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Dynamic chunk allocation
[btrfs-progs-unstable.git] / volumes.c
blob52a56f1e9e87c2cc23b85406fd372c21efb81636
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18 #include "ctree.h"
19 #include "disk-io.h"
20 #include "transaction.h"
21 #include "print-tree.h"
22 #include "volumes.h"
23
24 struct map_lookup {
25 struct cache_extent ce;
26 struct btrfs_device *dev;
27 u64 physical;
28 };
29
30 /*
31 * this uses a pretty simple search, the expectation is that it is
32 * called very infrequently and that a given device has a small number
33 * of extents
34 */
35 static int find_free_dev_extent(struct btrfs_trans_handle *trans,
36 struct btrfs_device *device,
37 struct btrfs_path *path,
38 u64 num_bytes, u64 *start)
39 {
40 struct btrfs_key key;
41 struct btrfs_root *root = device->dev_root;
42 struct btrfs_dev_extent *dev_extent = NULL;
43 u64 hole_size = 0;
44 u64 last_byte = 0;
45 u64 search_start = 0;
46 u64 search_end = device->total_bytes;
47 int ret;
48 int slot = 0;
49 int start_found;
50 struct extent_buffer *l;
51
52 start_found = 0;
53 path->reada = 2;
54
55 /* FIXME use last free of some kind */
56
57 key.objectid = device->devid;
58 key.offset = search_start;
59 key.type = BTRFS_DEV_EXTENT_KEY;
60 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
61 if (ret < 0)
62 goto error;
63 ret = btrfs_previous_item(root, path, 0, key.type);
64 if (ret < 0)
65 goto error;
66 l = path->nodes[0];
67 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
68 while (1) {
69 l = path->nodes[0];
70 slot = path->slots[0];
71 if (slot >= btrfs_header_nritems(l)) {
72 ret = btrfs_next_leaf(root, path);
73 if (ret == 0)
74 continue;
75 if (ret < 0)
76 goto error;
77 no_more_items:
78 if (!start_found) {
79 if (search_start >= search_end) {
80 ret = -ENOSPC;
81 goto error;
82 }
83 *start = search_start;
84 start_found = 1;
85 goto check_pending;
86 }
87 *start = last_byte > search_start ?
88 last_byte : search_start;
89 if (search_end <= *start) {
90 ret = -ENOSPC;
91 goto error;
92 }
93 goto check_pending;
94 }
95 btrfs_item_key_to_cpu(l, &key, slot);
96
97 if (key.objectid < device->devid)
98 goto next;
99
100 if (key.objectid > device->devid)
101 goto no_more_items;
102
103 if (key.offset >= search_start && key.offset > last_byte &&
104 start_found) {
105 if (last_byte < search_start)
106 last_byte = search_start;
107 hole_size = key.offset - last_byte;
108 if (key.offset > last_byte &&
109 hole_size >= num_bytes) {
110 *start = last_byte;
111 goto check_pending;
112 }
113 }
114 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY) {
115 goto next;
116 }
117
118 start_found = 1;
119 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
120 last_byte = key.offset + btrfs_dev_extent_length(l, dev_extent);
121 next:
122 path->slots[0]++;
123 cond_resched();
124 }
125 check_pending:
126 /* we have to make sure we didn't find an extent that has already
127 * been allocated by the map tree or the original allocation
128 */
129 btrfs_release_path(root, path);
130 BUG_ON(*start < search_start);
131
132 if (*start + num_bytes > search_end) {
133 ret = -ENOSPC;
134 goto error;
135 }
136 /* check for pending inserts here */
137 return 0;
138
139 error:
140 btrfs_release_path(root, path);
141 return ret;
142 }
143
144 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
145 struct btrfs_device *device,
146 u64 owner, u64 num_bytes, u64 *start)
147 {
148 int ret;
149 struct btrfs_path *path;
150 struct btrfs_root *root = device->dev_root;
