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Merge branch 'samsung-fixes-4' of git://github.com/kgene/linux-samsung
[linux-btrfs-devel.git] / fs / btrfs / volumes.c
blobf2a4cc79da61da62740d1de33552037f27b072a2
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 static int init_first_rw_device(struct btrfs_trans_handle *trans,
37 struct btrfs_root *root,
38 struct btrfs_device *device);
39 static int btrfs_relocate_sys_chunks(struct btrfs_root *root);
40
41 static DEFINE_MUTEX(uuid_mutex);
42 static LIST_HEAD(fs_uuids);
43
44 static void lock_chunks(struct btrfs_root *root)
45 {
46 mutex_lock(&root->fs_info->chunk_mutex);
47 }
48
49 static void unlock_chunks(struct btrfs_root *root)
50 {
51 mutex_unlock(&root->fs_info->chunk_mutex);
52 }
53
54 static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
55 {
56 struct btrfs_device *device;
57 WARN_ON(fs_devices->opened);
58 while (!list_empty(&fs_devices->devices)) {
59 device = list_entry(fs_devices->devices.next,
60 struct btrfs_device, dev_list);
61 list_del(&device->dev_list);
62 kfree(device->name);
63 kfree(device);
64 }
65 kfree(fs_devices);
66 }
67
68 int btrfs_cleanup_fs_uuids(void)
69 {
70 struct btrfs_fs_devices *fs_devices;
71
72 while (!list_empty(&fs_uuids)) {
73 fs_devices = list_entry(fs_uuids.next,
74 struct btrfs_fs_devices, list);
75 list_del(&fs_devices->list);
76 free_fs_devices(fs_devices);
77 }
78 return 0;
79 }
80
81 static noinline struct btrfs_device *__find_device(struct list_head *head,
82 u64 devid, u8 *uuid)
83 {
84 struct btrfs_device *dev;
85
86 list_for_each_entry(dev, head, dev_list) {
87 if (dev->devid == devid &&
88 (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
89 return dev;
90 }
91 }
92 return NULL;
93 }
94
95 static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
96 {
97 struct btrfs_fs_devices *fs_devices;
98
99 list_for_each_entry(fs_devices, &fs_uuids, list) {
100 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
101 return fs_devices;
102 }
103 return NULL;
104 }
105
106 static void requeue_list(struct btrfs_pending_bios *pending_bios,
107 struct bio *head, struct bio *tail)
108 {
109
110 struct bio *old_head;
111
112 old_head = pending_bios->head;
113 pending_bios->head = head;
114 if (pending_bios->tail)
115 tail->bi_next = old_head;
116 else
117 pending_bios->tail = tail;
118 }
119
120 /*
121 * we try to collect pending bios for a device so we don't get a large
122 * number of procs sending bios down to the same device. This greatly
123 * improves the schedulers ability to collect and merge the bios.
124 *
125 * But, it also turns into a long list of bios to process and that is sure
126 * to eventually make the worker thread block. The solution here is to
127 * make some progress and then put this work struct back at the end of
128 * the list if the block device is congested. This way, multiple devices
129 * can make progress from a single worker thread.
130 */
131 static noinline int run_scheduled_bios(struct btrfs_device *device)
132 {
133 struct bio *pending;
134 struct backing_dev_info *bdi;
135 struct btrfs_fs_info *fs_info;
136 struct btrfs_pending_bios *pending_bios;
137 struct bio *tail;
138 struct bio *cur;
139 int again = 0;
140 unsigned long num_run;
141 unsigned long batch_run = 0;
142 unsigned long limit;
143 unsigned long last_waited = 0;
144 int force_reg = 0;
145 int sync_pending = 0;
146 struct blk_plug plug;
147
148 /*
149 * this function runs all the bios we've collected for
150 * a particular device. We don't want to wander off to
151 * another device without first sending all of these down.
152 * So, setup a plug here and finish it off before we return
153 */
154 blk_start_plug(&plug);
155
156 bdi = blk_get_backing_dev_info(device->bdev);
157 fs_info = device->dev_root->fs_info;
158 limit = btrfs_async_submit_limit(fs_info);
159 limit = limit * 2 / 3;
160
161 loop:
162 spin_lock(&device->io_lock);
163
164 loop_lock:
165 num_run = 0;
166
167 /* take all the bios off the list at once and process them
168 * later on (without the lock held). But, remember the
169 * tail and other pointers so the bios can be properly reinserted
170 * into the list if we hit congestion
171 */
172 if (!force_reg && device->pending_sync_bios.head) {
173 pending_bios = &device->pending_sync_bios;
174 force_reg = 1;
175 } else {
176 pending_bios = &device->pending_bios;
177 force_reg = 0;
178 }
179
180 pending = pending_bios->head;
181 tail = pending_bios->tail;
182 WARN_ON(pending && !tail);
183
184 /*
185 * if pending was null this time around, no bios need processing
186 * at all and we can stop. Otherwise it'll loop back up again
187 * and do an additional check so no bios are missed.
188 *
189 * device->running_pending is used to synchronize with the
190 * schedule_bio code.
191 */
192 if (device->pending_sync_bios.head == NULL &&
193 device->pending_bios.head == NULL) {
194 again = 0;
195 device->running_pending = 0;
196 } else {
197 again = 1;
198 device->running_pending = 1;
199 }
200
201 pending_bios->head = NULL;
202 pending_bios->tail = NULL;
203
204 spin_unlock(&device->io_lock);
205
206 while (pending) {
207
208 rmb();
209 /* we want to work on both lists, but do more bios on the
210 * sync list than the regular list
211 */
212 if ((num_run > 32 &&
213 pending_bios != &device->pending_sync_bios &&
214 device->pending_sync_bios.head) ||
215 (num_run > 64 && pending_bios == &device->pending_sync_bios &&
216 device->pending_bios.head)) {
217 spin_lock(&device->io_lock);
218 requeue_list(pending_bios, pending, tail);
219 goto loop_lock;
220 }
221
222 cur = pending;
223 pending = pending->bi_next;
224 cur->bi_next = NULL;
225 atomic_dec(&fs_info->nr_async_bios);
226
227 if (atomic_read(&fs_info->nr_async_bios) < limit &&
228 waitqueue_active(&fs_info->async_submit_wait))
229 wake_up(&fs_info->async_submit_wait);
230
231 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
232
233 /*
234 * if we're doing the sync list, record that our
235 * plug has some sync requests on it
236 *
237 * If we're doing the regular list and there are
238 * sync requests sitting around, unplug before
239 * we add more
240 */
241 if (pending_bios == &device->pending_sync_bios) {
242 sync_pending = 1;
243 } else if (sync_pending) {
244 blk_finish_plug(&plug);
245 blk_start_plug(&plug);
246 sync_pending = 0;
247 }
248
249 submit_bio(cur->bi_rw, cur);
250 num_run++;
251 batch_run++;
252 if (need_resched())
253 cond_resched();
254
255 /*
256 * we made progress, there is more work to do and the bdi
257 * is now congested. Back off and let other work structs
258 * run instead
259 */
260 if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
261 fs_info->fs_devices->open_devices > 1) {
262 struct io_context *ioc;
263
264 ioc = current->io_context;
265
266 /*
267 * the main goal here is that we don't want to
268 * block if we're going to be able to submit
269 * more requests without blocking.
270 *
271 * This code does two great things, it pokes into
272 * the elevator code from a filesystem _and_
273 * it makes assumptions about how batching works.
274 */
275 if (ioc && ioc->nr_batch_requests > 0 &&
276 time_before(jiffies, ioc->last_waited + HZ/50UL) &&
277 (last_waited == 0 ||
278 ioc->last_waited == last_waited)) {
279 /*
280 * we want to go through our batch of
281 * requests and stop. So, we copy out
282 * the ioc->last_waited time and test
283 * against it before looping
284 */
285 last_waited = ioc->last_waited;
286 if (need_resched())
287 cond_resched();
288 continue;
289 }
290 spin_lock(&device->io_lock);
291 requeue_list(pending_bios, pending, tail);
292 device->running_pending = 1;
293
294 spin_unlock(&device->io_lock);
295 btrfs_requeue_work(&device->work);
296 goto done;
297 }
298 }
299
300 cond_resched();
301 if (again)
302 goto loop;
303
304 spin_lock(&device->io_lock);
305 if (device->pending_bios.head || device->pending_sync_bios.head)
306 goto loop_lock;
307 spin_unlock(&device->io_lock);
308
309 done:
310 blk_finish_plug(&plug);
311 return 0;
312 }
313
314 static void pending_bios_fn(struct btrfs_work *work)
315 {
316 struct btrfs_device *device;
317
318 device = container_of(work, struct btrfs_device, work);
319 run_scheduled_bios(device);
320 }
321
322 static noinline int device_list_add(const char *path,
323 struct btrfs_super_block *disk_super,
324 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
325 {
326 struct btrfs_device *device;
327 struct btrfs_fs_devices *fs_devices;
328 u64 found_transid = btrfs_super_generation(disk_super);
329 char *name;
330
331 fs_devices = find_fsid(disk_super->fsid);
332 if (!fs_devices) {
333 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
334 if (!fs_devices)
335 return -ENOMEM;
336 INIT_LIST_HEAD(&fs_devices->devices);
337 INIT_LIST_HEAD(&fs_devices->alloc_list);
338 list_add(&fs_devices->list, &fs_uuids);
339 memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
340 fs_devices->latest_devid = devid;
341 fs_devices->latest_trans = found_transid;
342 mutex_init(&fs_devices->device_list_mutex);
343 device = NULL;
344 } else {
345 device = __find_device(&fs_devices->devices, devid,
346 disk_super->dev_item.uuid);
347 }
348 if (!device) {
349 if (fs_devices->opened)
350 return -EBUSY;
351
352 device = kzalloc(sizeof(*device), GFP_NOFS);
353 if (!device) {
354 /* we can safely leave the fs_devices entry around */
355 return -ENOMEM;
356 }
357 device->devid = devid;
358 device->work.func = pending_bios_fn;
359 memcpy(device->uuid, disk_super->dev_item.uuid,
360 BTRFS_UUID_SIZE);
361 spin_lock_init(&device->io_lock);
362 device->name = kstrdup(path, GFP_NOFS);
363 if (!device->name) {
364 kfree(device);
365 return -ENOMEM;
366 }
367 INIT_LIST_HEAD(&device->dev_alloc_list);
368
369 mutex_lock(&fs_devices->device_list_mutex);
370 list_add_rcu(&device->dev_list, &fs_devices->devices);
371 mutex_unlock(&fs_devices->device_list_mutex);
372
373 device->fs_devices = fs_devices;
374 fs_devices->num_devices++;
375 } else if (!device->name || strcmp(device->name, path)) {
376 name = kstrdup(path, GFP_NOFS);
377 if (!name)
378 return -ENOMEM;
379 kfree(device->name);
380 device->name = name;
381 if (device->missing) {
382 fs_devices->missing_devices--;
383 device->missing = 0;
384 }
385 }
386
387 if (found_transid > fs_devices->latest_trans) {
388 fs_devices->latest_devid = devid;
389 fs_devices->latest_trans = found_transid;
390 }
391 *fs_devices_ret = fs_devices;
392 return 0;
393 }
394
395 static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
396 {
397 struct btrfs_fs_devices *fs_devices;
398 struct btrfs_device *device;
399 struct btrfs_device *orig_dev;
400
401 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
402 if (!fs_devices)
403 return ERR_PTR(-ENOMEM);
404
405 INIT_LIST_HEAD(&fs_devices->devices);
406 INIT_LIST_HEAD(&fs_devices->alloc_list);
407 INIT_LIST_HEAD(&fs_devices->list);
408 mutex_init(&fs_devices->device_list_mutex);
409 fs_devices->latest_devid = orig->latest_devid;
410 fs_devices->latest_trans = orig->latest_trans;
411 memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid));
412
413 /* We have held the volume lock, it is safe to get the devices. */
414 list_for_each_entry(orig_dev, &orig->devices, dev_list) {
415 device = kzalloc(sizeof(*device), GFP_NOFS);
416 if (!device)
417 goto error;
418
419 device->name = kstrdup(orig_dev->name, GFP_NOFS);
420 if (!device->name) {
421 kfree(device);
422 goto error;
423 }
424
425 device->devid = orig_dev->devid;
426 device->work.func = pending_bios_fn;
427 memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid));
428 spin_lock_init(&device->io_lock);
429 INIT_LIST_HEAD(&device->dev_list);
430 INIT_LIST_HEAD(&device->dev_alloc_list);
431
432 list_add(&device->dev_list, &fs_devices->devices);
433 device->fs_devices = fs_devices;
434 fs_devices->num_devices++;
435 }
436 return fs_devices;
437 error:
438 free_fs_devices(fs_devices);
439 return ERR_PTR(-ENOMEM);
440 }
441
442 int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
443 {
444 struct btrfs_device *device, *next;
445
446 mutex_lock(&uuid_mutex);
447 again:
448 /* This is the initialized path, it is safe to release the devices. */
449 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
450 if (device->in_fs_metadata)
451 continue;
452
