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Btrfs: fs/btrfs/volumes.c: remove useless kzalloc
[linux-2.6/mini2440.git] / fs / btrfs / volumes.c
blobc793b6f50d8d69628f56e6fc87d8b58b4326f7c9
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 "compat.h"
25 #include "ctree.h"
26 #include "extent_map.h"
27 #include "disk-io.h"
28 #include "transaction.h"
29 #include "print-tree.h"
30 #include "volumes.h"
31 #include "async-thread.h"
32
33 struct map_lookup {
34 u64 type;
35 int io_align;
36 int io_width;
37 int stripe_len;
38 int sector_size;
39 int num_stripes;
40 int sub_stripes;
41 struct btrfs_bio_stripe stripes[];
42 };
43
44 static int init_first_rw_device(struct btrfs_trans_handle *trans,
45 struct btrfs_root *root,
46 struct btrfs_device *device);
47 static int btrfs_relocate_sys_chunks(struct btrfs_root *root);
48
49 #define map_lookup_size(n) (sizeof(struct map_lookup) + \
50 (sizeof(struct btrfs_bio_stripe) * (n)))
51
52 static DEFINE_MUTEX(uuid_mutex);
53 static LIST_HEAD(fs_uuids);
54
55 void btrfs_lock_volumes(void)
56 {
57 mutex_lock(&uuid_mutex);
58 }
59
60 void btrfs_unlock_volumes(void)
61 {
62 mutex_unlock(&uuid_mutex);
63 }
64
65 static void lock_chunks(struct btrfs_root *root)
66 {
67 mutex_lock(&root->fs_info->chunk_mutex);
68 }
69
70 static void unlock_chunks(struct btrfs_root *root)
71 {
72 mutex_unlock(&root->fs_info->chunk_mutex);
73 }
74
75 static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
76 {
77 struct btrfs_device *device;
78 WARN_ON(fs_devices->opened);
79 while (!list_empty(&fs_devices->devices)) {
80 device = list_entry(fs_devices->devices.next,
81 struct btrfs_device, dev_list);
82 list_del(&device->dev_list);
83 kfree(device->name);
84 kfree(device);
85 }
86 kfree(fs_devices);
87 }
88
89 int btrfs_cleanup_fs_uuids(void)
90 {
91 struct btrfs_fs_devices *fs_devices;
92
93 while (!list_empty(&fs_uuids)) {
94 fs_devices = list_entry(fs_uuids.next,
95 struct btrfs_fs_devices, list);
96 list_del(&fs_devices->list);
97 free_fs_devices(fs_devices);
98 }
99 return 0;
100 }
101
102 static noinline struct btrfs_device *__find_device(struct list_head *head,
103 u64 devid, u8 *uuid)
104 {
105 struct btrfs_device *dev;
106
107 list_for_each_entry(dev, head, dev_list) {
108 if (dev->devid == devid &&
109 (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
110 return dev;
111 }
112 }
113 return NULL;
114 }
115
116 static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
117 {
118 struct btrfs_fs_devices *fs_devices;
119
120 list_for_each_entry(fs_devices, &fs_uuids, list) {
121 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
122 return fs_devices;
123 }
124 return NULL;
125 }
126
127 /*
128 * we try to collect pending bios for a device so we don't get a large
129 * number of procs sending bios down to the same device. This greatly
130 * improves the schedulers ability to collect and merge the bios.
131 *
132 * But, it also turns into a long list of bios to process and that is sure
133 * to eventually make the worker thread block. The solution here is to
134 * make some progress and then put this work struct back at the end of
135 * the list if the block device is congested. This way, multiple devices
136 * can make progress from a single worker thread.
137 */
138 static noinline int run_scheduled_bios(struct btrfs_device *device)
139 {
140 struct bio *pending;
141 struct backing_dev_info *bdi;
142 struct btrfs_fs_info *fs_info;
143 struct bio *tail;
144 struct bio *cur;
145 int again = 0;
146 unsigned long num_run = 0;
147 unsigned long limit;
148
149 bdi = device->bdev->bd_inode->i_mapping->backing_dev_info;
150 fs_info = device->dev_root->fs_info;
151 limit = btrfs_async_submit_limit(fs_info);
152 limit = limit * 2 / 3;
153
154 loop:
155 spin_lock(&device->io_lock);
156
157 loop_lock:
158 /* take all the bios off the list at once and process them
159 * later on (without the lock held). But, remember the
160 * tail and other pointers so the bios can be properly reinserted
161 * into the list if we hit congestion
162 */
163 pending = device->pending_bios;
164 tail = device->pending_bio_tail;
165 WARN_ON(pending && !tail);
166 device->pending_bios = NULL;
167 device->pending_bio_tail = NULL;
168
169 /*
170 * if pending was null this time around, no bios need processing
171 * at all and we can stop. Otherwise it'll loop back up again
172 * and do an additional check so no bios are missed.
173 *
174 * device->running_pending is used to synchronize with the
175 * schedule_bio code.
176 */
177 if (pending) {
178 again = 1;
179 device->running_pending = 1;
180 } else {
181 again = 0;
182 device->running_pending = 0;
183 }
184 spin_unlock(&device->io_lock);
185
186 while (pending) {
187 cur = pending;
188 pending = pending->bi_next;
189 cur->bi_next = NULL;
190 atomic_dec(&fs_info->nr_async_bios);
191
192 if (atomic_read(&fs_info->nr_async_bios) < limit &&
193 waitqueue_active(&fs_info->async_submit_wait))
194 wake_up(&fs_info->async_submit_wait);
195
196 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
197 bio_get(cur);
198 submit_bio(cur->bi_rw, cur);
199 bio_put(cur);
200 num_run++;
201
202 /*
203 * we made progress, there is more work to do and the bdi
204 * is now congested. Back off and let other work structs
205 * run instead
206 */
207 if (pending && bdi_write_congested(bdi) && num_run > 16 &&
208 fs_info->fs_devices->open_devices > 1) {
209 struct bio *old_head;
210
211 spin_lock(&device->io_lock);
212
213 old_head = device->pending_bios;
214 device->pending_bios = pending;
215 if (device->pending_bio_tail)
216 tail->bi_next = old_head;
217 else
218 device->pending_bio_tail = tail;
219
220 device->running_pending = 1;
221
222 spin_unlock(&device->io_lock);
223 btrfs_requeue_work(&device->work);
224 goto done;
225 }
226 }
227 if (again)
228 goto loop;
229
230 spin_lock(&device->io_lock);
231 if (device->pending_bios)
232 goto loop_lock;
233 spin_unlock(&device->io_lock);
234 done:
235 return 0;
236 }
237
238 static void pending_bios_fn(struct btrfs_work *work)
239 {
240 struct btrfs_device *device;
241
242 device = container_of(work, struct btrfs_device, work);
243 run_scheduled_bios(device);
244 }
245
246 static noinline int device_list_add(const char *path,
247 struct btrfs_super_block *disk_super,
248 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
249 {
250 struct btrfs_device *device;
251 struct btrfs_fs_devices *fs_devices;
252 u64 found_transid = btrfs_super_generation(disk_super);
253
254 fs_devices = find_fsid(disk_super->fsid);
255 if (!fs_devices) {
256 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
257 if (!fs_devices)
258 return -ENOMEM;
259 INIT_LIST_HEAD(&fs_devices->devices);
260 INIT_LIST_HEAD(&fs_devices->alloc_list);
261 list_add(&fs_devices->list, &fs_uuids);
262 memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
263 fs_devices->latest_devid = devid;
264 fs_devices->latest_trans = found_transid;
265 device = NULL;
266 } else {
267 device = __find_device(&fs_devices->devices, devid,
268 disk_super->dev_item.uuid);
269 }
270 if (!device) {
271 if (fs_devices->opened)
272 return -EBUSY;
273
274 device = kzalloc(sizeof(*device), GFP_NOFS);
275 if (!device) {
276 /* we can safely leave the fs_devices entry around */
277 return -ENOMEM;
278 }
279 device->devid = devid;
280 device->work.func = pending_bios_fn;
281 memcpy(device->uuid, disk_super->dev_item.uuid,
282 BTRFS_UUID_SIZE);
283 device->barriers = 1;
284 spin_lock_init(&device->io_lock);
285 device->name = kstrdup(path, GFP_NOFS);
286 if (!device->name) {
287 kfree(device);
288 return -ENOMEM;
289 }
290 INIT_LIST_HEAD(&device->dev_alloc_list);
291 list_add(&device->dev_list, &fs_devices->devices);
292 device->fs_devices = fs_devices;
293 fs_devices->num_devices++;
294 }
295
296 if (found_transid > fs_devices->latest_trans) {
297 fs_devices->latest_devid = devid;
298 fs_devices->latest_trans = found_transid;
299 }
300 *fs_devices_ret = fs_devices;
301 return 0;
302 }
303
304 static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
305 {
306 struct btrfs_fs_devices *fs_devices;
307 struct btrfs_device *device;
308 struct btrfs_device *orig_dev;
309
310 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
311 if (!fs_devices)
312 return ERR_PTR(-ENOMEM);
313
314 INIT_LIST_HEAD(&fs_devices->devices);
315 INIT_LIST_HEAD(&fs_devices->alloc_list);
316 INIT_LIST_HEAD(&fs_devices->list);
317 fs_devices->latest_devid = orig->latest_devid;
318 fs_devices->latest_trans = orig->latest_trans;
319 memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid));
320
321 list_for_each_entry(orig_dev, &orig->devices, dev_list) {
322 device = kzalloc(sizeof(*device), GFP_NOFS);
323 if (!device)
324 goto error;
325
326 device->name = kstrdup(orig_dev->name, GFP_NOFS);
327 if (!device->name)
328 goto error;
329
330 device->devid = orig_dev->devid;
331 device->work.func = pending_bios_fn;
332 memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid));
333 device->barriers = 1;
334 spin_lock_init(&device->io_lock);
335 INIT_LIST_HEAD(&device->dev_list);
336 INIT_LIST_HEAD(&device->dev_alloc_list);
337
338 list_add(&device->dev_list, &fs_devices->devices);
339 device->fs_devices = fs_devices;
340 fs_devices->num_devices++;
341 }
342 return fs_devices;
343 error:
344 free_fs_devices(fs_devices);
345 return ERR_PTR(-ENOMEM);
346 }
347
348 int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
349 {
350 struct btrfs_device *device, *next;
351
352 mutex_lock(&uuid_mutex);
353 again:
354 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
355 if (device->in_fs_metadata)
356 continue;
357
358 if (device->bdev) {
359 close_bdev_exclusive(device->bdev, device->mode);
360 device->bdev = NULL;
361 fs_devices->open_devices--;
362 }
363 if (device->writeable) {
364 list_del_init(&device->dev_alloc_list);
365 device->writeable = 0;
366 fs_devices->rw_devices--;
367 }
368 list_del_init(&device->dev_list);
369 fs_devices->num_devices--;
370 kfree(device->name);
371 kfree(device);
372 }
373
374 if (fs_devices->seed) {
375 fs_devices = fs_devices->seed;
376 goto again;
377 }
378
379 mutex_unlock(&uuid_mutex);
380 return 0;
381 }
382
383 static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
384 {
385 struct btrfs_device *device;
386
387 if (--fs_devices->opened > 0)
388 return 0;
389
390 list_for_each_entry(device, &fs_devices->devices, dev_list) {
391 if (device->bdev) {
392 close_bdev_exclusive(device->bdev, device->mode);
393 fs_devices->open_devices--;
394 }
395 if (device->writeable) {
396 list_del_init(&device->dev_alloc_list);
397 fs_devices->rw_devices--;
398 }
399
400 device->bdev = NULL;
401 device->writeable = 0;
402 device->in_fs_metadata = 0;
403 }
404 WARN_ON(fs_devices->open_devices);
405 WARN_ON(fs_devices->rw_devices);
406 fs_devices->opened = 0;
