Commit | Line | Data |
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fec577fb CM |
1 | #include <stdio.h> |
2 | #include <stdlib.h> | |
3 | #include "kerncompat.h" | |
4 | #include "radix-tree.h" | |
5 | #include "ctree.h" | |
6 | #include "disk-io.h" | |
7 | #include "print-tree.h" | |
8 | ||
234b63a0 | 9 | static int find_free_extent(struct btrfs_root *orig_root, u64 num_blocks, |
e2fa7227 CM |
10 | u64 search_start, u64 search_end, |
11 | struct btrfs_key *ins); | |
234b63a0 CM |
12 | static int finish_current_insert(struct btrfs_root *extent_root); |
13 | static int run_pending(struct btrfs_root *extent_root); | |
037e6390 | 14 | |
fec577fb CM |
15 | /* |
16 | * pending extents are blocks that we're trying to allocate in the extent | |
17 | * map while trying to grow the map because of other allocations. To avoid | |
18 | * recursing, they are tagged in the radix tree and cleaned up after | |
19 | * other allocations are done. The pending tag is also used in the same | |
20 | * manner for deletes. | |
21 | */ | |
037e6390 | 22 | #define CTREE_EXTENT_PENDING_DEL 0 |
fec577fb | 23 | |
234b63a0 | 24 | static int inc_block_ref(struct btrfs_root *root, u64 blocknr) |
02217ed2 | 25 | { |
234b63a0 | 26 | struct btrfs_path path; |
02217ed2 | 27 | int ret; |
e2fa7227 | 28 | struct btrfs_key key; |
234b63a0 CM |
29 | struct btrfs_leaf *l; |
30 | struct btrfs_extent_item *item; | |
e2fa7227 | 31 | struct btrfs_key ins; |
cf27e1ee | 32 | u32 refs; |
037e6390 CM |
33 | |
34 | find_free_extent(root->extent_root, 0, 0, (u64)-1, &ins); | |
234b63a0 | 35 | btrfs_init_path(&path); |
02217ed2 CM |
36 | key.objectid = blocknr; |
37 | key.flags = 0; | |
38 | key.offset = 1; | |
234b63a0 | 39 | ret = btrfs_search_slot(root->extent_root, &key, &path, 0, 1); |
a28ec197 CM |
40 | if (ret != 0) |
41 | BUG(); | |
02217ed2 CM |
42 | BUG_ON(ret != 0); |
43 | l = &path.nodes[0]->leaf; | |
4beb1b8b | 44 | item = btrfs_item_ptr(l, path.slots[0], struct btrfs_extent_item); |
cf27e1ee CM |
45 | refs = btrfs_extent_refs(item); |
46 | btrfs_set_extent_refs(item, refs + 1); | |
a28ec197 | 47 | |
02217ed2 | 48 | BUG_ON(list_empty(&path.nodes[0]->dirty)); |
234b63a0 | 49 | btrfs_release_path(root->extent_root, &path); |
037e6390 CM |
50 | finish_current_insert(root->extent_root); |
51 | run_pending(root->extent_root); | |
02217ed2 CM |
52 | return 0; |
53 | } | |
54 | ||
234b63a0 | 55 | static int lookup_block_ref(struct btrfs_root *root, u64 blocknr, u32 *refs) |
a28ec197 | 56 | { |
234b63a0 | 57 | struct btrfs_path path; |
a28ec197 | 58 | int ret; |
e2fa7227 | 59 | struct btrfs_key key; |
234b63a0 CM |
60 | struct btrfs_leaf *l; |
61 | struct btrfs_extent_item *item; | |
62 | btrfs_init_path(&path); | |
a28ec197 CM |
63 | key.objectid = blocknr; |
64 | key.flags = 0; | |
65 | key.offset = 1; | |
234b63a0 | 66 | ret = btrfs_search_slot(root->extent_root, &key, &path, 0, 0); |
a28ec197 CM |
67 | if (ret != 0) |
68 | BUG(); | |
69 | l = &path.nodes[0]->leaf; | |
