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btrfs-debug-tree: add -d option to print only the device mapping
[btrfs-progs-unstable.git] / volumes.c
blob76718550939096f99234826eb304246b8004b618
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 #define _XOPEN_SOURCE 600
19 #define __USE_XOPEN2K
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <sys/types.h>
23 #include <sys/stat.h>
24 #include <uuid/uuid.h>
25 #include <fcntl.h>
26 #include <unistd.h>
27 #include "ctree.h"
28 #include "disk-io.h"
29 #include "transaction.h"
30 #include "print-tree.h"
31 #include "volumes.h"
32
33 struct stripe {
34 struct btrfs_device *dev;
35 u64 physical;
36 };
37
38 struct map_lookup {
39 struct cache_extent ce;
40 u64 type;
41 int io_align;
42 int io_width;
43 int stripe_len;
44 int sector_size;
45 int num_stripes;
46 int sub_stripes;
47 struct btrfs_bio_stripe stripes[];
48 };
49
50 #define map_lookup_size(n) (sizeof(struct map_lookup) + \
51 (sizeof(struct btrfs_bio_stripe) * (n)))
52
53 static LIST_HEAD(fs_uuids);
54
55 static struct btrfs_device *__find_device(struct list_head *head, u64 devid,
56 u8 *uuid)
57 {
58 struct btrfs_device *dev;
59 struct list_head *cur;
60
61 list_for_each(cur, head) {
62 dev = list_entry(cur, struct btrfs_device, dev_list);
63 if (dev->devid == devid &&
64 !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE)) {
65 return dev;
66 }
67 }
68 return NULL;
69 }
70
71 static struct btrfs_fs_devices *find_fsid(u8 *fsid)
72 {
73 struct list_head *cur;
74 struct btrfs_fs_devices *fs_devices;
75
76 list_for_each(cur, &fs_uuids) {
77 fs_devices = list_entry(cur, struct btrfs_fs_devices, list);
78 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
79 return fs_devices;
80 }
81 return NULL;
82 }
83
84 static int device_list_add(const char *path,
85 struct btrfs_super_block *disk_super,
86 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
87 {
88 struct btrfs_device *device;
89 struct btrfs_fs_devices *fs_devices;
90 u64 found_transid = btrfs_super_generation(disk_super);
91
92 fs_devices = find_fsid(disk_super->fsid);
93 if (!fs_devices) {
94 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
95 if (!fs_devices)
96 return -ENOMEM;
97 INIT_LIST_HEAD(&fs_devices->devices);
98 list_add(&fs_devices->list, &fs_uuids);
99 memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
100 fs_devices->latest_devid = devid;
101 fs_devices->latest_trans = found_transid;
102 fs_devices->lowest_devid = (u64)-1;
103 device = NULL;
104 } else {
105 device = __find_device(&fs_devices->devices, devid,
106 disk_super->dev_item.uuid);
107 }
108 if (!device) {
109 device = kzalloc(sizeof(*device), GFP_NOFS);
110 if (!device) {
111 /* we can safely leave the fs_devices entry around */
112 return -ENOMEM;
113 }
114 device->devid = devid;
115 memcpy(device->uuid, disk_super->dev_item.uuid,
116 BTRFS_UUID_SIZE);
117 device->name = kstrdup(path, GFP_NOFS);
118 if (!device->name) {
119 kfree(device);
120 return -ENOMEM;
121 }
122 device->label = kstrdup(disk_super->label, GFP_NOFS);
123 device->total_devs = btrfs_super_num_devices(disk_super);
124 device->super_bytes_used = btrfs_super_bytes_used(disk_super);
125 device->total_bytes =
126 btrfs_stack_device_total_bytes(&disk_super->dev_item);
127 device->bytes_used =
128 btrfs_stack_device_bytes_used(&disk_super->dev_item);
129 list_add(&device->dev_list, &fs_devices->devices);
130 device->fs_devices = fs_devices;
131 }
132
133 if (found_transid > fs_devices->latest_trans) {
134 fs_devices->latest_devid = devid;
135 fs_devices->latest_trans = found_transid;
136 }
137 if (fs_devices->lowest_devid > devid) {
138 fs_devices->lowest_devid = devid;
139 }
140 *fs_devices_ret = fs_devices;
141 return 0;
142 }
143
144 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
145 {
146 struct btrfs_fs_devices *seed_devices;
147 struct list_head *cur;
148 struct btrfs_device *device;
149 again:
150 list_for_each(cur, &fs_devices->devices) {
151 device = list_entry(cur, struct btrfs_device, dev_list);
152 close(device->fd);
153 device->fd = -1;
154 device->writeable = 0;
155 }
156
157 seed_devices = fs_devices->seed;
158 fs_devices->seed = NULL;
159 if (seed_devices) {
160 fs_devices = seed_devices;
161 goto again;
162 }
163
164 return 0;
165 }
166
167 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices, int flags)
168 {
169 int fd;
170 struct list_head *head = &fs_devices->devices;
171 struct list_head *cur;
172 struct btrfs_device *device;
173 int ret;
174
175 list_for_each(cur, head) {
176 device = list_entry(cur, struct btrfs_device, dev_list);
177
178 fd = open(device->name, flags);
179 if (fd < 0) {
180 ret = -errno;
181 goto fail;
182 }
183
184 if (device->devid == fs_devices->latest_devid)
185 fs_devices->latest_bdev = fd;
186 if (device->devid == fs_devices->lowest_devid)
187 fs_devices->lowest_bdev = fd;
188 device->fd = fd;
189 if (flags == O_RDWR)
190 device->writeable = 1;
191 }
192 return 0;
193 fail:
194 btrfs_close_devices(fs_devices);
195 return ret;
196 }
197
198 int btrfs_scan_one_device(int fd, const char *path,
199 struct btrfs_fs_devices **fs_devices_ret,
