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); | |
b18c6685 | 114 | ret = btrfs_inc_extent_ref(trans, root, |
6407bf6d CM |
115 | btrfs_file_extent_disk_blocknr(fi), |
116 | btrfs_file_extent_disk_num_blocks(fi)); | |
117 | BUG_ON(ret); | |
118 | } else { | |
119 | blocknr = btrfs_node_blockptr(buf_node, i); | |
b18c6685 | 120 | ret = btrfs_inc_extent_ref(trans, root, blocknr, 1); |
6407bf6d CM |
121 | BUG_ON(ret); |
122 | } | |
02217ed2 CM |
123 | } |
124 | return 0; | |
125 | } | |
126 | ||
e089f05c CM |
127 | int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, struct |
128 | btrfs_root *root) | |
a28ec197 | 129 | { |
8ef97622 | 130 | unsigned long gang[8]; |
88fd146c | 131 | u64 first = 0; |
a28ec197 CM |
132 | int ret; |
133 | int i; | |
8ef97622 | 134 | struct radix_tree_root *pinned_radix = &root->fs_info->pinned_radix; |
a28ec197 CM |
135 | |
136 | while(1) { | |
8ef97622 CM |
137 | ret = find_first_radix_bit(pinned_radix, gang, |
138 | ARRAY_SIZE(gang)); | |
a28ec197 CM |
139 | if (!ret) |
140 | break; | |
88fd146c | 141 | if (!first) |
8ef97622 | 142 | first = gang[0]; |
0579da42 | 143 | for (i = 0; i < ret; i++) { |
8ef97622 | 144 | clear_radix_bit(pinned_radix, gang[i]); |
0579da42 | 145 | } |
a28ec197 | 146 | } |
d5719762 CM |
147 | if (root->fs_info->last_insert.objectid > first) |
148 | root->fs_info->last_insert.objectid = first; | |
9f5fae2f | 149 | root->fs_info->last_insert.offset = 0; |
a28ec197 CM |
150 | return 0; |
151 | } | |
152 | ||
e089f05c CM |
153 | static int finish_current_insert(struct btrfs_trans_handle *trans, struct |
154 | btrfs_root *extent_root) | |
037e6390 | 155 | { |
e2fa7227 | 156 | struct btrfs_key ins; |
234b63a0 | 157 | struct btrfs_extent_item extent_item; |
037e6390 CM |
158 | int i; |
159 | int ret; | |
1261ec42 CM |
160 | u64 super_blocks_used; |
161 | struct btrfs_fs_info *info = extent_root->fs_info; | |
037e6390 | 162 | |
cf27e1ee | 163 | btrfs_set_extent_refs(&extent_item, 1); |
037e6390 CM |
164 | ins.offset = 1; |
165 | ins.flags = 0; | |
62e2749e | 166 | btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY); |
037e6390 | 167 | |
9f5fae2f CM |
168 | for (i = 0; i < extent_root->fs_info->current_insert.flags; i++) { |
169 | ins.objectid = extent_root->fs_info->current_insert.objectid + | |
170 | i; | |
1261ec42 CM |
171 | super_blocks_used = btrfs_super_blocks_used(info->disk_super); |
172 | btrfs_set_super_blocks_used(info->disk_super, | |
173 | super_blocks_used + 1); | |
e089f05c CM |
174 | ret = btrfs_insert_item(trans, extent_root, &ins, &extent_item, |
175 | sizeof(extent_item)); | |
037e6390 CM |
176 | BUG_ON(ret); |
177 | } | |
9f5fae2f | 178 | extent_root->fs_info->current_insert.offset = 0; |
037e6390 CM |
179 | return 0; |
180 | } | |
181 | ||
8ef97622 | 182 | static int pin_down_block(struct btrfs_root *root, u64 blocknr, int pending) |
e20d96d6 CM |
183 | { |
184 | int err; | |
78fae27e | 185 | struct btrfs_header *header; |
8ef97622 CM |
186 | struct buffer_head *bh; |
187 | ||
f4b9aa8d | 188 | if (!pending) { |
d98237b3 | 189 | bh = btrfs_find_tree_block(root, blocknr); |
2c90e5d6 CM |
190 | if (bh) { |
191 | if (buffer_uptodate(bh)) { | |
192 | u64 transid = | |
193 | root->fs_info->running_transaction->transid; | |
194 | header = btrfs_buffer_header(bh); | |
195 | if (btrfs_header_generation(header) == | |
