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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> |
eb60ceac CM |
10 | #include "ctree.h" |
11 | #include "disk-io.h" | |
7f5c1516 | 12 | #include "transaction.h" |
5f39d397 | 13 | #include "print-tree.h" |
925baedd | 14 | #include "locking.h" |
de37aa51 | 15 | #include "volumes.h" |
f616f5cd | 16 | #include "qgroup.h" |
f3a84ccd | 17 | #include "tree-mod-log.h" |
9a8dd150 | 18 | |
e089f05c CM |
19 | static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root |
20 | *root, struct btrfs_path *path, int level); | |
310712b2 OS |
21 | static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
22 | const struct btrfs_key *ins_key, struct btrfs_path *path, | |
23 | int data_size, int extend); | |
5f39d397 | 24 | static int push_node_left(struct btrfs_trans_handle *trans, |
2ff7e61e | 25 | struct extent_buffer *dst, |
971a1f66 | 26 | struct extent_buffer *src, int empty); |
5f39d397 | 27 | static int balance_node_right(struct btrfs_trans_handle *trans, |
5f39d397 CM |
28 | struct extent_buffer *dst_buf, |
29 | struct extent_buffer *src_buf); | |
afe5fea7 TI |
30 | static void del_ptr(struct btrfs_root *root, struct btrfs_path *path, |
31 | int level, int slot); | |
d97e63b6 | 32 | |
af024ed2 JT |
33 | static const struct btrfs_csums { |
34 | u16 size; | |
59a0fcdb DS |
35 | const char name[10]; |
36 | const char driver[12]; | |
af024ed2 JT |
37 | } btrfs_csums[] = { |
38 | [BTRFS_CSUM_TYPE_CRC32] = { .size = 4, .name = "crc32c" }, | |
3951e7f0 | 39 | [BTRFS_CSUM_TYPE_XXHASH] = { .size = 8, .name = "xxhash64" }, |
3831bf00 | 40 | [BTRFS_CSUM_TYPE_SHA256] = { .size = 32, .name = "sha256" }, |
352ae07b DS |
41 | [BTRFS_CSUM_TYPE_BLAKE2] = { .size = 32, .name = "blake2b", |
42 | .driver = "blake2b-256" }, | |
af024ed2 JT |
43 | }; |
44 | ||
45 | int btrfs_super_csum_size(const struct btrfs_super_block *s) | |
46 | { | |
47 | u16 t = btrfs_super_csum_type(s); | |
48 | /* | |
49 | * csum type is validated at mount time | |
50 | */ | |
51 | return btrfs_csums[t].size; | |
52 | } | |
53 | ||
54 | const char *btrfs_super_csum_name(u16 csum_type) | |
55 | { | |
56 | /* csum type is validated at mount time */ | |
57 | return btrfs_csums[csum_type].name; | |
58 | } | |
59 | ||
b4e967be DS |
60 | /* |
61 | * Return driver name if defined, otherwise the name that's also a valid driver | |
62 | * name | |
63 | */ | |
64 | const char *btrfs_super_csum_driver(u16 csum_type) | |
65 | { | |
66 | /* csum type is validated at mount time */ | |
59a0fcdb DS |
67 | return btrfs_csums[csum_type].driver[0] ? |
68 | btrfs_csums[csum_type].driver : | |
b4e967be DS |
69 | btrfs_csums[csum_type].name; |
70 | } | |
71 | ||
604997b4 | 72 | size_t __attribute_const__ btrfs_get_num_csums(void) |
f7cea56c DS |
73 | { |
74 | return ARRAY_SIZE(btrfs_csums); | |
75 | } | |
76 | ||
df24a2b9 | 77 | struct btrfs_path *btrfs_alloc_path(void) |
2c90e5d6 | 78 | { |
e2c89907 | 79 | return kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS); |
2c90e5d6 CM |
80 | } |
81 | ||
d352ac68 | 82 | /* this also releases the path */ |
df24a2b9 | 83 | void btrfs_free_path(struct btrfs_path *p) |
be0e5c09 | 84 | { |
ff175d57 JJ |
85 | if (!p) |
86 | return; | |
b3b4aa74 | 87 | btrfs_release_path(p); |
df24a2b9 | 88 | kmem_cache_free(btrfs_path_cachep, p); |
be0e5c09 CM |
89 | } |
90 | ||
d352ac68 CM |
91 | /* |
92 | * path release drops references on the extent buffers in the path | |
93 | * and it drops any locks held by this path | |
94 | * | |
95 | * It is safe to call this on paths that no locks or extent buffers held. | |
96 | */ | |
b3b4aa74 | 97 | noinline void btrfs_release_path(struct btrfs_path *p) |
eb60ceac CM |
98 | { |
99 | int i; | |
a2135011 | 100 | |
234b63a0 | 101 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) { |
3f157a2f | 102 | p->slots[i] = 0; |
eb60ceac | 103 | if (!p->nodes[i]) |
925baedd CM |
104 | continue; |
105 | if (p->locks[i]) { | |
bd681513 | 106 | btrfs_tree_unlock_rw(p->nodes[i], p->locks[i]); |
925baedd CM |
107 | p->locks[i] = 0; |
108 | } | |
5f39d397 | 109 | free_extent_buffer(p->nodes[i]); |
3f157a2f | 110 | p->nodes[i] = NULL; |
eb60ceac CM |
111 | } |
112 | } | |
113 | ||
d352ac68 CM |
114 | /* |
115 | * safely gets a reference on the root node of a tree. A lock | |
116 | * is not taken, so a concurrent writer may put a different node | |
117 | * at the root of the tree. See btrfs_lock_root_node for the | |
118 | * looping required. | |
119 | * | |
120 | * The extent buffer returned by this has a reference taken, so | |
121 | * it won't disappear. It may stop being the root of the tree | |
122 | * at any time because there are no locks held. | |
123 | */ | |
925baedd CM |
124 | struct extent_buffer *btrfs_root_node(struct btrfs_root *root) |
125 | { | |
126 | struct extent_buffer *eb; | |
240f62c8 | 127 | |
3083ee2e JB |
128 | while (1) { |
129 | rcu_read_lock(); | |
130 | eb = rcu_dereference(root->node); | |
131 | ||
132 | /* | |
133 | * RCU really hurts here, we could free up the root node because | |
01327610 | 134 | * it was COWed but we may not get the new root node yet so do |
3083ee2e JB |
135 | * the inc_not_zero dance and if it doesn't work then |
136 | * synchronize_rcu and try again. | |
137 | */ | |
138 | if (atomic_inc_not_zero(&eb->refs)) { | |
139 | rcu_read_unlock(); | |
140 | break; | |
141 | } | |
142 | rcu_read_unlock(); | |
143 | synchronize_rcu(); | |
144 | } | |
925baedd CM |
145 | return eb; |
146 | } | |
147 | ||
92a7cc42 QW |
148 | /* |
149 | * Cowonly root (not-shareable trees, everything not subvolume or reloc roots), | |
150 | * just get put onto a simple dirty list. Transaction walks this list to make | |
151 | * sure they get properly updated on disk. | |
d352ac68 | 152 | */ |
0b86a832 CM |
153 | static void add_root_to_dirty_list(struct btrfs_root *root) |
154 | { | |
0b246afa JM |
155 | struct btrfs_fs_info *fs_info = root->fs_info; |
156 | ||
e7070be1 JB |
157 | if (test_bit(BTRFS_ROOT_DIRTY, &root->state) || |
158 | !test_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state)) | |
159 | return; | |
160 | ||
0b246afa | 161 | spin_lock(&fs_info->trans_lock); |
e7070be1 JB |
162 | if (!test_and_set_bit(BTRFS_ROOT_DIRTY, &root->state)) { |
163 | /* Want the extent tree to be the last on the list */ | |
4fd786e6 | 164 | if (root->root_key.objectid == BTRFS_EXTENT_TREE_OBJECTID) |
e7070be1 | 165 | list_move_tail(&root->dirty_list, |
0b246afa | 166 | &fs_info->dirty_cowonly_roots); |
e7070be1 JB |
167 | else |
168 | list_move(&root->dirty_list, | |
0b246afa | 169 | &fs_info->dirty_cowonly_roots); |
0b86a832 | 170 | } |
0b246afa | 171 | spin_unlock(&fs_info->trans_lock); |
0b86a832 CM |
172 | } |
173 | ||
d352ac68 CM |
174 | /* |
175 | * used by snapshot creation to make a copy of a root for a tree with | |
176 | * a given objectid. The buffer with the new root node is returned in | |
177 | * cow_ret, and this func returns zero on success or a negative error code. | |
178 | */ | |
be20aa9d CM |
179 | int btrfs_copy_root(struct btrfs_trans_handle *trans, |
180 | struct btrfs_root *root, | |
181 | struct extent_buffer *buf, | |
182 | struct extent_buffer **cow_ret, u64 new_root_objectid) | |
183 | { | |
0b246afa | 184 | struct btrfs_fs_info *fs_info = root->fs_info; |
be20aa9d | 185 | struct extent_buffer *cow; |
be20aa9d CM |
186 | int ret = 0; |
187 | int level; | |
5d4f98a2 | 188 | struct btrfs_disk_key disk_key; |
be20aa9d | 189 | |
92a7cc42 | 190 | WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && |
0b246afa | 191 | trans->transid != fs_info->running_transaction->transid); |
92a7cc42 | 192 | WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && |
27cdeb70 | 193 | trans->transid != root->last_trans); |
be20aa9d CM |
194 | |
195 | level = btrfs_header_level(buf); | |
5d4f98a2 YZ |
196 | if (level == 0) |
197 | btrfs_item_key(buf, &disk_key, 0); | |
198 | else | |
199 | btrfs_node_key(buf, &disk_key, 0); | |
31840ae1 | 200 | |
4d75f8a9 | 201 | cow = btrfs_alloc_tree_block(trans, root, 0, new_root_objectid, |
cf6f34aa JB |
202 | &disk_key, level, buf->start, 0, |
203 | BTRFS_NESTING_NEW_ROOT); | |
5d4f98a2 | 204 | if (IS_ERR(cow)) |
be20aa9d CM |
205 | return PTR_ERR(cow); |
206 | ||
58e8012c | 207 | copy_extent_buffer_full(cow, buf); |
be20aa9d CM |
208 | btrfs_set_header_bytenr(cow, cow->start); |
209 | btrfs_set_header_generation(cow, trans->transid); | |
5d4f98a2 YZ |
210 | btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); |
211 | btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | | |
212 | BTRFS_HEADER_FLAG_RELOC); | |
213 | if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) | |
214 | btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); | |
215 | else | |
216 | btrfs_set_header_owner(cow, new_root_objectid); | |
be20aa9d | 217 | |
de37aa51 | 218 | write_extent_buffer_fsid(cow, fs_info->fs_devices->metadata_uuid); |
2b82032c | 219 | |
be20aa9d | 220 | WARN_ON(btrfs_header_generation(buf) > trans->transid); |
5d4f98a2 | 221 | if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) |
e339a6b0 | 222 | ret = btrfs_inc_ref(trans, root, cow, 1); |
5d4f98a2 | 223 | else |
e339a6b0 | 224 | ret = btrfs_inc_ref(trans, root, cow, 0); |
867ed321 | 225 | if (ret) { |
72c9925f FM |
226 | btrfs_tree_unlock(cow); |
227 | free_extent_buffer(cow); | |
867ed321 | 228 | btrfs_abort_transaction(trans, ret); |
be20aa9d | 229 | return ret; |
867ed321 | 230 | } |
be20aa9d CM |
231 | |
232 | btrfs_mark_buffer_dirty(cow); | |
233 | *cow_ret = cow; | |
234 | return 0; | |
235 | } | |
236 | ||
5d4f98a2 YZ |
237 | /* |
238 | * check if the tree block can be shared by multiple trees | |
239 | */ | |
240 | int btrfs_block_can_be_shared(struct btrfs_root *root, | |
241 | struct extent_buffer *buf) | |
242 | { | |
243 | /* | |
92a7cc42 QW |
244 | * Tree blocks not in shareable trees and tree roots are never shared. |
245 | * If a block was allocated after the last snapshot and the block was | |
246 | * not allocated by tree relocation, we know the block is not shared. | |
5d4f98a2 | 247 | */ |
92a7cc42 | 248 | if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && |
5d4f98a2 YZ |
249 | buf != root->node && buf != root->commit_root && |
250 | (btrfs_header_generation(buf) <= | |
251 | btrfs_root_last_snapshot(&root->root_item) || | |
252 | btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))) | |
253 | return 1; | |
a79865c6 | 254 | |
5d4f98a2 YZ |
255 | return 0; |
256 | } | |
257 | ||
258 | static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, | |
259 | struct btrfs_root *root, | |
260 | struct extent_buffer *buf, | |
f0486c68 YZ |
261 | struct extent_buffer *cow, |
262 | int *last_ref) | |
5d4f98a2 | 263 | { |
0b246afa | 264 | struct btrfs_fs_info *fs_info = root->fs_info; |
5d4f98a2 YZ |
265 | u64 refs; |
266 | u64 owner; | |
267 | u64 flags; | |
268 | u64 new_flags = 0; | |
269 | int ret; | |
270 | ||
271 | /* | |
272 | * Backrefs update rules: | |
273 | * | |
274 | * Always use full backrefs for extent pointers in tree block | |
275 | * allocated by tree relocation. | |
276 | * | |
277 | * If a shared tree block is no longer referenced by its owner | |
278 | * tree (btrfs_header_owner(buf) == root->root_key.objectid), | |
279 | * use full backrefs for extent pointers in tree block. | |
280 | * | |
281 | * If a tree block is been relocating | |
282 | * (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID), | |
283 | * use full backrefs for extent pointers in tree block. | |
284 | * The reason for this is some operations (such as drop tree) | |
285 | * are only allowed for blocks use full backrefs. | |
286 | */ | |
287 | ||
288 | if (btrfs_block_can_be_shared(root, buf)) { | |
2ff7e61e | 289 | ret = btrfs_lookup_extent_info(trans, fs_info, buf->start, |
3173a18f JB |
290 | btrfs_header_level(buf), 1, |
291 | &refs, &flags); | |
be1a5564 MF |
292 | if (ret) |
293 | return ret; | |
e5df9573 MF |
294 | if (refs == 0) { |
295 | ret = -EROFS; | |
0b246afa | 296 | btrfs_handle_fs_error(fs_info, ret, NULL); |
e5df9573 MF |
297 | return ret; |
298 | } | |
5d4f98a2 YZ |
299 | } else { |
300 | refs = 1; | |
301 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || | |
302 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
303 | flags = BTRFS_BLOCK_FLAG_FULL_BACKREF; | |
304 | else | |
305 | flags = 0; | |
306 | } | |
307 | ||
308 | owner = btrfs_header_owner(buf); | |
309 | BUG_ON(owner == BTRFS_TREE_RELOC_OBJECTID && | |
310 | !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)); | |
311 | ||
312 | if (refs > 1) { | |
313 | if ((owner == root->root_key.objectid || | |
314 | root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && | |
315 | !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) { | |
e339a6b0 | 316 | ret = btrfs_inc_ref(trans, root, buf, 1); |
692826b2 JM |
317 | if (ret) |
318 | return ret; | |
5d4f98a2 YZ |
319 | |
320 | if (root->root_key.objectid == | |
321 | BTRFS_TREE_RELOC_OBJECTID) { | |
e339a6b0 | 322 | ret = btrfs_dec_ref(trans, root, buf, 0); |
692826b2 JM |
323 | if (ret) |
324 | return ret; | |
e339a6b0 | 325 | ret = btrfs_inc_ref(trans, root, cow, 1); |
692826b2 JM |
326 | if (ret) |
327 | return ret; | |
5d4f98a2 YZ |
328 | } |
329 | new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF; | |
330 | } else { | |
331 | ||
332 | if (root->root_key.objectid == | |
333 | BTRFS_TREE_RELOC_OBJECTID) | |
e339a6b0 | 334 | ret = btrfs_inc_ref(trans, root, cow, 1); |
5d4f98a2 | 335 | else |
e339a6b0 | 336 | ret = btrfs_inc_ref(trans, root, cow, 0); |
692826b2 JM |
337 | if (ret) |
338 | return ret; | |
5d4f98a2 YZ |
339 | } |
340 | if (new_flags != 0) { | |
b1c79e09 JB |
341 | int level = btrfs_header_level(buf); |
342 | ||
42c9d0b5 | 343 | ret = btrfs_set_disk_extent_flags(trans, buf, |
b1c79e09 | 344 | new_flags, level, 0); |
be1a5564 MF |
345 | if (ret) |
346 | return ret; | |
5d4f98a2 YZ |
347 | } |
348 | } else { | |
349 | if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) { | |
350 | if (root->root_key.objectid == | |
351 | BTRFS_TREE_RELOC_OBJECTID) | |
e339a6b0 | 352 | ret = btrfs_inc_ref(trans, root, cow, 1); |
5d4f98a2 | 353 | else |
e339a6b0 | 354 | ret = btrfs_inc_ref(trans, root, cow, 0); |
692826b2 JM |
355 | if (ret) |
356 | return ret; | |
e339a6b0 | 357 | ret = btrfs_dec_ref(trans, root, buf, 1); |
692826b2 JM |
358 | if (ret) |
359 | return ret; | |
5d4f98a2 | 360 | } |
6a884d7d | 361 | btrfs_clean_tree_block(buf); |
f0486c68 | 362 | *last_ref = 1; |
5d4f98a2 YZ |
363 | } |
364 | return 0; | |
365 | } | |
366 | ||
a6279470 FM |
367 | static struct extent_buffer *alloc_tree_block_no_bg_flush( |
368 | struct btrfs_trans_handle *trans, | |
369 | struct btrfs_root *root, | |
370 | u64 parent_start, | |
371 | const struct btrfs_disk_key *disk_key, | |
372 | int level, | |
373 | u64 hint, | |
9631e4cc JB |
374 | u64 empty_size, |
375 | enum btrfs_lock_nesting nest) | |
a6279470 FM |
376 | { |
377 | struct btrfs_fs_info *fs_info = root->fs_info; | |
378 | struct extent_buffer *ret; | |
379 | ||
380 | /* | |
381 | * If we are COWing a node/leaf from the extent, chunk, device or free | |
382 | * space trees, make sure that we do not finish block group creation of | |
383 | * pending block groups. We do this to avoid a deadlock. | |
384 | * COWing can result in allocation of a new chunk, and flushing pending | |
385 | * block groups (btrfs_create_pending_block_groups()) can be triggered | |
386 | * when finishing allocation of a new chunk. Creation of a pending block | |
387 | * group modifies the extent, chunk, device and free space trees, | |
388 | * therefore we could deadlock with ourselves since we are holding a | |
389 | * lock on an extent buffer that btrfs_create_pending_block_groups() may | |
390 | * try to COW later. | |
391 | * For similar reasons, we also need to delay flushing pending block | |
392 | * groups when splitting a leaf or node, from one of those trees, since | |
393 | * we are holding a write lock on it and its parent or when inserting a | |
394 | * new root node for one of those trees. | |
395 | */ | |
396 | if (root == fs_info->extent_root || | |
397 | root == fs_info->chunk_root || | |
398 | root == fs_info->dev_root || | |
399 | root == fs_info->free_space_root) | |
400 | trans->can_flush_pending_bgs = false; | |
401 | ||
402 | ret = btrfs_alloc_tree_block(trans, root, parent_start, | |
403 | root->root_key.objectid, disk_key, level, | |
9631e4cc | 404 | hint, empty_size, nest); |
a6279470 FM |
405 | trans->can_flush_pending_bgs = true; |
406 | ||
407 | return ret; | |
408 | } | |
409 | ||
d352ac68 | 410 | /* |
d397712b CM |
411 | * does the dirty work in cow of a single block. The parent block (if |
412 | * supplied) is updated to point to the new cow copy. The new buffer is marked | |
413 | * dirty and returned locked. If you modify the block it needs to be marked | |
414 | * dirty again. | |
d352ac68 CM |
415 | * |
416 | * search_start -- an allocation hint for the new block | |
417 | * | |
d397712b CM |
418 | * empty_size -- a hint that you plan on doing more cow. This is the size in |
419 | * bytes the allocator should try to find free next to the block it returns. | |
420 | * This is just a hint and may be ignored by the allocator. | |
d352ac68 | 421 | */ |
d397712b | 422 | static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, |
5f39d397 CM |
423 | struct btrfs_root *root, |
424 | struct extent_buffer *buf, | |
425 | struct extent_buffer *parent, int parent_slot, | |
426 | struct extent_buffer **cow_ret, | |
9631e4cc JB |
427 | u64 search_start, u64 empty_size, |
428 | enum btrfs_lock_nesting nest) | |
02217ed2 | 429 | { |
0b246afa | 430 | struct btrfs_fs_info *fs_info = root->fs_info; |
5d4f98a2 | 431 | struct btrfs_disk_key disk_key; |
5f39d397 | 432 | struct extent_buffer *cow; |
be1a5564 | 433 | int level, ret; |
f0486c68 | 434 | int last_ref = 0; |
925baedd | 435 | int unlock_orig = 0; |
0f5053eb | 436 | u64 parent_start = 0; |
7bb86316 | 437 | |
925baedd CM |
438 | if (*cow_ret == buf) |
439 | unlock_orig = 1; | |
440 | ||
b9447ef8 | 441 | btrfs_assert_tree_locked(buf); |
925baedd | 442 | |
92a7cc42 | 443 | WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && |
0b246afa | 444 | trans->transid != fs_info->running_transaction->transid); |
92a7cc42 | 445 | WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && |
27cdeb70 | 446 | trans->transid != root->last_trans); |
5f39d397 | 447 | |
7bb86316 | 448 | level = btrfs_header_level(buf); |
31840ae1 | 449 | |
5d4f98a2 YZ |
450 | if (level == 0) |
451 | btrfs_item_key(buf, &disk_key, 0); | |
452 | else | |
453 | btrfs_node_key(buf, &disk_key, 0); | |
454 | ||
0f5053eb GR |
455 | if ((root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && parent) |
456 | parent_start = parent->start; | |
5d4f98a2 | 457 | |
a6279470 | 458 | cow = alloc_tree_block_no_bg_flush(trans, root, parent_start, &disk_key, |
9631e4cc | 459 | level, search_start, empty_size, nest); |
54aa1f4d CM |
460 | if (IS_ERR(cow)) |
461 | return PTR_ERR(cow); | |
6702ed49 | 462 | |
b4ce94de CM |
463 | /* cow is set to blocking by btrfs_init_new_buffer */ |
464 | ||
58e8012c | 465 | copy_extent_buffer_full(cow, buf); |
db94535d | 466 | btrfs_set_header_bytenr(cow, cow->start); |
5f39d397 | 467 | btrfs_set_header_generation(cow, trans->transid); |
5d4f98a2 YZ |
468 | btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); |
469 | btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | | |
470 | BTRFS_HEADER_FLAG_RELOC); | |
471 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) | |
472 | btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); | |
473 | else | |
474 | btrfs_set_header_owner(cow, root->root_key.objectid); | |
6702ed49 | 475 | |
de37aa51 | 476 | write_extent_buffer_fsid(cow, fs_info->fs_devices->metadata_uuid); |
2b82032c | 477 | |
be1a5564 | 478 | ret = update_ref_for_cow(trans, root, buf, cow, &last_ref); |
b68dc2a9 | 479 | if (ret) { |
572c83ac JB |
480 | btrfs_tree_unlock(cow); |
481 | free_extent_buffer(cow); | |
66642832 | 482 | btrfs_abort_transaction(trans, ret); |
b68dc2a9 MF |
483 | return ret; |
484 | } | |
1a40e23b | 485 | |
92a7cc42 | 486 | if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) { |
83d4cfd4 | 487 | ret = btrfs_reloc_cow_block(trans, root, buf, cow); |
93314e3b | 488 | if (ret) { |
572c83ac JB |
489 | btrfs_tree_unlock(cow); |
490 | free_extent_buffer(cow); | |
66642832 | 491 | btrfs_abort_transaction(trans, ret); |
83d4cfd4 | 492 | return ret; |
93314e3b | 493 | } |
83d4cfd4 | 494 | } |
3fd0a558 | 495 | |
02217ed2 | 496 | if (buf == root->node) { |
925baedd | 497 | WARN_ON(parent && parent != buf); |
5d4f98a2 YZ |
498 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || |
499 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
500 | parent_start = buf->start; | |
925baedd | 501 | |
67439dad | 502 | atomic_inc(&cow->refs); |
406808ab | 503 | ret = btrfs_tree_mod_log_insert_root(root->node, cow, true); |
d9d19a01 | 504 | BUG_ON(ret < 0); |
240f62c8 | 505 | rcu_assign_pointer(root->node, cow); |
925baedd | 506 | |
f0486c68 | 507 | btrfs_free_tree_block(trans, root, buf, parent_start, |
5581a51a | 508 | last_ref); |
5f39d397 | 509 | free_extent_buffer(buf); |
0b86a832 | 510 | add_root_to_dirty_list(root); |
02217ed2 | 511 | } else { |
5d4f98a2 | 512 | WARN_ON(trans->transid != btrfs_header_generation(parent)); |
f3a84ccd FM |
513 | btrfs_tree_mod_log_insert_key(parent, parent_slot, |
514 | BTRFS_MOD_LOG_KEY_REPLACE, GFP_NOFS); | |
5f39d397 | 515 | btrfs_set_node_blockptr(parent, parent_slot, |
db94535d | 516 | cow->start); |
74493f7a CM |
517 | btrfs_set_node_ptr_generation(parent, parent_slot, |
518 | trans->transid); | |
d6025579 | 519 | btrfs_mark_buffer_dirty(parent); |
5de865ee | 520 | if (last_ref) { |
f3a84ccd | 521 | ret = btrfs_tree_mod_log_free_eb(buf); |
5de865ee | 522 | if (ret) { |
572c83ac JB |
523 | btrfs_tree_unlock(cow); |
524 | free_extent_buffer(cow); | |
66642832 | 525 | btrfs_abort_transaction(trans, ret); |
5de865ee FDBM |
526 | return ret; |
527 | } | |
528 | } | |
f0486c68 | 529 | btrfs_free_tree_block(trans, root, buf, parent_start, |
5581a51a | 530 | last_ref); |
02217ed2 | 531 | } |
925baedd CM |
532 | if (unlock_orig) |
533 | btrfs_tree_unlock(buf); | |
3083ee2e | 534 | free_extent_buffer_stale(buf); |
ccd467d6 | 535 | btrfs_mark_buffer_dirty(cow); |
2c90e5d6 | 536 | *cow_ret = cow; |
02217ed2 CM |
537 | return 0; |
538 | } | |
539 | ||
5d4f98a2 YZ |
540 | static inline int should_cow_block(struct btrfs_trans_handle *trans, |
541 | struct btrfs_root *root, | |
542 | struct extent_buffer *buf) | |
543 | { | |
f5ee5c9a | 544 | if (btrfs_is_testing(root->fs_info)) |
faa2dbf0 | 545 | return 0; |
fccb84c9 | 546 | |
d1980131 DS |
547 | /* Ensure we can see the FORCE_COW bit */ |
548 | smp_mb__before_atomic(); | |
f1ebcc74 LB |
549 | |
550 | /* | |
551 | * We do not need to cow a block if | |
552 | * 1) this block is not created or changed in this transaction; | |
553 | * 2) this block does not belong to TREE_RELOC tree; | |
554 | * 3) the root is not forced COW. | |
555 | * | |
556 | * What is forced COW: | |
01327610 | 557 | * when we create snapshot during committing the transaction, |
