fc28d8e LB |
1622 | b = btrfs_lock_root_node(root); |
1623 | root_lock = BTRFS_WRITE_LOCK; | |
1624 | ||
1625 | /* The level might have changed, check again */ | |
1626 | level = btrfs_header_level(b); | |
1627 | ||
1628 | out: | |
120de408 JB |
1629 | /* |
1630 | * The root may have failed to write out at some point, and thus is no | |
1631 | * longer valid, return an error in this case. | |
1632 | */ | |
1633 | if (!extent_buffer_uptodate(b)) { | |
1634 | if (root_lock) | |
1635 | btrfs_tree_unlock_rw(b, root_lock); | |
1636 | free_extent_buffer(b); | |
1637 | return ERR_PTR(-EIO); | |
1638 | } | |
1639 | ||
1fc28d8e LB |
1640 | p->nodes[level] = b; |
1641 | if (!p->skip_locking) | |
1642 | p->locks[level] = root_lock; | |
1643 | /* | |
1644 | * Callers are responsible for dropping b's references. | |
1645 | */ | |
1646 | return b; | |
1647 | } | |
1648 | ||
d96b3424 FM |
1649 | /* |
1650 | * Replace the extent buffer at the lowest level of the path with a cloned | |
1651 | * version. The purpose is to be able to use it safely, after releasing the | |
1652 | * commit root semaphore, even if relocation is happening in parallel, the | |
1653 | * transaction used for relocation is committed and the extent buffer is | |
1654 | * reallocated in the next transaction. | |
1655 | * | |
1656 | * This is used in a context where the caller does not prevent transaction | |
1657 | * commits from happening, either by holding a transaction handle or holding | |
1658 | * some lock, while it's doing searches through a commit root. | |
1659 | * At the moment it's only used for send operations. | |
1660 | */ | |
1661 | static int finish_need_commit_sem_search(struct btrfs_path *path) | |
1662 | { | |
1663 | const int i = path->lowest_level; | |
1664 | const int slot = path->slots[i]; | |
1665 | struct extent_buffer *lowest = path->nodes[i]; | |
1666 | struct extent_buffer *clone; | |
1667 | ||
1668 | ASSERT(path->need_commit_sem); | |
1669 | ||
1670 | if (!lowest) | |
1671 | return 0; | |
1672 | ||
1673 | lockdep_assert_held_read(&lowest->fs_info->commit_root_sem); | |
1674 | ||
1675 | clone = btrfs_clone_extent_buffer(lowest); | |
1676 | if (!clone) | |
1677 | return -ENOMEM; | |
1678 | ||
1679 | btrfs_release_path(path); | |
1680 | path->nodes[i] = clone; | |
1681 | path->slots[i] = slot; | |
1682 | ||
1683 | return 0; | |
1684 | } | |
1fc28d8e | 1685 | |
e2e58d0f FM |
1686 | static inline int search_for_key_slot(struct extent_buffer *eb, |
1687 | int search_low_slot, | |
1688 | const struct btrfs_key *key, | |
1689 | int prev_cmp, | |
1690 | int *slot) | |
1691 | { | |
1692 | /* | |
1693 | * If a previous call to btrfs_bin_search() on a parent node returned an | |
1694 | * exact match (prev_cmp == 0), we can safely assume the target key will | |
1695 | * always be at slot 0 on lower levels, since each key pointer | |
1696 | * (struct btrfs_key_ptr) refers to the lowest key accessible from the | |
1697 | * subtree it points to. Thus we can skip searching lower levels. | |
1698 | */ | |
1699 | if (prev_cmp == 0) { | |
1700 | *slot = 0; | |
1701 | return 0; | |
1702 | } | |
1703 | ||
1704 | return generic_bin_search(eb, search_low_slot, key, slot); | |
1705 | } | |
1706 | ||
109324cf FM |
1707 | static int search_leaf(struct btrfs_trans_handle *trans, |
1708 | struct btrfs_root *root, | |
1709 | const struct btrfs_key *key, | |
1710 | struct btrfs_path *path, | |
1711 | int ins_len, | |
1712 | int prev_cmp) | |
1713 | { | |
1714 | struct extent_buffer *leaf = path->nodes[0]; | |
1715 | int leaf_free_space = -1; | |
1716 | int search_low_slot = 0; | |
1717 | int ret; | |
1718 | bool do_bin_search = true; | |
1719 | ||
1720 | /* | |
1721 | * If we are doing an insertion, the leaf has enough free space and the | |
1722 | * destination slot for the key is not slot 0, then we can unlock our | |
1723 | * write lock on the parent, and any other upper nodes, before doing the | |
1724 | * binary search on the leaf (with search_for_key_slot()), allowing other | |
1725 | * tasks to lock the parent and any other upper nodes. | |
1726 | */ | |
1727 | if (ins_len > 0) { | |
1728 | /* | |
1729 | * Cache the leaf free space, since we will need it later and it | |
1730 | * will not change until then. | |
1731 | */ | |
1732 | leaf_free_space = btrfs_leaf_free_space(leaf); | |
1733 | ||
1734 | /* | |
1735 | * !path->locks[1] means we have a single node tree, the leaf is | |
1736 | * the root of the tree. | |
1737 | */ | |
1738 | if (path->locks[1] && leaf_free_space >= ins_len) { | |
1739 | struct btrfs_disk_key first_key; | |
1740 | ||
1741 | ASSERT(btrfs_header_nritems(leaf) > 0); | |
1742 | btrfs_item_key(leaf, &first_key, 0); | |
1743 | ||
1744 | /* | |
1745 | * Doing the extra comparison with the first key is cheap, | |
1746 | * taking into account that the first key is very likely | |
1747 | * already in a cache line because it immediately follows | |
1748 | * the extent buffer's header and we have recently accessed | |
1749 | * the header's level field. | |
1750 | */ | |
1751 | ret = comp_keys(&first_key, key); | |
1752 | if (ret < 0) { | |
1753 | /* | |
1754 | * The first key is smaller than the key we want | |
1755 | * to insert, so we are safe to unlock all upper | |
1756 | * nodes and we have to do the binary search. | |
1757 | * | |
1758 | * We do use btrfs_unlock_up_safe() and not | |
1759 | * unlock_up() because the later does not unlock | |
1760 | * nodes with a slot of 0 - we can safely unlock | |
1761 | * any node even if its slot is 0 since in this | |
1762 | * case the key does not end up at slot 0 of the | |
1763 | * leaf and there's no need to split the leaf. | |
1764 | */ | |
1765 | btrfs_unlock_up_safe(path, 1); | |
1766 | search_low_slot = 1; | |
1767 | } else { | |
1768 | /* | |
1769 | * The first key is >= then the key we want to | |
1770 | * insert, so we can skip the binary search as | |
1771 | * the target key will be at slot 0. | |
1772 | * | |
1773 | * We can not unlock upper nodes when the key is | |
1774 | * less than the first key, because we will need | |
1775 | * to update the key at slot 0 of the parent node | |
1776 | * and possibly of other upper nodes too. | |
1777 | * If the key matches the first key, then we can | |
1778 | * unlock all the upper nodes, using | |
1779 | * btrfs_unlock_up_safe() instead of unlock_up() | |
1780 | * as stated above. | |
1781 | */ | |
1782 | if (ret == 0) | |
1783 | btrfs_unlock_up_safe(path, 1); | |
1784 | /* | |
1785 | * ret is already 0 or 1, matching the result of | |
1786 | * a btrfs_bin_search() call, so there is no need | |
1787 | * to adjust it. | |
1788 | */ | |
1789 | do_bin_search = false; | |
1790 | path->slots[0] = 0; | |
1791 | } | |
1792 | } | |
1793 | } | |
1794 | ||
1795 | if (do_bin_search) { | |
1796 | ret = search_for_key_slot(leaf, search_low_slot, key, | |
1797 | prev_cmp, &path->slots[0]); | |
1798 | if (ret < 0) | |
1799 | return ret; | |
1800 | } | |
1801 | ||
1802 | if (ins_len > 0) { | |
1803 | /* | |
1804 | * Item key already exists. In this case, if we are allowed to | |
1805 | * insert the item (for example, in dir_item case, item key | |
1806 | * collision is allowed), it will be merged with the original | |
1807 | * item. Only the item size grows, no new btrfs item will be | |
1808 | * added. If search_for_extension is not set, ins_len already | |
1809 | * accounts the size btrfs_item, deduct it here so leaf space | |
1810 | * check will be correct. | |
1811 | */ | |
1812 | if (ret == 0 && !path->search_for_extension) { | |
1813 | ASSERT(ins_len >= sizeof(struct btrfs_item)); | |
1814 | ins_len -= sizeof(struct btrfs_item); | |
1815 | } | |
1816 | ||
1817 | ASSERT(leaf_free_space >= 0); | |
1818 | ||
1819 | if (leaf_free_space < ins_len) { | |
1820 | int err; | |
1821 | ||
1822 | err = split_leaf(trans, root, key, path, ins_len, | |
1823 | (ret == 0)); | |
bb8e9a60 FM |
1824 | ASSERT(err <= 0); |
1825 | if (WARN_ON(err > 0)) | |
1826 | err = -EUCLEAN; | |
109324cf FM |
1827 | if (err) |
1828 | ret = err; | |
1829 | } | |
1830 | } | |
1831 | ||
1832 | return ret; | |
1833 | } | |
1834 | ||
74123bd7 | 1835 | /* |
4271ecea NB |
1836 | * btrfs_search_slot - look for a key in a tree and perform necessary |
1837 | * modifications to preserve tree invariants. | |
74123bd7 | 1838 | * |
4271ecea NB |
1839 | * @trans: Handle of transaction, used when modifying the tree |
1840 | * @p: Holds all btree nodes along the search path | |
1841 | * @root: The root node of the tree | |
1842 | * @key: The key we are looking for | |
9a664971 | 1843 | * @ins_len: Indicates purpose of search: |
1844 | * >0 for inserts it's size of item inserted (*) | |
1845 | * <0 for deletions | |
1846 | * 0 for plain searches, not modifying the tree | |
1847 | * | |
1848 | * (*) If size of item inserted doesn't include | |
1849 | * sizeof(struct btrfs_item), then p->search_for_extension must | |
1850 | * be set. | |
4271ecea NB |
1851 | * @cow: boolean should CoW operations be performed. Must always be 1 |
1852 | * when modifying the tree. | |
97571fd0 | 1853 | * |
4271ecea NB |
1854 | * If @ins_len > 0, nodes and leaves will be split as we walk down the tree. |
1855 | * If @ins_len < 0, nodes will be merged as we walk down the tree (if possible) | |
1856 | * | |
1857 | * If @key is found, 0 is returned and you can find the item in the leaf level | |
1858 | * of the path (level 0) | |
1859 | * | |
1860 | * If @key isn't found, 1 is returned and the leaf level of the path (level 0) | |
1861 | * points to the slot where it should be inserted | |
1862 | * | |
1863 | * If an error is encountered while searching the tree a negative error number | |
1864 | * is returned | |
74123bd7 | 1865 | */ |
310712b2 OS |
1866 | int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
1867 | const struct btrfs_key *key, struct btrfs_path *p, | |
1868 | int ins_len, int cow) | |
be0e5c09 | 1869 | { |
d96b3424 | 1870 | struct btrfs_fs_info *fs_info = root->fs_info; |
5f39d397 | 1871 | struct extent_buffer *b; |
be0e5c09 CM |
1872 | int slot; |
1873 | int ret; | |
33c66f43 | 1874 | int err; |
be0e5c09 | 1875 | int level; |
925baedd | 1876 | int lowest_unlock = 1; |
bd681513 CM |
1877 | /* everything at write_lock_level or lower must be write locked */ |
1878 | int write_lock_level = 0; | |
9f3a7427 | 1879 | u8 lowest_level = 0; |
f7c79f30 | 1880 | int min_write_lock_level; |
d7396f07 | 1881 | int prev_cmp; |
9f3a7427 | 1882 | |
6702ed49 | 1883 | lowest_level = p->lowest_level; |
323ac95b | 1884 | WARN_ON(lowest_level && ins_len > 0); |
22b0ebda | 1885 | WARN_ON(p->nodes[0] != NULL); |
eb653de1 | 1886 | BUG_ON(!cow && ins_len); |
25179201 | 1887 | |
bd681513 | 1888 | if (ins_len < 0) { |
925baedd | 1889 | lowest_unlock = 2; |
65b51a00 | 1890 | |
bd681513 CM |
1891 | /* when we are removing items, we might have to go up to level |
1892 | * two as we update tree pointers Make sure we keep write | |
1893 | * for those levels as well | |
1894 | */ | |
1895 | write_lock_level = 2; | |
1896 | } else if (ins_len > 0) { | |
1897 | /* | |
1898 | * for inserting items, make sure we have a write lock on | |
1899 | * level 1 so we can update keys | |
1900 | */ | |
1901 | write_lock_level = 1; | |
1902 | } | |
1903 | ||
1904 | if (!cow) | |
1905 | write_lock_level = -1; | |
1906 | ||
09a2a8f9 | 1907 | if (cow && (p->keep_locks || p->lowest_level)) |
bd681513 CM |
1908 | write_lock_level = BTRFS_MAX_LEVEL; |
1909 | ||
f7c79f30 CM |
1910 | min_write_lock_level = write_lock_level; |
1911 | ||
d96b3424 FM |
1912 | if (p->need_commit_sem) { |
1913 | ASSERT(p->search_commit_root); | |
1914 | down_read(&fs_info->commit_root_sem); | |
1915 | } | |
1916 | ||
bb803951 | 1917 | again: |
d7396f07 | 1918 | prev_cmp = -1; |
1fc28d8e | 1919 | b = btrfs_search_slot_get_root(root, p, write_lock_level); |
be6821f8 FM |
1920 | if (IS_ERR(b)) { |
1921 | ret = PTR_ERR(b); | |
1922 | goto done; | |
1923 | } | |
925baedd | 1924 | |
eb60ceac | 1925 | while (b) { |
f624d976 QW |
1926 | int dec = 0; |
1927 | ||
5f39d397 | 1928 | level = btrfs_header_level(b); |
65b51a00 | 1929 | |
02217ed2 | 1930 | if (cow) { |
9ea2c7c9 NB |
1931 | bool last_level = (level == (BTRFS_MAX_LEVEL - 1)); |
1932 | ||
c8c42864 CM |
1933 | /* |
1934 | * if we don't really need to cow this block | |
1935 | * then we don't want to set the path blocking, | |
1936 | * so we test it here | |
1937 | */ | |
5963ffca | 1938 | if (!should_cow_block(trans, root, b)) |
65b51a00 | 1939 | goto cow_done; |
5d4f98a2 | 1940 | |
bd681513 CM |
1941 | /* |
1942 | * must have write locks on this node and the | |
1943 | * parent | |
1944 | */ | |
5124e00e JB |
1945 | if (level > write_lock_level || |
1946 | (level + 1 > write_lock_level && | |
1947 | level + 1 < BTRFS_MAX_LEVEL && | |
1948 | p->nodes[level + 1])) { | |
bd681513 CM |
1949 | write_lock_level = level + 1; |
1950 | btrfs_release_path(p); | |
1951 | goto again; | |
1952 | } | |
1953 | ||
9ea2c7c9 NB |
1954 | if (last_level) |
1955 | err = btrfs_cow_block(trans, root, b, NULL, 0, | |
9631e4cc JB |
1956 | &b, |
1957 | BTRFS_NESTING_COW); | |
9ea2c7c9 NB |
1958 | else |
1959 | err = btrfs_cow_block(trans, root, b, | |
1960 | p->nodes[level + 1], | |
9631e4cc JB |
1961 | p->slots[level + 1], &b, |
1962 | BTRFS_NESTING_COW); | |
33c66f43 | 1963 | if (err) { |
33c66f43 | 1964 | ret = err; |
65b51a00 | 1965 | goto done; |
54aa1f4d | 1966 | } |
02217ed2 | 1967 | } |
65b51a00 | 1968 | cow_done: |
eb60ceac | 1969 | p->nodes[level] = b; |
b4ce94de CM |
1970 | |
1971 | /* | |
1972 | * we have a lock on b and as long as we aren't changing | |
1973 | * the tree, there is no way to for the items in b to change. | |
1974 | * It is safe to drop the lock on our parent before we | |
1975 | * go through the expensive btree search on b. | |
1976 | * | |
eb653de1 FDBM |
1977 | * If we're inserting or deleting (ins_len != 0), then we might |
1978 | * be changing slot zero, which may require changing the parent. | |
1979 | * So, we can't drop the lock until after we know which slot | |
1980 | * we're operating on. | |
b4ce94de | 1981 | */ |
eb653de1 FDBM |
1982 | if (!ins_len && !p->keep_locks) { |
1983 | int u = level + 1; | |
1984 | ||
1985 | if (u < BTRFS_MAX_LEVEL && p->locks[u]) { | |
1986 | btrfs_tree_unlock_rw(p->nodes[u], p->locks[u]); | |
1987 | p->locks[u] = 0; | |
1988 | } | |
1989 | } | |
b4ce94de | 1990 | |
e2e58d0f | 1991 | if (level == 0) { |
109324cf | 1992 | if (ins_len > 0) |
e5e1c174 | 1993 | ASSERT(write_lock_level >= 1); |
bd681513 | 1994 | |
109324cf | 1995 | ret = search_leaf(trans, root, key, p, ins_len, prev_cmp); |
459931ec | 1996 | if (!p->search_for_split) |
f7c79f30 | 1997 | unlock_up(p, level, lowest_unlock, |
4b6f8e96 | 1998 | min_write_lock_level, NULL); |
65b51a00 | 1999 | goto done; |
be0e5c09 | 2000 | } |
e2e58d0f FM |
2001 | |
2002 | ret = search_for_key_slot(b, 0, key, prev_cmp, &slot); | |
2003 | if (ret < 0) | |
2004 | goto done; | |
2005 | prev_cmp = ret; | |
2006 | ||
f624d976 QW |
2007 | if (ret && slot > 0) { |
2008 | dec = 1; | |
2009 | slot--; | |
2010 | } | |
2011 | p->slots[level] = slot; | |
2012 | err = setup_nodes_for_search(trans, root, p, b, level, ins_len, | |
2013 | &write_lock_level); | |
2014 | if (err == -EAGAIN) | |
2015 | goto again; | |
2016 | if (err) { | |
2017 | ret = err; | |
2018 | goto done; | |
2019 | } | |
2020 | b = p->nodes[level]; | |
2021 | slot = p->slots[level]; | |
2022 | ||
2023 | /* | |
2024 | * Slot 0 is special, if we change the key we have to update | |
2025 | * the parent pointer which means we must have a write lock on | |
2026 | * the parent | |
2027 | */ | |
2028 | if (slot == 0 && ins_len && write_lock_level < level + 1) { | |
2029 | write_lock_level = level + 1; | |
2030 | btrfs_release_path(p); | |
2031 | goto again; | |
2032 | } | |
2033 | ||