196 | transid) { | |
197 | btrfs_block_release(root, bh); | |
198 | return 0; | |
199 | } | |
f4b9aa8d | 200 | } |
d6025579 | 201 | btrfs_block_release(root, bh); |
8ef97622 | 202 | } |
8ef97622 | 203 | err = set_radix_bit(&root->fs_info->pinned_radix, blocknr); |
f4b9aa8d CM |
204 | } else { |
205 | err = set_radix_bit(&root->fs_info->pending_del_radix, blocknr); | |
206 | } | |
8ef97622 | 207 | BUG_ON(err); |
e20d96d6 CM |
208 | return 0; |
209 | } | |
210 | ||
fec577fb | 211 | /* |
a28ec197 | 212 | * remove an extent from the root, returns 0 on success |
fec577fb | 213 | */ |
e089f05c | 214 | static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root |
78fae27e | 215 | *root, u64 blocknr, u64 num_blocks, int pin) |
a28ec197 | 216 | { |
5caf2a00 | 217 | struct btrfs_path *path; |
e2fa7227 | 218 | struct btrfs_key key; |
1261ec42 CM |
219 | struct btrfs_fs_info *info = root->fs_info; |
220 | struct btrfs_root *extent_root = info->extent_root; | |
a28ec197 | 221 | int ret; |
234b63a0 | 222 | struct btrfs_extent_item *ei; |
e2fa7227 | 223 | struct btrfs_key ins; |
cf27e1ee | 224 | u32 refs; |
037e6390 | 225 | |
a28ec197 CM |
226 | key.objectid = blocknr; |
227 | key.flags = 0; | |
62e2749e | 228 | btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); |
a28ec197 CM |
229 | key.offset = num_blocks; |
230 | ||
e089f05c | 231 | find_free_extent(trans, root, 0, 0, (u64)-1, &ins); |
5caf2a00 CM |
232 | path = btrfs_alloc_path(); |
233 | BUG_ON(!path); | |
234 | btrfs_init_path(path); | |
5f26f772 | 235 | |
5caf2a00 | 236 | ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1); |
a28ec197 | 237 | if (ret) { |
2e635a27 | 238 | printk("failed to find %Lu\n", key.objectid); |
234b63a0 | 239 | btrfs_print_tree(extent_root, extent_root->node); |
2e635a27 | 240 | printk("failed to find %Lu\n", key.objectid); |
a28ec197 CM |
241 | BUG(); |
242 | } | |
5caf2a00 | 243 | ei = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0], |
123abc88 | 244 | struct btrfs_extent_item); |
a28ec197 | 245 | BUG_ON(ei->refs == 0); |
cf27e1ee CM |
246 | refs = btrfs_extent_refs(ei) - 1; |
247 | btrfs_set_extent_refs(ei, refs); | |
5caf2a00 | 248 | btrfs_mark_buffer_dirty(path->nodes[0]); |
cf27e1ee | 249 | if (refs == 0) { |
1261ec42 | 250 | u64 super_blocks_used; |
78fae27e CM |
251 | |
252 | if (pin) { | |
8ef97622 | 253 | ret = pin_down_block(root, blocknr, 0); |
78fae27e CM |
254 | BUG_ON(ret); |
255 | } | |
256 | ||
1261ec42 CM |
257 | super_blocks_used = btrfs_super_blocks_used(info->disk_super); |
258 | btrfs_set_super_blocks_used(info->disk_super, | |
259 | super_blocks_used - num_blocks); | |
5caf2a00 | 260 | ret = btrfs_del_item(trans, extent_root, path); |
a28ec197 CM |
261 | if (ret) |
262 | BUG(); | |
263 | } | |
5caf2a00 CM |
264 | btrfs_release_path(extent_root, path); |
265 | btrfs_free_path(path); | |
e089f05c | 266 | finish_current_insert(trans, extent_root); |
a28ec197 CM |
267 | return ret; |
268 | } | |
269 | ||
a28ec197 CM |
270 | /* |
271 | * find all the blocks marked as pending in the radix tree and remove | |
272 | * them from the extent map | |
273 | */ | |
e089f05c CM |
274 | static int del_pending_extents(struct btrfs_trans_handle *trans, struct |
275 | btrfs_root *extent_root) | |
a28ec197 CM |
276 | { |
277 | int ret; | |
e20d96d6 CM |
278 | int wret; |