407 fs_devices->seeding = 0;
408
409 return 0;
410 }
411
412 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
413 {
414 struct btrfs_fs_devices *seed_devices = NULL;
415 int ret;
416
417 mutex_lock(&uuid_mutex);
418 ret = __btrfs_close_devices(fs_devices);
419 if (!fs_devices->opened) {
420 seed_devices = fs_devices->seed;
421 fs_devices->seed = NULL;
422 }
423 mutex_unlock(&uuid_mutex);
424
425 while (seed_devices) {
426 fs_devices = seed_devices;
427 seed_devices = fs_devices->seed;
428 __btrfs_close_devices(fs_devices);
429 free_fs_devices(fs_devices);
430 }
431 return ret;
432 }
433
434 static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
435 fmode_t flags, void *holder)
436 {
437 struct block_device *bdev;
438 struct list_head *head = &fs_devices->devices;
439 struct btrfs_device *device;
440 struct block_device *latest_bdev = NULL;
441 struct buffer_head *bh;
442 struct btrfs_super_block *disk_super;
443 u64 latest_devid = 0;
444 u64 latest_transid = 0;
445 u64 devid;
446 int seeding = 1;
447 int ret = 0;
448
449 list_for_each_entry(device, head, dev_list) {
450 if (device->bdev)
451 continue;
452 if (!device->name)
453 continue;
454
455 bdev = open_bdev_exclusive(device->name, flags, holder);
456 if (IS_ERR(bdev)) {
457 printk(KERN_INFO "open %s failed\n", device->name);
458 goto error;
459 }
460 set_blocksize(bdev, 4096);
461
462 bh = btrfs_read_dev_super(bdev);
463 if (!bh)
464 goto error_close;
465
466 disk_super = (struct btrfs_super_block *)bh->b_data;
467 devid = le64_to_cpu(disk_super->dev_item.devid);
468 if (devid != device->devid)
469 goto error_brelse;
470
471 if (memcmp(device->uuid, disk_super->dev_item.uuid,
472 BTRFS_UUID_SIZE))
473 goto error_brelse;
474
475 device->generation = btrfs_super_generation(disk_super);
476 if (!latest_transid || device->generation > latest_transid) {
477 latest_devid = devid;
478 latest_transid = device->generation;
479 latest_bdev = bdev;
480 }
481
482 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
483 device->writeable = 0;
484 } else {
485 device->writeable = !bdev_read_only(bdev);
486 seeding = 0;
487 }
488
489 device->bdev = bdev;
490 device->in_fs_metadata = 0;
491 device->mode = flags;
492
493 fs_devices->open_devices++;
494 if (device->writeable) {
495 fs_devices->rw_devices++;
496 list_add(&device->dev_alloc_list,
497 &fs_devices->alloc_list);
498 }
499 continue;
500
501 error_brelse:
502 brelse(bh);
503 error_close:
504 close_bdev_exclusive(bdev, FMODE_READ);
505 error:
506 continue;
507 }
508 if (fs_devices->open_devices == 0) {
509 ret = -EIO;
510 goto out;
511 }
512 fs_devices->seeding = seeding;
513 fs_devices->opened = 1;
514 fs_devices->latest_bdev = latest_bdev;
515 fs_devices->latest_devid = latest_devid;
516 fs_devices->latest_trans = latest_transid;
517 fs_devices->total_rw_bytes = 0;
518 out:
519 return ret;
520 }
521
522 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
523 fmode_t flags, void *holder)
524 {
525 int ret;
526
527 mutex_lock(&uuid_mutex);
528 if (fs_devices->opened) {
529 fs_devices->opened++;
530 ret = 0;
531 } else {
532 ret = __btrfs_open_devices(fs_devices, flags, holder);
533 }
534 mutex_unlock(&uuid_mutex);
535 return ret;
536 }
537
538 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
539 struct btrfs_fs_devices **fs_devices_ret)
540 {
541 struct btrfs_super_block *disk_super;
542 struct block_device *bdev;
543 struct buffer_head *bh;
544 int ret;
545 u64 devid;
546 u64 transid;
547
548 mutex_lock(&uuid_mutex);
549
550 bdev = open_bdev_exclusive(path, flags, holder);
551
552 if (IS_ERR(bdev)) {
553 ret = PTR_ERR(bdev);
554 goto error;
555 }
556
557 ret = set_blocksize(bdev, 4096);
558 if (ret)
559 goto error_close;
560 bh = btrfs_read_dev_super(bdev);
561 if (!bh) {
562 ret = -EIO;
563 goto error_close;
564 }
565 disk_super = (struct btrfs_super_block *)bh->b_data;
566 devid = le64_to_cpu(disk_super->dev_item.devid);
567 transid = btrfs_super_generation(disk_super);
568 if (disk_super->label[0])
569 printk(KERN_INFO "device label %s ", disk_super->label);
570 else {
571 /* FIXME, make a readl uuid parser */
572 printk(KERN_INFO "device fsid %llx-%llx ",
573 *(unsigned long long *)disk_super->fsid,
574 *(unsigned long long *)(disk_super->fsid + 8));
575 }
576 printk(KERN_CONT "devid %llu transid %llu %s\n",
577 (unsigned long long)devid, (unsigned long long)transid, path);
578 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
579
580 brelse(bh);
581 error_close:
582 close_bdev_exclusive(bdev, flags);
583 error:
584 mutex_unlock(&uuid_mutex);
585 return ret;
586 }
587
588 /*
589 * this uses a pretty simple search, the expectation is that it is
590 * called very infrequently and that a given device has a small number
591 * of extents
592 */
593 static noinline int find_free_dev_extent(struct btrfs_trans_handle *trans,
594 struct btrfs_device *device,
595 u64 num_bytes, u64 *start)
596 {
597 struct btrfs_key key;
598 struct btrfs_root *root = device->dev_root;
599 struct btrfs_dev_extent *dev_extent = NULL;
600 struct btrfs_path *path;
601 u64 hole_size = 0;
602 u64 last_byte = 0;
603 u64 search_start = 0;
604 u64 search_end = device->total_bytes;
605 int ret;
606 int slot = 0;
607 int start_found;
608 struct extent_buffer *l;
609
610 path = btrfs_alloc_path();
611 if (!path)
612 return -ENOMEM;
613 path->reada = 2;
614 start_found = 0;
615
616 /* FIXME use last free of some kind */
617
618 /* we don't want to overwrite the superblock on the drive,
619 * so we make sure to start at an offset of at least 1MB
620 */
621 search_start = max((u64)1024 * 1024, search_start);
622
623 if (root->fs_info->alloc_start + num_bytes <= device->total_bytes)
624 search_start = max(root->fs_info->alloc_start, search_start);
625
626 key.objectid = device->devid;
627 key.offset = search_start;
628 key.type = BTRFS_DEV_EXTENT_KEY;
629 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
630 if (ret < 0)
631 goto error;
632 ret = btrfs_previous_item(root, path, 0, key.type);
633 if (ret < 0)
634 goto error;
635 l = path->nodes[0];
636 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
637 while (1) {
638 l = path->nodes[0];
639 slot = path->slots[0];
640 if (slot >= btrfs_header_nritems(l)) {
641 ret = btrfs_next_leaf(root, path);
642 if (ret == 0)
643 continue;
644 if (ret < 0)
645 goto error;
646 no_more_items:
647 if (!start_found) {
648 if (search_start >= search_end) {
649 ret = -ENOSPC;
650 goto error;
651 }
652 *start = search_start;
653 start_found = 1;
654 goto check_pending;
655 }
656 *start = last_byte > search_start ?
657 last_byte : search_start;
658 if (search_end <= *start) {
659 ret = -ENOSPC;
660 goto error;
661 }
662 goto check_pending;
663 }
664 btrfs_item_key_to_cpu(l, &key, slot);
665
666 if (key.objectid < device->devid)
667 goto next;
668
669 if (key.objectid > device->devid)
670 goto no_more_items;
671
672 if (key.offset >= search_start && key.offset > last_byte &&
673 start_found) {
674 if (last_byte < search_start)
675 last_byte = search_start;
676 hole_size = key.offset - last_byte;
677 if (key.offset > last_byte &&
678 hole_size >= num_bytes) {
679 *start = last_byte;
680 goto check_pending;
681 }
682 }
683 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
684 goto next;
685
686 start_found = 1;
687 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
688 last_byte = key.offset + btrfs_dev_extent_length(l, dev_extent);
689 next:
690 path->slots[0]++;
691 cond_resched();
692 }
693 check_pending:
694 /* we have to make sure we didn't find an extent that has already
695 * been allocated by the map tree or the original allocation
696 */
697 BUG_ON(*start < search_start);
698
699 if (*start + num_bytes > search_end) {
700 ret = -ENOSPC;
701 goto error;
702 }
703 /* check for pending inserts here */
704 ret = 0;
705
706 error:
707 btrfs_free_path(path);
708 return ret;
709 }
710
711 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
712 struct btrfs_device *device,
713 u64 start)
714 {
715 int ret;
716 struct btrfs_path *path;
717 struct btrfs_root *root = device->dev_root;
718 struct btrfs_key key;
719 struct btrfs_key found_key;
720 struct extent_buffer *leaf = NULL;
721 struct btrfs_dev_extent *extent = NULL;
722
723 path = btrfs_alloc_path();
724 if (!path)
725 return -ENOMEM;
726
727 key.objectid = device->devid;
728 key.offset = start;
729 key.type = BTRFS_DEV_EXTENT_KEY;
730
731 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
732 if (ret > 0) {
733 ret = btrfs_previous_item(root, path, key.objectid,
734 BTRFS_DEV_EXTENT_KEY);
735 BUG_ON(ret);
736 leaf = path->nodes[0];
737 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
738 extent = btrfs_item_ptr(leaf, path->slots[0],
739 struct btrfs_dev_extent);
740 BUG_ON(found_key.offset > start || found_key.offset +
741 btrfs_dev_extent_length(leaf, extent) < start);
742 ret = 0;
743 } else if (ret == 0) {
744 leaf = path->nodes[0];
745 extent = btrfs_item_ptr(leaf, path->slots[0],
746 struct btrfs_dev_extent);
747 }
748 BUG_ON(ret);
749
750 if (device->bytes_used > 0)
751 device->bytes_used -= btrfs_dev_extent_length(leaf, extent);
752 ret = btrfs_del_item(trans, root, path);
753 BUG_ON(ret);
754
755 btrfs_free_path(path);
756 return ret;
757 }
758
759 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
760 struct btrfs_device *device,
761 u64 chunk_tree, u64 chunk_objectid,
762 u64 chunk_offset, u64 start, u64 num_bytes)
763 {
764 int ret;
765 struct btrfs_path *path;
766 struct btrfs_root *root = device->dev_root;
767 struct btrfs_dev_extent *extent;
768 struct extent_buffer *leaf;
769 struct btrfs_key key;
770
771 WARN_ON(!device->in_fs_metadata);
772 path = btrfs_alloc_path();
773 if (!path)
774 return -ENOMEM;
775
776 key.objectid = device->devid;
777 key.offset = start;
778 key.type = BTRFS_DEV_EXTENT_KEY;
779 ret = btrfs_insert_empty_item(trans, root, path, &key,
780 sizeof(*extent));
781 BUG_ON(ret);
782
783 leaf = path->nodes[0];
784 extent = btrfs_item_ptr(leaf, path->slots[0],
785 struct btrfs_dev_extent);
786 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
787 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
788 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
789
790 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
791 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
792 BTRFS_UUID_SIZE);
793
794 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
795 btrfs_mark_buffer_dirty(leaf);
796 btrfs_free_path(path);
797 return ret;
798 }
799
800 static noinline int find_next_chunk(struct btrfs_root *root,
801 u64 objectid, u64 *offset)
802 {
803 struct btrfs_path *path;
804 int ret;
805 struct btrfs_key key;
806 struct btrfs_chunk *chunk;
807 struct btrfs_key found_key;
808
809 path = btrfs_alloc_path();
810 BUG_ON(!path);
811
812 key.objectid = objectid;
