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6cbd5570 CM |
1 | /* |
2 | * Copyright (C) 2007 Oracle. All rights reserved. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public | |
6 | * License v2 as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | * General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public | |
14 | * License along with this program; if not, write to the | |
15 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
16 | * Boston, MA 021110-1307, USA. | |
17 | */ | |
18 | ||
eb60ceac CM |
19 | #include "ctree.h" |
20 | #include "disk-io.h" | |
7f5c1516 | 21 | #include "transaction.h" |
9a8dd150 | 22 | |
e089f05c CM |
23 | static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root |
24 | *root, struct btrfs_path *path, int level); | |
25 | static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root | |
d4dbff95 CM |
26 | *root, struct btrfs_key *ins_key, |
27 | struct btrfs_path *path, int data_size); | |
e089f05c | 28 | static int push_node_left(struct btrfs_trans_handle *trans, struct btrfs_root |
e20d96d6 | 29 | *root, struct buffer_head *dst, struct buffer_head |
e089f05c CM |
30 | *src); |
31 | static int balance_node_right(struct btrfs_trans_handle *trans, struct | |
e20d96d6 CM |
32 | btrfs_root *root, struct buffer_head *dst_buf, |
33 | struct buffer_head *src_buf); | |
e089f05c CM |
34 | static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
35 | struct btrfs_path *path, int level, int slot); | |
d97e63b6 | 36 | |
df24a2b9 | 37 | inline void btrfs_init_path(struct btrfs_path *p) |
2c90e5d6 | 38 | { |
df24a2b9 | 39 | memset(p, 0, sizeof(*p)); |
2c90e5d6 CM |
40 | } |
41 | ||
df24a2b9 | 42 | struct btrfs_path *btrfs_alloc_path(void) |
2c90e5d6 | 43 | { |
df24a2b9 CM |
44 | struct btrfs_path *path; |
45 | path = kmem_cache_alloc(btrfs_path_cachep, GFP_NOFS); | |
46 | if (path) | |
47 | btrfs_init_path(path); | |
48 | return path; | |
2c90e5d6 CM |
49 | } |
50 | ||
df24a2b9 | 51 | void btrfs_free_path(struct btrfs_path *p) |
be0e5c09 | 52 | { |
df24a2b9 CM |
53 | btrfs_release_path(NULL, p); |
54 | kmem_cache_free(btrfs_path_cachep, p); | |
be0e5c09 CM |
55 | } |
56 | ||
234b63a0 | 57 | void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p) |
eb60ceac CM |
58 | { |
59 | int i; | |
234b63a0 | 60 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) { |
eb60ceac CM |
61 | if (!p->nodes[i]) |
62 | break; | |
234b63a0 | 63 | btrfs_block_release(root, p->nodes[i]); |
eb60ceac | 64 | } |
aa5d6bed | 65 | memset(p, 0, sizeof(*p)); |
eb60ceac CM |
66 | } |
67 | ||
e089f05c | 68 | static int btrfs_cow_block(struct btrfs_trans_handle *trans, struct btrfs_root |
e20d96d6 CM |
69 | *root, struct buffer_head *buf, struct buffer_head |
70 | *parent, int parent_slot, struct buffer_head | |
e089f05c | 71 | **cow_ret) |
02217ed2 | 72 | { |
e20d96d6 CM |
73 | struct buffer_head *cow; |
74 | struct btrfs_node *cow_node; | |
54aa1f4d | 75 | int ret; |
02217ed2 | 76 | |
ccd467d6 CM |
77 | WARN_ON(!buffer_uptodate(buf)); |
78 | if (trans->transaction != root->fs_info->running_transaction) { | |
79 | printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid, | |
80 | root->fs_info->running_transaction->transid); | |
81 | WARN_ON(1); | |
82 | } | |
83 | if (trans->transid != root->fs_info->generation) { | |
84 | printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid, | |
85 | root->fs_info->generation); | |
86 | WARN_ON(1); | |
87 | } | |
7f5c1516 CM |
88 | if (btrfs_header_generation(btrfs_buffer_header(buf)) == |
89 | trans->transid) { | |
02217ed2 CM |
90 | *cow_ret = buf; |
91 | return 0; | |
92 | } | |
31f3c99b | 93 | cow = btrfs_alloc_free_block(trans, root, buf->b_blocknr); |
54aa1f4d CM |
94 | if (IS_ERR(cow)) |
95 | return PTR_ERR(cow); | |
e20d96d6 | 96 | cow_node = btrfs_buffer_node(cow); |
2c90e5d6 CM |
97 | if (buf->b_size != root->blocksize || cow->b_size != root->blocksize) |
98 | WARN_ON(1); | |
e20d96d6 | 99 | memcpy(cow_node, btrfs_buffer_node(buf), root->blocksize); |
7eccb903 | 100 | btrfs_set_header_blocknr(&cow_node->header, bh_blocknr(cow)); |
7f5c1516 | 101 | btrfs_set_header_generation(&cow_node->header, trans->transid); |
4d775673 | 102 | btrfs_set_header_owner(&cow_node->header, root->root_key.objectid); |
54aa1f4d CM |
103 | ret = btrfs_inc_ref(trans, root, buf); |
104 | if (ret) | |
105 | return ret; | |
02217ed2 CM |
106 | if (buf == root->node) { |
107 | root->node = cow; | |
e20d96d6 | 108 | get_bh(cow); |
2c90e5d6 | 109 | if (buf != root->commit_root) { |
7eccb903 | 110 | btrfs_free_extent(trans, root, bh_blocknr(buf), 1, 1); |
2c90e5d6 | 111 | } |
234b63a0 | 112 | btrfs_block_release(root, buf); |
02217ed2 | 113 | } else { |
e20d96d6 | 114 | btrfs_set_node_blockptr(btrfs_buffer_node(parent), parent_slot, |
7eccb903 | 115 | bh_blocknr(cow)); |
d6025579 | 116 | btrfs_mark_buffer_dirty(parent); |
7eccb903 | 117 | btrfs_free_extent(trans, root, bh_blocknr(buf), 1, 1); |
02217ed2 | 118 | } |
234b63a0 | 119 | btrfs_block_release(root, buf); |
ccd467d6 | 120 | btrfs_mark_buffer_dirty(cow); |
2c90e5d6 | 121 | *cow_ret = cow; |
02217ed2 CM |
122 | return 0; |
123 | } | |
124 | ||
74123bd7 CM |
125 | /* |
126 | * The leaf data grows from end-to-front in the node. | |
127 | * this returns the address of the start of the last item, | |
128 | * which is the stop of the leaf data stack | |
129 | */ | |
123abc88 CM |
130 | static inline unsigned int leaf_data_end(struct btrfs_root *root, |
131 | struct btrfs_leaf *leaf) | |
be0e5c09 | 132 | { |
7518a238 | 133 | u32 nr = btrfs_header_nritems(&leaf->header); |
be0e5c09 | 134 | if (nr == 0) |
123abc88 | 135 | return BTRFS_LEAF_DATA_SIZE(root); |
0783fcfc | 136 | return btrfs_item_offset(leaf->items + nr - 1); |
be0e5c09 CM |
137 | } |
138 | ||
74123bd7 CM |
139 | /* |
140 | * compare two keys in a memcmp fashion | |
141 | */ | |
9aca1d51 | 142 | static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2) |
be0e5c09 | 143 | { |
e2fa7227 CM |
144 | struct btrfs_key k1; |
145 | ||
146 | btrfs_disk_key_to_cpu(&k1, disk); | |
147 | ||
148 | if (k1.objectid > k2->objectid) | |
be0e5c09 | 149 | return 1; |
e2fa7227 | 150 | if (k1.objectid < k2->objectid) |
be0e5c09 | 151 | return -1; |
f254e52c CM |
152 | if (k1.flags > k2->flags) |
153 | return 1; | |
154 | if (k1.flags < k2->flags) | |
155 | return -1; | |
70b2befd CM |
156 | if (k1.offset > k2->offset) |
157 | return 1; | |
158 | if (k1.offset < k2->offset) | |
159 | return -1; | |
be0e5c09 CM |
160 | return 0; |
161 | } | |
74123bd7 | 162 | |
123abc88 CM |
163 | static int check_node(struct btrfs_root *root, struct btrfs_path *path, |
164 | int level) | |
aa5d6bed | 165 | { |
234b63a0 | 166 | struct btrfs_node *parent = NULL; |
e20d96d6 | 167 | struct btrfs_node *node = btrfs_buffer_node(path->nodes[level]); |
aa5d6bed | 168 | int parent_slot; |
8d7be552 CM |
169 | int slot; |
170 | struct btrfs_key cpukey; | |
7518a238 | 171 | u32 nritems = btrfs_header_nritems(&node->header); |
aa5d6bed CM |
172 | |
173 | if (path->nodes[level + 1]) | |
e20d96d6 | 174 | parent = btrfs_buffer_node(path->nodes[level + 1]); |
a1f39630 | 175 | |
8d7be552 | 176 | slot = path->slots[level]; |
7518a238 CM |
177 | BUG_ON(nritems == 0); |
178 | if (parent) { | |
e2fa7227 | 179 | struct btrfs_disk_key *parent_key; |
a1f39630 A |
180 | |
181 | parent_slot = path->slots[level + 1]; | |
123abc88 CM |
182 | parent_key = &parent->ptrs[parent_slot].key; |
183 | BUG_ON(memcmp(parent_key, &node->ptrs[0].key, | |
e2fa7227 | 184 | sizeof(struct btrfs_disk_key))); |
1d4f8a0c | 185 | BUG_ON(btrfs_node_blockptr(parent, parent_slot) != |
7518a238 | 186 | btrfs_header_blocknr(&node->header)); |
aa5d6bed | 187 | } |
123abc88 | 188 | BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root)); |
8d7be552 CM |
189 | if (slot != 0) { |
190 | btrfs_disk_key_to_cpu(&cpukey, &node->ptrs[slot - 1].key); | |
191 | BUG_ON(comp_keys(&node->ptrs[slot].key, &cpukey) <= 0); | |
192 | } | |
193 | if (slot < nritems - 1) { | |
194 | btrfs_disk_key_to_cpu(&cpukey, &node->ptrs[slot + 1].key); | |
195 | BUG_ON(comp_keys(&node->ptrs[slot].key, &cpukey) >= 0); | |
aa5d6bed CM |
196 | } |
197 | return 0; | |
198 | } | |
199 | ||
123abc88 CM |
200 | static int check_leaf(struct btrfs_root *root, struct btrfs_path *path, |
201 | int level) | |
aa5d6bed | 202 | { |
e20d96d6 | 203 | struct btrfs_leaf *leaf = btrfs_buffer_leaf(path->nodes[level]); |
234b63a0 | 204 | struct btrfs_node *parent = NULL; |
aa5d6bed | 205 | int parent_slot; |
8d7be552 CM |
206 | int slot = path->slots[0]; |
207 | struct btrfs_key cpukey; | |
208 | ||
7518a238 | 209 | u32 nritems = btrfs_header_nritems(&leaf->header); |
aa5d6bed CM |
210 | |
211 | if (path->nodes[level + 1]) | |
e20d96d6 | 212 | parent = btrfs_buffer_node(path->nodes[level + 1]); |
a1f39630 | 213 | |
123abc88 | 214 | BUG_ON(btrfs_leaf_free_space(root, leaf) < 0); |
7518a238 CM |
215 | |
216 | if (nritems == 0) | |
217 | return 0; | |
218 | ||
219 | if (parent) { | |
e2fa7227 | 220 | struct btrfs_disk_key *parent_key; |
a1f39630 A |
221 | |
222 | parent_slot = path->slots[level + 1]; | |
123abc88 | 223 | parent_key = &parent->ptrs[parent_slot].key; |
aa5d6bed | 224 | BUG_ON(memcmp(parent_key, &leaf->items[0].key, |
e2fa7227 | 225 | sizeof(struct btrfs_disk_key))); |
1d4f8a0c | 226 | BUG_ON(btrfs_node_blockptr(parent, parent_slot) != |
7518a238 | 227 | btrfs_header_blocknr(&leaf->header)); |
aa5d6bed | 228 | } |
8d7be552 CM |
229 | if (slot != 0) { |
230 | btrfs_disk_key_to_cpu(&cpukey, &leaf->items[slot - 1].key); | |
231 | BUG_ON(comp_keys(&leaf->items[slot].key, &cpukey) <= 0); | |
232 | BUG_ON(btrfs_item_offset(leaf->items + slot - 1) != | |
233 | btrfs_item_end(leaf->items + slot)); | |
234 | } | |
235 | if (slot < nritems - 1) { | |
236 | btrfs_disk_key_to_cpu(&cpukey, &leaf->items[slot + 1].key); | |
237 | BUG_ON(comp_keys(&leaf->items[slot].key, &cpukey) >= 0); | |
238 | BUG_ON(btrfs_item_offset(leaf->items + slot) != | |
239 | btrfs_item_end(leaf->items + slot + 1)); | |
aa5d6bed | 240 | } |
8d7be552 CM |
241 | BUG_ON(btrfs_item_offset(leaf->items) + |
242 | btrfs_item_size(leaf->items) != BTRFS_LEAF_DATA_SIZE(root)); | |
aa5d6bed CM |
243 | return 0; |
244 | } | |
245 | ||
123abc88 CM |
246 | static int check_block(struct btrfs_root *root, struct btrfs_path *path, |
247 | int level) | |
aa5d6bed | 248 | { |
3eb0314d CM |
249 | struct btrfs_node *node = btrfs_buffer_node(path->nodes[level]); |
