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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/slab.h>
21 #include <linux/buffer_head.h>
22 #include <linux/blkdev.h>
23 #include <linux/random.h>
24 #include <linux/iocontext.h>
25 #include <linux/capability.h>
26 #include <asm/div64.h>
27 #include "compat.h"
28 #include "ctree.h"
29 #include "extent_map.h"
30 #include "disk-io.h"
31 #include "transaction.h"
32 #include "print-tree.h"
33 #include "volumes.h"
34 #include "async-thread.h"
35
36 struct map_lookup {
37 u64 type;
38 int io_align;
39 int io_width;
40 int stripe_len;
41 int sector_size;
42 int num_stripes;
43 int sub_stripes;
44 struct btrfs_bio_stripe stripes[];
45 };
46
47 static int init_first_rw_device(struct btrfs_trans_handle *trans,
48 struct btrfs_root *root,
49 struct btrfs_device *device);
50 static int btrfs_relocate_sys_chunks(struct btrfs_root *root);
51
52 #define map_lookup_size(n) (sizeof(struct map_lookup) + \
53 (sizeof(struct btrfs_bio_stripe) * (n)))
54
55 static DEFINE_MUTEX(uuid_mutex);
56 static LIST_HEAD(fs_uuids);
57
58 void btrfs_lock_volumes(void)
59 {
60 mutex_lock(&uuid_mutex);
61 }
62
63 void btrfs_unlock_volumes(void)
64 {
65 mutex_unlock(&uuid_mutex);
66 }
67
68 static void lock_chunks(struct btrfs_root *root)
69 {
70 mutex_lock(&root->fs_info->chunk_mutex);
71 }
72
73 static void unlock_chunks(struct btrfs_root *root)
74 {
75 mutex_unlock(&root->fs_info->chunk_mutex);
76 }
77
78 static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
79 {
80 struct btrfs_device *device;
81 WARN_ON(fs_devices->opened);
82 while (!list_empty(&fs_devices->devices)) {
83 device = list_entry(fs_devices->devices.next,
84 struct btrfs_device, dev_list);
85 list_del(&device->dev_list);
86 kfree(device->name);
87 kfree(device);
88 }
89 kfree(fs_devices);
90 }
91
92 int btrfs_cleanup_fs_uuids(void)
93 {
94 struct btrfs_fs_devices *fs_devices;
95
96 while (!list_empty(&fs_uuids)) {
97 fs_devices = list_entry(fs_uuids.next,
98 struct btrfs_fs_devices, list);
99 list_del(&fs_devices->list);
100 free_fs_devices(fs_devices);
101 }
102 return 0;
103 }
104
105 static noinline struct btrfs_device *__find_device(struct list_head *head,
106 u64 devid, u8 *uuid)
107 {
108 struct btrfs_device *dev;
109
110 list_for_each_entry(dev, head, dev_list) {
111 if (dev->devid == devid &&
112 (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
113 return dev;
114 }
115 }
116 return NULL;
117 }
118
119 static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
120 {
121 struct btrfs_fs_devices *fs_devices;
122
123 list_for_each_entry(fs_devices, &fs_uuids, list) {
124 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
125 return fs_devices;
126 }
127 return NULL;
128 }
129
130 static void requeue_list(struct btrfs_pending_bios *pending_bios,
131 struct bio *head, struct bio *tail)
132 {
133
134 struct bio *old_head;
135
136 old_head = pending_bios->head;
137 pending_bios->head = head;
138 if (pending_bios->tail)
139 tail->bi_next = old_head;
140 else
141 pending_bios->tail = tail;
142 }
143
144 /*
145 * we try to collect pending bios for a device so we don't get a large
146 * number of procs sending bios down to the same device. This greatly
147 * improves the schedulers ability to collect and merge the bios.
148 *
149 * But, it also turns into a long list of bios to process and that is sure
150 * to eventually make the worker thread block. The solution here is to
151 * make some progress and then put this work struct back at the end of
152 * the list if the block device is congested. This way, multiple devices
153 * can make progress from a single worker thread.
154 */
155 static noinline int run_scheduled_bios(struct btrfs_device *device)
156 {
157 struct bio *pending;
158 struct backing_dev_info *bdi;
159 struct btrfs_fs_info *fs_info;
160 struct btrfs_pending_bios *pending_bios;
161 struct bio *tail;
162 struct bio *cur;
163 int again = 0;
164 unsigned long num_run;
165 unsigned long batch_run = 0;
166 unsigned long limit;
167 unsigned long last_waited = 0;
168 int force_reg = 0;
169
170 bdi = blk_get_backing_dev_info(device->bdev);
171 fs_info = device->dev_root->fs_info;
172 limit = btrfs_async_submit_limit(fs_info);
173 limit = limit * 2 / 3;
174
175 loop:
176 spin_lock(&device->io_lock);
177
178 loop_lock:
179 num_run = 0;
180
181 /* take all the bios off the list at once and process them
182 * later on (without the lock held). But, remember the
183 * tail and other pointers so the bios can be properly reinserted
184 * into the list if we hit congestion
185 */
186 if (!force_reg && device->pending_sync_bios.head) {
187 pending_bios = &device->pending_sync_bios;
188 force_reg = 1;
189 } else {
190 pending_bios = &device->pending_bios;
191 force_reg = 0;
192 }
193
194 pending = pending_bios->head;
195 tail = pending_bios->tail;
196 WARN_ON(pending && !tail);
197
198 /*
199 * if pending was null this time around, no bios need processing
200 * at all and we can stop. Otherwise it'll loop back up again
201 * and do an additional check so no bios are missed.
202 *
203 * device->running_pending is used to synchronize with the
204 * schedule_bio code.
205 */
206 if (device->pending_sync_bios.head == NULL &&
207 device->pending_bios.head == NULL) {
208 again = 0;
209 device->running_pending = 0;
210 } else {
211 again = 1;
212 device->running_pending = 1;
213 }
214
215 pending_bios->head = NULL;
216 pending_bios->tail = NULL;
217
218 spin_unlock(&device->io_lock);
219
220 while (pending) {
221
222 rmb();
223 /* we want to work on both lists, but do more bios on the
224 * sync list than the regular list
225 */
226 if ((num_run > 32 &&
227 pending_bios != &device->pending_sync_bios &&
228 device->pending_sync_bios.head) ||
229 (num_run > 64 && pending_bios == &device->pending_sync_bios &&
230 device->pending_bios.head)) {
231 spin_lock(&device->io_lock);
232 requeue_list(pending_bios, pending, tail);
233 goto loop_lock;
234 }
235
236 cur = pending;
237 pending = pending->bi_next;
238 cur->bi_next = NULL;
239 atomic_dec(&fs_info->nr_async_bios);
240
241 if (atomic_read(&fs_info->nr_async_bios) < limit &&
242 waitqueue_active(&fs_info->async_submit_wait))
243 wake_up(&fs_info->async_submit_wait);
244
245 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
246
247 submit_bio(cur->bi_rw, cur);
248 num_run++;
249 batch_run++;
250 if (need_resched())
251 cond_resched();
252
253 /*
254 * we made progress, there is more work to do and the bdi
255 * is now congested. Back off and let other work structs
256 * run instead
257 */
258 if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
259 fs_info->fs_devices->open_devices > 1) {
260 struct io_context *ioc;
261
262 ioc = current->io_context;
263
264 /*
265 * the main goal here is that we don't want to
266 * block if we're going to be able to submit
267 * more requests without blocking.
268 *
269 * This code does two great things, it pokes into
270 * the elevator code from a filesystem _and_
271 * it makes assumptions about how batching works.
272 */
273 if (ioc && ioc->nr_batch_requests > 0 &&
274 time_before(jiffies, ioc->last_waited + HZ/50UL) &&
275 (last_waited == 0 ||
276 ioc->last_waited == last_waited)) {
277 /*
278 * we want to go through our batch of
279 * requests and stop. So, we copy out
280 * the ioc->last_waited time and test
281 * against it before looping
282 */
283 last_waited = ioc->last_waited;
284 if (need_resched())
285 cond_resched();
286 continue;
287 }
288 spin_lock(&device->io_lock);
289 requeue_list(pending_bios, pending, tail);
290 device->running_pending = 1;
291
292 spin_unlock(&device->io_lock);
293 btrfs_requeue_work(&device->work);
294 goto done;
295 }
296 }
297
298 cond_resched();
299 if (again)
300 goto loop;
301
302 spin_lock(&device->io_lock);
303 if (device->pending_bios.head || device->pending_sync_bios.head)
304 goto loop_lock;
305 spin_unlock(&device->io_lock);
306
307 done:
308 return 0;
309 }
310
311 static void pending_bios_fn(struct btrfs_work *work)
312 {
313 struct btrfs_device *device;
314
315 device = container_of(work, struct btrfs_device, work);
316 run_scheduled_bios(device);
317 }
318
319 static noinline int device_list_add(const char *path,
320 struct btrfs_super_block *disk_super,
321 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
322 {
323 struct btrfs_device *device;
324 struct btrfs_fs_devices *fs_devices;
325 u64 found_transid = btrfs_super_generation(disk_super);
326 char *name;
327
328 fs_devices = find_fsid(disk_super->fsid);
329 if (!fs_devices) {
330 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
331 if (!fs_devices)
332 return -ENOMEM;
333 INIT_LIST_HEAD(&fs_devices->devices);
334 INIT_LIST_HEAD(&fs_devices->alloc_list);
335 list_add(&fs_devices->list, &fs_uuids);
336 memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
337 fs_devices->latest_devid = devid;
338 fs_devices->latest_trans = found_transid;
339 mutex_init(&fs_devices->device_list_mutex);
340 device = NULL;
341 } else {
342 device = __find_device(&fs_devices->devices, devid,
343 disk_super->dev_item.uuid);
344 }
345 if (!device) {
346 if (fs_devices->opened)
347 return -EBUSY;
348
349 device = kzalloc(sizeof(*device), GFP_NOFS);
350 if (!device) {
351 /* we can safely leave the fs_devices entry around */
352 return -ENOMEM;
353 }
354 device->devid = devid;
355 device->work.func = pending_bios_fn;
356 memcpy(device->uuid, disk_super->dev_item.uuid,
357 BTRFS_UUID_SIZE);
358 spin_lock_init(&device->io_lock);
359 device->name = kstrdup(path, GFP_NOFS);
360 if (!device->name) {
361 kfree(device);
362 return -ENOMEM;
363 }
364 INIT_LIST_HEAD(&device->dev_alloc_list);
365
366 mutex_lock(&fs_devices->device_list_mutex);
367 list_add(&device->dev_list, &fs_devices->devices);
368 mutex_unlock(&fs_devices->device_list_mutex);
369
370 device->fs_devices = fs_devices;
371 fs_devices->num_devices++;
372 } else if (!device->name || strcmp(device->name, path)) {
373 name = kstrdup(path, GFP_NOFS);
374 if (!name)
375 return -ENOMEM;
376 kfree(device->name);
377 device->name = name;
378 if (device->missing) {
379 fs_devices->missing_devices--;
380 device->missing = 0;
381 }
382 }
383
384 if (found_transid > fs_devices->latest_trans) {
385 fs_devices->latest_devid = devid;
386 fs_devices->latest_trans = found_transid;
387 }
388 *fs_devices_ret = fs_devices;
389 return 0;
390 }
391
392 static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
393 {
394 struct btrfs_fs_devices *fs_devices;
395 struct btrfs_device *device;
396 struct btrfs_device *orig_dev;
397
398 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
399 if (!fs_devices)
400 return ERR_PTR(-ENOMEM);
401
402 INIT_LIST_HEAD(&fs_devices->devices);
403 INIT_LIST_HEAD(&fs_devices->alloc_list);
404 INIT_LIST_HEAD(&fs_devices->list);
405 mutex_init(&fs_devices->device_list_mutex);
406 fs_devices->latest_devid = orig->latest_devid;
407 fs_devices->latest_trans = orig->latest_trans;
408 memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid));
409
410 mutex_lock(&orig->device_list_mutex);
411 list_for_each_entry(orig_dev, &orig->devices, dev_list) {
412 device = kzalloc(sizeof(*device), GFP_NOFS);
413 if (!device)
414 goto error;
415
416 device->name = kstrdup(orig_dev->name, GFP_NOFS);
417 if (!device->name) {
418 kfree(device);
419 goto error;
420 }
421
422 device->devid = orig_dev->devid;
423 device->work.func = pending_bios_fn;
424 memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid));
425 spin_lock_init(&device->io_lock);
426 INIT_LIST_HEAD(&device->dev_list);
427 INIT_LIST_HEAD(&device->dev_alloc_list);
428
429 list_add(&device->dev_list, &fs_devices->devices);
430 device->fs_devices = fs_devices;
431 fs_devices->num_devices++;
432 }
433 mutex_unlock(&orig->device_list_mutex);
434 return fs_devices;
435 error:
436 mutex_unlock(&orig->device_list_mutex);
437 free_fs_devices(fs_devices);
438 return ERR_PTR(-ENOMEM);
439 }
440
441 int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
442 {
443 struct btrfs_device *device, *next;
444
445 mutex_lock(&uuid_mutex);
446 again:
447 mutex_lock(&fs_devices->device_list_mutex);
448 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
449 if (device->in_fs_metadata)
450 continue;
451
452 if (device->bdev) {
453 blkdev_put(device->bdev, device->mode);
454 device->bdev = NULL;
455 fs_devices->open_devices--;
456 }
457 if (device->writeable) {
458 list_del_init(&device->dev_alloc_list);
459 device->writeable = 0;
460 fs_devices->rw_devices--;
461 }
462 list_del_init(&device->dev_list);
463 fs_devices->num_devices--;
464 kfree(device->name);
465 kfree(device);
466 }
467 mutex_unlock(&fs_devices->device_list_mutex);
468
469 if (fs_devices->seed) {
470 fs_devices = fs_devices->seed;
471 goto again;
472 }
473
474 mutex_unlock(&uuid_mutex);
475 return 0;
476 }
477
478 static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
479 {
480 struct btrfs_device *device;
481
482 if (--fs_devices->opened > 0)
483 return 0;
484
485 list_for_each_entry(device, &fs_devices->devices, dev_list) {
486 if (device->bdev) {
487 blkdev_put(device->bdev, device->mode);
488 fs_devices->open_devices--;
489 }
490 if (device->writeable) {
491 list_del_init(&device->dev_alloc_list);
492 fs_devices->rw_devices--;
493 }
494
495 device->bdev = NULL;
496 device->writeable = 0;
497 device->in_fs_metadata = 0;
498 }
499 WARN_ON(fs_devices->open_devices);
500 WARN_ON(fs_devices->rw_devices);
501 fs_devices->opened = 0;
502 fs_devices->seeding = 0;
503
504 return 0;
505 }
506
507 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
508 {
509 struct btrfs_fs_devices *seed_devices = NULL;
510 int ret;
511
512 mutex_lock(&uuid_mutex);
513 ret = __btrfs_close_devices(fs_devices);
514 if (!fs_devices->opened) {
515 seed_devices = fs_devices->seed;
516 fs_devices->seed = NULL;
517 }
518 mutex_unlock(&uuid_mutex);
519
520 while (seed_devices) {
521 fs_devices = seed_devices;
522 seed_devices = fs_devices->seed;
523 __btrfs_close_devices(fs_devices);
524 free_fs_devices(fs_devices);
525 }
526 return ret;
527 }
528
529 static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
530 fmode_t flags, void *holder)
531 {
532 struct block_device *bdev;
533 struct list_head *head = &fs_devices->devices;
534 struct btrfs_device *device;
535 struct block_device *latest_bdev = NULL;
536 struct buffer_head *bh;
537 struct btrfs_super_block *disk_super;
538 u64 latest_devid = 0;
539 u64 latest_transid = 0;
540 u64 devid;
541 int seeding = 1;
542 int ret = 0;
543
544 flags |= FMODE_EXCL;
545
546 list_for_each_entry(device, head, dev_list) {
547 if (device->bdev)
548 continue;
549 if (!device->name)
550 continue;
551
552 bdev = blkdev_get_by_path(device->name, flags, holder);
553 if (IS_ERR(bdev)) {
554 printk(KERN_INFO "open %s failed\n", device->name);
555 goto error;
556 }
557 set_blocksize(bdev, 4096);
558
559 bh = btrfs_read_dev_super(bdev);
560 if (!bh) {
561 ret = -EINVAL;
562 goto error_close;
563 }
564
565 disk_super = (struct btrfs_super_block *)bh->b_data;
566 devid = btrfs_stack_device_id(&disk_super->dev_item);
567 if (devid != device->devid)
568 goto error_brelse;
569
570 if (memcmp(device->uuid, disk_super->dev_item.uuid,
571 BTRFS_UUID_SIZE))
572 goto error_brelse;
573
574 device->generation = btrfs_super_generation(disk_super);
575 if (!latest_transid || device->generation > latest_transid) {
576 latest_devid = devid;
577 latest_transid = device->generation;
578 latest_bdev = bdev;
579 }
580
581 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
582 device->writeable = 0;
583 } else {
584 device->writeable = !bdev_read_only(bdev);
585 seeding = 0;
586 }
587
588 device->bdev = bdev;
589 device->in_fs_metadata = 0;
590 device->mode = flags;
591
592 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
593 fs_devices->rotating = 1;
594
595 fs_devices->open_devices++;
596 if (device->writeable) {
597 fs_devices->rw_devices++;
598 list_add(&device->dev_alloc_list,
599 &fs_devices->alloc_list);
600 }
601 continue;
602
603 error_brelse:
604 brelse(bh);
605 error_close:
606 blkdev_put(bdev, flags);
607 error:
608 continue;
609 }
610 if (fs_devices->open_devices == 0) {
611 ret = -EIO;
612 goto out;
613 }
614 fs_devices->seeding = seeding;
615 fs_devices->opened = 1;
616 fs_devices->latest_bdev = latest_bdev;
617 fs_devices->latest_devid = latest_devid;
618 fs_devices->latest_trans = latest_transid;
619 fs_devices->total_rw_bytes = 0;
620 out:
621 return ret;
622 }
623
624 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
625 fmode_t flags, void *holder)
626 {
627 int ret;
628
629 mutex_lock(&uuid_mutex);
630 if (fs_devices->opened) {
631 fs_devices->opened++;
632 ret = 0;
633 } else {
634 ret = __btrfs_open_devices(fs_devices, flags, holder);
635 }
636 mutex_unlock(&uuid_mutex);
637 return ret;
638 }
639
640 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
641 struct btrfs_fs_devices **fs_devices_ret)
642 {
643 struct btrfs_super_block *disk_super;
644 struct block_device *bdev;
645 struct buffer_head *bh;
646 int ret;
647 u64 devid;
648 u64 transid;
649
650 mutex_lock(&uuid_mutex);
651
652 flags |= FMODE_EXCL;
653 bdev = blkdev_get_by_path(path, flags, holder);
654
655 if (IS_ERR(bdev)) {
656 ret = PTR_ERR(bdev);
657 goto error;
658 }
659
660 ret = set_blocksize(bdev, 4096);
661 if (ret)
662 goto error_close;
663 bh = btrfs_read_dev_super(bdev);
664 if (!bh) {
665 ret = -EINVAL;
666 goto error_close;
667 }
668 disk_super = (struct btrfs_super_block *)bh->b_data;
669 devid = btrfs_stack_device_id(&disk_super->dev_item);
670 transid = btrfs_super_generation(disk_super);
671 if (disk_super->label[0])
672 printk(KERN_INFO "device label %s ", disk_super->label);
673 else {
674 /* FIXME, make a readl uuid parser */
675 printk(KERN_INFO "device fsid %llx-%llx ",
676 *(unsigned long long *)disk_super->fsid,
677 *(unsigned long long *)(disk_super->fsid + 8));
678 }
679 printk(KERN_CONT "devid %llu transid %llu %s\n",
680 (unsigned long long)devid, (unsigned long long)transid, path);
681 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
682
683 brelse(bh);
684 error_close:
685 blkdev_put(bdev, flags);
686 error:
687 mutex_unlock(&uuid_mutex);
688 return ret;
689 }
690
691 /* helper to account the used device space in the range */
692 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
693 u64 end, u64 *length)
694 {
695 struct btrfs_key key;
696 struct btrfs_root *root = device->dev_root;
697 struct btrfs_dev_extent *dev_extent;
698 struct btrfs_path *path;
699 u64 extent_end;
700 int ret;
701 int slot;
702 struct extent_buffer *l;
703
704 *length = 0;
705
706 if (start >= device->total_bytes)
707 return 0;
708
709 path = btrfs_alloc_path();
710 if (!path)
711 return -ENOMEM;
712 path->reada = 2;
713
714 key.objectid = device->devid;
715 key.offset = start;
716 key.type = BTRFS_DEV_EXTENT_KEY;
717
718 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
719 if (ret < 0)
720 goto out;
721 if (ret > 0) {
722 ret = btrfs_previous_item(root, path, key.objectid, key.type);
723 if (ret < 0)
724 goto out;
725 }
726
727 while (1) {
728 l = path->nodes[0];
729 slot = path->slots[0];
730 if (slot >= btrfs_header_nritems(l)) {
731 ret = btrfs_next_leaf(root, path);
732 if (ret == 0)
733 continue;
734 if (ret < 0)
735 goto out;
736
737 break;
738 }
739 btrfs_item_key_to_cpu(l, &key, slot);
740
741 if (key.objectid < device->devid)
742 goto next;
743
744 if (key.objectid > device->devid)
745 break;
746
747 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
748 goto next;
749
750 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
751 extent_end = key.offset + btrfs_dev_extent_length(l,
752 dev_extent);
753 if (key.offset <= start && extent_end > end) {
754 *length = end - start + 1;
755 break;
756 } else if (key.offset <= start && extent_end > start)
757 *length += extent_end - start;
758 else if (key.offset > start && extent_end <= end)
759 *length += extent_end - key.offset;
760 else if (key.offset > start && key.offset <= end) {
761 *length += end - key.offset + 1;
762 break;
763 } else if (key.offset > end)
764 break;
765
766 next:
767 path->slots[0]++;
768 }
769 ret = 0;
770 out:
771 btrfs_free_path(path);
772 return ret;
773 }
774
775 /*
776 * find_free_dev_extent - find free space in the specified device
777 * @trans: transaction handler
778 * @device: the device which we search the free space in
779 * @num_bytes: the size of the free space that we need
780 * @start: store the start of the free space.
781 * @len: the size of the free space. that we find, or the size of the max
782 * free space if we don't find suitable free space
783 *
784 * this uses a pretty simple search, the expectation is that it is
785 * called very infrequently and that a given device has a small number
786 * of extents
787 *
788 * @start is used to store the start of the free space if we find. But if we
789 * don't find suitable free space, it will be used to store the start position
790 * of the max free space.
791 *
792 * @len is used to store the size of the free space that we find.
793 * But if we don't find suitable free space, it is used to store the size of
794 * the max free space.
795 */
796 int find_free_dev_extent(struct btrfs_trans_handle *trans,
797 struct btrfs_device *device, u64 num_bytes,
798 u64 *start, u64 *len)
799 {
800 struct btrfs_key key;
801 struct btrfs_root *root = device->dev_root;
802 struct btrfs_dev_extent *dev_extent;
803 struct btrfs_path *path;
804 u64 hole_size;
805 u64 max_hole_start;
806 u64 max_hole_size;
807 u64 extent_end;
808 u64 search_start;
809 u64 search_end = device->total_bytes;
810 int ret;
811 int slot;
812 struct extent_buffer *l;
813
814 /* FIXME use last free of some kind */
815
816 /* we don't want to overwrite the superblock on the drive,
817 * so we make sure to start at an offset of at least 1MB
818 */
819 search_start = 1024 * 1024;
820
821 if (root->fs_info->alloc_start + num_bytes <= search_end)
822 search_start = max(root->fs_info->alloc_start, search_start);
823
824 max_hole_start = search_start;
825 max_hole_size = 0;
826
827 if (search_start >= search_end) {
828 ret = -ENOSPC;
829 goto error;
830 }
831
832 path = btrfs_alloc_path();
833 if (!path) {
834 ret = -ENOMEM;
835 goto error;
836 }
837 path->reada = 2;
838
839 key.objectid = device->devid;
840 key.offset = search_start;
841 key.type = BTRFS_DEV_EXTENT_KEY;
842
843 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
844 if (ret < 0)
845 goto out;
846 if (ret > 0) {
847 ret = btrfs_previous_item(root, path, key.objectid, key.type);
848 if (ret < 0)
849 goto out;
850 }
851
852 while (1) {
853 l = path->nodes[0];
854 slot = path->slots[0];
855 if (slot >= btrfs_header_nritems(l)) {
856 ret = btrfs_next_leaf(root, path);
857 if (ret == 0)
858 continue;
859 if (ret < 0)
860 goto out;
861
862 break;
863 }
864 btrfs_item_key_to_cpu(l, &key, slot);
865
866 if (key.objectid < device->devid)
867 goto next;
868
869 if (key.objectid > device->devid)
870 break;
871
872 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
873 goto next;
874
875 if (key.offset > search_start) {
876 hole_size = key.offset - search_start;
877
878 if (hole_size > max_hole_size) {
879 max_hole_start = search_start;
880 max_hole_size = hole_size;
881 }
882
883 /*
884 * If this free space is greater than which we need,
885 * it must be the max free space that we have found
886 * until now, so max_hole_start must point to the start
887 * of this free space and the length of this free space
888 * is stored in max_hole_size. Thus, we return
889 * max_hole_start and max_hole_size and go back to the
890 * caller.
