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 | |
e089f05c | 15 | static int inc_block_ref(struct btrfs_trans_handle *trans, struct btrfs_root |
6407bf6d | 16 | *root, u64 blocknr, u64 num_blocks) |
02217ed2 | 17 | { |
5caf2a00 | 18 | struct btrfs_path *path; |
02217ed2 | 19 | int ret; |
e2fa7227 | 20 | struct btrfs_key key; |
234b63a0 CM |
21 | struct btrfs_leaf *l; |
22 | struct btrfs_extent_item *item; | |
e2fa7227 | 23 | struct btrfs_key ins; |
cf27e1ee | 24 | u32 refs; |
037e6390 | 25 | |
9f5fae2f CM |
26 | find_free_extent(trans, root->fs_info->extent_root, 0, 0, (u64)-1, |
27 | &ins); | |
5caf2a00 CM |
28 | path = btrfs_alloc_path(); |
29 | BUG_ON(!path); | |
30 | btrfs_init_path(path); | |
02217ed2 CM |
31 | key.objectid = blocknr; |
32 | key.flags = 0; | |
62e2749e | 33 | btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); |
6407bf6d | 34 | key.offset = num_blocks; |
5caf2a00 | 35 | ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path, |
9f5fae2f | 36 | 0, 1); |
a28ec197 CM |
37 | if (ret != 0) |
38 | BUG(); | |
02217ed2 | 39 | BUG_ON(ret != 0); |
5caf2a00 CM |
40 | l = btrfs_buffer_leaf(path->nodes[0]); |
41 | item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item); | |
cf27e1ee CM |
42 | refs = btrfs_extent_refs(item); |
43 | btrfs_set_extent_refs(item, refs + 1); | |
5caf2a00 | 44 | btrfs_mark_buffer_dirty(path->nodes[0]); |
a28ec197 | 45 | |
5caf2a00 CM |
46 | btrfs_release_path(root->fs_info->extent_root, path); |
47 | btrfs_free_path(path); | |
9f5fae2f | 48 | finish_current_insert(trans, root->fs_info->extent_root); |
e20d96d6 | 49 | del_pending_extents(trans, root->fs_info->extent_root); |
02217ed2 CM |
50 | return 0; |
51 | } | |
52 | ||
e089f05c | 53 | static int lookup_block_ref(struct btrfs_trans_handle *trans, struct btrfs_root |
6407bf6d | 54 | *root, u64 blocknr, u64 num_blocks, u32 *refs) |
a28ec197 | 55 | { |
5caf2a00 | 56 | struct btrfs_path *path; |
a28ec197 | 57 | int ret; |
e2fa7227 | 58 | struct btrfs_key key; |
234b63a0 CM |
59 | struct btrfs_leaf *l; |
60 | struct btrfs_extent_item *item; | |
5caf2a00 CM |
61 | |
62 | path = btrfs_alloc_path(); | |
63 | btrfs_init_path(path); | |
a28ec197 | 64 | key.objectid = blocknr; |
6407bf6d | 65 | key.offset = num_blocks; |
62e2749e CM |
66 | key.flags = 0; |
67 | btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); | |
5caf2a00 | 68 | ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path, |
9f5fae2f | 69 | 0, 0); |
a28ec197 CM |
70 | if (ret != 0) |
71 | BUG(); | |
5caf2a00 CM |
72 | l = btrfs_buffer_leaf(path->nodes[0]); |
73 | item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item); | |
cf27e1ee | 74 | *refs = btrfs_extent_refs(item); |
5caf2a00 CM |
75 | btrfs_release_path(root->fs_info->extent_root, path); |
76 | btrfs_free_path(path); | |
a28ec197 CM |
77 | return 0; |
78 | } | |
79 | ||
c5739bba CM |
80 | int btrfs_inc_root_ref(struct btrfs_trans_handle *trans, |
81 | struct btrfs_root *root) | |
82 | { | |
83 | return inc_block_ref(trans, root, root->node->b_blocknr, 1); | |
