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c1d7c514 | 1 | // SPDX-License-Identifier: GPL-2.0 |
6cbd5570 | 2 | /* |
d352ac68 | 3 | * Copyright (C) 2007,2008 Oracle. All rights reserved. |
6cbd5570 CM |
4 | */ |
5 | ||
a6b6e75e | 6 | #include <linux/sched.h> |
5a0e3ad6 | 7 | #include <linux/slab.h> |
bd989ba3 | 8 | #include <linux/rbtree.h> |
adf02123 | 9 | #include <linux/mm.h> |
e41d12f5 | 10 | #include <linux/error-injection.h> |
9b569ea0 | 11 | #include "messages.h" |
eb60ceac CM |
12 | #include "ctree.h" |
13 | #include "disk-io.h" | |
7f5c1516 | 14 | #include "transaction.h" |
5f39d397 | 15 | #include "print-tree.h" |
925baedd | 16 | #include "locking.h" |
de37aa51 | 17 | #include "volumes.h" |
f616f5cd | 18 | #include "qgroup.h" |
f3a84ccd | 19 | #include "tree-mod-log.h" |
88c602ab | 20 | #include "tree-checker.h" |
ec8eb376 | 21 | #include "fs.h" |
ad1ac501 | 22 | #include "accessors.h" |
a0231804 | 23 | #include "extent-tree.h" |
67707479 | 24 | #include "relocation.h" |
9a8dd150 | 25 | |
226463d7 JB |
26 | static struct kmem_cache *btrfs_path_cachep; |
27 | ||
e089f05c CM |
28 | static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root |
29 | *root, struct btrfs_path *path, int level); | |
310712b2 OS |
30 | static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
31 | const struct btrfs_key *ins_key, struct btrfs_path *path, | |
32 | int data_size, int extend); | |
5f39d397 | 33 | static int push_node_left(struct btrfs_trans_handle *trans, |
2ff7e61e | 34 | struct extent_buffer *dst, |
971a1f66 | 35 | struct extent_buffer *src, int empty); |
5f39d397 | 36 | static int balance_node_right(struct btrfs_trans_handle *trans, |
5f39d397 CM |
37 | struct extent_buffer *dst_buf, |
38 | struct extent_buffer *src_buf); | |
afe5fea7 TI |
39 | static void del_ptr(struct btrfs_root *root, struct btrfs_path *path, |
40 | int level, int slot); | |
d97e63b6 | 41 | |
af024ed2 JT |
42 | static const struct btrfs_csums { |
43 | u16 size; | |
59a0fcdb DS |
44 | const char name[10]; |
45 | const char driver[12]; | |
af024ed2 JT |
46 | } btrfs_csums[] = { |
47 | [BTRFS_CSUM_TYPE_CRC32] = { .size = 4, .name = "crc32c" }, | |
3951e7f0 | 48 | [BTRFS_CSUM_TYPE_XXHASH] = { .size = 8, .name = "xxhash64" }, |
3831bf00 | 49 | [BTRFS_CSUM_TYPE_SHA256] = { .size = 32, .name = "sha256" }, |
352ae07b DS |
50 | [BTRFS_CSUM_TYPE_BLAKE2] = { .size = 32, .name = "blake2b", |
51 | .driver = "blake2b-256" }, | |
af024ed2 JT |
52 | }; |
53 | ||
54 | int btrfs_super_csum_size(const struct btrfs_super_block *s) | |
55 | { | |
56 | u16 t = btrfs_super_csum_type(s); | |
57 | /* | |
58 | * csum type is validated at mount time | |
59 | */ | |
60 | return btrfs_csums[t].size; | |
61 | } | |
62 | ||
63 | const char *btrfs_super_csum_name(u16 csum_type) | |
64 | { | |
65 | /* csum type is validated at mount time */ | |
66 | return btrfs_csums[csum_type].name; | |
67 | } | |
68 | ||
b4e967be DS |
69 | /* |
70 | * Return driver name if defined, otherwise the name that's also a valid driver | |
71 | * name | |
72 | */ | |
73 | const char *btrfs_super_csum_driver(u16 csum_type) | |
74 | { | |
75 | /* csum type is validated at mount time */ | |
59a0fcdb DS |
76 | return btrfs_csums[csum_type].driver[0] ? |
77 | btrfs_csums[csum_type].driver : | |
b4e967be DS |
78 | btrfs_csums[csum_type].name; |
79 | } | |
80 | ||
604997b4 | 81 | size_t __attribute_const__ btrfs_get_num_csums(void) |
f7cea56c DS |
82 | { |
83 | return ARRAY_SIZE(btrfs_csums); | |
84 | } | |
85 | ||
df24a2b9 | 86 | struct btrfs_path *btrfs_alloc_path(void) |
2c90e5d6 | 87 | { |
e2c89907 | 88 | return kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS); |
2c90e5d6 CM |
89 | } |
90 | ||
d352ac68 | 91 | /* this also releases the path */ |
df24a2b9 | 92 | void btrfs_free_path(struct btrfs_path *p) |
be0e5c09 | 93 | { |
ff175d57 JJ |
94 | if (!p) |
95 | return; | |
b3b4aa74 | 96 | btrfs_release_path(p); |
df24a2b9 | 97 | kmem_cache_free(btrfs_path_cachep, p); |
be0e5c09 CM |
98 | } |
99 | ||
d352ac68 CM |
100 | /* |
101 | * path release drops references on the extent buffers in the path | |
102 | * and it drops any locks held by this path | |
103 | * | |
104 | * It is safe to call this on paths that no locks or extent buffers held. | |
105 | */ | |
b3b4aa74 | 106 | noinline void btrfs_release_path(struct btrfs_path *p) |
eb60ceac CM |
107 | { |
108 | int i; | |
a2135011 | 109 | |
234b63a0 | 110 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) { |
3f157a2f | 111 | p->slots[i] = 0; |
eb60ceac | 112 | if (!p->nodes[i]) |
925baedd CM |
113 | continue; |
114 | if (p->locks[i]) { | |
bd681513 | 115 | btrfs_tree_unlock_rw(p->nodes[i], p->locks[i]); |
925baedd CM |
116 | p->locks[i] = 0; |
117 | } | |
5f39d397 | 118 | free_extent_buffer(p->nodes[i]); |
3f157a2f | 119 | p->nodes[i] = NULL; |
eb60ceac CM |
120 | } |
121 | } | |
122 | ||
8bb808c6 DS |
123 | /* |
124 | * We want the transaction abort to print stack trace only for errors where the | |
125 | * cause could be a bug, eg. due to ENOSPC, and not for common errors that are | |
126 | * caused by external factors. | |
127 | */ | |
128 | bool __cold abort_should_print_stack(int errno) | |
129 | { | |
130 | switch (errno) { | |
131 | case -EIO: | |
132 | case -EROFS: | |
133 | case -ENOMEM: | |
134 | return false; | |
135 | } | |
136 | return true; | |
137 | } | |
138 | ||
d352ac68 CM |
139 | /* |
140 | * safely gets a reference on the root node of a tree. A lock | |
141 | * is not taken, so a concurrent writer may put a different node | |
142 | * at the root of the tree. See btrfs_lock_root_node for the | |
143 | * looping required. | |
144 | * | |
145 | * The extent buffer returned by this has a reference taken, so | |
146 | * it won't disappear. It may stop being the root of the tree | |
147 | * at any time because there are no locks held. | |
148 | */ | |
925baedd CM |
149 | struct extent_buffer *btrfs_root_node(struct btrfs_root *root) |
150 | { | |
151 | struct extent_buffer *eb; | |
240f62c8 | 152 | |
3083ee2e JB |
153 | while (1) { |
154 | rcu_read_lock(); | |
155 | eb = rcu_dereference(root->node); | |
156 | ||
157 | /* | |
158 | * RCU really hurts here, we could free up the root node because | |
01327610 | 159 | * it was COWed but we may not get the new root node yet so do |
3083ee2e JB |
160 | * the inc_not_zero dance and if it doesn't work then |
161 | * synchronize_rcu and try again. | |
162 | */ | |
163 | if (atomic_inc_not_zero(&eb->refs)) { | |
164 | rcu_read_unlock(); | |
165 | break; | |
166 | } | |
167 | rcu_read_unlock(); | |
168 | synchronize_rcu(); | |
169 | } | |
925baedd CM |
170 | return eb; |
171 | } | |
172 | ||
92a7cc42 QW |
173 | /* |
174 | * Cowonly root (not-shareable trees, everything not subvolume or reloc roots), | |
175 | * just get put onto a simple dirty list. Transaction walks this list to make | |
176 | * sure they get properly updated on disk. | |
d352ac68 | 177 | */ |
0b86a832 CM |
178 | static void add_root_to_dirty_list(struct btrfs_root *root) |
179 | { | |
0b246afa JM |
180 | struct btrfs_fs_info *fs_info = root->fs_info; |
181 | ||
e7070be1 JB |
182 | if (test_bit(BTRFS_ROOT_DIRTY, &root->state) || |
183 | !test_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state)) | |
184 | return; | |
185 | ||
0b246afa | 186 | spin_lock(&fs_info->trans_lock); |
e7070be1 JB |
187 | if (!test_and_set_bit(BTRFS_ROOT_DIRTY, &root->state)) { |
188 | /* Want the extent tree to be the last on the list */ | |
4fd786e6 | 189 | if (root->root_key.objectid == BTRFS_EXTENT_TREE_OBJECTID) |
e7070be1 | 190 | list_move_tail(&root->dirty_list, |
0b246afa | 191 | &fs_info->dirty_cowonly_roots); |
e7070be1 JB |
192 | else |
193 | list_move(&root->dirty_list, | |
0b246afa | 194 | &fs_info->dirty_cowonly_roots); |
0b86a832 | 195 | } |
0b246afa | 196 | spin_unlock(&fs_info->trans_lock); |
0b86a832 CM |
197 | } |
198 | ||
d352ac68 CM |
199 | /* |
200 | * used by snapshot creation to make a copy of a root for a tree with | |
201 | * a given objectid. The buffer with the new root node is returned in | |
202 | * cow_ret, and this func returns zero on success or a negative error code. | |
203 | */ | |
be20aa9d CM |
204 | int btrfs_copy_root(struct btrfs_trans_handle *trans, |
205 | struct btrfs_root *root, | |
206 | struct extent_buffer *buf, | |
207 | struct extent_buffer **cow_ret, u64 new_root_objectid) | |
208 | { | |
0b246afa | 209 | struct btrfs_fs_info *fs_info = root->fs_info; |
be20aa9d | 210 | struct extent_buffer *cow; |
be20aa9d CM |
211 | int ret = 0; |
212 | int level; | |
5d4f98a2 | 213 | struct btrfs_disk_key disk_key; |
be20aa9d | 214 | |
92a7cc42 | 215 | WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && |
0b246afa | 216 | trans->transid != fs_info->running_transaction->transid); |
92a7cc42 | 217 | WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && |
27cdeb70 | 218 | trans->transid != root->last_trans); |
be20aa9d CM |
219 | |
220 | level = btrfs_header_level(buf); | |
5d4f98a2 YZ |
221 | if (level == 0) |
222 | btrfs_item_key(buf, &disk_key, 0); | |
223 | else | |
224 | btrfs_node_key(buf, &disk_key, 0); | |
31840ae1 | 225 | |
4d75f8a9 | 226 | cow = btrfs_alloc_tree_block(trans, root, 0, new_root_objectid, |
cf6f34aa JB |
227 | &disk_key, level, buf->start, 0, |
228 | BTRFS_NESTING_NEW_ROOT); | |
5d4f98a2 | 229 | if (IS_ERR(cow)) |
be20aa9d CM |
230 | return PTR_ERR(cow); |
231 | ||
58e8012c | 232 | copy_extent_buffer_full(cow, buf); |
be20aa9d CM |
233 | btrfs_set_header_bytenr(cow, cow->start); |
234 | btrfs_set_header_generation(cow, trans->transid); | |
5d4f98a2 YZ |
235 | btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); |
236 | btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | | |
237 | BTRFS_HEADER_FLAG_RELOC); | |
238 | if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) | |
239 | btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); | |
240 | else | |
241 | btrfs_set_header_owner(cow, new_root_objectid); | |
be20aa9d | 242 | |
de37aa51 | 243 | write_extent_buffer_fsid(cow, fs_info->fs_devices->metadata_uuid); |
2b82032c | 244 | |
be20aa9d | 245 | WARN_ON(btrfs_header_generation(buf) > trans->transid); |
5d4f98a2 | 246 | if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) |
e339a6b0 | 247 | ret = btrfs_inc_ref(trans, root, cow, 1); |
5d4f98a2 | 248 | else |
e339a6b0 | 249 | ret = btrfs_inc_ref(trans, root, cow, 0); |
867ed321 | 250 | if (ret) { |
72c9925f FM |
251 | btrfs_tree_unlock(cow); |
252 | free_extent_buffer(cow); | |
867ed321 | 253 | btrfs_abort_transaction(trans, ret); |
be20aa9d | 254 | return ret; |
867ed321 | 255 | } |
be20aa9d CM |
256 | |
257 | btrfs_mark_buffer_dirty(cow); | |
258 | *cow_ret = cow; | |
259 | return 0; | |
260 | } | |
261 | ||
5d4f98a2 YZ |
262 | /* |
263 | * check if the tree block can be shared by multiple trees | |
264 | */ | |
265 | int btrfs_block_can_be_shared(struct btrfs_root *root, | |
266 | struct extent_buffer *buf) | |
267 | { | |
268 | /* | |
92a7cc42 QW |
269 | * Tree blocks not in shareable trees and tree roots are never shared. |
270 | * If a block was allocated after the last snapshot and the block was | |
271 | * not allocated by tree relocation, we know the block is not shared. | |
5d4f98a2 | 272 | */ |
92a7cc42 | 273 | if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && |
5d4f98a2 YZ |
274 | buf != root->node && buf != root->commit_root && |
275 | (btrfs_header_generation(buf) <= | |
276 | btrfs_root_last_snapshot(&root->root_item) || | |
277 | btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))) | |
278 | return 1; | |
a79865c6 | 279 | |
5d4f98a2 YZ |
280 | return 0; |
281 | } | |
282 | ||
283 | static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, | |
284 | struct btrfs_root *root, | |
285 | struct extent_buffer *buf, | |
f0486c68 YZ |
286 | struct extent_buffer *cow, |
287 | int *last_ref) | |
5d4f98a2 | 288 | { |
0b246afa | 289 | struct btrfs_fs_info *fs_info = root->fs_info; |
5d4f98a2 YZ |
290 | u64 refs; |
291 | u64 owner; | |
292 | u64 flags; | |
293 | u64 new_flags = 0; | |
294 | int ret; | |
295 | ||
296 | /* | |
297 | * Backrefs update rules: | |
298 | * | |
299 | * Always use full backrefs for extent pointers in tree block | |
300 | * allocated by tree relocation. | |
301 | * | |
302 | * If a shared tree block is no longer referenced by its owner | |
303 | * tree (btrfs_header_owner(buf) == root->root_key.objectid), | |
304 | * use full backrefs for extent pointers in tree block. | |
305 | * | |
306 | * If a tree block is been relocating | |
307 | * (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID), | |
308 | * use full backrefs for extent pointers in tree block. | |
309 | * The reason for this is some operations (such as drop tree) | |
310 | * are only allowed for blocks use full backrefs. | |
311 | */ | |
312 | ||
313 | if (btrfs_block_can_be_shared(root, buf)) { | |
2ff7e61e | 314 | ret = btrfs_lookup_extent_info(trans, fs_info, buf->start, |
3173a18f JB |
315 | btrfs_header_level(buf), 1, |
316 | &refs, &flags); | |
be1a5564 MF |
317 | if (ret) |
318 | return ret; | |
e5df9573 MF |
319 | if (refs == 0) { |
320 | ret = -EROFS; | |
0b246afa | 321 | btrfs_handle_fs_error(fs_info, ret, NULL); |
e5df9573 MF |
322 | return ret; |
323 | } | |
5d4f98a2 YZ |
324 | } else { |
325 | refs = 1; | |
326 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || | |
327 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
328 | flags = BTRFS_BLOCK_FLAG_FULL_BACKREF; | |
329 | else | |
330 | flags = 0; | |
331 | } | |
332 | ||
333 | owner = btrfs_header_owner(buf); | |
334 | BUG_ON(owner == BTRFS_TREE_RELOC_OBJECTID && | |
335 | !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)); | |
336 | ||
337 | if (refs > 1) { | |
338 | if ((owner == root->root_key.objectid || | |
339 | root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && | |
340 | !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) { | |
e339a6b0 | 341 | ret = btrfs_inc_ref(trans, root, buf, 1); |
692826b2 JM |
342 | if (ret) |
343 | return ret; | |
5d4f98a2 YZ |
344 | |
345 | if (root->root_key.objectid == | |
346 | BTRFS_TREE_RELOC_OBJECTID) { | |
e339a6b0 | 347 | ret = btrfs_dec_ref(trans, root, buf, 0); |
692826b2 JM |
348 | if (ret) |
349 | return ret; | |
e339a6b0 | 350 | ret = btrfs_inc_ref(trans, root, cow, 1); |
692826b2 JM |
351 | if (ret) |
352 | return ret; | |
5d4f98a2 YZ |
353 | } |
354 | new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF; | |
355 | } else { | |
356 | ||
357 | if (root->root_key.objectid == | |
358 | BTRFS_TREE_RELOC_OBJECTID) | |
e339a6b0 | 359 | ret = btrfs_inc_ref(trans, root, cow, 1); |
5d4f98a2 | 360 | else |
e339a6b0 | 361 | ret = btrfs_inc_ref(trans, root, cow, 0); |
692826b2 JM |
362 | if (ret) |
363 | return ret; | |
5d4f98a2 YZ |
364 | } |
365 | if (new_flags != 0) { | |
b1c79e09 JB |
366 | int level = btrfs_header_level(buf); |
367 | ||
42c9d0b5 | 368 | ret = btrfs_set_disk_extent_flags(trans, buf, |
2fe6a5a1 | 369 | new_flags, level); |
be1a5564 MF |
370 | if (ret) |
371 | return ret; | |
5d4f98a2 YZ |
372 | } |
373 | } else { | |
374 | if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) { | |
375 | if (root->root_key.objectid == | |
376 | BTRFS_TREE_RELOC_OBJECTID) | |
e339a6b0 | 377 | ret = btrfs_inc_ref(trans, root, cow, 1); |
5d4f98a2 | 378 | else |
e339a6b0 | 379 | ret = btrfs_inc_ref(trans, root, cow, 0); |
692826b2 JM |
380 | if (ret) |
381 | return ret; | |
e339a6b0 | 382 | ret = btrfs_dec_ref(trans, root, buf, 1); |
692826b2 JM |
383 | if (ret) |
384 | return ret; | |
5d4f98a2 | 385 | } |
6a884d7d | 386 | btrfs_clean_tree_block(buf); |
f0486c68 | 387 | *last_ref = 1; |
5d4f98a2 YZ |
388 | } |
389 | return 0; | |
390 | } | |
391 | ||
d352ac68 | 392 | /* |
d397712b CM |
393 | * does the dirty work in cow of a single block. The parent block (if |
394 | * supplied) is updated to point to the new cow copy. The new buffer is marked | |
395 | * dirty and returned locked. If you modify the block it needs to be marked | |
396 | * dirty again. | |
d352ac68 CM |
397 | * |
398 | * search_start -- an allocation hint for the new block | |
399 | * | |
d397712b CM |
400 | * empty_size -- a hint that you plan on doing more cow. This is the size in |
401 | * bytes the allocator should try to find free next to the block it returns. | |
402 | * This is just a hint and may be ignored by the allocator. | |
d352ac68 | 403 | */ |
d397712b | 404 | static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, |
5f39d397 CM |
405 | struct btrfs_root *root, |
406 | struct extent_buffer *buf, | |
407 | struct extent_buffer *parent, int parent_slot, | |
408 | struct extent_buffer **cow_ret, | |
9631e4cc JB |
409 | u64 search_start, u64 empty_size, |
410 | enum btrfs_lock_nesting nest) | |
02217ed2 | 411 | { |
0b246afa | 412 | struct btrfs_fs_info *fs_info = root->fs_info; |
5d4f98a2 | 413 | struct btrfs_disk_key disk_key; |
5f39d397 | 414 | struct extent_buffer *cow; |
be1a5564 | 415 | int level, ret; |
f0486c68 | 416 | int last_ref = 0; |
925baedd | 417 | int unlock_orig = 0; |
0f5053eb | 418 | u64 parent_start = 0; |
7bb86316 | 419 | |
925baedd CM |
420 | if (*cow_ret == buf) |
421 | unlock_orig = 1; | |
422 | ||
49d0c642 | 423 | btrfs_assert_tree_write_locked(buf); |
925baedd | 424 | |
92a7cc42 | 425 | WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && |
0b246afa | 426 | trans->transid != fs_info->running_transaction->transid); |
92a7cc42 | 427 | WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && |
27cdeb70 | 428 | trans->transid != root->last_trans); |
5f39d397 | 429 | |
7bb86316 | 430 | level = btrfs_header_level(buf); |
31840ae1 | 431 | |
5d4f98a2 YZ |
432 | if (level == 0) |
433 | btrfs_item_key(buf, &disk_key, 0); | |
434 | else | |
435 | btrfs_node_key(buf, &disk_key, 0); | |
436 | ||
0f5053eb GR |
437 | if ((root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && parent) |
438 | parent_start = parent->start; | |
5d4f98a2 | 439 | |
79bd3712 FM |
440 | cow = btrfs_alloc_tree_block(trans, root, parent_start, |
441 | root->root_key.objectid, &disk_key, level, | |
442 | search_start, empty_size, nest); | |
54aa1f4d CM |
443 | if (IS_ERR(cow)) |
444 | return PTR_ERR(cow); | |
6702ed49 | 445 | |
b4ce94de CM |
446 | /* cow is set to blocking by btrfs_init_new_buffer */ |
447 | ||
58e8012c | 448 | copy_extent_buffer_full(cow, buf); |
db94535d | 449 | btrfs_set_header_bytenr(cow, cow->start); |
5f39d397 | 450 | btrfs_set_header_generation(cow, trans->transid); |
5d4f98a2 YZ |
451 | btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); |
452 | btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | | |
453 | BTRFS_HEADER_FLAG_RELOC); | |
454 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) | |
455 | btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); | |
456 | else | |
457 | btrfs_set_header_owner(cow, root->root_key.objectid); | |
6702ed49 | 458 | |
de37aa51 | 459 | write_extent_buffer_fsid(cow, fs_info->fs_devices->metadata_uuid); |
2b82032c | 460 | |
be1a5564 | 461 | ret = update_ref_for_cow(trans, root, buf, cow, &last_ref); |
b68dc2a9 | 462 | if (ret) { |
572c83ac JB |
463 | btrfs_tree_unlock(cow); |
464 | free_extent_buffer(cow); | |
66642832 | 465 | btrfs_abort_transaction(trans, ret); |
b68dc2a9 MF |
466 | return ret; |
467 | } | |
1a40e23b | 468 | |
92a7cc42 | 469 | if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) { |
83d4cfd4 | 470 | ret = btrfs_reloc_cow_block(trans, root, buf, cow); |
93314e3b | 471 | if (ret) { |
572c83ac JB |
472 | btrfs_tree_unlock(cow); |
473 | free_extent_buffer(cow); | |
66642832 | 474 | btrfs_abort_transaction(trans, ret); |
83d4cfd4 | 475 | return ret; |
93314e3b | 476 | } |
83d4cfd4 | 477 | } |
3fd0a558 | 478 | |
02217ed2 | 479 | if (buf == root->node) { |
925baedd | 480 | WARN_ON(parent && parent != buf); |
5d4f98a2 YZ |
481 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || |
482 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
483 | parent_start = buf->start; | |
925baedd | 484 | |
67439dad | 485 | atomic_inc(&cow->refs); |
406808ab | 486 | ret = btrfs_tree_mod_log_insert_root(root->node, cow, true); |
d9d19a01 | 487 | BUG_ON(ret < 0); |
240f62c8 | 488 | rcu_assign_pointer(root->node, cow); |
925baedd | 489 | |
7a163608 FM |
490 | btrfs_free_tree_block(trans, btrfs_root_id(root), buf, |
491 | parent_start, last_ref); | |
5f39d397 | 492 | free_extent_buffer(buf); |
0b86a832 | 493 | add_root_to_dirty_list(root); |
02217ed2 | 494 | } else { |
5d4f98a2 | 495 | WARN_ON(trans->transid != btrfs_header_generation(parent)); |
f3a84ccd | 496 | btrfs_tree_mod_log_insert_key(parent, parent_slot, |
33cff222 | 497 | BTRFS_MOD_LOG_KEY_REPLACE); |
5f39d397 | 498 | btrfs_set_node_blockptr(parent, parent_slot, |
db94535d | 499 | cow->start); |
74493f7a CM |
500 | btrfs_set_node_ptr_generation(parent, parent_slot, |
501 | trans->transid); | |
d6025579 | 502 | btrfs_mark_buffer_dirty(parent); |
5de865ee | 503 | if (last_ref) { |
f3a84ccd | 504 | ret = btrfs_tree_mod_log_free_eb(buf); |
5de865ee | 505 | if (ret) { |
572c83ac JB |
506 | btrfs_tree_unlock(cow); |
507 | free_extent_buffer(cow); | |
66642832 | 508 | btrfs_abort_transaction(trans, ret); |
5de865ee FDBM |
509 | return ret; |
510 | } | |
511 | } | |
7a163608 FM |
512 | btrfs_free_tree_block(trans, btrfs_root_id(root), buf, |
513 | parent_start, last_ref); | |
02217ed2 | 514 | } |
925baedd CM |
515 | if (unlock_orig) |
516 | btrfs_tree_unlock(buf); | |
3083ee2e | 517 | free_extent_buffer_stale(buf); |
ccd467d6 | 518 | btrfs_mark_buffer_dirty(cow); |
2c90e5d6 | 519 | *cow_ret = cow; |
02217ed2 CM |
520 | return 0; |
521 | } | |
522 | ||
5d4f98a2 YZ |
523 | static inline int should_cow_block(struct btrfs_trans_handle *trans, |
524 | struct btrfs_root *root, | |
525 | struct extent_buffer *buf) | |
526 | { | |
f5ee5c9a | 527 | if (btrfs_is_testing(root->fs_info)) |
faa2dbf0 | 528 | return 0; |
fccb84c9 | 529 | |
d1980131 DS |
530 | /* Ensure we can see the FORCE_COW bit */ |
531 | smp_mb__before_atomic(); | |
f1ebcc74 LB |
532 | |
533 | /* | |
534 | * We do not need to cow a block if | |
535 | * 1) this block is not created or changed in this transaction; | |
536 | * 2) this block does not belong to TREE_RELOC tree; | |
537 | * 3) the root is not forced COW. | |
538 | * | |
539 | * What is forced COW: | |
01327610 | 540 | * when we create snapshot during committing the transaction, |
52042d8e | 541 | * after we've finished copying src root, we must COW the shared |
f1ebcc74 LB |
542 | * block to ensure the metadata consistency. |
543 | */ | |
5d4f98a2 YZ |
544 | if (btrfs_header_generation(buf) == trans->transid && |
545 | !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) && | |
546 | !(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID && | |
f1ebcc74 | 547 | btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)) && |
27cdeb70 | 548 | !test_bit(BTRFS_ROOT_FORCE_COW, &root->state)) |
5d4f98a2 YZ |
549 | return 0; |
550 | return 1; | |
551 | } | |
552 | ||
d352ac68 CM |
553 | /* |
554 | * cows a single block, see __btrfs_cow_block for the real work. | |
01327610 | 555 | * This version of it has extra checks so that a block isn't COWed more than |
d352ac68 CM |
556 | * once per transaction, as long as it hasn't been written yet |
557 | */ | |
d397712b | 558 | noinline int btrfs_cow_block(struct btrfs_trans_handle *trans, |
5f39d397 CM |
559 | struct btrfs_root *root, struct extent_buffer *buf, |
560 | struct extent_buffer *parent, int parent_slot, | |
9631e4cc JB |
561 | struct extent_buffer **cow_ret, |
562 | enum btrfs_lock_nesting nest) | |
6702ed49 | 563 | { |
0b246afa | 564 | struct btrfs_fs_info *fs_info = root->fs_info; |
6702ed49 | 565 | u64 search_start; |
f510cfec | 566 | int ret; |
dc17ff8f | 567 | |
83354f07 JB |
568 | if (test_bit(BTRFS_ROOT_DELETING, &root->state)) |
569 | btrfs_err(fs_info, | |
570 | "COW'ing blocks on a fs root that's being dropped"); | |
571 | ||
0b246afa | 572 | if (trans->transaction != fs_info->running_transaction) |
31b1a2bd | 573 | WARN(1, KERN_CRIT "trans %llu running %llu\n", |
c1c9ff7c | 574 | trans->transid, |
0b246afa | 575 | fs_info->running_transaction->transid); |
31b1a2bd | 576 | |
0b246afa | 577 | if (trans->transid != fs_info->generation) |
31b1a2bd | 578 | WARN(1, KERN_CRIT "trans %llu running %llu\n", |
0b246afa | 579 | trans->transid, fs_info->generation); |
dc17ff8f | 580 | |
5d4f98a2 | 581 | if (!should_cow_block(trans, root, buf)) { |
6702ed49 CM |
582 | *cow_ret = buf; |
583 | return 0; | |
584 | } | |
c487685d | 585 | |
ee22184b | 586 | search_start = buf->start & ~((u64)SZ_1G - 1); |
b4ce94de | 587 | |
f616f5cd QW |
588 | /* |
589 | * Before CoWing this block for later modification, check if it's | |
