Commit | Line | Data |
---|---|---|
2e635a27 | 1 | #include <linux/module.h> |
fec577fb CM |
2 | #include "ctree.h" |
3 | #include "disk-io.h" | |
4 | #include "print-tree.h" | |
e089f05c | 5 | #include "transaction.h" |
fec577fb | 6 | |
e089f05c CM |
7 | static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root |
8 | *orig_root, u64 num_blocks, u64 search_start, u64 | |
9 | search_end, struct btrfs_key *ins); | |
10 | static int finish_current_insert(struct btrfs_trans_handle *trans, struct | |
11 | btrfs_root *extent_root); | |
e20d96d6 CM |
12 | static int del_pending_extents(struct btrfs_trans_handle *trans, struct |
13 | btrfs_root *extent_root); | |
fec577fb | 14 | |
b18c6685 CM |
15 | int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans, |
16 | struct btrfs_root *root, | |
17 | u64 blocknr, u64 num_blocks) | |
02217ed2 | 18 | { |
5caf2a00 | 19 | struct btrfs_path *path; |
02217ed2 | 20 | int ret; |
e2fa7227 | 21 | struct btrfs_key key; |
234b63a0 CM |
22 | struct btrfs_leaf *l; |
23 | struct btrfs_extent_item *item; | |
e2fa7227 | 24 | struct btrfs_key ins; |
cf27e1ee | 25 | u32 refs; |
037e6390 | 26 | |
9f5fae2f CM |
27 | find_free_extent(trans, root->fs_info->extent_root, 0, 0, (u64)-1, |
28 | &ins); | |
5caf2a00 CM |
29 | path = btrfs_alloc_path(); |
30 | BUG_ON(!path); | |
31 | btrfs_init_path(path); | |
02217ed2 CM |
32 | key.objectid = blocknr; |
33 | key.flags = 0; | |
62e2749e | 34 | btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); |
6407bf6d | 35 | key.offset = num_blocks; |
5caf2a00 | 36 | ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path, |
9f5fae2f | 37 | 0, 1); |
a429e513 CM |
38 | if (ret != 0) { |
39 | printk("can't find block %Lu %Lu\n", blocknr, num_blocks); | |
a28ec197 | 40 | BUG(); |
a429e513 | 41 | } |
02217ed2 | 42 | BUG_ON(ret != 0); |
5caf2a00 CM |
43 | l = btrfs_buffer_leaf(path->nodes[0]); |
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); | |
5caf2a00 | 47 | btrfs_mark_buffer_dirty(path->nodes[0]); |
a28ec197 | 48 | |
5caf2a00 CM |
49 | btrfs_release_path(root->fs_info->extent_root, path); |
50 | btrfs_free_path(path); | |
9f5fae2f | 51 | finish_current_insert(trans, root->fs_info->extent_root); |
e20d96d6 | 52 | del_pending_extents(trans, root->fs_info->extent_root); |
02217ed2 CM |
53 | return 0; |
54 | } | |
55 | ||
b18c6685 CM |
56 | static int lookup_extent_ref(struct btrfs_trans_handle *trans, |
57 | struct btrfs_root *root, u64 blocknr, | |
58 | u64 num_blocks, u32 *refs) | |
a28ec197 | 59 | { |
5caf2a00 | 60 | struct btrfs_path *path; |
a28ec197 | 61 | int ret; |
e2fa7227 | 62 | struct btrfs_key key; |
234b63a0 CM |
63 | struct btrfs_leaf *l; |
64 | struct btrfs_extent_item *item; | |
5caf2a00 CM |
65 | |
66 | path = btrfs_alloc_path(); | |
67 | btrfs_init_path(path); | |
a28ec197 | 68 | key.objectid = blocknr; |
6407bf6d | 69 | key.offset = num_blocks; |
62e2749e CM |
70 | key.flags = 0; |
71 | btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); | |
5caf2a00 | 72 | ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path, |
9f5fae2f | 73 | 0, 0); |
a28ec197 CM |
74 | if (ret != 0) |
75 | BUG(); | |
5caf2a00 CM |
76 | l = btrfs_buffer_leaf(path->nodes[0]); |
77 | item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item); | |
cf27e1ee | 78 | *refs = btrfs_extent_refs(item); |
5caf2a00 CM |
79 | btrfs_release_path(root->fs_info->extent_root, path); |
80 | btrfs_free_path(path); | |
a28ec197 CM |
81 | return 0; |
82 | } | |
83 | ||
c5739bba CM |
84 | int btrfs_inc_root_ref(struct btrfs_trans_handle *trans, |
85 | struct btrfs_root *root) | |