2034 | unlock_up(p, level, lowest_unlock, min_write_lock_level, | |
2035 | &write_lock_level); | |
2036 | ||
2037 | if (level == lowest_level) { | |
2038 | if (dec) | |
2039 | p->slots[level]++; | |
2040 | goto done; | |
2041 | } | |
2042 | ||
2043 | err = read_block_for_search(root, p, &b, level, slot, key); | |
2044 | if (err == -EAGAIN) | |
2045 | goto again; | |
2046 | if (err) { | |
2047 | ret = err; | |
2048 | goto done; | |
2049 | } | |
2050 | ||
2051 | if (!p->skip_locking) { | |
2052 | level = btrfs_header_level(b); | |
2053 | if (level <= write_lock_level) { | |
ac5887c8 | 2054 | btrfs_tree_lock(b); |
f624d976 QW |
2055 | p->locks[level] = BTRFS_WRITE_LOCK; |
2056 | } else { | |
fe596ca3 | 2057 | btrfs_tree_read_lock(b); |
f624d976 QW |
2058 | p->locks[level] = BTRFS_READ_LOCK; |
2059 | } | |
2060 | p->nodes[level] = b; | |
2061 | } | |
be0e5c09 | 2062 | } |
65b51a00 CM |
2063 | ret = 1; |
2064 | done: | |
5f5bc6b1 | 2065 | if (ret < 0 && !p->skip_release_on_error) |
b3b4aa74 | 2066 | btrfs_release_path(p); |
d96b3424 FM |
2067 | |
2068 | if (p->need_commit_sem) { | |
2069 | int ret2; | |
2070 | ||
2071 | ret2 = finish_need_commit_sem_search(p); | |
2072 | up_read(&fs_info->commit_root_sem); | |
2073 | if (ret2) | |
2074 | ret = ret2; | |
2075 | } | |
2076 | ||
65b51a00 | 2077 | return ret; |
be0e5c09 | 2078 | } |
f75e2b79 | 2079 | ALLOW_ERROR_INJECTION(btrfs_search_slot, ERRNO); |
be0e5c09 | 2080 | |
5d9e75c4 JS |
2081 | /* |
2082 | * Like btrfs_search_slot, this looks for a key in the given tree. It uses the | |
2083 | * current state of the tree together with the operations recorded in the tree | |
2084 | * modification log to search for the key in a previous version of this tree, as | |
2085 | * denoted by the time_seq parameter. | |
2086 | * | |
2087 | * Naturally, there is no support for insert, delete or cow operations. | |
2088 | * | |
2089 | * The resulting path and return value will be set up as if we called | |
2090 | * btrfs_search_slot at that point in time with ins_len and cow both set to 0. | |
2091 | */ | |
310712b2 | 2092 | int btrfs_search_old_slot(struct btrfs_root *root, const struct btrfs_key *key, |
5d9e75c4 JS |
2093 | struct btrfs_path *p, u64 time_seq) |
2094 | { | |
0b246afa | 2095 | struct btrfs_fs_info *fs_info = root->fs_info; |
5d9e75c4 JS |
2096 | struct extent_buffer *b; |
2097 | int slot; | |
2098 | int ret; | |
2099 | int err; | |
2100 | int level; | |
2101 | int lowest_unlock = 1; | |
2102 | u8 lowest_level = 0; | |
2103 | ||
2104 | lowest_level = p->lowest_level; | |
2105 | WARN_ON(p->nodes[0] != NULL); | |
2106 | ||
2107 | if (p->search_commit_root) { | |
2108 | BUG_ON(time_seq); | |
2109 | return btrfs_search_slot(NULL, root, key, p, 0, 0); | |
2110 | } | |
2111 | ||
2112 | again: | |
f3a84ccd | 2113 | b = btrfs_get_old_root(root, time_seq); |
315bed43 NB |
2114 | if (!b) { |
2115 | ret = -EIO; | |
2116 | goto done; | |
2117 | } | |
5d9e75c4 | 2118 | level = btrfs_header_level(b); |
5d9e75c4 JS |
2119 | p->locks[level] = BTRFS_READ_LOCK; |
2120 | ||
2121 | while (b) { | |
abe9339d QW |
2122 | int dec = 0; |
2123 | ||
5d9e75c4 JS |
2124 | level = btrfs_header_level(b); |
2125 | p->nodes[level] = b; | |
5d9e75c4 JS |
2126 | |
2127 | /* | |
2128 | * we have a lock on b and as long as we aren't changing | |
2129 | * the tree, there is no way to for the items in b to change. | |
2130 | * It is safe to drop the lock on our parent before we | |
2131 | * go through the expensive btree search on b. | |
2132 | */ | |
2133 | btrfs_unlock_up_safe(p, level + 1); | |
2134 | ||
995e9a16 | 2135 | ret = btrfs_bin_search(b, key, &slot); |
cbca7d59 FM |
2136 | if (ret < 0) |
2137 | goto done; | |
5d9e75c4 | 2138 | |
abe9339d | 2139 | if (level == 0) { |
5d9e75c4 JS |
2140 | p->slots[level] = slot; |
2141 | unlock_up(p, level, lowest_unlock, 0, NULL); | |
abe9339d QW |
2142 | goto done; |
2143 | } | |
5d9e75c4 | 2144 | |
abe9339d QW |
2145 | if (ret && slot > 0) { |
2146 | dec = 1; | |
2147 | slot--; | |
2148 | } | |
2149 | p->slots[level] = slot; | |
2150 | unlock_up(p, level, lowest_unlock, 0, NULL); | |
5d9e75c4 | 2151 | |
abe9339d QW |
2152 | if (level == lowest_level) { |
2153 | if (dec) | |
2154 | p->slots[level]++; | |
2155 | goto done; | |
2156 | } | |
5d9e75c4 | 2157 | |
abe9339d QW |
2158 | err = read_block_for_search(root, p, &b, level, slot, key); |
2159 | if (err == -EAGAIN) | |
2160 | goto again; | |
2161 | if (err) { | |
2162 | ret = err; | |
5d9e75c4 JS |
2163 | goto done; |
2164 | } | |
abe9339d QW |
2165 | |
2166 | level = btrfs_header_level(b); | |
ac5887c8 | 2167 | btrfs_tree_read_lock(b); |
f3a84ccd | 2168 | b = btrfs_tree_mod_log_rewind(fs_info, p, b, time_seq); |
abe9339d QW |
2169 | if (!b) { |
2170 | ret = -ENOMEM; | |
2171 | goto done; | |
2172 | } | |
2173 | p->locks[level] = BTRFS_READ_LOCK; | |
2174 | p->nodes[level] = b; | |
5d9e75c4 JS |
2175 | } |
2176 | ret = 1; | |
2177 | done: | |
5d9e75c4 JS |
2178 | if (ret < 0) |
2179 | btrfs_release_path(p); | |
2180 | ||
2181 | return ret; | |
2182 | } | |
2183 | ||
2f38b3e1 AJ |
2184 | /* |
2185 | * helper to use instead of search slot if no exact match is needed but | |
2186 | * instead the next or previous item should be returned. | |
2187 | * When find_higher is true, the next higher item is returned, the next lower | |
2188 | * otherwise. | |
2189 | * When return_any and find_higher are both true, and no higher item is found, | |
2190 | * return the next lower instead. | |
2191 | * When return_any is true and find_higher is false, and no lower item is found, | |
2192 | * return the next higher instead. | |
2193 | * It returns 0 if any item is found, 1 if none is found (tree empty), and | |
2194 | * < 0 on error | |
2195 | */ | |
2196 | int btrfs_search_slot_for_read(struct btrfs_root *root, | |
310712b2 OS |
2197 | const struct btrfs_key *key, |
2198 | struct btrfs_path *p, int find_higher, | |
2199 | int return_any) | |
2f38b3e1 AJ |
2200 | { |
2201 | int ret; | |
2202 | struct extent_buffer *leaf; | |
2203 | ||
2204 | again: | |
2205 | ret = btrfs_search_slot(NULL, root, key, p, 0, 0); | |
2206 | if (ret <= 0) | |
2207 | return ret; | |
2208 | /* | |
2209 | * a return value of 1 means the path is at the position where the | |
2210 | * item should be inserted. Normally this is the next bigger item, | |
2211 | * but in case the previous item is the last in a leaf, path points | |
2212 | * to the first free slot in the previous leaf, i.e. at an invalid | |
2213 | * item. | |
2214 | */ | |
2215 | leaf = p->nodes[0]; | |
2216 | ||
2217 | if (find_higher) { | |
2218 | if (p->slots[0] >= btrfs_header_nritems(leaf)) { | |
2219 | ret = btrfs_next_leaf(root, p); | |
2220 | if (ret <= 0) | |
2221 | return ret; | |
2222 | if (!return_any) | |
2223 | return 1; | |
2224 | /* | |
2225 | * no higher item found, return the next | |
2226 | * lower instead | |
2227 | */ | |
2228 | return_any = 0; | |
2229 | find_higher = 0; | |
2230 | btrfs_release_path(p); | |
2231 | goto again; | |
2232 | } | |
2233 | } else { | |
e6793769 AJ |
2234 | if (p->slots[0] == 0) { |
2235 | ret = btrfs_prev_leaf(root, p); | |
2236 | if (ret < 0) | |
2237 | return ret; | |
2238 | if (!ret) { | |
23c6bf6a FDBM |
2239 | leaf = p->nodes[0]; |
2240 | if (p->slots[0] == btrfs_header_nritems(leaf)) | |
2241 | p->slots[0]--; | |
e6793769 | 2242 | return 0; |
2f38b3e1 | 2243 | } |
e6793769 AJ |
2244 | if (!return_any) |
2245 | return 1; | |
2246 | /* | |
2247 | * no lower item found, return the next | |
2248 | * higher instead | |
2249 | */ | |
2250 | return_any = 0; | |
2251 | find_higher = 1; | |
2252 | btrfs_release_path(p); | |
2253 | goto again; | |
2254 | } else { | |
2f38b3e1 AJ |
2255 | --p->slots[0]; |
2256 | } | |
2257 | } | |
2258 | return 0; | |
2259 | } | |
2260 | ||
0ff40a91 MPS |
2261 | /* |
2262 | * Execute search and call btrfs_previous_item to traverse backwards if the item | |
2263 | * was not found. | |
2264 | * | |
2265 | * Return 0 if found, 1 if not found and < 0 if error. | |
2266 | */ | |
2267 | int btrfs_search_backwards(struct btrfs_root *root, struct btrfs_key *key, | |
2268 | struct btrfs_path *path) | |
2269 | { | |
2270 | int ret; | |
2271 | ||
2272 | ret = btrfs_search_slot(NULL, root, key, path, 0, 0); | |
2273 | if (ret > 0) | |
2274 | ret = btrfs_previous_item(root, path, key->objectid, key->type); | |
2275 | ||
2276 | if (ret == 0) | |
2277 | btrfs_item_key_to_cpu(path->nodes[0], key, path->slots[0]); | |
2278 | ||
2279 | return ret; | |
2280 | } | |
2281 | ||
74123bd7 CM |
2282 | /* |
2283 | * adjust the pointers going up the tree, starting at level | |
2284 | * making sure the right key of each node is points to 'key'. | |
2285 | * This is used after shifting pointers to the left, so it stops | |
2286 | * fixing up pointers when a given leaf/node is not in slot 0 of the | |
2287 | * higher levels | |
aa5d6bed | 2288 | * |
74123bd7 | 2289 | */ |
b167fa91 | 2290 | static void fixup_low_keys(struct btrfs_path *path, |
143bede5 | 2291 | struct btrfs_disk_key *key, int level) |
be0e5c09 CM |
2292 | { |
2293 | int i; | |
5f39d397 | 2294 | struct extent_buffer *t; |
0e82bcfe | 2295 | int ret; |
5f39d397 | 2296 | |
234b63a0 | 2297 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { |
be0e5c09 | 2298 | int tslot = path->slots[i]; |
0e82bcfe | 2299 | |
eb60ceac | 2300 | if (!path->nodes[i]) |
be0e5c09 | 2301 | break; |
5f39d397 | 2302 | t = path->nodes[i]; |
f3a84ccd FM |
2303 | ret = btrfs_tree_mod_log_insert_key(t, tslot, |
2304 | BTRFS_MOD_LOG_KEY_REPLACE, GFP_ATOMIC); | |
0e82bcfe | 2305 | BUG_ON(ret < 0); |
5f39d397 | 2306 | btrfs_set_node_key(t, key, tslot); |
d6025579 | 2307 | btrfs_mark_buffer_dirty(path->nodes[i]); |
be0e5c09 CM |
2308 | if (tslot != 0) |
2309 | break; | |
2310 | } | |
2311 | } | |
2312 | ||
31840ae1 ZY |
2313 | /* |
2314 | * update item key. | |
2315 | * | |
2316 | * This function isn't completely safe. It's the caller's responsibility | |
2317 | * that the new key won't break the order | |
2318 | */ | |
b7a0365e DD |
2319 | void btrfs_set_item_key_safe(struct btrfs_fs_info *fs_info, |
2320 | struct btrfs_path *path, | |
310712b2 | 2321 | const struct btrfs_key *new_key) |
31840ae1 ZY |
2322 | { |
2323 | struct btrfs_disk_key disk_key; | |
2324 | struct extent_buffer *eb; | |
2325 | int slot; | |
2326 | ||
2327 | eb = path->nodes[0]; | |
2328 | slot = path->slots[0]; | |
2329 | if (slot > 0) { | |
2330 | btrfs_item_key(eb, &disk_key, slot - 1); | |
7c15d410 QW |
2331 | if (unlikely(comp_keys(&disk_key, new_key) >= 0)) { |
2332 | btrfs_crit(fs_info, | |
2333 | "slot %u key (%llu %u %llu) new key (%llu %u %llu)", | |
2334 | slot, btrfs_disk_key_objectid(&disk_key), | |
2335 | btrfs_disk_key_type(&disk_key), | |
2336 | btrfs_disk_key_offset(&disk_key), | |
2337 | new_key->objectid, new_key->type, | |
2338 | new_key->offset); | |
2339 | btrfs_print_leaf(eb); | |
2340 | BUG(); | |
2341 | } | |
31840ae1 ZY |
2342 | } |
2343 | if (slot < btrfs_header_nritems(eb) - 1) { | |
2344 | btrfs_item_key(eb, &disk_key, slot + 1); | |
7c15d410 QW |
2345 | if (unlikely(comp_keys(&disk_key, new_key) <= 0)) { |
2346 | btrfs_crit(fs_info, | |
2347 | "slot %u key (%llu %u %llu) new key (%llu %u %llu)", | |
2348 | slot, btrfs_disk_key_objectid(&disk_key), | |
2349 | btrfs_disk_key_type(&disk_key), | |
2350 | btrfs_disk_key_offset(&disk_key), | |
2351 | new_key->objectid, new_key->type, | |
2352 | new_key->offset); | |
2353 | btrfs_print_leaf(eb); | |
2354 | BUG(); | |
2355 | } | |
31840ae1 ZY |
2356 | } |
2357 | ||
2358 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
2359 | btrfs_set_item_key(eb, &disk_key, slot); | |
2360 | btrfs_mark_buffer_dirty(eb); | |
2361 | if (slot == 0) | |
b167fa91 | 2362 | fixup_low_keys(path, &disk_key, 1); |
31840ae1 ZY |
2363 | } |
2364 | ||
d16c702f QW |
2365 | /* |
2366 | * Check key order of two sibling extent buffers. | |
2367 | * | |
2368 | * Return true if something is wrong. | |
2369 | * Return false if everything is fine. | |
2370 | * | |
2371 | * Tree-checker only works inside one tree block, thus the following | |
2372 | * corruption can not be detected by tree-checker: | |
2373 | * | |
2374 | * Leaf @left | Leaf @right | |
2375 | * -------------------------------------------------------------- | |
2376 | * | 1 | 2 | 3 | 4 | 5 | f6 | | 7 | 8 | | |
2377 | * | |
2378 | * Key f6 in leaf @left itself is valid, but not valid when the next | |
2379 | * key in leaf @right is 7. | |
2380 | * This can only be checked at tree block merge time. | |
2381 | * And since tree checker has ensured all key order in each tree block | |
2382 | * is correct, we only need to bother the last key of @left and the first | |
2383 | * key of @right. | |
2384 | */ | |
2385 | static bool check_sibling_keys(struct extent_buffer *left, | |
2386 | struct extent_buffer *right) | |
2387 | { | |
2388 | struct btrfs_key left_last; | |
2389 | struct btrfs_key right_first; | |
2390 | int level = btrfs_header_level(left); | |
2391 | int nr_left = btrfs_header_nritems(left); | |
2392 | int nr_right = btrfs_header_nritems(right); | |
2393 | ||
2394 | /* No key to check in one of the tree blocks */ | |
2395 | if (!nr_left || !nr_right) | |
2396 | return false; | |
2397 | ||
2398 | if (level) { | |
2399 | btrfs_node_key_to_cpu(left, &left_last, nr_left - 1); | |
2400 | btrfs_node_key_to_cpu(right, &right_first, 0); | |
2401 | } else { | |
2402 | btrfs_item_key_to_cpu(left, &left_last, nr_left - 1); | |
2403 | btrfs_item_key_to_cpu(right, &right_first, 0); | |
2404 | } | |
2405 | ||
2406 | if (btrfs_comp_cpu_keys(&left_last, &right_first) >= 0) { | |
2407 | btrfs_crit(left->fs_info, | |
2408 | "bad key order, sibling blocks, left last (%llu %u %llu) right first (%llu %u %llu)", | |
2409 | left_last.objectid, left_last.type, | |
2410 | left_last.offset, right_first.objectid, | |
2411 | right_first.type, right_first.offset); | |
2412 | return true; | |
2413 | } | |
2414 | return false; | |
2415 | } | |
2416 | ||
74123bd7 CM |
2417 | /* |
2418 | * try to push data from one node into the next node left in the | |
79f95c82 | 2419 | * tree. |
aa5d6bed CM |
2420 | * |
2421 | * returns 0 if some ptrs were pushed left, < 0 if there was some horrible | |
2422 | * error, and > 0 if there was no room in the left hand block. | |
74123bd7 | 2423 | */ |
98ed5174 | 2424 | static int push_node_left(struct btrfs_trans_handle *trans, |
2ff7e61e | 2425 | struct extent_buffer *dst, |
971a1f66 | 2426 | struct extent_buffer *src, int empty) |
be0e5c09 | 2427 | { |
d30a668f | 2428 | struct btrfs_fs_info *fs_info = trans->fs_info; |
be0e5c09 | 2429 | int push_items = 0; |
bb803951 CM |
2430 | int src_nritems; |
2431 | int dst_nritems; | |
aa5d6bed | 2432 | int ret = 0; |
be0e5c09 | 2433 | |
5f39d397 CM |
2434 | src_nritems = btrfs_header_nritems(src); |
2435 | dst_nritems = btrfs_header_nritems(dst); | |
0b246afa | 2436 | push_items = BTRFS_NODEPTRS_PER_BLOCK(fs_info) - dst_nritems; |
7bb86316 CM |
2437 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
2438 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
54aa1f4d | 2439 | |
bce4eae9 | 2440 | if (!empty && src_nritems <= 8) |
971a1f66 CM |
2441 | return 1; |
2442 | ||
d397712b | 2443 | if (push_items <= 0) |
be0e5c09 CM |
2444 | return 1; |
2445 | ||
bce4eae9 | 2446 | if (empty) { |
971a1f66 | 2447 | push_items = min(src_nritems, push_items); |
bce4eae9 CM |
2448 | if (push_items < src_nritems) { |
2449 | /* leave at least 8 pointers in the node if | |
2450 | * we aren't going to empty it | |
2451 | */ | |
2452 | if (src_nritems - push_items < 8) { | |
2453 | if (push_items <= 8) | |
2454 | return 1; | |
2455 | push_items -= 8; | |
2456 | } | |
2457 | } | |
2458 | } else | |
2459 | push_items = min(src_nritems - 8, push_items); | |
79f95c82 | 2460 | |
d16c702f QW |