279 | int err = 0; | |
8ef97622 | 280 | unsigned long gang[4]; |
a28ec197 | 281 | int i; |
8ef97622 CM |
282 | struct radix_tree_root *pending_radix; |
283 | struct radix_tree_root *pinned_radix; | |
284 | ||
285 | pending_radix = &extent_root->fs_info->pending_del_radix; | |
286 | pinned_radix = &extent_root->fs_info->pinned_radix; | |
a28ec197 CM |
287 | |
288 | while(1) { | |
8ef97622 CM |
289 | ret = find_first_radix_bit(pending_radix, gang, |
290 | ARRAY_SIZE(gang)); | |
a28ec197 CM |
291 | if (!ret) |
292 | break; | |
293 | for (i = 0; i < ret; i++) { | |
8ef97622 CM |
294 | wret = set_radix_bit(pinned_radix, gang[i]); |
295 | BUG_ON(wret); | |
296 | wret = clear_radix_bit(pending_radix, gang[i]); | |
297 | BUG_ON(wret); | |
d5719762 | 298 | wret = __free_extent(trans, extent_root, |
8ef97622 | 299 | gang[i], 1, 0); |
e20d96d6 CM |
300 | if (wret) |
301 | err = wret; | |
fec577fb CM |
302 | } |
303 | } | |
e20d96d6 | 304 | return err; |
fec577fb CM |
305 | } |
306 | ||
307 | /* | |
308 | * remove an extent from the root, returns 0 on success | |
309 | */ | |
e089f05c CM |
310 | int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root |
311 | *root, u64 blocknr, u64 num_blocks, int pin) | |
fec577fb | 312 | { |
9f5fae2f | 313 | struct btrfs_root *extent_root = root->fs_info->extent_root; |
fec577fb CM |
314 | int pending_ret; |
315 | int ret; | |
a28ec197 | 316 | |
fec577fb | 317 | if (root == extent_root) { |
8ef97622 | 318 | pin_down_block(root, blocknr, 1); |
fec577fb CM |
319 | return 0; |
320 | } | |
78fae27e | 321 | ret = __free_extent(trans, root, blocknr, num_blocks, pin); |
e20d96d6 | 322 | pending_ret = del_pending_extents(trans, root->fs_info->extent_root); |
fec577fb CM |
323 | return ret ? ret : pending_ret; |
324 | } | |
325 | ||
326 | /* | |
327 | * walks the btree of allocated extents and find a hole of a given size. | |
328 | * The key ins is changed to record the hole: | |
329 | * ins->objectid == block start | |
62e2749e | 330 | * ins->flags = BTRFS_EXTENT_ITEM_KEY |
fec577fb CM |
331 | * ins->offset == number of blocks |
332 | * Any available blocks before search_start are skipped. | |
333 | */ | |
e089f05c CM |
334 | static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root |
335 | *orig_root, u64 num_blocks, u64 search_start, u64 | |
336 | search_end, struct btrfs_key *ins) | |
fec577fb | 337 | { |
5caf2a00 | 338 | struct btrfs_path *path; |
e2fa7227 | 339 | struct btrfs_key key; |
fec577fb CM |
340 | int ret; |
341 | u64 hole_size = 0; | |
342 | int slot = 0; | |
e20d96d6 | 343 | u64 last_block = 0; |
037e6390 | 344 | u64 test_block; |
fec577fb | 345 | int start_found; |
234b63a0 | 346 | struct btrfs_leaf *l; |
9f5fae2f | 347 | struct btrfs_root * root = orig_root->fs_info->extent_root; |
0579da42 | 348 | int total_needed = num_blocks; |
e20d96d6 | 349 | int level; |
fec577fb | 350 | |
b1a4d965 CM |
351 | path = btrfs_alloc_path(); |
352 | ins->flags = 0; | |
353 | btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY); | |
354 | ||
e20d96d6 CM |
355 | level = btrfs_header_level(btrfs_buffer_header(root->node)); |
356 | total_needed += (level + 1) * 3; | |
b1a4d965 CM |
357 | if (root->fs_info->last_insert.objectid == 0 && search_end == (u64)-1) { |
358 | struct btrfs_disk_key *last_key; | |
359 | btrfs_init_path(path); | |
360 | ins->objectid = (u64)-1; | |