200 u64 *total_devs, u64 super_offset)
201 {
202 struct btrfs_super_block *disk_super;
203 char *buf;
204 int ret;
205 u64 devid;
206 char uuidbuf[37];
207
208 buf = malloc(4096);
209 if (!buf) {
210 ret = -ENOMEM;
211 goto error;
212 }
213 disk_super = (struct btrfs_super_block *)buf;
214 ret = btrfs_read_dev_super(fd, disk_super, super_offset);
215 if (ret < 0) {
216 ret = -EIO;
217 goto error_brelse;
218 }
219 devid = le64_to_cpu(disk_super->dev_item.devid);
220 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_METADUMP)
221 *total_devs = 1;
222 else
223 *total_devs = btrfs_super_num_devices(disk_super);
224 uuid_unparse(disk_super->fsid, uuidbuf);
225
226 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
227
228 error_brelse:
229 free(buf);
230 error:
231 return ret;
232 }
233
234 /*
235 * this uses a pretty simple search, the expectation is that it is
236 * called very infrequently and that a given device has a small number
237 * of extents
238 */
239 static int find_free_dev_extent(struct btrfs_trans_handle *trans,
240 struct btrfs_device *device,
241 struct btrfs_path *path,
242 u64 num_bytes, u64 *start)
243 {
244 struct btrfs_key key;
245 struct btrfs_root *root = device->dev_root;
246 struct btrfs_dev_extent *dev_extent = NULL;
247 u64 hole_size = 0;
248 u64 last_byte = 0;
249 u64 search_start = 0;
250 u64 search_end = device->total_bytes;
251 int ret;
252 int slot = 0;
253 int start_found;
254 struct extent_buffer *l;
255
256 start_found = 0;
257 path->reada = 2;
258
259 /* FIXME use last free of some kind */
260
261 /* we don't want to overwrite the superblock on the drive,
262 * so we make sure to start at an offset of at least 1MB
263 */
264 search_start = max((u64)1024 * 1024, search_start);
265
266 if (root->fs_info->alloc_start + num_bytes <= device->total_bytes)
267 search_start = max(root->fs_info->alloc_start, search_start);
268
269 key.objectid = device->devid;
270 key.offset = search_start;
271 key.type = BTRFS_DEV_EXTENT_KEY;
272 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
273 if (ret < 0)
274 goto error;
275 ret = btrfs_previous_item(root, path, 0, key.type);
276 if (ret < 0)
277 goto error;
278 l = path->nodes[0];
279 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
280 while (1) {
281 l = path->nodes[0];
282 slot = path->slots[0];
283 if (slot >= btrfs_header_nritems(l)) {
284 ret = btrfs_next_leaf(root, path);
285 if (ret == 0)
286 continue;
287 if (ret < 0)
288 goto error;
289 no_more_items:
290 if (!start_found) {
291 if (search_start >= search_end) {
292 ret = -ENOSPC;
293 goto error;
294 }
295 *start = search_start;
296 start_found = 1;
297 goto check_pending;
298 }
299 *start = last_byte > search_start ?
300 last_byte : search_start;
301 if (search_end <= *start) {
302 ret = -ENOSPC;
303 goto error;
304 }
305 goto check_pending;
306 }
307 btrfs_item_key_to_cpu(l, &key, slot);
308
309 if (key.objectid < device->devid)
310 goto next;
311
312 if (key.objectid > device->devid)
313 goto no_more_items;
314
315 if (key.offset >= search_start && key.offset > last_byte &&
316 start_found) {
317 if (last_byte < search_start)
318 last_byte = search_start;
319 hole_size = key.offset - last_byte;
320 if (key.offset > last_byte &&
321 hole_size >= num_bytes) {
322 *start = last_byte;
323 goto check_pending;
324 }
325 }
326 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY) {
327 goto next;
328 }
329
330 start_found = 1;
331 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
332 last_byte = key.offset + btrfs_dev_extent_length(l, dev_extent);
333 next:
334 path->slots[0]++;
335 cond_resched();
336 }
337 check_pending:
338 /* we have to make sure we didn't find an extent that has already
339 * been allocated by the map tree or the original allocation
340 */
341 btrfs_release_path(root, path);
342 BUG_ON(*start < search_start);
343
344 if (*start + num_bytes > search_end) {
345 ret = -ENOSPC;
346 goto error;
347 }
348 /* check for pending inserts here */
349 return 0;
350
351 error:
352 btrfs_release_path(root, path);
353 return ret;
354 }
355
356 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
357 struct btrfs_device *device,
358 u64 chunk_tree, u64 chunk_objectid,
359 u64 chunk_offset,
360 u64 num_bytes, u64 *start)
361 {
362 int ret;
363 struct btrfs_path *path;
364 struct btrfs_root *root = device->dev_root;
365 struct btrfs_dev_extent *extent;
366 struct extent_buffer *leaf;
367 struct btrfs_key key;
368
369 path = btrfs_alloc_path();
370 if (!path)
371 return -ENOMEM;
372
373 ret = find_free_dev_extent(trans, device, path, num_bytes, start);
374 if (ret) {
375 goto err;
376 }
377
378 key.objectid = device->devid;
379 key.offset = *start;
380 key.type = BTRFS_DEV_EXTENT_KEY;
381 ret = btrfs_insert_empty_item(trans, root, path, &key,
382 sizeof(*extent));
383 BUG_ON(ret);
384
385 leaf = path->nodes[0];
386 extent = btrfs_item_ptr(leaf, path->slots[0],
387 struct btrfs_dev_extent);
388 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
389 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
390 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
