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Commit | Line | Data |
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2e635a27 | 1 | #include <linux/module.h> |
eb60ceac CM |
2 | #include "ctree.h" |
3 | #include "disk-io.h" | |
7f5c1516 | 4 | #include "transaction.h" |
9a8dd150 | 5 | |
e089f05c CM |
6 | static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root |
7 | *root, struct btrfs_path *path, int level); | |
8 | static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root | |
9 | *root, struct btrfs_path *path, int data_size); | |
10 | static int push_node_left(struct btrfs_trans_handle *trans, struct btrfs_root | |
e20d96d6 | 11 | *root, struct buffer_head *dst, struct buffer_head |
e089f05c CM |
12 | *src); |
13 | static int balance_node_right(struct btrfs_trans_handle *trans, struct | |
e20d96d6 CM |
14 | btrfs_root *root, struct buffer_head *dst_buf, |
15 | struct buffer_head *src_buf); | |
e089f05c CM |
16 | static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
17 | struct btrfs_path *path, int level, int slot); | |
d97e63b6 | 18 | |
df24a2b9 | 19 | inline void btrfs_init_path(struct btrfs_path *p) |
2c90e5d6 | 20 | { |
df24a2b9 | 21 | memset(p, 0, sizeof(*p)); |
2c90e5d6 CM |
22 | } |
23 | ||
df24a2b9 | 24 | struct btrfs_path *btrfs_alloc_path(void) |
2c90e5d6 | 25 | { |
df24a2b9 CM |
26 | struct btrfs_path *path; |
27 | path = kmem_cache_alloc(btrfs_path_cachep, GFP_NOFS); | |
28 | if (path) | |
29 | btrfs_init_path(path); | |
30 | return path; | |
2c90e5d6 CM |
31 | } |
32 | ||
df24a2b9 | 33 | void btrfs_free_path(struct btrfs_path *p) |
be0e5c09 | 34 | { |
df24a2b9 CM |
35 | btrfs_release_path(NULL, p); |
36 | kmem_cache_free(btrfs_path_cachep, p); | |
be0e5c09 CM |
37 | } |
38 | ||
234b63a0 | 39 | void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p) |
eb60ceac CM |
40 | { |
41 | int i; | |
234b63a0 | 42 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) { |
eb60ceac CM |
43 | if (!p->nodes[i]) |
44 | break; | |
234b63a0 | 45 | btrfs_block_release(root, p->nodes[i]); |
eb60ceac | 46 | } |
aa5d6bed | 47 | memset(p, 0, sizeof(*p)); |
eb60ceac CM |
48 | } |
49 | ||
e089f05c | 50 | static int btrfs_cow_block(struct btrfs_trans_handle *trans, struct btrfs_root |
e20d96d6 CM |
51 | *root, struct buffer_head *buf, struct buffer_head |
52 | *parent, int parent_slot, struct buffer_head | |
e089f05c | 53 | **cow_ret) |
02217ed2 | 54 | { |
e20d96d6 CM |
55 | struct buffer_head *cow; |
56 | struct btrfs_node *cow_node; | |
02217ed2 | 57 | |
7f5c1516 CM |
58 | if (btrfs_header_generation(btrfs_buffer_header(buf)) == |
59 | trans->transid) { | |
02217ed2 CM |
60 | *cow_ret = buf; |
61 | return 0; | |
62 | } | |
e089f05c | 63 | cow = btrfs_alloc_free_block(trans, root); |
e20d96d6 | 64 | cow_node = btrfs_buffer_node(cow); |
2c90e5d6 CM |
65 | if (buf->b_size != root->blocksize || cow->b_size != root->blocksize) |
66 | WARN_ON(1); | |
e20d96d6 CM |
67 | memcpy(cow_node, btrfs_buffer_node(buf), root->blocksize); |
68 | btrfs_set_header_blocknr(&cow_node->header, cow->b_blocknr); | |
7f5c1516 | 69 | btrfs_set_header_generation(&cow_node->header, trans->transid); |
e089f05c | 70 | btrfs_inc_ref(trans, root, buf); |
02217ed2 CM |
71 | if (buf == root->node) { |
72 | root->node = cow; | |
e20d96d6 | 73 | get_bh(cow); |
2c90e5d6 | 74 | if (buf != root->commit_root) { |
e20d96d6 | 75 | btrfs_free_extent(trans, root, buf->b_blocknr, 1, 1); |
2c90e5d6 | 76 | } |
234b63a0 | 77 | btrfs_block_release(root, buf); |
02217ed2 | 78 | } else { |
e20d96d6 CM |
79 | btrfs_set_node_blockptr(btrfs_buffer_node(parent), parent_slot, |
80 | cow->b_blocknr); | |
d6025579 | 81 | btrfs_mark_buffer_dirty(parent); |
e20d96d6 | 82 | btrfs_free_extent(trans, root, buf->b_blocknr, 1, 1); |
02217ed2 | 83 | } |
234b63a0 | 84 | btrfs_block_release(root, buf); |
df24a2b9 | 85 | mark_buffer_dirty(cow); |
2c90e5d6 | 86 | *cow_ret = cow; |
02217ed2 CM |
87 | return 0; |
88 | } | |
89 | ||
74123bd7 CM |
90 | /* |
91 | * The leaf data grows from end-to-front in the node. | |
92 | * this returns the address of the start of the last item, | |
93 | * which is the stop of the leaf data stack | |
94 | */ | |
123abc88 CM |
95 | static inline unsigned int leaf_data_end(struct btrfs_root *root, |
96 | struct btrfs_leaf *leaf) | |
be0e5c09 | 97 | { |
7518a238 | 98 | u32 nr = btrfs_header_nritems(&leaf->header); |
be0e5c09 | 99 | if (nr == 0) |
123abc88 | 100 | return BTRFS_LEAF_DATA_SIZE(root); |
0783fcfc | 101 | return btrfs_item_offset(leaf->items + nr - 1); |
be0e5c09 CM |
102 | } |
103 | ||
74123bd7 CM |
104 | /* |
105 | * The space between the end of the leaf items and | |
106 | * the start of the leaf data. IOW, how much room | |
107 | * the leaf has left for both items and data | |
108 | */ | |
123abc88 | 109 | int btrfs_leaf_free_space(struct btrfs_root *root, struct btrfs_leaf *leaf) |
be0e5c09 | 110 | { |
123abc88 | 111 | int data_end = leaf_data_end(root, leaf); |
7518a238 | 112 | int nritems = btrfs_header_nritems(&leaf->header); |
be0e5c09 | 113 | char *items_end = (char *)(leaf->items + nritems + 1); |
123abc88 | 114 | return (char *)(btrfs_leaf_data(leaf) + data_end) - (char *)items_end; |
be0e5c09 CM |
115 | } |
116 | ||
74123bd7 CM |
117 | /* |
118 | * compare two keys in a memcmp fashion | |
119 | */ | |
9aca1d51 | 120 | static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2) |
be0e5c09 | 121 | { |
e2fa7227 CM |
122 | struct btrfs_key k1; |
123 | ||
124 | btrfs_disk_key_to_cpu(&k1, disk); | |
125 | ||
126 | if (k1.objectid > k2->objectid) | |
be0e5c09 | 127 | return 1; |
e2fa7227 | 128 | if (k1.objectid < k2->objectid) |
be0e5c09 | 129 | return -1; |
a8a2ee0c CM |
130 | if (k1.offset > k2->offset) |
131 | return 1; | |
132 | if (k1.offset < k2->offset) | |
133 | return -1; | |
f254e52c CM |
134 | if (k1.flags > k2->flags) |
135 | return 1; | |
136 | if (k1.flags < k2->flags) | |
137 | return -1; | |
be0e5c09 CM |
138 | return 0; |
139 | } | |
74123bd7 | 140 | |
123abc88 CM |
141 | static int check_node(struct btrfs_root *root, struct btrfs_path *path, |
142 | int level) | |
aa5d6bed CM |
143 | { |
144 | int i; | |
234b63a0 | 145 | struct btrfs_node *parent = NULL; |
e20d96d6 | 146 | struct btrfs_node *node = btrfs_buffer_node(path->nodes[level]); |
aa5d6bed | 147 | int parent_slot; |
7518a238 | 148 | u32 nritems = btrfs_header_nritems(&node->header); |
aa5d6bed CM |
149 | |
150 | if (path->nodes[level + 1]) | |
e20d96d6 | 151 | parent = btrfs_buffer_node(path->nodes[level + 1]); |
aa5d6bed | 152 | parent_slot = path->slots[level + 1]; |
7518a238 CM |
153 | BUG_ON(nritems == 0); |
154 | if (parent) { | |
e2fa7227 | 155 | struct btrfs_disk_key *parent_key; |
123abc88 CM |
156 | parent_key = &parent->ptrs[parent_slot].key; |
157 | BUG_ON(memcmp(parent_key, &node->ptrs[0].key, | |
e2fa7227 | 158 | sizeof(struct btrfs_disk_key))); |
1d4f8a0c | 159 | BUG_ON(btrfs_node_blockptr(parent, parent_slot) != |
7518a238 | 160 | btrfs_header_blocknr(&node->header)); |
aa5d6bed | 161 | } |
123abc88 | 162 | BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root)); |
7518a238 | 163 | for (i = 0; nritems > 1 && i < nritems - 2; i++) { |
e2fa7227 | 164 | struct btrfs_key cpukey; |
123abc88 CM |
165 | btrfs_disk_key_to_cpu(&cpukey, &node->ptrs[i + 1].key); |
166 | BUG_ON(comp_keys(&node->ptrs[i].key, &cpukey) >= 0); | |
aa5d6bed CM |
167 | } |
168 | return 0; | |
169 | } | |
170 | ||
123abc88 CM |
171 | static int check_leaf(struct btrfs_root *root, struct btrfs_path *path, |
172 | int level) | |
aa5d6bed CM |
173 | { |
174 | int i; | |
e20d96d6 | 175 | struct btrfs_leaf *leaf = btrfs_buffer_leaf(path->nodes[level]); |
234b63a0 | 176 | struct btrfs_node *parent = NULL; |
aa5d6bed | 177 | int parent_slot; |
7518a238 | 178 | u32 nritems = btrfs_header_nritems(&leaf->header); |
aa5d6bed CM |
179 | |
180 | if (path->nodes[level + 1]) | |
e20d96d6 | 181 | parent = btrfs_buffer_node(path->nodes[level + 1]); |
aa5d6bed | 182 | parent_slot = path->slots[level + 1]; |
123abc88 | 183 | BUG_ON(btrfs_leaf_free_space(root, leaf) < 0); |
7518a238 CM |