4beb1b8b | 70 | item = btrfs_item_ptr(l, path.slots[0], struct btrfs_extent_item); |
cf27e1ee | 71 | *refs = btrfs_extent_refs(item); |
234b63a0 | 72 | btrfs_release_path(root->extent_root, &path); |
a28ec197 CM |
73 | return 0; |
74 | } | |
75 | ||
234b63a0 | 76 | int btrfs_inc_ref(struct btrfs_root *root, struct btrfs_buffer *buf) |
02217ed2 CM |
77 | { |
78 | u64 blocknr; | |
79 | int i; | |
a28ec197 | 80 | |
3768f368 | 81 | if (!root->ref_cows) |
a28ec197 | 82 | return 0; |
7518a238 | 83 | if (btrfs_is_leaf(&buf->node)) |
a28ec197 CM |
84 | return 0; |
85 | ||
7518a238 | 86 | for (i = 0; i < btrfs_header_nritems(&buf->node.header); i++) { |
1d4f8a0c | 87 | blocknr = btrfs_node_blockptr(&buf->node, i); |
02217ed2 CM |
88 | inc_block_ref(root, blocknr); |
89 | } | |
90 | return 0; | |
91 | } | |
92 | ||
234b63a0 | 93 | int btrfs_finish_extent_commit(struct btrfs_root *root) |
a28ec197 | 94 | { |
a28ec197 CM |
95 | unsigned long gang[8]; |
96 | int ret; | |
97 | int i; | |
98 | ||
99 | while(1) { | |
3768f368 | 100 | ret = radix_tree_gang_lookup(&root->pinned_radix, |
a28ec197 CM |
101 | (void **)gang, 0, |
102 | ARRAY_SIZE(gang)); | |
103 | if (!ret) | |
104 | break; | |
0579da42 | 105 | for (i = 0; i < ret; i++) { |
3768f368 | 106 | radix_tree_delete(&root->pinned_radix, gang[i]); |
0579da42 | 107 | } |
a28ec197 | 108 | } |
3768f368 CM |
109 | root->last_insert.objectid = 0; |
110 | root->last_insert.offset = 0; | |
a28ec197 CM |
111 | return 0; |
112 | } | |
113 | ||
234b63a0 | 114 | static int finish_current_insert(struct btrfs_root *extent_root) |
037e6390 | 115 | { |
e2fa7227 | 116 | struct btrfs_key ins; |
234b63a0 | 117 | struct btrfs_extent_item extent_item; |
037e6390 CM |
118 | int i; |
119 | int ret; | |
120 | ||
cf27e1ee CM |
121 | btrfs_set_extent_refs(&extent_item, 1); |
122 | btrfs_set_extent_owner(&extent_item, | |
123 | btrfs_header_parentid(&extent_root->node->node.header)); | |
037e6390 CM |
124 | ins.offset = 1; |
125 | ins.flags = 0; | |
126 | ||
127 | for (i = 0; i < extent_root->current_insert.flags; i++) { | |
128 | ins.objectid = extent_root->current_insert.objectid + i; | |
234b63a0 | 129 | ret = btrfs_insert_item(extent_root, &ins, &extent_item, |
037e6390 CM |
130 | sizeof(extent_item)); |
131 | BUG_ON(ret); | |
132 | } | |
133 | extent_root->current_insert.offset = 0; | |
134 | return 0; | |
135 | } | |
136 | ||
fec577fb | 137 | /* |
a28ec197 | 138 | * remove an extent from the root, returns 0 on success |
fec577fb | 139 | */ |
234b63a0 | 140 | static int __free_extent(struct btrfs_root *root, u64 blocknr, u64 num_blocks) |
a28ec197 | 141 | { |
234b63a0 | 142 | struct btrfs_path path; |
e2fa7227 | 143 | struct btrfs_key key; |
234b63a0 | 144 | struct btrfs_root *extent_root = root->extent_root; |
a28ec197 | 145 | int ret; |
0783fcfc | 146 | struct btrfs_item *item; |
234b63a0 | 147 | struct btrfs_extent_item *ei; |
e2fa7227 | 148 | struct btrfs_key ins; |
cf27e1ee | 149 | u32 refs; |
037e6390 | 150 | |
a28ec197 CM |
151 | key.objectid = blocknr; |
152 | key.flags = 0; | |