391
392 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
393 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
394 BTRFS_UUID_SIZE);
395
396 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
397 btrfs_mark_buffer_dirty(leaf);
398 err:
399 btrfs_free_path(path);
400 return ret;
401 }
402
403 static int find_next_chunk(struct btrfs_root *root, u64 objectid, u64 *offset)
404 {
405 struct btrfs_path *path;
406 int ret;
407 struct btrfs_key key;
408 struct btrfs_chunk *chunk;
409 struct btrfs_key found_key;
410
411 path = btrfs_alloc_path();
412 BUG_ON(!path);
413
414 key.objectid = objectid;
415 key.offset = (u64)-1;
416 key.type = BTRFS_CHUNK_ITEM_KEY;
417
418 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
419 if (ret < 0)
420 goto error;
421
422 BUG_ON(ret == 0);
423
424 ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
425 if (ret) {
426 *offset = 0;
427 } else {
428 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
429 path->slots[0]);
430 if (found_key.objectid != objectid)
431 *offset = 0;
432 else {
433 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
434 struct btrfs_chunk);
435 *offset = found_key.offset +
436 btrfs_chunk_length(path->nodes[0], chunk);
437 }
438 }
439 ret = 0;
440 error:
441 btrfs_free_path(path);
442 return ret;
443 }
444
445 static int find_next_devid(struct btrfs_root *root, struct btrfs_path *path,
446 u64 *objectid)
447 {
448 int ret;
449 struct btrfs_key key;
450 struct btrfs_key found_key;
451
452 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
453 key.type = BTRFS_DEV_ITEM_KEY;
454 key.offset = (u64)-1;
455
456 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
457 if (ret < 0)
458 goto error;
459
460 BUG_ON(ret == 0);
461
462 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
463 BTRFS_DEV_ITEM_KEY);
464 if (ret) {
465 *objectid = 1;
466 } else {
467 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
468 path->slots[0]);
469 *objectid = found_key.offset + 1;
470 }
471 ret = 0;
472 error:
473 btrfs_release_path(root, path);
474 return ret;
475 }
476
477 /*
478 * the device information is stored in the chunk root
479 * the btrfs_device struct should be fully filled in
480 */
481 int btrfs_add_device(struct btrfs_trans_handle *trans,
482 struct btrfs_root *root,
483 struct btrfs_device *device)
484 {
485 int ret;
486 struct btrfs_path *path;
487 struct btrfs_dev_item *dev_item;
488 struct extent_buffer *leaf;
489 struct btrfs_key key;
490 unsigned long ptr;
491 u64 free_devid = 0;
492
493 root = root->fs_info->chunk_root;
494
495 path = btrfs_alloc_path();
496 if (!path)
497 return -ENOMEM;
498
499 ret = find_next_devid(root, path, &free_devid);
500 if (ret)
501 goto out;
502
503 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
504 key.type = BTRFS_DEV_ITEM_KEY;
505 key.offset = free_devid;
506
507 ret = btrfs_insert_empty_item(trans, root, path, &key,
508 sizeof(*dev_item));
509 if (ret)
510 goto out;
511
512 leaf = path->nodes[0];
513 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
514
515 device->devid = free_devid;
516 btrfs_set_device_id(leaf, dev_item, device->devid);
517 btrfs_set_device_generation(leaf, dev_item, 0);
518 btrfs_set_device_type(leaf, dev_item, device->type);
519 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
520 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
521 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
522 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
523 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
524 btrfs_set_device_group(leaf, dev_item, 0);
525 btrfs_set_device_seek_speed(leaf, dev_item, 0);
526 btrfs_set_device_bandwidth(leaf, dev_item, 0);
527 btrfs_set_device_start_offset(leaf, dev_item, 0);
528
529 ptr = (unsigned long)btrfs_device_uuid(dev_item);
530 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
531 ptr = (unsigned long)btrfs_device_fsid(dev_item);
532 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
533 btrfs_mark_buffer_dirty(leaf);
534 ret = 0;
535
536 out:
537 btrfs_free_path(path);
538 return ret;
539 }
540
541 int btrfs_update_device(struct btrfs_trans_handle *trans,
542 struct btrfs_device *device)
543 {
544 int ret;
545 struct btrfs_path *path;
546 struct btrfs_root *root;
547 struct btrfs_dev_item *dev_item;
548 struct extent_buffer *leaf;
549 struct btrfs_key key;
550
551 root = device->dev_root->fs_info->chunk_root;
552
553 path = btrfs_alloc_path();
554 if (!path)
555 return -ENOMEM;
556
557 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
558 key.type = BTRFS_DEV_ITEM_KEY;
559 key.offset = device->devid;
560
561 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
562 if (ret < 0)
563 goto out;
564
565 if (ret > 0) {
566 ret = -ENOENT;
567 goto out;
568 }
569
570 leaf = path->nodes[0];
571 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
572
573 btrfs_set_device_id(leaf, dev_item, device->devid);
574 btrfs_set_device_type(leaf, dev_item, device->type);
575 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
576 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
577 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