590 | * the subtree root and do the delayed subtree trace if needed. | |
591 | * | |
592 | * Also We don't care about the error, as it's handled internally. | |
593 | */ | |
594 | btrfs_qgroup_trace_subtree_after_cow(trans, root, buf); | |
f510cfec | 595 | ret = __btrfs_cow_block(trans, root, buf, parent, |
9631e4cc | 596 | parent_slot, cow_ret, search_start, 0, nest); |
1abe9b8a | 597 | |
598 | trace_btrfs_cow_block(root, buf, *cow_ret); | |
599 | ||
f510cfec | 600 | return ret; |
6702ed49 | 601 | } |
f75e2b79 | 602 | ALLOW_ERROR_INJECTION(btrfs_cow_block, ERRNO); |
6702ed49 | 603 | |
d352ac68 CM |
604 | /* |
605 | * helper function for defrag to decide if two blocks pointed to by a | |
606 | * node are actually close by | |
607 | */ | |
6b80053d | 608 | static int close_blocks(u64 blocknr, u64 other, u32 blocksize) |
6702ed49 | 609 | { |
6b80053d | 610 | if (blocknr < other && other - (blocknr + blocksize) < 32768) |
6702ed49 | 611 | return 1; |
6b80053d | 612 | if (blocknr > other && blocknr - (other + blocksize) < 32768) |
6702ed49 CM |
613 | return 1; |
614 | return 0; | |
615 | } | |
616 | ||
ce6ef5ab DS |
617 | #ifdef __LITTLE_ENDIAN |
618 | ||
619 | /* | |
620 | * Compare two keys, on little-endian the disk order is same as CPU order and | |
621 | * we can avoid the conversion. | |
622 | */ | |
623 | static int comp_keys(const struct btrfs_disk_key *disk_key, | |
624 | const struct btrfs_key *k2) | |
625 | { | |
626 | const struct btrfs_key *k1 = (const struct btrfs_key *)disk_key; | |
627 | ||
628 | return btrfs_comp_cpu_keys(k1, k2); | |
629 | } | |
630 | ||
631 | #else | |
632 | ||
081e9573 CM |
633 | /* |
634 | * compare two keys in a memcmp fashion | |
635 | */ | |
310712b2 OS |
636 | static int comp_keys(const struct btrfs_disk_key *disk, |
637 | const struct btrfs_key *k2) | |
081e9573 CM |
638 | { |
639 | struct btrfs_key k1; | |
640 | ||
641 | btrfs_disk_key_to_cpu(&k1, disk); | |
642 | ||
20736aba | 643 | return btrfs_comp_cpu_keys(&k1, k2); |
081e9573 | 644 | } |
ce6ef5ab | 645 | #endif |
081e9573 | 646 | |
f3465ca4 JB |
647 | /* |
648 | * same as comp_keys only with two btrfs_key's | |
649 | */ | |
e1f60a65 | 650 | int __pure btrfs_comp_cpu_keys(const struct btrfs_key *k1, const struct btrfs_key *k2) |
f3465ca4 JB |
651 | { |
652 | if (k1->objectid > k2->objectid) | |
653 | return 1; | |
654 | if (k1->objectid < k2->objectid) | |
655 | return -1; | |
656 | if (k1->type > k2->type) | |
657 | return 1; | |
658 | if (k1->type < k2->type) | |
659 | return -1; | |
660 | if (k1->offset > k2->offset) | |
661 | return 1; | |
662 | if (k1->offset < k2->offset) | |
663 | return -1; | |
664 | return 0; | |
665 | } | |
081e9573 | 666 | |
d352ac68 CM |
667 | /* |
668 | * this is used by the defrag code to go through all the | |
669 | * leaves pointed to by a node and reallocate them so that | |
670 | * disk order is close to key order | |
671 | */ | |
6702ed49 | 672 | int btrfs_realloc_node(struct btrfs_trans_handle *trans, |
5f39d397 | 673 | struct btrfs_root *root, struct extent_buffer *parent, |
de78b51a | 674 | int start_slot, u64 *last_ret, |
a6b6e75e | 675 | struct btrfs_key *progress) |
6702ed49 | 676 | { |
0b246afa | 677 | struct btrfs_fs_info *fs_info = root->fs_info; |
6b80053d | 678 | struct extent_buffer *cur; |
6702ed49 | 679 | u64 blocknr; |
e9d0b13b CM |
680 | u64 search_start = *last_ret; |
681 | u64 last_block = 0; | |
6702ed49 CM |
682 | u64 other; |
683 | u32 parent_nritems; | |
6702ed49 CM |
684 | int end_slot; |
685 | int i; | |
686 | int err = 0; | |
6b80053d | 687 | u32 blocksize; |
081e9573 CM |
688 | int progress_passed = 0; |
689 | struct btrfs_disk_key disk_key; | |
6702ed49 | 690 | |
0b246afa JM |
691 | WARN_ON(trans->transaction != fs_info->running_transaction); |
692 | WARN_ON(trans->transid != fs_info->generation); | |
86479a04 | 693 | |
6b80053d | 694 | parent_nritems = btrfs_header_nritems(parent); |
0b246afa | 695 | blocksize = fs_info->nodesize; |
5dfe2be7 | 696 | end_slot = parent_nritems - 1; |
6702ed49 | 697 | |
5dfe2be7 | 698 | if (parent_nritems <= 1) |
6702ed49 CM |
699 | return 0; |
700 | ||
5dfe2be7 | 701 | for (i = start_slot; i <= end_slot; i++) { |
6702ed49 | 702 | int close = 1; |
a6b6e75e | 703 | |
081e9573 CM |
704 | btrfs_node_key(parent, &disk_key, i); |
705 | if (!progress_passed && comp_keys(&disk_key, progress) < 0) | |
706 | continue; | |
707 | ||
708 | progress_passed = 1; | |
6b80053d | 709 | blocknr = btrfs_node_blockptr(parent, i); |
e9d0b13b CM |
710 | if (last_block == 0) |
711 | last_block = blocknr; | |
5708b959 | 712 | |
6702ed49 | 713 | if (i > 0) { |
6b80053d CM |
714 | other = btrfs_node_blockptr(parent, i - 1); |
715 | close = close_blocks(blocknr, other, blocksize); | |
6702ed49 | 716 | } |
5dfe2be7 | 717 | if (!close && i < end_slot) { |
6b80053d CM |
718 | other = btrfs_node_blockptr(parent, i + 1); |
719 | close = close_blocks(blocknr, other, blocksize); | |
6702ed49 | 720 | } |
e9d0b13b CM |
721 | if (close) { |
722 | last_block = blocknr; | |
6702ed49 | 723 | continue; |
e9d0b13b | 724 | } |
6702ed49 | 725 | |
206983b7 JB |
726 | cur = btrfs_read_node_slot(parent, i); |
727 | if (IS_ERR(cur)) | |
728 | return PTR_ERR(cur); | |
e9d0b13b | 729 | if (search_start == 0) |
6b80053d | 730 | search_start = last_block; |
e9d0b13b | 731 | |
e7a84565 | 732 | btrfs_tree_lock(cur); |
6b80053d | 733 | err = __btrfs_cow_block(trans, root, cur, parent, i, |
e7a84565 | 734 | &cur, search_start, |
6b80053d | 735 | min(16 * blocksize, |
9631e4cc JB |
736 | (end_slot - i) * blocksize), |
737 | BTRFS_NESTING_COW); | |
252c38f0 | 738 | if (err) { |
e7a84565 | 739 | btrfs_tree_unlock(cur); |
6b80053d | 740 | free_extent_buffer(cur); |
6702ed49 | 741 | break; |
252c38f0 | 742 | } |
e7a84565 CM |
743 | search_start = cur->start; |
744 | last_block = cur->start; | |
f2183bde | 745 | *last_ret = search_start; |
e7a84565 CM |
746 | btrfs_tree_unlock(cur); |
747 | free_extent_buffer(cur); | |
6702ed49 CM |
748 | } |
749 | return err; | |
750 | } | |
751 | ||
74123bd7 | 752 | /* |
fb81212c | 753 | * Search for a key in the given extent_buffer. |
5f39d397 | 754 | * |
fb81212c FM |
755 | * The lower boundary for the search is specified by the slot number @low. Use a |
756 | * value of 0 to search over the whole extent buffer. | |
74123bd7 | 757 | * |
fb81212c FM |
758 | * The slot in the extent buffer is returned via @slot. If the key exists in the |
759 | * extent buffer, then @slot will point to the slot where the key is, otherwise | |
760 | * it points to the slot where you would insert the key. | |
761 | * | |
762 | * Slot may point to the total number of items (i.e. one position beyond the last | |
763 | * key) if the key is bigger than the last key in the extent buffer. | |
74123bd7 | 764 | */ |
fb81212c | 765 | static noinline int generic_bin_search(struct extent_buffer *eb, int low, |
67d5e289 | 766 | const struct btrfs_key *key, int *slot) |
be0e5c09 | 767 | { |
fb81212c FM |
768 | unsigned long p; |
769 | int item_size; | |
67d5e289 | 770 | int high = btrfs_header_nritems(eb); |
be0e5c09 | 771 | int ret; |
5cd17f34 | 772 | const int key_size = sizeof(struct btrfs_disk_key); |
be0e5c09 | 773 | |
5e24e9af LB |
774 | if (low > high) { |
775 | btrfs_err(eb->fs_info, | |
776 | "%s: low (%d) > high (%d) eb %llu owner %llu level %d", | |
777 | __func__, low, high, eb->start, | |
778 | btrfs_header_owner(eb), btrfs_header_level(eb)); | |
779 | return -EINVAL; | |
780 | } | |
781 | ||
fb81212c FM |
782 | if (btrfs_header_level(eb) == 0) { |
783 | p = offsetof(struct btrfs_leaf, items); | |
784 | item_size = sizeof(struct btrfs_item); | |
785 | } else { | |
786 | p = offsetof(struct btrfs_node, ptrs); | |
787 | item_size = sizeof(struct btrfs_key_ptr); | |
788 | } | |
789 | ||
d397712b | 790 | while (low < high) { |
5cd17f34 DS |
791 | unsigned long oip; |
792 | unsigned long offset; | |
793 | struct btrfs_disk_key *tmp; | |
794 | struct btrfs_disk_key unaligned; | |
795 | int mid; | |
796 | ||
be0e5c09 | 797 | mid = (low + high) / 2; |
5f39d397 | 798 | offset = p + mid * item_size; |
5cd17f34 | 799 | oip = offset_in_page(offset); |
5f39d397 | 800 | |
5cd17f34 | 801 | if (oip + key_size <= PAGE_SIZE) { |
884b07d0 | 802 | const unsigned long idx = get_eb_page_index(offset); |
5cd17f34 | 803 | char *kaddr = page_address(eb->pages[idx]); |
5f39d397 | 804 | |
884b07d0 | 805 | oip = get_eb_offset_in_page(eb, offset); |
5cd17f34 | 806 | tmp = (struct btrfs_disk_key *)(kaddr + oip); |
5f39d397 | 807 | } else { |
5cd17f34 DS |
808 | read_extent_buffer(eb, &unaligned, offset, key_size); |
809 | tmp = &unaligned; | |
5f39d397 | 810 | } |
5cd17f34 | 811 | |
be0e5c09 CM |
812 | ret = comp_keys(tmp, key); |
813 | ||
814 | if (ret < 0) | |
815 | low = mid + 1; | |
816 | else if (ret > 0) | |
817 | high = mid; | |
818 | else { | |
819 | *slot = mid; | |
820 | return 0; | |
821 | } | |
822 | } | |
823 | *slot = low; | |
824 | return 1; | |
825 | } | |
826 | ||
97571fd0 | 827 | /* |
fb81212c FM |
828 | * Simple binary search on an extent buffer. Works for both leaves and nodes, and |
829 | * always searches over the whole range of keys (slot 0 to slot 'nritems - 1'). | |
97571fd0 | 830 | */ |
a74b35ec | 831 | int btrfs_bin_search(struct extent_buffer *eb, const struct btrfs_key *key, |
e3b83361 | 832 | int *slot) |
be0e5c09 | 833 | { |
fb81212c | 834 | return generic_bin_search(eb, 0, key, slot); |
be0e5c09 CM |
835 | } |
836 | ||
f0486c68 YZ |
837 | static void root_add_used(struct btrfs_root *root, u32 size) |
838 | { | |
839 | spin_lock(&root->accounting_lock); | |
840 | btrfs_set_root_used(&root->root_item, | |
841 | btrfs_root_used(&root->root_item) + size); | |
842 | spin_unlock(&root->accounting_lock); | |
843 | } | |
844 | ||
845 | static void root_sub_used(struct btrfs_root *root, u32 size) | |
846 | { | |
847 | spin_lock(&root->accounting_lock); | |
848 | btrfs_set_root_used(&root->root_item, | |
849 | btrfs_root_used(&root->root_item) - size); | |
850 | spin_unlock(&root->accounting_lock); | |
851 | } | |
852 | ||
d352ac68 CM |
853 | /* given a node and slot number, this reads the blocks it points to. The |
854 | * extent buffer is returned with a reference taken (but unlocked). | |
d352ac68 | 855 | */ |
4b231ae4 DS |
856 | struct extent_buffer *btrfs_read_node_slot(struct extent_buffer *parent, |
857 | int slot) | |
bb803951 | 858 | { |
ca7a79ad | 859 | int level = btrfs_header_level(parent); |
789d6a3a | 860 | struct btrfs_tree_parent_check check = { 0 }; |
416bc658 JB |
861 | struct extent_buffer *eb; |
862 | ||
fb770ae4 LB |
863 | if (slot < 0 || slot >= btrfs_header_nritems(parent)) |
864 | return ERR_PTR(-ENOENT); | |
ca7a79ad CM |
865 | |
866 | BUG_ON(level == 0); | |
867 | ||
789d6a3a QW |
868 | check.level = level - 1; |
869 | check.transid = btrfs_node_ptr_generation(parent, slot); | |
870 | check.owner_root = btrfs_header_owner(parent); | |
871 | check.has_first_key = true; | |
872 | btrfs_node_key_to_cpu(parent, &check.first_key, slot); | |
873 | ||
d0d20b0f | 874 | eb = read_tree_block(parent->fs_info, btrfs_node_blockptr(parent, slot), |
789d6a3a | 875 | &check); |
4eb150d6 QW |
876 | if (IS_ERR(eb)) |
877 | return eb; | |
878 | if (!extent_buffer_uptodate(eb)) { | |
fb770ae4 | 879 | free_extent_buffer(eb); |
4eb150d6 | 880 | return ERR_PTR(-EIO); |
416bc658 JB |
881 | } |
882 | ||
883 | return eb; | |
bb803951 CM |
884 | } |
885 | ||
d352ac68 CM |
886 | /* |
887 | * node level balancing, used to make sure nodes are in proper order for | |
888 | * item deletion. We balance from the top down, so we have to make sure | |
889 | * that a deletion won't leave an node completely empty later on. | |
890 | */ | |
e02119d5 | 891 | static noinline int balance_level(struct btrfs_trans_handle *trans, |
98ed5174 CM |
892 | struct btrfs_root *root, |
893 | struct btrfs_path *path, int level) | |
bb803951 | 894 | { |
0b246afa | 895 | struct btrfs_fs_info *fs_info = root->fs_info; |
5f39d397 CM |
896 | struct extent_buffer *right = NULL; |
897 | struct extent_buffer *mid; | |
898 | struct extent_buffer *left = NULL; | |
899 | struct extent_buffer *parent = NULL; | |
bb803951 CM |
900 | int ret = 0; |
901 | int wret; | |
902 | int pslot; | |
bb803951 | 903 | int orig_slot = path->slots[level]; |
79f95c82 | 904 | u64 orig_ptr; |
bb803951 | 905 | |
98e6b1eb | 906 | ASSERT(level > 0); |
bb803951 | 907 | |
5f39d397 | 908 | mid = path->nodes[level]; |
b4ce94de | 909 | |
ac5887c8 | 910 | WARN_ON(path->locks[level] != BTRFS_WRITE_LOCK); |
7bb86316 CM |
911 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
912 | ||
1d4f8a0c | 913 | orig_ptr = btrfs_node_blockptr(mid, orig_slot); |
79f95c82 | 914 | |
a05a9bb1 | 915 | if (level < BTRFS_MAX_LEVEL - 1) { |
5f39d397 | 916 | parent = path->nodes[level + 1]; |
a05a9bb1 LZ |
917 | pslot = path->slots[level + 1]; |
918 | } | |
bb803951 | 919 | |
40689478 CM |
920 | /* |
921 | * deal with the case where there is only one pointer in the root | |
922 | * by promoting the node below to a root | |
923 | */ | |
5f39d397 CM |
924 | if (!parent) { |
925 | struct extent_buffer *child; | |
bb803951 | 926 | |
5f39d397 | 927 | if (btrfs_header_nritems(mid) != 1) |
bb803951 CM |
928 | return 0; |
929 | ||
930 | /* promote the child to a root */ | |
4b231ae4 | 931 | child = btrfs_read_node_slot(mid, 0); |
fb770ae4 LB |
932 | if (IS_ERR(child)) { |
933 | ret = PTR_ERR(child); | |
0b246afa | 934 | btrfs_handle_fs_error(fs_info, ret, NULL); |
305a26af MF |
935 | goto enospc; |
936 | } | |
937 | ||
925baedd | 938 | btrfs_tree_lock(child); |
9631e4cc JB |
939 | ret = btrfs_cow_block(trans, root, child, mid, 0, &child, |
940 | BTRFS_NESTING_COW); | |
f0486c68 YZ |
941 | if (ret) { |
942 | btrfs_tree_unlock(child); | |
943 | free_extent_buffer(child); | |
944 | goto enospc; | |
945 | } | |
2f375ab9 | 946 | |
406808ab | 947 | ret = btrfs_tree_mod_log_insert_root(root->node, child, true); |
d9d19a01 | 948 | BUG_ON(ret < 0); |
240f62c8 | 949 | rcu_assign_pointer(root->node, child); |
925baedd | 950 | |
0b86a832 | 951 | add_root_to_dirty_list(root); |
925baedd | 952 | btrfs_tree_unlock(child); |
b4ce94de | 953 | |
925baedd | 954 | path->locks[level] = 0; |
bb803951 | 955 | path->nodes[level] = NULL; |
6a884d7d | 956 | btrfs_clean_tree_block(mid); |
925baedd | 957 | btrfs_tree_unlock(mid); |
bb803951 | 958 | /* once for the path */ |
5f39d397 | 959 | free_extent_buffer(mid); |
f0486c68 YZ |
960 | |
961 | root_sub_used(root, mid->len); | |
7a163608 | 962 | btrfs_free_tree_block(trans, btrfs_root_id(root), mid, 0, 1); |
bb803951 | 963 | /* once for the root ptr */ |
3083ee2e | 964 | free_extent_buffer_stale(mid); |
f0486c68 | 965 | return 0; |
bb803951 | 966 | } |
5f39d397 | 967 | if (btrfs_header_nritems(mid) > |
0b246afa | 968 | BTRFS_NODEPTRS_PER_BLOCK(fs_info) / 4) |
bb803951 CM |
969 | return 0; |
970 | ||
4b231ae4 | 971 | left = btrfs_read_node_slot(parent, pslot - 1); |
fb770ae4 LB |
972 | if (IS_ERR(left)) |
973 | left = NULL; | |
974 | ||
5f39d397 | 975 | if (left) { |
bf77467a | 976 | __btrfs_tree_lock(left, BTRFS_NESTING_LEFT); |
5f39d397 | 977 | wret = btrfs_cow_block(trans, root, left, |
9631e4cc | 978 | parent, pslot - 1, &left, |
bf59a5a2 | 979 | BTRFS_NESTING_LEFT_COW); |
54aa1f4d CM |
980 | if (wret) { |
981 | ret = wret; | |
982 | goto enospc; | |
983 | } | |
2cc58cf2 | 984 | } |
fb770ae4 | 985 | |
4b231ae4 | 986 | right = btrfs_read_node_slot(parent, pslot + 1); |
fb770ae4 LB |
987 | if (IS_ERR(right)) |
988 | right = NULL; | |
989 | ||
5f39d397 | 990 | if (right) { |
bf77467a | 991 | __btrfs_tree_lock(right, BTRFS_NESTING_RIGHT); |
5f39d397 | 992 | wret = btrfs_cow_block(trans, root, right, |
9631e4cc | 993 | parent, pslot + 1, &right, |
bf59a5a2 | 994 | BTRFS_NESTING_RIGHT_COW); |
2cc58cf2 CM |
995 | if (wret) { |
996 | ret = wret; | |
997 | goto enospc; | |
998 | } | |
999 | } | |
1000 | ||
1001 | /* first, try to make some room in the middle buffer */ | |
5f39d397 CM |
1002 | if (left) { |
1003 | orig_slot += btrfs_header_nritems(left); | |
d30a668f | 1004 | wret = push_node_left(trans, left, mid, 1); |
79f95c82 CM |
1005 | if (wret < 0) |
1006 | ret = wret; | |
bb803951 | 1007 | } |
79f95c82 CM |
1008 | |
1009 | /* | |
1010 | * then try to empty the right most buffer into the middle | |
1011 | */ | |
5f39d397 | 1012 | if (right) { |
d30a668f | 1013 | wret = push_node_left(trans, mid, right, 1); |
54aa1f4d | 1014 | if (wret < 0 && wret != -ENOSPC) |
79f95c82 | 1015 | ret = wret; |
5f39d397 | 1016 | if (btrfs_header_nritems(right) == 0) { |
6a884d7d | 1017 | btrfs_clean_tree_block(right); |
925baedd | 1018 | btrfs_tree_unlock(right); |
afe5fea7 | 1019 | del_ptr(root, path, level + 1, pslot + 1); |
f0486c68 | 1020 | root_sub_used(root, right->len); |
7a163608 FM |
1021 | btrfs_free_tree_block(trans, btrfs_root_id(root), right, |
1022 | 0, 1); | |
3083ee2e | 1023 | free_extent_buffer_stale(right); |
f0486c68 | 1024 | right = NULL; |
bb803951 | 1025 | } else { |
5f39d397 CM |
1026 | struct btrfs_disk_key right_key; |
1027 | btrfs_node_key(right, &right_key, 0); | |
f3a84ccd | 1028 | ret = btrfs_tree_mod_log_insert_key(parent, pslot + 1, |
33cff222 | 1029 | BTRFS_MOD_LOG_KEY_REPLACE); |
0e82bcfe | 1030 | BUG_ON(ret < 0); |
5f39d397 CM |
1031 | btrfs_set_node_key(parent, &right_key, pslot + 1); |
1032 | btrfs_mark_buffer_dirty(parent); | |
bb803951 CM |
1033 | } |
1034 | } | |
5f39d397 | 1035 | if (btrfs_header_nritems(mid) == 1) { |
79f95c82 CM |
1036 | /* |
1037 | * we're not allowed to leave a node with one item in the | |
1038 | * tree during a delete. A deletion from lower in the tree | |
1039 | * could try to delete the only pointer in this node. | |
1040 | * So, pull some keys from the left. | |
1041 | * There has to be a left pointer at this point because | |
1042 | * otherwise we would have pulled some pointers from the | |
1043 | * right | |
1044 | */ | |
305a26af MF |
1045 | if (!left) { |
1046 | ret = -EROFS; | |
0b246afa | 1047 | btrfs_handle_fs_error(fs_info, ret, NULL); |
305a26af MF |
1048 | goto enospc; |
1049 | } | |
55d32ed8 | 1050 | wret = balance_node_right(trans, mid, left); |
54aa1f4d | 1051 | if (wret < 0) { |
79f95c82 | 1052 | ret = wret; |
54aa1f4d CM |
1053 | goto enospc; |
1054 | } | |
bce4eae9 | 1055 | if (wret == 1) { |
d30a668f | 1056 | wret = push_node_left(trans, left, mid, 1); |
bce4eae9 CM |
1057 | if (wret < 0) |
1058 | ret = wret; | |
1059 | } | |
79f95c82 CM |
1060 | BUG_ON(wret == 1); |
1061 | } | |
5f39d397 | 1062 | if (btrfs_header_nritems(mid) == 0) { |
6a884d7d | 1063 | btrfs_clean_tree_block(mid); |
925baedd | 1064 | btrfs_tree_unlock(mid); |
afe5fea7 | 1065 | del_ptr(root, path, level + 1, pslot); |
f0486c68 | 1066 | root_sub_used(root, mid->len); |
7a163608 | 1067 | btrfs_free_tree_block(trans, btrfs_root_id(root), mid, 0, 1); |
3083ee2e | 1068 | free_extent_buffer_stale(mid); |
f0486c68 | 1069 | mid = NULL; |
79f95c82 CM |
1070 | } else { |
1071 | /* update the parent key to reflect our changes */ | |
5f39d397 CM |
1072 | struct btrfs_disk_key mid_key; |
1073 | btrfs_node_key(mid, &mid_key, 0); | |
f3a84ccd | 1074 | ret = btrfs_tree_mod_log_insert_key(parent, pslot, |
33cff222 | 1075 | BTRFS_MOD_LOG_KEY_REPLACE); |
0e82bcfe | 1076 | BUG_ON(ret < 0); |
5f39d397 CM |
1077 | btrfs_set_node_key(parent, &mid_key, pslot); |
1078 | btrfs_mark_buffer_dirty(parent); | |
79f95c82 | 1079 | } |
bb803951 | 1080 | |
79f95c82 | 1081 | /* update the path */ |
5f39d397 CM |
1082 | if (left) { |
1083 | if (btrfs_header_nritems(left) > orig_slot) { | |
67439dad | 1084 | atomic_inc(&left->refs); |
925baedd | 1085 | /* left was locked after cow */ |
5f39d397 | 1086 | path->nodes[level] = left; |
bb803951 CM |
1087 | path->slots[level + 1] -= 1; |
1088 | path->slots[level] = orig_slot; | |
925baedd CM |
1089 | if (mid) { |
1090 | btrfs_tree_unlock(mid); | |
5f39d397 | 1091 | free_extent_buffer(mid); |
925baedd | 1092 | } |
bb803951 | 1093 | } else { |
5f39d397 | 1094 | orig_slot -= btrfs_header_nritems(left); |
bb803951 CM |
1095 | path->slots[level] = orig_slot; |
1096 | } | |
1097 | } | |
79f95c82 | 1098 | /* double check we haven't messed things up */ |
e20d96d6 | 1099 | if (orig_ptr != |
5f39d397 | 1100 | btrfs_node_blockptr(path->nodes[level], path->slots[level])) |
79f95c82 | 1101 | BUG(); |
54aa1f4d | 1102 | enospc: |
925baedd CM |
1103 | if (right) { |
1104 | btrfs_tree_unlock(right); | |
5f39d397 | 1105 | free_extent_buffer(right); |
925baedd CM |
1106 | } |
1107 | if (left) { | |
1108 | if (path->nodes[level] != left) | |
1109 | btrfs_tree_unlock(left); | |
5f39d397 | 1110 | free_extent_buffer(left); |
925baedd | 1111 | } |
bb803951 CM |
1112 | return ret; |
1113 | } | |
1114 | ||
d352ac68 CM |
1115 | /* Node balancing for insertion. Here we only split or push nodes around |
1116 | * when they are completely full. This is also done top down, so we | |
1117 | * have to be pessimistic. | |
1118 | */ | |
d397712b | 1119 | static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, |
98ed5174 CM |
1120 | struct btrfs_root *root, |
1121 | struct btrfs_path *path, int level) | |
e66f709b | 1122 | { |
0b246afa | 1123 | struct btrfs_fs_info *fs_info = root->fs_info; |
5f39d397 CM |
1124 | struct extent_buffer *right = NULL; |
1125 | struct extent_buffer *mid; | |
1126 | struct extent_buffer *left = NULL; | |
1127 | struct extent_buffer *parent = NULL; | |
e66f709b CM |
1128 | int ret = 0; |
1129 | int wret; | |
1130 | int pslot; | |
1131 | int orig_slot = path->slots[level]; | |
e66f709b CM |
1132 | |
1133 | if (level == 0) | |
1134 | return 1; | |
1135 | ||
5f39d397 | 1136 | mid = path->nodes[level]; |
7bb86316 | 1137 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
e66f709b | 1138 | |
a05a9bb1 | 1139 | if (level < BTRFS_MAX_LEVEL - 1) { |
5f39d397 | 1140 | parent = path->nodes[level + 1]; |
a05a9bb1 LZ |
1141 | pslot = path->slots[level + 1]; |
1142 | } | |
e66f709b | 1143 | |
5f39d397 | 1144 | if (!parent) |
e66f709b | 1145 | return 1; |
e66f709b | 1146 | |
4b231ae4 | 1147 | left = btrfs_read_node_slot(parent, pslot - 1); |
fb770ae4 LB |
1148 | if (IS_ERR(left)) |
1149 | left = NULL; | |
e66f709b CM |
1150 | |
1151 | /* first, try to make some room in the middle buffer */ | |
5f39d397 | 1152 | if (left) { |
e66f709b | 1153 | u32 left_nr; |
925baedd | 1154 | |
bf77467a | 1155 | __btrfs_tree_lock(left, BTRFS_NESTING_LEFT); |
b4ce94de | 1156 | |
5f39d397 | 1157 | left_nr = btrfs_header_nritems(left); |
0b246afa | 1158 | if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 1) { |
33ade1f8 CM |
1159 | wret = 1; |
1160 | } else { | |
5f39d397 | 1161 | ret = btrfs_cow_block(trans, root, left, parent, |
9631e4cc | 1162 | pslot - 1, &left, |
bf59a5a2 | 1163 | BTRFS_NESTING_LEFT_COW); |
54aa1f4d CM |
1164 | if (ret) |
1165 | wret = 1; | |
1166 | else { | |
d30a668f | 1167 | wret = push_node_left(trans, left, mid, 0); |
54aa1f4d | 1168 | } |
33ade1f8 | 1169 | } |
e66f709b CM |
1170 | if (wret < 0) |
1171 | ret = wret; | |
1172 | if (wret == 0) { | |
5f39d397 | 1173 | struct btrfs_disk_key disk_key; |
e66f709b | 1174 | orig_slot += left_nr; |
5f39d397 | 1175 | btrfs_node_key(mid, &disk_key, 0); |
f3a84ccd | 1176 | ret = btrfs_tree_mod_log_insert_key(parent, pslot, |
33cff222 | 1177 | BTRFS_MOD_LOG_KEY_REPLACE); |
0e82bcfe | 1178 | BUG_ON(ret < 0); |
5f39d397 CM |
1179 | btrfs_set_node_key(parent, &disk_key, pslot); |
1180 | btrfs_mark_buffer_dirty(parent); | |
1181 | if (btrfs_header_nritems(left) > orig_slot) { | |
1182 | path->nodes[level] = left; | |
e66f709b CM |
1183 | path->slots[level + 1] -= 1; |
1184 | path->slots[level] = orig_slot; | |
925baedd | 1185 | btrfs_tree_unlock(mid); |
5f39d397 | 1186 | free_extent_buffer(mid); |
e66f709b CM |
1187 | } else { |
1188 | orig_slot -= | |
5f39d397 | 1189 | btrfs_header_nritems(left); |
e66f709b | 1190 | path->slots[level] = orig_slot; |
925baedd | 1191 | btrfs_tree_unlock(left); |
5f39d397 | 1192 | free_extent_buffer(left); |
e66f709b | 1193 | } |
e66f709b CM |
1194 | return 0; |
1195 | } | |
925baedd | 1196 | btrfs_tree_unlock(left); |
5f39d397 | 1197 | free_extent_buffer(left); |
e66f709b | 1198 | } |
4b231ae4 | 1199 | right = btrfs_read_node_slot(parent, pslot + 1); |
fb770ae4 LB |
1200 | if (IS_ERR(right)) |
1201 | right = NULL; | |
e66f709b CM |
1202 | |
1203 | /* | |
1204 | * then try to empty the right most buffer into the middle | |
1205 | */ | |
5f39d397 | 1206 | if (right) { |
33ade1f8 | 1207 | u32 right_nr; |
b4ce94de | 1208 | |
bf77467a | 1209 | __btrfs_tree_lock(right, BTRFS_NESTING_RIGHT); |
b4ce94de | 1210 | |
5f39d397 | 1211 | right_nr = btrfs_header_nritems(right); |
0b246afa | 1212 | if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 1) { |
