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Btrfs: A number of nodatacow fixes
[deliverable/linux.git] / fs / btrfs / volumes.c
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 <linux/sched.h>
19 #include <linux/bio.h>
20 #include <linux/buffer_head.h>
21 #include <linux/blkdev.h>
22 #include <linux/random.h>
23 #include <asm/div64.h>
24 #include "ctree.h"
25 #include "extent_map.h"
26 #include "disk-io.h"
27 #include "transaction.h"
28 #include "print-tree.h"
29 #include "volumes.h"
30
31 struct map_lookup {
32 u64 type;
33 int io_align;
34 int io_width;
35 int stripe_len;
36 int sector_size;
37 int num_stripes;
38 int sub_stripes;
39 struct btrfs_bio_stripe stripes[];
40 };
41
42 #define map_lookup_size(n) (sizeof(struct map_lookup) + \
43 (sizeof(struct btrfs_bio_stripe) * (n)))
44
45 static DEFINE_MUTEX(uuid_mutex);
46 static LIST_HEAD(fs_uuids);
47
48 void btrfs_lock_volumes(void)
49 {
50 mutex_lock(&uuid_mutex);
51 }
52
53 void btrfs_unlock_volumes(void)
54 {
55 mutex_unlock(&uuid_mutex);
56 }
57
58 int btrfs_cleanup_fs_uuids(void)
59 {
60 struct btrfs_fs_devices *fs_devices;
61 struct list_head *uuid_cur;
62 struct list_head *devices_cur;
63 struct btrfs_device *dev;
64
65 list_for_each(uuid_cur, &fs_uuids) {
66 fs_devices = list_entry(uuid_cur, struct btrfs_fs_devices,
67 list);
68 while(!list_empty(&fs_devices->devices)) {
69 devices_cur = fs_devices->devices.next;
70 dev = list_entry(devices_cur, struct btrfs_device,
71 dev_list);
72 if (dev->bdev) {
73 close_bdev_excl(dev->bdev);
74 }
75 list_del(&dev->dev_list);
76 kfree(dev);
77 }
78 }
79 return 0;
80 }
81
82 static struct btrfs_device *__find_device(struct list_head *head, u64 devid,
83 u8 *uuid)
84 {
85 struct btrfs_device *dev;
86 struct list_head *cur;
87
88 list_for_each(cur, head) {
89 dev = list_entry(cur, struct btrfs_device, dev_list);
90 if (dev->devid == devid &&
91 (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
92 return dev;
93 }
94 }
95 return NULL;
96 }
97
98 static struct btrfs_fs_devices *find_fsid(u8 *fsid)
99 {
100 struct list_head *cur;
101 struct btrfs_fs_devices *fs_devices;
102
103 list_for_each(cur, &fs_uuids) {
104 fs_devices = list_entry(cur, struct btrfs_fs_devices, list);
105 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
106 return fs_devices;
107 }
108 return NULL;
109 }
110
111 static int device_list_add(const char *path,
112 struct btrfs_super_block *disk_super,
113 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
114 {
115 struct btrfs_device *device;
116 struct btrfs_fs_devices *fs_devices;
117 u64 found_transid = btrfs_super_generation(disk_super);
118
119 fs_devices = find_fsid(disk_super->fsid);
120 if (!fs_devices) {
121 fs_devices = kmalloc(sizeof(*fs_devices), GFP_NOFS);
122 if (!fs_devices)
123 return -ENOMEM;
124 INIT_LIST_HEAD(&fs_devices->devices);
125 INIT_LIST_HEAD(&fs_devices->alloc_list);
126 list_add(&fs_devices->list, &fs_uuids);
127 memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
128 fs_devices->latest_devid = devid;
129 fs_devices->latest_trans = found_transid;
130 fs_devices->lowest_devid = (u64)-1;
131 fs_devices->num_devices = 0;
132 device = NULL;
133 } else {
134 device = __find_device(&fs_devices->devices, devid,
135 disk_super->dev_item.uuid);
136 }
137 if (!device) {
138 device = kzalloc(sizeof(*device), GFP_NOFS);
139 if (!device) {
140 /* we can safely leave the fs_devices entry around */
141 return -ENOMEM;
142 }
143 device->devid = devid;
144 memcpy(device->uuid, disk_super->dev_item.uuid,
145 BTRFS_UUID_SIZE);
146 device->barriers = 1;
147 spin_lock_init(&device->io_lock);
148 device->name = kstrdup(path, GFP_NOFS);
149 if (!device->name) {
150 kfree(device);
151 return -ENOMEM;
152 }
153 list_add(&device->dev_list, &fs_devices->devices);
154 list_add(&device->dev_alloc_list, &fs_devices->alloc_list);
155 fs_devices->num_devices++;
156 }
157
158 if (found_transid > fs_devices->latest_trans) {
159 fs_devices->latest_devid = devid;
160 fs_devices->latest_trans = found_transid;
161 }
162 if (fs_devices->lowest_devid > devid) {
163 fs_devices->lowest_devid = devid;
164 }
165 *fs_devices_ret = fs_devices;
166 return 0;
167 }
168
169 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
170 {
171 struct list_head *head = &fs_devices->devices;
172 struct list_head *cur;
173 struct btrfs_device *device;
174
175 mutex_lock(&uuid_mutex);
176 list_for_each(cur, head) {
177 device = list_entry(cur, struct btrfs_device, dev_list);
178 if (device->bdev) {
179 close_bdev_excl(device->bdev);
180 }
181 device->bdev = NULL;
182 }
183 mutex_unlock(&uuid_mutex);
184 return 0;
185 }
186
187 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
188 int flags, void *holder)
189 {
190 struct block_device *bdev;
191 struct list_head *head = &fs_devices->devices;
192 struct list_head *cur;
193 struct btrfs_device *device;
194 int ret;
195
196 mutex_lock(&uuid_mutex);
197 list_for_each(cur, head) {
198 device = list_entry(cur, struct btrfs_device, dev_list);
199 if (device->bdev)
200 continue;
201
202 bdev = open_bdev_excl(device->name, flags, holder);
203
204 if (IS_ERR(bdev)) {
205 printk("open %s failed\n", device->name);
206 ret = PTR_ERR(bdev);
207 goto fail;
208 }
209 set_blocksize(bdev, 4096);
210 if (device->devid == fs_devices->latest_devid)
211 fs_devices->latest_bdev = bdev;
212 if (device->devid == fs_devices->lowest_devid) {
213 fs_devices->lowest_bdev = bdev;
214 }
215 device->bdev = bdev;
216
217 }
218 mutex_unlock(&uuid_mutex);
219 return 0;
220 fail:
221 mutex_unlock(&uuid_mutex);
222 btrfs_close_devices(fs_devices);
223 return ret;
224 }
225
226 int btrfs_scan_one_device(const char *path, int flags, void *holder,
227 struct btrfs_fs_devices **fs_devices_ret)
228 {
229 struct btrfs_super_block *disk_super;
230 struct block_device *bdev;
231 struct buffer_head *bh;
232 int ret;
233 u64 devid;
234 u64 transid;
235
236 mutex_lock(&uuid_mutex);
237
238 bdev = open_bdev_excl(path, flags, holder);
239
240 if (IS_ERR(bdev)) {
241 ret = PTR_ERR(bdev);
242 goto error;
243 }
244
245 ret = set_blocksize(bdev, 4096);
246 if (ret)
247 goto error_close;
248 bh = __bread(bdev, BTRFS_SUPER_INFO_OFFSET / 4096, 4096);
249 if (!bh) {
250 ret = -EIO;
251 goto error_close;
252 }
253 disk_super = (struct btrfs_super_block *)bh->b_data;
254 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
255 sizeof(disk_super->magic))) {
256 ret = -EINVAL;
257 goto error_brelse;
258 }
259 devid = le64_to_cpu(disk_super->dev_item.devid);
260 transid = btrfs_super_generation(disk_super);
261 if (disk_super->label[0])
262 printk("device label %s ", disk_super->label);
263 else {
264 /* FIXME, make a readl uuid parser */
265 printk("device fsid %llx-%llx ",
266 *(unsigned long long *)disk_super->fsid,
267 *(unsigned long long *)(disk_super->fsid + 8));
268 }
269 printk("devid %Lu transid %Lu %s\n", devid, transid, path);
270 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
271
272 error_brelse:
273 brelse(bh);
274 error_close:
275 close_bdev_excl(bdev);
276 error:
277 mutex_unlock(&uuid_mutex);
278 return ret;
279 }
280
281 /*
282 * this uses a pretty simple search, the expectation is that it is
283 * called very infrequently and that a given device has a small number
284 * of extents
285 */
286 static int find_free_dev_extent(struct btrfs_trans_handle *trans,
287 struct btrfs_device *device,
288 struct btrfs_path *path,
289 u64 num_bytes, u64 *start)
290 {
291 struct btrfs_key key;
292 struct btrfs_root *root = device->dev_root;
293 struct btrfs_dev_extent *dev_extent = NULL;
294 u64 hole_size = 0;
295 u64 last_byte = 0;
296 u64 search_start = 0;
297 u64 search_end = device->total_bytes;
298 int ret;
299 int slot = 0;
300 int start_found;
301 struct extent_buffer *l;
302
303 start_found = 0;
304 path->reada = 2;
305
306 /* FIXME use last free of some kind */
307
308 /* we don't want to overwrite the superblock on the drive,
309 * so we make sure to start at an offset of at least 1MB
310 */
311 search_start = max((u64)1024 * 1024, search_start);
312
313 if (root->fs_info->alloc_start + num_bytes <= device->total_bytes)
314 search_start = max(root->fs_info->alloc_start, search_start);
315
316 key.objectid = device->devid;
317 key.offset = search_start;
318 key.type = BTRFS_DEV_EXTENT_KEY;
319 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
320 if (ret < 0)
321 goto error;
322 ret = btrfs_previous_item(root, path, 0, key.type);
323 if (ret < 0)
324 goto error;
325 l = path->nodes[0];
326 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
327 while (1) {
328 l = path->nodes[0];
329 slot = path->slots[0];
330 if (slot >= btrfs_header_nritems(l)) {
331 ret = btrfs_next_leaf(root, path);
332 if (ret == 0)
333 continue;
334 if (ret < 0)
335 goto error;
336 no_more_items:
337 if (!start_found) {
338 if (search_start >= search_end) {
339 ret = -ENOSPC;
340 goto error;
341 }
342 *start = search_start;
343 start_found = 1;
344 goto check_pending;
345 }
346 *start = last_byte > search_start ?
