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 | ||
9 | /* | |
10 | * pending extents are blocks that we're trying to allocate in the extent | |
11 | * map while trying to grow the map because of other allocations. To avoid | |
12 | * recursing, they are tagged in the radix tree and cleaned up after | |
13 | * other allocations are done. The pending tag is also used in the same | |
14 | * manner for deletes. | |
15 | */ | |
a28ec197 CM |
16 | #define CTREE_EXTENT_PENDING_ADD 0 |
17 | #define CTREE_EXTENT_PENDING_DEL 1 | |
fec577fb | 18 | |
02217ed2 CM |
19 | static int inc_block_ref(struct ctree_root *root, u64 blocknr) |
20 | { | |
21 | struct ctree_path path; | |
22 | int ret; | |
23 | struct key key; | |
24 | struct leaf *l; | |
25 | struct extent_item *item; | |
26 | init_path(&path); | |
27 | key.objectid = blocknr; | |
28 | key.flags = 0; | |
29 | key.offset = 1; | |
30 | ret = search_slot(root->extent_root, &key, &path, 0, 1); | |
a28ec197 CM |
31 | if (ret != 0) |
32 | BUG(); | |
02217ed2 CM |
33 | BUG_ON(ret != 0); |
34 | l = &path.nodes[0]->leaf; | |
35 | item = (struct extent_item *)(l->data + | |
36 | l->items[path.slots[0]].offset); | |
37 | item->refs++; | |
a28ec197 | 38 | |
02217ed2 CM |
39 | BUG_ON(list_empty(&path.nodes[0]->dirty)); |
40 | release_path(root->extent_root, &path); | |
41 | return 0; | |
42 | } | |
43 | ||
a28ec197 CM |
44 | static int lookup_block_ref(struct ctree_root *root, u64 blocknr, int *refs) |
45 | { | |
46 | struct ctree_path path; | |
47 | int ret; | |
48 | struct key key; | |
49 | struct leaf *l; | |
50 | struct extent_item *item; | |
51 | init_path(&path); | |
52 | key.objectid = blocknr; | |
53 | key.flags = 0; | |
54 | key.offset = 1; | |
55 | ret = search_slot(root->extent_root, &key, &path, 0, 0); | |
56 | if (ret != 0) | |
57 | BUG(); | |
58 | l = &path.nodes[0]->leaf; | |
59 | item = (struct extent_item *)(l->data + | |
60 | l->items[path.slots[0]].offset); | |
61 | *refs = item->refs; | |
62 | release_path(root->extent_root, &path); | |
63 | return 0; | |
64 | } | |
65 | ||
02217ed2 CM |
66 | int btrfs_inc_ref(struct ctree_root *root, struct tree_buffer *buf) |
67 | { | |
68 | u64 blocknr; | |
69 | int i; | |
a28ec197 CM |
70 | |
71 | if (root == root->extent_root) | |
72 | return 0; | |
73 | if (is_leaf(buf->node.header.flags)) | |
74 | return 0; | |
75 | ||
02217ed2 CM |
76 | for (i = 0; i < buf->node.header.nritems; i++) { |
77 | blocknr = buf->node.blockptrs[i]; | |
78 | inc_block_ref(root, blocknr); | |
79 | } | |
80 | return 0; | |
81 | } | |
82 | ||
a28ec197 CM |
83 | int btrfs_finish_extent_commit(struct ctree_root *root) |
84 | { | |
85 | struct ctree_root *extent_root = root->extent_root; | |
86 | unsigned long gang[8]; | |
87 | int ret; | |
88 | int i; | |
89 | ||
90 | while(1) { | |
91 | ret = radix_tree_gang_lookup(&extent_root->pinned_radix, | |
92 | (void **)gang, 0, | |
93 | ARRAY_SIZE(gang)); | |
94 | if (!ret) | |
95 | break; | |
96 | for (i = 0; i < ret; i++) | |
97 | radix_tree_delete(&extent_root->pinned_radix, gang[i]); | |
98 | } | |
99 | return 0; | |
100 | } | |
101 | ||
fec577fb | 102 | /* |
