Commit | Line | Data |
---|---|---|
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 | ||
037e6390 CM |
9 | static int find_free_extent(struct ctree_root *orig_root, u64 num_blocks, |
10 | u64 search_start, u64 search_end, struct key *ins); | |
11 | static int finish_current_insert(struct ctree_root *extent_root); | |
12 | static int run_pending(struct ctree_root *extent_root); | |
13 | ||
fec577fb CM |
14 | /* |
15 | * pending extents are blocks that we're trying to allocate in the extent | |
16 | * map while trying to grow the map because of other allocations. To avoid | |
17 | * recursing, they are tagged in the radix tree and cleaned up after | |
18 | * other allocations are done. The pending tag is also used in the same | |
19 | * manner for deletes. | |
20 | */ | |
037e6390 | 21 | #define CTREE_EXTENT_PENDING_DEL 0 |
fec577fb | 22 | |
02217ed2 CM |
23 | static int inc_block_ref(struct ctree_root *root, u64 blocknr) |
24 | { | |
25 | struct ctree_path path; | |
26 | int ret; | |
27 | struct key key; | |
28 | struct leaf *l; | |
29 | struct extent_item *item; | |
037e6390 CM |
30 | struct key ins; |
31 | ||
32 | find_free_extent(root->extent_root, 0, 0, (u64)-1, &ins); | |
02217ed2 CM |
33 | init_path(&path); |
34 | key.objectid = blocknr; | |
35 | key.flags = 0; | |
36 | key.offset = 1; | |
37 | ret = search_slot(root->extent_root, &key, &path, 0, 1); | |
a28ec197 CM |
38 | if (ret != 0) |
39 | BUG(); | |
02217ed2 CM |
40 | BUG_ON(ret != 0); |
41 | l = &path.nodes[0]->leaf; | |
42 | item = (struct extent_item *)(l->data + | |
43 | l->items[path.slots[0]].offset); | |
44 | item->refs++; | |
a28ec197 | 45 | |
02217ed2 CM |
46 | BUG_ON(list_empty(&path.nodes[0]->dirty)); |
47 | release_path(root->extent_root, &path); | |
037e6390 CM |
48 | finish_current_insert(root->extent_root); |
49 | run_pending(root->extent_root); | |
02217ed2 CM |
50 | return 0; |
51 | } | |
52 | ||
a28ec197 CM |
53 | static int lookup_block_ref(struct ctree_root *root, u64 blocknr, int *refs) |
54 | { | |
55 | struct ctree_path path; | |
56 | int ret; | |
57 | struct key key; | |
58 | struct leaf *l; | |
59 | struct extent_item *item; | |
60 | init_path(&path); | |
61 | key.objectid = blocknr; | |
62 | key.flags = 0; | |
63 | key.offset = 1; | |
64 | ret = search_slot(root->extent_root, &key, &path, 0, 0); | |
65 | if (ret != 0) | |
66 | BUG(); | |
67 | l = &path.nodes[0]->leaf; | |
68 | item = (struct extent_item *)(l->data + | |
69 | l->items[path.slots[0]].offset); | |
70 | *refs = item->refs; | |
71 | release_path(root->extent_root, &path); | |
72 | return 0; | |
73 | } | |
74 | ||
02217ed2 CM |
75 | int btrfs_inc_ref(struct ctree_root *root, struct tree_buffer *buf) |
76 | { | |
77 | u64 blocknr; | |
78 | int i; | |
a28ec197 CM |
79 | |
80 | if (root == root->extent_root) | |
81 | return 0; | |
82 | if (is_leaf(buf->node.header.flags)) | |
83 | return 0; | |
84 | ||
02217ed2 CM |
85 | for (i = 0; i < buf->node.header.nritems; i++) { |
86 | blocknr = buf->node.blockptrs[i]; | |
87 | inc_block_ref(root, blocknr); | |
88 | } | |
89 | return 0; | |
90 | } | |