52042d8e | 558 | * after we've finished copying src root, we must COW the shared |
f1ebcc74 LB |
559 | * block to ensure the metadata consistency. |
560 | */ | |
5d4f98a2 YZ |
561 | if (btrfs_header_generation(buf) == trans->transid && |
562 | !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) && | |
563 | !(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID && | |
f1ebcc74 | 564 | btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)) && |
27cdeb70 | 565 | !test_bit(BTRFS_ROOT_FORCE_COW, &root->state)) |
5d4f98a2 YZ |
566 | return 0; |
567 | return 1; | |
568 | } | |
569 | ||
d352ac68 CM |
570 | /* |
571 | * cows a single block, see __btrfs_cow_block for the real work. | |
01327610 | 572 | * This version of it has extra checks so that a block isn't COWed more than |
d352ac68 CM |
573 | * once per transaction, as long as it hasn't been written yet |
574 | */ | |
d397712b | 575 | noinline int btrfs_cow_block(struct btrfs_trans_handle *trans, |
5f39d397 CM |
576 | struct btrfs_root *root, struct extent_buffer *buf, |
577 | struct extent_buffer *parent, int parent_slot, | |
9631e4cc JB |
578 | struct extent_buffer **cow_ret, |
579 | enum btrfs_lock_nesting nest) | |
6702ed49 | 580 | { |
0b246afa | 581 | struct btrfs_fs_info *fs_info = root->fs_info; |
6702ed49 | 582 | u64 search_start; |
f510cfec | 583 | int ret; |
dc17ff8f | 584 | |
83354f07 JB |
585 | if (test_bit(BTRFS_ROOT_DELETING, &root->state)) |
586 | btrfs_err(fs_info, | |
587 | "COW'ing blocks on a fs root that's being dropped"); | |
588 | ||
0b246afa | 589 | if (trans->transaction != fs_info->running_transaction) |
31b1a2bd | 590 | WARN(1, KERN_CRIT "trans %llu running %llu\n", |
c1c9ff7c | 591 | trans->transid, |
0b246afa | 592 | fs_info->running_transaction->transid); |
31b1a2bd | 593 | |
0b246afa | 594 | if (trans->transid != fs_info->generation) |
31b1a2bd | 595 | WARN(1, KERN_CRIT "trans %llu running %llu\n", |
0b246afa | 596 | trans->transid, fs_info->generation); |
dc17ff8f | 597 | |
5d4f98a2 | 598 | if (!should_cow_block(trans, root, buf)) { |
6702ed49 CM |
599 | *cow_ret = buf; |
600 | return 0; | |
601 | } | |
c487685d | 602 | |
ee22184b | 603 | search_start = buf->start & ~((u64)SZ_1G - 1); |
b4ce94de | 604 | |
f616f5cd QW |
605 | /* |
606 | * Before CoWing this block for later modification, check if it's | |
607 | * the subtree root and do the delayed subtree trace if needed. | |
608 | * | |
609 | * Also We don't care about the error, as it's handled internally. | |
610 | */ | |
611 | btrfs_qgroup_trace_subtree_after_cow(trans, root, buf); | |
f510cfec | 612 | ret = __btrfs_cow_block(trans, root, buf, parent, |
9631e4cc | 613 | parent_slot, cow_ret, search_start, 0, nest); |
1abe9b8a | 614 | |
615 | trace_btrfs_cow_block(root, buf, *cow_ret); | |
616 | ||
f510cfec | 617 | return ret; |
6702ed49 | 618 | } |
f75e2b79 | 619 | ALLOW_ERROR_INJECTION(btrfs_cow_block, ERRNO); |
6702ed49 | 620 | |
d352ac68 CM |
621 | /* |
622 | * helper function for defrag to decide if two blocks pointed to by a | |
623 | * node are actually close by | |
624 | */ | |
6b80053d | 625 | static int close_blocks(u64 blocknr, u64 other, u32 blocksize) |
6702ed49 | 626 | { |
6b80053d | 627 | if (blocknr < other && other - (blocknr + blocksize) < 32768) |
6702ed49 | 628 | return 1; |
6b80053d | 629 | if (blocknr > other && blocknr - (other + blocksize) < 32768) |
6702ed49 CM |
630 | return 1; |
631 | return 0; | |
632 | } | |
633 | ||
ce6ef5ab DS |
634 | #ifdef __LITTLE_ENDIAN |
635 | ||
636 | /* | |
637 | * Compare two keys, on little-endian the disk order is same as CPU order and | |
638 | * we can avoid the conversion. | |
639 | */ | |
640 | static int comp_keys(const struct btrfs_disk_key *disk_key, | |
641 | const struct btrfs_key *k2) | |
642 | { | |
643 | const struct btrfs_key *k1 = (const struct btrfs_key *)disk_key; | |
644 | ||
645 | return btrfs_comp_cpu_keys(k1, k2); | |
646 | } | |
647 | ||
648 | #else | |
649 | ||
081e9573 CM |
650 | /* |
651 | * compare two keys in a memcmp fashion | |
652 | */ | |
310712b2 OS |
653 | static int comp_keys(const struct btrfs_disk_key *disk, |
654 | const struct btrfs_key *k2) | |
081e9573 CM |
655 | { |
656 | struct btrfs_key k1; | |
657 | ||
658 | btrfs_disk_key_to_cpu(&k1, disk); | |
659 | ||
20736aba | 660 | return btrfs_comp_cpu_keys(&k1, k2); |
081e9573 | 661 | } |
ce6ef5ab | 662 | #endif |
081e9573 | 663 | |
f3465ca4 JB |
664 | /* |
665 | * same as comp_keys only with two btrfs_key's | |
666 | */ | |
e1f60a65 | 667 | int __pure btrfs_comp_cpu_keys(const struct btrfs_key *k1, const struct btrfs_key *k2) |
f3465ca4 JB |
668 | { |
669 | if (k1->objectid > k2->objectid) | |
670 | return 1; | |
671 | if (k1->objectid < k2->objectid) | |
672 | return -1; | |
673 | if (k1->type > k2->type) | |
674 | return 1; | |
675 | if (k1->type < k2->type) | |
676 | return -1; | |
677 | if (k1->offset > k2->offset) | |
678 | return 1; | |
679 | if (k1->offset < k2->offset) | |
680 | return -1; | |
681 | return 0; | |
682 | } | |
081e9573 | 683 | |
d352ac68 CM |
684 | /* |
685 | * this is used by the defrag code to go through all the | |
686 | * leaves pointed to by a node and reallocate them so that | |
687 | * disk order is close to key order | |
688 | */ | |
6702ed49 | 689 | int btrfs_realloc_node(struct btrfs_trans_handle *trans, |
5f39d397 | 690 | struct btrfs_root *root, struct extent_buffer *parent, |
de78b51a | 691 | int start_slot, u64 *last_ret, |
a6b6e75e | 692 | struct btrfs_key *progress) |
6702ed49 | 693 | { |
0b246afa | 694 | struct btrfs_fs_info *fs_info = root->fs_info; |
6b80053d | 695 | struct extent_buffer *cur; |
6702ed49 | 696 | u64 blocknr; |
e9d0b13b CM |
697 | u64 search_start = *last_ret; |
698 | u64 last_block = 0; | |
6702ed49 CM |
699 | u64 other; |
700 | u32 parent_nritems; | |
6702ed49 CM |
701 | int end_slot; |
702 | int i; | |
703 | int err = 0; | |
6b80053d | 704 | u32 blocksize; |
081e9573 CM |
705 | int progress_passed = 0; |
706 | struct btrfs_disk_key disk_key; | |
6702ed49 | 707 | |
0b246afa JM |
708 | WARN_ON(trans->transaction != fs_info->running_transaction); |
709 | WARN_ON(trans->transid != fs_info->generation); | |
86479a04 | 710 | |
6b80053d | 711 | parent_nritems = btrfs_header_nritems(parent); |
0b246afa | 712 | blocksize = fs_info->nodesize; |
5dfe2be7 | 713 | end_slot = parent_nritems - 1; |
6702ed49 | 714 | |
5dfe2be7 | 715 | if (parent_nritems <= 1) |
6702ed49 CM |
716 | return 0; |
717 | ||
5dfe2be7 | 718 | for (i = start_slot; i <= end_slot; i++) { |
6702ed49 | 719 | int close = 1; |
a6b6e75e | 720 | |
081e9573 CM |
721 | btrfs_node_key(parent, &disk_key, i); |
722 | if (!progress_passed && comp_keys(&disk_key, progress) < 0) | |
723 | continue; | |
724 | ||
725 | progress_passed = 1; | |
6b80053d | 726 | blocknr = btrfs_node_blockptr(parent, i); |
e9d0b13b CM |
727 | if (last_block == 0) |
728 | last_block = blocknr; | |
5708b959 | 729 | |
6702ed49 | 730 | if (i > 0) { |
6b80053d CM |
731 | other = btrfs_node_blockptr(parent, i - 1); |
732 | close = close_blocks(blocknr, other, blocksize); | |
6702ed49 | 733 | } |
5dfe2be7 | 734 | if (!close && i < end_slot) { |
6b80053d CM |
735 | other = btrfs_node_blockptr(parent, i + 1); |
736 | close = close_blocks(blocknr, other, blocksize); | |
6702ed49 | 737 | } |
e9d0b13b CM |
738 | if (close) { |
739 | last_block = blocknr; | |
6702ed49 | 740 | continue; |
e9d0b13b | 741 | } |
6702ed49 | 742 | |
206983b7 JB |
743 | cur = btrfs_read_node_slot(parent, i); |
744 | if (IS_ERR(cur)) | |
745 | return PTR_ERR(cur); | |
e9d0b13b | 746 | if (search_start == 0) |
6b80053d | 747 | search_start = last_block; |
e9d0b13b | 748 | |
e7a84565 | 749 | btrfs_tree_lock(cur); |
6b80053d | 750 | err = __btrfs_cow_block(trans, root, cur, parent, i, |
e7a84565 | 751 | &cur, search_start, |
6b80053d | 752 | min(16 * blocksize, |
9631e4cc JB |
753 | (end_slot - i) * blocksize), |
754 | BTRFS_NESTING_COW); | |
252c38f0 | 755 | if (err) { |
e7a84565 | 756 | btrfs_tree_unlock(cur); |
6b80053d | 757 | free_extent_buffer(cur); |
6702ed49 | 758 | break; |
252c38f0 | 759 | } |
e7a84565 CM |
760 | search_start = cur->start; |
761 | last_block = cur->start; | |
f2183bde | 762 | *last_ret = search_start; |
e7a84565 CM |
763 | btrfs_tree_unlock(cur); |
764 | free_extent_buffer(cur); | |
6702ed49 CM |
765 | } |
766 | return err; | |
767 | } | |
768 | ||
74123bd7 | 769 | /* |
5f39d397 CM |
770 | * search for key in the extent_buffer. The items start at offset p, |
771 | * and they are item_size apart. There are 'max' items in p. | |
772 | * | |
74123bd7 CM |
773 | * the slot in the array is returned via slot, and it points to |
774 | * the place where you would insert key if it is not found in | |
775 | * the array. | |
776 | * | |
777 | * slot may point to max if the key is bigger than all of the keys | |
778 | */ | |
e02119d5 | 779 | static noinline int generic_bin_search(struct extent_buffer *eb, |
310712b2 OS |
780 | unsigned long p, int item_size, |
781 | const struct btrfs_key *key, | |
e02119d5 | 782 | int max, int *slot) |
be0e5c09 CM |
783 | { |
784 | int low = 0; | |
785 | int high = max; | |
be0e5c09 | 786 | int ret; |
5cd17f34 | 787 | const int key_size = sizeof(struct btrfs_disk_key); |
be0e5c09 | 788 | |
5e24e9af LB |
789 | if (low > high) { |
790 | btrfs_err(eb->fs_info, | |
791 | "%s: low (%d) > high (%d) eb %llu owner %llu level %d", | |
792 | __func__, low, high, eb->start, | |
793 | btrfs_header_owner(eb), btrfs_header_level(eb)); | |
794 | return -EINVAL; | |
795 | } | |
796 | ||
d397712b | 797 | while (low < high) { |
5cd17f34 DS |
798 | unsigned long oip; |
799 | unsigned long offset; | |
800 | struct btrfs_disk_key *tmp; | |
801 | struct btrfs_disk_key unaligned; | |
802 | int mid; | |
803 | ||
be0e5c09 | 804 | mid = (low + high) / 2; |
5f39d397 | 805 | offset = p + mid * item_size; |
5cd17f34 | 806 | oip = offset_in_page(offset); |
5f39d397 | 807 | |
5cd17f34 | 808 | if (oip + key_size <= PAGE_SIZE) { |
884b07d0 | 809 | const unsigned long idx = get_eb_page_index(offset); |
5cd17f34 | 810 | char *kaddr = page_address(eb->pages[idx]); |
5f39d397 | 811 | |
884b07d0 | 812 | oip = get_eb_offset_in_page(eb, offset); |
5cd17f34 | 813 | tmp = (struct btrfs_disk_key *)(kaddr + oip); |
5f39d397 | 814 | } else { |
5cd17f34 DS |
815 | read_extent_buffer(eb, &unaligned, offset, key_size); |
816 | tmp = &unaligned; | |
5f39d397 | 817 | } |
5cd17f34 | 818 | |
be0e5c09 CM |
819 | ret = comp_keys(tmp, key); |
820 | ||
821 | if (ret < 0) | |
822 | low = mid + 1; | |
823 | else if (ret > 0) | |
824 | high = mid; | |
825 | else { | |
826 | *slot = mid; | |
827 | return 0; | |
828 | } | |
829 | } | |
830 | *slot = low; | |
831 | return 1; | |
832 | } | |
833 | ||
97571fd0 CM |
834 | /* |
835 | * simple bin_search frontend that does the right thing for | |
836 | * leaves vs nodes | |
837 | */ | |
a74b35ec | 838 | int btrfs_bin_search(struct extent_buffer *eb, const struct btrfs_key *key, |
e3b83361 | 839 | int *slot) |
be0e5c09 | 840 | { |
e3b83361 | 841 | if (btrfs_header_level(eb) == 0) |
5f39d397 CM |
842 | return generic_bin_search(eb, |
843 | offsetof(struct btrfs_leaf, items), | |
0783fcfc | 844 | sizeof(struct btrfs_item), |
5f39d397 | 845 | key, btrfs_header_nritems(eb), |
7518a238 | 846 | slot); |
f775738f | 847 | else |
5f39d397 CM |
848 | return generic_bin_search(eb, |
849 | offsetof(struct btrfs_node, ptrs), | |
123abc88 | 850 | sizeof(struct btrfs_key_ptr), |
5f39d397 | 851 | key, btrfs_header_nritems(eb), |
7518a238 | 852 | slot); |
be0e5c09 CM |
853 | } |
854 | ||
f0486c68 YZ |
855 | static void root_add_used(struct btrfs_root *root, u32 size) |
856 | { | |
857 | spin_lock(&root->accounting_lock); | |
858 | btrfs_set_root_used(&root->root_item, | |
859 | btrfs_root_used(&root->root_item) + size); | |
860 | spin_unlock(&root->accounting_lock); | |
861 | } | |
862 | ||
863 | static void root_sub_used(struct btrfs_root *root, u32 size) | |
864 | { | |
865 | spin_lock(&root->accounting_lock); | |
866 | btrfs_set_root_used(&root->root_item, | |
867 | btrfs_root_used(&root->root_item) - size); | |
868 | spin_unlock(&root->accounting_lock); | |
869 | } | |
870 | ||
d352ac68 CM |
871 | /* given a node and slot number, this reads the blocks it points to. The |
872 | * extent buffer is returned with a reference taken (but unlocked). | |
d352ac68 | 873 | */ |
4b231ae4 DS |
874 | struct extent_buffer *btrfs_read_node_slot(struct extent_buffer *parent, |
875 | int slot) | |
bb803951 | 876 | { |
ca7a79ad | 877 | int level = btrfs_header_level(parent); |
416bc658 | 878 | struct extent_buffer *eb; |
581c1760 | 879 | struct btrfs_key first_key; |
416bc658 | 880 | |
fb770ae4 LB |
881 | if (slot < 0 || slot >= btrfs_header_nritems(parent)) |
882 | return ERR_PTR(-ENOENT); | |
ca7a79ad CM |
883 | |
884 | BUG_ON(level == 0); | |
885 | ||
581c1760 | 886 | btrfs_node_key_to_cpu(parent, &first_key, slot); |
d0d20b0f | 887 | eb = read_tree_block(parent->fs_info, btrfs_node_blockptr(parent, slot), |
1b7ec85e | 888 | btrfs_header_owner(parent), |
581c1760 QW |
889 | btrfs_node_ptr_generation(parent, slot), |
890 | level - 1, &first_key); | |
fb770ae4 LB |
891 | if (!IS_ERR(eb) && !extent_buffer_uptodate(eb)) { |
892 | free_extent_buffer(eb); | |
893 | eb = ERR_PTR(-EIO); | |
416bc658 JB |
894 | } |
895 | ||
896 | return eb; | |
bb803951 CM |
897 | } |
898 | ||
d352ac68 CM |
899 | /* |
900 | * node level balancing, used to make sure nodes are in proper order for | |
901 | * item deletion. We balance from the top down, so we have to make sure | |
902 | * that a deletion won't leave an node completely empty later on. | |
903 | */ | |
e02119d5 | 904 | static noinline int balance_level(struct btrfs_trans_handle *trans, |
98ed5174 CM |
905 | struct btrfs_root *root, |
906 | struct btrfs_path *path, int level) | |
bb803951 | 907 | { |
0b246afa | 908 | struct btrfs_fs_info *fs_info = root->fs_info; |
5f39d397 CM |
909 | struct extent_buffer *right = NULL; |
910 | struct extent_buffer *mid; | |
911 | struct extent_buffer *left = NULL; | |
912 | struct extent_buffer *parent = NULL; | |
bb803951 CM |
913 | int ret = 0; |
914 | int wret; | |
915 | int pslot; | |
bb803951 | 916 | int orig_slot = path->slots[level]; |
79f95c82 | 917 | u64 orig_ptr; |
bb803951 | 918 | |
98e6b1eb | 919 | ASSERT(level > 0); |
bb803951 | 920 | |
5f39d397 | 921 | mid = path->nodes[level]; |
b4ce94de | 922 | |
ac5887c8 | 923 | WARN_ON(path->locks[level] != BTRFS_WRITE_LOCK); |
7bb86316 CM |
924 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
925 | ||
1d4f8a0c | 926 | orig_ptr = btrfs_node_blockptr(mid, orig_slot); |
79f95c82 | 927 | |
a05a9bb1 | 928 | if (level < BTRFS_MAX_LEVEL - 1) { |
5f39d397 | 929 | parent = path->nodes[level + 1]; |
a05a9bb1 LZ |
930 | pslot = path->slots[level + 1]; |
931 | } | |
bb803951 | 932 | |
40689478 CM |
933 | /* |
934 | * deal with the case where there is only one pointer in the root | |
935 | * by promoting the node below to a root | |
936 | */ | |
5f39d397 CM |
937 | if (!parent) { |
938 | struct extent_buffer *child; | |
bb803951 | 939 | |
5f39d397 | 940 | if (btrfs_header_nritems(mid) != 1) |
bb803951 CM |
941 | return 0; |
942 | ||
943 | /* promote the child to a root */ | |
4b231ae4 | 944 | child = btrfs_read_node_slot(mid, 0); |
fb770ae4 LB |
945 | if (IS_ERR(child)) { |
946 | ret = PTR_ERR(child); | |
0b246afa | 947 | btrfs_handle_fs_error(fs_info, ret, NULL); |
305a26af MF |
948 | goto enospc; |
949 | } | |
950 | ||
925baedd | 951 | btrfs_tree_lock(child); |
9631e4cc JB |
952 | ret = btrfs_cow_block(trans, root, child, mid, 0, &child, |
953 | BTRFS_NESTING_COW); | |
f0486c68 YZ |
954 | if (ret) { |
955 | btrfs_tree_unlock(child); | |
956 | free_extent_buffer(child); | |
957 | goto enospc; | |
958 | } | |
2f375ab9 | 959 | |
406808ab | 960 | ret = btrfs_tree_mod_log_insert_root(root->node, child, true); |
d9d19a01 | 961 | BUG_ON(ret < 0); |
240f62c8 | 962 | rcu_assign_pointer(root->node, child); |
925baedd | 963 | |
0b86a832 | 964 | add_root_to_dirty_list(root); |
925baedd | 965 | btrfs_tree_unlock(child); |
b4ce94de | 966 | |
925baedd | 967 | path->locks[level] = 0; |
bb803951 | 968 | path->nodes[level] = NULL; |
6a884d7d | 969 | btrfs_clean_tree_block(mid); |
925baedd | 970 | btrfs_tree_unlock(mid); |
bb803951 | 971 | /* once for the path */ |
5f39d397 | 972 | free_extent_buffer(mid); |
f0486c68 YZ |
973 | |
974 | root_sub_used(root, mid->len); | |
5581a51a | 975 | btrfs_free_tree_block(trans, root, mid, 0, 1); |
bb803951 | 976 | /* once for the root ptr */ |
3083ee2e | 977 | free_extent_buffer_stale(mid); |
f0486c68 | 978 | return 0; |
bb803951 | 979 | } |
5f39d397 | 980 | if (btrfs_header_nritems(mid) > |
0b246afa | 981 | BTRFS_NODEPTRS_PER_BLOCK(fs_info) / 4) |
bb803951 CM |
982 | return 0; |
983 | ||
4b231ae4 | 984 | left = btrfs_read_node_slot(parent, pslot - 1); |
fb770ae4 LB |
985 | if (IS_ERR(left)) |
986 | left = NULL; | |
987 | ||
5f39d397 | 988 | if (left) { |
bf77467a | 989 | __btrfs_tree_lock(left, BTRFS_NESTING_LEFT); |
5f39d397 | 990 | wret = btrfs_cow_block(trans, root, left, |
9631e4cc | 991 | parent, pslot - 1, &left, |
bf59a5a2 | 992 | BTRFS_NESTING_LEFT_COW); |
54aa1f4d CM |
993 | if (wret) { |
994 | ret = wret; | |
995 | goto enospc; | |
996 | } | |
2cc58cf2 | 997 | } |
fb770ae4 | 998 | |
4b231ae4 | 999 | right = btrfs_read_node_slot(parent, pslot + 1); |
fb770ae4 LB |
1000 | if (IS_ERR(right)) |
1001 | right = NULL; | |
1002 | ||
5f39d397 | 1003 | if (right) { |
bf77467a | 1004 | __btrfs_tree_lock(right, BTRFS_NESTING_RIGHT); |
5f39d397 | 1005 | wret = btrfs_cow_block(trans, root, right, |
9631e4cc | 1006 | parent, pslot + 1, &right, |
bf59a5a2 | 1007 | BTRFS_NESTING_RIGHT_COW); |
2cc58cf2 CM |
1008 | if (wret) { |
1009 | ret = wret; | |
1010 | goto enospc; | |
1011 | } | |
1012 | } | |
1013 | ||
1014 | /* first, try to make some room in the middle buffer */ | |
5f39d397 CM |
1015 | if (left) { |
1016 | orig_slot += btrfs_header_nritems(left); | |
d30a668f | 1017 | wret = push_node_left(trans, left, mid, 1); |
79f95c82 CM |
1018 | if (wret < 0) |
1019 | ret = wret; | |
bb803951 | 1020 | } |
79f95c82 CM |
1021 | |
1022 | /* | |
1023 | * then try to empty the right most buffer into the middle | |
1024 | */ | |
5f39d397 | 1025 | if (right) { |
d30a668f | 1026 | wret = push_node_left(trans, mid, right, 1); |
54aa1f4d | 1027 | if (wret < 0 && wret != -ENOSPC) |
79f95c82 | 1028 | ret = wret; |
5f39d397 | 1029 | if (btrfs_header_nritems(right) == 0) { |
6a884d7d | 1030 | btrfs_clean_tree_block(right); |
925baedd | 1031 | btrfs_tree_unlock(right); |
afe5fea7 | 1032 | del_ptr(root, path, level + 1, pslot + 1); |
f0486c68 | 1033 | root_sub_used(root, right->len); |
5581a51a | 1034 | btrfs_free_tree_block(trans, root, right, 0, 1); |
3083ee2e | 1035 | free_extent_buffer_stale(right); |
f0486c68 | 1036 | right = NULL; |
bb803951 | 1037 | } else { |
5f39d397 CM |
1038 | struct btrfs_disk_key right_key; |
1039 | btrfs_node_key(right, &right_key, 0); | |
f3a84ccd FM |
1040 | ret = btrfs_tree_mod_log_insert_key(parent, pslot + 1, |
1041 | BTRFS_MOD_LOG_KEY_REPLACE, GFP_NOFS); | |
0e82bcfe | 1042 | BUG_ON(ret < 0); |
5f39d397 CM |
1043 | btrfs_set_node_key(parent, &right_key, pslot + 1); |
1044 | btrfs_mark_buffer_dirty(parent); | |
bb803951 CM |
1045 | } |
1046 | } | |
5f39d397 | 1047 | if (btrfs_header_nritems(mid) == 1) { |
79f95c82 CM |
1048 | /* |
1049 | * we're not allowed to leave a node with one item in the | |
1050 | * tree during a delete. A deletion from lower in the tree | |
1051 | * could try to delete the only pointer in this node. | |
1052 | * So, pull some keys from the left. | |
1053 | * There has to be a left pointer at this point because | |
1054 | * otherwise we would have pulled some pointers from the | |
1055 | * right | |
1056 | */ | |
305a26af MF |
1057 | if (!left) { |
1058 | ret = -EROFS; | |
0b246afa | 1059 | btrfs_handle_fs_error(fs_info, ret, NULL); |
305a26af MF |
1060 | goto enospc; |
1061 | } | |
55d32ed8 | 1062 | wret = balance_node_right(trans, mid, left); |
54aa1f4d | 1063 | if (wret < 0) { |
79f95c82 | 1064 | ret = wret; |
54aa1f4d CM |
1065 | goto enospc; |
1066 | } | |
bce4eae9 | 1067 | if (wret == 1) { |
d30a668f | 1068 | wret = push_node_left(trans, left, mid, 1); |
bce4eae9 CM |
1069 | if (wret < 0) |
1070 | ret = wret; | |
1071 | } | |
79f95c82 CM |
1072 | BUG_ON(wret == 1); |
1073 | } | |
5f39d397 | 1074 | if (btrfs_header_nritems(mid) == 0) { |
6a884d7d | 1075 | btrfs_clean_tree_block(mid); |
925baedd | 1076 | btrfs_tree_unlock(mid); |
afe5fea7 | 1077 | del_ptr(root, path, level + 1, pslot); |
f0486c68 | 1078 | root_sub_used(root, mid->len); |
5581a51a | 1079 | btrfs_free_tree_block(trans, root, mid, 0, 1); |
3083ee2e | 1080 | free_extent_buffer_stale(mid); |
f0486c68 | 1081 | mid = NULL; |
79f95c82 CM |
1082 | } else { |
1083 | /* update the parent key to reflect our changes */ | |
5f39d397 CM |
1084 | struct btrfs_disk_key mid_key; |
1085 | btrfs_node_key(mid, &mid_key, 0); | |
f3a84ccd FM |
1086 | ret = btrfs_tree_mod_log_insert_key(parent, pslot, |
1087 | BTRFS_MOD_LOG_KEY_REPLACE, GFP_NOFS); | |
0e82bcfe | 1088 | BUG_ON(ret < 0); |
5f39d397 CM |
1089 | btrfs_set_node_key(parent, &mid_key, pslot); |
1090 | btrfs_mark_buffer_dirty(parent); | |
79f95c82 | 1091 | } |
bb803951 | 1092 | |
79f95c82 | 1093 | /* update the path */ |
5f39d397 CM |
1094 | if (left) { |
1095 | if (btrfs_header_nritems(left) > orig_slot) { | |
67439dad | 1096 | atomic_inc(&left->refs); |
925baedd | 1097 | /* left was locked after cow */ |
5f39d397 | 1098 | path->nodes[level] = left; |
bb803951 CM |
1099 | path->slots[level + 1] -= 1; |
1100 | path->slots[level] = orig_slot; | |
925baedd CM |
1101 | if (mid) { |
1102 | btrfs_tree_unlock(mid); | |
5f39d397 | 1103 | free_extent_buffer(mid); |
925baedd | 1104 | } |
bb803951 | 1105 | } else { |
5f39d397 | 1106 | orig_slot -= btrfs_header_nritems(left); |
bb803951 CM |
1107 | path->slots[level] = orig_slot; |
1108 | } | |
1109 | } | |
79f95c82 | 1110 | /* double check we haven't messed things up */ |
e20d96d6 | 1111 | if (orig_ptr != |
5f39d397 | 1112 | btrfs_node_blockptr(path->nodes[level], path->slots[level])) |
79f95c82 | 1113 | BUG(); |
54aa1f4d | 1114 | enospc: |
925baedd CM |
1115 | if (right) { |
1116 | btrfs_tree_unlock(right); | |
5f39d397 | 1117 | free_extent_buffer(right); |
925baedd CM |
1118 | } |
1119 | if (left) { | |
1120 | if (path->nodes[level] != left) | |
1121 | btrfs_tree_unlock(left); | |
5f39d397 | 1122 | free_extent_buffer(left); |
925baedd | 1123 | } |
bb803951 CM |
1124 | return ret; |
1125 | } | |
1126 | ||
d352ac68 CM |
1127 | /* Node balancing for insertion. Here we only split or push nodes around |
1128 | * when they are completely full. This is also done top down, so we | |
1129 | * have to be pessimistic. | |
1130 | */ | |
d397712b | 1131 | static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, |
98ed5174 CM |
1132 | struct btrfs_root *root, |
1133 | struct btrfs_path *path, int level) | |
e66f709b | 1134 | { |
0b246afa | 1135 | struct btrfs_fs_info *fs_info = root->fs_info; |
5f39d397 CM |
1136 | struct extent_buffer *right = NULL; |
1137 | struct extent_buffer *mid; | |
1138 | struct extent_buffer *left = NULL; | |