578 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
579 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
580 btrfs_mark_buffer_dirty(leaf);
581
582 out:
583 btrfs_free_path(path);
584 return ret;
585 }
586
587 int btrfs_add_system_chunk(struct btrfs_trans_handle *trans,
588 struct btrfs_root *root,
589 struct btrfs_key *key,
590 struct btrfs_chunk *chunk, int item_size)
591 {
592 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
593 struct btrfs_disk_key disk_key;
594 u32 array_size;
595 u8 *ptr;
596
597 array_size = btrfs_super_sys_array_size(super_copy);
598 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
599 return -EFBIG;
600
601 ptr = super_copy->sys_chunk_array + array_size;
602 btrfs_cpu_key_to_disk(&disk_key, key);
603 memcpy(ptr, &disk_key, sizeof(disk_key));
604 ptr += sizeof(disk_key);
605 memcpy(ptr, chunk, item_size);
606 item_size += sizeof(disk_key);
607 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
608 return 0;
609 }
610
611 static u64 div_factor(u64 num, int factor)
612 {
613 if (factor == 10)
614 return num;
615 num *= factor;
616 return num / 10;
617 }
618
619 static u64 chunk_bytes_by_type(u64 type, u64 calc_size, int num_stripes,
620 int sub_stripes)
621 {
622 if (type & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_DUP))
623 return calc_size;
624 else if (type & BTRFS_BLOCK_GROUP_RAID10)
625 return calc_size * (num_stripes / sub_stripes);
626 else
627 return calc_size * num_stripes;
628 }
629
630
631 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
632 struct btrfs_root *extent_root, u64 *start,
633 u64 *num_bytes, u64 type)
634 {
635 u64 dev_offset;
636 struct btrfs_fs_info *info = extent_root->fs_info;
637 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
638 struct btrfs_stripe *stripes;
639 struct btrfs_device *device = NULL;
640 struct btrfs_chunk *chunk;
641 struct list_head private_devs;
642 struct list_head *dev_list = &extent_root->fs_info->fs_devices->devices;
643 struct list_head *cur;
644 struct map_lookup *map;
645 int min_stripe_size = 1 * 1024 * 1024;
646 u64 physical;
647 u64 calc_size = 8 * 1024 * 1024;
648 u64 min_free;
649 u64 max_chunk_size = 4 * calc_size;
650 u64 avail;
651 u64 max_avail = 0;
652 u64 percent_max;
653 int num_stripes = 1;
654 int min_stripes = 1;
655 int sub_stripes = 0;
656 int looped = 0;
657 int ret;
658 int index;
659 int stripe_len = 64 * 1024;
660 struct btrfs_key key;
661
662 if (list_empty(dev_list)) {
663 return -ENOSPC;
664 }
665
666 if (type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
667 BTRFS_BLOCK_GROUP_RAID10 |
668 BTRFS_BLOCK_GROUP_DUP)) {
669 if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
670 calc_size = 8 * 1024 * 1024;
671 max_chunk_size = calc_size * 2;
672 min_stripe_size = 1 * 1024 * 1024;
673 } else if (type & BTRFS_BLOCK_GROUP_DATA) {
674 calc_size = 1024 * 1024 * 1024;
675 max_chunk_size = 10 * calc_size;
676 min_stripe_size = 64 * 1024 * 1024;
677 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
678 calc_size = 1024 * 1024 * 1024;
679 max_chunk_size = 4 * calc_size;
680 min_stripe_size = 32 * 1024 * 1024;
681 }
682 }
683 if (type & BTRFS_BLOCK_GROUP_RAID1) {
684 num_stripes = min_t(u64, 2,
685 btrfs_super_num_devices(&info->super_copy));
686 if (num_stripes < 2)
687 return -ENOSPC;
688 min_stripes = 2;
689 }
690 if (type & BTRFS_BLOCK_GROUP_DUP) {
691 num_stripes = 2;
692 min_stripes = 2;
693 }
694 if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
695 num_stripes = btrfs_super_num_devices(&info->super_copy);
696 min_stripes = 2;
697 }
698 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
699 num_stripes = btrfs_super_num_devices(&info->super_copy);
700 if (num_stripes < 4)
701 return -ENOSPC;
702 num_stripes &= ~(u32)1;
703 sub_stripes = 2;
704 min_stripes = 4;
705 }
706
707 /* we don't want a chunk larger than 10% of the FS */
708 percent_max = div_factor(btrfs_super_total_bytes(&info->super_copy), 1);
709 max_chunk_size = min(percent_max, max_chunk_size);
710
711 again:
712 if (chunk_bytes_by_type(type, calc_size, num_stripes, sub_stripes) >
713 max_chunk_size) {
714 calc_size = max_chunk_size;
715 calc_size /= num_stripes;
716 calc_size /= stripe_len;
717 calc_size *= stripe_len;
718 }
719 /* we don't want tiny stripes */
720 calc_size = max_t(u64, calc_size, min_stripe_size);
721
722 calc_size /= stripe_len;
723 calc_size *= stripe_len;
724 INIT_LIST_HEAD(&private_devs);
725 cur = dev_list->next;
726 index = 0;
727
728 if (type & BTRFS_BLOCK_GROUP_DUP)
729 min_free = calc_size * 2;
730 else
731 min_free = calc_size;
732
733 /* build a private list of devices we will allocate from */
734 while(index < num_stripes) {
735 device = list_entry(cur, struct btrfs_device, dev_list);
736 avail = device->total_bytes - device->bytes_used;
737 cur = cur->next;
738 if (avail >= min_free) {
739 list_move_tail(&device->dev_list, &private_devs);
740 index++;
741 if (type & BTRFS_BLOCK_GROUP_DUP)
742 index++;
743 } else if (avail > max_avail)
744 max_avail = avail;
745 if (cur == dev_list)
746 break;
747 }
748 if (index < num_stripes) {