84 | } | |
85 | ||
e089f05c | 86 | int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
e20d96d6 | 87 | struct buffer_head *buf) |
02217ed2 CM |
88 | { |
89 | u64 blocknr; | |
e20d96d6 | 90 | struct btrfs_node *buf_node; |
6407bf6d CM |
91 | struct btrfs_leaf *buf_leaf; |
92 | struct btrfs_disk_key *key; | |
93 | struct btrfs_file_extent_item *fi; | |
02217ed2 | 94 | int i; |
6407bf6d CM |
95 | int leaf; |
96 | int ret; | |
a28ec197 | 97 | |
3768f368 | 98 | if (!root->ref_cows) |
a28ec197 | 99 | return 0; |
e20d96d6 | 100 | buf_node = btrfs_buffer_node(buf); |
6407bf6d CM |
101 | leaf = btrfs_is_leaf(buf_node); |
102 | buf_leaf = btrfs_buffer_leaf(buf); | |
e20d96d6 | 103 | for (i = 0; i < btrfs_header_nritems(&buf_node->header); i++) { |
6407bf6d CM |
104 | if (leaf) { |
105 | key = &buf_leaf->items[i].key; | |
106 | if (btrfs_disk_key_type(key) != BTRFS_EXTENT_DATA_KEY) | |
107 | continue; | |
108 | fi = btrfs_item_ptr(buf_leaf, i, | |
109 | struct btrfs_file_extent_item); | |
110 | ret = inc_block_ref(trans, root, | |
111 | btrfs_file_extent_disk_blocknr(fi), | |
112 | btrfs_file_extent_disk_num_blocks(fi)); | |
113 | BUG_ON(ret); | |
114 | } else { | |
115 | blocknr = btrfs_node_blockptr(buf_node, i); | |
116 | ret = inc_block_ref(trans, root, blocknr, 1); | |
117 | BUG_ON(ret); | |
118 | } | |
02217ed2 CM |
119 | } |
120 | return 0; | |
121 | } | |
122 | ||
e089f05c CM |
123 | int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, struct |
124 | btrfs_root *root) | |
a28ec197 | 125 | { |
8ef97622 | 126 | unsigned long gang[8]; |
88fd146c | 127 | u64 first = 0; |
a28ec197 CM |
128 | int ret; |
129 | int i; | |
8ef97622 | 130 | struct radix_tree_root *pinned_radix = &root->fs_info->pinned_radix; |
a28ec197 CM |
131 | |
132 | while(1) { | |
8ef97622 CM |
133 | ret = find_first_radix_bit(pinned_radix, gang, |
134 | ARRAY_SIZE(gang)); | |
a28ec197 CM |
135 | if (!ret) |
136 | break; | |
88fd146c | 137 | if (!first) |
8ef97622 | 138 | first = gang[0]; |
0579da42 | 139 | for (i = 0; i < ret; i++) { |
8ef97622 | 140 | clear_radix_bit(pinned_radix, gang[i]); |
0579da42 | 141 | } |
a28ec197 | 142 | } |
d5719762 CM |
143 | if (root->fs_info->last_insert.objectid > first) |
144 | root->fs_info->last_insert.objectid = first; | |
9f5fae2f | 145 | root->fs_info->last_insert.offset = 0; |
a28ec197 CM |
146 | return 0; |
147 | } | |
148 | ||
e089f05c CM |
149 | static int finish_current_insert(struct btrfs_trans_handle *trans, struct |
150 | btrfs_root *extent_root) | |
037e6390 | 151 | { |
e2fa7227 | 152 | struct btrfs_key ins; |
234b63a0 | 153 | struct btrfs_extent_item extent_item; |
037e6390 CM |
154 | int i; |
155 | int ret; | |
1261ec42 CM |
156 | u64 super_blocks_used; |
157 | struct btrfs_fs_info *info = extent_root->fs_info; | |
037e6390 | 158 | |
cf27e1ee CM |
159 | btrfs_set_extent_refs(&extent_item, 1); |
160 | btrfs_set_extent_owner(&extent_item, | |
e20d96d6 | 161 | btrfs_header_parentid(btrfs_buffer_header(extent_root->node))); |
037e6390 CM |
162 | ins.offset = 1; |