453 if (device->bdev) {
454 blkdev_put(device->bdev, device->mode);
455 device->bdev = NULL;
456 fs_devices->open_devices--;
457 }
458 if (device->writeable) {
459 list_del_init(&device->dev_alloc_list);
460 device->writeable = 0;
461 fs_devices->rw_devices--;
462 }
463 list_del_init(&device->dev_list);
464 fs_devices->num_devices--;
465 kfree(device->name);
466 kfree(device);
467 }
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 void __free_device(struct work_struct *work)
479 {
480 struct btrfs_device *device;
481
482 device = container_of(work, struct btrfs_device, rcu_work);
483
484 if (device->bdev)
485 blkdev_put(device->bdev, device->mode);
486
487 kfree(device->name);
488 kfree(device);
489 }
490
491 static void free_device(struct rcu_head *head)
492 {
493 struct btrfs_device *device;
494
495 device = container_of(head, struct btrfs_device, rcu);
496
497 INIT_WORK(&device->rcu_work, __free_device);
498 schedule_work(&device->rcu_work);
499 }
500
501 static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
502 {
503 struct btrfs_device *device;
504
505 if (--fs_devices->opened > 0)
506 return 0;
507
508 mutex_lock(&fs_devices->device_list_mutex);
509 list_for_each_entry(device, &fs_devices->devices, dev_list) {
510 struct btrfs_device *new_device;
511
512 if (device->bdev)
513 fs_devices->open_devices--;
514
515 if (device->writeable) {
516 list_del_init(&device->dev_alloc_list);
517 fs_devices->rw_devices--;
518 }
519
520 if (device->can_discard)
521 fs_devices->num_can_discard--;
522
523 new_device = kmalloc(sizeof(*new_device), GFP_NOFS);
524 BUG_ON(!new_device);
525 memcpy(new_device, device, sizeof(*new_device));
526 new_device->name = kstrdup(device->name, GFP_NOFS);
527 BUG_ON(device->name && !new_device->name);
528 new_device->bdev = NULL;
529 new_device->writeable = 0;
530 new_device->in_fs_metadata = 0;
531 new_device->can_discard = 0;
532 list_replace_rcu(&device->dev_list, &new_device->dev_list);
533
534 call_rcu(&device->rcu, free_device);
535 }
536 mutex_unlock(&fs_devices->device_list_mutex);
537
538 WARN_ON(fs_devices->open_devices);
539 WARN_ON(fs_devices->rw_devices);
540 fs_devices->opened = 0;
541 fs_devices->seeding = 0;
542
543 return 0;
544 }
545
546 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
547 {
548 struct btrfs_fs_devices *seed_devices = NULL;
549 int ret;
550
551 mutex_lock(&uuid_mutex);
552 ret = __btrfs_close_devices(fs_devices);
553 if (!fs_devices->opened) {
554 seed_devices = fs_devices->seed;
555 fs_devices->seed = NULL;
556 }
557 mutex_unlock(&uuid_mutex);
558
559 while (seed_devices) {
560 fs_devices = seed_devices;
561 seed_devices = fs_devices->seed;
562 __btrfs_close_devices(fs_devices);
563 free_fs_devices(fs_devices);
564 }
565 return ret;
566 }
567
568 static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
569 fmode_t flags, void *holder)
570 {
571 struct request_queue *q;
572 struct block_device *bdev;
573 struct list_head *head = &fs_devices->devices;
574 struct btrfs_device *device;
575 struct block_device *latest_bdev = NULL;
576 struct buffer_head *bh;
577 struct btrfs_super_block *disk_super;
578 u64 latest_devid = 0;
579 u64 latest_transid = 0;
580 u64 devid;
581 int seeding = 1;
582 int ret = 0;
583
584 flags |= FMODE_EXCL;
585
586 list_for_each_entry(device, head, dev_list) {
587 if (device->bdev)
588 continue;
589 if (!device->name)
590 continue;
591
592 bdev = blkdev_get_by_path(device->name, flags, holder);
593 if (IS_ERR(bdev)) {
594 printk(KERN_INFO "open %s failed\n", device->name);
595 goto error;
596 }
597 set_blocksize(bdev, 4096);
598
599 bh = btrfs_read_dev_super(bdev);
600 if (!bh) {
601 ret = -EINVAL;
602 goto error_close;
603 }
604
605 disk_super = (struct btrfs_super_block *)bh->b_data;
606 devid = btrfs_stack_device_id(&disk_super->dev_item);
607 if (devid != device->devid)
608 goto error_brelse;
609
610 if (memcmp(device->uuid, disk_super->dev_item.uuid,
611 BTRFS_UUID_SIZE))
612 goto error_brelse;
613
614 device->generation = btrfs_super_generation(disk_super);
615 if (!latest_transid || device->generation > latest_transid) {
616 latest_devid = devid;
617 latest_transid = device->generation;
618 latest_bdev = bdev;
619 }
620
621 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
622 device->writeable = 0;
623 } else {
624 device->writeable = !bdev_read_only(bdev);
625 seeding = 0;
626 }
627
628 q = bdev_get_queue(bdev);
629 if (blk_queue_discard(q)) {
630 device->can_discard = 1;
631 fs_devices->num_can_discard++;
632 }
633
634 device->bdev = bdev;
635 device->in_fs_metadata = 0;
636 device->mode = flags;
637
638 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
639 fs_devices->rotating = 1;
640
641 fs_devices->open_devices++;
642 if (device->writeable) {
643 fs_devices->rw_devices++;
644 list_add(&device->dev_alloc_list,
645 &fs_devices->alloc_list);
646 }
647 brelse(bh);
648 continue;
649
650 error_brelse:
651 brelse(bh);
652 error_close:
653 blkdev_put(bdev, flags);
654 error:
655 continue;
656 }
657 if (fs_devices->open_devices == 0) {
658 ret = -EIO;
659 goto out;
660 }
661 fs_devices->seeding = seeding;
662 fs_devices->opened = 1;
663 fs_devices->latest_bdev = latest_bdev;
664 fs_devices->latest_devid = latest_devid;
665 fs_devices->latest_trans = latest_transid;
666 fs_devices->total_rw_bytes = 0;
667 out:
668 return ret;
669 }
670
671 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
672 fmode_t flags, void *holder)
673 {
674 int ret;
675
676 mutex_lock(&uuid_mutex);
677 if (fs_devices->opened) {
678 fs_devices->opened++;
679 ret = 0;
680 } else {
681 ret = __btrfs_open_devices(fs_devices, flags, holder);
682 }
683 mutex_unlock(&uuid_mutex);
684 return ret;
685 }
686
687 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
688 struct btrfs_fs_devices **fs_devices_ret)
689 {
690 struct btrfs_super_block *disk_super;
691 struct block_device *bdev;
692 struct buffer_head *bh;
693 int ret;
694 u64 devid;
695 u64 transid;
696
697 mutex_lock(&uuid_mutex);
698
699 flags |= FMODE_EXCL;
700 bdev = blkdev_get_by_path(path, flags, holder);
701
702 if (IS_ERR(bdev)) {
703 ret = PTR_ERR(bdev);
704 goto error;
705 }
706
707 ret = set_blocksize(bdev, 4096);
708 if (ret)
709 goto error_close;
710 bh = btrfs_read_dev_super(bdev);
711 if (!bh) {
712 ret = -EINVAL;
713 goto error_close;
714 }
715 disk_super = (struct btrfs_super_block *)bh->b_data;
716 devid = btrfs_stack_device_id(&disk_super->dev_item);
717 transid = btrfs_super_generation(disk_super);
718 if (disk_super->label[0])
719 printk(KERN_INFO "device label %s ", disk_super->label);
720 else
721 printk(KERN_INFO "device fsid %pU ", disk_super->fsid);
722 printk(KERN_CONT "devid %llu transid %llu %s\n",
723 (unsigned long long)devid, (unsigned long long)transid, path);
724 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
725
726 brelse(bh);
727 error_close:
728 blkdev_put(bdev, flags);
729 error:
730 mutex_unlock(&uuid_mutex);
731 return ret;
732 }
733
734 /* helper to account the used device space in the range */
735 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
736 u64 end, u64 *length)
737 {
738 struct btrfs_key key;
739 struct btrfs_root *root = device->dev_root;
740 struct btrfs_dev_extent *dev_extent;
741 struct btrfs_path *path;
742 u64 extent_end;
743 int ret;
744 int slot;
745 struct extent_buffer *l;
746
747 *length = 0;
748
749 if (start >= device->total_bytes)
750 return 0;
751
752 path = btrfs_alloc_path();
753 if (!path)
754 return -ENOMEM;
755 path->reada = 2;
756
757 key.objectid = device->devid;
758 key.offset = start;
759 key.type = BTRFS_DEV_EXTENT_KEY;
760
761 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
762 if (ret < 0)
763 goto out;
764 if (ret > 0) {
765 ret = btrfs_previous_item(root, path, key.objectid, key.type);
766 if (ret < 0)
767 goto out;
768 }
769
770 while (1) {
771 l = path->nodes[0];
772 slot = path->slots[0];
773 if (slot >= btrfs_header_nritems(l)) {
774 ret = btrfs_next_leaf(root, path);
775 if (ret == 0)
776 continue;
777 if (ret < 0)
778 goto out;
779
780 break;
781 }
782 btrfs_item_key_to_cpu(l, &key, slot);
783
784 if (key.objectid < device->devid)
785 goto next;
786
787 if (key.objectid > device->devid)
788 break;
789
790 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
791 goto next;
792
793 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
794 extent_end = key.offset + btrfs_dev_extent_length(l,
795 dev_extent);
796 if (key.offset <= start && extent_end > end) {
797 *length = end - start + 1;
798 break;
799 } else if (key.offset <= start && extent_end > start)
800 *length += extent_end - start;
801 else if (key.offset > start && extent_end <= end)
802 *length += extent_end - key.offset;
803 else if (key.offset > start && key.offset <= end) {
804 *length += end - key.offset + 1;
805 break;
806 } else if (key.offset > end)
807 break;
808
809 next:
810 path->slots[0]++;
811 }
812 ret = 0;
813 out:
814 btrfs_free_path(path);
815 return ret;
816 }
817
818 /*
819 * find_free_dev_extent - find free space in the specified device
820 * @trans: transaction handler
821 * @device: the device which we search the free space in
822 * @num_bytes: the size of the free space that we need
823 * @start: store the start of the free space.
824 * @len: the size of the free space. that we find, or the size of the max
825 * free space if we don't find suitable free space
826 *
827 * this uses a pretty simple search, the expectation is that it is
828 * called very infrequently and that a given device has a small number
829 * of extents
830 *
831 * @start is used to store the start of the free space if we find. But if we
832 * don't find suitable free space, it will be used to store the start position
833 * of the max free space.
834 *
835 * @len is used to store the size of the free space that we find.
836 * But if we don't find suitable free space, it is used to store the size of
837 * the max free space.
838 */
839 int find_free_dev_extent(struct btrfs_trans_handle *trans,
840 struct btrfs_device *device, u64 num_bytes,
841 u64 *start, u64 *len)
842 {
843 struct btrfs_key key;
844 struct btrfs_root *root = device->dev_root;
845 struct btrfs_dev_extent *dev_extent;
846 struct btrfs_path *path;
847 u64 hole_size;
848 u64 max_hole_start;
849 u64 max_hole_size;
850 u64 extent_end;
851 u64 search_start;
852 u64 search_end = device->total_bytes;
853 int ret;
854 int slot;
855 struct extent_buffer *l;
856
857 /* FIXME use last free of some kind */
858
859 /* we don't want to overwrite the superblock on the drive,
860 * so we make sure to start at an offset of at least 1MB
861 */
862 search_start = max(root->fs_info->alloc_start, 1024ull * 1024);
863
864 max_hole_start = search_start;
865 max_hole_size = 0;
866 hole_size = 0;
867
868 if (search_start >= search_end) {
869 ret = -ENOSPC;
870 goto error;
871 }
872
873 path = btrfs_alloc_path();
874 if (!path) {
875 ret = -ENOMEM;
876 goto error;
877 }
878 path->reada = 2;
879
880 key.objectid = device->devid;
881 key.offset = search_start;
882 key.type = BTRFS_DEV_EXTENT_KEY;
883
884 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
885 if (ret < 0)
886 goto out;
887 if (ret > 0) {
888 ret = btrfs_previous_item(root, path, key.objectid, key.type);
889 if (ret < 0)
890 goto out;
891 }
892
893 while (1) {
894 l = path->nodes[0];
895 slot = path->slots[0];
896 if (slot >= btrfs_header_nritems(l)) {
897 ret = btrfs_next_leaf(root, path);
898 if (ret == 0)
899 continue;
900 if (ret < 0)
901 goto out;
902
903 break;
904 }
905 btrfs_item_key_to_cpu(l, &key, slot);
906
907 if (key.objectid < device->devid)
908 goto next;
909
910 if (key.objectid > device->devid)
911 break;
912
913 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
914 goto next;
915
916 if (key.offset > search_start) {
917 hole_size = key.offset - search_start;
918
919 if (hole_size > max_hole_size) {
920 max_hole_start = search_start;
921 max_hole_size = hole_size;
922 }
923
924 /*
925 * If this free space is greater than which we need,
926 * it must be the max free space that we have found
927 * until now, so max_hole_start must point to the start
928 * of this free space and the length of this free space
929 * is stored in max_hole_size. Thus, we return
930 * max_hole_start and max_hole_size and go back to the
931 * caller.