1139 | struct extent_buffer *parent = NULL; | |
e66f709b CM |
1140 | int ret = 0; |
1141 | int wret; | |
1142 | int pslot; | |
1143 | int orig_slot = path->slots[level]; | |
e66f709b CM |
1144 | |
1145 | if (level == 0) | |
1146 | return 1; | |
1147 | ||
5f39d397 | 1148 | mid = path->nodes[level]; |
7bb86316 | 1149 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
e66f709b | 1150 | |
a05a9bb1 | 1151 | if (level < BTRFS_MAX_LEVEL - 1) { |
5f39d397 | 1152 | parent = path->nodes[level + 1]; |
a05a9bb1 LZ |
1153 | pslot = path->slots[level + 1]; |
1154 | } | |
e66f709b | 1155 | |
5f39d397 | 1156 | if (!parent) |
e66f709b | 1157 | return 1; |
e66f709b | 1158 | |
4b231ae4 | 1159 | left = btrfs_read_node_slot(parent, pslot - 1); |
fb770ae4 LB |
1160 | if (IS_ERR(left)) |
1161 | left = NULL; | |
e66f709b CM |
1162 | |
1163 | /* first, try to make some room in the middle buffer */ | |
5f39d397 | 1164 | if (left) { |
e66f709b | 1165 | u32 left_nr; |
925baedd | 1166 | |
bf77467a | 1167 | __btrfs_tree_lock(left, BTRFS_NESTING_LEFT); |
b4ce94de | 1168 | |
5f39d397 | 1169 | left_nr = btrfs_header_nritems(left); |
0b246afa | 1170 | if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 1) { |
33ade1f8 CM |
1171 | wret = 1; |
1172 | } else { | |
5f39d397 | 1173 | ret = btrfs_cow_block(trans, root, left, parent, |
9631e4cc | 1174 | pslot - 1, &left, |
bf59a5a2 | 1175 | BTRFS_NESTING_LEFT_COW); |
54aa1f4d CM |
1176 | if (ret) |
1177 | wret = 1; | |
1178 | else { | |
d30a668f | 1179 | wret = push_node_left(trans, left, mid, 0); |
54aa1f4d | 1180 | } |
33ade1f8 | 1181 | } |
e66f709b CM |
1182 | if (wret < 0) |
1183 | ret = wret; | |
1184 | if (wret == 0) { | |
5f39d397 | 1185 | struct btrfs_disk_key disk_key; |
e66f709b | 1186 | orig_slot += left_nr; |
5f39d397 | 1187 | btrfs_node_key(mid, &disk_key, 0); |
f3a84ccd FM |
1188 | ret = btrfs_tree_mod_log_insert_key(parent, pslot, |
1189 | BTRFS_MOD_LOG_KEY_REPLACE, GFP_NOFS); | |
0e82bcfe | 1190 | BUG_ON(ret < 0); |
5f39d397 CM |
1191 | btrfs_set_node_key(parent, &disk_key, pslot); |
1192 | btrfs_mark_buffer_dirty(parent); | |
1193 | if (btrfs_header_nritems(left) > orig_slot) { | |
1194 | path->nodes[level] = left; | |
e66f709b CM |
1195 | path->slots[level + 1] -= 1; |
1196 | path->slots[level] = orig_slot; | |
925baedd | 1197 | btrfs_tree_unlock(mid); |
5f39d397 | 1198 | free_extent_buffer(mid); |
e66f709b CM |
1199 | } else { |
1200 | orig_slot -= | |
5f39d397 | 1201 | btrfs_header_nritems(left); |
e66f709b | 1202 | path->slots[level] = orig_slot; |
925baedd | 1203 | btrfs_tree_unlock(left); |
5f39d397 | 1204 | free_extent_buffer(left); |
e66f709b | 1205 | } |
e66f709b CM |
1206 | return 0; |
1207 | } | |
925baedd | 1208 | btrfs_tree_unlock(left); |
5f39d397 | 1209 | free_extent_buffer(left); |
e66f709b | 1210 | } |
4b231ae4 | 1211 | right = btrfs_read_node_slot(parent, pslot + 1); |
fb770ae4 LB |
1212 | if (IS_ERR(right)) |
1213 | right = NULL; | |
e66f709b CM |
1214 | |
1215 | /* | |
1216 | * then try to empty the right most buffer into the middle | |
1217 | */ | |
5f39d397 | 1218 | if (right) { |
33ade1f8 | 1219 | u32 right_nr; |
b4ce94de | 1220 | |
bf77467a | 1221 | __btrfs_tree_lock(right, BTRFS_NESTING_RIGHT); |
b4ce94de | 1222 | |
5f39d397 | 1223 | right_nr = btrfs_header_nritems(right); |
0b246afa | 1224 | if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 1) { |
33ade1f8 CM |
1225 | wret = 1; |
1226 | } else { | |
5f39d397 CM |
1227 | ret = btrfs_cow_block(trans, root, right, |
1228 | parent, pslot + 1, | |
bf59a5a2 | 1229 | &right, BTRFS_NESTING_RIGHT_COW); |
54aa1f4d CM |
1230 | if (ret) |
1231 | wret = 1; | |
1232 | else { | |
55d32ed8 | 1233 | wret = balance_node_right(trans, right, mid); |
54aa1f4d | 1234 | } |
33ade1f8 | 1235 | } |
e66f709b CM |
1236 | if (wret < 0) |
1237 | ret = wret; | |
1238 | if (wret == 0) { | |
5f39d397 CM |
1239 | struct btrfs_disk_key disk_key; |
1240 | ||
1241 | btrfs_node_key(right, &disk_key, 0); | |
f3a84ccd FM |
1242 | ret = btrfs_tree_mod_log_insert_key(parent, pslot + 1, |
1243 | BTRFS_MOD_LOG_KEY_REPLACE, GFP_NOFS); | |
0e82bcfe | 1244 | BUG_ON(ret < 0); |
5f39d397 CM |
1245 | btrfs_set_node_key(parent, &disk_key, pslot + 1); |
1246 | btrfs_mark_buffer_dirty(parent); | |
1247 | ||
1248 | if (btrfs_header_nritems(mid) <= orig_slot) { | |
1249 | path->nodes[level] = right; | |
e66f709b CM |
1250 | path->slots[level + 1] += 1; |
1251 | path->slots[level] = orig_slot - | |
5f39d397 | 1252 | btrfs_header_nritems(mid); |
925baedd | 1253 | btrfs_tree_unlock(mid); |
5f39d397 | 1254 | free_extent_buffer(mid); |
e66f709b | 1255 | } else { |
925baedd | 1256 | btrfs_tree_unlock(right); |
5f39d397 | 1257 | free_extent_buffer(right); |
e66f709b | 1258 | } |
e66f709b CM |
1259 | return 0; |
1260 | } | |
925baedd | 1261 | btrfs_tree_unlock(right); |
5f39d397 | 1262 | free_extent_buffer(right); |
e66f709b | 1263 | } |
e66f709b CM |
1264 | return 1; |
1265 | } | |
1266 | ||
3c69faec | 1267 | /* |
d352ac68 CM |
1268 | * readahead one full node of leaves, finding things that are close |
1269 | * to the block in 'slot', and triggering ra on them. | |
3c69faec | 1270 | */ |
2ff7e61e | 1271 | static void reada_for_search(struct btrfs_fs_info *fs_info, |
c8c42864 CM |
1272 | struct btrfs_path *path, |
1273 | int level, int slot, u64 objectid) | |
3c69faec | 1274 | { |
5f39d397 | 1275 | struct extent_buffer *node; |
01f46658 | 1276 | struct btrfs_disk_key disk_key; |
3c69faec | 1277 | u32 nritems; |
3c69faec | 1278 | u64 search; |
a7175319 | 1279 | u64 target; |
6b80053d | 1280 | u64 nread = 0; |
ace75066 | 1281 | u64 nread_max; |
5f39d397 | 1282 | struct extent_buffer *eb; |
6b80053d CM |
1283 | u32 nr; |
1284 | u32 blocksize; | |
1285 | u32 nscan = 0; | |
db94535d | 1286 | |
ace75066 | 1287 | if (level != 1 && path->reada != READA_FORWARD_ALWAYS) |
6702ed49 CM |
1288 | return; |
1289 | ||
1290 | if (!path->nodes[level]) | |
3c69faec CM |
1291 | return; |
1292 | ||
5f39d397 | 1293 | node = path->nodes[level]; |
925baedd | 1294 | |
ace75066 FM |
1295 | /* |
1296 | * Since the time between visiting leaves is much shorter than the time | |
1297 | * between visiting nodes, limit read ahead of nodes to 1, to avoid too | |
1298 | * much IO at once (possibly random). | |
1299 | */ | |
1300 | if (path->reada == READA_FORWARD_ALWAYS) { | |
1301 | if (level > 1) | |
1302 | nread_max = node->fs_info->nodesize; | |
1303 | else | |
1304 | nread_max = SZ_128K; | |
1305 | } else { | |
1306 | nread_max = SZ_64K; | |
1307 | } | |
1308 | ||
3c69faec | 1309 | search = btrfs_node_blockptr(node, slot); |
0b246afa JM |
1310 | blocksize = fs_info->nodesize; |
1311 | eb = find_extent_buffer(fs_info, search); | |
5f39d397 CM |
1312 | if (eb) { |
1313 | free_extent_buffer(eb); | |
3c69faec CM |
1314 | return; |
1315 | } | |
1316 | ||
a7175319 | 1317 | target = search; |
6b80053d | 1318 | |
5f39d397 | 1319 | nritems = btrfs_header_nritems(node); |
6b80053d | 1320 | nr = slot; |
25b8b936 | 1321 | |
d397712b | 1322 | while (1) { |
e4058b54 | 1323 | if (path->reada == READA_BACK) { |
6b80053d CM |
1324 | if (nr == 0) |
1325 | break; | |
1326 | nr--; | |
ace75066 FM |
1327 | } else if (path->reada == READA_FORWARD || |
1328 | path->reada == READA_FORWARD_ALWAYS) { | |
6b80053d CM |
1329 | nr++; |
1330 | if (nr >= nritems) | |
1331 | break; | |
3c69faec | 1332 | } |
e4058b54 | 1333 | if (path->reada == READA_BACK && objectid) { |
01f46658 CM |
1334 | btrfs_node_key(node, &disk_key, nr); |
1335 | if (btrfs_disk_key_objectid(&disk_key) != objectid) | |
1336 | break; | |
1337 | } | |
6b80053d | 1338 | search = btrfs_node_blockptr(node, nr); |
ace75066 FM |
1339 | if (path->reada == READA_FORWARD_ALWAYS || |
1340 | (search <= target && target - search <= 65536) || | |
a7175319 | 1341 | (search > target && search - target <= 65536)) { |
bfb484d9 | 1342 | btrfs_readahead_node_child(node, nr); |
6b80053d CM |
1343 | nread += blocksize; |
1344 | } | |
1345 | nscan++; | |
ace75066 | 1346 | if (nread > nread_max || nscan > 32) |
6b80053d | 1347 | break; |
3c69faec CM |
1348 | } |
1349 | } | |
925baedd | 1350 | |
bfb484d9 | 1351 | static noinline void reada_for_balance(struct btrfs_path *path, int level) |
b4ce94de | 1352 | { |
bfb484d9 | 1353 | struct extent_buffer *parent; |
b4ce94de CM |
1354 | int slot; |
1355 | int nritems; | |
b4ce94de | 1356 | |
8c594ea8 | 1357 | parent = path->nodes[level + 1]; |
b4ce94de | 1358 | if (!parent) |
0b08851f | 1359 | return; |
b4ce94de CM |
1360 | |
1361 | nritems = btrfs_header_nritems(parent); | |
8c594ea8 | 1362 | slot = path->slots[level + 1]; |
b4ce94de | 1363 | |
bfb484d9 JB |
1364 | if (slot > 0) |
1365 | btrfs_readahead_node_child(parent, slot - 1); | |
1366 | if (slot + 1 < nritems) | |
1367 | btrfs_readahead_node_child(parent, slot + 1); | |
b4ce94de CM |
1368 | } |
1369 | ||
1370 | ||
d352ac68 | 1371 | /* |
d397712b CM |
1372 | * when we walk down the tree, it is usually safe to unlock the higher layers |
1373 | * in the tree. The exceptions are when our path goes through slot 0, because | |
1374 | * operations on the tree might require changing key pointers higher up in the | |
1375 | * tree. | |
d352ac68 | 1376 | * |
d397712b CM |
1377 | * callers might also have set path->keep_locks, which tells this code to keep |
1378 | * the lock if the path points to the last slot in the block. This is part of | |
1379 | * walking through the tree, and selecting the next slot in the higher block. | |
d352ac68 | 1380 | * |
d397712b CM |
1381 | * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so |
1382 | * if lowest_unlock is 1, level 0 won't be unlocked | |
d352ac68 | 1383 | */ |
e02119d5 | 1384 | static noinline void unlock_up(struct btrfs_path *path, int level, |
f7c79f30 CM |
1385 | int lowest_unlock, int min_write_lock_level, |
1386 | int *write_lock_level) | |
925baedd CM |
1387 | { |
1388 | int i; | |
1389 | int skip_level = level; | |
051e1b9f | 1390 | int no_skips = 0; |
925baedd CM |
1391 | struct extent_buffer *t; |
1392 | ||
1393 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { | |
1394 | if (!path->nodes[i]) | |
1395 | break; | |
1396 | if (!path->locks[i]) | |
1397 | break; | |
051e1b9f | 1398 | if (!no_skips && path->slots[i] == 0) { |
925baedd CM |
1399 | skip_level = i + 1; |
1400 | continue; | |
1401 | } | |
051e1b9f | 1402 | if (!no_skips && path->keep_locks) { |
925baedd CM |
1403 | u32 nritems; |
1404 | t = path->nodes[i]; | |
1405 | nritems = btrfs_header_nritems(t); | |
051e1b9f | 1406 | if (nritems < 1 || path->slots[i] >= nritems - 1) { |
925baedd CM |
1407 | skip_level = i + 1; |
1408 | continue; | |
1409 | } | |
1410 | } | |
051e1b9f CM |
1411 | if (skip_level < i && i >= lowest_unlock) |
1412 | no_skips = 1; | |
1413 | ||
925baedd | 1414 | t = path->nodes[i]; |
d80bb3f9 | 1415 | if (i >= lowest_unlock && i > skip_level) { |
bd681513 | 1416 | btrfs_tree_unlock_rw(t, path->locks[i]); |
925baedd | 1417 | path->locks[i] = 0; |
f7c79f30 CM |
1418 | if (write_lock_level && |
1419 | i > min_write_lock_level && | |
1420 | i <= *write_lock_level) { | |
1421 | *write_lock_level = i - 1; | |
1422 | } | |
925baedd CM |
1423 | } |
1424 | } | |
1425 | } | |
1426 | ||
c8c42864 CM |
1427 | /* |
1428 | * helper function for btrfs_search_slot. The goal is to find a block | |
1429 | * in cache without setting the path to blocking. If we find the block | |
1430 | * we return zero and the path is unchanged. | |
1431 | * | |
1432 | * If we can't find the block, we set the path blocking and do some | |
1433 | * reada. -EAGAIN is returned and the search must be repeated. | |
1434 | */ | |
1435 | static int | |
d07b8528 LB |
1436 | read_block_for_search(struct btrfs_root *root, struct btrfs_path *p, |
1437 | struct extent_buffer **eb_ret, int level, int slot, | |
cda79c54 | 1438 | const struct btrfs_key *key) |
c8c42864 | 1439 | { |
0b246afa | 1440 | struct btrfs_fs_info *fs_info = root->fs_info; |
c8c42864 CM |
1441 | u64 blocknr; |
1442 | u64 gen; | |
c8c42864 | 1443 | struct extent_buffer *tmp; |
581c1760 | 1444 | struct btrfs_key first_key; |
76a05b35 | 1445 | int ret; |
581c1760 | 1446 | int parent_level; |
c8c42864 | 1447 | |
213ff4b7 NB |
1448 | blocknr = btrfs_node_blockptr(*eb_ret, slot); |
1449 | gen = btrfs_node_ptr_generation(*eb_ret, slot); | |
1450 | parent_level = btrfs_header_level(*eb_ret); | |
1451 | btrfs_node_key_to_cpu(*eb_ret, &first_key, slot); | |
c8c42864 | 1452 | |
0b246afa | 1453 | tmp = find_extent_buffer(fs_info, blocknr); |
cb44921a | 1454 | if (tmp) { |
ace75066 FM |
1455 | if (p->reada == READA_FORWARD_ALWAYS) |
1456 | reada_for_search(fs_info, p, level, slot, key->objectid); | |
1457 | ||
b9fab919 | 1458 | /* first we do an atomic uptodate check */ |
bdf7c00e | 1459 | if (btrfs_buffer_uptodate(tmp, gen, 1) > 0) { |
448de471 QW |
1460 | /* |
1461 | * Do extra check for first_key, eb can be stale due to | |
1462 | * being cached, read from scrub, or have multiple | |
1463 | * parents (shared tree blocks). | |
1464 | */ | |
e064d5e9 | 1465 | if (btrfs_verify_level_key(tmp, |
448de471 QW |
1466 | parent_level - 1, &first_key, gen)) { |
1467 | free_extent_buffer(tmp); | |
1468 | return -EUCLEAN; | |
1469 | } | |
bdf7c00e JB |
1470 | *eb_ret = tmp; |
1471 | return 0; | |
1472 | } | |
1473 | ||
bdf7c00e | 1474 | /* now we're allowed to do a blocking uptodate check */ |
581c1760 | 1475 | ret = btrfs_read_buffer(tmp, gen, parent_level - 1, &first_key); |
bdf7c00e JB |
1476 | if (!ret) { |
1477 | *eb_ret = tmp; | |
1478 | return 0; | |
cb44921a | 1479 | } |
bdf7c00e JB |
1480 | free_extent_buffer(tmp); |
1481 | btrfs_release_path(p); | |
1482 | return -EIO; | |
c8c42864 CM |
1483 | } |
1484 | ||
1485 | /* | |
1486 | * reduce lock contention at high levels | |
1487 | * of the btree by dropping locks before | |
76a05b35 CM |
1488 | * we read. Don't release the lock on the current |
1489 | * level because we need to walk this node to figure | |
1490 | * out which blocks to read. | |
c8c42864 | 1491 | */ |
8c594ea8 | 1492 | btrfs_unlock_up_safe(p, level + 1); |
8c594ea8 | 1493 | |
e4058b54 | 1494 | if (p->reada != READA_NONE) |
2ff7e61e | 1495 | reada_for_search(fs_info, p, level, slot, key->objectid); |
c8c42864 | 1496 | |
76a05b35 | 1497 | ret = -EAGAIN; |
1b7ec85e JB |
1498 | tmp = read_tree_block(fs_info, blocknr, root->root_key.objectid, |
1499 | gen, parent_level - 1, &first_key); | |
64c043de | 1500 | if (!IS_ERR(tmp)) { |
76a05b35 CM |
1501 | /* |
1502 | * If the read above didn't mark this buffer up to date, | |
1503 | * it will never end up being up to date. Set ret to EIO now | |
1504 | * and give up so that our caller doesn't loop forever | |
1505 | * on our EAGAINs. | |
1506 | */ | |
e6a1d6fd | 1507 | if (!extent_buffer_uptodate(tmp)) |
76a05b35 | 1508 | ret = -EIO; |
c8c42864 | 1509 | free_extent_buffer(tmp); |
c871b0f2 LB |
1510 | } else { |
1511 | ret = PTR_ERR(tmp); | |
76a05b35 | 1512 | } |
02a3307a LB |
1513 | |
1514 | btrfs_release_path(p); | |
76a05b35 | 1515 | return ret; |
c8c42864 CM |
1516 | } |
1517 | ||
1518 | /* | |
1519 | * helper function for btrfs_search_slot. This does all of the checks | |
1520 | * for node-level blocks and does any balancing required based on | |
1521 | * the ins_len. | |
1522 | * | |
1523 | * If no extra work was required, zero is returned. If we had to | |
1524 | * drop the path, -EAGAIN is returned and btrfs_search_slot must | |
1525 | * start over | |
1526 | */ | |
1527 | static int | |
1528 | setup_nodes_for_search(struct btrfs_trans_handle *trans, | |
1529 | struct btrfs_root *root, struct btrfs_path *p, | |
bd681513 CM |
1530 | struct extent_buffer *b, int level, int ins_len, |
1531 | int *write_lock_level) | |
c8c42864 | 1532 | { |
0b246afa | 1533 | struct btrfs_fs_info *fs_info = root->fs_info; |
95b982de | 1534 | int ret = 0; |
0b246afa | 1535 | |
c8c42864 | 1536 | if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >= |
0b246afa | 1537 | BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 3) { |
c8c42864 | 1538 | |
bd681513 CM |
1539 | if (*write_lock_level < level + 1) { |
1540 | *write_lock_level = level + 1; | |
1541 | btrfs_release_path(p); | |
95b982de | 1542 | return -EAGAIN; |
bd681513 CM |
1543 | } |
1544 | ||
bfb484d9 | 1545 | reada_for_balance(p, level); |
95b982de | 1546 | ret = split_node(trans, root, p, level); |
c8c42864 | 1547 | |
c8c42864 CM |
1548 | b = p->nodes[level]; |
1549 | } else if (ins_len < 0 && btrfs_header_nritems(b) < | |
0b246afa | 1550 | BTRFS_NODEPTRS_PER_BLOCK(fs_info) / 2) { |
c8c42864 | 1551 | |
bd681513 CM |
1552 | if (*write_lock_level < level + 1) { |
1553 | *write_lock_level = level + 1; | |
1554 | btrfs_release_path(p); | |
95b982de | 1555 | return -EAGAIN; |
bd681513 CM |
1556 | } |
1557 | ||
bfb484d9 | 1558 | reada_for_balance(p, level); |
95b982de NB |
1559 | ret = balance_level(trans, root, p, level); |
1560 | if (ret) | |
1561 | return ret; | |
c8c42864 | 1562 | |
c8c42864 CM |
1563 | b = p->nodes[level]; |
1564 | if (!b) { | |
b3b4aa74 | 1565 | btrfs_release_path(p); |
95b982de | 1566 | return -EAGAIN; |
c8c42864 CM |
1567 | } |
1568 | BUG_ON(btrfs_header_nritems(b) == 1); | |
1569 | } | |
c8c42864 CM |
1570 | return ret; |
1571 | } | |
1572 | ||
381cf658 | 1573 | int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *path, |
e33d5c3d KN |
1574 | u64 iobjectid, u64 ioff, u8 key_type, |
1575 | struct btrfs_key *found_key) | |
1576 | { | |
1577 | int ret; | |
1578 | struct btrfs_key key; | |
1579 | struct extent_buffer *eb; | |
381cf658 DS |
1580 | |
1581 | ASSERT(path); | |
1d4c08e0 | 1582 | ASSERT(found_key); |
e33d5c3d KN |
1583 | |
1584 | key.type = key_type; | |
1585 | key.objectid = iobjectid; | |
1586 | key.offset = ioff; | |
1587 | ||
1588 | ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0); | |
1d4c08e0 | 1589 | if (ret < 0) |
e33d5c3d KN |
1590 | return ret; |
1591 | ||
1592 | eb = path->nodes[0]; | |
1593 | if (ret && path->slots[0] >= btrfs_header_nritems(eb)) { | |
1594 | ret = btrfs_next_leaf(fs_root, path); | |
1595 | if (ret) | |
1596 | return ret; | |
1597 | eb = path->nodes[0]; | |
1598 | } | |
1599 | ||
1600 | btrfs_item_key_to_cpu(eb, found_key, path->slots[0]); | |
1601 | if (found_key->type != key.type || | |
1602 | found_key->objectid != key.objectid) | |
1603 | return 1; | |
1604 | ||
1605 | return 0; | |
1606 | } | |
1607 | ||
1fc28d8e LB |
1608 | static struct extent_buffer *btrfs_search_slot_get_root(struct btrfs_root *root, |
1609 | struct btrfs_path *p, | |
1610 | int write_lock_level) | |
1611 | { | |
1612 | struct btrfs_fs_info *fs_info = root->fs_info; | |
1613 | struct extent_buffer *b; | |
1614 | int root_lock; | |
1615 | int level = 0; | |
1616 | ||
1617 | /* We try very hard to do read locks on the root */ | |
1618 | root_lock = BTRFS_READ_LOCK; | |
1619 | ||
1620 | if (p->search_commit_root) { | |
be6821f8 FM |
1621 | /* |
1622 | * The commit roots are read only so we always do read locks, | |
1623 | * and we always must hold the commit_root_sem when doing | |
1624 | * searches on them, the only exception is send where we don't | |
1625 | * want to block transaction commits for a long time, so | |
1626 | * we need to clone the commit root in order to avoid races | |
1627 | * with transaction commits that create a snapshot of one of | |
1628 | * the roots used by a send operation. | |
1629 | */ | |
1630 | if (p->need_commit_sem) { | |
1fc28d8e | 1631 | down_read(&fs_info->commit_root_sem); |
be6821f8 | 1632 | b = btrfs_clone_extent_buffer(root->commit_root); |
1fc28d8e | 1633 | up_read(&fs_info->commit_root_sem); |
be6821f8 FM |
1634 | if (!b) |
1635 | return ERR_PTR(-ENOMEM); | |
1636 | ||
1637 | } else { | |
1638 | b = root->commit_root; | |
67439dad | 1639 | atomic_inc(&b->refs); |
be6821f8 FM |
1640 | } |
1641 | level = btrfs_header_level(b); | |
f9ddfd05 LB |
1642 | /* |
1643 | * Ensure that all callers have set skip_locking when | |
1644 | * p->search_commit_root = 1. | |
1645 | */ | |
1646 | ASSERT(p->skip_locking == 1); | |
1fc28d8e LB |
1647 | |
1648 | goto out; | |
1649 | } | |
1650 | ||
1651 | if (p->skip_locking) { | |
1652 | b = btrfs_root_node(root); | |
1653 | level = btrfs_header_level(b); | |
1654 | goto out; | |
1655 | } | |
1656 | ||
1657 | /* | |
662c653b LB |
1658 | * If the level is set to maximum, we can skip trying to get the read |
1659 | * lock. | |
1fc28d8e | 1660 | */ |
662c653b LB |
1661 | if (write_lock_level < BTRFS_MAX_LEVEL) { |
1662 | /* | |
1663 | * We don't know the level of the root node until we actually | |
1664 | * have it read locked | |
1665 | */ | |
1bb96598 | 1666 | b = btrfs_read_lock_root_node(root); |
662c653b LB |
1667 | level = btrfs_header_level(b); |
1668 | if (level > write_lock_level) | |
1669 | goto out; | |
1670 | ||
1671 | /* Whoops, must trade for write lock */ | |
1672 | btrfs_tree_read_unlock(b); | |
1673 | free_extent_buffer(b); | |
1674 | } | |
1fc28d8e | 1675 | |
1fc28d8e LB |
1676 | b = btrfs_lock_root_node(root); |
1677 | root_lock = BTRFS_WRITE_LOCK; | |
1678 | ||
1679 | /* The level might have changed, check again */ | |
1680 | level = btrfs_header_level(b); | |
1681 | ||
1682 | out: | |
1683 | p->nodes[level] = b; | |
1684 | if (!p->skip_locking) | |
1685 | p->locks[level] = root_lock; | |
1686 | /* | |
1687 | * Callers are responsible for dropping b's references. | |
1688 | */ | |
1689 | return b; | |
1690 | } | |
1691 | ||
1692 | ||
74123bd7 | 1693 | /* |
4271ecea NB |
1694 | * btrfs_search_slot - look for a key in a tree and perform necessary |
1695 | * modifications to preserve tree invariants. | |
74123bd7 | 1696 | * |
4271ecea NB |
1697 | * @trans: Handle of transaction, used when modifying the tree |
1698 | * @p: Holds all btree nodes along the search path | |
1699 | * @root: The root node of the tree | |
1700 | * @key: The key we are looking for | |
9a664971 | 1701 | * @ins_len: Indicates purpose of search: |
1702 | * >0 for inserts it's size of item inserted (*) | |
1703 | * <0 for deletions | |
1704 | * 0 for plain searches, not modifying the tree | |
1705 | * | |
1706 | * (*) If size of item inserted doesn't include | |
1707 | * sizeof(struct btrfs_item), then p->search_for_extension must | |
1708 | * be set. | |
4271ecea NB |
1709 | * @cow: boolean should CoW operations be performed. Must always be 1 |
1710 | * when modifying the tree. | |
97571fd0 | 1711 | * |
4271ecea NB |
1712 | * If @ins_len > 0, nodes and leaves will be split as we walk down the tree. |
1713 | * If @ins_len < 0, nodes will be merged as we walk down the tree (if possible) | |
1714 | * | |
1715 | * If @key is found, 0 is returned and you can find the item in the leaf level | |
1716 | * of the path (level 0) | |
1717 | * | |
1718 | * If @key isn't found, 1 is returned and the leaf level of the path (level 0) | |
1719 | * points to the slot where it should be inserted | |
1720 | * | |
1721 | * If an error is encountered while searching the tree a negative error number | |
1722 | * is returned | |
74123bd7 | 1723 | */ |
310712b2 OS |
1724 | int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
1725 | const struct btrfs_key *key, struct btrfs_path *p, | |
1726 | int ins_len, int cow) | |
be0e5c09 | 1727 | { |
5f39d397 | 1728 | struct extent_buffer *b; |
be0e5c09 CM |