891 */
892 if (hole_size >= num_bytes) {
893 ret = 0;
894 goto out;
895 }
896 }
897
898 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
899 extent_end = key.offset + btrfs_dev_extent_length(l,
900 dev_extent);
901 if (extent_end > search_start)
902 search_start = extent_end;
903 next:
904 path->slots[0]++;
905 cond_resched();
906 }
907
908 hole_size = search_end- search_start;
909 if (hole_size > max_hole_size) {
910 max_hole_start = search_start;
911 max_hole_size = hole_size;
912 }
913
914 /* See above. */
915 if (hole_size < num_bytes)
916 ret = -ENOSPC;
917 else
918 ret = 0;
919
920 out:
921 btrfs_free_path(path);
922 error:
923 *start = max_hole_start;
924 if (len)
925 *len = max_hole_size;
926 return ret;
927 }
928
929 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
930 struct btrfs_device *device,
931 u64 start)
932 {
933 int ret;
934 struct btrfs_path *path;
935 struct btrfs_root *root = device->dev_root;
936 struct btrfs_key key;
937 struct btrfs_key found_key;
938 struct extent_buffer *leaf = NULL;
939 struct btrfs_dev_extent *extent = NULL;
940
941 path = btrfs_alloc_path();
942 if (!path)
943 return -ENOMEM;
944
945 key.objectid = device->devid;
946 key.offset = start;
947 key.type = BTRFS_DEV_EXTENT_KEY;
948
949 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
950 if (ret > 0) {
951 ret = btrfs_previous_item(root, path, key.objectid,
952 BTRFS_DEV_EXTENT_KEY);
953 BUG_ON(ret);
954 leaf = path->nodes[0];
955 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
956 extent = btrfs_item_ptr(leaf, path->slots[0],
957 struct btrfs_dev_extent);
958 BUG_ON(found_key.offset > start || found_key.offset +
959 btrfs_dev_extent_length(leaf, extent) < start);
960 ret = 0;
961 } else if (ret == 0) {
962 leaf = path->nodes[0];
963 extent = btrfs_item_ptr(leaf, path->slots[0],
964 struct btrfs_dev_extent);
965 }
966 BUG_ON(ret);
967
968 if (device->bytes_used > 0)
969 device->bytes_used -= btrfs_dev_extent_length(leaf, extent);
970 ret = btrfs_del_item(trans, root, path);
971 BUG_ON(ret);
972
973 btrfs_free_path(path);
974 return ret;
975 }
976
977 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
978 struct btrfs_device *device,
979 u64 chunk_tree, u64 chunk_objectid,
980 u64 chunk_offset, u64 start, u64 num_bytes)
981 {
982 int ret;
983 struct btrfs_path *path;
984 struct btrfs_root *root = device->dev_root;
985 struct btrfs_dev_extent *extent;
986 struct extent_buffer *leaf;
987 struct btrfs_key key;
988
989 WARN_ON(!device->in_fs_metadata);
990 path = btrfs_alloc_path();
991 if (!path)
992 return -ENOMEM;
993
994 key.objectid = device->devid;
995 key.offset = start;
996 key.type = BTRFS_DEV_EXTENT_KEY;
997 ret = btrfs_insert_empty_item(trans, root, path, &key,
998 sizeof(*extent));
999 BUG_ON(ret);
1000
1001 leaf = path->nodes[0];
1002 extent = btrfs_item_ptr(leaf, path->slots[0],
1003 struct btrfs_dev_extent);
1004 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
1005 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
1006 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
1007
1008 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
1009 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
1010 BTRFS_UUID_SIZE);
1011
1012 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
1013 btrfs_mark_buffer_dirty(leaf);
1014 btrfs_free_path(path);
1015 return ret;
1016 }
1017
1018 static noinline int find_next_chunk(struct btrfs_root *root,
1019 u64 objectid, u64 *offset)
1020 {
1021 struct btrfs_path *path;
1022 int ret;
1023 struct btrfs_key key;
1024 struct btrfs_chunk *chunk;
1025 struct btrfs_key found_key;
1026
1027 path = btrfs_alloc_path();
1028 BUG_ON(!path);
1029
1030 key.objectid = objectid;
1031 key.offset = (u64)-1;
1032 key.type = BTRFS_CHUNK_ITEM_KEY;
1033
1034 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1035 if (ret < 0)
1036 goto error;
1037
1038 BUG_ON(ret == 0);
1039
1040 ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
1041 if (ret) {
1042 *offset = 0;
1043 } else {
1044 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1045 path->slots[0]);
1046 if (found_key.objectid != objectid)
1047 *offset = 0;
1048 else {
1049 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
1050 struct btrfs_chunk);
1051 *offset = found_key.offset +
1052 btrfs_chunk_length(path->nodes[0], chunk);
1053 }
1054 }
1055 ret = 0;
1056 error:
1057 btrfs_free_path(path);
1058 return ret;
1059 }
1060
1061 static noinline int find_next_devid(struct btrfs_root *root, u64 *objectid)
1062 {
1063 int ret;
1064 struct btrfs_key key;
1065 struct btrfs_key found_key;
1066 struct btrfs_path *path;
1067
1068 root = root->fs_info->chunk_root;
1069
1070 path = btrfs_alloc_path();
1071 if (!path)
1072 return -ENOMEM;
1073
1074 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1075 key.type = BTRFS_DEV_ITEM_KEY;
1076 key.offset = (u64)-1;
1077
1078 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1079 if (ret < 0)
1080 goto error;
1081
1082 BUG_ON(ret == 0);
1083
1084 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
1085 BTRFS_DEV_ITEM_KEY);
1086 if (ret) {
1087 *objectid = 1;
1088 } else {
1089 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1090 path->slots[0]);
1091 *objectid = found_key.offset + 1;
1092 }
1093 ret = 0;
1094 error:
1095 btrfs_free_path(path);
1096 return ret;
1097 }
1098
1099 /*
1100 * the device information is stored in the chunk root
1101 * the btrfs_device struct should be fully filled in
1102 */
1103 int btrfs_add_device(struct btrfs_trans_handle *trans,
1104 struct btrfs_root *root,
1105 struct btrfs_device *device)
1106 {
1107 int ret;
1108 struct btrfs_path *path;
1109 struct btrfs_dev_item *dev_item;
1110 struct extent_buffer *leaf;
1111 struct btrfs_key key;
1112 unsigned long ptr;
1113
1114 root = root->fs_info->chunk_root;
1115
1116 path = btrfs_alloc_path();
1117 if (!path)
1118 return -ENOMEM;
1119
1120 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1121 key.type = BTRFS_DEV_ITEM_KEY;
1122 key.offset = device->devid;
1123
1124 ret = btrfs_insert_empty_item(trans, root, path, &key,
1125 sizeof(*dev_item));
1126 if (ret)
1127 goto out;
1128
1129 leaf = path->nodes[0];
1130 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1131
1132 btrfs_set_device_id(leaf, dev_item, device->devid);
1133 btrfs_set_device_generation(leaf, dev_item, 0);
1134 btrfs_set_device_type(leaf, dev_item, device->type);
1135 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1136 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1137 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1138 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
1139 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1140 btrfs_set_device_group(leaf, dev_item, 0);
1141 btrfs_set_device_seek_speed(leaf, dev_item, 0);
1142 btrfs_set_device_bandwidth(leaf, dev_item, 0);
1143 btrfs_set_device_start_offset(leaf, dev_item, 0);
1144
1145 ptr = (unsigned long)btrfs_device_uuid(dev_item);
1146 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1147 ptr = (unsigned long)btrfs_device_fsid(dev_item);
1148 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
1149 btrfs_mark_buffer_dirty(leaf);
1150
1151 ret = 0;
1152 out:
1153 btrfs_free_path(path);
1154 return ret;
1155 }
1156
1157 static int btrfs_rm_dev_item(struct btrfs_root *root,
1158 struct btrfs_device *device)
1159 {
1160 int ret;
1161 struct btrfs_path *path;
1162 struct btrfs_key key;
1163 struct btrfs_trans_handle *trans;
1164
1165 root = root->fs_info->chunk_root;
1166
1167 path = btrfs_alloc_path();
1168 if (!path)
1169 return -ENOMEM;
1170
1171 trans = btrfs_start_transaction(root, 0);
1172 if (IS_ERR(trans)) {
1173 btrfs_free_path(path);
1174 return PTR_ERR(trans);
1175 }
1176 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1177 key.type = BTRFS_DEV_ITEM_KEY;
1178 key.offset = device->devid;
1179 lock_chunks(root);
1180
1181 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1182 if (ret < 0)
1183 goto out;
1184
1185 if (ret > 0) {
1186 ret = -ENOENT;
1187 goto out;
1188 }
1189
1190 ret = btrfs_del_item(trans, root, path);
1191 if (ret)
1192 goto out;
1193 out:
1194 btrfs_free_path(path);
1195 unlock_chunks(root);
1196 btrfs_commit_transaction(trans, root);
1197 return ret;
1198 }
1199
1200 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
1201 {
1202 struct btrfs_device *device;
1203 struct btrfs_device *next_device;
1204 struct block_device *bdev;
1205 struct buffer_head *bh = NULL;
1206 struct btrfs_super_block *disk_super;
1207 u64 all_avail;
1208 u64 devid;
1209 u64 num_devices;
1210 u8 *dev_uuid;
1211 int ret = 0;
1212
1213 mutex_lock(&uuid_mutex);
1214 mutex_lock(&root->fs_info->volume_mutex);
1215
1216 all_avail = root->fs_info->avail_data_alloc_bits |
1217 root->fs_info->avail_system_alloc_bits |
1218 root->fs_info->avail_metadata_alloc_bits;
1219
1220 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) &&
1221 root->fs_info->fs_devices->num_devices <= 4) {
1222 printk(KERN_ERR "btrfs: unable to go below four devices "
1223 "on raid10\n");
1224 ret = -EINVAL;
1225 goto out;
1226 }
1227
1228 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) &&
1229 root->fs_info->fs_devices->num_devices <= 2) {
1230 printk(KERN_ERR "btrfs: unable to go below two "
1231 "devices on raid1\n");
1232 ret = -EINVAL;
1233 goto out;
1234 }
1235
1236 if (strcmp(device_path, "missing") == 0) {
1237 struct list_head *devices;
1238 struct btrfs_device *tmp;
1239
1240 device = NULL;
1241 devices = &root->fs_info->fs_devices->devices;
1242 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1243 list_for_each_entry(tmp, devices, dev_list) {
1244 if (tmp->in_fs_metadata && !tmp->bdev) {
1245 device = tmp;
1246 break;
1247 }
1248 }
1249 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1250 bdev = NULL;
1251 bh = NULL;
1252 disk_super = NULL;
1253 if (!device) {
1254 printk(KERN_ERR "btrfs: no missing devices found to "
1255 "remove\n");
1256 goto out;
1257 }
1258 } else {
1259 bdev = blkdev_get_by_path(device_path, FMODE_READ | FMODE_EXCL,
1260 root->fs_info->bdev_holder);
1261 if (IS_ERR(bdev)) {
1262 ret = PTR_ERR(bdev);
1263 goto out;
1264 }
1265
1266 set_blocksize(bdev, 4096);
1267 bh = btrfs_read_dev_super(bdev);
1268 if (!bh) {
1269 ret = -EINVAL;
1270 goto error_close;
1271 }
1272 disk_super = (struct btrfs_super_block *)bh->b_data;
1273 devid = btrfs_stack_device_id(&disk_super->dev_item);
1274 dev_uuid = disk_super->dev_item.uuid;
1275 device = btrfs_find_device(root, devid, dev_uuid,
1276 disk_super->fsid);
1277 if (!device) {
1278 ret = -ENOENT;
1279 goto error_brelse;
1280 }
1281 }
1282
1283 if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
1284 printk(KERN_ERR "btrfs: unable to remove the only writeable "
1285 "device\n");
1286 ret = -EINVAL;
1287 goto error_brelse;
1288 }
1289
1290 if (device->writeable) {
1291 list_del_init(&device->dev_alloc_list);
1292 root->fs_info->fs_devices->rw_devices--;
1293 }
1294
1295 ret = btrfs_shrink_device(device, 0);
1296 if (ret)
1297 goto error_brelse;
1298
1299 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1300 if (ret)
1301 goto error_brelse;
1302
1303 device->in_fs_metadata = 0;
1304
1305 /*
1306 * the device list mutex makes sure that we don't change
1307 * the device list while someone else is writing out all
1308 * the device supers.
1309 */
1310 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1311 list_del_init(&device->dev_list);
1312 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1313
1314 device->fs_devices->num_devices--;
1315
1316 if (device->missing)
1317 root->fs_info->fs_devices->missing_devices--;
1318
1319 next_device = list_entry(root->fs_info->fs_devices->devices.next,
1320 struct btrfs_device, dev_list);
1321 if (device->bdev == root->fs_info->sb->s_bdev)
1322 root->fs_info->sb->s_bdev = next_device->bdev;
1323 if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1324 root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1325
1326 if (device->bdev) {
1327 blkdev_put(device->bdev, device->mode);
1328 device->bdev = NULL;
1329 device->fs_devices->open_devices--;
1330 }
1331
1332 num_devices = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
1333 btrfs_set_super_num_devices(&root->fs_info->super_copy, num_devices);
1334
1335 if (device->fs_devices->open_devices == 0) {
1336 struct btrfs_fs_devices *fs_devices;
1337 fs_devices = root->fs_info->fs_devices;
1338 while (fs_devices) {
1339 if (fs_devices->seed == device->fs_devices)
1340 break;
1341 fs_devices = fs_devices->seed;
1342 }
1343 fs_devices->seed = device->fs_devices->seed;
1344 device->fs_devices->seed = NULL;
1345 __btrfs_close_devices(device->fs_devices);
1346 free_fs_devices(device->fs_devices);
1347 }
1348
1349 /*
1350 * at this point, the device is zero sized. We want to
1351 * remove it from the devices list and zero out the old super
1352 */
1353 if (device->writeable) {
1354 /* make sure this device isn't detected as part of
1355 * the FS anymore
1356 */
1357 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1358 set_buffer_dirty(bh);
1359 sync_dirty_buffer(bh);
1360 }
1361
1362 kfree(device->name);
1363 kfree(device);
1364 ret = 0;
1365
1366 error_brelse:
1367 brelse(bh);
1368 error_close:
1369 if (bdev)
1370 blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
1371 out:
1372 mutex_unlock(&root->fs_info->volume_mutex);
1373 mutex_unlock(&uuid_mutex);
1374 return ret;
1375 }
1376
1377 /*
1378 * does all the dirty work required for changing file system's UUID.
1379 */
1380 static int btrfs_prepare_sprout(struct btrfs_trans_handle *trans,
1381 struct btrfs_root *root)
1382 {
1383 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1384 struct btrfs_fs_devices *old_devices;
1385 struct btrfs_fs_devices *seed_devices;
1386 struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
1387 struct btrfs_device *device;
1388 u64 super_flags;
1389
1390 BUG_ON(!mutex_is_locked(&uuid_mutex));
1391 if (!fs_devices->seeding)
1392 return -EINVAL;
1393
1394 seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
1395 if (!seed_devices)
1396 return -ENOMEM;
1397
1398 old_devices = clone_fs_devices(fs_devices);
1399 if (IS_ERR(old_devices)) {
1400 kfree(seed_devices);
1401 return PTR_ERR(old_devices);
1402 }
1403
1404 list_add(&old_devices->list, &fs_uuids);
1405
1406 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1407 seed_devices->opened = 1;
1408 INIT_LIST_HEAD(&seed_devices->devices);
1409 INIT_LIST_HEAD(&seed_devices->alloc_list);
1410 mutex_init(&seed_devices->device_list_mutex);
1411 list_splice_init(&fs_devices->devices, &seed_devices->devices);
1412 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1413 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1414 device->fs_devices = seed_devices;
1415 }
1416
1417 fs_devices->seeding = 0;
1418 fs_devices->num_devices = 0;
1419 fs_devices->open_devices = 0;
1420 fs_devices->seed = seed_devices;
1421
1422 generate_random_uuid(fs_devices->fsid);
1423 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1424 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1425 super_flags = btrfs_super_flags(disk_super) &
1426 ~BTRFS_SUPER_FLAG_SEEDING;
1427 btrfs_set_super_flags(disk_super, super_flags);
1428
1429 return 0;
1430 }
1431
1432 /*
1433 * strore the expected generation for seed devices in device items.