347 last_byte : search_start;
348 if (search_end <= *start) {
349 ret = -ENOSPC;
350 goto error;
351 }
352 goto check_pending;
353 }
354 btrfs_item_key_to_cpu(l, &key, slot);
355
356 if (key.objectid < device->devid)
357 goto next;
358
359 if (key.objectid > device->devid)
360 goto no_more_items;
361
362 if (key.offset >= search_start && key.offset > last_byte &&
363 start_found) {
364 if (last_byte < search_start)
365 last_byte = search_start;
366 hole_size = key.offset - last_byte;
367 if (key.offset > last_byte &&
368 hole_size >= num_bytes) {
369 *start = last_byte;
370 goto check_pending;
371 }
372 }
373 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY) {
374 goto next;
375 }
376
377 start_found = 1;
378 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
379 last_byte = key.offset + btrfs_dev_extent_length(l, dev_extent);
380 next:
381 path->slots[0]++;
382 cond_resched();
383 }
384 check_pending:
385 /* we have to make sure we didn't find an extent that has already
386 * been allocated by the map tree or the original allocation
387 */
388 btrfs_release_path(root, path);
389 BUG_ON(*start < search_start);
390
391 if (*start + num_bytes > search_end) {
392 ret = -ENOSPC;
393 goto error;
394 }
395 /* check for pending inserts here */
396 return 0;
397
398 error:
399 btrfs_release_path(root, path);
400 return ret;
401 }
402
403 int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
404 struct btrfs_device *device,
405 u64 start)
406 {
407 int ret;
408 struct btrfs_path *path;
409 struct btrfs_root *root = device->dev_root;
410 struct btrfs_key key;
411 struct btrfs_key found_key;
412 struct extent_buffer *leaf = NULL;
413 struct btrfs_dev_extent *extent = NULL;
414
415 path = btrfs_alloc_path();
416 if (!path)
417 return -ENOMEM;
418
419 key.objectid = device->devid;
420 key.offset = start;
421 key.type = BTRFS_DEV_EXTENT_KEY;
422
423 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
424 if (ret > 0) {
425 ret = btrfs_previous_item(root, path, key.objectid,
426 BTRFS_DEV_EXTENT_KEY);
427 BUG_ON(ret);
428 leaf = path->nodes[0];
429 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
430 extent = btrfs_item_ptr(leaf, path->slots[0],
431 struct btrfs_dev_extent);
432 BUG_ON(found_key.offset > start || found_key.offset +
433 btrfs_dev_extent_length(leaf, extent) < start);
434 ret = 0;
435 } else if (ret == 0) {
436 leaf = path->nodes[0];
437 extent = btrfs_item_ptr(leaf, path->slots[0],
438 struct btrfs_dev_extent);
439 }
440 BUG_ON(ret);
441
442 device->bytes_used -= btrfs_dev_extent_length(leaf, extent);
443 ret = btrfs_del_item(trans, root, path);
444 BUG_ON(ret);
445
446 btrfs_free_path(path);
447 return ret;
448 }
449
450 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
451 struct btrfs_device *device,
452 u64 chunk_tree, u64 chunk_objectid,
453 u64 chunk_offset,
454 u64 num_bytes, u64 *start)
455 {
456 int ret;
457 struct btrfs_path *path;
458 struct btrfs_root *root = device->dev_root;
459 struct btrfs_dev_extent *extent;
460 struct extent_buffer *leaf;
461 struct btrfs_key key;
462
463 path = btrfs_alloc_path();
464 if (!path)
465 return -ENOMEM;
466
467 ret = find_free_dev_extent(trans, device, path, num_bytes, start);
468 if (ret) {
469 goto err;
470 }
471
472 key.objectid = device->devid;
473 key.offset = *start;
474 key.type = BTRFS_DEV_EXTENT_KEY;
475 ret = btrfs_insert_empty_item(trans, root, path, &key,
476 sizeof(*extent));
477 BUG_ON(ret);
478
479 leaf = path->nodes[0];
480 extent = btrfs_item_ptr(leaf, path->slots[0],
481 struct btrfs_dev_extent);
482 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
483 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
484 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
485
486 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
487 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
488 BTRFS_UUID_SIZE);
489
490 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
491 btrfs_mark_buffer_dirty(leaf);
492 err:
493 btrfs_free_path(path);
494 return ret;
495 }
496
497 static int find_next_chunk(struct btrfs_root *root, u64 objectid, u64 *offset)
498 {
499 struct btrfs_path *path;
500 int ret;
501 struct btrfs_key key;
502 struct btrfs_chunk *chunk;
503 struct btrfs_key found_key;
504
505 path = btrfs_alloc_path();
506 BUG_ON(!path);
507
508 key.objectid = objectid;
509 key.offset = (u64)-1;
510 key.type = BTRFS_CHUNK_ITEM_KEY;
511
512 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
513 if (ret < 0)
514 goto error;
515
516 BUG_ON(ret == 0);
517
518 ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
519 if (ret) {
520 *offset = 0;
521 } else {
522 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
523 path->slots[0]);
524 if (found_key.objectid != objectid)
525 *offset = 0;
526 else {
527 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
528 struct btrfs_chunk);
529 *offset = found_key.offset +
530 btrfs_chunk_length(path->nodes[0], chunk);
531 }
532 }
533 ret = 0;
534 error:
535 btrfs_free_path(path);
536 return ret;
537 }
538
539 static int find_next_devid(struct btrfs_root *root, struct btrfs_path *path,
540 u64 *objectid)
541 {
542 int ret;
543 struct btrfs_key key;
544 struct btrfs_key found_key;
545
546 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
547 key.type = BTRFS_DEV_ITEM_KEY;
548 key.offset = (u64)-1;
549
550 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
551 if (ret < 0)
552 goto error;
553
554 BUG_ON(ret == 0);
555
556 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
557 BTRFS_DEV_ITEM_KEY);
558 if (ret) {
559 *objectid = 1;
560 } else {
561 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
562 path->slots[0]);
563 *objectid = found_key.offset + 1;
564 }
565 ret = 0;
566 error:
567 btrfs_release_path(root, path);
568 return ret;
569 }
570
571 /*
572 * the device information is stored in the chunk root
573 * the btrfs_device struct should be fully filled in
574 */
575 int btrfs_add_device(struct btrfs_trans_handle *trans,
576 struct btrfs_root *root,
577 struct btrfs_device *device)
578 {
579 int ret;
580 struct btrfs_path *path;
581 struct btrfs_dev_item *dev_item;
582 struct extent_buffer *leaf;
583 struct btrfs_key key;
584 unsigned long ptr;
585 u64 free_devid = 0;
586
587 root = root->fs_info->chunk_root;
588
589 path = btrfs_alloc_path();
590 if (!path)
591 return -ENOMEM;
592
593 ret = find_next_devid(root, path, &free_devid);
594 if (ret)
595 goto out;
596
597 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
598 key.type = BTRFS_DEV_ITEM_KEY;
599 key.offset = free_devid;
600
601 ret = btrfs_insert_empty_item(trans, root, path, &key,
602 sizeof(*dev_item));
603 if (ret)
604 goto out;
605
606 leaf = path->nodes[0];
607 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
608
609 device->devid = free_devid;
610 btrfs_set_device_id(leaf, dev_item, device->devid);
611 btrfs_set_device_type(leaf, dev_item, device->type);
612 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
613 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
614 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
615 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
616 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
617 btrfs_set_device_group(leaf, dev_item, 0);
618 btrfs_set_device_seek_speed(leaf, dev_item, 0);
619 btrfs_set_device_bandwidth(leaf, dev_item, 0);
620
621 ptr = (unsigned long)btrfs_device_uuid(dev_item);
622 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
623 btrfs_mark_buffer_dirty(leaf);