932 */
933 if (hole_size >= num_bytes) {
934 ret = 0;
935 goto out;
936 }
937 }
938
939 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
940 extent_end = key.offset + btrfs_dev_extent_length(l,
941 dev_extent);
942 if (extent_end > search_start)
943 search_start = extent_end;
944 next:
945 path->slots[0]++;
946 cond_resched();
947 }
948
949 /*
950 * At this point, search_start should be the end of
951 * allocated dev extents, and when shrinking the device,
952 * search_end may be smaller than search_start.
953 */
954 if (search_end > search_start)
955 hole_size = search_end - search_start;
956
957 if (hole_size > max_hole_size) {
958 max_hole_start = search_start;
959 max_hole_size = hole_size;
960 }
961
962 /* See above. */
963 if (hole_size < num_bytes)
964 ret = -ENOSPC;
965 else
966 ret = 0;
967
968 out:
969 btrfs_free_path(path);
970 error:
971 *start = max_hole_start;
972 if (len)
973 *len = max_hole_size;
974 return ret;
975 }
976
977 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
978 struct btrfs_device *device,
979 u64 start)
980 {
981 int ret;
982 struct btrfs_path *path;
983 struct btrfs_root *root = device->dev_root;
984 struct btrfs_key key;
985 struct btrfs_key found_key;
986 struct extent_buffer *leaf = NULL;
987 struct btrfs_dev_extent *extent = NULL;
988
989 path = btrfs_alloc_path();
990 if (!path)
991 return -ENOMEM;
992
993 key.objectid = device->devid;
994 key.offset = start;
995 key.type = BTRFS_DEV_EXTENT_KEY;
996
997 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
998 if (ret > 0) {
999 ret = btrfs_previous_item(root, path, key.objectid,
1000 BTRFS_DEV_EXTENT_KEY);
1001 if (ret)
1002 goto out;
1003 leaf = path->nodes[0];
1004 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1005 extent = btrfs_item_ptr(leaf, path->slots[0],
1006 struct btrfs_dev_extent);
1007 BUG_ON(found_key.offset > start || found_key.offset +
1008 btrfs_dev_extent_length(leaf, extent) < start);
1009 } else if (ret == 0) {
1010 leaf = path->nodes[0];
1011 extent = btrfs_item_ptr(leaf, path->slots[0],
1012 struct btrfs_dev_extent);
1013 }
1014 BUG_ON(ret);
1015
1016 if (device->bytes_used > 0)
1017 device->bytes_used -= btrfs_dev_extent_length(leaf, extent);
1018 ret = btrfs_del_item(trans, root, path);
1019
1020 out:
1021 btrfs_free_path(path);
1022 return ret;
1023 }
1024
1025 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
1026 struct btrfs_device *device,
1027 u64 chunk_tree, u64 chunk_objectid,
1028 u64 chunk_offset, u64 start, u64 num_bytes)
1029 {
1030 int ret;
1031 struct btrfs_path *path;
1032 struct btrfs_root *root = device->dev_root;
1033 struct btrfs_dev_extent *extent;
1034 struct extent_buffer *leaf;
1035 struct btrfs_key key;
1036
1037 WARN_ON(!device->in_fs_metadata);
1038 path = btrfs_alloc_path();
1039 if (!path)
1040 return -ENOMEM;
1041
1042 key.objectid = device->devid;
1043 key.offset = start;
1044 key.type = BTRFS_DEV_EXTENT_KEY;
1045 ret = btrfs_insert_empty_item(trans, root, path, &key,
1046 sizeof(*extent));
1047 BUG_ON(ret);
1048
1049 leaf = path->nodes[0];
1050 extent = btrfs_item_ptr(leaf, path->slots[0],
1051 struct btrfs_dev_extent);
1052 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
1053 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
1054 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
1055
1056 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
1057 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
1058 BTRFS_UUID_SIZE);
1059
1060 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
1061 btrfs_mark_buffer_dirty(leaf);
1062 btrfs_free_path(path);
1063 return ret;
1064 }
1065
1066 static noinline int find_next_chunk(struct btrfs_root *root,
1067 u64 objectid, u64 *offset)
1068 {
1069 struct btrfs_path *path;
1070 int ret;
1071 struct btrfs_key key;
1072 struct btrfs_chunk *chunk;
1073 struct btrfs_key found_key;
1074
1075 path = btrfs_alloc_path();
1076 if (!path)
1077 return -ENOMEM;
1078
1079 key.objectid = objectid;
1080 key.offset = (u64)-1;
1081 key.type = BTRFS_CHUNK_ITEM_KEY;
1082
1083 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1084 if (ret < 0)
1085 goto error;
1086
1087 BUG_ON(ret == 0);
1088
1089 ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
1090 if (ret) {
1091 *offset = 0;
1092 } else {
1093 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1094 path->slots[0]);
1095 if (found_key.objectid != objectid)
1096 *offset = 0;
1097 else {
1098 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
1099 struct btrfs_chunk);
1100 *offset = found_key.offset +
1101 btrfs_chunk_length(path->nodes[0], chunk);
1102 }
1103 }
1104 ret = 0;
1105 error:
1106 btrfs_free_path(path);
1107 return ret;
1108 }
1109
1110 static noinline int find_next_devid(struct btrfs_root *root, u64 *objectid)
1111 {
1112 int ret;
1113 struct btrfs_key key;
1114 struct btrfs_key found_key;
1115 struct btrfs_path *path;
1116
1117 root = root->fs_info->chunk_root;
1118
1119 path = btrfs_alloc_path();
1120 if (!path)
1121 return -ENOMEM;
1122
1123 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1124 key.type = BTRFS_DEV_ITEM_KEY;
1125 key.offset = (u64)-1;
1126
1127 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1128 if (ret < 0)
1129 goto error;
1130
1131 BUG_ON(ret == 0);
1132
1133 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
1134 BTRFS_DEV_ITEM_KEY);
1135 if (ret) {
1136 *objectid = 1;
1137 } else {
1138 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1139 path->slots[0]);
1140 *objectid = found_key.offset + 1;
1141 }
1142 ret = 0;
1143 error:
1144 btrfs_free_path(path);
1145 return ret;
1146 }
1147
1148 /*
1149 * the device information is stored in the chunk root
1150 * the btrfs_device struct should be fully filled in
1151 */
1152 int btrfs_add_device(struct btrfs_trans_handle *trans,
1153 struct btrfs_root *root,
1154 struct btrfs_device *device)
1155 {
1156 int ret;
1157 struct btrfs_path *path;
1158 struct btrfs_dev_item *dev_item;
1159 struct extent_buffer *leaf;
1160 struct btrfs_key key;
1161 unsigned long ptr;
1162
1163 root = root->fs_info->chunk_root;
1164
1165 path = btrfs_alloc_path();
1166 if (!path)
1167 return -ENOMEM;
1168
1169 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1170 key.type = BTRFS_DEV_ITEM_KEY;
1171 key.offset = device->devid;
1172
1173 ret = btrfs_insert_empty_item(trans, root, path, &key,
1174 sizeof(*dev_item));
1175 if (ret)
1176 goto out;
1177
1178 leaf = path->nodes[0];
1179 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1180
1181 btrfs_set_device_id(leaf, dev_item, device->devid);
1182 btrfs_set_device_generation(leaf, dev_item, 0);
1183 btrfs_set_device_type(leaf, dev_item, device->type);
1184 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1185 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1186 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1187 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
1188 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1189 btrfs_set_device_group(leaf, dev_item, 0);
1190 btrfs_set_device_seek_speed(leaf, dev_item, 0);
1191 btrfs_set_device_bandwidth(leaf, dev_item, 0);
1192 btrfs_set_device_start_offset(leaf, dev_item, 0);
1193
1194 ptr = (unsigned long)btrfs_device_uuid(dev_item);
1195 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1196 ptr = (unsigned long)btrfs_device_fsid(dev_item);
1197 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
1198 btrfs_mark_buffer_dirty(leaf);
1199
1200 ret = 0;
1201 out:
1202 btrfs_free_path(path);
1203 return ret;
1204 }
1205
1206 static int btrfs_rm_dev_item(struct btrfs_root *root,
1207 struct btrfs_device *device)
1208 {
1209 int ret;
1210 struct btrfs_path *path;
1211 struct btrfs_key key;
1212 struct btrfs_trans_handle *trans;
1213
1214 root = root->fs_info->chunk_root;
1215
1216 path = btrfs_alloc_path();
1217 if (!path)
1218 return -ENOMEM;
1219
1220 trans = btrfs_start_transaction(root, 0);
1221 if (IS_ERR(trans)) {
1222 btrfs_free_path(path);
1223 return PTR_ERR(trans);
1224 }
1225 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1226 key.type = BTRFS_DEV_ITEM_KEY;
1227 key.offset = device->devid;
1228 lock_chunks(root);
1229
1230 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1231 if (ret < 0)
1232 goto out;
1233
1234 if (ret > 0) {
1235 ret = -ENOENT;
1236 goto out;
1237 }
1238
1239 ret = btrfs_del_item(trans, root, path);
1240 if (ret)
1241 goto out;
1242 out:
1243 btrfs_free_path(path);
1244 unlock_chunks(root);
1245 btrfs_commit_transaction(trans, root);
1246 return ret;
1247 }
1248
1249 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
1250 {
1251 struct btrfs_device *device;
1252 struct btrfs_device *next_device;
1253 struct block_device *bdev;
1254 struct buffer_head *bh = NULL;
1255 struct btrfs_super_block *disk_super;
1256 struct btrfs_fs_devices *cur_devices;
1257 u64 all_avail;
1258 u64 devid;
1259 u64 num_devices;
1260 u8 *dev_uuid;
1261 int ret = 0;
1262 bool clear_super = false;
1263
1264 mutex_lock(&uuid_mutex);
1265 mutex_lock(&root->fs_info->volume_mutex);
1266
1267 all_avail = root->fs_info->avail_data_alloc_bits |
1268 root->fs_info->avail_system_alloc_bits |
1269 root->fs_info->avail_metadata_alloc_bits;
1270
1271 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) &&
1272 root->fs_info->fs_devices->num_devices <= 4) {
1273 printk(KERN_ERR "btrfs: unable to go below four devices "
1274 "on raid10\n");
1275 ret = -EINVAL;
1276 goto out;
1277 }
1278
1279 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) &&
1280 root->fs_info->fs_devices->num_devices <= 2) {
1281 printk(KERN_ERR "btrfs: unable to go below two "
1282 "devices on raid1\n");
1283 ret = -EINVAL;
1284 goto out;
1285 }
1286
1287 if (strcmp(device_path, "missing") == 0) {
1288 struct list_head *devices;
1289 struct btrfs_device *tmp;
1290
1291 device = NULL;
1292 devices = &root->fs_info->fs_devices->devices;
1293 /*
1294 * It is safe to read the devices since the volume_mutex
1295 * is held.
1296 */
1297 list_for_each_entry(tmp, devices, dev_list) {
1298 if (tmp->in_fs_metadata && !tmp->bdev) {
1299 device = tmp;
1300 break;
1301 }
1302 }
1303 bdev = NULL;
1304 bh = NULL;
1305 disk_super = NULL;
1306 if (!device) {
1307 printk(KERN_ERR "btrfs: no missing devices found to "
1308 "remove\n");
1309 goto out;
1310 }
1311 } else {
1312 bdev = blkdev_get_by_path(device_path, FMODE_READ | FMODE_EXCL,
1313 root->fs_info->bdev_holder);
1314 if (IS_ERR(bdev)) {
1315 ret = PTR_ERR(bdev);
1316 goto out;
1317 }
1318
1319 set_blocksize(bdev, 4096);
1320 bh = btrfs_read_dev_super(bdev);
1321 if (!bh) {
1322 ret = -EINVAL;
1323 goto error_close;
1324 }
1325 disk_super = (struct btrfs_super_block *)bh->b_data;
1326 devid = btrfs_stack_device_id(&disk_super->dev_item);
1327 dev_uuid = disk_super->dev_item.uuid;
1328 device = btrfs_find_device(root, devid, dev_uuid,
1329 disk_super->fsid);
1330 if (!device) {
1331 ret = -ENOENT;
1332 goto error_brelse;
1333 }
1334 }
1335
1336 if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
1337 printk(KERN_ERR "btrfs: unable to remove the only writeable "
1338 "device\n");
1339 ret = -EINVAL;
1340 goto error_brelse;
1341 }
1342
1343 if (device->writeable) {
1344 lock_chunks(root);
1345 list_del_init(&device->dev_alloc_list);
1346 unlock_chunks(root);
1347 root->fs_info->fs_devices->rw_devices--;
1348 clear_super = true;
1349 }
1350
1351 ret = btrfs_shrink_device(device, 0);
1352 if (ret)
1353 goto error_undo;
1354
1355 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1356 if (ret)
1357 goto error_undo;
1358
1359 device->in_fs_metadata = 0;
1360 btrfs_scrub_cancel_dev(root, device);
1361
1362 /*
1363 * the device list mutex makes sure that we don't change
1364 * the device list while someone else is writing out all
1365 * the device supers.