1729 | int slot; |
1730 | int ret; | |
33c66f43 | 1731 | int err; |
be0e5c09 | 1732 | int level; |
925baedd | 1733 | int lowest_unlock = 1; |
bd681513 CM |
1734 | /* everything at write_lock_level or lower must be write locked */ |
1735 | int write_lock_level = 0; | |
9f3a7427 | 1736 | u8 lowest_level = 0; |
f7c79f30 | 1737 | int min_write_lock_level; |
d7396f07 | 1738 | int prev_cmp; |
9f3a7427 | 1739 | |
6702ed49 | 1740 | lowest_level = p->lowest_level; |
323ac95b | 1741 | WARN_ON(lowest_level && ins_len > 0); |
22b0ebda | 1742 | WARN_ON(p->nodes[0] != NULL); |
eb653de1 | 1743 | BUG_ON(!cow && ins_len); |
25179201 | 1744 | |
bd681513 | 1745 | if (ins_len < 0) { |
925baedd | 1746 | lowest_unlock = 2; |
65b51a00 | 1747 | |
bd681513 CM |
1748 | /* when we are removing items, we might have to go up to level |
1749 | * two as we update tree pointers Make sure we keep write | |
1750 | * for those levels as well | |
1751 | */ | |
1752 | write_lock_level = 2; | |
1753 | } else if (ins_len > 0) { | |
1754 | /* | |
1755 | * for inserting items, make sure we have a write lock on | |
1756 | * level 1 so we can update keys | |
1757 | */ | |
1758 | write_lock_level = 1; | |
1759 | } | |
1760 | ||
1761 | if (!cow) | |
1762 | write_lock_level = -1; | |
1763 | ||
09a2a8f9 | 1764 | if (cow && (p->keep_locks || p->lowest_level)) |
bd681513 CM |
1765 | write_lock_level = BTRFS_MAX_LEVEL; |
1766 | ||
f7c79f30 CM |
1767 | min_write_lock_level = write_lock_level; |
1768 | ||
bb803951 | 1769 | again: |
d7396f07 | 1770 | prev_cmp = -1; |
1fc28d8e | 1771 | b = btrfs_search_slot_get_root(root, p, write_lock_level); |
be6821f8 FM |
1772 | if (IS_ERR(b)) { |
1773 | ret = PTR_ERR(b); | |
1774 | goto done; | |
1775 | } | |
925baedd | 1776 | |
eb60ceac | 1777 | while (b) { |
f624d976 QW |
1778 | int dec = 0; |
1779 | ||
5f39d397 | 1780 | level = btrfs_header_level(b); |
65b51a00 | 1781 | |
02217ed2 | 1782 | if (cow) { |
9ea2c7c9 NB |
1783 | bool last_level = (level == (BTRFS_MAX_LEVEL - 1)); |
1784 | ||
c8c42864 CM |
1785 | /* |
1786 | * if we don't really need to cow this block | |
1787 | * then we don't want to set the path blocking, | |
1788 | * so we test it here | |
1789 | */ | |
5963ffca | 1790 | if (!should_cow_block(trans, root, b)) |
65b51a00 | 1791 | goto cow_done; |
5d4f98a2 | 1792 | |
bd681513 CM |
1793 | /* |
1794 | * must have write locks on this node and the | |
1795 | * parent | |
1796 | */ | |
5124e00e JB |
1797 | if (level > write_lock_level || |
1798 | (level + 1 > write_lock_level && | |
1799 | level + 1 < BTRFS_MAX_LEVEL && | |
1800 | p->nodes[level + 1])) { | |
bd681513 CM |
1801 | write_lock_level = level + 1; |
1802 | btrfs_release_path(p); | |
1803 | goto again; | |
1804 | } | |
1805 | ||
9ea2c7c9 NB |
1806 | if (last_level) |
1807 | err = btrfs_cow_block(trans, root, b, NULL, 0, | |
9631e4cc JB |
1808 | &b, |
1809 | BTRFS_NESTING_COW); | |
9ea2c7c9 NB |
1810 | else |
1811 | err = btrfs_cow_block(trans, root, b, | |
1812 | p->nodes[level + 1], | |
9631e4cc JB |
1813 | p->slots[level + 1], &b, |
1814 | BTRFS_NESTING_COW); | |
33c66f43 | 1815 | if (err) { |
33c66f43 | 1816 | ret = err; |
65b51a00 | 1817 | goto done; |
54aa1f4d | 1818 | } |
02217ed2 | 1819 | } |
65b51a00 | 1820 | cow_done: |
eb60ceac | 1821 | p->nodes[level] = b; |
52398340 LB |
1822 | /* |
1823 | * Leave path with blocking locks to avoid massive | |
1824 | * lock context switch, this is made on purpose. | |
1825 | */ | |
b4ce94de CM |
1826 | |
1827 | /* | |
1828 | * we have a lock on b and as long as we aren't changing | |
1829 | * the tree, there is no way to for the items in b to change. | |
1830 | * It is safe to drop the lock on our parent before we | |
1831 | * go through the expensive btree search on b. | |
1832 | * | |
eb653de1 FDBM |
1833 | * If we're inserting or deleting (ins_len != 0), then we might |
1834 | * be changing slot zero, which may require changing the parent. | |
1835 | * So, we can't drop the lock until after we know which slot | |
1836 | * we're operating on. | |
b4ce94de | 1837 | */ |
eb653de1 FDBM |
1838 | if (!ins_len && !p->keep_locks) { |
1839 | int u = level + 1; | |
1840 | ||
1841 | if (u < BTRFS_MAX_LEVEL && p->locks[u]) { | |
1842 | btrfs_tree_unlock_rw(p->nodes[u], p->locks[u]); | |
1843 | p->locks[u] = 0; | |
1844 | } | |
1845 | } | |
b4ce94de | 1846 | |
995e9a16 NB |
1847 | /* |
1848 | * If btrfs_bin_search returns an exact match (prev_cmp == 0) | |
1849 | * we can safely assume the target key will always be in slot 0 | |
1850 | * on lower levels due to the invariants BTRFS' btree provides, | |
1851 | * namely that a btrfs_key_ptr entry always points to the | |
1852 | * lowest key in the child node, thus we can skip searching | |
1853 | * lower levels | |
1854 | */ | |
1855 | if (prev_cmp == 0) { | |
1856 | slot = 0; | |
1857 | ret = 0; | |
1858 | } else { | |
1859 | ret = btrfs_bin_search(b, key, &slot); | |
1860 | prev_cmp = ret; | |
1861 | if (ret < 0) | |
1862 | goto done; | |
1863 | } | |
b4ce94de | 1864 | |
f624d976 | 1865 | if (level == 0) { |
be0e5c09 | 1866 | p->slots[level] = slot; |
9a664971 | 1867 | /* |
1868 | * Item key already exists. In this case, if we are | |
1869 | * allowed to insert the item (for example, in dir_item | |
1870 | * case, item key collision is allowed), it will be | |
1871 | * merged with the original item. Only the item size | |
1872 | * grows, no new btrfs item will be added. If | |
1873 | * search_for_extension is not set, ins_len already | |
1874 | * accounts the size btrfs_item, deduct it here so leaf | |
1875 | * space check will be correct. | |
1876 | */ | |
1877 | if (ret == 0 && ins_len > 0 && !p->search_for_extension) { | |
1878 | ASSERT(ins_len >= sizeof(struct btrfs_item)); | |
1879 | ins_len -= sizeof(struct btrfs_item); | |
1880 | } | |
87b29b20 | 1881 | if (ins_len > 0 && |
e902baac | 1882 | btrfs_leaf_free_space(b) < ins_len) { |
bd681513 CM |
1883 | if (write_lock_level < 1) { |
1884 | write_lock_level = 1; | |
1885 | btrfs_release_path(p); | |
1886 | goto again; | |
1887 | } | |
1888 | ||
33c66f43 YZ |
1889 | err = split_leaf(trans, root, key, |
1890 | p, ins_len, ret == 0); | |
b4ce94de | 1891 | |
33c66f43 YZ |
1892 | BUG_ON(err > 0); |
1893 | if (err) { | |
1894 | ret = err; | |
65b51a00 CM |
1895 | goto done; |
1896 | } | |
5c680ed6 | 1897 | } |
459931ec | 1898 | if (!p->search_for_split) |
f7c79f30 | 1899 | unlock_up(p, level, lowest_unlock, |
4b6f8e96 | 1900 | min_write_lock_level, NULL); |
65b51a00 | 1901 | goto done; |
be0e5c09 | 1902 | } |
f624d976 QW |
1903 | if (ret && slot > 0) { |
1904 | dec = 1; | |
1905 | slot--; | |
1906 | } | |
1907 | p->slots[level] = slot; | |
1908 | err = setup_nodes_for_search(trans, root, p, b, level, ins_len, | |
1909 | &write_lock_level); | |
1910 | if (err == -EAGAIN) | |
1911 | goto again; | |
1912 | if (err) { | |
1913 | ret = err; | |
1914 | goto done; | |
1915 | } | |
1916 | b = p->nodes[level]; | |
1917 | slot = p->slots[level]; | |
1918 | ||
1919 | /* | |
1920 | * Slot 0 is special, if we change the key we have to update | |
1921 | * the parent pointer which means we must have a write lock on | |
1922 | * the parent | |
1923 | */ | |
1924 | if (slot == 0 && ins_len && write_lock_level < level + 1) { | |
1925 | write_lock_level = level + 1; | |
1926 | btrfs_release_path(p); | |
1927 | goto again; | |
1928 | } | |
1929 | ||
1930 | unlock_up(p, level, lowest_unlock, min_write_lock_level, | |
1931 | &write_lock_level); | |
1932 | ||
1933 | if (level == lowest_level) { | |
1934 | if (dec) | |
1935 | p->slots[level]++; | |
1936 | goto done; | |
1937 | } | |
1938 | ||
1939 | err = read_block_for_search(root, p, &b, level, slot, key); | |
1940 | if (err == -EAGAIN) | |
1941 | goto again; | |
1942 | if (err) { | |
1943 | ret = err; | |
1944 | goto done; | |
1945 | } | |
1946 | ||
1947 | if (!p->skip_locking) { | |
1948 | level = btrfs_header_level(b); | |
1949 | if (level <= write_lock_level) { | |
ac5887c8 | 1950 | btrfs_tree_lock(b); |
f624d976 QW |
1951 | p->locks[level] = BTRFS_WRITE_LOCK; |
1952 | } else { | |
fe596ca3 | 1953 | btrfs_tree_read_lock(b); |
f624d976 QW |
1954 | p->locks[level] = BTRFS_READ_LOCK; |
1955 | } | |
1956 | p->nodes[level] = b; | |
1957 | } | |
be0e5c09 | 1958 | } |
65b51a00 CM |
1959 | ret = 1; |
1960 | done: | |
5f5bc6b1 | 1961 | if (ret < 0 && !p->skip_release_on_error) |
b3b4aa74 | 1962 | btrfs_release_path(p); |
65b51a00 | 1963 | return ret; |
be0e5c09 | 1964 | } |
f75e2b79 | 1965 | ALLOW_ERROR_INJECTION(btrfs_search_slot, ERRNO); |
be0e5c09 | 1966 | |
5d9e75c4 JS |
1967 | /* |
1968 | * Like btrfs_search_slot, this looks for a key in the given tree. It uses the | |
1969 | * current state of the tree together with the operations recorded in the tree | |
1970 | * modification log to search for the key in a previous version of this tree, as | |
1971 | * denoted by the time_seq parameter. | |
1972 | * | |
1973 | * Naturally, there is no support for insert, delete or cow operations. | |
1974 | * | |
1975 | * The resulting path and return value will be set up as if we called | |
1976 | * btrfs_search_slot at that point in time with ins_len and cow both set to 0. | |
1977 | */ | |
310712b2 | 1978 | int btrfs_search_old_slot(struct btrfs_root *root, const struct btrfs_key *key, |
5d9e75c4 JS |
1979 | struct btrfs_path *p, u64 time_seq) |
1980 | { | |
0b246afa | 1981 | struct btrfs_fs_info *fs_info = root->fs_info; |
5d9e75c4 JS |
1982 | struct extent_buffer *b; |
1983 | int slot; | |
1984 | int ret; | |
1985 | int err; | |
1986 | int level; | |
1987 | int lowest_unlock = 1; | |
1988 | u8 lowest_level = 0; | |
1989 | ||
1990 | lowest_level = p->lowest_level; | |
1991 | WARN_ON(p->nodes[0] != NULL); | |
1992 | ||
1993 | if (p->search_commit_root) { | |
1994 | BUG_ON(time_seq); | |
1995 | return btrfs_search_slot(NULL, root, key, p, 0, 0); | |
1996 | } | |
1997 | ||
1998 | again: | |
f3a84ccd | 1999 | b = btrfs_get_old_root(root, time_seq); |
315bed43 NB |
2000 | if (!b) { |
2001 | ret = -EIO; | |
2002 | goto done; | |
2003 | } | |
5d9e75c4 | 2004 | level = btrfs_header_level(b); |
5d9e75c4 JS |
2005 | p->locks[level] = BTRFS_READ_LOCK; |
2006 | ||
2007 | while (b) { | |
abe9339d QW |
2008 | int dec = 0; |
2009 | ||
5d9e75c4 JS |
2010 | level = btrfs_header_level(b); |
2011 | p->nodes[level] = b; | |
5d9e75c4 JS |
2012 | |
2013 | /* | |
2014 | * we have a lock on b and as long as we aren't changing | |
2015 | * the tree, there is no way to for the items in b to change. | |
2016 | * It is safe to drop the lock on our parent before we | |
2017 | * go through the expensive btree search on b. | |
2018 | */ | |
2019 | btrfs_unlock_up_safe(p, level + 1); | |
2020 | ||
995e9a16 | 2021 | ret = btrfs_bin_search(b, key, &slot); |
cbca7d59 FM |
2022 | if (ret < 0) |
2023 | goto done; | |
5d9e75c4 | 2024 | |
abe9339d | 2025 | if (level == 0) { |
5d9e75c4 JS |
2026 | p->slots[level] = slot; |
2027 | unlock_up(p, level, lowest_unlock, 0, NULL); | |
abe9339d QW |
2028 | goto done; |
2029 | } | |
5d9e75c4 | 2030 | |
abe9339d QW |
2031 | if (ret && slot > 0) { |
2032 | dec = 1; | |
2033 | slot--; | |
2034 | } | |
2035 | p->slots[level] = slot; | |
2036 | unlock_up(p, level, lowest_unlock, 0, NULL); | |
5d9e75c4 | 2037 | |
abe9339d QW |
2038 | if (level == lowest_level) { |
2039 | if (dec) | |
2040 | p->slots[level]++; | |
2041 | goto done; | |
2042 | } | |
5d9e75c4 | 2043 | |
abe9339d QW |
2044 | err = read_block_for_search(root, p, &b, level, slot, key); |
2045 | if (err == -EAGAIN) | |
2046 | goto again; | |
2047 | if (err) { | |
2048 | ret = err; | |
5d9e75c4 JS |
2049 | goto done; |
2050 | } | |
abe9339d QW |
2051 | |
2052 | level = btrfs_header_level(b); | |
ac5887c8 | 2053 | btrfs_tree_read_lock(b); |
f3a84ccd | 2054 | b = btrfs_tree_mod_log_rewind(fs_info, p, b, time_seq); |
abe9339d QW |
2055 | if (!b) { |
2056 | ret = -ENOMEM; | |
2057 | goto done; | |
2058 | } | |
2059 | p->locks[level] = BTRFS_READ_LOCK; | |
2060 | p->nodes[level] = b; | |
5d9e75c4 JS |
2061 | } |
2062 | ret = 1; | |
2063 | done: | |
5d9e75c4 JS |
2064 | if (ret < 0) |
2065 | btrfs_release_path(p); | |
2066 | ||
2067 | return ret; | |
2068 | } | |
2069 | ||
2f38b3e1 AJ |
2070 | /* |
2071 | * helper to use instead of search slot if no exact match is needed but | |
2072 | * instead the next or previous item should be returned. | |
2073 | * When find_higher is true, the next higher item is returned, the next lower | |
2074 | * otherwise. | |
2075 | * When return_any and find_higher are both true, and no higher item is found, | |
2076 | * return the next lower instead. | |
2077 | * When return_any is true and find_higher is false, and no lower item is found, | |
2078 | * return the next higher instead. | |
2079 | * It returns 0 if any item is found, 1 if none is found (tree empty), and | |
2080 | * < 0 on error | |
2081 | */ | |
2082 | int btrfs_search_slot_for_read(struct btrfs_root *root, | |
310712b2 OS |
2083 | const struct btrfs_key *key, |
2084 | struct btrfs_path *p, int find_higher, | |
2085 | int return_any) | |
2f38b3e1 AJ |
2086 | { |
2087 | int ret; | |
2088 | struct extent_buffer *leaf; | |
2089 | ||
2090 | again: | |
2091 | ret = btrfs_search_slot(NULL, root, key, p, 0, 0); | |
2092 | if (ret <= 0) | |
2093 | return ret; | |
2094 | /* | |
2095 | * a return value of 1 means the path is at the position where the | |
2096 | * item should be inserted. Normally this is the next bigger item, | |
2097 | * but in case the previous item is the last in a leaf, path points | |
2098 | * to the first free slot in the previous leaf, i.e. at an invalid | |
2099 | * item. | |
2100 | */ | |
2101 | leaf = p->nodes[0]; | |
2102 | ||
2103 | if (find_higher) { | |
2104 | if (p->slots[0] >= btrfs_header_nritems(leaf)) { | |
2105 | ret = btrfs_next_leaf(root, p); | |
2106 | if (ret <= 0) | |
2107 | return ret; | |
2108 | if (!return_any) | |
2109 | return 1; | |
2110 | /* | |
2111 | * no higher item found, return the next | |
2112 | * lower instead | |
2113 | */ | |
2114 | return_any = 0; | |
2115 | find_higher = 0; | |
2116 | btrfs_release_path(p); | |
2117 | goto again; | |
2118 | } | |
2119 | } else { | |
e6793769 AJ |
2120 | if (p->slots[0] == 0) { |
2121 | ret = btrfs_prev_leaf(root, p); | |
2122 | if (ret < 0) | |
2123 | return ret; | |
2124 | if (!ret) { | |
23c6bf6a FDBM |
2125 | leaf = p->nodes[0]; |
2126 | if (p->slots[0] == btrfs_header_nritems(leaf)) | |
2127 | p->slots[0]--; | |
e6793769 | 2128 | return 0; |
2f38b3e1 | 2129 | } |
e6793769 AJ |
2130 | if (!return_any) |
2131 | return 1; | |
2132 | /* | |
2133 | * no lower item found, return the next | |
2134 | * higher instead | |
2135 | */ | |
2136 | return_any = 0; | |
2137 | find_higher = 1; | |
2138 | btrfs_release_path(p); | |
2139 | goto again; | |
2140 | } else { | |
2f38b3e1 AJ |
2141 | --p->slots[0]; |
2142 | } | |
2143 | } | |
2144 | return 0; | |
2145 | } | |
2146 | ||
74123bd7 CM |
2147 | /* |
2148 | * adjust the pointers going up the tree, starting at level | |
2149 | * making sure the right key of each node is points to 'key'. | |
2150 | * This is used after shifting pointers to the left, so it stops | |
2151 | * fixing up pointers when a given leaf/node is not in slot 0 of the | |
2152 | * higher levels | |
aa5d6bed | 2153 | * |
74123bd7 | 2154 | */ |
b167fa91 | 2155 | static void fixup_low_keys(struct btrfs_path *path, |
143bede5 | 2156 | struct btrfs_disk_key *key, int level) |
be0e5c09 CM |
2157 | { |
2158 | int i; | |
5f39d397 | 2159 | struct extent_buffer *t; |
0e82bcfe | 2160 | int ret; |
5f39d397 | 2161 | |
234b63a0 | 2162 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { |
be0e5c09 | 2163 | int tslot = path->slots[i]; |
0e82bcfe | 2164 | |
eb60ceac | 2165 | if (!path->nodes[i]) |
be0e5c09 | 2166 | break; |
5f39d397 | 2167 | t = path->nodes[i]; |
f3a84ccd FM |
2168 | ret = btrfs_tree_mod_log_insert_key(t, tslot, |
2169 | BTRFS_MOD_LOG_KEY_REPLACE, GFP_ATOMIC); | |
0e82bcfe | 2170 | BUG_ON(ret < 0); |
5f39d397 | 2171 | btrfs_set_node_key(t, key, tslot); |
d6025579 | 2172 | btrfs_mark_buffer_dirty(path->nodes[i]); |
be0e5c09 CM |
2173 | if (tslot != 0) |
2174 | break; | |
2175 | } | |
2176 | } | |
2177 | ||
31840ae1 ZY |
2178 | /* |
2179 | * update item key. | |
2180 | * | |
2181 | * This function isn't completely safe. It's the caller's responsibility | |
2182 | * that the new key won't break the order | |
2183 | */ | |
b7a0365e DD |
2184 | void btrfs_set_item_key_safe(struct btrfs_fs_info *fs_info, |
2185 | struct btrfs_path *path, | |
310712b2 | 2186 | const struct btrfs_key *new_key) |
31840ae1 ZY |
2187 | { |
2188 | struct btrfs_disk_key disk_key; | |
2189 | struct extent_buffer *eb; | |
2190 | int slot; | |
2191 | ||
2192 | eb = path->nodes[0]; | |
2193 | slot = path->slots[0]; | |
2194 | if (slot > 0) { | |
2195 | btrfs_item_key(eb, &disk_key, slot - 1); | |
7c15d410 QW |
2196 | if (unlikely(comp_keys(&disk_key, new_key) >= 0)) { |
2197 | btrfs_crit(fs_info, | |
2198 | "slot %u key (%llu %u %llu) new key (%llu %u %llu)", | |
2199 | slot, btrfs_disk_key_objectid(&disk_key), | |
2200 | btrfs_disk_key_type(&disk_key), | |
2201 | btrfs_disk_key_offset(&disk_key), | |
2202 | new_key->objectid, new_key->type, | |
2203 | new_key->offset); | |
2204 | btrfs_print_leaf(eb); | |
2205 | BUG(); | |
2206 | } | |
31840ae1 ZY |
2207 | } |
2208 | if (slot < btrfs_header_nritems(eb) - 1) { | |
2209 | btrfs_item_key(eb, &disk_key, slot + 1); | |
7c15d410 QW |
2210 | if (unlikely(comp_keys(&disk_key, new_key) <= 0)) { |
2211 | btrfs_crit(fs_info, | |
2212 | "slot %u key (%llu %u %llu) new key (%llu %u %llu)", | |
2213 | slot, btrfs_disk_key_objectid(&disk_key), | |
2214 | btrfs_disk_key_type(&disk_key), | |
2215 | btrfs_disk_key_offset(&disk_key), | |
2216 | new_key->objectid, new_key->type, | |
2217 | new_key->offset); | |
2218 | btrfs_print_leaf(eb); | |
2219 | BUG(); | |
2220 | } | |
31840ae1 ZY |
2221 | } |
2222 | ||
2223 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
2224 | btrfs_set_item_key(eb, &disk_key, slot); | |
2225 | btrfs_mark_buffer_dirty(eb); | |
2226 | if (slot == 0) | |
b167fa91 | 2227 | fixup_low_keys(path, &disk_key, 1); |
31840ae1 ZY |
2228 | } |
2229 | ||
d16c702f QW |
2230 | /* |
2231 | * Check key order of two sibling extent buffers. | |
2232 | * | |
2233 | * Return true if something is wrong. | |
2234 | * Return false if everything is fine. | |
2235 | * | |
2236 | * Tree-checker only works inside one tree block, thus the following | |
2237 | * corruption can not be detected by tree-checker: | |
2238 | * | |
2239 | * Leaf @left | Leaf @right | |
2240 | * -------------------------------------------------------------- | |
2241 | * | 1 | 2 | 3 | 4 | 5 | f6 | | 7 | 8 | | |
2242 | * | |
2243 | * Key f6 in leaf @left itself is valid, but not valid when the next | |
2244 | * key in leaf @right is 7. | |
2245 | * This can only be checked at tree block merge time. | |
2246 | * And since tree checker has ensured all key order in each tree block | |
2247 | * is correct, we only need to bother the last key of @left and the first | |
2248 | * key of @right. | |
2249 | */ | |
2250 | static bool check_sibling_keys(struct extent_buffer *left, | |
2251 | struct extent_buffer *right) | |
2252 | { | |
2253 | struct btrfs_key left_last; | |
2254 | struct btrfs_key right_first; | |
2255 | int level = btrfs_header_level(left); | |
2256 | int nr_left = btrfs_header_nritems(left); | |
2257 | int nr_right = btrfs_header_nritems(right); | |
2258 | ||
2259 | /* No key to check in one of the tree blocks */ | |
2260 | if (!nr_left || !nr_right) | |
2261 | return false; | |
2262 | ||
2263 | if (level) { | |
2264 | btrfs_node_key_to_cpu(left, &left_last, nr_left - 1); | |
2265 | btrfs_node_key_to_cpu(right, &right_first, 0); | |
2266 | } else { | |
2267 | btrfs_item_key_to_cpu(left, &left_last, nr_left - 1); | |
2268 | btrfs_item_key_to_cpu(right, &right_first, 0); | |
2269 | } | |
2270 | ||
2271 | if (btrfs_comp_cpu_keys(&left_last, &right_first) >= 0) { | |
2272 | btrfs_crit(left->fs_info, | |
2273 | "bad key order, sibling blocks, left last (%llu %u %llu) right first (%llu %u %llu)", | |
2274 | left_last.objectid, left_last.type, | |
2275 | left_last.offset, right_first.objectid, | |
2276 | right_first.type, right_first.offset); | |
2277 | return true; | |
2278 | } | |
2279 | return false; | |
2280 | } | |
2281 | ||
74123bd7 CM |
2282 | /* |
2283 | * try to push data from one node into the next node left in the | |
79f95c82 | 2284 | * tree. |
aa5d6bed CM |
2285 | * |
2286 | * returns 0 if some ptrs were pushed left, < 0 if there was some horrible | |
2287 | * error, and > 0 if there was no room in the left hand block. | |
74123bd7 | 2288 | */ |
98ed5174 | 2289 | static int push_node_left(struct btrfs_trans_handle *trans, |
2ff7e61e | 2290 | struct extent_buffer *dst, |
971a1f66 | 2291 | struct extent_buffer *src, int empty) |
be0e5c09 | 2292 | { |
d30a668f | 2293 | struct btrfs_fs_info *fs_info = trans->fs_info; |
be0e5c09 | 2294 | int push_items = 0; |
bb803951 CM |
2295 | int src_nritems; |
2296 | int dst_nritems; | |
aa5d6bed | 2297 | int ret = 0; |
be0e5c09 | 2298 | |
5f39d397 CM |
2299 | src_nritems = btrfs_header_nritems(src); |
2300 | dst_nritems = btrfs_header_nritems(dst); | |
0b246afa | 2301 | push_items = BTRFS_NODEPTRS_PER_BLOCK(fs_info) - dst_nritems; |
7bb86316 CM |
2302 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
2303 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
54aa1f4d | 2304 | |
bce4eae9 | 2305 | if (!empty && src_nritems <= 8) |
971a1f66 CM |
2306 | return 1; |
2307 | ||
d397712b | 2308 | if (push_items <= 0) |
be0e5c09 CM |
2309 | return 1; |
2310 | ||
bce4eae9 | 2311 | if (empty) { |
971a1f66 | 2312 | push_items = min(src_nritems, push_items); |
bce4eae9 CM |
2313 | if (push_items < src_nritems) { |
2314 | /* leave at least 8 pointers in the node if | |
2315 | * we aren't going to empty it | |
2316 | */ | |
2317 | if (src_nritems - push_items < 8) { | |
2318 | if (push_items <= 8) | |
2319 | return 1; | |
2320 | push_items -= 8; | |
2321 | } | |
2322 | } | |
2323 | } else | |
2324 | push_items = min(src_nritems - 8, push_items); | |
79f95c82 | 2325 | |
d16c702f QW |
2326 | /* dst is the left eb, src is the middle eb */ |
2327 | if (check_sibling_keys(dst, src)) { | |
2328 | ret = -EUCLEAN; | |
2329 | btrfs_abort_transaction(trans, ret); | |
2330 | return ret; | |
2331 | } | |
f3a84ccd | 2332 | ret = btrfs_tree_mod_log_eb_copy(dst, src, dst_nritems, 0, push_items); |
5de865ee | 2333 | if (ret) { |
66642832 | 2334 | btrfs_abort_transaction(trans, ret); |
5de865ee FDBM |
2335 | return ret; |
2336 | } | |
5f39d397 CM |
2337 | copy_extent_buffer(dst, src, |
2338 | btrfs_node_key_ptr_offset(dst_nritems), | |
2339 | btrfs_node_key_ptr_offset(0), | |
d397712b | 2340 | push_items * sizeof(struct btrfs_key_ptr)); |
5f39d397 | 2341 | |
bb803951 | 2342 | if (push_items < src_nritems) { |
57911b8b | 2343 | /* |
f3a84ccd FM |
2344 | * Don't call btrfs_tree_mod_log_insert_move() here, key removal |
2345 | * was already fully logged by btrfs_tree_mod_log_eb_copy() above. | |
57911b8b | 2346 | */ |
5f39d397 CM |
2347 | memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0), |
2348 | btrfs_node_key_ptr_offset(push_items), | |