624 ret = 0;
625
626 out:
627 btrfs_free_path(path);
628 return ret;
629 }
630
631 static int btrfs_rm_dev_item(struct btrfs_root *root,
632 struct btrfs_device *device)
633 {
634 int ret;
635 struct btrfs_path *path;
636 struct block_device *bdev = device->bdev;
637 struct btrfs_device *next_dev;
638 struct btrfs_key key;
639 u64 total_bytes;
640 struct btrfs_fs_devices *fs_devices;
641 struct btrfs_trans_handle *trans;
642
643 root = root->fs_info->chunk_root;
644
645 path = btrfs_alloc_path();
646 if (!path)
647 return -ENOMEM;
648
649 trans = btrfs_start_transaction(root, 1);
650 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
651 key.type = BTRFS_DEV_ITEM_KEY;
652 key.offset = device->devid;
653
654 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
655 if (ret < 0)
656 goto out;
657
658 if (ret > 0) {
659 ret = -ENOENT;
660 goto out;
661 }
662
663 ret = btrfs_del_item(trans, root, path);
664 if (ret)
665 goto out;
666
667 /*
668 * at this point, the device is zero sized. We want to
669 * remove it from the devices list and zero out the old super
670 */
671 list_del_init(&device->dev_list);
672 list_del_init(&device->dev_alloc_list);
673 fs_devices = root->fs_info->fs_devices;
674
675 next_dev = list_entry(fs_devices->devices.next, struct btrfs_device,
676 dev_list);
677 if (bdev == fs_devices->lowest_bdev)
678 fs_devices->lowest_bdev = next_dev->bdev;
679 if (bdev == root->fs_info->sb->s_bdev)
680 root->fs_info->sb->s_bdev = next_dev->bdev;
681 if (bdev == fs_devices->latest_bdev)
682 fs_devices->latest_bdev = next_dev->bdev;
683
684 total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
685 btrfs_set_super_total_bytes(&root->fs_info->super_copy,
686 total_bytes - device->total_bytes);
687
688 total_bytes = btrfs_super_num_devices(&root->fs_info->super_copy);
689 btrfs_set_super_num_devices(&root->fs_info->super_copy,
690 total_bytes - 1);
691 out:
692 btrfs_free_path(path);
693 btrfs_commit_transaction(trans, root);
694 return ret;
695 }
696
697 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
698 {
699 struct btrfs_device *device;
700 struct block_device *bdev;
701 struct buffer_head *bh;
702 struct btrfs_super_block *disk_super;
703 u64 all_avail;
704 u64 devid;
705 int ret = 0;
706
707 mutex_lock(&root->fs_info->fs_mutex);
708 mutex_lock(&uuid_mutex);
709
710 all_avail = root->fs_info->avail_data_alloc_bits |
711 root->fs_info->avail_system_alloc_bits |
712 root->fs_info->avail_metadata_alloc_bits;
713
714 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) &&
715 root->fs_info->fs_devices->num_devices <= 4) {
716 printk("btrfs: unable to go below four devices on raid10\n");
717 ret = -EINVAL;
718 goto out;
719 }
720
721 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) &&
722 root->fs_info->fs_devices->num_devices <= 2) {
723 printk("btrfs: unable to go below two devices on raid1\n");
724 ret = -EINVAL;
725 goto out;
726 }
727
728 bdev = open_bdev_excl(device_path, 0, root->fs_info->bdev_holder);
729 if (IS_ERR(bdev)) {
730 ret = PTR_ERR(bdev);
731 goto out;
732 }
733
734 bh = __bread(bdev, BTRFS_SUPER_INFO_OFFSET / 4096, 4096);
735 if (!bh) {
736 ret = -EIO;
737 goto error_close;
738 }
739 disk_super = (struct btrfs_super_block *)bh->b_data;
740 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
741 sizeof(disk_super->magic))) {
742 ret = -ENOENT;
743 goto error_brelse;
744 }
745 if (memcmp(disk_super->fsid, root->fs_info->fsid, BTRFS_FSID_SIZE)) {
746 ret = -ENOENT;
747 goto error_brelse;
748 }
749 devid = le64_to_cpu(disk_super->dev_item.devid);
750 device = btrfs_find_device(root, devid, NULL);
751 if (!device) {
752 ret = -ENOENT;
753 goto error_brelse;
754 }
755
756 root->fs_info->fs_devices->num_devices--;
757
758 ret = btrfs_shrink_device(device, 0);
759 if (ret)
760 goto error_brelse;
761
762
763 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
764 if (ret)
765 goto error_brelse;
766
767 /* make sure this device isn't detected as part of the FS anymore */
768 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
769 set_buffer_dirty(bh);
770 sync_dirty_buffer(bh);
771
772 brelse(bh);
773
774 /* one close for the device struct or super_block */
775 close_bdev_excl(device->bdev);
776
777 /* one close for us */
778 close_bdev_excl(device->bdev);
779
780 kfree(device->name);
781 kfree(device);
782 ret = 0;
783 goto out;
784
785 error_brelse:
786 brelse(bh);
787 error_close:
788 close_bdev_excl(bdev);
789 out:
790 mutex_unlock(&uuid_mutex);
791 mutex_unlock(&root->fs_info->fs_mutex);
792 return ret;
793 }
794
795 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
796 {
797 struct btrfs_trans_handle *trans;
798 struct btrfs_device *device;
799 struct block_device *bdev;
800 struct list_head *cur;
801 struct list_head *devices;
802 u64 total_bytes;
803 int ret = 0;
804
805
806 bdev = open_bdev_excl(device_path, 0, root->fs_info->bdev_holder);
807 if (!bdev) {
808 return -EIO;
809 }
810 mutex_lock(&root->fs_info->fs_mutex);
811 trans = btrfs_start_transaction(root, 1);
812 devices = &root->fs_info->fs_devices->devices;
813 list_for_each(cur, devices) {
814 device = list_entry(cur, struct btrfs_device, dev_list);
815 if (device->bdev == bdev) {
816 ret = -EEXIST;
817 goto out;
818 }
819 }
820
821 device = kzalloc(sizeof(*device), GFP_NOFS);
822 if (!device) {
823 /* we can safely leave the fs_devices entry around */
824 ret = -ENOMEM;
825 goto out_close_bdev;
826 }
827
828 device->barriers = 1;
829 generate_random_uuid(device->uuid);
830 spin_lock_init(&device->io_lock);
831 device->name = kstrdup(device_path, GFP_NOFS);
832 if (!device->name) {
833 kfree(device);
834 goto out_close_bdev;
835 }
836 device->io_width = root->sectorsize;
837 device->io_align = root->sectorsize;
838 device->sector_size = root->sectorsize;
839 device->total_bytes = i_size_read(bdev->bd_inode);
840 device->dev_root = root->fs_info->dev_root;
841 device->bdev = bdev;
842
843 ret = btrfs_add_device(trans, root, device);
844 if (ret)
845 goto out_close_bdev;
846
847 total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
848 btrfs_set_super_total_bytes(&root->fs_info->super_copy,
849 total_bytes + device->total_bytes);
850
851 total_bytes = btrfs_super_num_devices(&root->fs_info->super_copy);
852 btrfs_set_super_num_devices(&root->fs_info->super_copy,
853 total_bytes + 1);
854
855 list_add(&device->dev_list, &root->fs_info->fs_devices->devices);
856 list_add(&device->dev_alloc_list,
857 &root->fs_info->fs_devices->alloc_list);
858 root->fs_info->fs_devices->num_devices++;
859 out:
860 btrfs_end_transaction(trans, root);
861 mutex_unlock(&root->fs_info->fs_mutex);
862 return ret;
863
864 out_close_bdev:
865 close_bdev_excl(bdev);
866 goto out;
867 }
868
869 int btrfs_update_device(struct btrfs_trans_handle *trans,
870 struct btrfs_device *device)
871 {
872 int ret;
873 struct btrfs_path *path;
874 struct btrfs_root *root;
875 struct btrfs_dev_item *dev_item;
876 struct extent_buffer *leaf;
877 struct btrfs_key key;
878
879 root = device->dev_root->fs_info->chunk_root;
880
881 path = btrfs_alloc_path();
882 if (!path)
883 return -ENOMEM;
884
885 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
886 key.type = BTRFS_DEV_ITEM_KEY;
887 key.offset = device->devid;
888
889 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
890 if (ret < 0)
891 goto out;
892
893 if (ret > 0) {
894 ret = -ENOENT;
895 goto out;
896 }
897
898 leaf = path->nodes[0];
899 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