151 struct btrfs_dev_extent *extent;
152 struct extent_buffer *leaf;
153 struct btrfs_key key;
154
155 path = btrfs_alloc_path();
156 if (!path)
157 return -ENOMEM;
158
159 ret = find_free_dev_extent(trans, device, path, num_bytes, start);
160 if (ret) {
161 goto err;
162 }
163
164 key.objectid = device->devid;
165 key.offset = *start;
166 key.type = BTRFS_DEV_EXTENT_KEY;
167 ret = btrfs_insert_empty_item(trans, root, path, &key,
168 sizeof(*extent));
169 BUG_ON(ret);
170
171 leaf = path->nodes[0];
172 extent = btrfs_item_ptr(leaf, path->slots[0],
173 struct btrfs_dev_extent);
174 btrfs_set_dev_extent_owner(leaf, extent, owner);
175 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
176 btrfs_mark_buffer_dirty(leaf);
177 err:
178 btrfs_free_path(path);
179 return ret;
180 }
181
182 static int find_next_chunk(struct btrfs_root *root, u64 *objectid)
183 {
184 struct btrfs_path *path;
185 int ret;
186 struct btrfs_key key;
187 struct btrfs_key found_key;
188
189 path = btrfs_alloc_path();
190 BUG_ON(!path);
191
192 key.objectid = (u64)-1;
193 key.offset = (u64)-1;
194 key.type = BTRFS_CHUNK_ITEM_KEY;
195
196 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
197 if (ret < 0)
198 goto error;
199
200 BUG_ON(ret == 0);
201
202 ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
203 if (ret) {
204 *objectid = 0;
205 } else {
206 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
207 path->slots[0]);
208 *objectid = found_key.objectid + found_key.offset;
209 }
210 ret = 0;
211 error:
212 btrfs_free_path(path);
213 return ret;
214 }
215
216 static int find_next_devid(struct btrfs_root *root, struct btrfs_path *path,
217 u64 *objectid)
218 {
219 int ret;
220 struct btrfs_key key;
221 struct btrfs_key found_key;
222
223 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
224 key.type = BTRFS_DEV_ITEM_KEY;
225 key.offset = (u64)-1;
226
227 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
228 if (ret < 0)
229 goto error;
230
231 BUG_ON(ret == 0);
232
233 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
234 BTRFS_DEV_ITEM_KEY);
235 if (ret) {
236 *objectid = 1;
237 } else {
238 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
239 path->slots[0]);
240 *objectid = found_key.offset + 1;
241 }
242 ret = 0;
243 error:
244 btrfs_release_path(root, path);
245 return ret;
246 }
247
248 /*
249 * the device information is stored in the chunk root
250 * the btrfs_device struct should be fully filled in
251 */
252 int btrfs_add_device(struct btrfs_trans_handle *trans,
253 struct btrfs_root *root,
254 struct btrfs_device *device)
255 {
256 int ret;
257 struct btrfs_path *path;
258 struct btrfs_dev_item *dev_item;
259 struct extent_buffer *leaf;
260 struct btrfs_key key;
261 unsigned long ptr;
262 u64 free_devid;
263
264 root = root->fs_info->chunk_root;
265
266 path = btrfs_alloc_path();
267 if (!path)
268 return -ENOMEM;
269
270 ret = find_next_devid(root, path, &free_devid);
271 if (ret)
272 goto out;
273
274 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
275 key.type = BTRFS_DEV_ITEM_KEY;
276 key.offset = free_devid;
277
278 ret = btrfs_insert_empty_item(trans, root, path, &key,
279 sizeof(*dev_item) + device->name_len);
280 if (ret)
281 goto out;
282
283 leaf = path->nodes[0];
284 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
285
286 btrfs_set_device_id(leaf, dev_item, device->devid);
287 btrfs_set_device_type(leaf, dev_item, device->type);
288 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
289 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