86 | { | |
b18c6685 | 87 | return btrfs_inc_extent_ref(trans, root, bh_blocknr(root->node), 1); |
c5739bba CM |
88 | } |
89 | ||
e089f05c | 90 | int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
e20d96d6 | 91 | struct buffer_head *buf) |
02217ed2 CM |
92 | { |
93 | u64 blocknr; | |
e20d96d6 | 94 | struct btrfs_node *buf_node; |
6407bf6d CM |
95 | struct btrfs_leaf *buf_leaf; |
96 | struct btrfs_disk_key *key; | |
97 | struct btrfs_file_extent_item *fi; | |
02217ed2 | 98 | int i; |
6407bf6d CM |
99 | int leaf; |
100 | int ret; | |
a28ec197 | 101 | |
3768f368 | 102 | if (!root->ref_cows) |
a28ec197 | 103 | return 0; |
e20d96d6 | 104 | buf_node = btrfs_buffer_node(buf); |
6407bf6d CM |
105 | leaf = btrfs_is_leaf(buf_node); |
106 | buf_leaf = btrfs_buffer_leaf(buf); | |
e20d96d6 | 107 | for (i = 0; i < btrfs_header_nritems(&buf_node->header); i++) { |
6407bf6d CM |
108 | if (leaf) { |
109 | key = &buf_leaf->items[i].key; | |
110 | if (btrfs_disk_key_type(key) != BTRFS_EXTENT_DATA_KEY) | |
111 | continue; | |
112 | fi = btrfs_item_ptr(buf_leaf, i, | |
113 | struct btrfs_file_extent_item); | |
236454df CM |
114 | if (btrfs_file_extent_type(fi) == |
115 | BTRFS_FILE_EXTENT_INLINE) | |
116 | continue; | |
b18c6685 | 117 | ret = btrfs_inc_extent_ref(trans, root, |
6407bf6d CM |
118 | btrfs_file_extent_disk_blocknr(fi), |
119 | btrfs_file_extent_disk_num_blocks(fi)); | |
120 | BUG_ON(ret); | |
121 | } else { | |
122 | blocknr = btrfs_node_blockptr(buf_node, i); | |
b18c6685 | 123 | ret = btrfs_inc_extent_ref(trans, root, blocknr, 1); |
6407bf6d CM |
124 | BUG_ON(ret); |
125 | } | |
02217ed2 CM |
126 | } |
127 | return 0; | |
128 | } | |
129 | ||
e089f05c CM |
130 | int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, struct |
131 | btrfs_root *root) | |
a28ec197 | 132 | { |
8ef97622 | 133 | unsigned long gang[8]; |
88fd146c | 134 | u64 first = 0; |
a28ec197 CM |
135 | int ret; |
136 | int i; | |
8ef97622 | 137 | struct radix_tree_root *pinned_radix = &root->fs_info->pinned_radix; |
a28ec197 CM |
138 | |
139 | while(1) { | |
8ef97622 CM |
140 | ret = find_first_radix_bit(pinned_radix, gang, |
141 | ARRAY_SIZE(gang)); | |
a28ec197 CM |
142 | if (!ret) |
143 | break; | |
88fd146c | 144 | if (!first) |
8ef97622 | 145 | first = gang[0]; |
0579da42 | 146 | for (i = 0; i < ret; i++) { |
8ef97622 | 147 | clear_radix_bit(pinned_radix, gang[i]); |
0579da42 | 148 | } |
a28ec197 | 149 | } |
d5719762 CM |
150 | if (root->fs_info->last_insert.objectid > first) |
151 | root->fs_info->last_insert.objectid = first; | |
9f5fae2f | 152 | root->fs_info->last_insert.offset = 0; |
a28ec197 CM |
153 | return 0; |
154 | } | |
155 | ||
e089f05c CM |
156 | static int finish_current_insert(struct btrfs_trans_handle *trans, struct |
157 | btrfs_root *extent_root) | |
037e6390 | 158 | { |
e2fa7227 | 159 | struct btrfs_key ins; |
234b63a0 | 160 | struct btrfs_extent_item extent_item; |
037e6390 CM |
161 | int i; |
162 | int ret; | |
1261ec42 CM |
163 | u64 super_blocks_used; |
164 | struct btrfs_fs_info *info = extent_root->fs_info; | |
037e6390 | 165 | |
cf27e1ee | 166 | btrfs_set_extent_refs(&extent_item, 1); |
037e6390 CM |
167 | ins.offset = 1; |
168 | ins.flags = 0; | |
62e2749e | 169 | btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY); |
5d0c3e60 CM |
170 | btrfs_set_extent_type(&extent_item, BTRFS_EXTENT_TREE); |
171 | btrfs_set_extent_owner(&extent_item, extent_root->root_key.objectid); | |
037e6390 | 172 | |
9f5fae2f CM |
173 | for (i = 0; i < extent_root->fs_info->current_insert.flags; i++) { |