900
901 btrfs_set_device_id(leaf, dev_item, device->devid);
902 btrfs_set_device_type(leaf, dev_item, device->type);
903 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
904 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
905 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
906 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
907 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
908 btrfs_mark_buffer_dirty(leaf);
909
910 out:
911 btrfs_free_path(path);
912 return ret;
913 }
914
915 int btrfs_grow_device(struct btrfs_trans_handle *trans,
916 struct btrfs_device *device, u64 new_size)
917 {
918 struct btrfs_super_block *super_copy =
919 &device->dev_root->fs_info->super_copy;
920 u64 old_total = btrfs_super_total_bytes(super_copy);
921 u64 diff = new_size - device->total_bytes;
922
923 btrfs_set_super_total_bytes(super_copy, old_total + diff);
924 return btrfs_update_device(trans, device);
925 }
926
927 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
928 struct btrfs_root *root,
929 u64 chunk_tree, u64 chunk_objectid,
930 u64 chunk_offset)
931 {
932 int ret;
933 struct btrfs_path *path;
934 struct btrfs_key key;
935
936 root = root->fs_info->chunk_root;
937 path = btrfs_alloc_path();
938 if (!path)
939 return -ENOMEM;
940
941 key.objectid = chunk_objectid;
942 key.offset = chunk_offset;
943 key.type = BTRFS_CHUNK_ITEM_KEY;
944
945 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
946 BUG_ON(ret);
947
948 ret = btrfs_del_item(trans, root, path);
949 BUG_ON(ret);
950
951 btrfs_free_path(path);
952 return 0;
953 }
954
955 int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
956 chunk_offset)
957 {
958 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
959 struct btrfs_disk_key *disk_key;
960 struct btrfs_chunk *chunk;
961 u8 *ptr;
962 int ret = 0;
963 u32 num_stripes;
964 u32 array_size;
965 u32 len = 0;
966 u32 cur;
967 struct btrfs_key key;
968
969 array_size = btrfs_super_sys_array_size(super_copy);
970
971 ptr = super_copy->sys_chunk_array;
972 cur = 0;
973
974 while (cur < array_size) {
975 disk_key = (struct btrfs_disk_key *)ptr;
976 btrfs_disk_key_to_cpu(&key, disk_key);
977
978 len = sizeof(*disk_key);
979
980 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
981 chunk = (struct btrfs_chunk *)(ptr + len);
982 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
983 len += btrfs_chunk_item_size(num_stripes);
984 } else {
985 ret = -EIO;
986 break;
987 }
988 if (key.objectid == chunk_objectid &&
989 key.offset == chunk_offset) {
990 memmove(ptr, ptr + len, array_size - (cur + len));
991 array_size -= len;
992 btrfs_set_super_sys_array_size(super_copy, array_size);
993 } else {
994 ptr += len;
995 cur += len;
996 }
997 }
998 return ret;
999 }
1000
1001
1002 int btrfs_relocate_chunk(struct btrfs_root *root,
1003 u64 chunk_tree, u64 chunk_objectid,
1004 u64 chunk_offset)
1005 {
1006 struct extent_map_tree *em_tree;
1007 struct btrfs_root *extent_root;
1008 struct btrfs_trans_handle *trans;
1009 struct extent_map *em;
1010 struct map_lookup *map;
1011 int ret;
1012 int i;
1013
1014 root = root->fs_info->chunk_root;
1015 extent_root = root->fs_info->extent_root;
1016 em_tree = &root->fs_info->mapping_tree.map_tree;
1017
1018 /* step one, relocate all the extents inside this chunk */
1019 ret = btrfs_shrink_extent_tree(extent_root, chunk_offset);
1020 BUG_ON(ret);
1021
1022 trans = btrfs_start_transaction(root, 1);
1023 BUG_ON(!trans);
1024
1025 /*
1026 * step two, delete the device extents and the
1027 * chunk tree entries
1028 */
1029 spin_lock(&em_tree->lock);
1030 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
1031 spin_unlock(&em_tree->lock);
1032
1033 BUG_ON(em->start > chunk_offset ||
1034 em->start + em->len < chunk_offset);
1035 map = (struct map_lookup *)em->bdev;
1036
1037 for (i = 0; i < map->num_stripes; i++) {
1038 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
1039 map->stripes[i].physical);
1040 BUG_ON(ret);
1041
1042 ret = btrfs_update_device(trans, map->stripes[i].dev);
1043 BUG_ON(ret);
1044 }
1045 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
1046 chunk_offset);
1047
1048 BUG_ON(ret);
1049
1050 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
1051 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
1052 BUG_ON(ret);
1053 }
1054
1055 spin_lock(&em_tree->lock);
1056 remove_extent_mapping(em_tree, em);
1057 kfree(map);
1058 em->bdev = NULL;
1059
1060 /* once for the tree */
1061 free_extent_map(em);
1062 spin_unlock(&em_tree->lock);
1063
1064 /* once for us */
1065 free_extent_map(em);
1066
1067 btrfs_end_transaction(trans, root);
1068 return 0;
1069 }
1070
1071 static u64 div_factor(u64 num, int factor)
1072 {
1073 if (factor == 10)
1074 return num;
1075 num *= factor;
1076 do_div(num, 10);
1077 return num;
1078 }
1079
1080
1081 int btrfs_balance(struct btrfs_root *dev_root)
1082 {
1083 int ret;
1084 struct list_head *cur;
1085 struct list_head *devices = &dev_root->fs_info->fs_devices->devices;
1086 struct btrfs_device *device;
1087 u64 old_size;
1088 u64 size_to_free;
1089 struct btrfs_path *path;
1090 struct btrfs_key key;
1091 struct btrfs_chunk *chunk;
1092 struct btrfs_root *chunk_root = dev_root->fs_info->chunk_root;
1093 struct btrfs_trans_handle *trans;
1094 struct btrfs_key found_key;
1095
1096
1097 dev_root = dev_root->fs_info->dev_root;
1098
1099 mutex_lock(&dev_root->fs_info->fs_mutex);
1100 /* step one make some room on all the devices */
1101 list_for_each(cur, devices) {
1102 device = list_entry(cur, struct btrfs_device, dev_list);
1103 old_size = device->total_bytes;
1104 size_to_free = div_factor(old_size, 1);
1105 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
1106 if (device->total_bytes - device->bytes_used > size_to_free)
1107 continue;
1108
1109 ret = btrfs_shrink_device(device, old_size - size_to_free);
1110 BUG_ON(ret);
1111
1112 trans = btrfs_start_transaction(dev_root, 1);
1113 BUG_ON(!trans);
1114
1115 ret = btrfs_grow_device(trans, device, old_size);
1116 BUG_ON(ret);
1117
1118 btrfs_end_transaction(trans, dev_root);
1119 }
1120
1121 /* step two, relocate all the chunks */
1122 path = btrfs_alloc_path();
1123 BUG_ON(!path);
1124
1125 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
1126 key.offset = (u64)-1;
1127 key.type = BTRFS_CHUNK_ITEM_KEY;
1128
1129 while(1) {
1130 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
1131 if (ret < 0)
1132 goto error;
1133
1134 /*
1135 * this shouldn't happen, it means the last relocate
1136 * failed
1137 */
1138 if (ret == 0)
1139 break;
1140
1141 ret = btrfs_previous_item(chunk_root, path, 0,
1142 BTRFS_CHUNK_ITEM_KEY);
1143 if (ret) {
1144 break;
1145 }
1146 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1147 path->slots[0]);
1148 if (found_key.objectid != key.objectid)
1149 break;
1150 chunk = btrfs_item_ptr(path->nodes[0],
1151 path->slots[0],
1152 struct btrfs_chunk);
1153 key.offset = found_key.offset;
1154 /* chunk zero is special */
1155 if (key.offset == 0)
1156 break;
1157
1158 ret = btrfs_relocate_chunk(chunk_root,
1159 chunk_root->root_key.objectid,
1160 found_key.objectid,
1161 found_key.offset);
1162 BUG_ON(ret);
1163 btrfs_release_path(chunk_root, path);
1164 }
1165 ret = 0;
1166 error:
1167 btrfs_free_path(path);
1168 mutex_unlock(&dev_root->fs_info->fs_mutex);
1169 return ret;
1170 }
1171
1172 /*
1173 * shrinking a device means finding all of the device extents past
1174 * the new size, and then following the back refs to the chunks.