250 | if (memcmp(node->header.fsid, root->fs_info->disk_super->fsid, | |
251 | sizeof(node->header.fsid))) | |
252 | BUG(); | |
aa5d6bed | 253 | if (level == 0) |
123abc88 CM |
254 | return check_leaf(root, path, level); |
255 | return check_node(root, path, level); | |
aa5d6bed CM |
256 | } |
257 | ||
74123bd7 CM |
258 | /* |
259 | * search for key in the array p. items p are item_size apart | |
260 | * and there are 'max' items in p | |
261 | * the slot in the array is returned via slot, and it points to | |
262 | * the place where you would insert key if it is not found in | |
263 | * the array. | |
264 | * | |
265 | * slot may point to max if the key is bigger than all of the keys | |
266 | */ | |
9aca1d51 | 267 | static int generic_bin_search(char *p, int item_size, struct btrfs_key *key, |
be0e5c09 CM |
268 | int max, int *slot) |
269 | { | |
270 | int low = 0; | |
271 | int high = max; | |
272 | int mid; | |
273 | int ret; | |
e2fa7227 | 274 | struct btrfs_disk_key *tmp; |
be0e5c09 CM |
275 | |
276 | while(low < high) { | |
277 | mid = (low + high) / 2; | |
e2fa7227 | 278 | tmp = (struct btrfs_disk_key *)(p + mid * item_size); |
be0e5c09 CM |
279 | ret = comp_keys(tmp, key); |
280 | ||
281 | if (ret < 0) | |
282 | low = mid + 1; | |
283 | else if (ret > 0) | |
284 | high = mid; | |
285 | else { | |
286 | *slot = mid; | |
287 | return 0; | |
288 | } | |
289 | } | |
290 | *slot = low; | |
291 | return 1; | |
292 | } | |
293 | ||
97571fd0 CM |
294 | /* |
295 | * simple bin_search frontend that does the right thing for | |
296 | * leaves vs nodes | |
297 | */ | |
9aca1d51 | 298 | static int bin_search(struct btrfs_node *c, struct btrfs_key *key, int *slot) |
be0e5c09 | 299 | { |
7518a238 | 300 | if (btrfs_is_leaf(c)) { |
234b63a0 | 301 | struct btrfs_leaf *l = (struct btrfs_leaf *)c; |
0783fcfc CM |
302 | return generic_bin_search((void *)l->items, |
303 | sizeof(struct btrfs_item), | |
7518a238 CM |
304 | key, btrfs_header_nritems(&c->header), |
305 | slot); | |
be0e5c09 | 306 | } else { |
123abc88 CM |
307 | return generic_bin_search((void *)c->ptrs, |
308 | sizeof(struct btrfs_key_ptr), | |
7518a238 CM |
309 | key, btrfs_header_nritems(&c->header), |
310 | slot); | |
be0e5c09 CM |
311 | } |
312 | return -1; | |
313 | } | |
314 | ||
e20d96d6 CM |
315 | static struct buffer_head *read_node_slot(struct btrfs_root *root, |
316 | struct buffer_head *parent_buf, | |
bb803951 CM |
317 | int slot) |
318 | { | |
e20d96d6 | 319 | struct btrfs_node *node = btrfs_buffer_node(parent_buf); |
bb803951 CM |
320 | if (slot < 0) |
321 | return NULL; | |
7518a238 | 322 | if (slot >= btrfs_header_nritems(&node->header)) |
bb803951 | 323 | return NULL; |
1d4f8a0c | 324 | return read_tree_block(root, btrfs_node_blockptr(node, slot)); |
bb803951 CM |
325 | } |
326 | ||
e089f05c CM |
327 | static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root |
328 | *root, struct btrfs_path *path, int level) | |
bb803951 | 329 | { |
e20d96d6 CM |
330 | struct buffer_head *right_buf; |
331 | struct buffer_head *mid_buf; | |
332 | struct buffer_head *left_buf; | |
333 | struct buffer_head *parent_buf = NULL; | |
234b63a0 CM |
334 | struct btrfs_node *right = NULL; |
335 | struct btrfs_node *mid; | |
336 | struct btrfs_node *left = NULL; | |
337 | struct btrfs_node *parent = NULL; | |
bb803951 CM |
338 | int ret = 0; |
339 | int wret; | |
340 | int pslot; | |
bb803951 | 341 | int orig_slot = path->slots[level]; |
54aa1f4d | 342 | int err_on_enospc = 0; |
79f95c82 | 343 | u64 orig_ptr; |
bb803951 CM |
344 | |
345 | if (level == 0) | |
346 | return 0; | |
347 | ||
348 | mid_buf = path->nodes[level]; | |
e20d96d6 | 349 | mid = btrfs_buffer_node(mid_buf); |
1d4f8a0c | 350 | orig_ptr = btrfs_node_blockptr(mid, orig_slot); |
79f95c82 | 351 | |
234b63a0 | 352 | if (level < BTRFS_MAX_LEVEL - 1) |
bb803951 CM |
353 | parent_buf = path->nodes[level + 1]; |
354 | pslot = path->slots[level + 1]; | |
355 | ||
40689478 CM |
356 | /* |
357 | * deal with the case where there is only one pointer in the root | |
358 | * by promoting the node below to a root | |
359 | */ | |
bb803951 | 360 | if (!parent_buf) { |
e20d96d6 | 361 | struct buffer_head *child; |
7eccb903 | 362 | u64 blocknr = bh_blocknr(mid_buf); |
bb803951 | 363 | |
7518a238 | 364 | if (btrfs_header_nritems(&mid->header) != 1) |
bb803951 CM |
365 | return 0; |
366 | ||
367 | /* promote the child to a root */ | |
368 | child = read_node_slot(root, mid_buf, 0); | |
369 | BUG_ON(!child); | |
370 | root->node = child; | |
371 | path->nodes[level] = NULL; | |
d6025579 CM |
372 | clean_tree_block(trans, root, mid_buf); |
373 | wait_on_buffer(mid_buf); | |
bb803951 | 374 | /* once for the path */ |
234b63a0 | 375 | btrfs_block_release(root, mid_buf); |
bb803951 | 376 | /* once for the root ptr */ |
234b63a0 | 377 | btrfs_block_release(root, mid_buf); |
e089f05c | 378 | return btrfs_free_extent(trans, root, blocknr, 1, 1); |
bb803951 | 379 | } |
e20d96d6 | 380 | parent = btrfs_buffer_node(parent_buf); |
bb803951 | 381 | |
123abc88 CM |
382 | if (btrfs_header_nritems(&mid->header) > |
383 | BTRFS_NODEPTRS_PER_BLOCK(root) / 4) | |
bb803951 CM |
384 | return 0; |
385 | ||
54aa1f4d CM |
386 | if (btrfs_header_nritems(&mid->header) < 2) |
387 | err_on_enospc = 1; | |
388 | ||
bb803951 CM |
389 | left_buf = read_node_slot(root, parent_buf, pslot - 1); |
390 | right_buf = read_node_slot(root, parent_buf, pslot + 1); | |
79f95c82 CM |
391 | |
392 | /* first, try to make some room in the middle buffer */ | |
bb803951 | 393 | if (left_buf) { |
54aa1f4d CM |
394 | wret = btrfs_cow_block(trans, root, left_buf, |
395 | parent_buf, pslot - 1, &left_buf); | |
396 | if (wret) { | |
397 | ret = wret; | |
398 | goto enospc; | |
399 | } | |
e20d96d6 | 400 | left = btrfs_buffer_node(left_buf); |
7518a238 | 401 | orig_slot += btrfs_header_nritems(&left->header); |
e089f05c | 402 | wret = push_node_left(trans, root, left_buf, mid_buf); |
79f95c82 CM |
403 | if (wret < 0) |
404 | ret = wret; | |
54aa1f4d CM |
405 | if (btrfs_header_nritems(&mid->header) < 2) |
406 | err_on_enospc = 1; | |
bb803951 | 407 | } |
79f95c82 CM |
408 | |
409 | /* | |
410 | * then try to empty the right most buffer into the middle | |
411 | */ | |
bb803951 | 412 | if (right_buf) { |
54aa1f4d CM |
413 | wret = btrfs_cow_block(trans, root, right_buf, |
414 | parent_buf, pslot + 1, &right_buf); | |
415 | if (wret) { | |
416 | ret = wret; | |
417 | goto enospc; | |
418 | } | |
419 | ||
e20d96d6 | 420 | right = btrfs_buffer_node(right_buf); |
e089f05c | 421 | wret = push_node_left(trans, root, mid_buf, right_buf); |
54aa1f4d | 422 | if (wret < 0 && wret != -ENOSPC) |
79f95c82 | 423 | ret = wret; |
7518a238 | 424 | if (btrfs_header_nritems(&right->header) == 0) { |
7eccb903 | 425 | u64 blocknr = bh_blocknr(right_buf); |
e089f05c | 426 | clean_tree_block(trans, root, right_buf); |
d6025579 CM |
427 | wait_on_buffer(right_buf); |
428 | btrfs_block_release(root, right_buf); | |
bb803951 CM |
429 | right_buf = NULL; |
430 | right = NULL; | |
e089f05c CM |
431 | wret = del_ptr(trans, root, path, level + 1, pslot + |
432 | 1); | |
bb803951 CM |
433 | if (wret) |
434 | ret = wret; | |
e089f05c | 435 | wret = btrfs_free_extent(trans, root, blocknr, 1, 1); |
bb803951 CM |
436 | if (wret) |
437 | ret = wret; | |
438 | } else { | |
d6025579 CM |
439 | btrfs_memcpy(root, parent, |
440 | &parent->ptrs[pslot + 1].key, | |
441 | &right->ptrs[0].key, | |
442 | sizeof(struct btrfs_disk_key)); | |
443 | btrfs_mark_buffer_dirty(parent_buf); | |
bb803951 CM |
444 | } |
445 | } | |
7518a238 | 446 | if (btrfs_header_nritems(&mid->header) == 1) { |
79f95c82 CM |
447 | /* |
448 | * we're not allowed to leave a node with one item in the | |
449 | * tree during a delete. A deletion from lower in the tree | |
450 | * could try to delete the only pointer in this node. | |
451 | * So, pull some keys from the left. | |
452 | * There has to be a left pointer at this point because | |
453 | * otherwise we would have pulled some pointers from the | |
454 | * right | |
455 | */ | |
456 | BUG_ON(!left_buf); | |
e089f05c | 457 | wret = balance_node_right(trans, root, mid_buf, left_buf); |
54aa1f4d | 458 | if (wret < 0) { |
79f95c82 | 459 | ret = wret; |
54aa1f4d CM |
460 | goto enospc; |
461 | } | |
79f95c82 CM |
462 | BUG_ON(wret == 1); |
463 | } | |
7518a238 | 464 | if (btrfs_header_nritems(&mid->header) == 0) { |
79f95c82 | 465 | /* we've managed to empty the middle node, drop it */ |
7eccb903 | 466 | u64 blocknr = bh_blocknr(mid_buf); |
e089f05c | 467 | clean_tree_block(trans, root, mid_buf); |
d6025579 CM |
468 | wait_on_buffer(mid_buf); |
469 | btrfs_block_release(root, mid_buf); | |
bb803951 CM |
470 | mid_buf = NULL; |
471 | mid = NULL; | |
e089f05c | 472 | wret = del_ptr(trans, root, path, level + 1, pslot); |
bb803951 CM |
473 | if (wret) |
474 | ret = wret; | |
e089f05c | 475 | wret = btrfs_free_extent(trans, root, blocknr, 1, 1); |
bb803951 CM |
476 | if (wret) |
477 | ret = wret; | |
79f95c82 CM |
478 | } else { |
479 | /* update the parent key to reflect our changes */ | |
d6025579 CM |
480 | btrfs_memcpy(root, parent, |
481 | &parent->ptrs[pslot].key, &mid->ptrs[0].key, | |
482 | sizeof(struct btrfs_disk_key)); | |
483 | btrfs_mark_buffer_dirty(parent_buf); | |
79f95c82 | 484 | } |
bb803951 | 485 | |
79f95c82 | 486 | /* update the path */ |
bb803951 | 487 | if (left_buf) { |
7518a238 | 488 | if (btrfs_header_nritems(&left->header) > orig_slot) { |
e20d96d6 | 489 | get_bh(left_buf); |
bb803951 CM |
490 | path->nodes[level] = left_buf; |
491 | path->slots[level + 1] -= 1; | |
492 | path->slots[level] = orig_slot; | |
493 | if (mid_buf) | |
234b63a0 | 494 | btrfs_block_release(root, mid_buf); |
bb803951 | 495 | } else { |
7518a238 | 496 | orig_slot -= btrfs_header_nritems(&left->header); |
bb803951 CM |
497 | path->slots[level] = orig_slot; |
498 | } | |
499 | } | |
79f95c82 | 500 | /* double check we haven't messed things up */ |
123abc88 | 501 | check_block(root, path, level); |
e20d96d6 CM |
502 | if (orig_ptr != |
503 | btrfs_node_blockptr(btrfs_buffer_node(path->nodes[level]), | |
504 | path->slots[level])) | |
79f95c82 | 505 | BUG(); |
54aa1f4d | 506 | enospc: |
bb803951 | 507 | if (right_buf) |
234b63a0 | 508 | btrfs_block_release(root, right_buf); |
bb803951 | 509 | if (left_buf) |
234b63a0 | 510 | btrfs_block_release(root, left_buf); |
bb803951 CM |
511 | return ret; |
512 | } | |
513 | ||
e66f709b CM |