174 | ins.objectid = extent_root->fs_info->current_insert.objectid + | |
175 | i; | |
1261ec42 CM |
176 | super_blocks_used = btrfs_super_blocks_used(info->disk_super); |
177 | btrfs_set_super_blocks_used(info->disk_super, | |
178 | super_blocks_used + 1); | |
e089f05c CM |
179 | ret = btrfs_insert_item(trans, extent_root, &ins, &extent_item, |
180 | sizeof(extent_item)); | |
037e6390 CM |
181 | BUG_ON(ret); |
182 | } | |
9f5fae2f | 183 | extent_root->fs_info->current_insert.offset = 0; |
037e6390 CM |
184 | return 0; |
185 | } | |
186 | ||
8ef97622 | 187 | static int pin_down_block(struct btrfs_root *root, u64 blocknr, int pending) |
e20d96d6 CM |
188 | { |
189 | int err; | |
78fae27e | 190 | struct btrfs_header *header; |
8ef97622 CM |
191 | struct buffer_head *bh; |
192 | ||
f4b9aa8d | 193 | if (!pending) { |
d98237b3 | 194 | bh = btrfs_find_tree_block(root, blocknr); |
2c90e5d6 CM |
195 | if (bh) { |
196 | if (buffer_uptodate(bh)) { | |
197 | u64 transid = | |
198 | root->fs_info->running_transaction->transid; | |
199 | header = btrfs_buffer_header(bh); | |
200 | if (btrfs_header_generation(header) == | |
201 | transid) { | |
202 | btrfs_block_release(root, bh); | |
203 | return 0; | |
204 | } | |
f4b9aa8d | 205 | } |
d6025579 | 206 | btrfs_block_release(root, bh); |
8ef97622 | 207 | } |
8ef97622 | 208 | err = set_radix_bit(&root->fs_info->pinned_radix, blocknr); |
f4b9aa8d CM |
209 | } else { |
210 | err = set_radix_bit(&root->fs_info->pending_del_radix, blocknr); | |
211 | } | |
8ef97622 | 212 | BUG_ON(err); |
e20d96d6 CM |
213 | return 0; |
214 | } | |
215 | ||
fec577fb | 216 | /* |
a28ec197 | 217 | * remove an extent from the root, returns 0 on success |
fec577fb | 218 | */ |
e089f05c | 219 | static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root |
78fae27e | 220 | *root, u64 blocknr, u64 num_blocks, int pin) |
a28ec197 | 221 | { |
5caf2a00 | 222 | struct btrfs_path *path; |
e2fa7227 | 223 | struct btrfs_key key; |
1261ec42 CM |
224 | struct btrfs_fs_info *info = root->fs_info; |
225 | struct btrfs_root *extent_root = info->extent_root; | |
a28ec197 | 226 | int ret; |
234b63a0 | 227 | struct btrfs_extent_item *ei; |
e2fa7227 | 228 | struct btrfs_key ins; |
cf27e1ee | 229 | u32 refs; |
037e6390 | 230 | |
a28ec197 CM |
231 | key.objectid = blocknr; |
232 | key.flags = 0; | |
62e2749e | 233 | btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); |
a28ec197 CM |
234 | key.offset = num_blocks; |
235 | ||
e089f05c | 236 | find_free_extent(trans, root, 0, 0, (u64)-1, &ins); |
5caf2a00 CM |
237 | path = btrfs_alloc_path(); |
238 | BUG_ON(!path); | |
239 | btrfs_init_path(path); | |
5f26f772 | 240 | |
5caf2a00 | 241 | ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1); |
a28ec197 | 242 | if (ret) { |
2e635a27 | 243 | printk("failed to find %Lu\n", key.objectid); |
234b63a0 | 244 | btrfs_print_tree(extent_root, extent_root->node); |
2e635a27 | 245 | printk("failed to find %Lu\n", key.objectid); |
a28ec197 CM |
246 | BUG(); |
247 | } | |
5caf2a00 | 248 | ei = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0], |
123abc88 | 249 | struct btrfs_extent_item); |
a28ec197 | 250 | BUG_ON(ei->refs == 0); |
cf27e1ee CM |
251 | refs = btrfs_extent_refs(ei) - 1; |
252 | btrfs_set_extent_refs(ei, refs); | |
5caf2a00 | 253 | btrfs_mark_buffer_dirty(path->nodes[0]); |
cf27e1ee | 254 | if (refs == 0) { |
1261ec42 | 255 | u64 super_blocks_used; |
78fae27e CM |
256 | |
257 | if (pin) { | |
8ef97622 | 258 | ret = pin_down_block(root, blocknr, 0); |
78fae27e CM |
259 | BUG_ON(ret); |
260 | } | |
261 | ||
1261ec42 CM |