2461 | /* dst is the left eb, src is the middle eb */ |
2462 | if (check_sibling_keys(dst, src)) { | |
2463 | ret = -EUCLEAN; | |
2464 | btrfs_abort_transaction(trans, ret); | |
2465 | return ret; | |
2466 | } | |
f3a84ccd | 2467 | ret = btrfs_tree_mod_log_eb_copy(dst, src, dst_nritems, 0, push_items); |
5de865ee | 2468 | if (ret) { |
66642832 | 2469 | btrfs_abort_transaction(trans, ret); |
5de865ee FDBM |
2470 | return ret; |
2471 | } | |
5f39d397 CM |
2472 | copy_extent_buffer(dst, src, |
2473 | btrfs_node_key_ptr_offset(dst_nritems), | |
2474 | btrfs_node_key_ptr_offset(0), | |
d397712b | 2475 | push_items * sizeof(struct btrfs_key_ptr)); |
5f39d397 | 2476 | |
bb803951 | 2477 | if (push_items < src_nritems) { |
57911b8b | 2478 | /* |
f3a84ccd FM |
2479 | * Don't call btrfs_tree_mod_log_insert_move() here, key removal |
2480 | * was already fully logged by btrfs_tree_mod_log_eb_copy() above. | |
57911b8b | 2481 | */ |
5f39d397 CM |
2482 | memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0), |
2483 | btrfs_node_key_ptr_offset(push_items), | |
2484 | (src_nritems - push_items) * | |
2485 | sizeof(struct btrfs_key_ptr)); | |
2486 | } | |
2487 | btrfs_set_header_nritems(src, src_nritems - push_items); | |
2488 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
2489 | btrfs_mark_buffer_dirty(src); | |
2490 | btrfs_mark_buffer_dirty(dst); | |
31840ae1 | 2491 | |
79f95c82 CM |
2492 | return ret; |
2493 | } | |
2494 | ||
2495 | /* | |
2496 | * try to push data from one node into the next node right in the | |
2497 | * tree. | |
2498 | * | |
2499 | * returns 0 if some ptrs were pushed, < 0 if there was some horrible | |
2500 | * error, and > 0 if there was no room in the right hand block. | |
2501 | * | |
2502 | * this will only push up to 1/2 the contents of the left node over | |
2503 | */ | |
5f39d397 | 2504 | static int balance_node_right(struct btrfs_trans_handle *trans, |
5f39d397 CM |
2505 | struct extent_buffer *dst, |
2506 | struct extent_buffer *src) | |
79f95c82 | 2507 | { |
55d32ed8 | 2508 | struct btrfs_fs_info *fs_info = trans->fs_info; |
79f95c82 CM |
2509 | int push_items = 0; |
2510 | int max_push; | |
2511 | int src_nritems; | |
2512 | int dst_nritems; | |
2513 | int ret = 0; | |
79f95c82 | 2514 | |
7bb86316 CM |
2515 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
2516 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
2517 | ||
5f39d397 CM |
2518 | src_nritems = btrfs_header_nritems(src); |
2519 | dst_nritems = btrfs_header_nritems(dst); | |
0b246afa | 2520 | push_items = BTRFS_NODEPTRS_PER_BLOCK(fs_info) - dst_nritems; |
d397712b | 2521 | if (push_items <= 0) |
79f95c82 | 2522 | return 1; |
bce4eae9 | 2523 | |
d397712b | 2524 | if (src_nritems < 4) |
bce4eae9 | 2525 | return 1; |
79f95c82 CM |
2526 | |
2527 | max_push = src_nritems / 2 + 1; | |
2528 | /* don't try to empty the node */ | |
d397712b | 2529 | if (max_push >= src_nritems) |
79f95c82 | 2530 | return 1; |
252c38f0 | 2531 | |
79f95c82 CM |
2532 | if (max_push < push_items) |
2533 | push_items = max_push; | |
2534 | ||
d16c702f QW |
2535 | /* dst is the right eb, src is the middle eb */ |
2536 | if (check_sibling_keys(src, dst)) { | |
2537 | ret = -EUCLEAN; | |
2538 | btrfs_abort_transaction(trans, ret); | |
2539 | return ret; | |
2540 | } | |
f3a84ccd | 2541 | ret = btrfs_tree_mod_log_insert_move(dst, push_items, 0, dst_nritems); |
bf1d3425 | 2542 | BUG_ON(ret < 0); |
5f39d397 CM |
2543 | memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items), |
2544 | btrfs_node_key_ptr_offset(0), | |
2545 | (dst_nritems) * | |
2546 | sizeof(struct btrfs_key_ptr)); | |
d6025579 | 2547 | |
f3a84ccd FM |
2548 | ret = btrfs_tree_mod_log_eb_copy(dst, src, 0, src_nritems - push_items, |
2549 | push_items); | |
5de865ee | 2550 | if (ret) { |
66642832 | 2551 | btrfs_abort_transaction(trans, ret); |
5de865ee FDBM |
2552 | return ret; |
2553 | } | |
5f39d397 CM |
2554 | copy_extent_buffer(dst, src, |
2555 | btrfs_node_key_ptr_offset(0), | |
2556 | btrfs_node_key_ptr_offset(src_nritems - push_items), | |
d397712b | 2557 | push_items * sizeof(struct btrfs_key_ptr)); |
79f95c82 | 2558 | |
5f39d397 CM |
2559 | btrfs_set_header_nritems(src, src_nritems - push_items); |
2560 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
79f95c82 | 2561 | |
5f39d397 CM |
2562 | btrfs_mark_buffer_dirty(src); |
2563 | btrfs_mark_buffer_dirty(dst); | |
31840ae1 | 2564 | |
aa5d6bed | 2565 | return ret; |
be0e5c09 CM |
2566 | } |
2567 | ||
97571fd0 CM |
2568 | /* |
2569 | * helper function to insert a new root level in the tree. | |
2570 | * A new node is allocated, and a single item is inserted to | |
2571 | * point to the existing root | |
aa5d6bed CM |
2572 | * |
2573 | * returns zero on success or < 0 on failure. | |
97571fd0 | 2574 | */ |
d397712b | 2575 | static noinline int insert_new_root(struct btrfs_trans_handle *trans, |
5f39d397 | 2576 | struct btrfs_root *root, |
fdd99c72 | 2577 | struct btrfs_path *path, int level) |
5c680ed6 | 2578 | { |
0b246afa | 2579 | struct btrfs_fs_info *fs_info = root->fs_info; |
7bb86316 | 2580 | u64 lower_gen; |
5f39d397 CM |
2581 | struct extent_buffer *lower; |
2582 | struct extent_buffer *c; | |
925baedd | 2583 | struct extent_buffer *old; |
5f39d397 | 2584 | struct btrfs_disk_key lower_key; |
d9d19a01 | 2585 | int ret; |
5c680ed6 CM |
2586 | |
2587 | BUG_ON(path->nodes[level]); | |
2588 | BUG_ON(path->nodes[level-1] != root->node); | |
2589 | ||
7bb86316 CM |
2590 | lower = path->nodes[level-1]; |
2591 | if (level == 1) | |
2592 | btrfs_item_key(lower, &lower_key, 0); | |
2593 | else | |
2594 | btrfs_node_key(lower, &lower_key, 0); | |
2595 | ||
79bd3712 FM |
2596 | c = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid, |
2597 | &lower_key, level, root->node->start, 0, | |
2598 | BTRFS_NESTING_NEW_ROOT); | |
5f39d397 CM |
2599 | if (IS_ERR(c)) |
2600 | return PTR_ERR(c); | |
925baedd | 2601 | |
0b246afa | 2602 | root_add_used(root, fs_info->nodesize); |
f0486c68 | 2603 | |
5f39d397 | 2604 | btrfs_set_header_nritems(c, 1); |
5f39d397 | 2605 | btrfs_set_node_key(c, &lower_key, 0); |
db94535d | 2606 | btrfs_set_node_blockptr(c, 0, lower->start); |
7bb86316 | 2607 | lower_gen = btrfs_header_generation(lower); |
31840ae1 | 2608 | WARN_ON(lower_gen != trans->transid); |
7bb86316 CM |
2609 | |
2610 | btrfs_set_node_ptr_generation(c, 0, lower_gen); | |
d5719762 | 2611 | |
5f39d397 | 2612 | btrfs_mark_buffer_dirty(c); |
d5719762 | 2613 | |
925baedd | 2614 | old = root->node; |
406808ab | 2615 | ret = btrfs_tree_mod_log_insert_root(root->node, c, false); |
d9d19a01 | 2616 | BUG_ON(ret < 0); |
240f62c8 | 2617 | rcu_assign_pointer(root->node, c); |
925baedd CM |
2618 | |
2619 | /* the super has an extra ref to root->node */ | |
2620 | free_extent_buffer(old); | |
2621 | ||
0b86a832 | 2622 | add_root_to_dirty_list(root); |
67439dad | 2623 | atomic_inc(&c->refs); |
5f39d397 | 2624 | path->nodes[level] = c; |
ac5887c8 | 2625 | path->locks[level] = BTRFS_WRITE_LOCK; |
5c680ed6 CM |
2626 | path->slots[level] = 0; |
2627 | return 0; | |
2628 | } | |
2629 | ||
74123bd7 CM |
2630 | /* |
2631 | * worker function to insert a single pointer in a node. | |
2632 | * the node should have enough room for the pointer already | |
97571fd0 | 2633 | * |
74123bd7 CM |
2634 | * slot and level indicate where you want the key to go, and |
2635 | * blocknr is the block the key points to. | |
2636 | */ | |
143bede5 | 2637 | static void insert_ptr(struct btrfs_trans_handle *trans, |
6ad3cf6d | 2638 | struct btrfs_path *path, |
143bede5 | 2639 | struct btrfs_disk_key *key, u64 bytenr, |
c3e06965 | 2640 | int slot, int level) |
74123bd7 | 2641 | { |
5f39d397 | 2642 | struct extent_buffer *lower; |
74123bd7 | 2643 | int nritems; |
f3ea38da | 2644 | int ret; |
5c680ed6 CM |
2645 | |
2646 | BUG_ON(!path->nodes[level]); | |
49d0c642 | 2647 | btrfs_assert_tree_write_locked(path->nodes[level]); |
5f39d397 CM |
2648 | lower = path->nodes[level]; |
2649 | nritems = btrfs_header_nritems(lower); | |
c293498b | 2650 | BUG_ON(slot > nritems); |
6ad3cf6d | 2651 | BUG_ON(nritems == BTRFS_NODEPTRS_PER_BLOCK(trans->fs_info)); |
74123bd7 | 2652 | if (slot != nritems) { |
bf1d3425 | 2653 | if (level) { |
f3a84ccd FM |
2654 | ret = btrfs_tree_mod_log_insert_move(lower, slot + 1, |
2655 | slot, nritems - slot); | |
bf1d3425 DS |
2656 | BUG_ON(ret < 0); |
2657 | } | |
5f39d397 CM |
2658 | memmove_extent_buffer(lower, |
2659 | btrfs_node_key_ptr_offset(slot + 1), | |
2660 | btrfs_node_key_ptr_offset(slot), | |
d6025579 | 2661 | (nritems - slot) * sizeof(struct btrfs_key_ptr)); |
74123bd7 | 2662 | } |
c3e06965 | 2663 | if (level) { |
f3a84ccd FM |
2664 | ret = btrfs_tree_mod_log_insert_key(lower, slot, |
2665 | BTRFS_MOD_LOG_KEY_ADD, GFP_NOFS); | |
f3ea38da JS |
2666 | BUG_ON(ret < 0); |
2667 | } | |
5f39d397 | 2668 | btrfs_set_node_key(lower, key, slot); |
db94535d | 2669 | btrfs_set_node_blockptr(lower, slot, bytenr); |
74493f7a CM |
2670 | WARN_ON(trans->transid == 0); |
2671 | btrfs_set_node_ptr_generation(lower, slot, trans->transid); | |
5f39d397 CM |
2672 | btrfs_set_header_nritems(lower, nritems + 1); |
2673 | btrfs_mark_buffer_dirty(lower); | |
74123bd7 CM |
2674 | } |
2675 | ||
97571fd0 CM |
2676 | /* |
2677 | * split the node at the specified level in path in two. | |
2678 | * The path is corrected to point to the appropriate node after the split | |
2679 | * | |
2680 | * Before splitting this tries to make some room in the node by pushing | |
2681 | * left and right, if either one works, it returns right away. | |
aa5d6bed CM |
2682 | * |
2683 | * returns 0 on success and < 0 on failure | |
97571fd0 | 2684 | */ |
e02119d5 CM |
2685 | static noinline int split_node(struct btrfs_trans_handle *trans, |
2686 | struct btrfs_root *root, | |
2687 | struct btrfs_path *path, int level) | |
be0e5c09 | 2688 | { |
0b246afa | 2689 | struct btrfs_fs_info *fs_info = root->fs_info; |
5f39d397 CM |
2690 | struct extent_buffer *c; |
2691 | struct extent_buffer *split; | |
2692 | struct btrfs_disk_key disk_key; | |
be0e5c09 | 2693 | int mid; |
5c680ed6 | 2694 | int ret; |
7518a238 | 2695 | u32 c_nritems; |
eb60ceac | 2696 | |
5f39d397 | 2697 | c = path->nodes[level]; |
7bb86316 | 2698 | WARN_ON(btrfs_header_generation(c) != trans->transid); |
5f39d397 | 2699 | if (c == root->node) { |
d9abbf1c | 2700 | /* |
90f8d62e JS |
2701 | * trying to split the root, lets make a new one |
2702 | * | |
fdd99c72 | 2703 | * tree mod log: We don't log_removal old root in |
90f8d62e JS |
2704 | * insert_new_root, because that root buffer will be kept as a |
2705 | * normal node. We are going to log removal of half of the | |
f3a84ccd FM |
2706 | * elements below with btrfs_tree_mod_log_eb_copy(). We're |
2707 | * holding a tree lock on the buffer, which is why we cannot | |
2708 | * race with other tree_mod_log users. | |
d9abbf1c | 2709 | */ |
fdd99c72 | 2710 | ret = insert_new_root(trans, root, path, level + 1); |
5c680ed6 CM |
2711 | if (ret) |
2712 | return ret; | |
b3612421 | 2713 | } else { |
e66f709b | 2714 | ret = push_nodes_for_insert(trans, root, path, level); |
5f39d397 CM |
2715 | c = path->nodes[level]; |
2716 | if (!ret && btrfs_header_nritems(c) < | |
0b246afa | 2717 | BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 3) |
e66f709b | 2718 | return 0; |
54aa1f4d CM |
2719 | if (ret < 0) |
2720 | return ret; | |
be0e5c09 | 2721 | } |
e66f709b | 2722 | |
5f39d397 | 2723 | c_nritems = btrfs_header_nritems(c); |
5d4f98a2 YZ |
2724 | mid = (c_nritems + 1) / 2; |
2725 | btrfs_node_key(c, &disk_key, mid); | |
7bb86316 | 2726 | |
79bd3712 FM |
2727 | split = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid, |
2728 | &disk_key, level, c->start, 0, | |
2729 | BTRFS_NESTING_SPLIT); | |
5f39d397 CM |
2730 | if (IS_ERR(split)) |
2731 | return PTR_ERR(split); | |
2732 | ||
0b246afa | 2733 | root_add_used(root, fs_info->nodesize); |
bc877d28 | 2734 | ASSERT(btrfs_header_level(c) == level); |
54aa1f4d | 2735 | |
f3a84ccd | 2736 | ret = btrfs_tree_mod_log_eb_copy(split, c, 0, mid, c_nritems - mid); |
5de865ee | 2737 | if (ret) { |
66642832 | 2738 | btrfs_abort_transaction(trans, ret); |
5de865ee FDBM |
2739 | return ret; |
2740 | } | |
5f39d397 CM |
2741 | copy_extent_buffer(split, c, |
2742 | btrfs_node_key_ptr_offset(0), | |
2743 | btrfs_node_key_ptr_offset(mid), | |
2744 | (c_nritems - mid) * sizeof(struct btrfs_key_ptr)); | |
2745 | btrfs_set_header_nritems(split, c_nritems - mid); | |
2746 | btrfs_set_header_nritems(c, mid); | |
aa5d6bed | 2747 | |
5f39d397 CM |
2748 | btrfs_mark_buffer_dirty(c); |
2749 | btrfs_mark_buffer_dirty(split); | |
2750 | ||
6ad3cf6d | 2751 | insert_ptr(trans, path, &disk_key, split->start, |
c3e06965 | 2752 | path->slots[level + 1] + 1, level + 1); |
aa5d6bed | 2753 | |
5de08d7d | 2754 | if (path->slots[level] >= mid) { |
5c680ed6 | 2755 | path->slots[level] -= mid; |
925baedd | 2756 | btrfs_tree_unlock(c); |
5f39d397 CM |
2757 | free_extent_buffer(c); |
2758 | path->nodes[level] = split; | |
5c680ed6 CM |
2759 | path->slots[level + 1] += 1; |
2760 | } else { | |
925baedd | 2761 | btrfs_tree_unlock(split); |
5f39d397 | 2762 | free_extent_buffer(split); |
be0e5c09 | 2763 | } |
d5286a92 | 2764 | return 0; |
be0e5c09 CM |
2765 | } |
2766 | ||
74123bd7 CM |
2767 | /* |
2768 | * how many bytes are required to store the items in a leaf. start | |
2769 | * and nr indicate which items in the leaf to check. This totals up the | |
2770 | * space used both by the item structs and the item data | |
2771 | */ | |
5f39d397 | 2772 | static int leaf_space_used(struct extent_buffer *l, int start, int nr) |
be0e5c09 CM |
2773 | { |
2774 | int data_len; | |
5f39d397 | 2775 | int nritems = btrfs_header_nritems(l); |
d4dbff95 | 2776 | int end = min(nritems, start + nr) - 1; |
be0e5c09 CM |
2777 | |
2778 | if (!nr) | |
2779 | return 0; | |
3212fa14 JB |
2780 | data_len = btrfs_item_offset(l, start) + btrfs_item_size(l, start); |
2781 | data_len = data_len - btrfs_item_offset(l, end); | |
0783fcfc | 2782 | data_len += sizeof(struct btrfs_item) * nr; |
d4dbff95 | 2783 | WARN_ON(data_len < 0); |
be0e5c09 CM |
2784 | return data_len; |
2785 | } | |
2786 | ||
d4dbff95 CM |
2787 | /* |
2788 | * The space between the end of the leaf items and | |
2789 | * the start of the leaf data. IOW, how much room | |
2790 | * the leaf has left for both items and data | |
2791 | */ | |
e902baac | 2792 | noinline int btrfs_leaf_free_space(struct extent_buffer *leaf) |
d4dbff95 | 2793 | { |
e902baac | 2794 | struct btrfs_fs_info *fs_info = leaf->fs_info; |
5f39d397 CM |
2795 | int nritems = btrfs_header_nritems(leaf); |
2796 | int ret; | |
0b246afa JM |
2797 | |
2798 | ret = BTRFS_LEAF_DATA_SIZE(fs_info) - leaf_space_used(leaf, 0, nritems); | |
5f39d397 | 2799 | if (ret < 0) { |
0b246afa JM |
2800 | btrfs_crit(fs_info, |
2801 | "leaf free space ret %d, leaf data size %lu, used %d nritems %d", | |
2802 | ret, | |
2803 | (unsigned long) BTRFS_LEAF_DATA_SIZE(fs_info), | |
2804 | leaf_space_used(leaf, 0, nritems), nritems); | |
5f39d397 CM |
2805 | } |
2806 | return ret; | |
d4dbff95 CM |
2807 | } |
2808 | ||
99d8f83c CM |
2809 | /* |
2810 | * min slot controls the lowest index we're willing to push to the | |
2811 | * right. We'll push up to and including min_slot, but no lower | |
2812 | */ | |
f72f0010 | 2813 | static noinline int __push_leaf_right(struct btrfs_path *path, |
44871b1b CM |
2814 | int data_size, int empty, |
2815 | struct extent_buffer *right, | |
99d8f83c CM |
2816 | int free_space, u32 left_nritems, |
2817 | u32 min_slot) | |
00ec4c51 | 2818 | { |
f72f0010 | 2819 | struct btrfs_fs_info *fs_info = right->fs_info; |
5f39d397 | 2820 | struct extent_buffer *left = path->nodes[0]; |
44871b1b | 2821 | struct extent_buffer *upper = path->nodes[1]; |
cfed81a0 | 2822 | struct btrfs_map_token token; |