514 | /* returns zero if the push worked, non-zero otherwise */ |
515 | static int push_nodes_for_insert(struct btrfs_trans_handle *trans, | |
516 | struct btrfs_root *root, | |
517 | struct btrfs_path *path, int level) | |
518 | { | |
519 | struct buffer_head *right_buf; | |
520 | struct buffer_head *mid_buf; | |
521 | struct buffer_head *left_buf; | |
522 | struct buffer_head *parent_buf = NULL; | |
523 | struct btrfs_node *right = NULL; | |
524 | struct btrfs_node *mid; | |
525 | struct btrfs_node *left = NULL; | |
526 | struct btrfs_node *parent = NULL; | |
527 | int ret = 0; | |
528 | int wret; | |
529 | int pslot; | |
530 | int orig_slot = path->slots[level]; | |
531 | u64 orig_ptr; | |
532 | ||
533 | if (level == 0) | |
534 | return 1; | |
535 | ||
536 | mid_buf = path->nodes[level]; | |
537 | mid = btrfs_buffer_node(mid_buf); | |
538 | orig_ptr = btrfs_node_blockptr(mid, orig_slot); | |
539 | ||
540 | if (level < BTRFS_MAX_LEVEL - 1) | |
541 | parent_buf = path->nodes[level + 1]; | |
542 | pslot = path->slots[level + 1]; | |
543 | ||
544 | if (!parent_buf) | |
545 | return 1; | |
546 | parent = btrfs_buffer_node(parent_buf); | |
547 | ||
548 | left_buf = read_node_slot(root, parent_buf, pslot - 1); | |
549 | ||
550 | /* first, try to make some room in the middle buffer */ | |
551 | if (left_buf) { | |
552 | u32 left_nr; | |
e66f709b CM |
553 | left = btrfs_buffer_node(left_buf); |
554 | left_nr = btrfs_header_nritems(&left->header); | |
33ade1f8 CM |
555 | if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { |
556 | wret = 1; | |
557 | } else { | |
54aa1f4d CM |
558 | ret = btrfs_cow_block(trans, root, left_buf, parent_buf, |
559 | pslot - 1, &left_buf); | |
560 | if (ret) | |
561 | wret = 1; | |
562 | else { | |
563 | left = btrfs_buffer_node(left_buf); | |
564 | wret = push_node_left(trans, root, | |
565 | left_buf, mid_buf); | |
566 | } | |
33ade1f8 | 567 | } |
e66f709b CM |
568 | if (wret < 0) |
569 | ret = wret; | |
570 | if (wret == 0) { | |
571 | orig_slot += left_nr; | |
572 | btrfs_memcpy(root, parent, | |
573 | &parent->ptrs[pslot].key, | |
574 | &mid->ptrs[0].key, | |
575 | sizeof(struct btrfs_disk_key)); | |
576 | btrfs_mark_buffer_dirty(parent_buf); | |
577 | if (btrfs_header_nritems(&left->header) > orig_slot) { | |
578 | path->nodes[level] = left_buf; | |
579 | path->slots[level + 1] -= 1; | |
580 | path->slots[level] = orig_slot; | |
581 | btrfs_block_release(root, mid_buf); | |
582 | } else { | |
583 | orig_slot -= | |
584 | btrfs_header_nritems(&left->header); | |
585 | path->slots[level] = orig_slot; | |
586 | btrfs_block_release(root, left_buf); | |
587 | } | |
588 | check_node(root, path, level); | |
589 | return 0; | |
590 | } | |
591 | btrfs_block_release(root, left_buf); | |
592 | } | |
593 | right_buf = read_node_slot(root, parent_buf, pslot + 1); | |
594 | ||
595 | /* | |
596 | * then try to empty the right most buffer into the middle | |
597 | */ | |
598 | if (right_buf) { | |
33ade1f8 | 599 | u32 right_nr; |
e66f709b | 600 | right = btrfs_buffer_node(right_buf); |
33ade1f8 CM |
601 | right_nr = btrfs_header_nritems(&right->header); |
602 | if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { | |
603 | wret = 1; | |
604 | } else { | |
54aa1f4d CM |
605 | ret = btrfs_cow_block(trans, root, right_buf, |
606 | parent_buf, pslot + 1, | |
607 | &right_buf); | |
608 | if (ret) | |
609 | wret = 1; | |
610 | else { | |
611 | right = btrfs_buffer_node(right_buf); | |
612 | wret = balance_node_right(trans, root, | |
613 | right_buf, mid_buf); | |
614 | } | |
33ade1f8 | 615 | } |
e66f709b CM |
616 | if (wret < 0) |
617 | ret = wret; | |
618 | if (wret == 0) { | |
619 | btrfs_memcpy(root, parent, | |
620 | &parent->ptrs[pslot + 1].key, | |
621 | &right->ptrs[0].key, | |
622 | sizeof(struct btrfs_disk_key)); | |
623 | btrfs_mark_buffer_dirty(parent_buf); | |
624 | if (btrfs_header_nritems(&mid->header) <= orig_slot) { | |
625 | path->nodes[level] = right_buf; | |
626 | path->slots[level + 1] += 1; | |
627 | path->slots[level] = orig_slot - | |
628 | btrfs_header_nritems(&mid->header); | |
629 | btrfs_block_release(root, mid_buf); | |
630 | } else { | |
631 | btrfs_block_release(root, right_buf); | |
632 | } | |
633 | check_node(root, path, level); | |
634 | return 0; | |
635 | } | |
636 | btrfs_block_release(root, right_buf); | |
637 | } | |
638 | check_node(root, path, level); | |
639 | return 1; | |
640 | } | |
641 | ||
3c69faec CM |
642 | /* |
643 | * readahead one full node of leaves | |
644 | */ | |
645 | static void reada_for_search(struct btrfs_root *root, struct btrfs_path *path, | |
646 | int slot) | |
647 | { | |
648 | struct btrfs_node *node; | |
649 | int i; | |
650 | u32 nritems; | |
651 | u64 item_objectid; | |
652 | u64 blocknr; | |
653 | u64 search; | |
654 | u64 cluster_start; | |
655 | int ret; | |
656 | int nread = 0; | |
657 | int direction = path->reada; | |
658 | struct radix_tree_root found; | |
659 | unsigned long gang[8]; | |
660 | struct buffer_head *bh; | |
661 | ||
662 | if (!path->nodes[1]) | |
663 | return; | |
664 | ||
665 | node = btrfs_buffer_node(path->nodes[1]); | |
666 | search = btrfs_node_blockptr(node, slot); | |
667 | bh = btrfs_find_tree_block(root, search); | |
668 | if (bh) { | |
669 | brelse(bh); | |
670 | return; | |
671 | } | |
672 | ||
673 | init_bit_radix(&found); | |
674 | nritems = btrfs_header_nritems(&node->header); | |
675 | for (i = slot; i < nritems; i++) { | |
676 | item_objectid = btrfs_disk_key_objectid(&node->ptrs[i].key); | |
677 | blocknr = btrfs_node_blockptr(node, i); | |
678 | set_radix_bit(&found, blocknr); | |
679 | } | |
680 | if (direction > 0) { | |
681 | cluster_start = search - 4; | |
682 | if (cluster_start > search) | |
683 | cluster_start = 0; | |
684 | } else | |
685 | cluster_start = search + 4; | |
686 | while(1) { | |
687 | ret = find_first_radix_bit(&found, gang, 0, ARRAY_SIZE(gang)); | |
688 | if (!ret) | |
689 | break; | |
690 | for (i = 0; i < ret; i++) { | |
691 | blocknr = gang[i]; | |
692 | clear_radix_bit(&found, blocknr); | |
693 | if (nread > 64) | |
694 | continue; | |
695 | if (direction > 0 && cluster_start <= blocknr && | |
696 | cluster_start + 8 > blocknr) { | |
697 | cluster_start = blocknr; | |
698 | readahead_tree_block(root, blocknr); | |
699 | nread++; | |
700 | } else if (direction < 0 && cluster_start >= blocknr && | |
701 | blocknr + 8 > cluster_start) { | |
702 | cluster_start = blocknr; | |
703 | readahead_tree_block(root, blocknr); | |
704 | nread++; | |
705 | } | |
706 | } | |
707 | } | |
708 | } | |
74123bd7 CM |
709 | /* |
710 | * look for key in the tree. path is filled in with nodes along the way | |
711 | * if key is found, we return zero and you can find the item in the leaf | |
712 | * level of the path (level 0) | |
713 | * | |
714 | * If the key isn't found, the path points to the slot where it should | |
aa5d6bed CM |
715 | * be inserted, and 1 is returned. If there are other errors during the |
716 | * search a negative error number is returned. | |
97571fd0 CM |
717 | * |
718 | * if ins_len > 0, nodes and leaves will be split as we walk down the | |
719 | * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if | |
720 | * possible) | |
74123bd7 | 721 | */ |
e089f05c CM |
722 | int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root |
723 | *root, struct btrfs_key *key, struct btrfs_path *p, int | |
724 | ins_len, int cow) | |
be0e5c09 | 725 | { |
e20d96d6 CM |
726 | struct buffer_head *b; |
727 | struct buffer_head *cow_buf; | |
234b63a0 | 728 | struct btrfs_node *c; |
9f3a7427 | 729 | struct btrfs_root_item *root_item = &root->root_item; |
3c69faec | 730 | u64 blocknr; |
be0e5c09 CM |
731 | int slot; |
732 | int ret; | |
733 | int level; | |
3c69faec | 734 | int should_reada = p->reada; |
9f3a7427 CM |
735 | u8 lowest_level = 0; |
736 | ||
737 | if (btrfs_root_refs(root_item) == 0 && root->ref_cows) { | |
738 | lowest_level = root_item->drop_level; | |
739 | WARN_ON(ins_len || cow); | |
740 | } | |
5c680ed6 | 741 | |
22b0ebda CM |
742 | WARN_ON(p->nodes[0] != NULL); |
743 | WARN_ON(!mutex_is_locked(&root->fs_info->fs_mutex)); | |
bb803951 CM |
744 | again: |
745 | b = root->node; | |
e20d96d6 | 746 | get_bh(b); |
eb60ceac | 747 | while (b) { |
e20d96d6 CM |
748 | c = btrfs_buffer_node(b); |
749 | level = btrfs_header_level(&c->header); | |
02217ed2 CM |
750 | if (cow) { |
751 | int wret; | |
e20d96d6 CM |
752 | wret = btrfs_cow_block(trans, root, b, |
753 | p->nodes[level + 1], | |
754 | p->slots[level + 1], | |
e089f05c | 755 | &cow_buf); |
54aa1f4d CM |
756 | if (wret) { |
757 | btrfs_block_release(root, cow_buf); | |
758 | return wret; | |
759 | } | |
02217ed2 | 760 | b = cow_buf; |
2c90e5d6 | 761 | c = btrfs_buffer_node(b); |
02217ed2 CM |
762 | } |
763 | BUG_ON(!cow && ins_len); | |
2c90e5d6 CM |
764 | if (level != btrfs_header_level(&c->header)) |
765 | WARN_ON(1); | |
766 | level = btrfs_header_level(&c->header); | |
eb60ceac | 767 | p->nodes[level] = b; |
123abc88 | 768 | ret = check_block(root, p, level); |
aa5d6bed CM |
769 | if (ret) |
770 | return -1; | |
be0e5c09 | 771 | ret = bin_search(c, key, &slot); |
7518a238 | 772 | if (!btrfs_is_leaf(c)) { |
be0e5c09 CM |
773 | if (ret && slot > 0) |
774 | slot -= 1; | |
775 | p->slots[level] = slot; | |
d4dbff95 CM |
776 | if (ins_len > 0 && btrfs_header_nritems(&c->header) >= |
777 | BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { | |
e089f05c | 778 | int sret = split_node(trans, root, p, level); |
5c680ed6 CM |
779 | BUG_ON(sret > 0); |
780 | if (sret) | |
781 | return sret; | |
782 | b = p->nodes[level]; | |
e20d96d6 | 783 | c = btrfs_buffer_node(b); |
5c680ed6 | 784 | slot = p->slots[level]; |
bb803951 | 785 | } else if (ins_len < 0) { |
e089f05c CM |
786 | int sret = balance_level(trans, root, p, |
787 | level); | |
bb803951 CM |
788 | if (sret) |
789 | return sret; | |
790 | b = p->nodes[level]; | |
791 | if (!b) | |
792 | goto again; | |
e20d96d6 | 793 | c = btrfs_buffer_node(b); |
bb803951 | 794 | slot = p->slots[level]; |
7518a238 | 795 | BUG_ON(btrfs_header_nritems(&c->header) == 1); |
5c680ed6 | 796 | } |
9f3a7427 CM |
797 | /* this is only true while dropping a snapshot */ |
798 | if (level == lowest_level) | |
799 | break; | |
3c69faec CM |
800 | blocknr = btrfs_node_blockptr(c, slot); |
801 | if (level == 1 && should_reada) | |
802 | reada_for_search(root, p, slot); | |
1d4f8a0c | 803 | b = read_tree_block(root, btrfs_node_blockptr(c, slot)); |