33ade1f8 CM |
1213 | wret = 1; |
1214 | } else { | |
5f39d397 CM |
1215 | ret = btrfs_cow_block(trans, root, right, |
1216 | parent, pslot + 1, | |
bf59a5a2 | 1217 | &right, BTRFS_NESTING_RIGHT_COW); |
54aa1f4d CM |
1218 | if (ret) |
1219 | wret = 1; | |
1220 | else { | |
55d32ed8 | 1221 | wret = balance_node_right(trans, right, mid); |
54aa1f4d | 1222 | } |
33ade1f8 | 1223 | } |
e66f709b CM |
1224 | if (wret < 0) |
1225 | ret = wret; | |
1226 | if (wret == 0) { | |
5f39d397 CM |
1227 | struct btrfs_disk_key disk_key; |
1228 | ||
1229 | btrfs_node_key(right, &disk_key, 0); | |
f3a84ccd | 1230 | ret = btrfs_tree_mod_log_insert_key(parent, pslot + 1, |
33cff222 | 1231 | BTRFS_MOD_LOG_KEY_REPLACE); |
0e82bcfe | 1232 | BUG_ON(ret < 0); |
5f39d397 CM |
1233 | btrfs_set_node_key(parent, &disk_key, pslot + 1); |
1234 | btrfs_mark_buffer_dirty(parent); | |
1235 | ||
1236 | if (btrfs_header_nritems(mid) <= orig_slot) { | |
1237 | path->nodes[level] = right; | |
e66f709b CM |
1238 | path->slots[level + 1] += 1; |
1239 | path->slots[level] = orig_slot - | |
5f39d397 | 1240 | btrfs_header_nritems(mid); |
925baedd | 1241 | btrfs_tree_unlock(mid); |
5f39d397 | 1242 | free_extent_buffer(mid); |
e66f709b | 1243 | } else { |
925baedd | 1244 | btrfs_tree_unlock(right); |
5f39d397 | 1245 | free_extent_buffer(right); |
e66f709b | 1246 | } |
e66f709b CM |
1247 | return 0; |
1248 | } | |
925baedd | 1249 | btrfs_tree_unlock(right); |
5f39d397 | 1250 | free_extent_buffer(right); |
e66f709b | 1251 | } |
e66f709b CM |
1252 | return 1; |
1253 | } | |
1254 | ||
3c69faec | 1255 | /* |
d352ac68 CM |
1256 | * readahead one full node of leaves, finding things that are close |
1257 | * to the block in 'slot', and triggering ra on them. | |
3c69faec | 1258 | */ |
2ff7e61e | 1259 | static void reada_for_search(struct btrfs_fs_info *fs_info, |
c8c42864 CM |
1260 | struct btrfs_path *path, |
1261 | int level, int slot, u64 objectid) | |
3c69faec | 1262 | { |
5f39d397 | 1263 | struct extent_buffer *node; |
01f46658 | 1264 | struct btrfs_disk_key disk_key; |
3c69faec | 1265 | u32 nritems; |
3c69faec | 1266 | u64 search; |
a7175319 | 1267 | u64 target; |
6b80053d | 1268 | u64 nread = 0; |
ace75066 | 1269 | u64 nread_max; |
6b80053d CM |
1270 | u32 nr; |
1271 | u32 blocksize; | |
1272 | u32 nscan = 0; | |
db94535d | 1273 | |
ace75066 | 1274 | if (level != 1 && path->reada != READA_FORWARD_ALWAYS) |
6702ed49 CM |
1275 | return; |
1276 | ||
1277 | if (!path->nodes[level]) | |
3c69faec CM |
1278 | return; |
1279 | ||
5f39d397 | 1280 | node = path->nodes[level]; |
925baedd | 1281 | |
ace75066 FM |
1282 | /* |
1283 | * Since the time between visiting leaves is much shorter than the time | |
1284 | * between visiting nodes, limit read ahead of nodes to 1, to avoid too | |
1285 | * much IO at once (possibly random). | |
1286 | */ | |
1287 | if (path->reada == READA_FORWARD_ALWAYS) { | |
1288 | if (level > 1) | |
1289 | nread_max = node->fs_info->nodesize; | |
1290 | else | |
1291 | nread_max = SZ_128K; | |
1292 | } else { | |
1293 | nread_max = SZ_64K; | |
1294 | } | |
1295 | ||
3c69faec | 1296 | search = btrfs_node_blockptr(node, slot); |
0b246afa | 1297 | blocksize = fs_info->nodesize; |
069a2e37 FM |
1298 | if (path->reada != READA_FORWARD_ALWAYS) { |
1299 | struct extent_buffer *eb; | |
1300 | ||
1301 | eb = find_extent_buffer(fs_info, search); | |
1302 | if (eb) { | |
1303 | free_extent_buffer(eb); | |
1304 | return; | |
1305 | } | |
3c69faec CM |
1306 | } |
1307 | ||
a7175319 | 1308 | target = search; |
6b80053d | 1309 | |
5f39d397 | 1310 | nritems = btrfs_header_nritems(node); |
6b80053d | 1311 | nr = slot; |
25b8b936 | 1312 | |
d397712b | 1313 | while (1) { |
e4058b54 | 1314 | if (path->reada == READA_BACK) { |
6b80053d CM |
1315 | if (nr == 0) |
1316 | break; | |
1317 | nr--; | |
ace75066 FM |
1318 | } else if (path->reada == READA_FORWARD || |
1319 | path->reada == READA_FORWARD_ALWAYS) { | |
6b80053d CM |
1320 | nr++; |
1321 | if (nr >= nritems) | |
1322 | break; | |
3c69faec | 1323 | } |
e4058b54 | 1324 | if (path->reada == READA_BACK && objectid) { |
01f46658 CM |
1325 | btrfs_node_key(node, &disk_key, nr); |
1326 | if (btrfs_disk_key_objectid(&disk_key) != objectid) | |
1327 | break; | |
1328 | } | |
6b80053d | 1329 | search = btrfs_node_blockptr(node, nr); |
ace75066 FM |
1330 | if (path->reada == READA_FORWARD_ALWAYS || |
1331 | (search <= target && target - search <= 65536) || | |
a7175319 | 1332 | (search > target && search - target <= 65536)) { |
bfb484d9 | 1333 | btrfs_readahead_node_child(node, nr); |
6b80053d CM |
1334 | nread += blocksize; |
1335 | } | |
1336 | nscan++; | |
ace75066 | 1337 | if (nread > nread_max || nscan > 32) |
6b80053d | 1338 | break; |
3c69faec CM |
1339 | } |
1340 | } | |
925baedd | 1341 | |
bfb484d9 | 1342 | static noinline void reada_for_balance(struct btrfs_path *path, int level) |
b4ce94de | 1343 | { |
bfb484d9 | 1344 | struct extent_buffer *parent; |
b4ce94de CM |
1345 | int slot; |
1346 | int nritems; | |
b4ce94de | 1347 | |
8c594ea8 | 1348 | parent = path->nodes[level + 1]; |
b4ce94de | 1349 | if (!parent) |
0b08851f | 1350 | return; |
b4ce94de CM |
1351 | |
1352 | nritems = btrfs_header_nritems(parent); | |
8c594ea8 | 1353 | slot = path->slots[level + 1]; |
b4ce94de | 1354 | |
bfb484d9 JB |
1355 | if (slot > 0) |
1356 | btrfs_readahead_node_child(parent, slot - 1); | |
1357 | if (slot + 1 < nritems) | |
1358 | btrfs_readahead_node_child(parent, slot + 1); | |
b4ce94de CM |
1359 | } |
1360 | ||
1361 | ||
d352ac68 | 1362 | /* |
d397712b CM |
1363 | * when we walk down the tree, it is usually safe to unlock the higher layers |
1364 | * in the tree. The exceptions are when our path goes through slot 0, because | |
1365 | * operations on the tree might require changing key pointers higher up in the | |
1366 | * tree. | |
d352ac68 | 1367 | * |
d397712b CM |
1368 | * callers might also have set path->keep_locks, which tells this code to keep |
1369 | * the lock if the path points to the last slot in the block. This is part of | |
1370 | * walking through the tree, and selecting the next slot in the higher block. | |
d352ac68 | 1371 | * |
d397712b CM |
1372 | * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so |
1373 | * if lowest_unlock is 1, level 0 won't be unlocked | |
d352ac68 | 1374 | */ |
e02119d5 | 1375 | static noinline void unlock_up(struct btrfs_path *path, int level, |
f7c79f30 CM |
1376 | int lowest_unlock, int min_write_lock_level, |
1377 | int *write_lock_level) | |
925baedd CM |
1378 | { |
1379 | int i; | |
1380 | int skip_level = level; | |
c1227996 | 1381 | bool check_skip = true; |
925baedd CM |
1382 | |
1383 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { | |
1384 | if (!path->nodes[i]) | |
1385 | break; | |
1386 | if (!path->locks[i]) | |
1387 | break; | |
c1227996 NB |
1388 | |
1389 | if (check_skip) { | |
1390 | if (path->slots[i] == 0) { | |
925baedd CM |
1391 | skip_level = i + 1; |
1392 | continue; | |
1393 | } | |
c1227996 NB |
1394 | |
1395 | if (path->keep_locks) { | |
1396 | u32 nritems; | |
1397 | ||
1398 | nritems = btrfs_header_nritems(path->nodes[i]); | |
1399 | if (nritems < 1 || path->slots[i] >= nritems - 1) { | |
1400 | skip_level = i + 1; | |
1401 | continue; | |
1402 | } | |
1403 | } | |
925baedd | 1404 | } |
051e1b9f | 1405 | |
d80bb3f9 | 1406 | if (i >= lowest_unlock && i > skip_level) { |
c1227996 NB |
1407 | check_skip = false; |
1408 | btrfs_tree_unlock_rw(path->nodes[i], path->locks[i]); | |
925baedd | 1409 | path->locks[i] = 0; |
f7c79f30 CM |
1410 | if (write_lock_level && |
1411 | i > min_write_lock_level && | |
1412 | i <= *write_lock_level) { | |
1413 | *write_lock_level = i - 1; | |
1414 | } | |
925baedd CM |
1415 | } |
1416 | } | |
1417 | } | |
1418 | ||
c8c42864 | 1419 | /* |
376a21d7 FM |
1420 | * Helper function for btrfs_search_slot() and other functions that do a search |
1421 | * on a btree. The goal is to find a tree block in the cache (the radix tree at | |
1422 | * fs_info->buffer_radix), but if we can't find it, or it's not up to date, read | |
1423 | * its pages from disk. | |
c8c42864 | 1424 | * |
376a21d7 FM |
1425 | * Returns -EAGAIN, with the path unlocked, if the caller needs to repeat the |
1426 | * whole btree search, starting again from the current root node. | |
c8c42864 CM |
1427 | */ |
1428 | static int | |
d07b8528 LB |
1429 | read_block_for_search(struct btrfs_root *root, struct btrfs_path *p, |
1430 | struct extent_buffer **eb_ret, int level, int slot, | |
cda79c54 | 1431 | const struct btrfs_key *key) |
c8c42864 | 1432 | { |
0b246afa | 1433 | struct btrfs_fs_info *fs_info = root->fs_info; |
789d6a3a | 1434 | struct btrfs_tree_parent_check check = { 0 }; |
c8c42864 CM |
1435 | u64 blocknr; |
1436 | u64 gen; | |
c8c42864 | 1437 | struct extent_buffer *tmp; |
76a05b35 | 1438 | int ret; |
581c1760 | 1439 | int parent_level; |
b246666e | 1440 | bool unlock_up; |
c8c42864 | 1441 | |
b246666e | 1442 | unlock_up = ((level + 1 < BTRFS_MAX_LEVEL) && p->locks[level + 1]); |
213ff4b7 NB |
1443 | blocknr = btrfs_node_blockptr(*eb_ret, slot); |
1444 | gen = btrfs_node_ptr_generation(*eb_ret, slot); | |
1445 | parent_level = btrfs_header_level(*eb_ret); | |
789d6a3a QW |
1446 | btrfs_node_key_to_cpu(*eb_ret, &check.first_key, slot); |
1447 | check.has_first_key = true; | |
1448 | check.level = parent_level - 1; | |
1449 | check.transid = gen; | |
1450 | check.owner_root = root->root_key.objectid; | |
c8c42864 | 1451 | |
b246666e FM |
1452 | /* |
1453 | * If we need to read an extent buffer from disk and we are holding locks | |
1454 | * on upper level nodes, we unlock all the upper nodes before reading the | |
1455 | * extent buffer, and then return -EAGAIN to the caller as it needs to | |
1456 | * restart the search. We don't release the lock on the current level | |
1457 | * because we need to walk this node to figure out which blocks to read. | |
1458 | */ | |
0b246afa | 1459 | tmp = find_extent_buffer(fs_info, blocknr); |
cb44921a | 1460 | if (tmp) { |
ace75066 FM |
1461 | if (p->reada == READA_FORWARD_ALWAYS) |
1462 | reada_for_search(fs_info, p, level, slot, key->objectid); | |
1463 | ||
b9fab919 | 1464 | /* first we do an atomic uptodate check */ |
bdf7c00e | 1465 | if (btrfs_buffer_uptodate(tmp, gen, 1) > 0) { |
448de471 QW |
1466 | /* |
1467 | * Do extra check for first_key, eb can be stale due to | |
1468 | * being cached, read from scrub, or have multiple | |
1469 | * parents (shared tree blocks). | |
1470 | */ | |
e064d5e9 | 1471 | if (btrfs_verify_level_key(tmp, |
789d6a3a | 1472 | parent_level - 1, &check.first_key, gen)) { |
448de471 QW |
1473 | free_extent_buffer(tmp); |
1474 | return -EUCLEAN; | |
1475 | } | |
bdf7c00e JB |
1476 | *eb_ret = tmp; |
1477 | return 0; | |
1478 | } | |
1479 | ||
857bc13f JB |
1480 | if (p->nowait) { |
1481 | free_extent_buffer(tmp); | |
1482 | return -EAGAIN; | |
1483 | } | |
1484 | ||
b246666e FM |
1485 | if (unlock_up) |
1486 | btrfs_unlock_up_safe(p, level + 1); | |
1487 | ||
bdf7c00e | 1488 | /* now we're allowed to do a blocking uptodate check */ |
789d6a3a | 1489 | ret = btrfs_read_extent_buffer(tmp, &check); |
9a4ffa1b QW |
1490 | if (ret) { |
1491 | free_extent_buffer(tmp); | |
1492 | btrfs_release_path(p); | |
1493 | return -EIO; | |
cb44921a | 1494 | } |
88c602ab QW |
1495 | if (btrfs_check_eb_owner(tmp, root->root_key.objectid)) { |
1496 | free_extent_buffer(tmp); | |
1497 | btrfs_release_path(p); | |
1498 | return -EUCLEAN; | |
1499 | } | |
b246666e FM |
1500 | |
1501 | if (unlock_up) | |
1502 | ret = -EAGAIN; | |
1503 | ||
1504 | goto out; | |
857bc13f JB |
1505 | } else if (p->nowait) { |
1506 | return -EAGAIN; | |
c8c42864 CM |
1507 | } |
1508 | ||
b246666e | 1509 | if (unlock_up) { |
4bb59055 FM |
1510 | btrfs_unlock_up_safe(p, level + 1); |
1511 | ret = -EAGAIN; | |
1512 | } else { | |
1513 | ret = 0; | |
1514 | } | |
8c594ea8 | 1515 | |
e4058b54 | 1516 | if (p->reada != READA_NONE) |
2ff7e61e | 1517 | reada_for_search(fs_info, p, level, slot, key->objectid); |
c8c42864 | 1518 | |
789d6a3a | 1519 | tmp = read_tree_block(fs_info, blocknr, &check); |
4eb150d6 QW |
1520 | if (IS_ERR(tmp)) { |
1521 | btrfs_release_path(p); | |
1522 | return PTR_ERR(tmp); | |
76a05b35 | 1523 | } |
4eb150d6 QW |
1524 | /* |
1525 | * If the read above didn't mark this buffer up to date, | |
1526 | * it will never end up being up to date. Set ret to EIO now | |
1527 | * and give up so that our caller doesn't loop forever | |
1528 | * on our EAGAINs. | |
1529 | */ | |
1530 | if (!extent_buffer_uptodate(tmp)) | |
1531 | ret = -EIO; | |
02a3307a | 1532 | |
b246666e | 1533 | out: |
4bb59055 FM |
1534 | if (ret == 0) { |
1535 | *eb_ret = tmp; | |
1536 | } else { | |
1537 | free_extent_buffer(tmp); | |
1538 | btrfs_release_path(p); | |
1539 | } | |
1540 | ||
76a05b35 | 1541 | return ret; |
c8c42864 CM |
1542 | } |
1543 | ||
1544 | /* | |
1545 | * helper function for btrfs_search_slot. This does all of the checks | |
1546 | * for node-level blocks and does any balancing required based on | |
1547 | * the ins_len. | |
1548 | * | |
1549 | * If no extra work was required, zero is returned. If we had to | |
1550 | * drop the path, -EAGAIN is returned and btrfs_search_slot must | |
1551 | * start over | |
1552 | */ | |
1553 | static int | |
1554 | setup_nodes_for_search(struct btrfs_trans_handle *trans, | |
1555 | struct btrfs_root *root, struct btrfs_path *p, | |
bd681513 CM |
1556 | struct extent_buffer *b, int level, int ins_len, |
1557 | int *write_lock_level) | |
c8c42864 | 1558 | { |
0b246afa | 1559 | struct btrfs_fs_info *fs_info = root->fs_info; |
95b982de | 1560 | int ret = 0; |
0b246afa | 1561 | |
c8c42864 | 1562 | if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >= |
0b246afa | 1563 | BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 3) { |
c8c42864 | 1564 | |
bd681513 CM |
1565 | if (*write_lock_level < level + 1) { |
1566 | *write_lock_level = level + 1; | |
1567 | btrfs_release_path(p); | |
95b982de | 1568 | return -EAGAIN; |
bd681513 CM |
1569 | } |
1570 | ||
bfb484d9 | 1571 | reada_for_balance(p, level); |
95b982de | 1572 | ret = split_node(trans, root, p, level); |
c8c42864 | 1573 | |
c8c42864 CM |
1574 | b = p->nodes[level]; |
1575 | } else if (ins_len < 0 && btrfs_header_nritems(b) < | |
0b246afa | 1576 | BTRFS_NODEPTRS_PER_BLOCK(fs_info) / 2) { |
c8c42864 | 1577 | |
bd681513 CM |
1578 | if (*write_lock_level < level + 1) { |
1579 | *write_lock_level = level + 1; | |
1580 | btrfs_release_path(p); | |
95b982de | 1581 | return -EAGAIN; |
bd681513 CM |
1582 | } |
1583 | ||
bfb484d9 | 1584 | reada_for_balance(p, level); |
95b982de NB |
1585 | ret = balance_level(trans, root, p, level); |
1586 | if (ret) | |
1587 | return ret; | |
c8c42864 | 1588 | |
c8c42864 CM |
1589 | b = p->nodes[level]; |
1590 | if (!b) { | |
b3b4aa74 | 1591 | btrfs_release_path(p); |
95b982de | 1592 | return -EAGAIN; |
c8c42864 CM |
1593 | } |
1594 | BUG_ON(btrfs_header_nritems(b) == 1); | |
1595 | } | |
c8c42864 CM |
1596 | return ret; |
1597 | } | |
1598 | ||
381cf658 | 1599 | int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *path, |
e33d5c3d KN |
1600 | u64 iobjectid, u64 ioff, u8 key_type, |
1601 | struct btrfs_key *found_key) | |
1602 | { | |
1603 | int ret; | |
1604 | struct btrfs_key key; | |
1605 | struct extent_buffer *eb; | |
381cf658 DS |
1606 | |
1607 | ASSERT(path); | |
1d4c08e0 | 1608 | ASSERT(found_key); |
e33d5c3d KN |
1609 | |
1610 | key.type = key_type; | |
1611 | key.objectid = iobjectid; | |
1612 | key.offset = ioff; | |
1613 | ||
1614 | ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0); | |
1d4c08e0 | 1615 | if (ret < 0) |
e33d5c3d KN |
1616 | return ret; |
1617 | ||
1618 | eb = path->nodes[0]; | |
1619 | if (ret && path->slots[0] >= btrfs_header_nritems(eb)) { | |
1620 | ret = btrfs_next_leaf(fs_root, path); | |
1621 | if (ret) | |
1622 | return ret; | |
1623 | eb = path->nodes[0]; | |
1624 | } | |
1625 | ||
1626 | btrfs_item_key_to_cpu(eb, found_key, path->slots[0]); | |
1627 | if (found_key->type != key.type || | |
1628 | found_key->objectid != key.objectid) | |
1629 | return 1; | |
1630 | ||
1631 | return 0; | |
1632 | } | |
1633 | ||
1fc28d8e LB |
1634 | static struct extent_buffer *btrfs_search_slot_get_root(struct btrfs_root *root, |
1635 | struct btrfs_path *p, | |
1636 | int write_lock_level) | |
1637 | { | |
1fc28d8e | 1638 | struct extent_buffer *b; |
120de408 | 1639 | int root_lock = 0; |
1fc28d8e LB |
1640 | int level = 0; |
1641 | ||
1fc28d8e | 1642 | if (p->search_commit_root) { |
d96b3424 FM |
1643 | b = root->commit_root; |
1644 | atomic_inc(&b->refs); | |
be6821f8 | 1645 | level = btrfs_header_level(b); |
f9ddfd05 LB |
1646 | /* |
1647 | * Ensure that all callers have set skip_locking when | |
1648 | * p->search_commit_root = 1. | |
1649 | */ | |
1650 | ASSERT(p->skip_locking == 1); | |
1fc28d8e LB |
1651 | |
1652 | goto out; | |
1653 | } | |
1654 | ||
1655 | if (p->skip_locking) { | |
1656 | b = btrfs_root_node(root); | |
1657 | level = btrfs_header_level(b); | |
1658 | goto out; | |
1659 | } | |
1660 | ||
120de408 JB |
1661 | /* We try very hard to do read locks on the root */ |
1662 | root_lock = BTRFS_READ_LOCK; | |
1663 | ||
1fc28d8e | 1664 | /* |
662c653b LB |
1665 | * If the level is set to maximum, we can skip trying to get the read |
1666 | * lock. | |
1fc28d8e | 1667 | */ |
662c653b LB |
1668 | if (write_lock_level < BTRFS_MAX_LEVEL) { |
1669 | /* | |
1670 | * We don't know the level of the root node until we actually | |
1671 | * have it read locked | |
1672 | */ | |
857bc13f JB |
1673 | if (p->nowait) { |
1674 | b = btrfs_try_read_lock_root_node(root); | |
1675 | if (IS_ERR(b)) | |
1676 | return b; | |
1677 | } else { | |
1678 | b = btrfs_read_lock_root_node(root); | |
1679 | } | |
662c653b LB |
1680 | level = btrfs_header_level(b); |
1681 | if (level > write_lock_level) | |
1682 | goto out; | |
1683 | ||
1684 | /* Whoops, must trade for write lock */ | |
1685 | btrfs_tree_read_unlock(b); | |
1686 | free_extent_buffer(b); | |
1687 | } | |
1fc28d8e | 1688 | |
1fc28d8e LB |
1689 | b = btrfs_lock_root_node(root); |
1690 | root_lock = BTRFS_WRITE_LOCK; | |
1691 | ||
1692 | /* The level might have changed, check again */ | |
1693 | level = btrfs_header_level(b); | |
1694 | ||
1695 | out: | |
120de408 JB |
1696 | /* |
1697 | * The root may have failed to write out at some point, and thus is no | |
1698 | * longer valid, return an error in this case. | |
1699 | */ | |
1700 | if (!extent_buffer_uptodate(b)) { | |
1701 | if (root_lock) | |
1702 | btrfs_tree_unlock_rw(b, root_lock); | |
1703 | free_extent_buffer(b); | |
1704 | return ERR_PTR(-EIO); | |
1705 | } | |
1706 | ||
1fc28d8e LB |
1707 | p->nodes[level] = b; |
1708 | if (!p->skip_locking) | |
1709 | p->locks[level] = root_lock; | |
1710 | /* | |
1711 | * Callers are responsible for dropping b's references. | |
1712 | */ | |
1713 | return b; | |
1714 | } | |
1715 | ||
d96b3424 FM |
1716 | /* |
1717 | * Replace the extent buffer at the lowest level of the path with a cloned | |
1718 | * version. The purpose is to be able to use it safely, after releasing the | |
1719 | * commit root semaphore, even if relocation is happening in parallel, the | |
1720 | * transaction used for relocation is committed and the extent buffer is | |
1721 | * reallocated in the next transaction. | |
1722 | * | |
1723 | * This is used in a context where the caller does not prevent transaction | |
1724 | * commits from happening, either by holding a transaction handle or holding | |
1725 | * some lock, while it's doing searches through a commit root. | |
1726 | * At the moment it's only used for send operations. | |
1727 | */ | |
1728 | static int finish_need_commit_sem_search(struct btrfs_path *path) | |
1729 | { | |
1730 | const int i = path->lowest_level; | |
1731 | const int slot = path->slots[i]; | |
1732 | struct extent_buffer *lowest = path->nodes[i]; | |
1733 | struct extent_buffer *clone; | |
1734 | ||
1735 | ASSERT(path->need_commit_sem); | |
1736 | ||
1737 | if (!lowest) | |
1738 | return 0; | |
1739 | ||
1740 | lockdep_assert_held_read(&lowest->fs_info->commit_root_sem); | |
1741 | ||
1742 | clone = btrfs_clone_extent_buffer(lowest); | |
1743 | if (!clone) | |
1744 | return -ENOMEM; | |
1745 | ||
1746 | btrfs_release_path(path); | |
1747 | path->nodes[i] = clone; | |
1748 | path->slots[i] = slot; | |
1749 | ||
1750 | return 0; | |
1751 | } | |
1fc28d8e | 1752 | |
e2e58d0f FM |
1753 | static inline int search_for_key_slot(struct extent_buffer *eb, |
1754 | int search_low_slot, | |
1755 | const struct btrfs_key *key, | |
1756 | int prev_cmp, | |
1757 | int *slot) | |
1758 | { | |
1759 | /* | |
1760 | * If a previous call to btrfs_bin_search() on a parent node returned an | |
1761 | * exact match (prev_cmp == 0), we can safely assume the target key will | |
1762 | * always be at slot 0 on lower levels, since each key pointer | |
1763 | * (struct btrfs_key_ptr) refers to the lowest key accessible from the | |
1764 | * subtree it points to. Thus we can skip searching lower levels. | |
1765 | */ | |
1766 | if (prev_cmp == 0) { | |
1767 | *slot = 0; | |
1768 | return 0; | |
1769 | } | |
1770 | ||
1771 | return generic_bin_search(eb, search_low_slot, key, slot); | |
1772 | } | |
1773 | ||
109324cf FM |
1774 | static int search_leaf(struct btrfs_trans_handle *trans, |
1775 | struct btrfs_root *root, | |
1776 | const struct btrfs_key *key, | |
1777 | struct btrfs_path *path, | |
1778 | int ins_len, | |
1779 | int prev_cmp) | |
1780 | { | |
1781 | struct extent_buffer *leaf = path->nodes[0]; | |
1782 | int leaf_free_space = -1; | |
1783 | int search_low_slot = 0; | |
1784 | int ret; | |
1785 | bool do_bin_search = true; | |
1786 | ||
1787 | /* | |
1788 | * If we are doing an insertion, the leaf has enough free space and the | |
1789 | * destination slot for the key is not slot 0, then we can unlock our | |
1790 | * write lock on the parent, and any other upper nodes, before doing the | |
1791 | * binary search on the leaf (with search_for_key_slot()), allowing other | |
1792 | * tasks to lock the parent and any other upper nodes. | |
1793 | */ | |
1794 | if (ins_len > 0) { | |
1795 | /* | |
1796 | * Cache the leaf free space, since we will need it later and it | |
1797 | * will not change until then. | |
1798 | */ | |
1799 | leaf_free_space = btrfs_leaf_free_space(leaf); | |
1800 | ||
1801 | /* | |
1802 | * !path->locks[1] means we have a single node tree, the leaf is | |
1803 | * the root of the tree. | |
1804 | */ | |
1805 | if (path->locks[1] && leaf_free_space >= ins_len) { | |
1806 | struct btrfs_disk_key first_key; | |
1807 | ||
1808 | ASSERT(btrfs_header_nritems(leaf) > 0); | |
1809 | btrfs_item_key(leaf, &first_key, 0); | |
1810 | ||
1811 | /* | |
1812 | * Doing the extra comparison with the first key is cheap, | |
1813 | * taking into account that the first key is very likely | |
1814 | * already in a cache line because it immediately follows | |
1815 | * the extent buffer's header and we have recently accessed | |
1816 | * the header's level field. | |
1817 | */ | |
1818 | ret = comp_keys(&first_key, key); | |
1819 | if (ret < 0) { | |
1820 | /* | |
1821 | * The first key is smaller than the key we want | |
1822 | * to insert, so we are safe to unlock all upper | |
1823 | * nodes and we have to do the binary search. | |
1824 | * | |
1825 | * We do use btrfs_unlock_up_safe() and not | |
1826 | * unlock_up() because the later does not unlock | |
1827 | * nodes with a slot of 0 - we can safely unlock | |
1828 | * any node even if its slot is 0 since in this | |
1829 | * case the key does not end up at slot 0 of the | |
1830 | * leaf and there's no need to split the leaf. | |
1831 | */ | |
1832 | btrfs_unlock_up_safe(path, 1); | |
1833 | search_low_slot = 1; | |
1834 | } else { | |
1835 | /* | |
1836 | * The first key is >= then the key we want to | |
1837 | * insert, so we can skip the binary search as | |
1838 | * the target key will be at slot 0. | |
1839 | * | |
1840 | * We can not unlock upper nodes when the key is | |
1841 | * less than the first key, because we will need | |
1842 | * to update the key at slot 0 of the parent node | |
1843 | * and possibly of other upper nodes too. | |
1844 | * If the key matches the first key, then we can | |
1845 | * unlock all the upper nodes, using | |
1846 | * btrfs_unlock_up_safe() instead of unlock_up() | |
1847 | * as stated above. | |
1848 | */ | |
1849 | if (ret == 0) | |
1850 | btrfs_unlock_up_safe(path, 1); | |
1851 | /* | |
1852 | * ret is already 0 or 1, matching the result of | |
1853 | * a btrfs_bin_search() call, so there is no need | |
1854 | * to adjust it. | |