262 | super_blocks_used = btrfs_super_blocks_used(info->disk_super); |
263 | btrfs_set_super_blocks_used(info->disk_super, | |
264 | super_blocks_used - num_blocks); | |
5caf2a00 | 265 | ret = btrfs_del_item(trans, extent_root, path); |
a28ec197 CM |
266 | if (ret) |
267 | BUG(); | |
268 | } | |
5caf2a00 CM |
269 | btrfs_release_path(extent_root, path); |
270 | btrfs_free_path(path); | |
e089f05c | 271 | finish_current_insert(trans, extent_root); |
a28ec197 CM |
272 | return ret; |
273 | } | |
274 | ||
a28ec197 CM |
275 | /* |
276 | * find all the blocks marked as pending in the radix tree and remove | |
277 | * them from the extent map | |
278 | */ | |
e089f05c CM |
279 | static int del_pending_extents(struct btrfs_trans_handle *trans, struct |
280 | btrfs_root *extent_root) | |
a28ec197 CM |
281 | { |
282 | int ret; | |
e20d96d6 CM |
283 | int wret; |
284 | int err = 0; | |
8ef97622 | 285 | unsigned long gang[4]; |
a28ec197 | 286 | int i; |
8ef97622 CM |
287 | struct radix_tree_root *pending_radix; |
288 | struct radix_tree_root *pinned_radix; | |
289 | ||
290 | pending_radix = &extent_root->fs_info->pending_del_radix; | |
291 | pinned_radix = &extent_root->fs_info->pinned_radix; | |
a28ec197 CM |
292 | |
293 | while(1) { | |
8ef97622 CM |
294 | ret = find_first_radix_bit(pending_radix, gang, |
295 | ARRAY_SIZE(gang)); | |
a28ec197 CM |
296 | if (!ret) |
297 | break; | |
298 | for (i = 0; i < ret; i++) { | |
8ef97622 CM |
299 | wret = set_radix_bit(pinned_radix, gang[i]); |
300 | BUG_ON(wret); | |
301 | wret = clear_radix_bit(pending_radix, gang[i]); | |
302 | BUG_ON(wret); | |
d5719762 | 303 | wret = __free_extent(trans, extent_root, |
8ef97622 | 304 | gang[i], 1, 0); |
e20d96d6 CM |
305 | if (wret) |
306 | err = wret; | |
fec577fb CM |
307 | } |
308 | } | |
e20d96d6 | 309 | return err; |
fec577fb CM |
310 | } |
311 | ||
312 | /* | |
313 | * remove an extent from the root, returns 0 on success | |
314 | */ | |
e089f05c CM |
315 | int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root |
316 | *root, u64 blocknr, u64 num_blocks, int pin) | |
fec577fb | 317 | { |
9f5fae2f | 318 | struct btrfs_root *extent_root = root->fs_info->extent_root; |
fec577fb CM |
319 | int pending_ret; |
320 | int ret; | |
a28ec197 | 321 | |
fec577fb | 322 | if (root == extent_root) { |
8ef97622 | 323 | pin_down_block(root, blocknr, 1); |
fec577fb CM |
324 | return 0; |
325 | } | |
78fae27e | 326 | ret = __free_extent(trans, root, blocknr, num_blocks, pin); |
e20d96d6 | 327 | pending_ret = del_pending_extents(trans, root->fs_info->extent_root); |
fec577fb CM |
328 | return ret ? ret : pending_ret; |
329 | } | |
330 | ||
331 | /* | |
332 | * walks the btree of allocated extents and find a hole of a given size. | |
333 | * The key ins is changed to record the hole: | |
334 | * ins->objectid == block start | |
62e2749e | 335 | * ins->flags = BTRFS_EXTENT_ITEM_KEY |
fec577fb CM |
336 | * ins->offset == number of blocks |
337 | * Any available blocks before search_start are skipped. | |
338 | */ | |
e089f05c CM |
339 | static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root |
340 | *orig_root, u64 num_blocks, u64 search_start, u64 | |
341 | search_end, struct btrfs_key *ins) | |
fec577fb | 342 | { |
5caf2a00 | 343 | struct btrfs_path *path; |
e2fa7227 | 344 | struct btrfs_key key; |
fec577fb CM |
345 | int ret; |
346 | u64 hole_size = 0; | |
347 | int slot = 0; | |
e20d96d6 | 348 | u64 last_block = 0; |
037e6390 | 349 | u64 test_block; |
fec577fb | 350 | int start_found; |
234b63a0 | 351 | struct btrfs_leaf *l; |