290 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
291 btrfs_set_device_rdev(leaf, dev_item, device->rdev);
292 btrfs_set_device_partition(leaf, dev_item, device->partition);
293 btrfs_set_device_name_len(leaf, dev_item, device->name_len);
294 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
295 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
296
297 ptr = (unsigned long)btrfs_device_name(dev_item);
298 write_extent_buffer(leaf, device->name, ptr, device->name_len);
299
300 ptr = (unsigned long)btrfs_device_uuid(dev_item);
301 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_DEV_UUID_SIZE);
302 btrfs_mark_buffer_dirty(leaf);
303 ret = 0;
304
305 out:
306 btrfs_free_path(path);
307 return ret;
308 }
309 int btrfs_update_device(struct btrfs_trans_handle *trans,
310 struct btrfs_device *device)
311 {
312 int ret;
313 struct btrfs_path *path;
314 struct btrfs_root *root;
315 struct btrfs_dev_item *dev_item;
316 struct extent_buffer *leaf;
317 struct btrfs_key key;
318
319 root = device->dev_root->fs_info->chunk_root;
320
321 path = btrfs_alloc_path();
322 if (!path)
323 return -ENOMEM;
324
325 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
326 key.type = BTRFS_DEV_ITEM_KEY;
327 key.offset = device->devid;
328
329 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
330 if (ret < 0)
331 goto out;
332
333 if (ret > 0) {
334 ret = -ENOENT;
335 goto out;
336 }
337
338 leaf = path->nodes[0];
339 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
340
341 btrfs_set_device_id(leaf, dev_item, device->devid);
342 btrfs_set_device_type(leaf, dev_item, device->type);
343 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
344 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
345 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
346 btrfs_set_device_rdev(leaf, dev_item, device->rdev);
347 btrfs_set_device_partition(leaf, dev_item, device->partition);
348 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
349 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
350 btrfs_mark_buffer_dirty(leaf);
351
352 out:
353 btrfs_free_path(path);
354 return ret;
355 }
356
357 int btrfs_add_system_chunk(struct btrfs_trans_handle *trans,
358 struct btrfs_root *root,
359 struct btrfs_key *key,
360 struct btrfs_chunk *chunk, int item_size)
361 {
362 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
363 struct btrfs_disk_key disk_key;
364 u32 array_size;
365 u8 *ptr;
366
367 array_size = btrfs_super_sys_array_size(super_copy);
368 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
369 return -EFBIG;
370
371 ptr = super_copy->sys_chunk_array + array_size;
372 btrfs_cpu_key_to_disk(&disk_key, key);
373 memcpy(ptr, &disk_key, sizeof(disk_key));
374 ptr += sizeof(disk_key);
375 memcpy(ptr, chunk, item_size);
376 item_size += sizeof(disk_key);
377 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
378 return 0;
379 }
380
381 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
382 struct btrfs_root *extent_root, u64 *start,
383 u64 *num_bytes, u64 type)
384 {
385 u64 dev_offset;
386 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
387 struct btrfs_stripe *stripes;
388 struct btrfs_device *device = NULL;
389 struct btrfs_chunk *chunk;
390 struct list_head private_devs;
391 struct list_head *dev_list = &extent_root->fs_info->devices;
392 struct list_head *cur;
393 struct map_lookup *map;
394 u64 physical;
395 u64 calc_size = 1024 * 1024 * 1024;
396 u64 avail;
397 u64 max_avail = 0;
398 int num_stripes = 1;
399 int looped = 0;