a28ec197 | 103 | * remove an extent from the root, returns 0 on success |
fec577fb | 104 | */ |
a28ec197 CM |
105 | int __free_extent(struct ctree_root *root, u64 blocknr, u64 num_blocks) |
106 | { | |
107 | struct ctree_path path; | |
108 | struct key key; | |
109 | struct ctree_root *extent_root = root->extent_root; | |
110 | int ret; | |
111 | struct item *item; | |
112 | struct extent_item *ei; | |
113 | key.objectid = blocknr; | |
114 | key.flags = 0; | |
115 | key.offset = num_blocks; | |
116 | ||
117 | init_path(&path); | |
118 | ret = search_slot(extent_root, &key, &path, -1, 1); | |
119 | if (ret) { | |
120 | printf("failed to find %Lu\n", key.objectid); | |
121 | print_tree(extent_root, extent_root->node); | |
122 | printf("failed to find %Lu\n", key.objectid); | |
123 | BUG(); | |
124 | } | |
125 | item = path.nodes[0]->leaf.items + path.slots[0]; | |
126 | ei = (struct extent_item *)(path.nodes[0]->leaf.data + item->offset); | |
127 | BUG_ON(ei->refs == 0); | |
128 | ei->refs--; | |
129 | if (ei->refs == 0) { | |
130 | if (root == extent_root) { | |
131 | int err; | |
132 | radix_tree_preload(GFP_KERNEL); | |
133 | err = radix_tree_insert(&extent_root->pinned_radix, | |
134 | blocknr, (void *)blocknr); | |
135 | BUG_ON(err); | |
136 | radix_tree_preload_end(); | |
137 | } | |
138 | ret = del_item(extent_root, &path); | |
139 | if (ret) | |
140 | BUG(); | |
141 | } | |
142 | release_path(extent_root, &path); | |
143 | return ret; | |
144 | } | |
145 | ||
146 | /* | |
147 | * insert all of the pending extents reserved during the original | |
148 | * allocation. (CTREE_EXTENT_PENDING). Returns zero if it all worked out | |
149 | */ | |
150 | static int insert_pending_extents(struct ctree_root *extent_root) | |
fec577fb CM |
151 | { |
152 | int ret; | |
153 | struct key key; | |
a28ec197 | 154 | struct extent_item item; |
fec577fb CM |
155 | struct tree_buffer *gang[4]; |
156 | int i; | |
fec577fb | 157 | |
a28ec197 CM |
158 | // FIXME -ENOSPC |
159 | item.owner = extent_root->node->node.header.parentid; | |
160 | item.refs = 1; | |
fec577fb CM |
161 | while(1) { |
162 | ret = radix_tree_gang_lookup_tag(&extent_root->cache_radix, | |
163 | (void **)gang, 0, | |
164 | ARRAY_SIZE(gang), | |
a28ec197 | 165 | CTREE_EXTENT_PENDING_ADD); |
fec577fb CM |
166 | if (!ret) |
167 | break; | |
168 | for (i = 0; i < ret; i++) { | |
169 | key.objectid = gang[i]->blocknr; | |
170 | key.flags = 0; | |
171 | key.offset = 1; | |
a28ec197 CM |
172 | ret = insert_item(extent_root, &key, &item, |
173 | sizeof(item)); | |
fec577fb | 174 | if (ret) { |
a28ec197 | 175 | printf("%Lu already in tree\n", key.objectid); |
fec577fb | 176 | print_tree(extent_root, extent_root->node); |
fec577fb CM |
177 | BUG(); |
178 | // FIXME undo it and return sane | |
179 | return ret; | |
180 | } | |
a28ec197 CM |
181 | radix_tree_tag_clear(&extent_root->cache_radix, |
182 | gang[i]->blocknr, | |
183 | CTREE_EXTENT_PENDING_ADD); | |
184 | tree_block_release(extent_root, gang[i]); | |
185 | } | |
186 | } | |
187 | return 0; | |
188 | } | |
189 | ||
190 | /* | |
191 | * find all the blocks marked as pending in the radix tree and remove | |
192 | * them from the extent map | |