1175 * The chunk relocation code actually frees the device extent
1176 */
1177 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
1178 {
1179 struct btrfs_trans_handle *trans;
1180 struct btrfs_root *root = device->dev_root;
1181 struct btrfs_dev_extent *dev_extent = NULL;
1182 struct btrfs_path *path;
1183 u64 length;
1184 u64 chunk_tree;
1185 u64 chunk_objectid;
1186 u64 chunk_offset;
1187 int ret;
1188 int slot;
1189 struct extent_buffer *l;
1190 struct btrfs_key key;
1191 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
1192 u64 old_total = btrfs_super_total_bytes(super_copy);
1193 u64 diff = device->total_bytes - new_size;
1194
1195
1196 path = btrfs_alloc_path();
1197 if (!path)
1198 return -ENOMEM;
1199
1200 trans = btrfs_start_transaction(root, 1);
1201 if (!trans) {
1202 ret = -ENOMEM;
1203 goto done;
1204 }
1205
1206 path->reada = 2;
1207
1208 device->total_bytes = new_size;
1209 ret = btrfs_update_device(trans, device);
1210 if (ret) {
1211 btrfs_end_transaction(trans, root);
1212 goto done;
1213 }
1214 WARN_ON(diff > old_total);
1215 btrfs_set_super_total_bytes(super_copy, old_total - diff);
1216 btrfs_end_transaction(trans, root);
1217
1218 key.objectid = device->devid;
1219 key.offset = (u64)-1;
1220 key.type = BTRFS_DEV_EXTENT_KEY;
1221
1222 while (1) {
1223 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1224 if (ret < 0)
1225 goto done;
1226
1227 ret = btrfs_previous_item(root, path, 0, key.type);
1228 if (ret < 0)
1229 goto done;
1230 if (ret) {
1231 ret = 0;
1232 goto done;
1233 }
1234
1235 l = path->nodes[0];
1236 slot = path->slots[0];
1237 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
1238
1239 if (key.objectid != device->devid)
1240 goto done;
1241
1242 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
1243 length = btrfs_dev_extent_length(l, dev_extent);
1244
1245 if (key.offset + length <= new_size)
1246 goto done;
1247
1248 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
1249 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
1250 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
1251 btrfs_release_path(root, path);
1252
1253 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
1254 chunk_offset);
1255 if (ret)
1256 goto done;
1257 }
1258
1259 done:
1260 btrfs_free_path(path);
1261 return ret;
1262 }
1263
1264 int btrfs_add_system_chunk(struct btrfs_trans_handle *trans,
1265 struct btrfs_root *root,
1266 struct btrfs_key *key,
1267 struct btrfs_chunk *chunk, int item_size)
1268 {
1269 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
1270 struct btrfs_disk_key disk_key;
1271 u32 array_size;
1272 u8 *ptr;
1273
1274 array_size = btrfs_super_sys_array_size(super_copy);
1275 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
1276 return -EFBIG;
1277
1278 ptr = super_copy->sys_chunk_array + array_size;
1279 btrfs_cpu_key_to_disk(&disk_key, key);
1280 memcpy(ptr, &disk_key, sizeof(disk_key));
1281 ptr += sizeof(disk_key);
1282 memcpy(ptr, chunk, item_size);
1283 item_size += sizeof(disk_key);
1284 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
1285 return 0;
1286 }
1287
1288 static u64 chunk_bytes_by_type(u64 type, u64 calc_size, int num_stripes,
1289 int sub_stripes)
1290 {
1291 if (type & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_DUP))
1292 return calc_size;
1293 else if (type & BTRFS_BLOCK_GROUP_RAID10)
1294 return calc_size * (num_stripes / sub_stripes);
1295 else
1296 return calc_size * num_stripes;
1297 }
1298
1299
1300 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
1301 struct btrfs_root *extent_root, u64 *start,
1302 u64 *num_bytes, u64 type)
1303 {
1304 u64 dev_offset;
1305 struct btrfs_fs_info *info = extent_root->fs_info;
1306 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
1307 struct btrfs_path *path;
1308 struct btrfs_stripe *stripes;
1309 struct btrfs_device *device = NULL;
1310 struct btrfs_chunk *chunk;
1311 struct list_head private_devs;
1312 struct list_head *dev_list;
1313 struct list_head *cur;
1314 struct extent_map_tree *em_tree;
1315 struct map_lookup *map;
1316 struct extent_map *em;
1317 int min_stripe_size = 1 * 1024 * 1024;
1318 u64 physical;
1319 u64 calc_size = 1024 * 1024 * 1024;
1320 u64 max_chunk_size = calc_size;
1321 u64 min_free;
1322 u64 avail;
1323 u64 max_avail = 0;
1324 u64 percent_max;
1325 int num_stripes = 1;
1326 int min_stripes = 1;
1327 int sub_stripes = 0;
1328 int looped = 0;
1329 int ret;
1330 int index;
1331 int stripe_len = 64 * 1024;
1332 struct btrfs_key key;
1333
1334 if ((type & BTRFS_BLOCK_GROUP_RAID1) &&
1335 (type & BTRFS_BLOCK_GROUP_DUP)) {
1336 WARN_ON(1);
1337 type &= ~BTRFS_BLOCK_GROUP_DUP;
1338 }
1339 dev_list = &extent_root->fs_info->fs_devices->alloc_list;
1340 if (list_empty(dev_list))
1341 return -ENOSPC;
1342
1343 if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
1344 num_stripes = btrfs_super_num_devices(&info->super_copy);
1345 min_stripes = 2;
1346 }
1347 if (type & (BTRFS_BLOCK_GROUP_DUP)) {
1348 num_stripes = 2;
1349 min_stripes = 2;
1350 }
1351 if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
1352 num_stripes = min_t(u64, 2,
1353 btrfs_super_num_devices(&info->super_copy));
1354 if (num_stripes < 2)
1355 return -ENOSPC;
1356 min_stripes = 2;
1357 }
1358 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
1359 num_stripes = btrfs_super_num_devices(&info->super_copy);
1360 if (num_stripes < 4)
1361 return -ENOSPC;
1362 num_stripes &= ~(u32)1;
1363 sub_stripes = 2;
1364 min_stripes = 4;
1365 }
1366
1367 if (type & BTRFS_BLOCK_GROUP_DATA) {
1368 max_chunk_size = 10 * calc_size;
1369 min_stripe_size = 64 * 1024 * 1024;
1370 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
1371 max_chunk_size = 4 * calc_size;
1372 min_stripe_size = 32 * 1024 * 1024;
1373 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
1374 calc_size = 8 * 1024 * 1024;
1375 max_chunk_size = calc_size * 2;
1376 min_stripe_size = 1 * 1024 * 1024;
1377 }
1378
1379 path = btrfs_alloc_path();
1380 if (!path)
1381 return -ENOMEM;
1382
1383 /* we don't want a chunk larger than 10% of the FS */
1384 percent_max = div_factor(btrfs_super_total_bytes(&info->super_copy), 1);
1385 max_chunk_size = min(percent_max, max_chunk_size);
1386
1387 again:
1388 if (calc_size * num_stripes > max_chunk_size) {
1389 calc_size = max_chunk_size;
1390 do_div(calc_size, num_stripes);
1391 do_div(calc_size, stripe_len);
1392 calc_size *= stripe_len;
1393 }
1394 /* we don't want tiny stripes */
1395 calc_size = max_t(u64, min_stripe_size, calc_size);
1396
1397 do_div(calc_size, stripe_len);
1398 calc_size *= stripe_len;
1399
1400 INIT_LIST_HEAD(&private_devs);
1401 cur = dev_list->next;
1402 index = 0;
1403
1404 if (type & BTRFS_BLOCK_GROUP_DUP)
1405 min_free = calc_size * 2;
1406 else
1407 min_free = calc_size;
1408
1409 /* we add 1MB because we never use the first 1MB of the device */
1410 min_free += 1024 * 1024;
1411
1412 /* build a private list of devices we will allocate from */
1413 while(index < num_stripes) {
1414 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
1415
1416 avail = device->total_bytes - device->bytes_used;
1417 cur = cur->next;
1418
1419 if (avail >= min_free) {
1420 u64 ignored_start = 0;