184 | |
185 | if (nritems == 0) | |
186 | return 0; | |
187 | ||
188 | if (parent) { | |
e2fa7227 | 189 | struct btrfs_disk_key *parent_key; |
123abc88 | 190 | parent_key = &parent->ptrs[parent_slot].key; |
aa5d6bed | 191 | BUG_ON(memcmp(parent_key, &leaf->items[0].key, |
e2fa7227 | 192 | sizeof(struct btrfs_disk_key))); |
1d4f8a0c | 193 | BUG_ON(btrfs_node_blockptr(parent, parent_slot) != |
7518a238 | 194 | btrfs_header_blocknr(&leaf->header)); |
aa5d6bed | 195 | } |
7518a238 | 196 | for (i = 0; nritems > 1 && i < nritems - 2; i++) { |
e2fa7227 CM |
197 | struct btrfs_key cpukey; |
198 | btrfs_disk_key_to_cpu(&cpukey, &leaf->items[i + 1].key); | |
aa5d6bed | 199 | BUG_ON(comp_keys(&leaf->items[i].key, |
e2fa7227 | 200 | &cpukey) >= 0); |
0783fcfc CM |
201 | BUG_ON(btrfs_item_offset(leaf->items + i) != |
202 | btrfs_item_end(leaf->items + i + 1)); | |
aa5d6bed | 203 | if (i == 0) { |
0783fcfc CM |
204 | BUG_ON(btrfs_item_offset(leaf->items + i) + |
205 | btrfs_item_size(leaf->items + i) != | |
123abc88 | 206 | BTRFS_LEAF_DATA_SIZE(root)); |
aa5d6bed CM |
207 | } |
208 | } | |
aa5d6bed CM |
209 | return 0; |
210 | } | |
211 | ||
123abc88 CM |
212 | static int check_block(struct btrfs_root *root, struct btrfs_path *path, |
213 | int level) | |
aa5d6bed CM |
214 | { |
215 | if (level == 0) | |
123abc88 CM |
216 | return check_leaf(root, path, level); |
217 | return check_node(root, path, level); | |
aa5d6bed CM |
218 | } |
219 | ||
74123bd7 CM |
220 | /* |
221 | * search for key in the array p. items p are item_size apart | |
222 | * and there are 'max' items in p | |
223 | * the slot in the array is returned via slot, and it points to | |
224 | * the place where you would insert key if it is not found in | |
225 | * the array. | |
226 | * | |
227 | * slot may point to max if the key is bigger than all of the keys | |
228 | */ | |
9aca1d51 | 229 | static int generic_bin_search(char *p, int item_size, struct btrfs_key *key, |
be0e5c09 CM |
230 | int max, int *slot) |
231 | { | |
232 | int low = 0; | |
233 | int high = max; | |
234 | int mid; | |
235 | int ret; | |
e2fa7227 | 236 | struct btrfs_disk_key *tmp; |
be0e5c09 CM |
237 | |
238 | while(low < high) { | |
239 | mid = (low + high) / 2; | |
e2fa7227 | 240 | tmp = (struct btrfs_disk_key *)(p + mid * item_size); |
be0e5c09 CM |
241 | ret = comp_keys(tmp, key); |
242 | ||
243 | if (ret < 0) | |
244 | low = mid + 1; | |
245 | else if (ret > 0) | |
246 | high = mid; | |
247 | else { | |
248 | *slot = mid; | |
249 | return 0; | |
250 | } | |
251 | } | |
252 | *slot = low; | |
253 | return 1; | |
254 | } | |
255 | ||
97571fd0 CM |
256 | /* |
257 | * simple bin_search frontend that does the right thing for | |
258 | * leaves vs nodes | |
259 | */ | |
9aca1d51 | 260 | static int bin_search(struct btrfs_node *c, struct btrfs_key *key, int *slot) |
be0e5c09 | 261 | { |
7518a238 | 262 | if (btrfs_is_leaf(c)) { |
234b63a0 | 263 | struct btrfs_leaf *l = (struct btrfs_leaf *)c; |
0783fcfc CM |
264 | return generic_bin_search((void *)l->items, |
265 | sizeof(struct btrfs_item), | |
7518a238 CM |
266 | key, btrfs_header_nritems(&c->header), |
267 | slot); | |
be0e5c09 | 268 | } else { |
123abc88 CM |
269 | return generic_bin_search((void *)c->ptrs, |
270 | sizeof(struct btrfs_key_ptr), | |
7518a238 CM |
271 | key, btrfs_header_nritems(&c->header), |
272 | slot); | |
be0e5c09 CM |
273 | } |
274 | return -1; | |
275 | } | |
276 | ||
e20d96d6 CM |
277 | static struct buffer_head *read_node_slot(struct btrfs_root *root, |
278 | struct buffer_head *parent_buf, | |
bb803951 CM |
279 | int slot) |
280 | { | |
e20d96d6 | 281 | struct btrfs_node *node = btrfs_buffer_node(parent_buf); |
bb803951 CM |
282 | if (slot < 0) |
283 | return NULL; | |
7518a238 | 284 | if (slot >= btrfs_header_nritems(&node->header)) |
bb803951 | 285 | return NULL; |
1d4f8a0c | 286 | return read_tree_block(root, btrfs_node_blockptr(node, slot)); |
bb803951 CM |
287 | } |
288 | ||
e089f05c CM |
289 | static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root |
290 | *root, struct btrfs_path *path, int level) | |
bb803951 | 291 | { |
e20d96d6 CM |
292 | struct buffer_head *right_buf; |
293 | struct buffer_head *mid_buf; | |
294 | struct buffer_head *left_buf; | |
295 | struct buffer_head *parent_buf = NULL; | |
234b63a0 CM |
296 | struct btrfs_node *right = NULL; |
297 | struct btrfs_node *mid; | |
298 | struct btrfs_node *left = NULL; | |
299 | struct btrfs_node *parent = NULL; | |
bb803951 CM |
300 | int ret = 0; |
301 | int wret; | |
302 | int pslot; | |
bb803951 | 303 | int orig_slot = path->slots[level]; |
79f95c82 | 304 | u64 orig_ptr; |
bb803951 CM |
305 | |
306 | if (level == 0) | |
307 | return 0; | |
308 | ||
309 | mid_buf = path->nodes[level]; | |
e20d96d6 | 310 | mid = btrfs_buffer_node(mid_buf); |
1d4f8a0c | 311 | orig_ptr = btrfs_node_blockptr(mid, orig_slot); |
79f95c82 | 312 | |
234b63a0 | 313 | if (level < BTRFS_MAX_LEVEL - 1) |
bb803951 CM |
314 | parent_buf = path->nodes[level + 1]; |
315 | pslot = path->slots[level + 1]; | |
316 | ||
40689478 CM |
317 | /* |
318 | * deal with the case where there is only one pointer in the root | |
319 | * by promoting the node below to a root | |
320 | */ | |
bb803951 | 321 | if (!parent_buf) { |
e20d96d6 CM |
322 | struct buffer_head *child; |
323 | u64 blocknr = mid_buf->b_blocknr; | |
bb803951 | 324 | |
7518a238 | 325 | if (btrfs_header_nritems(&mid->header) != 1) |
bb803951 CM |
326 | return 0; |
327 | ||
328 | /* promote the child to a root */ | |
329 | child = read_node_slot(root, mid_buf, 0); | |
330 | BUG_ON(!child); | |
331 | root->node = child; | |
332 | path->nodes[level] = NULL; | |
d6025579 CM |
333 | clean_tree_block(trans, root, mid_buf); |
334 | wait_on_buffer(mid_buf); | |
bb803951 | 335 | /* once for the path */ |
234b63a0 | 336 | btrfs_block_release(root, mid_buf); |
bb803951 | 337 | /* once for the root ptr */ |
234b63a0 | 338 | btrfs_block_release(root, mid_buf); |
e089f05c | 339 | return btrfs_free_extent(trans, root, blocknr, 1, 1); |
bb803951 | 340 | } |
e20d96d6 | 341 | parent = btrfs_buffer_node(parent_buf); |
bb803951 | 342 | |
123abc88 CM |
343 | if (btrfs_header_nritems(&mid->header) > |
344 | BTRFS_NODEPTRS_PER_BLOCK(root) / 4) | |
bb803951 CM |
345 | return 0; |
346 | ||
bb803951 CM |
347 | left_buf = read_node_slot(root, parent_buf, pslot - 1); |
348 | right_buf = read_node_slot(root, parent_buf, pslot + 1); | |
79f95c82 CM |
349 | |
350 | /* first, try to make some room in the middle buffer */ | |
bb803951 | 351 | if (left_buf) { |
e089f05c CM |
352 | btrfs_cow_block(trans, root, left_buf, parent_buf, pslot - 1, |
353 | &left_buf); | |
e20d96d6 | 354 | left = btrfs_buffer_node(left_buf); |
7518a238 | 355 | orig_slot += btrfs_header_nritems(&left->header); |
e089f05c | 356 | wret = push_node_left(trans, root, left_buf, mid_buf); |
79f95c82 CM |
357 | if (wret < 0) |
358 | ret = wret; | |
bb803951 | 359 | } |
79f95c82 CM |
360 | |
361 | /* | |
362 | * then try to empty the right most buffer into the middle | |
363 | */ | |
bb803951 | 364 | if (right_buf) { |
e089f05c CM |
365 | btrfs_cow_block(trans, root, right_buf, parent_buf, pslot + 1, |
366 | &right_buf); | |
e20d96d6 | 367 | right = btrfs_buffer_node(right_buf); |
e089f05c | 368 | wret = push_node_left(trans, root, mid_buf, right_buf); |
79f95c82 CM |
369 | if (wret < 0) |
370 | ret = wret; | |
7518a238 | 371 | if (btrfs_header_nritems(&right->header) == 0) { |
e20d96d6 | 372 | u64 blocknr = right_buf->b_blocknr; |
e089f05c | 373 | clean_tree_block(trans, root, right_buf); |
d6025579 CM |
374 | wait_on_buffer(right_buf); |
375 | btrfs_block_release(root, right_buf); | |
bb803951 CM |
376 | right_buf = NULL; |
377 | right = NULL; | |
e089f05c CM |
378 | wret = del_ptr(trans, root, path, level + 1, pslot + |
379 | 1); | |
bb803951 CM |
380 | if (wret) |
381 | ret = wret; | |
e089f05c | 382 | wret = btrfs_free_extent(trans, root, blocknr, 1, 1); |
bb803951 CM |
383 | if (wret) |
384 | ret = wret; | |
385 | } else { | |
d6025579 CM |
386 | btrfs_memcpy(root, parent, |
387 | &parent->ptrs[pslot + 1].key, | |