153 | key.offset = num_blocks; | |
154 | ||
037e6390 | 155 | find_free_extent(root, 0, 0, (u64)-1, &ins); |
234b63a0 CM |
156 | btrfs_init_path(&path); |
157 | ret = btrfs_search_slot(extent_root, &key, &path, -1, 1); | |
a28ec197 CM |
158 | if (ret) { |
159 | printf("failed to find %Lu\n", key.objectid); | |
234b63a0 | 160 | btrfs_print_tree(extent_root, extent_root->node); |
a28ec197 CM |
161 | printf("failed to find %Lu\n", key.objectid); |
162 | BUG(); | |
163 | } | |
164 | item = path.nodes[0]->leaf.items + path.slots[0]; | |
234b63a0 | 165 | ei = (struct btrfs_extent_item *)(path.nodes[0]->leaf.data + |
0783fcfc | 166 | btrfs_item_offset(item)); |
a28ec197 | 167 | BUG_ON(ei->refs == 0); |
cf27e1ee CM |
168 | refs = btrfs_extent_refs(ei) - 1; |
169 | btrfs_set_extent_refs(ei, refs); | |
170 | if (refs == 0) { | |
3768f368 | 171 | if (!root->ref_cows) { |
a28ec197 CM |
172 | int err; |
173 | radix_tree_preload(GFP_KERNEL); | |
174 | err = radix_tree_insert(&extent_root->pinned_radix, | |
175 | blocknr, (void *)blocknr); | |
176 | BUG_ON(err); | |
177 | radix_tree_preload_end(); | |
178 | } | |
234b63a0 | 179 | ret = btrfs_del_item(extent_root, &path); |
0579da42 | 180 | if (root != extent_root && |
71087494 | 181 | extent_root->last_insert.objectid > blocknr) |
0579da42 | 182 | extent_root->last_insert.objectid = blocknr; |
a28ec197 CM |
183 | if (ret) |
184 | BUG(); | |
185 | } | |
234b63a0 | 186 | btrfs_release_path(extent_root, &path); |
037e6390 | 187 | finish_current_insert(extent_root); |
a28ec197 CM |
188 | return ret; |
189 | } | |
190 | ||
a28ec197 CM |
191 | /* |
192 | * find all the blocks marked as pending in the radix tree and remove | |
193 | * them from the extent map | |
194 | */ | |
234b63a0 | 195 | static int del_pending_extents(struct btrfs_root *extent_root) |
a28ec197 CM |
196 | { |
197 | int ret; | |
234b63a0 | 198 | struct btrfs_buffer *gang[4]; |
a28ec197 CM |
199 | int i; |
200 | ||
201 | while(1) { | |
202 | ret = radix_tree_gang_lookup_tag(&extent_root->cache_radix, | |
203 | (void **)gang, 0, | |
204 | ARRAY_SIZE(gang), | |
205 | CTREE_EXTENT_PENDING_DEL); | |
206 | if (!ret) | |
207 | break; | |
208 | for (i = 0; i < ret; i++) { | |
209 | ret = __free_extent(extent_root, gang[i]->blocknr, 1); | |
fec577fb CM |
210 | radix_tree_tag_clear(&extent_root->cache_radix, |
211 | gang[i]->blocknr, | |
a28ec197 | 212 | CTREE_EXTENT_PENDING_DEL); |
234b63a0 | 213 | btrfs_block_release(extent_root, gang[i]); |
fec577fb CM |
214 | } |
215 | } | |
216 | return 0; | |
217 | } | |
218 | ||
234b63a0 | 219 | static int run_pending(struct btrfs_root *extent_root) |
a28ec197 CM |
220 | { |
221 | while(radix_tree_tagged(&extent_root->cache_radix, | |
037e6390 | 222 | CTREE_EXTENT_PENDING_DEL)) |
a28ec197 | 223 | del_pending_extents(extent_root); |
a28ec197 CM |
224 | return 0; |
225 | } | |
226 | ||
227 | ||
fec577fb CM |
228 | /* |
229 | * remove an extent from the root, returns 0 on success | |
230 | */ | |