1421 ret = find_free_dev_extent(trans, device, path,
1422 min_free,
1423 &ignored_start);
1424 if (ret == 0) {
1425 list_move_tail(&device->dev_alloc_list,
1426 &private_devs);
1427 index++;
1428 if (type & BTRFS_BLOCK_GROUP_DUP)
1429 index++;
1430 }
1431 } else if (avail > max_avail)
1432 max_avail = avail;
1433 if (cur == dev_list)
1434 break;
1435 }
1436 if (index < num_stripes) {
1437 list_splice(&private_devs, dev_list);
1438 if (index >= min_stripes) {
1439 num_stripes = index;
1440 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
1441 num_stripes /= sub_stripes;
1442 num_stripes *= sub_stripes;
1443 }
1444 looped = 1;
1445 goto again;
1446 }
1447 if (!looped && max_avail > 0) {
1448 looped = 1;
1449 calc_size = max_avail;
1450 goto again;
1451 }
1452 btrfs_free_path(path);
1453 return -ENOSPC;
1454 }
1455 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
1456 key.type = BTRFS_CHUNK_ITEM_KEY;
1457 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
1458 &key.offset);
1459 if (ret) {
1460 btrfs_free_path(path);
1461 return ret;
1462 }
1463
1464 chunk = kmalloc(btrfs_chunk_item_size(num_stripes), GFP_NOFS);
1465 if (!chunk) {
1466 btrfs_free_path(path);
1467 return -ENOMEM;
1468 }
1469
1470 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
1471 if (!map) {
1472 kfree(chunk);
1473 btrfs_free_path(path);
1474 return -ENOMEM;
1475 }
1476 btrfs_free_path(path);
1477 path = NULL;
1478
1479 stripes = &chunk->stripe;
1480 *num_bytes = chunk_bytes_by_type(type, calc_size,
1481 num_stripes, sub_stripes);
1482
1483 index = 0;
1484 while(index < num_stripes) {
1485 struct btrfs_stripe *stripe;
1486 BUG_ON(list_empty(&private_devs));
1487 cur = private_devs.next;
1488 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
1489
1490 /* loop over this device again if we're doing a dup group */
1491 if (!(type & BTRFS_BLOCK_GROUP_DUP) ||
1492 (index == num_stripes - 1))
1493 list_move_tail(&device->dev_alloc_list, dev_list);
1494
1495 ret = btrfs_alloc_dev_extent(trans, device,
1496 info->chunk_root->root_key.objectid,
1497 BTRFS_FIRST_CHUNK_TREE_OBJECTID, key.offset,
1498 calc_size, &dev_offset);
1499 BUG_ON(ret);
1500 device->bytes_used += calc_size;
1501 ret = btrfs_update_device(trans, device);
1502 BUG_ON(ret);
1503
1504 map->stripes[index].dev = device;
1505 map->stripes[index].physical = dev_offset;
1506 stripe = stripes + index;
1507 btrfs_set_stack_stripe_devid(stripe, device->devid);
1508 btrfs_set_stack_stripe_offset(stripe, dev_offset);
1509 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
1510 physical = dev_offset;
1511 index++;
1512 }
1513 BUG_ON(!list_empty(&private_devs));
1514
1515 /* key was set above */
1516 btrfs_set_stack_chunk_length(chunk, *num_bytes);
1517 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
1518 btrfs_set_stack_chunk_stripe_len(chunk, stripe_len);
1519 btrfs_set_stack_chunk_type(chunk, type);
1520 btrfs_set_stack_chunk_num_stripes(chunk, num_stripes);
1521 btrfs_set_stack_chunk_io_align(chunk, stripe_len);
1522 btrfs_set_stack_chunk_io_width(chunk, stripe_len);
1523 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
1524 btrfs_set_stack_chunk_sub_stripes(chunk, sub_stripes);
1525 map->sector_size = extent_root->sectorsize;
1526 map->stripe_len = stripe_len;
1527 map->io_align = stripe_len;
1528 map->io_width = stripe_len;
1529 map->type = type;
1530 map->num_stripes = num_stripes;
1531 map->sub_stripes = sub_stripes;
1532
1533 ret = btrfs_insert_item(trans, chunk_root, &key, chunk,
1534 btrfs_chunk_item_size(num_stripes));
1535 BUG_ON(ret);
1536 *start = key.offset;;
1537
1538 em = alloc_extent_map(GFP_NOFS);
1539 if (!em)
1540 return -ENOMEM;
1541 em->bdev = (struct block_device *)map;
1542 em->start = key.offset;
1543 em->len = *num_bytes;
1544 em->block_start = 0;
1545
1546 if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
1547 ret = btrfs_add_system_chunk(trans, chunk_root, &key,
1548 chunk, btrfs_chunk_item_size(num_stripes));
1549 BUG_ON(ret);
1550 }
1551 kfree(chunk);
1552
1553 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
1554 spin_lock(&em_tree->lock);
1555 ret = add_extent_mapping(em_tree, em);
1556 spin_unlock(&em_tree->lock);
1557 BUG_ON(ret);
1558 free_extent_map(em);
1559 return ret;
1560 }
1561
1562 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
1563 {
1564 extent_map_tree_init(&tree->map_tree, GFP_NOFS);
1565 }
1566
1567 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
1568 {
1569 struct extent_map *em;
1570
1571 while(1) {
1572 spin_lock(&tree->map_tree.lock);
1573 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
1574 if (em)
1575 remove_extent_mapping(&tree->map_tree, em);
1576 spin_unlock(&tree->map_tree.lock);
1577 if (!em)
1578 break;
1579 kfree(em->bdev);
1580 /* once for us */
1581 free_extent_map(em);
1582 /* once for the tree */
1583 free_extent_map(em);
1584 }
1585 }
1586
1587 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
1588 {
1589 struct extent_map *em;
1590 struct map_lookup *map;
1591 struct extent_map_tree *em_tree = &map_tree->map_tree;
1592 int ret;
1593
1594 spin_lock(&em_tree->lock);
1595 em = lookup_extent_mapping(em_tree, logical, len);
1596 spin_unlock(&em_tree->lock);
1597 BUG_ON(!em);
1598
1599 BUG_ON(em->start > logical || em->start + em->len < logical);
1600 map = (struct map_lookup *)em->bdev;
1601 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
1602 ret = map->num_stripes;
1603 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
1604 ret = map->sub_stripes;
1605 else
1606 ret = 1;
1607 free_extent_map(em);
1608 return ret;
1609 }
1610
1611 static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
1612 u64 logical, u64 *length,
1613 struct btrfs_multi_bio **multi_ret,
1614 int mirror_num, struct page *unplug_page)
1615 {
1616 struct extent_map *em;
1617 struct map_lookup *map;
1618 struct extent_map_tree *em_tree = &map_tree->map_tree;
1619 u64 offset;
1620 u64 stripe_offset;
1621 u64 stripe_nr;
1622 int stripes_allocated = 8;
1623 int stripes_required = 1;
1624 int stripe_index;
1625 int i;
1626 int num_stripes;
1627 int max_errors = 0;
1628 struct btrfs_multi_bio *multi = NULL;
1629
1630 if (multi_ret && !(rw & (1 << BIO_RW))) {
1631 stripes_allocated = 1;
1632 }
1633 again:
1634 if (multi_ret) {
1635 multi = kzalloc(btrfs_multi_bio_size(stripes_allocated),
1636 GFP_NOFS);
1637 if (!multi)
1638 return -ENOMEM;
1639
1640 atomic_set(&multi->error, 0);
1641 }
1642
1643 spin_lock(&em_tree->lock);
1644 em = lookup_extent_mapping(em_tree, logical, *length);
1645 spin_unlock(&em_tree->lock);
1646
1647 if (!em && unplug_page)
1648 return 0;
1649
1650 if (!em) {
1651 printk("unable to find logical %Lu len %Lu\n", logical, *length);
1652 BUG();
1653 }
1654
1655 BUG_ON(em->start > logical || em->start + em->len < logical);
1656 map = (struct map_lookup *)em->bdev;
1657 offset = logical - em->start;
1658
1659 if (mirror_num > map->num_stripes)
1660 mirror_num = 0;
1661
1662 /* if our multi bio struct is too small, back off and try again */
1663 if (rw & (1 << BIO_RW)) {
1664 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
1665 BTRFS_BLOCK_GROUP_DUP)) {
1666 stripes_required = map->num_stripes;
1667 max_errors = 1;