1366 */
1367
1368 cur_devices = device->fs_devices;
1369 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1370 list_del_rcu(&device->dev_list);
1371
1372 device->fs_devices->num_devices--;
1373
1374 if (device->missing)
1375 root->fs_info->fs_devices->missing_devices--;
1376
1377 next_device = list_entry(root->fs_info->fs_devices->devices.next,
1378 struct btrfs_device, dev_list);
1379 if (device->bdev == root->fs_info->sb->s_bdev)
1380 root->fs_info->sb->s_bdev = next_device->bdev;
1381 if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1382 root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1383
1384 if (device->bdev)
1385 device->fs_devices->open_devices--;
1386
1387 call_rcu(&device->rcu, free_device);
1388 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1389
1390 num_devices = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
1391 btrfs_set_super_num_devices(&root->fs_info->super_copy, num_devices);
1392
1393 if (cur_devices->open_devices == 0) {
1394 struct btrfs_fs_devices *fs_devices;
1395 fs_devices = root->fs_info->fs_devices;
1396 while (fs_devices) {
1397 if (fs_devices->seed == cur_devices)
1398 break;
1399 fs_devices = fs_devices->seed;
1400 }
1401 fs_devices->seed = cur_devices->seed;
1402 cur_devices->seed = NULL;
1403 lock_chunks(root);
1404 __btrfs_close_devices(cur_devices);
1405 unlock_chunks(root);
1406 free_fs_devices(cur_devices);
1407 }
1408
1409 /*
1410 * at this point, the device is zero sized. We want to
1411 * remove it from the devices list and zero out the old super
1412 */
1413 if (clear_super) {
1414 /* make sure this device isn't detected as part of
1415 * the FS anymore
1416 */
1417 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1418 set_buffer_dirty(bh);
1419 sync_dirty_buffer(bh);
1420 }
1421
1422 ret = 0;
1423
1424 error_brelse:
1425 brelse(bh);
1426 error_close:
1427 if (bdev)
1428 blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
1429 out:
1430 mutex_unlock(&root->fs_info->volume_mutex);
1431 mutex_unlock(&uuid_mutex);
1432 return ret;
1433 error_undo:
1434 if (device->writeable) {
1435 lock_chunks(root);
1436 list_add(&device->dev_alloc_list,
1437 &root->fs_info->fs_devices->alloc_list);
1438 unlock_chunks(root);
1439 root->fs_info->fs_devices->rw_devices++;
1440 }
1441 goto error_brelse;
1442 }
1443
1444 /*
1445 * does all the dirty work required for changing file system's UUID.
1446 */
1447 static int btrfs_prepare_sprout(struct btrfs_trans_handle *trans,
1448 struct btrfs_root *root)
1449 {
1450 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1451 struct btrfs_fs_devices *old_devices;
1452 struct btrfs_fs_devices *seed_devices;
1453 struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
1454 struct btrfs_device *device;
1455 u64 super_flags;
1456
1457 BUG_ON(!mutex_is_locked(&uuid_mutex));
1458 if (!fs_devices->seeding)
1459 return -EINVAL;
1460
1461 seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
1462 if (!seed_devices)
1463 return -ENOMEM;
1464
1465 old_devices = clone_fs_devices(fs_devices);
1466 if (IS_ERR(old_devices)) {
1467 kfree(seed_devices);
1468 return PTR_ERR(old_devices);
1469 }
1470
1471 list_add(&old_devices->list, &fs_uuids);
1472
1473 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1474 seed_devices->opened = 1;
1475 INIT_LIST_HEAD(&seed_devices->devices);
1476 INIT_LIST_HEAD(&seed_devices->alloc_list);
1477 mutex_init(&seed_devices->device_list_mutex);
1478
1479 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1480 list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
1481 synchronize_rcu);
1482 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1483
1484 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1485 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1486 device->fs_devices = seed_devices;
1487 }
1488
1489 fs_devices->seeding = 0;
1490 fs_devices->num_devices = 0;
1491 fs_devices->open_devices = 0;
1492 fs_devices->seed = seed_devices;
1493
1494 generate_random_uuid(fs_devices->fsid);
1495 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1496 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1497 super_flags = btrfs_super_flags(disk_super) &
1498 ~BTRFS_SUPER_FLAG_SEEDING;
1499 btrfs_set_super_flags(disk_super, super_flags);
1500
1501 return 0;
1502 }
1503
1504 /*
1505 * strore the expected generation for seed devices in device items.
1506 */
1507 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1508 struct btrfs_root *root)
1509 {
1510 struct btrfs_path *path;
1511 struct extent_buffer *leaf;
1512 struct btrfs_dev_item *dev_item;
1513 struct btrfs_device *device;
1514 struct btrfs_key key;
1515 u8 fs_uuid[BTRFS_UUID_SIZE];
1516 u8 dev_uuid[BTRFS_UUID_SIZE];
1517 u64 devid;
1518 int ret;
1519
1520 path = btrfs_alloc_path();
1521 if (!path)
1522 return -ENOMEM;
1523
1524 root = root->fs_info->chunk_root;
1525 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1526 key.offset = 0;
1527 key.type = BTRFS_DEV_ITEM_KEY;
1528
1529 while (1) {
1530 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1531 if (ret < 0)
1532 goto error;
1533
1534 leaf = path->nodes[0];
1535 next_slot:
1536 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1537 ret = btrfs_next_leaf(root, path);
1538 if (ret > 0)
1539 break;
1540 if (ret < 0)
1541 goto error;
1542 leaf = path->nodes[0];
1543 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1544 btrfs_release_path(path);
1545 continue;
1546 }
1547
1548 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1549 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1550 key.type != BTRFS_DEV_ITEM_KEY)
1551 break;
1552
1553 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1554 struct btrfs_dev_item);
1555 devid = btrfs_device_id(leaf, dev_item);
1556 read_extent_buffer(leaf, dev_uuid,
1557 (unsigned long)btrfs_device_uuid(dev_item),
1558 BTRFS_UUID_SIZE);
1559 read_extent_buffer(leaf, fs_uuid,
1560 (unsigned long)btrfs_device_fsid(dev_item),
1561 BTRFS_UUID_SIZE);
1562 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
1563 BUG_ON(!device);
1564
1565 if (device->fs_devices->seeding) {
1566 btrfs_set_device_generation(leaf, dev_item,
1567 device->generation);
1568 btrfs_mark_buffer_dirty(leaf);
1569 }
1570
1571 path->slots[0]++;
1572 goto next_slot;
1573 }
1574 ret = 0;
1575 error:
1576 btrfs_free_path(path);
1577 return ret;
1578 }
1579
1580 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1581 {
1582 struct request_queue *q;
1583 struct btrfs_trans_handle *trans;
1584 struct btrfs_device *device;
1585 struct block_device *bdev;
1586 struct list_head *devices;
1587 struct super_block *sb = root->fs_info->sb;
1588 u64 total_bytes;
1589 int seeding_dev = 0;
1590 int ret = 0;
1591
1592 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1593 return -EINVAL;
1594
1595 bdev = blkdev_get_by_path(device_path, FMODE_EXCL,
1596 root->fs_info->bdev_holder);
1597 if (IS_ERR(bdev))
1598 return PTR_ERR(bdev);
1599
1600 if (root->fs_info->fs_devices->seeding) {
1601 seeding_dev = 1;
1602 down_write(&sb->s_umount);
1603 mutex_lock(&uuid_mutex);
1604 }
1605
1606 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1607 mutex_lock(&root->fs_info->volume_mutex);
1608
1609 devices = &root->fs_info->fs_devices->devices;
1610 /*
1611 * we have the volume lock, so we don't need the extra
1612 * device list mutex while reading the list here.
1613 */
1614 list_for_each_entry(device, devices, dev_list) {
1615 if (device->bdev == bdev) {
1616 ret = -EEXIST;
1617 goto error;
1618 }
1619 }
1620
1621 device = kzalloc(sizeof(*device), GFP_NOFS);
1622 if (!device) {
1623 /* we can safely leave the fs_devices entry around */
1624 ret = -ENOMEM;
1625 goto error;
1626 }
1627
1628 device->name = kstrdup(device_path, GFP_NOFS);
1629 if (!device->name) {
1630 kfree(device);
1631 ret = -ENOMEM;
1632 goto error;
1633 }
1634
1635 ret = find_next_devid(root, &device->devid);
1636 if (ret) {
1637 kfree(device->name);
1638 kfree(device);
1639 goto error;
1640 }
1641
1642 trans = btrfs_start_transaction(root, 0);
1643 if (IS_ERR(trans)) {
1644 kfree(device->name);
1645 kfree(device);
1646 ret = PTR_ERR(trans);
1647 goto error;
1648 }
1649
1650 lock_chunks(root);
1651
1652 q = bdev_get_queue(bdev);
1653 if (blk_queue_discard(q))
1654 device->can_discard = 1;
1655 device->writeable = 1;
1656 device->work.func = pending_bios_fn;
1657 generate_random_uuid(device->uuid);
1658 spin_lock_init(&device->io_lock);
1659 device->generation = trans->transid;
1660 device->io_width = root->sectorsize;
1661 device->io_align = root->sectorsize;
1662 device->sector_size = root->sectorsize;
1663 device->total_bytes = i_size_read(bdev->bd_inode);
1664 device->disk_total_bytes = device->total_bytes;
1665 device->dev_root = root->fs_info->dev_root;
1666 device->bdev = bdev;
1667 device->in_fs_metadata = 1;
1668 device->mode = FMODE_EXCL;
1669 set_blocksize(device->bdev, 4096);
1670
1671 if (seeding_dev) {
1672 sb->s_flags &= ~MS_RDONLY;
1673 ret = btrfs_prepare_sprout(trans, root);
1674 BUG_ON(ret);
1675 }
1676
1677 device->fs_devices = root->fs_info->fs_devices;
1678
1679 /*
1680 * we don't want write_supers to jump in here with our device
1681 * half setup
1682 */
1683 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1684 list_add_rcu(&device->dev_list, &root->fs_info->fs_devices->devices);
1685 list_add(&device->dev_alloc_list,
1686 &root->fs_info->fs_devices->alloc_list);
1687 root->fs_info->fs_devices->num_devices++;
1688 root->fs_info->fs_devices->open_devices++;
1689 root->fs_info->fs_devices->rw_devices++;
1690 if (device->can_discard)
1691 root->fs_info->fs_devices->num_can_discard++;
1692 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
1693
1694 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
1695 root->fs_info->fs_devices->rotating = 1;
1696
1697 total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
1698 btrfs_set_super_total_bytes(&root->fs_info->super_copy,
1699 total_bytes + device->total_bytes);
1700
1701 total_bytes = btrfs_super_num_devices(&root->fs_info->super_copy);
1702 btrfs_set_super_num_devices(&root->fs_info->super_copy,
1703 total_bytes + 1);
1704 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1705
1706 if (seeding_dev) {
1707 ret = init_first_rw_device(trans, root, device);
1708 BUG_ON(ret);
1709 ret = btrfs_finish_sprout(trans, root);
1710 BUG_ON(ret);
1711 } else {
1712 ret = btrfs_add_device(trans, root, device);
1713 }
1714
1715 /*
1716 * we've got more storage, clear any full flags on the space
1717 * infos
1718 */
1719 btrfs_clear_space_info_full(root->fs_info);
1720
1721 unlock_chunks(root);
1722 btrfs_commit_transaction(trans, root);
1723
1724 if (seeding_dev) {
1725 mutex_unlock(&uuid_mutex);
1726 up_write(&sb->s_umount);
1727
1728 ret = btrfs_relocate_sys_chunks(root);
1729 BUG_ON(ret);
1730 }
1731 out:
1732 mutex_unlock(&root->fs_info->volume_mutex);
1733 return ret;
1734 error:
1735 blkdev_put(bdev, FMODE_EXCL);
1736 if (seeding_dev) {
1737 mutex_unlock(&uuid_mutex);
1738 up_write(&sb->s_umount);
1739 }
1740 goto out;
1741 }
1742
1743 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