5f39d397 | 2823 | struct btrfs_disk_key disk_key; |
00ec4c51 | 2824 | int slot; |
34a38218 | 2825 | u32 i; |
00ec4c51 CM |
2826 | int push_space = 0; |
2827 | int push_items = 0; | |
34a38218 | 2828 | u32 nr; |
7518a238 | 2829 | u32 right_nritems; |
5f39d397 | 2830 | u32 data_end; |
db94535d | 2831 | u32 this_item_size; |
00ec4c51 | 2832 | |
34a38218 CM |
2833 | if (empty) |
2834 | nr = 0; | |
2835 | else | |
99d8f83c | 2836 | nr = max_t(u32, 1, min_slot); |
34a38218 | 2837 | |
31840ae1 | 2838 | if (path->slots[0] >= left_nritems) |
87b29b20 | 2839 | push_space += data_size; |
31840ae1 | 2840 | |
44871b1b | 2841 | slot = path->slots[1]; |
34a38218 CM |
2842 | i = left_nritems - 1; |
2843 | while (i >= nr) { | |
31840ae1 ZY |
2844 | if (!empty && push_items > 0) { |
2845 | if (path->slots[0] > i) | |
2846 | break; | |
2847 | if (path->slots[0] == i) { | |
e902baac DS |
2848 | int space = btrfs_leaf_free_space(left); |
2849 | ||
31840ae1 ZY |
2850 | if (space + push_space * 2 > free_space) |
2851 | break; | |
2852 | } | |
2853 | } | |
2854 | ||
00ec4c51 | 2855 | if (path->slots[0] == i) |
87b29b20 | 2856 | push_space += data_size; |
db94535d | 2857 | |
3212fa14 | 2858 | this_item_size = btrfs_item_size(left, i); |
74794207 JB |
2859 | if (this_item_size + sizeof(struct btrfs_item) + |
2860 | push_space > free_space) | |
00ec4c51 | 2861 | break; |
31840ae1 | 2862 | |
00ec4c51 | 2863 | push_items++; |
74794207 | 2864 | push_space += this_item_size + sizeof(struct btrfs_item); |
34a38218 CM |
2865 | if (i == 0) |
2866 | break; | |
2867 | i--; | |
db94535d | 2868 | } |
5f39d397 | 2869 | |
925baedd CM |
2870 | if (push_items == 0) |
2871 | goto out_unlock; | |
5f39d397 | 2872 | |
6c1500f2 | 2873 | WARN_ON(!empty && push_items == left_nritems); |
5f39d397 | 2874 | |
00ec4c51 | 2875 | /* push left to right */ |
5f39d397 | 2876 | right_nritems = btrfs_header_nritems(right); |
34a38218 | 2877 | |
dc2e724e | 2878 | push_space = btrfs_item_data_end(left, left_nritems - push_items); |
8f881e8c | 2879 | push_space -= leaf_data_end(left); |
5f39d397 | 2880 | |
00ec4c51 | 2881 | /* make room in the right data area */ |
8f881e8c | 2882 | data_end = leaf_data_end(right); |
5f39d397 | 2883 | memmove_extent_buffer(right, |
3d9ec8c4 NB |
2884 | BTRFS_LEAF_DATA_OFFSET + data_end - push_space, |
2885 | BTRFS_LEAF_DATA_OFFSET + data_end, | |
0b246afa | 2886 | BTRFS_LEAF_DATA_SIZE(fs_info) - data_end); |
5f39d397 | 2887 | |
00ec4c51 | 2888 | /* copy from the left data area */ |
3d9ec8c4 | 2889 | copy_extent_buffer(right, left, BTRFS_LEAF_DATA_OFFSET + |
0b246afa | 2890 | BTRFS_LEAF_DATA_SIZE(fs_info) - push_space, |
8f881e8c | 2891 | BTRFS_LEAF_DATA_OFFSET + leaf_data_end(left), |
d6025579 | 2892 | push_space); |
5f39d397 CM |
2893 | |
2894 | memmove_extent_buffer(right, btrfs_item_nr_offset(push_items), | |
2895 | btrfs_item_nr_offset(0), | |
2896 | right_nritems * sizeof(struct btrfs_item)); | |
2897 | ||
00ec4c51 | 2898 | /* copy the items from left to right */ |
5f39d397 CM |
2899 | copy_extent_buffer(right, left, btrfs_item_nr_offset(0), |
2900 | btrfs_item_nr_offset(left_nritems - push_items), | |
2901 | push_items * sizeof(struct btrfs_item)); | |
00ec4c51 CM |
2902 | |
2903 | /* update the item pointers */ | |
c82f823c | 2904 | btrfs_init_map_token(&token, right); |
7518a238 | 2905 | right_nritems += push_items; |
5f39d397 | 2906 | btrfs_set_header_nritems(right, right_nritems); |
0b246afa | 2907 | push_space = BTRFS_LEAF_DATA_SIZE(fs_info); |
7518a238 | 2908 | for (i = 0; i < right_nritems; i++) { |
3212fa14 JB |
2909 | push_space -= btrfs_token_item_size(&token, i); |
2910 | btrfs_set_token_item_offset(&token, i, push_space); | |
db94535d CM |
2911 | } |
2912 | ||
7518a238 | 2913 | left_nritems -= push_items; |
5f39d397 | 2914 | btrfs_set_header_nritems(left, left_nritems); |
00ec4c51 | 2915 | |
34a38218 CM |
2916 | if (left_nritems) |
2917 | btrfs_mark_buffer_dirty(left); | |
f0486c68 | 2918 | else |
6a884d7d | 2919 | btrfs_clean_tree_block(left); |
f0486c68 | 2920 | |
5f39d397 | 2921 | btrfs_mark_buffer_dirty(right); |
a429e513 | 2922 | |
5f39d397 CM |
2923 | btrfs_item_key(right, &disk_key, 0); |
2924 | btrfs_set_node_key(upper, &disk_key, slot + 1); | |
d6025579 | 2925 | btrfs_mark_buffer_dirty(upper); |
02217ed2 | 2926 | |
00ec4c51 | 2927 | /* then fixup the leaf pointer in the path */ |
7518a238 CM |
2928 | if (path->slots[0] >= left_nritems) { |
2929 | path->slots[0] -= left_nritems; | |
925baedd | 2930 | if (btrfs_header_nritems(path->nodes[0]) == 0) |
6a884d7d | 2931 | btrfs_clean_tree_block(path->nodes[0]); |
925baedd | 2932 | btrfs_tree_unlock(path->nodes[0]); |
5f39d397 CM |
2933 | free_extent_buffer(path->nodes[0]); |
2934 | path->nodes[0] = right; | |
00ec4c51 CM |
2935 | path->slots[1] += 1; |
2936 | } else { | |
925baedd | 2937 | btrfs_tree_unlock(right); |
5f39d397 | 2938 | free_extent_buffer(right); |
00ec4c51 CM |
2939 | } |
2940 | return 0; | |
925baedd CM |
2941 | |
2942 | out_unlock: | |
2943 | btrfs_tree_unlock(right); | |
2944 | free_extent_buffer(right); | |
2945 | return 1; | |
00ec4c51 | 2946 | } |
925baedd | 2947 | |
44871b1b CM |
2948 | /* |
2949 | * push some data in the path leaf to the right, trying to free up at | |
2950 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
2951 | * | |
2952 | * returns 1 if the push failed because the other node didn't have enough | |
2953 | * room, 0 if everything worked out and < 0 if there were major errors. | |
99d8f83c CM |
2954 | * |
2955 | * this will push starting from min_slot to the end of the leaf. It won't | |
2956 | * push any slot lower than min_slot | |
44871b1b CM |
2957 | */ |
2958 | static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root | |
99d8f83c CM |
2959 | *root, struct btrfs_path *path, |
2960 | int min_data_size, int data_size, | |
2961 | int empty, u32 min_slot) | |
44871b1b CM |
2962 | { |
2963 | struct extent_buffer *left = path->nodes[0]; | |
2964 | struct extent_buffer *right; | |
2965 | struct extent_buffer *upper; | |
2966 | int slot; | |
2967 | int free_space; | |
2968 | u32 left_nritems; | |
2969 | int ret; | |
2970 | ||
2971 | if (!path->nodes[1]) | |
2972 | return 1; | |
2973 | ||
2974 | slot = path->slots[1]; | |
2975 | upper = path->nodes[1]; | |
2976 | if (slot >= btrfs_header_nritems(upper) - 1) | |
2977 | return 1; | |
2978 | ||
49d0c642 | 2979 | btrfs_assert_tree_write_locked(path->nodes[1]); |
44871b1b | 2980 | |
4b231ae4 | 2981 | right = btrfs_read_node_slot(upper, slot + 1); |
fb770ae4 LB |
2982 | /* |
2983 | * slot + 1 is not valid or we fail to read the right node, | |
2984 | * no big deal, just return. | |
2985 | */ | |
2986 | if (IS_ERR(right)) | |
91ca338d TI |
2987 | return 1; |
2988 | ||
bf77467a | 2989 | __btrfs_tree_lock(right, BTRFS_NESTING_RIGHT); |
44871b1b | 2990 | |
e902baac | 2991 | free_space = btrfs_leaf_free_space(right); |
44871b1b CM |
2992 | if (free_space < data_size) |
2993 | goto out_unlock; | |
2994 | ||
44871b1b | 2995 | ret = btrfs_cow_block(trans, root, right, upper, |
bf59a5a2 | 2996 | slot + 1, &right, BTRFS_NESTING_RIGHT_COW); |
44871b1b CM |
2997 | if (ret) |
2998 | goto out_unlock; | |
2999 | ||
44871b1b CM |
3000 | left_nritems = btrfs_header_nritems(left); |
3001 | if (left_nritems == 0) | |
3002 | goto out_unlock; | |
3003 | ||
d16c702f QW |
3004 | if (check_sibling_keys(left, right)) { |
3005 | ret = -EUCLEAN; | |
3006 | btrfs_tree_unlock(right); | |
3007 | free_extent_buffer(right); | |
3008 | return ret; | |
3009 | } | |
2ef1fed2 FDBM |
3010 | if (path->slots[0] == left_nritems && !empty) { |
3011 | /* Key greater than all keys in the leaf, right neighbor has | |
3012 | * enough room for it and we're not emptying our leaf to delete | |
3013 | * it, therefore use right neighbor to insert the new item and | |
52042d8e | 3014 | * no need to touch/dirty our left leaf. */ |
2ef1fed2 FDBM |
3015 | btrfs_tree_unlock(left); |
3016 | free_extent_buffer(left); | |
3017 | path->nodes[0] = right; | |
3018 | path->slots[0] = 0; | |
3019 | path->slots[1]++; | |
3020 | return 0; | |
3021 | } | |
3022 | ||
f72f0010 | 3023 | return __push_leaf_right(path, min_data_size, empty, |
99d8f83c | 3024 | right, free_space, left_nritems, min_slot); |
44871b1b CM |
3025 | out_unlock: |
3026 | btrfs_tree_unlock(right); | |
3027 | free_extent_buffer(right); | |
3028 | return 1; | |
3029 | } | |
3030 | ||
74123bd7 CM |
3031 | /* |
3032 | * push some data in the path leaf to the left, trying to free up at | |
3033 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
99d8f83c CM |
3034 | * |
3035 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
3036 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us do all the | |
3037 | * items | |
74123bd7 | 3038 | */ |
8087c193 | 3039 | static noinline int __push_leaf_left(struct btrfs_path *path, int data_size, |
44871b1b | 3040 | int empty, struct extent_buffer *left, |
99d8f83c CM |
3041 | int free_space, u32 right_nritems, |
3042 | u32 max_slot) | |
be0e5c09 | 3043 | { |
8087c193 | 3044 | struct btrfs_fs_info *fs_info = left->fs_info; |
5f39d397 CM |
3045 | struct btrfs_disk_key disk_key; |
3046 | struct extent_buffer *right = path->nodes[0]; | |
be0e5c09 | 3047 | int i; |
be0e5c09 CM |
3048 | int push_space = 0; |
3049 | int push_items = 0; | |
7518a238 | 3050 | u32 old_left_nritems; |
34a38218 | 3051 | u32 nr; |
aa5d6bed | 3052 | int ret = 0; |
db94535d CM |
3053 | u32 this_item_size; |
3054 | u32 old_left_item_size; | |
cfed81a0 CM |
3055 | struct btrfs_map_token token; |
3056 | ||
34a38218 | 3057 | if (empty) |
99d8f83c | 3058 | nr = min(right_nritems, max_slot); |
34a38218 | 3059 | else |
99d8f83c | 3060 | nr = min(right_nritems - 1, max_slot); |
34a38218 CM |
3061 | |
3062 | for (i = 0; i < nr; i++) { | |
31840ae1 ZY |
3063 | if (!empty && push_items > 0) { |
3064 | if (path->slots[0] < i) | |
3065 | break; | |
3066 | if (path->slots[0] == i) { | |
e902baac DS |
3067 | int space = btrfs_leaf_free_space(right); |
3068 | ||
31840ae1 ZY |
3069 | if (space + push_space * 2 > free_space) |
3070 | break; | |
3071 | } | |
3072 | } | |
3073 | ||
be0e5c09 | 3074 | if (path->slots[0] == i) |
87b29b20 | 3075 | push_space += data_size; |
db94535d | 3076 | |
3212fa14 | 3077 | this_item_size = btrfs_item_size(right, i); |
74794207 JB |
3078 | if (this_item_size + sizeof(struct btrfs_item) + push_space > |
3079 | free_space) | |
be0e5c09 | 3080 | break; |
db94535d | 3081 | |
be0e5c09 | 3082 | push_items++; |
74794207 | 3083 | push_space += this_item_size + sizeof(struct btrfs_item); |
db94535d CM |
3084 | } |
3085 | ||
be0e5c09 | 3086 | if (push_items == 0) { |
925baedd CM |
3087 | ret = 1; |
3088 | goto out; | |
be0e5c09 | 3089 | } |
fae7f21c | 3090 | WARN_ON(!empty && push_items == btrfs_header_nritems(right)); |
5f39d397 | 3091 | |
be0e5c09 | 3092 | /* push data from right to left */ |
5f39d397 CM |
3093 | copy_extent_buffer(left, right, |
3094 | btrfs_item_nr_offset(btrfs_header_nritems(left)), | |
3095 | btrfs_item_nr_offset(0), | |
3096 | push_items * sizeof(struct btrfs_item)); | |
3097 | ||
0b246afa | 3098 | push_space = BTRFS_LEAF_DATA_SIZE(fs_info) - |
3212fa14 | 3099 | btrfs_item_offset(right, push_items - 1); |
5f39d397 | 3100 | |
3d9ec8c4 | 3101 | copy_extent_buffer(left, right, BTRFS_LEAF_DATA_OFFSET + |
8f881e8c | 3102 | leaf_data_end(left) - push_space, |
3d9ec8c4 | 3103 | BTRFS_LEAF_DATA_OFFSET + |
3212fa14 | 3104 | btrfs_item_offset(right, push_items - 1), |
d6025579 | 3105 | push_space); |
5f39d397 | 3106 | old_left_nritems = btrfs_header_nritems(left); |
87b29b20 | 3107 | BUG_ON(old_left_nritems <= 0); |
eb60ceac | 3108 | |
c82f823c | 3109 | btrfs_init_map_token(&token, left); |
3212fa14 | 3110 | old_left_item_size = btrfs_item_offset(left, old_left_nritems - 1); |
0783fcfc | 3111 | for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { |
5f39d397 | 3112 | u32 ioff; |
db94535d | 3113 | |
3212fa14 JB |
3114 | ioff = btrfs_token_item_offset(&token, i); |
3115 | btrfs_set_token_item_offset(&token, i, | |
cc4c13d5 | 3116 | ioff - (BTRFS_LEAF_DATA_SIZE(fs_info) - old_left_item_size)); |
be0e5c09 | 3117 | } |
5f39d397 | 3118 | btrfs_set_header_nritems(left, old_left_nritems + push_items); |
be0e5c09 CM |
3119 | |
3120 | /* fixup right node */ | |
31b1a2bd JL |
3121 | if (push_items > right_nritems) |
3122 | WARN(1, KERN_CRIT "push items %d nr %u\n", push_items, | |
d397712b | 3123 | right_nritems); |
34a38218 CM |
3124 | |
3125 | if (push_items < right_nritems) { | |
3212fa14 | 3126 | push_space = btrfs_item_offset(right, push_items - 1) - |
8f881e8c | 3127 | leaf_data_end(right); |
3d9ec8c4 | 3128 | memmove_extent_buffer(right, BTRFS_LEAF_DATA_OFFSET + |
0b246afa | 3129 | BTRFS_LEAF_DATA_SIZE(fs_info) - push_space, |
3d9ec8c4 | 3130 | BTRFS_LEAF_DATA_OFFSET + |
8f881e8c | 3131 | leaf_data_end(right), push_space); |
34a38218 CM |
3132 | |
3133 | memmove_extent_buffer(right, btrfs_item_nr_offset(0), | |
5f39d397 CM |
3134 | btrfs_item_nr_offset(push_items), |
3135 | (btrfs_header_nritems(right) - push_items) * | |
3136 | sizeof(struct btrfs_item)); | |
34a38218 | 3137 | } |
c82f823c DS |
3138 | |
3139 | btrfs_init_map_token(&token, right); | |
eef1c494 Y |
3140 | right_nritems -= push_items; |
3141 | btrfs_set_header_nritems(right, right_nritems); | |
0b246afa | 3142 | push_space = BTRFS_LEAF_DATA_SIZE(fs_info); |
5f39d397 | 3143 | for (i = 0; i < right_nritems; i++) { |
3212fa14 JB |
3144 | push_space = push_space - btrfs_token_item_size(&token, i); |
3145 | btrfs_set_token_item_offset(&token, i, push_space); | |
db94535d | 3146 | } |
eb60ceac | 3147 | |
5f39d397 | 3148 | btrfs_mark_buffer_dirty(left); |
34a38218 CM |
3149 | if (right_nritems) |
3150 | btrfs_mark_buffer_dirty(right); | |
f0486c68 | 3151 | else |
6a884d7d | 3152 | btrfs_clean_tree_block(right); |
098f59c2 | 3153 | |
5f39d397 | 3154 | btrfs_item_key(right, &disk_key, 0); |
b167fa91 | 3155 | fixup_low_keys(path, &disk_key, 1); |
be0e5c09 CM |
3156 | |
3157 | /* then fixup the leaf pointer in the path */ | |
3158 | if (path->slots[0] < push_items) { | |
3159 | path->slots[0] += old_left_nritems; | |
925baedd | 3160 | btrfs_tree_unlock(path->nodes[0]); |
5f39d397 CM |
3161 | free_extent_buffer(path->nodes[0]); |
3162 | path->nodes[0] = left; | |
be0e5c09 CM |
3163 | path->slots[1] -= 1; |
3164 | } else { | |
925baedd | 3165 | btrfs_tree_unlock(left); |
5f39d397 | 3166 | free_extent_buffer(left); |
be0e5c09 CM |
3167 | path->slots[0] -= push_items; |
3168 | } | |
eb60ceac | 3169 | BUG_ON(path->slots[0] < 0); |
aa5d6bed | 3170 | return ret; |
925baedd CM |
3171 | out: |
3172 | btrfs_tree_unlock(left); | |
3173 | free_extent_buffer(left); | |
3174 | return ret; | |
be0e5c09 CM |
3175 | } |
3176 | ||
44871b1b CM |
3177 | /* |
3178 | * push some data in the path leaf to the left, trying to free up at | |
3179 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
99d8f83c CM |
3180 | * |
3181 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
3182 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us push all the | |
3183 | * items | |
44871b1b CM |
3184 | */ |
3185 | static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root | |
99d8f83c CM |
3186 | *root, struct btrfs_path *path, int min_data_size, |
3187 | int data_size, int empty, u32 max_slot) | |
44871b1b CM |
3188 | { |
3189 | struct extent_buffer *right = path->nodes[0]; | |
3190 | struct extent_buffer *left; | |
3191 | int slot; | |
3192 | int free_space; | |
3193 | u32 right_nritems; | |
3194 | int ret = 0; | |
3195 | ||
3196 | slot = path->slots[1]; | |
3197 | if (slot == 0) | |
3198 | return 1; | |
3199 | if (!path->nodes[1]) | |
3200 | return 1; | |
3201 | ||
3202 | right_nritems = btrfs_header_nritems(right); | |
3203 | if (right_nritems == 0) | |
3204 | return 1; | |
3205 | ||