749 list_splice(&private_devs, dev_list);
750 if (index >= min_stripes) {
751 num_stripes = index;
752 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
753 num_stripes /= sub_stripes;
754 num_stripes *= sub_stripes;
755 }
756 looped = 1;
757 goto again;
758 }
759 if (!looped && max_avail > 0) {
760 looped = 1;
761 calc_size = max_avail;
762 goto again;
763 }
764 return -ENOSPC;
765 }
766 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
767 key.type = BTRFS_CHUNK_ITEM_KEY;
768 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
769 &key.offset);
770 if (ret)
771 return ret;
772
773 chunk = kmalloc(btrfs_chunk_item_size(num_stripes), GFP_NOFS);
774 if (!chunk)
775 return -ENOMEM;
776
777 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
778 if (!map) {
779 kfree(chunk);
780 return -ENOMEM;
781 }
782
783 stripes = &chunk->stripe;
784 *num_bytes = chunk_bytes_by_type(type, calc_size,
785 num_stripes, sub_stripes);
786 index = 0;
787 while(index < num_stripes) {
788 struct btrfs_stripe *stripe;
789 BUG_ON(list_empty(&private_devs));
790 cur = private_devs.next;
791 device = list_entry(cur, struct btrfs_device, dev_list);
792
793 /* loop over this device again if we're doing a dup group */
794 if (!(type & BTRFS_BLOCK_GROUP_DUP) ||
795 (index == num_stripes - 1))
796 list_move_tail(&device->dev_list, dev_list);
797
798 ret = btrfs_alloc_dev_extent(trans, device,
799 info->chunk_root->root_key.objectid,
800 BTRFS_FIRST_CHUNK_TREE_OBJECTID, key.offset,
801 calc_size, &dev_offset);
802 BUG_ON(ret);
803
804 device->bytes_used += calc_size;
805 ret = btrfs_update_device(trans, device);
806 BUG_ON(ret);
807
808 map->stripes[index].dev = device;
809 map->stripes[index].physical = dev_offset;
810 stripe = stripes + index;
811 btrfs_set_stack_stripe_devid(stripe, device->devid);
812 btrfs_set_stack_stripe_offset(stripe, dev_offset);
813 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
814 physical = dev_offset;
815 index++;
816 }
817 BUG_ON(!list_empty(&private_devs));
818
819 /* key was set above */
820 btrfs_set_stack_chunk_length(chunk, *num_bytes);
821 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
822 btrfs_set_stack_chunk_stripe_len(chunk, stripe_len);
823 btrfs_set_stack_chunk_type(chunk, type);
824 btrfs_set_stack_chunk_num_stripes(chunk, num_stripes);
825 btrfs_set_stack_chunk_io_align(chunk, stripe_len);
826 btrfs_set_stack_chunk_io_width(chunk, stripe_len);
827 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
828 btrfs_set_stack_chunk_sub_stripes(chunk, sub_stripes);
829 map->sector_size = extent_root->sectorsize;
830 map->stripe_len = stripe_len;
831 map->io_align = stripe_len;
832 map->io_width = stripe_len;
833 map->type = type;
834 map->num_stripes = num_stripes;
835 map->sub_stripes = sub_stripes;
836
837 ret = btrfs_insert_item(trans, chunk_root, &key, chunk,
838 btrfs_chunk_item_size(num_stripes));
839 BUG_ON(ret);
840 *start = key.offset;;
841
842 map->ce.start = key.offset;
843 map->ce.size = *num_bytes;
844
845 ret = insert_existing_cache_extent(
846 &extent_root->fs_info->mapping_tree.cache_tree,
847 &map->ce);
848 BUG_ON(ret);
849
850 if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
851 ret = btrfs_add_system_chunk(trans, chunk_root, &key,
852 chunk, btrfs_chunk_item_size(num_stripes));
853 BUG_ON(ret);
854 }
855
856 kfree(chunk);
857 return ret;
858 }
859
860 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
861 {
862 cache_tree_init(&tree->cache_tree);
863 }
864
865 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
866 {
867 struct cache_extent *ce;
868 struct map_lookup *map;
869 int ret;
870 u64 offset;
871
872 ce = find_first_cache_extent(&map_tree->cache_tree, logical);
873 BUG_ON(!ce);
874 BUG_ON(ce->start > logical || ce->start + ce->size < logical);
875 map = container_of(ce, struct map_lookup, ce);
876
877 offset = logical - ce->start;
878 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
879 ret = map->num_stripes;
880 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
881 ret = map->sub_stripes;
882 else
883 ret = 1;
884 return ret;
885 }
886
887 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
888 u64 chunk_start, u64 physical, u64 devid,
889 u64 **logical, int *naddrs, int *stripe_len)
890 {
891 struct cache_extent *ce;
892 struct map_lookup *map;
893 u64 *buf;
894 u64 bytenr;
895 u64 length;
896 u64 stripe_nr;
897 int i, j, nr = 0;
898
899 ce = find_first_cache_extent(&map_tree->cache_tree, chunk_start);
900 BUG_ON(!ce);
901 map = container_of(ce, struct map_lookup, ce);
902
903 length = ce->size;
904 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
905 length = ce->size / (map->num_stripes / map->sub_stripes);
906 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
907 length = ce->size / map->num_stripes;
908
909 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
910
911 for (i = 0; i < map->num_stripes; i++) {
912 if (devid && map->stripes[i].dev->devid != devid)
913 continue;
914 if (map->stripes[i].physical > physical ||
915 map->stripes[i].physical + length <= physical)
916 continue;
917
918 stripe_nr = (physical - map->stripes[i].physical) /