1855 | */ | |
1856 | do_bin_search = false; | |
1857 | path->slots[0] = 0; | |
1858 | } | |
1859 | } | |
1860 | } | |
1861 | ||
1862 | if (do_bin_search) { | |
1863 | ret = search_for_key_slot(leaf, search_low_slot, key, | |
1864 | prev_cmp, &path->slots[0]); | |
1865 | if (ret < 0) | |
1866 | return ret; | |
1867 | } | |
1868 | ||
1869 | if (ins_len > 0) { | |
1870 | /* | |
1871 | * Item key already exists. In this case, if we are allowed to | |
1872 | * insert the item (for example, in dir_item case, item key | |
1873 | * collision is allowed), it will be merged with the original | |
1874 | * item. Only the item size grows, no new btrfs item will be | |
1875 | * added. If search_for_extension is not set, ins_len already | |
1876 | * accounts the size btrfs_item, deduct it here so leaf space | |
1877 | * check will be correct. | |
1878 | */ | |
1879 | if (ret == 0 && !path->search_for_extension) { | |
1880 | ASSERT(ins_len >= sizeof(struct btrfs_item)); | |
1881 | ins_len -= sizeof(struct btrfs_item); | |
1882 | } | |
1883 | ||
1884 | ASSERT(leaf_free_space >= 0); | |
1885 | ||
1886 | if (leaf_free_space < ins_len) { | |
1887 | int err; | |
1888 | ||
1889 | err = split_leaf(trans, root, key, path, ins_len, | |
1890 | (ret == 0)); | |
bb8e9a60 FM |
1891 | ASSERT(err <= 0); |
1892 | if (WARN_ON(err > 0)) | |
1893 | err = -EUCLEAN; | |
109324cf FM |
1894 | if (err) |
1895 | ret = err; | |
1896 | } | |
1897 | } | |
1898 | ||
1899 | return ret; | |
1900 | } | |
1901 | ||
74123bd7 | 1902 | /* |
4271ecea NB |
1903 | * btrfs_search_slot - look for a key in a tree and perform necessary |
1904 | * modifications to preserve tree invariants. | |
74123bd7 | 1905 | * |
4271ecea NB |
1906 | * @trans: Handle of transaction, used when modifying the tree |
1907 | * @p: Holds all btree nodes along the search path | |
1908 | * @root: The root node of the tree | |
1909 | * @key: The key we are looking for | |
9a664971 | 1910 | * @ins_len: Indicates purpose of search: |
1911 | * >0 for inserts it's size of item inserted (*) | |
1912 | * <0 for deletions | |
1913 | * 0 for plain searches, not modifying the tree | |
1914 | * | |
1915 | * (*) If size of item inserted doesn't include | |
1916 | * sizeof(struct btrfs_item), then p->search_for_extension must | |
1917 | * be set. | |
4271ecea NB |
1918 | * @cow: boolean should CoW operations be performed. Must always be 1 |
1919 | * when modifying the tree. | |
97571fd0 | 1920 | * |
4271ecea NB |
1921 | * If @ins_len > 0, nodes and leaves will be split as we walk down the tree. |
1922 | * If @ins_len < 0, nodes will be merged as we walk down the tree (if possible) | |
1923 | * | |
1924 | * If @key is found, 0 is returned and you can find the item in the leaf level | |
1925 | * of the path (level 0) | |
1926 | * | |
1927 | * If @key isn't found, 1 is returned and the leaf level of the path (level 0) | |
1928 | * points to the slot where it should be inserted | |
1929 | * | |
1930 | * If an error is encountered while searching the tree a negative error number | |
1931 | * is returned | |
74123bd7 | 1932 | */ |
310712b2 OS |
1933 | int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
1934 | const struct btrfs_key *key, struct btrfs_path *p, | |
1935 | int ins_len, int cow) | |
be0e5c09 | 1936 | { |
d96b3424 | 1937 | struct btrfs_fs_info *fs_info = root->fs_info; |
5f39d397 | 1938 | struct extent_buffer *b; |
be0e5c09 CM |
1939 | int slot; |
1940 | int ret; | |
33c66f43 | 1941 | int err; |
be0e5c09 | 1942 | int level; |
925baedd | 1943 | int lowest_unlock = 1; |
bd681513 CM |
1944 | /* everything at write_lock_level or lower must be write locked */ |
1945 | int write_lock_level = 0; | |
9f3a7427 | 1946 | u8 lowest_level = 0; |
f7c79f30 | 1947 | int min_write_lock_level; |
d7396f07 | 1948 | int prev_cmp; |
9f3a7427 | 1949 | |
6702ed49 | 1950 | lowest_level = p->lowest_level; |
323ac95b | 1951 | WARN_ON(lowest_level && ins_len > 0); |
22b0ebda | 1952 | WARN_ON(p->nodes[0] != NULL); |
eb653de1 | 1953 | BUG_ON(!cow && ins_len); |
25179201 | 1954 | |
857bc13f JB |
1955 | /* |
1956 | * For now only allow nowait for read only operations. There's no | |
1957 | * strict reason why we can't, we just only need it for reads so it's | |
1958 | * only implemented for reads. | |
1959 | */ | |
1960 | ASSERT(!p->nowait || !cow); | |
1961 | ||
bd681513 | 1962 | if (ins_len < 0) { |
925baedd | 1963 | lowest_unlock = 2; |
65b51a00 | 1964 | |
bd681513 CM |
1965 | /* when we are removing items, we might have to go up to level |
1966 | * two as we update tree pointers Make sure we keep write | |
1967 | * for those levels as well | |
1968 | */ | |
1969 | write_lock_level = 2; | |
1970 | } else if (ins_len > 0) { | |
1971 | /* | |
1972 | * for inserting items, make sure we have a write lock on | |
1973 | * level 1 so we can update keys | |
1974 | */ | |
1975 | write_lock_level = 1; | |
1976 | } | |
1977 | ||
1978 | if (!cow) | |
1979 | write_lock_level = -1; | |
1980 | ||
09a2a8f9 | 1981 | if (cow && (p->keep_locks || p->lowest_level)) |
bd681513 CM |
1982 | write_lock_level = BTRFS_MAX_LEVEL; |
1983 | ||
f7c79f30 CM |
1984 | min_write_lock_level = write_lock_level; |
1985 | ||
d96b3424 FM |
1986 | if (p->need_commit_sem) { |
1987 | ASSERT(p->search_commit_root); | |
857bc13f JB |
1988 | if (p->nowait) { |
1989 | if (!down_read_trylock(&fs_info->commit_root_sem)) | |
1990 | return -EAGAIN; | |
1991 | } else { | |
1992 | down_read(&fs_info->commit_root_sem); | |
1993 | } | |
d96b3424 FM |
1994 | } |
1995 | ||
bb803951 | 1996 | again: |
d7396f07 | 1997 | prev_cmp = -1; |
1fc28d8e | 1998 | b = btrfs_search_slot_get_root(root, p, write_lock_level); |
be6821f8 FM |
1999 | if (IS_ERR(b)) { |
2000 | ret = PTR_ERR(b); | |
2001 | goto done; | |
2002 | } | |
925baedd | 2003 | |
eb60ceac | 2004 | while (b) { |
f624d976 QW |
2005 | int dec = 0; |
2006 | ||
5f39d397 | 2007 | level = btrfs_header_level(b); |
65b51a00 | 2008 | |
02217ed2 | 2009 | if (cow) { |
9ea2c7c9 NB |
2010 | bool last_level = (level == (BTRFS_MAX_LEVEL - 1)); |
2011 | ||
c8c42864 CM |
2012 | /* |
2013 | * if we don't really need to cow this block | |
2014 | * then we don't want to set the path blocking, | |
2015 | * so we test it here | |
2016 | */ | |
5963ffca | 2017 | if (!should_cow_block(trans, root, b)) |
65b51a00 | 2018 | goto cow_done; |
5d4f98a2 | 2019 | |
bd681513 CM |
2020 | /* |
2021 | * must have write locks on this node and the | |
2022 | * parent | |
2023 | */ | |
5124e00e JB |
2024 | if (level > write_lock_level || |
2025 | (level + 1 > write_lock_level && | |
2026 | level + 1 < BTRFS_MAX_LEVEL && | |
2027 | p->nodes[level + 1])) { | |
bd681513 CM |
2028 | write_lock_level = level + 1; |
2029 | btrfs_release_path(p); | |
2030 | goto again; | |
2031 | } | |
2032 | ||
9ea2c7c9 NB |
2033 | if (last_level) |
2034 | err = btrfs_cow_block(trans, root, b, NULL, 0, | |
9631e4cc JB |
2035 | &b, |
2036 | BTRFS_NESTING_COW); | |
9ea2c7c9 NB |
2037 | else |
2038 | err = btrfs_cow_block(trans, root, b, | |
2039 | p->nodes[level + 1], | |
9631e4cc JB |
2040 | p->slots[level + 1], &b, |
2041 | BTRFS_NESTING_COW); | |
33c66f43 | 2042 | if (err) { |
33c66f43 | 2043 | ret = err; |
65b51a00 | 2044 | goto done; |
54aa1f4d | 2045 | } |
02217ed2 | 2046 | } |
65b51a00 | 2047 | cow_done: |
eb60ceac | 2048 | p->nodes[level] = b; |
b4ce94de CM |
2049 | |
2050 | /* | |
2051 | * we have a lock on b and as long as we aren't changing | |
2052 | * the tree, there is no way to for the items in b to change. | |
2053 | * It is safe to drop the lock on our parent before we | |
2054 | * go through the expensive btree search on b. | |
2055 | * | |
eb653de1 FDBM |
2056 | * If we're inserting or deleting (ins_len != 0), then we might |
2057 | * be changing slot zero, which may require changing the parent. | |
2058 | * So, we can't drop the lock until after we know which slot | |
2059 | * we're operating on. | |
b4ce94de | 2060 | */ |
eb653de1 FDBM |
2061 | if (!ins_len && !p->keep_locks) { |
2062 | int u = level + 1; | |
2063 | ||
2064 | if (u < BTRFS_MAX_LEVEL && p->locks[u]) { | |
2065 | btrfs_tree_unlock_rw(p->nodes[u], p->locks[u]); | |
2066 | p->locks[u] = 0; | |
2067 | } | |
2068 | } | |
b4ce94de | 2069 | |
e2e58d0f | 2070 | if (level == 0) { |
109324cf | 2071 | if (ins_len > 0) |
e5e1c174 | 2072 | ASSERT(write_lock_level >= 1); |
bd681513 | 2073 | |
109324cf | 2074 | ret = search_leaf(trans, root, key, p, ins_len, prev_cmp); |
459931ec | 2075 | if (!p->search_for_split) |
f7c79f30 | 2076 | unlock_up(p, level, lowest_unlock, |
4b6f8e96 | 2077 | min_write_lock_level, NULL); |
65b51a00 | 2078 | goto done; |
be0e5c09 | 2079 | } |
e2e58d0f FM |
2080 | |
2081 | ret = search_for_key_slot(b, 0, key, prev_cmp, &slot); | |
2082 | if (ret < 0) | |
2083 | goto done; | |
2084 | prev_cmp = ret; | |
2085 | ||
f624d976 QW |
2086 | if (ret && slot > 0) { |
2087 | dec = 1; | |
2088 | slot--; | |
2089 | } | |
2090 | p->slots[level] = slot; | |
2091 | err = setup_nodes_for_search(trans, root, p, b, level, ins_len, | |
2092 | &write_lock_level); | |
2093 | if (err == -EAGAIN) | |
2094 | goto again; | |
2095 | if (err) { | |
2096 | ret = err; | |
2097 | goto done; | |
2098 | } | |
2099 | b = p->nodes[level]; | |
2100 | slot = p->slots[level]; | |
2101 | ||
2102 | /* | |
2103 | * Slot 0 is special, if we change the key we have to update | |
2104 | * the parent pointer which means we must have a write lock on | |
2105 | * the parent | |
2106 | */ | |
2107 | if (slot == 0 && ins_len && write_lock_level < level + 1) { | |
2108 | write_lock_level = level + 1; | |
2109 | btrfs_release_path(p); | |
2110 | goto again; | |
2111 | } | |
2112 | ||
2113 | unlock_up(p, level, lowest_unlock, min_write_lock_level, | |
2114 | &write_lock_level); | |
2115 | ||
2116 | if (level == lowest_level) { | |
2117 | if (dec) | |
2118 | p->slots[level]++; | |
2119 | goto done; | |
2120 | } | |
2121 | ||
2122 | err = read_block_for_search(root, p, &b, level, slot, key); | |
2123 | if (err == -EAGAIN) | |
2124 | goto again; | |
2125 | if (err) { | |
2126 | ret = err; | |
2127 | goto done; | |
2128 | } | |
2129 | ||
2130 | if (!p->skip_locking) { | |
2131 | level = btrfs_header_level(b); | |
b40130b2 JB |
2132 | |
2133 | btrfs_maybe_reset_lockdep_class(root, b); | |
2134 | ||
f624d976 | 2135 | if (level <= write_lock_level) { |
ac5887c8 | 2136 | btrfs_tree_lock(b); |
f624d976 QW |
2137 | p->locks[level] = BTRFS_WRITE_LOCK; |
2138 | } else { | |
857bc13f JB |
2139 | if (p->nowait) { |
2140 | if (!btrfs_try_tree_read_lock(b)) { | |
2141 | free_extent_buffer(b); | |
2142 | ret = -EAGAIN; | |
2143 | goto done; | |
2144 | } | |
2145 | } else { | |
2146 | btrfs_tree_read_lock(b); | |
2147 | } | |
f624d976 QW |
2148 | p->locks[level] = BTRFS_READ_LOCK; |
2149 | } | |
2150 | p->nodes[level] = b; | |
2151 | } | |
be0e5c09 | 2152 | } |
65b51a00 CM |
2153 | ret = 1; |
2154 | done: | |
5f5bc6b1 | 2155 | if (ret < 0 && !p->skip_release_on_error) |
b3b4aa74 | 2156 | btrfs_release_path(p); |
d96b3424 FM |
2157 | |
2158 | if (p->need_commit_sem) { | |
2159 | int ret2; | |
2160 | ||
2161 | ret2 = finish_need_commit_sem_search(p); | |
2162 | up_read(&fs_info->commit_root_sem); | |
2163 | if (ret2) | |
2164 | ret = ret2; | |
2165 | } | |
2166 | ||
65b51a00 | 2167 | return ret; |
be0e5c09 | 2168 | } |
f75e2b79 | 2169 | ALLOW_ERROR_INJECTION(btrfs_search_slot, ERRNO); |
be0e5c09 | 2170 | |
5d9e75c4 JS |
2171 | /* |
2172 | * Like btrfs_search_slot, this looks for a key in the given tree. It uses the | |
2173 | * current state of the tree together with the operations recorded in the tree | |
2174 | * modification log to search for the key in a previous version of this tree, as | |
2175 | * denoted by the time_seq parameter. | |
2176 | * | |
2177 | * Naturally, there is no support for insert, delete or cow operations. | |
2178 | * | |
2179 | * The resulting path and return value will be set up as if we called | |
2180 | * btrfs_search_slot at that point in time with ins_len and cow both set to 0. | |
2181 | */ | |
310712b2 | 2182 | int btrfs_search_old_slot(struct btrfs_root *root, const struct btrfs_key *key, |
5d9e75c4 JS |
2183 | struct btrfs_path *p, u64 time_seq) |
2184 | { | |
0b246afa | 2185 | struct btrfs_fs_info *fs_info = root->fs_info; |
5d9e75c4 JS |
2186 | struct extent_buffer *b; |
2187 | int slot; | |
2188 | int ret; | |
2189 | int err; | |
2190 | int level; | |
2191 | int lowest_unlock = 1; | |
2192 | u8 lowest_level = 0; | |
2193 | ||
2194 | lowest_level = p->lowest_level; | |
2195 | WARN_ON(p->nodes[0] != NULL); | |
c922b016 | 2196 | ASSERT(!p->nowait); |
5d9e75c4 JS |
2197 | |
2198 | if (p->search_commit_root) { | |
2199 | BUG_ON(time_seq); | |
2200 | return btrfs_search_slot(NULL, root, key, p, 0, 0); | |
2201 | } | |
2202 | ||
2203 | again: | |
f3a84ccd | 2204 | b = btrfs_get_old_root(root, time_seq); |
315bed43 NB |
2205 | if (!b) { |
2206 | ret = -EIO; | |
2207 | goto done; | |
2208 | } | |
5d9e75c4 | 2209 | level = btrfs_header_level(b); |
5d9e75c4 JS |
2210 | p->locks[level] = BTRFS_READ_LOCK; |
2211 | ||
2212 | while (b) { | |
abe9339d QW |
2213 | int dec = 0; |
2214 | ||
5d9e75c4 JS |
2215 | level = btrfs_header_level(b); |
2216 | p->nodes[level] = b; | |
5d9e75c4 JS |
2217 | |
2218 | /* | |
2219 | * we have a lock on b and as long as we aren't changing | |
2220 | * the tree, there is no way to for the items in b to change. | |
2221 | * It is safe to drop the lock on our parent before we | |
2222 | * go through the expensive btree search on b. | |
2223 | */ | |
2224 | btrfs_unlock_up_safe(p, level + 1); | |
2225 | ||
995e9a16 | 2226 | ret = btrfs_bin_search(b, key, &slot); |
cbca7d59 FM |
2227 | if (ret < 0) |
2228 | goto done; | |
5d9e75c4 | 2229 | |
abe9339d | 2230 | if (level == 0) { |
5d9e75c4 JS |
2231 | p->slots[level] = slot; |
2232 | unlock_up(p, level, lowest_unlock, 0, NULL); | |
abe9339d QW |
2233 | goto done; |
2234 | } | |
5d9e75c4 | 2235 | |
abe9339d QW |
2236 | if (ret && slot > 0) { |
2237 | dec = 1; | |
2238 | slot--; | |
2239 | } | |
2240 | p->slots[level] = slot; | |
2241 | unlock_up(p, level, lowest_unlock, 0, NULL); | |
5d9e75c4 | 2242 | |
abe9339d QW |
2243 | if (level == lowest_level) { |
2244 | if (dec) | |
2245 | p->slots[level]++; | |
2246 | goto done; | |
2247 | } | |
5d9e75c4 | 2248 | |
abe9339d QW |
2249 | err = read_block_for_search(root, p, &b, level, slot, key); |
2250 | if (err == -EAGAIN) | |
2251 | goto again; | |
2252 | if (err) { | |
2253 | ret = err; | |
5d9e75c4 JS |
2254 | goto done; |
2255 | } | |
abe9339d QW |
2256 | |
2257 | level = btrfs_header_level(b); | |
ac5887c8 | 2258 | btrfs_tree_read_lock(b); |
f3a84ccd | 2259 | b = btrfs_tree_mod_log_rewind(fs_info, p, b, time_seq); |
abe9339d QW |
2260 | if (!b) { |
2261 | ret = -ENOMEM; | |
2262 | goto done; | |
2263 | } | |
2264 | p->locks[level] = BTRFS_READ_LOCK; | |
2265 | p->nodes[level] = b; | |
5d9e75c4 JS |
2266 | } |
2267 | ret = 1; | |
2268 | done: | |
5d9e75c4 JS |
2269 | if (ret < 0) |
2270 | btrfs_release_path(p); | |
2271 | ||
2272 | return ret; | |
2273 | } | |
2274 | ||
2f38b3e1 AJ |
2275 | /* |
2276 | * helper to use instead of search slot if no exact match is needed but | |
2277 | * instead the next or previous item should be returned. | |
2278 | * When find_higher is true, the next higher item is returned, the next lower | |
2279 | * otherwise. | |
2280 | * When return_any and find_higher are both true, and no higher item is found, | |
2281 | * return the next lower instead. | |
2282 | * When return_any is true and find_higher is false, and no lower item is found, | |
2283 | * return the next higher instead. | |
2284 | * It returns 0 if any item is found, 1 if none is found (tree empty), and | |
2285 | * < 0 on error | |
2286 | */ | |
2287 | int btrfs_search_slot_for_read(struct btrfs_root *root, | |
310712b2 OS |
2288 | const struct btrfs_key *key, |
2289 | struct btrfs_path *p, int find_higher, | |
2290 | int return_any) | |
2f38b3e1 AJ |
2291 | { |
2292 | int ret; | |
2293 | struct extent_buffer *leaf; | |
2294 | ||
2295 | again: | |
2296 | ret = btrfs_search_slot(NULL, root, key, p, 0, 0); | |
2297 | if (ret <= 0) | |
2298 | return ret; | |
2299 | /* | |
2300 | * a return value of 1 means the path is at the position where the | |
2301 | * item should be inserted. Normally this is the next bigger item, | |
2302 | * but in case the previous item is the last in a leaf, path points | |
2303 | * to the first free slot in the previous leaf, i.e. at an invalid | |
2304 | * item. | |
2305 | */ | |
2306 | leaf = p->nodes[0]; | |
2307 | ||
2308 | if (find_higher) { | |
2309 | if (p->slots[0] >= btrfs_header_nritems(leaf)) { | |
2310 | ret = btrfs_next_leaf(root, p); | |
2311 | if (ret <= 0) | |
2312 | return ret; | |
2313 | if (!return_any) | |
2314 | return 1; | |
2315 | /* | |
2316 | * no higher item found, return the next | |
2317 | * lower instead | |
2318 | */ | |
2319 | return_any = 0; | |
2320 | find_higher = 0; | |
2321 | btrfs_release_path(p); | |
2322 | goto again; | |
2323 | } | |
2324 | } else { | |
e6793769 AJ |
2325 | if (p->slots[0] == 0) { |
2326 | ret = btrfs_prev_leaf(root, p); | |
2327 | if (ret < 0) | |
2328 | return ret; | |
2329 | if (!ret) { | |
23c6bf6a FDBM |
2330 | leaf = p->nodes[0]; |
2331 | if (p->slots[0] == btrfs_header_nritems(leaf)) | |
2332 | p->slots[0]--; | |
e6793769 | 2333 | return 0; |
2f38b3e1 | 2334 | } |
e6793769 AJ |
2335 | if (!return_any) |
2336 | return 1; | |
2337 | /* | |
2338 | * no lower item found, return the next | |
2339 | * higher instead | |
2340 | */ | |
2341 | return_any = 0; | |
2342 | find_higher = 1; | |
2343 | btrfs_release_path(p); | |
2344 | goto again; | |
2345 | } else { | |
2f38b3e1 AJ |
2346 | --p->slots[0]; |
2347 | } | |
2348 | } | |
2349 | return 0; | |
2350 | } | |
2351 | ||
0ff40a91 MPS |
2352 | /* |
2353 | * Execute search and call btrfs_previous_item to traverse backwards if the item | |
2354 | * was not found. | |
2355 | * | |
2356 | * Return 0 if found, 1 if not found and < 0 if error. | |
2357 | */ | |
2358 | int btrfs_search_backwards(struct btrfs_root *root, struct btrfs_key *key, | |
2359 | struct btrfs_path *path) | |
2360 | { | |
2361 | int ret; | |
2362 | ||
2363 | ret = btrfs_search_slot(NULL, root, key, path, 0, 0); | |
2364 | if (ret > 0) | |
2365 | ret = btrfs_previous_item(root, path, key->objectid, key->type); | |
2366 | ||
2367 | if (ret == 0) | |
2368 | btrfs_item_key_to_cpu(path->nodes[0], key, path->slots[0]); | |
2369 | ||
2370 | return ret; | |
2371 | } | |
2372 | ||
43dd529a | 2373 | /* |
62142be3 GN |
2374 | * Search for a valid slot for the given path. |
2375 | * | |
2376 | * @root: The root node of the tree. | |
2377 | * @key: Will contain a valid item if found. | |
2378 | * @path: The starting point to validate the slot. | |
2379 | * | |
2380 | * Return: 0 if the item is valid | |
2381 | * 1 if not found | |
2382 | * <0 if error. | |
2383 | */ | |
2384 | int btrfs_get_next_valid_item(struct btrfs_root *root, struct btrfs_key *key, | |
2385 | struct btrfs_path *path) | |
2386 | { | |
2387 | while (1) { | |
2388 | int ret; | |
2389 | const int slot = path->slots[0]; | |
2390 | const struct extent_buffer *leaf = path->nodes[0]; | |
2391 | ||
2392 | /* This is where we start walking the path. */ | |
2393 | if (slot >= btrfs_header_nritems(leaf)) { | |
2394 | /* | |
2395 | * If we've reached the last slot in this leaf we need | |
2396 | * to go to the next leaf and reset the path. | |
2397 | */ | |
2398 | ret = btrfs_next_leaf(root, path); | |
2399 | if (ret) | |
2400 | return ret; | |
2401 | continue; | |
2402 | } | |
2403 | /* Store the found, valid item in @key. */ | |
2404 | btrfs_item_key_to_cpu(leaf, key, slot); | |
2405 | break; | |
2406 | } | |
2407 | return 0; | |
2408 | } | |
2409 | ||
74123bd7 CM |
2410 | /* |
2411 | * adjust the pointers going up the tree, starting at level | |
2412 | * making sure the right key of each node is points to 'key'. | |
2413 | * This is used after shifting pointers to the left, so it stops | |
2414 | * fixing up pointers when a given leaf/node is not in slot 0 of the | |
2415 | * higher levels | |
aa5d6bed | 2416 | * |
74123bd7 | 2417 | */ |
b167fa91 | 2418 | static void fixup_low_keys(struct btrfs_path *path, |
143bede5 | 2419 | struct btrfs_disk_key *key, int level) |
be0e5c09 CM |
2420 | { |
2421 | int i; | |
5f39d397 | 2422 | struct extent_buffer *t; |
0e82bcfe | 2423 | int ret; |
5f39d397 | 2424 | |
234b63a0 | 2425 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { |
be0e5c09 | 2426 | int tslot = path->slots[i]; |
0e82bcfe | 2427 | |
eb60ceac | 2428 | if (!path->nodes[i]) |
be0e5c09 | 2429 | break; |
5f39d397 | 2430 | t = path->nodes[i]; |
f3a84ccd | 2431 | ret = btrfs_tree_mod_log_insert_key(t, tslot, |
33cff222 | 2432 | BTRFS_MOD_LOG_KEY_REPLACE); |
0e82bcfe | 2433 | BUG_ON(ret < 0); |
5f39d397 | 2434 | btrfs_set_node_key(t, key, tslot); |
d6025579 | 2435 | btrfs_mark_buffer_dirty(path->nodes[i]); |
be0e5c09 CM |
2436 | if (tslot != 0) |
2437 | break; | |
2438 | } | |
2439 | } | |
2440 | ||
31840ae1 ZY |
2441 | /* |
2442 | * update item key. | |
2443 | * | |
2444 | * This function isn't completely safe. It's the caller's responsibility | |
2445 | * that the new key won't break the order | |
2446 | */ | |
b7a0365e DD |
2447 | void btrfs_set_item_key_safe(struct btrfs_fs_info *fs_info, |
2448 | struct btrfs_path *path, | |
310712b2 | 2449 | const struct btrfs_key *new_key) |
31840ae1 ZY |
2450 | { |
2451 | struct btrfs_disk_key disk_key; | |
2452 | struct extent_buffer *eb; | |
2453 | int slot; | |
2454 | ||
2455 | eb = path->nodes[0]; | |
2456 | slot = path->slots[0]; | |
2457 | if (slot > 0) { | |
2458 | btrfs_item_key(eb, &disk_key, slot - 1); | |
7c15d410 QW |
2459 | if (unlikely(comp_keys(&disk_key, new_key) >= 0)) { |
2460 | btrfs_crit(fs_info, | |
2461 | "slot %u key (%llu %u %llu) new key (%llu %u %llu)", | |
2462 | slot, btrfs_disk_key_objectid(&disk_key), | |
2463 | btrfs_disk_key_type(&disk_key), | |
2464 | btrfs_disk_key_offset(&disk_key), | |
2465 | new_key->objectid, new_key->type, | |
2466 | new_key->offset); | |
2467 | btrfs_print_leaf(eb); | |
2468 | BUG(); | |
2469 | } | |
31840ae1 ZY |
2470 | } |
2471 | if (slot < btrfs_header_nritems(eb) - 1) { | |
2472 | btrfs_item_key(eb, &disk_key, slot + 1); | |
7c15d410 QW |
2473 | if (unlikely(comp_keys(&disk_key, new_key) <= 0)) { |
2474 | btrfs_crit(fs_info, | |
2475 | "slot %u key (%llu %u %llu) new key (%llu %u %llu)", | |
2476 | slot, btrfs_disk_key_objectid(&disk_key), | |
2477 | btrfs_disk_key_type(&disk_key), | |
2478 | btrfs_disk_key_offset(&disk_key), | |
2479 | new_key->objectid, new_key->type, | |
2480 | new_key->offset); | |
2481 | btrfs_print_leaf(eb); | |
2482 | BUG(); | |
2483 | } | |
31840ae1 ZY |
2484 | } |
2485 | ||
2486 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
2487 | btrfs_set_item_key(eb, &disk_key, slot); | |
2488 | btrfs_mark_buffer_dirty(eb); | |
2489 | if (slot == 0) | |
b167fa91 | 2490 | fixup_low_keys(path, &disk_key, 1); |
31840ae1 ZY |
2491 | } |
2492 | ||
d16c702f QW |
2493 | /* |
2494 | * Check key order of two sibling extent buffers. | |
2495 | * | |
2496 | * Return true if something is wrong. | |
2497 | * Return false if everything is fine. | |
2498 | * | |
2499 | * Tree-checker only works inside one tree block, thus the following | |
2500 | * corruption can not be detected by tree-checker: | |
2501 | * | |
2502 | * Leaf @left | Leaf @right | |
2503 | * -------------------------------------------------------------- | |
2504 | * | 1 | 2 | 3 | 4 | 5 | f6 | | 7 | 8 | | |
2505 | * | |
2506 | * Key f6 in leaf @left itself is valid, but not valid when the next | |
2507 | * key in leaf @right is 7. | |
2508 | * This can only be checked at tree block merge time. | |
2509 | * And since tree checker has ensured all key order in each tree block | |
2510 | * is correct, we only need to bother the last key of @left and the first | |
2511 | * key of @right. | |
2512 | */ | |
2513 | static bool check_sibling_keys(struct extent_buffer *left, | |
2514 | struct extent_buffer *right) | |
2515 | { | |
2516 | struct btrfs_key left_last; | |
2517 | struct btrfs_key right_first; | |
2518 | int level = btrfs_header_level(left); | |
2519 | int nr_left = btrfs_header_nritems(left); | |
2520 | int nr_right = btrfs_header_nritems(right); | |
2521 | ||
2522 | /* No key to check in one of the tree blocks */ | |
2523 | if (!nr_left || !nr_right) | |
2524 | return false; | |
2525 | ||
2526 | if (level) { | |
2527 | btrfs_node_key_to_cpu(left, &left_last, nr_left - 1); | |
2528 | btrfs_node_key_to_cpu(right, &right_first, 0); | |
2529 | } else { | |
2530 | btrfs_item_key_to_cpu(left, &left_last, nr_left - 1); | |