1744 struct btrfs_device *device)
1745 {
1746 int ret;
1747 struct btrfs_path *path;
1748 struct btrfs_root *root;
1749 struct btrfs_dev_item *dev_item;
1750 struct extent_buffer *leaf;
1751 struct btrfs_key key;
1752
1753 root = device->dev_root->fs_info->chunk_root;
1754
1755 path = btrfs_alloc_path();
1756 if (!path)
1757 return -ENOMEM;
1758
1759 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1760 key.type = BTRFS_DEV_ITEM_KEY;
1761 key.offset = device->devid;
1762
1763 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1764 if (ret < 0)
1765 goto out;
1766
1767 if (ret > 0) {
1768 ret = -ENOENT;
1769 goto out;
1770 }
1771
1772 leaf = path->nodes[0];
1773 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1774
1775 btrfs_set_device_id(leaf, dev_item, device->devid);
1776 btrfs_set_device_type(leaf, dev_item, device->type);
1777 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1778 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1779 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1780 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
1781 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1782 btrfs_mark_buffer_dirty(leaf);
1783
1784 out:
1785 btrfs_free_path(path);
1786 return ret;
1787 }
1788
1789 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
1790 struct btrfs_device *device, u64 new_size)
1791 {
1792 struct btrfs_super_block *super_copy =
1793 &device->dev_root->fs_info->super_copy;
1794 u64 old_total = btrfs_super_total_bytes(super_copy);
1795 u64 diff = new_size - device->total_bytes;
1796
1797 if (!device->writeable)
1798 return -EACCES;
1799 if (new_size <= device->total_bytes)
1800 return -EINVAL;
1801
1802 btrfs_set_super_total_bytes(super_copy, old_total + diff);
1803 device->fs_devices->total_rw_bytes += diff;
1804
1805 device->total_bytes = new_size;
1806 device->disk_total_bytes = new_size;
1807 btrfs_clear_space_info_full(device->dev_root->fs_info);
1808
1809 return btrfs_update_device(trans, device);
1810 }
1811
1812 int btrfs_grow_device(struct btrfs_trans_handle *trans,
1813 struct btrfs_device *device, u64 new_size)
1814 {
1815 int ret;
1816 lock_chunks(device->dev_root);
1817 ret = __btrfs_grow_device(trans, device, new_size);
1818 unlock_chunks(device->dev_root);
1819 return ret;
1820 }
1821
1822 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
1823 struct btrfs_root *root,
1824 u64 chunk_tree, u64 chunk_objectid,
1825 u64 chunk_offset)
1826 {
1827 int ret;
1828 struct btrfs_path *path;
1829 struct btrfs_key key;
1830
1831 root = root->fs_info->chunk_root;
1832 path = btrfs_alloc_path();
1833 if (!path)
1834 return -ENOMEM;
1835
1836 key.objectid = chunk_objectid;
1837 key.offset = chunk_offset;
1838 key.type = BTRFS_CHUNK_ITEM_KEY;
1839
1840 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1841 BUG_ON(ret);
1842
1843 ret = btrfs_del_item(trans, root, path);
1844
1845 btrfs_free_path(path);
1846 return ret;
1847 }
1848
1849 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
1850 chunk_offset)
1851 {
1852 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
1853 struct btrfs_disk_key *disk_key;
1854 struct btrfs_chunk *chunk;
1855 u8 *ptr;
1856 int ret = 0;
1857 u32 num_stripes;
1858 u32 array_size;
1859 u32 len = 0;
1860 u32 cur;
1861 struct btrfs_key key;
1862
1863 array_size = btrfs_super_sys_array_size(super_copy);
1864
1865 ptr = super_copy->sys_chunk_array;
1866 cur = 0;
1867
1868 while (cur < array_size) {
1869 disk_key = (struct btrfs_disk_key *)ptr;
1870 btrfs_disk_key_to_cpu(&key, disk_key);
1871
1872 len = sizeof(*disk_key);
1873
1874 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
1875 chunk = (struct btrfs_chunk *)(ptr + len);
1876 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
1877 len += btrfs_chunk_item_size(num_stripes);
1878 } else {
1879 ret = -EIO;
1880 break;
1881 }
1882 if (key.objectid == chunk_objectid &&
1883 key.offset == chunk_offset) {
1884 memmove(ptr, ptr + len, array_size - (cur + len));
1885 array_size -= len;
1886 btrfs_set_super_sys_array_size(super_copy, array_size);
1887 } else {
1888 ptr += len;
1889 cur += len;
1890 }
1891 }
1892 return ret;
1893 }
1894
1895 static int btrfs_relocate_chunk(struct btrfs_root *root,
1896 u64 chunk_tree, u64 chunk_objectid,
1897 u64 chunk_offset)
1898 {
1899 struct extent_map_tree *em_tree;
1900 struct btrfs_root *extent_root;
1901 struct btrfs_trans_handle *trans;
1902 struct extent_map *em;
1903 struct map_lookup *map;
1904 int ret;
1905 int i;
1906
1907 root = root->fs_info->chunk_root;
1908 extent_root = root->fs_info->extent_root;
1909 em_tree = &root->fs_info->mapping_tree.map_tree;
1910
1911 ret = btrfs_can_relocate(extent_root, chunk_offset);
1912 if (ret)
1913 return -ENOSPC;
1914
1915 /* step one, relocate all the extents inside this chunk */
1916 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
1917 if (ret)
1918 return ret;
1919
1920 trans = btrfs_start_transaction(root, 0);
1921 BUG_ON(IS_ERR(trans));
1922
1923 lock_chunks(root);
1924
1925 /*
1926 * step two, delete the device extents and the
1927 * chunk tree entries
1928 */
1929 read_lock(&em_tree->lock);
1930 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
1931 read_unlock(&em_tree->lock);
1932
1933 BUG_ON(em->start > chunk_offset ||
1934 em->start + em->len < chunk_offset);
1935 map = (struct map_lookup *)em->bdev;
1936
1937 for (i = 0; i < map->num_stripes; i++) {
1938 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
1939 map->stripes[i].physical);
1940 BUG_ON(ret);
1941
1942 if (map->stripes[i].dev) {
1943 ret = btrfs_update_device(trans, map->stripes[i].dev);
1944 BUG_ON(ret);
1945 }
1946 }
1947 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
1948 chunk_offset);
1949
1950 BUG_ON(ret);
1951
1952 trace_btrfs_chunk_free(root, map, chunk_offset, em->len);
1953
1954 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
1955 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
1956 BUG_ON(ret);
1957 }
1958
1959 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
1960 BUG_ON(ret);
1961
1962 write_lock(&em_tree->lock);
1963 remove_extent_mapping(em_tree, em);
1964 write_unlock(&em_tree->lock);
1965
1966 kfree(map);
1967 em->bdev = NULL;
1968
1969 /* once for the tree */
1970 free_extent_map(em);
1971 /* once for us */
1972 free_extent_map(em);
1973
1974 unlock_chunks(root);
1975 btrfs_end_transaction(trans, root);
1976 return 0;
1977 }
1978
1979 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
1980 {
1981 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
1982 struct btrfs_path *path;
1983 struct extent_buffer *leaf;
1984 struct btrfs_chunk *chunk;
1985 struct btrfs_key key;
1986 struct btrfs_key found_key;
1987 u64 chunk_tree = chunk_root->root_key.objectid;
1988 u64 chunk_type;
1989 bool retried = false;
1990 int failed = 0;
1991 int ret;
1992
1993 path = btrfs_alloc_path();
1994 if (!path)
1995 return -ENOMEM;
1996
1997 again:
1998 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
1999 key.offset = (u64)-1;
2000 key.type = BTRFS_CHUNK_ITEM_KEY;
2001
2002 while (1) {
2003 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2004 if (ret < 0)
2005 goto error;
2006 BUG_ON(ret == 0);
2007
2008 ret = btrfs_previous_item(chunk_root, path, key.objectid,
2009 key.type);
2010 if (ret < 0)
2011 goto error;
2012 if (ret > 0)
2013 break;
2014
2015 leaf = path->nodes[0];
2016 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2017
2018 chunk = btrfs_item_ptr(leaf, path->slots[0],
2019 struct btrfs_chunk);
2020 chunk_type = btrfs_chunk_type(leaf, chunk);
2021 btrfs_release_path(path);
2022
2023 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
2024 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
2025 found_key.objectid,
2026 found_key.offset);
2027 if (ret == -ENOSPC)
2028 failed++;
2029 else if (ret)
2030 BUG();
2031 }
2032
2033 if (found_key.offset == 0)
2034 break;
2035 key.offset = found_key.offset - 1;
2036 }
2037 ret = 0;
2038 if (failed && !retried) {
2039 failed = 0;
2040 retried = true;
2041 goto again;
2042 } else if (failed && retried) {
2043 WARN_ON(1);
2044 ret = -ENOSPC;
2045 }
2046 error:
2047 btrfs_free_path(path);
2048 return ret;
2049 }
2050
2051 static u64 div_factor(u64 num, int factor)
2052 {
2053 if (factor == 10)
2054 return num;
2055 num *= factor;
2056 do_div(num, 10);
2057 return num;
2058 }
2059
2060 int btrfs_balance(struct btrfs_root *dev_root)
2061 {
2062 int ret;
2063 struct list_head *devices = &dev_root->fs_info->fs_devices->devices;
2064 struct btrfs_device *device;
2065 u64 old_size;
2066 u64 size_to_free;
2067 struct btrfs_path *path;
2068 struct btrfs_key key;
2069 struct btrfs_root *chunk_root = dev_root->fs_info->chunk_root;
2070 struct btrfs_trans_handle *trans;
2071 struct btrfs_key found_key;
2072
2073 if (dev_root->fs_info->sb->s_flags & MS_RDONLY)
2074 return -EROFS;
2075
2076 if (!capable(CAP_SYS_ADMIN))
2077 return -EPERM;
2078
2079 mutex_lock(&dev_root->fs_info->volume_mutex);
2080 dev_root = dev_root->fs_info->dev_root;
2081
2082 /* step one make some room on all the devices */
2083 list_for_each_entry(device, devices, dev_list) {
2084 old_size = device->total_bytes;
2085 size_to_free = div_factor(old_size, 1);
2086 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
2087 if (!device->writeable ||
2088 device->total_bytes - device->bytes_used > size_to_free)
2089 continue;
2090
2091 ret = btrfs_shrink_device(device, old_size - size_to_free);
2092 if (ret == -ENOSPC)
2093 break;
2094 BUG_ON(ret);
2095
2096 trans = btrfs_start_transaction(dev_root, 0);
2097 BUG_ON(IS_ERR(trans));
2098
2099 ret = btrfs_grow_device(trans, device, old_size);
2100 BUG_ON(ret);
2101
2102 btrfs_end_transaction(trans, dev_root);
2103 }
2104
2105 /* step two, relocate all the chunks */
2106 path = btrfs_alloc_path();
2107 if (!path) {
2108 ret = -ENOMEM;
2109 goto error;
2110 }
2111 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2112 key.offset = (u64)-1;
2113 key.type = BTRFS_CHUNK_ITEM_KEY;
2114
2115 while (1) {
2116 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2117 if (ret < 0)
2118 goto error;
2119
2120 /*
2121 * this shouldn't happen, it means the last relocate
2122 * failed
2123 */
2124 if (ret == 0)
2125 break;
2126
2127 ret = btrfs_previous_item(chunk_root, path, 0,
2128 BTRFS_CHUNK_ITEM_KEY);
2129 if (ret)
2130 break;
2131
2132 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2133 path->slots[0]);
2134 if (found_key.objectid != key.objectid)
2135 break;
2136
2137 /* chunk zero is special */
2138 if (found_key.offset == 0)
2139 break;
2140
2141 btrfs_release_path(path);
2142 ret = btrfs_relocate_chunk(chunk_root,
2143 chunk_root->root_key.objectid,
2144 found_key.objectid,
2145 found_key.offset);
2146 if (ret && ret != -ENOSPC)
2147 goto error;
2148 key.offset = found_key.offset - 1;
2149 }
2150 ret = 0;
2151 error:
2152 btrfs_free_path(path);
2153 mutex_unlock(&dev_root->fs_info->volume_mutex);
2154 return ret;
2155 }
2156
2157 /*
2158 * shrinking a device means finding all of the device extents past
2159 * the new size, and then following the back refs to the chunks.