813 key.offset = (u64)-1;
814 key.type = BTRFS_CHUNK_ITEM_KEY;
815
816 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
817 if (ret < 0)
818 goto error;
819
820 BUG_ON(ret == 0);
821
822 ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
823 if (ret) {
824 *offset = 0;
825 } else {
826 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
827 path->slots[0]);
828 if (found_key.objectid != objectid)
829 *offset = 0;
830 else {
831 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
832 struct btrfs_chunk);
833 *offset = found_key.offset +
834 btrfs_chunk_length(path->nodes[0], chunk);
835 }
836 }
837 ret = 0;
838 error:
839 btrfs_free_path(path);
840 return ret;
841 }
842
843 static noinline int find_next_devid(struct btrfs_root *root, u64 *objectid)
844 {
845 int ret;
846 struct btrfs_key key;
847 struct btrfs_key found_key;
848 struct btrfs_path *path;
849
850 root = root->fs_info->chunk_root;
851
852 path = btrfs_alloc_path();
853 if (!path)
854 return -ENOMEM;
855
856 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
857 key.type = BTRFS_DEV_ITEM_KEY;
858 key.offset = (u64)-1;
859
860 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
861 if (ret < 0)
862 goto error;
863
864 BUG_ON(ret == 0);
865
866 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
867 BTRFS_DEV_ITEM_KEY);
868 if (ret) {
869 *objectid = 1;
870 } else {
871 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
872 path->slots[0]);
873 *objectid = found_key.offset + 1;
874 }
875 ret = 0;
876 error:
877 btrfs_free_path(path);
878 return ret;
879 }
880
881 /*
882 * the device information is stored in the chunk root
883 * the btrfs_device struct should be fully filled in
884 */
885 int btrfs_add_device(struct btrfs_trans_handle *trans,
886 struct btrfs_root *root,
887 struct btrfs_device *device)
888 {
889 int ret;
890 struct btrfs_path *path;
891 struct btrfs_dev_item *dev_item;
892 struct extent_buffer *leaf;
893 struct btrfs_key key;
894 unsigned long ptr;
895
896 root = root->fs_info->chunk_root;
897
898 path = btrfs_alloc_path();
899 if (!path)
900 return -ENOMEM;
901
902 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
903 key.type = BTRFS_DEV_ITEM_KEY;
904 key.offset = device->devid;
905
906 ret = btrfs_insert_empty_item(trans, root, path, &key,
907 sizeof(*dev_item));
908 if (ret)
909 goto out;
910
911 leaf = path->nodes[0];
912 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
913
914 btrfs_set_device_id(leaf, dev_item, device->devid);
915 btrfs_set_device_generation(leaf, dev_item, 0);
916 btrfs_set_device_type(leaf, dev_item, device->type);
917 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
918 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
919 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
920 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
921 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
922 btrfs_set_device_group(leaf, dev_item, 0);
923 btrfs_set_device_seek_speed(leaf, dev_item, 0);
924 btrfs_set_device_bandwidth(leaf, dev_item, 0);
925 btrfs_set_device_start_offset(leaf, dev_item, 0);
926
927 ptr = (unsigned long)btrfs_device_uuid(dev_item);
928 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
929 ptr = (unsigned long)btrfs_device_fsid(dev_item);
930 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
931 btrfs_mark_buffer_dirty(leaf);
932
933 ret = 0;
934 out:
935 btrfs_free_path(path);
936 return ret;
937 }
938
939 static int btrfs_rm_dev_item(struct btrfs_root *root,
940 struct btrfs_device *device)
941 {
942 int ret;
943 struct btrfs_path *path;
944 struct btrfs_key key;
945 struct btrfs_trans_handle *trans;
946
947 root = root->fs_info->chunk_root;
948
949 path = btrfs_alloc_path();
950 if (!path)
951 return -ENOMEM;
952
953 trans = btrfs_start_transaction(root, 1);
954 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
955 key.type = BTRFS_DEV_ITEM_KEY;
956 key.offset = device->devid;
957 lock_chunks(root);
958
959 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
960 if (ret < 0)
961 goto out;
962
963 if (ret > 0) {
964 ret = -ENOENT;
965 goto out;
966 }
967
968 ret = btrfs_del_item(trans, root, path);
969 if (ret)
970 goto out;
971 out:
972 btrfs_free_path(path);
973 unlock_chunks(root);
974 btrfs_commit_transaction(trans, root);
975 return ret;
976 }
977
978 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
979 {
980 struct btrfs_device *device;
981 struct btrfs_device *next_device;
982 struct block_device *bdev;
983 struct buffer_head *bh = NULL;
984 struct btrfs_super_block *disk_super;
985 u64 all_avail;
986 u64 devid;
987 u64 num_devices;
988 u8 *dev_uuid;
989 int ret = 0;
990
991 mutex_lock(&uuid_mutex);
992 mutex_lock(&root->fs_info->volume_mutex);
993
994 all_avail = root->fs_info->avail_data_alloc_bits |
995 root->fs_info->avail_system_alloc_bits |
996 root->fs_info->avail_metadata_alloc_bits;
997
998 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) &&
999 root->fs_info->fs_devices->rw_devices <= 4) {
1000 printk(KERN_ERR "btrfs: unable to go below four devices "
1001 "on raid10\n");
1002 ret = -EINVAL;
1003 goto out;
1004 }
1005
1006 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) &&
1007 root->fs_info->fs_devices->rw_devices <= 2) {
1008 printk(KERN_ERR "btrfs: unable to go below two "
1009 "devices on raid1\n");
1010 ret = -EINVAL;
1011 goto out;
1012 }
1013
1014 if (strcmp(device_path, "missing") == 0) {
1015 struct list_head *devices;
1016 struct btrfs_device *tmp;
1017
1018 device = NULL;
1019 devices = &root->fs_info->fs_devices->devices;
1020 list_for_each_entry(tmp, devices, dev_list) {
1021 if (tmp->in_fs_metadata && !tmp->bdev) {
1022 device = tmp;
1023 break;
1024 }
1025 }
1026 bdev = NULL;
1027 bh = NULL;
1028 disk_super = NULL;
1029 if (!device) {
1030 printk(KERN_ERR "btrfs: no missing devices found to "
1031 "remove\n");
1032 goto out;
1033 }
1034 } else {
1035 bdev = open_bdev_exclusive(device_path, FMODE_READ,
1036 root->fs_info->bdev_holder);
1037 if (IS_ERR(bdev)) {
1038 ret = PTR_ERR(bdev);
1039 goto out;
1040 }
1041
1042 set_blocksize(bdev, 4096);
1043 bh = btrfs_read_dev_super(bdev);
1044 if (!bh) {
1045 ret = -EIO;
1046 goto error_close;
1047 }
1048 disk_super = (struct btrfs_super_block *)bh->b_data;
1049 devid = le64_to_cpu(disk_super->dev_item.devid);
1050 dev_uuid = disk_super->dev_item.uuid;
1051 device = btrfs_find_device(root, devid, dev_uuid,
1052 disk_super->fsid);
1053 if (!device) {
1054 ret = -ENOENT;
1055 goto error_brelse;
1056 }
1057 }
1058
1059 if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
1060 printk(KERN_ERR "btrfs: unable to remove the only writeable "
1061 "device\n");
1062 ret = -EINVAL;
1063 goto error_brelse;
1064 }
1065
1066 if (device->writeable) {
1067 list_del_init(&device->dev_alloc_list);
1068 root->fs_info->fs_devices->rw_devices--;
1069 }
1070
1071 ret = btrfs_shrink_device(device, 0);
1072 if (ret)
1073 goto error_brelse;
1074
1075 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1076 if (ret)
1077 goto error_brelse;
1078
1079 device->in_fs_metadata = 0;
1080 list_del_init(&device->dev_list);
1081 device->fs_devices->num_devices--;
1082
1083 next_device = list_entry(root->fs_info->fs_devices->devices.next,
1084 struct btrfs_device, dev_list);
1085 if (device->bdev == root->fs_info->sb->s_bdev)
1086 root->fs_info->sb->s_bdev = next_device->bdev;
1087 if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1088 root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1089
1090 if (device->bdev) {
1091 close_bdev_exclusive(device->bdev, device->mode);
1092 device->bdev = NULL;
1093 device->fs_devices->open_devices--;
1094 }
1095
1096 num_devices = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
1097 btrfs_set_super_num_devices(&root->fs_info->super_copy, num_devices);
1098
1099 if (device->fs_devices->open_devices == 0) {
1100 struct btrfs_fs_devices *fs_devices;
1101 fs_devices = root->fs_info->fs_devices;
1102 while (fs_devices) {
1103 if (fs_devices->seed == device->fs_devices)
1104 break;
1105 fs_devices = fs_devices->seed;
1106 }
1107 fs_devices->seed = device->fs_devices->seed;
1108 device->fs_devices->seed = NULL;
1109 __btrfs_close_devices(device->fs_devices);
1110 free_fs_devices(device->fs_devices);
1111 }
1112
1113 /*
1114 * at this point, the device is zero sized. We want to
1115 * remove it from the devices list and zero out the old super
1116 */
1117 if (device->writeable) {
1118 /* make sure this device isn't detected as part of
1119 * the FS anymore
1120 */
1121 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1122 set_buffer_dirty(bh);
1123 sync_dirty_buffer(bh);
1124 }
1125
1126 kfree(device->name);
1127 kfree(device);
1128 ret = 0;
1129
1130 error_brelse:
1131 brelse(bh);
1132 error_close:
1133 if (bdev)
1134 close_bdev_exclusive(bdev, FMODE_READ);
1135 out:
1136 mutex_unlock(&root->fs_info->volume_mutex);
1137 mutex_unlock(&uuid_mutex);
1138 return ret;
1139 }
1140
1141 /*
1142 * does all the dirty work required for changing file system's UUID.
1143 */
1144 static int btrfs_prepare_sprout(struct btrfs_trans_handle *trans,
1145 struct btrfs_root *root)
1146 {
1147 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1148 struct btrfs_fs_devices *old_devices;
1149 struct btrfs_fs_devices *seed_devices;
1150 struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
1151 struct btrfs_device *device;
1152 u64 super_flags;
1153
1154 BUG_ON(!mutex_is_locked(&uuid_mutex));
1155 if (!fs_devices->seeding)
1156 return -EINVAL;
1157
1158 seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
1159 if (!seed_devices)
1160 return -ENOMEM;
1161
1162 old_devices = clone_fs_devices(fs_devices);
1163 if (IS_ERR(old_devices)) {
1164 kfree(seed_devices);
1165 return PTR_ERR(old_devices);
1166 }
1167
1168 list_add(&old_devices->list, &fs_uuids);
1169
1170 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1171 seed_devices->opened = 1;
1172 INIT_LIST_HEAD(&seed_devices->devices);
1173 INIT_LIST_HEAD(&seed_devices->alloc_list);
1174 list_splice_init(&fs_devices->devices, &seed_devices->devices);
1175 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1176 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1177 device->fs_devices = seed_devices;
1178 }
1179
1180 fs_devices->seeding = 0;
1181 fs_devices->num_devices = 0;
1182 fs_devices->open_devices = 0;
1183 fs_devices->seed = seed_devices;
1184
1185 generate_random_uuid(fs_devices->fsid);
1186 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1187 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1188 super_flags = btrfs_super_flags(disk_super) &
1189 ~BTRFS_SUPER_FLAG_SEEDING;
1190 btrfs_set_super_flags(disk_super, super_flags);
1191
1192 return 0;
1193 }
1194
1195 /*
1196 * strore the expected generation for seed devices in device items.