91 | ||
a28ec197 CM |
92 | int btrfs_finish_extent_commit(struct ctree_root *root) |
93 | { | |
94 | struct ctree_root *extent_root = root->extent_root; | |
95 | unsigned long gang[8]; | |
96 | int ret; | |
97 | int i; | |
98 | ||
99 | while(1) { | |
100 | ret = radix_tree_gang_lookup(&extent_root->pinned_radix, | |
101 | (void **)gang, 0, | |
102 | ARRAY_SIZE(gang)); | |
103 | if (!ret) | |
104 | break; | |
105 | for (i = 0; i < ret; i++) | |
106 | radix_tree_delete(&extent_root->pinned_radix, gang[i]); | |
107 | } | |
108 | return 0; | |
109 | } | |
110 | ||
037e6390 CM |
111 | static int finish_current_insert(struct ctree_root *extent_root) |
112 | { | |
113 | struct key ins; | |
114 | struct extent_item extent_item; | |
115 | int i; | |
116 | int ret; | |
117 | ||
118 | extent_item.refs = 1; | |
119 | extent_item.owner = extent_root->node->node.header.parentid; | |
120 | ins.offset = 1; | |
121 | ins.flags = 0; | |
122 | ||
123 | for (i = 0; i < extent_root->current_insert.flags; i++) { | |
124 | ins.objectid = extent_root->current_insert.objectid + i; | |
125 | ret = insert_item(extent_root, &ins, &extent_item, | |
126 | sizeof(extent_item)); | |
127 | BUG_ON(ret); | |
128 | } | |
129 | extent_root->current_insert.offset = 0; | |
130 | return 0; | |
131 | } | |
132 | ||
fec577fb | 133 | /* |
a28ec197 | 134 | * remove an extent from the root, returns 0 on success |
fec577fb | 135 | */ |
a28ec197 CM |
136 | int __free_extent(struct ctree_root *root, u64 blocknr, u64 num_blocks) |
137 | { | |
138 | struct ctree_path path; | |
139 | struct key key; | |
140 | struct ctree_root *extent_root = root->extent_root; | |
141 | int ret; | |
142 | struct item *item; | |
143 | struct extent_item *ei; | |
037e6390 CM |
144 | struct key ins; |
145 | ||
a28ec197 CM |
146 | key.objectid = blocknr; |
147 | key.flags = 0; | |
148 | key.offset = num_blocks; | |
149 | ||
037e6390 | 150 | find_free_extent(root, 0, 0, (u64)-1, &ins); |
a28ec197 CM |
151 | init_path(&path); |
152 | ret = search_slot(extent_root, &key, &path, -1, 1); | |
153 | if (ret) { | |
154 | printf("failed to find %Lu\n", key.objectid); | |
155 | print_tree(extent_root, extent_root->node); | |
156 | printf("failed to find %Lu\n", key.objectid); | |
157 | BUG(); | |
158 | } | |
159 | item = path.nodes[0]->leaf.items + path.slots[0]; | |
160 | ei = (struct extent_item *)(path.nodes[0]->leaf.data + item->offset); | |
161 | BUG_ON(ei->refs == 0); | |
162 | ei->refs--; | |
163 | if (ei->refs == 0) { | |
164 | if (root == extent_root) { | |
165 | int err; | |
166 | radix_tree_preload(GFP_KERNEL); | |
167 | err = radix_tree_insert(&extent_root->pinned_radix, | |
168 | blocknr, (void *)blocknr); | |
169 | BUG_ON(err); | |
170 | radix_tree_preload_end(); | |
171 | } | |
172 | ret = del_item(extent_root, &path); | |
173 | if (ret) | |
174 | BUG(); | |
175 | } | |
176 | release_path(extent_root, &path); | |
037e6390 | 177 | finish_current_insert(extent_root); |
a28ec197 CM |
178 | return ret; |
179 | } | |
180 | ||
a28ec197 CM |
181 | /* |
182 | * find all the blocks marked as pending in the radix tree and remove | |