361 | ins->offset = (u64)-1; | |
362 | ret = btrfs_search_slot(trans, root, ins, path, 0, 0); | |
363 | if (ret < 0) | |
364 | goto error; | |
365 | BUG_ON(ret == 0); | |
366 | if (path->slots[0] > 0) | |
367 | path->slots[0]--; | |
368 | l = btrfs_buffer_leaf(path->nodes[0]); | |
369 | last_key = &l->items[path->slots[0]].key; | |
370 | search_start = btrfs_disk_key_objectid(last_key); | |
371 | } | |
9f5fae2f CM |
372 | if (root->fs_info->last_insert.objectid > search_start) |
373 | search_start = root->fs_info->last_insert.objectid; | |
62e2749e | 374 | |
fec577fb | 375 | check_failed: |
5caf2a00 | 376 | btrfs_init_path(path); |
fec577fb CM |
377 | ins->objectid = search_start; |
378 | ins->offset = 0; | |
fec577fb | 379 | start_found = 0; |
5caf2a00 | 380 | ret = btrfs_search_slot(trans, root, ins, path, 0, 0); |
0f70abe2 CM |
381 | if (ret < 0) |
382 | goto error; | |
aa5d6bed | 383 | |
5caf2a00 CM |
384 | if (path->slots[0] > 0) |
385 | path->slots[0]--; | |
0579da42 | 386 | |
fec577fb | 387 | while (1) { |
5caf2a00 CM |
388 | l = btrfs_buffer_leaf(path->nodes[0]); |
389 | slot = path->slots[0]; | |
7518a238 | 390 | if (slot >= btrfs_header_nritems(&l->header)) { |
5caf2a00 | 391 | ret = btrfs_next_leaf(root, path); |
fec577fb CM |
392 | if (ret == 0) |
393 | continue; | |
0f70abe2 CM |
394 | if (ret < 0) |
395 | goto error; | |
fec577fb CM |
396 | if (!start_found) { |
397 | ins->objectid = search_start; | |
037e6390 | 398 | ins->offset = (u64)-1; |
fec577fb CM |
399 | start_found = 1; |
400 | goto check_pending; | |
401 | } | |
402 | ins->objectid = last_block > search_start ? | |
403 | last_block : search_start; | |
037e6390 | 404 | ins->offset = (u64)-1; |
fec577fb CM |
405 | goto check_pending; |
406 | } | |
e2fa7227 CM |
407 | btrfs_disk_key_to_cpu(&key, &l->items[slot].key); |
408 | if (key.objectid >= search_start) { | |
fec577fb | 409 | if (start_found) { |
0579da42 CM |
410 | if (last_block < search_start) |
411 | last_block = search_start; | |
e2fa7227 | 412 | hole_size = key.objectid - last_block; |
037e6390 | 413 | if (hole_size > total_needed) { |
fec577fb | 414 | ins->objectid = last_block; |
037e6390 | 415 | ins->offset = hole_size; |
fec577fb CM |
416 | goto check_pending; |
417 | } | |
0579da42 | 418 | } |
fec577fb | 419 | } |
0579da42 | 420 | start_found = 1; |
e2fa7227 | 421 | last_block = key.objectid + key.offset; |
5caf2a00 | 422 | path->slots[0]++; |
fec577fb CM |
423 | } |
424 | // FIXME -ENOSPC | |
425 | check_pending: | |
426 | /* we have to make sure we didn't find an extent that has already | |
427 | * been allocated by the map tree or the original allocation | |
428 | */ | |
5caf2a00 | 429 | btrfs_release_path(root, path); |
fec577fb | 430 | BUG_ON(ins->objectid < search_start); |
037e6390 CM |
431 | for (test_block = ins->objectid; |
432 | test_block < ins->objectid + total_needed; test_block++) { | |
8ef97622 | 433 | if (test_radix_bit(&root->fs_info->pinned_radix, |
9f5fae2f | 434 | test_block)) { |
037e6390 | 435 | search_start = test_block + 1; |
fec577fb CM |
436 | goto check_failed; |
437 | } | |
438 | } | |
9f5fae2f CM |
439 | BUG_ON(root->fs_info->current_insert.offset); |
440 | root->fs_info->current_insert.offset = total_needed - num_blocks; | |
441 | root->fs_info->current_insert.objectid = ins->objectid + num_blocks; | |