1197 */
1198 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1199 struct btrfs_root *root)
1200 {
1201 struct btrfs_path *path;
1202 struct extent_buffer *leaf;
1203 struct btrfs_dev_item *dev_item;
1204 struct btrfs_device *device;
1205 struct btrfs_key key;
1206 u8 fs_uuid[BTRFS_UUID_SIZE];
1207 u8 dev_uuid[BTRFS_UUID_SIZE];
1208 u64 devid;
1209 int ret;
1210
1211 path = btrfs_alloc_path();
1212 if (!path)
1213 return -ENOMEM;
1214
1215 root = root->fs_info->chunk_root;
1216 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1217 key.offset = 0;
1218 key.type = BTRFS_DEV_ITEM_KEY;
1219
1220 while (1) {
1221 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1222 if (ret < 0)
1223 goto error;
1224
1225 leaf = path->nodes[0];
1226 next_slot:
1227 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1228 ret = btrfs_next_leaf(root, path);
1229 if (ret > 0)
1230 break;
1231 if (ret < 0)
1232 goto error;
1233 leaf = path->nodes[0];
1234 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1235 btrfs_release_path(root, path);
1236 continue;
1237 }
1238
1239 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1240 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1241 key.type != BTRFS_DEV_ITEM_KEY)
1242 break;
1243
1244 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1245 struct btrfs_dev_item);
1246 devid = btrfs_device_id(leaf, dev_item);
1247 read_extent_buffer(leaf, dev_uuid,
1248 (unsigned long)btrfs_device_uuid(dev_item),
1249 BTRFS_UUID_SIZE);
1250 read_extent_buffer(leaf, fs_uuid,
1251 (unsigned long)btrfs_device_fsid(dev_item),
1252 BTRFS_UUID_SIZE);
1253 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
1254 BUG_ON(!device);
1255
1256 if (device->fs_devices->seeding) {
1257 btrfs_set_device_generation(leaf, dev_item,
1258 device->generation);
1259 btrfs_mark_buffer_dirty(leaf);
1260 }
1261
1262 path->slots[0]++;
1263 goto next_slot;
1264 }
1265 ret = 0;
1266 error:
1267 btrfs_free_path(path);
1268 return ret;
1269 }
1270
1271 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1272 {
1273 struct btrfs_trans_handle *trans;
1274 struct btrfs_device *device;
1275 struct block_device *bdev;
1276 struct list_head *devices;
1277 struct super_block *sb = root->fs_info->sb;
1278 u64 total_bytes;
1279 int seeding_dev = 0;
1280 int ret = 0;
1281
1282 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1283 return -EINVAL;
1284
1285 bdev = open_bdev_exclusive(device_path, 0, root->fs_info->bdev_holder);
1286 if (!bdev)
1287 return -EIO;
1288
1289 if (root->fs_info->fs_devices->seeding) {
1290 seeding_dev = 1;
1291 down_write(&sb->s_umount);
1292 mutex_lock(&uuid_mutex);
1293 }
1294
1295 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1296 mutex_lock(&root->fs_info->volume_mutex);
1297
1298 devices = &root->fs_info->fs_devices->devices;
1299 list_for_each_entry(device, devices, dev_list) {
1300 if (device->bdev == bdev) {
1301 ret = -EEXIST;
1302 goto error;
1303 }
1304 }
1305
1306 device = kzalloc(sizeof(*device), GFP_NOFS);
1307 if (!device) {
1308 /* we can safely leave the fs_devices entry around */
1309 ret = -ENOMEM;
1310 goto error;
1311 }
1312
1313 device->name = kstrdup(device_path, GFP_NOFS);
1314 if (!device->name) {
1315 kfree(device);
1316 ret = -ENOMEM;
1317 goto error;
1318 }
1319
1320 ret = find_next_devid(root, &device->devid);
1321 if (ret) {
1322 kfree(device);
1323 goto error;
1324 }
1325
1326 trans = btrfs_start_transaction(root, 1);
1327 lock_chunks(root);
1328
1329 device->barriers = 1;
1330 device->writeable = 1;
1331 device->work.func = pending_bios_fn;
1332 generate_random_uuid(device->uuid);
1333 spin_lock_init(&device->io_lock);
1334 device->generation = trans->transid;
1335 device->io_width = root->sectorsize;
1336 device->io_align = root->sectorsize;
1337 device->sector_size = root->sectorsize;
1338 device->total_bytes = i_size_read(bdev->bd_inode);
1339 device->dev_root = root->fs_info->dev_root;
1340 device->bdev = bdev;
1341 device->in_fs_metadata = 1;
1342 device->mode = 0;
1343 set_blocksize(device->bdev, 4096);
1344
1345 if (seeding_dev) {
1346 sb->s_flags &= ~MS_RDONLY;
1347 ret = btrfs_prepare_sprout(trans, root);
1348 BUG_ON(ret);
1349 }
1350
1351 device->fs_devices = root->fs_info->fs_devices;
1352 list_add(&device->dev_list, &root->fs_info->fs_devices->devices);
1353 list_add(&device->dev_alloc_list,
1354 &root->fs_info->fs_devices->alloc_list);
1355 root->fs_info->fs_devices->num_devices++;
1356 root->fs_info->fs_devices->open_devices++;
1357 root->fs_info->fs_devices->rw_devices++;
1358 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
1359
1360 total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
1361 btrfs_set_super_total_bytes(&root->fs_info->super_copy,
1362 total_bytes + device->total_bytes);
1363
1364 total_bytes = btrfs_super_num_devices(&root->fs_info->super_copy);
1365 btrfs_set_super_num_devices(&root->fs_info->super_copy,
1366 total_bytes + 1);
1367
1368 if (seeding_dev) {
1369 ret = init_first_rw_device(trans, root, device);
1370 BUG_ON(ret);
1371 ret = btrfs_finish_sprout(trans, root);
1372 BUG_ON(ret);
1373 } else {
1374 ret = btrfs_add_device(trans, root, device);
1375 }
1376
1377 unlock_chunks(root);
1378 btrfs_commit_transaction(trans, root);
1379
1380 if (seeding_dev) {
1381 mutex_unlock(&uuid_mutex);
1382 up_write(&sb->s_umount);
1383
1384 ret = btrfs_relocate_sys_chunks(root);
1385 BUG_ON(ret);
1386 }
1387 out:
1388 mutex_unlock(&root->fs_info->volume_mutex);
1389 return ret;
1390 error:
1391 close_bdev_exclusive(bdev, 0);
1392 if (seeding_dev) {
1393 mutex_unlock(&uuid_mutex);
1394 up_write(&sb->s_umount);
1395 }
1396 goto out;
1397 }
1398
1399 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
1400 struct btrfs_device *device)
1401 {
1402 int ret;
1403 struct btrfs_path *path;
1404 struct btrfs_root *root;
1405 struct btrfs_dev_item *dev_item;
1406 struct extent_buffer *leaf;
1407 struct btrfs_key key;
1408
1409 root = device->dev_root->fs_info->chunk_root;
1410
1411 path = btrfs_alloc_path();
1412 if (!path)
1413 return -ENOMEM;
1414
1415 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1416 key.type = BTRFS_DEV_ITEM_KEY;
1417 key.offset = device->devid;
1418
1419 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1420 if (ret < 0)
1421 goto out;
1422
1423 if (ret > 0) {
1424 ret = -ENOENT;
1425 goto out;
1426 }
1427
1428 leaf = path->nodes[0];
1429 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1430
1431 btrfs_set_device_id(leaf, dev_item, device->devid);
1432 btrfs_set_device_type(leaf, dev_item, device->type);
1433 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1434 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1435 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1436 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
1437 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1438 btrfs_mark_buffer_dirty(leaf);
1439
1440 out:
1441 btrfs_free_path(path);
1442 return ret;
1443 }
1444
1445 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
1446 struct btrfs_device *device, u64 new_size)
1447 {
1448 struct btrfs_super_block *super_copy =
1449 &device->dev_root->fs_info->super_copy;
1450 u64 old_total = btrfs_super_total_bytes(super_copy);
1451 u64 diff = new_size - device->total_bytes;
1452
1453 if (!device->writeable)
1454 return -EACCES;
1455 if (new_size <= device->total_bytes)
1456 return -EINVAL;
1457
1458 btrfs_set_super_total_bytes(super_copy, old_total + diff);
1459 device->fs_devices->total_rw_bytes += diff;
1460
1461 device->total_bytes = new_size;
1462 return btrfs_update_device(trans, device);
1463 }
1464
1465 int btrfs_grow_device(struct btrfs_trans_handle *trans,
1466 struct btrfs_device *device, u64 new_size)
1467 {
1468 int ret;
1469 lock_chunks(device->dev_root);
1470 ret = __btrfs_grow_device(trans, device, new_size);
1471 unlock_chunks(device->dev_root);
1472 return ret;
1473 }
1474
1475 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
1476 struct btrfs_root *root,
1477 u64 chunk_tree, u64 chunk_objectid,
1478 u64 chunk_offset)
1479 {
1480 int ret;
1481 struct btrfs_path *path;
1482 struct btrfs_key key;
1483
1484 root = root->fs_info->chunk_root;
1485 path = btrfs_alloc_path();
1486 if (!path)
1487 return -ENOMEM;
1488
1489 key.objectid = chunk_objectid;
1490 key.offset = chunk_offset;
1491 key.type = BTRFS_CHUNK_ITEM_KEY;
1492
1493 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1494 BUG_ON(ret);
1495
1496 ret = btrfs_del_item(trans, root, path);
1497 BUG_ON(ret);
1498
1499 btrfs_free_path(path);
1500 return 0;
1501 }
1502
1503 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
1504 chunk_offset)
1505 {
1506 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
1507 struct btrfs_disk_key *disk_key;
1508 struct btrfs_chunk *chunk;
1509 u8 *ptr;
1510 int ret = 0;
1511 u32 num_stripes;
1512 u32 array_size;
1513 u32 len = 0;
1514 u32 cur;
1515 struct btrfs_key key;
1516
1517 array_size = btrfs_super_sys_array_size(super_copy);
1518
1519 ptr = super_copy->sys_chunk_array;
1520 cur = 0;
1521
1522 while (cur < array_size) {
1523 disk_key = (struct btrfs_disk_key *)ptr;
1524 btrfs_disk_key_to_cpu(&key, disk_key);
1525
1526 len = sizeof(*disk_key);
1527
1528 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
1529 chunk = (struct btrfs_chunk *)(ptr + len);
1530 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
1531 len += btrfs_chunk_item_size(num_stripes);
1532 } else {
1533 ret = -EIO;
1534 break;
1535 }
1536 if (key.objectid == chunk_objectid &&
1537 key.offset == chunk_offset) {
1538 memmove(ptr, ptr + len, array_size - (cur + len));
1539 array_size -= len;
1540 btrfs_set_super_sys_array_size(super_copy, array_size);
1541 } else {
1542 ptr += len;
1543 cur += len;
1544 }
1545 }
1546 return ret;
1547 }
1548
1549 static int btrfs_relocate_chunk(struct btrfs_root *root,
1550 u64 chunk_tree, u64 chunk_objectid,
1551 u64 chunk_offset)
1552 {
1553 struct extent_map_tree *em_tree;
1554 struct btrfs_root *extent_root;
1555 struct btrfs_trans_handle *trans;
1556 struct extent_map *em;
1557 struct map_lookup *map;
1558 int ret;
1559 int i;
1560
1561 printk(KERN_INFO "btrfs relocating chunk %llu\n",
1562 (unsigned long long)chunk_offset);
1563 root = root->fs_info->chunk_root;
1564 extent_root = root->fs_info->extent_root;
1565 em_tree = &root->fs_info->mapping_tree.map_tree;
1566
1567 /* step one, relocate all the extents inside this chunk */
1568 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
1569 BUG_ON(ret);
1570
1571 trans = btrfs_start_transaction(root, 1);
1572 BUG_ON(!trans);
1573
1574 lock_chunks(root);
1575
1576 /*
1577 * step two, delete the device extents and the
1578 * chunk tree entries
1579 */
1580 spin_lock(&em_tree->lock);
1581 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