1668 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
1669 stripes_required = map->sub_stripes;
1670 max_errors = 1;
1671 }
1672 }
1673 if (multi_ret && rw == WRITE &&
1674 stripes_allocated < stripes_required) {
1675 stripes_allocated = map->num_stripes;
1676 free_extent_map(em);
1677 kfree(multi);
1678 goto again;
1679 }
1680 stripe_nr = offset;
1681 /*
1682 * stripe_nr counts the total number of stripes we have to stride
1683 * to get to this block
1684 */
1685 do_div(stripe_nr, map->stripe_len);
1686
1687 stripe_offset = stripe_nr * map->stripe_len;
1688 BUG_ON(offset < stripe_offset);
1689
1690 /* stripe_offset is the offset of this block in its stripe*/
1691 stripe_offset = offset - stripe_offset;
1692
1693 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
1694 BTRFS_BLOCK_GROUP_RAID10 |
1695 BTRFS_BLOCK_GROUP_DUP)) {
1696 /* we limit the length of each bio to what fits in a stripe */
1697 *length = min_t(u64, em->len - offset,
1698 map->stripe_len - stripe_offset);
1699 } else {
1700 *length = em->len - offset;
1701 }
1702
1703 if (!multi_ret && !unplug_page)
1704 goto out;
1705
1706 num_stripes = 1;
1707 stripe_index = 0;
1708 if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
1709 if (unplug_page || (rw & (1 << BIO_RW)))
1710 num_stripes = map->num_stripes;
1711 else if (mirror_num)
1712 stripe_index = mirror_num - 1;
1713 else
1714 stripe_index = current->pid % map->num_stripes;
1715
1716 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
1717 if (rw & (1 << BIO_RW))
1718 num_stripes = map->num_stripes;
1719 else if (mirror_num)
1720 stripe_index = mirror_num - 1;
1721
1722 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
1723 int factor = map->num_stripes / map->sub_stripes;
1724
1725 stripe_index = do_div(stripe_nr, factor);
1726 stripe_index *= map->sub_stripes;
1727
1728 if (unplug_page || (rw & (1 << BIO_RW)))
1729 num_stripes = map->sub_stripes;
1730 else if (mirror_num)
1731 stripe_index += mirror_num - 1;
1732 else
1733 stripe_index += current->pid % map->sub_stripes;
1734 } else {
1735 /*
1736 * after this do_div call, stripe_nr is the number of stripes
1737 * on this device we have to walk to find the data, and
1738 * stripe_index is the number of our device in the stripe array
1739 */
1740 stripe_index = do_div(stripe_nr, map->num_stripes);
1741 }
1742 BUG_ON(stripe_index >= map->num_stripes);
1743
1744 for (i = 0; i < num_stripes; i++) {
1745 if (unplug_page) {
1746 struct btrfs_device *device;
1747 struct backing_dev_info *bdi;
1748
1749 device = map->stripes[stripe_index].dev;
1750 bdi = blk_get_backing_dev_info(device->bdev);
1751 if (bdi->unplug_io_fn) {
1752 bdi->unplug_io_fn(bdi, unplug_page);
1753 }
1754 } else {
1755 multi->stripes[i].physical =
1756 map->stripes[stripe_index].physical +
1757 stripe_offset + stripe_nr * map->stripe_len;
1758 multi->stripes[i].dev = map->stripes[stripe_index].dev;
1759 }
1760 stripe_index++;
1761 }
1762 if (multi_ret) {
1763 *multi_ret = multi;
1764 multi->num_stripes = num_stripes;
1765 multi->max_errors = max_errors;
1766 }
1767 out:
1768 free_extent_map(em);
1769 return 0;
1770 }
1771
1772 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
1773 u64 logical, u64 *length,
1774 struct btrfs_multi_bio **multi_ret, int mirror_num)
1775 {
1776 return __btrfs_map_block(map_tree, rw, logical, length, multi_ret,
1777 mirror_num, NULL);
1778 }
1779
1780 int btrfs_unplug_page(struct btrfs_mapping_tree *map_tree,
1781 u64 logical, struct page *page)
1782 {
1783 u64 length = PAGE_CACHE_SIZE;
1784 return __btrfs_map_block(map_tree, READ, logical, &length,
1785 NULL, 0, page);
1786 }
1787
1788
1789 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
1790 static void end_bio_multi_stripe(struct bio *bio, int err)
1791 #else
1792 static int end_bio_multi_stripe(struct bio *bio,
1793 unsigned int bytes_done, int err)
1794 #endif
1795 {
1796 struct btrfs_multi_bio *multi = bio->bi_private;
1797
1798 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1799 if (bio->bi_size)
1800 return 1;
1801 #endif
1802 if (err)
1803 atomic_inc(&multi->error);
1804
1805 if (atomic_dec_and_test(&multi->stripes_pending)) {
1806 bio->bi_private = multi->private;
1807 bio->bi_end_io = multi->end_io;
1808
1809 /* only send an error to the higher layers if it is
1810 * beyond the tolerance of the multi-bio
1811 */
1812 if (atomic_read(&multi->error) > multi->max_errors)
1813 err = -EIO;
1814 else
1815 err = 0;
1816 kfree(multi);
1817
1818 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1819 bio_endio(bio, bio->bi_size, err);
1820 #else
1821 bio_endio(bio, err);
1822 #endif
1823 } else {
1824 bio_put(bio);
1825 }
1826 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1827 return 0;
1828 #endif
1829 }
1830
1831 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
1832 int mirror_num)
1833 {
1834 struct btrfs_mapping_tree *map_tree;
1835 struct btrfs_device *dev;
1836 struct bio *first_bio = bio;
1837 u64 logical = bio->bi_sector << 9;
1838 u64 length = 0;
1839 u64 map_length;
1840 struct btrfs_multi_bio *multi = NULL;
1841 int ret;
1842 int dev_nr = 0;
1843 int total_devs = 1;
1844
1845 length = bio->bi_size;
1846 map_tree = &root->fs_info->mapping_tree;
1847 map_length = length;
1848
1849 ret = btrfs_map_block(map_tree, rw, logical, &map_length, &multi,
1850 mirror_num);
1851 BUG_ON(ret);
1852
1853 total_devs = multi->num_stripes;
1854 if (map_length < length) {
1855 printk("mapping failed logical %Lu bio len %Lu "
1856 "len %Lu\n", logical, length, map_length);
1857 BUG();
1858 }
1859 multi->end_io = first_bio->bi_end_io;
1860 multi->private = first_bio->bi_private;
1861 atomic_set(&multi->stripes_pending, multi->num_stripes);
1862
1863 while(dev_nr < total_devs) {
1864 if (total_devs > 1) {
1865 if (dev_nr < total_devs - 1) {
1866 bio = bio_clone(first_bio, GFP_NOFS);
1867 BUG_ON(!bio);
1868 } else {
1869 bio = first_bio;
1870 }
1871 bio->bi_private = multi;
1872 bio->bi_end_io = end_bio_multi_stripe;
1873 }
1874 bio->bi_sector = multi->stripes[dev_nr].physical >> 9;
1875 dev = multi->stripes[dev_nr].dev;
1876
1877 bio->bi_bdev = dev->bdev;
1878 spin_lock(&dev->io_lock);
1879 dev->total_ios++;
1880 spin_unlock(&dev->io_lock);
1881 submit_bio(rw, bio);
1882 dev_nr++;
1883 }
1884 if (total_devs == 1)
1885 kfree(multi);
1886 return 0;
1887 }
1888
1889 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
1890 u8 *uuid)
1891 {
1892 struct list_head *head = &root->fs_info->fs_devices->devices;
1893
1894 return __find_device(head, devid, uuid);
1895 }
1896
1897 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
1898 struct extent_buffer *leaf,
1899 struct btrfs_chunk *chunk)
1900 {
1901 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
1902 struct map_lookup *map;
1903 struct extent_map *em;
1904 u64 logical;
1905 u64 length;
1906 u64 devid;
1907 u8 uuid[BTRFS_UUID_SIZE];
1908 int num_stripes;
1909 int ret;
1910 int i;
1911
1912 logical = key->offset;
1913 length = btrfs_chunk_length(leaf, chunk);
1914
1915 spin_lock(&map_tree->map_tree.lock);
1916 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
1917 spin_unlock(&map_tree->map_tree.lock);
1918
1919 /* already mapped? */
1920 if (em && em->start <= logical && em->start + em->len > logical) {