1434 */
1435 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1436 struct btrfs_root *root)
1437 {
1438 struct btrfs_path *path;
1439 struct extent_buffer *leaf;
1440 struct btrfs_dev_item *dev_item;
1441 struct btrfs_device *device;
1442 struct btrfs_key key;
1443 u8 fs_uuid[BTRFS_UUID_SIZE];
1444 u8 dev_uuid[BTRFS_UUID_SIZE];
1445 u64 devid;
1446 int ret;
1447
1448 path = btrfs_alloc_path();
1449 if (!path)
1450 return -ENOMEM;
1451
1452 root = root->fs_info->chunk_root;
1453 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1454 key.offset = 0;
1455 key.type = BTRFS_DEV_ITEM_KEY;
1456
1457 while (1) {
1458 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1459 if (ret < 0)
1460 goto error;
1461
1462 leaf = path->nodes[0];
1463 next_slot:
1464 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1465 ret = btrfs_next_leaf(root, path);
1466 if (ret > 0)
1467 break;
1468 if (ret < 0)
1469 goto error;
1470 leaf = path->nodes[0];
1471 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1472 btrfs_release_path(root, path);
1473 continue;
1474 }
1475
1476 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1477 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1478 key.type != BTRFS_DEV_ITEM_KEY)
1479 break;
1480
1481 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1482 struct btrfs_dev_item);
1483 devid = btrfs_device_id(leaf, dev_item);
1484 read_extent_buffer(leaf, dev_uuid,
1485 (unsigned long)btrfs_device_uuid(dev_item),
1486 BTRFS_UUID_SIZE);
1487 read_extent_buffer(leaf, fs_uuid,
1488 (unsigned long)btrfs_device_fsid(dev_item),
1489 BTRFS_UUID_SIZE);
1490 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
1491 BUG_ON(!device);
1492
1493 if (device->fs_devices->seeding) {
1494 btrfs_set_device_generation(leaf, dev_item,
1495 device->generation);
1496 btrfs_mark_buffer_dirty(leaf);
1497 }
1498
1499 path->slots[0]++;
1500 goto next_slot;
1501 }
1502 ret = 0;
1503 error:
1504 btrfs_free_path(path);
1505 return ret;
1506 }
1507
1508 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1509 {
1510 struct btrfs_trans_handle *trans;
1511 struct btrfs_device *device;
1512 struct block_device *bdev;
1513 struct list_head *devices;
1514 struct super_block *sb = root->fs_info->sb;
1515 u64 total_bytes;
1516 int seeding_dev = 0;
1517 int ret = 0;
1518
1519 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1520 return -EINVAL;
1521
1522 bdev = blkdev_get_by_path(device_path, FMODE_EXCL,
1523 root->fs_info->bdev_holder);
1524 if (IS_ERR(bdev))
1525 return PTR_ERR(bdev);
1526
1527 if (root->fs_info->fs_devices->seeding) {
1528 seeding_dev = 1;
1529 down_write(&sb->s_umount);
1530 mutex_lock(&uuid_mutex);
1531 }
1532
1533 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1534 mutex_lock(&root->fs_info->volume_mutex);
1535
1536 devices = &root->fs_info->fs_devices->devices;
1537 /*
1538 * we have the volume lock, so we don't need the extra
1539 * device list mutex while reading the list here.
1540 */
1541 list_for_each_entry(device, devices, dev_list) {
1542 if (device->bdev == bdev) {
1543 ret = -EEXIST;
1544 goto error;
1545 }
1546 }
1547
1548 device = kzalloc(sizeof(*device), GFP_NOFS);
1549 if (!device) {
1550 /* we can safely leave the fs_devices entry around */
1551 ret = -ENOMEM;
1552 goto error;
1553 }
1554
1555 device->name = kstrdup(device_path, GFP_NOFS);
1556 if (!device->name) {
1557 kfree(device);
1558 ret = -ENOMEM;
1559 goto error;
1560 }
1561
1562 ret = find_next_devid(root, &device->devid);
1563 if (ret) {
1564 kfree(device->name);
1565 kfree(device);
1566 goto error;
1567 }
1568
1569 trans = btrfs_start_transaction(root, 0);
1570 if (IS_ERR(trans)) {
1571 kfree(device->name);
1572 kfree(device);
1573 ret = PTR_ERR(trans);
1574 goto error;
1575 }
1576
1577 lock_chunks(root);
1578
1579 device->writeable = 1;
1580 device->work.func = pending_bios_fn;
1581 generate_random_uuid(device->uuid);
1582 spin_lock_init(&device->io_lock);
1583 device->generation = trans->transid;
1584 device->io_width = root->sectorsize;
1585 device->io_align = root->sectorsize;
1586 device->sector_size = root->sectorsize;
1587 device->total_bytes = i_size_read(bdev->bd_inode);
1588 device->disk_total_bytes = device->total_bytes;
1589 device->dev_root = root->fs_info->dev_root;
1590 device->bdev = bdev;
1591 device->in_fs_metadata = 1;
1592 device->mode = 0;
1593 set_blocksize(device->bdev, 4096);
1594
1595 if (seeding_dev) {
1596 sb->s_flags &= ~MS_RDONLY;
1597 ret = btrfs_prepare_sprout(trans, root);
1598 BUG_ON(ret);
1599 }
1600
1601 device->fs_devices = root->fs_info->fs_devices;
1602
1603 /*
1604 * we don't want write_supers to jump in here with our device
1605 * half setup
1606 */
1607 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1608 list_add(&device->dev_list, &root->fs_info->fs_devices->devices);
1609 list_add(&device->dev_alloc_list,
1610 &root->fs_info->fs_devices->alloc_list);
1611 root->fs_info->fs_devices->num_devices++;
1612 root->fs_info->fs_devices->open_devices++;
1613 root->fs_info->fs_devices->rw_devices++;
1614 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
1615
1616 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
1617 root->fs_info->fs_devices->rotating = 1;
1618
1619 total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
1620 btrfs_set_super_total_bytes(&root->fs_info->super_copy,
1621 total_bytes + device->total_bytes);
1622
1623 total_bytes = btrfs_super_num_devices(&root->fs_info->super_copy);
1624 btrfs_set_super_num_devices(&root->fs_info->super_copy,
1625 total_bytes + 1);
1626 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1627
1628 if (seeding_dev) {
1629 ret = init_first_rw_device(trans, root, device);
1630 BUG_ON(ret);
1631 ret = btrfs_finish_sprout(trans, root);
1632 BUG_ON(ret);
1633 } else {
1634 ret = btrfs_add_device(trans, root, device);
1635 }
1636
1637 /*
1638 * we've got more storage, clear any full flags on the space
1639 * infos
1640 */
1641 btrfs_clear_space_info_full(root->fs_info);
1642
1643 unlock_chunks(root);
1644 btrfs_commit_transaction(trans, root);
1645
1646 if (seeding_dev) {
1647 mutex_unlock(&uuid_mutex);
1648 up_write(&sb->s_umount);
1649
1650 ret = btrfs_relocate_sys_chunks(root);
1651 BUG_ON(ret);
1652 }
1653 out:
1654 mutex_unlock(&root->fs_info->volume_mutex);
1655 return ret;
1656 error:
1657 blkdev_put(bdev, FMODE_EXCL);
1658 if (seeding_dev) {
1659 mutex_unlock(&uuid_mutex);
1660 up_write(&sb->s_umount);
1661 }
1662 goto out;
1663 }
1664
1665 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
1666 struct btrfs_device *device)
1667 {
1668 int ret;
1669 struct btrfs_path *path;
1670 struct btrfs_root *root;
1671 struct btrfs_dev_item *dev_item;
1672 struct extent_buffer *leaf;
1673 struct btrfs_key key;
1674
1675 root = device->dev_root->fs_info->chunk_root;
1676
1677 path = btrfs_alloc_path();
1678 if (!path)
1679 return -ENOMEM;
1680
1681 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1682 key.type = BTRFS_DEV_ITEM_KEY;
1683 key.offset = device->devid;
1684
1685 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1686 if (ret < 0)
1687 goto out;
1688
1689 if (ret > 0) {
1690 ret = -ENOENT;
1691 goto out;
1692 }
1693
1694 leaf = path->nodes[0];
1695 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1696
1697 btrfs_set_device_id(leaf, dev_item, device->devid);
1698 btrfs_set_device_type(leaf, dev_item, device->type);
1699 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1700 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1701 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1702 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
1703 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1704 btrfs_mark_buffer_dirty(leaf);
1705
1706 out:
1707 btrfs_free_path(path);
1708 return ret;
1709 }
1710
1711 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
1712 struct btrfs_device *device, u64 new_size)
1713 {
1714 struct btrfs_super_block *super_copy =
1715 &device->dev_root->fs_info->super_copy;
1716 u64 old_total = btrfs_super_total_bytes(super_copy);
1717 u64 diff = new_size - device->total_bytes;
1718
1719 if (!device->writeable)
1720 return -EACCES;
1721 if (new_size <= device->total_bytes)
1722 return -EINVAL;
1723
1724 btrfs_set_super_total_bytes(super_copy, old_total + diff);
1725 device->fs_devices->total_rw_bytes += diff;
1726
1727 device->total_bytes = new_size;
1728 device->disk_total_bytes = new_size;
1729 btrfs_clear_space_info_full(device->dev_root->fs_info);
1730
1731 return btrfs_update_device(trans, device);
1732 }
1733
1734 int btrfs_grow_device(struct btrfs_trans_handle *trans,
1735 struct btrfs_device *device, u64 new_size)
1736 {
1737 int ret;
1738 lock_chunks(device->dev_root);
1739 ret = __btrfs_grow_device(trans, device, new_size);
1740 unlock_chunks(device->dev_root);
1741 return ret;
1742 }
1743
1744 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
1745 struct btrfs_root *root,
1746 u64 chunk_tree, u64 chunk_objectid,
1747 u64 chunk_offset)
1748 {
1749 int ret;
1750 struct btrfs_path *path;
1751 struct btrfs_key key;
1752
1753 root = root->fs_info->chunk_root;
1754 path = btrfs_alloc_path();
1755 if (!path)
1756 return -ENOMEM;
1757
1758 key.objectid = chunk_objectid;
1759 key.offset = chunk_offset;
1760 key.type = BTRFS_CHUNK_ITEM_KEY;
1761
1762 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1763 BUG_ON(ret);
1764
1765 ret = btrfs_del_item(trans, root, path);
1766 BUG_ON(ret);
1767
1768 btrfs_free_path(path);
1769 return 0;
1770 }
1771
1772 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
1773 chunk_offset)
1774 {
1775 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
1776 struct btrfs_disk_key *disk_key;
1777 struct btrfs_chunk *chunk;
1778 u8 *ptr;
1779 int ret = 0;
1780 u32 num_stripes;
1781 u32 array_size;
1782 u32 len = 0;
1783 u32 cur;
1784 struct btrfs_key key;
1785
1786 array_size = btrfs_super_sys_array_size(super_copy);
1787
1788 ptr = super_copy->sys_chunk_array;
1789 cur = 0;
1790
1791 while (cur < array_size) {
1792 disk_key = (struct btrfs_disk_key *)ptr;
1793 btrfs_disk_key_to_cpu(&key, disk_key);
1794
1795 len = sizeof(*disk_key);
1796
1797 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
1798 chunk = (struct btrfs_chunk *)(ptr + len);
1799 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
1800 len += btrfs_chunk_item_size(num_stripes);
1801 } else {
1802 ret = -EIO;
1803 break;
1804 }
1805 if (key.objectid == chunk_objectid &&
1806 key.offset == chunk_offset) {
1807 memmove(ptr, ptr + len, array_size - (cur + len));
1808 array_size -= len;
1809 btrfs_set_super_sys_array_size(super_copy, array_size);
1810 } else {
1811 ptr += len;
1812 cur += len;
1813 }
1814 }
1815 return ret;
1816 }
1817
1818 static int btrfs_relocate_chunk(struct btrfs_root *root,
1819 u64 chunk_tree, u64 chunk_objectid,
1820 u64 chunk_offset)
1821 {
1822 struct extent_map_tree *em_tree;
1823 struct btrfs_root *extent_root;
1824 struct btrfs_trans_handle *trans;
1825 struct extent_map *em;
1826 struct map_lookup *map;
1827 int ret;
1828 int i;
1829
1830 root = root->fs_info->chunk_root;
1831 extent_root = root->fs_info->extent_root;
1832 em_tree = &root->fs_info->mapping_tree.map_tree;
1833
1834 ret = btrfs_can_relocate(extent_root, chunk_offset);
1835 if (ret)
1836 return -ENOSPC;
1837
1838 /* step one, relocate all the extents inside this chunk */
1839 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
1840 if (ret)
1841 return ret;
1842
1843 trans = btrfs_start_transaction(root, 0);
1844 BUG_ON(IS_ERR(trans));
1845
1846 lock_chunks(root);
1847
1848 /*
1849 * step two, delete the device extents and the
1850 * chunk tree entries
1851 */
1852 read_lock(&em_tree->lock);
1853 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
1854 read_unlock(&em_tree->lock);
1855
1856 BUG_ON(em->start > chunk_offset ||
1857 em->start + em->len < chunk_offset);
1858 map = (struct map_lookup *)em->bdev;
1859
1860 for (i = 0; i < map->num_stripes; i++) {
1861 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
1862 map->stripes[i].physical);
1863 BUG_ON(ret);
1864
1865 if (map->stripes[i].dev) {
1866 ret = btrfs_update_device(trans, map->stripes[i].dev);
1867 BUG_ON(ret);
1868 }
1869 }
1870 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
1871 chunk_offset);
1872
1873 BUG_ON(ret);
1874
1875 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
1876 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
1877 BUG_ON(ret);
1878 }
1879
1880 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
1881 BUG_ON(ret);
1882
1883 write_lock(&em_tree->lock);
1884 remove_extent_mapping(em_tree, em);
1885 write_unlock(&em_tree->lock);
1886
1887 kfree(map);
1888 em->bdev = NULL;
1889
1890 /* once for the tree */
1891 free_extent_map(em);
1892 /* once for us */
1893 free_extent_map(em);
1894
1895 unlock_chunks(root);
1896 btrfs_end_transaction(trans, root);
1897 return 0;
1898 }
1899
1900 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
1901 {
1902 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