400 int ret;
401 int index;
402 struct btrfs_key key;
403
404 if (list_empty(dev_list))
405 return -ENOSPC;
406 again:
407 INIT_LIST_HEAD(&private_devs);
408 cur = dev_list->next;
409 index = 0;
410 /* build a private list of devices we will allocate from */
411 while(index < num_stripes) {
412 device = list_entry(cur, struct btrfs_device, dev_list);
413 avail = device->total_bytes - device->bytes_used;
414 cur = cur->next;
415 if (avail > max_avail)
416 max_avail = avail;
417 if (avail >= calc_size) {
418 list_move_tail(&device->dev_list, &private_devs);
419 index++;
420 }
421 if (cur == dev_list)
422 break;
423 }
424 if (index < num_stripes) {
425 list_splice(&private_devs, dev_list);
426 if (!looped && max_avail > 0) {
427 looped = 1;
428 calc_size = max_avail;
429 goto again;
430 }
431 return -ENOSPC;
432 }
433
434 ret = find_next_chunk(chunk_root, &key.objectid);
435 if (ret)
436 return ret;
437
438 chunk = kmalloc(btrfs_chunk_item_size(num_stripes), GFP_NOFS);
439 if (!chunk)
440 return -ENOMEM;
441
442 stripes = &chunk->stripe;
443
444 *num_bytes = calc_size;
445 index = 0;
446 while(index < num_stripes) {
447 BUG_ON(list_empty(&private_devs));
448 cur = private_devs.next;
449 device = list_entry(cur, struct btrfs_device, dev_list);
450 list_move_tail(&device->dev_list, dev_list);
451
452 ret = btrfs_alloc_dev_extent(trans, device,
453 key.objectid,
454 calc_size, &dev_offset);
455 BUG_ON(ret);
456
457 device->bytes_used += calc_size;
458 ret = btrfs_update_device(trans, device);
459 BUG_ON(ret);
460
461 btrfs_set_stack_stripe_devid(stripes + index, device->devid);
462 btrfs_set_stack_stripe_offset(stripes + index, dev_offset);
463 physical = dev_offset;
464 index++;
465 }
466 BUG_ON(!list_empty(&private_devs));
467
468 /* key.objectid was set above */
469 key.offset = *num_bytes;
470 key.type = BTRFS_CHUNK_ITEM_KEY;
471 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
472 btrfs_set_stack_chunk_stripe_len(chunk, 64 * 1024);
473 btrfs_set_stack_chunk_type(chunk, type);
474 btrfs_set_stack_chunk_num_stripes(chunk, num_stripes);
475 btrfs_set_stack_chunk_io_align(chunk, extent_root->sectorsize);
476 btrfs_set_stack_chunk_io_width(chunk, extent_root->sectorsize);
477 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
478
479 ret = btrfs_insert_item(trans, chunk_root, &key, chunk,
480 btrfs_chunk_item_size(num_stripes));
481 BUG_ON(ret);
482 *start = key.objectid;
483
484 map = kmalloc(sizeof(*map), GFP_NOFS);
485 if (!map)
486 return -ENOMEM;
487
488 map->ce.start = key.objectid;
489 map->ce.size = key.offset;
490
491 map->physical = physical;
492 map->dev = device;
493
494 if (!map->dev) {
495 kfree(map);
496 return -EIO;
497 }
498 ret = insert_existing_cache_extent(
499 &extent_root->fs_info->mapping_tree.cache_tree,
500 &map->ce);
501 BUG_ON(ret);
502
503 kfree(chunk);
504 return ret;
505 }
506
507 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
508 {
509 cache_tree_init(&tree->cache_tree);
510 }
511
512 int btrfs_map_block(struct btrfs_mapping_tree *map_tree,
513 u64 logical, u64 *phys, u64 *length,
514 struct btrfs_device **dev)
515 {
516 struct cache_extent *ce;
517 struct map_lookup *map;
518 u64 offset;
519
520 ce = find_first_cache_extent(&map_tree->cache_tree, logical);
521 BUG_ON(!ce);
522 BUG_ON(ce->start > logical || ce->start + ce->size < logical);
523 map = container_of(ce, struct map_lookup, ce);
524 offset = logical - ce->start;
525 *phys = map->physical + offset;
526 *length = ce->size - offset;
527 *dev = map->dev;
528 return 0;