49d0c642 | 3206 | btrfs_assert_tree_write_locked(path->nodes[1]); |
44871b1b | 3207 | |
4b231ae4 | 3208 | left = btrfs_read_node_slot(path->nodes[1], slot - 1); |
fb770ae4 LB |
3209 | /* |
3210 | * slot - 1 is not valid or we fail to read the left node, | |
3211 | * no big deal, just return. | |
3212 | */ | |
3213 | if (IS_ERR(left)) | |
91ca338d TI |
3214 | return 1; |
3215 | ||
bf77467a | 3216 | __btrfs_tree_lock(left, BTRFS_NESTING_LEFT); |
44871b1b | 3217 | |
e902baac | 3218 | free_space = btrfs_leaf_free_space(left); |
44871b1b CM |
3219 | if (free_space < data_size) { |
3220 | ret = 1; | |
3221 | goto out; | |
3222 | } | |
3223 | ||
44871b1b | 3224 | ret = btrfs_cow_block(trans, root, left, |
9631e4cc | 3225 | path->nodes[1], slot - 1, &left, |
bf59a5a2 | 3226 | BTRFS_NESTING_LEFT_COW); |
44871b1b CM |
3227 | if (ret) { |
3228 | /* we hit -ENOSPC, but it isn't fatal here */ | |
79787eaa JM |
3229 | if (ret == -ENOSPC) |
3230 | ret = 1; | |
44871b1b CM |
3231 | goto out; |
3232 | } | |
3233 | ||
d16c702f QW |
3234 | if (check_sibling_keys(left, right)) { |
3235 | ret = -EUCLEAN; | |
3236 | goto out; | |
3237 | } | |
8087c193 | 3238 | return __push_leaf_left(path, min_data_size, |
99d8f83c CM |
3239 | empty, left, free_space, right_nritems, |
3240 | max_slot); | |
44871b1b CM |
3241 | out: |
3242 | btrfs_tree_unlock(left); | |
3243 | free_extent_buffer(left); | |
3244 | return ret; | |
3245 | } | |
3246 | ||
3247 | /* | |
3248 | * split the path's leaf in two, making sure there is at least data_size | |
3249 | * available for the resulting leaf level of the path. | |
44871b1b | 3250 | */ |
143bede5 | 3251 | static noinline void copy_for_split(struct btrfs_trans_handle *trans, |
143bede5 JM |
3252 | struct btrfs_path *path, |
3253 | struct extent_buffer *l, | |
3254 | struct extent_buffer *right, | |
3255 | int slot, int mid, int nritems) | |
44871b1b | 3256 | { |
94f94ad9 | 3257 | struct btrfs_fs_info *fs_info = trans->fs_info; |
44871b1b CM |
3258 | int data_copy_size; |
3259 | int rt_data_off; | |
3260 | int i; | |
44871b1b | 3261 | struct btrfs_disk_key disk_key; |
cfed81a0 CM |
3262 | struct btrfs_map_token token; |
3263 | ||
44871b1b CM |
3264 | nritems = nritems - mid; |
3265 | btrfs_set_header_nritems(right, nritems); | |
dc2e724e | 3266 | data_copy_size = btrfs_item_data_end(l, mid) - leaf_data_end(l); |
44871b1b CM |
3267 | |
3268 | copy_extent_buffer(right, l, btrfs_item_nr_offset(0), | |
3269 | btrfs_item_nr_offset(mid), | |
3270 | nritems * sizeof(struct btrfs_item)); | |
3271 | ||
3272 | copy_extent_buffer(right, l, | |
3d9ec8c4 NB |
3273 | BTRFS_LEAF_DATA_OFFSET + BTRFS_LEAF_DATA_SIZE(fs_info) - |
3274 | data_copy_size, BTRFS_LEAF_DATA_OFFSET + | |
8f881e8c | 3275 | leaf_data_end(l), data_copy_size); |
44871b1b | 3276 | |
dc2e724e | 3277 | rt_data_off = BTRFS_LEAF_DATA_SIZE(fs_info) - btrfs_item_data_end(l, mid); |
44871b1b | 3278 | |
c82f823c | 3279 | btrfs_init_map_token(&token, right); |
44871b1b | 3280 | for (i = 0; i < nritems; i++) { |
44871b1b CM |
3281 | u32 ioff; |
3282 | ||
3212fa14 JB |
3283 | ioff = btrfs_token_item_offset(&token, i); |
3284 | btrfs_set_token_item_offset(&token, i, ioff + rt_data_off); | |
44871b1b CM |
3285 | } |
3286 | ||
44871b1b | 3287 | btrfs_set_header_nritems(l, mid); |
44871b1b | 3288 | btrfs_item_key(right, &disk_key, 0); |
6ad3cf6d | 3289 | insert_ptr(trans, path, &disk_key, right->start, path->slots[1] + 1, 1); |
44871b1b CM |
3290 | |
3291 | btrfs_mark_buffer_dirty(right); | |
3292 | btrfs_mark_buffer_dirty(l); | |
3293 | BUG_ON(path->slots[0] != slot); | |
3294 | ||
44871b1b CM |
3295 | if (mid <= slot) { |
3296 | btrfs_tree_unlock(path->nodes[0]); | |
3297 | free_extent_buffer(path->nodes[0]); | |
3298 | path->nodes[0] = right; | |
3299 | path->slots[0] -= mid; | |
3300 | path->slots[1] += 1; | |
3301 | } else { | |
3302 | btrfs_tree_unlock(right); | |
3303 | free_extent_buffer(right); | |
3304 | } | |
3305 | ||
3306 | BUG_ON(path->slots[0] < 0); | |
44871b1b CM |
3307 | } |
3308 | ||
99d8f83c CM |
3309 | /* |
3310 | * double splits happen when we need to insert a big item in the middle | |
3311 | * of a leaf. A double split can leave us with 3 mostly empty leaves: | |
3312 | * leaf: [ slots 0 - N] [ our target ] [ N + 1 - total in leaf ] | |
3313 | * A B C | |
3314 | * | |
3315 | * We avoid this by trying to push the items on either side of our target | |
3316 | * into the adjacent leaves. If all goes well we can avoid the double split | |
3317 | * completely. | |
3318 | */ | |
3319 | static noinline int push_for_double_split(struct btrfs_trans_handle *trans, | |
3320 | struct btrfs_root *root, | |
3321 | struct btrfs_path *path, | |
3322 | int data_size) | |
3323 | { | |
3324 | int ret; | |
3325 | int progress = 0; | |
3326 | int slot; | |
3327 | u32 nritems; | |
5a4267ca | 3328 | int space_needed = data_size; |
99d8f83c CM |
3329 | |
3330 | slot = path->slots[0]; | |
5a4267ca | 3331 | if (slot < btrfs_header_nritems(path->nodes[0])) |
e902baac | 3332 | space_needed -= btrfs_leaf_free_space(path->nodes[0]); |
99d8f83c CM |
3333 | |
3334 | /* | |
3335 | * try to push all the items after our slot into the | |
3336 | * right leaf | |
3337 | */ | |
5a4267ca | 3338 | ret = push_leaf_right(trans, root, path, 1, space_needed, 0, slot); |
99d8f83c CM |
3339 | if (ret < 0) |
3340 | return ret; | |
3341 | ||
3342 | if (ret == 0) | |
3343 | progress++; | |
3344 | ||
3345 | nritems = btrfs_header_nritems(path->nodes[0]); | |
3346 | /* | |
3347 | * our goal is to get our slot at the start or end of a leaf. If | |
3348 | * we've done so we're done | |
3349 | */ | |
3350 | if (path->slots[0] == 0 || path->slots[0] == nritems) | |
3351 | return 0; | |
3352 | ||
e902baac | 3353 | if (btrfs_leaf_free_space(path->nodes[0]) >= data_size) |
99d8f83c CM |
3354 | return 0; |
3355 | ||
3356 | /* try to push all the items before our slot into the next leaf */ | |
3357 | slot = path->slots[0]; | |
263d3995 FM |
3358 | space_needed = data_size; |
3359 | if (slot > 0) | |
e902baac | 3360 | space_needed -= btrfs_leaf_free_space(path->nodes[0]); |
5a4267ca | 3361 | ret = push_leaf_left(trans, root, path, 1, space_needed, 0, slot); |
99d8f83c CM |
3362 | if (ret < 0) |
3363 | return ret; | |
3364 | ||
3365 | if (ret == 0) | |
3366 | progress++; | |
3367 | ||
3368 | if (progress) | |
3369 | return 0; | |
3370 | return 1; | |
3371 | } | |
3372 | ||
74123bd7 CM |
3373 | /* |
3374 | * split the path's leaf in two, making sure there is at least data_size | |
3375 | * available for the resulting leaf level of the path. | |
aa5d6bed CM |
3376 | * |
3377 | * returns 0 if all went well and < 0 on failure. | |
74123bd7 | 3378 | */ |
e02119d5 CM |
3379 | static noinline int split_leaf(struct btrfs_trans_handle *trans, |
3380 | struct btrfs_root *root, | |
310712b2 | 3381 | const struct btrfs_key *ins_key, |
e02119d5 CM |
3382 | struct btrfs_path *path, int data_size, |
3383 | int extend) | |
be0e5c09 | 3384 | { |
5d4f98a2 | 3385 | struct btrfs_disk_key disk_key; |
5f39d397 | 3386 | struct extent_buffer *l; |
7518a238 | 3387 | u32 nritems; |
eb60ceac CM |
3388 | int mid; |
3389 | int slot; | |
5f39d397 | 3390 | struct extent_buffer *right; |
b7a0365e | 3391 | struct btrfs_fs_info *fs_info = root->fs_info; |
d4dbff95 | 3392 | int ret = 0; |
aa5d6bed | 3393 | int wret; |
5d4f98a2 | 3394 | int split; |
cc0c5538 | 3395 | int num_doubles = 0; |
99d8f83c | 3396 | int tried_avoid_double = 0; |
aa5d6bed | 3397 | |
a5719521 YZ |
3398 | l = path->nodes[0]; |
3399 | slot = path->slots[0]; | |
3212fa14 | 3400 | if (extend && data_size + btrfs_item_size(l, slot) + |
0b246afa | 3401 | sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(fs_info)) |
a5719521 YZ |
3402 | return -EOVERFLOW; |
3403 | ||
40689478 | 3404 | /* first try to make some room by pushing left and right */ |
33157e05 | 3405 | if (data_size && path->nodes[1]) { |
5a4267ca FDBM |
3406 | int space_needed = data_size; |
3407 | ||
3408 | if (slot < btrfs_header_nritems(l)) | |
e902baac | 3409 | space_needed -= btrfs_leaf_free_space(l); |
5a4267ca FDBM |
3410 | |
3411 | wret = push_leaf_right(trans, root, path, space_needed, | |
3412 | space_needed, 0, 0); | |
d397712b | 3413 | if (wret < 0) |
eaee50e8 | 3414 | return wret; |
3685f791 | 3415 | if (wret) { |
263d3995 FM |
3416 | space_needed = data_size; |
3417 | if (slot > 0) | |
e902baac | 3418 | space_needed -= btrfs_leaf_free_space(l); |
5a4267ca FDBM |
3419 | wret = push_leaf_left(trans, root, path, space_needed, |
3420 | space_needed, 0, (u32)-1); | |
3685f791 CM |
3421 | if (wret < 0) |
3422 | return wret; | |
3423 | } | |
3424 | l = path->nodes[0]; | |
aa5d6bed | 3425 | |
3685f791 | 3426 | /* did the pushes work? */ |
e902baac | 3427 | if (btrfs_leaf_free_space(l) >= data_size) |
3685f791 | 3428 | return 0; |
3326d1b0 | 3429 | } |
aa5d6bed | 3430 | |
5c680ed6 | 3431 | if (!path->nodes[1]) { |
fdd99c72 | 3432 | ret = insert_new_root(trans, root, path, 1); |
5c680ed6 CM |
3433 | if (ret) |
3434 | return ret; | |
3435 | } | |
cc0c5538 | 3436 | again: |
5d4f98a2 | 3437 | split = 1; |
cc0c5538 | 3438 | l = path->nodes[0]; |
eb60ceac | 3439 | slot = path->slots[0]; |
5f39d397 | 3440 | nritems = btrfs_header_nritems(l); |
d397712b | 3441 | mid = (nritems + 1) / 2; |
54aa1f4d | 3442 | |
5d4f98a2 YZ |
3443 | if (mid <= slot) { |
3444 | if (nritems == 1 || | |
3445 | leaf_space_used(l, mid, nritems - mid) + data_size > | |
0b246afa | 3446 | BTRFS_LEAF_DATA_SIZE(fs_info)) { |
5d4f98a2 YZ |
3447 | if (slot >= nritems) { |
3448 | split = 0; | |
3449 | } else { | |
3450 | mid = slot; | |
3451 | if (mid != nritems && | |
3452 | leaf_space_used(l, mid, nritems - mid) + | |
0b246afa | 3453 | data_size > BTRFS_LEAF_DATA_SIZE(fs_info)) { |
99d8f83c CM |
3454 | if (data_size && !tried_avoid_double) |
3455 | goto push_for_double; | |
5d4f98a2 YZ |
3456 | split = 2; |
3457 | } | |
3458 | } | |
3459 | } | |
3460 | } else { | |
3461 | if (leaf_space_used(l, 0, mid) + data_size > | |
0b246afa | 3462 | BTRFS_LEAF_DATA_SIZE(fs_info)) { |
5d4f98a2 YZ |
3463 | if (!extend && data_size && slot == 0) { |
3464 | split = 0; | |
3465 | } else if ((extend || !data_size) && slot == 0) { | |
3466 | mid = 1; | |
3467 | } else { | |
3468 | mid = slot; | |
3469 | if (mid != nritems && | |
3470 | leaf_space_used(l, mid, nritems - mid) + | |
0b246afa | 3471 | data_size > BTRFS_LEAF_DATA_SIZE(fs_info)) { |
99d8f83c CM |
3472 | if (data_size && !tried_avoid_double) |
3473 | goto push_for_double; | |
67871254 | 3474 | split = 2; |
5d4f98a2 YZ |
3475 | } |
3476 | } | |
3477 | } | |
3478 | } | |
3479 | ||
3480 | if (split == 0) | |
3481 | btrfs_cpu_key_to_disk(&disk_key, ins_key); | |
3482 | else | |
3483 | btrfs_item_key(l, &disk_key, mid); | |
3484 | ||
ca9d473a JB |
3485 | /* |
3486 | * We have to about BTRFS_NESTING_NEW_ROOT here if we've done a double | |
3487 | * split, because we're only allowed to have MAX_LOCKDEP_SUBCLASSES | |
3488 | * subclasses, which is 8 at the time of this patch, and we've maxed it | |
3489 | * out. In the future we could add a | |
3490 | * BTRFS_NESTING_SPLIT_THE_SPLITTENING if we need to, but for now just | |
3491 | * use BTRFS_NESTING_NEW_ROOT. | |
3492 | */ | |
79bd3712 FM |
3493 | right = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid, |
3494 | &disk_key, 0, l->start, 0, | |
3495 | num_doubles ? BTRFS_NESTING_NEW_ROOT : | |
3496 | BTRFS_NESTING_SPLIT); | |
f0486c68 | 3497 | if (IS_ERR(right)) |
5f39d397 | 3498 | return PTR_ERR(right); |
f0486c68 | 3499 | |
0b246afa | 3500 | root_add_used(root, fs_info->nodesize); |
5f39d397 | 3501 | |
5d4f98a2 YZ |
3502 | if (split == 0) { |
3503 | if (mid <= slot) { | |
3504 | btrfs_set_header_nritems(right, 0); | |
6ad3cf6d | 3505 | insert_ptr(trans, path, &disk_key, |
2ff7e61e | 3506 | right->start, path->slots[1] + 1, 1); |
5d4f98a2 YZ |
3507 | btrfs_tree_unlock(path->nodes[0]); |
3508 | free_extent_buffer(path->nodes[0]); | |
3509 | path->nodes[0] = right; | |
3510 | path->slots[0] = 0; | |
3511 | path->slots[1] += 1; | |
3512 | } else { | |
3513 | btrfs_set_header_nritems(right, 0); | |
6ad3cf6d | 3514 | insert_ptr(trans, path, &disk_key, |
2ff7e61e | 3515 | right->start, path->slots[1], 1); |
5d4f98a2 YZ |
3516 | btrfs_tree_unlock(path->nodes[0]); |
3517 | free_extent_buffer(path->nodes[0]); | |
3518 | path->nodes[0] = right; | |
3519 | path->slots[0] = 0; | |
143bede5 | 3520 | if (path->slots[1] == 0) |
b167fa91 | 3521 | fixup_low_keys(path, &disk_key, 1); |
d4dbff95 | 3522 | } |
196e0249 LB |
3523 | /* |
3524 | * We create a new leaf 'right' for the required ins_len and | |
3525 | * we'll do btrfs_mark_buffer_dirty() on this leaf after copying | |
3526 | * the content of ins_len to 'right'. | |
3527 | */ | |
5d4f98a2 | 3528 | return ret; |
d4dbff95 | 3529 | } |
74123bd7 | 3530 | |
94f94ad9 | 3531 | copy_for_split(trans, path, l, right, slot, mid, nritems); |
31840ae1 | 3532 | |
5d4f98a2 | 3533 | if (split == 2) { |
cc0c5538 CM |
3534 | BUG_ON(num_doubles != 0); |
3535 | num_doubles++; | |
3536 | goto again; | |
a429e513 | 3537 | } |
44871b1b | 3538 | |
143bede5 | 3539 | return 0; |
99d8f83c CM |
3540 | |
3541 | push_for_double: | |
3542 | push_for_double_split(trans, root, path, data_size); | |
3543 | tried_avoid_double = 1; | |
e902baac | 3544 | if (btrfs_leaf_free_space(path->nodes[0]) >= data_size) |
99d8f83c CM |
3545 | return 0; |
3546 | goto again; | |
be0e5c09 CM |
3547 | } |
3548 | ||
ad48fd75 YZ |
3549 | static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans, |
3550 | struct btrfs_root *root, | |
3551 | struct btrfs_path *path, int ins_len) | |
459931ec | 3552 | { |
ad48fd75 | 3553 | struct btrfs_key key; |
459931ec | 3554 | struct extent_buffer *leaf; |
ad48fd75 YZ |
3555 | struct btrfs_file_extent_item *fi; |
3556 | u64 extent_len = 0; | |
3557 | u32 item_size; | |
3558 | int ret; | |
459931ec CM |
3559 | |
3560 | leaf = path->nodes[0]; | |
ad48fd75 YZ |
3561 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
3562 | ||
3563 | BUG_ON(key.type != BTRFS_EXTENT_DATA_KEY && | |
3564 | key.type != BTRFS_EXTENT_CSUM_KEY); | |
3565 | ||
e902baac | 3566 | if (btrfs_leaf_free_space(leaf) >= ins_len) |
ad48fd75 | 3567 | return 0; |
459931ec | 3568 | |
3212fa14 | 3569 | item_size = btrfs_item_size(leaf, path->slots[0]); |
ad48fd75 YZ |
3570 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
3571 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
3572 | struct btrfs_file_extent_item); | |
3573 | extent_len = btrfs_file_extent_num_bytes(leaf, fi); | |
3574 | } | |
b3b4aa74 | 3575 | btrfs_release_path(path); |
459931ec | 3576 | |
459931ec | 3577 | path->keep_locks = 1; |
ad48fd75 YZ |
3578 | path->search_for_split = 1; |
3579 | ret = btrfs_search_slot(trans, root, &key, path, 0, 1); | |
459931ec | 3580 | path->search_for_split = 0; |
a8df6fe6 FM |
3581 | if (ret > 0) |
3582 | ret = -EAGAIN; | |
ad48fd75 YZ |
3583 | if (ret < 0) |
3584 | goto err; | |
459931ec | 3585 | |
ad48fd75 YZ |
3586 | ret = -EAGAIN; |
3587 | leaf = path->nodes[0]; | |
a8df6fe6 | 3588 | /* if our item isn't there, return now */ |
3212fa14 | 3589 | if (item_size != btrfs_item_size(leaf, path->slots[0])) |
ad48fd75 YZ |
3590 | goto err; |
3591 | ||
109f6aef | 3592 | /* the leaf has changed, it now has room. return now */ |
e902baac | 3593 | if (btrfs_leaf_free_space(path->nodes[0]) >= ins_len) |
109f6aef CM |
3594 | goto err; |
3595 | ||
ad48fd75 YZ |
3596 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
3597 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
3598 | struct btrfs_file_extent_item); | |
3599 | if (extent_len != btrfs_file_extent_num_bytes(leaf, fi)) | |
3600 | goto err; | |
459931ec CM |
3601 | } |
3602 | ||
ad48fd75 | 3603 | ret = split_leaf(trans, root, &key, path, ins_len, 1); |
f0486c68 YZ |
3604 | if (ret) |
3605 | goto err; | |