388 | &right->ptrs[0].key, | |
389 | sizeof(struct btrfs_disk_key)); | |
390 | btrfs_mark_buffer_dirty(parent_buf); | |
bb803951 CM |
391 | } |
392 | } | |
7518a238 | 393 | if (btrfs_header_nritems(&mid->header) == 1) { |
79f95c82 CM |
394 | /* |
395 | * we're not allowed to leave a node with one item in the | |
396 | * tree during a delete. A deletion from lower in the tree | |
397 | * could try to delete the only pointer in this node. | |
398 | * So, pull some keys from the left. | |
399 | * There has to be a left pointer at this point because | |
400 | * otherwise we would have pulled some pointers from the | |
401 | * right | |
402 | */ | |
403 | BUG_ON(!left_buf); | |
e089f05c | 404 | wret = balance_node_right(trans, root, mid_buf, left_buf); |
79f95c82 CM |
405 | if (wret < 0) |
406 | ret = wret; | |
407 | BUG_ON(wret == 1); | |
408 | } | |
7518a238 | 409 | if (btrfs_header_nritems(&mid->header) == 0) { |
79f95c82 | 410 | /* we've managed to empty the middle node, drop it */ |
e20d96d6 | 411 | u64 blocknr = mid_buf->b_blocknr; |
e089f05c | 412 | clean_tree_block(trans, root, mid_buf); |
d6025579 CM |
413 | wait_on_buffer(mid_buf); |
414 | btrfs_block_release(root, mid_buf); | |
bb803951 CM |
415 | mid_buf = NULL; |
416 | mid = NULL; | |
e089f05c | 417 | wret = del_ptr(trans, root, path, level + 1, pslot); |
bb803951 CM |
418 | if (wret) |
419 | ret = wret; | |
e089f05c | 420 | wret = btrfs_free_extent(trans, root, blocknr, 1, 1); |
bb803951 CM |
421 | if (wret) |
422 | ret = wret; | |
79f95c82 CM |
423 | } else { |
424 | /* update the parent key to reflect our changes */ | |
d6025579 CM |
425 | btrfs_memcpy(root, parent, |
426 | &parent->ptrs[pslot].key, &mid->ptrs[0].key, | |
427 | sizeof(struct btrfs_disk_key)); | |
428 | btrfs_mark_buffer_dirty(parent_buf); | |
79f95c82 | 429 | } |
bb803951 | 430 | |
79f95c82 | 431 | /* update the path */ |
bb803951 | 432 | if (left_buf) { |
7518a238 | 433 | if (btrfs_header_nritems(&left->header) > orig_slot) { |
e20d96d6 | 434 | get_bh(left_buf); |
bb803951 CM |
435 | path->nodes[level] = left_buf; |
436 | path->slots[level + 1] -= 1; | |
437 | path->slots[level] = orig_slot; | |
438 | if (mid_buf) | |
234b63a0 | 439 | btrfs_block_release(root, mid_buf); |
bb803951 | 440 | } else { |
7518a238 | 441 | orig_slot -= btrfs_header_nritems(&left->header); |
bb803951 CM |
442 | path->slots[level] = orig_slot; |
443 | } | |
444 | } | |
79f95c82 | 445 | /* double check we haven't messed things up */ |
123abc88 | 446 | check_block(root, path, level); |
e20d96d6 CM |
447 | if (orig_ptr != |
448 | btrfs_node_blockptr(btrfs_buffer_node(path->nodes[level]), | |
449 | path->slots[level])) | |
79f95c82 | 450 | BUG(); |
bb803951 CM |
451 | |
452 | if (right_buf) | |
234b63a0 | 453 | btrfs_block_release(root, right_buf); |
bb803951 | 454 | if (left_buf) |
234b63a0 | 455 | btrfs_block_release(root, left_buf); |
bb803951 CM |
456 | return ret; |
457 | } | |
458 | ||
74123bd7 CM |
459 | /* |
460 | * look for key in the tree. path is filled in with nodes along the way | |
461 | * if key is found, we return zero and you can find the item in the leaf | |
462 | * level of the path (level 0) | |
463 | * | |
464 | * If the key isn't found, the path points to the slot where it should | |
aa5d6bed CM |
465 | * be inserted, and 1 is returned. If there are other errors during the |
466 | * search a negative error number is returned. | |
97571fd0 CM |
467 | * |
468 | * if ins_len > 0, nodes and leaves will be split as we walk down the | |
469 | * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if | |
470 | * possible) | |
74123bd7 | 471 | */ |
e089f05c CM |
472 | int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root |
473 | *root, struct btrfs_key *key, struct btrfs_path *p, int | |
474 | ins_len, int cow) | |
be0e5c09 | 475 | { |
e20d96d6 CM |
476 | struct buffer_head *b; |
477 | struct buffer_head *cow_buf; | |
234b63a0 | 478 | struct btrfs_node *c; |
be0e5c09 CM |
479 | int slot; |
480 | int ret; | |
481 | int level; | |
5c680ed6 | 482 | |
22b0ebda CM |
483 | WARN_ON(p->nodes[0] != NULL); |
484 | WARN_ON(!mutex_is_locked(&root->fs_info->fs_mutex)); | |
bb803951 CM |
485 | again: |
486 | b = root->node; | |
e20d96d6 | 487 | get_bh(b); |
eb60ceac | 488 | while (b) { |
e20d96d6 CM |
489 | c = btrfs_buffer_node(b); |
490 | level = btrfs_header_level(&c->header); | |
02217ed2 CM |
491 | if (cow) { |
492 | int wret; | |
e20d96d6 CM |
493 | wret = btrfs_cow_block(trans, root, b, |
494 | p->nodes[level + 1], | |
495 | p->slots[level + 1], | |
e089f05c | 496 | &cow_buf); |
02217ed2 | 497 | b = cow_buf; |
2c90e5d6 | 498 | c = btrfs_buffer_node(b); |
02217ed2 CM |
499 | } |
500 | BUG_ON(!cow && ins_len); | |
2c90e5d6 CM |
501 | if (level != btrfs_header_level(&c->header)) |
502 | WARN_ON(1); | |
503 | level = btrfs_header_level(&c->header); | |
eb60ceac | 504 | p->nodes[level] = b; |
123abc88 | 505 | ret = check_block(root, p, level); |
aa5d6bed CM |
506 | if (ret) |
507 | return -1; | |
be0e5c09 | 508 | ret = bin_search(c, key, &slot); |
7518a238 | 509 | if (!btrfs_is_leaf(c)) { |
be0e5c09 CM |
510 | if (ret && slot > 0) |
511 | slot -= 1; | |
512 | p->slots[level] = slot; | |
7518a238 | 513 | if (ins_len > 0 && btrfs_header_nritems(&c->header) == |
123abc88 | 514 | BTRFS_NODEPTRS_PER_BLOCK(root)) { |
e089f05c | 515 | int sret = split_node(trans, root, p, level); |
5c680ed6 CM |
516 | BUG_ON(sret > 0); |
517 | if (sret) | |
518 | return sret; | |
519 | b = p->nodes[level]; | |
e20d96d6 | 520 | c = btrfs_buffer_node(b); |
5c680ed6 | 521 | slot = p->slots[level]; |
bb803951 | 522 | } else if (ins_len < 0) { |
e089f05c CM |
523 | int sret = balance_level(trans, root, p, |
524 | level); | |
bb803951 CM |
525 | if (sret) |
526 | return sret; | |
527 | b = p->nodes[level]; | |
528 | if (!b) | |
529 | goto again; | |
e20d96d6 | 530 | c = btrfs_buffer_node(b); |
bb803951 | 531 | slot = p->slots[level]; |
7518a238 | 532 | BUG_ON(btrfs_header_nritems(&c->header) == 1); |
5c680ed6 | 533 | } |
1d4f8a0c | 534 | b = read_tree_block(root, btrfs_node_blockptr(c, slot)); |
be0e5c09 | 535 | } else { |
234b63a0 | 536 | struct btrfs_leaf *l = (struct btrfs_leaf *)c; |
be0e5c09 | 537 | p->slots[level] = slot; |
123abc88 | 538 | if (ins_len > 0 && btrfs_leaf_free_space(root, l) < |
0783fcfc | 539 | sizeof(struct btrfs_item) + ins_len) { |
e089f05c | 540 | int sret = split_leaf(trans, root, p, ins_len); |
5c680ed6 CM |
541 | BUG_ON(sret > 0); |
542 | if (sret) | |
543 | return sret; | |
544 | } | |
be0e5c09 CM |
545 | return ret; |
546 | } | |
547 | } | |
aa5d6bed | 548 | return 1; |
be0e5c09 CM |
549 | } |
550 | ||
74123bd7 CM |
551 | /* |
552 | * adjust the pointers going up the tree, starting at level | |
553 | * making sure the right key of each node is points to 'key'. | |
554 | * This is used after shifting pointers to the left, so it stops | |
555 | * fixing up pointers when a given leaf/node is not in slot 0 of the | |
556 | * higher levels | |
aa5d6bed CM |
557 | * |
558 | * If this fails to write a tree block, it returns -1, but continues | |
559 | * fixing up the blocks in ram so the tree is consistent. | |
74123bd7 | 560 | */ |
e089f05c CM |
561 | static int fixup_low_keys(struct btrfs_trans_handle *trans, struct btrfs_root |
562 | *root, struct btrfs_path *path, struct btrfs_disk_key | |
563 | *key, int level) | |
be0e5c09 CM |
564 | { |
565 | int i; | |
aa5d6bed | 566 | int ret = 0; |
234b63a0 CM |
567 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { |
568 | struct btrfs_node *t; | |
be0e5c09 | 569 | int tslot = path->slots[i]; |
eb60ceac | 570 | if (!path->nodes[i]) |
be0e5c09 | 571 | break; |
e20d96d6 | 572 | t = btrfs_buffer_node(path->nodes[i]); |
d6025579 CM |
573 | btrfs_memcpy(root, t, &t->ptrs[tslot].key, key, sizeof(*key)); |
574 | btrfs_mark_buffer_dirty(path->nodes[i]); | |
be0e5c09 CM |
575 | if (tslot != 0) |
576 | break; | |
577 | } | |
aa5d6bed | 578 | return ret; |
be0e5c09 CM |
579 | } |
580 | ||
74123bd7 CM |
581 | /* |
582 | * try to push data from one node into the next node left in the | |