2160 * The chunk relocation code actually frees the device extent
2161 */
2162 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
2163 {
2164 struct btrfs_trans_handle *trans;
2165 struct btrfs_root *root = device->dev_root;
2166 struct btrfs_dev_extent *dev_extent = NULL;
2167 struct btrfs_path *path;
2168 u64 length;
2169 u64 chunk_tree;
2170 u64 chunk_objectid;
2171 u64 chunk_offset;
2172 int ret;
2173 int slot;
2174 int failed = 0;
2175 bool retried = false;
2176 struct extent_buffer *l;
2177 struct btrfs_key key;
2178 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
2179 u64 old_total = btrfs_super_total_bytes(super_copy);
2180 u64 old_size = device->total_bytes;
2181 u64 diff = device->total_bytes - new_size;
2182
2183 if (new_size >= device->total_bytes)
2184 return -EINVAL;
2185
2186 path = btrfs_alloc_path();
2187 if (!path)
2188 return -ENOMEM;
2189
2190 path->reada = 2;
2191
2192 lock_chunks(root);
2193
2194 device->total_bytes = new_size;
2195 if (device->writeable)
2196 device->fs_devices->total_rw_bytes -= diff;
2197 unlock_chunks(root);
2198
2199 again:
2200 key.objectid = device->devid;
2201 key.offset = (u64)-1;
2202 key.type = BTRFS_DEV_EXTENT_KEY;
2203
2204 while (1) {
2205 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2206 if (ret < 0)
2207 goto done;
2208
2209 ret = btrfs_previous_item(root, path, 0, key.type);
2210 if (ret < 0)
2211 goto done;
2212 if (ret) {
2213 ret = 0;
2214 btrfs_release_path(path);
2215 break;
2216 }
2217
2218 l = path->nodes[0];
2219 slot = path->slots[0];
2220 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
2221
2222 if (key.objectid != device->devid) {
2223 btrfs_release_path(path);
2224 break;
2225 }
2226
2227 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
2228 length = btrfs_dev_extent_length(l, dev_extent);
2229
2230 if (key.offset + length <= new_size) {
2231 btrfs_release_path(path);
2232 break;
2233 }
2234
2235 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
2236 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
2237 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
2238 btrfs_release_path(path);
2239
2240 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
2241 chunk_offset);
2242 if (ret && ret != -ENOSPC)
2243 goto done;
2244 if (ret == -ENOSPC)
2245 failed++;
2246 key.offset -= 1;
2247 }
2248
2249 if (failed && !retried) {
2250 failed = 0;
2251 retried = true;
2252 goto again;
2253 } else if (failed && retried) {
2254 ret = -ENOSPC;
2255 lock_chunks(root);
2256
2257 device->total_bytes = old_size;
2258 if (device->writeable)
2259 device->fs_devices->total_rw_bytes += diff;
2260 unlock_chunks(root);
2261 goto done;
2262 }
2263
2264 /* Shrinking succeeded, else we would be at "done". */
2265 trans = btrfs_start_transaction(root, 0);
2266 if (IS_ERR(trans)) {
2267 ret = PTR_ERR(trans);
2268 goto done;
2269 }
2270
2271 lock_chunks(root);
2272
2273 device->disk_total_bytes = new_size;
2274 /* Now btrfs_update_device() will change the on-disk size. */
2275 ret = btrfs_update_device(trans, device);
2276 if (ret) {
2277 unlock_chunks(root);
2278 btrfs_end_transaction(trans, root);
2279 goto done;
2280 }
2281 WARN_ON(diff > old_total);
2282 btrfs_set_super_total_bytes(super_copy, old_total - diff);
2283 unlock_chunks(root);
2284 btrfs_end_transaction(trans, root);
2285 done:
2286 btrfs_free_path(path);
2287 return ret;
2288 }
2289
2290 static int btrfs_add_system_chunk(struct btrfs_trans_handle *trans,
2291 struct btrfs_root *root,
2292 struct btrfs_key *key,
2293 struct btrfs_chunk *chunk, int item_size)
2294 {
2295 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
2296 struct btrfs_disk_key disk_key;
2297 u32 array_size;
2298 u8 *ptr;
2299
2300 array_size = btrfs_super_sys_array_size(super_copy);
2301 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
2302 return -EFBIG;
2303
2304 ptr = super_copy->sys_chunk_array + array_size;
2305 btrfs_cpu_key_to_disk(&disk_key, key);
2306 memcpy(ptr, &disk_key, sizeof(disk_key));
2307 ptr += sizeof(disk_key);
2308 memcpy(ptr, chunk, item_size);
2309 item_size += sizeof(disk_key);
2310 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
2311 return 0;
2312 }
2313
2314 /*
2315 * sort the devices in descending order by max_avail, total_avail
2316 */
2317 static int btrfs_cmp_device_info(const void *a, const void *b)
2318 {
2319 const struct btrfs_device_info *di_a = a;
2320 const struct btrfs_device_info *di_b = b;
2321
2322 if (di_a->max_avail > di_b->max_avail)
2323 return -1;
2324 if (di_a->max_avail < di_b->max_avail)
2325 return 1;
2326 if (di_a->total_avail > di_b->total_avail)
2327 return -1;
2328 if (di_a->total_avail < di_b->total_avail)
2329 return 1;
2330 return 0;
2331 }
2332
2333 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
2334 struct btrfs_root *extent_root,
2335 struct map_lookup **map_ret,
2336 u64 *num_bytes_out, u64 *stripe_size_out,
2337 u64 start, u64 type)
2338 {
2339 struct btrfs_fs_info *info = extent_root->fs_info;
2340 struct btrfs_fs_devices *fs_devices = info->fs_devices;
2341 struct list_head *cur;
2342 struct map_lookup *map = NULL;
2343 struct extent_map_tree *em_tree;
2344 struct extent_map *em;
2345 struct btrfs_device_info *devices_info = NULL;
2346 u64 total_avail;
2347 int num_stripes; /* total number of stripes to allocate */
2348 int sub_stripes; /* sub_stripes info for map */
2349 int dev_stripes; /* stripes per dev */
2350 int devs_max; /* max devs to use */
2351 int devs_min; /* min devs needed */
2352 int devs_increment; /* ndevs has to be a multiple of this */
2353 int ncopies; /* how many copies to data has */
2354 int ret;
2355 u64 max_stripe_size;
2356 u64 max_chunk_size;
2357 u64 stripe_size;
2358 u64 num_bytes;
2359 int ndevs;
2360 int i;
2361 int j;
2362
2363 if ((type & BTRFS_BLOCK_GROUP_RAID1) &&
2364 (type & BTRFS_BLOCK_GROUP_DUP)) {
2365 WARN_ON(1);
2366 type &= ~BTRFS_BLOCK_GROUP_DUP;
2367 }
2368
2369 if (list_empty(&fs_devices->alloc_list))
2370 return -ENOSPC;
2371
2372 sub_stripes = 1;
2373 dev_stripes = 1;
2374 devs_increment = 1;
2375 ncopies = 1;
2376 devs_max = 0; /* 0 == as many as possible */
2377 devs_min = 1;
2378
2379 /*
2380 * define the properties of each RAID type.
2381 * FIXME: move this to a global table and use it in all RAID
2382 * calculation code
2383 */
2384 if (type & (BTRFS_BLOCK_GROUP_DUP)) {
2385 dev_stripes = 2;
2386 ncopies = 2;
2387 devs_max = 1;
2388 } else if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
2389 devs_min = 2;
2390 } else if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
2391 devs_increment = 2;
2392 ncopies = 2;
2393 devs_max = 2;
2394 devs_min = 2;
2395 } else if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
2396 sub_stripes = 2;
2397 devs_increment = 2;
2398 ncopies = 2;
2399 devs_min = 4;
2400 } else {
2401 devs_max = 1;
2402 }
2403
2404 if (type & BTRFS_BLOCK_GROUP_DATA) {
2405 max_stripe_size = 1024 * 1024 * 1024;
2406 max_chunk_size = 10 * max_stripe_size;
2407 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
2408 max_stripe_size = 256 * 1024 * 1024;
2409 max_chunk_size = max_stripe_size;
2410 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
2411 max_stripe_size = 8 * 1024 * 1024;
2412 max_chunk_size = 2 * max_stripe_size;
2413 } else {
2414 printk(KERN_ERR "btrfs: invalid chunk type 0x%llx requested\n",
2415 type);
2416 BUG_ON(1);
2417 }
2418
2419 /* we don't want a chunk larger than 10% of writeable space */
2420 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
2421 max_chunk_size);
2422
2423 devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices,
2424 GFP_NOFS);
2425 if (!devices_info)
2426 return -ENOMEM;
2427
2428 cur = fs_devices->alloc_list.next;
2429
2430 /*
2431 * in the first pass through the devices list, we gather information
2432 * about the available holes on each device.
2433 */
2434 ndevs = 0;
2435 while (cur != &fs_devices->alloc_list) {
2436 struct btrfs_device *device;
2437 u64 max_avail;
2438 u64 dev_offset;
2439
2440 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
2441
2442 cur = cur->next;
2443
2444 if (!device->writeable) {
2445 printk(KERN_ERR
2446 "btrfs: read-only device in alloc_list\n");
2447 WARN_ON(1);
2448 continue;
2449 }
2450
2451 if (!device->in_fs_metadata)
2452 continue;
2453
2454 if (device->total_bytes > device->bytes_used)
2455 total_avail = device->total_bytes - device->bytes_used;
2456 else
2457 total_avail = 0;
2458
2459 /* If there is no space on this device, skip it. */
2460 if (total_avail == 0)
2461 continue;
2462
2463 ret = find_free_dev_extent(trans, device,
2464 max_stripe_size * dev_stripes,
2465 &dev_offset, &max_avail);
2466 if (ret && ret != -ENOSPC)
2467 goto error;
2468
2469 if (ret == 0)
2470 max_avail = max_stripe_size * dev_stripes;
2471
2472 if (max_avail < BTRFS_STRIPE_LEN * dev_stripes)
2473 continue;
2474
2475 devices_info[ndevs].dev_offset = dev_offset;
2476 devices_info[ndevs].max_avail = max_avail;
2477 devices_info[ndevs].total_avail = total_avail;
2478 devices_info[ndevs].dev = device;
2479 ++ndevs;
2480 }
2481
2482 /*
2483 * now sort the devices by hole size / available space
2484 */
2485 sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
2486 btrfs_cmp_device_info, NULL);
2487
2488 /* round down to number of usable stripes */
2489 ndevs -= ndevs % devs_increment;
2490
2491 if (ndevs < devs_increment * sub_stripes || ndevs < devs_min) {
2492 ret = -ENOSPC;
2493 goto error;
2494 }
2495
2496 if (devs_max && ndevs > devs_max)
2497 ndevs = devs_max;
2498 /*
2499 * the primary goal is to maximize the number of stripes, so use as many
2500 * devices as possible, even if the stripes are not maximum sized.
2501 */
2502 stripe_size = devices_info[ndevs-1].max_avail;
2503 num_stripes = ndevs * dev_stripes;
2504
2505 if (stripe_size * num_stripes > max_chunk_size * ncopies) {
2506 stripe_size = max_chunk_size * ncopies;
2507 do_div(stripe_size, num_stripes);
2508 }
2509
2510 do_div(stripe_size, dev_stripes);
2511 do_div(stripe_size, BTRFS_STRIPE_LEN);
2512 stripe_size *= BTRFS_STRIPE_LEN;
2513
2514 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
2515 if (!map) {
2516 ret = -ENOMEM;
2517 goto error;
2518 }
2519 map->num_stripes = num_stripes;
2520
2521 for (i = 0; i < ndevs; ++i) {
2522 for (j = 0; j < dev_stripes; ++j) {
2523 int s = i * dev_stripes + j;
2524 map->stripes[s].dev = devices_info[i].dev;
2525 map->stripes[s].physical = devices_info[i].dev_offset +
2526 j * stripe_size;
2527 }
2528 }
2529 map->sector_size = extent_root->sectorsize;
2530 map->stripe_len = BTRFS_STRIPE_LEN;
2531 map->io_align = BTRFS_STRIPE_LEN;
2532 map->io_width = BTRFS_STRIPE_LEN;
2533 map->type = type;
2534 map->sub_stripes = sub_stripes;
2535
2536 *map_ret = map;
2537 num_bytes = stripe_size * (num_stripes / ncopies);
2538
2539 *stripe_size_out = stripe_size;
2540 *num_bytes_out = num_bytes;
2541
2542 trace_btrfs_chunk_alloc(info->chunk_root, map, start, num_bytes);
2543
2544 em = alloc_extent_map();
2545 if (!em) {
2546 ret = -ENOMEM;
2547 goto error;
2548 }
2549 em->bdev = (struct block_device *)map;
2550 em->start = start;
2551 em->len = num_bytes;
2552 em->block_start = 0;
2553 em->block_len = em->len;
2554
2555 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
2556 write_lock(&em_tree->lock);
2557 ret = add_extent_mapping(em_tree, em);
2558 write_unlock(&em_tree->lock);
2559 BUG_ON(ret);
2560 free_extent_map(em);
2561
2562 ret = btrfs_make_block_group(trans, extent_root, 0, type,
2563 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2564 start, num_bytes);
2565 BUG_ON(ret);
2566
2567 for (i = 0; i < map->num_stripes; ++i) {
2568 struct btrfs_device *device;
2569 u64 dev_offset;
2570
2571 device = map->stripes[i].dev;
2572 dev_offset = map->stripes[i].physical;
2573
2574 ret = btrfs_alloc_dev_extent(trans, device,
2575 info->chunk_root->root_key.objectid,
2576 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2577 start, dev_offset, stripe_size);
2578 BUG_ON(ret);
2579 }
2580
2581 kfree(devices_info);
2582 return 0;
2583
2584 error:
2585 kfree(map);
2586 kfree(devices_info);
2587 return ret;
2588 }
2589
2590 static int __finish_chunk_alloc(struct btrfs_trans_handle *trans,
2591 struct btrfs_root *extent_root,
2592 struct map_lookup *map, u64 chunk_offset,
2593 u64 chunk_size, u64 stripe_size)
2594 {
2595 u64 dev_offset;
2596 struct btrfs_key key;
2597 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
2598 struct btrfs_device *device;
2599 struct btrfs_chunk *chunk;
2600 struct btrfs_stripe *stripe;
2601 size_t item_size = btrfs_chunk_item_size(map->num_stripes);
2602 int index = 0;
2603 int ret;
2604
2605 chunk = kzalloc(item_size, GFP_NOFS);
2606 if (!chunk)
2607 return -ENOMEM;
2608
2609 index = 0;
2610 while (index < map->num_stripes) {
2611 device = map->stripes[index].dev;
2612 device->bytes_used += stripe_size;
2613 ret = btrfs_update_device(trans, device);
2614 BUG_ON(ret);
2615 index++;
2616 }
2617
2618 index = 0;
2619 stripe = &chunk->stripe;
2620 while (index < map->num_stripes) {
2621 device = map->stripes[index].dev;
2622 dev_offset = map->stripes[index].physical;
2623
2624 btrfs_set_stack_stripe_devid(stripe, device->devid);
2625 btrfs_set_stack_stripe_offset(stripe, dev_offset);
2626 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
2627 stripe++;
2628 index++;
2629 }
2630
2631 btrfs_set_stack_chunk_length(chunk, chunk_size);
2632 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
2633 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
2634 btrfs_set_stack_chunk_type(chunk, map->type);
2635 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
2636 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
2637 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
2638 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
2639 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
2640
2641 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2642 key.type = BTRFS_CHUNK_ITEM_KEY;
2643 key.offset = chunk_offset;
2644
2645 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
2646 BUG_ON(ret);
2647
2648 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2649 ret = btrfs_add_system_chunk(trans, chunk_root, &key, chunk,
2650 item_size);
2651 BUG_ON(ret);
2652 }
2653
2654 kfree(chunk);
2655 return 0;
2656 }
2657
2658 /*
2659 * Chunk allocation falls into two parts. The first part does works
2660 * that make the new allocated chunk useable, but not do any operation
2661 * that modifies the chunk tree. The second part does the works that
2662 * require modifying the chunk tree. This division is important for the
2663 * bootstrap process of adding storage to a seed btrfs.
