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); |
e089f05c | 71 | btrfs_inc_ref(trans, root, buf); |
02217ed2 CM |
72 | if (buf == root->node) { |
73 | root->node = cow; | |
e20d96d6 | 74 | get_bh(cow); |
2c90e5d6 | 75 | if (buf != root->commit_root) { |
7eccb903 | 76 | btrfs_free_extent(trans, root, bh_blocknr(buf), 1, 1); |
2c90e5d6 | 77 | } |
234b63a0 | 78 | btrfs_block_release(root, buf); |
02217ed2 | 79 | } else { |
e20d96d6 | 80 | btrfs_set_node_blockptr(btrfs_buffer_node(parent), parent_slot, |
7eccb903 | 81 | bh_blocknr(cow)); |
d6025579 | 82 | btrfs_mark_buffer_dirty(parent); |
7eccb903 | 83 | btrfs_free_extent(trans, root, bh_blocknr(buf), 1, 1); |
02217ed2 | 84 | } |
234b63a0 | 85 | btrfs_block_release(root, buf); |
df24a2b9 | 86 | mark_buffer_dirty(cow); |
2c90e5d6 | 87 | *cow_ret = cow; |
02217ed2 CM |
88 | return 0; |
89 | } | |
90 | ||
74123bd7 CM |
91 | /* |
92 | * The leaf data grows from end-to-front in the node. | |
93 | * this returns the address of the start of the last item, | |
94 | * which is the stop of the leaf data stack | |
95 | */ | |
123abc88 CM |
96 | static inline unsigned int leaf_data_end(struct btrfs_root *root, |
97 | struct btrfs_leaf *leaf) | |
be0e5c09 | 98 | { |
7518a238 | 99 | u32 nr = btrfs_header_nritems(&leaf->header); |
be0e5c09 | 100 | if (nr == 0) |
123abc88 | 101 | return BTRFS_LEAF_DATA_SIZE(root); |
0783fcfc | 102 | return btrfs_item_offset(leaf->items + nr - 1); |
be0e5c09 CM |
103 | } |
104 | ||
74123bd7 CM |
105 | /* |
106 | * compare two keys in a memcmp fashion | |
107 | */ | |
9aca1d51 | 108 | static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2) |
be0e5c09 | 109 | { |
e2fa7227 CM |
110 | struct btrfs_key k1; |
111 | ||
112 | btrfs_disk_key_to_cpu(&k1, disk); | |
113 | ||
114 | if (k1.objectid > k2->objectid) | |
be0e5c09 | 115 | return 1; |
e2fa7227 | 116 | if (k1.objectid < k2->objectid) |
be0e5c09 | 117 | return -1; |
a8a2ee0c CM |
118 | if (k1.offset > k2->offset) |
119 | return 1; | |
120 | if (k1.offset < k2->offset) | |
121 | return -1; | |
f254e52c CM |
122 | if (k1.flags > k2->flags) |
123 | return 1; | |
124 | if (k1.flags < k2->flags) | |
125 | return -1; | |
be0e5c09 CM |
126 | return 0; |
127 | } | |
74123bd7 | 128 | |
123abc88 CM |
129 | static int check_node(struct btrfs_root *root, struct btrfs_path *path, |
130 | int level) | |
aa5d6bed CM |
131 | { |
132 | int i; | |
234b63a0 | 133 | struct btrfs_node *parent = NULL; |
e20d96d6 | 134 | struct btrfs_node *node = btrfs_buffer_node(path->nodes[level]); |
aa5d6bed | 135 | int parent_slot; |
7518a238 | 136 | u32 nritems = btrfs_header_nritems(&node->header); |
aa5d6bed CM |
137 | |
138 | if (path->nodes[level + 1]) | |
e20d96d6 | 139 | parent = btrfs_buffer_node(path->nodes[level + 1]); |
aa5d6bed | 140 | parent_slot = path->slots[level + 1]; |
7518a238 CM |
141 | BUG_ON(nritems == 0); |
142 | if (parent) { | |
e2fa7227 | 143 | struct btrfs_disk_key *parent_key; |
123abc88 CM |
144 | parent_key = &parent->ptrs[parent_slot].key; |
145 | BUG_ON(memcmp(parent_key, &node->ptrs[0].key, | |
e2fa7227 | 146 | sizeof(struct btrfs_disk_key))); |
1d4f8a0c | 147 | BUG_ON(btrfs_node_blockptr(parent, parent_slot) != |
7518a238 | 148 | btrfs_header_blocknr(&node->header)); |
aa5d6bed | 149 | } |
123abc88 | 150 | BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root)); |
7518a238 | 151 | for (i = 0; nritems > 1 && i < nritems - 2; i++) { |
e2fa7227 | 152 | struct btrfs_key cpukey; |
123abc88 CM |
153 | btrfs_disk_key_to_cpu(&cpukey, &node->ptrs[i + 1].key); |
154 | BUG_ON(comp_keys(&node->ptrs[i].key, &cpukey) >= 0); | |
aa5d6bed CM |
155 | } |
156 | return 0; | |
157 | } | |
158 | ||
123abc88 CM |
159 | static int check_leaf(struct btrfs_root *root, struct btrfs_path *path, |
160 | int level) | |
aa5d6bed CM |
161 | { |
162 | int i; | |
e20d96d6 | 163 | struct btrfs_leaf *leaf = btrfs_buffer_leaf(path->nodes[level]); |
234b63a0 | 164 | struct btrfs_node *parent = NULL; |
aa5d6bed | 165 | int parent_slot; |
7518a238 | 166 | u32 nritems = btrfs_header_nritems(&leaf->header); |
aa5d6bed CM |
167 | |
168 | if (path->nodes[level + 1]) | |
e20d96d6 | 169 | parent = btrfs_buffer_node(path->nodes[level + 1]); |
aa5d6bed | 170 | parent_slot = path->slots[level + 1]; |
123abc88 | 171 | BUG_ON(btrfs_leaf_free_space(root, leaf) < 0); |
7518a238 CM |
172 | |
173 | if (nritems == 0) | |
174 | return 0; | |
175 | ||
176 | if (parent) { | |
e2fa7227 | 177 | struct btrfs_disk_key *parent_key; |
123abc88 | 178 | parent_key = &parent->ptrs[parent_slot].key; |
aa5d6bed | 179 | BUG_ON(memcmp(parent_key, &leaf->items[0].key, |
e2fa7227 | 180 | sizeof(struct btrfs_disk_key))); |
1d4f8a0c | 181 | BUG_ON(btrfs_node_blockptr(parent, parent_slot) != |
7518a238 | 182 | btrfs_header_blocknr(&leaf->header)); |
aa5d6bed | 183 | } |
7518a238 | 184 | for (i = 0; nritems > 1 && i < nritems - 2; i++) { |
e2fa7227 CM |
185 | struct btrfs_key cpukey; |
186 | btrfs_disk_key_to_cpu(&cpukey, &leaf->items[i + 1].key); | |
aa5d6bed | 187 | BUG_ON(comp_keys(&leaf->items[i].key, |
e2fa7227 | 188 | &cpukey) >= 0); |
0783fcfc CM |
189 | BUG_ON(btrfs_item_offset(leaf->items + i) != |
190 | btrfs_item_end(leaf->items + i + 1)); | |
aa5d6bed | 191 | if (i == 0) { |
0783fcfc CM |
192 | BUG_ON(btrfs_item_offset(leaf->items + i) + |
193 | btrfs_item_size(leaf->items + i) != | |
123abc88 | 194 | BTRFS_LEAF_DATA_SIZE(root)); |
aa5d6bed CM |
195 | } |
196 | } | |
aa5d6bed CM |
197 | return 0; |
198 | } | |
199 | ||
123abc88 CM |
200 | static int check_block(struct btrfs_root *root, struct btrfs_path *path, |
201 | int level) | |
aa5d6bed | 202 | { |
3eb0314d CM |
203 | struct btrfs_node *node = btrfs_buffer_node(path->nodes[level]); |
204 | if (memcmp(node->header.fsid, root->fs_info->disk_super->fsid, | |
205 | sizeof(node->header.fsid))) | |
206 | BUG(); | |
aa5d6bed | 207 | if (level == 0) |
123abc88 CM |
208 | return check_leaf(root, path, level); |
209 | return check_node(root, path, level); | |
aa5d6bed CM |
210 | } |
211 | ||
74123bd7 CM |
212 | /* |
213 | * search for key in the array p. items p are item_size apart | |
214 | * and there are 'max' items in p | |
215 | * the slot in the array is returned via slot, and it points to | |
216 | * the place where you would insert key if it is not found in | |
217 | * the array. | |
218 | * | |
219 | * slot may point to max if the key is bigger than all of the keys | |
220 | */ | |
9aca1d51 | 221 | static int generic_bin_search(char *p, int item_size, struct btrfs_key *key, |
be0e5c09 CM |
222 | int max, int *slot) |
223 | { | |
224 | int low = 0; | |
225 | int high = max; | |
226 | int mid; | |
227 | int ret; | |
e2fa7227 | 228 | struct btrfs_disk_key *tmp; |
be0e5c09 CM |
229 | |
230 | while(low < high) { | |
231 | mid = (low + high) / 2; | |
e2fa7227 | 232 | tmp = (struct btrfs_disk_key *)(p + mid * item_size); |
be0e5c09 CM |
233 | ret = comp_keys(tmp, key); |
234 | ||
235 | if (ret < 0) | |
236 | low = mid + 1; | |
237 | else if (ret > 0) | |
238 | high = mid; | |
239 | else { | |
240 | *slot = mid; | |
241 | return 0; | |
242 | } | |
243 | } | |
244 | *slot = low; | |
245 | return 1; | |
246 | } | |
247 | ||
97571fd0 CM |
248 | /* |
249 | * simple bin_search frontend that does the right thing for | |
250 | * leaves vs nodes | |
251 | */ | |
9aca1d51 | 252 | static int bin_search(struct btrfs_node *c, struct btrfs_key *key, int *slot) |
be0e5c09 | 253 | { |
7518a238 | 254 | if (btrfs_is_leaf(c)) { |
234b63a0 | 255 | struct btrfs_leaf *l = (struct btrfs_leaf *)c; |
0783fcfc CM |
256 | return generic_bin_search((void *)l->items, |
257 | sizeof(struct btrfs_item), | |
7518a238 CM |
258 | key, btrfs_header_nritems(&c->header), |
259 | slot); | |
be0e5c09 | 260 | } else { |
123abc88 CM |
261 | return generic_bin_search((void *)c->ptrs, |
262 | sizeof(struct btrfs_key_ptr), | |
7518a238 CM |
263 | key, btrfs_header_nritems(&c->header), |
264 | slot); | |
be0e5c09 CM |
265 | } |
266 | return -1; | |
267 | } | |
268 | ||