529 }
530
531 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid)
532 {
533 struct btrfs_device *dev;
534 struct list_head *cur = root->fs_info->devices.next;
535 struct list_head *head = &root->fs_info->devices;
536
537 while(cur != head) {
538 dev = list_entry(cur, struct btrfs_device, dev_list);
539 if (dev->devid == devid)
540 return dev;
541 cur = cur->next;
542 }
543 return NULL;
544 }
545
546 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
547 struct extent_buffer *leaf,
548 struct btrfs_chunk *chunk)
549 {
550 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
551 struct map_lookup *map;
552 struct cache_extent *ce;
553 u64 logical;
554 u64 length;
555 u64 devid;
556 int ret;
557
558 logical = key->objectid;
559 length = key->offset;
560 ce = find_first_cache_extent(&map_tree->cache_tree, logical);
561
562 /* already mapped? */
563 if (ce && ce->start <= logical && ce->start + ce->size > logical) {
564 return 0;
565 }
566
567 map = kmalloc(sizeof(*map), GFP_NOFS);
568 if (!map)
569 return -ENOMEM;
570
571 map->ce.start = logical;
572 map->ce.size = length;
573
574 map->physical = btrfs_stripe_offset_nr(leaf, chunk, 0);
575 devid = btrfs_stripe_devid_nr(leaf, chunk, 0);
576 map->dev = btrfs_find_device(root, devid);
577
578 if (!map->dev) {
579 kfree(map);
580 return -EIO;
581 }
582 ret = insert_existing_cache_extent(&map_tree->cache_tree, &map->ce);
583 BUG_ON(ret);
584
585 return 0;
586 }
587
588 static int fill_device_from_item(struct extent_buffer *leaf,
589 struct btrfs_dev_item *dev_item,
590 struct btrfs_device *device)
591 {
592 unsigned long ptr;
593 char *name;
594
595 device->devid = btrfs_device_id(leaf, dev_item);
596 device->total_bytes = btrfs_device_total_bytes(leaf, dev_item);
597 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
598 device->type = btrfs_device_type(leaf, dev_item);
599 device->io_align = btrfs_device_io_align(leaf, dev_item);
600 device->io_width = btrfs_device_io_width(leaf, dev_item);
601 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
602 device->rdev = btrfs_device_rdev(leaf, dev_item);
603 device->partition = btrfs_device_partition(leaf, dev_item);
604 device->name_len = btrfs_device_name_len(leaf, dev_item);
605
606 ptr = (unsigned long)btrfs_device_uuid(dev_item);
607 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_DEV_UUID_SIZE);
608
609 name = kmalloc(device->name_len + 1, GFP_NOFS);
610 if (!name)
611 return -ENOMEM;
612 device->name = name;
613 ptr = (unsigned long)btrfs_device_name(dev_item);
614 read_extent_buffer(leaf, name, ptr, device->name_len);
615 name[device->name_len] = '\0';
616 return 0;
617 }
618
619 static int read_one_dev(struct btrfs_root *root, struct btrfs_key *key,
620 struct extent_buffer *leaf,
621 struct btrfs_dev_item *dev_item)
622 {
623 struct btrfs_device *device;
624 u64 devid;
625 int ret;
626
627 devid = btrfs_device_id(leaf, dev_item);
628 device = btrfs_find_device(root, devid);
629 if (!device) {
630 device = kmalloc(sizeof(*device), GFP_NOFS);
631 if (!device)
632 return -ENOMEM;
633 list_add(&device->dev_list, &root->fs_info->devices);
634 }
635
636 fill_device_from_item(leaf, dev_item, device);
637 device->dev_root = root->fs_info->dev_root;
638 device->fd = 0;
639 memcpy(&device->dev_key, key, sizeof(*key));
640 ret = btrfs_open_device(device);
641 if (ret) {
642 kfree(device);
643 }
644 return ret;
645 }
646
647 int btrfs_read_sys_array(struct btrfs_root *root)
648 {
649 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