2531 | btrfs_item_key_to_cpu(right, &right_first, 0); | |
2532 | } | |
2533 | ||
2534 | if (btrfs_comp_cpu_keys(&left_last, &right_first) >= 0) { | |
2535 | btrfs_crit(left->fs_info, | |
2536 | "bad key order, sibling blocks, left last (%llu %u %llu) right first (%llu %u %llu)", | |
2537 | left_last.objectid, left_last.type, | |
2538 | left_last.offset, right_first.objectid, | |
2539 | right_first.type, right_first.offset); | |
2540 | return true; | |
2541 | } | |
2542 | return false; | |
2543 | } | |
2544 | ||
74123bd7 CM |
2545 | /* |
2546 | * try to push data from one node into the next node left in the | |
79f95c82 | 2547 | * tree. |
aa5d6bed CM |
2548 | * |
2549 | * returns 0 if some ptrs were pushed left, < 0 if there was some horrible | |
2550 | * error, and > 0 if there was no room in the left hand block. | |
74123bd7 | 2551 | */ |
98ed5174 | 2552 | static int push_node_left(struct btrfs_trans_handle *trans, |
2ff7e61e | 2553 | struct extent_buffer *dst, |
971a1f66 | 2554 | struct extent_buffer *src, int empty) |
be0e5c09 | 2555 | { |
d30a668f | 2556 | struct btrfs_fs_info *fs_info = trans->fs_info; |
be0e5c09 | 2557 | int push_items = 0; |
bb803951 CM |
2558 | int src_nritems; |
2559 | int dst_nritems; | |
aa5d6bed | 2560 | int ret = 0; |
be0e5c09 | 2561 | |
5f39d397 CM |
2562 | src_nritems = btrfs_header_nritems(src); |
2563 | dst_nritems = btrfs_header_nritems(dst); | |
0b246afa | 2564 | push_items = BTRFS_NODEPTRS_PER_BLOCK(fs_info) - dst_nritems; |
7bb86316 CM |
2565 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
2566 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
54aa1f4d | 2567 | |
bce4eae9 | 2568 | if (!empty && src_nritems <= 8) |
971a1f66 CM |
2569 | return 1; |
2570 | ||
d397712b | 2571 | if (push_items <= 0) |
be0e5c09 CM |
2572 | return 1; |
2573 | ||
bce4eae9 | 2574 | if (empty) { |
971a1f66 | 2575 | push_items = min(src_nritems, push_items); |
bce4eae9 CM |
2576 | if (push_items < src_nritems) { |
2577 | /* leave at least 8 pointers in the node if | |
2578 | * we aren't going to empty it | |
2579 | */ | |
2580 | if (src_nritems - push_items < 8) { | |
2581 | if (push_items <= 8) | |
2582 | return 1; | |
2583 | push_items -= 8; | |
2584 | } | |
2585 | } | |
2586 | } else | |
2587 | push_items = min(src_nritems - 8, push_items); | |
79f95c82 | 2588 | |
d16c702f QW |
2589 | /* dst is the left eb, src is the middle eb */ |
2590 | if (check_sibling_keys(dst, src)) { | |
2591 | ret = -EUCLEAN; | |
2592 | btrfs_abort_transaction(trans, ret); | |
2593 | return ret; | |
2594 | } | |
f3a84ccd | 2595 | ret = btrfs_tree_mod_log_eb_copy(dst, src, dst_nritems, 0, push_items); |
5de865ee | 2596 | if (ret) { |
66642832 | 2597 | btrfs_abort_transaction(trans, ret); |
5de865ee FDBM |
2598 | return ret; |
2599 | } | |
5f39d397 CM |
2600 | copy_extent_buffer(dst, src, |
2601 | btrfs_node_key_ptr_offset(dst_nritems), | |
2602 | btrfs_node_key_ptr_offset(0), | |
d397712b | 2603 | push_items * sizeof(struct btrfs_key_ptr)); |
5f39d397 | 2604 | |
bb803951 | 2605 | if (push_items < src_nritems) { |
57911b8b | 2606 | /* |
f3a84ccd FM |
2607 | * Don't call btrfs_tree_mod_log_insert_move() here, key removal |
2608 | * was already fully logged by btrfs_tree_mod_log_eb_copy() above. | |
57911b8b | 2609 | */ |
5f39d397 CM |
2610 | memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0), |
2611 | btrfs_node_key_ptr_offset(push_items), | |
2612 | (src_nritems - push_items) * | |
2613 | sizeof(struct btrfs_key_ptr)); | |
2614 | } | |
2615 | btrfs_set_header_nritems(src, src_nritems - push_items); | |
2616 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
2617 | btrfs_mark_buffer_dirty(src); | |
2618 | btrfs_mark_buffer_dirty(dst); | |
31840ae1 | 2619 | |
79f95c82 CM |
2620 | return ret; |
2621 | } | |
2622 | ||
2623 | /* | |
2624 | * try to push data from one node into the next node right in the | |
2625 | * tree. | |
2626 | * | |
2627 | * returns 0 if some ptrs were pushed, < 0 if there was some horrible | |
2628 | * error, and > 0 if there was no room in the right hand block. | |
2629 | * | |
2630 | * this will only push up to 1/2 the contents of the left node over | |
2631 | */ | |
5f39d397 | 2632 | static int balance_node_right(struct btrfs_trans_handle *trans, |
5f39d397 CM |
2633 | struct extent_buffer *dst, |
2634 | struct extent_buffer *src) | |
79f95c82 | 2635 | { |
55d32ed8 | 2636 | struct btrfs_fs_info *fs_info = trans->fs_info; |
79f95c82 CM |
2637 | int push_items = 0; |
2638 | int max_push; | |
2639 | int src_nritems; | |
2640 | int dst_nritems; | |
2641 | int ret = 0; | |
79f95c82 | 2642 | |
7bb86316 CM |
2643 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
2644 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
2645 | ||
5f39d397 CM |
2646 | src_nritems = btrfs_header_nritems(src); |
2647 | dst_nritems = btrfs_header_nritems(dst); | |
0b246afa | 2648 | push_items = BTRFS_NODEPTRS_PER_BLOCK(fs_info) - dst_nritems; |
d397712b | 2649 | if (push_items <= 0) |
79f95c82 | 2650 | return 1; |
bce4eae9 | 2651 | |
d397712b | 2652 | if (src_nritems < 4) |
bce4eae9 | 2653 | return 1; |
79f95c82 CM |
2654 | |
2655 | max_push = src_nritems / 2 + 1; | |
2656 | /* don't try to empty the node */ | |
d397712b | 2657 | if (max_push >= src_nritems) |
79f95c82 | 2658 | return 1; |
252c38f0 | 2659 | |
79f95c82 CM |
2660 | if (max_push < push_items) |
2661 | push_items = max_push; | |
2662 | ||
d16c702f QW |
2663 | /* dst is the right eb, src is the middle eb */ |
2664 | if (check_sibling_keys(src, dst)) { | |
2665 | ret = -EUCLEAN; | |
2666 | btrfs_abort_transaction(trans, ret); | |
2667 | return ret; | |
2668 | } | |
f3a84ccd | 2669 | ret = btrfs_tree_mod_log_insert_move(dst, push_items, 0, dst_nritems); |
bf1d3425 | 2670 | BUG_ON(ret < 0); |
5f39d397 CM |
2671 | memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items), |
2672 | btrfs_node_key_ptr_offset(0), | |
2673 | (dst_nritems) * | |
2674 | sizeof(struct btrfs_key_ptr)); | |
d6025579 | 2675 | |
f3a84ccd FM |
2676 | ret = btrfs_tree_mod_log_eb_copy(dst, src, 0, src_nritems - push_items, |
2677 | push_items); | |
5de865ee | 2678 | if (ret) { |
66642832 | 2679 | btrfs_abort_transaction(trans, ret); |
5de865ee FDBM |
2680 | return ret; |
2681 | } | |
5f39d397 CM |
2682 | copy_extent_buffer(dst, src, |
2683 | btrfs_node_key_ptr_offset(0), | |
2684 | btrfs_node_key_ptr_offset(src_nritems - push_items), | |
d397712b | 2685 | push_items * sizeof(struct btrfs_key_ptr)); |
79f95c82 | 2686 | |
5f39d397 CM |
2687 | btrfs_set_header_nritems(src, src_nritems - push_items); |
2688 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
79f95c82 | 2689 | |
5f39d397 CM |
2690 | btrfs_mark_buffer_dirty(src); |
2691 | btrfs_mark_buffer_dirty(dst); | |
31840ae1 | 2692 | |
aa5d6bed | 2693 | return ret; |
be0e5c09 CM |
2694 | } |
2695 | ||
97571fd0 CM |
2696 | /* |
2697 | * helper function to insert a new root level in the tree. | |
2698 | * A new node is allocated, and a single item is inserted to | |
2699 | * point to the existing root | |
aa5d6bed CM |
2700 | * |
2701 | * returns zero on success or < 0 on failure. | |
97571fd0 | 2702 | */ |
d397712b | 2703 | static noinline int insert_new_root(struct btrfs_trans_handle *trans, |
5f39d397 | 2704 | struct btrfs_root *root, |
fdd99c72 | 2705 | struct btrfs_path *path, int level) |
5c680ed6 | 2706 | { |
0b246afa | 2707 | struct btrfs_fs_info *fs_info = root->fs_info; |
7bb86316 | 2708 | u64 lower_gen; |
5f39d397 CM |
2709 | struct extent_buffer *lower; |
2710 | struct extent_buffer *c; | |
925baedd | 2711 | struct extent_buffer *old; |
5f39d397 | 2712 | struct btrfs_disk_key lower_key; |
d9d19a01 | 2713 | int ret; |
5c680ed6 CM |
2714 | |
2715 | BUG_ON(path->nodes[level]); | |
2716 | BUG_ON(path->nodes[level-1] != root->node); | |
2717 | ||
7bb86316 CM |
2718 | lower = path->nodes[level-1]; |
2719 | if (level == 1) | |
2720 | btrfs_item_key(lower, &lower_key, 0); | |
2721 | else | |
2722 | btrfs_node_key(lower, &lower_key, 0); | |
2723 | ||
79bd3712 FM |
2724 | c = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid, |
2725 | &lower_key, level, root->node->start, 0, | |
2726 | BTRFS_NESTING_NEW_ROOT); | |
5f39d397 CM |
2727 | if (IS_ERR(c)) |
2728 | return PTR_ERR(c); | |
925baedd | 2729 | |
0b246afa | 2730 | root_add_used(root, fs_info->nodesize); |
f0486c68 | 2731 | |
5f39d397 | 2732 | btrfs_set_header_nritems(c, 1); |
5f39d397 | 2733 | btrfs_set_node_key(c, &lower_key, 0); |
db94535d | 2734 | btrfs_set_node_blockptr(c, 0, lower->start); |
7bb86316 | 2735 | lower_gen = btrfs_header_generation(lower); |
31840ae1 | 2736 | WARN_ON(lower_gen != trans->transid); |
7bb86316 CM |
2737 | |
2738 | btrfs_set_node_ptr_generation(c, 0, lower_gen); | |
d5719762 | 2739 | |
5f39d397 | 2740 | btrfs_mark_buffer_dirty(c); |
d5719762 | 2741 | |
925baedd | 2742 | old = root->node; |
406808ab | 2743 | ret = btrfs_tree_mod_log_insert_root(root->node, c, false); |
d9d19a01 | 2744 | BUG_ON(ret < 0); |
240f62c8 | 2745 | rcu_assign_pointer(root->node, c); |
925baedd CM |
2746 | |
2747 | /* the super has an extra ref to root->node */ | |
2748 | free_extent_buffer(old); | |
2749 | ||
0b86a832 | 2750 | add_root_to_dirty_list(root); |
67439dad | 2751 | atomic_inc(&c->refs); |
5f39d397 | 2752 | path->nodes[level] = c; |
ac5887c8 | 2753 | path->locks[level] = BTRFS_WRITE_LOCK; |
5c680ed6 CM |
2754 | path->slots[level] = 0; |
2755 | return 0; | |
2756 | } | |
2757 | ||
74123bd7 CM |
2758 | /* |
2759 | * worker function to insert a single pointer in a node. | |
2760 | * the node should have enough room for the pointer already | |
97571fd0 | 2761 | * |
74123bd7 CM |
2762 | * slot and level indicate where you want the key to go, and |
2763 | * blocknr is the block the key points to. | |
2764 | */ | |
143bede5 | 2765 | static void insert_ptr(struct btrfs_trans_handle *trans, |
6ad3cf6d | 2766 | struct btrfs_path *path, |
143bede5 | 2767 | struct btrfs_disk_key *key, u64 bytenr, |
c3e06965 | 2768 | int slot, int level) |
74123bd7 | 2769 | { |
5f39d397 | 2770 | struct extent_buffer *lower; |
74123bd7 | 2771 | int nritems; |
f3ea38da | 2772 | int ret; |
5c680ed6 CM |
2773 | |
2774 | BUG_ON(!path->nodes[level]); | |
49d0c642 | 2775 | btrfs_assert_tree_write_locked(path->nodes[level]); |
5f39d397 CM |
2776 | lower = path->nodes[level]; |
2777 | nritems = btrfs_header_nritems(lower); | |
c293498b | 2778 | BUG_ON(slot > nritems); |
6ad3cf6d | 2779 | BUG_ON(nritems == BTRFS_NODEPTRS_PER_BLOCK(trans->fs_info)); |
74123bd7 | 2780 | if (slot != nritems) { |
bf1d3425 | 2781 | if (level) { |
f3a84ccd FM |
2782 | ret = btrfs_tree_mod_log_insert_move(lower, slot + 1, |
2783 | slot, nritems - slot); | |
bf1d3425 DS |
2784 | BUG_ON(ret < 0); |
2785 | } | |
5f39d397 CM |
2786 | memmove_extent_buffer(lower, |
2787 | btrfs_node_key_ptr_offset(slot + 1), | |
2788 | btrfs_node_key_ptr_offset(slot), | |
d6025579 | 2789 | (nritems - slot) * sizeof(struct btrfs_key_ptr)); |
74123bd7 | 2790 | } |
c3e06965 | 2791 | if (level) { |
f3a84ccd | 2792 | ret = btrfs_tree_mod_log_insert_key(lower, slot, |
33cff222 | 2793 | BTRFS_MOD_LOG_KEY_ADD); |
f3ea38da JS |
2794 | BUG_ON(ret < 0); |
2795 | } | |
5f39d397 | 2796 | btrfs_set_node_key(lower, key, slot); |
db94535d | 2797 | btrfs_set_node_blockptr(lower, slot, bytenr); |
74493f7a CM |
2798 | WARN_ON(trans->transid == 0); |
2799 | btrfs_set_node_ptr_generation(lower, slot, trans->transid); | |
5f39d397 CM |
2800 | btrfs_set_header_nritems(lower, nritems + 1); |
2801 | btrfs_mark_buffer_dirty(lower); | |
74123bd7 CM |
2802 | } |
2803 | ||
97571fd0 CM |
2804 | /* |
2805 | * split the node at the specified level in path in two. | |
2806 | * The path is corrected to point to the appropriate node after the split | |
2807 | * | |
2808 | * Before splitting this tries to make some room in the node by pushing | |
2809 | * left and right, if either one works, it returns right away. | |
aa5d6bed CM |
2810 | * |
2811 | * returns 0 on success and < 0 on failure | |
97571fd0 | 2812 | */ |
e02119d5 CM |
2813 | static noinline int split_node(struct btrfs_trans_handle *trans, |
2814 | struct btrfs_root *root, | |
2815 | struct btrfs_path *path, int level) | |
be0e5c09 | 2816 | { |
0b246afa | 2817 | struct btrfs_fs_info *fs_info = root->fs_info; |
5f39d397 CM |
2818 | struct extent_buffer *c; |
2819 | struct extent_buffer *split; | |
2820 | struct btrfs_disk_key disk_key; | |
be0e5c09 | 2821 | int mid; |
5c680ed6 | 2822 | int ret; |
7518a238 | 2823 | u32 c_nritems; |
eb60ceac | 2824 | |
5f39d397 | 2825 | c = path->nodes[level]; |
7bb86316 | 2826 | WARN_ON(btrfs_header_generation(c) != trans->transid); |
5f39d397 | 2827 | if (c == root->node) { |
d9abbf1c | 2828 | /* |
90f8d62e JS |
2829 | * trying to split the root, lets make a new one |
2830 | * | |
fdd99c72 | 2831 | * tree mod log: We don't log_removal old root in |
90f8d62e JS |
2832 | * insert_new_root, because that root buffer will be kept as a |
2833 | * normal node. We are going to log removal of half of the | |
f3a84ccd FM |
2834 | * elements below with btrfs_tree_mod_log_eb_copy(). We're |
2835 | * holding a tree lock on the buffer, which is why we cannot | |
2836 | * race with other tree_mod_log users. | |
d9abbf1c | 2837 | */ |
fdd99c72 | 2838 | ret = insert_new_root(trans, root, path, level + 1); |
5c680ed6 CM |
2839 | if (ret) |
2840 | return ret; | |
b3612421 | 2841 | } else { |
e66f709b | 2842 | ret = push_nodes_for_insert(trans, root, path, level); |
5f39d397 CM |
2843 | c = path->nodes[level]; |
2844 | if (!ret && btrfs_header_nritems(c) < | |
0b246afa | 2845 | BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 3) |
e66f709b | 2846 | return 0; |
54aa1f4d CM |
2847 | if (ret < 0) |
2848 | return ret; | |
be0e5c09 | 2849 | } |
e66f709b | 2850 | |
5f39d397 | 2851 | c_nritems = btrfs_header_nritems(c); |
5d4f98a2 YZ |
2852 | mid = (c_nritems + 1) / 2; |
2853 | btrfs_node_key(c, &disk_key, mid); | |
7bb86316 | 2854 | |
79bd3712 FM |
2855 | split = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid, |
2856 | &disk_key, level, c->start, 0, | |
2857 | BTRFS_NESTING_SPLIT); | |
5f39d397 CM |
2858 | if (IS_ERR(split)) |
2859 | return PTR_ERR(split); | |
2860 | ||
0b246afa | 2861 | root_add_used(root, fs_info->nodesize); |
bc877d28 | 2862 | ASSERT(btrfs_header_level(c) == level); |
54aa1f4d | 2863 | |
f3a84ccd | 2864 | ret = btrfs_tree_mod_log_eb_copy(split, c, 0, mid, c_nritems - mid); |
5de865ee | 2865 | if (ret) { |
66642832 | 2866 | btrfs_abort_transaction(trans, ret); |
5de865ee FDBM |
2867 | return ret; |
2868 | } | |
5f39d397 CM |
2869 | copy_extent_buffer(split, c, |
2870 | btrfs_node_key_ptr_offset(0), | |
2871 | btrfs_node_key_ptr_offset(mid), | |
2872 | (c_nritems - mid) * sizeof(struct btrfs_key_ptr)); | |
2873 | btrfs_set_header_nritems(split, c_nritems - mid); | |
2874 | btrfs_set_header_nritems(c, mid); | |
aa5d6bed | 2875 | |
5f39d397 CM |
2876 | btrfs_mark_buffer_dirty(c); |
2877 | btrfs_mark_buffer_dirty(split); | |
2878 | ||
6ad3cf6d | 2879 | insert_ptr(trans, path, &disk_key, split->start, |
c3e06965 | 2880 | path->slots[level + 1] + 1, level + 1); |
aa5d6bed | 2881 | |
5de08d7d | 2882 | if (path->slots[level] >= mid) { |
5c680ed6 | 2883 | path->slots[level] -= mid; |
925baedd | 2884 | btrfs_tree_unlock(c); |
5f39d397 CM |
2885 | free_extent_buffer(c); |
2886 | path->nodes[level] = split; | |
5c680ed6 CM |
2887 | path->slots[level + 1] += 1; |
2888 | } else { | |
925baedd | 2889 | btrfs_tree_unlock(split); |
5f39d397 | 2890 | free_extent_buffer(split); |
be0e5c09 | 2891 | } |
d5286a92 | 2892 | return 0; |
be0e5c09 CM |
2893 | } |
2894 | ||
74123bd7 CM |
2895 | /* |
2896 | * how many bytes are required to store the items in a leaf. start | |
2897 | * and nr indicate which items in the leaf to check. This totals up the | |
2898 | * space used both by the item structs and the item data | |
2899 | */ | |
5f39d397 | 2900 | static int leaf_space_used(struct extent_buffer *l, int start, int nr) |
be0e5c09 CM |
2901 | { |
2902 | int data_len; | |
5f39d397 | 2903 | int nritems = btrfs_header_nritems(l); |
d4dbff95 | 2904 | int end = min(nritems, start + nr) - 1; |
be0e5c09 CM |
2905 | |
2906 | if (!nr) | |
2907 | return 0; | |
3212fa14 JB |
2908 | data_len = btrfs_item_offset(l, start) + btrfs_item_size(l, start); |
2909 | data_len = data_len - btrfs_item_offset(l, end); | |
0783fcfc | 2910 | data_len += sizeof(struct btrfs_item) * nr; |
d4dbff95 | 2911 | WARN_ON(data_len < 0); |
be0e5c09 CM |
2912 | return data_len; |
2913 | } | |
2914 | ||
d4dbff95 CM |
2915 | /* |
2916 | * The space between the end of the leaf items and | |
2917 | * the start of the leaf data. IOW, how much room | |
2918 | * the leaf has left for both items and data | |
2919 | */ | |
e902baac | 2920 | noinline int btrfs_leaf_free_space(struct extent_buffer *leaf) |
d4dbff95 | 2921 | { |
e902baac | 2922 | struct btrfs_fs_info *fs_info = leaf->fs_info; |
5f39d397 CM |
2923 | int nritems = btrfs_header_nritems(leaf); |
2924 | int ret; | |
0b246afa JM |
2925 | |
2926 | ret = BTRFS_LEAF_DATA_SIZE(fs_info) - leaf_space_used(leaf, 0, nritems); | |
5f39d397 | 2927 | if (ret < 0) { |
0b246afa JM |
2928 | btrfs_crit(fs_info, |
2929 | "leaf free space ret %d, leaf data size %lu, used %d nritems %d", | |
2930 | ret, | |
2931 | (unsigned long) BTRFS_LEAF_DATA_SIZE(fs_info), | |
2932 | leaf_space_used(leaf, 0, nritems), nritems); | |
5f39d397 CM |
2933 | } |
2934 | return ret; | |
d4dbff95 CM |
2935 | } |
2936 | ||
99d8f83c CM |
2937 | /* |
2938 | * min slot controls the lowest index we're willing to push to the | |
2939 | * right. We'll push up to and including min_slot, but no lower | |
2940 | */ | |
f72f0010 | 2941 | static noinline int __push_leaf_right(struct btrfs_path *path, |
44871b1b CM |
2942 | int data_size, int empty, |
2943 | struct extent_buffer *right, | |
99d8f83c CM |
2944 | int free_space, u32 left_nritems, |
2945 | u32 min_slot) | |
00ec4c51 | 2946 | { |
f72f0010 | 2947 | struct btrfs_fs_info *fs_info = right->fs_info; |
5f39d397 | 2948 | struct extent_buffer *left = path->nodes[0]; |
44871b1b | 2949 | struct extent_buffer *upper = path->nodes[1]; |
cfed81a0 | 2950 | struct btrfs_map_token token; |
5f39d397 | 2951 | struct btrfs_disk_key disk_key; |
00ec4c51 | 2952 | int slot; |
34a38218 | 2953 | u32 i; |
00ec4c51 CM |
2954 | int push_space = 0; |
2955 | int push_items = 0; | |
34a38218 | 2956 | u32 nr; |
7518a238 | 2957 | u32 right_nritems; |
5f39d397 | 2958 | u32 data_end; |
db94535d | 2959 | u32 this_item_size; |
00ec4c51 | 2960 | |
34a38218 CM |
2961 | if (empty) |
2962 | nr = 0; | |
2963 | else | |
99d8f83c | 2964 | nr = max_t(u32, 1, min_slot); |
34a38218 | 2965 | |
31840ae1 | 2966 | if (path->slots[0] >= left_nritems) |
87b29b20 | 2967 | push_space += data_size; |
31840ae1 | 2968 | |
44871b1b | 2969 | slot = path->slots[1]; |
34a38218 CM |
2970 | i = left_nritems - 1; |
2971 | while (i >= nr) { | |
31840ae1 ZY |
2972 | if (!empty && push_items > 0) { |
2973 | if (path->slots[0] > i) | |
2974 | break; | |
2975 | if (path->slots[0] == i) { | |
e902baac DS |
2976 | int space = btrfs_leaf_free_space(left); |
2977 | ||
31840ae1 ZY |
2978 | if (space + push_space * 2 > free_space) |
2979 | break; | |
2980 | } | |
2981 | } | |
2982 | ||
00ec4c51 | 2983 | if (path->slots[0] == i) |
87b29b20 | 2984 | push_space += data_size; |
db94535d | 2985 | |
3212fa14 | 2986 | this_item_size = btrfs_item_size(left, i); |
74794207 JB |
2987 | if (this_item_size + sizeof(struct btrfs_item) + |
2988 | push_space > free_space) | |
00ec4c51 | 2989 | break; |
31840ae1 | 2990 | |
00ec4c51 | 2991 | push_items++; |
74794207 | 2992 | push_space += this_item_size + sizeof(struct btrfs_item); |
34a38218 CM |
2993 | if (i == 0) |
2994 | break; | |
2995 | i--; | |
db94535d | 2996 | } |
5f39d397 | 2997 | |
925baedd CM |
2998 | if (push_items == 0) |
2999 | goto out_unlock; | |
5f39d397 | 3000 | |
6c1500f2 | 3001 | WARN_ON(!empty && push_items == left_nritems); |
5f39d397 | 3002 | |
00ec4c51 | 3003 | /* push left to right */ |
5f39d397 | 3004 | right_nritems = btrfs_header_nritems(right); |
34a38218 | 3005 | |
dc2e724e | 3006 | push_space = btrfs_item_data_end(left, left_nritems - push_items); |
8f881e8c | 3007 | push_space -= leaf_data_end(left); |
5f39d397 | 3008 | |
00ec4c51 | 3009 | /* make room in the right data area */ |
8f881e8c | 3010 | data_end = leaf_data_end(right); |
5f39d397 | 3011 | memmove_extent_buffer(right, |
3d9ec8c4 NB |
3012 | BTRFS_LEAF_DATA_OFFSET + data_end - push_space, |
3013 | BTRFS_LEAF_DATA_OFFSET + data_end, | |
0b246afa | 3014 | BTRFS_LEAF_DATA_SIZE(fs_info) - data_end); |
5f39d397 | 3015 | |
00ec4c51 | 3016 | /* copy from the left data area */ |
3d9ec8c4 | 3017 | copy_extent_buffer(right, left, BTRFS_LEAF_DATA_OFFSET + |
0b246afa | 3018 | BTRFS_LEAF_DATA_SIZE(fs_info) - push_space, |
8f881e8c | 3019 | BTRFS_LEAF_DATA_OFFSET + leaf_data_end(left), |
d6025579 | 3020 | push_space); |
5f39d397 CM |
3021 | |
3022 | memmove_extent_buffer(right, btrfs_item_nr_offset(push_items), | |
3023 | btrfs_item_nr_offset(0), | |
3024 | right_nritems * sizeof(struct btrfs_item)); | |
3025 | ||
00ec4c51 | 3026 | /* copy the items from left to right */ |
5f39d397 CM |
3027 | copy_extent_buffer(right, left, btrfs_item_nr_offset(0), |
3028 | btrfs_item_nr_offset(left_nritems - push_items), | |
3029 | push_items * sizeof(struct btrfs_item)); | |
00ec4c51 CM |
3030 | |
3031 | /* update the item pointers */ | |
c82f823c | 3032 | btrfs_init_map_token(&token, right); |
7518a238 | 3033 | right_nritems += push_items; |
5f39d397 | 3034 | btrfs_set_header_nritems(right, right_nritems); |
0b246afa | 3035 | push_space = BTRFS_LEAF_DATA_SIZE(fs_info); |
7518a238 | 3036 | for (i = 0; i < right_nritems; i++) { |
3212fa14 JB |
3037 | push_space -= btrfs_token_item_size(&token, i); |
3038 | btrfs_set_token_item_offset(&token, i, push_space); | |
db94535d CM |
3039 | } |
3040 | ||
7518a238 | 3041 | left_nritems -= push_items; |
5f39d397 | 3042 | btrfs_set_header_nritems(left, left_nritems); |
00ec4c51 | 3043 | |
34a38218 CM |
3044 | if (left_nritems) |
3045 | btrfs_mark_buffer_dirty(left); | |
f0486c68 | 3046 | else |
6a884d7d | 3047 | btrfs_clean_tree_block(left); |
f0486c68 | 3048 | |
5f39d397 | 3049 | btrfs_mark_buffer_dirty(right); |
a429e513 | 3050 | |
5f39d397 CM |
3051 | btrfs_item_key(right, &disk_key, 0); |
3052 | btrfs_set_node_key(upper, &disk_key, slot + 1); | |
d6025579 | 3053 | btrfs_mark_buffer_dirty(upper); |
02217ed2 | 3054 | |
00ec4c51 | 3055 | /* then fixup the leaf pointer in the path */ |
7518a238 CM |
3056 | if (path->slots[0] >= left_nritems) { |
3057 | path->slots[0] -= left_nritems; | |
925baedd | 3058 | if (btrfs_header_nritems(path->nodes[0]) == 0) |
6a884d7d | 3059 | btrfs_clean_tree_block(path->nodes[0]); |
925baedd | 3060 | btrfs_tree_unlock(path->nodes[0]); |
5f39d397 CM |
3061 | free_extent_buffer(path->nodes[0]); |
3062 | path->nodes[0] = right; | |
00ec4c51 CM |
3063 | path->slots[1] += 1; |
3064 | } else { | |
925baedd | 3065 | btrfs_tree_unlock(right); |
5f39d397 | 3066 | free_extent_buffer(right); |
00ec4c51 CM |
3067 | } |
3068 | return 0; | |
925baedd CM |
3069 | |
3070 | out_unlock: | |
3071 | btrfs_tree_unlock(right); | |
3072 | free_extent_buffer(right); | |
3073 | return 1; | |
00ec4c51 | 3074 | } |
925baedd | 3075 | |
44871b1b CM |
3076 | /* |
3077 | * push some data in the path leaf to the right, trying to free up at | |
3078 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
3079 | * | |
3080 | * returns 1 if the push failed because the other node didn't have enough | |
3081 | * room, 0 if everything worked out and < 0 if there were major errors. | |
99d8f83c CM |
3082 | * |
3083 | * this will push starting from min_slot to the end of the leaf. It won't | |
3084 | * push any slot lower than min_slot | |
44871b1b CM |
3085 | */ |
3086 | static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root | |
99d8f83c CM |
3087 | *root, struct btrfs_path *path, |
3088 | int min_data_size, int data_size, | |
3089 | int empty, u32 min_slot) | |
44871b1b CM |
3090 | { |
3091 | struct extent_buffer *left = path->nodes[0]; | |
3092 | struct extent_buffer *right; | |
3093 | struct extent_buffer *upper; | |
3094 | int slot; | |
3095 | int free_space; | |
3096 | u32 left_nritems; | |
3097 | int ret; | |
3098 | ||
3099 | if (!path->nodes[1]) | |
3100 | return 1; | |
3101 | ||
3102 | slot = path->slots[1]; | |
3103 | upper = path->nodes[1]; | |
3104 | if (slot >= btrfs_header_nritems(upper) - 1) | |
3105 | return 1; | |
3106 | ||
49d0c642 | 3107 | btrfs_assert_tree_write_locked(path->nodes[1]); |
44871b1b | 3108 | |
4b231ae4 | 3109 | right = btrfs_read_node_slot(upper, slot + 1); |
fb770ae4 LB |
3110 | /* |