1582 spin_unlock(&em_tree->lock);
1583
1584 BUG_ON(em->start > chunk_offset ||
1585 em->start + em->len < chunk_offset);
1586 map = (struct map_lookup *)em->bdev;
1587
1588 for (i = 0; i < map->num_stripes; i++) {
1589 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
1590 map->stripes[i].physical);
1591 BUG_ON(ret);
1592
1593 if (map->stripes[i].dev) {
1594 ret = btrfs_update_device(trans, map->stripes[i].dev);
1595 BUG_ON(ret);
1596 }
1597 }
1598 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
1599 chunk_offset);
1600
1601 BUG_ON(ret);
1602
1603 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
1604 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
1605 BUG_ON(ret);
1606 }
1607
1608 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
1609 BUG_ON(ret);
1610
1611 spin_lock(&em_tree->lock);
1612 remove_extent_mapping(em_tree, em);
1613 spin_unlock(&em_tree->lock);
1614
1615 kfree(map);
1616 em->bdev = NULL;
1617
1618 /* once for the tree */
1619 free_extent_map(em);
1620 /* once for us */
1621 free_extent_map(em);
1622
1623 unlock_chunks(root);
1624 btrfs_end_transaction(trans, root);
1625 return 0;
1626 }
1627
1628 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
1629 {
1630 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
1631 struct btrfs_path *path;
1632 struct extent_buffer *leaf;
1633 struct btrfs_chunk *chunk;
1634 struct btrfs_key key;
1635 struct btrfs_key found_key;
1636 u64 chunk_tree = chunk_root->root_key.objectid;
1637 u64 chunk_type;
1638 int ret;
1639
1640 path = btrfs_alloc_path();
1641 if (!path)
1642 return -ENOMEM;
1643
1644 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
1645 key.offset = (u64)-1;
1646 key.type = BTRFS_CHUNK_ITEM_KEY;
1647
1648 while (1) {
1649 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
1650 if (ret < 0)
1651 goto error;
1652 BUG_ON(ret == 0);
1653
1654 ret = btrfs_previous_item(chunk_root, path, key.objectid,
1655 key.type);
1656 if (ret < 0)
1657 goto error;
1658 if (ret > 0)
1659 break;
1660
1661 leaf = path->nodes[0];
1662 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1663
1664 chunk = btrfs_item_ptr(leaf, path->slots[0],
1665 struct btrfs_chunk);
1666 chunk_type = btrfs_chunk_type(leaf, chunk);
1667 btrfs_release_path(chunk_root, path);
1668
1669 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
1670 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
1671 found_key.objectid,
1672 found_key.offset);
1673 BUG_ON(ret);
1674 }
1675
1676 if (found_key.offset == 0)
1677 break;
1678 key.offset = found_key.offset - 1;
1679 }
1680 ret = 0;
1681 error:
1682 btrfs_free_path(path);
1683 return ret;
1684 }
1685
1686 static u64 div_factor(u64 num, int factor)
1687 {
1688 if (factor == 10)
1689 return num;
1690 num *= factor;
1691 do_div(num, 10);
1692 return num;
1693 }
1694
1695 int btrfs_balance(struct btrfs_root *dev_root)
1696 {
1697 int ret;
1698 struct list_head *devices = &dev_root->fs_info->fs_devices->devices;
1699 struct btrfs_device *device;
1700 u64 old_size;
1701 u64 size_to_free;
1702 struct btrfs_path *path;
1703 struct btrfs_key key;
1704 struct btrfs_chunk *chunk;
1705 struct btrfs_root *chunk_root = dev_root->fs_info->chunk_root;
1706 struct btrfs_trans_handle *trans;
1707 struct btrfs_key found_key;
1708
1709 if (dev_root->fs_info->sb->s_flags & MS_RDONLY)
1710 return -EROFS;
1711
1712 mutex_lock(&dev_root->fs_info->volume_mutex);
1713 dev_root = dev_root->fs_info->dev_root;
1714
1715 /* step one make some room on all the devices */
1716 list_for_each_entry(device, devices, dev_list) {
1717 old_size = device->total_bytes;
1718 size_to_free = div_factor(old_size, 1);
1719 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
1720 if (!device->writeable ||
1721 device->total_bytes - device->bytes_used > size_to_free)
1722 continue;
1723
1724 ret = btrfs_shrink_device(device, old_size - size_to_free);
1725 BUG_ON(ret);
1726
1727 trans = btrfs_start_transaction(dev_root, 1);
1728 BUG_ON(!trans);
1729
1730 ret = btrfs_grow_device(trans, device, old_size);
1731 BUG_ON(ret);
1732
1733 btrfs_end_transaction(trans, dev_root);
1734 }
1735
1736 /* step two, relocate all the chunks */
1737 path = btrfs_alloc_path();
1738 BUG_ON(!path);
1739
1740 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
1741 key.offset = (u64)-1;
1742 key.type = BTRFS_CHUNK_ITEM_KEY;
1743
1744 while (1) {
1745 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
1746 if (ret < 0)
1747 goto error;
1748
1749 /*
1750 * this shouldn't happen, it means the last relocate
1751 * failed
1752 */
1753 if (ret == 0)
1754 break;
1755
1756 ret = btrfs_previous_item(chunk_root, path, 0,
1757 BTRFS_CHUNK_ITEM_KEY);
1758 if (ret)
1759 break;
1760
1761 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1762 path->slots[0]);
1763 if (found_key.objectid != key.objectid)
1764 break;
1765
1766 chunk = btrfs_item_ptr(path->nodes[0],
1767 path->slots[0],
1768 struct btrfs_chunk);
1769 key.offset = found_key.offset;
1770 /* chunk zero is special */
1771 if (key.offset == 0)
1772 break;
1773
1774 btrfs_release_path(chunk_root, path);
1775 ret = btrfs_relocate_chunk(chunk_root,
1776 chunk_root->root_key.objectid,
1777 found_key.objectid,
1778 found_key.offset);
1779 BUG_ON(ret);
1780 }
1781 ret = 0;
1782 error:
1783 btrfs_free_path(path);
1784 mutex_unlock(&dev_root->fs_info->volume_mutex);
1785 return ret;
1786 }
1787
1788 /*
1789 * shrinking a device means finding all of the device extents past
1790 * the new size, and then following the back refs to the chunks.
1791 * The chunk relocation code actually frees the device extent
1792 */
1793 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
1794 {
1795 struct btrfs_trans_handle *trans;
1796 struct btrfs_root *root = device->dev_root;
1797 struct btrfs_dev_extent *dev_extent = NULL;
1798 struct btrfs_path *path;
1799 u64 length;
1800 u64 chunk_tree;
1801 u64 chunk_objectid;
1802 u64 chunk_offset;
1803 int ret;
1804 int slot;
1805 struct extent_buffer *l;
1806 struct btrfs_key key;
1807 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
1808 u64 old_total = btrfs_super_total_bytes(super_copy);
1809 u64 diff = device->total_bytes - new_size;
1810
1811 if (new_size >= device->total_bytes)
1812 return -EINVAL;
1813
1814 path = btrfs_alloc_path();
1815 if (!path)
1816 return -ENOMEM;
1817
1818 trans = btrfs_start_transaction(root, 1);
1819 if (!trans) {
1820 ret = -ENOMEM;
1821 goto done;
1822 }
1823
1824 path->reada = 2;
1825
1826 lock_chunks(root);
1827
1828 device->total_bytes = new_size;
1829 if (device->writeable)
1830 device->fs_devices->total_rw_bytes -= diff;
1831 ret = btrfs_update_device(trans, device);
1832 if (ret) {
1833 unlock_chunks(root);
1834 btrfs_end_transaction(trans, root);
1835 goto done;
1836 }
1837 WARN_ON(diff > old_total);
1838 btrfs_set_super_total_bytes(super_copy, old_total - diff);
1839 unlock_chunks(root);
1840 btrfs_end_transaction(trans, root);
1841
1842 key.objectid = device->devid;
1843 key.offset = (u64)-1;
1844 key.type = BTRFS_DEV_EXTENT_KEY;
1845
1846 while (1) {
1847 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1848 if (ret < 0)
1849 goto done;
1850
1851 ret = btrfs_previous_item(root, path, 0, key.type);
1852 if (ret < 0)
1853 goto done;
1854 if (ret) {
1855 ret = 0;
1856 goto done;
1857 }
1858
1859 l = path->nodes[0];
1860 slot = path->slots[0];
1861 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
1862
1863 if (key.objectid != device->devid)
1864 goto done;
1865
1866 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
1867 length = btrfs_dev_extent_length(l, dev_extent);
1868
1869 if (key.offset + length <= new_size)
1870 goto done;
1871
1872 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
1873 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
1874 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
1875 btrfs_release_path(root, path);
1876
1877 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
1878 chunk_offset);
1879 if (ret)
1880 goto done;
1881 }
1882
1883 done:
1884 btrfs_free_path(path);
1885 return ret;
1886 }
1887
1888 static int btrfs_add_system_chunk(struct btrfs_trans_handle *trans,
1889 struct btrfs_root *root,
1890 struct btrfs_key *key,
1891 struct btrfs_chunk *chunk, int item_size)
1892 {
1893 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
1894 struct btrfs_disk_key disk_key;
1895 u32 array_size;
1896 u8 *ptr;
1897
1898 array_size = btrfs_super_sys_array_size(super_copy);
1899 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
1900 return -EFBIG;
1901
1902 ptr = super_copy->sys_chunk_array + array_size;
1903 btrfs_cpu_key_to_disk(&disk_key, key);
1904 memcpy(ptr, &disk_key, sizeof(disk_key));
1905 ptr += sizeof(disk_key);
1906 memcpy(ptr, chunk, item_size);
1907 item_size += sizeof(disk_key);
1908 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
1909 return 0;
1910 }
1911
1912 static noinline u64 chunk_bytes_by_type(u64 type, u64 calc_size,
1913 int num_stripes, int sub_stripes)
1914 {
1915 if (type & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_DUP))
1916 return calc_size;
1917 else if (type & BTRFS_BLOCK_GROUP_RAID10)
1918 return calc_size * (num_stripes / sub_stripes);
1919 else
1920 return calc_size * num_stripes;
1921 }
1922
1923 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
1924 struct btrfs_root *extent_root,
1925 struct map_lookup **map_ret,
1926 u64 *num_bytes, u64 *stripe_size,
1927 u64 start, u64 type)
1928 {
1929 struct btrfs_fs_info *info = extent_root->fs_info;
1930 struct btrfs_device *device = NULL;
1931 struct btrfs_fs_devices *fs_devices = info->fs_devices;
1932 struct list_head *cur;
1933 struct map_lookup *map = NULL;
1934 struct extent_map_tree *em_tree;
1935 struct extent_map *em;
1936 struct list_head private_devs;
1937 int min_stripe_size = 1 * 1024 * 1024;
1938 u64 calc_size = 1024 * 1024 * 1024;
1939 u64 max_chunk_size = calc_size;
1940 u64 min_free;
1941 u64 avail;
1942 u64 max_avail = 0;
1943 u64 dev_offset;
1944 int num_stripes = 1;
1945 int min_stripes = 1;
1946 int sub_stripes = 0;
1947 int looped = 0;
1948 int ret;
1949 int index;
1950 int stripe_len = 64 * 1024;
1951
1952 if ((type & BTRFS_BLOCK_GROUP_RAID1) &&
1953 (type & BTRFS_BLOCK_GROUP_DUP)) {
1954 WARN_ON(1);
1955 type &= ~BTRFS_BLOCK_GROUP_DUP;
1956 }
1957 if (list_empty(&fs_devices->alloc_list))
1958 return -ENOSPC;
1959
1960 if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
1961 num_stripes = fs_devices->rw_devices;
1962 min_stripes = 2;
1963 }
1964 if (type & (BTRFS_BLOCK_GROUP_DUP)) {
1965 num_stripes = 2;
1966 min_stripes = 2;
1967 }
1968 if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
1969 num_stripes = min_t(u64, 2, fs_devices->rw_devices);
1970 if (num_stripes < 2)
1971 return -ENOSPC;
1972 min_stripes = 2;
1973 }