459931ec | 3606 | |
ad48fd75 | 3607 | path->keep_locks = 0; |
b9473439 | 3608 | btrfs_unlock_up_safe(path, 1); |
ad48fd75 YZ |
3609 | return 0; |
3610 | err: | |
3611 | path->keep_locks = 0; | |
3612 | return ret; | |
3613 | } | |
3614 | ||
25263cd7 | 3615 | static noinline int split_item(struct btrfs_path *path, |
310712b2 | 3616 | const struct btrfs_key *new_key, |
ad48fd75 YZ |
3617 | unsigned long split_offset) |
3618 | { | |
3619 | struct extent_buffer *leaf; | |
c91666b1 | 3620 | int orig_slot, slot; |
ad48fd75 YZ |
3621 | char *buf; |
3622 | u32 nritems; | |
3623 | u32 item_size; | |
3624 | u32 orig_offset; | |
3625 | struct btrfs_disk_key disk_key; | |
3626 | ||
b9473439 | 3627 | leaf = path->nodes[0]; |
e902baac | 3628 | BUG_ON(btrfs_leaf_free_space(leaf) < sizeof(struct btrfs_item)); |
b9473439 | 3629 | |
c91666b1 | 3630 | orig_slot = path->slots[0]; |
3212fa14 JB |
3631 | orig_offset = btrfs_item_offset(leaf, path->slots[0]); |
3632 | item_size = btrfs_item_size(leaf, path->slots[0]); | |
459931ec | 3633 | |
459931ec | 3634 | buf = kmalloc(item_size, GFP_NOFS); |
ad48fd75 YZ |
3635 | if (!buf) |
3636 | return -ENOMEM; | |
3637 | ||
459931ec CM |
3638 | read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf, |
3639 | path->slots[0]), item_size); | |
459931ec | 3640 | |
ad48fd75 | 3641 | slot = path->slots[0] + 1; |
459931ec | 3642 | nritems = btrfs_header_nritems(leaf); |
459931ec CM |
3643 | if (slot != nritems) { |
3644 | /* shift the items */ | |
3645 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1), | |
ad48fd75 YZ |
3646 | btrfs_item_nr_offset(slot), |
3647 | (nritems - slot) * sizeof(struct btrfs_item)); | |
459931ec CM |
3648 | } |
3649 | ||
3650 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
3651 | btrfs_set_item_key(leaf, &disk_key, slot); | |
3652 | ||
3212fa14 JB |
3653 | btrfs_set_item_offset(leaf, slot, orig_offset); |
3654 | btrfs_set_item_size(leaf, slot, item_size - split_offset); | |
459931ec | 3655 | |
3212fa14 | 3656 | btrfs_set_item_offset(leaf, orig_slot, |
c91666b1 | 3657 | orig_offset + item_size - split_offset); |
3212fa14 | 3658 | btrfs_set_item_size(leaf, orig_slot, split_offset); |
459931ec CM |
3659 | |
3660 | btrfs_set_header_nritems(leaf, nritems + 1); | |
3661 | ||
3662 | /* write the data for the start of the original item */ | |
3663 | write_extent_buffer(leaf, buf, | |
3664 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
3665 | split_offset); | |
3666 | ||
3667 | /* write the data for the new item */ | |
3668 | write_extent_buffer(leaf, buf + split_offset, | |
3669 | btrfs_item_ptr_offset(leaf, slot), | |
3670 | item_size - split_offset); | |
3671 | btrfs_mark_buffer_dirty(leaf); | |
3672 | ||
e902baac | 3673 | BUG_ON(btrfs_leaf_free_space(leaf) < 0); |
459931ec | 3674 | kfree(buf); |
ad48fd75 YZ |
3675 | return 0; |
3676 | } | |
3677 | ||
3678 | /* | |
3679 | * This function splits a single item into two items, | |
3680 | * giving 'new_key' to the new item and splitting the | |
3681 | * old one at split_offset (from the start of the item). | |
3682 | * | |
3683 | * The path may be released by this operation. After | |
3684 | * the split, the path is pointing to the old item. The | |
3685 | * new item is going to be in the same node as the old one. | |
3686 | * | |
3687 | * Note, the item being split must be smaller enough to live alone on | |
3688 | * a tree block with room for one extra struct btrfs_item | |
3689 | * | |
3690 | * This allows us to split the item in place, keeping a lock on the | |
3691 | * leaf the entire time. | |
3692 | */ | |
3693 | int btrfs_split_item(struct btrfs_trans_handle *trans, | |
3694 | struct btrfs_root *root, | |
3695 | struct btrfs_path *path, | |
310712b2 | 3696 | const struct btrfs_key *new_key, |
ad48fd75 YZ |
3697 | unsigned long split_offset) |
3698 | { | |
3699 | int ret; | |
3700 | ret = setup_leaf_for_split(trans, root, path, | |
3701 | sizeof(struct btrfs_item)); | |
3702 | if (ret) | |
3703 | return ret; | |
3704 | ||
25263cd7 | 3705 | ret = split_item(path, new_key, split_offset); |
459931ec CM |
3706 | return ret; |
3707 | } | |
3708 | ||
d352ac68 CM |
3709 | /* |
3710 | * make the item pointed to by the path smaller. new_size indicates | |
3711 | * how small to make it, and from_end tells us if we just chop bytes | |
3712 | * off the end of the item or if we shift the item to chop bytes off | |
3713 | * the front. | |
3714 | */ | |
78ac4f9e | 3715 | void btrfs_truncate_item(struct btrfs_path *path, u32 new_size, int from_end) |
b18c6685 | 3716 | { |
b18c6685 | 3717 | int slot; |
5f39d397 | 3718 | struct extent_buffer *leaf; |
b18c6685 CM |
3719 | u32 nritems; |
3720 | unsigned int data_end; | |
3721 | unsigned int old_data_start; | |
3722 | unsigned int old_size; | |
3723 | unsigned int size_diff; | |
3724 | int i; | |
cfed81a0 CM |
3725 | struct btrfs_map_token token; |
3726 | ||
5f39d397 | 3727 | leaf = path->nodes[0]; |
179e29e4 CM |
3728 | slot = path->slots[0]; |
3729 | ||
3212fa14 | 3730 | old_size = btrfs_item_size(leaf, slot); |
179e29e4 | 3731 | if (old_size == new_size) |
143bede5 | 3732 | return; |
b18c6685 | 3733 | |
5f39d397 | 3734 | nritems = btrfs_header_nritems(leaf); |
8f881e8c | 3735 | data_end = leaf_data_end(leaf); |
b18c6685 | 3736 | |
3212fa14 | 3737 | old_data_start = btrfs_item_offset(leaf, slot); |
179e29e4 | 3738 | |
b18c6685 CM |
3739 | size_diff = old_size - new_size; |
3740 | ||
3741 | BUG_ON(slot < 0); | |
3742 | BUG_ON(slot >= nritems); | |
3743 | ||
3744 | /* | |
3745 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3746 | */ | |
3747 | /* first correct the data pointers */ | |
c82f823c | 3748 | btrfs_init_map_token(&token, leaf); |
b18c6685 | 3749 | for (i = slot; i < nritems; i++) { |
5f39d397 | 3750 | u32 ioff; |
db94535d | 3751 | |
3212fa14 JB |
3752 | ioff = btrfs_token_item_offset(&token, i); |
3753 | btrfs_set_token_item_offset(&token, i, ioff + size_diff); | |
b18c6685 | 3754 | } |
db94535d | 3755 | |
b18c6685 | 3756 | /* shift the data */ |
179e29e4 | 3757 | if (from_end) { |
3d9ec8c4 NB |
3758 | memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + |
3759 | data_end + size_diff, BTRFS_LEAF_DATA_OFFSET + | |
179e29e4 CM |
3760 | data_end, old_data_start + new_size - data_end); |
3761 | } else { | |
3762 | struct btrfs_disk_key disk_key; | |
3763 | u64 offset; | |
3764 | ||
3765 | btrfs_item_key(leaf, &disk_key, slot); | |
3766 | ||
3767 | if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) { | |
3768 | unsigned long ptr; | |
3769 | struct btrfs_file_extent_item *fi; | |
3770 | ||
3771 | fi = btrfs_item_ptr(leaf, slot, | |
3772 | struct btrfs_file_extent_item); | |
3773 | fi = (struct btrfs_file_extent_item *)( | |
3774 | (unsigned long)fi - size_diff); | |
3775 | ||
3776 | if (btrfs_file_extent_type(leaf, fi) == | |
3777 | BTRFS_FILE_EXTENT_INLINE) { | |
3778 | ptr = btrfs_item_ptr_offset(leaf, slot); | |
3779 | memmove_extent_buffer(leaf, ptr, | |
d397712b | 3780 | (unsigned long)fi, |
7ec20afb | 3781 | BTRFS_FILE_EXTENT_INLINE_DATA_START); |
179e29e4 CM |
3782 | } |
3783 | } | |
3784 | ||
3d9ec8c4 NB |
3785 | memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + |
3786 | data_end + size_diff, BTRFS_LEAF_DATA_OFFSET + | |
179e29e4 CM |
3787 | data_end, old_data_start - data_end); |
3788 | ||
3789 | offset = btrfs_disk_key_offset(&disk_key); | |
3790 | btrfs_set_disk_key_offset(&disk_key, offset + size_diff); | |
3791 | btrfs_set_item_key(leaf, &disk_key, slot); | |
3792 | if (slot == 0) | |
b167fa91 | 3793 | fixup_low_keys(path, &disk_key, 1); |
179e29e4 | 3794 | } |
5f39d397 | 3795 | |
3212fa14 | 3796 | btrfs_set_item_size(leaf, slot, new_size); |
5f39d397 | 3797 | btrfs_mark_buffer_dirty(leaf); |
b18c6685 | 3798 | |
e902baac | 3799 | if (btrfs_leaf_free_space(leaf) < 0) { |
a4f78750 | 3800 | btrfs_print_leaf(leaf); |
b18c6685 | 3801 | BUG(); |
5f39d397 | 3802 | } |
b18c6685 CM |
3803 | } |
3804 | ||
d352ac68 | 3805 | /* |
8f69dbd2 | 3806 | * make the item pointed to by the path bigger, data_size is the added size. |
d352ac68 | 3807 | */ |
c71dd880 | 3808 | void btrfs_extend_item(struct btrfs_path *path, u32 data_size) |
6567e837 | 3809 | { |
6567e837 | 3810 | int slot; |
5f39d397 | 3811 | struct extent_buffer *leaf; |
6567e837 CM |
3812 | u32 nritems; |
3813 | unsigned int data_end; | |
3814 | unsigned int old_data; | |
3815 | unsigned int old_size; | |
3816 | int i; | |
cfed81a0 CM |
3817 | struct btrfs_map_token token; |
3818 | ||
5f39d397 | 3819 | leaf = path->nodes[0]; |
6567e837 | 3820 | |
5f39d397 | 3821 | nritems = btrfs_header_nritems(leaf); |
8f881e8c | 3822 | data_end = leaf_data_end(leaf); |
6567e837 | 3823 | |
e902baac | 3824 | if (btrfs_leaf_free_space(leaf) < data_size) { |
a4f78750 | 3825 | btrfs_print_leaf(leaf); |
6567e837 | 3826 | BUG(); |
5f39d397 | 3827 | } |
6567e837 | 3828 | slot = path->slots[0]; |
dc2e724e | 3829 | old_data = btrfs_item_data_end(leaf, slot); |
6567e837 CM |
3830 | |
3831 | BUG_ON(slot < 0); | |
3326d1b0 | 3832 | if (slot >= nritems) { |
a4f78750 | 3833 | btrfs_print_leaf(leaf); |
c71dd880 | 3834 | btrfs_crit(leaf->fs_info, "slot %d too large, nritems %d", |
0b246afa | 3835 | slot, nritems); |
290342f6 | 3836 | BUG(); |
3326d1b0 | 3837 | } |
6567e837 CM |
3838 | |
3839 | /* | |
3840 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3841 | */ | |
3842 | /* first correct the data pointers */ | |
c82f823c | 3843 | btrfs_init_map_token(&token, leaf); |
6567e837 | 3844 | for (i = slot; i < nritems; i++) { |
5f39d397 | 3845 | u32 ioff; |
db94535d | 3846 | |
3212fa14 JB |
3847 | ioff = btrfs_token_item_offset(&token, i); |
3848 | btrfs_set_token_item_offset(&token, i, ioff - data_size); | |
6567e837 | 3849 | } |
5f39d397 | 3850 | |
6567e837 | 3851 | /* shift the data */ |
3d9ec8c4 NB |
3852 | memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + |
3853 | data_end - data_size, BTRFS_LEAF_DATA_OFFSET + | |
6567e837 | 3854 | data_end, old_data - data_end); |
5f39d397 | 3855 | |
6567e837 | 3856 | data_end = old_data; |
3212fa14 JB |
3857 | old_size = btrfs_item_size(leaf, slot); |
3858 | btrfs_set_item_size(leaf, slot, old_size + data_size); | |
5f39d397 | 3859 | btrfs_mark_buffer_dirty(leaf); |
6567e837 | 3860 | |
e902baac | 3861 | if (btrfs_leaf_free_space(leaf) < 0) { |
a4f78750 | 3862 | btrfs_print_leaf(leaf); |
6567e837 | 3863 | BUG(); |
5f39d397 | 3864 | } |
6567e837 CM |
3865 | } |
3866 | ||
da9ffb24 NB |
3867 | /** |
3868 | * setup_items_for_insert - Helper called before inserting one or more items | |
3869 | * to a leaf. Main purpose is to save stack depth by doing the bulk of the work | |
3870 | * in a function that doesn't call btrfs_search_slot | |
3871 | * | |
3872 | * @root: root we are inserting items to | |
3873 | * @path: points to the leaf/slot where we are going to insert new items | |
b7ef5f3a | 3874 | * @batch: information about the batch of items to insert |
74123bd7 | 3875 | */ |
f0641656 FM |
3876 | static void setup_items_for_insert(struct btrfs_root *root, struct btrfs_path *path, |
3877 | const struct btrfs_item_batch *batch) | |
be0e5c09 | 3878 | { |
0b246afa | 3879 | struct btrfs_fs_info *fs_info = root->fs_info; |
9c58309d | 3880 | int i; |
7518a238 | 3881 | u32 nritems; |
be0e5c09 | 3882 | unsigned int data_end; |
e2fa7227 | 3883 | struct btrfs_disk_key disk_key; |
44871b1b CM |
3884 | struct extent_buffer *leaf; |
3885 | int slot; | |
cfed81a0 | 3886 | struct btrfs_map_token token; |
fc0d82e1 | 3887 | u32 total_size; |
cfed81a0 | 3888 | |
b7ef5f3a FM |
3889 | /* |
3890 | * Before anything else, update keys in the parent and other ancestors | |
3891 | * if needed, then release the write locks on them, so that other tasks | |
3892 | * can use them while we modify the leaf. | |
3893 | */ | |
24cdc847 | 3894 | if (path->slots[0] == 0) { |
b7ef5f3a | 3895 | btrfs_cpu_key_to_disk(&disk_key, &batch->keys[0]); |
b167fa91 | 3896 | fixup_low_keys(path, &disk_key, 1); |
24cdc847 FM |
3897 | } |
3898 | btrfs_unlock_up_safe(path, 1); | |
3899 | ||
5f39d397 | 3900 | leaf = path->nodes[0]; |
44871b1b | 3901 | slot = path->slots[0]; |
74123bd7 | 3902 | |
5f39d397 | 3903 | nritems = btrfs_header_nritems(leaf); |
8f881e8c | 3904 | data_end = leaf_data_end(leaf); |
b7ef5f3a | 3905 | total_size = batch->total_data_size + (batch->nr * sizeof(struct btrfs_item)); |
eb60ceac | 3906 | |
e902baac | 3907 | if (btrfs_leaf_free_space(leaf) < total_size) { |
a4f78750 | 3908 | btrfs_print_leaf(leaf); |
0b246afa | 3909 | btrfs_crit(fs_info, "not enough freespace need %u have %d", |
e902baac | 3910 | total_size, btrfs_leaf_free_space(leaf)); |
be0e5c09 | 3911 | BUG(); |
d4dbff95 | 3912 | } |
5f39d397 | 3913 | |
c82f823c | 3914 | btrfs_init_map_token(&token, leaf); |
be0e5c09 | 3915 | if (slot != nritems) { |
dc2e724e | 3916 | unsigned int old_data = btrfs_item_data_end(leaf, slot); |
be0e5c09 | 3917 | |
5f39d397 | 3918 | if (old_data < data_end) { |
a4f78750 | 3919 | btrfs_print_leaf(leaf); |
7269ddd2 NB |
3920 | btrfs_crit(fs_info, |
3921 | "item at slot %d with data offset %u beyond data end of leaf %u", | |
5d163e0e | 3922 | slot, old_data, data_end); |
290342f6 | 3923 | BUG(); |
5f39d397 | 3924 | } |
be0e5c09 CM |
3925 | /* |
3926 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3927 | */ | |
3928 | /* first correct the data pointers */ | |
0783fcfc | 3929 | for (i = slot; i < nritems; i++) { |
5f39d397 | 3930 | u32 ioff; |
db94535d | 3931 | |
3212fa14 JB |
3932 | ioff = btrfs_token_item_offset(&token, i); |
3933 | btrfs_set_token_item_offset(&token, i, | |
74794207 | 3934 | ioff - batch->total_data_size); |
0783fcfc | 3935 | } |
be0e5c09 | 3936 | /* shift the items */ |
b7ef5f3a | 3937 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + batch->nr), |
5f39d397 | 3938 | btrfs_item_nr_offset(slot), |
d6025579 | 3939 | (nritems - slot) * sizeof(struct btrfs_item)); |
be0e5c09 CM |
3940 | |
3941 | /* shift the data */ | |
3d9ec8c4 | 3942 | memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + |
b7ef5f3a FM |
3943 | data_end - batch->total_data_size, |
3944 | BTRFS_LEAF_DATA_OFFSET + data_end, | |
3945 | old_data - data_end); | |
be0e5c09 CM |
3946 | data_end = old_data; |
3947 | } | |
5f39d397 | 3948 | |
62e2749e | 3949 | /* setup the item for the new data */ |
b7ef5f3a FM |
3950 | for (i = 0; i < batch->nr; i++) { |
3951 | btrfs_cpu_key_to_disk(&disk_key, &batch->keys[i]); | |
9c58309d | 3952 | btrfs_set_item_key(leaf, &disk_key, slot + i); |
b7ef5f3a | 3953 | data_end -= batch->data_sizes[i]; |
3212fa14 JB |
3954 | btrfs_set_token_item_offset(&token, slot + i, data_end); |
3955 | btrfs_set_token_item_size(&token, slot + i, batch->data_sizes[i]); | |
9c58309d | 3956 | } |
44871b1b | 3957 | |
b7ef5f3a | 3958 | btrfs_set_header_nritems(leaf, nritems + batch->nr); |
b9473439 | 3959 | btrfs_mark_buffer_dirty(leaf); |
aa5d6bed | 3960 | |
e902baac | 3961 | if (btrfs_leaf_free_space(leaf) < 0) { |
a4f78750 | 3962 | btrfs_print_leaf(leaf); |
be0e5c09 | 3963 | BUG(); |
5f39d397 | 3964 | } |
44871b1b CM |
3965 | } |
3966 | ||
f0641656 FM |
3967 | /* |
3968 | * Insert a new item into a leaf. | |
3969 | * | |
3970 | * @root: The root of the btree. | |
3971 | * @path: A path pointing to the target leaf and slot. | |
3972 | * @key: The key of the new item. | |
3973 | * @data_size: The size of the data associated with the new key. | |
3974 | */ | |
3975 | void btrfs_setup_item_for_insert(struct btrfs_root *root, | |
3976 | struct btrfs_path *path, | |
3977 | const struct btrfs_key *key, | |
3978 | u32 data_size) | |
3979 | { | |
3980 | struct btrfs_item_batch batch; | |
3981 | ||
3982 | batch.keys = key; | |
3983 | batch.data_sizes = &data_size; | |
3984 | batch.total_data_size = data_size; | |
3985 | batch.nr = 1; | |
3986 | ||
3987 | setup_items_for_insert(root, path, &batch); | |