3111 | * slot + 1 is not valid or we fail to read the right node, | |
3112 | * no big deal, just return. | |
3113 | */ | |
3114 | if (IS_ERR(right)) | |
91ca338d TI |
3115 | return 1; |
3116 | ||
bf77467a | 3117 | __btrfs_tree_lock(right, BTRFS_NESTING_RIGHT); |
44871b1b | 3118 | |
e902baac | 3119 | free_space = btrfs_leaf_free_space(right); |
44871b1b CM |
3120 | if (free_space < data_size) |
3121 | goto out_unlock; | |
3122 | ||
44871b1b | 3123 | ret = btrfs_cow_block(trans, root, right, upper, |
bf59a5a2 | 3124 | slot + 1, &right, BTRFS_NESTING_RIGHT_COW); |
44871b1b CM |
3125 | if (ret) |
3126 | goto out_unlock; | |
3127 | ||
44871b1b CM |
3128 | left_nritems = btrfs_header_nritems(left); |
3129 | if (left_nritems == 0) | |
3130 | goto out_unlock; | |
3131 | ||
d16c702f QW |
3132 | if (check_sibling_keys(left, right)) { |
3133 | ret = -EUCLEAN; | |
3134 | btrfs_tree_unlock(right); | |
3135 | free_extent_buffer(right); | |
3136 | return ret; | |
3137 | } | |
2ef1fed2 FDBM |
3138 | if (path->slots[0] == left_nritems && !empty) { |
3139 | /* Key greater than all keys in the leaf, right neighbor has | |
3140 | * enough room for it and we're not emptying our leaf to delete | |
3141 | * it, therefore use right neighbor to insert the new item and | |
52042d8e | 3142 | * no need to touch/dirty our left leaf. */ |
2ef1fed2 FDBM |
3143 | btrfs_tree_unlock(left); |
3144 | free_extent_buffer(left); | |
3145 | path->nodes[0] = right; | |
3146 | path->slots[0] = 0; | |
3147 | path->slots[1]++; | |
3148 | return 0; | |
3149 | } | |
3150 | ||
f72f0010 | 3151 | return __push_leaf_right(path, min_data_size, empty, |
99d8f83c | 3152 | right, free_space, left_nritems, min_slot); |
44871b1b CM |
3153 | out_unlock: |
3154 | btrfs_tree_unlock(right); | |
3155 | free_extent_buffer(right); | |
3156 | return 1; | |
3157 | } | |
3158 | ||
74123bd7 CM |
3159 | /* |
3160 | * push some data in the path leaf to the left, trying to free up at | |
3161 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
99d8f83c CM |
3162 | * |
3163 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
3164 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us do all the | |
3165 | * items | |
74123bd7 | 3166 | */ |
8087c193 | 3167 | static noinline int __push_leaf_left(struct btrfs_path *path, int data_size, |
44871b1b | 3168 | int empty, struct extent_buffer *left, |
99d8f83c CM |
3169 | int free_space, u32 right_nritems, |
3170 | u32 max_slot) | |
be0e5c09 | 3171 | { |
8087c193 | 3172 | struct btrfs_fs_info *fs_info = left->fs_info; |
5f39d397 CM |
3173 | struct btrfs_disk_key disk_key; |
3174 | struct extent_buffer *right = path->nodes[0]; | |
be0e5c09 | 3175 | int i; |
be0e5c09 CM |
3176 | int push_space = 0; |
3177 | int push_items = 0; | |
7518a238 | 3178 | u32 old_left_nritems; |
34a38218 | 3179 | u32 nr; |
aa5d6bed | 3180 | int ret = 0; |
db94535d CM |
3181 | u32 this_item_size; |
3182 | u32 old_left_item_size; | |
cfed81a0 CM |
3183 | struct btrfs_map_token token; |
3184 | ||
34a38218 | 3185 | if (empty) |
99d8f83c | 3186 | nr = min(right_nritems, max_slot); |
34a38218 | 3187 | else |
99d8f83c | 3188 | nr = min(right_nritems - 1, max_slot); |
34a38218 CM |
3189 | |
3190 | for (i = 0; i < nr; i++) { | |
31840ae1 ZY |
3191 | if (!empty && push_items > 0) { |
3192 | if (path->slots[0] < i) | |
3193 | break; | |
3194 | if (path->slots[0] == i) { | |
e902baac DS |
3195 | int space = btrfs_leaf_free_space(right); |
3196 | ||
31840ae1 ZY |
3197 | if (space + push_space * 2 > free_space) |
3198 | break; | |
3199 | } | |
3200 | } | |
3201 | ||
be0e5c09 | 3202 | if (path->slots[0] == i) |
87b29b20 | 3203 | push_space += data_size; |
db94535d | 3204 | |
3212fa14 | 3205 | this_item_size = btrfs_item_size(right, i); |
74794207 JB |
3206 | if (this_item_size + sizeof(struct btrfs_item) + push_space > |
3207 | free_space) | |
be0e5c09 | 3208 | break; |
db94535d | 3209 | |
be0e5c09 | 3210 | push_items++; |
74794207 | 3211 | push_space += this_item_size + sizeof(struct btrfs_item); |
db94535d CM |
3212 | } |
3213 | ||
be0e5c09 | 3214 | if (push_items == 0) { |
925baedd CM |
3215 | ret = 1; |
3216 | goto out; | |
be0e5c09 | 3217 | } |
fae7f21c | 3218 | WARN_ON(!empty && push_items == btrfs_header_nritems(right)); |
5f39d397 | 3219 | |
be0e5c09 | 3220 | /* push data from right to left */ |
5f39d397 CM |
3221 | copy_extent_buffer(left, right, |
3222 | btrfs_item_nr_offset(btrfs_header_nritems(left)), | |
3223 | btrfs_item_nr_offset(0), | |
3224 | push_items * sizeof(struct btrfs_item)); | |
3225 | ||
0b246afa | 3226 | push_space = BTRFS_LEAF_DATA_SIZE(fs_info) - |
3212fa14 | 3227 | btrfs_item_offset(right, push_items - 1); |
5f39d397 | 3228 | |
3d9ec8c4 | 3229 | copy_extent_buffer(left, right, BTRFS_LEAF_DATA_OFFSET + |
8f881e8c | 3230 | leaf_data_end(left) - push_space, |
3d9ec8c4 | 3231 | BTRFS_LEAF_DATA_OFFSET + |
3212fa14 | 3232 | btrfs_item_offset(right, push_items - 1), |
d6025579 | 3233 | push_space); |
5f39d397 | 3234 | old_left_nritems = btrfs_header_nritems(left); |
87b29b20 | 3235 | BUG_ON(old_left_nritems <= 0); |
eb60ceac | 3236 | |
c82f823c | 3237 | btrfs_init_map_token(&token, left); |
3212fa14 | 3238 | old_left_item_size = btrfs_item_offset(left, old_left_nritems - 1); |
0783fcfc | 3239 | for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { |
5f39d397 | 3240 | u32 ioff; |
db94535d | 3241 | |
3212fa14 JB |
3242 | ioff = btrfs_token_item_offset(&token, i); |
3243 | btrfs_set_token_item_offset(&token, i, | |
cc4c13d5 | 3244 | ioff - (BTRFS_LEAF_DATA_SIZE(fs_info) - old_left_item_size)); |
be0e5c09 | 3245 | } |
5f39d397 | 3246 | btrfs_set_header_nritems(left, old_left_nritems + push_items); |
be0e5c09 CM |
3247 | |
3248 | /* fixup right node */ | |
31b1a2bd JL |
3249 | if (push_items > right_nritems) |
3250 | WARN(1, KERN_CRIT "push items %d nr %u\n", push_items, | |
d397712b | 3251 | right_nritems); |
34a38218 CM |
3252 | |
3253 | if (push_items < right_nritems) { | |
3212fa14 | 3254 | push_space = btrfs_item_offset(right, push_items - 1) - |
8f881e8c | 3255 | leaf_data_end(right); |
3d9ec8c4 | 3256 | memmove_extent_buffer(right, BTRFS_LEAF_DATA_OFFSET + |
0b246afa | 3257 | BTRFS_LEAF_DATA_SIZE(fs_info) - push_space, |
3d9ec8c4 | 3258 | BTRFS_LEAF_DATA_OFFSET + |
8f881e8c | 3259 | leaf_data_end(right), push_space); |
34a38218 CM |
3260 | |
3261 | memmove_extent_buffer(right, btrfs_item_nr_offset(0), | |
5f39d397 CM |
3262 | btrfs_item_nr_offset(push_items), |
3263 | (btrfs_header_nritems(right) - push_items) * | |
3264 | sizeof(struct btrfs_item)); | |
34a38218 | 3265 | } |
c82f823c DS |
3266 | |
3267 | btrfs_init_map_token(&token, right); | |
eef1c494 Y |
3268 | right_nritems -= push_items; |
3269 | btrfs_set_header_nritems(right, right_nritems); | |
0b246afa | 3270 | push_space = BTRFS_LEAF_DATA_SIZE(fs_info); |
5f39d397 | 3271 | for (i = 0; i < right_nritems; i++) { |
3212fa14 JB |
3272 | push_space = push_space - btrfs_token_item_size(&token, i); |
3273 | btrfs_set_token_item_offset(&token, i, push_space); | |
db94535d | 3274 | } |
eb60ceac | 3275 | |
5f39d397 | 3276 | btrfs_mark_buffer_dirty(left); |
34a38218 CM |
3277 | if (right_nritems) |
3278 | btrfs_mark_buffer_dirty(right); | |
f0486c68 | 3279 | else |
6a884d7d | 3280 | btrfs_clean_tree_block(right); |
098f59c2 | 3281 | |
5f39d397 | 3282 | btrfs_item_key(right, &disk_key, 0); |
b167fa91 | 3283 | fixup_low_keys(path, &disk_key, 1); |
be0e5c09 CM |
3284 | |
3285 | /* then fixup the leaf pointer in the path */ | |
3286 | if (path->slots[0] < push_items) { | |
3287 | path->slots[0] += old_left_nritems; | |
925baedd | 3288 | btrfs_tree_unlock(path->nodes[0]); |
5f39d397 CM |
3289 | free_extent_buffer(path->nodes[0]); |
3290 | path->nodes[0] = left; | |
be0e5c09 CM |
3291 | path->slots[1] -= 1; |
3292 | } else { | |
925baedd | 3293 | btrfs_tree_unlock(left); |
5f39d397 | 3294 | free_extent_buffer(left); |
be0e5c09 CM |
3295 | path->slots[0] -= push_items; |
3296 | } | |
eb60ceac | 3297 | BUG_ON(path->slots[0] < 0); |
aa5d6bed | 3298 | return ret; |
925baedd CM |
3299 | out: |
3300 | btrfs_tree_unlock(left); | |
3301 | free_extent_buffer(left); | |
3302 | return ret; | |
be0e5c09 CM |
3303 | } |
3304 | ||
44871b1b CM |
3305 | /* |
3306 | * push some data in the path leaf to the left, trying to free up at | |
3307 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
99d8f83c CM |
3308 | * |
3309 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
3310 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us push all the | |
3311 | * items | |
44871b1b CM |
3312 | */ |
3313 | static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root | |
99d8f83c CM |
3314 | *root, struct btrfs_path *path, int min_data_size, |
3315 | int data_size, int empty, u32 max_slot) | |
44871b1b CM |
3316 | { |
3317 | struct extent_buffer *right = path->nodes[0]; | |
3318 | struct extent_buffer *left; | |
3319 | int slot; | |
3320 | int free_space; | |
3321 | u32 right_nritems; | |
3322 | int ret = 0; | |
3323 | ||
3324 | slot = path->slots[1]; | |
3325 | if (slot == 0) | |
3326 | return 1; | |
3327 | if (!path->nodes[1]) | |
3328 | return 1; | |
3329 | ||
3330 | right_nritems = btrfs_header_nritems(right); | |
3331 | if (right_nritems == 0) | |
3332 | return 1; | |
3333 | ||
49d0c642 | 3334 | btrfs_assert_tree_write_locked(path->nodes[1]); |
44871b1b | 3335 | |
4b231ae4 | 3336 | left = btrfs_read_node_slot(path->nodes[1], slot - 1); |
fb770ae4 LB |
3337 | /* |
3338 | * slot - 1 is not valid or we fail to read the left node, | |
3339 | * no big deal, just return. | |
3340 | */ | |
3341 | if (IS_ERR(left)) | |
91ca338d TI |
3342 | return 1; |
3343 | ||
bf77467a | 3344 | __btrfs_tree_lock(left, BTRFS_NESTING_LEFT); |
44871b1b | 3345 | |
e902baac | 3346 | free_space = btrfs_leaf_free_space(left); |
44871b1b CM |
3347 | if (free_space < data_size) { |
3348 | ret = 1; | |
3349 | goto out; | |
3350 | } | |
3351 | ||
44871b1b | 3352 | ret = btrfs_cow_block(trans, root, left, |
9631e4cc | 3353 | path->nodes[1], slot - 1, &left, |
bf59a5a2 | 3354 | BTRFS_NESTING_LEFT_COW); |
44871b1b CM |
3355 | if (ret) { |
3356 | /* we hit -ENOSPC, but it isn't fatal here */ | |
79787eaa JM |
3357 | if (ret == -ENOSPC) |
3358 | ret = 1; | |
44871b1b CM |
3359 | goto out; |
3360 | } | |
3361 | ||
d16c702f QW |
3362 | if (check_sibling_keys(left, right)) { |
3363 | ret = -EUCLEAN; | |
3364 | goto out; | |
3365 | } | |
8087c193 | 3366 | return __push_leaf_left(path, min_data_size, |
99d8f83c CM |
3367 | empty, left, free_space, right_nritems, |
3368 | max_slot); | |
44871b1b CM |
3369 | out: |
3370 | btrfs_tree_unlock(left); | |
3371 | free_extent_buffer(left); | |
3372 | return ret; | |
3373 | } | |
3374 | ||
3375 | /* | |
3376 | * split the path's leaf in two, making sure there is at least data_size | |
3377 | * available for the resulting leaf level of the path. | |
44871b1b | 3378 | */ |
143bede5 | 3379 | static noinline void copy_for_split(struct btrfs_trans_handle *trans, |
143bede5 JM |
3380 | struct btrfs_path *path, |
3381 | struct extent_buffer *l, | |
3382 | struct extent_buffer *right, | |
3383 | int slot, int mid, int nritems) | |
44871b1b | 3384 | { |
94f94ad9 | 3385 | struct btrfs_fs_info *fs_info = trans->fs_info; |
44871b1b CM |
3386 | int data_copy_size; |
3387 | int rt_data_off; | |
3388 | int i; | |
44871b1b | 3389 | struct btrfs_disk_key disk_key; |
cfed81a0 CM |
3390 | struct btrfs_map_token token; |
3391 | ||
44871b1b CM |
3392 | nritems = nritems - mid; |
3393 | btrfs_set_header_nritems(right, nritems); | |
dc2e724e | 3394 | data_copy_size = btrfs_item_data_end(l, mid) - leaf_data_end(l); |
44871b1b CM |
3395 | |
3396 | copy_extent_buffer(right, l, btrfs_item_nr_offset(0), | |
3397 | btrfs_item_nr_offset(mid), | |
3398 | nritems * sizeof(struct btrfs_item)); | |
3399 | ||
3400 | copy_extent_buffer(right, l, | |
3d9ec8c4 NB |
3401 | BTRFS_LEAF_DATA_OFFSET + BTRFS_LEAF_DATA_SIZE(fs_info) - |
3402 | data_copy_size, BTRFS_LEAF_DATA_OFFSET + | |
8f881e8c | 3403 | leaf_data_end(l), data_copy_size); |
44871b1b | 3404 | |
dc2e724e | 3405 | rt_data_off = BTRFS_LEAF_DATA_SIZE(fs_info) - btrfs_item_data_end(l, mid); |
44871b1b | 3406 | |
c82f823c | 3407 | btrfs_init_map_token(&token, right); |
44871b1b | 3408 | for (i = 0; i < nritems; i++) { |
44871b1b CM |
3409 | u32 ioff; |
3410 | ||
3212fa14 JB |
3411 | ioff = btrfs_token_item_offset(&token, i); |
3412 | btrfs_set_token_item_offset(&token, i, ioff + rt_data_off); | |
44871b1b CM |
3413 | } |
3414 | ||
44871b1b | 3415 | btrfs_set_header_nritems(l, mid); |
44871b1b | 3416 | btrfs_item_key(right, &disk_key, 0); |
6ad3cf6d | 3417 | insert_ptr(trans, path, &disk_key, right->start, path->slots[1] + 1, 1); |
44871b1b CM |
3418 | |
3419 | btrfs_mark_buffer_dirty(right); | |
3420 | btrfs_mark_buffer_dirty(l); | |
3421 | BUG_ON(path->slots[0] != slot); | |
3422 | ||
44871b1b CM |
3423 | if (mid <= slot) { |
3424 | btrfs_tree_unlock(path->nodes[0]); | |
3425 | free_extent_buffer(path->nodes[0]); | |
3426 | path->nodes[0] = right; | |
3427 | path->slots[0] -= mid; | |
3428 | path->slots[1] += 1; | |
3429 | } else { | |
3430 | btrfs_tree_unlock(right); | |
3431 | free_extent_buffer(right); | |
3432 | } | |
3433 | ||
3434 | BUG_ON(path->slots[0] < 0); | |
44871b1b CM |
3435 | } |
3436 | ||
99d8f83c CM |
3437 | /* |
3438 | * double splits happen when we need to insert a big item in the middle | |
3439 | * of a leaf. A double split can leave us with 3 mostly empty leaves: | |
3440 | * leaf: [ slots 0 - N] [ our target ] [ N + 1 - total in leaf ] | |
3441 | * A B C | |
3442 | * | |
3443 | * We avoid this by trying to push the items on either side of our target | |
3444 | * into the adjacent leaves. If all goes well we can avoid the double split | |
3445 | * completely. | |
3446 | */ | |
3447 | static noinline int push_for_double_split(struct btrfs_trans_handle *trans, | |
3448 | struct btrfs_root *root, | |
3449 | struct btrfs_path *path, | |
3450 | int data_size) | |
3451 | { | |
3452 | int ret; | |
3453 | int progress = 0; | |
3454 | int slot; | |
3455 | u32 nritems; | |
5a4267ca | 3456 | int space_needed = data_size; |
99d8f83c CM |
3457 | |
3458 | slot = path->slots[0]; | |
5a4267ca | 3459 | if (slot < btrfs_header_nritems(path->nodes[0])) |
e902baac | 3460 | space_needed -= btrfs_leaf_free_space(path->nodes[0]); |
99d8f83c CM |
3461 | |
3462 | /* | |
3463 | * try to push all the items after our slot into the | |
3464 | * right leaf | |
3465 | */ | |
5a4267ca | 3466 | ret = push_leaf_right(trans, root, path, 1, space_needed, 0, slot); |
99d8f83c CM |
3467 | if (ret < 0) |
3468 | return ret; | |
3469 | ||
3470 | if (ret == 0) | |
3471 | progress++; | |
3472 | ||
3473 | nritems = btrfs_header_nritems(path->nodes[0]); | |
3474 | /* | |
3475 | * our goal is to get our slot at the start or end of a leaf. If | |
3476 | * we've done so we're done | |
3477 | */ | |
3478 | if (path->slots[0] == 0 || path->slots[0] == nritems) | |
3479 | return 0; | |
3480 | ||
e902baac | 3481 | if (btrfs_leaf_free_space(path->nodes[0]) >= data_size) |
99d8f83c CM |
3482 | return 0; |
3483 | ||
3484 | /* try to push all the items before our slot into the next leaf */ | |
3485 | slot = path->slots[0]; | |
263d3995 FM |
3486 | space_needed = data_size; |
3487 | if (slot > 0) | |
e902baac | 3488 | space_needed -= btrfs_leaf_free_space(path->nodes[0]); |
5a4267ca | 3489 | ret = push_leaf_left(trans, root, path, 1, space_needed, 0, slot); |
99d8f83c CM |
3490 | if (ret < 0) |
3491 | return ret; | |
3492 | ||
3493 | if (ret == 0) | |
3494 | progress++; | |
3495 | ||
3496 | if (progress) | |
3497 | return 0; | |
3498 | return 1; | |
3499 | } | |
3500 | ||
74123bd7 CM |
3501 | /* |
3502 | * split the path's leaf in two, making sure there is at least data_size | |
3503 | * available for the resulting leaf level of the path. | |
aa5d6bed CM |
3504 | * |
3505 | * returns 0 if all went well and < 0 on failure. | |
74123bd7 | 3506 | */ |
e02119d5 CM |
3507 | static noinline int split_leaf(struct btrfs_trans_handle *trans, |
3508 | struct btrfs_root *root, | |
310712b2 | 3509 | const struct btrfs_key *ins_key, |
e02119d5 CM |
3510 | struct btrfs_path *path, int data_size, |
3511 | int extend) | |
be0e5c09 | 3512 | { |
5d4f98a2 | 3513 | struct btrfs_disk_key disk_key; |
5f39d397 | 3514 | struct extent_buffer *l; |
7518a238 | 3515 | u32 nritems; |
eb60ceac CM |
3516 | int mid; |
3517 | int slot; | |
5f39d397 | 3518 | struct extent_buffer *right; |
b7a0365e | 3519 | struct btrfs_fs_info *fs_info = root->fs_info; |
d4dbff95 | 3520 | int ret = 0; |
aa5d6bed | 3521 | int wret; |
5d4f98a2 | 3522 | int split; |
cc0c5538 | 3523 | int num_doubles = 0; |
99d8f83c | 3524 | int tried_avoid_double = 0; |
aa5d6bed | 3525 | |
a5719521 YZ |
3526 | l = path->nodes[0]; |
3527 | slot = path->slots[0]; | |
3212fa14 | 3528 | if (extend && data_size + btrfs_item_size(l, slot) + |
0b246afa | 3529 | sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(fs_info)) |
a5719521 YZ |
3530 | return -EOVERFLOW; |
3531 | ||
40689478 | 3532 | /* first try to make some room by pushing left and right */ |
33157e05 | 3533 | if (data_size && path->nodes[1]) { |
5a4267ca FDBM |
3534 | int space_needed = data_size; |
3535 | ||
3536 | if (slot < btrfs_header_nritems(l)) | |
e902baac | 3537 | space_needed -= btrfs_leaf_free_space(l); |
5a4267ca FDBM |
3538 | |
3539 | wret = push_leaf_right(trans, root, path, space_needed, | |
3540 | space_needed, 0, 0); | |
d397712b | 3541 | if (wret < 0) |
eaee50e8 | 3542 | return wret; |
3685f791 | 3543 | if (wret) { |
263d3995 FM |
3544 | space_needed = data_size; |
3545 | if (slot > 0) | |
e902baac | 3546 | space_needed -= btrfs_leaf_free_space(l); |
5a4267ca FDBM |
3547 | wret = push_leaf_left(trans, root, path, space_needed, |
3548 | space_needed, 0, (u32)-1); | |
3685f791 CM |
3549 | if (wret < 0) |
3550 | return wret; | |
3551 | } | |
3552 | l = path->nodes[0]; | |
aa5d6bed | 3553 | |
3685f791 | 3554 | /* did the pushes work? */ |
e902baac | 3555 | if (btrfs_leaf_free_space(l) >= data_size) |
3685f791 | 3556 | return 0; |
3326d1b0 | 3557 | } |
aa5d6bed | 3558 | |
5c680ed6 | 3559 | if (!path->nodes[1]) { |
fdd99c72 | 3560 | ret = insert_new_root(trans, root, path, 1); |
5c680ed6 CM |
3561 | if (ret) |
3562 | return ret; | |
3563 | } | |
cc0c5538 | 3564 | again: |
5d4f98a2 | 3565 | split = 1; |
cc0c5538 | 3566 | l = path->nodes[0]; |
eb60ceac | 3567 | slot = path->slots[0]; |
5f39d397 | 3568 | nritems = btrfs_header_nritems(l); |
d397712b | 3569 | mid = (nritems + 1) / 2; |
54aa1f4d | 3570 | |
5d4f98a2 YZ |
3571 | if (mid <= slot) { |
3572 | if (nritems == 1 || | |
3573 | leaf_space_used(l, mid, nritems - mid) + data_size > | |
0b246afa | 3574 | BTRFS_LEAF_DATA_SIZE(fs_info)) { |
5d4f98a2 YZ |
3575 | if (slot >= nritems) { |
3576 | split = 0; | |
3577 | } else { | |
3578 | mid = slot; | |
3579 | if (mid != nritems && | |
3580 | leaf_space_used(l, mid, nritems - mid) + | |
0b246afa | 3581 | data_size > BTRFS_LEAF_DATA_SIZE(fs_info)) { |
99d8f83c CM |
3582 | if (data_size && !tried_avoid_double) |
3583 | goto push_for_double; | |
5d4f98a2 YZ |
3584 | split = 2; |
3585 | } | |
3586 | } | |
3587 | } | |
3588 | } else { | |
3589 | if (leaf_space_used(l, 0, mid) + data_size > | |
0b246afa | 3590 | BTRFS_LEAF_DATA_SIZE(fs_info)) { |
5d4f98a2 YZ |
3591 | if (!extend && data_size && slot == 0) { |
3592 | split = 0; | |
3593 | } else if ((extend || !data_size) && slot == 0) { | |
3594 | mid = 1; | |
3595 | } else { | |
3596 | mid = slot; | |
3597 | if (mid != nritems && | |
3598 | leaf_space_used(l, mid, nritems - mid) + | |
0b246afa | 3599 | data_size > BTRFS_LEAF_DATA_SIZE(fs_info)) { |
99d8f83c CM |
3600 | if (data_size && !tried_avoid_double) |
3601 | goto push_for_double; | |
67871254 | 3602 | split = 2; |
5d4f98a2 YZ |
3603 | } |
3604 | } | |
3605 | } | |
3606 | } | |
3607 | ||
3608 | if (split == 0) | |
3609 | btrfs_cpu_key_to_disk(&disk_key, ins_key); | |
3610 | else | |
3611 | btrfs_item_key(l, &disk_key, mid); | |
3612 | ||
ca9d473a JB |
3613 | /* |
3614 | * We have to about BTRFS_NESTING_NEW_ROOT here if we've done a double | |
3615 | * split, because we're only allowed to have MAX_LOCKDEP_SUBCLASSES | |
3616 | * subclasses, which is 8 at the time of this patch, and we've maxed it | |
3617 | * out. In the future we could add a | |
3618 | * BTRFS_NESTING_SPLIT_THE_SPLITTENING if we need to, but for now just | |
3619 | * use BTRFS_NESTING_NEW_ROOT. | |
3620 | */ | |
79bd3712 FM |
3621 | right = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid, |
3622 | &disk_key, 0, l->start, 0, | |
3623 | num_doubles ? BTRFS_NESTING_NEW_ROOT : | |
3624 | BTRFS_NESTING_SPLIT); | |
f0486c68 | 3625 | if (IS_ERR(right)) |
5f39d397 | 3626 | return PTR_ERR(right); |
f0486c68 | 3627 | |
0b246afa | 3628 | root_add_used(root, fs_info->nodesize); |
5f39d397 | 3629 | |
5d4f98a2 YZ |
3630 | if (split == 0) { |
3631 | if (mid <= slot) { | |
3632 | btrfs_set_header_nritems(right, 0); | |
6ad3cf6d | 3633 | insert_ptr(trans, path, &disk_key, |
2ff7e61e | 3634 | right->start, path->slots[1] + 1, 1); |
5d4f98a2 YZ |
3635 | btrfs_tree_unlock(path->nodes[0]); |
3636 | free_extent_buffer(path->nodes[0]); | |
3637 | path->nodes[0] = right; | |
3638 | path->slots[0] = 0; | |
3639 | path->slots[1] += 1; | |
3640 | } else { | |
3641 | btrfs_set_header_nritems(right, 0); | |
6ad3cf6d | 3642 | insert_ptr(trans, path, &disk_key, |
2ff7e61e | 3643 | right->start, path->slots[1], 1); |
5d4f98a2 YZ |
3644 | btrfs_tree_unlock(path->nodes[0]); |
3645 | free_extent_buffer(path->nodes[0]); | |
3646 | path->nodes[0] = right; | |
3647 | path->slots[0] = 0; | |
143bede5 | 3648 | if (path->slots[1] == 0) |
b167fa91 | 3649 | fixup_low_keys(path, &disk_key, 1); |
d4dbff95 | 3650 | } |
196e0249 LB |
3651 | /* |
3652 | * We create a new leaf 'right' for the required ins_len and | |
3653 | * we'll do btrfs_mark_buffer_dirty() on this leaf after copying | |
3654 | * the content of ins_len to 'right'. | |
3655 | */ | |
5d4f98a2 | 3656 | return ret; |
d4dbff95 | 3657 | } |
74123bd7 | 3658 | |
94f94ad9 | 3659 | copy_for_split(trans, path, l, right, slot, mid, nritems); |
31840ae1 | 3660 | |
5d4f98a2 | 3661 | if (split == 2) { |
cc0c5538 CM |
3662 | BUG_ON(num_doubles != 0); |
3663 | num_doubles++; | |
3664 | goto again; | |
a429e513 | 3665 | } |
44871b1b | 3666 | |
143bede5 | 3667 | return 0; |
99d8f83c CM |
3668 | |
3669 | push_for_double: | |
3670 | push_for_double_split(trans, root, path, data_size); | |
3671 | tried_avoid_double = 1; | |
e902baac | 3672 | if (btrfs_leaf_free_space(path->nodes[0]) >= data_size) |
99d8f83c CM |
3673 | return 0; |
3674 | goto again; | |
be0e5c09 CM |
3675 | } |
3676 | ||
ad48fd75 YZ |
3677 | static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans, |
3678 | struct btrfs_root *root, | |
3679 | struct btrfs_path *path, int ins_len) | |
459931ec | 3680 | { |
ad48fd75 | 3681 | struct btrfs_key key; |
459931ec | 3682 | struct extent_buffer *leaf; |
ad48fd75 YZ |
3683 | struct btrfs_file_extent_item *fi; |
3684 | u64 extent_len = 0; | |
3685 | u32 item_size; | |
3686 | int ret; | |
459931ec CM |
3687 | |
3688 | leaf = path->nodes[0]; | |
ad48fd75 YZ |
3689 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
3690 | ||
3691 | BUG_ON(key.type != BTRFS_EXTENT_DATA_KEY && | |
3692 | key.type != BTRFS_EXTENT_CSUM_KEY); | |
3693 | ||
e902baac | 3694 | if (btrfs_leaf_free_space(leaf) >= ins_len) |
ad48fd75 | 3695 | return 0; |
459931ec | 3696 | |
3212fa14 | 3697 | item_size = btrfs_item_size(leaf, path->slots[0]); |
ad48fd75 YZ |
3698 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
3699 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
3700 | struct btrfs_file_extent_item); | |
3701 | extent_len = btrfs_file_extent_num_bytes(leaf, fi); | |
3702 | } | |
b3b4aa74 | 3703 | btrfs_release_path(path); |
459931ec | 3704 | |
459931ec | 3705 | path->keep_locks = 1; |
ad48fd75 YZ |
3706 | path->search_for_split = 1; |
3707 | ret = btrfs_search_slot(trans, root, &key, path, 0, 1); | |
459931ec | 3708 | path->search_for_split = 0; |
a8df6fe6 FM |
3709 | if (ret > 0) |
3710 | ret = -EAGAIN; | |
ad48fd75 YZ |
3711 | if (ret < 0) |
3712 | goto err; | |
459931ec | 3713 | |
ad48fd75 YZ |
3714 | ret = -EAGAIN; |
3715 | leaf = path->nodes[0]; | |
a8df6fe6 | 3716 | /* if our item isn't there, return now */ |
3212fa14 | 3717 | if (item_size != btrfs_item_size(leaf, path->slots[0])) |
ad48fd75 YZ |
3718 | goto err; |
3719 | ||
109f6aef | 3720 | /* the leaf has changed, it now has room. return now */ |
e902baac | 3721 | if (btrfs_leaf_free_space(path->nodes[0]) >= ins_len) |
109f6aef CM |
3722 | goto err; |
3723 | ||
ad48fd75 YZ |
3724 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