1974 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
1975 num_stripes = fs_devices->rw_devices;
1976 if (num_stripes < 4)
1977 return -ENOSPC;
1978 num_stripes &= ~(u32)1;
1979 sub_stripes = 2;
1980 min_stripes = 4;
1981 }
1982
1983 if (type & BTRFS_BLOCK_GROUP_DATA) {
1984 max_chunk_size = 10 * calc_size;
1985 min_stripe_size = 64 * 1024 * 1024;
1986 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
1987 max_chunk_size = 4 * calc_size;
1988 min_stripe_size = 32 * 1024 * 1024;
1989 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
1990 calc_size = 8 * 1024 * 1024;
1991 max_chunk_size = calc_size * 2;
1992 min_stripe_size = 1 * 1024 * 1024;
1993 }
1994
1995 /* we don't want a chunk larger than 10% of writeable space */
1996 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
1997 max_chunk_size);
1998
1999 again:
2000 if (!map || map->num_stripes != num_stripes) {
2001 kfree(map);
2002 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
2003 if (!map)
2004 return -ENOMEM;
2005 map->num_stripes = num_stripes;
2006 }
2007
2008 if (calc_size * num_stripes > max_chunk_size) {
2009 calc_size = max_chunk_size;
2010 do_div(calc_size, num_stripes);
2011 do_div(calc_size, stripe_len);
2012 calc_size *= stripe_len;
2013 }
2014 /* we don't want tiny stripes */
2015 calc_size = max_t(u64, min_stripe_size, calc_size);
2016
2017 do_div(calc_size, stripe_len);
2018 calc_size *= stripe_len;
2019
2020 cur = fs_devices->alloc_list.next;
2021 index = 0;
2022
2023 if (type & BTRFS_BLOCK_GROUP_DUP)
2024 min_free = calc_size * 2;
2025 else
2026 min_free = calc_size;
2027
2028 /*
2029 * we add 1MB because we never use the first 1MB of the device, unless
2030 * we've looped, then we are likely allocating the maximum amount of
2031 * space left already
2032 */
2033 if (!looped)
2034 min_free += 1024 * 1024;
2035
2036 INIT_LIST_HEAD(&private_devs);
2037 while (index < num_stripes) {
2038 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
2039 BUG_ON(!device->writeable);
2040 if (device->total_bytes > device->bytes_used)
2041 avail = device->total_bytes - device->bytes_used;
2042 else
2043 avail = 0;
2044 cur = cur->next;
2045
2046 if (device->in_fs_metadata && avail >= min_free) {
2047 ret = find_free_dev_extent(trans, device,
2048 min_free, &dev_offset);
2049 if (ret == 0) {
2050 list_move_tail(&device->dev_alloc_list,
2051 &private_devs);
2052 map->stripes[index].dev = device;
2053 map->stripes[index].physical = dev_offset;
2054 index++;
2055 if (type & BTRFS_BLOCK_GROUP_DUP) {
2056 map->stripes[index].dev = device;
2057 map->stripes[index].physical =
2058 dev_offset + calc_size;
2059 index++;
2060 }
2061 }
2062 } else if (device->in_fs_metadata && avail > max_avail)
2063 max_avail = avail;
2064 if (cur == &fs_devices->alloc_list)
2065 break;
2066 }
2067 list_splice(&private_devs, &fs_devices->alloc_list);
2068 if (index < num_stripes) {
2069 if (index >= min_stripes) {
2070 num_stripes = index;
2071 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
2072 num_stripes /= sub_stripes;
2073 num_stripes *= sub_stripes;
2074 }
2075 looped = 1;
2076 goto again;
2077 }
2078 if (!looped && max_avail > 0) {
2079 looped = 1;
2080 calc_size = max_avail;
2081 goto again;
2082 }
2083 kfree(map);
2084 return -ENOSPC;
2085 }
2086 map->sector_size = extent_root->sectorsize;
2087 map->stripe_len = stripe_len;
2088 map->io_align = stripe_len;
2089 map->io_width = stripe_len;
2090 map->type = type;
2091 map->num_stripes = num_stripes;
2092 map->sub_stripes = sub_stripes;
2093
2094 *map_ret = map;
2095 *stripe_size = calc_size;
2096 *num_bytes = chunk_bytes_by_type(type, calc_size,
2097 num_stripes, sub_stripes);
2098
2099 em = alloc_extent_map(GFP_NOFS);
2100 if (!em) {
2101 kfree(map);
2102 return -ENOMEM;
2103 }
2104 em->bdev = (struct block_device *)map;
2105 em->start = start;
2106 em->len = *num_bytes;
2107 em->block_start = 0;
2108 em->block_len = em->len;
2109
2110 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
2111 spin_lock(&em_tree->lock);
2112 ret = add_extent_mapping(em_tree, em);
2113 spin_unlock(&em_tree->lock);
2114 BUG_ON(ret);
2115 free_extent_map(em);
2116
2117 ret = btrfs_make_block_group(trans, extent_root, 0, type,
2118 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2119 start, *num_bytes);
2120 BUG_ON(ret);
2121
2122 index = 0;
2123 while (index < map->num_stripes) {
2124 device = map->stripes[index].dev;
2125 dev_offset = map->stripes[index].physical;
2126
2127 ret = btrfs_alloc_dev_extent(trans, device,
2128 info->chunk_root->root_key.objectid,
2129 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2130 start, dev_offset, calc_size);
2131 BUG_ON(ret);
2132 index++;
2133 }
2134
2135 return 0;
2136 }
2137
2138 static int __finish_chunk_alloc(struct btrfs_trans_handle *trans,
2139 struct btrfs_root *extent_root,
2140 struct map_lookup *map, u64 chunk_offset,
2141 u64 chunk_size, u64 stripe_size)
2142 {
2143 u64 dev_offset;
2144 struct btrfs_key key;
2145 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
2146 struct btrfs_device *device;
2147 struct btrfs_chunk *chunk;
2148 struct btrfs_stripe *stripe;
2149 size_t item_size = btrfs_chunk_item_size(map->num_stripes);
2150 int index = 0;
2151 int ret;
2152
2153 chunk = kzalloc(item_size, GFP_NOFS);
2154 if (!chunk)
2155 return -ENOMEM;
2156
2157 index = 0;
2158 while (index < map->num_stripes) {
2159 device = map->stripes[index].dev;
2160 device->bytes_used += stripe_size;
2161 ret = btrfs_update_device(trans, device);
2162 BUG_ON(ret);
2163 index++;
2164 }
2165
2166 index = 0;
2167 stripe = &chunk->stripe;
2168 while (index < map->num_stripes) {
2169 device = map->stripes[index].dev;
2170 dev_offset = map->stripes[index].physical;
2171
2172 btrfs_set_stack_stripe_devid(stripe, device->devid);
2173 btrfs_set_stack_stripe_offset(stripe, dev_offset);
2174 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
2175 stripe++;
2176 index++;
2177 }
2178
2179 btrfs_set_stack_chunk_length(chunk, chunk_size);
2180 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
2181 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
2182 btrfs_set_stack_chunk_type(chunk, map->type);
2183 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
2184 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
2185 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
2186 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
2187 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
2188
2189 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2190 key.type = BTRFS_CHUNK_ITEM_KEY;
2191 key.offset = chunk_offset;
2192
2193 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
2194 BUG_ON(ret);
2195
2196 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2197 ret = btrfs_add_system_chunk(trans, chunk_root, &key, chunk,
2198 item_size);
2199 BUG_ON(ret);
2200 }
2201 kfree(chunk);
2202 return 0;
2203 }
2204
2205 /*
2206 * Chunk allocation falls into two parts. The first part does works
2207 * that make the new allocated chunk useable, but not do any operation
2208 * that modifies the chunk tree. The second part does the works that
2209 * require modifying the chunk tree. This division is important for the
2210 * bootstrap process of adding storage to a seed btrfs.
2211 */
2212 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
2213 struct btrfs_root *extent_root, u64 type)
2214 {
2215 u64 chunk_offset;
2216 u64 chunk_size;
2217 u64 stripe_size;
2218 struct map_lookup *map;
2219 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
2220 int ret;
2221
2222 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2223 &chunk_offset);
2224 if (ret)
2225 return ret;
2226
2227 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
2228 &stripe_size, chunk_offset, type);
2229 if (ret)
2230 return ret;
2231
2232 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
2233 chunk_size, stripe_size);
2234 BUG_ON(ret);
2235 return 0;
2236 }
2237
2238 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
2239 struct btrfs_root *root,
2240 struct btrfs_device *device)
2241 {
2242 u64 chunk_offset;
2243 u64 sys_chunk_offset;
2244 u64 chunk_size;
2245 u64 sys_chunk_size;
2246 u64 stripe_size;
2247 u64 sys_stripe_size;
2248 u64 alloc_profile;
2249 struct map_lookup *map;
2250 struct map_lookup *sys_map;
2251 struct btrfs_fs_info *fs_info = root->fs_info;
2252 struct btrfs_root *extent_root = fs_info->extent_root;
2253 int ret;
2254
2255 ret = find_next_chunk(fs_info->chunk_root,
2256 BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset);
2257 BUG_ON(ret);
2258
2259 alloc_profile = BTRFS_BLOCK_GROUP_METADATA |
2260 (fs_info->metadata_alloc_profile &
2261 fs_info->avail_metadata_alloc_bits);
2262 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
2263
2264 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
2265 &stripe_size, chunk_offset, alloc_profile);
2266 BUG_ON(ret);
2267
2268 sys_chunk_offset = chunk_offset + chunk_size;
2269
2270 alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM |
2271 (fs_info->system_alloc_profile &
2272 fs_info->avail_system_alloc_bits);
2273 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
2274
2275 ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,
2276 &sys_chunk_size, &sys_stripe_size,
2277 sys_chunk_offset, alloc_profile);
2278 BUG_ON(ret);
2279
2280 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
2281 BUG_ON(ret);
2282
2283 /*
2284 * Modifying chunk tree needs allocating new blocks from both
2285 * system block group and metadata block group. So we only can
2286 * do operations require modifying the chunk tree after both
2287 * block groups were created.
2288 */
2289 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
2290 chunk_size, stripe_size);
2291 BUG_ON(ret);
2292
2293 ret = __finish_chunk_alloc(trans, extent_root, sys_map,
2294 sys_chunk_offset, sys_chunk_size,
2295 sys_stripe_size);
2296 BUG_ON(ret);
2297 return 0;
2298 }
2299
2300 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
2301 {
2302 struct extent_map *em;
2303 struct map_lookup *map;
2304 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
2305 int readonly = 0;
2306 int i;
2307
2308 spin_lock(&map_tree->map_tree.lock);
2309 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
2310 spin_unlock(&map_tree->map_tree.lock);
2311 if (!em)
2312 return 1;
2313
2314 map = (struct map_lookup *)em->bdev;
2315 for (i = 0; i < map->num_stripes; i++) {
2316 if (!map->stripes[i].dev->writeable) {
2317 readonly = 1;
2318 break;
2319 }
2320 }
2321 free_extent_map(em);
2322 return readonly;
2323 }
2324
2325 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
2326 {
2327 extent_map_tree_init(&tree->map_tree, GFP_NOFS);
2328 }
2329
2330 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
2331 {
2332 struct extent_map *em;
2333
2334 while (1) {