163 | ins.flags = 0; | |
62e2749e | 164 | btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY); |
037e6390 | 165 | |
9f5fae2f CM |
166 | for (i = 0; i < extent_root->fs_info->current_insert.flags; i++) { |
167 | ins.objectid = extent_root->fs_info->current_insert.objectid + | |
168 | i; | |
1261ec42 CM |
169 | super_blocks_used = btrfs_super_blocks_used(info->disk_super); |
170 | btrfs_set_super_blocks_used(info->disk_super, | |
171 | super_blocks_used + 1); | |
e089f05c CM |
172 | ret = btrfs_insert_item(trans, extent_root, &ins, &extent_item, |
173 | sizeof(extent_item)); | |
037e6390 CM |
174 | BUG_ON(ret); |
175 | } | |
9f5fae2f | 176 | extent_root->fs_info->current_insert.offset = 0; |
037e6390 CM |
177 | return 0; |
178 | } | |
179 | ||
8ef97622 | 180 | static int pin_down_block(struct btrfs_root *root, u64 blocknr, int pending) |
e20d96d6 CM |
181 | { |
182 | int err; | |
78fae27e | 183 | struct btrfs_header *header; |
8ef97622 CM |
184 | struct buffer_head *bh; |
185 | ||
f4b9aa8d | 186 | if (!pending) { |
d98237b3 | 187 | bh = btrfs_find_tree_block(root, blocknr); |
2c90e5d6 CM |
188 | if (bh) { |
189 | if (buffer_uptodate(bh)) { | |
190 | u64 transid = | |
191 | root->fs_info->running_transaction->transid; | |
192 | header = btrfs_buffer_header(bh); | |
193 | if (btrfs_header_generation(header) == | |
194 | transid) { | |
195 | btrfs_block_release(root, bh); | |
196 | return 0; | |
197 | } | |
f4b9aa8d | 198 | } |
d6025579 | 199 | btrfs_block_release(root, bh); |
8ef97622 | 200 | } |
8ef97622 | 201 | err = set_radix_bit(&root->fs_info->pinned_radix, blocknr); |
f4b9aa8d CM |
202 | } else { |
203 | err = set_radix_bit(&root->fs_info->pending_del_radix, blocknr); | |
204 | } | |
8ef97622 | 205 | BUG_ON(err); |
e20d96d6 CM |
206 | return 0; |
207 | } | |
208 | ||
fec577fb | 209 | /* |
a28ec197 | 210 | * remove an extent from the root, returns 0 on success |
fec577fb | 211 | */ |
e089f05c | 212 | static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root |
78fae27e | 213 | *root, u64 blocknr, u64 num_blocks, int pin) |
a28ec197 | 214 | { |
5caf2a00 | 215 | struct btrfs_path *path; |
e2fa7227 | 216 | struct btrfs_key key; |
1261ec42 CM |
217 | struct btrfs_fs_info *info = root->fs_info; |
218 | struct btrfs_root *extent_root = info->extent_root; | |
a28ec197 | 219 | int ret; |
234b63a0 | 220 | struct btrfs_extent_item *ei; |
e2fa7227 | 221 | struct btrfs_key ins; |
cf27e1ee | 222 | u32 refs; |
037e6390 | 223 | |
a28ec197 CM |
224 | key.objectid = blocknr; |
225 | key.flags = 0; | |
62e2749e | 226 | btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); |
a28ec197 CM |
227 | key.offset = num_blocks; |
228 | ||
e089f05c | 229 | find_free_extent(trans, root, 0, 0, (u64)-1, &ins); |
5caf2a00 CM |
230 | path = btrfs_alloc_path(); |
231 | BUG_ON(!path); | |
232 | btrfs_init_path(path); | |
5f26f772 | 233 | |
5caf2a00 | 234 | ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1); |
a28ec197 | 235 | if (ret) { |
2e635a27 | 236 | printk("failed to find %Lu\n", key.objectid); |