3c69faec | 804 | |
be0e5c09 | 805 | } else { |
234b63a0 | 806 | struct btrfs_leaf *l = (struct btrfs_leaf *)c; |
be0e5c09 | 807 | p->slots[level] = slot; |
123abc88 | 808 | if (ins_len > 0 && btrfs_leaf_free_space(root, l) < |
0783fcfc | 809 | sizeof(struct btrfs_item) + ins_len) { |
d4dbff95 CM |
810 | int sret = split_leaf(trans, root, key, |
811 | p, ins_len); | |
5c680ed6 CM |
812 | BUG_ON(sret > 0); |
813 | if (sret) | |
814 | return sret; | |
815 | } | |
be0e5c09 CM |
816 | return ret; |
817 | } | |
818 | } | |
aa5d6bed | 819 | return 1; |
be0e5c09 CM |
820 | } |
821 | ||
74123bd7 CM |
822 | /* |
823 | * adjust the pointers going up the tree, starting at level | |
824 | * making sure the right key of each node is points to 'key'. | |
825 | * This is used after shifting pointers to the left, so it stops | |
826 | * fixing up pointers when a given leaf/node is not in slot 0 of the | |
827 | * higher levels | |
aa5d6bed CM |
828 | * |
829 | * If this fails to write a tree block, it returns -1, but continues | |
830 | * fixing up the blocks in ram so the tree is consistent. | |
74123bd7 | 831 | */ |
e089f05c CM |
832 | static int fixup_low_keys(struct btrfs_trans_handle *trans, struct btrfs_root |
833 | *root, struct btrfs_path *path, struct btrfs_disk_key | |
834 | *key, int level) | |
be0e5c09 CM |
835 | { |
836 | int i; | |
aa5d6bed | 837 | int ret = 0; |
234b63a0 CM |
838 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { |
839 | struct btrfs_node *t; | |
be0e5c09 | 840 | int tslot = path->slots[i]; |
eb60ceac | 841 | if (!path->nodes[i]) |
be0e5c09 | 842 | break; |
e20d96d6 | 843 | t = btrfs_buffer_node(path->nodes[i]); |
d6025579 CM |
844 | btrfs_memcpy(root, t, &t->ptrs[tslot].key, key, sizeof(*key)); |
845 | btrfs_mark_buffer_dirty(path->nodes[i]); | |
be0e5c09 CM |
846 | if (tslot != 0) |
847 | break; | |
848 | } | |
aa5d6bed | 849 | return ret; |
be0e5c09 CM |
850 | } |
851 | ||
74123bd7 CM |
852 | /* |
853 | * try to push data from one node into the next node left in the | |
79f95c82 | 854 | * tree. |
aa5d6bed CM |
855 | * |
856 | * returns 0 if some ptrs were pushed left, < 0 if there was some horrible | |
857 | * error, and > 0 if there was no room in the left hand block. | |
74123bd7 | 858 | */ |
e089f05c | 859 | static int push_node_left(struct btrfs_trans_handle *trans, struct btrfs_root |
e20d96d6 CM |
860 | *root, struct buffer_head *dst_buf, struct |
861 | buffer_head *src_buf) | |
be0e5c09 | 862 | { |
e20d96d6 CM |
863 | struct btrfs_node *src = btrfs_buffer_node(src_buf); |
864 | struct btrfs_node *dst = btrfs_buffer_node(dst_buf); | |
be0e5c09 | 865 | int push_items = 0; |
bb803951 CM |
866 | int src_nritems; |
867 | int dst_nritems; | |
aa5d6bed | 868 | int ret = 0; |
be0e5c09 | 869 | |
7518a238 CM |
870 | src_nritems = btrfs_header_nritems(&src->header); |
871 | dst_nritems = btrfs_header_nritems(&dst->header); | |
123abc88 | 872 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
54aa1f4d | 873 | |
eb60ceac | 874 | if (push_items <= 0) { |
be0e5c09 | 875 | return 1; |
eb60ceac | 876 | } |
be0e5c09 | 877 | |
bb803951 | 878 | if (src_nritems < push_items) |
79f95c82 CM |
879 | push_items = src_nritems; |
880 | ||
d6025579 CM |
881 | btrfs_memcpy(root, dst, dst->ptrs + dst_nritems, src->ptrs, |
882 | push_items * sizeof(struct btrfs_key_ptr)); | |
bb803951 | 883 | if (push_items < src_nritems) { |
d6025579 | 884 | btrfs_memmove(root, src, src->ptrs, src->ptrs + push_items, |
e2fa7227 | 885 | (src_nritems - push_items) * |
123abc88 | 886 | sizeof(struct btrfs_key_ptr)); |
bb803951 | 887 | } |
7518a238 CM |
888 | btrfs_set_header_nritems(&src->header, src_nritems - push_items); |
889 | btrfs_set_header_nritems(&dst->header, dst_nritems + push_items); | |
d6025579 CM |
890 | btrfs_mark_buffer_dirty(src_buf); |
891 | btrfs_mark_buffer_dirty(dst_buf); | |
79f95c82 CM |
892 | return ret; |
893 | } | |
894 | ||
895 | /* | |
896 | * try to push data from one node into the next node right in the | |
897 | * tree. | |
898 | * | |
899 | * returns 0 if some ptrs were pushed, < 0 if there was some horrible | |
900 | * error, and > 0 if there was no room in the right hand block. | |
901 | * | |
902 | * this will only push up to 1/2 the contents of the left node over | |
903 | */ | |
e089f05c | 904 | static int balance_node_right(struct btrfs_trans_handle *trans, struct |
e20d96d6 CM |
905 | btrfs_root *root, struct buffer_head *dst_buf, |
906 | struct buffer_head *src_buf) | |
79f95c82 | 907 | { |
e20d96d6 CM |
908 | struct btrfs_node *src = btrfs_buffer_node(src_buf); |
909 | struct btrfs_node *dst = btrfs_buffer_node(dst_buf); | |
79f95c82 CM |
910 | int push_items = 0; |
911 | int max_push; | |
912 | int src_nritems; | |
913 | int dst_nritems; | |
914 | int ret = 0; | |
79f95c82 | 915 | |
7518a238 CM |
916 | src_nritems = btrfs_header_nritems(&src->header); |
917 | dst_nritems = btrfs_header_nritems(&dst->header); | |
123abc88 | 918 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
79f95c82 CM |
919 | if (push_items <= 0) { |
920 | return 1; | |
921 | } | |
922 | ||
923 | max_push = src_nritems / 2 + 1; | |
924 | /* don't try to empty the node */ | |
925 | if (max_push > src_nritems) | |
926 | return 1; | |
927 | if (max_push < push_items) | |
928 | push_items = max_push; | |
929 | ||
d6025579 CM |
930 | btrfs_memmove(root, dst, dst->ptrs + push_items, dst->ptrs, |
931 | dst_nritems * sizeof(struct btrfs_key_ptr)); | |
932 | ||
933 | btrfs_memcpy(root, dst, dst->ptrs, | |
934 | src->ptrs + src_nritems - push_items, | |
935 | push_items * sizeof(struct btrfs_key_ptr)); | |
79f95c82 | 936 | |
7518a238 CM |
937 | btrfs_set_header_nritems(&src->header, src_nritems - push_items); |
938 | btrfs_set_header_nritems(&dst->header, dst_nritems + push_items); | |
79f95c82 | 939 | |
d6025579 CM |
940 | btrfs_mark_buffer_dirty(src_buf); |
941 | btrfs_mark_buffer_dirty(dst_buf); | |
aa5d6bed | 942 | return ret; |
be0e5c09 CM |
943 | } |
944 | ||
97571fd0 CM |
945 | /* |
946 | * helper function to insert a new root level in the tree. | |
947 | * A new node is allocated, and a single item is inserted to | |
948 | * point to the existing root | |
aa5d6bed CM |
949 | * |
950 | * returns zero on success or < 0 on failure. | |
97571fd0 | 951 | */ |
e089f05c CM |
952 | static int insert_new_root(struct btrfs_trans_handle *trans, struct btrfs_root |
953 | *root, struct btrfs_path *path, int level) | |
5c680ed6 | 954 | { |
e20d96d6 | 955 | struct buffer_head *t; |
234b63a0 CM |
956 | struct btrfs_node *lower; |
957 | struct btrfs_node *c; | |
e2fa7227 | 958 | struct btrfs_disk_key *lower_key; |
5c680ed6 CM |
959 | |
960 | BUG_ON(path->nodes[level]); | |
961 | BUG_ON(path->nodes[level-1] != root->node); | |
962 | ||
31f3c99b | 963 | t = btrfs_alloc_free_block(trans, root, root->node->b_blocknr); |
54aa1f4d CM |
964 | if (IS_ERR(t)) |
965 | return PTR_ERR(t); | |
e20d96d6 | 966 | c = btrfs_buffer_node(t); |
123abc88 | 967 | memset(c, 0, root->blocksize); |
7518a238 CM |
968 | btrfs_set_header_nritems(&c->header, 1); |
969 | btrfs_set_header_level(&c->header, level); | |
7eccb903 | 970 | btrfs_set_header_blocknr(&c->header, bh_blocknr(t)); |
7f5c1516 | 971 | btrfs_set_header_generation(&c->header, trans->transid); |
4d775673 | 972 | btrfs_set_header_owner(&c->header, root->root_key.objectid); |
e20d96d6 | 973 | lower = btrfs_buffer_node(path->nodes[level-1]); |
3eb0314d CM |
974 | memcpy(c->header.fsid, root->fs_info->disk_super->fsid, |
975 | sizeof(c->header.fsid)); | |
7518a238 | 976 | if (btrfs_is_leaf(lower)) |
234b63a0 | 977 | lower_key = &((struct btrfs_leaf *)lower)->items[0].key; |
5c680ed6 | 978 | else |
123abc88 | 979 | lower_key = &lower->ptrs[0].key; |
d6025579 CM |
980 | btrfs_memcpy(root, c, &c->ptrs[0].key, lower_key, |
981 | sizeof(struct btrfs_disk_key)); | |
7eccb903 | 982 | btrfs_set_node_blockptr(c, 0, bh_blocknr(path->nodes[level - 1])); |
d5719762 | 983 | |
d6025579 | 984 | btrfs_mark_buffer_dirty(t); |
d5719762 | 985 | |
5c680ed6 | 986 | /* the super has an extra ref to root->node */ |
234b63a0 | 987 | btrfs_block_release(root, root->node); |
5c680ed6 | 988 | root->node = t; |
e20d96d6 | 989 | get_bh(t); |
5c680ed6 CM |
990 | path->nodes[level] = t; |
991 | path->slots[level] = 0; | |
992 | return 0; | |
993 | } | |
994 | ||
74123bd7 CM |
995 | /* |
996 | * worker function to insert a single pointer in a node. | |
997 | * the node should have enough room for the pointer already | |
97571fd0 | 998 | * |
74123bd7 CM |
999 | * slot and level indicate where you want the key to go, and |
1000 | * blocknr is the block the key points to. | |
aa5d6bed CM |
1001 | * |
1002 | * returns zero on success and < 0 on any error | |
74123bd7 | 1003 | */ |
e089f05c CM |
1004 | static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root |
1005 | *root, struct btrfs_path *path, struct btrfs_disk_key | |
1006 | *key, u64 blocknr, int slot, int level) | |
74123bd7 | 1007 | { |
234b63a0 | 1008 | struct btrfs_node *lower; |
74123bd7 | 1009 | int nritems; |
5c680ed6 CM |
1010 | |
1011 | BUG_ON(!path->nodes[level]); | |
e20d96d6 | 1012 | lower = btrfs_buffer_node(path->nodes[level]); |
7518a238 | 1013 | nritems = btrfs_header_nritems(&lower->header); |
74123bd7 CM |
1014 | if (slot > nritems) |
1015 | BUG(); | |
123abc88 | 1016 | if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root)) |
74123bd7 CM |
1017 | BUG(); |
1018 | if (slot != nritems) { | |
d6025579 CM |
1019 | btrfs_memmove(root, lower, lower->ptrs + slot + 1, |
1020 | lower->ptrs + slot, | |
1021 | (nritems - slot) * sizeof(struct btrfs_key_ptr)); | |
74123bd7 | 1022 | } |
d6025579 CM |
1023 | btrfs_memcpy(root, lower, &lower->ptrs[slot].key, |
1024 | key, sizeof(struct btrfs_disk_key)); | |
1d4f8a0c | 1025 | btrfs_set_node_blockptr(lower, slot, blocknr); |
7518a238 | 1026 | btrfs_set_header_nritems(&lower->header, nritems + 1); |
d6025579 | 1027 | btrfs_mark_buffer_dirty(path->nodes[level]); |
098f59c2 | 1028 | check_node(root, path, level); |
74123bd7 CM |
1029 | return 0; |
1030 | } | |
1031 | ||
97571fd0 CM |
1032 | /* |
1033 | * split the node at the specified level in path in two. | |
1034 | * The path is corrected to point to the appropriate node after the split | |
1035 | * | |
1036 | * Before splitting this tries to make some room in the node by pushing | |
1037 | * left and right, if either one works, it returns right away. | |
aa5d6bed CM |
1038 | * |