1903 struct btrfs_path *path;
1904 struct extent_buffer *leaf;
1905 struct btrfs_chunk *chunk;
1906 struct btrfs_key key;
1907 struct btrfs_key found_key;
1908 u64 chunk_tree = chunk_root->root_key.objectid;
1909 u64 chunk_type;
1910 bool retried = false;
1911 int failed = 0;
1912 int ret;
1913
1914 path = btrfs_alloc_path();
1915 if (!path)
1916 return -ENOMEM;
1917
1918 again:
1919 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
1920 key.offset = (u64)-1;
1921 key.type = BTRFS_CHUNK_ITEM_KEY;
1922
1923 while (1) {
1924 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
1925 if (ret < 0)
1926 goto error;
1927 BUG_ON(ret == 0);
1928
1929 ret = btrfs_previous_item(chunk_root, path, key.objectid,
1930 key.type);
1931 if (ret < 0)
1932 goto error;
1933 if (ret > 0)
1934 break;
1935
1936 leaf = path->nodes[0];
1937 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1938
1939 chunk = btrfs_item_ptr(leaf, path->slots[0],
1940 struct btrfs_chunk);
1941 chunk_type = btrfs_chunk_type(leaf, chunk);
1942 btrfs_release_path(chunk_root, path);
1943
1944 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
1945 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
1946 found_key.objectid,
1947 found_key.offset);
1948 if (ret == -ENOSPC)
1949 failed++;
1950 else if (ret)
1951 BUG();
1952 }
1953
1954 if (found_key.offset == 0)
1955 break;
1956 key.offset = found_key.offset - 1;
1957 }
1958 ret = 0;
1959 if (failed && !retried) {
1960 failed = 0;
1961 retried = true;
1962 goto again;
1963 } else if (failed && retried) {
1964 WARN_ON(1);
1965 ret = -ENOSPC;
1966 }
1967 error:
1968 btrfs_free_path(path);
1969 return ret;
1970 }
1971
1972 static u64 div_factor(u64 num, int factor)
1973 {
1974 if (factor == 10)
1975 return num;
1976 num *= factor;
1977 do_div(num, 10);
1978 return num;
1979 }
1980
1981 int btrfs_balance(struct btrfs_root *dev_root)
1982 {
1983 int ret;
1984 struct list_head *devices = &dev_root->fs_info->fs_devices->devices;
1985 struct btrfs_device *device;
1986 u64 old_size;
1987 u64 size_to_free;
1988 struct btrfs_path *path;
1989 struct btrfs_key key;
1990 struct btrfs_root *chunk_root = dev_root->fs_info->chunk_root;
1991 struct btrfs_trans_handle *trans;
1992 struct btrfs_key found_key;
1993
1994 if (dev_root->fs_info->sb->s_flags & MS_RDONLY)
1995 return -EROFS;
1996
1997 if (!capable(CAP_SYS_ADMIN))
1998 return -EPERM;
1999
2000 mutex_lock(&dev_root->fs_info->volume_mutex);
2001 dev_root = dev_root->fs_info->dev_root;
2002
2003 /* step one make some room on all the devices */
2004 list_for_each_entry(device, devices, dev_list) {
2005 old_size = device->total_bytes;
2006 size_to_free = div_factor(old_size, 1);
2007 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
2008 if (!device->writeable ||
2009 device->total_bytes - device->bytes_used > size_to_free)
2010 continue;
2011
2012 ret = btrfs_shrink_device(device, old_size - size_to_free);
2013 if (ret == -ENOSPC)
2014 break;
2015 BUG_ON(ret);
2016
2017 trans = btrfs_start_transaction(dev_root, 0);
2018 BUG_ON(IS_ERR(trans));
2019
2020 ret = btrfs_grow_device(trans, device, old_size);
2021 BUG_ON(ret);
2022
2023 btrfs_end_transaction(trans, dev_root);
2024 }
2025
2026 /* step two, relocate all the chunks */
2027 path = btrfs_alloc_path();
2028 BUG_ON(!path);
2029
2030 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2031 key.offset = (u64)-1;
2032 key.type = BTRFS_CHUNK_ITEM_KEY;
2033
2034 while (1) {
2035 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2036 if (ret < 0)
2037 goto error;
2038
2039 /*
2040 * this shouldn't happen, it means the last relocate
2041 * failed
2042 */
2043 if (ret == 0)
2044 break;
2045
2046 ret = btrfs_previous_item(chunk_root, path, 0,
2047 BTRFS_CHUNK_ITEM_KEY);
2048 if (ret)
2049 break;
2050
2051 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2052 path->slots[0]);
2053 if (found_key.objectid != key.objectid)
2054 break;
2055
2056 /* chunk zero is special */
2057 if (found_key.offset == 0)
2058 break;
2059
2060 btrfs_release_path(chunk_root, path);
2061 ret = btrfs_relocate_chunk(chunk_root,
2062 chunk_root->root_key.objectid,
2063 found_key.objectid,
2064 found_key.offset);
2065 BUG_ON(ret && ret != -ENOSPC);
2066 key.offset = found_key.offset - 1;
2067 }
2068 ret = 0;
2069 error:
2070 btrfs_free_path(path);
2071 mutex_unlock(&dev_root->fs_info->volume_mutex);
2072 return ret;
2073 }
2074
2075 /*
2076 * shrinking a device means finding all of the device extents past
2077 * the new size, and then following the back refs to the chunks.
2078 * The chunk relocation code actually frees the device extent
2079 */
2080 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
2081 {
2082 struct btrfs_trans_handle *trans;
2083 struct btrfs_root *root = device->dev_root;
2084 struct btrfs_dev_extent *dev_extent = NULL;
2085 struct btrfs_path *path;
2086 u64 length;
2087 u64 chunk_tree;
2088 u64 chunk_objectid;
2089 u64 chunk_offset;
2090 int ret;
2091 int slot;
2092 int failed = 0;
2093 bool retried = false;
2094 struct extent_buffer *l;
2095 struct btrfs_key key;
2096 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
2097 u64 old_total = btrfs_super_total_bytes(super_copy);
2098 u64 old_size = device->total_bytes;
2099 u64 diff = device->total_bytes - new_size;
2100
2101 if (new_size >= device->total_bytes)
2102 return -EINVAL;
2103
2104 path = btrfs_alloc_path();
2105 if (!path)
2106 return -ENOMEM;
2107
2108 path->reada = 2;
2109
2110 lock_chunks(root);
2111
2112 device->total_bytes = new_size;
2113 if (device->writeable)
2114 device->fs_devices->total_rw_bytes -= diff;
2115 unlock_chunks(root);
2116
2117 again:
2118 key.objectid = device->devid;
2119 key.offset = (u64)-1;
2120 key.type = BTRFS_DEV_EXTENT_KEY;
2121
2122 while (1) {
2123 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2124 if (ret < 0)
2125 goto done;
2126
2127 ret = btrfs_previous_item(root, path, 0, key.type);
2128 if (ret < 0)
2129 goto done;
2130 if (ret) {
2131 ret = 0;
2132 btrfs_release_path(root, path);
2133 break;
2134 }
2135
2136 l = path->nodes[0];
2137 slot = path->slots[0];
2138 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
2139
2140 if (key.objectid != device->devid) {
2141 btrfs_release_path(root, path);
2142 break;
2143 }
2144
2145 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
2146 length = btrfs_dev_extent_length(l, dev_extent);
2147
2148 if (key.offset + length <= new_size) {
2149 btrfs_release_path(root, path);
2150 break;
2151 }
2152
2153 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
2154 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
2155 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
2156 btrfs_release_path(root, path);
2157
2158 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
2159 chunk_offset);
2160 if (ret && ret != -ENOSPC)
2161 goto done;
2162 if (ret == -ENOSPC)
2163 failed++;
2164 key.offset -= 1;
2165 }
2166
2167 if (failed && !retried) {
2168 failed = 0;
2169 retried = true;
2170 goto again;
2171 } else if (failed && retried) {
2172 ret = -ENOSPC;
2173 lock_chunks(root);
2174
2175 device->total_bytes = old_size;
2176 if (device->writeable)
2177 device->fs_devices->total_rw_bytes += diff;
2178 unlock_chunks(root);
2179 goto done;
2180 }
2181
2182 /* Shrinking succeeded, else we would be at "done". */
2183 trans = btrfs_start_transaction(root, 0);
2184 if (IS_ERR(trans)) {
2185 ret = PTR_ERR(trans);
2186 goto done;
2187 }
2188
2189 lock_chunks(root);
2190
2191 device->disk_total_bytes = new_size;
2192 /* Now btrfs_update_device() will change the on-disk size. */
2193 ret = btrfs_update_device(trans, device);
2194 if (ret) {
2195 unlock_chunks(root);
2196 btrfs_end_transaction(trans, root);
2197 goto done;
2198 }
2199 WARN_ON(diff > old_total);
2200 btrfs_set_super_total_bytes(super_copy, old_total - diff);
2201 unlock_chunks(root);
2202 btrfs_end_transaction(trans, root);
2203 done:
2204 btrfs_free_path(path);
2205 return ret;
2206 }
2207
2208 static int btrfs_add_system_chunk(struct btrfs_trans_handle *trans,
2209 struct btrfs_root *root,
2210 struct btrfs_key *key,
2211 struct btrfs_chunk *chunk, int item_size)
2212 {
2213 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
2214 struct btrfs_disk_key disk_key;
2215 u32 array_size;
2216 u8 *ptr;
2217
2218 array_size = btrfs_super_sys_array_size(super_copy);
2219 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
2220 return -EFBIG;
2221
2222 ptr = super_copy->sys_chunk_array + array_size;
2223 btrfs_cpu_key_to_disk(&disk_key, key);
2224 memcpy(ptr, &disk_key, sizeof(disk_key));
2225 ptr += sizeof(disk_key);
2226 memcpy(ptr, chunk, item_size);
2227 item_size += sizeof(disk_key);
2228 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
2229 return 0;
2230 }
2231
2232 static noinline u64 chunk_bytes_by_type(u64 type, u64 calc_size,
2233 int num_stripes, int sub_stripes)
2234 {
2235 if (type & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_DUP))
2236 return calc_size;
2237 else if (type & BTRFS_BLOCK_GROUP_RAID10)
2238 return calc_size * (num_stripes / sub_stripes);
2239 else
2240 return calc_size * num_stripes;
2241 }
2242
2243 /* Used to sort the devices by max_avail(descending sort) */
2244 int btrfs_cmp_device_free_bytes(const void *dev_info1, const void *dev_info2)
2245 {
2246 if (((struct btrfs_device_info *)dev_info1)->max_avail >
2247 ((struct btrfs_device_info *)dev_info2)->max_avail)
2248 return -1;
2249 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
2250 ((struct btrfs_device_info *)dev_info2)->max_avail)
2251 return 1;
2252 else
2253 return 0;
2254 }
2255
2256 static int __btrfs_calc_nstripes(struct btrfs_fs_devices *fs_devices, u64 type,
2257 int *num_stripes, int *min_stripes,
2258 int *sub_stripes)
2259 {
2260 *num_stripes = 1;
2261 *min_stripes = 1;
2262 *sub_stripes = 0;
2263
2264 if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
2265 *num_stripes = fs_devices->rw_devices;
2266 *min_stripes = 2;
2267 }
2268 if (type & (BTRFS_BLOCK_GROUP_DUP)) {
2269 *num_stripes = 2;
2270 *min_stripes = 2;
2271 }
2272 if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
2273 if (fs_devices->rw_devices < 2)
2274 return -ENOSPC;
2275 *num_stripes = 2;
2276 *min_stripes = 2;
2277 }
2278 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
2279 *num_stripes = fs_devices->rw_devices;
2280 if (*num_stripes < 4)
2281 return -ENOSPC;
2282 *num_stripes &= ~(u32)1;
2283 *sub_stripes = 2;
2284 *min_stripes = 4;
2285 }
2286
2287 return 0;
2288 }
2289
2290 static u64 __btrfs_calc_stripe_size(struct btrfs_fs_devices *fs_devices,
2291 u64 proposed_size, u64 type,
2292 int num_stripes, int small_stripe)
2293 {
2294 int min_stripe_size = 1 * 1024 * 1024;
2295 u64 calc_size = proposed_size;
2296 u64 max_chunk_size = calc_size;
2297 int ncopies = 1;
2298
2299 if (type & (BTRFS_BLOCK_GROUP_RAID1 |
2300 BTRFS_BLOCK_GROUP_DUP |
2301 BTRFS_BLOCK_GROUP_RAID10))
2302 ncopies = 2;
2303
2304 if (type & BTRFS_BLOCK_GROUP_DATA) {
2305 max_chunk_size = 10 * calc_size;
2306 min_stripe_size = 64 * 1024 * 1024;
2307 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
2308 max_chunk_size = 256 * 1024 * 1024;
2309 min_stripe_size = 32 * 1024 * 1024;
2310 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
2311 calc_size = 8 * 1024 * 1024;
2312 max_chunk_size = calc_size * 2;
2313 min_stripe_size = 1 * 1024 * 1024;
2314 }
2315
2316 /* we don't want a chunk larger than 10% of writeable space */
2317 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
2318 max_chunk_size);
2319
2320 if (calc_size * num_stripes > max_chunk_size * ncopies) {
2321 calc_size = max_chunk_size * ncopies;
2322 do_div(calc_size, num_stripes);
2323 do_div(calc_size, BTRFS_STRIPE_LEN);
2324 calc_size *= BTRFS_STRIPE_LEN;
2325 }
2326
2327 /* we don't want tiny stripes */
2328 if (!small_stripe)
2329 calc_size = max_t(u64, min_stripe_size, calc_size);
2330
2331 /*
2332 * we're about to do_div by the BTRFS_STRIPE_LEN so lets make sure
2333 * we end up with something bigger than a stripe
2334 */
2335 calc_size = max_t(u64, calc_size, BTRFS_STRIPE_LEN);
2336
2337 do_div(calc_size, BTRFS_STRIPE_LEN);
2338 calc_size *= BTRFS_STRIPE_LEN;
2339
2340 return calc_size;
2341 }
2342
2343 static struct map_lookup *__shrink_map_lookup_stripes(struct map_lookup *map,
2344 int num_stripes)
2345 {
2346 struct map_lookup *new;
2347 size_t len = map_lookup_size(num_stripes);
2348
2349 BUG_ON(map->num_stripes < num_stripes);
2350
2351 if (map->num_stripes == num_stripes)
2352 return map;
2353
2354 new = kmalloc(len, GFP_NOFS);
2355 if (!new) {
2356 /* just change map->num_stripes */
2357 map->num_stripes = num_stripes;
2358 return map;
2359 }
2360
2361 memcpy(new, map, len);
2362 new->num_stripes = num_stripes;
2363 kfree(map);
2364 return new;
2365 }
2366
2367 /*
2368 * helper to allocate device space from btrfs_device_info, in which we stored
2369 * max free space information of every device. It is used when we can not
2370 * allocate chunks by default size.