234b63a0 | 231 | int btrfs_free_extent(struct btrfs_root *root, u64 blocknr, u64 num_blocks) |
fec577fb | 232 | { |
e2fa7227 | 233 | struct btrfs_key key; |
234b63a0 CM |
234 | struct btrfs_root *extent_root = root->extent_root; |
235 | struct btrfs_buffer *t; | |
fec577fb CM |
236 | int pending_ret; |
237 | int ret; | |
a28ec197 | 238 | |
fec577fb | 239 | if (root == extent_root) { |
a28ec197 | 240 | t = find_tree_block(root, blocknr); |
037e6390 | 241 | radix_tree_tag_set(&root->cache_radix, blocknr, |
a28ec197 | 242 | CTREE_EXTENT_PENDING_DEL); |
fec577fb CM |
243 | return 0; |
244 | } | |
a28ec197 CM |
245 | key.objectid = blocknr; |
246 | key.flags = 0; | |
247 | key.offset = num_blocks; | |
248 | ret = __free_extent(root, blocknr, num_blocks); | |
249 | pending_ret = run_pending(root->extent_root); | |
fec577fb CM |
250 | return ret ? ret : pending_ret; |
251 | } | |
252 | ||
253 | /* | |
254 | * walks the btree of allocated extents and find a hole of a given size. | |
255 | * The key ins is changed to record the hole: | |
256 | * ins->objectid == block start | |
257 | * ins->flags = 0 | |
258 | * ins->offset == number of blocks | |
259 | * Any available blocks before search_start are skipped. | |
260 | */ | |
234b63a0 | 261 | static int find_free_extent(struct btrfs_root *orig_root, u64 num_blocks, |
e2fa7227 CM |
262 | u64 search_start, u64 search_end, |
263 | struct btrfs_key *ins) | |
fec577fb | 264 | { |
234b63a0 | 265 | struct btrfs_path path; |
e2fa7227 | 266 | struct btrfs_key key; |
fec577fb CM |
267 | int ret; |
268 | u64 hole_size = 0; | |
269 | int slot = 0; | |
270 | u64 last_block; | |
037e6390 | 271 | u64 test_block; |
fec577fb | 272 | int start_found; |
234b63a0 CM |
273 | struct btrfs_leaf *l; |
274 | struct btrfs_root * root = orig_root->extent_root; | |
0579da42 | 275 | int total_needed = num_blocks; |
fec577fb | 276 | |
7518a238 | 277 | total_needed += (btrfs_header_level(&root->node->node.header) + 1) * 3; |
0579da42 CM |
278 | if (root->last_insert.objectid > search_start) |
279 | search_start = root->last_insert.objectid; | |
fec577fb | 280 | check_failed: |
234b63a0 | 281 | btrfs_init_path(&path); |
fec577fb CM |
282 | ins->objectid = search_start; |
283 | ins->offset = 0; | |
284 | ins->flags = 0; | |
285 | start_found = 0; | |
234b63a0 | 286 | ret = btrfs_search_slot(root, ins, &path, 0, 0); |
0f70abe2 CM |
287 | if (ret < 0) |
288 | goto error; | |
aa5d6bed | 289 | |
0579da42 CM |
290 | if (path.slots[0] > 0) |
291 | path.slots[0]--; | |
292 | ||
fec577fb CM |
293 | while (1) { |
294 | l = &path.nodes[0]->leaf; | |
295 | slot = path.slots[0]; | |
7518a238 | 296 | if (slot >= btrfs_header_nritems(&l->header)) { |
234b63a0 | 297 | ret = btrfs_next_leaf(root, &path); |
fec577fb CM |
298 | if (ret == 0) |
299 | continue; | |
0f70abe2 CM |
300 | if (ret < 0) |
301 | goto error; | |
fec577fb CM |
302 | if (!start_found) { |
303 | ins->objectid = search_start; | |
037e6390 | 304 | ins->offset = (u64)-1; |
fec577fb CM |
305 | start_found = 1; |
306 | goto check_pending; | |