2664 */
2665 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
2666 struct btrfs_root *extent_root, u64 type)
2667 {
2668 u64 chunk_offset;
2669 u64 chunk_size;
2670 u64 stripe_size;
2671 struct map_lookup *map;
2672 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
2673 int ret;
2674
2675 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2676 &chunk_offset);
2677 if (ret)
2678 return ret;
2679
2680 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
2681 &stripe_size, chunk_offset, type);
2682 if (ret)
2683 return ret;
2684
2685 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
2686 chunk_size, stripe_size);
2687 BUG_ON(ret);
2688 return 0;
2689 }
2690
2691 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
2692 struct btrfs_root *root,
2693 struct btrfs_device *device)
2694 {
2695 u64 chunk_offset;
2696 u64 sys_chunk_offset;
2697 u64 chunk_size;
2698 u64 sys_chunk_size;
2699 u64 stripe_size;
2700 u64 sys_stripe_size;
2701 u64 alloc_profile;
2702 struct map_lookup *map;
2703 struct map_lookup *sys_map;
2704 struct btrfs_fs_info *fs_info = root->fs_info;
2705 struct btrfs_root *extent_root = fs_info->extent_root;
2706 int ret;
2707
2708 ret = find_next_chunk(fs_info->chunk_root,
2709 BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset);
2710 if (ret)
2711 return ret;
2712
2713 alloc_profile = BTRFS_BLOCK_GROUP_METADATA |
2714 (fs_info->metadata_alloc_profile &
2715 fs_info->avail_metadata_alloc_bits);
2716 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
2717
2718 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
2719 &stripe_size, chunk_offset, alloc_profile);
2720 BUG_ON(ret);
2721
2722 sys_chunk_offset = chunk_offset + chunk_size;
2723
2724 alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM |
2725 (fs_info->system_alloc_profile &
2726 fs_info->avail_system_alloc_bits);
2727 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
2728
2729 ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,
2730 &sys_chunk_size, &sys_stripe_size,
2731 sys_chunk_offset, alloc_profile);
2732 BUG_ON(ret);
2733
2734 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
2735 BUG_ON(ret);
2736
2737 /*
2738 * Modifying chunk tree needs allocating new blocks from both
2739 * system block group and metadata block group. So we only can
2740 * do operations require modifying the chunk tree after both
2741 * block groups were created.
2742 */
2743 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
2744 chunk_size, stripe_size);
2745 BUG_ON(ret);
2746
2747 ret = __finish_chunk_alloc(trans, extent_root, sys_map,
2748 sys_chunk_offset, sys_chunk_size,
2749 sys_stripe_size);
2750 BUG_ON(ret);
2751 return 0;
2752 }
2753
2754 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
2755 {
2756 struct extent_map *em;
2757 struct map_lookup *map;
2758 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
2759 int readonly = 0;
2760 int i;
2761
2762 read_lock(&map_tree->map_tree.lock);
2763 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
2764 read_unlock(&map_tree->map_tree.lock);
2765 if (!em)
2766 return 1;
2767
2768 if (btrfs_test_opt(root, DEGRADED)) {
2769 free_extent_map(em);
2770 return 0;
2771 }
2772
2773 map = (struct map_lookup *)em->bdev;
2774 for (i = 0; i < map->num_stripes; i++) {
2775 if (!map->stripes[i].dev->writeable) {
2776 readonly = 1;
2777 break;
2778 }
2779 }
2780 free_extent_map(em);
2781 return readonly;
2782 }
2783
2784 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
2785 {
2786 extent_map_tree_init(&tree->map_tree);
2787 }
2788
2789 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
2790 {
2791 struct extent_map *em;
2792
2793 while (1) {
2794 write_lock(&tree->map_tree.lock);
2795 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
2796 if (em)
2797 remove_extent_mapping(&tree->map_tree, em);
2798 write_unlock(&tree->map_tree.lock);
2799 if (!em)
2800 break;
2801 kfree(em->bdev);
2802 /* once for us */
2803 free_extent_map(em);
2804 /* once for the tree */
2805 free_extent_map(em);
2806 }
2807 }
2808
2809 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
2810 {
2811 struct extent_map *em;
2812 struct map_lookup *map;
2813 struct extent_map_tree *em_tree = &map_tree->map_tree;
2814 int ret;
2815
2816 read_lock(&em_tree->lock);
2817 em = lookup_extent_mapping(em_tree, logical, len);
2818 read_unlock(&em_tree->lock);
2819 BUG_ON(!em);
2820
2821 BUG_ON(em->start > logical || em->start + em->len < logical);
2822 map = (struct map_lookup *)em->bdev;
2823 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
2824 ret = map->num_stripes;
2825 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
2826 ret = map->sub_stripes;
2827 else
2828 ret = 1;
2829 free_extent_map(em);
2830 return ret;
2831 }
2832
2833 static int find_live_mirror(struct map_lookup *map, int first, int num,
2834 int optimal)
2835 {
2836 int i;
2837 if (map->stripes[optimal].dev->bdev)
2838 return optimal;
2839 for (i = first; i < first + num; i++) {
2840 if (map->stripes[i].dev->bdev)
2841 return i;
2842 }
2843 /* we couldn't find one that doesn't fail. Just return something
2844 * and the io error handling code will clean up eventually
2845 */
2846 return optimal;
2847 }
2848
2849 static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
2850 u64 logical, u64 *length,
2851 struct btrfs_multi_bio **multi_ret,
2852 int mirror_num)
2853 {
2854 struct extent_map *em;
2855 struct map_lookup *map;
2856 struct extent_map_tree *em_tree = &map_tree->map_tree;
2857 u64 offset;
2858 u64 stripe_offset;
2859 u64 stripe_end_offset;
2860 u64 stripe_nr;
2861 u64 stripe_nr_orig;
2862 u64 stripe_nr_end;
2863 int stripes_allocated = 8;
2864 int stripes_required = 1;
2865 int stripe_index;
2866 int i;
2867 int num_stripes;
2868 int max_errors = 0;
2869 struct btrfs_multi_bio *multi = NULL;
2870
2871 if (multi_ret && !(rw & (REQ_WRITE | REQ_DISCARD)))
2872 stripes_allocated = 1;
2873 again:
2874 if (multi_ret) {
2875 multi = kzalloc(btrfs_multi_bio_size(stripes_allocated),
2876 GFP_NOFS);
2877 if (!multi)
2878 return -ENOMEM;
2879
2880 atomic_set(&multi->error, 0);
2881 }
2882
2883 read_lock(&em_tree->lock);
2884 em = lookup_extent_mapping(em_tree, logical, *length);
2885 read_unlock(&em_tree->lock);
2886
2887 if (!em) {
2888 printk(KERN_CRIT "unable to find logical %llu len %llu\n",
2889 (unsigned long long)logical,
2890 (unsigned long long)*length);
2891 BUG();
2892 }
2893
2894 BUG_ON(em->start > logical || em->start + em->len < logical);
2895 map = (struct map_lookup *)em->bdev;
2896 offset = logical - em->start;
2897
2898 if (mirror_num > map->num_stripes)
2899 mirror_num = 0;
2900
2901 /* if our multi bio struct is too small, back off and try again */
2902 if (rw & REQ_WRITE) {
2903 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
2904 BTRFS_BLOCK_GROUP_DUP)) {
2905 stripes_required = map->num_stripes;
2906 max_errors = 1;
2907 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2908 stripes_required = map->sub_stripes;
2909 max_errors = 1;
2910 }
2911 }
2912 if (rw & REQ_DISCARD) {
2913 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
2914 BTRFS_BLOCK_GROUP_RAID1 |
2915 BTRFS_BLOCK_GROUP_DUP |
2916 BTRFS_BLOCK_GROUP_RAID10)) {
2917 stripes_required = map->num_stripes;
2918 }
2919 }
2920 if (multi_ret && (rw & (REQ_WRITE | REQ_DISCARD)) &&
2921 stripes_allocated < stripes_required) {
2922 stripes_allocated = map->num_stripes;
2923 free_extent_map(em);
2924 kfree(multi);
2925 goto again;
2926 }
2927 stripe_nr = offset;
2928 /*
2929 * stripe_nr counts the total number of stripes we have to stride
2930 * to get to this block
2931 */
2932 do_div(stripe_nr, map->stripe_len);
2933
2934 stripe_offset = stripe_nr * map->stripe_len;
2935 BUG_ON(offset < stripe_offset);
2936
2937 /* stripe_offset is the offset of this block in its stripe*/
2938 stripe_offset = offset - stripe_offset;
2939
2940 if (rw & REQ_DISCARD)
2941 *length = min_t(u64, em->len - offset, *length);
2942 else if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
2943 BTRFS_BLOCK_GROUP_RAID1 |
2944 BTRFS_BLOCK_GROUP_RAID10 |
2945 BTRFS_BLOCK_GROUP_DUP)) {
2946 /* we limit the length of each bio to what fits in a stripe */
2947 *length = min_t(u64, em->len - offset,
2948 map->stripe_len - stripe_offset);
2949 } else {
2950 *length = em->len - offset;
2951 }
2952
2953 if (!multi_ret)
2954 goto out;
2955
2956 num_stripes = 1;
2957 stripe_index = 0;
2958 stripe_nr_orig = stripe_nr;
2959 stripe_nr_end = (offset + *length + map->stripe_len - 1) &
2960 (~(map->stripe_len - 1));
2961 do_div(stripe_nr_end, map->stripe_len);
2962 stripe_end_offset = stripe_nr_end * map->stripe_len -
2963 (offset + *length);
2964 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
2965 if (rw & REQ_DISCARD)
2966 num_stripes = min_t(u64, map->num_stripes,
2967 stripe_nr_end - stripe_nr_orig);
2968 stripe_index = do_div(stripe_nr, map->num_stripes);
2969 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
2970 if (rw & (REQ_WRITE | REQ_DISCARD))
2971 num_stripes = map->num_stripes;
2972 else if (mirror_num)
2973 stripe_index = mirror_num - 1;
2974 else {
2975 stripe_index = find_live_mirror(map, 0,
2976 map->num_stripes,
2977 current->pid % map->num_stripes);
2978 }
2979
2980 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
2981 if (rw & (REQ_WRITE | REQ_DISCARD))
2982 num_stripes = map->num_stripes;
2983 else if (mirror_num)
2984 stripe_index = mirror_num - 1;
2985
2986 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2987 int factor = map->num_stripes / map->sub_stripes;
2988
2989 stripe_index = do_div(stripe_nr, factor);
2990 stripe_index *= map->sub_stripes;
2991
2992 if (rw & REQ_WRITE)
2993 num_stripes = map->sub_stripes;
2994 else if (rw & REQ_DISCARD)
2995 num_stripes = min_t(u64, map->sub_stripes *
2996 (stripe_nr_end - stripe_nr_orig),
2997 map->num_stripes);
2998 else if (mirror_num)
2999 stripe_index += mirror_num - 1;
3000 else {
3001 stripe_index = find_live_mirror(map, stripe_index,
3002 map->sub_stripes, stripe_index +
3003 current->pid % map->sub_stripes);
3004 }
3005 } else {
3006 /*
3007 * after this do_div call, stripe_nr is the number of stripes
3008 * on this device we have to walk to find the data, and