650 struct extent_buffer *sb = root->fs_info->sb_buffer;
651 struct btrfs_disk_key *disk_key;
652 struct btrfs_dev_item *dev_item;
653 struct btrfs_chunk *chunk;
654 struct btrfs_key key;
655 u32 num_stripes;
656 u32 array_size;
657 u32 len = 0;
658 u8 *ptr;
659 unsigned long sb_ptr;
660 u32 cur;
661 int ret;
662 int dev_only = 1;
663
664 array_size = btrfs_super_sys_array_size(super_copy);
665
666 /*
667 * we do this loop twice, once for the device items and
668 * once for all of the chunks. This way there are device
669 * structs filled in for every chunk
670 */
671 again:
672 ptr = super_copy->sys_chunk_array;
673 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
674 cur = 0;
675
676 while (cur < array_size) {
677 disk_key = (struct btrfs_disk_key *)ptr;
678 btrfs_disk_key_to_cpu(&key, disk_key);
679
680 len = sizeof(*disk_key);
681 ptr += len;
682 sb_ptr += len;
683 cur += len;
684
685 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID &&
686 key.type == BTRFS_DEV_ITEM_KEY) {
687 dev_item = (struct btrfs_dev_item *)sb_ptr;
688 if (dev_only) {
689 ret = read_one_dev(root, &key, sb, dev_item);
690 BUG_ON(ret);
691 }
692 len = sizeof(*dev_item);
693 len += btrfs_device_name_len(sb, dev_item);
694 } else if (key.type == BTRFS_CHUNK_ITEM_KEY) {
695
696 chunk = (struct btrfs_chunk *)sb_ptr;
697 if (!dev_only) {
698 ret = read_one_chunk(root, &key, sb, chunk);
699 BUG_ON(ret);
700 }
701 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
702 len = btrfs_chunk_item_size(num_stripes);
703 } else {
704 BUG();
705 }
706 ptr += len;
707 sb_ptr += len;
708 cur += len;
709 }
710 if (dev_only == 1) {
711 dev_only = 0;
712 goto again;
713 }
714 return 0;
715 }
716
717 int btrfs_read_chunk_tree(struct btrfs_root *root)
718 {
719 struct btrfs_path *path;
720 struct extent_buffer *leaf;
721 struct btrfs_key key;
722 struct btrfs_key found_key;
723 int ret;
724 int slot;
725
726 root = root->fs_info->chunk_root;
727
728 path = btrfs_alloc_path();
729 if (!path)
730 return -ENOMEM;
731
732 /* first we search for all of the device items, and then we
733 * read in all of the chunk items. This way we can create chunk
734 * mappings that reference all of the devices that are afound
735 */
736 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
737 key.offset = 0;
738 key.type = 0;
739 again:
740 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
741 while(1) {
742 leaf = path->nodes[0];
743 slot = path->slots[0];
744 if (slot >= btrfs_header_nritems(leaf)) {
745 ret = btrfs_next_leaf(root, path);
746 if (ret == 0)
747 continue;
748 if (ret < 0)
749 goto error;
750 break;
751 }
752 btrfs_item_key_to_cpu(leaf, &found_key, slot);
753 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
754 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
755 break;
756 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
757 struct btrfs_dev_item *dev_item;
758 dev_item = btrfs_item_ptr(leaf, slot,
759 struct btrfs_dev_item);
760 ret = read_one_dev(root, &found_key, leaf,
761 dev_item);
762 BUG_ON(ret);
763 }
764 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
765 struct btrfs_chunk *chunk;
766 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
767 ret = read_one_chunk(root, &found_key, leaf, chunk);
768 }
769 path->slots[0]++;
770 }
771 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
772 key.objectid = 0;
773 btrfs_release_path(root, path);
774 goto again;
775 }
776
777 btrfs_free_path(path);
778 ret = 0;
779 error:
780 return ret;
781 }
782
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