307 | } | |
308 | ins->objectid = last_block > search_start ? | |
309 | last_block : search_start; | |
037e6390 | 310 | ins->offset = (u64)-1; |
fec577fb CM |
311 | goto check_pending; |
312 | } | |
e2fa7227 CM |
313 | btrfs_disk_key_to_cpu(&key, &l->items[slot].key); |
314 | if (key.objectid >= search_start) { | |
fec577fb | 315 | if (start_found) { |
0579da42 CM |
316 | if (last_block < search_start) |
317 | last_block = search_start; | |
e2fa7227 | 318 | hole_size = key.objectid - last_block; |
037e6390 | 319 | if (hole_size > total_needed) { |
fec577fb | 320 | ins->objectid = last_block; |
037e6390 | 321 | ins->offset = hole_size; |
fec577fb CM |
322 | goto check_pending; |
323 | } | |
0579da42 | 324 | } |
fec577fb | 325 | } |
0579da42 | 326 | start_found = 1; |
e2fa7227 | 327 | last_block = key.objectid + key.offset; |
fec577fb CM |
328 | path.slots[0]++; |
329 | } | |
330 | // FIXME -ENOSPC | |
331 | check_pending: | |
332 | /* we have to make sure we didn't find an extent that has already | |
333 | * been allocated by the map tree or the original allocation | |
334 | */ | |
234b63a0 | 335 | btrfs_release_path(root, &path); |
fec577fb | 336 | BUG_ON(ins->objectid < search_start); |
037e6390 CM |
337 | for (test_block = ins->objectid; |
338 | test_block < ins->objectid + total_needed; test_block++) { | |
339 | if (radix_tree_lookup(&root->pinned_radix, test_block)) { | |
340 | search_start = test_block + 1; | |
fec577fb CM |
341 | goto check_failed; |
342 | } | |
343 | } | |
037e6390 | 344 | BUG_ON(root->current_insert.offset); |
0579da42 | 345 | root->current_insert.offset = total_needed - num_blocks; |
037e6390 CM |
346 | root->current_insert.objectid = ins->objectid + num_blocks; |
347 | root->current_insert.flags = 0; | |
0579da42 | 348 | root->last_insert.objectid = ins->objectid; |
037e6390 | 349 | ins->offset = num_blocks; |
fec577fb | 350 | return 0; |
0f70abe2 | 351 | error: |
234b63a0 | 352 | btrfs_release_path(root, &path); |
0f70abe2 | 353 | return ret; |
fec577fb CM |
354 | } |
355 | ||
fec577fb CM |
356 | /* |
357 | * finds a free extent and does all the dirty work required for allocation | |
358 | * returns the key for the extent through ins, and a tree buffer for | |
359 | * the first block of the extent through buf. | |
360 | * | |
361 | * returns 0 if everything worked, non-zero otherwise. | |
362 | */ | |
9aca1d51 CM |
363 | static int alloc_extent(struct btrfs_root *root, u64 num_blocks, |
364 | u64 search_start, u64 search_end, u64 owner, | |
365 | struct btrfs_key *ins) | |
fec577fb CM |
366 | { |
367 | int ret; | |
368 | int pending_ret; | |
234b63a0 CM |
369 | struct btrfs_root *extent_root = root->extent_root; |
370 | struct btrfs_extent_item extent_item; | |
037e6390 | 371 | |
cf27e1ee CM |
372 | btrfs_set_extent_refs(&extent_item, 1); |
373 | btrfs_set_extent_owner(&extent_item, owner); | |
fec577fb | 374 | |
037e6390 CM |
375 | if (root == extent_root) { |
376 | BUG_ON(extent_root->current_insert.offset == 0); | |
