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