183 | * them from the extent map | |
184 | */ | |
185 | static int del_pending_extents(struct ctree_root *extent_root) | |
186 | { | |
187 | int ret; | |
188 | struct tree_buffer *gang[4]; | |
189 | int i; | |
190 | ||
191 | while(1) { | |
192 | ret = radix_tree_gang_lookup_tag(&extent_root->cache_radix, | |
193 | (void **)gang, 0, | |
194 | ARRAY_SIZE(gang), | |
195 | CTREE_EXTENT_PENDING_DEL); | |
196 | if (!ret) | |
197 | break; | |
198 | for (i = 0; i < ret; i++) { | |
199 | ret = __free_extent(extent_root, gang[i]->blocknr, 1); | |
fec577fb CM |
200 | radix_tree_tag_clear(&extent_root->cache_radix, |
201 | gang[i]->blocknr, | |
a28ec197 | 202 | CTREE_EXTENT_PENDING_DEL); |
fec577fb CM |
203 | tree_block_release(extent_root, gang[i]); |
204 | } | |
205 | } | |
206 | return 0; | |
207 | } | |
208 | ||
a28ec197 CM |
209 | static int run_pending(struct ctree_root *extent_root) |
210 | { | |
211 | while(radix_tree_tagged(&extent_root->cache_radix, | |
037e6390 | 212 | CTREE_EXTENT_PENDING_DEL)) |
a28ec197 | 213 | del_pending_extents(extent_root); |
a28ec197 CM |
214 | return 0; |
215 | } | |
216 | ||
217 | ||
fec577fb CM |
218 | /* |
219 | * remove an extent from the root, returns 0 on success | |
220 | */ | |
221 | int free_extent(struct ctree_root *root, u64 blocknr, u64 num_blocks) | |
222 | { | |
fec577fb CM |
223 | struct key key; |
224 | struct ctree_root *extent_root = root->extent_root; | |
225 | struct tree_buffer *t; | |
226 | int pending_ret; | |
227 | int ret; | |
a28ec197 | 228 | |
fec577fb | 229 | if (root == extent_root) { |
a28ec197 | 230 | t = find_tree_block(root, blocknr); |
037e6390 | 231 | radix_tree_tag_set(&root->cache_radix, blocknr, |
a28ec197 | 232 | CTREE_EXTENT_PENDING_DEL); |
fec577fb CM |
233 | return 0; |
234 | } | |
a28ec197 CM |
235 | key.objectid = blocknr; |
236 | key.flags = 0; | |
237 | key.offset = num_blocks; | |
238 | ret = __free_extent(root, blocknr, num_blocks); | |
239 | pending_ret = run_pending(root->extent_root); | |
fec577fb CM |
240 | return ret ? ret : pending_ret; |
241 | } | |
242 | ||
243 | /* | |
244 | * walks the btree of allocated extents and find a hole of a given size. | |
245 | * The key ins is changed to record the hole: | |
246 | * ins->objectid == block start | |
247 | * ins->flags = 0 | |
248 | * ins->offset == number of blocks | |
249 | * Any available blocks before search_start are skipped. | |
250 | */ | |
0f70abe2 CM |
251 | static int find_free_extent(struct ctree_root *orig_root, u64 num_blocks, |
252 | u64 search_start, u64 search_end, struct key *ins) | |
fec577fb CM |
253 | { |
254 | struct ctree_path path; | |
255 | struct key *key; | |
256 | int ret; | |
257 | u64 hole_size = 0; | |
258 | int slot = 0; | |
259 | u64 last_block; | |
037e6390 | 260 | u64 test_block; |
fec577fb CM |
261 | int start_found; |
262 | struct leaf *l; | |
263 | struct ctree_root * root = orig_root->extent_root; | |
037e6390 | 264 | int total_needed = num_blocks + MAX_LEVEL * 3; |
fec577fb CM |
265 | |
266 | check_failed: | |
267 | init_path(&path); | |
268 | ins->objectid = search_start; | |