234b63a0 | 237 | btrfs_print_tree(extent_root, extent_root->node); |
2e635a27 | 238 | printk("failed to find %Lu\n", key.objectid); |
a28ec197 CM |
239 | BUG(); |
240 | } | |
5caf2a00 | 241 | ei = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0], |
123abc88 | 242 | struct btrfs_extent_item); |
a28ec197 | 243 | BUG_ON(ei->refs == 0); |
cf27e1ee CM |
244 | refs = btrfs_extent_refs(ei) - 1; |
245 | btrfs_set_extent_refs(ei, refs); | |
5caf2a00 | 246 | btrfs_mark_buffer_dirty(path->nodes[0]); |
cf27e1ee | 247 | if (refs == 0) { |
1261ec42 | 248 | u64 super_blocks_used; |
78fae27e CM |
249 | |
250 | if (pin) { | |
8ef97622 | 251 | ret = pin_down_block(root, blocknr, 0); |
78fae27e CM |
252 | BUG_ON(ret); |
253 | } | |
254 | ||
1261ec42 CM |
255 | super_blocks_used = btrfs_super_blocks_used(info->disk_super); |
256 | btrfs_set_super_blocks_used(info->disk_super, | |
257 | super_blocks_used - num_blocks); | |
5caf2a00 | 258 | ret = btrfs_del_item(trans, extent_root, path); |
a28ec197 CM |
259 | if (ret) |
260 | BUG(); | |
261 | } | |
5caf2a00 CM |
262 | btrfs_release_path(extent_root, path); |
263 | btrfs_free_path(path); | |
e089f05c | 264 | finish_current_insert(trans, extent_root); |
a28ec197 CM |
265 | return ret; |
266 | } | |
267 | ||
a28ec197 CM |
268 | /* |
269 | * find all the blocks marked as pending in the radix tree and remove | |
270 | * them from the extent map | |
271 | */ | |
e089f05c CM |
272 | static int del_pending_extents(struct btrfs_trans_handle *trans, struct |
273 | btrfs_root *extent_root) | |
a28ec197 CM |
274 | { |
275 | int ret; | |
e20d96d6 CM |
276 | int wret; |
277 | int err = 0; | |
8ef97622 | 278 | unsigned long gang[4]; |
a28ec197 | 279 | int i; |
8ef97622 CM |
280 | struct radix_tree_root *pending_radix; |
281 | struct radix_tree_root *pinned_radix; | |
282 | ||
283 | pending_radix = &extent_root->fs_info->pending_del_radix; | |
284 | pinned_radix = &extent_root->fs_info->pinned_radix; | |
a28ec197 CM |
285 | |
286 | while(1) { | |
8ef97622 CM |
287 | ret = find_first_radix_bit(pending_radix, gang, |
288 | ARRAY_SIZE(gang)); | |
a28ec197 CM |
289 | if (!ret) |
290 | break; | |
291 | for (i = 0; i < ret; i++) { | |
8ef97622 CM |
292 | wret = set_radix_bit(pinned_radix, gang[i]); |
293 | BUG_ON(wret); | |
294 | wret = clear_radix_bit(pending_radix, gang[i]); | |
295 | BUG_ON(wret); | |
d5719762 | 296 | wret = __free_extent(trans, extent_root, |
8ef97622 | 297 | gang[i], 1, 0); |
e20d96d6 CM |
298 | if (wret) |
299 | err = wret; | |
fec577fb CM |
300 | } |
301 | } | |
e20d96d6 | 302 | return err; |
fec577fb CM |
303 | } |
304 | ||
305 | /* | |
306 | * remove an extent from the root, returns 0 on success | |
307 | */ | |
e089f05c CM |
308 | int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root |
309 | *root, u64 blocknr, u64 num_blocks, int pin) | |
fec577fb | 310 | { |
9f5fae2f | 311 | struct btrfs_root *extent_root = root->fs_info->extent_root; |
fec577fb CM |
312 | int pending_ret; |
313 | int ret; | |
a28ec197 | 314 | |
fec577fb | 315 | if (root == extent_root) { |