2349 | (src_nritems - push_items) * | |
2350 | sizeof(struct btrfs_key_ptr)); | |
2351 | } | |
2352 | btrfs_set_header_nritems(src, src_nritems - push_items); | |
2353 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
2354 | btrfs_mark_buffer_dirty(src); | |
2355 | btrfs_mark_buffer_dirty(dst); | |
31840ae1 | 2356 | |
79f95c82 CM |
2357 | return ret; |
2358 | } | |
2359 | ||
2360 | /* | |
2361 | * try to push data from one node into the next node right in the | |
2362 | * tree. | |
2363 | * | |
2364 | * returns 0 if some ptrs were pushed, < 0 if there was some horrible | |
2365 | * error, and > 0 if there was no room in the right hand block. | |
2366 | * | |
2367 | * this will only push up to 1/2 the contents of the left node over | |
2368 | */ | |
5f39d397 | 2369 | static int balance_node_right(struct btrfs_trans_handle *trans, |
5f39d397 CM |
2370 | struct extent_buffer *dst, |
2371 | struct extent_buffer *src) | |
79f95c82 | 2372 | { |
55d32ed8 | 2373 | struct btrfs_fs_info *fs_info = trans->fs_info; |
79f95c82 CM |
2374 | int push_items = 0; |
2375 | int max_push; | |
2376 | int src_nritems; | |
2377 | int dst_nritems; | |
2378 | int ret = 0; | |
79f95c82 | 2379 | |
7bb86316 CM |
2380 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
2381 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
2382 | ||
5f39d397 CM |
2383 | src_nritems = btrfs_header_nritems(src); |
2384 | dst_nritems = btrfs_header_nritems(dst); | |
0b246afa | 2385 | push_items = BTRFS_NODEPTRS_PER_BLOCK(fs_info) - dst_nritems; |
d397712b | 2386 | if (push_items <= 0) |
79f95c82 | 2387 | return 1; |
bce4eae9 | 2388 | |
d397712b | 2389 | if (src_nritems < 4) |
bce4eae9 | 2390 | return 1; |
79f95c82 CM |
2391 | |
2392 | max_push = src_nritems / 2 + 1; | |
2393 | /* don't try to empty the node */ | |
d397712b | 2394 | if (max_push >= src_nritems) |
79f95c82 | 2395 | return 1; |
252c38f0 | 2396 | |
79f95c82 CM |
2397 | if (max_push < push_items) |
2398 | push_items = max_push; | |
2399 | ||
d16c702f QW |
2400 | /* dst is the right eb, src is the middle eb */ |
2401 | if (check_sibling_keys(src, dst)) { | |
2402 | ret = -EUCLEAN; | |
2403 | btrfs_abort_transaction(trans, ret); | |
2404 | return ret; | |
2405 | } | |
f3a84ccd | 2406 | ret = btrfs_tree_mod_log_insert_move(dst, push_items, 0, dst_nritems); |
bf1d3425 | 2407 | BUG_ON(ret < 0); |
5f39d397 CM |
2408 | memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items), |
2409 | btrfs_node_key_ptr_offset(0), | |
2410 | (dst_nritems) * | |
2411 | sizeof(struct btrfs_key_ptr)); | |
d6025579 | 2412 | |
f3a84ccd FM |
2413 | ret = btrfs_tree_mod_log_eb_copy(dst, src, 0, src_nritems - push_items, |
2414 | push_items); | |
5de865ee | 2415 | if (ret) { |
66642832 | 2416 | btrfs_abort_transaction(trans, ret); |
5de865ee FDBM |
2417 | return ret; |
2418 | } | |
5f39d397 CM |
2419 | copy_extent_buffer(dst, src, |
2420 | btrfs_node_key_ptr_offset(0), | |
2421 | btrfs_node_key_ptr_offset(src_nritems - push_items), | |
d397712b | 2422 | push_items * sizeof(struct btrfs_key_ptr)); |
79f95c82 | 2423 | |
5f39d397 CM |
2424 | btrfs_set_header_nritems(src, src_nritems - push_items); |
2425 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
79f95c82 | 2426 | |
5f39d397 CM |
2427 | btrfs_mark_buffer_dirty(src); |
2428 | btrfs_mark_buffer_dirty(dst); | |
31840ae1 | 2429 | |
aa5d6bed | 2430 | return ret; |
be0e5c09 CM |
2431 | } |
2432 | ||
97571fd0 CM |
2433 | /* |
2434 | * helper function to insert a new root level in the tree. | |
2435 | * A new node is allocated, and a single item is inserted to | |
2436 | * point to the existing root | |
aa5d6bed CM |
2437 | * |
2438 | * returns zero on success or < 0 on failure. | |
97571fd0 | 2439 | */ |
d397712b | 2440 | static noinline int insert_new_root(struct btrfs_trans_handle *trans, |
5f39d397 | 2441 | struct btrfs_root *root, |
fdd99c72 | 2442 | struct btrfs_path *path, int level) |
5c680ed6 | 2443 | { |
0b246afa | 2444 | struct btrfs_fs_info *fs_info = root->fs_info; |
7bb86316 | 2445 | u64 lower_gen; |
5f39d397 CM |
2446 | struct extent_buffer *lower; |
2447 | struct extent_buffer *c; | |
925baedd | 2448 | struct extent_buffer *old; |
5f39d397 | 2449 | struct btrfs_disk_key lower_key; |
d9d19a01 | 2450 | int ret; |
5c680ed6 CM |
2451 | |
2452 | BUG_ON(path->nodes[level]); | |
2453 | BUG_ON(path->nodes[level-1] != root->node); | |
2454 | ||
7bb86316 CM |
2455 | lower = path->nodes[level-1]; |
2456 | if (level == 1) | |
2457 | btrfs_item_key(lower, &lower_key, 0); | |
2458 | else | |
2459 | btrfs_node_key(lower, &lower_key, 0); | |
2460 | ||
a6279470 | 2461 | c = alloc_tree_block_no_bg_flush(trans, root, 0, &lower_key, level, |
9631e4cc | 2462 | root->node->start, 0, |
cf6f34aa | 2463 | BTRFS_NESTING_NEW_ROOT); |
5f39d397 CM |
2464 | if (IS_ERR(c)) |
2465 | return PTR_ERR(c); | |
925baedd | 2466 | |
0b246afa | 2467 | root_add_used(root, fs_info->nodesize); |
f0486c68 | 2468 | |
5f39d397 | 2469 | btrfs_set_header_nritems(c, 1); |
5f39d397 | 2470 | btrfs_set_node_key(c, &lower_key, 0); |
db94535d | 2471 | btrfs_set_node_blockptr(c, 0, lower->start); |
7bb86316 | 2472 | lower_gen = btrfs_header_generation(lower); |
31840ae1 | 2473 | WARN_ON(lower_gen != trans->transid); |
7bb86316 CM |
2474 | |
2475 | btrfs_set_node_ptr_generation(c, 0, lower_gen); | |
d5719762 | 2476 | |
5f39d397 | 2477 | btrfs_mark_buffer_dirty(c); |
d5719762 | 2478 | |
925baedd | 2479 | old = root->node; |
406808ab | 2480 | ret = btrfs_tree_mod_log_insert_root(root->node, c, false); |
d9d19a01 | 2481 | BUG_ON(ret < 0); |
240f62c8 | 2482 | rcu_assign_pointer(root->node, c); |
925baedd CM |
2483 | |
2484 | /* the super has an extra ref to root->node */ | |
2485 | free_extent_buffer(old); | |
2486 | ||
0b86a832 | 2487 | add_root_to_dirty_list(root); |
67439dad | 2488 | atomic_inc(&c->refs); |
5f39d397 | 2489 | path->nodes[level] = c; |
ac5887c8 | 2490 | path->locks[level] = BTRFS_WRITE_LOCK; |
5c680ed6 CM |
2491 | path->slots[level] = 0; |
2492 | return 0; | |
2493 | } | |
2494 | ||
74123bd7 CM |
2495 | /* |
2496 | * worker function to insert a single pointer in a node. | |
2497 | * the node should have enough room for the pointer already | |
97571fd0 | 2498 | * |
74123bd7 CM |
2499 | * slot and level indicate where you want the key to go, and |
2500 | * blocknr is the block the key points to. | |
2501 | */ | |
143bede5 | 2502 | static void insert_ptr(struct btrfs_trans_handle *trans, |
6ad3cf6d | 2503 | struct btrfs_path *path, |
143bede5 | 2504 | struct btrfs_disk_key *key, u64 bytenr, |
c3e06965 | 2505 | int slot, int level) |
74123bd7 | 2506 | { |
5f39d397 | 2507 | struct extent_buffer *lower; |
74123bd7 | 2508 | int nritems; |
f3ea38da | 2509 | int ret; |
5c680ed6 CM |
2510 | |
2511 | BUG_ON(!path->nodes[level]); | |
f0486c68 | 2512 | btrfs_assert_tree_locked(path->nodes[level]); |
5f39d397 CM |
2513 | lower = path->nodes[level]; |
2514 | nritems = btrfs_header_nritems(lower); | |
c293498b | 2515 | BUG_ON(slot > nritems); |
6ad3cf6d | 2516 | BUG_ON(nritems == BTRFS_NODEPTRS_PER_BLOCK(trans->fs_info)); |
74123bd7 | 2517 | if (slot != nritems) { |
bf1d3425 | 2518 | if (level) { |
f3a84ccd FM |
2519 | ret = btrfs_tree_mod_log_insert_move(lower, slot + 1, |
2520 | slot, nritems - slot); | |
bf1d3425 DS |
2521 | BUG_ON(ret < 0); |
2522 | } | |
5f39d397 CM |
2523 | memmove_extent_buffer(lower, |
2524 | btrfs_node_key_ptr_offset(slot + 1), | |
2525 | btrfs_node_key_ptr_offset(slot), | |
d6025579 | 2526 | (nritems - slot) * sizeof(struct btrfs_key_ptr)); |
74123bd7 | 2527 | } |
c3e06965 | 2528 | if (level) { |
f3a84ccd FM |
2529 | ret = btrfs_tree_mod_log_insert_key(lower, slot, |
2530 | BTRFS_MOD_LOG_KEY_ADD, GFP_NOFS); | |
f3ea38da JS |
2531 | BUG_ON(ret < 0); |
2532 | } | |
5f39d397 | 2533 | btrfs_set_node_key(lower, key, slot); |
db94535d | 2534 | btrfs_set_node_blockptr(lower, slot, bytenr); |
74493f7a CM |
2535 | WARN_ON(trans->transid == 0); |
2536 | btrfs_set_node_ptr_generation(lower, slot, trans->transid); | |
5f39d397 CM |
2537 | btrfs_set_header_nritems(lower, nritems + 1); |
2538 | btrfs_mark_buffer_dirty(lower); | |
74123bd7 CM |
2539 | } |
2540 | ||
97571fd0 CM |
2541 | /* |
2542 | * split the node at the specified level in path in two. | |
2543 | * The path is corrected to point to the appropriate node after the split | |
2544 | * | |
2545 | * Before splitting this tries to make some room in the node by pushing | |
2546 | * left and right, if either one works, it returns right away. | |
aa5d6bed CM |
2547 | * |
2548 | * returns 0 on success and < 0 on failure | |
97571fd0 | 2549 | */ |
e02119d5 CM |
2550 | static noinline int split_node(struct btrfs_trans_handle *trans, |
2551 | struct btrfs_root *root, | |
2552 | struct btrfs_path *path, int level) | |
be0e5c09 | 2553 | { |
0b246afa | 2554 | struct btrfs_fs_info *fs_info = root->fs_info; |
5f39d397 CM |
2555 | struct extent_buffer *c; |
2556 | struct extent_buffer *split; | |
2557 | struct btrfs_disk_key disk_key; | |
be0e5c09 | 2558 | int mid; |
5c680ed6 | 2559 | int ret; |
7518a238 | 2560 | u32 c_nritems; |
eb60ceac | 2561 | |
5f39d397 | 2562 | c = path->nodes[level]; |
7bb86316 | 2563 | WARN_ON(btrfs_header_generation(c) != trans->transid); |
5f39d397 | 2564 | if (c == root->node) { |
d9abbf1c | 2565 | /* |
90f8d62e JS |
2566 | * trying to split the root, lets make a new one |
2567 | * | |
fdd99c72 | 2568 | * tree mod log: We don't log_removal old root in |
90f8d62e JS |
2569 | * insert_new_root, because that root buffer will be kept as a |
2570 | * normal node. We are going to log removal of half of the | |
f3a84ccd FM |
2571 | * elements below with btrfs_tree_mod_log_eb_copy(). We're |
2572 | * holding a tree lock on the buffer, which is why we cannot | |
2573 | * race with other tree_mod_log users. | |
d9abbf1c | 2574 | */ |
fdd99c72 | 2575 | ret = insert_new_root(trans, root, path, level + 1); |
5c680ed6 CM |
2576 | if (ret) |
2577 | return ret; | |
b3612421 | 2578 | } else { |
e66f709b | 2579 | ret = push_nodes_for_insert(trans, root, path, level); |
5f39d397 CM |
2580 | c = path->nodes[level]; |
2581 | if (!ret && btrfs_header_nritems(c) < | |
0b246afa | 2582 | BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 3) |
e66f709b | 2583 | return 0; |
54aa1f4d CM |
2584 | if (ret < 0) |
2585 | return ret; | |
be0e5c09 | 2586 | } |
e66f709b | 2587 | |
5f39d397 | 2588 | c_nritems = btrfs_header_nritems(c); |
5d4f98a2 YZ |
2589 | mid = (c_nritems + 1) / 2; |
2590 | btrfs_node_key(c, &disk_key, mid); | |
7bb86316 | 2591 | |
a6279470 | 2592 | split = alloc_tree_block_no_bg_flush(trans, root, 0, &disk_key, level, |
4dff97e6 | 2593 | c->start, 0, BTRFS_NESTING_SPLIT); |
5f39d397 CM |
2594 | if (IS_ERR(split)) |
2595 | return PTR_ERR(split); | |
2596 | ||
0b246afa | 2597 | root_add_used(root, fs_info->nodesize); |
bc877d28 | 2598 | ASSERT(btrfs_header_level(c) == level); |
54aa1f4d | 2599 | |
f3a84ccd | 2600 | ret = btrfs_tree_mod_log_eb_copy(split, c, 0, mid, c_nritems - mid); |
5de865ee | 2601 | if (ret) { |
66642832 | 2602 | btrfs_abort_transaction(trans, ret); |
5de865ee FDBM |
2603 | return ret; |
2604 | } | |
5f39d397 CM |
2605 | copy_extent_buffer(split, c, |
2606 | btrfs_node_key_ptr_offset(0), | |
2607 | btrfs_node_key_ptr_offset(mid), | |
2608 | (c_nritems - mid) * sizeof(struct btrfs_key_ptr)); | |
2609 | btrfs_set_header_nritems(split, c_nritems - mid); | |
2610 | btrfs_set_header_nritems(c, mid); | |
aa5d6bed | 2611 | |
5f39d397 CM |
2612 | btrfs_mark_buffer_dirty(c); |
2613 | btrfs_mark_buffer_dirty(split); | |
2614 | ||
6ad3cf6d | 2615 | insert_ptr(trans, path, &disk_key, split->start, |
c3e06965 | 2616 | path->slots[level + 1] + 1, level + 1); |
aa5d6bed | 2617 | |
5de08d7d | 2618 | if (path->slots[level] >= mid) { |
5c680ed6 | 2619 | path->slots[level] -= mid; |
925baedd | 2620 | btrfs_tree_unlock(c); |
5f39d397 CM |
2621 | free_extent_buffer(c); |
2622 | path->nodes[level] = split; | |
5c680ed6 CM |
2623 | path->slots[level + 1] += 1; |
2624 | } else { | |
925baedd | 2625 | btrfs_tree_unlock(split); |
5f39d397 | 2626 | free_extent_buffer(split); |
be0e5c09 | 2627 | } |
d5286a92 | 2628 | return 0; |
be0e5c09 CM |
2629 | } |
2630 | ||
74123bd7 CM |
2631 | /* |
2632 | * how many bytes are required to store the items in a leaf. start | |
2633 | * and nr indicate which items in the leaf to check. This totals up the | |
2634 | * space used both by the item structs and the item data | |
2635 | */ | |
5f39d397 | 2636 | static int leaf_space_used(struct extent_buffer *l, int start, int nr) |
be0e5c09 | 2637 | { |
41be1f3b JB |
2638 | struct btrfs_item *start_item; |
2639 | struct btrfs_item *end_item; | |
be0e5c09 | 2640 | int data_len; |
5f39d397 | 2641 | int nritems = btrfs_header_nritems(l); |
d4dbff95 | 2642 | int end = min(nritems, start + nr) - 1; |
be0e5c09 CM |
2643 | |
2644 | if (!nr) | |
2645 | return 0; | |
dd3cc16b RK |
2646 | start_item = btrfs_item_nr(start); |
2647 | end_item = btrfs_item_nr(end); | |
a31356b9 DS |
2648 | data_len = btrfs_item_offset(l, start_item) + |
2649 | btrfs_item_size(l, start_item); | |
2650 | data_len = data_len - btrfs_item_offset(l, end_item); | |
0783fcfc | 2651 | data_len += sizeof(struct btrfs_item) * nr; |
d4dbff95 | 2652 | WARN_ON(data_len < 0); |
be0e5c09 CM |
2653 | return data_len; |
2654 | } | |
2655 | ||
d4dbff95 CM |
2656 | /* |
2657 | * The space between the end of the leaf items and | |
2658 | * the start of the leaf data. IOW, how much room | |
2659 | * the leaf has left for both items and data | |
2660 | */ | |
e902baac | 2661 | noinline int btrfs_leaf_free_space(struct extent_buffer *leaf) |
d4dbff95 | 2662 | { |
e902baac | 2663 | struct btrfs_fs_info *fs_info = leaf->fs_info; |
5f39d397 CM |
2664 | int nritems = btrfs_header_nritems(leaf); |
2665 | int ret; | |
0b246afa JM |
2666 | |
2667 | ret = BTRFS_LEAF_DATA_SIZE(fs_info) - leaf_space_used(leaf, 0, nritems); | |
5f39d397 | 2668 | if (ret < 0) { |
0b246afa JM |
2669 | btrfs_crit(fs_info, |
2670 | "leaf free space ret %d, leaf data size %lu, used %d nritems %d", | |
2671 | ret, | |
2672 | (unsigned long) BTRFS_LEAF_DATA_SIZE(fs_info), | |
2673 | leaf_space_used(leaf, 0, nritems), nritems); | |
5f39d397 CM |
2674 | } |
2675 | return ret; | |
d4dbff95 CM |
2676 | } |
2677 | ||
99d8f83c CM |
2678 | /* |
2679 | * min slot controls the lowest index we're willing to push to the | |
2680 | * right. We'll push up to and including min_slot, but no lower | |
2681 | */ | |
f72f0010 | 2682 | static noinline int __push_leaf_right(struct btrfs_path *path, |
44871b1b CM |
2683 | int data_size, int empty, |
2684 | struct extent_buffer *right, | |
99d8f83c CM |
2685 | int free_space, u32 left_nritems, |
2686 | u32 min_slot) | |
00ec4c51 | 2687 | { |
f72f0010 | 2688 | struct btrfs_fs_info *fs_info = right->fs_info; |
5f39d397 | 2689 | struct extent_buffer *left = path->nodes[0]; |
44871b1b | 2690 | struct extent_buffer *upper = path->nodes[1]; |
cfed81a0 | 2691 | struct btrfs_map_token token; |
5f39d397 | 2692 | struct btrfs_disk_key disk_key; |
00ec4c51 | 2693 | int slot; |
34a38218 | 2694 | u32 i; |
00ec4c51 CM |
2695 | int push_space = 0; |
2696 | int push_items = 0; | |
0783fcfc | 2697 | struct btrfs_item *item; |
34a38218 | 2698 | u32 nr; |
7518a238 | 2699 | u32 right_nritems; |
5f39d397 | 2700 | u32 data_end; |
db94535d | 2701 | u32 this_item_size; |
00ec4c51 | 2702 | |
34a38218 CM |
2703 | if (empty) |
2704 | nr = 0; | |
2705 | else | |
99d8f83c | 2706 | nr = max_t(u32, 1, min_slot); |
34a38218 | 2707 | |
31840ae1 | 2708 | if (path->slots[0] >= left_nritems) |
87b29b20 | 2709 | push_space += data_size; |
31840ae1 | 2710 | |
44871b1b | 2711 | slot = path->slots[1]; |
34a38218 CM |
2712 | i = left_nritems - 1; |
2713 | while (i >= nr) { | |
dd3cc16b | 2714 | item = btrfs_item_nr(i); |
db94535d | 2715 | |
31840ae1 ZY |
2716 | if (!empty && push_items > 0) { |
2717 | if (path->slots[0] > i) | |
2718 | break; | |
2719 | if (path->slots[0] == i) { | |
e902baac DS |
2720 | int space = btrfs_leaf_free_space(left); |
2721 | ||
31840ae1 ZY |
2722 | if (space + push_space * 2 > free_space) |
2723 | break; | |
2724 | } | |
2725 | } | |
2726 | ||
00ec4c51 | 2727 | if (path->slots[0] == i) |
87b29b20 | 2728 | push_space += data_size; |
db94535d | 2729 | |
db94535d CM |
2730 | this_item_size = btrfs_item_size(left, item); |
2731 | if (this_item_size + sizeof(*item) + push_space > free_space) | |
00ec4c51 | 2732 | break; |
31840ae1 | 2733 | |
00ec4c51 | 2734 | push_items++; |
db94535d | 2735 | push_space += this_item_size + sizeof(*item); |
34a38218 CM |
2736 | if (i == 0) |
2737 | break; | |
2738 | i--; | |
db94535d | 2739 | } |
5f39d397 | 2740 | |
925baedd CM |
2741 | if (push_items == 0) |
2742 | goto out_unlock; | |
5f39d397 | 2743 | |
6c1500f2 | 2744 | WARN_ON(!empty && push_items == left_nritems); |
5f39d397 | 2745 | |
00ec4c51 | 2746 | /* push left to right */ |
5f39d397 | 2747 | right_nritems = btrfs_header_nritems(right); |
34a38218 | 2748 | |
5f39d397 | 2749 | push_space = btrfs_item_end_nr(left, left_nritems - push_items); |
8f881e8c | 2750 | push_space -= leaf_data_end(left); |
5f39d397 | 2751 | |
00ec4c51 | 2752 | /* make room in the right data area */ |
8f881e8c | 2753 | data_end = leaf_data_end(right); |
5f39d397 | 2754 | memmove_extent_buffer(right, |
3d9ec8c4 NB |
2755 | BTRFS_LEAF_DATA_OFFSET + data_end - push_space, |
2756 | BTRFS_LEAF_DATA_OFFSET + data_end, | |
0b246afa | 2757 | BTRFS_LEAF_DATA_SIZE(fs_info) - data_end); |
5f39d397 | 2758 | |
00ec4c51 | 2759 | /* copy from the left data area */ |
3d9ec8c4 | 2760 | copy_extent_buffer(right, left, BTRFS_LEAF_DATA_OFFSET + |
0b246afa | 2761 | BTRFS_LEAF_DATA_SIZE(fs_info) - push_space, |
8f881e8c | 2762 | BTRFS_LEAF_DATA_OFFSET + leaf_data_end(left), |
d6025579 | 2763 | push_space); |
5f39d397 CM |
2764 | |
2765 | memmove_extent_buffer(right, btrfs_item_nr_offset(push_items), | |
2766 | btrfs_item_nr_offset(0), | |
2767 | right_nritems * sizeof(struct btrfs_item)); | |
2768 | ||
00ec4c51 | 2769 | /* copy the items from left to right */ |
5f39d397 CM |
2770 | copy_extent_buffer(right, left, btrfs_item_nr_offset(0), |
2771 | btrfs_item_nr_offset(left_nritems - push_items), | |
2772 | push_items * sizeof(struct btrfs_item)); | |
00ec4c51 CM |
2773 | |
2774 | /* update the item pointers */ | |
c82f823c | 2775 | btrfs_init_map_token(&token, right); |
7518a238 | 2776 | right_nritems += push_items; |
5f39d397 | 2777 | btrfs_set_header_nritems(right, right_nritems); |
0b246afa | 2778 | push_space = BTRFS_LEAF_DATA_SIZE(fs_info); |
7518a238 | 2779 | for (i = 0; i < right_nritems; i++) { |
dd3cc16b | 2780 | item = btrfs_item_nr(i); |
cc4c13d5 DS |
2781 | push_space -= btrfs_token_item_size(&token, item); |
2782 | btrfs_set_token_item_offset(&token, item, push_space); | |
db94535d CM |
2783 | } |
2784 | ||
7518a238 | 2785 | left_nritems -= push_items; |
5f39d397 | 2786 | btrfs_set_header_nritems(left, left_nritems); |
00ec4c51 | 2787 | |
34a38218 CM |
2788 | if (left_nritems) |
2789 | btrfs_mark_buffer_dirty(left); | |
f0486c68 | 2790 | else |
6a884d7d | 2791 | btrfs_clean_tree_block(left); |
f0486c68 | 2792 | |
5f39d397 | 2793 | btrfs_mark_buffer_dirty(right); |
a429e513 | 2794 | |
5f39d397 CM |
2795 | btrfs_item_key(right, &disk_key, 0); |
2796 | btrfs_set_node_key(upper, &disk_key, slot + 1); | |
d6025579 | 2797 | btrfs_mark_buffer_dirty(upper); |
02217ed2 | 2798 | |
00ec4c51 | 2799 | /* then fixup the leaf pointer in the path */ |
7518a238 CM |
2800 | if (path->slots[0] >= left_nritems) { |
2801 | path->slots[0] -= left_nritems; | |
925baedd | 2802 | if (btrfs_header_nritems(path->nodes[0]) == 0) |
6a884d7d | 2803 | btrfs_clean_tree_block(path->nodes[0]); |
925baedd | 2804 | btrfs_tree_unlock(path->nodes[0]); |
5f39d397 CM |
2805 | free_extent_buffer(path->nodes[0]); |
2806 | path->nodes[0] = right; | |
00ec4c51 CM |
2807 | path->slots[1] += 1; |
2808 | } else { | |
925baedd | 2809 | btrfs_tree_unlock(right); |
5f39d397 | 2810 | free_extent_buffer(right); |
00ec4c51 CM |
2811 | } |
2812 | return 0; | |
925baedd CM |
2813 | |
2814 | out_unlock: | |
2815 | btrfs_tree_unlock(right); | |
2816 | free_extent_buffer(right); | |
2817 | return 1; | |
00ec4c51 | 2818 | } |
925baedd | 2819 | |
44871b1b CM |
2820 | /* |
2821 | * push some data in the path leaf to the right, trying to free up at | |
2822 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
2823 | * | |
2824 | * returns 1 if the push failed because the other node didn't have enough | |
2825 | * room, 0 if everything worked out and < 0 if there were major errors. | |
99d8f83c CM |
2826 | * |
2827 | * this will push starting from min_slot to the end of the leaf. It won't | |
2828 | * push any slot lower than min_slot | |
44871b1b CM |
2829 | */ |
2830 | static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root | |
99d8f83c CM |
2831 | *root, struct btrfs_path *path, |
2832 | int min_data_size, int data_size, | |
2833 | int empty, u32 min_slot) | |
44871b1b CM |
2834 | { |
2835 | struct extent_buffer *left = path->nodes[0]; | |
2836 | struct extent_buffer *right; | |
2837 | struct extent_buffer *upper; | |
2838 | int slot; | |
2839 | int free_space; | |
2840 | u32 left_nritems; | |
2841 | int ret; | |
2842 | ||
2843 | if (!path->nodes[1]) | |
2844 | return 1; | |
2845 | ||
2846 | slot = path->slots[1]; | |
2847 | upper = path->nodes[1]; | |
2848 | if (slot >= btrfs_header_nritems(upper) - 1) | |
2849 | return 1; | |
2850 | ||
2851 | btrfs_assert_tree_locked(path->nodes[1]); | |
2852 | ||
4b231ae4 | 2853 | right = btrfs_read_node_slot(upper, slot + 1); |
fb770ae4 LB |
2854 | /* |
2855 | * slot + 1 is not valid or we fail to read the right node, | |
2856 | * no big deal, just return. | |
2857 | */ | |
2858 | if (IS_ERR(right)) | |
91ca338d TI |
2859 | return 1; |
2860 | ||
bf77467a | 2861 | __btrfs_tree_lock(right, BTRFS_NESTING_RIGHT); |
44871b1b | 2862 | |
e902baac | 2863 | free_space = btrfs_leaf_free_space(right); |
44871b1b CM |
2864 | if (free_space < data_size) |
2865 | goto out_unlock; | |
2866 | ||
2867 | /* cow and double check */ | |
2868 | ret = btrfs_cow_block(trans, root, right, upper, | |
bf59a5a2 | 2869 | slot + 1, &right, BTRFS_NESTING_RIGHT_COW); |
44871b1b CM |
2870 | if (ret) |
2871 | goto out_unlock; | |
2872 | ||
e902baac | 2873 | free_space = btrfs_leaf_free_space(right); |
44871b1b CM |
2874 | if (free_space < data_size) |
2875 | goto out_unlock; | |
2876 | ||
2877 | left_nritems = btrfs_header_nritems(left); | |
2878 | if (left_nritems == 0) | |
2879 | goto out_unlock; | |
2880 | ||
d16c702f QW |
2881 | if (check_sibling_keys(left, right)) { |
2882 | ret = -EUCLEAN; | |
2883 | btrfs_tree_unlock(right); | |
2884 | free_extent_buffer(right); | |
2885 | return ret; | |
2886 | } | |
2ef1fed2 FDBM |
2887 | if (path->slots[0] == left_nritems && !empty) { |
2888 | /* Key greater than all keys in the leaf, right neighbor has | |
2889 | * enough room for it and we're not emptying our leaf to delete | |
2890 | * it, therefore use right neighbor to insert the new item and | |
52042d8e | 2891 | * no need to touch/dirty our left leaf. */ |
2ef1fed2 FDBM |
2892 | btrfs_tree_unlock(left); |
2893 | free_extent_buffer(left); | |
2894 | path->nodes[0] = right; | |