269 | ins->offset = 0; | |
270 | ins->flags = 0; | |
271 | start_found = 0; | |
02217ed2 | 272 | ret = search_slot(root, ins, &path, 0, 0); |
0f70abe2 CM |
273 | if (ret < 0) |
274 | goto error; | |
aa5d6bed | 275 | |
fec577fb CM |
276 | while (1) { |
277 | l = &path.nodes[0]->leaf; | |
278 | slot = path.slots[0]; | |
279 | if (slot >= l->header.nritems) { | |
280 | ret = next_leaf(root, &path); | |
281 | if (ret == 0) | |
282 | continue; | |
0f70abe2 CM |
283 | if (ret < 0) |
284 | goto error; | |
fec577fb CM |
285 | if (!start_found) { |
286 | ins->objectid = search_start; | |
037e6390 | 287 | ins->offset = (u64)-1; |
fec577fb CM |
288 | start_found = 1; |
289 | goto check_pending; | |
290 | } | |
291 | ins->objectid = last_block > search_start ? | |
292 | last_block : search_start; | |
037e6390 | 293 | ins->offset = (u64)-1; |
fec577fb CM |
294 | goto check_pending; |
295 | } | |
037e6390 CM |
296 | if (slot == 0) { |
297 | int last_slot = l->header.nritems - 1; | |
298 | u64 span = l->items[last_slot].key.objectid; | |
299 | span -= l->items[slot].key.objectid; | |
300 | if (span + total_needed > last_slot - slot) { | |
301 | path.slots[0] = last_slot + 1; | |
302 | key = &l->items[last_slot].key; | |
303 | last_block = key->objectid + key->offset; | |
304 | start_found = 1; | |
305 | continue; | |
306 | } | |
307 | } | |
fec577fb CM |
308 | key = &l->items[slot].key; |
309 | if (key->objectid >= search_start) { | |
310 | if (start_found) { | |
311 | hole_size = key->objectid - last_block; | |
037e6390 | 312 | if (hole_size > total_needed) { |
fec577fb | 313 | ins->objectid = last_block; |
037e6390 | 314 | ins->offset = hole_size; |
fec577fb CM |
315 | goto check_pending; |
316 | } | |
317 | } else | |
318 | start_found = 1; | |
319 | last_block = key->objectid + key->offset; | |
320 | } | |
321 | path.slots[0]++; | |
322 | } | |
323 | // FIXME -ENOSPC | |
324 | check_pending: | |
325 | /* we have to make sure we didn't find an extent that has already | |
326 | * been allocated by the map tree or the original allocation | |
327 | */ | |
328 | release_path(root, &path); | |
329 | BUG_ON(ins->objectid < search_start); | |
037e6390 CM |
330 | for (test_block = ins->objectid; |
331 | test_block < ins->objectid + total_needed; test_block++) { | |
332 | if (radix_tree_lookup(&root->pinned_radix, test_block)) { | |
333 | search_start = test_block + 1; | |
fec577fb CM |
334 | goto check_failed; |
335 | } | |
336 | } | |
037e6390 CM |
337 | BUG_ON(root->current_insert.offset); |
338 | root->current_insert.offset = total_needed; | |
339 | root->current_insert.objectid = ins->objectid + num_blocks; | |
340 | root->current_insert.flags = 0; | |
341 | ins->offset = num_blocks; | |
fec577fb | 342 | return 0; |
0f70abe2 CM |
343 | error: |
344 | release_path(root, &path); | |
345 | return ret; | |
fec577fb CM |
346 | } |
347 | ||
fec577fb CM |
348 | /* |
349 | * finds a free extent and does all the dirty work required for allocation | |
350 | * returns the key for the extent through ins, and a tree buffer for | |
351 | * the first block of the extent through buf. | |