8ef97622 | 316 | pin_down_block(root, blocknr, 1); |
fec577fb CM |
317 | return 0; |
318 | } | |
78fae27e | 319 | ret = __free_extent(trans, root, blocknr, num_blocks, pin); |
e20d96d6 | 320 | pending_ret = del_pending_extents(trans, root->fs_info->extent_root); |
fec577fb CM |
321 | return ret ? ret : pending_ret; |
322 | } | |
323 | ||
324 | /* | |
325 | * walks the btree of allocated extents and find a hole of a given size. | |
326 | * The key ins is changed to record the hole: | |
327 | * ins->objectid == block start | |
62e2749e | 328 | * ins->flags = BTRFS_EXTENT_ITEM_KEY |
fec577fb CM |
329 | * ins->offset == number of blocks |
330 | * Any available blocks before search_start are skipped. | |
331 | */ | |
e089f05c CM |
332 | static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root |
333 | *orig_root, u64 num_blocks, u64 search_start, u64 | |
334 | search_end, struct btrfs_key *ins) | |
fec577fb | 335 | { |
5caf2a00 | 336 | struct btrfs_path *path; |
e2fa7227 | 337 | struct btrfs_key key; |
fec577fb CM |
338 | int ret; |
339 | u64 hole_size = 0; | |
340 | int slot = 0; | |
e20d96d6 | 341 | u64 last_block = 0; |
037e6390 | 342 | u64 test_block; |
fec577fb | 343 | int start_found; |
234b63a0 | 344 | struct btrfs_leaf *l; |
9f5fae2f | 345 | struct btrfs_root * root = orig_root->fs_info->extent_root; |
0579da42 | 346 | int total_needed = num_blocks; |
e20d96d6 | 347 | int level; |
fec577fb | 348 | |
b1a4d965 CM |
349 | path = btrfs_alloc_path(); |
350 | ins->flags = 0; | |
351 | btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY); | |
352 | ||
e20d96d6 CM |
353 | level = btrfs_header_level(btrfs_buffer_header(root->node)); |
354 | total_needed += (level + 1) * 3; | |
b1a4d965 CM |
355 | if (root->fs_info->last_insert.objectid == 0 && search_end == (u64)-1) { |
356 | struct btrfs_disk_key *last_key; | |
357 | btrfs_init_path(path); | |
358 | ins->objectid = (u64)-1; | |
359 | ins->offset = (u64)-1; | |
360 | ret = btrfs_search_slot(trans, root, ins, path, 0, 0); | |
361 | if (ret < 0) | |
362 | goto error; | |
363 | BUG_ON(ret == 0); | |
364 | if (path->slots[0] > 0) | |
365 | path->slots[0]--; | |
366 | l = btrfs_buffer_leaf(path->nodes[0]); | |
367 | last_key = &l->items[path->slots[0]].key; | |
368 | search_start = btrfs_disk_key_objectid(last_key); | |
369 | } | |
9f5fae2f CM |
370 | if (root->fs_info->last_insert.objectid > search_start) |
371 | search_start = root->fs_info->last_insert.objectid; | |
62e2749e | 372 | |
fec577fb | 373 | check_failed: |
5caf2a00 | 374 | btrfs_init_path(path); |
fec577fb CM |
375 | ins->objectid = search_start; |
376 | ins->offset = 0; | |
fec577fb | 377 | start_found = 0; |
5caf2a00 | 378 | ret = btrfs_search_slot(trans, root, ins, path, 0, 0); |
0f70abe2 CM |
379 | if (ret < 0) |
380 | goto error; | |
aa5d6bed | 381 | |
5caf2a00 CM |
382 | if (path->slots[0] > 0) |
383 | path->slots[0]--; | |
0579da42 | 384 | |
fec577fb | 385 | while (1) { |
5caf2a00 CM |
386 | l = btrfs_buffer_leaf(path->nodes[0]); |
387 | slot = path->slots[0]; | |