2371 *
2372 * By this helper, we can allocate a new chunk as larger as possible.
2373 */
2374 static int __btrfs_alloc_tiny_space(struct btrfs_trans_handle *trans,
2375 struct btrfs_fs_devices *fs_devices,
2376 struct btrfs_device_info *devices,
2377 int nr_device, u64 type,
2378 struct map_lookup **map_lookup,
2379 int min_stripes, u64 *stripe_size)
2380 {
2381 int i, index, sort_again = 0;
2382 int min_devices = min_stripes;
2383 u64 max_avail, min_free;
2384 struct map_lookup *map = *map_lookup;
2385 int ret;
2386
2387 if (nr_device < min_stripes)
2388 return -ENOSPC;
2389
2390 btrfs_descending_sort_devices(devices, nr_device);
2391
2392 max_avail = devices[0].max_avail;
2393 if (!max_avail)
2394 return -ENOSPC;
2395
2396 for (i = 0; i < nr_device; i++) {
2397 /*
2398 * if dev_offset = 0, it means the free space of this device
2399 * is less than what we need, and we didn't search max avail
2400 * extent on this device, so do it now.
2401 */
2402 if (!devices[i].dev_offset) {
2403 ret = find_free_dev_extent(trans, devices[i].dev,
2404 max_avail,
2405 &devices[i].dev_offset,
2406 &devices[i].max_avail);
2407 if (ret != 0 && ret != -ENOSPC)
2408 return ret;
2409 sort_again = 1;
2410 }
2411 }
2412
2413 /* we update the max avail free extent of each devices, sort again */
2414 if (sort_again)
2415 btrfs_descending_sort_devices(devices, nr_device);
2416
2417 if (type & BTRFS_BLOCK_GROUP_DUP)
2418 min_devices = 1;
2419
2420 if (!devices[min_devices - 1].max_avail)
2421 return -ENOSPC;
2422
2423 max_avail = devices[min_devices - 1].max_avail;
2424 if (type & BTRFS_BLOCK_GROUP_DUP)
2425 do_div(max_avail, 2);
2426
2427 max_avail = __btrfs_calc_stripe_size(fs_devices, max_avail, type,
2428 min_stripes, 1);
2429 if (type & BTRFS_BLOCK_GROUP_DUP)
2430 min_free = max_avail * 2;
2431 else
2432 min_free = max_avail;
2433
2434 if (min_free > devices[min_devices - 1].max_avail)
2435 return -ENOSPC;
2436
2437 map = __shrink_map_lookup_stripes(map, min_stripes);
2438 *stripe_size = max_avail;
2439
2440 index = 0;
2441 for (i = 0; i < min_stripes; i++) {
2442 map->stripes[i].dev = devices[index].dev;
2443 map->stripes[i].physical = devices[index].dev_offset;
2444 if (type & BTRFS_BLOCK_GROUP_DUP) {
2445 i++;
2446 map->stripes[i].dev = devices[index].dev;
2447 map->stripes[i].physical = devices[index].dev_offset +
2448 max_avail;
2449 }
2450 index++;
2451 }
2452 *map_lookup = map;
2453
2454 return 0;
2455 }
2456
2457 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
2458 struct btrfs_root *extent_root,
2459 struct map_lookup **map_ret,
2460 u64 *num_bytes, u64 *stripe_size,
2461 u64 start, u64 type)
2462 {
2463 struct btrfs_fs_info *info = extent_root->fs_info;
2464 struct btrfs_device *device = NULL;
2465 struct btrfs_fs_devices *fs_devices = info->fs_devices;
2466 struct list_head *cur;
2467 struct map_lookup *map;
2468 struct extent_map_tree *em_tree;
2469 struct extent_map *em;
2470 struct btrfs_device_info *devices_info;
2471 struct list_head private_devs;
2472 u64 calc_size = 1024 * 1024 * 1024;
2473 u64 min_free;
2474 u64 avail;
2475 u64 dev_offset;
2476 int num_stripes;
2477 int min_stripes;
2478 int sub_stripes;
2479 int min_devices; /* the min number of devices we need */
2480 int i;
2481 int ret;
2482 int index;
2483
2484 if ((type & BTRFS_BLOCK_GROUP_RAID1) &&
2485 (type & BTRFS_BLOCK_GROUP_DUP)) {
2486 WARN_ON(1);
2487 type &= ~BTRFS_BLOCK_GROUP_DUP;
2488 }
2489 if (list_empty(&fs_devices->alloc_list))
2490 return -ENOSPC;
2491
2492 ret = __btrfs_calc_nstripes(fs_devices, type, &num_stripes,
2493 &min_stripes, &sub_stripes);
2494 if (ret)
2495 return ret;
2496
2497 devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices,
2498 GFP_NOFS);
2499 if (!devices_info)
2500 return -ENOMEM;
2501
2502 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
2503 if (!map) {
2504 ret = -ENOMEM;
2505 goto error;
2506 }
2507 map->num_stripes = num_stripes;
2508
2509 cur = fs_devices->alloc_list.next;
2510 index = 0;
2511 i = 0;
2512
2513 calc_size = __btrfs_calc_stripe_size(fs_devices, calc_size, type,
2514 num_stripes, 0);
2515
2516 if (type & BTRFS_BLOCK_GROUP_DUP) {
2517 min_free = calc_size * 2;
2518 min_devices = 1;
2519 } else {
2520 min_free = calc_size;
2521 min_devices = min_stripes;
2522 }
2523
2524 INIT_LIST_HEAD(&private_devs);
2525 while (index < num_stripes) {
2526 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
2527 BUG_ON(!device->writeable);
2528 if (device->total_bytes > device->bytes_used)
2529 avail = device->total_bytes - device->bytes_used;
2530 else
2531 avail = 0;
2532 cur = cur->next;
2533
2534 if (device->in_fs_metadata && avail >= min_free) {
2535 ret = find_free_dev_extent(trans, device, min_free,
2536 &devices_info[i].dev_offset,
2537 &devices_info[i].max_avail);
2538 if (ret == 0) {
2539 list_move_tail(&device->dev_alloc_list,
2540 &private_devs);
2541 map->stripes[index].dev = device;
2542 map->stripes[index].physical =
2543 devices_info[i].dev_offset;
2544 index++;
2545 if (type & BTRFS_BLOCK_GROUP_DUP) {
2546 map->stripes[index].dev = device;
2547 map->stripes[index].physical =
2548 devices_info[i].dev_offset +
2549 calc_size;
2550 index++;
2551 }
2552 } else if (ret != -ENOSPC)
2553 goto error;
2554
2555 devices_info[i].dev = device;
2556 i++;
2557 } else if (device->in_fs_metadata &&
2558 avail >= BTRFS_STRIPE_LEN) {
2559 devices_info[i].dev = device;
2560 devices_info[i].max_avail = avail;
2561 i++;
2562 }
2563
2564 if (cur == &fs_devices->alloc_list)
2565 break;
2566 }
2567
2568 list_splice(&private_devs, &fs_devices->alloc_list);
2569 if (index < num_stripes) {
2570 if (index >= min_stripes) {
2571 num_stripes = index;
2572 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
2573 num_stripes /= sub_stripes;
2574 num_stripes *= sub_stripes;
2575 }
2576
2577 map = __shrink_map_lookup_stripes(map, num_stripes);
2578 } else if (i >= min_devices) {
2579 ret = __btrfs_alloc_tiny_space(trans, fs_devices,
2580 devices_info, i, type,
2581 &map, min_stripes,
2582 &calc_size);
2583 if (ret)
2584 goto error;
2585 } else {
2586 ret = -ENOSPC;
2587 goto error;
2588 }
2589 }
2590 map->sector_size = extent_root->sectorsize;
2591 map->stripe_len = BTRFS_STRIPE_LEN;
2592 map->io_align = BTRFS_STRIPE_LEN;
2593 map->io_width = BTRFS_STRIPE_LEN;
2594 map->type = type;
2595 map->sub_stripes = sub_stripes;
2596
2597 *map_ret = map;
2598 *stripe_size = calc_size;
2599 *num_bytes = chunk_bytes_by_type(type, calc_size,
2600 map->num_stripes, sub_stripes);
2601
2602 em = alloc_extent_map(GFP_NOFS);
2603 if (!em) {
2604 ret = -ENOMEM;
2605 goto error;
2606 }
2607 em->bdev = (struct block_device *)map;
2608 em->start = start;
2609 em->len = *num_bytes;
2610 em->block_start = 0;
2611 em->block_len = em->len;
2612
2613 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
2614 write_lock(&em_tree->lock);
2615 ret = add_extent_mapping(em_tree, em);
2616 write_unlock(&em_tree->lock);
2617 BUG_ON(ret);
2618 free_extent_map(em);
2619
2620 ret = btrfs_make_block_group(trans, extent_root, 0, type,
2621 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2622 start, *num_bytes);
2623 BUG_ON(ret);
2624
2625 index = 0;
2626 while (index < map->num_stripes) {
2627 device = map->stripes[index].dev;
2628 dev_offset = map->stripes[index].physical;
2629
2630 ret = btrfs_alloc_dev_extent(trans, device,
2631 info->chunk_root->root_key.objectid,
2632 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2633 start, dev_offset, calc_size);
2634 BUG_ON(ret);
2635 index++;
2636 }
2637
2638 kfree(devices_info);
2639 return 0;
2640
2641 error:
2642 kfree(map);
2643 kfree(devices_info);
2644 return ret;
2645 }
2646
2647 static int __finish_chunk_alloc(struct btrfs_trans_handle *trans,
2648 struct btrfs_root *extent_root,
2649 struct map_lookup *map, u64 chunk_offset,
2650 u64 chunk_size, u64 stripe_size)
2651 {
2652 u64 dev_offset;
2653 struct btrfs_key key;
2654 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
2655 struct btrfs_device *device;
2656 struct btrfs_chunk *chunk;
2657 struct btrfs_stripe *stripe;
2658 size_t item_size = btrfs_chunk_item_size(map->num_stripes);
2659 int index = 0;
2660 int ret;
2661
2662 chunk = kzalloc(item_size, GFP_NOFS);
2663 if (!chunk)
2664 return -ENOMEM;
2665
2666 index = 0;
2667 while (index < map->num_stripes) {
2668 device = map->stripes[index].dev;
2669 device->bytes_used += stripe_size;
2670 ret = btrfs_update_device(trans, device);
2671 BUG_ON(ret);
2672 index++;
2673 }
2674
2675 index = 0;
2676 stripe = &chunk->stripe;
2677 while (index < map->num_stripes) {
2678 device = map->stripes[index].dev;
2679 dev_offset = map->stripes[index].physical;
2680
2681 btrfs_set_stack_stripe_devid(stripe, device->devid);
2682 btrfs_set_stack_stripe_offset(stripe, dev_offset);
2683 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
2684 stripe++;
2685 index++;
2686 }
2687
2688 btrfs_set_stack_chunk_length(chunk, chunk_size);
2689 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
2690 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
2691 btrfs_set_stack_chunk_type(chunk, map->type);
2692 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
2693 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
2694 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
2695 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
2696 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
2697
2698 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2699 key.type = BTRFS_CHUNK_ITEM_KEY;
2700 key.offset = chunk_offset;
2701
2702 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
2703 BUG_ON(ret);
2704
2705 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2706 ret = btrfs_add_system_chunk(trans, chunk_root, &key, chunk,
2707 item_size);
2708 BUG_ON(ret);
2709 }
2710 kfree(chunk);
2711 return 0;
2712 }
2713
2714 /*
2715 * Chunk allocation falls into two parts. The first part does works
2716 * that make the new allocated chunk useable, but not do any operation
2717 * that modifies the chunk tree. The second part does the works that
2718 * require modifying the chunk tree. This division is important for the
2719 * bootstrap process of adding storage to a seed btrfs.
2720 */
2721 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
2722 struct btrfs_root *extent_root, u64 type)
2723 {
2724 u64 chunk_offset;
2725 u64 chunk_size;
2726 u64 stripe_size;
2727 struct map_lookup *map;
2728 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
2729 int ret;
2730
2731 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2732 &chunk_offset);
2733 if (ret)
2734 return ret;
2735
2736 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
2737 &stripe_size, chunk_offset, type);
2738 if (ret)
2739 return ret;
2740
2741 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
2742 chunk_size, stripe_size);
2743 BUG_ON(ret);
2744 return 0;
2745 }
2746
2747 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
2748 struct btrfs_root *root,
2749 struct btrfs_device *device)
2750 {
2751 u64 chunk_offset;
2752 u64 sys_chunk_offset;
2753 u64 chunk_size;
2754 u64 sys_chunk_size;
2755 u64 stripe_size;
2756 u64 sys_stripe_size;
2757 u64 alloc_profile;
2758 struct map_lookup *map;
2759 struct map_lookup *sys_map;
2760 struct btrfs_fs_info *fs_info = root->fs_info;
2761 struct btrfs_root *extent_root = fs_info->extent_root;
2762 int ret;
2763
2764 ret = find_next_chunk(fs_info->chunk_root,
2765 BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset);
2766 BUG_ON(ret);
2767
2768 alloc_profile = BTRFS_BLOCK_GROUP_METADATA |
2769 (fs_info->metadata_alloc_profile &
2770 fs_info->avail_metadata_alloc_bits);
2771 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
2772
2773 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
2774 &stripe_size, chunk_offset, alloc_profile);
2775 BUG_ON(ret);
2776
2777 sys_chunk_offset = chunk_offset + chunk_size;
2778
2779 alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM |
2780 (fs_info->system_alloc_profile &
2781 fs_info->avail_system_alloc_bits);
2782 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
2783
2784 ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,
2785 &sys_chunk_size, &sys_stripe_size,
2786 sys_chunk_offset, alloc_profile);
2787 BUG_ON(ret);
2788
2789 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
2790 BUG_ON(ret);
2791
2792 /*
2793 * Modifying chunk tree needs allocating new blocks from both
2794 * system block group and metadata block group. So we only can
2795 * do operations require modifying the chunk tree after both
2796 * block groups were created.