e20d96d6 CM |
269 | static struct buffer_head *read_node_slot(struct btrfs_root *root, |
270 | struct buffer_head *parent_buf, | |
bb803951 CM |
271 | int slot) |
272 | { | |
e20d96d6 | 273 | struct btrfs_node *node = btrfs_buffer_node(parent_buf); |
bb803951 CM |
274 | if (slot < 0) |
275 | return NULL; | |
7518a238 | 276 | if (slot >= btrfs_header_nritems(&node->header)) |
bb803951 | 277 | return NULL; |
1d4f8a0c | 278 | return read_tree_block(root, btrfs_node_blockptr(node, slot)); |
bb803951 CM |
279 | } |
280 | ||
e089f05c CM |
281 | static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root |
282 | *root, struct btrfs_path *path, int level) | |
bb803951 | 283 | { |
e20d96d6 CM |
284 | struct buffer_head *right_buf; |
285 | struct buffer_head *mid_buf; | |
286 | struct buffer_head *left_buf; | |
287 | struct buffer_head *parent_buf = NULL; | |
234b63a0 CM |
288 | struct btrfs_node *right = NULL; |
289 | struct btrfs_node *mid; | |
290 | struct btrfs_node *left = NULL; | |
291 | struct btrfs_node *parent = NULL; | |
bb803951 CM |
292 | int ret = 0; |
293 | int wret; | |
294 | int pslot; | |
bb803951 | 295 | int orig_slot = path->slots[level]; |
79f95c82 | 296 | u64 orig_ptr; |
bb803951 CM |
297 | |
298 | if (level == 0) | |
299 | return 0; | |
300 | ||
301 | mid_buf = path->nodes[level]; | |
e20d96d6 | 302 | mid = btrfs_buffer_node(mid_buf); |
1d4f8a0c | 303 | orig_ptr = btrfs_node_blockptr(mid, orig_slot); |
79f95c82 | 304 | |
234b63a0 | 305 | if (level < BTRFS_MAX_LEVEL - 1) |
bb803951 CM |
306 | parent_buf = path->nodes[level + 1]; |
307 | pslot = path->slots[level + 1]; | |
308 | ||
40689478 CM |
309 | /* |
310 | * deal with the case where there is only one pointer in the root | |
311 | * by promoting the node below to a root | |
312 | */ | |
bb803951 | 313 | if (!parent_buf) { |
e20d96d6 | 314 | struct buffer_head *child; |
7eccb903 | 315 | u64 blocknr = bh_blocknr(mid_buf); |
bb803951 | 316 | |
7518a238 | 317 | if (btrfs_header_nritems(&mid->header) != 1) |
bb803951 CM |
318 | return 0; |
319 | ||
320 | /* promote the child to a root */ | |
321 | child = read_node_slot(root, mid_buf, 0); | |
322 | BUG_ON(!child); | |
323 | root->node = child; | |
324 | path->nodes[level] = NULL; | |
d6025579 CM |
325 | clean_tree_block(trans, root, mid_buf); |
326 | wait_on_buffer(mid_buf); | |
bb803951 | 327 | /* once for the path */ |
234b63a0 | 328 | btrfs_block_release(root, mid_buf); |
bb803951 | 329 | /* once for the root ptr */ |
234b63a0 | 330 | btrfs_block_release(root, mid_buf); |
e089f05c | 331 | return btrfs_free_extent(trans, root, blocknr, 1, 1); |
bb803951 | 332 | } |
e20d96d6 | 333 | parent = btrfs_buffer_node(parent_buf); |
bb803951 | 334 | |
123abc88 CM |
335 | if (btrfs_header_nritems(&mid->header) > |
336 | BTRFS_NODEPTRS_PER_BLOCK(root) / 4) | |
bb803951 CM |
337 | return 0; |
338 | ||
bb803951 CM |
339 | left_buf = read_node_slot(root, parent_buf, pslot - 1); |
340 | right_buf = read_node_slot(root, parent_buf, pslot + 1); | |
79f95c82 CM |
341 | |
342 | /* first, try to make some room in the middle buffer */ | |
bb803951 | 343 | if (left_buf) { |
e089f05c CM |
344 | btrfs_cow_block(trans, root, left_buf, parent_buf, pslot - 1, |
345 | &left_buf); | |
e20d96d6 | 346 | left = btrfs_buffer_node(left_buf); |
7518a238 | 347 | orig_slot += btrfs_header_nritems(&left->header); |
e089f05c | 348 | wret = push_node_left(trans, root, left_buf, mid_buf); |
79f95c82 CM |
349 | if (wret < 0) |
350 | ret = wret; | |
bb803951 | 351 | } |
79f95c82 CM |
352 | |
353 | /* | |
354 | * then try to empty the right most buffer into the middle | |
355 | */ | |
bb803951 | 356 | if (right_buf) { |
e089f05c CM |
357 | btrfs_cow_block(trans, root, right_buf, parent_buf, pslot + 1, |
358 | &right_buf); | |
e20d96d6 | 359 | right = btrfs_buffer_node(right_buf); |
e089f05c | 360 | wret = push_node_left(trans, root, mid_buf, right_buf); |
79f95c82 CM |
361 | if (wret < 0) |
362 | ret = wret; | |
7518a238 | 363 | if (btrfs_header_nritems(&right->header) == 0) { |
7eccb903 | 364 | u64 blocknr = bh_blocknr(right_buf); |
e089f05c | 365 | clean_tree_block(trans, root, right_buf); |
d6025579 CM |
366 | wait_on_buffer(right_buf); |
367 | btrfs_block_release(root, right_buf); | |
bb803951 CM |
368 | right_buf = NULL; |
369 | right = NULL; | |
e089f05c CM |
370 | wret = del_ptr(trans, root, path, level + 1, pslot + |
371 | 1); | |
bb803951 CM |
372 | if (wret) |
373 | ret = wret; | |
e089f05c | 374 | wret = btrfs_free_extent(trans, root, blocknr, 1, 1); |
bb803951 CM |
375 | if (wret) |
376 | ret = wret; | |
377 | } else { | |
d6025579 CM |
378 | btrfs_memcpy(root, parent, |
379 | &parent->ptrs[pslot + 1].key, | |
380 | &right->ptrs[0].key, | |
381 | sizeof(struct btrfs_disk_key)); | |
382 | btrfs_mark_buffer_dirty(parent_buf); | |
bb803951 CM |
383 | } |
384 | } | |
7518a238 | 385 | if (btrfs_header_nritems(&mid->header) == 1) { |
79f95c82 CM |
386 | /* |
387 | * we're not allowed to leave a node with one item in the | |
388 | * tree during a delete. A deletion from lower in the tree | |
389 | * could try to delete the only pointer in this node. | |
390 | * So, pull some keys from the left. | |
391 | * There has to be a left pointer at this point because | |
392 | * otherwise we would have pulled some pointers from the | |
393 | * right | |
394 | */ | |
395 | BUG_ON(!left_buf); | |
e089f05c | 396 | wret = balance_node_right(trans, root, mid_buf, left_buf); |
79f95c82 CM |
397 | if (wret < 0) |
398 | ret = wret; | |
399 | BUG_ON(wret == 1); | |
400 | } | |
7518a238 | 401 | if (btrfs_header_nritems(&mid->header) == 0) { |
79f95c82 | 402 | /* we've managed to empty the middle node, drop it */ |
7eccb903 | 403 | u64 blocknr = bh_blocknr(mid_buf); |
e089f05c | 404 | clean_tree_block(trans, root, mid_buf); |
d6025579 CM |
405 | wait_on_buffer(mid_buf); |
406 | btrfs_block_release(root, mid_buf); | |
bb803951 CM |
407 | mid_buf = NULL; |
408 | mid = NULL; | |
e089f05c | 409 | wret = del_ptr(trans, root, path, level + 1, pslot); |
bb803951 CM |
410 | if (wret) |
411 | ret = wret; | |
e089f05c | 412 | wret = btrfs_free_extent(trans, root, blocknr, 1, 1); |
bb803951 CM |
413 | if (wret) |
414 | ret = wret; | |
79f95c82 CM |
415 | } else { |
416 | /* update the parent key to reflect our changes */ | |
d6025579 CM |
417 | btrfs_memcpy(root, parent, |
418 | &parent->ptrs[pslot].key, &mid->ptrs[0].key, | |
419 | sizeof(struct btrfs_disk_key)); | |
420 | btrfs_mark_buffer_dirty(parent_buf); | |
79f95c82 | 421 | } |
bb803951 | 422 | |
79f95c82 | 423 | /* update the path */ |
bb803951 | 424 | if (left_buf) { |
7518a238 | 425 | if (btrfs_header_nritems(&left->header) > orig_slot) { |
e20d96d6 | 426 | get_bh(left_buf); |
bb803951 CM |
427 | path->nodes[level] = left_buf; |
428 | path->slots[level + 1] -= 1; | |
429 | path->slots[level] = orig_slot; | |
430 | if (mid_buf) | |
234b63a0 | 431 | btrfs_block_release(root, mid_buf); |
bb803951 | 432 | } else { |
7518a238 | 433 | orig_slot -= btrfs_header_nritems(&left->header); |
bb803951 CM |
434 | path->slots[level] = orig_slot; |
435 | } | |
436 | } | |
79f95c82 | 437 | /* double check we haven't messed things up */ |
123abc88 | 438 | check_block(root, path, level); |
e20d96d6 CM |
439 | if (orig_ptr != |
440 | btrfs_node_blockptr(btrfs_buffer_node(path->nodes[level]), | |
441 | path->slots[level])) | |
79f95c82 | 442 | BUG(); |
bb803951 CM |
443 | |
444 | if (right_buf) | |
234b63a0 | 445 | btrfs_block_release(root, right_buf); |
bb803951 | 446 | if (left_buf) |
234b63a0 | 447 | btrfs_block_release(root, left_buf); |
bb803951 CM |
448 | return ret; |
449 | } | |
450 | ||
74123bd7 CM |
451 | /* |
452 | * look for key in the tree. path is filled in with nodes along the way | |
453 | * if key is found, we return zero and you can find the item in the leaf | |
454 | * level of the path (level 0) | |
455 | * | |
456 | * If the key isn't found, the path points to the slot where it should | |
aa5d6bed CM |