919 map->stripe_len;
920
921 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
922 stripe_nr = (stripe_nr * map->num_stripes + i) /
923 map->sub_stripes;
924 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
925 stripe_nr = stripe_nr * map->num_stripes + i;
926 }
927 bytenr = ce->start + stripe_nr * map->stripe_len;
928 for (j = 0; j < nr; j++) {
929 if (buf[j] == bytenr)
930 break;
931 }
932 if (j == nr)
933 buf[nr++] = bytenr;
934 }
935
936 *logical = buf;
937 *naddrs = nr;
938 *stripe_len = map->stripe_len;
939
940 return 0;
941 }
942
943 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
944 u64 logical, u64 *length,
945 struct btrfs_multi_bio **multi_ret, int mirror_num)
946 {
947 struct cache_extent *ce;
948 struct map_lookup *map;
949 u64 offset;
950 u64 stripe_offset;
951 u64 stripe_nr;
952 int stripes_allocated = 8;
953 int stripes_required = 1;
954 int stripe_index;
955 int i;
956 struct btrfs_multi_bio *multi = NULL;
957
958 if (multi_ret && rw == READ) {
959 stripes_allocated = 1;
960 }
961 again:
962 if (multi_ret) {
963 multi = kzalloc(btrfs_multi_bio_size(stripes_allocated),
964 GFP_NOFS);
965 if (!multi)
966 return -ENOMEM;
967 }
968
969 ce = find_first_cache_extent(&map_tree->cache_tree, logical);
970 BUG_ON(!ce);
971 BUG_ON(ce->start > logical || ce->start + ce->size < logical);
972 map = container_of(ce, struct map_lookup, ce);
973 offset = logical - ce->start;
974
975 if (rw == WRITE) {
976 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
977 BTRFS_BLOCK_GROUP_DUP)) {
978 stripes_required = map->num_stripes;
979 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
980 stripes_required = map->sub_stripes;
981 }
982 }
983 /* if our multi bio struct is too small, back off and try again */
984 if (multi_ret && rw == WRITE &&
985 stripes_allocated < stripes_required) {
986 stripes_allocated = map->num_stripes;
987 kfree(multi);
988 goto again;
989 }
990 stripe_nr = offset;
991 /*
992 * stripe_nr counts the total number of stripes we have to stride
993 * to get to this block
994 */
995 stripe_nr = stripe_nr / map->stripe_len;
996
997 stripe_offset = stripe_nr * map->stripe_len;
998 BUG_ON(offset < stripe_offset);
999
1000 /* stripe_offset is the offset of this block in its stripe*/
1001 stripe_offset = offset - stripe_offset;
1002
1003 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
1004 BTRFS_BLOCK_GROUP_RAID10 |
1005 BTRFS_BLOCK_GROUP_DUP)) {
1006 /* we limit the length of each bio to what fits in a stripe */
1007 *length = min_t(u64, ce->size - offset,
1008 map->stripe_len - stripe_offset);
1009 } else {
1010 *length = ce->size - offset;
1011 }
1012
1013 if (!multi_ret)
1014 goto out;
1015
1016 multi->num_stripes = 1;
1017 stripe_index = 0;
1018 if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
1019 if (rw == WRITE)
1020 multi->num_stripes = map->num_stripes;
1021 else if (mirror_num)
1022 stripe_index = mirror_num - 1;
1023 else
1024 stripe_index = stripe_nr % map->num_stripes;
1025 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
1026 int factor = map->num_stripes / map->sub_stripes;
1027
1028 stripe_index = stripe_nr % factor;
1029 stripe_index *= map->sub_stripes;
1030
1031 if (rw == WRITE)
1032 multi->num_stripes = map->sub_stripes;
1033 else if (mirror_num)
1034 stripe_index += mirror_num - 1;
1035 else
1036 stripe_index = stripe_nr % map->sub_stripes;
1037
1038 stripe_nr = stripe_nr / factor;
1039 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
1040 if (rw == WRITE)
1041 multi->num_stripes = map->num_stripes;
1042 else if (mirror_num)
1043 stripe_index = mirror_num - 1;
1044 } else {
1045 /*
1046 * after this do_div call, stripe_nr is the number of stripes
1047 * on this device we have to walk to find the data, and
1048 * stripe_index is the number of our device in the stripe array
1049 */
1050 stripe_index = stripe_nr % map->num_stripes;
1051 stripe_nr = stripe_nr / map->num_stripes;
1052 }
1053 BUG_ON(stripe_index >= map->num_stripes);
1054
1055 for (i = 0; i < multi->num_stripes; i++) {
1056 multi->stripes[i].physical =
1057 map->stripes[stripe_index].physical + stripe_offset +
1058 stripe_nr * map->stripe_len;
1059 multi->stripes[i].dev = map->stripes[stripe_index].dev;
1060 stripe_index++;
1061 }
1062 *multi_ret = multi;
1063 out:
1064 return 0;
1065 }
1066
1067 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
1068 u8 *uuid, u8 *fsid)
1069 {
1070 struct btrfs_device *device;
1071 struct btrfs_fs_devices *cur_devices;
1072
1073 cur_devices = root->fs_info->fs_devices;
1074 while (cur_devices) {
1075 if (!fsid ||
1076 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
1077 device = __find_device(&cur_devices->devices,
1078 devid, uuid);
1079 if (device)
1080 return device;
1081 }
1082 cur_devices = cur_devices->seed;
1083 }
1084 return NULL;
1085 }
1086
1087 int btrfs_bootstrap_super_map(struct btrfs_mapping_tree *map_tree,
1088 struct btrfs_fs_devices *fs_devices)
1089 {
1090 struct map_lookup *map;
1091 u64 logical = BTRFS_SUPER_INFO_OFFSET;
1092 u64 length = BTRFS_SUPER_INFO_SIZE;
1093 int num_stripes = 0;