3988 | } | |
3989 | ||
44871b1b CM |
3990 | /* |
3991 | * Given a key and some data, insert items into the tree. | |
3992 | * This does all the path init required, making room in the tree if needed. | |
3993 | */ | |
3994 | int btrfs_insert_empty_items(struct btrfs_trans_handle *trans, | |
3995 | struct btrfs_root *root, | |
3996 | struct btrfs_path *path, | |
b7ef5f3a | 3997 | const struct btrfs_item_batch *batch) |
44871b1b | 3998 | { |
44871b1b CM |
3999 | int ret = 0; |
4000 | int slot; | |
b7ef5f3a | 4001 | u32 total_size; |
44871b1b | 4002 | |
b7ef5f3a FM |
4003 | total_size = batch->total_data_size + (batch->nr * sizeof(struct btrfs_item)); |
4004 | ret = btrfs_search_slot(trans, root, &batch->keys[0], path, total_size, 1); | |
44871b1b CM |
4005 | if (ret == 0) |
4006 | return -EEXIST; | |
4007 | if (ret < 0) | |
143bede5 | 4008 | return ret; |
44871b1b | 4009 | |
44871b1b CM |
4010 | slot = path->slots[0]; |
4011 | BUG_ON(slot < 0); | |
4012 | ||
b7ef5f3a | 4013 | setup_items_for_insert(root, path, batch); |
143bede5 | 4014 | return 0; |
62e2749e CM |
4015 | } |
4016 | ||
4017 | /* | |
4018 | * Given a key and some data, insert an item into the tree. | |
4019 | * This does all the path init required, making room in the tree if needed. | |
4020 | */ | |
310712b2 OS |
4021 | int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
4022 | const struct btrfs_key *cpu_key, void *data, | |
4023 | u32 data_size) | |
62e2749e CM |
4024 | { |
4025 | int ret = 0; | |
2c90e5d6 | 4026 | struct btrfs_path *path; |
5f39d397 CM |
4027 | struct extent_buffer *leaf; |
4028 | unsigned long ptr; | |
62e2749e | 4029 | |
2c90e5d6 | 4030 | path = btrfs_alloc_path(); |
db5b493a TI |
4031 | if (!path) |
4032 | return -ENOMEM; | |
2c90e5d6 | 4033 | ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size); |
62e2749e | 4034 | if (!ret) { |
5f39d397 CM |
4035 | leaf = path->nodes[0]; |
4036 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
4037 | write_extent_buffer(leaf, data, ptr, data_size); | |
4038 | btrfs_mark_buffer_dirty(leaf); | |
62e2749e | 4039 | } |
2c90e5d6 | 4040 | btrfs_free_path(path); |
aa5d6bed | 4041 | return ret; |
be0e5c09 CM |
4042 | } |
4043 | ||
f0641656 FM |
4044 | /* |
4045 | * This function duplicates an item, giving 'new_key' to the new item. | |
4046 | * It guarantees both items live in the same tree leaf and the new item is | |
4047 | * contiguous with the original item. | |
4048 | * | |
4049 | * This allows us to split a file extent in place, keeping a lock on the leaf | |
4050 | * the entire time. | |
4051 | */ | |
4052 | int btrfs_duplicate_item(struct btrfs_trans_handle *trans, | |
4053 | struct btrfs_root *root, | |
4054 | struct btrfs_path *path, | |
4055 | const struct btrfs_key *new_key) | |
4056 | { | |
4057 | struct extent_buffer *leaf; | |
4058 | int ret; | |
4059 | u32 item_size; | |
4060 | ||
4061 | leaf = path->nodes[0]; | |
3212fa14 | 4062 | item_size = btrfs_item_size(leaf, path->slots[0]); |
f0641656 FM |
4063 | ret = setup_leaf_for_split(trans, root, path, |
4064 | item_size + sizeof(struct btrfs_item)); | |
4065 | if (ret) | |
4066 | return ret; | |
4067 | ||
4068 | path->slots[0]++; | |
4069 | btrfs_setup_item_for_insert(root, path, new_key, item_size); | |
4070 | leaf = path->nodes[0]; | |
4071 | memcpy_extent_buffer(leaf, | |
4072 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
4073 | btrfs_item_ptr_offset(leaf, path->slots[0] - 1), | |
4074 | item_size); | |
4075 | return 0; | |
4076 | } | |
4077 | ||
74123bd7 | 4078 | /* |
5de08d7d | 4079 | * delete the pointer from a given node. |
74123bd7 | 4080 | * |
d352ac68 CM |
4081 | * the tree should have been previously balanced so the deletion does not |
4082 | * empty a node. | |
74123bd7 | 4083 | */ |
afe5fea7 TI |
4084 | static void del_ptr(struct btrfs_root *root, struct btrfs_path *path, |
4085 | int level, int slot) | |
be0e5c09 | 4086 | { |
5f39d397 | 4087 | struct extent_buffer *parent = path->nodes[level]; |
7518a238 | 4088 | u32 nritems; |
f3ea38da | 4089 | int ret; |
be0e5c09 | 4090 | |
5f39d397 | 4091 | nritems = btrfs_header_nritems(parent); |
d397712b | 4092 | if (slot != nritems - 1) { |
bf1d3425 | 4093 | if (level) { |
f3a84ccd FM |
4094 | ret = btrfs_tree_mod_log_insert_move(parent, slot, |
4095 | slot + 1, nritems - slot - 1); | |
bf1d3425 DS |
4096 | BUG_ON(ret < 0); |
4097 | } | |
5f39d397 CM |
4098 | memmove_extent_buffer(parent, |
4099 | btrfs_node_key_ptr_offset(slot), | |
4100 | btrfs_node_key_ptr_offset(slot + 1), | |
d6025579 CM |
4101 | sizeof(struct btrfs_key_ptr) * |
4102 | (nritems - slot - 1)); | |
57ba86c0 | 4103 | } else if (level) { |
f3a84ccd FM |
4104 | ret = btrfs_tree_mod_log_insert_key(parent, slot, |
4105 | BTRFS_MOD_LOG_KEY_REMOVE, GFP_NOFS); | |
57ba86c0 | 4106 | BUG_ON(ret < 0); |
bb803951 | 4107 | } |
f3ea38da | 4108 | |
7518a238 | 4109 | nritems--; |
5f39d397 | 4110 | btrfs_set_header_nritems(parent, nritems); |
7518a238 | 4111 | if (nritems == 0 && parent == root->node) { |
5f39d397 | 4112 | BUG_ON(btrfs_header_level(root->node) != 1); |
bb803951 | 4113 | /* just turn the root into a leaf and break */ |
5f39d397 | 4114 | btrfs_set_header_level(root->node, 0); |
bb803951 | 4115 | } else if (slot == 0) { |
5f39d397 CM |
4116 | struct btrfs_disk_key disk_key; |
4117 | ||
4118 | btrfs_node_key(parent, &disk_key, 0); | |
b167fa91 | 4119 | fixup_low_keys(path, &disk_key, level + 1); |
be0e5c09 | 4120 | } |
d6025579 | 4121 | btrfs_mark_buffer_dirty(parent); |
be0e5c09 CM |
4122 | } |
4123 | ||
323ac95b CM |
4124 | /* |
4125 | * a helper function to delete the leaf pointed to by path->slots[1] and | |
5d4f98a2 | 4126 | * path->nodes[1]. |
323ac95b CM |
4127 | * |
4128 | * This deletes the pointer in path->nodes[1] and frees the leaf | |
4129 | * block extent. zero is returned if it all worked out, < 0 otherwise. | |
4130 | * | |
4131 | * The path must have already been setup for deleting the leaf, including | |
4132 | * all the proper balancing. path->nodes[1] must be locked. | |
4133 | */ | |
143bede5 JM |
4134 | static noinline void btrfs_del_leaf(struct btrfs_trans_handle *trans, |
4135 | struct btrfs_root *root, | |
4136 | struct btrfs_path *path, | |
4137 | struct extent_buffer *leaf) | |
323ac95b | 4138 | { |
5d4f98a2 | 4139 | WARN_ON(btrfs_header_generation(leaf) != trans->transid); |
afe5fea7 | 4140 | del_ptr(root, path, 1, path->slots[1]); |
323ac95b | 4141 | |
4d081c41 CM |
4142 | /* |
4143 | * btrfs_free_extent is expensive, we want to make sure we | |
4144 | * aren't holding any locks when we call it | |
4145 | */ | |
4146 | btrfs_unlock_up_safe(path, 0); | |
4147 | ||
f0486c68 YZ |
4148 | root_sub_used(root, leaf->len); |
4149 | ||
67439dad | 4150 | atomic_inc(&leaf->refs); |
7a163608 | 4151 | btrfs_free_tree_block(trans, btrfs_root_id(root), leaf, 0, 1); |
3083ee2e | 4152 | free_extent_buffer_stale(leaf); |
323ac95b | 4153 | } |
74123bd7 CM |
4154 | /* |
4155 | * delete the item at the leaf level in path. If that empties | |
4156 | * the leaf, remove it from the tree | |
4157 | */ | |
85e21bac CM |
4158 | int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
4159 | struct btrfs_path *path, int slot, int nr) | |
be0e5c09 | 4160 | { |
0b246afa | 4161 | struct btrfs_fs_info *fs_info = root->fs_info; |
5f39d397 | 4162 | struct extent_buffer *leaf; |
aa5d6bed CM |
4163 | int ret = 0; |
4164 | int wret; | |
7518a238 | 4165 | u32 nritems; |
be0e5c09 | 4166 | |
5f39d397 | 4167 | leaf = path->nodes[0]; |
5f39d397 | 4168 | nritems = btrfs_header_nritems(leaf); |
be0e5c09 | 4169 | |
85e21bac | 4170 | if (slot + nr != nritems) { |
0cae23b6 FM |
4171 | const u32 last_off = btrfs_item_offset(leaf, slot + nr - 1); |
4172 | const int data_end = leaf_data_end(leaf); | |
c82f823c | 4173 | struct btrfs_map_token token; |
0cae23b6 FM |
4174 | u32 dsize = 0; |
4175 | int i; | |
4176 | ||
4177 | for (i = 0; i < nr; i++) | |
4178 | dsize += btrfs_item_size(leaf, slot + i); | |
5f39d397 | 4179 | |
3d9ec8c4 | 4180 | memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + |
d6025579 | 4181 | data_end + dsize, |
3d9ec8c4 | 4182 | BTRFS_LEAF_DATA_OFFSET + data_end, |
85e21bac | 4183 | last_off - data_end); |
5f39d397 | 4184 | |
c82f823c | 4185 | btrfs_init_map_token(&token, leaf); |
85e21bac | 4186 | for (i = slot + nr; i < nritems; i++) { |
5f39d397 | 4187 | u32 ioff; |
db94535d | 4188 | |
3212fa14 JB |
4189 | ioff = btrfs_token_item_offset(&token, i); |
4190 | btrfs_set_token_item_offset(&token, i, ioff + dsize); | |
0783fcfc | 4191 | } |
db94535d | 4192 | |
5f39d397 | 4193 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot), |
85e21bac | 4194 | btrfs_item_nr_offset(slot + nr), |
d6025579 | 4195 | sizeof(struct btrfs_item) * |
85e21bac | 4196 | (nritems - slot - nr)); |
be0e5c09 | 4197 | } |
85e21bac CM |
4198 | btrfs_set_header_nritems(leaf, nritems - nr); |
4199 | nritems -= nr; | |
5f39d397 | 4200 | |
74123bd7 | 4201 | /* delete the leaf if we've emptied it */ |
7518a238 | 4202 | if (nritems == 0) { |
5f39d397 CM |
4203 | if (leaf == root->node) { |
4204 | btrfs_set_header_level(leaf, 0); | |
9a8dd150 | 4205 | } else { |
6a884d7d | 4206 | btrfs_clean_tree_block(leaf); |
143bede5 | 4207 | btrfs_del_leaf(trans, root, path, leaf); |
9a8dd150 | 4208 | } |
be0e5c09 | 4209 | } else { |
7518a238 | 4210 | int used = leaf_space_used(leaf, 0, nritems); |
aa5d6bed | 4211 | if (slot == 0) { |
5f39d397 CM |
4212 | struct btrfs_disk_key disk_key; |
4213 | ||
4214 | btrfs_item_key(leaf, &disk_key, 0); | |
b167fa91 | 4215 | fixup_low_keys(path, &disk_key, 1); |
aa5d6bed | 4216 | } |
aa5d6bed | 4217 | |
7c4063d1 FM |
4218 | /* |
4219 | * Try to delete the leaf if it is mostly empty. We do this by | |
4220 | * trying to move all its items into its left and right neighbours. | |
4221 | * If we can't move all the items, then we don't delete it - it's | |
4222 | * not ideal, but future insertions might fill the leaf with more | |
4223 | * items, or items from other leaves might be moved later into our | |
4224 | * leaf due to deletions on those leaves. | |
4225 | */ | |
0b246afa | 4226 | if (used < BTRFS_LEAF_DATA_SIZE(fs_info) / 3) { |
7c4063d1 FM |
4227 | u32 min_push_space; |
4228 | ||
be0e5c09 CM |
4229 | /* push_leaf_left fixes the path. |
4230 | * make sure the path still points to our leaf | |
4231 | * for possible call to del_ptr below | |
4232 | */ | |
4920c9ac | 4233 | slot = path->slots[1]; |
67439dad | 4234 | atomic_inc(&leaf->refs); |
7c4063d1 FM |
4235 | /* |
4236 | * We want to be able to at least push one item to the | |
4237 | * left neighbour leaf, and that's the first item. | |
4238 | */ | |
4239 | min_push_space = sizeof(struct btrfs_item) + | |
4240 | btrfs_item_size(leaf, 0); | |
4241 | wret = push_leaf_left(trans, root, path, 0, | |
4242 | min_push_space, 1, (u32)-1); | |
54aa1f4d | 4243 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed | 4244 | ret = wret; |
5f39d397 CM |
4245 | |
4246 | if (path->nodes[0] == leaf && | |
4247 | btrfs_header_nritems(leaf)) { | |
7c4063d1 FM |
4248 | /* |
4249 | * If we were not able to push all items from our | |
4250 | * leaf to its left neighbour, then attempt to | |
4251 | * either push all the remaining items to the | |
4252 | * right neighbour or none. There's no advantage | |
4253 | * in pushing only some items, instead of all, as | |
4254 | * it's pointless to end up with a leaf having | |
4255 | * too few items while the neighbours can be full | |
4256 | * or nearly full. | |
4257 | */ | |
4258 | nritems = btrfs_header_nritems(leaf); | |
4259 | min_push_space = leaf_space_used(leaf, 0, nritems); | |
4260 | wret = push_leaf_right(trans, root, path, 0, | |
4261 | min_push_space, 1, 0); | |
54aa1f4d | 4262 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed CM |
4263 | ret = wret; |
4264 | } | |
5f39d397 CM |
4265 | |
4266 | if (btrfs_header_nritems(leaf) == 0) { | |
323ac95b | 4267 | path->slots[1] = slot; |
143bede5 | 4268 | btrfs_del_leaf(trans, root, path, leaf); |
5f39d397 | 4269 | free_extent_buffer(leaf); |
143bede5 | 4270 | ret = 0; |
5de08d7d | 4271 | } else { |
925baedd CM |
4272 | /* if we're still in the path, make sure |
4273 | * we're dirty. Otherwise, one of the | |
4274 | * push_leaf functions must have already | |
4275 | * dirtied this buffer | |
4276 | */ | |
4277 | if (path->nodes[0] == leaf) | |
4278 | btrfs_mark_buffer_dirty(leaf); | |
5f39d397 | 4279 | free_extent_buffer(leaf); |
be0e5c09 | 4280 | } |
d5719762 | 4281 | } else { |
5f39d397 | 4282 | btrfs_mark_buffer_dirty(leaf); |
be0e5c09 CM |
4283 | } |
4284 | } | |
aa5d6bed | 4285 | return ret; |
be0e5c09 CM |
4286 | } |
4287 | ||
7bb86316 | 4288 | /* |
925baedd | 4289 | * search the tree again to find a leaf with lesser keys |
7bb86316 CM |
4290 | * returns 0 if it found something or 1 if there are no lesser leaves. |
4291 | * returns < 0 on io errors. | |
d352ac68 CM |
4292 | * |
4293 | * This may release the path, and so you may lose any locks held at the | |
4294 | * time you call it. | |
7bb86316 | 4295 | */ |
16e7549f | 4296 | int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) |
7bb86316 | 4297 | { |
925baedd CM |
4298 | struct btrfs_key key; |
4299 | struct btrfs_disk_key found_key; | |
4300 | int ret; | |
7bb86316 | 4301 | |
925baedd | 4302 | btrfs_item_key_to_cpu(path->nodes[0], &key, 0); |
7bb86316 | 4303 | |
e8b0d724 | 4304 | if (key.offset > 0) { |
925baedd | 4305 | key.offset--; |
e8b0d724 | 4306 | } else if (key.type > 0) { |
925baedd | 4307 | key.type--; |
e8b0d724 FDBM |
4308 | key.offset = (u64)-1; |
4309 | } else if (key.objectid > 0) { | |
925baedd | 4310 | key.objectid--; |
e8b0d724 FDBM |
4311 | key.type = (u8)-1; |
4312 | key.offset = (u64)-1; | |
4313 | } else { | |
925baedd | 4314 | return 1; |
e8b0d724 | 4315 | } |
7bb86316 | 4316 | |
b3b4aa74 | 4317 | btrfs_release_path(path); |
925baedd CM |
4318 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
4319 | if (ret < 0) | |
4320 | return ret; | |
4321 | btrfs_item_key(path->nodes[0], &found_key, 0); | |
4322 | ret = comp_keys(&found_key, &key); | |
337c6f68 FM |
4323 | /* |
4324 | * We might have had an item with the previous key in the tree right | |
4325 | * before we released our path. And after we released our path, that | |
4326 | * item might have been pushed to the first slot (0) of the leaf we | |
4327 | * were holding due to a tree balance. Alternatively, an item with the | |
4328 | * previous key can exist as the only element of a leaf (big fat item). | |
4329 | * Therefore account for these 2 cases, so that our callers (like | |
4330 | * btrfs_previous_item) don't miss an existing item with a key matching | |
4331 | * the previous key we computed above. | |
4332 | */ | |
4333 | if (ret <= 0) | |
925baedd CM |
4334 | return 0; |
4335 | return 1; | |
7bb86316 CM |
4336 | } |
4337 | ||
3f157a2f CM |
4338 | /* |
4339 | * A helper function to walk down the tree starting at min_key, and looking | |
de78b51a ES |
4340 | * for nodes or leaves that are have a minimum transaction id. |
4341 | * This is used by the btree defrag code, and tree logging | |
3f157a2f CM |
4342 | * |
4343 | * This does not cow, but it does stuff the starting key it finds back | |
4344 | * into min_key, so you can call btrfs_search_slot with cow=1 on the | |
4345 | * key and get a writable path. | |
4346 | * | |
3f157a2f CM |
4347 | * This honors path->lowest_level to prevent descent past a given level |
4348 | * of the tree. | |
4349 | * | |
d352ac68 CM |
4350 | * min_trans indicates the oldest transaction that you are interested |
4351 | * in walking through. Any nodes or leaves older than min_trans are | |
4352 | * skipped over (without reading them). | |
4353 | * | |
3f157a2f CM |
4354 | * returns zero if something useful was found, < 0 on error and 1 if there |