2895 | path->slots[0] = 0; | |
2896 | path->slots[1]++; | |
2897 | return 0; | |
2898 | } | |
2899 | ||
f72f0010 | 2900 | return __push_leaf_right(path, min_data_size, empty, |
99d8f83c | 2901 | right, free_space, left_nritems, min_slot); |
44871b1b CM |
2902 | out_unlock: |
2903 | btrfs_tree_unlock(right); | |
2904 | free_extent_buffer(right); | |
2905 | return 1; | |
2906 | } | |
2907 | ||
74123bd7 CM |
2908 | /* |
2909 | * push some data in the path leaf to the left, trying to free up at | |
2910 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
99d8f83c CM |
2911 | * |
2912 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
2913 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us do all the | |
2914 | * items | |
74123bd7 | 2915 | */ |
8087c193 | 2916 | static noinline int __push_leaf_left(struct btrfs_path *path, int data_size, |
44871b1b | 2917 | int empty, struct extent_buffer *left, |
99d8f83c CM |
2918 | int free_space, u32 right_nritems, |
2919 | u32 max_slot) | |
be0e5c09 | 2920 | { |
8087c193 | 2921 | struct btrfs_fs_info *fs_info = left->fs_info; |
5f39d397 CM |
2922 | struct btrfs_disk_key disk_key; |
2923 | struct extent_buffer *right = path->nodes[0]; | |
be0e5c09 | 2924 | int i; |
be0e5c09 CM |
2925 | int push_space = 0; |
2926 | int push_items = 0; | |
0783fcfc | 2927 | struct btrfs_item *item; |
7518a238 | 2928 | u32 old_left_nritems; |
34a38218 | 2929 | u32 nr; |
aa5d6bed | 2930 | int ret = 0; |
db94535d CM |
2931 | u32 this_item_size; |
2932 | u32 old_left_item_size; | |
cfed81a0 CM |
2933 | struct btrfs_map_token token; |
2934 | ||
34a38218 | 2935 | if (empty) |
99d8f83c | 2936 | nr = min(right_nritems, max_slot); |
34a38218 | 2937 | else |
99d8f83c | 2938 | nr = min(right_nritems - 1, max_slot); |
34a38218 CM |
2939 | |
2940 | for (i = 0; i < nr; i++) { | |
dd3cc16b | 2941 | item = btrfs_item_nr(i); |
db94535d | 2942 | |
31840ae1 ZY |
2943 | if (!empty && push_items > 0) { |
2944 | if (path->slots[0] < i) | |
2945 | break; | |
2946 | if (path->slots[0] == i) { | |
e902baac DS |
2947 | int space = btrfs_leaf_free_space(right); |
2948 | ||
31840ae1 ZY |
2949 | if (space + push_space * 2 > free_space) |
2950 | break; | |
2951 | } | |
2952 | } | |
2953 | ||
be0e5c09 | 2954 | if (path->slots[0] == i) |
87b29b20 | 2955 | push_space += data_size; |
db94535d CM |
2956 | |
2957 | this_item_size = btrfs_item_size(right, item); | |
2958 | if (this_item_size + sizeof(*item) + push_space > free_space) | |
be0e5c09 | 2959 | break; |
db94535d | 2960 | |
be0e5c09 | 2961 | push_items++; |
db94535d CM |
2962 | push_space += this_item_size + sizeof(*item); |
2963 | } | |
2964 | ||
be0e5c09 | 2965 | if (push_items == 0) { |
925baedd CM |
2966 | ret = 1; |
2967 | goto out; | |
be0e5c09 | 2968 | } |
fae7f21c | 2969 | WARN_ON(!empty && push_items == btrfs_header_nritems(right)); |
5f39d397 | 2970 | |
be0e5c09 | 2971 | /* push data from right to left */ |
5f39d397 CM |
2972 | copy_extent_buffer(left, right, |
2973 | btrfs_item_nr_offset(btrfs_header_nritems(left)), | |
2974 | btrfs_item_nr_offset(0), | |
2975 | push_items * sizeof(struct btrfs_item)); | |
2976 | ||
0b246afa | 2977 | push_space = BTRFS_LEAF_DATA_SIZE(fs_info) - |
d397712b | 2978 | btrfs_item_offset_nr(right, push_items - 1); |
5f39d397 | 2979 | |
3d9ec8c4 | 2980 | copy_extent_buffer(left, right, BTRFS_LEAF_DATA_OFFSET + |
8f881e8c | 2981 | leaf_data_end(left) - push_space, |
3d9ec8c4 | 2982 | BTRFS_LEAF_DATA_OFFSET + |
5f39d397 | 2983 | btrfs_item_offset_nr(right, push_items - 1), |
d6025579 | 2984 | push_space); |
5f39d397 | 2985 | old_left_nritems = btrfs_header_nritems(left); |
87b29b20 | 2986 | BUG_ON(old_left_nritems <= 0); |
eb60ceac | 2987 | |
c82f823c | 2988 | btrfs_init_map_token(&token, left); |
db94535d | 2989 | old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1); |
0783fcfc | 2990 | for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { |
5f39d397 | 2991 | u32 ioff; |
db94535d | 2992 | |
dd3cc16b | 2993 | item = btrfs_item_nr(i); |
db94535d | 2994 | |
cc4c13d5 DS |
2995 | ioff = btrfs_token_item_offset(&token, item); |
2996 | btrfs_set_token_item_offset(&token, item, | |
2997 | ioff - (BTRFS_LEAF_DATA_SIZE(fs_info) - old_left_item_size)); | |
be0e5c09 | 2998 | } |
5f39d397 | 2999 | btrfs_set_header_nritems(left, old_left_nritems + push_items); |
be0e5c09 CM |
3000 | |
3001 | /* fixup right node */ | |
31b1a2bd JL |
3002 | if (push_items > right_nritems) |
3003 | WARN(1, KERN_CRIT "push items %d nr %u\n", push_items, | |
d397712b | 3004 | right_nritems); |
34a38218 CM |
3005 | |
3006 | if (push_items < right_nritems) { | |
3007 | push_space = btrfs_item_offset_nr(right, push_items - 1) - | |
8f881e8c | 3008 | leaf_data_end(right); |
3d9ec8c4 | 3009 | memmove_extent_buffer(right, BTRFS_LEAF_DATA_OFFSET + |
0b246afa | 3010 | BTRFS_LEAF_DATA_SIZE(fs_info) - push_space, |
3d9ec8c4 | 3011 | BTRFS_LEAF_DATA_OFFSET + |
8f881e8c | 3012 | leaf_data_end(right), push_space); |
34a38218 CM |
3013 | |
3014 | memmove_extent_buffer(right, btrfs_item_nr_offset(0), | |
5f39d397 CM |
3015 | btrfs_item_nr_offset(push_items), |
3016 | (btrfs_header_nritems(right) - push_items) * | |
3017 | sizeof(struct btrfs_item)); | |
34a38218 | 3018 | } |
c82f823c DS |
3019 | |
3020 | btrfs_init_map_token(&token, right); | |
eef1c494 Y |
3021 | right_nritems -= push_items; |
3022 | btrfs_set_header_nritems(right, right_nritems); | |
0b246afa | 3023 | push_space = BTRFS_LEAF_DATA_SIZE(fs_info); |
5f39d397 | 3024 | for (i = 0; i < right_nritems; i++) { |
dd3cc16b | 3025 | item = btrfs_item_nr(i); |
db94535d | 3026 | |
cc4c13d5 DS |
3027 | push_space = push_space - btrfs_token_item_size(&token, item); |
3028 | btrfs_set_token_item_offset(&token, item, push_space); | |
db94535d | 3029 | } |
eb60ceac | 3030 | |
5f39d397 | 3031 | btrfs_mark_buffer_dirty(left); |
34a38218 CM |
3032 | if (right_nritems) |
3033 | btrfs_mark_buffer_dirty(right); | |
f0486c68 | 3034 | else |
6a884d7d | 3035 | btrfs_clean_tree_block(right); |
098f59c2 | 3036 | |
5f39d397 | 3037 | btrfs_item_key(right, &disk_key, 0); |
b167fa91 | 3038 | fixup_low_keys(path, &disk_key, 1); |
be0e5c09 CM |
3039 | |
3040 | /* then fixup the leaf pointer in the path */ | |
3041 | if (path->slots[0] < push_items) { | |
3042 | path->slots[0] += old_left_nritems; | |
925baedd | 3043 | btrfs_tree_unlock(path->nodes[0]); |
5f39d397 CM |
3044 | free_extent_buffer(path->nodes[0]); |
3045 | path->nodes[0] = left; | |
be0e5c09 CM |
3046 | path->slots[1] -= 1; |
3047 | } else { | |
925baedd | 3048 | btrfs_tree_unlock(left); |
5f39d397 | 3049 | free_extent_buffer(left); |
be0e5c09 CM |
3050 | path->slots[0] -= push_items; |
3051 | } | |
eb60ceac | 3052 | BUG_ON(path->slots[0] < 0); |
aa5d6bed | 3053 | return ret; |
925baedd CM |
3054 | out: |
3055 | btrfs_tree_unlock(left); | |
3056 | free_extent_buffer(left); | |
3057 | return ret; | |
be0e5c09 CM |
3058 | } |
3059 | ||
44871b1b CM |
3060 | /* |
3061 | * push some data in the path leaf to the left, trying to free up at | |
3062 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
99d8f83c CM |
3063 | * |
3064 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
3065 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us push all the | |
3066 | * items | |
44871b1b CM |
3067 | */ |
3068 | static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root | |
99d8f83c CM |
3069 | *root, struct btrfs_path *path, int min_data_size, |
3070 | int data_size, int empty, u32 max_slot) | |
44871b1b CM |
3071 | { |
3072 | struct extent_buffer *right = path->nodes[0]; | |
3073 | struct extent_buffer *left; | |
3074 | int slot; | |
3075 | int free_space; | |
3076 | u32 right_nritems; | |
3077 | int ret = 0; | |
3078 | ||
3079 | slot = path->slots[1]; | |
3080 | if (slot == 0) | |
3081 | return 1; | |
3082 | if (!path->nodes[1]) | |
3083 | return 1; | |
3084 | ||
3085 | right_nritems = btrfs_header_nritems(right); | |
3086 | if (right_nritems == 0) | |
3087 | return 1; | |
3088 | ||
3089 | btrfs_assert_tree_locked(path->nodes[1]); | |
3090 | ||
4b231ae4 | 3091 | left = btrfs_read_node_slot(path->nodes[1], slot - 1); |
fb770ae4 LB |
3092 | /* |
3093 | * slot - 1 is not valid or we fail to read the left node, | |
3094 | * no big deal, just return. | |
3095 | */ | |
3096 | if (IS_ERR(left)) | |
91ca338d TI |
3097 | return 1; |
3098 | ||
bf77467a | 3099 | __btrfs_tree_lock(left, BTRFS_NESTING_LEFT); |
44871b1b | 3100 | |
e902baac | 3101 | free_space = btrfs_leaf_free_space(left); |
44871b1b CM |
3102 | if (free_space < data_size) { |
3103 | ret = 1; | |
3104 | goto out; | |
3105 | } | |
3106 | ||
3107 | /* cow and double check */ | |
3108 | ret = btrfs_cow_block(trans, root, left, | |
9631e4cc | 3109 | path->nodes[1], slot - 1, &left, |
bf59a5a2 | 3110 | BTRFS_NESTING_LEFT_COW); |
44871b1b CM |
3111 | if (ret) { |
3112 | /* we hit -ENOSPC, but it isn't fatal here */ | |
79787eaa JM |
3113 | if (ret == -ENOSPC) |
3114 | ret = 1; | |
44871b1b CM |
3115 | goto out; |
3116 | } | |
3117 | ||
e902baac | 3118 | free_space = btrfs_leaf_free_space(left); |
44871b1b CM |
3119 | if (free_space < data_size) { |
3120 | ret = 1; | |
3121 | goto out; | |
3122 | } | |
3123 | ||
d16c702f QW |
3124 | if (check_sibling_keys(left, right)) { |
3125 | ret = -EUCLEAN; | |
3126 | goto out; | |
3127 | } | |
8087c193 | 3128 | return __push_leaf_left(path, min_data_size, |
99d8f83c CM |
3129 | empty, left, free_space, right_nritems, |
3130 | max_slot); | |
44871b1b CM |
3131 | out: |
3132 | btrfs_tree_unlock(left); | |
3133 | free_extent_buffer(left); | |
3134 | return ret; | |
3135 | } | |
3136 | ||
3137 | /* | |
3138 | * split the path's leaf in two, making sure there is at least data_size | |
3139 | * available for the resulting leaf level of the path. | |
44871b1b | 3140 | */ |
143bede5 | 3141 | static noinline void copy_for_split(struct btrfs_trans_handle *trans, |
143bede5 JM |
3142 | struct btrfs_path *path, |
3143 | struct extent_buffer *l, | |
3144 | struct extent_buffer *right, | |
3145 | int slot, int mid, int nritems) | |
44871b1b | 3146 | { |
94f94ad9 | 3147 | struct btrfs_fs_info *fs_info = trans->fs_info; |
44871b1b CM |
3148 | int data_copy_size; |
3149 | int rt_data_off; | |
3150 | int i; | |
44871b1b | 3151 | struct btrfs_disk_key disk_key; |
cfed81a0 CM |
3152 | struct btrfs_map_token token; |
3153 | ||
44871b1b CM |
3154 | nritems = nritems - mid; |
3155 | btrfs_set_header_nritems(right, nritems); | |
8f881e8c | 3156 | data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(l); |
44871b1b CM |
3157 | |
3158 | copy_extent_buffer(right, l, btrfs_item_nr_offset(0), | |
3159 | btrfs_item_nr_offset(mid), | |
3160 | nritems * sizeof(struct btrfs_item)); | |
3161 | ||
3162 | copy_extent_buffer(right, l, | |
3d9ec8c4 NB |
3163 | BTRFS_LEAF_DATA_OFFSET + BTRFS_LEAF_DATA_SIZE(fs_info) - |
3164 | data_copy_size, BTRFS_LEAF_DATA_OFFSET + | |
8f881e8c | 3165 | leaf_data_end(l), data_copy_size); |
44871b1b | 3166 | |
0b246afa | 3167 | rt_data_off = BTRFS_LEAF_DATA_SIZE(fs_info) - btrfs_item_end_nr(l, mid); |
44871b1b | 3168 | |
c82f823c | 3169 | btrfs_init_map_token(&token, right); |
44871b1b | 3170 | for (i = 0; i < nritems; i++) { |
dd3cc16b | 3171 | struct btrfs_item *item = btrfs_item_nr(i); |
44871b1b CM |
3172 | u32 ioff; |
3173 | ||
cc4c13d5 DS |
3174 | ioff = btrfs_token_item_offset(&token, item); |
3175 | btrfs_set_token_item_offset(&token, item, ioff + rt_data_off); | |
44871b1b CM |
3176 | } |
3177 | ||
44871b1b | 3178 | btrfs_set_header_nritems(l, mid); |
44871b1b | 3179 | btrfs_item_key(right, &disk_key, 0); |
6ad3cf6d | 3180 | insert_ptr(trans, path, &disk_key, right->start, path->slots[1] + 1, 1); |
44871b1b CM |
3181 | |
3182 | btrfs_mark_buffer_dirty(right); | |
3183 | btrfs_mark_buffer_dirty(l); | |
3184 | BUG_ON(path->slots[0] != slot); | |
3185 | ||
44871b1b CM |
3186 | if (mid <= slot) { |
3187 | btrfs_tree_unlock(path->nodes[0]); | |
3188 | free_extent_buffer(path->nodes[0]); | |
3189 | path->nodes[0] = right; | |
3190 | path->slots[0] -= mid; | |
3191 | path->slots[1] += 1; | |
3192 | } else { | |
3193 | btrfs_tree_unlock(right); | |
3194 | free_extent_buffer(right); | |
3195 | } | |
3196 | ||
3197 | BUG_ON(path->slots[0] < 0); | |
44871b1b CM |
3198 | } |
3199 | ||
99d8f83c CM |
3200 | /* |
3201 | * double splits happen when we need to insert a big item in the middle | |
3202 | * of a leaf. A double split can leave us with 3 mostly empty leaves: | |
3203 | * leaf: [ slots 0 - N] [ our target ] [ N + 1 - total in leaf ] | |
3204 | * A B C | |
3205 | * | |
3206 | * We avoid this by trying to push the items on either side of our target | |
3207 | * into the adjacent leaves. If all goes well we can avoid the double split | |
3208 | * completely. | |
3209 | */ | |
3210 | static noinline int push_for_double_split(struct btrfs_trans_handle *trans, | |
3211 | struct btrfs_root *root, | |
3212 | struct btrfs_path *path, | |
3213 | int data_size) | |
3214 | { | |
3215 | int ret; | |
3216 | int progress = 0; | |
3217 | int slot; | |
3218 | u32 nritems; | |
5a4267ca | 3219 | int space_needed = data_size; |
99d8f83c CM |
3220 | |
3221 | slot = path->slots[0]; | |
5a4267ca | 3222 | if (slot < btrfs_header_nritems(path->nodes[0])) |
e902baac | 3223 | space_needed -= btrfs_leaf_free_space(path->nodes[0]); |
99d8f83c CM |
3224 | |
3225 | /* | |
3226 | * try to push all the items after our slot into the | |
3227 | * right leaf | |
3228 | */ | |
5a4267ca | 3229 | ret = push_leaf_right(trans, root, path, 1, space_needed, 0, slot); |
99d8f83c CM |
3230 | if (ret < 0) |
3231 | return ret; | |
3232 | ||
3233 | if (ret == 0) | |
3234 | progress++; | |
3235 | ||
3236 | nritems = btrfs_header_nritems(path->nodes[0]); | |
3237 | /* | |
3238 | * our goal is to get our slot at the start or end of a leaf. If | |
3239 | * we've done so we're done | |
3240 | */ | |
3241 | if (path->slots[0] == 0 || path->slots[0] == nritems) | |
3242 | return 0; | |
3243 | ||
e902baac | 3244 | if (btrfs_leaf_free_space(path->nodes[0]) >= data_size) |
99d8f83c CM |
3245 | return 0; |
3246 | ||
3247 | /* try to push all the items before our slot into the next leaf */ | |
3248 | slot = path->slots[0]; | |
263d3995 FM |
3249 | space_needed = data_size; |
3250 | if (slot > 0) | |
e902baac | 3251 | space_needed -= btrfs_leaf_free_space(path->nodes[0]); |
5a4267ca | 3252 | ret = push_leaf_left(trans, root, path, 1, space_needed, 0, slot); |
99d8f83c CM |
3253 | if (ret < 0) |
3254 | return ret; | |
3255 | ||
3256 | if (ret == 0) | |
3257 | progress++; | |
3258 | ||
3259 | if (progress) | |
3260 | return 0; | |
3261 | return 1; | |
3262 | } | |
3263 | ||
74123bd7 CM |
3264 | /* |
3265 | * split the path's leaf in two, making sure there is at least data_size | |
3266 | * available for the resulting leaf level of the path. | |
aa5d6bed CM |
3267 | * |
3268 | * returns 0 if all went well and < 0 on failure. | |
74123bd7 | 3269 | */ |
e02119d5 CM |
3270 | static noinline int split_leaf(struct btrfs_trans_handle *trans, |
3271 | struct btrfs_root *root, | |
310712b2 | 3272 | const struct btrfs_key *ins_key, |
e02119d5 CM |
3273 | struct btrfs_path *path, int data_size, |
3274 | int extend) | |
be0e5c09 | 3275 | { |
5d4f98a2 | 3276 | struct btrfs_disk_key disk_key; |
5f39d397 | 3277 | struct extent_buffer *l; |
7518a238 | 3278 | u32 nritems; |
eb60ceac CM |
3279 | int mid; |
3280 | int slot; | |
5f39d397 | 3281 | struct extent_buffer *right; |
b7a0365e | 3282 | struct btrfs_fs_info *fs_info = root->fs_info; |
d4dbff95 | 3283 | int ret = 0; |
aa5d6bed | 3284 | int wret; |
5d4f98a2 | 3285 | int split; |
cc0c5538 | 3286 | int num_doubles = 0; |
99d8f83c | 3287 | int tried_avoid_double = 0; |
aa5d6bed | 3288 | |
a5719521 YZ |
3289 | l = path->nodes[0]; |
3290 | slot = path->slots[0]; | |
3291 | if (extend && data_size + btrfs_item_size_nr(l, slot) + | |
0b246afa | 3292 | sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(fs_info)) |
a5719521 YZ |
3293 | return -EOVERFLOW; |
3294 | ||
40689478 | 3295 | /* first try to make some room by pushing left and right */ |
33157e05 | 3296 | if (data_size && path->nodes[1]) { |
5a4267ca FDBM |
3297 | int space_needed = data_size; |
3298 | ||
3299 | if (slot < btrfs_header_nritems(l)) | |
e902baac | 3300 | space_needed -= btrfs_leaf_free_space(l); |
5a4267ca FDBM |
3301 | |
3302 | wret = push_leaf_right(trans, root, path, space_needed, | |
3303 | space_needed, 0, 0); | |
d397712b | 3304 | if (wret < 0) |
eaee50e8 | 3305 | return wret; |
3685f791 | 3306 | if (wret) { |
263d3995 FM |
3307 | space_needed = data_size; |
3308 | if (slot > 0) | |
e902baac | 3309 | space_needed -= btrfs_leaf_free_space(l); |
5a4267ca FDBM |
3310 | wret = push_leaf_left(trans, root, path, space_needed, |
3311 | space_needed, 0, (u32)-1); | |
3685f791 CM |
3312 | if (wret < 0) |
3313 | return wret; | |
3314 | } | |
3315 | l = path->nodes[0]; | |
aa5d6bed | 3316 | |
3685f791 | 3317 | /* did the pushes work? */ |
e902baac | 3318 | if (btrfs_leaf_free_space(l) >= data_size) |
3685f791 | 3319 | return 0; |
3326d1b0 | 3320 | } |
aa5d6bed | 3321 | |
5c680ed6 | 3322 | if (!path->nodes[1]) { |
fdd99c72 | 3323 | ret = insert_new_root(trans, root, path, 1); |
5c680ed6 CM |
3324 | if (ret) |
3325 | return ret; | |
3326 | } | |
cc0c5538 | 3327 | again: |
5d4f98a2 | 3328 | split = 1; |
cc0c5538 | 3329 | l = path->nodes[0]; |
eb60ceac | 3330 | slot = path->slots[0]; |
5f39d397 | 3331 | nritems = btrfs_header_nritems(l); |
d397712b | 3332 | mid = (nritems + 1) / 2; |
54aa1f4d | 3333 | |
5d4f98a2 YZ |
3334 | if (mid <= slot) { |
3335 | if (nritems == 1 || | |
3336 | leaf_space_used(l, mid, nritems - mid) + data_size > | |
0b246afa | 3337 | BTRFS_LEAF_DATA_SIZE(fs_info)) { |
5d4f98a2 YZ |
3338 | if (slot >= nritems) { |
3339 | split = 0; | |
3340 | } else { | |
3341 | mid = slot; | |
3342 | if (mid != nritems && | |
3343 | leaf_space_used(l, mid, nritems - mid) + | |
0b246afa | 3344 | data_size > BTRFS_LEAF_DATA_SIZE(fs_info)) { |
99d8f83c CM |
3345 | if (data_size && !tried_avoid_double) |
3346 | goto push_for_double; | |
5d4f98a2 YZ |
3347 | split = 2; |
3348 | } | |
3349 | } | |
3350 | } | |
3351 | } else { | |
3352 | if (leaf_space_used(l, 0, mid) + data_size > | |
0b246afa | 3353 | BTRFS_LEAF_DATA_SIZE(fs_info)) { |
5d4f98a2 YZ |
3354 | if (!extend && data_size && slot == 0) { |
3355 | split = 0; | |
3356 | } else if ((extend || !data_size) && slot == 0) { | |
3357 | mid = 1; | |
3358 | } else { | |
3359 | mid = slot; | |
3360 | if (mid != nritems && | |
3361 | leaf_space_used(l, mid, nritems - mid) + | |
0b246afa | 3362 | data_size > BTRFS_LEAF_DATA_SIZE(fs_info)) { |
99d8f83c CM |
3363 | if (data_size && !tried_avoid_double) |
3364 | goto push_for_double; | |
67871254 | 3365 | split = 2; |
5d4f98a2 YZ |
3366 | } |
3367 | } | |
3368 | } | |
3369 | } | |
3370 | ||
3371 | if (split == 0) | |
3372 | btrfs_cpu_key_to_disk(&disk_key, ins_key); | |
3373 | else | |
3374 | btrfs_item_key(l, &disk_key, mid); | |
3375 | ||
ca9d473a JB |
3376 | /* |
3377 | * We have to about BTRFS_NESTING_NEW_ROOT here if we've done a double | |
3378 | * split, because we're only allowed to have MAX_LOCKDEP_SUBCLASSES | |
3379 | * subclasses, which is 8 at the time of this patch, and we've maxed it | |
3380 | * out. In the future we could add a | |
3381 | * BTRFS_NESTING_SPLIT_THE_SPLITTENING if we need to, but for now just | |
3382 | * use BTRFS_NESTING_NEW_ROOT. | |
3383 | */ | |
a6279470 | 3384 | right = alloc_tree_block_no_bg_flush(trans, root, 0, &disk_key, 0, |
ca9d473a JB |
3385 | l->start, 0, num_doubles ? |
3386 | BTRFS_NESTING_NEW_ROOT : | |
3387 | BTRFS_NESTING_SPLIT); | |
f0486c68 | 3388 | if (IS_ERR(right)) |
5f39d397 | 3389 | return PTR_ERR(right); |
f0486c68 | 3390 | |
0b246afa | 3391 | root_add_used(root, fs_info->nodesize); |
5f39d397 | 3392 | |
5d4f98a2 YZ |
3393 | if (split == 0) { |
3394 | if (mid <= slot) { | |
3395 | btrfs_set_header_nritems(right, 0); | |
6ad3cf6d | 3396 | insert_ptr(trans, path, &disk_key, |
2ff7e61e | 3397 | right->start, path->slots[1] + 1, 1); |
5d4f98a2 YZ |
3398 | btrfs_tree_unlock(path->nodes[0]); |
3399 | free_extent_buffer(path->nodes[0]); | |
3400 | path->nodes[0] = right; | |
3401 | path->slots[0] = 0; | |
3402 | path->slots[1] += 1; | |
3403 | } else { | |
3404 | btrfs_set_header_nritems(right, 0); | |
6ad3cf6d | 3405 | insert_ptr(trans, path, &disk_key, |
2ff7e61e | 3406 | right->start, path->slots[1], 1); |
5d4f98a2 YZ |
3407 | btrfs_tree_unlock(path->nodes[0]); |
3408 | free_extent_buffer(path->nodes[0]); | |
3409 | path->nodes[0] = right; | |
3410 | path->slots[0] = 0; | |
143bede5 | 3411 | if (path->slots[1] == 0) |
b167fa91 | 3412 | fixup_low_keys(path, &disk_key, 1); |
d4dbff95 | 3413 | } |
196e0249 LB |
3414 | /* |
3415 | * We create a new leaf 'right' for the required ins_len and | |
3416 | * we'll do btrfs_mark_buffer_dirty() on this leaf after copying | |
3417 | * the content of ins_len to 'right'. | |
3418 | */ | |
5d4f98a2 | 3419 | return ret; |
d4dbff95 | 3420 | } |
74123bd7 | 3421 | |
94f94ad9 | 3422 | copy_for_split(trans, path, l, right, slot, mid, nritems); |
31840ae1 | 3423 | |
5d4f98a2 | 3424 | if (split == 2) { |
cc0c5538 CM |
3425 | BUG_ON(num_doubles != 0); |
3426 | num_doubles++; | |
3427 | goto again; | |
a429e513 | 3428 | } |
44871b1b | 3429 | |
143bede5 | 3430 | return 0; |
99d8f83c CM |
3431 | |
3432 | push_for_double: | |
3433 | push_for_double_split(trans, root, path, data_size); | |
3434 | tried_avoid_double = 1; | |
e902baac | 3435 | if (btrfs_leaf_free_space(path->nodes[0]) >= data_size) |
99d8f83c CM |
3436 | return 0; |
3437 | goto again; | |
be0e5c09 CM |
3438 | } |
3439 | ||
ad48fd75 YZ |
3440 | static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans, |
3441 | struct btrfs_root *root, | |
3442 | struct btrfs_path *path, int ins_len) | |
459931ec | 3443 | { |
ad48fd75 | 3444 | struct btrfs_key key; |
459931ec | 3445 | struct extent_buffer *leaf; |
ad48fd75 YZ |
3446 | struct btrfs_file_extent_item *fi; |
3447 | u64 extent_len = 0; | |
3448 | u32 item_size; | |
3449 | int ret; | |
459931ec CM |
3450 | |
3451 | leaf = path->nodes[0]; | |
ad48fd75 YZ |
3452 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
3453 | ||
3454 | BUG_ON(key.type != BTRFS_EXTENT_DATA_KEY && | |
3455 | key.type != BTRFS_EXTENT_CSUM_KEY); | |
3456 | ||
e902baac | 3457 | if (btrfs_leaf_free_space(leaf) >= ins_len) |
ad48fd75 | 3458 | return 0; |
459931ec CM |
3459 | |
3460 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
ad48fd75 YZ |
3461 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
3462 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
3463 | struct btrfs_file_extent_item); | |
3464 | extent_len = btrfs_file_extent_num_bytes(leaf, fi); | |
3465 | } | |
b3b4aa74 | 3466 | btrfs_release_path(path); |
459931ec | 3467 | |
459931ec | 3468 | path->keep_locks = 1; |
ad48fd75 YZ |
3469 | path->search_for_split = 1; |
3470 | ret = btrfs_search_slot(trans, root, &key, path, 0, 1); | |
459931ec | 3471 | path->search_for_split = 0; |
a8df6fe6 FM |
3472 | if (ret > 0) |
3473 | ret = -EAGAIN; | |
ad48fd75 YZ |
3474 | if (ret < 0) |
3475 | goto err; | |
459931ec | 3476 | |
ad48fd75 YZ |
3477 | ret = -EAGAIN; |
3478 | leaf = path->nodes[0]; | |