1039 | * returns 0 on success and < 0 on failure | |
97571fd0 | 1040 | */ |
e089f05c CM |
1041 | static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root |
1042 | *root, struct btrfs_path *path, int level) | |
be0e5c09 | 1043 | { |
e20d96d6 | 1044 | struct buffer_head *t; |
234b63a0 | 1045 | struct btrfs_node *c; |
e20d96d6 | 1046 | struct buffer_head *split_buffer; |
234b63a0 | 1047 | struct btrfs_node *split; |
be0e5c09 | 1048 | int mid; |
5c680ed6 | 1049 | int ret; |
aa5d6bed | 1050 | int wret; |
7518a238 | 1051 | u32 c_nritems; |
eb60ceac | 1052 | |
5c680ed6 | 1053 | t = path->nodes[level]; |
e20d96d6 | 1054 | c = btrfs_buffer_node(t); |
5c680ed6 CM |
1055 | if (t == root->node) { |
1056 | /* trying to split the root, lets make a new one */ | |
e089f05c | 1057 | ret = insert_new_root(trans, root, path, level + 1); |
5c680ed6 CM |
1058 | if (ret) |
1059 | return ret; | |
e66f709b CM |
1060 | } else { |
1061 | ret = push_nodes_for_insert(trans, root, path, level); | |
1062 | t = path->nodes[level]; | |
1063 | c = btrfs_buffer_node(t); | |
1064 | if (!ret && | |
1065 | btrfs_header_nritems(&c->header) < | |
1066 | BTRFS_NODEPTRS_PER_BLOCK(root) - 1) | |
1067 | return 0; | |
54aa1f4d CM |
1068 | if (ret < 0) |
1069 | return ret; | |
be0e5c09 | 1070 | } |
e66f709b | 1071 | |
7518a238 | 1072 | c_nritems = btrfs_header_nritems(&c->header); |
31f3c99b | 1073 | split_buffer = btrfs_alloc_free_block(trans, root, t->b_blocknr); |
54aa1f4d CM |
1074 | if (IS_ERR(split_buffer)) |
1075 | return PTR_ERR(split_buffer); | |
1076 | ||
e20d96d6 | 1077 | split = btrfs_buffer_node(split_buffer); |
7518a238 | 1078 | btrfs_set_header_flags(&split->header, btrfs_header_flags(&c->header)); |
9a6f11ed | 1079 | btrfs_set_header_level(&split->header, btrfs_header_level(&c->header)); |
7eccb903 | 1080 | btrfs_set_header_blocknr(&split->header, bh_blocknr(split_buffer)); |
7f5c1516 | 1081 | btrfs_set_header_generation(&split->header, trans->transid); |
4d775673 | 1082 | btrfs_set_header_owner(&split->header, root->root_key.objectid); |
3eb0314d CM |
1083 | memcpy(split->header.fsid, root->fs_info->disk_super->fsid, |
1084 | sizeof(split->header.fsid)); | |
7518a238 | 1085 | mid = (c_nritems + 1) / 2; |
d6025579 CM |
1086 | btrfs_memcpy(root, split, split->ptrs, c->ptrs + mid, |
1087 | (c_nritems - mid) * sizeof(struct btrfs_key_ptr)); | |
7518a238 CM |
1088 | btrfs_set_header_nritems(&split->header, c_nritems - mid); |
1089 | btrfs_set_header_nritems(&c->header, mid); | |
aa5d6bed CM |
1090 | ret = 0; |
1091 | ||
d6025579 CM |
1092 | btrfs_mark_buffer_dirty(t); |
1093 | btrfs_mark_buffer_dirty(split_buffer); | |
e089f05c | 1094 | wret = insert_ptr(trans, root, path, &split->ptrs[0].key, |
7eccb903 | 1095 | bh_blocknr(split_buffer), path->slots[level + 1] + 1, |
123abc88 | 1096 | level + 1); |
aa5d6bed CM |
1097 | if (wret) |
1098 | ret = wret; | |
1099 | ||
5de08d7d | 1100 | if (path->slots[level] >= mid) { |
5c680ed6 | 1101 | path->slots[level] -= mid; |
234b63a0 | 1102 | btrfs_block_release(root, t); |
5c680ed6 CM |
1103 | path->nodes[level] = split_buffer; |
1104 | path->slots[level + 1] += 1; | |
1105 | } else { | |
234b63a0 | 1106 | btrfs_block_release(root, split_buffer); |
be0e5c09 | 1107 | } |
aa5d6bed | 1108 | return ret; |
be0e5c09 CM |
1109 | } |
1110 | ||
74123bd7 CM |
1111 | /* |
1112 | * how many bytes are required to store the items in a leaf. start | |
1113 | * and nr indicate which items in the leaf to check. This totals up the | |
1114 | * space used both by the item structs and the item data | |
1115 | */ | |
234b63a0 | 1116 | static int leaf_space_used(struct btrfs_leaf *l, int start, int nr) |
be0e5c09 CM |
1117 | { |
1118 | int data_len; | |
d4dbff95 CM |
1119 | int nritems = btrfs_header_nritems(&l->header); |
1120 | int end = min(nritems, start + nr) - 1; | |
be0e5c09 CM |
1121 | |
1122 | if (!nr) | |
1123 | return 0; | |
0783fcfc CM |
1124 | data_len = btrfs_item_end(l->items + start); |
1125 | data_len = data_len - btrfs_item_offset(l->items + end); | |
1126 | data_len += sizeof(struct btrfs_item) * nr; | |
d4dbff95 | 1127 | WARN_ON(data_len < 0); |
be0e5c09 CM |
1128 | return data_len; |
1129 | } | |
1130 | ||
d4dbff95 CM |
1131 | /* |
1132 | * The space between the end of the leaf items and | |
1133 | * the start of the leaf data. IOW, how much room | |
1134 | * the leaf has left for both items and data | |
1135 | */ | |
1136 | int btrfs_leaf_free_space(struct btrfs_root *root, struct btrfs_leaf *leaf) | |
1137 | { | |
1138 | int nritems = btrfs_header_nritems(&leaf->header); | |
1139 | return BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems); | |
1140 | } | |
1141 | ||
00ec4c51 CM |
1142 | /* |
1143 | * push some data in the path leaf to the right, trying to free up at | |
1144 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
aa5d6bed CM |
1145 | * |
1146 | * returns 1 if the push failed because the other node didn't have enough | |
1147 | * room, 0 if everything worked out and < 0 if there were major errors. | |
00ec4c51 | 1148 | */ |
e089f05c CM |
1149 | static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root |
1150 | *root, struct btrfs_path *path, int data_size) | |
00ec4c51 | 1151 | { |
e20d96d6 CM |
1152 | struct buffer_head *left_buf = path->nodes[0]; |
1153 | struct btrfs_leaf *left = btrfs_buffer_leaf(left_buf); | |
234b63a0 | 1154 | struct btrfs_leaf *right; |
e20d96d6 CM |
1155 | struct buffer_head *right_buf; |
1156 | struct buffer_head *upper; | |
1157 | struct btrfs_node *upper_node; | |
00ec4c51 CM |
1158 | int slot; |
1159 | int i; | |
1160 | int free_space; | |
1161 | int push_space = 0; | |
1162 | int push_items = 0; | |
0783fcfc | 1163 | struct btrfs_item *item; |
7518a238 CM |
1164 | u32 left_nritems; |
1165 | u32 right_nritems; | |
54aa1f4d | 1166 | int ret; |
00ec4c51 CM |
1167 | |
1168 | slot = path->slots[1]; | |
1169 | if (!path->nodes[1]) { | |
1170 | return 1; | |
1171 | } | |
1172 | upper = path->nodes[1]; | |
e20d96d6 CM |
1173 | upper_node = btrfs_buffer_node(upper); |
1174 | if (slot >= btrfs_header_nritems(&upper_node->header) - 1) { | |
00ec4c51 CM |
1175 | return 1; |
1176 | } | |
e20d96d6 CM |
1177 | right_buf = read_tree_block(root, |
1178 | btrfs_node_blockptr(btrfs_buffer_node(upper), slot + 1)); | |
1179 | right = btrfs_buffer_leaf(right_buf); | |
123abc88 | 1180 | free_space = btrfs_leaf_free_space(root, right); |
0783fcfc | 1181 | if (free_space < data_size + sizeof(struct btrfs_item)) { |
234b63a0 | 1182 | btrfs_block_release(root, right_buf); |
00ec4c51 CM |
1183 | return 1; |
1184 | } | |
02217ed2 | 1185 | /* cow and double check */ |
54aa1f4d CM |
1186 | ret = btrfs_cow_block(trans, root, right_buf, upper, |
1187 | slot + 1, &right_buf); | |
1188 | if (ret) { | |
1189 | btrfs_block_release(root, right_buf); | |
1190 | return 1; | |
1191 | } | |
e20d96d6 | 1192 | right = btrfs_buffer_leaf(right_buf); |
123abc88 | 1193 | free_space = btrfs_leaf_free_space(root, right); |
0783fcfc | 1194 | if (free_space < data_size + sizeof(struct btrfs_item)) { |
234b63a0 | 1195 | btrfs_block_release(root, right_buf); |
02217ed2 CM |
1196 | return 1; |
1197 | } | |
1198 | ||
7518a238 | 1199 | left_nritems = btrfs_header_nritems(&left->header); |
a429e513 CM |
1200 | if (left_nritems == 0) { |
1201 | btrfs_block_release(root, right_buf); | |
1202 | return 1; | |
1203 | } | |
1204 | for (i = left_nritems - 1; i >= 1; i--) { | |
00ec4c51 CM |
1205 | item = left->items + i; |
1206 | if (path->slots[0] == i) | |
1207 | push_space += data_size + sizeof(*item); | |
0783fcfc CM |
1208 | if (btrfs_item_size(item) + sizeof(*item) + push_space > |
1209 | free_space) | |
00ec4c51 CM |
1210 | break; |
1211 | push_items++; | |
0783fcfc | 1212 | push_space += btrfs_item_size(item) + sizeof(*item); |
00ec4c51 CM |
1213 | } |
1214 | if (push_items == 0) { | |
234b63a0 | 1215 | btrfs_block_release(root, right_buf); |
00ec4c51 CM |
1216 | return 1; |
1217 | } | |
a429e513 CM |
1218 | if (push_items == left_nritems) |
1219 | WARN_ON(1); | |
7518a238 | 1220 | right_nritems = btrfs_header_nritems(&right->header); |
00ec4c51 | 1221 | /* push left to right */ |
0783fcfc | 1222 | push_space = btrfs_item_end(left->items + left_nritems - push_items); |
123abc88 | 1223 | push_space -= leaf_data_end(root, left); |
00ec4c51 | 1224 | /* make room in the right data area */ |
d6025579 CM |
1225 | btrfs_memmove(root, right, btrfs_leaf_data(right) + |
1226 | leaf_data_end(root, right) - push_space, | |
1227 | btrfs_leaf_data(right) + | |
1228 | leaf_data_end(root, right), BTRFS_LEAF_DATA_SIZE(root) - | |
1229 | leaf_data_end(root, right)); | |
00ec4c51 | 1230 | /* copy from the left data area */ |
d6025579 CM |
1231 | btrfs_memcpy(root, right, btrfs_leaf_data(right) + |
1232 | BTRFS_LEAF_DATA_SIZE(root) - push_space, | |
1233 | btrfs_leaf_data(left) + leaf_data_end(root, left), | |
1234 | push_space); | |
1235 | btrfs_memmove(root, right, right->items + push_items, right->items, | |
0783fcfc | 1236 | right_nritems * sizeof(struct btrfs_item)); |
00ec4c51 | 1237 | /* copy the items from left to right */ |
d6025579 CM |
1238 | btrfs_memcpy(root, right, right->items, left->items + |
1239 | left_nritems - push_items, | |
1240 | push_items * sizeof(struct btrfs_item)); | |
00ec4c51 CM |
1241 | |
1242 | /* update the item pointers */ | |
7518a238 CM |
1243 | right_nritems += push_items; |
1244 | btrfs_set_header_nritems(&right->header, right_nritems); | |
123abc88 | 1245 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
7518a238 | 1246 | for (i = 0; i < right_nritems; i++) { |
0783fcfc CM |
1247 | btrfs_set_item_offset(right->items + i, push_space - |
1248 | btrfs_item_size(right->items + i)); | |
1249 | push_space = btrfs_item_offset(right->items + i); | |
00ec4c51 | 1250 | } |
7518a238 CM |
1251 | left_nritems -= push_items; |
1252 | btrfs_set_header_nritems(&left->header, left_nritems); | |
00ec4c51 | 1253 | |
d6025579 CM |
1254 | btrfs_mark_buffer_dirty(left_buf); |
1255 | btrfs_mark_buffer_dirty(right_buf); | |
a429e513 | 1256 | |
d6025579 | 1257 | btrfs_memcpy(root, upper_node, &upper_node->ptrs[slot + 1].key, |
e2fa7227 | 1258 | &right->items[0].key, sizeof(struct btrfs_disk_key)); |
d6025579 | 1259 | btrfs_mark_buffer_dirty(upper); |
02217ed2 | 1260 | |
00ec4c51 | 1261 | /* then fixup the leaf pointer in the path */ |
7518a238 CM |
1262 | if (path->slots[0] >= left_nritems) { |
1263 | path->slots[0] -= left_nritems; | |