79f95c82 | 583 | * tree. |
aa5d6bed CM |
584 | * |
585 | * returns 0 if some ptrs were pushed left, < 0 if there was some horrible | |
586 | * error, and > 0 if there was no room in the left hand block. | |
74123bd7 | 587 | */ |
e089f05c | 588 | static int push_node_left(struct btrfs_trans_handle *trans, struct btrfs_root |
e20d96d6 CM |
589 | *root, struct buffer_head *dst_buf, struct |
590 | buffer_head *src_buf) | |
be0e5c09 | 591 | { |
e20d96d6 CM |
592 | struct btrfs_node *src = btrfs_buffer_node(src_buf); |
593 | struct btrfs_node *dst = btrfs_buffer_node(dst_buf); | |
be0e5c09 | 594 | int push_items = 0; |
bb803951 CM |
595 | int src_nritems; |
596 | int dst_nritems; | |
aa5d6bed | 597 | int ret = 0; |
be0e5c09 | 598 | |
7518a238 CM |
599 | src_nritems = btrfs_header_nritems(&src->header); |
600 | dst_nritems = btrfs_header_nritems(&dst->header); | |
123abc88 | 601 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
eb60ceac | 602 | if (push_items <= 0) { |
be0e5c09 | 603 | return 1; |
eb60ceac | 604 | } |
be0e5c09 | 605 | |
bb803951 | 606 | if (src_nritems < push_items) |
79f95c82 CM |
607 | push_items = src_nritems; |
608 | ||
d6025579 CM |
609 | btrfs_memcpy(root, dst, dst->ptrs + dst_nritems, src->ptrs, |
610 | push_items * sizeof(struct btrfs_key_ptr)); | |
bb803951 | 611 | if (push_items < src_nritems) { |
d6025579 | 612 | btrfs_memmove(root, src, src->ptrs, src->ptrs + push_items, |
e2fa7227 | 613 | (src_nritems - push_items) * |
123abc88 | 614 | sizeof(struct btrfs_key_ptr)); |
bb803951 | 615 | } |
7518a238 CM |
616 | btrfs_set_header_nritems(&src->header, src_nritems - push_items); |
617 | btrfs_set_header_nritems(&dst->header, dst_nritems + push_items); | |
d6025579 CM |
618 | btrfs_mark_buffer_dirty(src_buf); |
619 | btrfs_mark_buffer_dirty(dst_buf); | |
79f95c82 CM |
620 | return ret; |
621 | } | |
622 | ||
623 | /* | |
624 | * try to push data from one node into the next node right in the | |
625 | * tree. | |
626 | * | |
627 | * returns 0 if some ptrs were pushed, < 0 if there was some horrible | |
628 | * error, and > 0 if there was no room in the right hand block. | |
629 | * | |
630 | * this will only push up to 1/2 the contents of the left node over | |
631 | */ | |
e089f05c | 632 | static int balance_node_right(struct btrfs_trans_handle *trans, struct |
e20d96d6 CM |
633 | btrfs_root *root, struct buffer_head *dst_buf, |
634 | struct buffer_head *src_buf) | |
79f95c82 | 635 | { |
e20d96d6 CM |
636 | struct btrfs_node *src = btrfs_buffer_node(src_buf); |
637 | struct btrfs_node *dst = btrfs_buffer_node(dst_buf); | |
79f95c82 CM |
638 | int push_items = 0; |
639 | int max_push; | |
640 | int src_nritems; | |
641 | int dst_nritems; | |
642 | int ret = 0; | |
79f95c82 | 643 | |
7518a238 CM |
644 | src_nritems = btrfs_header_nritems(&src->header); |
645 | dst_nritems = btrfs_header_nritems(&dst->header); | |
123abc88 | 646 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
79f95c82 CM |
647 | if (push_items <= 0) { |
648 | return 1; | |
649 | } | |
650 | ||
651 | max_push = src_nritems / 2 + 1; | |
652 | /* don't try to empty the node */ | |
653 | if (max_push > src_nritems) | |
654 | return 1; | |
655 | if (max_push < push_items) | |
656 | push_items = max_push; | |
657 | ||
d6025579 CM |
658 | btrfs_memmove(root, dst, dst->ptrs + push_items, dst->ptrs, |
659 | dst_nritems * sizeof(struct btrfs_key_ptr)); | |
660 | ||
661 | btrfs_memcpy(root, dst, dst->ptrs, | |
662 | src->ptrs + src_nritems - push_items, | |
663 | push_items * sizeof(struct btrfs_key_ptr)); | |
79f95c82 | 664 | |
7518a238 CM |
665 | btrfs_set_header_nritems(&src->header, src_nritems - push_items); |
666 | btrfs_set_header_nritems(&dst->header, dst_nritems + push_items); | |
79f95c82 | 667 | |
d6025579 CM |
668 | btrfs_mark_buffer_dirty(src_buf); |
669 | btrfs_mark_buffer_dirty(dst_buf); | |
aa5d6bed | 670 | return ret; |
be0e5c09 CM |
671 | } |
672 | ||
97571fd0 CM |
673 | /* |
674 | * helper function to insert a new root level in the tree. | |
675 | * A new node is allocated, and a single item is inserted to | |
676 | * point to the existing root | |
aa5d6bed CM |
677 | * |
678 | * returns zero on success or < 0 on failure. | |
97571fd0 | 679 | */ |
e089f05c CM |
680 | static int insert_new_root(struct btrfs_trans_handle *trans, struct btrfs_root |
681 | *root, struct btrfs_path *path, int level) | |
5c680ed6 | 682 | { |
e20d96d6 | 683 | struct buffer_head *t; |
234b63a0 CM |
684 | struct btrfs_node *lower; |
685 | struct btrfs_node *c; | |
e2fa7227 | 686 | struct btrfs_disk_key *lower_key; |
5c680ed6 CM |
687 | |
688 | BUG_ON(path->nodes[level]); | |
689 | BUG_ON(path->nodes[level-1] != root->node); | |
690 | ||
e089f05c | 691 | t = btrfs_alloc_free_block(trans, root); |
e20d96d6 | 692 | c = btrfs_buffer_node(t); |
123abc88 | 693 | memset(c, 0, root->blocksize); |
7518a238 CM |
694 | btrfs_set_header_nritems(&c->header, 1); |
695 | btrfs_set_header_level(&c->header, level); | |
e20d96d6 | 696 | btrfs_set_header_blocknr(&c->header, t->b_blocknr); |
7f5c1516 | 697 | btrfs_set_header_generation(&c->header, trans->transid); |
7518a238 | 698 | btrfs_set_header_parentid(&c->header, |
e20d96d6 CM |
699 | btrfs_header_parentid(btrfs_buffer_header(root->node))); |
700 | lower = btrfs_buffer_node(path->nodes[level-1]); | |
7518a238 | 701 | if (btrfs_is_leaf(lower)) |
234b63a0 | 702 | lower_key = &((struct btrfs_leaf *)lower)->items[0].key; |
5c680ed6 | 703 | else |
123abc88 | 704 | lower_key = &lower->ptrs[0].key; |
d6025579 CM |
705 | btrfs_memcpy(root, c, &c->ptrs[0].key, lower_key, |
706 | sizeof(struct btrfs_disk_key)); | |
e20d96d6 | 707 | btrfs_set_node_blockptr(c, 0, path->nodes[level - 1]->b_blocknr); |
d5719762 | 708 | |
d6025579 | 709 | btrfs_mark_buffer_dirty(t); |
d5719762 | 710 | |
5c680ed6 | 711 | /* the super has an extra ref to root->node */ |
234b63a0 | 712 | btrfs_block_release(root, root->node); |
5c680ed6 | 713 | root->node = t; |
e20d96d6 | 714 | get_bh(t); |
5c680ed6 CM |
715 | path->nodes[level] = t; |
716 | path->slots[level] = 0; | |
717 | return 0; | |
718 | } | |
719 | ||
74123bd7 CM |
720 | /* |
721 | * worker function to insert a single pointer in a node. | |
722 | * the node should have enough room for the pointer already | |
97571fd0 | 723 | * |
74123bd7 CM |
724 | * slot and level indicate where you want the key to go, and |
725 | * blocknr is the block the key points to. | |
aa5d6bed CM |
726 | * |
727 | * returns zero on success and < 0 on any error | |
74123bd7 | 728 | */ |
e089f05c CM |
729 | static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root |
730 | *root, struct btrfs_path *path, struct btrfs_disk_key | |
731 | *key, u64 blocknr, int slot, int level) | |
74123bd7 | 732 | { |
234b63a0 | 733 | struct btrfs_node *lower; |
74123bd7 | 734 | int nritems; |
5c680ed6 CM |
735 | |
736 | BUG_ON(!path->nodes[level]); | |
e20d96d6 | 737 | lower = btrfs_buffer_node(path->nodes[level]); |
7518a238 | 738 | nritems = btrfs_header_nritems(&lower->header); |
74123bd7 CM |
739 | if (slot > nritems) |
740 | BUG(); | |
123abc88 | 741 | if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root)) |
74123bd7 CM |
742 | BUG(); |
743 | if (slot != nritems) { | |
d6025579 CM |
744 | btrfs_memmove(root, lower, lower->ptrs + slot + 1, |
745 | lower->ptrs + slot, | |
746 | (nritems - slot) * sizeof(struct btrfs_key_ptr)); | |
74123bd7 | 747 | } |
d6025579 CM |
748 | btrfs_memcpy(root, lower, &lower->ptrs[slot].key, |
749 | key, sizeof(struct btrfs_disk_key)); | |
1d4f8a0c | 750 | btrfs_set_node_blockptr(lower, slot, blocknr); |
7518a238 | 751 | btrfs_set_header_nritems(&lower->header, nritems + 1); |
d6025579 | 752 | btrfs_mark_buffer_dirty(path->nodes[level]); |
74123bd7 CM |
753 | return 0; |
754 | } | |
755 | ||
97571fd0 CM |
756 | /* |
757 | * split the node at the specified level in path in two. | |
758 | * The path is corrected to point to the appropriate node after the split | |
759 | * | |
760 | * Before splitting this tries to make some room in the node by pushing | |