2797 */
2798 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
2799 chunk_size, stripe_size);
2800 BUG_ON(ret);
2801
2802 ret = __finish_chunk_alloc(trans, extent_root, sys_map,
2803 sys_chunk_offset, sys_chunk_size,
2804 sys_stripe_size);
2805 BUG_ON(ret);
2806 return 0;
2807 }
2808
2809 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
2810 {
2811 struct extent_map *em;
2812 struct map_lookup *map;
2813 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
2814 int readonly = 0;
2815 int i;
2816
2817 read_lock(&map_tree->map_tree.lock);
2818 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
2819 read_unlock(&map_tree->map_tree.lock);
2820 if (!em)
2821 return 1;
2822
2823 if (btrfs_test_opt(root, DEGRADED)) {
2824 free_extent_map(em);
2825 return 0;
2826 }
2827
2828 map = (struct map_lookup *)em->bdev;
2829 for (i = 0; i < map->num_stripes; i++) {
2830 if (!map->stripes[i].dev->writeable) {
2831 readonly = 1;
2832 break;
2833 }
2834 }
2835 free_extent_map(em);
2836 return readonly;
2837 }
2838
2839 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
2840 {
2841 extent_map_tree_init(&tree->map_tree, GFP_NOFS);
2842 }
2843
2844 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
2845 {
2846 struct extent_map *em;
2847
2848 while (1) {
2849 write_lock(&tree->map_tree.lock);
2850 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
2851 if (em)
2852 remove_extent_mapping(&tree->map_tree, em);
2853 write_unlock(&tree->map_tree.lock);
2854 if (!em)
2855 break;
2856 kfree(em->bdev);
2857 /* once for us */
2858 free_extent_map(em);
2859 /* once for the tree */
2860 free_extent_map(em);
2861 }
2862 }
2863
2864 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
2865 {
2866 struct extent_map *em;
2867 struct map_lookup *map;
2868 struct extent_map_tree *em_tree = &map_tree->map_tree;
2869 int ret;
2870
2871 read_lock(&em_tree->lock);
2872 em = lookup_extent_mapping(em_tree, logical, len);
2873 read_unlock(&em_tree->lock);
2874 BUG_ON(!em);
2875
2876 BUG_ON(em->start > logical || em->start + em->len < logical);
2877 map = (struct map_lookup *)em->bdev;
2878 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
2879 ret = map->num_stripes;
2880 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
2881 ret = map->sub_stripes;
2882 else
2883 ret = 1;
2884 free_extent_map(em);
2885 return ret;
2886 }
2887
2888 static int find_live_mirror(struct map_lookup *map, int first, int num,
2889 int optimal)
2890 {
2891 int i;
2892 if (map->stripes[optimal].dev->bdev)
2893 return optimal;
2894 for (i = first; i < first + num; i++) {
2895 if (map->stripes[i].dev->bdev)
2896 return i;
2897 }
2898 /* we couldn't find one that doesn't fail. Just return something
2899 * and the io error handling code will clean up eventually
2900 */
2901 return optimal;
2902 }
2903
2904 static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
2905 u64 logical, u64 *length,
2906 struct btrfs_multi_bio **multi_ret,
2907 int mirror_num)
2908 {
2909 struct extent_map *em;
2910 struct map_lookup *map;
2911 struct extent_map_tree *em_tree = &map_tree->map_tree;
2912 u64 offset;
2913 u64 stripe_offset;
2914 u64 stripe_nr;
2915 int stripes_allocated = 8;
2916 int stripes_required = 1;
2917 int stripe_index;
2918 int i;
2919 int num_stripes;
2920 int max_errors = 0;
2921 struct btrfs_multi_bio *multi = NULL;
2922
2923 if (multi_ret && !(rw & REQ_WRITE))
2924 stripes_allocated = 1;
2925 again:
2926 if (multi_ret) {
2927 multi = kzalloc(btrfs_multi_bio_size(stripes_allocated),
2928 GFP_NOFS);
2929 if (!multi)
2930 return -ENOMEM;
2931
2932 atomic_set(&multi->error, 0);
2933 }
2934
2935 read_lock(&em_tree->lock);
2936 em = lookup_extent_mapping(em_tree, logical, *length);
2937 read_unlock(&em_tree->lock);
2938
2939 if (!em) {
2940 printk(KERN_CRIT "unable to find logical %llu len %llu\n",
2941 (unsigned long long)logical,
2942 (unsigned long long)*length);
2943 BUG();
2944 }
2945
2946 BUG_ON(em->start > logical || em->start + em->len < logical);
2947 map = (struct map_lookup *)em->bdev;
2948 offset = logical - em->start;
2949
2950 if (mirror_num > map->num_stripes)
2951 mirror_num = 0;
2952
2953 /* if our multi bio struct is too small, back off and try again */
2954 if (rw & REQ_WRITE) {
2955 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
2956 BTRFS_BLOCK_GROUP_DUP)) {
2957 stripes_required = map->num_stripes;
2958 max_errors = 1;
2959 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2960 stripes_required = map->sub_stripes;
2961 max_errors = 1;
2962 }
2963 }
2964 if (multi_ret && (rw & REQ_WRITE) &&
2965 stripes_allocated < stripes_required) {
2966 stripes_allocated = map->num_stripes;
2967 free_extent_map(em);
2968 kfree(multi);
2969 goto again;
2970 }
2971 stripe_nr = offset;
2972 /*
2973 * stripe_nr counts the total number of stripes we have to stride
2974 * to get to this block
2975 */
2976 do_div(stripe_nr, map->stripe_len);
2977
2978 stripe_offset = stripe_nr * map->stripe_len;
2979 BUG_ON(offset < stripe_offset);
2980
2981 /* stripe_offset is the offset of this block in its stripe*/
2982 stripe_offset = offset - stripe_offset;
2983
2984 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
2985 BTRFS_BLOCK_GROUP_RAID10 |
2986 BTRFS_BLOCK_GROUP_DUP)) {
2987 /* we limit the length of each bio to what fits in a stripe */
2988 *length = min_t(u64, em->len - offset,
2989 map->stripe_len - stripe_offset);
2990 } else {
2991 *length = em->len - offset;
2992 }
2993
2994 if (!multi_ret)
2995 goto out;
2996
2997 num_stripes = 1;
2998 stripe_index = 0;
2999 if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
3000 if (rw & REQ_WRITE)
3001 num_stripes = map->num_stripes;
3002 else if (mirror_num)
3003 stripe_index = mirror_num - 1;
3004 else {
3005 stripe_index = find_live_mirror(map, 0,
3006 map->num_stripes,
3007 current->pid % map->num_stripes);
3008 }
3009
3010 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
3011 if (rw & REQ_WRITE)
3012 num_stripes = map->num_stripes;
3013 else if (mirror_num)
3014 stripe_index = mirror_num - 1;
3015
3016 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3017 int factor = map->num_stripes / map->sub_stripes;
3018
3019 stripe_index = do_div(stripe_nr, factor);
3020 stripe_index *= map->sub_stripes;
3021
3022 if (rw & REQ_WRITE)
3023 num_stripes = map->sub_stripes;
3024 else if (mirror_num)
3025 stripe_index += mirror_num - 1;
3026 else {
3027 stripe_index = find_live_mirror(map, stripe_index,
3028 map->sub_stripes, stripe_index +
3029 current->pid % map->sub_stripes);
3030 }
3031 } else {
3032 /*
3033 * after this do_div call, stripe_nr is the number of stripes
3034 * on this device we have to walk to find the data, and
3035 * stripe_index is the number of our device in the stripe array
3036 */
3037 stripe_index = do_div(stripe_nr, map->num_stripes);
3038 }
3039 BUG_ON(stripe_index >= map->num_stripes);
3040
3041 for (i = 0; i < num_stripes; i++) {
3042 multi->stripes[i].physical =
3043 map->stripes[stripe_index].physical +
3044 stripe_offset + stripe_nr * map->stripe_len;
3045 multi->stripes[i].dev = map->stripes[stripe_index].dev;
3046 stripe_index++;
3047 }
3048 if (multi_ret) {
3049 *multi_ret = multi;
3050 multi->num_stripes = num_stripes;
3051 multi->max_errors = max_errors;
3052 }
3053 out:
3054 free_extent_map(em);
3055 return 0;
3056 }
3057
3058 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
3059 u64 logical, u64 *length,
3060 struct btrfs_multi_bio **multi_ret, int mirror_num)
3061 {
3062 return __btrfs_map_block(map_tree, rw, logical, length, multi_ret,
3063 mirror_num);
3064 }
3065
3066 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
3067 u64 chunk_start, u64 physical, u64 devid,
3068 u64 **logical, int *naddrs, int *stripe_len)
3069 {
3070 struct extent_map_tree *em_tree = &map_tree->map_tree;
3071 struct extent_map *em;
3072 struct map_lookup *map;
3073 u64 *buf;
3074 u64 bytenr;
3075 u64 length;
3076 u64 stripe_nr;
3077 int i, j, nr = 0;
3078
3079 read_lock(&em_tree->lock);
3080 em = lookup_extent_mapping(em_tree, chunk_start, 1);
3081 read_unlock(&em_tree->lock);
3082
3083 BUG_ON(!em || em->start != chunk_start);
3084 map = (struct map_lookup *)em->bdev;
3085
3086 length = em->len;
3087 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
3088 do_div(length, map->num_stripes / map->sub_stripes);
3089 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
3090 do_div(length, map->num_stripes);
3091
3092 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
3093 BUG_ON(!buf);
3094
3095 for (i = 0; i < map->num_stripes; i++) {
3096 if (devid && map->stripes[i].dev->devid != devid)
3097 continue;
3098 if (map->stripes[i].physical > physical ||
3099 map->stripes[i].physical + length <= physical)
3100 continue;
3101
3102 stripe_nr = physical - map->stripes[i].physical;
3103 do_div(stripe_nr, map->stripe_len);
3104
3105 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3106 stripe_nr = stripe_nr * map->num_stripes + i;
3107 do_div(stripe_nr, map->sub_stripes);
3108 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3109 stripe_nr = stripe_nr * map->num_stripes + i;
3110 }
3111 bytenr = chunk_start + stripe_nr * map->stripe_len;
3112 WARN_ON(nr >= map->num_stripes);
3113 for (j = 0; j < nr; j++) {
3114 if (buf[j] == bytenr)
3115 break;
3116 }
3117 if (j == nr) {
3118 WARN_ON(nr >= map->num_stripes);
3119 buf[nr++] = bytenr;
3120 }
3121 }
3122
3123 *logical = buf;
3124 *naddrs = nr;
3125 *stripe_len = map->stripe_len;
3126
3127 free_extent_map(em);
3128 return 0;
3129 }
3130
3131 static void end_bio_multi_stripe(struct bio *bio, int err)
3132 {
3133 struct btrfs_multi_bio *multi = bio->bi_private;
3134 int is_orig_bio = 0;
3135
3136 if (err)
3137 atomic_inc(&multi->error);
3138
3139 if (bio == multi->orig_bio)
3140 is_orig_bio = 1;
3141
3142 if (atomic_dec_and_test(&multi->stripes_pending)) {
3143 if (!is_orig_bio) {
3144 bio_put(bio);
3145 bio = multi->orig_bio;
3146 }
3147 bio->bi_private = multi->private;
3148 bio->bi_end_io = multi->end_io;
3149 /* only send an error to the higher layers if it is
3150 * beyond the tolerance of the multi-bio
3151 */
3152 if (atomic_read(&multi->error) > multi->max_errors) {
3153 err = -EIO;
3154 } else if (err) {
3155 /*
3156 * this bio is actually up to date, we didn't
3157 * go over the max number of errors
3158 */
3159 set_bit(BIO_UPTODATE, &bio->bi_flags);
3160 err = 0;
3161 }
3162 kfree(multi);
3163
3164 bio_endio(bio, err);
3165 } else if (!is_orig_bio) {
3166 bio_put(bio);
3167 }
3168 }
3169
3170 struct async_sched {
3171 struct bio *bio;
3172 int rw;
3173 struct btrfs_fs_info *info;
3174 struct btrfs_work work;
3175 };
3176
3177 /*
3178 * see run_scheduled_bios for a description of why bios are collected for
3179 * async submit.
3180 *
3181 * This will add one bio to the pending list for a device and make sure
3182 * the work struct is scheduled.