234b63a0 | 1264 | btrfs_block_release(root, path->nodes[0]); |
00ec4c51 CM |
1265 | path->nodes[0] = right_buf; |
1266 | path->slots[1] += 1; | |
1267 | } else { | |
234b63a0 | 1268 | btrfs_block_release(root, right_buf); |
00ec4c51 | 1269 | } |
098f59c2 CM |
1270 | if (path->nodes[1]) |
1271 | check_node(root, path, 1); | |
00ec4c51 CM |
1272 | return 0; |
1273 | } | |
74123bd7 CM |
1274 | /* |
1275 | * push some data in the path leaf to the left, trying to free up at | |
1276 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
1277 | */ | |
e089f05c CM |
1278 | static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root |
1279 | *root, struct btrfs_path *path, int data_size) | |
be0e5c09 | 1280 | { |
e20d96d6 CM |
1281 | struct buffer_head *right_buf = path->nodes[0]; |
1282 | struct btrfs_leaf *right = btrfs_buffer_leaf(right_buf); | |
1283 | struct buffer_head *t; | |
234b63a0 | 1284 | struct btrfs_leaf *left; |
be0e5c09 CM |
1285 | int slot; |
1286 | int i; | |
1287 | int free_space; | |
1288 | int push_space = 0; | |
1289 | int push_items = 0; | |
0783fcfc | 1290 | struct btrfs_item *item; |
7518a238 | 1291 | u32 old_left_nritems; |
aa5d6bed CM |
1292 | int ret = 0; |
1293 | int wret; | |
be0e5c09 CM |
1294 | |
1295 | slot = path->slots[1]; | |
1296 | if (slot == 0) { | |
1297 | return 1; | |
1298 | } | |
1299 | if (!path->nodes[1]) { | |
1300 | return 1; | |
1301 | } | |
e20d96d6 CM |
1302 | t = read_tree_block(root, |
1303 | btrfs_node_blockptr(btrfs_buffer_node(path->nodes[1]), slot - 1)); | |
1304 | left = btrfs_buffer_leaf(t); | |
123abc88 | 1305 | free_space = btrfs_leaf_free_space(root, left); |
0783fcfc | 1306 | if (free_space < data_size + sizeof(struct btrfs_item)) { |
234b63a0 | 1307 | btrfs_block_release(root, t); |
be0e5c09 CM |
1308 | return 1; |
1309 | } | |
02217ed2 CM |
1310 | |
1311 | /* cow and double check */ | |
54aa1f4d CM |
1312 | ret = btrfs_cow_block(trans, root, t, path->nodes[1], slot - 1, &t); |
1313 | if (ret) { | |
1314 | /* we hit -ENOSPC, but it isn't fatal here */ | |
1315 | return 1; | |
1316 | } | |
e20d96d6 | 1317 | left = btrfs_buffer_leaf(t); |
123abc88 | 1318 | free_space = btrfs_leaf_free_space(root, left); |
0783fcfc | 1319 | if (free_space < data_size + sizeof(struct btrfs_item)) { |
234b63a0 | 1320 | btrfs_block_release(root, t); |
02217ed2 CM |
1321 | return 1; |
1322 | } | |
1323 | ||
a429e513 CM |
1324 | if (btrfs_header_nritems(&right->header) == 0) { |
1325 | btrfs_block_release(root, t); | |
1326 | return 1; | |
1327 | } | |
1328 | ||
1329 | for (i = 0; i < btrfs_header_nritems(&right->header) - 1; i++) { | |
be0e5c09 CM |
1330 | item = right->items + i; |
1331 | if (path->slots[0] == i) | |
1332 | push_space += data_size + sizeof(*item); | |
0783fcfc CM |
1333 | if (btrfs_item_size(item) + sizeof(*item) + push_space > |
1334 | free_space) | |
be0e5c09 CM |
1335 | break; |
1336 | push_items++; | |
0783fcfc | 1337 | push_space += btrfs_item_size(item) + sizeof(*item); |
be0e5c09 CM |
1338 | } |
1339 | if (push_items == 0) { | |
234b63a0 | 1340 | btrfs_block_release(root, t); |
be0e5c09 CM |
1341 | return 1; |
1342 | } | |
a429e513 CM |
1343 | if (push_items == btrfs_header_nritems(&right->header)) |
1344 | WARN_ON(1); | |
be0e5c09 | 1345 | /* push data from right to left */ |
d6025579 CM |
1346 | btrfs_memcpy(root, left, left->items + |
1347 | btrfs_header_nritems(&left->header), | |
1348 | right->items, push_items * sizeof(struct btrfs_item)); | |
123abc88 | 1349 | push_space = BTRFS_LEAF_DATA_SIZE(root) - |
0783fcfc | 1350 | btrfs_item_offset(right->items + push_items -1); |
d6025579 CM |
1351 | btrfs_memcpy(root, left, btrfs_leaf_data(left) + |
1352 | leaf_data_end(root, left) - push_space, | |
1353 | btrfs_leaf_data(right) + | |
1354 | btrfs_item_offset(right->items + push_items - 1), | |
1355 | push_space); | |
7518a238 | 1356 | old_left_nritems = btrfs_header_nritems(&left->header); |
eb60ceac CM |
1357 | BUG_ON(old_left_nritems < 0); |
1358 | ||
0783fcfc | 1359 | for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { |
123abc88 CM |
1360 | u32 ioff = btrfs_item_offset(left->items + i); |
1361 | btrfs_set_item_offset(left->items + i, ioff - | |
1362 | (BTRFS_LEAF_DATA_SIZE(root) - | |
0783fcfc CM |
1363 | btrfs_item_offset(left->items + |
1364 | old_left_nritems - 1))); | |
be0e5c09 | 1365 | } |
7518a238 | 1366 | btrfs_set_header_nritems(&left->header, old_left_nritems + push_items); |
be0e5c09 CM |
1367 | |
1368 | /* fixup right node */ | |
0783fcfc | 1369 | push_space = btrfs_item_offset(right->items + push_items - 1) - |
123abc88 | 1370 | leaf_data_end(root, right); |
d6025579 CM |
1371 | btrfs_memmove(root, right, btrfs_leaf_data(right) + |
1372 | BTRFS_LEAF_DATA_SIZE(root) - push_space, | |
1373 | btrfs_leaf_data(right) + | |
1374 | leaf_data_end(root, right), push_space); | |
1375 | btrfs_memmove(root, right, right->items, right->items + push_items, | |
7518a238 | 1376 | (btrfs_header_nritems(&right->header) - push_items) * |
0783fcfc | 1377 | sizeof(struct btrfs_item)); |
7518a238 CM |
1378 | btrfs_set_header_nritems(&right->header, |
1379 | btrfs_header_nritems(&right->header) - | |
1380 | push_items); | |
123abc88 | 1381 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
eb60ceac | 1382 | |
7518a238 | 1383 | for (i = 0; i < btrfs_header_nritems(&right->header); i++) { |
0783fcfc CM |
1384 | btrfs_set_item_offset(right->items + i, push_space - |
1385 | btrfs_item_size(right->items + i)); | |
1386 | push_space = btrfs_item_offset(right->items + i); | |
be0e5c09 | 1387 | } |
eb60ceac | 1388 | |
d6025579 CM |
1389 | btrfs_mark_buffer_dirty(t); |
1390 | btrfs_mark_buffer_dirty(right_buf); | |
098f59c2 | 1391 | |
e089f05c | 1392 | wret = fixup_low_keys(trans, root, path, &right->items[0].key, 1); |
aa5d6bed CM |
1393 | if (wret) |
1394 | ret = wret; | |
be0e5c09 CM |
1395 | |
1396 | /* then fixup the leaf pointer in the path */ | |
1397 | if (path->slots[0] < push_items) { | |
1398 | path->slots[0] += old_left_nritems; | |
234b63a0 | 1399 | btrfs_block_release(root, path->nodes[0]); |
eb60ceac | 1400 | path->nodes[0] = t; |
be0e5c09 CM |
1401 | path->slots[1] -= 1; |
1402 | } else { | |
234b63a0 | 1403 | btrfs_block_release(root, t); |
be0e5c09 CM |
1404 | path->slots[0] -= push_items; |
1405 | } | |
eb60ceac | 1406 | BUG_ON(path->slots[0] < 0); |
098f59c2 CM |
1407 | if (path->nodes[1]) |
1408 | check_node(root, path, 1); | |
aa5d6bed | 1409 | return ret; |
be0e5c09 CM |
1410 | } |
1411 | ||
74123bd7 CM |
1412 | /* |
1413 | * split the path's leaf in two, making sure there is at least data_size | |
1414 | * available for the resulting leaf level of the path. | |
aa5d6bed CM |
1415 | * |
1416 | * returns 0 if all went well and < 0 on failure. | |
74123bd7 | 1417 | */ |
e089f05c | 1418 | static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root |
d4dbff95 CM |
1419 | *root, struct btrfs_key *ins_key, |
1420 | struct btrfs_path *path, int data_size) | |
be0e5c09 | 1421 | { |
e20d96d6 | 1422 | struct buffer_head *l_buf; |
234b63a0 | 1423 | struct btrfs_leaf *l; |
7518a238 | 1424 | u32 nritems; |
eb60ceac CM |
1425 | int mid; |
1426 | int slot; | |
234b63a0 | 1427 | struct btrfs_leaf *right; |
e20d96d6 | 1428 | struct buffer_head *right_buffer; |
0783fcfc | 1429 | int space_needed = data_size + sizeof(struct btrfs_item); |
be0e5c09 CM |
1430 | int data_copy_size; |
1431 | int rt_data_off; | |
1432 | int i; | |
d4dbff95 | 1433 | int ret = 0; |
aa5d6bed | 1434 | int wret; |
d4dbff95 CM |
1435 | int double_split = 0; |
1436 | struct btrfs_disk_key disk_key; | |
aa5d6bed | 1437 | |
40689478 | 1438 | /* first try to make some room by pushing left and right */ |
e089f05c | 1439 | wret = push_leaf_left(trans, root, path, data_size); |
eaee50e8 CM |
1440 | if (wret < 0) |
1441 | return wret; | |
1442 | if (wret) { | |
e089f05c | 1443 | wret = push_leaf_right(trans, root, path, data_size); |
eaee50e8 CM |
1444 | if (wret < 0) |
1445 | return wret; | |
1446 | } | |
aa5d6bed | 1447 | l_buf = path->nodes[0]; |
e20d96d6 | 1448 | l = btrfs_buffer_leaf(l_buf); |
aa5d6bed CM |
1449 | |
1450 | /* did the pushes work? */ | |
123abc88 CM |
1451 | if (btrfs_leaf_free_space(root, l) >= |
1452 | sizeof(struct btrfs_item) + data_size) | |
aa5d6bed CM |
1453 | return 0; |
1454 | ||
5c680ed6 | 1455 | if (!path->nodes[1]) { |
e089f05c | 1456 | ret = insert_new_root(trans, root, path, 1); |
5c680ed6 CM |
1457 | if (ret) |
1458 | return ret; | |
1459 | } | |
eb60ceac | 1460 | slot = path->slots[0]; |
7518a238 | 1461 | nritems = btrfs_header_nritems(&l->header); |
eb60ceac | 1462 | mid = (nritems + 1)/ 2; |
54aa1f4d | 1463 | |
31f3c99b | 1464 | right_buffer = btrfs_alloc_free_block(trans, root, l_buf->b_blocknr); |
54aa1f4d CM |
1465 | if (IS_ERR(right_buffer)) |
1466 | return PTR_ERR(right_buffer); | |
1467 | ||
e20d96d6 | 1468 | right = btrfs_buffer_leaf(right_buffer); |
123abc88 | 1469 | memset(&right->header, 0, sizeof(right->header)); |
7eccb903 | 1470 | btrfs_set_header_blocknr(&right->header, bh_blocknr(right_buffer)); |
7f5c1516 | 1471 | btrfs_set_header_generation(&right->header, trans->transid); |
4d775673 | 1472 | btrfs_set_header_owner(&right->header, root->root_key.objectid); |
7518a238 | 1473 | btrfs_set_header_level(&right->header, 0); |
3eb0314d CM |
1474 | memcpy(right->header.fsid, root->fs_info->disk_super->fsid, |
1475 | sizeof(right->header.fsid)); | |
d4dbff95 CM |
1476 | if (mid <= slot) { |
1477 | if (nritems == 1 || | |
1478 | leaf_space_used(l, mid, nritems - mid) + space_needed > | |
1479 | BTRFS_LEAF_DATA_SIZE(root)) { | |
1480 | if (slot >= nritems) { | |
1481 | btrfs_cpu_key_to_disk(&disk_key, ins_key); | |
1482 | btrfs_set_header_nritems(&right->header, 0); | |
1483 | wret = insert_ptr(trans, root, path, | |
1484 | &disk_key, | |
7eccb903 | 1485 | bh_blocknr(right_buffer), |
d4dbff95 CM |
1486 | path->slots[1] + 1, 1); |
1487 | if (wret) | |
1488 | ret = wret; | |
1489 | btrfs_block_release(root, path->nodes[0]); | |
1490 | path->nodes[0] = right_buffer; | |
1491 | path->slots[0] = 0; | |
1492 | path->slots[1] += 1; | |
1493 | return ret; | |
1494 | } | |
1495 | mid = slot; | |
1496 | double_split = 1; | |
1497 | } | |
1498 | } else { | |
1499 | if (leaf_space_used(l, 0, mid + 1) + space_needed > | |
1500 | BTRFS_LEAF_DATA_SIZE(root)) { | |
1501 | if (slot == 0) { | |
1502 | btrfs_cpu_key_to_disk(&disk_key, ins_key); | |
1503 | btrfs_set_header_nritems(&right->header, 0); | |