9f5fae2f | 352 | struct btrfs_root * root = orig_root->fs_info->extent_root; |
0579da42 | 353 | int total_needed = num_blocks; |
e20d96d6 | 354 | int level; |
fec577fb | 355 | |
b1a4d965 CM |
356 | path = btrfs_alloc_path(); |
357 | ins->flags = 0; | |
358 | btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY); | |
359 | ||
e20d96d6 | 360 | level = btrfs_header_level(btrfs_buffer_header(root->node)); |
5d0c3e60 | 361 | total_needed += (level + 2) * 3; |
b1a4d965 CM |
362 | if (root->fs_info->last_insert.objectid == 0 && search_end == (u64)-1) { |
363 | struct btrfs_disk_key *last_key; | |
364 | btrfs_init_path(path); | |
365 | ins->objectid = (u64)-1; | |
366 | ins->offset = (u64)-1; | |
367 | ret = btrfs_search_slot(trans, root, ins, path, 0, 0); | |
368 | if (ret < 0) | |
369 | goto error; | |
370 | BUG_ON(ret == 0); | |
371 | if (path->slots[0] > 0) | |
372 | path->slots[0]--; | |
373 | l = btrfs_buffer_leaf(path->nodes[0]); | |
374 | last_key = &l->items[path->slots[0]].key; | |
375 | search_start = btrfs_disk_key_objectid(last_key); | |
376 | } | |
9f5fae2f CM |
377 | if (root->fs_info->last_insert.objectid > search_start) |
378 | search_start = root->fs_info->last_insert.objectid; | |
62e2749e | 379 | |
fec577fb | 380 | check_failed: |
5caf2a00 | 381 | btrfs_init_path(path); |
fec577fb CM |
382 | ins->objectid = search_start; |
383 | ins->offset = 0; | |
fec577fb | 384 | start_found = 0; |
5caf2a00 | 385 | ret = btrfs_search_slot(trans, root, ins, path, 0, 0); |
0f70abe2 CM |
386 | if (ret < 0) |
387 | goto error; | |
aa5d6bed | 388 | |
5caf2a00 CM |
389 | if (path->slots[0] > 0) |
390 | path->slots[0]--; | |
0579da42 | 391 | |
fec577fb | 392 | while (1) { |
5caf2a00 CM |
393 | l = btrfs_buffer_leaf(path->nodes[0]); |
394 | slot = path->slots[0]; | |
7518a238 | 395 | if (slot >= btrfs_header_nritems(&l->header)) { |
5caf2a00 | 396 | ret = btrfs_next_leaf(root, path); |
fec577fb CM |
397 | if (ret == 0) |
398 | continue; | |
0f70abe2 CM |
399 | if (ret < 0) |
400 | goto error; | |
fec577fb CM |
401 | if (!start_found) { |
402 | ins->objectid = search_start; | |
037e6390 | 403 | ins->offset = (u64)-1; |
fec577fb CM |
404 | start_found = 1; |
405 | goto check_pending; | |
406 | } | |
407 | ins->objectid = last_block > search_start ? | |
408 | last_block : search_start; | |
037e6390 | 409 | ins->offset = (u64)-1; |
fec577fb CM |
410 | goto check_pending; |
411 | } | |
e2fa7227 CM |
412 | btrfs_disk_key_to_cpu(&key, &l->items[slot].key); |
413 | if (key.objectid >= search_start) { | |
fec577fb | 414 | if (start_found) { |
0579da42 CM |
415 | if (last_block < search_start) |
416 | last_block = search_start; | |
e2fa7227 | 417 | hole_size = key.objectid - last_block; |
037e6390 | 418 | if (hole_size > total_needed) { |
fec577fb | 419 | ins->objectid = last_block; |
037e6390 | 420 | ins->offset = hole_size; |
fec577fb CM |
421 | goto check_pending; |
422 | } | |
0579da42 | 423 | } |
fec577fb | 424 | } |
0579da42 | 425 | start_found = 1; |
e2fa7227 | 426 | last_block = key.objectid + key.offset; |
5caf2a00 | 427 | path->slots[0]++; |
fec577fb CM |
428 | } |
429 | // FIXME -ENOSPC | |
430 | check_pending: | |
431 | /* we have to make sure we didn't find an extent that has already | |
432 | * been allocated by the map tree or the original allocation | |
433 | */ | |
5caf2a00 | 434 | btrfs_release_path(root, path); |
fec577fb | 435 | BUG_ON(ins->objectid < search_start); |
037e6390 CM |
436 | for (test_block = ins->objectid; |
437 | test_block < ins->objectid + total_needed; test_block++) { | |
8ef97622 | 438 | if (test_radix_bit(&root->fs_info->pinned_radix, |