442 | root->fs_info->current_insert.flags = 0; | |
443 | root->fs_info->last_insert.objectid = ins->objectid; | |
037e6390 | 444 | ins->offset = num_blocks; |
5caf2a00 | 445 | btrfs_free_path(path); |
fec577fb | 446 | return 0; |
0f70abe2 | 447 | error: |
5caf2a00 CM |
448 | btrfs_release_path(root, path); |
449 | btrfs_free_path(path); | |
0f70abe2 | 450 | return ret; |
fec577fb CM |
451 | } |
452 | ||
fec577fb CM |
453 | /* |
454 | * finds a free extent and does all the dirty work required for allocation | |
455 | * returns the key for the extent through ins, and a tree buffer for | |
456 | * the first block of the extent through buf. | |
457 | * | |
458 | * returns 0 if everything worked, non-zero otherwise. | |
459 | */ | |
dee26a9f | 460 | int btrfs_alloc_extent(struct btrfs_trans_handle *trans, struct btrfs_root |
e089f05c | 461 | *root, u64 num_blocks, u64 search_start, u64 |
d0dbc624 | 462 | search_end, struct btrfs_key *ins) |
fec577fb CM |
463 | { |
464 | int ret; | |
465 | int pending_ret; | |
1261ec42 CM |
466 | u64 super_blocks_used; |
467 | struct btrfs_fs_info *info = root->fs_info; | |
468 | struct btrfs_root *extent_root = info->extent_root; | |
234b63a0 | 469 | struct btrfs_extent_item extent_item; |
037e6390 | 470 | |
cf27e1ee | 471 | btrfs_set_extent_refs(&extent_item, 1); |
fec577fb | 472 | |
037e6390 | 473 | if (root == extent_root) { |
9f5fae2f | 474 | BUG_ON(extent_root->fs_info->current_insert.offset == 0); |
037e6390 | 475 | BUG_ON(num_blocks != 1); |
9f5fae2f CM |
476 | BUG_ON(extent_root->fs_info->current_insert.flags == |
477 | extent_root->fs_info->current_insert.offset); | |
037e6390 | 478 | ins->offset = 1; |
9f5fae2f CM |
479 | ins->objectid = extent_root->fs_info->current_insert.objectid + |
480 | extent_root->fs_info->current_insert.flags++; | |
fec577fb CM |
481 | return 0; |
482 | } | |
e089f05c | 483 | ret = find_free_extent(trans, root, num_blocks, search_start, |
037e6390 CM |
484 | search_end, ins); |
485 | if (ret) | |
486 | return ret; | |
fec577fb | 487 | |
1261ec42 CM |
488 | super_blocks_used = btrfs_super_blocks_used(info->disk_super); |
489 | btrfs_set_super_blocks_used(info->disk_super, super_blocks_used + | |
490 | num_blocks); | |
e089f05c CM |
491 | ret = btrfs_insert_item(trans, extent_root, ins, &extent_item, |
492 | sizeof(extent_item)); | |
037e6390 | 493 | |
e089f05c | 494 | finish_current_insert(trans, extent_root); |
e20d96d6 | 495 | pending_ret = del_pending_extents(trans, extent_root); |
037e6390 CM |
496 | if (ret) |
497 | return ret; | |
498 | if (pending_ret) | |
499 | return pending_ret; | |
500 | return 0; | |
fec577fb CM |
501 | } |
502 | ||
503 | /* | |
504 | * helper function to allocate a block for a given tree | |
505 | * returns the tree buffer or NULL. | |
506 | */ | |
e20d96d6 | 507 | struct buffer_head *btrfs_alloc_free_block(struct btrfs_trans_handle *trans, |
e089f05c | 508 | struct btrfs_root *root) |
fec577fb | 509 | { |
e2fa7227 | 510 | struct btrfs_key ins; |
fec577fb | 511 | int ret; |
e20d96d6 | 512 | struct buffer_head *buf; |
fec577fb | 513 | |
d0dbc624 | 514 | ret = btrfs_alloc_extent(trans, root, 1, 0, (unsigned long)-1, &ins); |
fec577fb CM |
515 | if (ret) { |
516 | BUG(); | |
517 | return NULL; | |
518 | } | |
d98237b3 | 519 | buf = btrfs_find_create_tree_block(root, ins.objectid); |