193 | */ | |
194 | static int del_pending_extents(struct ctree_root *extent_root) | |
195 | { | |
196 | int ret; | |
197 | struct tree_buffer *gang[4]; | |
198 | int i; | |
199 | ||
200 | while(1) { | |
201 | ret = radix_tree_gang_lookup_tag(&extent_root->cache_radix, | |
202 | (void **)gang, 0, | |
203 | ARRAY_SIZE(gang), | |
204 | CTREE_EXTENT_PENDING_DEL); | |
205 | if (!ret) | |
206 | break; | |
207 | for (i = 0; i < ret; i++) { | |
208 | ret = __free_extent(extent_root, gang[i]->blocknr, 1); | |
fec577fb CM |
209 | radix_tree_tag_clear(&extent_root->cache_radix, |
210 | gang[i]->blocknr, | |
a28ec197 | 211 | CTREE_EXTENT_PENDING_DEL); |
fec577fb CM |
212 | tree_block_release(extent_root, gang[i]); |
213 | } | |
214 | } | |
215 | return 0; | |
216 | } | |
217 | ||
a28ec197 CM |
218 | static int run_pending(struct ctree_root *extent_root) |
219 | { | |
220 | while(radix_tree_tagged(&extent_root->cache_radix, | |
221 | CTREE_EXTENT_PENDING_DEL) || | |
222 | radix_tree_tagged(&extent_root->cache_radix, | |
223 | CTREE_EXTENT_PENDING_ADD)) { | |
224 | insert_pending_extents(extent_root); | |
225 | del_pending_extents(extent_root); | |
226 | } | |
227 | return 0; | |
228 | } | |
229 | ||
230 | ||
fec577fb CM |
231 | /* |
232 | * remove an extent from the root, returns 0 on success | |
233 | */ | |
234 | int free_extent(struct ctree_root *root, u64 blocknr, u64 num_blocks) | |
235 | { | |
fec577fb CM |
236 | struct key key; |
237 | struct ctree_root *extent_root = root->extent_root; | |
238 | struct tree_buffer *t; | |
239 | int pending_ret; | |
240 | int ret; | |
a28ec197 | 241 | |
fec577fb | 242 | if (root == extent_root) { |
a28ec197 CM |
243 | t = find_tree_block(root, blocknr); |
244 | if (radix_tree_tag_get(&root->cache_radix, blocknr, | |
245 | CTREE_EXTENT_PENDING_ADD)) { | |
246 | radix_tree_tag_clear(&root->cache_radix, | |
247 | blocknr, | |
248 | CTREE_EXTENT_PENDING_ADD); | |
249 | /* once for us */ | |
250 | tree_block_release(root, t); | |
251 | /* once for the pending add */ | |
252 | tree_block_release(root, t); | |
253 | } else { | |
254 | radix_tree_tag_set(&root->cache_radix, blocknr, | |
255 | CTREE_EXTENT_PENDING_DEL); | |
256 | } | |
fec577fb CM |
257 | return 0; |
258 | } | |
a28ec197 CM |
259 | key.objectid = blocknr; |
260 | key.flags = 0; | |
261 | key.offset = num_blocks; | |
262 | ret = __free_extent(root, blocknr, num_blocks); | |
263 | pending_ret = run_pending(root->extent_root); | |
fec577fb CM |
264 | return ret ? ret : pending_ret; |
265 | } | |
266 | ||
267 | /* | |
268 | * walks the btree of allocated extents and find a hole of a given size. | |
269 | * The key ins is changed to record the hole: | |
270 | * ins->objectid == block start | |
271 | * ins->flags = 0 | |
272 | * ins->offset == number of blocks | |
273 | * Any available blocks before search_start are skipped. | |
274 | */ | |
0f70abe2 CM |
275 | static int find_free_extent(struct ctree_root *orig_root, u64 num_blocks, |
276 | u64 search_start, u64 search_end, struct key *ins) | |
fec577fb CM |
277 | { |
278 | struct ctree_path path; | |
279 | struct key *key; | |
280 | int ret; | |
281 | u64 hole_size = 0; | |