457 | * be inserted, and 1 is returned. If there are other errors during the |
458 | * search a negative error number is returned. | |
97571fd0 CM |
459 | * |
460 | * if ins_len > 0, nodes and leaves will be split as we walk down the | |
461 | * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if | |
462 | * possible) | |
74123bd7 | 463 | */ |
e089f05c CM |
464 | int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root |
465 | *root, struct btrfs_key *key, struct btrfs_path *p, int | |
466 | ins_len, int cow) | |
be0e5c09 | 467 | { |
e20d96d6 CM |
468 | struct buffer_head *b; |
469 | struct buffer_head *cow_buf; | |
234b63a0 | 470 | struct btrfs_node *c; |
be0e5c09 CM |
471 | int slot; |
472 | int ret; | |
473 | int level; | |
5c680ed6 | 474 | |
22b0ebda CM |
475 | WARN_ON(p->nodes[0] != NULL); |
476 | WARN_ON(!mutex_is_locked(&root->fs_info->fs_mutex)); | |
bb803951 CM |
477 | again: |
478 | b = root->node; | |
e20d96d6 | 479 | get_bh(b); |
eb60ceac | 480 | while (b) { |
e20d96d6 CM |
481 | c = btrfs_buffer_node(b); |
482 | level = btrfs_header_level(&c->header); | |
02217ed2 CM |
483 | if (cow) { |
484 | int wret; | |
e20d96d6 CM |
485 | wret = btrfs_cow_block(trans, root, b, |
486 | p->nodes[level + 1], | |
487 | p->slots[level + 1], | |
e089f05c | 488 | &cow_buf); |
02217ed2 | 489 | b = cow_buf; |
2c90e5d6 | 490 | c = btrfs_buffer_node(b); |
02217ed2 CM |
491 | } |
492 | BUG_ON(!cow && ins_len); | |
2c90e5d6 CM |
493 | if (level != btrfs_header_level(&c->header)) |
494 | WARN_ON(1); | |
495 | level = btrfs_header_level(&c->header); | |
eb60ceac | 496 | p->nodes[level] = b; |
123abc88 | 497 | ret = check_block(root, p, level); |
aa5d6bed CM |
498 | if (ret) |
499 | return -1; | |
be0e5c09 | 500 | ret = bin_search(c, key, &slot); |
7518a238 | 501 | if (!btrfs_is_leaf(c)) { |
be0e5c09 CM |
502 | if (ret && slot > 0) |
503 | slot -= 1; | |
504 | p->slots[level] = slot; | |
d4dbff95 CM |
505 | if (ins_len > 0 && btrfs_header_nritems(&c->header) >= |
506 | BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { | |
e089f05c | 507 | int sret = split_node(trans, root, p, level); |
5c680ed6 CM |
508 | BUG_ON(sret > 0); |
509 | if (sret) | |
510 | return sret; | |
511 | b = p->nodes[level]; | |
e20d96d6 | 512 | c = btrfs_buffer_node(b); |
5c680ed6 | 513 | slot = p->slots[level]; |
bb803951 | 514 | } else if (ins_len < 0) { |
e089f05c CM |
515 | int sret = balance_level(trans, root, p, |
516 | level); | |
bb803951 CM |
517 | if (sret) |
518 | return sret; | |
519 | b = p->nodes[level]; | |
520 | if (!b) | |
521 | goto again; | |
e20d96d6 | 522 | c = btrfs_buffer_node(b); |
bb803951 | 523 | slot = p->slots[level]; |
7518a238 | 524 | BUG_ON(btrfs_header_nritems(&c->header) == 1); |
5c680ed6 | 525 | } |
1d4f8a0c | 526 | b = read_tree_block(root, btrfs_node_blockptr(c, slot)); |
be0e5c09 | 527 | } else { |
234b63a0 | 528 | struct btrfs_leaf *l = (struct btrfs_leaf *)c; |
be0e5c09 | 529 | p->slots[level] = slot; |
123abc88 | 530 | if (ins_len > 0 && btrfs_leaf_free_space(root, l) < |
0783fcfc | 531 | sizeof(struct btrfs_item) + ins_len) { |
d4dbff95 CM |
532 | int sret = split_leaf(trans, root, key, |
533 | p, ins_len); | |
5c680ed6 CM |
534 | BUG_ON(sret > 0); |
535 | if (sret) | |
536 | return sret; | |
537 | } | |
be0e5c09 CM |
538 | return ret; |
539 | } | |
540 | } | |
aa5d6bed | 541 | return 1; |
be0e5c09 CM |
542 | } |
543 | ||
74123bd7 CM |
544 | /* |
545 | * adjust the pointers going up the tree, starting at level | |
546 | * making sure the right key of each node is points to 'key'. | |
547 | * This is used after shifting pointers to the left, so it stops | |
548 | * fixing up pointers when a given leaf/node is not in slot 0 of the | |
549 | * higher levels | |
aa5d6bed CM |
550 | * |
551 | * If this fails to write a tree block, it returns -1, but continues | |
552 | * fixing up the blocks in ram so the tree is consistent. | |
74123bd7 | 553 | */ |
e089f05c CM |
554 | static int fixup_low_keys(struct btrfs_trans_handle *trans, struct btrfs_root |
555 | *root, struct btrfs_path *path, struct btrfs_disk_key | |
556 | *key, int level) | |
be0e5c09 CM |
557 | { |
558 | int i; | |
aa5d6bed | 559 | int ret = 0; |
234b63a0 CM |
560 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { |
561 | struct btrfs_node *t; | |
be0e5c09 | 562 | int tslot = path->slots[i]; |
eb60ceac | 563 | if (!path->nodes[i]) |
be0e5c09 | 564 | break; |
e20d96d6 | 565 | t = btrfs_buffer_node(path->nodes[i]); |
d6025579 CM |
566 | btrfs_memcpy(root, t, &t->ptrs[tslot].key, key, sizeof(*key)); |
567 | btrfs_mark_buffer_dirty(path->nodes[i]); | |
be0e5c09 CM |
568 | if (tslot != 0) |
569 | break; | |
570 | } | |
aa5d6bed | 571 | return ret; |
be0e5c09 CM |
572 | } |
573 | ||
74123bd7 CM |
574 | /* |
575 | * try to push data from one node into the next node left in the | |
79f95c82 | 576 | * tree. |
aa5d6bed CM |
577 | * |
578 | * returns 0 if some ptrs were pushed left, < 0 if there was some horrible | |
579 | * error, and > 0 if there was no room in the left hand block. | |
74123bd7 | 580 | */ |
e089f05c | 581 | static int push_node_left(struct btrfs_trans_handle *trans, struct btrfs_root |
e20d96d6 CM |
582 | *root, struct buffer_head *dst_buf, struct |
583 | buffer_head *src_buf) | |
be0e5c09 | 584 | { |
e20d96d6 CM |
585 | struct btrfs_node *src = btrfs_buffer_node(src_buf); |
586 | struct btrfs_node *dst = btrfs_buffer_node(dst_buf); | |
be0e5c09 | 587 | int push_items = 0; |
bb803951 CM |
588 | int src_nritems; |
589 | int dst_nritems; | |
aa5d6bed | 590 | int ret = 0; |
be0e5c09 | 591 | |
7518a238 CM |
592 | src_nritems = btrfs_header_nritems(&src->header); |
593 | dst_nritems = btrfs_header_nritems(&dst->header); | |
123abc88 | 594 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
eb60ceac | 595 | if (push_items <= 0) { |
be0e5c09 | 596 | return 1; |
eb60ceac | 597 | } |
be0e5c09 | 598 | |
bb803951 | 599 | if (src_nritems < push_items) |
79f95c82 CM |
600 | push_items = src_nritems; |
601 | ||
d6025579 CM |
602 | btrfs_memcpy(root, dst, dst->ptrs + dst_nritems, src->ptrs, |
603 | push_items * sizeof(struct btrfs_key_ptr)); | |
bb803951 | 604 | if (push_items < src_nritems) { |
d6025579 | 605 | btrfs_memmove(root, src, src->ptrs, src->ptrs + push_items, |
e2fa7227 | 606 | (src_nritems - push_items) * |
123abc88 | 607 | sizeof(struct btrfs_key_ptr)); |
bb803951 | 608 | } |
7518a238 CM |
609 | btrfs_set_header_nritems(&src->header, src_nritems - push_items); |
610 | btrfs_set_header_nritems(&dst->header, dst_nritems + push_items); | |
d6025579 CM |
611 | btrfs_mark_buffer_dirty(src_buf); |
612 | btrfs_mark_buffer_dirty(dst_buf); | |
79f95c82 CM |
613 | return ret; |
614 | } | |
615 | ||
616 | /* | |
617 | * try to push data from one node into the next node right in the | |
618 | * tree. | |
619 | * | |
620 | * returns 0 if some ptrs were pushed, < 0 if there was some horrible | |
621 | * error, and > 0 if there was no room in the right hand block. | |
622 | * | |
623 | * this will only push up to 1/2 the contents of the left node over | |
624 | */ | |
e089f05c | 625 | static int balance_node_right(struct btrfs_trans_handle *trans, struct |
e20d96d6 CM |
626 | btrfs_root *root, struct buffer_head *dst_buf, |
627 | struct buffer_head *src_buf) | |
79f95c82 | 628 | { |
e20d96d6 CM |
629 | struct btrfs_node *src = btrfs_buffer_node(src_buf); |
630 | struct btrfs_node *dst = btrfs_buffer_node(dst_buf); | |
79f95c82 CM |
631 | int push_items = 0; |
632 | int max_push; | |
633 | int src_nritems; | |
634 | int dst_nritems; | |
635 | int ret = 0; | |
79f95c82 | 636 | |
7518a238 CM |
637 | src_nritems = btrfs_header_nritems(&src->header); |
638 | dst_nritems = btrfs_header_nritems(&dst->header); | |
123abc88 | 639 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
79f95c82 CM |
640 | if (push_items <= 0) { |
641 | return 1; | |
642 | } | |
643 | ||
644 | max_push = src_nritems / 2 + 1; | |
645 | /* don't try to empty the node */ | |
646 | if (max_push > src_nritems) | |
647 | return 1; | |