1504 | wret = insert_ptr(trans, root, path, | |
1505 | &disk_key, | |
7eccb903 | 1506 | bh_blocknr(right_buffer), |
098f59c2 | 1507 | path->slots[1], 1); |
d4dbff95 CM |
1508 | if (wret) |
1509 | ret = wret; | |
1510 | btrfs_block_release(root, path->nodes[0]); | |
1511 | path->nodes[0] = right_buffer; | |
1512 | path->slots[0] = 0; | |
a429e513 CM |
1513 | if (path->slots[1] == 0) { |
1514 | wret = fixup_low_keys(trans, root, | |
1515 | path, &disk_key, 1); | |
1516 | if (wret) | |
1517 | ret = wret; | |
1518 | } | |
d4dbff95 CM |
1519 | return ret; |
1520 | } | |
1521 | mid = slot; | |
1522 | double_split = 1; | |
1523 | } | |
1524 | } | |
1525 | btrfs_set_header_nritems(&right->header, nritems - mid); | |
123abc88 CM |
1526 | data_copy_size = btrfs_item_end(l->items + mid) - |
1527 | leaf_data_end(root, l); | |
d6025579 CM |
1528 | btrfs_memcpy(root, right, right->items, l->items + mid, |
1529 | (nritems - mid) * sizeof(struct btrfs_item)); | |
1530 | btrfs_memcpy(root, right, | |
1531 | btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) - | |
1532 | data_copy_size, btrfs_leaf_data(l) + | |
1533 | leaf_data_end(root, l), data_copy_size); | |
123abc88 CM |
1534 | rt_data_off = BTRFS_LEAF_DATA_SIZE(root) - |
1535 | btrfs_item_end(l->items + mid); | |
74123bd7 | 1536 | |
0783fcfc | 1537 | for (i = 0; i < btrfs_header_nritems(&right->header); i++) { |
123abc88 | 1538 | u32 ioff = btrfs_item_offset(right->items + i); |
0783fcfc CM |
1539 | btrfs_set_item_offset(right->items + i, ioff + rt_data_off); |
1540 | } | |
74123bd7 | 1541 | |
7518a238 | 1542 | btrfs_set_header_nritems(&l->header, mid); |
aa5d6bed | 1543 | ret = 0; |
e089f05c | 1544 | wret = insert_ptr(trans, root, path, &right->items[0].key, |
7eccb903 | 1545 | bh_blocknr(right_buffer), path->slots[1] + 1, 1); |
aa5d6bed CM |
1546 | if (wret) |
1547 | ret = wret; | |
d6025579 CM |
1548 | btrfs_mark_buffer_dirty(right_buffer); |
1549 | btrfs_mark_buffer_dirty(l_buf); | |
eb60ceac | 1550 | BUG_ON(path->slots[0] != slot); |
be0e5c09 | 1551 | if (mid <= slot) { |
234b63a0 | 1552 | btrfs_block_release(root, path->nodes[0]); |
eb60ceac | 1553 | path->nodes[0] = right_buffer; |
be0e5c09 CM |
1554 | path->slots[0] -= mid; |
1555 | path->slots[1] += 1; | |
eb60ceac | 1556 | } else |
234b63a0 | 1557 | btrfs_block_release(root, right_buffer); |
eb60ceac | 1558 | BUG_ON(path->slots[0] < 0); |
098f59c2 | 1559 | check_node(root, path, 1); |
d4dbff95 CM |
1560 | |
1561 | if (!double_split) | |
1562 | return ret; | |
31f3c99b | 1563 | right_buffer = btrfs_alloc_free_block(trans, root, l_buf->b_blocknr); |
54aa1f4d CM |
1564 | if (IS_ERR(right_buffer)) |
1565 | return PTR_ERR(right_buffer); | |
1566 | ||
d4dbff95 CM |
1567 | right = btrfs_buffer_leaf(right_buffer); |
1568 | memset(&right->header, 0, sizeof(right->header)); | |
7eccb903 | 1569 | btrfs_set_header_blocknr(&right->header, bh_blocknr(right_buffer)); |
d4dbff95 | 1570 | btrfs_set_header_generation(&right->header, trans->transid); |
4d775673 | 1571 | btrfs_set_header_owner(&right->header, root->root_key.objectid); |
d4dbff95 | 1572 | btrfs_set_header_level(&right->header, 0); |
3eb0314d CM |
1573 | memcpy(right->header.fsid, root->fs_info->disk_super->fsid, |
1574 | sizeof(right->header.fsid)); | |
d4dbff95 CM |
1575 | btrfs_cpu_key_to_disk(&disk_key, ins_key); |
1576 | btrfs_set_header_nritems(&right->header, 0); | |
1577 | wret = insert_ptr(trans, root, path, | |
1578 | &disk_key, | |
7eccb903 | 1579 | bh_blocknr(right_buffer), |
d4dbff95 CM |
1580 | path->slots[1], 1); |
1581 | if (wret) | |
1582 | ret = wret; | |
a429e513 CM |
1583 | if (path->slots[1] == 0) { |
1584 | wret = fixup_low_keys(trans, root, path, &disk_key, 1); | |
1585 | if (wret) | |
1586 | ret = wret; | |
1587 | } | |
d4dbff95 CM |
1588 | btrfs_block_release(root, path->nodes[0]); |
1589 | path->nodes[0] = right_buffer; | |
1590 | path->slots[0] = 0; | |
1591 | check_node(root, path, 1); | |
1592 | check_leaf(root, path, 0); | |
be0e5c09 CM |
1593 | return ret; |
1594 | } | |
1595 | ||
b18c6685 CM |
1596 | int btrfs_truncate_item(struct btrfs_trans_handle *trans, |
1597 | struct btrfs_root *root, | |
1598 | struct btrfs_path *path, | |
1599 | u32 new_size) | |
1600 | { | |
1601 | int ret = 0; | |
1602 | int slot; | |
1603 | int slot_orig; | |
1604 | struct btrfs_leaf *leaf; | |
1605 | struct buffer_head *leaf_buf; | |
1606 | u32 nritems; | |
1607 | unsigned int data_end; | |
1608 | unsigned int old_data_start; | |
1609 | unsigned int old_size; | |
1610 | unsigned int size_diff; | |
1611 | int i; | |
1612 | ||
1613 | slot_orig = path->slots[0]; | |
1614 | leaf_buf = path->nodes[0]; | |
1615 | leaf = btrfs_buffer_leaf(leaf_buf); | |
1616 | ||
1617 | nritems = btrfs_header_nritems(&leaf->header); | |
1618 | data_end = leaf_data_end(root, leaf); | |
1619 | ||
1620 | slot = path->slots[0]; | |
1621 | old_data_start = btrfs_item_offset(leaf->items + slot); | |
1622 | old_size = btrfs_item_size(leaf->items + slot); | |
1623 | BUG_ON(old_size <= new_size); | |
1624 | size_diff = old_size - new_size; | |
1625 | ||
1626 | BUG_ON(slot < 0); | |
1627 | BUG_ON(slot >= nritems); | |
1628 | ||
1629 | /* | |
1630 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
1631 | */ | |
1632 | /* first correct the data pointers */ | |
1633 | for (i = slot; i < nritems; i++) { | |
1634 | u32 ioff = btrfs_item_offset(leaf->items + i); | |
1635 | btrfs_set_item_offset(leaf->items + i, | |
1636 | ioff + size_diff); | |
1637 | } | |
1638 | /* shift the data */ | |
b18c6685 CM |
1639 | btrfs_memmove(root, leaf, btrfs_leaf_data(leaf) + |
1640 | data_end + size_diff, btrfs_leaf_data(leaf) + | |
1641 | data_end, old_data_start + new_size - data_end); | |
1642 | btrfs_set_item_size(leaf->items + slot, new_size); | |
1643 | btrfs_mark_buffer_dirty(leaf_buf); | |
1644 | ||
1645 | ret = 0; | |
1646 | if (btrfs_leaf_free_space(root, leaf) < 0) | |
1647 | BUG(); | |
1648 | check_leaf(root, path, 0); | |
1649 | return ret; | |
1650 | } | |
1651 | ||
6567e837 CM |
1652 | int btrfs_extend_item(struct btrfs_trans_handle *trans, struct btrfs_root |
1653 | *root, struct btrfs_path *path, u32 data_size) | |
1654 | { | |
1655 | int ret = 0; | |
1656 | int slot; | |
1657 | int slot_orig; | |
1658 | struct btrfs_leaf *leaf; | |
1659 | struct buffer_head *leaf_buf; | |
1660 | u32 nritems; | |
1661 | unsigned int data_end; | |
1662 | unsigned int old_data; | |
1663 | unsigned int old_size; | |
1664 | int i; | |
1665 | ||
1666 | slot_orig = path->slots[0]; | |
1667 | leaf_buf = path->nodes[0]; | |
1668 | leaf = btrfs_buffer_leaf(leaf_buf); | |
1669 | ||
1670 | nritems = btrfs_header_nritems(&leaf->header); | |
1671 | data_end = leaf_data_end(root, leaf); | |
1672 | ||
1673 | if (btrfs_leaf_free_space(root, leaf) < data_size) | |
1674 | BUG(); | |
1675 | slot = path->slots[0]; | |
1676 | old_data = btrfs_item_end(leaf->items + slot); | |
1677 | ||
1678 | BUG_ON(slot < 0); | |
1679 | BUG_ON(slot >= nritems); | |
1680 | ||
1681 | /* | |
1682 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
1683 | */ | |
1684 | /* first correct the data pointers */ | |
1685 | for (i = slot; i < nritems; i++) { | |
1686 | u32 ioff = btrfs_item_offset(leaf->items + i); | |
1687 | btrfs_set_item_offset(leaf->items + i, | |
1688 | ioff - data_size); | |
1689 | } | |
1690 | /* shift the data */ | |
1691 | btrfs_memmove(root, leaf, btrfs_leaf_data(leaf) + | |
1692 | data_end - data_size, btrfs_leaf_data(leaf) + | |
1693 | data_end, old_data - data_end); | |
1694 | data_end = old_data; | |
1695 | old_size = btrfs_item_size(leaf->items + slot); | |
1696 | btrfs_set_item_size(leaf->items + slot, old_size + data_size); | |
1697 | btrfs_mark_buffer_dirty(leaf_buf); | |
1698 | ||
1699 | ret = 0; | |
1700 | if (btrfs_leaf_free_space(root, leaf) < 0) | |
1701 | BUG(); | |
1702 | check_leaf(root, path, 0); | |
1703 | return ret; | |
1704 | } | |
1705 | ||
74123bd7 CM |
1706 | /* |
1707 | * Given a key and some data, insert an item into the tree. | |
1708 | * This does all the path init required, making room in the tree if needed. | |
1709 | */ | |
e089f05c CM |
1710 | int btrfs_insert_empty_item(struct btrfs_trans_handle *trans, struct btrfs_root |
1711 | *root, struct btrfs_path *path, struct btrfs_key | |
1712 | *cpu_key, u32 data_size) | |
be0e5c09 | 1713 | { |
aa5d6bed | 1714 | int ret = 0; |
be0e5c09 | 1715 | int slot; |
eb60ceac | 1716 | int slot_orig; |
234b63a0 | 1717 | struct btrfs_leaf *leaf; |
e20d96d6 | 1718 | struct buffer_head *leaf_buf; |
7518a238 | 1719 | u32 nritems; |
be0e5c09 | 1720 | unsigned int data_end; |
e2fa7227 CM |
1721 | struct btrfs_disk_key disk_key; |
1722 | ||
1723 | btrfs_cpu_key_to_disk(&disk_key, cpu_key); | |
be0e5c09 | 1724 | |
74123bd7 | 1725 | /* create a root if there isn't one */ |
5c680ed6 | 1726 | if (!root->node) |
cfaa7295 | 1727 | BUG(); |
e089f05c | 1728 | ret = btrfs_search_slot(trans, root, cpu_key, path, data_size, 1); |
eb60ceac | 1729 | if (ret == 0) { |
f0930a37 | 1730 | return -EEXIST; |
aa5d6bed | 1731 | } |
ed2ff2cb CM |
1732 | if (ret < 0) |
1733 | goto out; | |
be0e5c09 | 1734 | |
62e2749e CM |
1735 | slot_orig = path->slots[0]; |
1736 | leaf_buf = path->nodes[0]; | |
e20d96d6 | 1737 | leaf = btrfs_buffer_leaf(leaf_buf); |
74123bd7 | 1738 | |
7518a238 | 1739 | nritems = btrfs_header_nritems(&leaf->header); |
123abc88 | 1740 | data_end = leaf_data_end(root, leaf); |
eb60ceac | 1741 | |
123abc88 | 1742 | if (btrfs_leaf_free_space(root, leaf) < |
d4dbff95 | 1743 | sizeof(struct btrfs_item) + data_size) { |
be0e5c09 | 1744 | BUG(); |
d4dbff95 | 1745 | } |
62e2749e | 1746 | slot = path->slots[0]; |
eb60ceac | 1747 | BUG_ON(slot < 0); |
be0e5c09 CM |
1748 | if (slot != nritems) { |
1749 | int i; | |
0783fcfc | 1750 | unsigned int old_data = btrfs_item_end(leaf->items + slot); |
be0e5c09 CM |
1751 | |
1752 | /* | |
1753 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
1754 | */ | |
1755 | /* first correct the data pointers */ | |
0783fcfc | 1756 | for (i = slot; i < nritems; i++) { |
123abc88 | 1757 | u32 ioff = btrfs_item_offset(leaf->items + i); |
0783fcfc CM |
1758 | btrfs_set_item_offset(leaf->items + i, |
1759 | ioff - data_size); | |
1760 | } | |
be0e5c09 CM |
1761 | |
1762 | /* shift the items */ | |
d6025579 CM |
1763 | btrfs_memmove(root, leaf, leaf->items + slot + 1, |
1764 | leaf->items + slot, | |
1765 | (nritems - slot) * sizeof(struct btrfs_item)); | |
be0e5c09 CM |
1766 | |