3183 */
3184 static noinline int schedule_bio(struct btrfs_root *root,
3185 struct btrfs_device *device,
3186 int rw, struct bio *bio)
3187 {
3188 int should_queue = 1;
3189 struct btrfs_pending_bios *pending_bios;
3190
3191 /* don't bother with additional async steps for reads, right now */
3192 if (!(rw & REQ_WRITE)) {
3193 bio_get(bio);
3194 submit_bio(rw, bio);
3195 bio_put(bio);
3196 return 0;
3197 }
3198
3199 /*
3200 * nr_async_bios allows us to reliably return congestion to the
3201 * higher layers. Otherwise, the async bio makes it appear we have
3202 * made progress against dirty pages when we've really just put it
3203 * on a queue for later
3204 */
3205 atomic_inc(&root->fs_info->nr_async_bios);
3206 WARN_ON(bio->bi_next);
3207 bio->bi_next = NULL;
3208 bio->bi_rw |= rw;
3209
3210 spin_lock(&device->io_lock);
3211 if (bio->bi_rw & REQ_SYNC)
3212 pending_bios = &device->pending_sync_bios;
3213 else
3214 pending_bios = &device->pending_bios;
3215
3216 if (pending_bios->tail)
3217 pending_bios->tail->bi_next = bio;
3218
3219 pending_bios->tail = bio;
3220 if (!pending_bios->head)
3221 pending_bios->head = bio;
3222 if (device->running_pending)
3223 should_queue = 0;
3224
3225 spin_unlock(&device->io_lock);
3226
3227 if (should_queue)
3228 btrfs_queue_worker(&root->fs_info->submit_workers,
3229 &device->work);
3230 return 0;
3231 }
3232
3233 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
3234 int mirror_num, int async_submit)
3235 {
3236 struct btrfs_mapping_tree *map_tree;
3237 struct btrfs_device *dev;
3238 struct bio *first_bio = bio;
3239 u64 logical = (u64)bio->bi_sector << 9;
3240 u64 length = 0;
3241 u64 map_length;
3242 struct btrfs_multi_bio *multi = NULL;
3243 int ret;
3244 int dev_nr = 0;
3245 int total_devs = 1;
3246
3247 length = bio->bi_size;
3248 map_tree = &root->fs_info->mapping_tree;
3249 map_length = length;
3250
3251 ret = btrfs_map_block(map_tree, rw, logical, &map_length, &multi,
3252 mirror_num);
3253 BUG_ON(ret);
3254
3255 total_devs = multi->num_stripes;
3256 if (map_length < length) {
3257 printk(KERN_CRIT "mapping failed logical %llu bio len %llu "
3258 "len %llu\n", (unsigned long long)logical,
3259 (unsigned long long)length,
3260 (unsigned long long)map_length);
3261 BUG();
3262 }
3263 multi->end_io = first_bio->bi_end_io;
3264 multi->private = first_bio->bi_private;
3265 multi->orig_bio = first_bio;
3266 atomic_set(&multi->stripes_pending, multi->num_stripes);
3267
3268 while (dev_nr < total_devs) {
3269 if (total_devs > 1) {
3270 if (dev_nr < total_devs - 1) {
3271 bio = bio_clone(first_bio, GFP_NOFS);
3272 BUG_ON(!bio);
3273 } else {
3274 bio = first_bio;
3275 }
3276 bio->bi_private = multi;
3277 bio->bi_end_io = end_bio_multi_stripe;
3278 }
3279 bio->bi_sector = multi->stripes[dev_nr].physical >> 9;
3280 dev = multi->stripes[dev_nr].dev;
3281 if (dev && dev->bdev && (rw != WRITE || dev->writeable)) {
3282 bio->bi_bdev = dev->bdev;
3283 if (async_submit)
3284 schedule_bio(root, dev, rw, bio);
3285 else
3286 submit_bio(rw, bio);
3287 } else {
3288 bio->bi_bdev = root->fs_info->fs_devices->latest_bdev;
3289 bio->bi_sector = logical >> 9;
3290 bio_endio(bio, -EIO);
3291 }
3292 dev_nr++;
3293 }
3294 if (total_devs == 1)
3295 kfree(multi);
3296 return 0;
3297 }
3298
3299 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
3300 u8 *uuid, u8 *fsid)
3301 {
3302 struct btrfs_device *device;
3303 struct btrfs_fs_devices *cur_devices;
3304
3305 cur_devices = root->fs_info->fs_devices;
3306 while (cur_devices) {
3307 if (!fsid ||
3308 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
3309 device = __find_device(&cur_devices->devices,
3310 devid, uuid);
3311 if (device)
3312 return device;
3313 }
3314 cur_devices = cur_devices->seed;
3315 }
3316 return NULL;
3317 }
3318
3319 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
3320 u64 devid, u8 *dev_uuid)
3321 {
3322 struct btrfs_device *device;
3323 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
3324
3325 device = kzalloc(sizeof(*device), GFP_NOFS);
3326 if (!device)
3327 return NULL;
3328 list_add(&device->dev_list,
3329 &fs_devices->devices);
3330 device->dev_root = root->fs_info->dev_root;
3331 device->devid = devid;
3332 device->work.func = pending_bios_fn;
3333 device->fs_devices = fs_devices;
3334 device->missing = 1;
3335 fs_devices->num_devices++;
3336 fs_devices->missing_devices++;
3337 spin_lock_init(&device->io_lock);
3338 INIT_LIST_HEAD(&device->dev_alloc_list);
3339 memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
3340 return device;
3341 }
3342
3343 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
3344 struct extent_buffer *leaf,
3345 struct btrfs_chunk *chunk)
3346 {
3347 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
3348 struct map_lookup *map;
3349 struct extent_map *em;
3350 u64 logical;
3351 u64 length;
3352 u64 devid;
3353 u8 uuid[BTRFS_UUID_SIZE];
3354 int num_stripes;
3355 int ret;
3356 int i;
3357
3358 logical = key->offset;
3359 length = btrfs_chunk_length(leaf, chunk);
3360
3361 read_lock(&map_tree->map_tree.lock);
3362 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
3363 read_unlock(&map_tree->map_tree.lock);
3364
3365 /* already mapped? */
3366 if (em && em->start <= logical && em->start + em->len > logical) {
3367 free_extent_map(em);
3368 return 0;
3369 } else if (em) {
3370 free_extent_map(em);
3371 }
3372
3373 em = alloc_extent_map(GFP_NOFS);
3374 if (!em)
3375 return -ENOMEM;
3376 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
3377 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
3378 if (!map) {
3379 free_extent_map(em);
3380 return -ENOMEM;
3381 }
3382
3383 em->bdev = (struct block_device *)map;
3384 em->start = logical;
3385 em->len = length;
3386 em->block_start = 0;
3387 em->block_len = em->len;
3388
3389 map->num_stripes = num_stripes;
3390 map->io_width = btrfs_chunk_io_width(leaf, chunk);
3391 map->io_align = btrfs_chunk_io_align(leaf, chunk);
3392 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
3393 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
3394 map->type = btrfs_chunk_type(leaf, chunk);
3395 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
3396 for (i = 0; i < num_stripes; i++) {
3397 map->stripes[i].physical =
3398 btrfs_stripe_offset_nr(leaf, chunk, i);
3399 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
3400 read_extent_buffer(leaf, uuid, (unsigned long)
3401 btrfs_stripe_dev_uuid_nr(chunk, i),
3402 BTRFS_UUID_SIZE);
3403 map->stripes[i].dev = btrfs_find_device(root, devid, uuid,
3404 NULL);
3405 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
3406 kfree(map);
3407 free_extent_map(em);
3408 return -EIO;
3409 }
3410 if (!map->stripes[i].dev) {
3411 map->stripes[i].dev =
3412 add_missing_dev(root, devid, uuid);
3413 if (!map->stripes[i].dev) {
3414 kfree(map);
3415 free_extent_map(em);
3416 return -EIO;
3417 }
3418 }
3419 map->stripes[i].dev->in_fs_metadata = 1;
3420 }
3421
3422 write_lock(&map_tree->map_tree.lock);
3423 ret = add_extent_mapping(&map_tree->map_tree, em);
3424 write_unlock(&map_tree->map_tree.lock);
3425 BUG_ON(ret);
3426 free_extent_map(em);
3427
3428 return 0;
3429 }
3430
3431 static int fill_device_from_item(struct extent_buffer *leaf,
3432 struct btrfs_dev_item *dev_item,
3433 struct btrfs_device *device)
3434 {
3435 unsigned long ptr;
3436
3437 device->devid = btrfs_device_id(leaf, dev_item);
3438 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
3439 device->total_bytes = device->disk_total_bytes;
3440 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
3441 device->type = btrfs_device_type(leaf, dev_item);
3442 device->io_align = btrfs_device_io_align(leaf, dev_item);
3443 device->io_width = btrfs_device_io_width(leaf, dev_item);
3444 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
3445
3446 ptr = (unsigned long)btrfs_device_uuid(dev_item);
3447 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
3448
3449 return 0;
3450 }
3451
3452 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
3453 {
3454 struct btrfs_fs_devices *fs_devices;
3455 int ret;
3456
3457 mutex_lock(&uuid_mutex);
3458
3459 fs_devices = root->fs_info->fs_devices->seed;
3460 while (fs_devices) {
3461 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
3462 ret = 0;
3463 goto out;
3464 }
3465 fs_devices = fs_devices->seed;
3466 }
3467
3468 fs_devices = find_fsid(fsid);
3469 if (!fs_devices) {
3470 ret = -ENOENT;
3471 goto out;
3472 }
3473
3474 fs_devices = clone_fs_devices(fs_devices);
3475 if (IS_ERR(fs_devices)) {
3476 ret = PTR_ERR(fs_devices);
3477 goto out;
3478 }
3479
3480 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
3481 root->fs_info->bdev_holder);
3482 if (ret)
3483 goto out;
3484
3485 if (!fs_devices->seeding) {
3486 __btrfs_close_devices(fs_devices);
3487 free_fs_devices(fs_devices);
3488 ret = -EINVAL;
3489 goto out;
3490 }
3491
3492 fs_devices->seed = root->fs_info->fs_devices->seed;
3493 root->fs_info->fs_devices->seed = fs_devices;
3494 out:
3495 mutex_unlock(&uuid_mutex);
3496 return ret;
3497 }
3498
3499 static int read_one_dev(struct btrfs_root *root,
3500 struct extent_buffer *leaf,
3501 struct btrfs_dev_item *dev_item)
3502 {
3503 struct btrfs_device *device;
3504 u64 devid;
3505 int ret;
3506 u8 fs_uuid[BTRFS_UUID_SIZE];
3507 u8 dev_uuid[BTRFS_UUID_SIZE];
3508
3509 devid = btrfs_device_id(leaf, dev_item);
3510 read_extent_buffer(leaf, dev_uuid,
3511 (unsigned long)btrfs_device_uuid(dev_item),
3512 BTRFS_UUID_SIZE);
3513 read_extent_buffer(leaf, fs_uuid,
3514 (unsigned long)btrfs_device_fsid(dev_item),
3515 BTRFS_UUID_SIZE);
3516
3517 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
3518 ret = open_seed_devices(root, fs_uuid);
3519 if (ret && !btrfs_test_opt(root, DEGRADED))
3520 return ret;
3521 }
3522
3523 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
3524 if (!device || !device->bdev) {
3525 if (!btrfs_test_opt(root, DEGRADED))
3526 return -EIO;
3527
3528 if (!device) {
3529 printk(KERN_WARNING "warning devid %llu missing\n",
3530 (unsigned long long)devid);
3531 device = add_missing_dev(root, devid, dev_uuid);
3532 if (!device)
3533 return -ENOMEM;
3534 } else if (!device->missing) {
3535 /*
3536 * this happens when a device that was properly setup
3537 * in the device info lists suddenly goes bad.
3538 * device->bdev is NULL, and so we have to set
3539 * device->missing to one here
3540 */
3541 root->fs_info->fs_devices->missing_devices++;
3542 device->missing = 1;
3543 }
3544 }
3545
3546 if (device->fs_devices != root->fs_info->fs_devices) {
3547 BUG_ON(device->writeable);
3548 if (device->generation !=
3549 btrfs_device_generation(leaf, dev_item))
3550 return -EINVAL;
3551 }
3552
3553 fill_device_from_item(leaf, dev_item, device);
3554 device->dev_root = root->fs_info->dev_root;
3555 device->in_fs_metadata = 1;
3556 if (device->writeable)
3557 device->fs_devices->total_rw_bytes += device->total_bytes;
3558 ret = 0;
3559 return ret;
3560 }
3561
3562 int btrfs_read_super_device(struct btrfs_root *root, struct extent_buffer *buf)
3563 {
3564 struct btrfs_dev_item *dev_item;
3565
3566 dev_item = (struct btrfs_dev_item *)offsetof(struct btrfs_super_block,
3567 dev_item);
3568 return read_one_dev(root, buf, dev_item);
3569 }
3570
3571 int btrfs_read_sys_array(struct btrfs_root *root)
3572 {
3573 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
3574 struct extent_buffer *sb;
3575 struct btrfs_disk_key *disk_key;
3576 struct btrfs_chunk *chunk;
3577 u8 *ptr;
3578 unsigned long sb_ptr;
3579 int ret = 0;
3580 u32 num_stripes;
3581 u32 array_size;
3582 u32 len = 0;
3583 u32 cur;
3584 struct btrfs_key key;
3585
3586 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
3587 BTRFS_SUPER_INFO_SIZE);
3588 if (!sb)
3589 return -ENOMEM;
3590 btrfs_set_buffer_uptodate(sb);
3591 btrfs_set_buffer_lockdep_class(sb, 0);
3592
3593 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
3594 array_size = btrfs_super_sys_array_size(super_copy);
3595
3596 ptr = super_copy->sys_chunk_array;
3597 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
3598 cur = 0;
3599
3600 while (cur < array_size) {
3601 disk_key = (struct btrfs_disk_key *)ptr;
3602 btrfs_disk_key_to_cpu(&key, disk_key);
3603
3604 len = sizeof(*disk_key); ptr += len;
3605 sb_ptr += len;
3606 cur += len;
3607
3608 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
3609 chunk = (struct btrfs_chunk *)sb_ptr;
3610 ret = read_one_chunk(root, &key, sb, chunk);
3611 if (ret)
3612 break;
3613 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
3614 len = btrfs_chunk_item_size(num_stripes);
3615 } else {
3616 ret = -EIO;
3617 break;
3618 }
3619 ptr += len;
3620 sb_ptr += len;
3621 cur += len;
3622 }
3623 free_extent_buffer(sb);
3624 return ret;
3625 }
3626
3627 int btrfs_read_chunk_tree(struct btrfs_root *root)
3628 {
3629 struct btrfs_path *path;
3630 struct extent_buffer *leaf;
3631 struct btrfs_key key;
3632 struct btrfs_key found_key;
3633 int ret;
3634 int slot;
3635
3636 root = root->fs_info->chunk_root;
3637
3638 path = btrfs_alloc_path();
3639 if (!path)
3640 return -ENOMEM;
3641
3642 /* first we search for all of the device items, and then we
3643 * read in all of the chunk items. This way we can create chunk
3644 * mappings that reference all of the devices that are afound
3645 */
3646 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
3647 key.offset = 0;
3648 key.type = 0;
3649 again:
3650 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3651 if (ret < 0)
3652 goto error;
3653 while (1) {
3654 leaf = path->nodes[0];
3655 slot = path->slots[0];
3656 if (slot >= btrfs_header_nritems(leaf)) {
3657 ret = btrfs_next_leaf(root, path);
3658 if (ret == 0)
3659 continue;
3660 if (ret < 0)
3661 goto error;
3662 break;
3663 }
3664 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3665 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
3666 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
3667 break;
3668 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
3669 struct btrfs_dev_item *dev_item;
3670 dev_item = btrfs_item_ptr(leaf, slot,
3671 struct btrfs_dev_item);
3672 ret = read_one_dev(root, leaf, dev_item);
3673 if (ret)
3674 goto error;
3675 }
3676 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
3677 struct btrfs_chunk *chunk;
3678 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
3679 ret = read_one_chunk(root, &found_key, leaf, chunk);
3680 if (ret)
3681 goto error;
3682 }
3683 path->slots[0]++;
3684 }
3685 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
3686 key.objectid = 0;
3687 btrfs_release_path(root, path);
3688 goto again;
3689 }
3690 ret = 0;
3691 error:
3692 btrfs_free_path(path);
3693 return ret;
3694 }