7518a238 | 388 | if (slot >= btrfs_header_nritems(&l->header)) { |
5caf2a00 | 389 | ret = btrfs_next_leaf(root, path); |
fec577fb CM |
390 | if (ret == 0) |
391 | continue; | |
0f70abe2 CM |
392 | if (ret < 0) |
393 | goto error; | |
fec577fb CM |
394 | if (!start_found) { |
395 | ins->objectid = search_start; | |
037e6390 | 396 | ins->offset = (u64)-1; |
fec577fb CM |
397 | start_found = 1; |
398 | goto check_pending; | |
399 | } | |
400 | ins->objectid = last_block > search_start ? | |
401 | last_block : search_start; | |
037e6390 | 402 | ins->offset = (u64)-1; |
fec577fb CM |
403 | goto check_pending; |
404 | } | |
e2fa7227 CM |
405 | btrfs_disk_key_to_cpu(&key, &l->items[slot].key); |
406 | if (key.objectid >= search_start) { | |
fec577fb | 407 | if (start_found) { |
0579da42 CM |
408 | if (last_block < search_start) |
409 | last_block = search_start; | |
e2fa7227 | 410 | hole_size = key.objectid - last_block; |
037e6390 | 411 | if (hole_size > total_needed) { |
fec577fb | 412 | ins->objectid = last_block; |
037e6390 | 413 | ins->offset = hole_size; |
fec577fb CM |
414 | goto check_pending; |
415 | } | |
0579da42 | 416 | } |
fec577fb | 417 | } |
0579da42 | 418 | start_found = 1; |
e2fa7227 | 419 | last_block = key.objectid + key.offset; |
5caf2a00 | 420 | path->slots[0]++; |
fec577fb CM |
421 | } |
422 | // FIXME -ENOSPC | |
423 | check_pending: | |
424 | /* we have to make sure we didn't find an extent that has already | |
425 | * been allocated by the map tree or the original allocation | |
426 | */ | |
5caf2a00 | 427 | btrfs_release_path(root, path); |
fec577fb | 428 | BUG_ON(ins->objectid < search_start); |
037e6390 CM |
429 | for (test_block = ins->objectid; |
430 | test_block < ins->objectid + total_needed; test_block++) { | |
8ef97622 | 431 | if (test_radix_bit(&root->fs_info->pinned_radix, |
9f5fae2f | 432 | test_block)) { |
037e6390 | 433 | search_start = test_block + 1; |
fec577fb CM |
434 | goto check_failed; |
435 | } | |
436 | } | |
9f5fae2f CM |
437 | BUG_ON(root->fs_info->current_insert.offset); |
438 | root->fs_info->current_insert.offset = total_needed - num_blocks; | |
439 | root->fs_info->current_insert.objectid = ins->objectid + num_blocks; | |
440 | root->fs_info->current_insert.flags = 0; | |
441 | root->fs_info->last_insert.objectid = ins->objectid; | |
037e6390 | 442 | ins->offset = num_blocks; |
5caf2a00 | 443 | btrfs_free_path(path); |
fec577fb | 444 | return 0; |
0f70abe2 | 445 | error: |
5caf2a00 CM |
446 | btrfs_release_path(root, path); |
447 | btrfs_free_path(path); | |
0f70abe2 | 448 | return ret; |
fec577fb CM |
449 | } |
450 | ||
fec577fb CM |
451 | /* |
452 | * finds a free extent and does all the dirty work required for allocation | |
453 | * returns the key for the extent through ins, and a tree buffer for | |
454 | * the first block of the extent through buf. | |
455 | * | |
456 | * returns 0 if everything worked, non-zero otherwise. | |
457 | */ | |
dee26a9f | 458 | int btrfs_alloc_extent(struct btrfs_trans_handle *trans, struct btrfs_root |
e089f05c CM |