1767 | /* shift the data */ | |
d6025579 CM |
1768 | btrfs_memmove(root, leaf, btrfs_leaf_data(leaf) + |
1769 | data_end - data_size, btrfs_leaf_data(leaf) + | |
1770 | data_end, old_data - data_end); | |
be0e5c09 CM |
1771 | data_end = old_data; |
1772 | } | |
62e2749e | 1773 | /* setup the item for the new data */ |
d6025579 CM |
1774 | btrfs_memcpy(root, leaf, &leaf->items[slot].key, &disk_key, |
1775 | sizeof(struct btrfs_disk_key)); | |
0783fcfc CM |
1776 | btrfs_set_item_offset(leaf->items + slot, data_end - data_size); |
1777 | btrfs_set_item_size(leaf->items + slot, data_size); | |
7518a238 | 1778 | btrfs_set_header_nritems(&leaf->header, nritems + 1); |
d6025579 | 1779 | btrfs_mark_buffer_dirty(leaf_buf); |
aa5d6bed CM |
1780 | |
1781 | ret = 0; | |
8e19f2cd | 1782 | if (slot == 0) |
e089f05c | 1783 | ret = fixup_low_keys(trans, root, path, &disk_key, 1); |
aa5d6bed | 1784 | |
123abc88 | 1785 | if (btrfs_leaf_free_space(root, leaf) < 0) |
be0e5c09 | 1786 | BUG(); |
62e2749e | 1787 | check_leaf(root, path, 0); |
ed2ff2cb | 1788 | out: |
62e2749e CM |
1789 | return ret; |
1790 | } | |
1791 | ||
1792 | /* | |
1793 | * Given a key and some data, insert an item into the tree. | |
1794 | * This does all the path init required, making room in the tree if needed. | |
1795 | */ | |
e089f05c CM |
1796 | int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root |
1797 | *root, struct btrfs_key *cpu_key, void *data, u32 | |
1798 | data_size) | |
62e2749e CM |
1799 | { |
1800 | int ret = 0; | |
2c90e5d6 | 1801 | struct btrfs_path *path; |
62e2749e CM |
1802 | u8 *ptr; |
1803 | ||
2c90e5d6 CM |
1804 | path = btrfs_alloc_path(); |
1805 | BUG_ON(!path); | |
2c90e5d6 | 1806 | ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size); |
62e2749e | 1807 | if (!ret) { |
2c90e5d6 CM |
1808 | ptr = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), |
1809 | path->slots[0], u8); | |
1810 | btrfs_memcpy(root, path->nodes[0]->b_data, | |
d6025579 | 1811 | ptr, data, data_size); |
2c90e5d6 | 1812 | btrfs_mark_buffer_dirty(path->nodes[0]); |
62e2749e | 1813 | } |
2c90e5d6 | 1814 | btrfs_free_path(path); |
aa5d6bed | 1815 | return ret; |
be0e5c09 CM |
1816 | } |
1817 | ||
74123bd7 | 1818 | /* |
5de08d7d | 1819 | * delete the pointer from a given node. |
74123bd7 CM |
1820 | * |
1821 | * If the delete empties a node, the node is removed from the tree, | |
1822 | * continuing all the way the root if required. The root is converted into | |
1823 | * a leaf if all the nodes are emptied. | |
1824 | */ | |
e089f05c CM |
1825 | static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
1826 | struct btrfs_path *path, int level, int slot) | |
be0e5c09 | 1827 | { |
234b63a0 | 1828 | struct btrfs_node *node; |
e20d96d6 | 1829 | struct buffer_head *parent = path->nodes[level]; |
7518a238 | 1830 | u32 nritems; |
aa5d6bed | 1831 | int ret = 0; |
bb803951 | 1832 | int wret; |
be0e5c09 | 1833 | |
e20d96d6 | 1834 | node = btrfs_buffer_node(parent); |
7518a238 | 1835 | nritems = btrfs_header_nritems(&node->header); |
bb803951 | 1836 | if (slot != nritems -1) { |
d6025579 CM |
1837 | btrfs_memmove(root, node, node->ptrs + slot, |
1838 | node->ptrs + slot + 1, | |
1839 | sizeof(struct btrfs_key_ptr) * | |
1840 | (nritems - slot - 1)); | |
bb803951 | 1841 | } |
7518a238 CM |
1842 | nritems--; |
1843 | btrfs_set_header_nritems(&node->header, nritems); | |
1844 | if (nritems == 0 && parent == root->node) { | |
e20d96d6 CM |
1845 | struct btrfs_header *header = btrfs_buffer_header(root->node); |
1846 | BUG_ON(btrfs_header_level(header) != 1); | |
bb803951 | 1847 | /* just turn the root into a leaf and break */ |
e20d96d6 | 1848 | btrfs_set_header_level(header, 0); |
bb803951 | 1849 | } else if (slot == 0) { |
e089f05c | 1850 | wret = fixup_low_keys(trans, root, path, &node->ptrs[0].key, |
123abc88 | 1851 | level + 1); |
0f70abe2 CM |
1852 | if (wret) |
1853 | ret = wret; | |
be0e5c09 | 1854 | } |
d6025579 | 1855 | btrfs_mark_buffer_dirty(parent); |
aa5d6bed | 1856 | return ret; |
be0e5c09 CM |
1857 | } |
1858 | ||
74123bd7 CM |
1859 | /* |
1860 | * delete the item at the leaf level in path. If that empties | |
1861 | * the leaf, remove it from the tree | |
1862 | */ | |
e089f05c CM |
1863 | int btrfs_del_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
1864 | struct btrfs_path *path) | |
be0e5c09 | 1865 | { |
be0e5c09 | 1866 | int slot; |
234b63a0 | 1867 | struct btrfs_leaf *leaf; |
e20d96d6 | 1868 | struct buffer_head *leaf_buf; |
be0e5c09 CM |
1869 | int doff; |
1870 | int dsize; | |
aa5d6bed CM |
1871 | int ret = 0; |
1872 | int wret; | |
7518a238 | 1873 | u32 nritems; |
be0e5c09 | 1874 | |
eb60ceac | 1875 | leaf_buf = path->nodes[0]; |
e20d96d6 | 1876 | leaf = btrfs_buffer_leaf(leaf_buf); |
4920c9ac | 1877 | slot = path->slots[0]; |
0783fcfc CM |
1878 | doff = btrfs_item_offset(leaf->items + slot); |
1879 | dsize = btrfs_item_size(leaf->items + slot); | |
7518a238 | 1880 | nritems = btrfs_header_nritems(&leaf->header); |
be0e5c09 | 1881 | |
7518a238 | 1882 | if (slot != nritems - 1) { |
be0e5c09 | 1883 | int i; |
123abc88 | 1884 | int data_end = leaf_data_end(root, leaf); |
d6025579 CM |
1885 | btrfs_memmove(root, leaf, btrfs_leaf_data(leaf) + |
1886 | data_end + dsize, | |
1887 | btrfs_leaf_data(leaf) + data_end, | |
1888 | doff - data_end); | |
0783fcfc | 1889 | for (i = slot + 1; i < nritems; i++) { |
123abc88 | 1890 | u32 ioff = btrfs_item_offset(leaf->items + i); |
0783fcfc CM |
1891 | btrfs_set_item_offset(leaf->items + i, ioff + dsize); |
1892 | } | |
d6025579 CM |
1893 | btrfs_memmove(root, leaf, leaf->items + slot, |
1894 | leaf->items + slot + 1, | |
1895 | sizeof(struct btrfs_item) * | |
1896 | (nritems - slot - 1)); | |
be0e5c09 | 1897 | } |
7518a238 CM |
1898 | btrfs_set_header_nritems(&leaf->header, nritems - 1); |
1899 | nritems--; | |
74123bd7 | 1900 | /* delete the leaf if we've emptied it */ |
7518a238 | 1901 | if (nritems == 0) { |
eb60ceac | 1902 | if (leaf_buf == root->node) { |
7518a238 | 1903 | btrfs_set_header_level(&leaf->header, 0); |
9a8dd150 | 1904 | } else { |
e089f05c | 1905 | clean_tree_block(trans, root, leaf_buf); |
d6025579 | 1906 | wait_on_buffer(leaf_buf); |
e089f05c | 1907 | wret = del_ptr(trans, root, path, 1, path->slots[1]); |
aa5d6bed CM |
1908 | if (wret) |
1909 | ret = wret; | |
e089f05c | 1910 | wret = btrfs_free_extent(trans, root, |
7eccb903 | 1911 | bh_blocknr(leaf_buf), 1, 1); |
0f70abe2 CM |
1912 | if (wret) |
1913 | ret = wret; | |
9a8dd150 | 1914 | } |
be0e5c09 | 1915 | } else { |
7518a238 | 1916 | int used = leaf_space_used(leaf, 0, nritems); |
aa5d6bed | 1917 | if (slot == 0) { |
e089f05c CM |
1918 | wret = fixup_low_keys(trans, root, path, |
1919 | &leaf->items[0].key, 1); | |
aa5d6bed CM |
1920 | if (wret) |
1921 | ret = wret; | |
1922 | } | |
aa5d6bed | 1923 | |
74123bd7 | 1924 | /* delete the leaf if it is mostly empty */ |
123abc88 | 1925 | if (used < BTRFS_LEAF_DATA_SIZE(root) / 3) { |
be0e5c09 CM |
1926 | /* push_leaf_left fixes the path. |
1927 | * make sure the path still points to our leaf | |
1928 | * for possible call to del_ptr below | |
1929 | */ | |
4920c9ac | 1930 | slot = path->slots[1]; |
e20d96d6 | 1931 | get_bh(leaf_buf); |
e089f05c | 1932 | wret = push_leaf_left(trans, root, path, 1); |
54aa1f4d | 1933 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed | 1934 | ret = wret; |
f0930a37 | 1935 | if (path->nodes[0] == leaf_buf && |
7518a238 | 1936 | btrfs_header_nritems(&leaf->header)) { |
e089f05c | 1937 | wret = push_leaf_right(trans, root, path, 1); |
54aa1f4d | 1938 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed CM |
1939 | ret = wret; |
1940 | } | |
7518a238 | 1941 | if (btrfs_header_nritems(&leaf->header) == 0) { |
7eccb903 | 1942 | u64 blocknr = bh_blocknr(leaf_buf); |
e089f05c | 1943 | clean_tree_block(trans, root, leaf_buf); |
d6025579 | 1944 | wait_on_buffer(leaf_buf); |
e089f05c | 1945 | wret = del_ptr(trans, root, path, 1, slot); |
aa5d6bed CM |
1946 | if (wret) |
1947 | ret = wret; | |
234b63a0 | 1948 | btrfs_block_release(root, leaf_buf); |
e089f05c CM |
1949 | wret = btrfs_free_extent(trans, root, blocknr, |
1950 | 1, 1); | |
0f70abe2 CM |
1951 | if (wret) |
1952 | ret = wret; | |
5de08d7d | 1953 | } else { |
d6025579 | 1954 | btrfs_mark_buffer_dirty(leaf_buf); |
234b63a0 | 1955 | btrfs_block_release(root, leaf_buf); |
be0e5c09 | 1956 | } |
d5719762 | 1957 | } else { |
d6025579 | 1958 | btrfs_mark_buffer_dirty(leaf_buf); |
be0e5c09 CM |
1959 | } |
1960 | } | |
aa5d6bed | 1961 | return ret; |
be0e5c09 CM |
1962 | } |
1963 | ||
97571fd0 CM |
1964 | /* |
1965 | * walk up the tree as far as required to find the next leaf. | |
0f70abe2 CM |
1966 | * returns 0 if it found something or 1 if there are no greater leaves. |
1967 | * returns < 0 on io errors. | |
97571fd0 | 1968 | */ |
234b63a0 | 1969 | int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) |
d97e63b6 CM |
1970 | { |
1971 | int slot; | |
1972 | int level = 1; | |
1973 | u64 blocknr; | |
e20d96d6 CM |
1974 | struct buffer_head *c; |
1975 | struct btrfs_node *c_node; | |
1976 | struct buffer_head *next = NULL; | |
d97e63b6 | 1977 | |
234b63a0 | 1978 | while(level < BTRFS_MAX_LEVEL) { |
d97e63b6 | 1979 | if (!path->nodes[level]) |
0f70abe2 | 1980 | return 1; |
d97e63b6 CM |
1981 | slot = path->slots[level] + 1; |
1982 | c = path->nodes[level]; | |
e20d96d6 CM |
1983 | c_node = btrfs_buffer_node(c); |
1984 | if (slot >= btrfs_header_nritems(&c_node->header)) { | |
d97e63b6 CM |
1985 | level++; |
1986 | continue; | |
1987 | } | |
e20d96d6 | 1988 | blocknr = btrfs_node_blockptr(c_node, slot); |
cfaa7295 | 1989 | if (next) |
234b63a0 | 1990 | btrfs_block_release(root, next); |
3c69faec CM |
1991 | if (level == 1 && path->reada) |
1992 | reada_for_search(root, path, slot); | |
d97e63b6 CM |
1993 | next = read_tree_block(root, blocknr); |
1994 | break; | |
1995 | } | |
1996 | path->slots[level] = slot; | |
1997 | while(1) { | |
1998 | level--; | |
1999 | c = path->nodes[level]; | |
234b63a0 | 2000 | btrfs_block_release(root, c); |
d97e63b6 CM |
2001 | path->nodes[level] = next; |
2002 | path->slots[level] = 0; | |
2003 | if (!level) | |
2004 | break; | |
3c69faec CM |
2005 | if (level == 1 && path->reada) |
2006 | reada_for_search(root, path, slot); | |
1d4f8a0c | 2007 | next = read_tree_block(root, |
e20d96d6 | 2008 | btrfs_node_blockptr(btrfs_buffer_node(next), 0)); |
d97e63b6 CM |
2009 | } |
2010 | return 0; | |
2011 | } |