4355 | * was nothing in the tree that matched the search criteria. | |
4356 | */ | |
4357 | int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key, | |
de78b51a | 4358 | struct btrfs_path *path, |
3f157a2f CM |
4359 | u64 min_trans) |
4360 | { | |
4361 | struct extent_buffer *cur; | |
4362 | struct btrfs_key found_key; | |
4363 | int slot; | |
9652480b | 4364 | int sret; |
3f157a2f CM |
4365 | u32 nritems; |
4366 | int level; | |
4367 | int ret = 1; | |
f98de9b9 | 4368 | int keep_locks = path->keep_locks; |
3f157a2f | 4369 | |
f98de9b9 | 4370 | path->keep_locks = 1; |
3f157a2f | 4371 | again: |
bd681513 | 4372 | cur = btrfs_read_lock_root_node(root); |
3f157a2f | 4373 | level = btrfs_header_level(cur); |
e02119d5 | 4374 | WARN_ON(path->nodes[level]); |
3f157a2f | 4375 | path->nodes[level] = cur; |
bd681513 | 4376 | path->locks[level] = BTRFS_READ_LOCK; |
3f157a2f CM |
4377 | |
4378 | if (btrfs_header_generation(cur) < min_trans) { | |
4379 | ret = 1; | |
4380 | goto out; | |
4381 | } | |
d397712b | 4382 | while (1) { |
3f157a2f CM |
4383 | nritems = btrfs_header_nritems(cur); |
4384 | level = btrfs_header_level(cur); | |
e3b83361 | 4385 | sret = btrfs_bin_search(cur, min_key, &slot); |
cbca7d59 FM |
4386 | if (sret < 0) { |
4387 | ret = sret; | |
4388 | goto out; | |
4389 | } | |
3f157a2f | 4390 | |
323ac95b CM |
4391 | /* at the lowest level, we're done, setup the path and exit */ |
4392 | if (level == path->lowest_level) { | |
e02119d5 CM |
4393 | if (slot >= nritems) |
4394 | goto find_next_key; | |
3f157a2f CM |
4395 | ret = 0; |
4396 | path->slots[level] = slot; | |
4397 | btrfs_item_key_to_cpu(cur, &found_key, slot); | |
4398 | goto out; | |
4399 | } | |
9652480b Y |
4400 | if (sret && slot > 0) |
4401 | slot--; | |
3f157a2f | 4402 | /* |
de78b51a | 4403 | * check this node pointer against the min_trans parameters. |
260db43c | 4404 | * If it is too old, skip to the next one. |
3f157a2f | 4405 | */ |
d397712b | 4406 | while (slot < nritems) { |
3f157a2f | 4407 | u64 gen; |
e02119d5 | 4408 | |
3f157a2f CM |
4409 | gen = btrfs_node_ptr_generation(cur, slot); |
4410 | if (gen < min_trans) { | |
4411 | slot++; | |
4412 | continue; | |
4413 | } | |
de78b51a | 4414 | break; |
3f157a2f | 4415 | } |
e02119d5 | 4416 | find_next_key: |
3f157a2f CM |
4417 | /* |
4418 | * we didn't find a candidate key in this node, walk forward | |
4419 | * and find another one | |
4420 | */ | |
4421 | if (slot >= nritems) { | |
e02119d5 CM |
4422 | path->slots[level] = slot; |
4423 | sret = btrfs_find_next_key(root, path, min_key, level, | |
de78b51a | 4424 | min_trans); |
e02119d5 | 4425 | if (sret == 0) { |
b3b4aa74 | 4426 | btrfs_release_path(path); |
3f157a2f CM |
4427 | goto again; |
4428 | } else { | |
4429 | goto out; | |
4430 | } | |
4431 | } | |
4432 | /* save our key for returning back */ | |
4433 | btrfs_node_key_to_cpu(cur, &found_key, slot); | |
4434 | path->slots[level] = slot; | |
4435 | if (level == path->lowest_level) { | |
4436 | ret = 0; | |
3f157a2f CM |
4437 | goto out; |
4438 | } | |
4b231ae4 | 4439 | cur = btrfs_read_node_slot(cur, slot); |
fb770ae4 LB |
4440 | if (IS_ERR(cur)) { |
4441 | ret = PTR_ERR(cur); | |
4442 | goto out; | |
4443 | } | |
3f157a2f | 4444 | |
bd681513 | 4445 | btrfs_tree_read_lock(cur); |
b4ce94de | 4446 | |
bd681513 | 4447 | path->locks[level - 1] = BTRFS_READ_LOCK; |
3f157a2f | 4448 | path->nodes[level - 1] = cur; |
f7c79f30 | 4449 | unlock_up(path, level, 1, 0, NULL); |
3f157a2f CM |
4450 | } |
4451 | out: | |
f98de9b9 FM |
4452 | path->keep_locks = keep_locks; |
4453 | if (ret == 0) { | |
4454 | btrfs_unlock_up_safe(path, path->lowest_level + 1); | |
3f157a2f | 4455 | memcpy(min_key, &found_key, sizeof(found_key)); |
f98de9b9 | 4456 | } |
3f157a2f CM |
4457 | return ret; |
4458 | } | |
4459 | ||
4460 | /* | |
4461 | * this is similar to btrfs_next_leaf, but does not try to preserve | |
4462 | * and fixup the path. It looks for and returns the next key in the | |
de78b51a | 4463 | * tree based on the current path and the min_trans parameters. |
3f157a2f CM |
4464 | * |
4465 | * 0 is returned if another key is found, < 0 if there are any errors | |
4466 | * and 1 is returned if there are no higher keys in the tree | |
4467 | * | |
4468 | * path->keep_locks should be set to 1 on the search made before | |
4469 | * calling this function. | |
4470 | */ | |
e7a84565 | 4471 | int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path, |
de78b51a | 4472 | struct btrfs_key *key, int level, u64 min_trans) |
e7a84565 | 4473 | { |
e7a84565 CM |
4474 | int slot; |
4475 | struct extent_buffer *c; | |
4476 | ||
6a9fb468 | 4477 | WARN_ON(!path->keep_locks && !path->skip_locking); |
d397712b | 4478 | while (level < BTRFS_MAX_LEVEL) { |
e7a84565 CM |
4479 | if (!path->nodes[level]) |
4480 | return 1; | |
4481 | ||
4482 | slot = path->slots[level] + 1; | |
4483 | c = path->nodes[level]; | |
3f157a2f | 4484 | next: |
e7a84565 | 4485 | if (slot >= btrfs_header_nritems(c)) { |
33c66f43 YZ |
4486 | int ret; |
4487 | int orig_lowest; | |
4488 | struct btrfs_key cur_key; | |
4489 | if (level + 1 >= BTRFS_MAX_LEVEL || | |
4490 | !path->nodes[level + 1]) | |
e7a84565 | 4491 | return 1; |
33c66f43 | 4492 | |
6a9fb468 | 4493 | if (path->locks[level + 1] || path->skip_locking) { |
33c66f43 YZ |
4494 | level++; |
4495 | continue; | |
4496 | } | |
4497 | ||
4498 | slot = btrfs_header_nritems(c) - 1; | |
4499 | if (level == 0) | |
4500 | btrfs_item_key_to_cpu(c, &cur_key, slot); | |
4501 | else | |
4502 | btrfs_node_key_to_cpu(c, &cur_key, slot); | |
4503 | ||
4504 | orig_lowest = path->lowest_level; | |
b3b4aa74 | 4505 | btrfs_release_path(path); |
33c66f43 YZ |
4506 | path->lowest_level = level; |
4507 | ret = btrfs_search_slot(NULL, root, &cur_key, path, | |
4508 | 0, 0); | |
4509 | path->lowest_level = orig_lowest; | |
4510 | if (ret < 0) | |
4511 | return ret; | |
4512 | ||
4513 | c = path->nodes[level]; | |
4514 | slot = path->slots[level]; | |
4515 | if (ret == 0) | |
4516 | slot++; | |
4517 | goto next; | |
e7a84565 | 4518 | } |
33c66f43 | 4519 | |
e7a84565 CM |
4520 | if (level == 0) |
4521 | btrfs_item_key_to_cpu(c, key, slot); | |
3f157a2f | 4522 | else { |
3f157a2f CM |
4523 | u64 gen = btrfs_node_ptr_generation(c, slot); |
4524 | ||
3f157a2f CM |
4525 | if (gen < min_trans) { |
4526 | slot++; | |
4527 | goto next; | |
4528 | } | |
e7a84565 | 4529 | btrfs_node_key_to_cpu(c, key, slot); |
3f157a2f | 4530 | } |
e7a84565 CM |
4531 | return 0; |
4532 | } | |
4533 | return 1; | |
4534 | } | |
4535 | ||
3d7806ec JS |
4536 | int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path, |
4537 | u64 time_seq) | |
d97e63b6 CM |
4538 | { |
4539 | int slot; | |
8e73f275 | 4540 | int level; |
5f39d397 | 4541 | struct extent_buffer *c; |
8e73f275 | 4542 | struct extent_buffer *next; |
d96b3424 | 4543 | struct btrfs_fs_info *fs_info = root->fs_info; |
925baedd | 4544 | struct btrfs_key key; |
d96b3424 | 4545 | bool need_commit_sem = false; |
925baedd CM |
4546 | u32 nritems; |
4547 | int ret; | |
0e46318d | 4548 | int i; |
925baedd CM |
4549 | |
4550 | nritems = btrfs_header_nritems(path->nodes[0]); | |
d397712b | 4551 | if (nritems == 0) |
925baedd | 4552 | return 1; |
925baedd | 4553 | |
8e73f275 CM |
4554 | btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1); |
4555 | again: | |
4556 | level = 1; | |
4557 | next = NULL; | |
b3b4aa74 | 4558 | btrfs_release_path(path); |
8e73f275 | 4559 | |
a2135011 | 4560 | path->keep_locks = 1; |
8e73f275 | 4561 | |
d96b3424 | 4562 | if (time_seq) { |
3d7806ec | 4563 | ret = btrfs_search_old_slot(root, &key, path, time_seq); |
d96b3424 FM |
4564 | } else { |
4565 | if (path->need_commit_sem) { | |
4566 | path->need_commit_sem = 0; | |
4567 | need_commit_sem = true; | |
4568 | down_read(&fs_info->commit_root_sem); | |
4569 | } | |
3d7806ec | 4570 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
d96b3424 | 4571 | } |
925baedd CM |
4572 | path->keep_locks = 0; |
4573 | ||
4574 | if (ret < 0) | |
d96b3424 | 4575 | goto done; |
925baedd | 4576 | |
a2135011 | 4577 | nritems = btrfs_header_nritems(path->nodes[0]); |
168fd7d2 CM |
4578 | /* |
4579 | * by releasing the path above we dropped all our locks. A balance | |
4580 | * could have added more items next to the key that used to be | |
4581 | * at the very end of the block. So, check again here and | |
4582 | * advance the path if there are now more items available. | |
4583 | */ | |
a2135011 | 4584 | if (nritems > 0 && path->slots[0] < nritems - 1) { |
e457afec YZ |
4585 | if (ret == 0) |
4586 | path->slots[0]++; | |
8e73f275 | 4587 | ret = 0; |
925baedd CM |
4588 | goto done; |
4589 | } | |
0b43e04f LB |
4590 | /* |
4591 | * So the above check misses one case: | |
4592 | * - after releasing the path above, someone has removed the item that | |
4593 | * used to be at the very end of the block, and balance between leafs | |
4594 | * gets another one with bigger key.offset to replace it. | |
4595 | * | |
4596 | * This one should be returned as well, or we can get leaf corruption | |
4597 | * later(esp. in __btrfs_drop_extents()). | |
4598 | * | |
4599 | * And a bit more explanation about this check, | |
4600 | * with ret > 0, the key isn't found, the path points to the slot | |
4601 | * where it should be inserted, so the path->slots[0] item must be the | |
4602 | * bigger one. | |
4603 | */ | |
4604 | if (nritems > 0 && ret > 0 && path->slots[0] == nritems - 1) { | |
4605 | ret = 0; | |
4606 | goto done; | |
4607 | } | |
d97e63b6 | 4608 | |
d397712b | 4609 | while (level < BTRFS_MAX_LEVEL) { |
8e73f275 CM |
4610 | if (!path->nodes[level]) { |
4611 | ret = 1; | |
4612 | goto done; | |
4613 | } | |
5f39d397 | 4614 | |
d97e63b6 CM |
4615 | slot = path->slots[level] + 1; |
4616 | c = path->nodes[level]; | |
5f39d397 | 4617 | if (slot >= btrfs_header_nritems(c)) { |
d97e63b6 | 4618 | level++; |
8e73f275 CM |
4619 | if (level == BTRFS_MAX_LEVEL) { |
4620 | ret = 1; | |
4621 | goto done; | |
4622 | } | |
d97e63b6 CM |
4623 | continue; |
4624 | } | |
5f39d397 | 4625 | |
0e46318d JB |
4626 | |
4627 | /* | |
4628 | * Our current level is where we're going to start from, and to | |
4629 | * make sure lockdep doesn't complain we need to drop our locks | |
4630 | * and nodes from 0 to our current level. | |
4631 | */ | |
4632 | for (i = 0; i < level; i++) { | |
4633 | if (path->locks[level]) { | |
4634 | btrfs_tree_read_unlock(path->nodes[i]); | |
4635 | path->locks[i] = 0; | |
4636 | } | |
4637 | free_extent_buffer(path->nodes[i]); | |
4638 | path->nodes[i] = NULL; | |
925baedd | 4639 | } |
5f39d397 | 4640 | |
8e73f275 | 4641 | next = c; |
d07b8528 | 4642 | ret = read_block_for_search(root, path, &next, level, |
cda79c54 | 4643 | slot, &key); |
8e73f275 CM |
4644 | if (ret == -EAGAIN) |
4645 | goto again; | |
5f39d397 | 4646 | |
76a05b35 | 4647 | if (ret < 0) { |
b3b4aa74 | 4648 | btrfs_release_path(path); |
76a05b35 CM |
4649 | goto done; |
4650 | } | |
4651 | ||
5cd57b2c | 4652 | if (!path->skip_locking) { |
bd681513 | 4653 | ret = btrfs_try_tree_read_lock(next); |
d42244a0 JS |
4654 | if (!ret && time_seq) { |
4655 | /* | |
4656 | * If we don't get the lock, we may be racing | |
4657 | * with push_leaf_left, holding that lock while | |
4658 | * itself waiting for the leaf we've currently | |
4659 | * locked. To solve this situation, we give up | |
4660 | * on our lock and cycle. | |
4661 | */ | |
cf538830 | 4662 | free_extent_buffer(next); |
d42244a0 JS |
4663 | btrfs_release_path(path); |
4664 | cond_resched(); | |
4665 | goto again; | |
4666 | } | |
0e46318d JB |
4667 | if (!ret) |
4668 | btrfs_tree_read_lock(next); | |
5cd57b2c | 4669 | } |
d97e63b6 CM |
4670 | break; |
4671 | } | |
4672 | path->slots[level] = slot; | |
d397712b | 4673 | while (1) { |
d97e63b6 | 4674 | level--; |
d97e63b6 CM |
4675 | path->nodes[level] = next; |
4676 | path->slots[level] = 0; | |
a74a4b97 | 4677 | if (!path->skip_locking) |
ffeb03cf | 4678 | path->locks[level] = BTRFS_READ_LOCK; |
d97e63b6 CM |
4679 | if (!level) |
4680 | break; | |
b4ce94de | 4681 | |
d07b8528 | 4682 | ret = read_block_for_search(root, path, &next, level, |
cda79c54 | 4683 | 0, &key); |
8e73f275 CM |
4684 | if (ret == -EAGAIN) |
4685 | goto again; | |
4686 | ||
76a05b35 | 4687 | if (ret < 0) { |
b3b4aa74 | 4688 | btrfs_release_path(path); |
76a05b35 CM |
4689 | goto done; |
4690 | } | |
4691 | ||
ffeb03cf | 4692 | if (!path->skip_locking) |
0e46318d | 4693 | btrfs_tree_read_lock(next); |
d97e63b6 | 4694 | } |
8e73f275 | 4695 | ret = 0; |
925baedd | 4696 | done: |
f7c79f30 | 4697 | unlock_up(path, 0, 1, 0, NULL); |
d96b3424 FM |
4698 | if (need_commit_sem) { |
4699 | int ret2; | |
4700 | ||
4701 | path->need_commit_sem = 1; | |
4702 | ret2 = finish_need_commit_sem_search(path); | |
4703 | up_read(&fs_info->commit_root_sem); | |
4704 | if (ret2) | |
4705 | ret = ret2; | |
4706 | } | |
8e73f275 CM |
4707 | |
4708 | return ret; | |
d97e63b6 | 4709 | } |
0b86a832 | 4710 | |
3f157a2f CM |
4711 | /* |
4712 | * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps | |
4713 | * searching until it gets past min_objectid or finds an item of 'type' | |
4714 | * | |
4715 | * returns 0 if something is found, 1 if nothing was found and < 0 on error | |
4716 | */ | |
0b86a832 CM |
4717 | int btrfs_previous_item(struct btrfs_root *root, |
4718 | struct btrfs_path *path, u64 min_objectid, | |
4719 | int type) | |
4720 | { | |
4721 | struct btrfs_key found_key; | |
4722 | struct extent_buffer *leaf; | |
e02119d5 | 4723 | u32 nritems; |
0b86a832 CM |
4724 | int ret; |
4725 | ||
d397712b | 4726 | while (1) { |
0b86a832 CM |
4727 | if (path->slots[0] == 0) { |
4728 | ret = btrfs_prev_leaf(root, path); | |
4729 | if (ret != 0) | |
4730 | return ret; | |
4731 | } else { | |
4732 | path->slots[0]--; | |
4733 | } | |
4734 | leaf = path->nodes[0]; | |
e02119d5 CM |
4735 | nritems = btrfs_header_nritems(leaf); |
4736 | if (nritems == 0) | |
4737 | return 1; | |
4738 | if (path->slots[0] == nritems) | |
4739 | path->slots[0]--; | |
4740 | ||
0b86a832 | 4741 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
e02119d5 CM |
4742 | if (found_key.objectid < min_objectid) |
4743 | break; | |
0a4eefbb YZ |
4744 | if (found_key.type == type) |
4745 | return 0; | |
e02119d5 CM |
4746 | if (found_key.objectid == min_objectid && |
4747 | found_key.type < type) | |
4748 | break; | |
0b86a832 CM |
4749 | } |
4750 | return 1; | |
4751 | } | |
ade2e0b3 WS |
4752 | |
4753 | /* | |
4754 | * search in extent tree to find a previous Metadata/Data extent item with | |
4755 | * min objecitd. | |
4756 | * | |
4757 | * returns 0 if something is found, 1 if nothing was found and < 0 on error | |
4758 | */ | |
4759 | int btrfs_previous_extent_item(struct btrfs_root *root, | |
4760 | struct btrfs_path *path, u64 min_objectid) | |
4761 | { | |
4762 | struct btrfs_key found_key; | |
4763 | struct extent_buffer *leaf; | |
4764 | u32 nritems; | |
4765 | int ret; | |
4766 | ||
4767 | while (1) { | |
4768 | if (path->slots[0] == 0) { | |
ade2e0b3 WS |
4769 | ret = btrfs_prev_leaf(root, path); |
4770 | if (ret != 0) | |
4771 | return ret; | |
4772 | } else { | |
4773 | path->slots[0]--; | |
4774 | } | |
4775 | leaf = path->nodes[0]; | |
4776 | nritems = btrfs_header_nritems(leaf); | |
4777 | if (nritems == 0) | |
4778 | return 1; | |
4779 | if (path->slots[0] == nritems) | |
4780 | path->slots[0]--; | |
4781 | ||
4782 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); | |
4783 | if (found_key.objectid < min_objectid) | |
4784 | break; | |
4785 | if (found_key.type == BTRFS_EXTENT_ITEM_KEY || | |
4786 | found_key.type == BTRFS_METADATA_ITEM_KEY) | |
4787 | return 0; | |
4788 | if (found_key.objectid == min_objectid && | |
4789 | found_key.type < BTRFS_EXTENT_ITEM_KEY) | |
4790 | break; | |
4791 | } | |
4792 | return 1; | |
4793 | } |