648 | if (max_push < push_items) | |
649 | push_items = max_push; | |
650 | ||
d6025579 CM |
651 | btrfs_memmove(root, dst, dst->ptrs + push_items, dst->ptrs, |
652 | dst_nritems * sizeof(struct btrfs_key_ptr)); | |
653 | ||
654 | btrfs_memcpy(root, dst, dst->ptrs, | |
655 | src->ptrs + src_nritems - push_items, | |
656 | push_items * sizeof(struct btrfs_key_ptr)); | |
79f95c82 | 657 | |
7518a238 CM |
658 | btrfs_set_header_nritems(&src->header, src_nritems - push_items); |
659 | btrfs_set_header_nritems(&dst->header, dst_nritems + push_items); | |
79f95c82 | 660 | |
d6025579 CM |
661 | btrfs_mark_buffer_dirty(src_buf); |
662 | btrfs_mark_buffer_dirty(dst_buf); | |
aa5d6bed | 663 | return ret; |
be0e5c09 CM |
664 | } |
665 | ||
97571fd0 CM |
666 | /* |
667 | * helper function to insert a new root level in the tree. | |
668 | * A new node is allocated, and a single item is inserted to | |
669 | * point to the existing root | |
aa5d6bed CM |
670 | * |
671 | * returns zero on success or < 0 on failure. | |
97571fd0 | 672 | */ |
e089f05c CM |
673 | static int insert_new_root(struct btrfs_trans_handle *trans, struct btrfs_root |
674 | *root, struct btrfs_path *path, int level) | |
5c680ed6 | 675 | { |
e20d96d6 | 676 | struct buffer_head *t; |
234b63a0 CM |
677 | struct btrfs_node *lower; |
678 | struct btrfs_node *c; | |
e2fa7227 | 679 | struct btrfs_disk_key *lower_key; |
5c680ed6 CM |
680 | |
681 | BUG_ON(path->nodes[level]); | |
682 | BUG_ON(path->nodes[level-1] != root->node); | |
683 | ||
e089f05c | 684 | t = btrfs_alloc_free_block(trans, root); |
e20d96d6 | 685 | c = btrfs_buffer_node(t); |
123abc88 | 686 | memset(c, 0, root->blocksize); |
7518a238 CM |
687 | btrfs_set_header_nritems(&c->header, 1); |
688 | btrfs_set_header_level(&c->header, level); | |
7eccb903 | 689 | btrfs_set_header_blocknr(&c->header, bh_blocknr(t)); |
7f5c1516 | 690 | btrfs_set_header_generation(&c->header, trans->transid); |
e20d96d6 | 691 | lower = btrfs_buffer_node(path->nodes[level-1]); |
3eb0314d CM |
692 | memcpy(c->header.fsid, root->fs_info->disk_super->fsid, |
693 | sizeof(c->header.fsid)); | |
7518a238 | 694 | if (btrfs_is_leaf(lower)) |
234b63a0 | 695 | lower_key = &((struct btrfs_leaf *)lower)->items[0].key; |
5c680ed6 | 696 | else |
123abc88 | 697 | lower_key = &lower->ptrs[0].key; |
d6025579 CM |
698 | btrfs_memcpy(root, c, &c->ptrs[0].key, lower_key, |
699 | sizeof(struct btrfs_disk_key)); | |
7eccb903 | 700 | btrfs_set_node_blockptr(c, 0, bh_blocknr(path->nodes[level - 1])); |
d5719762 | 701 | |
d6025579 | 702 | btrfs_mark_buffer_dirty(t); |
d5719762 | 703 | |
5c680ed6 | 704 | /* the super has an extra ref to root->node */ |
234b63a0 | 705 | btrfs_block_release(root, root->node); |
5c680ed6 | 706 | root->node = t; |
e20d96d6 | 707 | get_bh(t); |
5c680ed6 CM |
708 | path->nodes[level] = t; |
709 | path->slots[level] = 0; | |
710 | return 0; | |
711 | } | |
712 | ||
74123bd7 CM |
713 | /* |
714 | * worker function to insert a single pointer in a node. | |
715 | * the node should have enough room for the pointer already | |
97571fd0 | 716 | * |
74123bd7 CM |
717 | * slot and level indicate where you want the key to go, and |
718 | * blocknr is the block the key points to. | |
aa5d6bed CM |
719 | * |
720 | * returns zero on success and < 0 on any error | |
74123bd7 | 721 | */ |
e089f05c CM |
722 | static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root |
723 | *root, struct btrfs_path *path, struct btrfs_disk_key | |
724 | *key, u64 blocknr, int slot, int level) | |
74123bd7 | 725 | { |
234b63a0 | 726 | struct btrfs_node *lower; |
74123bd7 | 727 | int nritems; |
5c680ed6 CM |
728 | |
729 | BUG_ON(!path->nodes[level]); | |
e20d96d6 | 730 | lower = btrfs_buffer_node(path->nodes[level]); |
7518a238 | 731 | nritems = btrfs_header_nritems(&lower->header); |
74123bd7 CM |
732 | if (slot > nritems) |
733 | BUG(); | |
123abc88 | 734 | if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root)) |
74123bd7 CM |
735 | BUG(); |
736 | if (slot != nritems) { | |
d6025579 CM |
737 | btrfs_memmove(root, lower, lower->ptrs + slot + 1, |
738 | lower->ptrs + slot, | |
739 | (nritems - slot) * sizeof(struct btrfs_key_ptr)); | |
74123bd7 | 740 | } |
d6025579 CM |
741 | btrfs_memcpy(root, lower, &lower->ptrs[slot].key, |
742 | key, sizeof(struct btrfs_disk_key)); | |
1d4f8a0c | 743 | btrfs_set_node_blockptr(lower, slot, blocknr); |
7518a238 | 744 | btrfs_set_header_nritems(&lower->header, nritems + 1); |
d6025579 | 745 | btrfs_mark_buffer_dirty(path->nodes[level]); |
74123bd7 CM |
746 | return 0; |
747 | } | |
748 | ||
97571fd0 CM |
749 | /* |
750 | * split the node at the specified level in path in two. | |
751 | * The path is corrected to point to the appropriate node after the split | |
752 | * | |
753 | * Before splitting this tries to make some room in the node by pushing | |
754 | * left and right, if either one works, it returns right away. | |
aa5d6bed CM |
755 | * |
756 | * returns 0 on success and < 0 on failure | |
97571fd0 | 757 | */ |
e089f05c CM |
758 | static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root |
759 | *root, struct btrfs_path *path, int level) | |
be0e5c09 | 760 | { |
e20d96d6 | 761 | struct buffer_head *t; |
234b63a0 | 762 | struct btrfs_node *c; |
e20d96d6 | 763 | struct buffer_head *split_buffer; |
234b63a0 | 764 | struct btrfs_node *split; |
be0e5c09 | 765 | int mid; |
5c680ed6 | 766 | int ret; |
aa5d6bed | 767 | int wret; |
7518a238 | 768 | u32 c_nritems; |
eb60ceac | 769 | |
5c680ed6 | 770 | t = path->nodes[level]; |
e20d96d6 | 771 | c = btrfs_buffer_node(t); |
5c680ed6 CM |
772 | if (t == root->node) { |
773 | /* trying to split the root, lets make a new one */ | |
e089f05c | 774 | ret = insert_new_root(trans, root, path, level + 1); |
5c680ed6 CM |
775 | if (ret) |
776 | return ret; | |
be0e5c09 | 777 | } |
7518a238 | 778 | c_nritems = btrfs_header_nritems(&c->header); |
e089f05c | 779 | split_buffer = btrfs_alloc_free_block(trans, root); |
e20d96d6 | 780 | split = btrfs_buffer_node(split_buffer); |
7518a238 | 781 | btrfs_set_header_flags(&split->header, btrfs_header_flags(&c->header)); |
9a6f11ed | 782 | btrfs_set_header_level(&split->header, btrfs_header_level(&c->header)); |
7eccb903 | 783 | btrfs_set_header_blocknr(&split->header, bh_blocknr(split_buffer)); |
7f5c1516 | 784 | btrfs_set_header_generation(&split->header, trans->transid); |
3eb0314d CM |
785 | memcpy(split->header.fsid, root->fs_info->disk_super->fsid, |
786 | sizeof(split->header.fsid)); | |
7518a238 | 787 | mid = (c_nritems + 1) / 2; |
d6025579 CM |
788 | btrfs_memcpy(root, split, split->ptrs, c->ptrs + mid, |
789 | (c_nritems - mid) * sizeof(struct btrfs_key_ptr)); | |
7518a238 CM |
790 | btrfs_set_header_nritems(&split->header, c_nritems - mid); |
791 | btrfs_set_header_nritems(&c->header, mid); | |
aa5d6bed CM |
792 | ret = 0; |
793 | ||
d6025579 CM |
794 | btrfs_mark_buffer_dirty(t); |
795 | btrfs_mark_buffer_dirty(split_buffer); | |
e089f05c | 796 | wret = insert_ptr(trans, root, path, &split->ptrs[0].key, |
7eccb903 | 797 | bh_blocknr(split_buffer), path->slots[level + 1] + 1, |
123abc88 | 798 | level + 1); |
aa5d6bed CM |
799 | if (wret) |
800 | ret = wret; | |
801 | ||
5de08d7d | 802 | if (path->slots[level] >= mid) { |
5c680ed6 | 803 | path->slots[level] -= mid; |
234b63a0 | 804 | btrfs_block_release(root, t); |
5c680ed6 CM |
805 | path->nodes[level] = split_buffer; |
806 | path->slots[level + 1] += 1; | |
807 | } else { | |
234b63a0 | 808 | btrfs_block_release(root, split_buffer); |
be0e5c09 | 809 | } |
aa5d6bed | 810 | return ret; |
be0e5c09 CM |
811 | } |
812 | ||
74123bd7 CM |
813 | /* |
814 | * how many bytes are required to store the items in a leaf. start | |
815 | * and nr indicate which items in the leaf to check. This totals up the | |
816 | * space used both by the item structs and the item data | |
817 | */ | |
234b63a0 | 818 | static int leaf_space_used(struct btrfs_leaf *l, int start, int nr) |
be0e5c09 CM |
819 | { |