1094 int sub_stripes = 0;
1095 int ret;
1096 int i;
1097 struct list_head *cur;
1098
1099 list_for_each(cur, &fs_devices->devices) {
1100 num_stripes++;
1101 }
1102 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
1103 if (!map)
1104 return -ENOMEM;
1105
1106 map->ce.start = logical;
1107 map->ce.size = length;
1108 map->num_stripes = num_stripes;
1109 map->sub_stripes = sub_stripes;
1110 map->io_width = length;
1111 map->io_align = length;
1112 map->sector_size = length;
1113 map->stripe_len = length;
1114 map->type = BTRFS_BLOCK_GROUP_RAID1;
1115
1116 i = 0;
1117 list_for_each(cur, &fs_devices->devices) {
1118 struct btrfs_device *device = list_entry(cur,
1119 struct btrfs_device,
1120 dev_list);
1121 map->stripes[i].physical = logical;
1122 map->stripes[i].dev = device;
1123 i++;
1124 }
1125 ret = insert_existing_cache_extent(&map_tree->cache_tree, &map->ce);
1126 if (ret == -EEXIST) {
1127 struct cache_extent *old;
1128 struct map_lookup *old_map;
1129 old = find_cache_extent(&map_tree->cache_tree, logical, length);
1130 old_map = container_of(old, struct map_lookup, ce);
1131 remove_cache_extent(&map_tree->cache_tree, old);
1132 kfree(old_map);
1133 ret = insert_existing_cache_extent(&map_tree->cache_tree,
1134 &map->ce);
1135 }
1136 BUG_ON(ret);
1137 return 0;
1138 }
1139
1140 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
1141 {
1142 struct cache_extent *ce;
1143 struct map_lookup *map;
1144 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
1145 int readonly = 0;
1146 int i;
1147
1148 ce = find_first_cache_extent(&map_tree->cache_tree, chunk_offset);
1149 BUG_ON(!ce);
1150
1151 map = container_of(ce, struct map_lookup, ce);
1152 for (i = 0; i < map->num_stripes; i++) {
1153 if (!map->stripes[i].dev->writeable) {
1154 readonly = 1;
1155 break;
1156 }
1157 }
1158
1159 return readonly;
1160 }
1161
1162 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
1163 struct extent_buffer *leaf,
1164 struct btrfs_chunk *chunk)
1165 {
1166 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
1167 struct map_lookup *map;
1168 struct cache_extent *ce;
1169 u64 logical;
1170 u64 length;
1171 u64 devid;
1172 u8 uuid[BTRFS_UUID_SIZE];
1173 int num_stripes;
1174 int ret;
1175 int i;
1176
1177 logical = key->offset;
1178 length = btrfs_chunk_length(leaf, chunk);
1179
1180 ce = find_first_cache_extent(&map_tree->cache_tree, logical);
1181
1182 /* already mapped? */
1183 if (ce && ce->start <= logical && ce->start + ce->size > logical) {
1184 return 0;
1185 }
1186
1187 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
1188 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
1189 if (!map)
1190 return -ENOMEM;
1191
1192 map->ce.start = logical;
1193 map->ce.size = length;
1194 map->num_stripes = num_stripes;
1195 map->io_width = btrfs_chunk_io_width(leaf, chunk);
1196 map->io_align = btrfs_chunk_io_align(leaf, chunk);
1197 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
1198 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
1199 map->type = btrfs_chunk_type(leaf, chunk);
1200 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
1201
1202 for (i = 0; i < num_stripes; i++) {
1203 map->stripes[i].physical =
1204 btrfs_stripe_offset_nr(leaf, chunk, i);
1205 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
1206 read_extent_buffer(leaf, uuid, (unsigned long)
1207 btrfs_stripe_dev_uuid_nr(chunk, i),
1208 BTRFS_UUID_SIZE);
1209 map->stripes[i].dev = btrfs_find_device(root, devid, uuid,
1210 NULL);
1211 if (!map->stripes[i].dev) {
1212 kfree(map);
1213 return -EIO;
1214 }
1215
1216 }
1217 ret = insert_existing_cache_extent(&map_tree->cache_tree, &map->ce);
1218 BUG_ON(ret);
1219
1220 return 0;
1221 }
1222
1223 static int fill_device_from_item(struct extent_buffer *leaf,
1224 struct btrfs_dev_item *dev_item,
1225 struct btrfs_device *device)
1226 {
1227 unsigned long ptr;
1228
1229 device->devid = btrfs_device_id(leaf, dev_item);
1230 device->total_bytes = btrfs_device_total_bytes(leaf, dev_item);
1231 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
1232 device->type = btrfs_device_type(leaf, dev_item);
1233 device->io_align = btrfs_device_io_align(leaf, dev_item);
1234 device->io_width = btrfs_device_io_width(leaf, dev_item);
1235 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
1236
1237 ptr = (unsigned long)btrfs_device_uuid(dev_item);
1238 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1239
1240 return 0;
1241 }
1242
1243 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
1244 {
1245 struct btrfs_fs_devices *fs_devices;
1246 int ret;
1247
1248 fs_devices = root->fs_info->fs_devices->seed;
1249 while (fs_devices) {
1250 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
1251 ret = 0;
1252 goto out;
1253 }
1254 fs_devices = fs_devices->seed;
1255 }
1256
1257 fs_devices = find_fsid(fsid);
1258 if (!fs_devices) {
1259 ret = -ENOENT;
1260 goto out;
1261 }
1262
1263 ret = btrfs_open_devices(fs_devices, O_RDONLY);
1264 if (ret)
1265 goto out;
1266
1267 fs_devices->seed = root->fs_info->fs_devices->seed;
1268 root->fs_info->fs_devices->seed = fs_devices;
1269 out:
1270 return ret;
1271 }
1272