df2ce34c | 520 | set_buffer_uptodate(buf); |
fec577fb CM |
521 | return buf; |
522 | } | |
a28ec197 | 523 | |
6407bf6d CM |
524 | static int drop_leaf_ref(struct btrfs_trans_handle *trans, |
525 | struct btrfs_root *root, struct buffer_head *cur) | |
526 | { | |
527 | struct btrfs_disk_key *key; | |
528 | struct btrfs_leaf *leaf; | |
529 | struct btrfs_file_extent_item *fi; | |
530 | int i; | |
531 | int nritems; | |
532 | int ret; | |
533 | ||
534 | BUG_ON(!btrfs_is_leaf(btrfs_buffer_node(cur))); | |
535 | leaf = btrfs_buffer_leaf(cur); | |
536 | nritems = btrfs_header_nritems(&leaf->header); | |
537 | for (i = 0; i < nritems; i++) { | |
538 | key = &leaf->items[i].key; | |
539 | if (btrfs_disk_key_type(key) != BTRFS_EXTENT_DATA_KEY) | |
540 | continue; | |
541 | fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item); | |
542 | /* | |
543 | * FIXME make sure to insert a trans record that | |
544 | * repeats the snapshot del on crash | |
545 | */ | |
546 | ret = btrfs_free_extent(trans, root, | |
547 | btrfs_file_extent_disk_blocknr(fi), | |
548 | btrfs_file_extent_disk_num_blocks(fi), | |
549 | 0); | |
550 | BUG_ON(ret); | |
551 | } | |
552 | return 0; | |
553 | } | |
554 | ||
9aca1d51 CM |
555 | /* |
556 | * helper function for drop_snapshot, this walks down the tree dropping ref | |
557 | * counts as it goes. | |
558 | */ | |
e089f05c CM |
559 | static int walk_down_tree(struct btrfs_trans_handle *trans, struct btrfs_root |
560 | *root, struct btrfs_path *path, int *level) | |
20524f02 | 561 | { |
e20d96d6 CM |
562 | struct buffer_head *next; |
563 | struct buffer_head *cur; | |
20524f02 CM |
564 | u64 blocknr; |
565 | int ret; | |
566 | u32 refs; | |
567 | ||
5caf2a00 CM |
568 | WARN_ON(*level < 0); |
569 | WARN_ON(*level >= BTRFS_MAX_LEVEL); | |
b18c6685 | 570 | ret = lookup_extent_ref(trans, root, bh_blocknr(path->nodes[*level]), |
6407bf6d | 571 | 1, &refs); |
20524f02 CM |
572 | BUG_ON(ret); |
573 | if (refs > 1) | |
574 | goto out; | |
9aca1d51 CM |
575 | /* |
576 | * walk down to the last node level and free all the leaves | |
577 | */ | |
6407bf6d | 578 | while(*level >= 0) { |
5caf2a00 CM |
579 | WARN_ON(*level < 0); |
580 | WARN_ON(*level >= BTRFS_MAX_LEVEL); | |
20524f02 | 581 | cur = path->nodes[*level]; |
2c90e5d6 CM |
582 | if (btrfs_header_level(btrfs_buffer_header(cur)) != *level) |
583 | WARN_ON(1); | |
7518a238 | 584 | if (path->slots[*level] >= |
e20d96d6 | 585 | btrfs_header_nritems(btrfs_buffer_header(cur))) |
20524f02 | 586 | break; |
6407bf6d CM |
587 | if (*level == 0) { |
588 | ret = drop_leaf_ref(trans, root, cur); | |
589 | BUG_ON(ret); | |
590 | break; | |
591 | } | |
e20d96d6 CM |
592 | blocknr = btrfs_node_blockptr(btrfs_buffer_node(cur), |
593 | path->slots[*level]); | |
b18c6685 | 594 | ret = lookup_extent_ref(trans, root, blocknr, 1, &refs); |
6407bf6d CM |
595 | BUG_ON(ret); |
596 | if (refs != 1) { | |
20524f02 | 597 | path->slots[*level]++; |
e089f05c | 598 | ret = btrfs_free_extent(trans, root, blocknr, 1, 1); |
20524f02 CM |
599 | BUG_ON(ret); |
600 | continue; | |
601 | } | |
20524f02 | 602 | next = read_tree_block(root, blocknr); |
5caf2a00 | 603 | WARN_ON(*level <= 0); |
83e15a28 | 604 | if (path->nodes[*level-1]) |
234b63a0 | 605 | btrfs_block_release(root, path->nodes[*level-1]); |
20524f02 | 606 | path->nodes[*level-1] = next; |