820 | int data_len; | |
d4dbff95 CM |
821 | int nritems = btrfs_header_nritems(&l->header); |
822 | int end = min(nritems, start + nr) - 1; | |
be0e5c09 CM |
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; | |
d4dbff95 | 829 | WARN_ON(data_len < 0); |
be0e5c09 CM |
830 | return data_len; |
831 | } | |
832 | ||
d4dbff95 CM |
833 | /* |
834 | * The space between the end of the leaf items and | |
835 | * the start of the leaf data. IOW, how much room | |
836 | * the leaf has left for both items and data | |
837 | */ | |
838 | int btrfs_leaf_free_space(struct btrfs_root *root, struct btrfs_leaf *leaf) | |
839 | { | |
840 | int nritems = btrfs_header_nritems(&leaf->header); | |
841 | return BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems); | |
842 | } | |
843 | ||
00ec4c51 CM |
844 | /* |
845 | * push some data in the path leaf to the right, trying to free up at | |
846 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
aa5d6bed CM |
847 | * |
848 | * returns 1 if the push failed because the other node didn't have enough | |
849 | * room, 0 if everything worked out and < 0 if there were major errors. | |
00ec4c51 | 850 | */ |
e089f05c CM |
851 | static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root |
852 | *root, struct btrfs_path *path, int data_size) | |
00ec4c51 | 853 | { |
e20d96d6 CM |
854 | struct buffer_head *left_buf = path->nodes[0]; |
855 | struct btrfs_leaf *left = btrfs_buffer_leaf(left_buf); | |
234b63a0 | 856 | struct btrfs_leaf *right; |
e20d96d6 CM |
857 | struct buffer_head *right_buf; |
858 | struct buffer_head *upper; | |
859 | struct btrfs_node *upper_node; | |
00ec4c51 CM |
860 | int slot; |
861 | int i; | |
862 | int free_space; | |
863 | int push_space = 0; | |
864 | int push_items = 0; | |
0783fcfc | 865 | struct btrfs_item *item; |
7518a238 CM |
866 | u32 left_nritems; |
867 | u32 right_nritems; | |
00ec4c51 CM |
868 | |
869 | slot = path->slots[1]; | |
870 | if (!path->nodes[1]) { | |
871 | return 1; | |
872 | } | |
873 | upper = path->nodes[1]; | |
e20d96d6 CM |
874 | upper_node = btrfs_buffer_node(upper); |
875 | if (slot >= btrfs_header_nritems(&upper_node->header) - 1) { | |
00ec4c51 CM |
876 | return 1; |
877 | } | |
e20d96d6 CM |
878 | right_buf = read_tree_block(root, |
879 | btrfs_node_blockptr(btrfs_buffer_node(upper), slot + 1)); | |
880 | right = btrfs_buffer_leaf(right_buf); | |
123abc88 | 881 | free_space = btrfs_leaf_free_space(root, right); |
0783fcfc | 882 | if (free_space < data_size + sizeof(struct btrfs_item)) { |
234b63a0 | 883 | btrfs_block_release(root, right_buf); |
00ec4c51 CM |
884 | return 1; |
885 | } | |
02217ed2 | 886 | /* cow and double check */ |
e089f05c | 887 | btrfs_cow_block(trans, root, right_buf, upper, slot + 1, &right_buf); |
e20d96d6 | 888 | right = btrfs_buffer_leaf(right_buf); |
123abc88 | 889 | free_space = btrfs_leaf_free_space(root, right); |
0783fcfc | 890 | if (free_space < data_size + sizeof(struct btrfs_item)) { |
234b63a0 | 891 | btrfs_block_release(root, right_buf); |
02217ed2 CM |
892 | return 1; |
893 | } | |
894 | ||
7518a238 CM |
895 | left_nritems = btrfs_header_nritems(&left->header); |
896 | for (i = left_nritems - 1; i >= 0; i--) { | |
00ec4c51 CM |
897 | item = left->items + i; |
898 | if (path->slots[0] == i) | |
899 | push_space += data_size + sizeof(*item); | |
0783fcfc CM |
900 | if (btrfs_item_size(item) + sizeof(*item) + push_space > |
901 | free_space) | |
00ec4c51 CM |
902 | break; |
903 | push_items++; | |
0783fcfc | 904 | push_space += btrfs_item_size(item) + sizeof(*item); |
00ec4c51 CM |
905 | } |
906 | if (push_items == 0) { | |
234b63a0 | 907 | btrfs_block_release(root, right_buf); |
00ec4c51 CM |
908 | return 1; |
909 | } | |
7518a238 | 910 | right_nritems = btrfs_header_nritems(&right->header); |
00ec4c51 | 911 | /* push left to right */ |
0783fcfc | 912 | push_space = btrfs_item_end(left->items + left_nritems - push_items); |
123abc88 | 913 | push_space -= leaf_data_end(root, left); |
00ec4c51 | 914 | /* make room in the right data area */ |
d6025579 CM |
915 | btrfs_memmove(root, right, btrfs_leaf_data(right) + |
916 | leaf_data_end(root, right) - push_space, | |
917 | btrfs_leaf_data(right) + | |
918 | leaf_data_end(root, right), BTRFS_LEAF_DATA_SIZE(root) - | |
919 | leaf_data_end(root, right)); | |
00ec4c51 | 920 | /* copy from the left data area */ |
d6025579 CM |
921 | btrfs_memcpy(root, right, btrfs_leaf_data(right) + |
922 | BTRFS_LEAF_DATA_SIZE(root) - push_space, | |
923 | btrfs_leaf_data(left) + leaf_data_end(root, left), | |
924 | push_space); | |
925 | btrfs_memmove(root, right, right->items + push_items, right->items, | |
0783fcfc | 926 | right_nritems * sizeof(struct btrfs_item)); |
00ec4c51 | 927 | /* copy the items from left to right */ |
d6025579 CM |
928 | btrfs_memcpy(root, right, right->items, left->items + |
929 | left_nritems - push_items, | |
930 | push_items * sizeof(struct btrfs_item)); | |
00ec4c51 CM |
931 | |
932 | /* update the item pointers */ | |
7518a238 CM |
933 | right_nritems += push_items; |
934 | btrfs_set_header_nritems(&right->header, right_nritems); | |
123abc88 | 935 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
7518a238 | 936 | for (i = 0; i < right_nritems; i++) { |
0783fcfc CM |
937 | btrfs_set_item_offset(right->items + i, push_space - |
938 | btrfs_item_size(right->items + i)); | |
939 | push_space = btrfs_item_offset(right->items + i); | |
00ec4c51 | 940 | } |
7518a238 CM |
941 | left_nritems -= push_items; |
942 | btrfs_set_header_nritems(&left->header, left_nritems); | |
00ec4c51 | 943 | |
d6025579 CM |
944 | btrfs_mark_buffer_dirty(left_buf); |
945 | btrfs_mark_buffer_dirty(right_buf); | |
946 | btrfs_memcpy(root, upper_node, &upper_node->ptrs[slot + 1].key, | |
e2fa7227 | 947 | &right->items[0].key, sizeof(struct btrfs_disk_key)); |
d6025579 | 948 | btrfs_mark_buffer_dirty(upper); |
02217ed2 | 949 | |
00ec4c51 | 950 | /* then fixup the leaf pointer in the path */ |
7518a238 CM |
951 | if (path->slots[0] >= left_nritems) { |
952 | path->slots[0] -= left_nritems; | |
234b63a0 | 953 | btrfs_block_release(root, path->nodes[0]); |
00ec4c51 CM |
954 | path->nodes[0] = right_buf; |
955 | path->slots[1] += 1; | |
956 | } else { | |
234b63a0 | 957 | btrfs_block_release(root, right_buf); |
00ec4c51 CM |
958 | } |
959 | return 0; | |
960 | } | |
74123bd7 CM |
961 | /* |
962 | * push some data in the path leaf to the left, trying to free up at | |
963 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
964 | */ | |
e089f05c CM |
965 | static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root |
966 | *root, struct btrfs_path *path, int data_size) | |
be0e5c09 | 967 | { |
e20d96d6 CM |
968 | struct buffer_head *right_buf = path->nodes[0]; |
969 | struct btrfs_leaf *right = btrfs_buffer_leaf(right_buf); | |
970 | struct buffer_head *t; | |
234b63a0 | 971 | struct btrfs_leaf *left; |
be0e5c09 CM |
972 | int slot; |
973 | int i; | |
974 | int free_space; | |
975 | int push_space = 0; | |
976 | int push_items = 0; | |
0783fcfc | 977 | struct btrfs_item *item; |
7518a238 | 978 | u32 old_left_nritems; |
aa5d6bed CM |
979 | int ret = 0; |
980 | int wret; | |
be0e5c09 CM |
981 | |
982 | slot = path->slots[1]; | |
983 | if (slot == 0) { | |
984 | return 1; | |
985 | } | |
986 | if (!path->nodes[1]) { | |
987 | return 1; | |
988 | } | |
e20d96d6 CM |
989 | t = read_tree_block(root, |
990 | btrfs_node_blockptr(btrfs_buffer_node(path->nodes[1]), slot - 1)); | |
991 | left = btrfs_buffer_leaf(t); | |
123abc88 | 992 | free_space = btrfs_leaf_free_space(root, left); |
0783fcfc | 993 | if (free_space < data_size + sizeof(struct btrfs_item)) { |
234b63a0 | 994 | btrfs_block_release(root, t); |
be0e5c09 CM |
995 | return 1; |
996 | } | |
02217ed2 CM |
997 | |
998 | /* cow and double check */ | |
e089f05c | 999 | btrfs_cow_block(trans, root, t, path->nodes[1], slot - 1, &t); |
e20d96d6 | 1000 | left = btrfs_buffer_leaf(t); |
123abc88 | 1001 | free_space = btrfs_leaf_free_space(root, left); |