352 | * | |
353 | * returns 0 if everything worked, non-zero otherwise. | |
354 | */ | |
355 | int alloc_extent(struct ctree_root *root, u64 num_blocks, u64 search_start, | |
037e6390 | 356 | u64 search_end, u64 owner, struct key *ins) |
fec577fb CM |
357 | { |
358 | int ret; | |
359 | int pending_ret; | |
037e6390 | 360 | struct ctree_root *extent_root = root->extent_root; |
fec577fb | 361 | struct extent_item extent_item; |
037e6390 | 362 | |
fec577fb CM |
363 | extent_item.refs = 1; |
364 | extent_item.owner = owner; | |
365 | ||
037e6390 CM |
366 | if (root == extent_root) { |
367 | BUG_ON(extent_root->current_insert.offset == 0); | |
368 | BUG_ON(num_blocks != 1); | |
369 | BUG_ON(extent_root->current_insert.flags == | |
370 | extent_root->current_insert.offset); | |
371 | ins->offset = 1; | |
372 | ins->objectid = extent_root->current_insert.objectid + | |
373 | extent_root->current_insert.flags++; | |
fec577fb CM |
374 | return 0; |
375 | } | |
037e6390 CM |
376 | ret = find_free_extent(root, num_blocks, search_start, |
377 | search_end, ins); | |
378 | if (ret) | |
379 | return ret; | |
fec577fb | 380 | |
037e6390 CM |
381 | ret = insert_item(extent_root, ins, &extent_item, |
382 | sizeof(extent_item)); | |
383 | ||
384 | finish_current_insert(extent_root); | |
385 | pending_ret = run_pending(extent_root); | |
386 | if (ret) | |
387 | return ret; | |
388 | if (pending_ret) | |
389 | return pending_ret; | |
390 | return 0; | |
fec577fb CM |
391 | } |
392 | ||
393 | /* | |
394 | * helper function to allocate a block for a given tree | |
395 | * returns the tree buffer or NULL. | |
396 | */ | |
397 | struct tree_buffer *alloc_free_block(struct ctree_root *root) | |
398 | { | |
399 | struct key ins; | |
400 | int ret; | |
037e6390 | 401 | struct tree_buffer *buf; |
fec577fb CM |
402 | |
403 | ret = alloc_extent(root, 1, 0, (unsigned long)-1, | |
404 | root->node->node.header.parentid, | |
037e6390 | 405 | &ins); |
fec577fb CM |
406 | if (ret) { |
407 | BUG(); | |
408 | return NULL; | |
409 | } | |
037e6390 CM |
410 | buf = find_tree_block(root, ins.objectid); |
411 | dirty_tree_block(root, buf); | |
fec577fb CM |
412 | return buf; |
413 | } | |
a28ec197 CM |
414 | |
415 | int btrfs_drop_snapshot(struct ctree_root *root, struct tree_buffer *snap) | |
416 | { | |
417 | int ret; | |
418 | int level; | |
419 | int refs; | |
420 | u64 blocknr = snap->blocknr; | |
421 | ||
422 | level = node_level(snap->node.header.flags); | |
423 | ret = lookup_block_ref(root, snap->blocknr, &refs); | |
424 | BUG_ON(ret); | |
425 | if (refs == 1 && level != 0) { | |
426 | struct node *n = &snap->node; | |
427 | struct tree_buffer *b; | |
428 | int i; | |
429 | for (i = 0; i < n->header.nritems; i++) { | |
430 | b = read_tree_block(root, n->blockptrs[i]); | |
431 | /* FIXME, don't recurse here */ | |
432 | ret = btrfs_drop_snapshot(root, b); | |
433 | BUG_ON(ret); | |
434 | tree_block_release(root, b); | |
435 | } | |
436 | } | |
437 | ret = free_extent(root, blocknr, 1); | |
438 | BUG_ON(ret); | |
439 | return 0; | |
440 | } | |
441 |