761 | * left and right, if either one works, it returns right away. | |
aa5d6bed CM |
762 | * |
763 | * returns 0 on success and < 0 on failure | |
97571fd0 | 764 | */ |
e089f05c CM |
765 | static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root |
766 | *root, struct btrfs_path *path, int level) | |
be0e5c09 | 767 | { |
e20d96d6 | 768 | struct buffer_head *t; |
234b63a0 | 769 | struct btrfs_node *c; |
e20d96d6 | 770 | struct buffer_head *split_buffer; |
234b63a0 | 771 | struct btrfs_node *split; |
be0e5c09 | 772 | int mid; |
5c680ed6 | 773 | int ret; |
aa5d6bed | 774 | int wret; |
7518a238 | 775 | u32 c_nritems; |
eb60ceac | 776 | |
5c680ed6 | 777 | t = path->nodes[level]; |
e20d96d6 | 778 | c = btrfs_buffer_node(t); |
5c680ed6 CM |
779 | if (t == root->node) { |
780 | /* trying to split the root, lets make a new one */ | |
e089f05c | 781 | ret = insert_new_root(trans, root, path, level + 1); |
5c680ed6 CM |
782 | if (ret) |
783 | return ret; | |
be0e5c09 | 784 | } |
7518a238 | 785 | c_nritems = btrfs_header_nritems(&c->header); |
e089f05c | 786 | split_buffer = btrfs_alloc_free_block(trans, root); |
e20d96d6 | 787 | split = btrfs_buffer_node(split_buffer); |
7518a238 | 788 | btrfs_set_header_flags(&split->header, btrfs_header_flags(&c->header)); |
9a6f11ed | 789 | btrfs_set_header_level(&split->header, btrfs_header_level(&c->header)); |
e20d96d6 | 790 | btrfs_set_header_blocknr(&split->header, split_buffer->b_blocknr); |
7f5c1516 | 791 | btrfs_set_header_generation(&split->header, trans->transid); |
7518a238 | 792 | btrfs_set_header_parentid(&split->header, |
e20d96d6 | 793 | btrfs_header_parentid(btrfs_buffer_header(root->node))); |
7518a238 | 794 | mid = (c_nritems + 1) / 2; |
d6025579 CM |
795 | btrfs_memcpy(root, split, split->ptrs, c->ptrs + mid, |
796 | (c_nritems - mid) * sizeof(struct btrfs_key_ptr)); | |
7518a238 CM |
797 | btrfs_set_header_nritems(&split->header, c_nritems - mid); |
798 | btrfs_set_header_nritems(&c->header, mid); | |
aa5d6bed CM |
799 | ret = 0; |
800 | ||
d6025579 CM |
801 | btrfs_mark_buffer_dirty(t); |
802 | btrfs_mark_buffer_dirty(split_buffer); | |
e089f05c | 803 | wret = insert_ptr(trans, root, path, &split->ptrs[0].key, |
e20d96d6 | 804 | split_buffer->b_blocknr, path->slots[level + 1] + 1, |
123abc88 | 805 | level + 1); |
aa5d6bed CM |
806 | if (wret) |
807 | ret = wret; | |
808 | ||
5de08d7d | 809 | if (path->slots[level] >= mid) { |
5c680ed6 | 810 | path->slots[level] -= mid; |
234b63a0 | 811 | btrfs_block_release(root, t); |
5c680ed6 CM |
812 | path->nodes[level] = split_buffer; |
813 | path->slots[level + 1] += 1; | |
814 | } else { | |
234b63a0 | 815 | btrfs_block_release(root, split_buffer); |
be0e5c09 | 816 | } |
aa5d6bed | 817 | return ret; |
be0e5c09 CM |
818 | } |
819 | ||
74123bd7 CM |
820 | /* |
821 | * how many bytes are required to store the items in a leaf. start | |
822 | * and nr indicate which items in the leaf to check. This totals up the | |
823 | * space used both by the item structs and the item data | |
824 | */ | |
234b63a0 | 825 | static int leaf_space_used(struct btrfs_leaf *l, int start, int nr) |
be0e5c09 CM |
826 | { |
827 | int data_len; | |
828 | int end = start + nr - 1; | |
829 | ||
830 | if (!nr) | |
831 | return 0; | |
0783fcfc CM |
832 | data_len = btrfs_item_end(l->items + start); |
833 | data_len = data_len - btrfs_item_offset(l->items + end); | |
834 | data_len += sizeof(struct btrfs_item) * nr; | |
be0e5c09 CM |
835 | return data_len; |
836 | } | |
837 | ||
00ec4c51 CM |
838 | /* |
839 | * push some data in the path leaf to the right, trying to free up at | |
840 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
aa5d6bed CM |
841 | * |
842 | * returns 1 if the push failed because the other node didn't have enough | |
843 | * room, 0 if everything worked out and < 0 if there were major errors. | |
00ec4c51 | 844 | */ |
e089f05c CM |
845 | static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root |
846 | *root, struct btrfs_path *path, int data_size) | |
00ec4c51 | 847 | { |
e20d96d6 CM |
848 | struct buffer_head *left_buf = path->nodes[0]; |
849 | struct btrfs_leaf *left = btrfs_buffer_leaf(left_buf); | |
234b63a0 | 850 | struct btrfs_leaf *right; |
e20d96d6 CM |
851 | struct buffer_head *right_buf; |
852 | struct buffer_head *upper; | |
853 | struct btrfs_node *upper_node; | |
00ec4c51 CM |
854 | int slot; |
855 | int i; | |
856 | int free_space; | |
857 | int push_space = 0; | |
858 | int push_items = 0; | |
0783fcfc | 859 | struct btrfs_item *item; |
7518a238 CM |
860 | u32 left_nritems; |
861 | u32 right_nritems; | |
00ec4c51 CM |
862 | |
863 | slot = path->slots[1]; | |
864 | if (!path->nodes[1]) { | |
865 | return 1; | |
866 | } | |
867 | upper = path->nodes[1]; | |
e20d96d6 CM |
868 | upper_node = btrfs_buffer_node(upper); |
869 | if (slot >= btrfs_header_nritems(&upper_node->header) - 1) { | |
00ec4c51 CM |
870 | return 1; |
871 | } | |
e20d96d6 CM |
872 | right_buf = read_tree_block(root, |
873 | btrfs_node_blockptr(btrfs_buffer_node(upper), slot + 1)); | |
874 | right = btrfs_buffer_leaf(right_buf); | |
123abc88 | 875 | free_space = btrfs_leaf_free_space(root, right); |
0783fcfc | 876 | if (free_space < data_size + sizeof(struct btrfs_item)) { |
234b63a0 | 877 | btrfs_block_release(root, right_buf); |
00ec4c51 CM |
878 | return 1; |
879 | } | |
02217ed2 | 880 | /* cow and double check */ |
e089f05c | 881 | btrfs_cow_block(trans, root, right_buf, upper, slot + 1, &right_buf); |
e20d96d6 | 882 | right = btrfs_buffer_leaf(right_buf); |
123abc88 | 883 | free_space = btrfs_leaf_free_space(root, right); |
0783fcfc | 884 | if (free_space < data_size + sizeof(struct btrfs_item)) { |
234b63a0 | 885 | btrfs_block_release(root, right_buf); |
02217ed2 CM |
886 | return 1; |
887 | } | |
888 | ||
7518a238 CM |
889 | left_nritems = btrfs_header_nritems(&left->header); |
890 | for (i = left_nritems - 1; i >= 0; i--) { | |
00ec4c51 CM |
891 | item = left->items + i; |
892 | if (path->slots[0] == i) | |
893 | push_space += data_size + sizeof(*item); | |
0783fcfc CM |
894 | if (btrfs_item_size(item) + sizeof(*item) + push_space > |
895 | free_space) | |
00ec4c51 CM |
896 | break; |
897 | push_items++; | |
0783fcfc | 898 | push_space += btrfs_item_size(item) + sizeof(*item); |
00ec4c51 CM |
899 | } |
900 | if (push_items == 0) { | |
234b63a0 | 901 | btrfs_block_release(root, right_buf); |
00ec4c51 CM |
902 | return 1; |
903 | } | |
7518a238 | 904 | right_nritems = btrfs_header_nritems(&right->header); |
00ec4c51 | 905 | /* push left to right */ |
0783fcfc | 906 | push_space = btrfs_item_end(left->items + left_nritems - push_items); |
123abc88 | 907 | push_space -= leaf_data_end(root, left); |
00ec4c51 | 908 | /* make room in the right data area */ |
d6025579 CM |
909 | btrfs_memmove(root, right, btrfs_leaf_data(right) + |
910 | leaf_data_end(root, right) - push_space, | |
911 | btrfs_leaf_data(right) + | |
912 | leaf_data_end(root, right), BTRFS_LEAF_DATA_SIZE(root) - | |
913 | leaf_data_end(root, right)); | |
00ec4c51 | 914 | /* copy from the left data area */ |
d6025579 CM |
915 | btrfs_memcpy(root, right, btrfs_leaf_data(right) + |
916 | BTRFS_LEAF_DATA_SIZE(root) - push_space, | |
917 | btrfs_leaf_data(left) + leaf_data_end(root, left), | |
918 | push_space); | |
919 | btrfs_memmove(root, right, right->items + push_items, right->items, | |
0783fcfc | 920 | right_nritems * sizeof(struct btrfs_item)); |
00ec4c51 | 921 | /* copy the items from left to right */ |
d6025579 CM |
922 | btrfs_memcpy(root, right, right->items, left->items + |
923 | left_nritems - push_items, | |
924 | push_items * sizeof(struct btrfs_item)); | |
00ec4c51 CM |
925 | |
926 | /* update the item pointers */ | |
7518a238 CM |
927 | right_nritems += push_items; |
928 | btrfs_set_header_nritems(&right->header, right_nritems); | |
123abc88 | 929 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
7518a238 | 930 | for (i = 0; i < right_nritems; i++) { |
0783fcfc CM |
931 | btrfs_set_item_offset(right->items + i, push_space - |
932 | btrfs_item_size(right->items + i)); | |