0783fcfc | 1002 | if (free_space < data_size + sizeof(struct btrfs_item)) { |
234b63a0 | 1003 | btrfs_block_release(root, t); |
02217ed2 CM |
1004 | return 1; |
1005 | } | |
1006 | ||
7518a238 | 1007 | for (i = 0; i < btrfs_header_nritems(&right->header); i++) { |
be0e5c09 CM |
1008 | item = right->items + i; |
1009 | if (path->slots[0] == i) | |
1010 | push_space += data_size + sizeof(*item); | |
0783fcfc CM |
1011 | if (btrfs_item_size(item) + sizeof(*item) + push_space > |
1012 | free_space) | |
be0e5c09 CM |
1013 | break; |
1014 | push_items++; | |
0783fcfc | 1015 | push_space += btrfs_item_size(item) + sizeof(*item); |
be0e5c09 CM |
1016 | } |
1017 | if (push_items == 0) { | |
234b63a0 | 1018 | btrfs_block_release(root, t); |
be0e5c09 CM |
1019 | return 1; |
1020 | } | |
1021 | /* push data from right to left */ | |
d6025579 CM |
1022 | btrfs_memcpy(root, left, left->items + |
1023 | btrfs_header_nritems(&left->header), | |
1024 | right->items, push_items * sizeof(struct btrfs_item)); | |
123abc88 | 1025 | push_space = BTRFS_LEAF_DATA_SIZE(root) - |
0783fcfc | 1026 | btrfs_item_offset(right->items + push_items -1); |
d6025579 CM |
1027 | btrfs_memcpy(root, left, btrfs_leaf_data(left) + |
1028 | leaf_data_end(root, left) - push_space, | |
1029 | btrfs_leaf_data(right) + | |
1030 | btrfs_item_offset(right->items + push_items - 1), | |
1031 | push_space); | |
7518a238 | 1032 | old_left_nritems = btrfs_header_nritems(&left->header); |
eb60ceac CM |
1033 | BUG_ON(old_left_nritems < 0); |
1034 | ||
0783fcfc | 1035 | for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { |
123abc88 CM |
1036 | u32 ioff = btrfs_item_offset(left->items + i); |
1037 | btrfs_set_item_offset(left->items + i, ioff - | |
1038 | (BTRFS_LEAF_DATA_SIZE(root) - | |
0783fcfc CM |
1039 | btrfs_item_offset(left->items + |
1040 | old_left_nritems - 1))); | |
be0e5c09 | 1041 | } |
7518a238 | 1042 | btrfs_set_header_nritems(&left->header, old_left_nritems + push_items); |
be0e5c09 CM |
1043 | |
1044 | /* fixup right node */ | |
0783fcfc | 1045 | push_space = btrfs_item_offset(right->items + push_items - 1) - |
123abc88 | 1046 | leaf_data_end(root, right); |
d6025579 CM |
1047 | btrfs_memmove(root, right, btrfs_leaf_data(right) + |
1048 | BTRFS_LEAF_DATA_SIZE(root) - push_space, | |
1049 | btrfs_leaf_data(right) + | |
1050 | leaf_data_end(root, right), push_space); | |
1051 | btrfs_memmove(root, right, right->items, right->items + push_items, | |
7518a238 | 1052 | (btrfs_header_nritems(&right->header) - push_items) * |
0783fcfc | 1053 | sizeof(struct btrfs_item)); |
7518a238 CM |
1054 | btrfs_set_header_nritems(&right->header, |
1055 | btrfs_header_nritems(&right->header) - | |
1056 | push_items); | |
123abc88 | 1057 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
eb60ceac | 1058 | |
7518a238 | 1059 | for (i = 0; i < btrfs_header_nritems(&right->header); i++) { |
0783fcfc CM |
1060 | btrfs_set_item_offset(right->items + i, push_space - |
1061 | btrfs_item_size(right->items + i)); | |
1062 | push_space = btrfs_item_offset(right->items + i); | |
be0e5c09 | 1063 | } |
eb60ceac | 1064 | |
d6025579 CM |
1065 | btrfs_mark_buffer_dirty(t); |
1066 | btrfs_mark_buffer_dirty(right_buf); | |
eb60ceac | 1067 | |
e089f05c | 1068 | wret = fixup_low_keys(trans, root, path, &right->items[0].key, 1); |
aa5d6bed CM |
1069 | if (wret) |
1070 | ret = wret; | |
be0e5c09 CM |
1071 | |
1072 | /* then fixup the leaf pointer in the path */ | |
1073 | if (path->slots[0] < push_items) { | |
1074 | path->slots[0] += old_left_nritems; | |
234b63a0 | 1075 | btrfs_block_release(root, path->nodes[0]); |
eb60ceac | 1076 | path->nodes[0] = t; |
be0e5c09 CM |
1077 | path->slots[1] -= 1; |
1078 | } else { | |
234b63a0 | 1079 | btrfs_block_release(root, t); |
be0e5c09 CM |
1080 | path->slots[0] -= push_items; |
1081 | } | |
eb60ceac | 1082 | BUG_ON(path->slots[0] < 0); |
aa5d6bed | 1083 | return ret; |
be0e5c09 CM |
1084 | } |
1085 | ||
74123bd7 CM |
1086 | /* |
1087 | * split the path's leaf in two, making sure there is at least data_size | |
1088 | * available for the resulting leaf level of the path. | |
aa5d6bed CM |
1089 | * |
1090 | * returns 0 if all went well and < 0 on failure. | |
74123bd7 | 1091 | */ |
e089f05c | 1092 | static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root |
d4dbff95 CM |
1093 | *root, struct btrfs_key *ins_key, |
1094 | struct btrfs_path *path, int data_size) | |
be0e5c09 | 1095 | { |
e20d96d6 | 1096 | struct buffer_head *l_buf; |
234b63a0 | 1097 | struct btrfs_leaf *l; |
7518a238 | 1098 | u32 nritems; |
eb60ceac CM |
1099 | int mid; |
1100 | int slot; | |
234b63a0 | 1101 | struct btrfs_leaf *right; |
e20d96d6 | 1102 | struct buffer_head *right_buffer; |
0783fcfc | 1103 | int space_needed = data_size + sizeof(struct btrfs_item); |
be0e5c09 CM |
1104 | int data_copy_size; |
1105 | int rt_data_off; | |
1106 | int i; | |
d4dbff95 | 1107 | int ret = 0; |
aa5d6bed | 1108 | int wret; |
d4dbff95 CM |
1109 | int double_split = 0; |
1110 | struct btrfs_disk_key disk_key; | |
aa5d6bed | 1111 | |
40689478 | 1112 | /* first try to make some room by pushing left and right */ |
e089f05c | 1113 | wret = push_leaf_left(trans, root, path, data_size); |
eaee50e8 CM |
1114 | if (wret < 0) |
1115 | return wret; | |
1116 | if (wret) { | |
e089f05c | 1117 | wret = push_leaf_right(trans, root, path, data_size); |
eaee50e8 CM |
1118 | if (wret < 0) |
1119 | return wret; | |
1120 | } | |
aa5d6bed | 1121 | l_buf = path->nodes[0]; |
e20d96d6 | 1122 | l = btrfs_buffer_leaf(l_buf); |
aa5d6bed CM |
1123 | |
1124 | /* did the pushes work? */ | |
123abc88 CM |
1125 | if (btrfs_leaf_free_space(root, l) >= |
1126 | sizeof(struct btrfs_item) + data_size) | |
aa5d6bed CM |
1127 | return 0; |
1128 | ||
5c680ed6 | 1129 | if (!path->nodes[1]) { |
e089f05c | 1130 | ret = insert_new_root(trans, root, path, 1); |
5c680ed6 CM |
1131 | if (ret) |
1132 | return ret; | |
1133 | } | |
eb60ceac | 1134 | slot = path->slots[0]; |
7518a238 | 1135 | nritems = btrfs_header_nritems(&l->header); |
eb60ceac | 1136 | mid = (nritems + 1)/ 2; |
e089f05c | 1137 | right_buffer = btrfs_alloc_free_block(trans, root); |
eb60ceac | 1138 | BUG_ON(!right_buffer); |
e20d96d6 | 1139 | right = btrfs_buffer_leaf(right_buffer); |
123abc88 | 1140 | memset(&right->header, 0, sizeof(right->header)); |
7eccb903 | 1141 | btrfs_set_header_blocknr(&right->header, bh_blocknr(right_buffer)); |
7f5c1516 | 1142 | btrfs_set_header_generation(&right->header, trans->transid); |
7518a238 | 1143 | btrfs_set_header_level(&right->header, 0); |
3eb0314d CM |
1144 | memcpy(right->header.fsid, root->fs_info->disk_super->fsid, |
1145 | sizeof(right->header.fsid)); | |
d4dbff95 CM |
1146 | if (mid <= slot) { |
1147 | if (nritems == 1 || | |
1148 | leaf_space_used(l, mid, nritems - mid) + space_needed > | |
1149 | BTRFS_LEAF_DATA_SIZE(root)) { | |
1150 | if (slot >= nritems) { | |
1151 | btrfs_cpu_key_to_disk(&disk_key, ins_key); | |
1152 | btrfs_set_header_nritems(&right->header, 0); | |
1153 | wret = insert_ptr(trans, root, path, | |
1154 | &disk_key, | |
7eccb903 | 1155 | bh_blocknr(right_buffer), |
d4dbff95 CM |
1156 | path->slots[1] + 1, 1); |
1157 | if (wret) | |
1158 | ret = wret; | |
1159 | btrfs_block_release(root, path->nodes[0]); | |
1160 | path->nodes[0] = right_buffer; | |
1161 | path->slots[0] = 0; | |
1162 | path->slots[1] += 1; | |
1163 | return ret; | |
1164 | } | |
1165 | mid = slot; | |
1166 | double_split = 1; | |
1167 | } | |
1168 | } else { | |
1169 | if (leaf_space_used(l, 0, mid + 1) + space_needed > | |
1170 | BTRFS_LEAF_DATA_SIZE(root)) { | |
1171 | if (slot == 0) { | |
1172 | btrfs_cpu_key_to_disk(&disk_key, ins_key); | |
1173 | btrfs_set_header_nritems(&right->header, 0); | |
1174 | wret = insert_ptr(trans, root, path, | |
1175 | &disk_key, | |
7eccb903 | 1176 | bh_blocknr(right_buffer), |
d4dbff95 CM |
1177 | path->slots[1] - 1, 1); |
1178 | if (wret) | |
1179 | ret = wret; | |
1180 | btrfs_block_release(root, path->nodes[0]); | |