a8df6fe6 FM |
3479 | /* if our item isn't there, return now */ |
3480 | if (item_size != btrfs_item_size_nr(leaf, path->slots[0])) | |
ad48fd75 YZ |
3481 | goto err; |
3482 | ||
109f6aef | 3483 | /* the leaf has changed, it now has room. return now */ |
e902baac | 3484 | if (btrfs_leaf_free_space(path->nodes[0]) >= ins_len) |
109f6aef CM |
3485 | goto err; |
3486 | ||
ad48fd75 YZ |
3487 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
3488 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
3489 | struct btrfs_file_extent_item); | |
3490 | if (extent_len != btrfs_file_extent_num_bytes(leaf, fi)) | |
3491 | goto err; | |
459931ec CM |
3492 | } |
3493 | ||
ad48fd75 | 3494 | ret = split_leaf(trans, root, &key, path, ins_len, 1); |
f0486c68 YZ |
3495 | if (ret) |
3496 | goto err; | |
459931ec | 3497 | |
ad48fd75 | 3498 | path->keep_locks = 0; |
b9473439 | 3499 | btrfs_unlock_up_safe(path, 1); |
ad48fd75 YZ |
3500 | return 0; |
3501 | err: | |
3502 | path->keep_locks = 0; | |
3503 | return ret; | |
3504 | } | |
3505 | ||
25263cd7 | 3506 | static noinline int split_item(struct btrfs_path *path, |
310712b2 | 3507 | const struct btrfs_key *new_key, |
ad48fd75 YZ |
3508 | unsigned long split_offset) |
3509 | { | |
3510 | struct extent_buffer *leaf; | |
3511 | struct btrfs_item *item; | |
3512 | struct btrfs_item *new_item; | |
3513 | int slot; | |
3514 | char *buf; | |
3515 | u32 nritems; | |
3516 | u32 item_size; | |
3517 | u32 orig_offset; | |
3518 | struct btrfs_disk_key disk_key; | |
3519 | ||
b9473439 | 3520 | leaf = path->nodes[0]; |
e902baac | 3521 | BUG_ON(btrfs_leaf_free_space(leaf) < sizeof(struct btrfs_item)); |
b9473439 | 3522 | |
dd3cc16b | 3523 | item = btrfs_item_nr(path->slots[0]); |
459931ec CM |
3524 | orig_offset = btrfs_item_offset(leaf, item); |
3525 | item_size = btrfs_item_size(leaf, item); | |
3526 | ||
459931ec | 3527 | buf = kmalloc(item_size, GFP_NOFS); |
ad48fd75 YZ |
3528 | if (!buf) |
3529 | return -ENOMEM; | |
3530 | ||
459931ec CM |
3531 | read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf, |
3532 | path->slots[0]), item_size); | |
459931ec | 3533 | |
ad48fd75 | 3534 | slot = path->slots[0] + 1; |
459931ec | 3535 | nritems = btrfs_header_nritems(leaf); |
459931ec CM |
3536 | if (slot != nritems) { |
3537 | /* shift the items */ | |
3538 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1), | |
ad48fd75 YZ |
3539 | btrfs_item_nr_offset(slot), |
3540 | (nritems - slot) * sizeof(struct btrfs_item)); | |
459931ec CM |
3541 | } |
3542 | ||
3543 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
3544 | btrfs_set_item_key(leaf, &disk_key, slot); | |
3545 | ||
dd3cc16b | 3546 | new_item = btrfs_item_nr(slot); |
459931ec CM |
3547 | |
3548 | btrfs_set_item_offset(leaf, new_item, orig_offset); | |
3549 | btrfs_set_item_size(leaf, new_item, item_size - split_offset); | |
3550 | ||
3551 | btrfs_set_item_offset(leaf, item, | |
3552 | orig_offset + item_size - split_offset); | |
3553 | btrfs_set_item_size(leaf, item, split_offset); | |
3554 | ||
3555 | btrfs_set_header_nritems(leaf, nritems + 1); | |
3556 | ||
3557 | /* write the data for the start of the original item */ | |
3558 | write_extent_buffer(leaf, buf, | |
3559 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
3560 | split_offset); | |
3561 | ||
3562 | /* write the data for the new item */ | |
3563 | write_extent_buffer(leaf, buf + split_offset, | |
3564 | btrfs_item_ptr_offset(leaf, slot), | |
3565 | item_size - split_offset); | |
3566 | btrfs_mark_buffer_dirty(leaf); | |
3567 | ||
e902baac | 3568 | BUG_ON(btrfs_leaf_free_space(leaf) < 0); |
459931ec | 3569 | kfree(buf); |
ad48fd75 YZ |
3570 | return 0; |
3571 | } | |
3572 | ||
3573 | /* | |
3574 | * This function splits a single item into two items, | |
3575 | * giving 'new_key' to the new item and splitting the | |
3576 | * old one at split_offset (from the start of the item). | |
3577 | * | |
3578 | * The path may be released by this operation. After | |
3579 | * the split, the path is pointing to the old item. The | |
3580 | * new item is going to be in the same node as the old one. | |
3581 | * | |
3582 | * Note, the item being split must be smaller enough to live alone on | |
3583 | * a tree block with room for one extra struct btrfs_item | |
3584 | * | |
3585 | * This allows us to split the item in place, keeping a lock on the | |
3586 | * leaf the entire time. | |
3587 | */ | |
3588 | int btrfs_split_item(struct btrfs_trans_handle *trans, | |
3589 | struct btrfs_root *root, | |
3590 | struct btrfs_path *path, | |
310712b2 | 3591 | const struct btrfs_key *new_key, |
ad48fd75 YZ |
3592 | unsigned long split_offset) |
3593 | { | |
3594 | int ret; | |
3595 | ret = setup_leaf_for_split(trans, root, path, | |
3596 | sizeof(struct btrfs_item)); | |
3597 | if (ret) | |
3598 | return ret; | |
3599 | ||
25263cd7 | 3600 | ret = split_item(path, new_key, split_offset); |
459931ec CM |
3601 | return ret; |
3602 | } | |
3603 | ||
ad48fd75 YZ |
3604 | /* |
3605 | * This function duplicate a item, giving 'new_key' to the new item. | |
3606 | * It guarantees both items live in the same tree leaf and the new item | |
3607 | * is contiguous with the original item. | |
3608 | * | |
3609 | * This allows us to split file extent in place, keeping a lock on the | |
3610 | * leaf the entire time. | |
3611 | */ | |
3612 | int btrfs_duplicate_item(struct btrfs_trans_handle *trans, | |
3613 | struct btrfs_root *root, | |
3614 | struct btrfs_path *path, | |
310712b2 | 3615 | const struct btrfs_key *new_key) |
ad48fd75 YZ |
3616 | { |
3617 | struct extent_buffer *leaf; | |
3618 | int ret; | |
3619 | u32 item_size; | |
3620 | ||
3621 | leaf = path->nodes[0]; | |
3622 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
3623 | ret = setup_leaf_for_split(trans, root, path, | |
3624 | item_size + sizeof(struct btrfs_item)); | |
3625 | if (ret) | |
3626 | return ret; | |
3627 | ||
3628 | path->slots[0]++; | |
fc0d82e1 | 3629 | setup_items_for_insert(root, path, new_key, &item_size, 1); |
ad48fd75 YZ |
3630 | leaf = path->nodes[0]; |
3631 | memcpy_extent_buffer(leaf, | |
3632 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
3633 | btrfs_item_ptr_offset(leaf, path->slots[0] - 1), | |
3634 | item_size); | |
3635 | return 0; | |
3636 | } | |
3637 | ||
d352ac68 CM |
3638 | /* |
3639 | * make the item pointed to by the path smaller. new_size indicates | |
3640 | * how small to make it, and from_end tells us if we just chop bytes | |
3641 | * off the end of the item or if we shift the item to chop bytes off | |
3642 | * the front. | |
3643 | */ | |
78ac4f9e | 3644 | void btrfs_truncate_item(struct btrfs_path *path, u32 new_size, int from_end) |
b18c6685 | 3645 | { |
b18c6685 | 3646 | int slot; |
5f39d397 CM |
3647 | struct extent_buffer *leaf; |
3648 | struct btrfs_item *item; | |
b18c6685 CM |
3649 | u32 nritems; |
3650 | unsigned int data_end; | |
3651 | unsigned int old_data_start; | |
3652 | unsigned int old_size; | |
3653 | unsigned int size_diff; | |
3654 | int i; | |
cfed81a0 CM |
3655 | struct btrfs_map_token token; |
3656 | ||
5f39d397 | 3657 | leaf = path->nodes[0]; |
179e29e4 CM |
3658 | slot = path->slots[0]; |
3659 | ||
3660 | old_size = btrfs_item_size_nr(leaf, slot); | |
3661 | if (old_size == new_size) | |
143bede5 | 3662 | return; |
b18c6685 | 3663 | |
5f39d397 | 3664 | nritems = btrfs_header_nritems(leaf); |
8f881e8c | 3665 | data_end = leaf_data_end(leaf); |
b18c6685 | 3666 | |
5f39d397 | 3667 | old_data_start = btrfs_item_offset_nr(leaf, slot); |
179e29e4 | 3668 | |
b18c6685 CM |
3669 | size_diff = old_size - new_size; |
3670 | ||
3671 | BUG_ON(slot < 0); | |
3672 | BUG_ON(slot >= nritems); | |
3673 | ||
3674 | /* | |
3675 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3676 | */ | |
3677 | /* first correct the data pointers */ | |
c82f823c | 3678 | btrfs_init_map_token(&token, leaf); |
b18c6685 | 3679 | for (i = slot; i < nritems; i++) { |
5f39d397 | 3680 | u32 ioff; |
dd3cc16b | 3681 | item = btrfs_item_nr(i); |
db94535d | 3682 | |
cc4c13d5 DS |
3683 | ioff = btrfs_token_item_offset(&token, item); |
3684 | btrfs_set_token_item_offset(&token, item, ioff + size_diff); | |
b18c6685 | 3685 | } |
db94535d | 3686 | |
b18c6685 | 3687 | /* shift the data */ |
179e29e4 | 3688 | if (from_end) { |
3d9ec8c4 NB |
3689 | memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + |
3690 | data_end + size_diff, BTRFS_LEAF_DATA_OFFSET + | |
179e29e4 CM |
3691 | data_end, old_data_start + new_size - data_end); |
3692 | } else { | |
3693 | struct btrfs_disk_key disk_key; | |
3694 | u64 offset; | |
3695 | ||
3696 | btrfs_item_key(leaf, &disk_key, slot); | |
3697 | ||
3698 | if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) { | |
3699 | unsigned long ptr; | |
3700 | struct btrfs_file_extent_item *fi; | |
3701 | ||
3702 | fi = btrfs_item_ptr(leaf, slot, | |
3703 | struct btrfs_file_extent_item); | |
3704 | fi = (struct btrfs_file_extent_item *)( | |
3705 | (unsigned long)fi - size_diff); | |
3706 | ||
3707 | if (btrfs_file_extent_type(leaf, fi) == | |
3708 | BTRFS_FILE_EXTENT_INLINE) { | |
3709 | ptr = btrfs_item_ptr_offset(leaf, slot); | |
3710 | memmove_extent_buffer(leaf, ptr, | |
d397712b | 3711 | (unsigned long)fi, |
7ec20afb | 3712 | BTRFS_FILE_EXTENT_INLINE_DATA_START); |
179e29e4 CM |
3713 | } |
3714 | } | |
3715 | ||
3d9ec8c4 NB |
3716 | memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + |
3717 | data_end + size_diff, BTRFS_LEAF_DATA_OFFSET + | |
179e29e4 CM |
3718 | data_end, old_data_start - data_end); |
3719 | ||
3720 | offset = btrfs_disk_key_offset(&disk_key); | |
3721 | btrfs_set_disk_key_offset(&disk_key, offset + size_diff); | |
3722 | btrfs_set_item_key(leaf, &disk_key, slot); | |
3723 | if (slot == 0) | |
b167fa91 | 3724 | fixup_low_keys(path, &disk_key, 1); |
179e29e4 | 3725 | } |
5f39d397 | 3726 | |
dd3cc16b | 3727 | item = btrfs_item_nr(slot); |
5f39d397 CM |
3728 | btrfs_set_item_size(leaf, item, new_size); |
3729 | btrfs_mark_buffer_dirty(leaf); | |
b18c6685 | 3730 | |
e902baac | 3731 | if (btrfs_leaf_free_space(leaf) < 0) { |
a4f78750 | 3732 | btrfs_print_leaf(leaf); |
b18c6685 | 3733 | BUG(); |
5f39d397 | 3734 | } |
b18c6685 CM |
3735 | } |
3736 | ||
d352ac68 | 3737 | /* |
8f69dbd2 | 3738 | * make the item pointed to by the path bigger, data_size is the added size. |
d352ac68 | 3739 | */ |
c71dd880 | 3740 | void btrfs_extend_item(struct btrfs_path *path, u32 data_size) |
6567e837 | 3741 | { |
6567e837 | 3742 | int slot; |
5f39d397 CM |
3743 | struct extent_buffer *leaf; |
3744 | struct btrfs_item *item; | |
6567e837 CM |
3745 | u32 nritems; |
3746 | unsigned int data_end; | |
3747 | unsigned int old_data; | |
3748 | unsigned int old_size; | |
3749 | int i; | |
cfed81a0 CM |
3750 | struct btrfs_map_token token; |
3751 | ||
5f39d397 | 3752 | leaf = path->nodes[0]; |
6567e837 | 3753 | |
5f39d397 | 3754 | nritems = btrfs_header_nritems(leaf); |
8f881e8c | 3755 | data_end = leaf_data_end(leaf); |
6567e837 | 3756 | |
e902baac | 3757 | if (btrfs_leaf_free_space(leaf) < data_size) { |
a4f78750 | 3758 | btrfs_print_leaf(leaf); |
6567e837 | 3759 | BUG(); |
5f39d397 | 3760 | } |
6567e837 | 3761 | slot = path->slots[0]; |
5f39d397 | 3762 | old_data = btrfs_item_end_nr(leaf, slot); |
6567e837 CM |
3763 | |
3764 | BUG_ON(slot < 0); | |
3326d1b0 | 3765 | if (slot >= nritems) { |
a4f78750 | 3766 | btrfs_print_leaf(leaf); |
c71dd880 | 3767 | btrfs_crit(leaf->fs_info, "slot %d too large, nritems %d", |
0b246afa | 3768 | slot, nritems); |
290342f6 | 3769 | BUG(); |
3326d1b0 | 3770 | } |
6567e837 CM |
3771 | |
3772 | /* | |
3773 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3774 | */ | |
3775 | /* first correct the data pointers */ | |
c82f823c | 3776 | btrfs_init_map_token(&token, leaf); |
6567e837 | 3777 | for (i = slot; i < nritems; i++) { |
5f39d397 | 3778 | u32 ioff; |
dd3cc16b | 3779 | item = btrfs_item_nr(i); |
db94535d | 3780 | |
cc4c13d5 DS |
3781 | ioff = btrfs_token_item_offset(&token, item); |
3782 | btrfs_set_token_item_offset(&token, item, ioff - data_size); | |
6567e837 | 3783 | } |
5f39d397 | 3784 | |
6567e837 | 3785 | /* shift the data */ |
3d9ec8c4 NB |
3786 | memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + |
3787 | data_end - data_size, BTRFS_LEAF_DATA_OFFSET + | |
6567e837 | 3788 | data_end, old_data - data_end); |
5f39d397 | 3789 | |
6567e837 | 3790 | data_end = old_data; |
5f39d397 | 3791 | old_size = btrfs_item_size_nr(leaf, slot); |
dd3cc16b | 3792 | item = btrfs_item_nr(slot); |
5f39d397 CM |
3793 | btrfs_set_item_size(leaf, item, old_size + data_size); |
3794 | btrfs_mark_buffer_dirty(leaf); | |
6567e837 | 3795 | |
e902baac | 3796 | if (btrfs_leaf_free_space(leaf) < 0) { |
a4f78750 | 3797 | btrfs_print_leaf(leaf); |
6567e837 | 3798 | BUG(); |
5f39d397 | 3799 | } |
6567e837 CM |
3800 | } |
3801 | ||
da9ffb24 NB |
3802 | /** |
3803 | * setup_items_for_insert - Helper called before inserting one or more items | |
3804 | * to a leaf. Main purpose is to save stack depth by doing the bulk of the work | |
3805 | * in a function that doesn't call btrfs_search_slot | |
3806 | * | |
3807 | * @root: root we are inserting items to | |
3808 | * @path: points to the leaf/slot where we are going to insert new items | |
3809 | * @cpu_key: array of keys for items to be inserted | |
3810 | * @data_size: size of the body of each item we are going to insert | |
3811 | * @nr: size of @cpu_key/@data_size arrays | |
74123bd7 | 3812 | */ |
afe5fea7 | 3813 | void setup_items_for_insert(struct btrfs_root *root, struct btrfs_path *path, |
310712b2 | 3814 | const struct btrfs_key *cpu_key, u32 *data_size, |
fc0d82e1 | 3815 | int nr) |
be0e5c09 | 3816 | { |
0b246afa | 3817 | struct btrfs_fs_info *fs_info = root->fs_info; |
5f39d397 | 3818 | struct btrfs_item *item; |
9c58309d | 3819 | int i; |
7518a238 | 3820 | u32 nritems; |
be0e5c09 | 3821 | unsigned int data_end; |
e2fa7227 | 3822 | struct btrfs_disk_key disk_key; |
44871b1b CM |
3823 | struct extent_buffer *leaf; |
3824 | int slot; | |
cfed81a0 | 3825 | struct btrfs_map_token token; |
fc0d82e1 NB |
3826 | u32 total_size; |
3827 | u32 total_data = 0; | |
3828 | ||
3829 | for (i = 0; i < nr; i++) | |
3830 | total_data += data_size[i]; | |
3831 | total_size = total_data + (nr * sizeof(struct btrfs_item)); | |
cfed81a0 | 3832 | |
24cdc847 FM |
3833 | if (path->slots[0] == 0) { |
3834 | btrfs_cpu_key_to_disk(&disk_key, cpu_key); | |
b167fa91 | 3835 | fixup_low_keys(path, &disk_key, 1); |
24cdc847 FM |
3836 | } |
3837 | btrfs_unlock_up_safe(path, 1); | |
3838 | ||
5f39d397 | 3839 | leaf = path->nodes[0]; |
44871b1b | 3840 | slot = path->slots[0]; |
74123bd7 | 3841 | |
5f39d397 | 3842 | nritems = btrfs_header_nritems(leaf); |
8f881e8c | 3843 | data_end = leaf_data_end(leaf); |
eb60ceac | 3844 | |
e902baac | 3845 | if (btrfs_leaf_free_space(leaf) < total_size) { |
a4f78750 | 3846 | btrfs_print_leaf(leaf); |
0b246afa | 3847 | btrfs_crit(fs_info, "not enough freespace need %u have %d", |
e902baac | 3848 | total_size, btrfs_leaf_free_space(leaf)); |
be0e5c09 | 3849 | BUG(); |
d4dbff95 | 3850 | } |
5f39d397 | 3851 | |
c82f823c | 3852 | btrfs_init_map_token(&token, leaf); |
be0e5c09 | 3853 | if (slot != nritems) { |
5f39d397 | 3854 | unsigned int old_data = btrfs_item_end_nr(leaf, slot); |
be0e5c09 | 3855 | |
5f39d397 | 3856 | if (old_data < data_end) { |
a4f78750 | 3857 | btrfs_print_leaf(leaf); |
7269ddd2 NB |
3858 | btrfs_crit(fs_info, |
3859 | "item at slot %d with data offset %u beyond data end of leaf %u", | |
5d163e0e | 3860 | slot, old_data, data_end); |
290342f6 | 3861 | BUG(); |
5f39d397 | 3862 | } |
be0e5c09 CM |
3863 | /* |
3864 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3865 | */ | |
3866 | /* first correct the data pointers */ | |
0783fcfc | 3867 | for (i = slot; i < nritems; i++) { |
5f39d397 | 3868 | u32 ioff; |
db94535d | 3869 | |
62e85577 | 3870 | item = btrfs_item_nr(i); |
cc4c13d5 DS |
3871 | ioff = btrfs_token_item_offset(&token, item); |
3872 | btrfs_set_token_item_offset(&token, item, | |
3873 | ioff - total_data); | |
0783fcfc | 3874 | } |
be0e5c09 | 3875 | /* shift the items */ |
9c58309d | 3876 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr), |
5f39d397 | 3877 | btrfs_item_nr_offset(slot), |
d6025579 | 3878 | (nritems - slot) * sizeof(struct btrfs_item)); |
be0e5c09 CM |
3879 | |
3880 | /* shift the data */ | |
3d9ec8c4 NB |
3881 | memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + |
3882 | data_end - total_data, BTRFS_LEAF_DATA_OFFSET + | |
d6025579 | 3883 | data_end, old_data - data_end); |
be0e5c09 CM |
3884 | data_end = old_data; |
3885 | } | |
5f39d397 | 3886 | |
62e2749e | 3887 | /* setup the item for the new data */ |
9c58309d CM |
3888 | for (i = 0; i < nr; i++) { |
3889 | btrfs_cpu_key_to_disk(&disk_key, cpu_key + i); | |
3890 | btrfs_set_item_key(leaf, &disk_key, slot + i); | |
dd3cc16b | 3891 | item = btrfs_item_nr(slot + i); |
9c58309d | 3892 | data_end -= data_size[i]; |
fc0716c2 | 3893 | btrfs_set_token_item_offset(&token, item, data_end); |
cc4c13d5 | 3894 | btrfs_set_token_item_size(&token, item, data_size[i]); |
9c58309d | 3895 | } |
44871b1b | 3896 | |
9c58309d | 3897 | btrfs_set_header_nritems(leaf, nritems + nr); |
b9473439 | 3898 | btrfs_mark_buffer_dirty(leaf); |
aa5d6bed | 3899 | |
e902baac | 3900 | if (btrfs_leaf_free_space(leaf) < 0) { |
a4f78750 | 3901 | btrfs_print_leaf(leaf); |
be0e5c09 | 3902 | BUG(); |
5f39d397 | 3903 | } |
44871b1b CM |
3904 | } |
3905 | ||
3906 | /* | |
3907 | * Given a key and some data, insert items into the tree. | |
3908 | * This does all the path init required, making room in the tree if needed. | |
3909 | */ | |
3910 | int btrfs_insert_empty_items(struct btrfs_trans_handle *trans, | |
3911 | struct btrfs_root *root, | |
3912 | struct btrfs_path *path, | |
310712b2 | 3913 | const struct btrfs_key *cpu_key, u32 *data_size, |
44871b1b CM |
3914 | int nr) |
3915 | { | |
44871b1b CM |
3916 | int ret = 0; |
3917 | int slot; | |
3918 | int i; | |
3919 | u32 total_size = 0; | |
3920 | u32 total_data = 0; | |
3921 | ||
3922 | for (i = 0; i < nr; i++) | |
3923 | total_data += data_size[i]; | |
3924 | ||
3925 | total_size = total_data + (nr * sizeof(struct btrfs_item)); | |
3926 | ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1); | |
3927 | if (ret == 0) | |
3928 | return -EEXIST; | |
3929 | if (ret < 0) | |
143bede5 | 3930 | return ret; |
44871b1b | 3931 | |
44871b1b CM |
3932 | slot = path->slots[0]; |
3933 | BUG_ON(slot < 0); | |
3934 | ||
fc0d82e1 | 3935 | setup_items_for_insert(root, path, cpu_key, data_size, nr); |
143bede5 | 3936 | return 0; |
62e2749e CM |
3937 | } |
3938 | ||
3939 | /* | |
3940 | * Given a key and some data, insert an item into the tree. | |
3941 | * This does all the path init required, making room in the tree if needed. | |
3942 | */ | |
310712b2 OS |
3943 | int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
3944 | const struct btrfs_key *cpu_key, void *data, | |
3945 | u32 data_size) | |
62e2749e CM |
3946 | { |
3947 | int ret = 0; | |
2c90e5d6 | 3948 | struct btrfs_path *path; |
5f39d397 CM |
3949 | struct extent_buffer *leaf; |
3950 | unsigned long ptr; | |
62e2749e | 3951 | |
2c90e5d6 | 3952 | path = btrfs_alloc_path(); |
db5b493a TI |
3953 | if (!path) |
3954 | return -ENOMEM; | |
2c90e5d6 | 3955 | ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size); |
62e2749e | 3956 | if (!ret) { |
5f39d397 CM |
3957 | leaf = path->nodes[0]; |
3958 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
3959 | write_extent_buffer(leaf, data, ptr, data_size); | |
3960 | btrfs_mark_buffer_dirty(leaf); | |
62e2749e | 3961 | } |
2c90e5d6 | 3962 | btrfs_free_path(path); |
aa5d6bed | 3963 | return ret; |
be0e5c09 CM |
3964 | } |
3965 | ||
74123bd7 | 3966 | /* |
5de08d7d | 3967 | * delete the pointer from a given node. |
74123bd7 | 3968 | * |
d352ac68 CM |
3969 | * the tree should have been previously balanced so the deletion does not |
3970 | * empty a node. | |
74123bd7 | 3971 | */ |
afe5fea7 TI |
3972 | static void del_ptr(struct btrfs_root *root, struct btrfs_path *path, |
3973 | int level, int slot) | |
be0e5c09 | 3974 | { |
5f39d397 | 3975 | struct extent_buffer *parent = path->nodes[level]; |
7518a238 | 3976 | u32 nritems; |
f3ea38da | 3977 | int ret; |
be0e5c09 | 3978 | |
5f39d397 | 3979 | nritems = btrfs_header_nritems(parent); |
d397712b | 3980 | if (slot != nritems - 1) { |
bf1d3425 | 3981 | if (level) { |
f3a84ccd FM |
3982 | ret = btrfs_tree_mod_log_insert_move(parent, slot, |
3983 | slot + 1, nritems - slot - 1); | |
bf1d3425 DS |
3984 | BUG_ON(ret < 0); |
3985 | } | |
5f39d397 CM |
3986 | memmove_extent_buffer(parent, |
3987 | btrfs_node_key_ptr_offset(slot), | |
3988 | btrfs_node_key_ptr_offset(slot + 1), | |
d6025579 CM |
3989 | sizeof(struct btrfs_key_ptr) * |
3990 | (nritems - slot - 1)); | |
57ba86c0 | 3991 | } else if (level) { |
f3a84ccd FM |
3992 | ret = btrfs_tree_mod_log_insert_key(parent, slot, |
3993 | BTRFS_MOD_LOG_KEY_REMOVE, GFP_NOFS); | |
57ba86c0 | 3994 | BUG_ON(ret < 0); |
bb803951 | 3995 | } |
f3ea38da | 3996 | |
7518a238 | 3997 | nritems--; |
5f39d397 | 3998 | btrfs_set_header_nritems(parent, nritems); |
7518a238 | 3999 | if (nritems == 0 && parent == root->node) { |
5f39d397 | 4000 | BUG_ON(btrfs_header_level(root->node) != 1); |
bb803951 | 4001 | /* just turn the root into a leaf and break */ |
5f39d397 | 4002 | btrfs_set_header_level(root->node, 0); |
bb803951 | 4003 | } else if (slot == 0) { |
5f39d397 CM |
4004 | struct btrfs_disk_key disk_key; |
4005 | ||
4006 | btrfs_node_key(parent, &disk_key, 0); | |
b167fa91 | 4007 | fixup_low_keys(path, &disk_key, level + 1); |
be0e5c09 | 4008 | } |
d6025579 | 4009 | btrfs_mark_buffer_dirty(parent); |
be0e5c09 CM |
4010 | } |
4011 | ||
323ac95b CM |
4012 | /* |
4013 | * a helper function to delete the leaf pointed to by path->slots[1] and | |
5d4f98a2 | 4014 | * path->nodes[1]. |
323ac95b CM |
4015 | * |
4016 | * This deletes the pointer in path->nodes[1] and frees the leaf | |
4017 | * block extent. zero is returned if it all worked out, < 0 otherwise. | |
4018 | * | |
4019 | * The path must have already been setup for deleting the leaf, including | |
4020 | * all the proper balancing. path->nodes[1] must be locked. | |
4021 | */ | |
143bede5 JM |
4022 | static noinline void btrfs_del_leaf(struct btrfs_trans_handle *trans, |
4023 | struct btrfs_root *root, | |
4024 | struct btrfs_path *path, | |
4025 | struct extent_buffer *leaf) | |
323ac95b | 4026 | { |
5d4f98a2 | 4027 | WARN_ON(btrfs_header_generation(leaf) != trans->transid); |
afe5fea7 | 4028 | del_ptr(root, path, 1, path->slots[1]); |
323ac95b | 4029 | |
4d081c41 CM |
4030 | /* |
4031 | * btrfs_free_extent is expensive, we want to make sure we | |
4032 | * aren't holding any locks when we call it | |
4033 | */ | |
4034 | btrfs_unlock_up_safe(path, 0); | |
4035 | ||
f0486c68 YZ |
4036 | root_sub_used(root, leaf->len); |
4037 | ||
67439dad | 4038 | atomic_inc(&leaf->refs); |
5581a51a | 4039 | btrfs_free_tree_block(trans, root, leaf, 0, 1); |
3083ee2e | 4040 | free_extent_buffer_stale(leaf); |
323ac95b | 4041 | } |
74123bd7 CM |
4042 | /* |
4043 | * delete the item at the leaf level in path. If that empties | |