e20d96d6 | 607 | *level = btrfs_header_level(btrfs_buffer_header(next)); |
20524f02 CM |
608 | path->slots[*level] = 0; |
609 | } | |
610 | out: | |
5caf2a00 CM |
611 | WARN_ON(*level < 0); |
612 | WARN_ON(*level >= BTRFS_MAX_LEVEL); | |
6407bf6d | 613 | ret = btrfs_free_extent(trans, root, |
7eccb903 | 614 | bh_blocknr(path->nodes[*level]), 1, 1); |
234b63a0 | 615 | btrfs_block_release(root, path->nodes[*level]); |
20524f02 CM |
616 | path->nodes[*level] = NULL; |
617 | *level += 1; | |
618 | BUG_ON(ret); | |
619 | return 0; | |
620 | } | |
621 | ||
9aca1d51 CM |
622 | /* |
623 | * helper for dropping snapshots. This walks back up the tree in the path | |
624 | * to find the first node higher up where we haven't yet gone through | |
625 | * all the slots | |
626 | */ | |
e089f05c CM |
627 | static int walk_up_tree(struct btrfs_trans_handle *trans, struct btrfs_root |
628 | *root, struct btrfs_path *path, int *level) | |
20524f02 CM |
629 | { |
630 | int i; | |
631 | int slot; | |
632 | int ret; | |
234b63a0 | 633 | for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) { |
20524f02 | 634 | slot = path->slots[i]; |
e20d96d6 CM |
635 | if (slot < btrfs_header_nritems( |
636 | btrfs_buffer_header(path->nodes[i])) - 1) { | |
20524f02 CM |
637 | path->slots[i]++; |
638 | *level = i; | |
639 | return 0; | |
640 | } else { | |
e089f05c | 641 | ret = btrfs_free_extent(trans, root, |
7eccb903 | 642 | bh_blocknr(path->nodes[*level]), |
e089f05c | 643 | 1, 1); |
6407bf6d | 644 | BUG_ON(ret); |
234b63a0 | 645 | btrfs_block_release(root, path->nodes[*level]); |
83e15a28 | 646 | path->nodes[*level] = NULL; |
20524f02 | 647 | *level = i + 1; |
20524f02 CM |
648 | } |
649 | } | |
650 | return 1; | |
651 | } | |
652 | ||
9aca1d51 CM |
653 | /* |
654 | * drop the reference count on the tree rooted at 'snap'. This traverses | |
655 | * the tree freeing any blocks that have a ref count of zero after being | |
656 | * decremented. | |
657 | */ | |
e089f05c | 658 | int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root |
e20d96d6 | 659 | *root, struct buffer_head *snap) |
20524f02 | 660 | { |
3768f368 | 661 | int ret = 0; |
9aca1d51 | 662 | int wret; |
20524f02 | 663 | int level; |
5caf2a00 | 664 | struct btrfs_path *path; |
20524f02 CM |
665 | int i; |
666 | int orig_level; | |
667 | ||
5caf2a00 CM |
668 | path = btrfs_alloc_path(); |
669 | BUG_ON(!path); | |
670 | btrfs_init_path(path); | |
20524f02 | 671 | |
e20d96d6 | 672 | level = btrfs_header_level(btrfs_buffer_header(snap)); |
20524f02 | 673 | orig_level = level; |
5caf2a00 CM |
674 | path->nodes[level] = snap; |
675 | path->slots[level] = 0; | |
20524f02 | 676 | while(1) { |
5caf2a00 | 677 | wret = walk_down_tree(trans, root, path, &level); |
9aca1d51 | 678 | if (wret > 0) |
20524f02 | 679 | break; |
9aca1d51 CM |
680 | if (wret < 0) |
681 | ret = wret; | |
682 | ||
5caf2a00 | 683 | wret = walk_up_tree(trans, root, path, &level); |
9aca1d51 | 684 | if (wret > 0) |
20524f02 | 685 | break; |
9aca1d51 CM |
686 | if (wret < 0) |
687 | ret = wret; | |
20524f02 | 688 | } |
83e15a28 | 689 | for (i = 0; i <= orig_level; i++) { |
5caf2a00 CM |
690 | if (path->nodes[i]) { |
691 | btrfs_block_release(root, path->nodes[i]); | |
83e15a28 | 692 | } |
20524f02 | 693 | } |
5caf2a00 | 694 | btrfs_free_path(path); |
9aca1d51 | 695 | return ret; |
20524f02 | 696 | } |