282 | int slot = 0; | |
283 | u64 last_block; | |
284 | int start_found; | |
285 | struct leaf *l; | |
286 | struct ctree_root * root = orig_root->extent_root; | |
287 | ||
288 | check_failed: | |
289 | init_path(&path); | |
290 | ins->objectid = search_start; | |
291 | ins->offset = 0; | |
292 | ins->flags = 0; | |
293 | start_found = 0; | |
02217ed2 | 294 | ret = search_slot(root, ins, &path, 0, 0); |
0f70abe2 CM |
295 | if (ret < 0) |
296 | goto error; | |
aa5d6bed | 297 | |
fec577fb CM |
298 | while (1) { |
299 | l = &path.nodes[0]->leaf; | |
300 | slot = path.slots[0]; | |
301 | if (slot >= l->header.nritems) { | |
302 | ret = next_leaf(root, &path); | |
303 | if (ret == 0) | |
304 | continue; | |
0f70abe2 CM |
305 | if (ret < 0) |
306 | goto error; | |
fec577fb CM |
307 | if (!start_found) { |
308 | ins->objectid = search_start; | |
309 | ins->offset = num_blocks; | |
310 | start_found = 1; | |
311 | goto check_pending; | |
312 | } | |
313 | ins->objectid = last_block > search_start ? | |
314 | last_block : search_start; | |
315 | ins->offset = num_blocks; | |
316 | goto check_pending; | |
317 | } | |
318 | key = &l->items[slot].key; | |
319 | if (key->objectid >= search_start) { | |
320 | if (start_found) { | |
321 | hole_size = key->objectid - last_block; | |
322 | if (hole_size > num_blocks) { | |
323 | ins->objectid = last_block; | |
324 | ins->offset = num_blocks; | |
325 | goto check_pending; | |
326 | } | |
327 | } else | |
328 | start_found = 1; | |
329 | last_block = key->objectid + key->offset; | |
330 | } | |
331 | path.slots[0]++; | |
332 | } | |
333 | // FIXME -ENOSPC | |
334 | check_pending: | |
335 | /* we have to make sure we didn't find an extent that has already | |
336 | * been allocated by the map tree or the original allocation | |
337 | */ | |
338 | release_path(root, &path); | |
339 | BUG_ON(ins->objectid < search_start); | |
a28ec197 | 340 | if (1 || orig_root->extent_root == orig_root) { |
fec577fb CM |
341 | BUG_ON(num_blocks != 1); |
342 | if ((root->current_insert.objectid <= ins->objectid && | |
343 | root->current_insert.objectid + | |
344 | root->current_insert.offset > ins->objectid) || | |
345 | (root->current_insert.objectid > ins->objectid && | |
346 | root->current_insert.objectid <= ins->objectid + | |
347 | ins->offset) || | |
a28ec197 | 348 | radix_tree_lookup(&root->pinned_radix, ins->objectid) || |
fec577fb | 349 | radix_tree_tag_get(&root->cache_radix, ins->objectid, |
a28ec197 | 350 | CTREE_EXTENT_PENDING_ADD)) { |
fec577fb CM |
351 | search_start = ins->objectid + 1; |
352 | goto check_failed; | |
353 | } | |
354 | } | |
355 | if (ins->offset != 1) | |
356 | BUG(); | |
357 | return 0; | |
0f70abe2 CM |
358 | error: |
359 | release_path(root, &path); | |
360 | return ret; | |
fec577fb CM |
361 | } |
362 | ||
fec577fb CM |
363 | /* |
364 | * finds a free extent and does all the dirty work required for allocation | |
365 | * returns the key for the extent through ins, and a tree buffer for | |
366 | * the first block of the extent through buf. | |
367 | * | |
368 | * returns 0 if everything worked, non-zero otherwise. | |
369 | */ | |