3725 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
3726 | struct btrfs_file_extent_item); | |
3727 | if (extent_len != btrfs_file_extent_num_bytes(leaf, fi)) | |
3728 | goto err; | |
459931ec CM |
3729 | } |
3730 | ||
ad48fd75 | 3731 | ret = split_leaf(trans, root, &key, path, ins_len, 1); |
f0486c68 YZ |
3732 | if (ret) |
3733 | goto err; | |
459931ec | 3734 | |
ad48fd75 | 3735 | path->keep_locks = 0; |
b9473439 | 3736 | btrfs_unlock_up_safe(path, 1); |
ad48fd75 YZ |
3737 | return 0; |
3738 | err: | |
3739 | path->keep_locks = 0; | |
3740 | return ret; | |
3741 | } | |
3742 | ||
25263cd7 | 3743 | static noinline int split_item(struct btrfs_path *path, |
310712b2 | 3744 | const struct btrfs_key *new_key, |
ad48fd75 YZ |
3745 | unsigned long split_offset) |
3746 | { | |
3747 | struct extent_buffer *leaf; | |
c91666b1 | 3748 | int orig_slot, slot; |
ad48fd75 YZ |
3749 | char *buf; |
3750 | u32 nritems; | |
3751 | u32 item_size; | |
3752 | u32 orig_offset; | |
3753 | struct btrfs_disk_key disk_key; | |
3754 | ||
b9473439 | 3755 | leaf = path->nodes[0]; |
e902baac | 3756 | BUG_ON(btrfs_leaf_free_space(leaf) < sizeof(struct btrfs_item)); |
b9473439 | 3757 | |
c91666b1 | 3758 | orig_slot = path->slots[0]; |
3212fa14 JB |
3759 | orig_offset = btrfs_item_offset(leaf, path->slots[0]); |
3760 | item_size = btrfs_item_size(leaf, path->slots[0]); | |
459931ec | 3761 | |
459931ec | 3762 | buf = kmalloc(item_size, GFP_NOFS); |
ad48fd75 YZ |
3763 | if (!buf) |
3764 | return -ENOMEM; | |
3765 | ||
459931ec CM |
3766 | read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf, |
3767 | path->slots[0]), item_size); | |
459931ec | 3768 | |
ad48fd75 | 3769 | slot = path->slots[0] + 1; |
459931ec | 3770 | nritems = btrfs_header_nritems(leaf); |
459931ec CM |
3771 | if (slot != nritems) { |
3772 | /* shift the items */ | |
3773 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1), | |
ad48fd75 YZ |
3774 | btrfs_item_nr_offset(slot), |
3775 | (nritems - slot) * sizeof(struct btrfs_item)); | |
459931ec CM |
3776 | } |
3777 | ||
3778 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
3779 | btrfs_set_item_key(leaf, &disk_key, slot); | |
3780 | ||
3212fa14 JB |
3781 | btrfs_set_item_offset(leaf, slot, orig_offset); |
3782 | btrfs_set_item_size(leaf, slot, item_size - split_offset); | |
459931ec | 3783 | |
3212fa14 | 3784 | btrfs_set_item_offset(leaf, orig_slot, |
c91666b1 | 3785 | orig_offset + item_size - split_offset); |
3212fa14 | 3786 | btrfs_set_item_size(leaf, orig_slot, split_offset); |
459931ec CM |
3787 | |
3788 | btrfs_set_header_nritems(leaf, nritems + 1); | |
3789 | ||
3790 | /* write the data for the start of the original item */ | |
3791 | write_extent_buffer(leaf, buf, | |
3792 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
3793 | split_offset); | |
3794 | ||
3795 | /* write the data for the new item */ | |
3796 | write_extent_buffer(leaf, buf + split_offset, | |
3797 | btrfs_item_ptr_offset(leaf, slot), | |
3798 | item_size - split_offset); | |
3799 | btrfs_mark_buffer_dirty(leaf); | |
3800 | ||
e902baac | 3801 | BUG_ON(btrfs_leaf_free_space(leaf) < 0); |
459931ec | 3802 | kfree(buf); |
ad48fd75 YZ |
3803 | return 0; |
3804 | } | |
3805 | ||
3806 | /* | |
3807 | * This function splits a single item into two items, | |
3808 | * giving 'new_key' to the new item and splitting the | |
3809 | * old one at split_offset (from the start of the item). | |
3810 | * | |
3811 | * The path may be released by this operation. After | |
3812 | * the split, the path is pointing to the old item. The | |
3813 | * new item is going to be in the same node as the old one. | |
3814 | * | |
3815 | * Note, the item being split must be smaller enough to live alone on | |
3816 | * a tree block with room for one extra struct btrfs_item | |
3817 | * | |
3818 | * This allows us to split the item in place, keeping a lock on the | |
3819 | * leaf the entire time. | |
3820 | */ | |
3821 | int btrfs_split_item(struct btrfs_trans_handle *trans, | |
3822 | struct btrfs_root *root, | |
3823 | struct btrfs_path *path, | |
310712b2 | 3824 | const struct btrfs_key *new_key, |
ad48fd75 YZ |
3825 | unsigned long split_offset) |
3826 | { | |
3827 | int ret; | |
3828 | ret = setup_leaf_for_split(trans, root, path, | |
3829 | sizeof(struct btrfs_item)); | |
3830 | if (ret) | |
3831 | return ret; | |
3832 | ||
25263cd7 | 3833 | ret = split_item(path, new_key, split_offset); |
459931ec CM |
3834 | return ret; |
3835 | } | |
3836 | ||
d352ac68 CM |
3837 | /* |
3838 | * make the item pointed to by the path smaller. new_size indicates | |
3839 | * how small to make it, and from_end tells us if we just chop bytes | |
3840 | * off the end of the item or if we shift the item to chop bytes off | |
3841 | * the front. | |
3842 | */ | |
78ac4f9e | 3843 | void btrfs_truncate_item(struct btrfs_path *path, u32 new_size, int from_end) |
b18c6685 | 3844 | { |
b18c6685 | 3845 | int slot; |
5f39d397 | 3846 | struct extent_buffer *leaf; |
b18c6685 CM |
3847 | u32 nritems; |
3848 | unsigned int data_end; | |
3849 | unsigned int old_data_start; | |
3850 | unsigned int old_size; | |
3851 | unsigned int size_diff; | |
3852 | int i; | |
cfed81a0 CM |
3853 | struct btrfs_map_token token; |
3854 | ||
5f39d397 | 3855 | leaf = path->nodes[0]; |
179e29e4 CM |
3856 | slot = path->slots[0]; |
3857 | ||
3212fa14 | 3858 | old_size = btrfs_item_size(leaf, slot); |
179e29e4 | 3859 | if (old_size == new_size) |
143bede5 | 3860 | return; |
b18c6685 | 3861 | |
5f39d397 | 3862 | nritems = btrfs_header_nritems(leaf); |
8f881e8c | 3863 | data_end = leaf_data_end(leaf); |
b18c6685 | 3864 | |
3212fa14 | 3865 | old_data_start = btrfs_item_offset(leaf, slot); |
179e29e4 | 3866 | |
b18c6685 CM |
3867 | size_diff = old_size - new_size; |
3868 | ||
3869 | BUG_ON(slot < 0); | |
3870 | BUG_ON(slot >= nritems); | |
3871 | ||
3872 | /* | |
3873 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3874 | */ | |
3875 | /* first correct the data pointers */ | |
c82f823c | 3876 | btrfs_init_map_token(&token, leaf); |
b18c6685 | 3877 | for (i = slot; i < nritems; i++) { |
5f39d397 | 3878 | u32 ioff; |
db94535d | 3879 | |
3212fa14 JB |
3880 | ioff = btrfs_token_item_offset(&token, i); |
3881 | btrfs_set_token_item_offset(&token, i, ioff + size_diff); | |
b18c6685 | 3882 | } |
db94535d | 3883 | |
b18c6685 | 3884 | /* shift the data */ |
179e29e4 | 3885 | if (from_end) { |
3d9ec8c4 NB |
3886 | memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + |
3887 | data_end + size_diff, BTRFS_LEAF_DATA_OFFSET + | |
179e29e4 CM |
3888 | data_end, old_data_start + new_size - data_end); |
3889 | } else { | |
3890 | struct btrfs_disk_key disk_key; | |
3891 | u64 offset; | |
3892 | ||
3893 | btrfs_item_key(leaf, &disk_key, slot); | |
3894 | ||
3895 | if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) { | |
3896 | unsigned long ptr; | |
3897 | struct btrfs_file_extent_item *fi; | |
3898 | ||
3899 | fi = btrfs_item_ptr(leaf, slot, | |
3900 | struct btrfs_file_extent_item); | |
3901 | fi = (struct btrfs_file_extent_item *)( | |
3902 | (unsigned long)fi - size_diff); | |
3903 | ||
3904 | if (btrfs_file_extent_type(leaf, fi) == | |
3905 | BTRFS_FILE_EXTENT_INLINE) { | |
3906 | ptr = btrfs_item_ptr_offset(leaf, slot); | |
3907 | memmove_extent_buffer(leaf, ptr, | |
d397712b | 3908 | (unsigned long)fi, |
7ec20afb | 3909 | BTRFS_FILE_EXTENT_INLINE_DATA_START); |
179e29e4 CM |
3910 | } |
3911 | } | |
3912 | ||
3d9ec8c4 NB |
3913 | memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + |
3914 | data_end + size_diff, BTRFS_LEAF_DATA_OFFSET + | |
179e29e4 CM |
3915 | data_end, old_data_start - data_end); |
3916 | ||
3917 | offset = btrfs_disk_key_offset(&disk_key); | |
3918 | btrfs_set_disk_key_offset(&disk_key, offset + size_diff); | |
3919 | btrfs_set_item_key(leaf, &disk_key, slot); | |
3920 | if (slot == 0) | |
b167fa91 | 3921 | fixup_low_keys(path, &disk_key, 1); |
179e29e4 | 3922 | } |
5f39d397 | 3923 | |
3212fa14 | 3924 | btrfs_set_item_size(leaf, slot, new_size); |
5f39d397 | 3925 | btrfs_mark_buffer_dirty(leaf); |
b18c6685 | 3926 | |
e902baac | 3927 | if (btrfs_leaf_free_space(leaf) < 0) { |
a4f78750 | 3928 | btrfs_print_leaf(leaf); |
b18c6685 | 3929 | BUG(); |
5f39d397 | 3930 | } |
b18c6685 CM |
3931 | } |
3932 | ||
d352ac68 | 3933 | /* |
8f69dbd2 | 3934 | * make the item pointed to by the path bigger, data_size is the added size. |
d352ac68 | 3935 | */ |
c71dd880 | 3936 | void btrfs_extend_item(struct btrfs_path *path, u32 data_size) |
6567e837 | 3937 | { |
6567e837 | 3938 | int slot; |
5f39d397 | 3939 | struct extent_buffer *leaf; |
6567e837 CM |
3940 | u32 nritems; |
3941 | unsigned int data_end; | |
3942 | unsigned int old_data; | |
3943 | unsigned int old_size; | |
3944 | int i; | |
cfed81a0 CM |
3945 | struct btrfs_map_token token; |
3946 | ||
5f39d397 | 3947 | leaf = path->nodes[0]; |
6567e837 | 3948 | |
5f39d397 | 3949 | nritems = btrfs_header_nritems(leaf); |
8f881e8c | 3950 | data_end = leaf_data_end(leaf); |
6567e837 | 3951 | |
e902baac | 3952 | if (btrfs_leaf_free_space(leaf) < data_size) { |
a4f78750 | 3953 | btrfs_print_leaf(leaf); |
6567e837 | 3954 | BUG(); |
5f39d397 | 3955 | } |
6567e837 | 3956 | slot = path->slots[0]; |
dc2e724e | 3957 | old_data = btrfs_item_data_end(leaf, slot); |
6567e837 CM |
3958 | |
3959 | BUG_ON(slot < 0); | |
3326d1b0 | 3960 | if (slot >= nritems) { |
a4f78750 | 3961 | btrfs_print_leaf(leaf); |
c71dd880 | 3962 | btrfs_crit(leaf->fs_info, "slot %d too large, nritems %d", |
0b246afa | 3963 | slot, nritems); |
290342f6 | 3964 | BUG(); |
3326d1b0 | 3965 | } |
6567e837 CM |
3966 | |
3967 | /* | |
3968 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3969 | */ | |
3970 | /* first correct the data pointers */ | |
c82f823c | 3971 | btrfs_init_map_token(&token, leaf); |
6567e837 | 3972 | for (i = slot; i < nritems; i++) { |
5f39d397 | 3973 | u32 ioff; |
db94535d | 3974 | |
3212fa14 JB |
3975 | ioff = btrfs_token_item_offset(&token, i); |
3976 | btrfs_set_token_item_offset(&token, i, ioff - data_size); | |
6567e837 | 3977 | } |
5f39d397 | 3978 | |
6567e837 | 3979 | /* shift the data */ |
3d9ec8c4 NB |
3980 | memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + |
3981 | data_end - data_size, BTRFS_LEAF_DATA_OFFSET + | |
6567e837 | 3982 | data_end, old_data - data_end); |
5f39d397 | 3983 | |
6567e837 | 3984 | data_end = old_data; |
3212fa14 JB |
3985 | old_size = btrfs_item_size(leaf, slot); |
3986 | btrfs_set_item_size(leaf, slot, old_size + data_size); | |
5f39d397 | 3987 | btrfs_mark_buffer_dirty(leaf); |
6567e837 | 3988 | |
e902baac | 3989 | if (btrfs_leaf_free_space(leaf) < 0) { |
a4f78750 | 3990 | btrfs_print_leaf(leaf); |
6567e837 | 3991 | BUG(); |
5f39d397 | 3992 | } |
6567e837 CM |
3993 | } |
3994 | ||
43dd529a DS |
3995 | /* |
3996 | * Make space in the node before inserting one or more items. | |
da9ffb24 NB |
3997 | * |
3998 | * @root: root we are inserting items to | |
3999 | * @path: points to the leaf/slot where we are going to insert new items | |
b7ef5f3a | 4000 | * @batch: information about the batch of items to insert |
43dd529a DS |
4001 | * |
4002 | * Main purpose is to save stack depth by doing the bulk of the work in a | |
4003 | * function that doesn't call btrfs_search_slot | |
74123bd7 | 4004 | */ |
f0641656 FM |
4005 | static void setup_items_for_insert(struct btrfs_root *root, struct btrfs_path *path, |
4006 | const struct btrfs_item_batch *batch) | |
be0e5c09 | 4007 | { |
0b246afa | 4008 | struct btrfs_fs_info *fs_info = root->fs_info; |
9c58309d | 4009 | int i; |
7518a238 | 4010 | u32 nritems; |
be0e5c09 | 4011 | unsigned int data_end; |
e2fa7227 | 4012 | struct btrfs_disk_key disk_key; |
44871b1b CM |
4013 | struct extent_buffer *leaf; |
4014 | int slot; | |
cfed81a0 | 4015 | struct btrfs_map_token token; |
fc0d82e1 | 4016 | u32 total_size; |
cfed81a0 | 4017 | |
b7ef5f3a FM |
4018 | /* |
4019 | * Before anything else, update keys in the parent and other ancestors | |
4020 | * if needed, then release the write locks on them, so that other tasks | |
4021 | * can use them while we modify the leaf. | |
4022 | */ | |
24cdc847 | 4023 | if (path->slots[0] == 0) { |
b7ef5f3a | 4024 | btrfs_cpu_key_to_disk(&disk_key, &batch->keys[0]); |
b167fa91 | 4025 | fixup_low_keys(path, &disk_key, 1); |
24cdc847 FM |
4026 | } |
4027 | btrfs_unlock_up_safe(path, 1); | |
4028 | ||
5f39d397 | 4029 | leaf = path->nodes[0]; |
44871b1b | 4030 | slot = path->slots[0]; |
74123bd7 | 4031 | |
5f39d397 | 4032 | nritems = btrfs_header_nritems(leaf); |
8f881e8c | 4033 | data_end = leaf_data_end(leaf); |
b7ef5f3a | 4034 | total_size = batch->total_data_size + (batch->nr * sizeof(struct btrfs_item)); |
eb60ceac | 4035 | |
e902baac | 4036 | if (btrfs_leaf_free_space(leaf) < total_size) { |
a4f78750 | 4037 | btrfs_print_leaf(leaf); |
0b246afa | 4038 | btrfs_crit(fs_info, "not enough freespace need %u have %d", |
e902baac | 4039 | total_size, btrfs_leaf_free_space(leaf)); |
be0e5c09 | 4040 | BUG(); |
d4dbff95 | 4041 | } |
5f39d397 | 4042 | |
c82f823c | 4043 | btrfs_init_map_token(&token, leaf); |
be0e5c09 | 4044 | if (slot != nritems) { |
dc2e724e | 4045 | unsigned int old_data = btrfs_item_data_end(leaf, slot); |
be0e5c09 | 4046 | |
5f39d397 | 4047 | if (old_data < data_end) { |
a4f78750 | 4048 | btrfs_print_leaf(leaf); |
7269ddd2 NB |
4049 | btrfs_crit(fs_info, |
4050 | "item at slot %d with data offset %u beyond data end of leaf %u", | |
5d163e0e | 4051 | slot, old_data, data_end); |
290342f6 | 4052 | BUG(); |
5f39d397 | 4053 | } |
be0e5c09 CM |
4054 | /* |
4055 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
4056 | */ | |
4057 | /* first correct the data pointers */ | |
0783fcfc | 4058 | for (i = slot; i < nritems; i++) { |
5f39d397 | 4059 | u32 ioff; |
db94535d | 4060 | |
3212fa14 JB |
4061 | ioff = btrfs_token_item_offset(&token, i); |
4062 | btrfs_set_token_item_offset(&token, i, | |
74794207 | 4063 | ioff - batch->total_data_size); |
0783fcfc | 4064 | } |
be0e5c09 | 4065 | /* shift the items */ |
b7ef5f3a | 4066 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + batch->nr), |
5f39d397 | 4067 | btrfs_item_nr_offset(slot), |
d6025579 | 4068 | (nritems - slot) * sizeof(struct btrfs_item)); |
be0e5c09 CM |
4069 | |
4070 | /* shift the data */ | |
3d9ec8c4 | 4071 | memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + |
b7ef5f3a FM |
4072 | data_end - batch->total_data_size, |
4073 | BTRFS_LEAF_DATA_OFFSET + data_end, | |
4074 | old_data - data_end); | |
be0e5c09 CM |
4075 | data_end = old_data; |
4076 | } | |
5f39d397 | 4077 | |
62e2749e | 4078 | /* setup the item for the new data */ |
b7ef5f3a FM |
4079 | for (i = 0; i < batch->nr; i++) { |
4080 | btrfs_cpu_key_to_disk(&disk_key, &batch->keys[i]); | |
9c58309d | 4081 | btrfs_set_item_key(leaf, &disk_key, slot + i); |
b7ef5f3a | 4082 | data_end -= batch->data_sizes[i]; |
3212fa14 JB |
4083 | btrfs_set_token_item_offset(&token, slot + i, data_end); |
4084 | btrfs_set_token_item_size(&token, slot + i, batch->data_sizes[i]); | |
9c58309d | 4085 | } |
44871b1b | 4086 | |
b7ef5f3a | 4087 | btrfs_set_header_nritems(leaf, nritems + batch->nr); |
b9473439 | 4088 | btrfs_mark_buffer_dirty(leaf); |
aa5d6bed | 4089 | |
e902baac | 4090 | if (btrfs_leaf_free_space(leaf) < 0) { |
a4f78750 | 4091 | btrfs_print_leaf(leaf); |
be0e5c09 | 4092 | BUG(); |
5f39d397 | 4093 | } |
44871b1b CM |
4094 | } |
4095 | ||
f0641656 FM |
4096 | /* |
4097 | * Insert a new item into a leaf. | |
4098 | * | |
4099 | * @root: The root of the btree. | |
4100 | * @path: A path pointing to the target leaf and slot. | |
4101 | * @key: The key of the new item. | |
4102 | * @data_size: The size of the data associated with the new key. | |
4103 | */ | |
4104 | void btrfs_setup_item_for_insert(struct btrfs_root *root, | |
4105 | struct btrfs_path *path, | |
4106 | const struct btrfs_key *key, | |
4107 | u32 data_size) | |
4108 | { | |
4109 | struct btrfs_item_batch batch; | |
4110 | ||
4111 | batch.keys = key; | |
4112 | batch.data_sizes = &data_size; | |
4113 | batch.total_data_size = data_size; | |
4114 | batch.nr = 1; | |
4115 | ||
4116 | setup_items_for_insert(root, path, &batch); | |
4117 | } | |
4118 | ||
44871b1b CM |
4119 | /* |
4120 | * Given a key and some data, insert items into the tree. | |
4121 | * This does all the path init required, making room in the tree if needed. | |
4122 | */ | |
4123 | int btrfs_insert_empty_items(struct btrfs_trans_handle *trans, | |
4124 | struct btrfs_root *root, | |
4125 | struct btrfs_path *path, | |
b7ef5f3a | 4126 | const struct btrfs_item_batch *batch) |
44871b1b | 4127 | { |
44871b1b CM |
4128 | int ret = 0; |
4129 | int slot; | |
b7ef5f3a | 4130 | u32 total_size; |
44871b1b | 4131 | |
b7ef5f3a FM |
4132 | total_size = batch->total_data_size + (batch->nr * sizeof(struct btrfs_item)); |
4133 | ret = btrfs_search_slot(trans, root, &batch->keys[0], path, total_size, 1); | |
44871b1b CM |
4134 | if (ret == 0) |
4135 | return -EEXIST; | |
4136 | if (ret < 0) | |
143bede5 | 4137 | return ret; |
44871b1b | 4138 | |
44871b1b CM |
4139 | slot = path->slots[0]; |
4140 | BUG_ON(slot < 0); | |
4141 | ||
b7ef5f3a | 4142 | setup_items_for_insert(root, path, batch); |
143bede5 | 4143 | return 0; |
62e2749e CM |
4144 | } |
4145 | ||
4146 | /* | |
4147 | * Given a key and some data, insert an item into the tree. | |
4148 | * This does all the path init required, making room in the tree if needed. | |
4149 | */ | |
310712b2 OS |
4150 | int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
4151 | const struct btrfs_key *cpu_key, void *data, | |
4152 | u32 data_size) | |
62e2749e CM |
4153 | { |
4154 | int ret = 0; | |
2c90e5d6 | 4155 | struct btrfs_path *path; |
5f39d397 CM |
4156 | struct extent_buffer *leaf; |
4157 | unsigned long ptr; | |
62e2749e | 4158 | |
2c90e5d6 | 4159 | path = btrfs_alloc_path(); |
db5b493a TI |
4160 | if (!path) |
4161 | return -ENOMEM; | |
2c90e5d6 | 4162 | ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size); |
62e2749e | 4163 | if (!ret) { |
5f39d397 CM |
4164 | leaf = path->nodes[0]; |
4165 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
4166 | write_extent_buffer(leaf, data, ptr, data_size); | |
4167 | btrfs_mark_buffer_dirty(leaf); | |
62e2749e | 4168 | } |
2c90e5d6 | 4169 | btrfs_free_path(path); |
aa5d6bed | 4170 | return ret; |
be0e5c09 CM |
4171 | } |
4172 | ||
f0641656 FM |
4173 | /* |
4174 | * This function duplicates an item, giving 'new_key' to the new item. | |
4175 | * It guarantees both items live in the same tree leaf and the new item is | |
4176 | * contiguous with the original item. | |
4177 | * | |
4178 | * This allows us to split a file extent in place, keeping a lock on the leaf | |
4179 | * the entire time. | |
4180 | */ | |
4181 | int btrfs_duplicate_item(struct btrfs_trans_handle *trans, | |
4182 | struct btrfs_root *root, | |
4183 | struct btrfs_path *path, | |
4184 | const struct btrfs_key *new_key) | |
4185 | { | |
4186 | struct extent_buffer *leaf; | |
4187 | int ret; | |
4188 | u32 item_size; | |
4189 | ||
4190 | leaf = path->nodes[0]; | |
3212fa14 | 4191 | item_size = btrfs_item_size(leaf, path->slots[0]); |
f0641656 FM |
4192 | ret = setup_leaf_for_split(trans, root, path, |
4193 | item_size + sizeof(struct btrfs_item)); | |
4194 | if (ret) | |
4195 | return ret; | |
4196 | ||
4197 | path->slots[0]++; | |
4198 | btrfs_setup_item_for_insert(root, path, new_key, item_size); | |
4199 | leaf = path->nodes[0]; | |
4200 | memcpy_extent_buffer(leaf, | |
4201 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
4202 | btrfs_item_ptr_offset(leaf, path->slots[0] - 1), | |
4203 | item_size); | |
4204 | return 0; | |
4205 | } | |
4206 | ||
74123bd7 | 4207 | /* |
5de08d7d | 4208 | * delete the pointer from a given node. |
74123bd7 | 4209 | * |
d352ac68 CM |
4210 | * the tree should have been previously balanced so the deletion does not |
4211 | * empty a node. | |
74123bd7 | 4212 | */ |
afe5fea7 TI |
4213 | static void del_ptr(struct btrfs_root *root, struct btrfs_path *path, |
4214 | int level, int slot) | |
be0e5c09 | 4215 | { |
5f39d397 | 4216 | struct extent_buffer *parent = path->nodes[level]; |
7518a238 | 4217 | u32 nritems; |
f3ea38da | 4218 | int ret; |
be0e5c09 | 4219 | |
5f39d397 | 4220 | nritems = btrfs_header_nritems(parent); |
d397712b | 4221 | if (slot != nritems - 1) { |
bf1d3425 | 4222 | if (level) { |
f3a84ccd FM |
4223 | ret = btrfs_tree_mod_log_insert_move(parent, slot, |
4224 | slot + 1, nritems - slot - 1); | |
bf1d3425 DS |
4225 | BUG_ON(ret < 0); |
4226 | } | |
5f39d397 CM |
4227 | memmove_extent_buffer(parent, |
4228 | btrfs_node_key_ptr_offset(slot), | |
4229 | btrfs_node_key_ptr_offset(slot + 1), | |
d6025579 CM |
4230 | sizeof(struct btrfs_key_ptr) * |
4231 | (nritems - slot - 1)); | |
57ba86c0 | 4232 | } else if (level) { |
f3a84ccd | 4233 | ret = btrfs_tree_mod_log_insert_key(parent, slot, |
33cff222 | 4234 | BTRFS_MOD_LOG_KEY_REMOVE); |
57ba86c0 | 4235 | BUG_ON(ret < 0); |
bb803951 | 4236 | } |
f3ea38da | 4237 | |
7518a238 | 4238 | nritems--; |
5f39d397 | 4239 | btrfs_set_header_nritems(parent, nritems); |
7518a238 | 4240 | if (nritems == 0 && parent == root->node) { |
5f39d397 | 4241 | BUG_ON(btrfs_header_level(root->node) != 1); |
bb803951 | 4242 | /* just turn the root into a leaf and break */ |
5f39d397 | 4243 | btrfs_set_header_level(root->node, 0); |
bb803951 | 4244 | } else if (slot == 0) { |
5f39d397 CM |
4245 | struct btrfs_disk_key disk_key; |
4246 | ||
4247 | btrfs_node_key(parent, &disk_key, 0); | |
b167fa91 | 4248 | fixup_low_keys(path, &disk_key, level + 1); |
be0e5c09 | 4249 | } |
d6025579 | 4250 | btrfs_mark_buffer_dirty(parent); |
be0e5c09 CM |
4251 | } |
4252 | ||
323ac95b CM |
4253 | /* |
4254 | * a helper function to delete the leaf pointed to by path->slots[1] and | |
5d4f98a2 | 4255 | * path->nodes[1]. |
323ac95b CM |
4256 | * |
4257 | * This deletes the pointer in path->nodes[1] and frees the leaf | |
4258 | * block extent. zero is returned if it all worked out, < 0 otherwise. | |
4259 | * | |
4260 | * The path must have already been setup for deleting the leaf, including | |
4261 | * all the proper balancing. path->nodes[1] must be locked. | |
4262 | */ | |
143bede5 JM |
4263 | static noinline void btrfs_del_leaf(struct btrfs_trans_handle *trans, |
4264 | struct btrfs_root *root, | |
4265 | struct btrfs_path *path, | |
4266 | struct extent_buffer *leaf) | |
323ac95b | 4267 | { |
5d4f98a2 | 4268 | WARN_ON(btrfs_header_generation(leaf) != trans->transid); |
afe5fea7 | 4269 | del_ptr(root, path, 1, path->slots[1]); |
323ac95b | 4270 | |
4d081c41 CM |
4271 | /* |
4272 | * btrfs_free_extent is expensive, we want to make sure we | |
4273 | * aren't holding any locks when we call it | |
4274 | */ | |
4275 | btrfs_unlock_up_safe(path, 0); | |
4276 | ||
f0486c68 YZ |
4277 | root_sub_used(root, leaf->len); |
4278 | ||
67439dad | 4279 | atomic_inc(&leaf->refs); |
7a163608 | 4280 | btrfs_free_tree_block(trans, btrfs_root_id(root), leaf, 0, 1); |
3083ee2e | 4281 | free_extent_buffer_stale(leaf); |
323ac95b | 4282 | } |
74123bd7 CM |
4283 | /* |
4284 | * delete the item at the leaf level in path. If that empties | |
4285 | * the leaf, remove it from the tree | |
4286 | */ | |
85e21bac CM |
4287 | int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
4288 | struct btrfs_path *path, int slot, int nr) | |
be0e5c09 | 4289 | { |
0b246afa | 4290 | struct btrfs_fs_info *fs_info = root->fs_info; |
5f39d397 | 4291 | struct extent_buffer *leaf; |
aa5d6bed CM |
4292 | int ret = 0; |
4293 | int wret; | |
7518a238 | 4294 | u32 nritems; |
be0e5c09 | 4295 | |
5f39d397 | 4296 | leaf = path->nodes[0]; |
5f39d397 | 4297 | nritems = btrfs_header_nritems(leaf); |
be0e5c09 | 4298 | |
85e21bac | 4299 | if (slot + nr != nritems) { |
0cae23b6 FM |
4300 | const u32 last_off = btrfs_item_offset(leaf, slot + nr - 1); |
4301 | const int data_end = leaf_data_end(leaf); | |
c82f823c | 4302 | struct btrfs_map_token token; |
0cae23b6 FM |
4303 | u32 dsize = 0; |
4304 | int i; | |
4305 | ||
4306 | for (i = 0; i < nr; i++) | |
4307 | dsize += btrfs_item_size(leaf, slot + i); | |
5f39d397 | 4308 | |
3d9ec8c4 | 4309 | memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + |
d6025579 | 4310 | data_end + dsize, |
3d9ec8c4 | 4311 | BTRFS_LEAF_DATA_OFFSET + data_end, |
85e21bac | 4312 | last_off - data_end); |
5f39d397 | 4313 | |
c82f823c | 4314 | btrfs_init_map_token(&token, leaf); |
85e21bac | 4315 | for (i = slot + nr; i < nritems; i++) { |
5f39d397 | 4316 | u32 ioff; |
db94535d | 4317 | |
3212fa14 JB |
4318 | ioff = btrfs_token_item_offset(&token, i); |
4319 | btrfs_set_token_item_offset(&token, i, ioff + dsize); | |
0783fcfc | 4320 | } |
db94535d | 4321 | |