9f5fae2f | 439 | test_block)) { |
037e6390 | 440 | search_start = test_block + 1; |
fec577fb CM |
441 | goto check_failed; |
442 | } | |
443 | } | |
9f5fae2f CM |
444 | BUG_ON(root->fs_info->current_insert.offset); |
445 | root->fs_info->current_insert.offset = total_needed - num_blocks; | |
446 | root->fs_info->current_insert.objectid = ins->objectid + num_blocks; | |
447 | root->fs_info->current_insert.flags = 0; | |
448 | root->fs_info->last_insert.objectid = ins->objectid; | |
037e6390 | 449 | ins->offset = num_blocks; |
5caf2a00 | 450 | btrfs_free_path(path); |
fec577fb | 451 | return 0; |
0f70abe2 | 452 | error: |
5caf2a00 CM |
453 | btrfs_release_path(root, path); |
454 | btrfs_free_path(path); | |
0f70abe2 | 455 | return ret; |
fec577fb CM |
456 | } |
457 | ||
fec577fb CM |
458 | /* |
459 | * finds a free extent and does all the dirty work required for allocation | |
460 | * returns the key for the extent through ins, and a tree buffer for | |
461 | * the first block of the extent through buf. | |
462 | * | |
463 | * returns 0 if everything worked, non-zero otherwise. | |
464 | */ | |
4d775673 CM |
465 | int btrfs_alloc_extent(struct btrfs_trans_handle *trans, |
466 | struct btrfs_root *root, u64 owner, | |
467 | u8 type, u64 num_blocks, u64 search_start, | |
468 | u64 search_end, struct btrfs_key *ins) | |
fec577fb CM |
469 | { |
470 | int ret; | |
471 | int pending_ret; | |
1261ec42 CM |
472 | u64 super_blocks_used; |
473 | struct btrfs_fs_info *info = root->fs_info; | |
474 | struct btrfs_root *extent_root = info->extent_root; | |
234b63a0 | 475 | struct btrfs_extent_item extent_item; |
037e6390 | 476 | |
cf27e1ee | 477 | btrfs_set_extent_refs(&extent_item, 1); |
4d775673 CM |
478 | btrfs_set_extent_owner(&extent_item, owner); |
479 | btrfs_set_extent_type(&extent_item, type); | |
fec577fb | 480 | |
037e6390 | 481 | if (root == extent_root) { |
9f5fae2f | 482 | BUG_ON(extent_root->fs_info->current_insert.offset == 0); |
037e6390 | 483 | BUG_ON(num_blocks != 1); |
9f5fae2f CM |
484 | BUG_ON(extent_root->fs_info->current_insert.flags == |
485 | extent_root->fs_info->current_insert.offset); | |
037e6390 | 486 | ins->offset = 1; |
9f5fae2f CM |
487 | ins->objectid = extent_root->fs_info->current_insert.objectid + |
488 | extent_root->fs_info->current_insert.flags++; | |
fec577fb CM |
489 | return 0; |
490 | } | |
e089f05c | 491 | ret = find_free_extent(trans, root, num_blocks, search_start, |
037e6390 CM |
492 | search_end, ins); |
493 | if (ret) | |
494 | return ret; | |
fec577fb | 495 | |
1261ec42 CM |
496 | super_blocks_used = btrfs_super_blocks_used(info->disk_super); |
497 | btrfs_set_super_blocks_used(info->disk_super, super_blocks_used + | |
498 | num_blocks); | |
e089f05c CM |
499 | ret = btrfs_insert_item(trans, extent_root, ins, &extent_item, |
500 | sizeof(extent_item)); | |
037e6390 | 501 | |
e089f05c | 502 | finish_current_insert(trans, extent_root); |
e20d96d6 | 503 | pending_ret = del_pending_extents(trans, extent_root); |
037e6390 CM |
504 | if (ret) |
505 | return ret; | |
506 | if (pending_ret) | |
507 | return pending_ret; | |
508 | return 0; | |
fec577fb CM |
509 | } |
510 | ||
511 | /* | |
512 | * helper function to allocate a block for a given tree | |
513 | * returns the tree buffer or NULL. | |
514 | */ | |
e20d96d6 | 515 | struct buffer_head *btrfs_alloc_free_block(struct btrfs_trans_handle *trans, |
4d775673 | 516 | struct btrfs_root *root) |
fec577fb | 517 | { |
e2fa7227 | 518 | struct btrfs_key ins; |
fec577fb | 519 | int ret; |
e20d96d6 | 520 | struct buffer_head *buf; |