933 | push_space = btrfs_item_offset(right->items + i); | |
00ec4c51 | 934 | } |
7518a238 CM |
935 | left_nritems -= push_items; |
936 | btrfs_set_header_nritems(&left->header, left_nritems); | |
00ec4c51 | 937 | |
d6025579 CM |
938 | btrfs_mark_buffer_dirty(left_buf); |
939 | btrfs_mark_buffer_dirty(right_buf); | |
940 | btrfs_memcpy(root, upper_node, &upper_node->ptrs[slot + 1].key, | |
e2fa7227 | 941 | &right->items[0].key, sizeof(struct btrfs_disk_key)); |
d6025579 | 942 | btrfs_mark_buffer_dirty(upper); |
02217ed2 | 943 | |
00ec4c51 | 944 | /* then fixup the leaf pointer in the path */ |
7518a238 CM |
945 | if (path->slots[0] >= left_nritems) { |
946 | path->slots[0] -= left_nritems; | |
234b63a0 | 947 | btrfs_block_release(root, path->nodes[0]); |
00ec4c51 CM |
948 | path->nodes[0] = right_buf; |
949 | path->slots[1] += 1; | |
950 | } else { | |
234b63a0 | 951 | btrfs_block_release(root, right_buf); |
00ec4c51 CM |
952 | } |
953 | return 0; | |
954 | } | |
74123bd7 CM |
955 | /* |
956 | * push some data in the path leaf to the left, trying to free up at | |
957 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
958 | */ | |
e089f05c CM |
959 | static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root |
960 | *root, struct btrfs_path *path, int data_size) | |
be0e5c09 | 961 | { |
e20d96d6 CM |
962 | struct buffer_head *right_buf = path->nodes[0]; |
963 | struct btrfs_leaf *right = btrfs_buffer_leaf(right_buf); | |
964 | struct buffer_head *t; | |
234b63a0 | 965 | struct btrfs_leaf *left; |
be0e5c09 CM |
966 | int slot; |
967 | int i; | |
968 | int free_space; | |
969 | int push_space = 0; | |
970 | int push_items = 0; | |
0783fcfc | 971 | struct btrfs_item *item; |
7518a238 | 972 | u32 old_left_nritems; |
aa5d6bed CM |
973 | int ret = 0; |
974 | int wret; | |
be0e5c09 CM |
975 | |
976 | slot = path->slots[1]; | |
977 | if (slot == 0) { | |
978 | return 1; | |
979 | } | |
980 | if (!path->nodes[1]) { | |
981 | return 1; | |
982 | } | |
e20d96d6 CM |
983 | t = read_tree_block(root, |
984 | btrfs_node_blockptr(btrfs_buffer_node(path->nodes[1]), slot - 1)); | |
985 | left = btrfs_buffer_leaf(t); | |
123abc88 | 986 | free_space = btrfs_leaf_free_space(root, left); |
0783fcfc | 987 | if (free_space < data_size + sizeof(struct btrfs_item)) { |
234b63a0 | 988 | btrfs_block_release(root, t); |
be0e5c09 CM |
989 | return 1; |
990 | } | |
02217ed2 CM |
991 | |
992 | /* cow and double check */ | |
e089f05c | 993 | btrfs_cow_block(trans, root, t, path->nodes[1], slot - 1, &t); |
e20d96d6 | 994 | left = btrfs_buffer_leaf(t); |
123abc88 | 995 | free_space = btrfs_leaf_free_space(root, left); |
0783fcfc | 996 | if (free_space < data_size + sizeof(struct btrfs_item)) { |
234b63a0 | 997 | btrfs_block_release(root, t); |
02217ed2 CM |
998 | return 1; |
999 | } | |
1000 | ||
7518a238 | 1001 | for (i = 0; i < btrfs_header_nritems(&right->header); i++) { |
be0e5c09 CM |
1002 | item = right->items + i; |
1003 | if (path->slots[0] == i) | |
1004 | push_space += data_size + sizeof(*item); | |
0783fcfc CM |
1005 | if (btrfs_item_size(item) + sizeof(*item) + push_space > |
1006 | free_space) | |
be0e5c09 CM |
1007 | break; |
1008 | push_items++; | |
0783fcfc | 1009 | push_space += btrfs_item_size(item) + sizeof(*item); |
be0e5c09 CM |
1010 | } |
1011 | if (push_items == 0) { | |
234b63a0 | 1012 | btrfs_block_release(root, t); |
be0e5c09 CM |
1013 | return 1; |
1014 | } | |
1015 | /* push data from right to left */ | |
d6025579 CM |
1016 | btrfs_memcpy(root, left, left->items + |
1017 | btrfs_header_nritems(&left->header), | |
1018 | right->items, push_items * sizeof(struct btrfs_item)); | |
123abc88 | 1019 | push_space = BTRFS_LEAF_DATA_SIZE(root) - |
0783fcfc | 1020 | btrfs_item_offset(right->items + push_items -1); |
d6025579 CM |
1021 | btrfs_memcpy(root, left, btrfs_leaf_data(left) + |
1022 | leaf_data_end(root, left) - push_space, | |
1023 | btrfs_leaf_data(right) + | |
1024 | btrfs_item_offset(right->items + push_items - 1), | |
1025 | push_space); | |
7518a238 | 1026 | old_left_nritems = btrfs_header_nritems(&left->header); |
eb60ceac CM |
1027 | BUG_ON(old_left_nritems < 0); |
1028 | ||
0783fcfc | 1029 | for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { |
123abc88 CM |
1030 | u32 ioff = btrfs_item_offset(left->items + i); |
1031 | btrfs_set_item_offset(left->items + i, ioff - | |
1032 | (BTRFS_LEAF_DATA_SIZE(root) - | |
0783fcfc CM |
1033 | btrfs_item_offset(left->items + |
1034 | old_left_nritems - 1))); | |
be0e5c09 | 1035 | } |
7518a238 | 1036 | btrfs_set_header_nritems(&left->header, old_left_nritems + push_items); |
be0e5c09 CM |
1037 | |
1038 | /* fixup right node */ | |
0783fcfc | 1039 | push_space = btrfs_item_offset(right->items + push_items - 1) - |
123abc88 | 1040 | leaf_data_end(root, right); |
d6025579 CM |
1041 | btrfs_memmove(root, right, btrfs_leaf_data(right) + |
1042 | BTRFS_LEAF_DATA_SIZE(root) - push_space, | |
1043 | btrfs_leaf_data(right) + | |
1044 | leaf_data_end(root, right), push_space); | |
1045 | btrfs_memmove(root, right, right->items, right->items + push_items, | |
7518a238 | 1046 | (btrfs_header_nritems(&right->header) - push_items) * |
0783fcfc | 1047 | sizeof(struct btrfs_item)); |
7518a238 CM |
1048 | btrfs_set_header_nritems(&right->header, |
1049 | btrfs_header_nritems(&right->header) - | |
1050 | push_items); | |
123abc88 | 1051 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
eb60ceac | 1052 | |
7518a238 | 1053 | for (i = 0; i < btrfs_header_nritems(&right->header); i++) { |
0783fcfc CM |
1054 | btrfs_set_item_offset(right->items + i, push_space - |
1055 | btrfs_item_size(right->items + i)); | |
1056 | push_space = btrfs_item_offset(right->items + i); | |
be0e5c09 | 1057 | } |
eb60ceac | 1058 | |
d6025579 CM |
1059 | btrfs_mark_buffer_dirty(t); |
1060 | btrfs_mark_buffer_dirty(right_buf); | |
eb60ceac | 1061 | |
e089f05c | 1062 | wret = fixup_low_keys(trans, root, path, &right->items[0].key, 1); |
aa5d6bed CM |
1063 | if (wret) |
1064 | ret = wret; | |
be0e5c09 CM |
1065 | |
1066 | /* then fixup the leaf pointer in the path */ | |
1067 | if (path->slots[0] < push_items) { | |
1068 | path->slots[0] += old_left_nritems; | |
234b63a0 | 1069 | btrfs_block_release(root, path->nodes[0]); |
eb60ceac | 1070 | path->nodes[0] = t; |
be0e5c09 CM |
1071 | path->slots[1] -= 1; |
1072 | } else { | |
234b63a0 | 1073 | btrfs_block_release(root, t); |
be0e5c09 CM |
1074 | path->slots[0] -= push_items; |
1075 | } | |
eb60ceac | 1076 | BUG_ON(path->slots[0] < 0); |
aa5d6bed | 1077 | return ret; |
be0e5c09 CM |
1078 | } |
1079 | ||
74123bd7 CM |
1080 | /* |
1081 | * split the path's leaf in two, making sure there is at least data_size | |
1082 | * available for the resulting leaf level of the path. | |
aa5d6bed CM |
1083 | * |
1084 | * returns 0 if all went well and < 0 on failure. | |
74123bd7 | 1085 | */ |
e089f05c CM |
1086 | static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root |
1087 | *root, struct btrfs_path *path, int data_size) | |
be0e5c09 | 1088 | { |
e20d96d6 | 1089 | struct buffer_head *l_buf; |
234b63a0 | 1090 | struct btrfs_leaf *l; |
7518a238 | 1091 | u32 nritems; |
eb60ceac CM |
1092 | int mid; |
1093 | int slot; | |
234b63a0 | 1094 | struct btrfs_leaf *right; |
e20d96d6 | 1095 | struct buffer_head *right_buffer; |
0783fcfc | 1096 | int space_needed = data_size + sizeof(struct btrfs_item); |
be0e5c09 CM |
1097 | int data_copy_size; |
1098 | int rt_data_off; | |
1099 | int i; | |
1100 | int ret; | |
aa5d6bed CM |
1101 | int wret; |
1102 | ||
40689478 | 1103 | /* first try to make some room by pushing left and right */ |
e089f05c | 1104 | wret = push_leaf_left(trans, root, path, data_size); |
eaee50e8 CM |
1105 | if (wret < 0) |
1106 | return wret; | |
1107 | if (wret) { | |
e089f05c | 1108 | wret = push_leaf_right(trans, root, path, data_size); |
eaee50e8 CM |
1109 | if (wret < 0) |
1110 | return wret; | |
1111 | } | |
aa5d6bed | 1112 | l_buf = path->nodes[0]; |
e20d96d6 | 1113 | l = btrfs_buffer_leaf(l_buf); |
aa5d6bed CM |
1114 | |
1115 | /* did the pushes work? */ | |
123abc88 CM |