5f39d397 | 4322 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot), |
85e21bac | 4323 | btrfs_item_nr_offset(slot + nr), |
d6025579 | 4324 | sizeof(struct btrfs_item) * |
85e21bac | 4325 | (nritems - slot - nr)); |
be0e5c09 | 4326 | } |
85e21bac CM |
4327 | btrfs_set_header_nritems(leaf, nritems - nr); |
4328 | nritems -= nr; | |
5f39d397 | 4329 | |
74123bd7 | 4330 | /* delete the leaf if we've emptied it */ |
7518a238 | 4331 | if (nritems == 0) { |
5f39d397 CM |
4332 | if (leaf == root->node) { |
4333 | btrfs_set_header_level(leaf, 0); | |
9a8dd150 | 4334 | } else { |
6a884d7d | 4335 | btrfs_clean_tree_block(leaf); |
143bede5 | 4336 | btrfs_del_leaf(trans, root, path, leaf); |
9a8dd150 | 4337 | } |
be0e5c09 | 4338 | } else { |
7518a238 | 4339 | int used = leaf_space_used(leaf, 0, nritems); |
aa5d6bed | 4340 | if (slot == 0) { |
5f39d397 CM |
4341 | struct btrfs_disk_key disk_key; |
4342 | ||
4343 | btrfs_item_key(leaf, &disk_key, 0); | |
b167fa91 | 4344 | fixup_low_keys(path, &disk_key, 1); |
aa5d6bed | 4345 | } |
aa5d6bed | 4346 | |
7c4063d1 FM |
4347 | /* |
4348 | * Try to delete the leaf if it is mostly empty. We do this by | |
4349 | * trying to move all its items into its left and right neighbours. | |
4350 | * If we can't move all the items, then we don't delete it - it's | |
4351 | * not ideal, but future insertions might fill the leaf with more | |
4352 | * items, or items from other leaves might be moved later into our | |
4353 | * leaf due to deletions on those leaves. | |
4354 | */ | |
0b246afa | 4355 | if (used < BTRFS_LEAF_DATA_SIZE(fs_info) / 3) { |
7c4063d1 FM |
4356 | u32 min_push_space; |
4357 | ||
be0e5c09 CM |
4358 | /* push_leaf_left fixes the path. |
4359 | * make sure the path still points to our leaf | |
4360 | * for possible call to del_ptr below | |
4361 | */ | |
4920c9ac | 4362 | slot = path->slots[1]; |
67439dad | 4363 | atomic_inc(&leaf->refs); |
7c4063d1 FM |
4364 | /* |
4365 | * We want to be able to at least push one item to the | |
4366 | * left neighbour leaf, and that's the first item. | |
4367 | */ | |
4368 | min_push_space = sizeof(struct btrfs_item) + | |
4369 | btrfs_item_size(leaf, 0); | |
4370 | wret = push_leaf_left(trans, root, path, 0, | |
4371 | min_push_space, 1, (u32)-1); | |
54aa1f4d | 4372 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed | 4373 | ret = wret; |
5f39d397 CM |
4374 | |
4375 | if (path->nodes[0] == leaf && | |
4376 | btrfs_header_nritems(leaf)) { | |
7c4063d1 FM |
4377 | /* |
4378 | * If we were not able to push all items from our | |
4379 | * leaf to its left neighbour, then attempt to | |
4380 | * either push all the remaining items to the | |
4381 | * right neighbour or none. There's no advantage | |
4382 | * in pushing only some items, instead of all, as | |
4383 | * it's pointless to end up with a leaf having | |
4384 | * too few items while the neighbours can be full | |
4385 | * or nearly full. | |
4386 | */ | |
4387 | nritems = btrfs_header_nritems(leaf); | |
4388 | min_push_space = leaf_space_used(leaf, 0, nritems); | |
4389 | wret = push_leaf_right(trans, root, path, 0, | |
4390 | min_push_space, 1, 0); | |
54aa1f4d | 4391 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed CM |
4392 | ret = wret; |
4393 | } | |
5f39d397 CM |
4394 | |
4395 | if (btrfs_header_nritems(leaf) == 0) { | |
323ac95b | 4396 | path->slots[1] = slot; |
143bede5 | 4397 | btrfs_del_leaf(trans, root, path, leaf); |
5f39d397 | 4398 | free_extent_buffer(leaf); |
143bede5 | 4399 | ret = 0; |
5de08d7d | 4400 | } else { |
925baedd CM |
4401 | /* if we're still in the path, make sure |
4402 | * we're dirty. Otherwise, one of the | |
4403 | * push_leaf functions must have already | |
4404 | * dirtied this buffer | |
4405 | */ | |
4406 | if (path->nodes[0] == leaf) | |
4407 | btrfs_mark_buffer_dirty(leaf); | |
5f39d397 | 4408 | free_extent_buffer(leaf); |
be0e5c09 | 4409 | } |
d5719762 | 4410 | } else { |
5f39d397 | 4411 | btrfs_mark_buffer_dirty(leaf); |
be0e5c09 CM |
4412 | } |
4413 | } | |
aa5d6bed | 4414 | return ret; |
be0e5c09 CM |
4415 | } |
4416 | ||
7bb86316 | 4417 | /* |
925baedd | 4418 | * search the tree again to find a leaf with lesser keys |
7bb86316 CM |
4419 | * returns 0 if it found something or 1 if there are no lesser leaves. |
4420 | * returns < 0 on io errors. | |
d352ac68 CM |
4421 | * |
4422 | * This may release the path, and so you may lose any locks held at the | |
4423 | * time you call it. | |
7bb86316 | 4424 | */ |
16e7549f | 4425 | int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) |
7bb86316 | 4426 | { |
925baedd CM |
4427 | struct btrfs_key key; |
4428 | struct btrfs_disk_key found_key; | |
4429 | int ret; | |
7bb86316 | 4430 | |
925baedd | 4431 | btrfs_item_key_to_cpu(path->nodes[0], &key, 0); |
7bb86316 | 4432 | |
e8b0d724 | 4433 | if (key.offset > 0) { |
925baedd | 4434 | key.offset--; |
e8b0d724 | 4435 | } else if (key.type > 0) { |
925baedd | 4436 | key.type--; |
e8b0d724 FDBM |
4437 | key.offset = (u64)-1; |
4438 | } else if (key.objectid > 0) { | |
925baedd | 4439 | key.objectid--; |
e8b0d724 FDBM |
4440 | key.type = (u8)-1; |
4441 | key.offset = (u64)-1; | |
4442 | } else { | |
925baedd | 4443 | return 1; |
e8b0d724 | 4444 | } |
7bb86316 | 4445 | |
b3b4aa74 | 4446 | btrfs_release_path(path); |
925baedd CM |
4447 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
4448 | if (ret < 0) | |
4449 | return ret; | |
4450 | btrfs_item_key(path->nodes[0], &found_key, 0); | |
4451 | ret = comp_keys(&found_key, &key); | |
337c6f68 FM |
4452 | /* |
4453 | * We might have had an item with the previous key in the tree right | |
4454 | * before we released our path. And after we released our path, that | |
4455 | * item might have been pushed to the first slot (0) of the leaf we | |
4456 | * were holding due to a tree balance. Alternatively, an item with the | |
4457 | * previous key can exist as the only element of a leaf (big fat item). | |
4458 | * Therefore account for these 2 cases, so that our callers (like | |
4459 | * btrfs_previous_item) don't miss an existing item with a key matching | |
4460 | * the previous key we computed above. | |
4461 | */ | |
4462 | if (ret <= 0) | |
925baedd CM |
4463 | return 0; |
4464 | return 1; | |
7bb86316 CM |
4465 | } |
4466 | ||
3f157a2f CM |
4467 | /* |
4468 | * A helper function to walk down the tree starting at min_key, and looking | |
de78b51a ES |
4469 | * for nodes or leaves that are have a minimum transaction id. |
4470 | * This is used by the btree defrag code, and tree logging | |
3f157a2f CM |
4471 | * |
4472 | * This does not cow, but it does stuff the starting key it finds back | |
4473 | * into min_key, so you can call btrfs_search_slot with cow=1 on the | |
4474 | * key and get a writable path. | |
4475 | * | |
3f157a2f CM |
4476 | * This honors path->lowest_level to prevent descent past a given level |
4477 | * of the tree. | |
4478 | * | |
d352ac68 CM |
4479 | * min_trans indicates the oldest transaction that you are interested |
4480 | * in walking through. Any nodes or leaves older than min_trans are | |
4481 | * skipped over (without reading them). | |
4482 | * | |
3f157a2f CM |
4483 | * returns zero if something useful was found, < 0 on error and 1 if there |
4484 | * was nothing in the tree that matched the search criteria. | |
4485 | */ | |
4486 | int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key, | |
de78b51a | 4487 | struct btrfs_path *path, |
3f157a2f CM |
4488 | u64 min_trans) |
4489 | { | |
4490 | struct extent_buffer *cur; | |
4491 | struct btrfs_key found_key; | |
4492 | int slot; | |
9652480b | 4493 | int sret; |
3f157a2f CM |
4494 | u32 nritems; |
4495 | int level; | |
4496 | int ret = 1; | |
f98de9b9 | 4497 | int keep_locks = path->keep_locks; |
3f157a2f | 4498 | |
c922b016 | 4499 | ASSERT(!path->nowait); |
f98de9b9 | 4500 | path->keep_locks = 1; |
3f157a2f | 4501 | again: |
bd681513 | 4502 | cur = btrfs_read_lock_root_node(root); |
3f157a2f | 4503 | level = btrfs_header_level(cur); |
e02119d5 | 4504 | WARN_ON(path->nodes[level]); |
3f157a2f | 4505 | path->nodes[level] = cur; |
bd681513 | 4506 | path->locks[level] = BTRFS_READ_LOCK; |
3f157a2f CM |
4507 | |
4508 | if (btrfs_header_generation(cur) < min_trans) { | |
4509 | ret = 1; | |
4510 | goto out; | |
4511 | } | |
d397712b | 4512 | while (1) { |
3f157a2f CM |
4513 | nritems = btrfs_header_nritems(cur); |
4514 | level = btrfs_header_level(cur); | |
e3b83361 | 4515 | sret = btrfs_bin_search(cur, min_key, &slot); |
cbca7d59 FM |
4516 | if (sret < 0) { |
4517 | ret = sret; | |
4518 | goto out; | |
4519 | } | |
3f157a2f | 4520 | |
323ac95b CM |
4521 | /* at the lowest level, we're done, setup the path and exit */ |
4522 | if (level == path->lowest_level) { | |
e02119d5 CM |
4523 | if (slot >= nritems) |
4524 | goto find_next_key; | |
3f157a2f CM |
4525 | ret = 0; |
4526 | path->slots[level] = slot; | |
4527 | btrfs_item_key_to_cpu(cur, &found_key, slot); | |
4528 | goto out; | |
4529 | } | |
9652480b Y |
4530 | if (sret && slot > 0) |
4531 | slot--; | |
3f157a2f | 4532 | /* |
de78b51a | 4533 | * check this node pointer against the min_trans parameters. |
260db43c | 4534 | * If it is too old, skip to the next one. |
3f157a2f | 4535 | */ |
d397712b | 4536 | while (slot < nritems) { |
3f157a2f | 4537 | u64 gen; |
e02119d5 | 4538 | |
3f157a2f CM |
4539 | gen = btrfs_node_ptr_generation(cur, slot); |
4540 | if (gen < min_trans) { | |
4541 | slot++; | |
4542 | continue; | |
4543 | } | |
de78b51a | 4544 | break; |
3f157a2f | 4545 | } |
e02119d5 | 4546 | find_next_key: |
3f157a2f CM |
4547 | /* |
4548 | * we didn't find a candidate key in this node, walk forward | |
4549 | * and find another one | |
4550 | */ | |
4551 | if (slot >= nritems) { | |
e02119d5 CM |
4552 | path->slots[level] = slot; |
4553 | sret = btrfs_find_next_key(root, path, min_key, level, | |
de78b51a | 4554 | min_trans); |
e02119d5 | 4555 | if (sret == 0) { |
b3b4aa74 | 4556 | btrfs_release_path(path); |
3f157a2f CM |
4557 | goto again; |
4558 | } else { | |
4559 | goto out; | |
4560 | } | |
4561 | } | |
4562 | /* save our key for returning back */ | |
4563 | btrfs_node_key_to_cpu(cur, &found_key, slot); | |
4564 | path->slots[level] = slot; | |
4565 | if (level == path->lowest_level) { | |
4566 | ret = 0; | |
3f157a2f CM |
4567 | goto out; |
4568 | } | |
4b231ae4 | 4569 | cur = btrfs_read_node_slot(cur, slot); |
fb770ae4 LB |
4570 | if (IS_ERR(cur)) { |
4571 | ret = PTR_ERR(cur); | |
4572 | goto out; | |
4573 | } | |
3f157a2f | 4574 | |
bd681513 | 4575 | btrfs_tree_read_lock(cur); |
b4ce94de | 4576 | |
bd681513 | 4577 | path->locks[level - 1] = BTRFS_READ_LOCK; |
3f157a2f | 4578 | path->nodes[level - 1] = cur; |
f7c79f30 | 4579 | unlock_up(path, level, 1, 0, NULL); |
3f157a2f CM |
4580 | } |
4581 | out: | |
f98de9b9 FM |
4582 | path->keep_locks = keep_locks; |
4583 | if (ret == 0) { | |
4584 | btrfs_unlock_up_safe(path, path->lowest_level + 1); | |
3f157a2f | 4585 | memcpy(min_key, &found_key, sizeof(found_key)); |
f98de9b9 | 4586 | } |
3f157a2f CM |
4587 | return ret; |
4588 | } | |
4589 | ||
4590 | /* | |
4591 | * this is similar to btrfs_next_leaf, but does not try to preserve | |
4592 | * and fixup the path. It looks for and returns the next key in the | |
de78b51a | 4593 | * tree based on the current path and the min_trans parameters. |
3f157a2f CM |
4594 | * |
4595 | * 0 is returned if another key is found, < 0 if there are any errors | |
4596 | * and 1 is returned if there are no higher keys in the tree | |
4597 | * | |
4598 | * path->keep_locks should be set to 1 on the search made before | |
4599 | * calling this function. | |
4600 | */ | |
e7a84565 | 4601 | int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path, |
de78b51a | 4602 | struct btrfs_key *key, int level, u64 min_trans) |
e7a84565 | 4603 | { |
e7a84565 CM |
4604 | int slot; |
4605 | struct extent_buffer *c; | |
4606 | ||
6a9fb468 | 4607 | WARN_ON(!path->keep_locks && !path->skip_locking); |
d397712b | 4608 | while (level < BTRFS_MAX_LEVEL) { |
e7a84565 CM |
4609 | if (!path->nodes[level]) |
4610 | return 1; | |
4611 | ||
4612 | slot = path->slots[level] + 1; | |
4613 | c = path->nodes[level]; | |
3f157a2f | 4614 | next: |
e7a84565 | 4615 | if (slot >= btrfs_header_nritems(c)) { |
33c66f43 YZ |
4616 | int ret; |
4617 | int orig_lowest; | |
4618 | struct btrfs_key cur_key; | |
4619 | if (level + 1 >= BTRFS_MAX_LEVEL || | |
4620 | !path->nodes[level + 1]) | |
e7a84565 | 4621 | return 1; |
33c66f43 | 4622 | |
6a9fb468 | 4623 | if (path->locks[level + 1] || path->skip_locking) { |
33c66f43 YZ |
4624 | level++; |
4625 | continue; | |
4626 | } | |
4627 | ||
4628 | slot = btrfs_header_nritems(c) - 1; | |
4629 | if (level == 0) | |
4630 | btrfs_item_key_to_cpu(c, &cur_key, slot); | |
4631 | else | |
4632 | btrfs_node_key_to_cpu(c, &cur_key, slot); | |
4633 | ||
4634 | orig_lowest = path->lowest_level; | |
b3b4aa74 | 4635 | btrfs_release_path(path); |
33c66f43 YZ |
4636 | path->lowest_level = level; |
4637 | ret = btrfs_search_slot(NULL, root, &cur_key, path, | |
4638 | 0, 0); | |
4639 | path->lowest_level = orig_lowest; | |
4640 | if (ret < 0) | |
4641 | return ret; | |
4642 | ||
4643 | c = path->nodes[level]; | |
4644 | slot = path->slots[level]; | |
4645 | if (ret == 0) | |
4646 | slot++; | |
4647 | goto next; | |
e7a84565 | 4648 | } |
33c66f43 | 4649 | |
e7a84565 CM |
4650 | if (level == 0) |
4651 | btrfs_item_key_to_cpu(c, key, slot); | |
3f157a2f | 4652 | else { |
3f157a2f CM |
4653 | u64 gen = btrfs_node_ptr_generation(c, slot); |
4654 | ||
3f157a2f CM |
4655 | if (gen < min_trans) { |
4656 | slot++; | |
4657 | goto next; | |
4658 | } | |
e7a84565 | 4659 | btrfs_node_key_to_cpu(c, key, slot); |
3f157a2f | 4660 | } |
e7a84565 CM |
4661 | return 0; |
4662 | } | |
4663 | return 1; | |
4664 | } | |
4665 | ||
3d7806ec JS |
4666 | int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path, |
4667 | u64 time_seq) | |
d97e63b6 CM |
4668 | { |
4669 | int slot; | |
8e73f275 | 4670 | int level; |
5f39d397 | 4671 | struct extent_buffer *c; |
8e73f275 | 4672 | struct extent_buffer *next; |
d96b3424 | 4673 | struct btrfs_fs_info *fs_info = root->fs_info; |
925baedd | 4674 | struct btrfs_key key; |
d96b3424 | 4675 | bool need_commit_sem = false; |
925baedd CM |
4676 | u32 nritems; |
4677 | int ret; | |
0e46318d | 4678 | int i; |
925baedd | 4679 | |
bdcdd86c FM |
4680 | /* |
4681 | * The nowait semantics are used only for write paths, where we don't | |
4682 | * use the tree mod log and sequence numbers. | |
4683 | */ | |
4684 | if (time_seq) | |
4685 | ASSERT(!path->nowait); | |
c922b016 | 4686 | |
925baedd | 4687 | nritems = btrfs_header_nritems(path->nodes[0]); |
d397712b | 4688 | if (nritems == 0) |
925baedd | 4689 | return 1; |
925baedd | 4690 | |
8e73f275 CM |
4691 | btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1); |
4692 | again: | |
4693 | level = 1; | |
4694 | next = NULL; | |
b3b4aa74 | 4695 | btrfs_release_path(path); |
8e73f275 | 4696 | |
a2135011 | 4697 | path->keep_locks = 1; |
8e73f275 | 4698 | |
d96b3424 | 4699 | if (time_seq) { |
3d7806ec | 4700 | ret = btrfs_search_old_slot(root, &key, path, time_seq); |
d96b3424 FM |
4701 | } else { |
4702 | if (path->need_commit_sem) { | |
4703 | path->need_commit_sem = 0; | |
4704 | need_commit_sem = true; | |
bdcdd86c FM |
4705 | if (path->nowait) { |
4706 | if (!down_read_trylock(&fs_info->commit_root_sem)) { | |
4707 | ret = -EAGAIN; | |
4708 | goto done; | |
4709 | } | |
4710 | } else { | |
4711 | down_read(&fs_info->commit_root_sem); | |
4712 | } | |
d96b3424 | 4713 | } |
3d7806ec | 4714 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
d96b3424 | 4715 | } |
925baedd CM |
4716 | path->keep_locks = 0; |
4717 | ||
4718 | if (ret < 0) | |
d96b3424 | 4719 | goto done; |
925baedd | 4720 | |
a2135011 | 4721 | nritems = btrfs_header_nritems(path->nodes[0]); |
168fd7d2 CM |
4722 | /* |
4723 | * by releasing the path above we dropped all our locks. A balance | |
4724 | * could have added more items next to the key that used to be | |
4725 | * at the very end of the block. So, check again here and | |
4726 | * advance the path if there are now more items available. | |
4727 | */ | |
a2135011 | 4728 | if (nritems > 0 && path->slots[0] < nritems - 1) { |
e457afec YZ |
4729 | if (ret == 0) |
4730 | path->slots[0]++; | |
8e73f275 | 4731 | ret = 0; |
925baedd CM |
4732 | goto done; |
4733 | } | |
0b43e04f LB |
4734 | /* |
4735 | * So the above check misses one case: | |
4736 | * - after releasing the path above, someone has removed the item that | |
4737 | * used to be at the very end of the block, and balance between leafs | |
4738 | * gets another one with bigger key.offset to replace it. | |
4739 | * | |
4740 | * This one should be returned as well, or we can get leaf corruption | |
4741 | * later(esp. in __btrfs_drop_extents()). | |
4742 | * | |
4743 | * And a bit more explanation about this check, | |
4744 | * with ret > 0, the key isn't found, the path points to the slot | |
4745 | * where it should be inserted, so the path->slots[0] item must be the | |
4746 | * bigger one. | |
4747 | */ | |
4748 | if (nritems > 0 && ret > 0 && path->slots[0] == nritems - 1) { | |
4749 | ret = 0; | |
4750 | goto done; | |
4751 | } | |
d97e63b6 | 4752 | |
d397712b | 4753 | while (level < BTRFS_MAX_LEVEL) { |
8e73f275 CM |
4754 | if (!path->nodes[level]) { |
4755 | ret = 1; | |
4756 | goto done; | |
4757 | } | |
5f39d397 | 4758 | |
d97e63b6 CM |
4759 | slot = path->slots[level] + 1; |
4760 | c = path->nodes[level]; | |
5f39d397 | 4761 | if (slot >= btrfs_header_nritems(c)) { |
d97e63b6 | 4762 | level++; |
8e73f275 CM |
4763 | if (level == BTRFS_MAX_LEVEL) { |
4764 | ret = 1; | |
4765 | goto done; | |
4766 | } | |
d97e63b6 CM |
4767 | continue; |
4768 | } | |
5f39d397 | 4769 | |
0e46318d JB |
4770 | |
4771 | /* | |
4772 | * Our current level is where we're going to start from, and to | |
4773 | * make sure lockdep doesn't complain we need to drop our locks | |
4774 | * and nodes from 0 to our current level. | |
4775 | */ | |
4776 | for (i = 0; i < level; i++) { | |
4777 | if (path->locks[level]) { | |
4778 | btrfs_tree_read_unlock(path->nodes[i]); | |
4779 | path->locks[i] = 0; | |
4780 | } | |
4781 | free_extent_buffer(path->nodes[i]); | |
4782 | path->nodes[i] = NULL; | |
925baedd | 4783 | } |
5f39d397 | 4784 | |
8e73f275 | 4785 | next = c; |
d07b8528 | 4786 | ret = read_block_for_search(root, path, &next, level, |
cda79c54 | 4787 | slot, &key); |
bdcdd86c | 4788 | if (ret == -EAGAIN && !path->nowait) |
8e73f275 | 4789 | goto again; |
5f39d397 | 4790 | |
76a05b35 | 4791 | if (ret < 0) { |
b3b4aa74 | 4792 | btrfs_release_path(path); |
76a05b35 CM |
4793 | goto done; |
4794 | } | |
4795 | ||
5cd57b2c | 4796 | if (!path->skip_locking) { |
bd681513 | 4797 | ret = btrfs_try_tree_read_lock(next); |
bdcdd86c FM |
4798 | if (!ret && path->nowait) { |
4799 | ret = -EAGAIN; | |
4800 | goto done; | |
4801 | } | |
d42244a0 JS |
4802 | if (!ret && time_seq) { |
4803 | /* | |
4804 | * If we don't get the lock, we may be racing | |
4805 | * with push_leaf_left, holding that lock while | |
4806 | * itself waiting for the leaf we've currently | |
4807 | * locked. To solve this situation, we give up | |
4808 | * on our lock and cycle. | |
4809 | */ | |
cf538830 | 4810 | free_extent_buffer(next); |
d42244a0 JS |
4811 | btrfs_release_path(path); |
4812 | cond_resched(); | |
4813 | goto again; | |
4814 | } | |
0e46318d JB |
4815 | if (!ret) |
4816 | btrfs_tree_read_lock(next); | |
5cd57b2c | 4817 | } |
d97e63b6 CM |
4818 | break; |
4819 | } | |
4820 | path->slots[level] = slot; | |
d397712b | 4821 | while (1) { |
d97e63b6 | 4822 | level--; |
d97e63b6 CM |
4823 | path->nodes[level] = next; |
4824 | path->slots[level] = 0; | |
a74a4b97 | 4825 | if (!path->skip_locking) |
ffeb03cf | 4826 | path->locks[level] = BTRFS_READ_LOCK; |
d97e63b6 CM |
4827 | if (!level) |
4828 | break; | |
b4ce94de | 4829 | |
d07b8528 | 4830 | ret = read_block_for_search(root, path, &next, level, |
cda79c54 | 4831 | 0, &key); |
bdcdd86c | 4832 | if (ret == -EAGAIN && !path->nowait) |
8e73f275 CM |
4833 | goto again; |
4834 | ||
76a05b35 | 4835 | if (ret < 0) { |
b3b4aa74 | 4836 | btrfs_release_path(path); |
76a05b35 CM |
4837 | goto done; |
4838 | } | |
4839 | ||
bdcdd86c FM |
4840 | if (!path->skip_locking) { |
4841 | if (path->nowait) { | |
4842 | if (!btrfs_try_tree_read_lock(next)) { | |
4843 | ret = -EAGAIN; | |
4844 | goto done; | |
4845 | } | |
4846 | } else { | |
4847 | btrfs_tree_read_lock(next); | |
4848 | } | |
4849 | } | |
d97e63b6 | 4850 | } |
8e73f275 | 4851 | ret = 0; |
925baedd | 4852 | done: |
f7c79f30 | 4853 | unlock_up(path, 0, 1, 0, NULL); |
d96b3424 FM |
4854 | if (need_commit_sem) { |
4855 | int ret2; | |
4856 | ||
4857 | path->need_commit_sem = 1; | |
4858 | ret2 = finish_need_commit_sem_search(path); | |
4859 | up_read(&fs_info->commit_root_sem); | |
4860 | if (ret2) | |
4861 | ret = ret2; | |
4862 | } | |
8e73f275 CM |
4863 | |
4864 | return ret; | |
d97e63b6 | 4865 | } |
0b86a832 | 4866 | |
890d2b1a JB |
4867 | int btrfs_next_old_item(struct btrfs_root *root, struct btrfs_path *path, u64 time_seq) |
4868 | { | |
4869 | path->slots[0]++; | |
4870 | if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) | |
4871 | return btrfs_next_old_leaf(root, path, time_seq); | |
4872 | return 0; | |
4873 | } | |
4874 | ||
3f157a2f CM |
4875 | /* |
4876 | * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps | |
4877 | * searching until it gets past min_objectid or finds an item of 'type' | |
4878 | * | |
4879 | * returns 0 if something is found, 1 if nothing was found and < 0 on error | |
4880 | */ | |
0b86a832 CM |
4881 | int btrfs_previous_item(struct btrfs_root *root, |
4882 | struct btrfs_path *path, u64 min_objectid, | |
4883 | int type) | |
4884 | { | |
4885 | struct btrfs_key found_key; | |
4886 | struct extent_buffer *leaf; | |
e02119d5 | 4887 | u32 nritems; |
0b86a832 CM |
4888 | int ret; |
4889 | ||
d397712b | 4890 | while (1) { |
0b86a832 CM |
4891 | if (path->slots[0] == 0) { |
4892 | ret = btrfs_prev_leaf(root, path); | |
4893 | if (ret != 0) | |
4894 | return ret; | |
4895 | } else { | |
4896 | path->slots[0]--; | |
4897 | } | |
4898 | leaf = path->nodes[0]; | |
e02119d5 CM |
4899 | nritems = btrfs_header_nritems(leaf); |
4900 | if (nritems == 0) | |
4901 | return 1; | |
4902 | if (path->slots[0] == nritems) | |
4903 | path->slots[0]--; | |
4904 | ||
0b86a832 | 4905 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
e02119d5 CM |
4906 | if (found_key.objectid < min_objectid) |
4907 | break; | |
0a4eefbb YZ |
4908 | if (found_key.type == type) |
4909 | return 0; | |
e02119d5 CM |
4910 | if (found_key.objectid == min_objectid && |
4911 | found_key.type < type) | |
4912 | break; | |
0b86a832 CM |
4913 | } |
4914 | return 1; | |
4915 | } | |
ade2e0b3 WS |
4916 | |
4917 | /* | |
4918 | * search in extent tree to find a previous Metadata/Data extent item with | |
4919 | * min objecitd. | |
4920 | * | |
4921 | * returns 0 if something is found, 1 if nothing was found and < 0 on error | |
4922 | */ | |
4923 | int btrfs_previous_extent_item(struct btrfs_root *root, | |
4924 | struct btrfs_path *path, u64 min_objectid) | |
4925 | { | |
4926 | struct btrfs_key found_key; | |
4927 | struct extent_buffer *leaf; | |
4928 | u32 nritems; | |
4929 | int ret; | |
4930 | ||
4931 | while (1) { | |
4932 | if (path->slots[0] == 0) { | |
ade2e0b3 WS |
4933 | ret = btrfs_prev_leaf(root, path); |
4934 | if (ret != 0) | |
4935 | return ret; | |
4936 | } else { | |
4937 | path->slots[0]--; | |
4938 | } | |
4939 | leaf = path->nodes[0]; | |
4940 | nritems = btrfs_header_nritems(leaf); | |
4941 | if (nritems == 0) | |
4942 | return 1; | |
4943 | if (path->slots[0] == nritems) | |
4944 | path->slots[0]--; | |
4945 | ||
4946 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); | |
4947 | if (found_key.objectid < min_objectid) | |
4948 | break; | |
4949 | if (found_key.type == BTRFS_EXTENT_ITEM_KEY || | |
4950 | found_key.type == BTRFS_METADATA_ITEM_KEY) | |
4951 | return 0; | |
4952 | if (found_key.objectid == min_objectid && | |
4953 | found_key.type < BTRFS_EXTENT_ITEM_KEY) | |
4954 | break; | |
4955 | } | |
4956 | return 1; | |
4957 | } | |
226463d7 JB |
4958 | |
4959 | int __init btrfs_ctree_init(void) | |
4960 | { | |
4961 | btrfs_path_cachep = kmem_cache_create("btrfs_path", | |
4962 | sizeof(struct btrfs_path), 0, | |
4963 | SLAB_MEM_SPREAD, NULL); | |
4964 | if (!btrfs_path_cachep) | |
4965 | return -ENOMEM; | |
4966 | return 0; | |
4967 | } | |
4968 | ||
4969 | void __cold btrfs_ctree_exit(void) | |
4970 | { | |
4971 | kmem_cache_destroy(btrfs_path_cachep); | |
4972 | } |