fec577fb | 521 | |
4d775673 CM |
522 | ret = btrfs_alloc_extent(trans, root, root->root_key.objectid, |
523 | BTRFS_EXTENT_TREE, | |
524 | 1, 0, (unsigned long)-1, &ins); | |
fec577fb CM |
525 | if (ret) { |
526 | BUG(); | |
527 | return NULL; | |
528 | } | |
d98237b3 | 529 | buf = btrfs_find_create_tree_block(root, ins.objectid); |
df2ce34c | 530 | set_buffer_uptodate(buf); |
fec577fb CM |
531 | return buf; |
532 | } | |
a28ec197 | 533 | |
6407bf6d CM |
534 | static int drop_leaf_ref(struct btrfs_trans_handle *trans, |
535 | struct btrfs_root *root, struct buffer_head *cur) | |
536 | { | |
537 | struct btrfs_disk_key *key; | |
538 | struct btrfs_leaf *leaf; | |
539 | struct btrfs_file_extent_item *fi; | |
540 | int i; | |
541 | int nritems; | |
542 | int ret; | |
543 | ||
544 | BUG_ON(!btrfs_is_leaf(btrfs_buffer_node(cur))); | |
545 | leaf = btrfs_buffer_leaf(cur); | |
546 | nritems = btrfs_header_nritems(&leaf->header); | |
547 | for (i = 0; i < nritems; i++) { | |
548 | key = &leaf->items[i].key; | |
549 | if (btrfs_disk_key_type(key) != BTRFS_EXTENT_DATA_KEY) | |
550 | continue; | |
551 | fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item); | |
236454df CM |
552 | if (btrfs_file_extent_type(fi) == BTRFS_FILE_EXTENT_INLINE) |
553 | continue; | |
6407bf6d CM |
554 | /* |
555 | * FIXME make sure to insert a trans record that | |
556 | * repeats the snapshot del on crash | |
557 | */ | |
558 | ret = btrfs_free_extent(trans, root, | |
559 | btrfs_file_extent_disk_blocknr(fi), | |
560 | btrfs_file_extent_disk_num_blocks(fi), | |
561 | 0); | |
562 | BUG_ON(ret); | |
563 | } | |
564 | return 0; | |
565 | } | |
566 | ||
9aca1d51 CM |
567 | /* |
568 | * helper function for drop_snapshot, this walks down the tree dropping ref | |
569 | * counts as it goes. | |
570 | */ | |
e089f05c CM |
571 | static int walk_down_tree(struct btrfs_trans_handle *trans, struct btrfs_root |
572 | *root, struct btrfs_path *path, int *level) | |
20524f02 | 573 | { |
e20d96d6 CM |
574 | struct buffer_head *next; |
575 | struct buffer_head *cur; | |
20524f02 CM |
576 | u64 blocknr; |
577 | int ret; | |
578 | u32 refs; | |
579 | ||
5caf2a00 CM |
580 | WARN_ON(*level < 0); |
581 | WARN_ON(*level >= BTRFS_MAX_LEVEL); | |
b18c6685 | 582 | ret = lookup_extent_ref(trans, root, bh_blocknr(path->nodes[*level]), |
6407bf6d | 583 | 1, &refs); |
20524f02 CM |
584 | BUG_ON(ret); |
585 | if (refs > 1) | |
586 | goto out; | |
9aca1d51 CM |
587 | /* |
588 | * walk down to the last node level and free all the leaves | |
589 | */ | |
6407bf6d | 590 | while(*level >= 0) { |
5caf2a00 CM |
591 | WARN_ON(*level < 0); |
592 | WARN_ON(*level >= BTRFS_MAX_LEVEL); | |
20524f02 | 593 | cur = path->nodes[*level]; |
2c90e5d6 CM |
594 | if (btrfs_header_level(btrfs_buffer_header(cur)) != *level) |
595 | WARN_ON(1); | |
7518a238 | 596 | if (path->slots[*level] >= |
e20d96d6 | 597 | btrfs_header_nritems(btrfs_buffer_header(cur))) |
20524f02 | 598 | break; |
6407bf6d CM |
599 | if (*level == 0) { |
600 | ret = drop_leaf_ref(trans, root, cur); | |
601 | BUG_ON(ret); | |
602 | break; | |
603 | } | |
e20d96d6 CM |
604 | blocknr = btrfs_node_blockptr(btrfs_buffer_node(cur), |
605 | path->slots[*level]); | |
b18c6685 | 606 | ret = lookup_extent_ref(trans, root, blocknr, 1, &refs); |
6407bf6d CM |
607 | BUG_ON(ret); |
608 | if (refs != 1) { | |
20524f02 | 609 | path->slots[*level]++; |
e089f05c | 610 | ret = btrfs_free_extent(trans, root, blocknr, 1, 1); |
20524f02 CM |
611 | BUG_ON(ret); |
612 | continue; | |
613 | } | |
20524f02 | 614 | next = read_tree_block(root, blocknr); |