1921 free_extent_map(em);
1922 return 0;
1923 } else if (em) {
1924 free_extent_map(em);
1925 }
1926
1927 map = kzalloc(sizeof(*map), GFP_NOFS);
1928 if (!map)
1929 return -ENOMEM;
1930
1931 em = alloc_extent_map(GFP_NOFS);
1932 if (!em)
1933 return -ENOMEM;
1934 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
1935 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
1936 if (!map) {
1937 free_extent_map(em);
1938 return -ENOMEM;
1939 }
1940
1941 em->bdev = (struct block_device *)map;
1942 em->start = logical;
1943 em->len = length;
1944 em->block_start = 0;
1945
1946 map->num_stripes = num_stripes;
1947 map->io_width = btrfs_chunk_io_width(leaf, chunk);
1948 map->io_align = btrfs_chunk_io_align(leaf, chunk);
1949 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
1950 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
1951 map->type = btrfs_chunk_type(leaf, chunk);
1952 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
1953 for (i = 0; i < num_stripes; i++) {
1954 map->stripes[i].physical =
1955 btrfs_stripe_offset_nr(leaf, chunk, i);
1956 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
1957 read_extent_buffer(leaf, uuid, (unsigned long)
1958 btrfs_stripe_dev_uuid_nr(chunk, i),
1959 BTRFS_UUID_SIZE);
1960 map->stripes[i].dev = btrfs_find_device(root, devid, uuid);
1961 if (!map->stripes[i].dev) {
1962 kfree(map);
1963 free_extent_map(em);
1964 return -EIO;
1965 }
1966 }
1967
1968 spin_lock(&map_tree->map_tree.lock);
1969 ret = add_extent_mapping(&map_tree->map_tree, em);
1970 spin_unlock(&map_tree->map_tree.lock);
1971 BUG_ON(ret);
1972 free_extent_map(em);
1973
1974 return 0;
1975 }
1976
1977 static int fill_device_from_item(struct extent_buffer *leaf,
1978 struct btrfs_dev_item *dev_item,
1979 struct btrfs_device *device)
1980 {
1981 unsigned long ptr;
1982
1983 device->devid = btrfs_device_id(leaf, dev_item);
1984 device->total_bytes = btrfs_device_total_bytes(leaf, dev_item);
1985 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
1986 device->type = btrfs_device_type(leaf, dev_item);
1987 device->io_align = btrfs_device_io_align(leaf, dev_item);
1988 device->io_width = btrfs_device_io_width(leaf, dev_item);
1989 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
1990
1991 ptr = (unsigned long)btrfs_device_uuid(dev_item);
1992 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1993
1994 return 0;
1995 }
1996
1997 static int read_one_dev(struct btrfs_root *root,
1998 struct extent_buffer *leaf,
1999 struct btrfs_dev_item *dev_item)
2000 {
2001 struct btrfs_device *device;
2002 u64 devid;
2003 int ret;
2004 u8 dev_uuid[BTRFS_UUID_SIZE];
2005
2006 devid = btrfs_device_id(leaf, dev_item);
2007 read_extent_buffer(leaf, dev_uuid,
2008 (unsigned long)btrfs_device_uuid(dev_item),
2009 BTRFS_UUID_SIZE);
2010 device = btrfs_find_device(root, devid, dev_uuid);
2011 if (!device) {
2012 printk("warning devid %Lu not found already\n", devid);
2013 device = kzalloc(sizeof(*device), GFP_NOFS);
2014 if (!device)
2015 return -ENOMEM;
2016 list_add(&device->dev_list,
2017 &root->fs_info->fs_devices->devices);
2018 list_add(&device->dev_alloc_list,
2019 &root->fs_info->fs_devices->alloc_list);
2020 device->barriers = 1;
2021 spin_lock_init(&device->io_lock);
2022 }
2023
2024 fill_device_from_item(leaf, dev_item, device);
2025 device->dev_root = root->fs_info->dev_root;
2026 ret = 0;
2027 #if 0
2028 ret = btrfs_open_device(device);
2029 if (ret) {
2030 kfree(device);
2031 }
2032 #endif
2033 return ret;
2034 }
2035
2036 int btrfs_read_super_device(struct btrfs_root *root, struct extent_buffer *buf)
2037 {
2038 struct btrfs_dev_item *dev_item;
2039
2040 dev_item = (struct btrfs_dev_item *)offsetof(struct btrfs_super_block,
2041 dev_item);
2042 return read_one_dev(root, buf, dev_item);
2043 }
2044
2045 int btrfs_read_sys_array(struct btrfs_root *root)
2046 {
2047 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
2048 struct extent_buffer *sb;
2049 struct btrfs_disk_key *disk_key;
2050 struct btrfs_chunk *chunk;
2051 u8 *ptr;
2052 unsigned long sb_ptr;
2053 int ret = 0;
2054 u32 num_stripes;
2055 u32 array_size;
2056 u32 len = 0;
2057 u32 cur;
2058 struct btrfs_key key;
2059
2060 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
2061 BTRFS_SUPER_INFO_SIZE);
2062 if (!sb)
2063 return -ENOMEM;
2064 btrfs_set_buffer_uptodate(sb);
2065 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
2066 array_size = btrfs_super_sys_array_size(super_copy);
2067
2068 ptr = super_copy->sys_chunk_array;
2069 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
2070 cur = 0;
2071
2072 while (cur < array_size) {
2073 disk_key = (struct btrfs_disk_key *)ptr;
2074 btrfs_disk_key_to_cpu(&key, disk_key);
2075
2076 len = sizeof(*disk_key); ptr += len;
2077 sb_ptr += len;
2078 cur += len;
2079
2080 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
2081 chunk = (struct btrfs_chunk *)sb_ptr;
2082 ret = read_one_chunk(root, &key, sb, chunk);
2083 if (ret)
2084 break;
2085 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
2086 len = btrfs_chunk_item_size(num_stripes);
2087 } else {
2088 ret = -EIO;
2089 break;
2090 }
2091 ptr += len;
2092 sb_ptr += len;
2093 cur += len;
2094 }
2095 free_extent_buffer(sb);
2096 return ret;
2097 }
2098
2099 int btrfs_read_chunk_tree(struct btrfs_root *root)
2100 {
2101 struct btrfs_path *path;
2102 struct extent_buffer *leaf;
2103 struct btrfs_key key;
2104 struct btrfs_key found_key;
2105 int ret;
2106 int slot;
2107
2108 root = root->fs_info->chunk_root;
2109
2110 path = btrfs_alloc_path();
2111 if (!path)
2112 return -ENOMEM;
2113
2114 /* first we search for all of the device items, and then we
2115 * read in all of the chunk items. This way we can create chunk
2116 * mappings that reference all of the devices that are afound
2117 */
2118 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
2119 key.offset = 0;
2120 key.type = 0;
2121 again:
2122 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2123 while(1) {
2124 leaf = path->nodes[0];
2125 slot = path->slots[0];
2126 if (slot >= btrfs_header_nritems(leaf)) {
2127 ret = btrfs_next_leaf(root, path);
2128 if (ret == 0)
2129 continue;
2130 if (ret < 0)
2131 goto error;
2132 break;
2133 }
2134 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2135 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
2136 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
2137 break;
2138 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
2139 struct btrfs_dev_item *dev_item;
2140 dev_item = btrfs_item_ptr(leaf, slot,
2141 struct btrfs_dev_item);
2142 ret = read_one_dev(root, leaf, dev_item);
2143 BUG_ON(ret);
2144 }
2145 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
2146 struct btrfs_chunk *chunk;
2147 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
2148 ret = read_one_chunk(root, &found_key, leaf, chunk);
2149 }
2150 path->slots[0]++;
2151 }
2152 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
2153 key.objectid = 0;
2154 btrfs_release_path(root, path);
2155 goto again;
2156 }
2157
2158 btrfs_free_path(path);
2159 ret = 0;
2160 error:
2161 return ret;
2162 }
2163
Linux kernel - Deliverables
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