1181 | path->nodes[0] = right_buffer; | |
1182 | path->slots[0] = 0; | |
1183 | path->slots[1] -= 1; | |
1184 | return ret; | |
1185 | } | |
1186 | mid = slot; | |
1187 | double_split = 1; | |
1188 | } | |
1189 | } | |
1190 | btrfs_set_header_nritems(&right->header, nritems - mid); | |
123abc88 CM |
1191 | data_copy_size = btrfs_item_end(l->items + mid) - |
1192 | leaf_data_end(root, l); | |
d6025579 CM |
1193 | btrfs_memcpy(root, right, right->items, l->items + mid, |
1194 | (nritems - mid) * sizeof(struct btrfs_item)); | |
1195 | btrfs_memcpy(root, right, | |
1196 | btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) - | |
1197 | data_copy_size, btrfs_leaf_data(l) + | |
1198 | leaf_data_end(root, l), data_copy_size); | |
123abc88 CM |
1199 | rt_data_off = BTRFS_LEAF_DATA_SIZE(root) - |
1200 | btrfs_item_end(l->items + mid); | |
74123bd7 | 1201 | |
0783fcfc | 1202 | for (i = 0; i < btrfs_header_nritems(&right->header); i++) { |
123abc88 | 1203 | u32 ioff = btrfs_item_offset(right->items + i); |
0783fcfc CM |
1204 | btrfs_set_item_offset(right->items + i, ioff + rt_data_off); |
1205 | } | |
74123bd7 | 1206 | |
7518a238 | 1207 | btrfs_set_header_nritems(&l->header, mid); |
aa5d6bed | 1208 | ret = 0; |
e089f05c | 1209 | wret = insert_ptr(trans, root, path, &right->items[0].key, |
7eccb903 | 1210 | bh_blocknr(right_buffer), path->slots[1] + 1, 1); |
aa5d6bed CM |
1211 | if (wret) |
1212 | ret = wret; | |
d6025579 CM |
1213 | btrfs_mark_buffer_dirty(right_buffer); |
1214 | btrfs_mark_buffer_dirty(l_buf); | |
eb60ceac | 1215 | BUG_ON(path->slots[0] != slot); |
be0e5c09 | 1216 | if (mid <= slot) { |
234b63a0 | 1217 | btrfs_block_release(root, path->nodes[0]); |
eb60ceac | 1218 | path->nodes[0] = right_buffer; |
be0e5c09 CM |
1219 | path->slots[0] -= mid; |
1220 | path->slots[1] += 1; | |
eb60ceac | 1221 | } else |
234b63a0 | 1222 | btrfs_block_release(root, right_buffer); |
eb60ceac | 1223 | BUG_ON(path->slots[0] < 0); |
d4dbff95 CM |
1224 | |
1225 | if (!double_split) | |
1226 | return ret; | |
1227 | right_buffer = btrfs_alloc_free_block(trans, root); | |
1228 | BUG_ON(!right_buffer); | |
1229 | right = btrfs_buffer_leaf(right_buffer); | |
1230 | memset(&right->header, 0, sizeof(right->header)); | |
7eccb903 | 1231 | btrfs_set_header_blocknr(&right->header, bh_blocknr(right_buffer)); |
d4dbff95 CM |
1232 | btrfs_set_header_generation(&right->header, trans->transid); |
1233 | btrfs_set_header_level(&right->header, 0); | |
3eb0314d CM |
1234 | memcpy(right->header.fsid, root->fs_info->disk_super->fsid, |
1235 | sizeof(right->header.fsid)); | |
d4dbff95 CM |
1236 | btrfs_cpu_key_to_disk(&disk_key, ins_key); |
1237 | btrfs_set_header_nritems(&right->header, 0); | |
1238 | wret = insert_ptr(trans, root, path, | |
1239 | &disk_key, | |
7eccb903 | 1240 | bh_blocknr(right_buffer), |
d4dbff95 CM |
1241 | path->slots[1], 1); |
1242 | if (wret) | |
1243 | ret = wret; | |
1244 | btrfs_block_release(root, path->nodes[0]); | |
1245 | path->nodes[0] = right_buffer; | |
1246 | path->slots[0] = 0; | |
1247 | check_node(root, path, 1); | |
1248 | check_leaf(root, path, 0); | |
be0e5c09 CM |
1249 | return ret; |
1250 | } | |
1251 | ||
74123bd7 CM |
1252 | /* |
1253 | * Given a key and some data, insert an item into the tree. | |
1254 | * This does all the path init required, making room in the tree if needed. | |
1255 | */ | |
e089f05c CM |
1256 | int btrfs_insert_empty_item(struct btrfs_trans_handle *trans, struct btrfs_root |
1257 | *root, struct btrfs_path *path, struct btrfs_key | |
1258 | *cpu_key, u32 data_size) | |
be0e5c09 | 1259 | { |
aa5d6bed | 1260 | int ret = 0; |
be0e5c09 | 1261 | int slot; |
eb60ceac | 1262 | int slot_orig; |
234b63a0 | 1263 | struct btrfs_leaf *leaf; |
e20d96d6 | 1264 | struct buffer_head *leaf_buf; |
7518a238 | 1265 | u32 nritems; |
be0e5c09 | 1266 | unsigned int data_end; |
e2fa7227 CM |
1267 | struct btrfs_disk_key disk_key; |
1268 | ||
1269 | btrfs_cpu_key_to_disk(&disk_key, cpu_key); | |
be0e5c09 | 1270 | |
74123bd7 | 1271 | /* create a root if there isn't one */ |
5c680ed6 | 1272 | if (!root->node) |
cfaa7295 | 1273 | BUG(); |
e089f05c | 1274 | ret = btrfs_search_slot(trans, root, cpu_key, path, data_size, 1); |
eb60ceac | 1275 | if (ret == 0) { |
f0930a37 | 1276 | return -EEXIST; |
aa5d6bed | 1277 | } |
ed2ff2cb CM |
1278 | if (ret < 0) |
1279 | goto out; | |
be0e5c09 | 1280 | |
62e2749e CM |
1281 | slot_orig = path->slots[0]; |
1282 | leaf_buf = path->nodes[0]; | |
e20d96d6 | 1283 | leaf = btrfs_buffer_leaf(leaf_buf); |
74123bd7 | 1284 | |
7518a238 | 1285 | nritems = btrfs_header_nritems(&leaf->header); |
123abc88 | 1286 | data_end = leaf_data_end(root, leaf); |
eb60ceac | 1287 | |
123abc88 | 1288 | if (btrfs_leaf_free_space(root, leaf) < |
d4dbff95 | 1289 | sizeof(struct btrfs_item) + data_size) { |
be0e5c09 | 1290 | BUG(); |
d4dbff95 | 1291 | } |
62e2749e | 1292 | slot = path->slots[0]; |
eb60ceac | 1293 | BUG_ON(slot < 0); |
be0e5c09 CM |
1294 | if (slot != nritems) { |
1295 | int i; | |
0783fcfc | 1296 | unsigned int old_data = btrfs_item_end(leaf->items + slot); |
be0e5c09 CM |
1297 | |
1298 | /* | |
1299 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
1300 | */ | |
1301 | /* first correct the data pointers */ | |
0783fcfc | 1302 | for (i = slot; i < nritems; i++) { |
123abc88 | 1303 | u32 ioff = btrfs_item_offset(leaf->items + i); |
0783fcfc CM |
1304 | btrfs_set_item_offset(leaf->items + i, |
1305 | ioff - data_size); | |
1306 | } | |
be0e5c09 CM |
1307 | |
1308 | /* shift the items */ | |
d6025579 CM |
1309 | btrfs_memmove(root, leaf, leaf->items + slot + 1, |
1310 | leaf->items + slot, | |
1311 | (nritems - slot) * sizeof(struct btrfs_item)); | |
be0e5c09 CM |
1312 | |
1313 | /* shift the data */ | |
d6025579 CM |
1314 | btrfs_memmove(root, leaf, btrfs_leaf_data(leaf) + |
1315 | data_end - data_size, btrfs_leaf_data(leaf) + | |
1316 | data_end, old_data - data_end); | |
be0e5c09 CM |
1317 | data_end = old_data; |
1318 | } | |
62e2749e | 1319 | /* setup the item for the new data */ |
d6025579 CM |
1320 | btrfs_memcpy(root, leaf, &leaf->items[slot].key, &disk_key, |
1321 | sizeof(struct btrfs_disk_key)); | |
0783fcfc CM |
1322 | btrfs_set_item_offset(leaf->items + slot, data_end - data_size); |
1323 | btrfs_set_item_size(leaf->items + slot, data_size); | |
7518a238 | 1324 | btrfs_set_header_nritems(&leaf->header, nritems + 1); |
d6025579 | 1325 | btrfs_mark_buffer_dirty(leaf_buf); |
aa5d6bed CM |
1326 | |
1327 | ret = 0; | |
8e19f2cd | 1328 | if (slot == 0) |
e089f05c | 1329 | ret = fixup_low_keys(trans, root, path, &disk_key, 1); |
aa5d6bed | 1330 | |
123abc88 | 1331 | if (btrfs_leaf_free_space(root, leaf) < 0) |
be0e5c09 | 1332 | BUG(); |
62e2749e | 1333 | check_leaf(root, path, 0); |
ed2ff2cb | 1334 | out: |
62e2749e CM |
1335 | return ret; |
1336 | } | |
1337 | ||
1338 | /* | |
1339 | * Given a key and some data, insert an item into the tree. | |
1340 | * This does all the path init required, making room in the tree if needed. | |
1341 | */ | |
e089f05c CM |
1342 | int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root |
1343 | *root, struct btrfs_key *cpu_key, void *data, u32 | |
1344 | data_size) | |
62e2749e CM |
1345 | { |
1346 | int ret = 0; | |
2c90e5d6 | 1347 | struct btrfs_path *path; |
62e2749e CM |
1348 | u8 *ptr; |
1349 | ||
2c90e5d6 CM |
1350 | path = btrfs_alloc_path(); |
1351 | BUG_ON(!path); | |
1352 | btrfs_init_path(path); | |
1353 | ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size); | |
62e2749e | 1354 | if (!ret) { |
2c90e5d6 CM |
1355 | ptr = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), |
1356 | path->slots[0], u8); | |
1357 | btrfs_memcpy(root, path->nodes[0]->b_data, | |
d6025579 | 1358 | ptr, data, data_size); |
2c90e5d6 | 1359 | btrfs_mark_buffer_dirty(path->nodes[0]); |
62e2749e | 1360 | } |
2c90e5d6 CM |
1361 | btrfs_release_path(root, path); |
1362 | btrfs_free_path(path); | |
aa5d6bed | 1363 | return ret; |
be0e5c09 CM |
1364 | } |