370 | int alloc_extent(struct ctree_root *root, u64 num_blocks, u64 search_start, | |
371 | u64 search_end, u64 owner, struct key *ins, | |
372 | struct tree_buffer **buf) | |
373 | { | |
374 | int ret; | |
375 | int pending_ret; | |
376 | struct extent_item extent_item; | |
377 | extent_item.refs = 1; | |
378 | extent_item.owner = owner; | |
379 | ||
380 | ret = find_free_extent(root, num_blocks, search_start, search_end, ins); | |
381 | if (ret) | |
382 | return ret; | |
383 | if (root != root->extent_root) { | |
384 | memcpy(&root->extent_root->current_insert, ins, sizeof(*ins)); | |
385 | ret = insert_item(root->extent_root, ins, &extent_item, | |
386 | sizeof(extent_item)); | |
387 | memset(&root->extent_root->current_insert, 0, | |
388 | sizeof(struct key)); | |
a28ec197 | 389 | pending_ret = run_pending(root->extent_root); |
fec577fb CM |
390 | if (ret) |
391 | return ret; | |
392 | if (pending_ret) | |
393 | return pending_ret; | |
394 | *buf = find_tree_block(root, ins->objectid); | |
02217ed2 | 395 | dirty_tree_block(root, *buf); |
fec577fb CM |
396 | return 0; |
397 | } | |
398 | /* we're allocating an extent for the extent tree, don't recurse */ | |
399 | BUG_ON(ins->offset != 1); | |
400 | *buf = find_tree_block(root, ins->objectid); | |
401 | BUG_ON(!*buf); | |
402 | radix_tree_tag_set(&root->cache_radix, ins->objectid, | |
a28ec197 | 403 | CTREE_EXTENT_PENDING_ADD); |
fec577fb | 404 | (*buf)->count++; |
02217ed2 | 405 | dirty_tree_block(root, *buf); |
fec577fb CM |
406 | return 0; |
407 | ||
408 | } | |
409 | ||
410 | /* | |
411 | * helper function to allocate a block for a given tree | |
412 | * returns the tree buffer or NULL. | |
413 | */ | |
414 | struct tree_buffer *alloc_free_block(struct ctree_root *root) | |
415 | { | |
416 | struct key ins; | |
417 | int ret; | |
418 | struct tree_buffer *buf = NULL; | |
419 | ||
420 | ret = alloc_extent(root, 1, 0, (unsigned long)-1, | |
421 | root->node->node.header.parentid, | |
422 | &ins, &buf); | |
fec577fb CM |
423 | if (ret) { |
424 | BUG(); | |
425 | return NULL; | |
426 | } | |
427 | if (root != root->extent_root) | |
428 | BUG_ON(radix_tree_tag_get(&root->extent_root->cache_radix, | |
a28ec197 CM |
429 | buf->blocknr, |
430 | CTREE_EXTENT_PENDING_ADD)); | |
fec577fb CM |
431 | return buf; |
432 | } | |
a28ec197 CM |
433 | |
434 | int btrfs_drop_snapshot(struct ctree_root *root, struct tree_buffer *snap) | |
435 | { | |
436 | int ret; | |
437 | int level; | |
438 | int refs; | |
439 | u64 blocknr = snap->blocknr; | |
440 | ||
441 | level = node_level(snap->node.header.flags); | |
442 | ret = lookup_block_ref(root, snap->blocknr, &refs); | |
443 | BUG_ON(ret); | |
444 | if (refs == 1 && level != 0) { | |
445 | struct node *n = &snap->node; | |
446 | struct tree_buffer *b; | |
447 | int i; | |
448 | for (i = 0; i < n->header.nritems; i++) { | |
449 | b = read_tree_block(root, n->blockptrs[i]); | |
450 | /* FIXME, don't recurse here */ | |
451 | ret = btrfs_drop_snapshot(root, b); | |
452 | BUG_ON(ret); | |
453 | tree_block_release(root, b); | |
454 | } | |
455 | } | |
456 | ret = free_extent(root, blocknr, 1); | |
457 | BUG_ON(ret); | |
458 | return 0; | |
459 | } | |
460 |