459 | *root, u64 num_blocks, u64 search_start, u64 |
460 | search_end, u64 owner, struct btrfs_key *ins) | |
fec577fb CM |
461 | { |
462 | int ret; | |
463 | int pending_ret; | |
1261ec42 CM |
464 | u64 super_blocks_used; |
465 | struct btrfs_fs_info *info = root->fs_info; | |
466 | struct btrfs_root *extent_root = info->extent_root; | |
234b63a0 | 467 | struct btrfs_extent_item extent_item; |
037e6390 | 468 | |
cf27e1ee CM |
469 | btrfs_set_extent_refs(&extent_item, 1); |
470 | btrfs_set_extent_owner(&extent_item, owner); | |
fec577fb | 471 | |
037e6390 | 472 | if (root == extent_root) { |
9f5fae2f | 473 | BUG_ON(extent_root->fs_info->current_insert.offset == 0); |
037e6390 | 474 | BUG_ON(num_blocks != 1); |
9f5fae2f CM |
475 | BUG_ON(extent_root->fs_info->current_insert.flags == |
476 | extent_root->fs_info->current_insert.offset); | |
037e6390 | 477 | ins->offset = 1; |
9f5fae2f CM |
478 | ins->objectid = extent_root->fs_info->current_insert.objectid + |
479 | extent_root->fs_info->current_insert.flags++; | |
fec577fb CM |
480 | return 0; |
481 | } | |
e089f05c | 482 | ret = find_free_extent(trans, root, num_blocks, search_start, |
037e6390 CM |
483 | search_end, ins); |
484 | if (ret) | |
485 | return ret; | |
fec577fb | 486 | |
1261ec42 CM |
487 | super_blocks_used = btrfs_super_blocks_used(info->disk_super); |
488 | btrfs_set_super_blocks_used(info->disk_super, super_blocks_used + | |
489 | num_blocks); | |
e089f05c CM |
490 | ret = btrfs_insert_item(trans, extent_root, ins, &extent_item, |
491 | sizeof(extent_item)); | |
037e6390 | 492 | |
e089f05c | 493 | finish_current_insert(trans, extent_root); |
e20d96d6 | 494 | pending_ret = del_pending_extents(trans, extent_root); |
037e6390 CM |
495 | if (ret) |
496 | return ret; | |
497 | if (pending_ret) | |
498 | return pending_ret; | |
499 | return 0; | |
fec577fb CM |
500 | } |
501 | ||
502 | /* | |
503 | * helper function to allocate a block for a given tree | |
504 | * returns the tree buffer or NULL. | |
505 | */ | |
e20d96d6 | 506 | struct buffer_head *btrfs_alloc_free_block(struct btrfs_trans_handle *trans, |
e089f05c | 507 | struct btrfs_root *root) |
fec577fb | 508 | { |
e2fa7227 | 509 | struct btrfs_key ins; |
fec577fb | 510 | int ret; |
e20d96d6 | 511 | struct buffer_head *buf; |
fec577fb | 512 | |
dee26a9f | 513 | ret = btrfs_alloc_extent(trans, root, 1, 0, (unsigned long)-1, |
e20d96d6 | 514 | btrfs_header_parentid(btrfs_buffer_header(root->node)), &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); | |
e20d96d6 | 570 | ret = lookup_block_ref(trans, root, path->nodes[*level]->b_blocknr, |
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]); | |
6407bf6d CM |
594 | ret = lookup_block_ref(trans, root, blocknr, 1, &refs); |
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 CM |
613 | ret = btrfs_free_extent(trans, root, |
614 | path->nodes[*level]->b_blocknr, 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, |
e20d96d6 | 642 | path->nodes[*level]->b_blocknr, |
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 | } |