377 | BUG_ON(num_blocks != 1); | |
378 | BUG_ON(extent_root->current_insert.flags == | |
379 | extent_root->current_insert.offset); | |
380 | ins->offset = 1; | |
381 | ins->objectid = extent_root->current_insert.objectid + | |
382 | extent_root->current_insert.flags++; | |
fec577fb CM |
383 | return 0; |
384 | } | |
037e6390 CM |
385 | ret = find_free_extent(root, num_blocks, search_start, |
386 | search_end, ins); | |
387 | if (ret) | |
388 | return ret; | |
fec577fb | 389 | |
234b63a0 | 390 | ret = btrfs_insert_item(extent_root, ins, &extent_item, |
037e6390 CM |
391 | sizeof(extent_item)); |
392 | ||
393 | finish_current_insert(extent_root); | |
394 | pending_ret = run_pending(extent_root); | |
395 | if (ret) | |
396 | return ret; | |
397 | if (pending_ret) | |
398 | return pending_ret; | |
399 | return 0; | |
fec577fb CM |
400 | } |
401 | ||
402 | /* | |
403 | * helper function to allocate a block for a given tree | |
404 | * returns the tree buffer or NULL. | |
405 | */ | |
234b63a0 | 406 | struct btrfs_buffer *btrfs_alloc_free_block(struct btrfs_root *root) |
fec577fb | 407 | { |
e2fa7227 | 408 | struct btrfs_key ins; |
fec577fb | 409 | int ret; |
234b63a0 | 410 | struct btrfs_buffer *buf; |
fec577fb CM |
411 | |
412 | ret = alloc_extent(root, 1, 0, (unsigned long)-1, | |
7518a238 | 413 | btrfs_header_parentid(&root->node->node.header), |
037e6390 | 414 | &ins); |
fec577fb CM |
415 | if (ret) { |
416 | BUG(); | |
417 | return NULL; | |
418 | } | |
037e6390 CM |
419 | buf = find_tree_block(root, ins.objectid); |
420 | dirty_tree_block(root, buf); | |
fec577fb CM |
421 | return buf; |
422 | } | |
a28ec197 | 423 | |
9aca1d51 CM |
424 | /* |
425 | * helper function for drop_snapshot, this walks down the tree dropping ref | |
426 | * counts as it goes. | |
427 | */ | |
428 | static int walk_down_tree(struct btrfs_root *root, | |
429 | struct btrfs_path *path, int *level) | |
20524f02 | 430 | { |
234b63a0 CM |
431 | struct btrfs_buffer *next; |
432 | struct btrfs_buffer *cur; | |
20524f02 CM |
433 | u64 blocknr; |
434 | int ret; | |
435 | u32 refs; | |
436 | ||
437 | ret = lookup_block_ref(root, path->nodes[*level]->blocknr, &refs); | |
438 | BUG_ON(ret); | |
439 | if (refs > 1) | |
440 | goto out; | |
9aca1d51 CM |
441 | /* |
442 | * walk down to the last node level and free all the leaves | |
443 | */ | |
20524f02 CM |
444 | while(*level > 0) { |
445 | cur = path->nodes[*level]; | |
7518a238 CM |
446 | if (path->slots[*level] >= |
447 | btrfs_header_nritems(&cur->node.header)) | |
20524f02 | 448 | break; |
1d4f8a0c | 449 | blocknr = btrfs_node_blockptr(&cur->node, path->slots[*level]); |
20524f02 CM |
450 | ret = lookup_block_ref(root, blocknr, &refs); |
451 | if (refs != 1 || *level == 1) { | |
452 | path->slots[*level]++; | |
234b63a0 | 453 | ret = btrfs_free_extent(root, blocknr, 1); |
20524f02 CM |
454 | BUG_ON(ret); |
455 | continue; | |
456 | } | |
457 | BUG_ON(ret); | |
458 | next = read_tree_block(root, blocknr); | |
83e15a28 | 459 | if (path->nodes[*level-1]) |
