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