4044 | * the leaf, remove it from the tree | |
4045 | */ | |
85e21bac CM |
4046 | int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
4047 | struct btrfs_path *path, int slot, int nr) | |
be0e5c09 | 4048 | { |
0b246afa | 4049 | struct btrfs_fs_info *fs_info = root->fs_info; |
5f39d397 CM |
4050 | struct extent_buffer *leaf; |
4051 | struct btrfs_item *item; | |
ce0eac2a AM |
4052 | u32 last_off; |
4053 | u32 dsize = 0; | |
aa5d6bed CM |
4054 | int ret = 0; |
4055 | int wret; | |
85e21bac | 4056 | int i; |
7518a238 | 4057 | u32 nritems; |
be0e5c09 | 4058 | |
5f39d397 | 4059 | leaf = path->nodes[0]; |
85e21bac CM |
4060 | last_off = btrfs_item_offset_nr(leaf, slot + nr - 1); |
4061 | ||
4062 | for (i = 0; i < nr; i++) | |
4063 | dsize += btrfs_item_size_nr(leaf, slot + i); | |
4064 | ||
5f39d397 | 4065 | nritems = btrfs_header_nritems(leaf); |
be0e5c09 | 4066 | |
85e21bac | 4067 | if (slot + nr != nritems) { |
8f881e8c | 4068 | int data_end = leaf_data_end(leaf); |
c82f823c | 4069 | struct btrfs_map_token token; |
5f39d397 | 4070 | |
3d9ec8c4 | 4071 | memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + |
d6025579 | 4072 | data_end + dsize, |
3d9ec8c4 | 4073 | BTRFS_LEAF_DATA_OFFSET + data_end, |
85e21bac | 4074 | last_off - data_end); |
5f39d397 | 4075 | |
c82f823c | 4076 | btrfs_init_map_token(&token, leaf); |
85e21bac | 4077 | for (i = slot + nr; i < nritems; i++) { |
5f39d397 | 4078 | u32 ioff; |
db94535d | 4079 | |
dd3cc16b | 4080 | item = btrfs_item_nr(i); |
cc4c13d5 DS |
4081 | ioff = btrfs_token_item_offset(&token, item); |
4082 | btrfs_set_token_item_offset(&token, item, ioff + dsize); | |
0783fcfc | 4083 | } |
db94535d | 4084 | |
5f39d397 | 4085 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot), |
85e21bac | 4086 | btrfs_item_nr_offset(slot + nr), |
d6025579 | 4087 | sizeof(struct btrfs_item) * |
85e21bac | 4088 | (nritems - slot - nr)); |
be0e5c09 | 4089 | } |
85e21bac CM |
4090 | btrfs_set_header_nritems(leaf, nritems - nr); |
4091 | nritems -= nr; | |
5f39d397 | 4092 | |
74123bd7 | 4093 | /* delete the leaf if we've emptied it */ |
7518a238 | 4094 | if (nritems == 0) { |
5f39d397 CM |
4095 | if (leaf == root->node) { |
4096 | btrfs_set_header_level(leaf, 0); | |
9a8dd150 | 4097 | } else { |
6a884d7d | 4098 | btrfs_clean_tree_block(leaf); |
143bede5 | 4099 | btrfs_del_leaf(trans, root, path, leaf); |
9a8dd150 | 4100 | } |
be0e5c09 | 4101 | } else { |
7518a238 | 4102 | int used = leaf_space_used(leaf, 0, nritems); |
aa5d6bed | 4103 | if (slot == 0) { |
5f39d397 CM |
4104 | struct btrfs_disk_key disk_key; |
4105 | ||
4106 | btrfs_item_key(leaf, &disk_key, 0); | |
b167fa91 | 4107 | fixup_low_keys(path, &disk_key, 1); |
aa5d6bed | 4108 | } |
aa5d6bed | 4109 | |
74123bd7 | 4110 | /* delete the leaf if it is mostly empty */ |
0b246afa | 4111 | if (used < BTRFS_LEAF_DATA_SIZE(fs_info) / 3) { |
be0e5c09 CM |
4112 | /* push_leaf_left fixes the path. |
4113 | * make sure the path still points to our leaf | |
4114 | * for possible call to del_ptr below | |
4115 | */ | |
4920c9ac | 4116 | slot = path->slots[1]; |
67439dad | 4117 | atomic_inc(&leaf->refs); |
5f39d397 | 4118 | |
99d8f83c CM |
4119 | wret = push_leaf_left(trans, root, path, 1, 1, |
4120 | 1, (u32)-1); | |
54aa1f4d | 4121 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed | 4122 | ret = wret; |
5f39d397 CM |
4123 | |
4124 | if (path->nodes[0] == leaf && | |
4125 | btrfs_header_nritems(leaf)) { | |
99d8f83c CM |
4126 | wret = push_leaf_right(trans, root, path, 1, |
4127 | 1, 1, 0); | |
54aa1f4d | 4128 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed CM |
4129 | ret = wret; |
4130 | } | |
5f39d397 CM |
4131 | |
4132 | if (btrfs_header_nritems(leaf) == 0) { | |
323ac95b | 4133 | path->slots[1] = slot; |
143bede5 | 4134 | btrfs_del_leaf(trans, root, path, leaf); |
5f39d397 | 4135 | free_extent_buffer(leaf); |
143bede5 | 4136 | ret = 0; |
5de08d7d | 4137 | } else { |
925baedd CM |
4138 | /* if we're still in the path, make sure |
4139 | * we're dirty. Otherwise, one of the | |
4140 | * push_leaf functions must have already | |
4141 | * dirtied this buffer | |
4142 | */ | |
4143 | if (path->nodes[0] == leaf) | |
4144 | btrfs_mark_buffer_dirty(leaf); | |
5f39d397 | 4145 | free_extent_buffer(leaf); |
be0e5c09 | 4146 | } |
d5719762 | 4147 | } else { |
5f39d397 | 4148 | btrfs_mark_buffer_dirty(leaf); |
be0e5c09 CM |
4149 | } |
4150 | } | |
aa5d6bed | 4151 | return ret; |
be0e5c09 CM |
4152 | } |
4153 | ||
7bb86316 | 4154 | /* |
925baedd | 4155 | * search the tree again to find a leaf with lesser keys |
7bb86316 CM |
4156 | * returns 0 if it found something or 1 if there are no lesser leaves. |
4157 | * returns < 0 on io errors. | |
d352ac68 CM |
4158 | * |
4159 | * This may release the path, and so you may lose any locks held at the | |
4160 | * time you call it. | |
7bb86316 | 4161 | */ |
16e7549f | 4162 | int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) |
7bb86316 | 4163 | { |
925baedd CM |
4164 | struct btrfs_key key; |
4165 | struct btrfs_disk_key found_key; | |
4166 | int ret; | |
7bb86316 | 4167 | |
925baedd | 4168 | btrfs_item_key_to_cpu(path->nodes[0], &key, 0); |
7bb86316 | 4169 | |
e8b0d724 | 4170 | if (key.offset > 0) { |
925baedd | 4171 | key.offset--; |
e8b0d724 | 4172 | } else if (key.type > 0) { |
925baedd | 4173 | key.type--; |
e8b0d724 FDBM |
4174 | key.offset = (u64)-1; |
4175 | } else if (key.objectid > 0) { | |
925baedd | 4176 | key.objectid--; |
e8b0d724 FDBM |
4177 | key.type = (u8)-1; |
4178 | key.offset = (u64)-1; | |
4179 | } else { | |
925baedd | 4180 | return 1; |
e8b0d724 | 4181 | } |
7bb86316 | 4182 | |
b3b4aa74 | 4183 | btrfs_release_path(path); |
925baedd CM |
4184 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
4185 | if (ret < 0) | |
4186 | return ret; | |
4187 | btrfs_item_key(path->nodes[0], &found_key, 0); | |
4188 | ret = comp_keys(&found_key, &key); | |
337c6f68 FM |
4189 | /* |
4190 | * We might have had an item with the previous key in the tree right | |
4191 | * before we released our path. And after we released our path, that | |
4192 | * item might have been pushed to the first slot (0) of the leaf we | |
4193 | * were holding due to a tree balance. Alternatively, an item with the | |
4194 | * previous key can exist as the only element of a leaf (big fat item). | |
4195 | * Therefore account for these 2 cases, so that our callers (like | |
4196 | * btrfs_previous_item) don't miss an existing item with a key matching | |
4197 | * the previous key we computed above. | |
4198 | */ | |
4199 | if (ret <= 0) | |
925baedd CM |
4200 | return 0; |
4201 | return 1; | |
7bb86316 CM |
4202 | } |
4203 | ||
3f157a2f CM |
4204 | /* |
4205 | * A helper function to walk down the tree starting at min_key, and looking | |
de78b51a ES |
4206 | * for nodes or leaves that are have a minimum transaction id. |
4207 | * This is used by the btree defrag code, and tree logging | |
3f157a2f CM |
4208 | * |
4209 | * This does not cow, but it does stuff the starting key it finds back | |
4210 | * into min_key, so you can call btrfs_search_slot with cow=1 on the | |
4211 | * key and get a writable path. | |
4212 | * | |
3f157a2f CM |
4213 | * This honors path->lowest_level to prevent descent past a given level |
4214 | * of the tree. | |
4215 | * | |
d352ac68 CM |
4216 | * min_trans indicates the oldest transaction that you are interested |
4217 | * in walking through. Any nodes or leaves older than min_trans are | |
4218 | * skipped over (without reading them). | |
4219 | * | |
3f157a2f CM |
4220 | * returns zero if something useful was found, < 0 on error and 1 if there |
4221 | * was nothing in the tree that matched the search criteria. | |
4222 | */ | |
4223 | int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key, | |
de78b51a | 4224 | struct btrfs_path *path, |
3f157a2f CM |
4225 | u64 min_trans) |
4226 | { | |
4227 | struct extent_buffer *cur; | |
4228 | struct btrfs_key found_key; | |
4229 | int slot; | |
9652480b | 4230 | int sret; |
3f157a2f CM |
4231 | u32 nritems; |
4232 | int level; | |
4233 | int ret = 1; | |
f98de9b9 | 4234 | int keep_locks = path->keep_locks; |
3f157a2f | 4235 | |
f98de9b9 | 4236 | path->keep_locks = 1; |
3f157a2f | 4237 | again: |
bd681513 | 4238 | cur = btrfs_read_lock_root_node(root); |
3f157a2f | 4239 | level = btrfs_header_level(cur); |
e02119d5 | 4240 | WARN_ON(path->nodes[level]); |
3f157a2f | 4241 | path->nodes[level] = cur; |
bd681513 | 4242 | path->locks[level] = BTRFS_READ_LOCK; |
3f157a2f CM |
4243 | |
4244 | if (btrfs_header_generation(cur) < min_trans) { | |
4245 | ret = 1; | |
4246 | goto out; | |
4247 | } | |
d397712b | 4248 | while (1) { |
3f157a2f CM |
4249 | nritems = btrfs_header_nritems(cur); |
4250 | level = btrfs_header_level(cur); | |
e3b83361 | 4251 | sret = btrfs_bin_search(cur, min_key, &slot); |
cbca7d59 FM |
4252 | if (sret < 0) { |
4253 | ret = sret; | |
4254 | goto out; | |
4255 | } | |
3f157a2f | 4256 | |
323ac95b CM |
4257 | /* at the lowest level, we're done, setup the path and exit */ |
4258 | if (level == path->lowest_level) { | |
e02119d5 CM |
4259 | if (slot >= nritems) |
4260 | goto find_next_key; | |
3f157a2f CM |
4261 | ret = 0; |
4262 | path->slots[level] = slot; | |
4263 | btrfs_item_key_to_cpu(cur, &found_key, slot); | |
4264 | goto out; | |
4265 | } | |
9652480b Y |
4266 | if (sret && slot > 0) |
4267 | slot--; | |
3f157a2f | 4268 | /* |
de78b51a | 4269 | * check this node pointer against the min_trans parameters. |
260db43c | 4270 | * If it is too old, skip to the next one. |
3f157a2f | 4271 | */ |
d397712b | 4272 | while (slot < nritems) { |
3f157a2f | 4273 | u64 gen; |
e02119d5 | 4274 | |
3f157a2f CM |
4275 | gen = btrfs_node_ptr_generation(cur, slot); |
4276 | if (gen < min_trans) { | |
4277 | slot++; | |
4278 | continue; | |
4279 | } | |
de78b51a | 4280 | break; |
3f157a2f | 4281 | } |
e02119d5 | 4282 | find_next_key: |
3f157a2f CM |
4283 | /* |
4284 | * we didn't find a candidate key in this node, walk forward | |
4285 | * and find another one | |
4286 | */ | |
4287 | if (slot >= nritems) { | |
e02119d5 CM |
4288 | path->slots[level] = slot; |
4289 | sret = btrfs_find_next_key(root, path, min_key, level, | |
de78b51a | 4290 | min_trans); |
e02119d5 | 4291 | if (sret == 0) { |
b3b4aa74 | 4292 | btrfs_release_path(path); |
3f157a2f CM |
4293 | goto again; |
4294 | } else { | |
4295 | goto out; | |
4296 | } | |
4297 | } | |
4298 | /* save our key for returning back */ | |
4299 | btrfs_node_key_to_cpu(cur, &found_key, slot); | |
4300 | path->slots[level] = slot; | |
4301 | if (level == path->lowest_level) { | |
4302 | ret = 0; | |
3f157a2f CM |
4303 | goto out; |
4304 | } | |
4b231ae4 | 4305 | cur = btrfs_read_node_slot(cur, slot); |
fb770ae4 LB |
4306 | if (IS_ERR(cur)) { |
4307 | ret = PTR_ERR(cur); | |
4308 | goto out; | |
4309 | } | |
3f157a2f | 4310 | |
bd681513 | 4311 | btrfs_tree_read_lock(cur); |
b4ce94de | 4312 | |
bd681513 | 4313 | path->locks[level - 1] = BTRFS_READ_LOCK; |
3f157a2f | 4314 | path->nodes[level - 1] = cur; |
f7c79f30 | 4315 | unlock_up(path, level, 1, 0, NULL); |
3f157a2f CM |
4316 | } |
4317 | out: | |
f98de9b9 FM |
4318 | path->keep_locks = keep_locks; |
4319 | if (ret == 0) { | |
4320 | btrfs_unlock_up_safe(path, path->lowest_level + 1); | |
3f157a2f | 4321 | memcpy(min_key, &found_key, sizeof(found_key)); |
f98de9b9 | 4322 | } |
3f157a2f CM |
4323 | return ret; |
4324 | } | |
4325 | ||
4326 | /* | |
4327 | * this is similar to btrfs_next_leaf, but does not try to preserve | |
4328 | * and fixup the path. It looks for and returns the next key in the | |
de78b51a | 4329 | * tree based on the current path and the min_trans parameters. |
3f157a2f CM |
4330 | * |
4331 | * 0 is returned if another key is found, < 0 if there are any errors | |
4332 | * and 1 is returned if there are no higher keys in the tree | |
4333 | * | |
4334 | * path->keep_locks should be set to 1 on the search made before | |
4335 | * calling this function. | |
4336 | */ | |
e7a84565 | 4337 | int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path, |
de78b51a | 4338 | struct btrfs_key *key, int level, u64 min_trans) |
e7a84565 | 4339 | { |
e7a84565 CM |
4340 | int slot; |
4341 | struct extent_buffer *c; | |
4342 | ||
6a9fb468 | 4343 | WARN_ON(!path->keep_locks && !path->skip_locking); |
d397712b | 4344 | while (level < BTRFS_MAX_LEVEL) { |
e7a84565 CM |
4345 | if (!path->nodes[level]) |
4346 | return 1; | |
4347 | ||
4348 | slot = path->slots[level] + 1; | |
4349 | c = path->nodes[level]; | |
3f157a2f | 4350 | next: |
e7a84565 | 4351 | if (slot >= btrfs_header_nritems(c)) { |
33c66f43 YZ |
4352 | int ret; |
4353 | int orig_lowest; | |
4354 | struct btrfs_key cur_key; | |
4355 | if (level + 1 >= BTRFS_MAX_LEVEL || | |
4356 | !path->nodes[level + 1]) | |
e7a84565 | 4357 | return 1; |
33c66f43 | 4358 | |
6a9fb468 | 4359 | if (path->locks[level + 1] || path->skip_locking) { |
33c66f43 YZ |
4360 | level++; |
4361 | continue; | |
4362 | } | |
4363 | ||
4364 | slot = btrfs_header_nritems(c) - 1; | |
4365 | if (level == 0) | |
4366 | btrfs_item_key_to_cpu(c, &cur_key, slot); | |
4367 | else | |
4368 | btrfs_node_key_to_cpu(c, &cur_key, slot); | |
4369 | ||
4370 | orig_lowest = path->lowest_level; | |
b3b4aa74 | 4371 | btrfs_release_path(path); |
33c66f43 YZ |
4372 | path->lowest_level = level; |
4373 | ret = btrfs_search_slot(NULL, root, &cur_key, path, | |
4374 | 0, 0); | |
4375 | path->lowest_level = orig_lowest; | |
4376 | if (ret < 0) | |
4377 | return ret; | |
4378 | ||
4379 | c = path->nodes[level]; | |
4380 | slot = path->slots[level]; | |
4381 | if (ret == 0) | |
4382 | slot++; | |
4383 | goto next; | |
e7a84565 | 4384 | } |
33c66f43 | 4385 | |
e7a84565 CM |
4386 | if (level == 0) |
4387 | btrfs_item_key_to_cpu(c, key, slot); | |
3f157a2f | 4388 | else { |
3f157a2f CM |
4389 | u64 gen = btrfs_node_ptr_generation(c, slot); |
4390 | ||
3f157a2f CM |
4391 | if (gen < min_trans) { |
4392 | slot++; | |
4393 | goto next; | |
4394 | } | |
e7a84565 | 4395 | btrfs_node_key_to_cpu(c, key, slot); |
3f157a2f | 4396 | } |
e7a84565 CM |
4397 | return 0; |
4398 | } | |
4399 | return 1; | |
4400 | } | |
4401 | ||
97571fd0 | 4402 | /* |
925baedd | 4403 | * search the tree again to find a leaf with greater keys |
0f70abe2 CM |
4404 | * returns 0 if it found something or 1 if there are no greater leaves. |
4405 | * returns < 0 on io errors. | |
97571fd0 | 4406 | */ |
234b63a0 | 4407 | int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) |
3d7806ec JS |
4408 | { |
4409 | return btrfs_next_old_leaf(root, path, 0); | |
4410 | } | |
4411 | ||
4412 | int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path, | |
4413 | u64 time_seq) | |
d97e63b6 CM |
4414 | { |
4415 | int slot; | |
8e73f275 | 4416 | int level; |
5f39d397 | 4417 | struct extent_buffer *c; |
8e73f275 | 4418 | struct extent_buffer *next; |
925baedd CM |
4419 | struct btrfs_key key; |
4420 | u32 nritems; | |
4421 | int ret; | |
0e46318d | 4422 | int i; |
925baedd CM |
4423 | |
4424 | nritems = btrfs_header_nritems(path->nodes[0]); | |
d397712b | 4425 | if (nritems == 0) |
925baedd | 4426 | return 1; |
925baedd | 4427 | |
8e73f275 CM |
4428 | btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1); |
4429 | again: | |
4430 | level = 1; | |
4431 | next = NULL; | |
b3b4aa74 | 4432 | btrfs_release_path(path); |
8e73f275 | 4433 | |
a2135011 | 4434 | path->keep_locks = 1; |
8e73f275 | 4435 | |
3d7806ec JS |
4436 | if (time_seq) |
4437 | ret = btrfs_search_old_slot(root, &key, path, time_seq); | |
4438 | else | |
4439 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); | |
925baedd CM |
4440 | path->keep_locks = 0; |
4441 | ||
4442 | if (ret < 0) | |
4443 | return ret; | |
4444 | ||
a2135011 | 4445 | nritems = btrfs_header_nritems(path->nodes[0]); |
168fd7d2 CM |
4446 | /* |
4447 | * by releasing the path above we dropped all our locks. A balance | |
4448 | * could have added more items next to the key that used to be | |
4449 | * at the very end of the block. So, check again here and | |
4450 | * advance the path if there are now more items available. | |
4451 | */ | |
a2135011 | 4452 | if (nritems > 0 && path->slots[0] < nritems - 1) { |
e457afec YZ |
4453 | if (ret == 0) |
4454 | path->slots[0]++; | |
8e73f275 | 4455 | ret = 0; |
925baedd CM |
4456 | goto done; |
4457 | } | |
0b43e04f LB |
4458 | /* |
4459 | * So the above check misses one case: | |
4460 | * - after releasing the path above, someone has removed the item that | |
4461 | * used to be at the very end of the block, and balance between leafs | |
4462 | * gets another one with bigger key.offset to replace it. | |
4463 | * | |
4464 | * This one should be returned as well, or we can get leaf corruption | |
4465 | * later(esp. in __btrfs_drop_extents()). | |
4466 | * | |
4467 | * And a bit more explanation about this check, | |
4468 | * with ret > 0, the key isn't found, the path points to the slot | |
4469 | * where it should be inserted, so the path->slots[0] item must be the | |
4470 | * bigger one. | |
4471 | */ | |
4472 | if (nritems > 0 && ret > 0 && path->slots[0] == nritems - 1) { | |
4473 | ret = 0; | |
4474 | goto done; | |
4475 | } | |
d97e63b6 | 4476 | |
d397712b | 4477 | while (level < BTRFS_MAX_LEVEL) { |
8e73f275 CM |
4478 | if (!path->nodes[level]) { |
4479 | ret = 1; | |
4480 | goto done; | |
4481 | } | |
5f39d397 | 4482 | |
d97e63b6 CM |
4483 | slot = path->slots[level] + 1; |
4484 | c = path->nodes[level]; | |
5f39d397 | 4485 | if (slot >= btrfs_header_nritems(c)) { |
d97e63b6 | 4486 | level++; |
8e73f275 CM |
4487 | if (level == BTRFS_MAX_LEVEL) { |
4488 | ret = 1; | |
4489 | goto done; | |
4490 | } | |
d97e63b6 CM |
4491 | continue; |
4492 | } | |
5f39d397 | 4493 | |
0e46318d JB |
4494 | |
4495 | /* | |
4496 | * Our current level is where we're going to start from, and to | |
4497 | * make sure lockdep doesn't complain we need to drop our locks | |
4498 | * and nodes from 0 to our current level. | |
4499 | */ | |
4500 | for (i = 0; i < level; i++) { | |
4501 | if (path->locks[level]) { | |
4502 | btrfs_tree_read_unlock(path->nodes[i]); | |
4503 | path->locks[i] = 0; | |
4504 | } | |
4505 | free_extent_buffer(path->nodes[i]); | |
4506 | path->nodes[i] = NULL; | |
925baedd | 4507 | } |
5f39d397 | 4508 | |
8e73f275 | 4509 | next = c; |
d07b8528 | 4510 | ret = read_block_for_search(root, path, &next, level, |
cda79c54 | 4511 | slot, &key); |
8e73f275 CM |
4512 | if (ret == -EAGAIN) |
4513 | goto again; | |
5f39d397 | 4514 | |
76a05b35 | 4515 | if (ret < 0) { |
b3b4aa74 | 4516 | btrfs_release_path(path); |
76a05b35 CM |
4517 | goto done; |
4518 | } | |
4519 | ||
5cd57b2c | 4520 | if (!path->skip_locking) { |
bd681513 | 4521 | ret = btrfs_try_tree_read_lock(next); |
d42244a0 JS |
4522 | if (!ret && time_seq) { |
4523 | /* | |
4524 | * If we don't get the lock, we may be racing | |
4525 | * with push_leaf_left, holding that lock while | |
4526 | * itself waiting for the leaf we've currently | |
4527 | * locked. To solve this situation, we give up | |
4528 | * on our lock and cycle. | |
4529 | */ | |
cf538830 | 4530 | free_extent_buffer(next); |
d42244a0 JS |
4531 | btrfs_release_path(path); |
4532 | cond_resched(); | |
4533 | goto again; | |
4534 | } | |
0e46318d JB |
4535 | if (!ret) |
4536 | btrfs_tree_read_lock(next); | |
5cd57b2c | 4537 | } |
d97e63b6 CM |
4538 | break; |
4539 | } | |
4540 | path->slots[level] = slot; | |
d397712b | 4541 | while (1) { |
d97e63b6 | 4542 | level--; |
d97e63b6 CM |
4543 | path->nodes[level] = next; |
4544 | path->slots[level] = 0; | |
a74a4b97 | 4545 | if (!path->skip_locking) |
ffeb03cf | 4546 | path->locks[level] = BTRFS_READ_LOCK; |
d97e63b6 CM |
4547 | if (!level) |
4548 | break; | |
b4ce94de | 4549 | |
d07b8528 | 4550 | ret = read_block_for_search(root, path, &next, level, |
cda79c54 | 4551 | 0, &key); |
8e73f275 CM |
4552 | if (ret == -EAGAIN) |
4553 | goto again; | |
4554 | ||
76a05b35 | 4555 | if (ret < 0) { |
b3b4aa74 | 4556 | btrfs_release_path(path); |
76a05b35 CM |
4557 | goto done; |
4558 | } | |
4559 | ||
ffeb03cf | 4560 | if (!path->skip_locking) |
0e46318d | 4561 | btrfs_tree_read_lock(next); |
d97e63b6 | 4562 | } |
8e73f275 | 4563 | ret = 0; |
925baedd | 4564 | done: |
f7c79f30 | 4565 | unlock_up(path, 0, 1, 0, NULL); |
8e73f275 CM |
4566 | |
4567 | return ret; | |
d97e63b6 | 4568 | } |
0b86a832 | 4569 | |
3f157a2f CM |
4570 | /* |
4571 | * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps | |
4572 | * searching until it gets past min_objectid or finds an item of 'type' | |
4573 | * | |
4574 | * returns 0 if something is found, 1 if nothing was found and < 0 on error | |
4575 | */ | |
0b86a832 CM |
4576 | int btrfs_previous_item(struct btrfs_root *root, |
4577 | struct btrfs_path *path, u64 min_objectid, | |
4578 | int type) | |
4579 | { | |
4580 | struct btrfs_key found_key; | |
4581 | struct extent_buffer *leaf; | |
e02119d5 | 4582 | u32 nritems; |
0b86a832 CM |
4583 | int ret; |
4584 | ||
d397712b | 4585 | while (1) { |
0b86a832 CM |
4586 | if (path->slots[0] == 0) { |
4587 | ret = btrfs_prev_leaf(root, path); | |
4588 | if (ret != 0) | |
4589 | return ret; | |
4590 | } else { | |
4591 | path->slots[0]--; | |
4592 | } | |
4593 | leaf = path->nodes[0]; | |
e02119d5 CM |
4594 | nritems = btrfs_header_nritems(leaf); |
4595 | if (nritems == 0) | |
4596 | return 1; | |
4597 | if (path->slots[0] == nritems) | |
4598 | path->slots[0]--; | |
4599 | ||
0b86a832 | 4600 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
e02119d5 CM |
4601 | if (found_key.objectid < min_objectid) |
4602 | break; | |
0a4eefbb YZ |
4603 | if (found_key.type == type) |
4604 | return 0; | |
e02119d5 CM |
4605 | if (found_key.objectid == min_objectid && |
4606 | found_key.type < type) | |
4607 | break; | |
0b86a832 CM |
4608 | } |
4609 | return 1; | |
4610 | } | |
ade2e0b3 WS |
4611 | |
4612 | /* | |
4613 | * search in extent tree to find a previous Metadata/Data extent item with | |
4614 | * min objecitd. | |
4615 | * | |
4616 | * returns 0 if something is found, 1 if nothing was found and < 0 on error | |
4617 | */ | |
4618 | int btrfs_previous_extent_item(struct btrfs_root *root, | |
4619 | struct btrfs_path *path, u64 min_objectid) | |
4620 | { | |
4621 | struct btrfs_key found_key; | |
4622 | struct extent_buffer *leaf; | |
4623 | u32 nritems; | |
4624 | int ret; | |
4625 | ||
4626 | while (1) { | |
4627 | if (path->slots[0] == 0) { | |
ade2e0b3 WS |
4628 | ret = btrfs_prev_leaf(root, path); |
4629 | if (ret != 0) | |
4630 | return ret; | |
4631 | } else { | |
4632 | path->slots[0]--; | |
4633 | } | |
4634 | leaf = path->nodes[0]; | |
4635 | nritems = btrfs_header_nritems(leaf); | |
4636 | if (nritems == 0) | |
4637 | return 1; | |
4638 | if (path->slots[0] == nritems) | |
4639 | path->slots[0]--; | |
4640 | ||
4641 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); | |
4642 | if (found_key.objectid < min_objectid) | |
4643 | break; | |
4644 | if (found_key.type == BTRFS_EXTENT_ITEM_KEY || | |
4645 | found_key.type == BTRFS_METADATA_ITEM_KEY) | |
4646 | return 0; | |
4647 | if (found_key.objectid == min_objectid && | |
4648 | found_key.type < BTRFS_EXTENT_ITEM_KEY) | |
4649 | break; | |
4650 | } | |
4651 | return 1; | |
4652 | } |