1273 static int read_one_dev(struct btrfs_root *root,
1274 struct extent_buffer *leaf,
1275 struct btrfs_dev_item *dev_item)
1276 {
1277 struct btrfs_device *device;
1278 u64 devid;
1279 int ret = 0;
1280 u8 fs_uuid[BTRFS_UUID_SIZE];
1281 u8 dev_uuid[BTRFS_UUID_SIZE];
1282
1283 devid = btrfs_device_id(leaf, dev_item);
1284 read_extent_buffer(leaf, dev_uuid,
1285 (unsigned long)btrfs_device_uuid(dev_item),
1286 BTRFS_UUID_SIZE);
1287 read_extent_buffer(leaf, fs_uuid,
1288 (unsigned long)btrfs_device_fsid(dev_item),
1289 BTRFS_UUID_SIZE);
1290
1291 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
1292 ret = open_seed_devices(root, fs_uuid);
1293 if (ret)
1294 return ret;
1295 }
1296
1297 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
1298 if (!device) {
1299 printk("warning devid %llu not found already\n",
1300 (unsigned long long)devid);
1301 device = kmalloc(sizeof(*device), GFP_NOFS);
1302 if (!device)
1303 return -ENOMEM;
1304 device->total_ios = 0;
1305 list_add(&device->dev_list,
1306 &root->fs_info->fs_devices->devices);
1307 }
1308
1309 fill_device_from_item(leaf, dev_item, device);
1310 device->dev_root = root->fs_info->dev_root;
1311 return ret;
1312 }
1313
1314 int btrfs_read_super_device(struct btrfs_root *root, struct extent_buffer *buf)
1315 {
1316 struct btrfs_dev_item *dev_item;
1317
1318 dev_item = (struct btrfs_dev_item *)offsetof(struct btrfs_super_block,
1319 dev_item);
1320 return read_one_dev(root, buf, dev_item);
1321 }
1322
1323 int btrfs_read_sys_array(struct btrfs_root *root)
1324 {
1325 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
1326 struct extent_buffer *sb;
1327 struct btrfs_disk_key *disk_key;
1328 struct btrfs_chunk *chunk;
1329 struct btrfs_key key;
1330 u32 num_stripes;
1331 u32 array_size;
1332 u32 len = 0;
1333 u8 *ptr;
1334 unsigned long sb_ptr;
1335 u32 cur;
1336 int ret;
1337
1338 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
1339 BTRFS_SUPER_INFO_SIZE);
1340 if (!sb)
1341 return -ENOMEM;
1342 btrfs_set_buffer_uptodate(sb);
1343 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
1344 array_size = btrfs_super_sys_array_size(super_copy);
1345
1346 /*
1347 * we do this loop twice, once for the device items and
1348 * once for all of the chunks. This way there are device
1349 * structs filled in for every chunk
1350 */
1351 ptr = super_copy->sys_chunk_array;
1352 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
1353 cur = 0;
1354
1355 while (cur < array_size) {
1356 disk_key = (struct btrfs_disk_key *)ptr;
1357 btrfs_disk_key_to_cpu(&key, disk_key);
1358
1359 len = sizeof(*disk_key);
1360 ptr += len;
1361 sb_ptr += len;
1362 cur += len;
1363
1364 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
1365 chunk = (struct btrfs_chunk *)sb_ptr;
1366 ret = read_one_chunk(root, &key, sb, chunk);
1367 BUG_ON(ret);
1368 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
1369 len = btrfs_chunk_item_size(num_stripes);
1370 } else {
1371 BUG();
1372 }
1373 ptr += len;
1374 sb_ptr += len;
1375 cur += len;
1376 }
1377 free_extent_buffer(sb);
1378 return 0;
1379 }
1380
1381 int btrfs_read_chunk_tree(struct btrfs_root *root)
1382 {
1383 struct btrfs_path *path;
1384 struct extent_buffer *leaf;
1385 struct btrfs_key key;
1386 struct btrfs_key found_key;
1387 int ret;
1388 int slot;
1389
1390 root = root->fs_info->chunk_root;
1391
1392 path = btrfs_alloc_path();
1393 if (!path)
1394 return -ENOMEM;
1395
1396 /* first we search for all of the device items, and then we
1397 * read in all of the chunk items. This way we can create chunk
1398 * mappings that reference all of the devices that are afound
1399 */
1400 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1401 key.offset = 0;
1402 key.type = 0;
1403 again:
1404 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1405 while(1) {
1406 leaf = path->nodes[0];
1407 slot = path->slots[0];
1408 if (slot >= btrfs_header_nritems(leaf)) {
1409 ret = btrfs_next_leaf(root, path);
1410 if (ret == 0)
1411 continue;
1412 if (ret < 0)
1413 goto error;
1414 break;
1415 }
1416 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1417 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
1418 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
1419 break;
1420 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
1421 struct btrfs_dev_item *dev_item;
1422 dev_item = btrfs_item_ptr(leaf, slot,
1423 struct btrfs_dev_item);
1424 ret = read_one_dev(root, leaf, dev_item);
1425 BUG_ON(ret);
1426 }
1427 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
1428 struct btrfs_chunk *chunk;
1429 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
1430 ret = read_one_chunk(root, &found_key, leaf, chunk);
1431 BUG_ON(ret);
1432 }
1433 path->slots[0]++;
1434 }
1435 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
1436 key.objectid = 0;
1437 btrfs_release_path(root, path);
1438 goto again;
1439 }
1440
1441 btrfs_free_path(path);
1442 ret = 0;
1443 error:
1444 return ret;
1445 }
1446
1447 struct list_head *btrfs_scanned_uuids(void)
1448 {
1449 return &fs_uuids;
1450 }
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