2335 spin_lock(&tree->map_tree.lock);
2336 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
2337 if (em)
2338 remove_extent_mapping(&tree->map_tree, em);
2339 spin_unlock(&tree->map_tree.lock);
2340 if (!em)
2341 break;
2342 kfree(em->bdev);
2343 /* once for us */
2344 free_extent_map(em);
2345 /* once for the tree */
2346 free_extent_map(em);
2347 }
2348 }
2349
2350 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
2351 {
2352 struct extent_map *em;
2353 struct map_lookup *map;
2354 struct extent_map_tree *em_tree = &map_tree->map_tree;
2355 int ret;
2356
2357 spin_lock(&em_tree->lock);
2358 em = lookup_extent_mapping(em_tree, logical, len);
2359 spin_unlock(&em_tree->lock);
2360 BUG_ON(!em);
2361
2362 BUG_ON(em->start > logical || em->start + em->len < logical);
2363 map = (struct map_lookup *)em->bdev;
2364 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
2365 ret = map->num_stripes;
2366 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
2367 ret = map->sub_stripes;
2368 else
2369 ret = 1;
2370 free_extent_map(em);
2371 return ret;
2372 }
2373
2374 static int find_live_mirror(struct map_lookup *map, int first, int num,
2375 int optimal)
2376 {
2377 int i;
2378 if (map->stripes[optimal].dev->bdev)
2379 return optimal;
2380 for (i = first; i < first + num; i++) {
2381 if (map->stripes[i].dev->bdev)
2382 return i;
2383 }
2384 /* we couldn't find one that doesn't fail. Just return something
2385 * and the io error handling code will clean up eventually
2386 */
2387 return optimal;
2388 }
2389
2390 static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
2391 u64 logical, u64 *length,
2392 struct btrfs_multi_bio **multi_ret,
2393 int mirror_num, struct page *unplug_page)
2394 {
2395 struct extent_map *em;
2396 struct map_lookup *map;
2397 struct extent_map_tree *em_tree = &map_tree->map_tree;
2398 u64 offset;
2399 u64 stripe_offset;
2400 u64 stripe_nr;
2401 int stripes_allocated = 8;
2402 int stripes_required = 1;
2403 int stripe_index;
2404 int i;
2405 int num_stripes;
2406 int max_errors = 0;
2407 struct btrfs_multi_bio *multi = NULL;
2408
2409 if (multi_ret && !(rw & (1 << BIO_RW)))
2410 stripes_allocated = 1;
2411 again:
2412 if (multi_ret) {
2413 multi = kzalloc(btrfs_multi_bio_size(stripes_allocated),
2414 GFP_NOFS);
2415 if (!multi)
2416 return -ENOMEM;
2417
2418 atomic_set(&multi->error, 0);
2419 }
2420
2421 spin_lock(&em_tree->lock);
2422 em = lookup_extent_mapping(em_tree, logical, *length);
2423 spin_unlock(&em_tree->lock);
2424
2425 if (!em && unplug_page)
2426 return 0;
2427
2428 if (!em) {
2429 printk(KERN_CRIT "unable to find logical %llu len %llu\n",
2430 (unsigned long long)logical,
2431 (unsigned long long)*length);
2432 BUG();
2433 }
2434
2435 BUG_ON(em->start > logical || em->start + em->len < logical);
2436 map = (struct map_lookup *)em->bdev;
2437 offset = logical - em->start;
2438
2439 if (mirror_num > map->num_stripes)
2440 mirror_num = 0;
2441
2442 /* if our multi bio struct is too small, back off and try again */
2443 if (rw & (1 << BIO_RW)) {
2444 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
2445 BTRFS_BLOCK_GROUP_DUP)) {
2446 stripes_required = map->num_stripes;
2447 max_errors = 1;
2448 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2449 stripes_required = map->sub_stripes;
2450 max_errors = 1;
2451 }
2452 }
2453 if (multi_ret && rw == WRITE &&
2454 stripes_allocated < stripes_required) {
2455 stripes_allocated = map->num_stripes;
2456 free_extent_map(em);
2457 kfree(multi);
2458 goto again;
2459 }
2460 stripe_nr = offset;
2461 /*
2462 * stripe_nr counts the total number of stripes we have to stride
2463 * to get to this block
2464 */
2465 do_div(stripe_nr, map->stripe_len);
2466
2467 stripe_offset = stripe_nr * map->stripe_len;
2468 BUG_ON(offset < stripe_offset);
2469
2470 /* stripe_offset is the offset of this block in its stripe*/
2471 stripe_offset = offset - stripe_offset;
2472
2473 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
2474 BTRFS_BLOCK_GROUP_RAID10 |
2475 BTRFS_BLOCK_GROUP_DUP)) {
2476 /* we limit the length of each bio to what fits in a stripe */
2477 *length = min_t(u64, em->len - offset,
2478 map->stripe_len - stripe_offset);
2479 } else {
2480 *length = em->len - offset;
2481 }
2482
2483 if (!multi_ret && !unplug_page)
2484 goto out;
2485
2486 num_stripes = 1;
2487 stripe_index = 0;
2488 if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
2489 if (unplug_page || (rw & (1 << BIO_RW)))
2490 num_stripes = map->num_stripes;
2491 else if (mirror_num)
2492 stripe_index = mirror_num - 1;
2493 else {
2494 stripe_index = find_live_mirror(map, 0,
2495 map->num_stripes,
2496 current->pid % map->num_stripes);
2497 }
2498
2499 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
2500 if (rw & (1 << BIO_RW))
2501 num_stripes = map->num_stripes;
2502 else if (mirror_num)
2503 stripe_index = mirror_num - 1;
2504
2505 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2506 int factor = map->num_stripes / map->sub_stripes;
2507
2508 stripe_index = do_div(stripe_nr, factor);
2509 stripe_index *= map->sub_stripes;
2510
2511 if (unplug_page || (rw & (1 << BIO_RW)))
2512 num_stripes = map->sub_stripes;
2513 else if (mirror_num)
2514 stripe_index += mirror_num - 1;
2515 else {
2516 stripe_index = find_live_mirror(map, stripe_index,
2517 map->sub_stripes, stripe_index +
2518 current->pid % map->sub_stripes);
2519 }
2520 } else {
2521 /*
2522 * after this do_div call, stripe_nr is the number of stripes
2523 * on this device we have to walk to find the data, and
2524 * stripe_index is the number of our device in the stripe array
2525 */
2526 stripe_index = do_div(stripe_nr, map->num_stripes);
2527 }
2528 BUG_ON(stripe_index >= map->num_stripes);
2529
2530 for (i = 0; i < num_stripes; i++) {
2531 if (unplug_page) {
2532 struct btrfs_device *device;
2533 struct backing_dev_info *bdi;
2534
2535 device = map->stripes[stripe_index].dev;
2536 if (device->bdev) {
2537 bdi = blk_get_backing_dev_info(device->bdev);
2538 if (bdi->unplug_io_fn)
2539 bdi->unplug_io_fn(bdi, unplug_page);
2540 }
2541 } else {
2542 multi->stripes[i].physical =
2543 map->stripes[stripe_index].physical +
2544 stripe_offset + stripe_nr * map->stripe_len;
2545 multi->stripes[i].dev = map->stripes[stripe_index].dev;
2546 }
2547 stripe_index++;
2548 }
2549 if (multi_ret) {
2550 *multi_ret = multi;
2551 multi->num_stripes = num_stripes;
2552 multi->max_errors = max_errors;
2553 }
2554 out:
2555 free_extent_map(em);
2556 return 0;
2557 }
2558
2559 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
2560 u64 logical, u64 *length,
2561 struct btrfs_multi_bio **multi_ret, int mirror_num)
2562 {
2563 return __btrfs_map_block(map_tree, rw, logical, length, multi_ret,
2564 mirror_num, NULL);
2565 }
2566
2567 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
2568 u64 chunk_start, u64 physical, u64 devid,
2569 u64 **logical, int *naddrs, int *stripe_len)
2570 {
2571 struct extent_map_tree *em_tree = &map_tree->map_tree;
2572 struct extent_map *em;
2573 struct map_lookup *map;
2574 u64 *buf;
2575 u64 bytenr;
2576 u64 length;
2577 u64 stripe_nr;
2578 int i, j, nr = 0;
2579
2580 spin_lock(&em_tree->lock);
2581 em = lookup_extent_mapping(em_tree, chunk_start, 1);
2582 spin_unlock(&em_tree->lock);
2583
2584 BUG_ON(!em || em->start != chunk_start);
2585 map = (struct map_lookup *)em->bdev;
2586
2587 length = em->len;
2588 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
2589 do_div(length, map->num_stripes / map->sub_stripes);
2590 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
2591 do_div(length, map->num_stripes);
2592
2593 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
2594 BUG_ON(!buf);
2595
2596 for (i = 0; i < map->num_stripes; i++) {
2597 if (devid && map->stripes[i].dev->devid != devid)
2598 continue;
2599 if (map->stripes[i].physical > physical ||
2600 map->stripes[i].physical + length <= physical)
2601 continue;
2602
2603 stripe_nr = physical - map->stripes[i].physical;
2604 do_div(stripe_nr, map->stripe_len);
2605
2606 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2607 stripe_nr = stripe_nr * map->num_stripes + i;
2608 do_div(stripe_nr, map->sub_stripes);
2609 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
2610 stripe_nr = stripe_nr * map->num_stripes + i;
2611 }
2612 bytenr = chunk_start + stripe_nr * map->stripe_len;
2613 WARN_ON(nr >= map->num_stripes);
2614 for (j = 0; j < nr; j++) {
2615 if (buf[j] == bytenr)
2616 break;
2617 }
2618 if (j == nr) {
2619 WARN_ON(nr >= map->num_stripes);
2620 buf[nr++] = bytenr;
2621 }
2622 }
2623
2624 for (i = 0; i > nr; i++) {
2625 struct btrfs_multi_bio *multi;
2626 struct btrfs_bio_stripe *stripe;
2627 int ret;
2628
2629 length = 1;
2630 ret = btrfs_map_block(map_tree, WRITE, buf[i],
2631 &length, &multi, 0);
2632 BUG_ON(ret);
2633
2634 stripe = multi->stripes;
2635 for (j = 0; j < multi->num_stripes; j++) {
2636 if (stripe->physical >= physical &&
2637 physical < stripe->physical + length)
2638 break;
2639 }
2640 BUG_ON(j >= multi->num_stripes);
2641 kfree(multi);
2642 }
2643
2644 *logical = buf;
2645 *naddrs = nr;
2646 *stripe_len = map->stripe_len;
2647
2648 free_extent_map(em);
2649 return 0;
2650 }
2651
2652 int btrfs_unplug_page(struct btrfs_mapping_tree *map_tree,
2653 u64 logical, struct page *page)
2654 {
2655 u64 length = PAGE_CACHE_SIZE;
2656 return __btrfs_map_block(map_tree, READ, logical, &length,
2657 NULL, 0, page);
2658 }
2659
2660 static void end_bio_multi_stripe(struct bio *bio, int err)
2661 {
2662 struct btrfs_multi_bio *multi = bio->bi_private;
2663 int is_orig_bio = 0;
2664
2665 if (err)
2666 atomic_inc(&multi->error);
2667
2668 if (bio == multi->orig_bio)
2669 is_orig_bio = 1;
2670
2671 if (atomic_dec_and_test(&multi->stripes_pending)) {
2672 if (!is_orig_bio) {
2673 bio_put(bio);
2674 bio = multi->orig_bio;
2675 }
2676 bio->bi_private = multi->private;
2677 bio->bi_end_io = multi->end_io;
2678 /* only send an error to the higher layers if it is
2679 * beyond the tolerance of the multi-bio
2680 */
2681 if (atomic_read(&multi->error) > multi->max_errors) {
2682 err = -EIO;
2683 } else if (err) {
2684 /*
2685 * this bio is actually up to date, we didn't
2686 * go over the max number of errors
2687 */
2688 set_bit(BIO_UPTODATE, &bio->bi_flags);
2689 err = 0;
2690 }
2691 kfree(multi);
2692
2693 bio_endio(bio, err);
2694 } else if (!is_orig_bio) {
2695 bio_put(bio);
2696 }
2697 }
2698
2699 struct async_sched {
2700 struct bio *bio;
2701 int rw;
2702 struct btrfs_fs_info *info;
2703 struct btrfs_work work;
2704 };
2705
2706 /*
2707 * see run_scheduled_bios for a description of why bios are collected for
2708 * async submit.
2709 *
2710 * This will add one bio to the pending list for a device and make sure
2711 * the work struct is scheduled.