1365 | ||
74123bd7 | 1366 | /* |
5de08d7d | 1367 | * delete the pointer from a given node. |
74123bd7 CM |
1368 | * |
1369 | * If the delete empties a node, the node is removed from the tree, | |
1370 | * continuing all the way the root if required. The root is converted into | |
1371 | * a leaf if all the nodes are emptied. | |
1372 | */ | |
e089f05c CM |
1373 | static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
1374 | struct btrfs_path *path, int level, int slot) | |
be0e5c09 | 1375 | { |
234b63a0 | 1376 | struct btrfs_node *node; |
e20d96d6 | 1377 | struct buffer_head *parent = path->nodes[level]; |
7518a238 | 1378 | u32 nritems; |
aa5d6bed | 1379 | int ret = 0; |
bb803951 | 1380 | int wret; |
be0e5c09 | 1381 | |
e20d96d6 | 1382 | node = btrfs_buffer_node(parent); |
7518a238 | 1383 | nritems = btrfs_header_nritems(&node->header); |
bb803951 | 1384 | if (slot != nritems -1) { |
d6025579 CM |
1385 | btrfs_memmove(root, node, node->ptrs + slot, |
1386 | node->ptrs + slot + 1, | |
1387 | sizeof(struct btrfs_key_ptr) * | |
1388 | (nritems - slot - 1)); | |
bb803951 | 1389 | } |
7518a238 CM |
1390 | nritems--; |
1391 | btrfs_set_header_nritems(&node->header, nritems); | |
1392 | if (nritems == 0 && parent == root->node) { | |
e20d96d6 CM |
1393 | struct btrfs_header *header = btrfs_buffer_header(root->node); |
1394 | BUG_ON(btrfs_header_level(header) != 1); | |
bb803951 | 1395 | /* just turn the root into a leaf and break */ |
e20d96d6 | 1396 | btrfs_set_header_level(header, 0); |
bb803951 | 1397 | } else if (slot == 0) { |
e089f05c | 1398 | wret = fixup_low_keys(trans, root, path, &node->ptrs[0].key, |
123abc88 | 1399 | level + 1); |
0f70abe2 CM |
1400 | if (wret) |
1401 | ret = wret; | |
be0e5c09 | 1402 | } |
d6025579 | 1403 | btrfs_mark_buffer_dirty(parent); |
aa5d6bed | 1404 | return ret; |
be0e5c09 CM |
1405 | } |
1406 | ||
74123bd7 CM |
1407 | /* |
1408 | * delete the item at the leaf level in path. If that empties | |
1409 | * the leaf, remove it from the tree | |
1410 | */ | |
e089f05c CM |
1411 | int btrfs_del_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
1412 | struct btrfs_path *path) | |
be0e5c09 | 1413 | { |
be0e5c09 | 1414 | int slot; |
234b63a0 | 1415 | struct btrfs_leaf *leaf; |
e20d96d6 | 1416 | struct buffer_head *leaf_buf; |
be0e5c09 CM |
1417 | int doff; |
1418 | int dsize; | |
aa5d6bed CM |
1419 | int ret = 0; |
1420 | int wret; | |
7518a238 | 1421 | u32 nritems; |
be0e5c09 | 1422 | |
eb60ceac | 1423 | leaf_buf = path->nodes[0]; |
e20d96d6 | 1424 | leaf = btrfs_buffer_leaf(leaf_buf); |
4920c9ac | 1425 | slot = path->slots[0]; |
0783fcfc CM |
1426 | doff = btrfs_item_offset(leaf->items + slot); |
1427 | dsize = btrfs_item_size(leaf->items + slot); | |
7518a238 | 1428 | nritems = btrfs_header_nritems(&leaf->header); |
be0e5c09 | 1429 | |
7518a238 | 1430 | if (slot != nritems - 1) { |
be0e5c09 | 1431 | int i; |
123abc88 | 1432 | int data_end = leaf_data_end(root, leaf); |
d6025579 CM |
1433 | btrfs_memmove(root, leaf, btrfs_leaf_data(leaf) + |
1434 | data_end + dsize, | |
1435 | btrfs_leaf_data(leaf) + data_end, | |
1436 | doff - data_end); | |
0783fcfc | 1437 | for (i = slot + 1; i < nritems; i++) { |
123abc88 | 1438 | u32 ioff = btrfs_item_offset(leaf->items + i); |
0783fcfc CM |
1439 | btrfs_set_item_offset(leaf->items + i, ioff + dsize); |
1440 | } | |
d6025579 CM |
1441 | btrfs_memmove(root, leaf, leaf->items + slot, |
1442 | leaf->items + slot + 1, | |
1443 | sizeof(struct btrfs_item) * | |
1444 | (nritems - slot - 1)); | |
be0e5c09 | 1445 | } |
7518a238 CM |
1446 | btrfs_set_header_nritems(&leaf->header, nritems - 1); |
1447 | nritems--; | |
74123bd7 | 1448 | /* delete the leaf if we've emptied it */ |
7518a238 | 1449 | if (nritems == 0) { |
eb60ceac | 1450 | if (leaf_buf == root->node) { |
7518a238 | 1451 | btrfs_set_header_level(&leaf->header, 0); |
9a8dd150 | 1452 | } else { |
e089f05c | 1453 | clean_tree_block(trans, root, leaf_buf); |
d6025579 | 1454 | wait_on_buffer(leaf_buf); |
e089f05c | 1455 | wret = del_ptr(trans, root, path, 1, path->slots[1]); |
aa5d6bed CM |
1456 | if (wret) |
1457 | ret = wret; | |
e089f05c | 1458 | wret = btrfs_free_extent(trans, root, |
7eccb903 | 1459 | bh_blocknr(leaf_buf), 1, 1); |
0f70abe2 CM |
1460 | if (wret) |
1461 | ret = wret; | |
9a8dd150 | 1462 | } |
be0e5c09 | 1463 | } else { |
7518a238 | 1464 | int used = leaf_space_used(leaf, 0, nritems); |
aa5d6bed | 1465 | if (slot == 0) { |
e089f05c CM |
1466 | wret = fixup_low_keys(trans, root, path, |
1467 | &leaf->items[0].key, 1); | |
aa5d6bed CM |
1468 | if (wret) |
1469 | ret = wret; | |
1470 | } | |
aa5d6bed | 1471 | |
74123bd7 | 1472 | /* delete the leaf if it is mostly empty */ |
123abc88 | 1473 | if (used < BTRFS_LEAF_DATA_SIZE(root) / 3) { |
be0e5c09 CM |
1474 | /* push_leaf_left fixes the path. |
1475 | * make sure the path still points to our leaf | |
1476 | * for possible call to del_ptr below | |
1477 | */ | |
4920c9ac | 1478 | slot = path->slots[1]; |
e20d96d6 | 1479 | get_bh(leaf_buf); |
e089f05c | 1480 | wret = push_leaf_left(trans, root, path, 1); |
aa5d6bed CM |
1481 | if (wret < 0) |
1482 | ret = wret; | |
f0930a37 | 1483 | if (path->nodes[0] == leaf_buf && |
7518a238 | 1484 | btrfs_header_nritems(&leaf->header)) { |
e089f05c | 1485 | wret = push_leaf_right(trans, root, path, 1); |
aa5d6bed CM |
1486 | if (wret < 0) |
1487 | ret = wret; | |
1488 | } | |
7518a238 | 1489 | if (btrfs_header_nritems(&leaf->header) == 0) { |
7eccb903 | 1490 | u64 blocknr = bh_blocknr(leaf_buf); |
e089f05c | 1491 | clean_tree_block(trans, root, leaf_buf); |
d6025579 | 1492 | wait_on_buffer(leaf_buf); |
e089f05c | 1493 | wret = del_ptr(trans, root, path, 1, slot); |
aa5d6bed CM |
1494 | if (wret) |
1495 | ret = wret; | |
234b63a0 | 1496 | btrfs_block_release(root, leaf_buf); |
e089f05c CM |
1497 | wret = btrfs_free_extent(trans, root, blocknr, |
1498 | 1, 1); | |
0f70abe2 CM |
1499 | if (wret) |
1500 | ret = wret; | |
5de08d7d | 1501 | } else { |
d6025579 | 1502 | btrfs_mark_buffer_dirty(leaf_buf); |
234b63a0 | 1503 | btrfs_block_release(root, leaf_buf); |
be0e5c09 | 1504 | } |
d5719762 | 1505 | } else { |
d6025579 | 1506 | btrfs_mark_buffer_dirty(leaf_buf); |
be0e5c09 CM |
1507 | } |
1508 | } | |
aa5d6bed | 1509 | return ret; |
be0e5c09 CM |
1510 | } |
1511 | ||
97571fd0 CM |
1512 | /* |
1513 | * walk up the tree as far as required to find the next leaf. | |
0f70abe2 CM |
1514 | * returns 0 if it found something or 1 if there are no greater leaves. |
1515 | * returns < 0 on io errors. | |
97571fd0 | 1516 | */ |
234b63a0 | 1517 | int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) |
d97e63b6 CM |
1518 | { |
1519 | int slot; | |
1520 | int level = 1; | |
1521 | u64 blocknr; | |
e20d96d6 CM |
1522 | struct buffer_head *c; |
1523 | struct btrfs_node *c_node; | |
1524 | struct buffer_head *next = NULL; | |
d97e63b6 | 1525 | |
234b63a0 | 1526 | while(level < BTRFS_MAX_LEVEL) { |
d97e63b6 | 1527 | if (!path->nodes[level]) |
0f70abe2 | 1528 | return 1; |
d97e63b6 CM |
1529 | slot = path->slots[level] + 1; |
1530 | c = path->nodes[level]; | |
e20d96d6 CM |
1531 | c_node = btrfs_buffer_node(c); |
1532 | if (slot >= btrfs_header_nritems(&c_node->header)) { | |
d97e63b6 CM |
1533 | level++; |
1534 | continue; | |
1535 | } | |
e20d96d6 | 1536 | blocknr = btrfs_node_blockptr(c_node, slot); |
cfaa7295 | 1537 | if (next) |
234b63a0 | 1538 | btrfs_block_release(root, next); |
d97e63b6 CM |
1539 | next = read_tree_block(root, blocknr); |
1540 | break; | |
1541 | } | |
1542 | path->slots[level] = slot; | |
1543 | while(1) { | |
1544 | level--; | |
1545 | c = path->nodes[level]; | |
234b63a0 | 1546 | btrfs_block_release(root, c); |
d97e63b6 CM |
1547 | path->nodes[level] = next; |
1548 | path->slots[level] = 0; | |
1549 | if (!level) | |
1550 | break; | |
1d4f8a0c | 1551 | next = read_tree_block(root, |
e20d96d6 | 1552 | btrfs_node_blockptr(btrfs_buffer_node(next), 0)); |
d97e63b6 CM |
1553 | } |
1554 | return 0; | |
1555 | } |