234b63a0 | 460 | btrfs_block_release(root, path->nodes[*level-1]); |
20524f02 | 461 | path->nodes[*level-1] = next; |
7518a238 | 462 | *level = btrfs_header_level(&next->node.header); |
20524f02 CM |
463 | path->slots[*level] = 0; |
464 | } | |
465 | out: | |
234b63a0 CM |
466 | ret = btrfs_free_extent(root, path->nodes[*level]->blocknr, 1); |
467 | btrfs_block_release(root, path->nodes[*level]); | |
20524f02 CM |
468 | path->nodes[*level] = NULL; |
469 | *level += 1; | |
470 | BUG_ON(ret); | |
471 | return 0; | |
472 | } | |
473 | ||
9aca1d51 CM |
474 | /* |
475 | * helper for dropping snapshots. This walks back up the tree in the path | |
476 | * to find the first node higher up where we haven't yet gone through | |
477 | * all the slots | |
478 | */ | |
479 | static int walk_up_tree(struct btrfs_root *root, struct btrfs_path *path, | |
480 | int *level) | |
20524f02 CM |
481 | { |
482 | int i; | |
483 | int slot; | |
484 | int ret; | |
234b63a0 | 485 | for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) { |
20524f02 | 486 | slot = path->slots[i]; |
7518a238 CM |
487 | if (slot < |
488 | btrfs_header_nritems(&path->nodes[i]->node.header)- 1) { | |
20524f02 CM |
489 | path->slots[i]++; |
490 | *level = i; | |
491 | return 0; | |
492 | } else { | |
234b63a0 | 493 | ret = btrfs_free_extent(root, |
20524f02 | 494 | path->nodes[*level]->blocknr, 1); |
234b63a0 | 495 | btrfs_block_release(root, path->nodes[*level]); |
83e15a28 | 496 | path->nodes[*level] = NULL; |
20524f02 CM |
497 | *level = i + 1; |
498 | BUG_ON(ret); | |
499 | } | |
500 | } | |
501 | return 1; | |
502 | } | |
503 | ||
9aca1d51 CM |
504 | /* |
505 | * drop the reference count on the tree rooted at 'snap'. This traverses | |
506 | * the tree freeing any blocks that have a ref count of zero after being | |
507 | * decremented. | |
508 | */ | |
234b63a0 | 509 | int btrfs_drop_snapshot(struct btrfs_root *root, struct btrfs_buffer *snap) |
20524f02 | 510 | { |
3768f368 | 511 | int ret = 0; |
9aca1d51 | 512 | int wret; |
20524f02 | 513 | int level; |
234b63a0 | 514 | struct btrfs_path path; |
20524f02 CM |
515 | int i; |
516 | int orig_level; | |
517 | ||
234b63a0 | 518 | btrfs_init_path(&path); |
20524f02 | 519 | |
7518a238 | 520 | level = btrfs_header_level(&snap->node.header); |
20524f02 CM |
521 | orig_level = level; |
522 | path.nodes[level] = snap; | |
523 | path.slots[level] = 0; | |
524 | while(1) { | |
9aca1d51 CM |
525 | wret = walk_down_tree(root, &path, &level); |
526 | if (wret > 0) | |
20524f02 | 527 | break; |
9aca1d51 CM |
528 | if (wret < 0) |
529 | ret = wret; | |
530 | ||
531 | wret = walk_up_tree(root, &path, &level); | |
532 | if (wret > 0) | |
20524f02 | 533 | break; |
9aca1d51 CM |
534 | if (wret < 0) |
535 | ret = wret; | |
20524f02 | 536 | } |
83e15a28 CM |
537 | for (i = 0; i <= orig_level; i++) { |
538 | if (path.nodes[i]) { | |
234b63a0 | 539 | btrfs_block_release(root, path.nodes[i]); |
83e15a28 | 540 | } |
20524f02 | 541 | } |
9aca1d51 | 542 | return ret; |
20524f02 | 543 | } |