2712 */
2713 static noinline int schedule_bio(struct btrfs_root *root,
2714 struct btrfs_device *device,
2715 int rw, struct bio *bio)
2716 {
2717 int should_queue = 1;
2718
2719 /* don't bother with additional async steps for reads, right now */
2720 if (!(rw & (1 << BIO_RW))) {
2721 bio_get(bio);
2722 submit_bio(rw, bio);
2723 bio_put(bio);
2724 return 0;
2725 }
2726
2727 /*
2728 * nr_async_bios allows us to reliably return congestion to the
2729 * higher layers. Otherwise, the async bio makes it appear we have
2730 * made progress against dirty pages when we've really just put it
2731 * on a queue for later
2732 */
2733 atomic_inc(&root->fs_info->nr_async_bios);
2734 WARN_ON(bio->bi_next);
2735 bio->bi_next = NULL;
2736 bio->bi_rw |= rw;
2737
2738 spin_lock(&device->io_lock);
2739
2740 if (device->pending_bio_tail)
2741 device->pending_bio_tail->bi_next = bio;
2742
2743 device->pending_bio_tail = bio;
2744 if (!device->pending_bios)
2745 device->pending_bios = bio;
2746 if (device->running_pending)
2747 should_queue = 0;
2748
2749 spin_unlock(&device->io_lock);
2750
2751 if (should_queue)
2752 btrfs_queue_worker(&root->fs_info->submit_workers,
2753 &device->work);
2754 return 0;
2755 }
2756
2757 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
2758 int mirror_num, int async_submit)
2759 {
2760 struct btrfs_mapping_tree *map_tree;
2761 struct btrfs_device *dev;
2762 struct bio *first_bio = bio;
2763 u64 logical = (u64)bio->bi_sector << 9;
2764 u64 length = 0;
2765 u64 map_length;
2766 struct btrfs_multi_bio *multi = NULL;
2767 int ret;
2768 int dev_nr = 0;
2769 int total_devs = 1;
2770
2771 length = bio->bi_size;
2772 map_tree = &root->fs_info->mapping_tree;
2773 map_length = length;
2774
2775 ret = btrfs_map_block(map_tree, rw, logical, &map_length, &multi,
2776 mirror_num);
2777 BUG_ON(ret);
2778
2779 total_devs = multi->num_stripes;
2780 if (map_length < length) {
2781 printk(KERN_CRIT "mapping failed logical %llu bio len %llu "
2782 "len %llu\n", (unsigned long long)logical,
2783 (unsigned long long)length,
2784 (unsigned long long)map_length);
2785 BUG();
2786 }
2787 multi->end_io = first_bio->bi_end_io;
2788 multi->private = first_bio->bi_private;
2789 multi->orig_bio = first_bio;
2790 atomic_set(&multi->stripes_pending, multi->num_stripes);
2791
2792 while (dev_nr < total_devs) {
2793 if (total_devs > 1) {
2794 if (dev_nr < total_devs - 1) {
2795 bio = bio_clone(first_bio, GFP_NOFS);
2796 BUG_ON(!bio);
2797 } else {
2798 bio = first_bio;
2799 }
2800 bio->bi_private = multi;
2801 bio->bi_end_io = end_bio_multi_stripe;
2802 }
2803 bio->bi_sector = multi->stripes[dev_nr].physical >> 9;
2804 dev = multi->stripes[dev_nr].dev;
2805 BUG_ON(rw == WRITE && !dev->writeable);
2806 if (dev && dev->bdev) {
2807 bio->bi_bdev = dev->bdev;
2808 if (async_submit)
2809 schedule_bio(root, dev, rw, bio);
2810 else
2811 submit_bio(rw, bio);
2812 } else {
2813 bio->bi_bdev = root->fs_info->fs_devices->latest_bdev;
2814 bio->bi_sector = logical >> 9;
2815 bio_endio(bio, -EIO);
2816 }
2817 dev_nr++;
2818 }
2819 if (total_devs == 1)
2820 kfree(multi);
2821 return 0;
2822 }
2823
2824 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
2825 u8 *uuid, u8 *fsid)
2826 {
2827 struct btrfs_device *device;
2828 struct btrfs_fs_devices *cur_devices;
2829
2830 cur_devices = root->fs_info->fs_devices;
2831 while (cur_devices) {
2832 if (!fsid ||
2833 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
2834 device = __find_device(&cur_devices->devices,
2835 devid, uuid);
2836 if (device)
2837 return device;
2838 }
2839 cur_devices = cur_devices->seed;
2840 }
2841 return NULL;
2842 }
2843
2844 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
2845 u64 devid, u8 *dev_uuid)
2846 {
2847 struct btrfs_device *device;
2848 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2849
2850 device = kzalloc(sizeof(*device), GFP_NOFS);
2851 if (!device)
2852 return NULL;
2853 list_add(&device->dev_list,
2854 &fs_devices->devices);
2855 device->barriers = 1;
2856 device->dev_root = root->fs_info->dev_root;
2857 device->devid = devid;
2858 device->work.func = pending_bios_fn;
2859 device->fs_devices = fs_devices;
2860 fs_devices->num_devices++;
2861 spin_lock_init(&device->io_lock);
2862 INIT_LIST_HEAD(&device->dev_alloc_list);
2863 memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
2864 return device;
2865 }
2866
2867 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
2868 struct extent_buffer *leaf,
2869 struct btrfs_chunk *chunk)
2870 {
2871 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
2872 struct map_lookup *map;
2873 struct extent_map *em;
2874 u64 logical;
2875 u64 length;
2876 u64 devid;
2877 u8 uuid[BTRFS_UUID_SIZE];
2878 int num_stripes;
2879 int ret;
2880 int i;
2881
2882 logical = key->offset;
2883 length = btrfs_chunk_length(leaf, chunk);
2884
2885 spin_lock(&map_tree->map_tree.lock);
2886 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
2887 spin_unlock(&map_tree->map_tree.lock);
2888
2889 /* already mapped? */
2890 if (em && em->start <= logical && em->start + em->len > logical) {
2891 free_extent_map(em);
2892 return 0;
2893 } else if (em) {
2894 free_extent_map(em);
2895 }
2896
2897 em = alloc_extent_map(GFP_NOFS);
2898 if (!em)
2899 return -ENOMEM;
2900 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2901 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
2902 if (!map) {
2903 free_extent_map(em);
2904 return -ENOMEM;
2905 }
2906
2907 em->bdev = (struct block_device *)map;
2908 em->start = logical;
2909 em->len = length;
2910 em->block_start = 0;
2911 em->block_len = em->len;
2912
2913 map->num_stripes = num_stripes;
2914 map->io_width = btrfs_chunk_io_width(leaf, chunk);
2915 map->io_align = btrfs_chunk_io_align(leaf, chunk);
2916 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
2917 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
2918 map->type = btrfs_chunk_type(leaf, chunk);
2919 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
2920 for (i = 0; i < num_stripes; i++) {
2921 map->stripes[i].physical =
2922 btrfs_stripe_offset_nr(leaf, chunk, i);
2923 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
2924 read_extent_buffer(leaf, uuid, (unsigned long)
2925 btrfs_stripe_dev_uuid_nr(chunk, i),
2926 BTRFS_UUID_SIZE);
2927 map->stripes[i].dev = btrfs_find_device(root, devid, uuid,
2928 NULL);
2929 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
2930 kfree(map);
2931 free_extent_map(em);
2932 return -EIO;
2933 }
2934 if (!map->stripes[i].dev) {
2935 map->stripes[i].dev =
2936 add_missing_dev(root, devid, uuid);
2937 if (!map->stripes[i].dev) {
2938 kfree(map);
2939 free_extent_map(em);
2940 return -EIO;
2941 }
2942 }
2943 map->stripes[i].dev->in_fs_metadata = 1;
2944 }
2945
2946 spin_lock(&map_tree->map_tree.lock);
2947 ret = add_extent_mapping(&map_tree->map_tree, em);
2948 spin_unlock(&map_tree->map_tree.lock);
2949 BUG_ON(ret);
2950 free_extent_map(em);
2951
2952 return 0;
2953 }
2954
2955 static int fill_device_from_item(struct extent_buffer *leaf,
2956 struct btrfs_dev_item *dev_item,
2957 struct btrfs_device *device)
2958 {
2959 unsigned long ptr;
2960
2961 device->devid = btrfs_device_id(leaf, dev_item);
2962 device->total_bytes = btrfs_device_total_bytes(leaf, dev_item);
2963 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
2964 device->type = btrfs_device_type(leaf, dev_item);
2965 device->io_align = btrfs_device_io_align(leaf, dev_item);
2966 device->io_width = btrfs_device_io_width(leaf, dev_item);
2967 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
2968
2969 ptr = (unsigned long)btrfs_device_uuid(dev_item);
2970 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
2971
2972 return 0;
2973 }
2974
2975 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
2976 {
2977 struct btrfs_fs_devices *fs_devices;
2978 int ret;
2979
2980 mutex_lock(&uuid_mutex);
2981
2982 fs_devices = root->fs_info->fs_devices->seed;
2983 while (fs_devices) {
2984 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
2985 ret = 0;
2986 goto out;
2987 }
2988 fs_devices = fs_devices->seed;
2989 }
2990
2991 fs_devices = find_fsid(fsid);
2992 if (!fs_devices) {
2993 ret = -ENOENT;
2994 goto out;
2995 }
2996
2997 fs_devices = clone_fs_devices(fs_devices);
2998 if (IS_ERR(fs_devices)) {
2999 ret = PTR_ERR(fs_devices);
3000 goto out;
3001 }
3002
3003 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
3004 root->fs_info->bdev_holder);
3005 if (ret)
3006 goto out;
3007
3008 if (!fs_devices->seeding) {
3009 __btrfs_close_devices(fs_devices);
3010 free_fs_devices(fs_devices);
3011 ret = -EINVAL;
3012 goto out;
3013 }
3014
3015 fs_devices->seed = root->fs_info->fs_devices->seed;
3016 root->fs_info->fs_devices->seed = fs_devices;
3017 out:
3018 mutex_unlock(&uuid_mutex);
3019 return ret;
3020 }
3021
3022 static int read_one_dev(struct btrfs_root *root,
3023 struct extent_buffer *leaf,
3024 struct btrfs_dev_item *dev_item)
3025 {
3026 struct btrfs_device *device;
3027 u64 devid;
3028 int ret;
3029 u8 fs_uuid[BTRFS_UUID_SIZE];
3030 u8 dev_uuid[BTRFS_UUID_SIZE];
3031
3032 devid = btrfs_device_id(leaf, dev_item);
3033 read_extent_buffer(leaf, dev_uuid,
3034 (unsigned long)btrfs_device_uuid(dev_item),
3035 BTRFS_UUID_SIZE);
3036 read_extent_buffer(leaf, fs_uuid,
3037 (unsigned long)btrfs_device_fsid(dev_item),
3038 BTRFS_UUID_SIZE);
3039
3040 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
3041 ret = open_seed_devices(root, fs_uuid);
3042 if (ret && !btrfs_test_opt(root, DEGRADED))
3043 return ret;
3044 }
3045
3046 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
3047 if (!device || !device->bdev) {
3048 if (!btrfs_test_opt(root, DEGRADED))
3049 return -EIO;
3050
3051 if (!device) {
3052 printk(KERN_WARNING "warning devid %llu missing\n",
3053 (unsigned long long)devid);
3054 device = add_missing_dev(root, devid, dev_uuid);
3055 if (!device)
3056 return -ENOMEM;
3057 }
3058 }
3059
3060 if (device->fs_devices != root->fs_info->fs_devices) {
3061 BUG_ON(device->writeable);
3062 if (device->generation !=
3063 btrfs_device_generation(leaf, dev_item))
3064 return -EINVAL;
3065 }
3066
3067 fill_device_from_item(leaf, dev_item, device);
3068 device->dev_root = root->fs_info->dev_root;
3069 device->in_fs_metadata = 1;
3070 if (device->writeable)
3071 device->fs_devices->total_rw_bytes += device->total_bytes;
3072 ret = 0;
3073 return ret;
3074 }
3075
3076 int btrfs_read_super_device(struct btrfs_root *root, struct extent_buffer *buf)
3077 {
3078 struct btrfs_dev_item *dev_item;
3079
3080 dev_item = (struct btrfs_dev_item *)offsetof(struct btrfs_super_block,
3081 dev_item);
3082 return read_one_dev(root, buf, dev_item);
3083 }
3084
3085 int btrfs_read_sys_array(struct btrfs_root *root)
3086 {
3087 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
3088 struct extent_buffer *sb;
3089 struct btrfs_disk_key *disk_key;
3090 struct btrfs_chunk *chunk;
3091 u8 *ptr;
3092 unsigned long sb_ptr;
3093 int ret = 0;
3094 u32 num_stripes;
3095 u32 array_size;
3096 u32 len = 0;
3097 u32 cur;
3098 struct btrfs_key key;
3099
3100 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
3101 BTRFS_SUPER_INFO_SIZE);
3102 if (!sb)
3103 return -ENOMEM;
3104 btrfs_set_buffer_uptodate(sb);
3105 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
3106 array_size = btrfs_super_sys_array_size(super_copy);
3107
3108 ptr = super_copy->sys_chunk_array;
3109 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
3110 cur = 0;
3111
3112 while (cur < array_size) {
3113 disk_key = (struct btrfs_disk_key *)ptr;
3114 btrfs_disk_key_to_cpu(&key, disk_key);
3115
3116 len = sizeof(*disk_key); ptr += len;
3117 sb_ptr += len;
3118 cur += len;
3119
3120 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
3121 chunk = (struct btrfs_chunk *)sb_ptr;
3122 ret = read_one_chunk(root, &key, sb, chunk);
3123 if (ret)
3124 break;
3125 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
3126 len = btrfs_chunk_item_size(num_stripes);
3127 } else {
3128 ret = -EIO;
3129 break;
3130 }
3131 ptr += len;
3132 sb_ptr += len;
3133 cur += len;
3134 }
3135 free_extent_buffer(sb);
3136 return ret;
3137 }
3138
3139 int btrfs_read_chunk_tree(struct btrfs_root *root)
3140 {
3141 struct btrfs_path *path;
3142 struct extent_buffer *leaf;
3143 struct btrfs_key key;
3144 struct btrfs_key found_key;
3145 int ret;
3146 int slot;
3147
3148 root = root->fs_info->chunk_root;
3149
3150 path = btrfs_alloc_path();
3151 if (!path)
3152 return -ENOMEM;
3153
3154 /* first we search for all of the device items, and then we
3155 * read in all of the chunk items. This way we can create chunk
3156 * mappings that reference all of the devices that are afound
3157 */
3158 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
3159 key.offset = 0;
3160 key.type = 0;
3161 again:
3162 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3163 while (1) {
3164 leaf = path->nodes[0];
3165 slot = path->slots[0];
3166 if (slot >= btrfs_header_nritems(leaf)) {
3167 ret = btrfs_next_leaf(root, path);
3168 if (ret == 0)
3169 continue;
3170 if (ret < 0)
3171 goto error;
3172 break;
3173 }
3174 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3175 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
3176 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
3177 break;
3178 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
3179 struct btrfs_dev_item *dev_item;
3180 dev_item = btrfs_item_ptr(leaf, slot,
3181 struct btrfs_dev_item);
3182 ret = read_one_dev(root, leaf, dev_item);
3183 if (ret)
3184 goto error;
3185 }
3186 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
3187 struct btrfs_chunk *chunk;
3188 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
3189 ret = read_one_chunk(root, &found_key, leaf, chunk);
3190 if (ret)
3191 goto error;
3192 }
3193 path->slots[0]++;
3194 }
3195 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
3196 key.objectid = 0;
3197 btrfs_release_path(root, path);
3198 goto again;
3199 }
3200 ret = 0;
3201 error:
3202 btrfs_free_path(path);
3203 return ret;
3204 }
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