1116 | if (btrfs_leaf_free_space(root, l) >= |
1117 | sizeof(struct btrfs_item) + data_size) | |
aa5d6bed CM |
1118 | return 0; |
1119 | ||
5c680ed6 | 1120 | if (!path->nodes[1]) { |
e089f05c | 1121 | ret = insert_new_root(trans, root, path, 1); |
5c680ed6 CM |
1122 | if (ret) |
1123 | return ret; | |
1124 | } | |
eb60ceac | 1125 | slot = path->slots[0]; |
7518a238 | 1126 | nritems = btrfs_header_nritems(&l->header); |
eb60ceac | 1127 | mid = (nritems + 1)/ 2; |
e089f05c | 1128 | right_buffer = btrfs_alloc_free_block(trans, root); |
eb60ceac CM |
1129 | BUG_ON(!right_buffer); |
1130 | BUG_ON(mid == nritems); | |
e20d96d6 | 1131 | right = btrfs_buffer_leaf(right_buffer); |
123abc88 | 1132 | memset(&right->header, 0, sizeof(right->header)); |
be0e5c09 | 1133 | if (mid <= slot) { |
97571fd0 | 1134 | /* FIXME, just alloc a new leaf here */ |
be0e5c09 | 1135 | if (leaf_space_used(l, mid, nritems - mid) + space_needed > |
123abc88 | 1136 | BTRFS_LEAF_DATA_SIZE(root)) |
be0e5c09 CM |
1137 | BUG(); |
1138 | } else { | |
97571fd0 | 1139 | /* FIXME, just alloc a new leaf here */ |
be0e5c09 | 1140 | if (leaf_space_used(l, 0, mid + 1) + space_needed > |
123abc88 | 1141 | BTRFS_LEAF_DATA_SIZE(root)) |
be0e5c09 CM |
1142 | BUG(); |
1143 | } | |
7518a238 | 1144 | btrfs_set_header_nritems(&right->header, nritems - mid); |
e20d96d6 | 1145 | btrfs_set_header_blocknr(&right->header, right_buffer->b_blocknr); |
7f5c1516 | 1146 | btrfs_set_header_generation(&right->header, trans->transid); |
7518a238 CM |
1147 | btrfs_set_header_level(&right->header, 0); |
1148 | btrfs_set_header_parentid(&right->header, | |
e20d96d6 | 1149 | btrfs_header_parentid(btrfs_buffer_header(root->node))); |
123abc88 CM |
1150 | data_copy_size = btrfs_item_end(l->items + mid) - |
1151 | leaf_data_end(root, l); | |
d6025579 CM |
1152 | btrfs_memcpy(root, right, right->items, l->items + mid, |
1153 | (nritems - mid) * sizeof(struct btrfs_item)); | |
1154 | btrfs_memcpy(root, right, | |
1155 | btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) - | |
1156 | data_copy_size, btrfs_leaf_data(l) + | |
1157 | leaf_data_end(root, l), data_copy_size); | |
123abc88 CM |
1158 | rt_data_off = BTRFS_LEAF_DATA_SIZE(root) - |
1159 | btrfs_item_end(l->items + mid); | |
74123bd7 | 1160 | |
0783fcfc | 1161 | for (i = 0; i < btrfs_header_nritems(&right->header); i++) { |
123abc88 | 1162 | u32 ioff = btrfs_item_offset(right->items + i); |
0783fcfc CM |
1163 | btrfs_set_item_offset(right->items + i, ioff + rt_data_off); |
1164 | } | |
74123bd7 | 1165 | |
7518a238 | 1166 | btrfs_set_header_nritems(&l->header, mid); |
aa5d6bed | 1167 | ret = 0; |
e089f05c | 1168 | wret = insert_ptr(trans, root, path, &right->items[0].key, |
e20d96d6 | 1169 | right_buffer->b_blocknr, path->slots[1] + 1, 1); |
aa5d6bed CM |
1170 | if (wret) |
1171 | ret = wret; | |
d6025579 CM |
1172 | btrfs_mark_buffer_dirty(right_buffer); |
1173 | btrfs_mark_buffer_dirty(l_buf); | |
eb60ceac | 1174 | BUG_ON(path->slots[0] != slot); |
be0e5c09 | 1175 | if (mid <= slot) { |
234b63a0 | 1176 | btrfs_block_release(root, path->nodes[0]); |
eb60ceac | 1177 | path->nodes[0] = right_buffer; |
be0e5c09 CM |
1178 | path->slots[0] -= mid; |
1179 | path->slots[1] += 1; | |
eb60ceac | 1180 | } else |
234b63a0 | 1181 | btrfs_block_release(root, right_buffer); |
eb60ceac | 1182 | BUG_ON(path->slots[0] < 0); |
be0e5c09 CM |
1183 | return ret; |
1184 | } | |
1185 | ||
74123bd7 CM |
1186 | /* |
1187 | * Given a key and some data, insert an item into the tree. | |
1188 | * This does all the path init required, making room in the tree if needed. | |
1189 | */ | |
e089f05c CM |
1190 | int btrfs_insert_empty_item(struct btrfs_trans_handle *trans, struct btrfs_root |
1191 | *root, struct btrfs_path *path, struct btrfs_key | |
1192 | *cpu_key, u32 data_size) | |
be0e5c09 | 1193 | { |
aa5d6bed | 1194 | int ret = 0; |
be0e5c09 | 1195 | int slot; |
eb60ceac | 1196 | int slot_orig; |
234b63a0 | 1197 | struct btrfs_leaf *leaf; |
e20d96d6 | 1198 | struct buffer_head *leaf_buf; |
7518a238 | 1199 | u32 nritems; |
be0e5c09 | 1200 | unsigned int data_end; |
e2fa7227 CM |
1201 | struct btrfs_disk_key disk_key; |
1202 | ||
1203 | btrfs_cpu_key_to_disk(&disk_key, cpu_key); | |
be0e5c09 | 1204 | |
74123bd7 | 1205 | /* create a root if there isn't one */ |
5c680ed6 | 1206 | if (!root->node) |
cfaa7295 | 1207 | BUG(); |
e089f05c | 1208 | ret = btrfs_search_slot(trans, root, cpu_key, path, data_size, 1); |
eb60ceac | 1209 | if (ret == 0) { |
f0930a37 | 1210 | return -EEXIST; |
aa5d6bed | 1211 | } |
ed2ff2cb CM |
1212 | if (ret < 0) |
1213 | goto out; | |
be0e5c09 | 1214 | |
62e2749e CM |
1215 | slot_orig = path->slots[0]; |
1216 | leaf_buf = path->nodes[0]; | |
e20d96d6 | 1217 | leaf = btrfs_buffer_leaf(leaf_buf); |
74123bd7 | 1218 | |
7518a238 | 1219 | nritems = btrfs_header_nritems(&leaf->header); |
123abc88 | 1220 | data_end = leaf_data_end(root, leaf); |
eb60ceac | 1221 | |
123abc88 | 1222 | if (btrfs_leaf_free_space(root, leaf) < |
234b63a0 | 1223 | sizeof(struct btrfs_item) + data_size) |
be0e5c09 CM |
1224 | BUG(); |
1225 | ||
62e2749e | 1226 | slot = path->slots[0]; |
eb60ceac | 1227 | BUG_ON(slot < 0); |
be0e5c09 CM |
1228 | if (slot != nritems) { |
1229 | int i; | |
0783fcfc | 1230 | unsigned int old_data = btrfs_item_end(leaf->items + slot); |
be0e5c09 CM |
1231 | |
1232 | /* | |
1233 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
1234 | */ | |
1235 | /* first correct the data pointers */ | |
0783fcfc | 1236 | for (i = slot; i < nritems; i++) { |
123abc88 | 1237 | u32 ioff = btrfs_item_offset(leaf->items + i); |
0783fcfc CM |
1238 | btrfs_set_item_offset(leaf->items + i, |
1239 | ioff - data_size); | |
1240 | } | |
be0e5c09 CM |
1241 | |
1242 | /* shift the items */ | |
d6025579 CM |
1243 | btrfs_memmove(root, leaf, leaf->items + slot + 1, |
1244 | leaf->items + slot, | |
1245 | (nritems - slot) * sizeof(struct btrfs_item)); | |
be0e5c09 CM |
1246 | |
1247 | /* shift the data */ | |
d6025579 CM |
1248 | btrfs_memmove(root, leaf, btrfs_leaf_data(leaf) + |
1249 | data_end - data_size, btrfs_leaf_data(leaf) + | |
1250 | data_end, old_data - data_end); | |
be0e5c09 CM |
1251 | data_end = old_data; |
1252 | } | |
62e2749e | 1253 | /* setup the item for the new data */ |
d6025579 CM |
1254 | btrfs_memcpy(root, leaf, &leaf->items[slot].key, &disk_key, |
1255 | sizeof(struct btrfs_disk_key)); | |
0783fcfc CM |
1256 | btrfs_set_item_offset(leaf->items + slot, data_end - data_size); |
1257 | btrfs_set_item_size(leaf->items + slot, data_size); | |
7518a238 | 1258 | btrfs_set_header_nritems(&leaf->header, nritems + 1); |
d6025579 | 1259 | btrfs_mark_buffer_dirty(leaf_buf); |
aa5d6bed CM |
1260 | |
1261 | ret = 0; | |
8e19f2cd | 1262 | if (slot == 0) |
e089f05c | 1263 | ret = fixup_low_keys(trans, root, path, &disk_key, 1); |
aa5d6bed | 1264 | |
123abc88 | 1265 | if (btrfs_leaf_free_space(root, leaf) < 0) |
be0e5c09 | 1266 | BUG(); |
62e2749e | 1267 | check_leaf(root, path, 0); |
ed2ff2cb | 1268 | out: |
62e2749e CM |
1269 | return ret; |
1270 | } | |
1271 | ||
1272 | /* | |
1273 | * Given a key and some data, insert an item into the tree. | |
1274 | * This does all the path init required, making room in the tree if needed. | |
1275 | */ | |
e089f05c CM |
1276 | int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root |
1277 | *root, struct btrfs_key *cpu_key, void *data, u32 | |
1278 | data_size) | |
62e2749e CM |
1279 | { |
1280 | int ret = 0; | |
2c90e5d6 | 1281 | struct btrfs_path *path; |
62e2749e CM |
1282 | u8 *ptr; |
1283 | ||
2c90e5d6 CM |
1284 | path = btrfs_alloc_path(); |
1285 | BUG_ON(!path); | |
1286 | btrfs_init_path(path); | |
1287 | ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size); | |
62e2749e | 1288 | if (!ret) { |
2c90e5d6 CM |
1289 | ptr = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), |
1290 | path->slots[0], u8); | |
1291 | btrfs_memcpy(root, path->nodes[0]->b_data, | |
d6025579 | 1292 | ptr, data, data_size); |
2c90e5d6 | 1293 | btrfs_mark_buffer_dirty(path->nodes[0]); |
62e2749e | 1294 | } |
2c90e5d6 CM |
1295 | btrfs_release_path(root, path); |