5caf2a00 | 615 | WARN_ON(*level <= 0); |
83e15a28 | 616 | if (path->nodes[*level-1]) |
234b63a0 | 617 | btrfs_block_release(root, path->nodes[*level-1]); |
20524f02 | 618 | path->nodes[*level-1] = next; |
e20d96d6 | 619 | *level = btrfs_header_level(btrfs_buffer_header(next)); |
20524f02 CM |
620 | path->slots[*level] = 0; |
621 | } | |
622 | out: | |
5caf2a00 CM |
623 | WARN_ON(*level < 0); |
624 | WARN_ON(*level >= BTRFS_MAX_LEVEL); | |
6407bf6d | 625 | ret = btrfs_free_extent(trans, root, |
7eccb903 | 626 | bh_blocknr(path->nodes[*level]), 1, 1); |
234b63a0 | 627 | btrfs_block_release(root, path->nodes[*level]); |
20524f02 CM |
628 | path->nodes[*level] = NULL; |
629 | *level += 1; | |
630 | BUG_ON(ret); | |
631 | return 0; | |
632 | } | |
633 | ||
9aca1d51 CM |
634 | /* |
635 | * helper for dropping snapshots. This walks back up the tree in the path | |
636 | * to find the first node higher up where we haven't yet gone through | |
637 | * all the slots | |
638 | */ | |
e089f05c CM |
639 | static int walk_up_tree(struct btrfs_trans_handle *trans, struct btrfs_root |
640 | *root, struct btrfs_path *path, int *level) | |
20524f02 CM |
641 | { |
642 | int i; | |
643 | int slot; | |
644 | int ret; | |
234b63a0 | 645 | for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) { |
20524f02 | 646 | slot = path->slots[i]; |
e20d96d6 CM |
647 | if (slot < btrfs_header_nritems( |
648 | btrfs_buffer_header(path->nodes[i])) - 1) { | |
20524f02 CM |
649 | path->slots[i]++; |
650 | *level = i; | |
651 | return 0; | |
652 | } else { | |
e089f05c | 653 | ret = btrfs_free_extent(trans, root, |
7eccb903 | 654 | bh_blocknr(path->nodes[*level]), |
e089f05c | 655 | 1, 1); |
6407bf6d | 656 | BUG_ON(ret); |
234b63a0 | 657 | btrfs_block_release(root, path->nodes[*level]); |
83e15a28 | 658 | path->nodes[*level] = NULL; |
20524f02 | 659 | *level = i + 1; |
20524f02 CM |
660 | } |
661 | } | |
662 | return 1; | |
663 | } | |
664 | ||
9aca1d51 CM |
665 | /* |
666 | * drop the reference count on the tree rooted at 'snap'. This traverses | |
667 | * the tree freeing any blocks that have a ref count of zero after being | |
668 | * decremented. | |
669 | */ | |
e089f05c | 670 | int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root |
e20d96d6 | 671 | *root, struct buffer_head *snap) |
20524f02 | 672 | { |
3768f368 | 673 | int ret = 0; |
9aca1d51 | 674 | int wret; |
20524f02 | 675 | int level; |
5caf2a00 | 676 | struct btrfs_path *path; |
20524f02 CM |
677 | int i; |
678 | int orig_level; | |
679 | ||
5caf2a00 CM |
680 | path = btrfs_alloc_path(); |
681 | BUG_ON(!path); | |
682 | btrfs_init_path(path); | |
20524f02 | 683 | |
e20d96d6 | 684 | level = btrfs_header_level(btrfs_buffer_header(snap)); |
20524f02 | 685 | orig_level = level; |
5caf2a00 CM |
686 | path->nodes[level] = snap; |
687 | path->slots[level] = 0; | |
20524f02 | 688 | while(1) { |
5caf2a00 | 689 | wret = walk_down_tree(trans, root, path, &level); |
9aca1d51 | 690 | if (wret > 0) |
20524f02 | 691 | break; |
9aca1d51 CM |
692 | if (wret < 0) |
693 | ret = wret; | |
694 | ||
5caf2a00 | 695 | wret = walk_up_tree(trans, root, path, &level); |
9aca1d51 | 696 | if (wret > 0) |
20524f02 | 697 | break; |
9aca1d51 CM |
698 | if (wret < 0) |
699 | ret = wret; | |
20524f02 | 700 | } |
83e15a28 | 701 | for (i = 0; i <= orig_level; i++) { |
5caf2a00 CM |
702 | if (path->nodes[i]) { |
703 | btrfs_block_release(root, path->nodes[i]); | |
83e15a28 | 704 | } |
20524f02 | 705 | } |
5caf2a00 | 706 | btrfs_free_path(path); |
9aca1d51 | 707 | return ret; |
20524f02 | 708 | } |