1296 | btrfs_free_path(path); | |
aa5d6bed | 1297 | return ret; |
be0e5c09 CM |
1298 | } |
1299 | ||
74123bd7 | 1300 | /* |
5de08d7d | 1301 | * delete the pointer from a given node. |
74123bd7 CM |
1302 | * |
1303 | * If the delete empties a node, the node is removed from the tree, | |
1304 | * continuing all the way the root if required. The root is converted into | |
1305 | * a leaf if all the nodes are emptied. | |
1306 | */ | |
e089f05c CM |
1307 | static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
1308 | struct btrfs_path *path, int level, int slot) | |
be0e5c09 | 1309 | { |
234b63a0 | 1310 | struct btrfs_node *node; |
e20d96d6 | 1311 | struct buffer_head *parent = path->nodes[level]; |
7518a238 | 1312 | u32 nritems; |
aa5d6bed | 1313 | int ret = 0; |
bb803951 | 1314 | int wret; |
be0e5c09 | 1315 | |
e20d96d6 | 1316 | node = btrfs_buffer_node(parent); |
7518a238 | 1317 | nritems = btrfs_header_nritems(&node->header); |
bb803951 | 1318 | if (slot != nritems -1) { |
d6025579 CM |
1319 | btrfs_memmove(root, node, node->ptrs + slot, |
1320 | node->ptrs + slot + 1, | |
1321 | sizeof(struct btrfs_key_ptr) * | |
1322 | (nritems - slot - 1)); | |
bb803951 | 1323 | } |
7518a238 CM |
1324 | nritems--; |
1325 | btrfs_set_header_nritems(&node->header, nritems); | |
1326 | if (nritems == 0 && parent == root->node) { | |
e20d96d6 CM |
1327 | struct btrfs_header *header = btrfs_buffer_header(root->node); |
1328 | BUG_ON(btrfs_header_level(header) != 1); | |
bb803951 | 1329 | /* just turn the root into a leaf and break */ |
e20d96d6 | 1330 | btrfs_set_header_level(header, 0); |
bb803951 | 1331 | } else if (slot == 0) { |
e089f05c | 1332 | wret = fixup_low_keys(trans, root, path, &node->ptrs[0].key, |
123abc88 | 1333 | level + 1); |
0f70abe2 CM |
1334 | if (wret) |
1335 | ret = wret; | |
be0e5c09 | 1336 | } |
d6025579 | 1337 | btrfs_mark_buffer_dirty(parent); |
aa5d6bed | 1338 | return ret; |
be0e5c09 CM |
1339 | } |
1340 | ||
74123bd7 CM |
1341 | /* |
1342 | * delete the item at the leaf level in path. If that empties | |
1343 | * the leaf, remove it from the tree | |
1344 | */ | |
e089f05c CM |
1345 | int btrfs_del_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
1346 | struct btrfs_path *path) | |
be0e5c09 | 1347 | { |
be0e5c09 | 1348 | int slot; |
234b63a0 | 1349 | struct btrfs_leaf *leaf; |
e20d96d6 | 1350 | struct buffer_head *leaf_buf; |
be0e5c09 CM |
1351 | int doff; |
1352 | int dsize; | |
aa5d6bed CM |
1353 | int ret = 0; |
1354 | int wret; | |
7518a238 | 1355 | u32 nritems; |
be0e5c09 | 1356 | |
eb60ceac | 1357 | leaf_buf = path->nodes[0]; |
e20d96d6 | 1358 | leaf = btrfs_buffer_leaf(leaf_buf); |
4920c9ac | 1359 | slot = path->slots[0]; |
0783fcfc CM |
1360 | doff = btrfs_item_offset(leaf->items + slot); |
1361 | dsize = btrfs_item_size(leaf->items + slot); | |
7518a238 | 1362 | nritems = btrfs_header_nritems(&leaf->header); |
be0e5c09 | 1363 | |
7518a238 | 1364 | if (slot != nritems - 1) { |
be0e5c09 | 1365 | int i; |
123abc88 | 1366 | int data_end = leaf_data_end(root, leaf); |
d6025579 CM |
1367 | btrfs_memmove(root, leaf, btrfs_leaf_data(leaf) + |
1368 | data_end + dsize, | |
1369 | btrfs_leaf_data(leaf) + data_end, | |
1370 | doff - data_end); | |
0783fcfc | 1371 | for (i = slot + 1; i < nritems; i++) { |
123abc88 | 1372 | u32 ioff = btrfs_item_offset(leaf->items + i); |
0783fcfc CM |
1373 | btrfs_set_item_offset(leaf->items + i, ioff + dsize); |
1374 | } | |
d6025579 CM |
1375 | btrfs_memmove(root, leaf, leaf->items + slot, |
1376 | leaf->items + slot + 1, | |
1377 | sizeof(struct btrfs_item) * | |
1378 | (nritems - slot - 1)); | |
be0e5c09 | 1379 | } |
7518a238 CM |
1380 | btrfs_set_header_nritems(&leaf->header, nritems - 1); |
1381 | nritems--; | |
74123bd7 | 1382 | /* delete the leaf if we've emptied it */ |
7518a238 | 1383 | if (nritems == 0) { |
eb60ceac | 1384 | if (leaf_buf == root->node) { |
7518a238 | 1385 | btrfs_set_header_level(&leaf->header, 0); |
9a8dd150 | 1386 | } else { |
e089f05c | 1387 | clean_tree_block(trans, root, leaf_buf); |
d6025579 | 1388 | wait_on_buffer(leaf_buf); |
e089f05c | 1389 | wret = del_ptr(trans, root, path, 1, path->slots[1]); |
aa5d6bed CM |
1390 | if (wret) |
1391 | ret = wret; | |
e089f05c | 1392 | wret = btrfs_free_extent(trans, root, |
e20d96d6 | 1393 | leaf_buf->b_blocknr, 1, 1); |
0f70abe2 CM |
1394 | if (wret) |
1395 | ret = wret; | |
9a8dd150 | 1396 | } |
be0e5c09 | 1397 | } else { |
7518a238 | 1398 | int used = leaf_space_used(leaf, 0, nritems); |
aa5d6bed | 1399 | if (slot == 0) { |
e089f05c CM |
1400 | wret = fixup_low_keys(trans, root, path, |
1401 | &leaf->items[0].key, 1); | |
aa5d6bed CM |
1402 | if (wret) |
1403 | ret = wret; | |
1404 | } | |
aa5d6bed | 1405 | |
74123bd7 | 1406 | /* delete the leaf if it is mostly empty */ |
123abc88 | 1407 | if (used < BTRFS_LEAF_DATA_SIZE(root) / 3) { |
be0e5c09 CM |
1408 | /* push_leaf_left fixes the path. |
1409 | * make sure the path still points to our leaf | |
1410 | * for possible call to del_ptr below | |
1411 | */ | |
4920c9ac | 1412 | slot = path->slots[1]; |
e20d96d6 | 1413 | get_bh(leaf_buf); |
e089f05c | 1414 | wret = push_leaf_left(trans, root, path, 1); |
aa5d6bed CM |
1415 | if (wret < 0) |
1416 | ret = wret; | |
f0930a37 | 1417 | if (path->nodes[0] == leaf_buf && |
7518a238 | 1418 | btrfs_header_nritems(&leaf->header)) { |
e089f05c | 1419 | wret = push_leaf_right(trans, root, path, 1); |
aa5d6bed CM |
1420 | if (wret < 0) |
1421 | ret = wret; | |
1422 | } | |
7518a238 | 1423 | if (btrfs_header_nritems(&leaf->header) == 0) { |
e20d96d6 | 1424 | u64 blocknr = leaf_buf->b_blocknr; |
e089f05c | 1425 | clean_tree_block(trans, root, leaf_buf); |
d6025579 | 1426 | wait_on_buffer(leaf_buf); |
e089f05c | 1427 | wret = del_ptr(trans, root, path, 1, slot); |
aa5d6bed CM |
1428 | if (wret) |
1429 | ret = wret; | |
234b63a0 | 1430 | btrfs_block_release(root, leaf_buf); |
e089f05c CM |
1431 | wret = btrfs_free_extent(trans, root, blocknr, |
1432 | 1, 1); | |
0f70abe2 CM |
1433 | if (wret) |
1434 | ret = wret; | |
5de08d7d | 1435 | } else { |
d6025579 | 1436 | btrfs_mark_buffer_dirty(leaf_buf); |
234b63a0 | 1437 | btrfs_block_release(root, leaf_buf); |
be0e5c09 | 1438 | } |
d5719762 | 1439 | } else { |
d6025579 | 1440 | btrfs_mark_buffer_dirty(leaf_buf); |
be0e5c09 CM |
1441 | } |
1442 | } | |
aa5d6bed | 1443 | return ret; |
be0e5c09 CM |
1444 | } |
1445 | ||
97571fd0 CM |
1446 | /* |
1447 | * walk up the tree as far as required to find the next leaf. | |
0f70abe2 CM |
1448 | * returns 0 if it found something or 1 if there are no greater leaves. |
1449 | * returns < 0 on io errors. | |
97571fd0 | 1450 | */ |
234b63a0 | 1451 | int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) |
d97e63b6 CM |
1452 | { |
1453 | int slot; | |
1454 | int level = 1; | |
1455 | u64 blocknr; | |
e20d96d6 CM |
1456 | struct buffer_head *c; |
1457 | struct btrfs_node *c_node; | |
1458 | struct buffer_head *next = NULL; | |
d97e63b6 | 1459 | |
234b63a0 | 1460 | while(level < BTRFS_MAX_LEVEL) { |
d97e63b6 | 1461 | if (!path->nodes[level]) |
0f70abe2 | 1462 | return 1; |
d97e63b6 CM |
1463 | slot = path->slots[level] + 1; |
1464 | c = path->nodes[level]; | |
e20d96d6 CM |
1465 | c_node = btrfs_buffer_node(c); |
1466 | if (slot >= btrfs_header_nritems(&c_node->header)) { | |
d97e63b6 CM |
1467 | level++; |
1468 | continue; | |
1469 | } | |
e20d96d6 | 1470 | blocknr = btrfs_node_blockptr(c_node, slot); |
cfaa7295 | 1471 | if (next) |
234b63a0 | 1472 | btrfs_block_release(root, next); |
d97e63b6 CM |
1473 | next = read_tree_block(root, blocknr); |
1474 | break; | |
1475 | } | |
1476 | path->slots[level] = slot; | |
1477 | while(1) { | |
1478 | level--; | |
1479 | c = path->nodes[level]; | |
234b63a0 | 1480 | btrfs_block_release(root, c); |
d97e63b6 CM |
1481 | path->nodes[level] = next; |
1482 | path->slots[level] = 0; | |
1483 | if (!level) | |
1484 | break; | |
1d4f8a0c | 1485 | next = read_tree_block(root, |
e20d96d6 | 1486 | btrfs_node_blockptr(btrfs_buffer_node(next), 0)); |
d97e63b6 CM |
1487 | } |
1488 | return 0; | |
1489 | } |