3009 * stripe_index is the number of our device in the stripe array
3010 */
3011 stripe_index = do_div(stripe_nr, map->num_stripes);
3012 }
3013 BUG_ON(stripe_index >= map->num_stripes);
3014
3015 if (rw & REQ_DISCARD) {
3016 for (i = 0; i < num_stripes; i++) {
3017 multi->stripes[i].physical =
3018 map->stripes[stripe_index].physical +
3019 stripe_offset + stripe_nr * map->stripe_len;
3020 multi->stripes[i].dev = map->stripes[stripe_index].dev;
3021
3022 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3023 u64 stripes;
3024 u32 last_stripe = 0;
3025 int j;
3026
3027 div_u64_rem(stripe_nr_end - 1,
3028 map->num_stripes,
3029 &last_stripe);
3030
3031 for (j = 0; j < map->num_stripes; j++) {
3032 u32 test;
3033
3034 div_u64_rem(stripe_nr_end - 1 - j,
3035 map->num_stripes, &test);
3036 if (test == stripe_index)
3037 break;
3038 }
3039 stripes = stripe_nr_end - 1 - j;
3040 do_div(stripes, map->num_stripes);
3041 multi->stripes[i].length = map->stripe_len *
3042 (stripes - stripe_nr + 1);
3043
3044 if (i == 0) {
3045 multi->stripes[i].length -=
3046 stripe_offset;
3047 stripe_offset = 0;
3048 }
3049 if (stripe_index == last_stripe)
3050 multi->stripes[i].length -=
3051 stripe_end_offset;
3052 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3053 u64 stripes;
3054 int j;
3055 int factor = map->num_stripes /
3056 map->sub_stripes;
3057 u32 last_stripe = 0;
3058
3059 div_u64_rem(stripe_nr_end - 1,
3060 factor, &last_stripe);
3061 last_stripe *= map->sub_stripes;
3062
3063 for (j = 0; j < factor; j++) {
3064 u32 test;
3065
3066 div_u64_rem(stripe_nr_end - 1 - j,
3067 factor, &test);
3068
3069 if (test ==
3070 stripe_index / map->sub_stripes)
3071 break;
3072 }
3073 stripes = stripe_nr_end - 1 - j;
3074 do_div(stripes, factor);
3075 multi->stripes[i].length = map->stripe_len *
3076 (stripes - stripe_nr + 1);
3077
3078 if (i < map->sub_stripes) {
3079 multi->stripes[i].length -=
3080 stripe_offset;
3081 if (i == map->sub_stripes - 1)
3082 stripe_offset = 0;
3083 }
3084 if (stripe_index >= last_stripe &&
3085 stripe_index <= (last_stripe +
3086 map->sub_stripes - 1)) {
3087 multi->stripes[i].length -=
3088 stripe_end_offset;
3089 }
3090 } else
3091 multi->stripes[i].length = *length;
3092
3093 stripe_index++;
3094 if (stripe_index == map->num_stripes) {
3095 /* This could only happen for RAID0/10 */
3096 stripe_index = 0;
3097 stripe_nr++;
3098 }
3099 }
3100 } else {
3101 for (i = 0; i < num_stripes; i++) {
3102 multi->stripes[i].physical =
3103 map->stripes[stripe_index].physical +
3104 stripe_offset +
3105 stripe_nr * map->stripe_len;
3106 multi->stripes[i].dev =
3107 map->stripes[stripe_index].dev;
3108 stripe_index++;
3109 }
3110 }
3111 if (multi_ret) {
3112 *multi_ret = multi;
3113 multi->num_stripes = num_stripes;
3114 multi->max_errors = max_errors;
3115 }
3116 out:
3117 free_extent_map(em);
3118 return 0;
3119 }
3120
3121 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
3122 u64 logical, u64 *length,
3123 struct btrfs_multi_bio **multi_ret, int mirror_num)
3124 {
3125 return __btrfs_map_block(map_tree, rw, logical, length, multi_ret,
3126 mirror_num);
3127 }
3128
3129 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
3130 u64 chunk_start, u64 physical, u64 devid,
3131 u64 **logical, int *naddrs, int *stripe_len)
3132 {
3133 struct extent_map_tree *em_tree = &map_tree->map_tree;
3134 struct extent_map *em;
3135 struct map_lookup *map;
3136 u64 *buf;
3137 u64 bytenr;
3138 u64 length;
3139 u64 stripe_nr;
3140 int i, j, nr = 0;
3141
3142 read_lock(&em_tree->lock);
3143 em = lookup_extent_mapping(em_tree, chunk_start, 1);
3144 read_unlock(&em_tree->lock);
3145
3146 BUG_ON(!em || em->start != chunk_start);
3147 map = (struct map_lookup *)em->bdev;
3148
3149 length = em->len;
3150 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
3151 do_div(length, map->num_stripes / map->sub_stripes);
3152 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
3153 do_div(length, map->num_stripes);
3154
3155 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
3156 BUG_ON(!buf);
3157
3158 for (i = 0; i < map->num_stripes; i++) {
3159 if (devid && map->stripes[i].dev->devid != devid)
3160 continue;
3161 if (map->stripes[i].physical > physical ||
3162 map->stripes[i].physical + length <= physical)
3163 continue;
3164
3165 stripe_nr = physical - map->stripes[i].physical;
3166 do_div(stripe_nr, map->stripe_len);
3167
3168 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3169 stripe_nr = stripe_nr * map->num_stripes + i;
3170 do_div(stripe_nr, map->sub_stripes);
3171 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3172 stripe_nr = stripe_nr * map->num_stripes + i;
3173 }
3174 bytenr = chunk_start + stripe_nr * map->stripe_len;
3175 WARN_ON(nr >= map->num_stripes);
3176 for (j = 0; j < nr; j++) {
3177 if (buf[j] == bytenr)
3178 break;
3179 }
3180 if (j == nr) {
3181 WARN_ON(nr >= map->num_stripes);
3182 buf[nr++] = bytenr;
3183 }
3184 }
3185
3186 *logical = buf;
3187 *naddrs = nr;
3188 *stripe_len = map->stripe_len;
3189
3190 free_extent_map(em);
3191 return 0;
3192 }
3193
3194 static void end_bio_multi_stripe(struct bio *bio, int err)
3195 {
3196 struct btrfs_multi_bio *multi = bio->bi_private;
3197 int is_orig_bio = 0;
3198
3199 if (err)
3200 atomic_inc(&multi->error);
3201
3202 if (bio == multi->orig_bio)
3203 is_orig_bio = 1;
3204
3205 if (atomic_dec_and_test(&multi->stripes_pending)) {
3206 if (!is_orig_bio) {
3207 bio_put(bio);
3208 bio = multi->orig_bio;
3209 }
3210 bio->bi_private = multi->private;
3211 bio->bi_end_io = multi->end_io;
3212 /* only send an error to the higher layers if it is
3213 * beyond the tolerance of the multi-bio
3214 */
3215 if (atomic_read(&multi->error) > multi->max_errors) {
3216 err = -EIO;
3217 } else if (err) {
3218 /*
3219 * this bio is actually up to date, we didn't
3220 * go over the max number of errors
3221 */
3222 set_bit(BIO_UPTODATE, &bio->bi_flags);
3223 err = 0;
3224 }
3225 kfree(multi);
3226
3227 bio_endio(bio, err);
3228 } else if (!is_orig_bio) {
3229 bio_put(bio);
3230 }
3231 }
3232
3233 struct async_sched {
3234 struct bio *bio;
3235 int rw;
3236 struct btrfs_fs_info *info;
3237 struct btrfs_work work;
3238 };
3239
3240 /*
3241 * see run_scheduled_bios for a description of why bios are collected for
3242 * async submit.
3243 *
3244 * This will add one bio to the pending list for a device and make sure
3245 * the work struct is scheduled.
3246 */
3247 static noinline int schedule_bio(struct btrfs_root *root,
3248 struct btrfs_device *device,
3249 int rw, struct bio *bio)
3250 {
3251 int should_queue = 1;
3252 struct btrfs_pending_bios *pending_bios;
3253
3254 /* don't bother with additional async steps for reads, right now */
3255 if (!(rw & REQ_WRITE)) {
3256 bio_get(bio);
3257 submit_bio(rw, bio);
3258 bio_put(bio);
3259 return 0;
3260 }
3261
3262 /*
3263 * nr_async_bios allows us to reliably return congestion to the
3264 * higher layers. Otherwise, the async bio makes it appear we have
3265 * made progress against dirty pages when we've really just put it
3266 * on a queue for later
3267 */
3268 atomic_inc(&root->fs_info->nr_async_bios);
3269 WARN_ON(bio->bi_next);
3270 bio->bi_next = NULL;
3271 bio->bi_rw |= rw;
3272
3273 spin_lock(&device->io_lock);
3274 if (bio->bi_rw & REQ_SYNC)
3275 pending_bios = &device->pending_sync_bios;
3276 else
3277 pending_bios = &device->pending_bios;
3278
3279 if (pending_bios->tail)
3280 pending_bios->tail->bi_next = bio;
3281
3282 pending_bios->tail = bio;
3283 if (!pending_bios->head)
3284 pending_bios->head = bio;
3285 if (device->running_pending)
3286 should_queue = 0;
3287
3288 spin_unlock(&device->io_lock);
3289
3290 if (should_queue)
3291 btrfs_queue_worker(&root->fs_info->submit_workers,
3292 &device->work);
3293 return 0;
3294 }
3295
3296 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
3297 int mirror_num, int async_submit)
3298 {
3299 struct btrfs_mapping_tree *map_tree;
3300 struct btrfs_device *dev;
3301 struct bio *first_bio = bio;
3302 u64 logical = (u64)bio->bi_sector << 9;
3303 u64 length = 0;
3304 u64 map_length;
3305 struct btrfs_multi_bio *multi = NULL;
3306 int ret;
3307 int dev_nr = 0;
3308 int total_devs = 1;
3309
3310 length = bio->bi_size;
3311 map_tree = &root->fs_info->mapping_tree;
3312 map_length = length;
3313
3314 ret = btrfs_map_block(map_tree, rw, logical, &map_length, &multi,
3315 mirror_num);
3316 BUG_ON(ret);
3317
3318 total_devs = multi->num_stripes;
3319 if (map_length < length) {
3320 printk(KERN_CRIT "mapping failed logical %llu bio len %llu "
3321 "len %llu\n", (unsigned long long)logical,
3322 (unsigned long long)length,
3323 (unsigned long long)map_length);
3324 BUG();
3325 }
3326 multi->end_io = first_bio->bi_end_io;
3327 multi->private = first_bio->bi_private;
3328 multi->orig_bio = first_bio;
3329 atomic_set(&multi->stripes_pending, multi->num_stripes);
3330
3331 while (dev_nr < total_devs) {
3332 if (total_devs > 1) {
3333 if (dev_nr < total_devs - 1) {
3334 bio = bio_clone(first_bio, GFP_NOFS);
3335 BUG_ON(!bio);
3336 } else {
3337 bio = first_bio;
3338 }
3339 bio->bi_private = multi;
3340 bio->bi_end_io = end_bio_multi_stripe;
3341 }
3342 bio->bi_sector = multi->stripes[dev_nr].physical >> 9;
3343 dev = multi->stripes[dev_nr].dev;
3344 if (dev && dev->bdev && (rw != WRITE || dev->writeable)) {
3345 bio->bi_bdev = dev->bdev;
3346 if (async_submit)
3347 schedule_bio(root, dev, rw, bio);
3348 else
3349 submit_bio(rw, bio);
3350 } else {
3351 bio->bi_bdev = root->fs_info->fs_devices->latest_bdev;
3352 bio->bi_sector = logical >> 9;
3353 bio_endio(bio, -EIO);
3354 }
3355 dev_nr++;
3356 }
3357 if (total_devs == 1)
3358 kfree(multi);
3359 return 0;
3360 }
3361
3362 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
3363 u8 *uuid, u8 *fsid)
3364 {
3365 struct btrfs_device *device;
3366 struct btrfs_fs_devices *cur_devices;
3367
3368 cur_devices = root->fs_info->fs_devices;
3369 while (cur_devices) {
3370 if (!fsid ||
3371 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
3372 device = __find_device(&cur_devices->devices,
3373 devid, uuid);
3374 if (device)
3375 return device;
3376 }
3377 cur_devices = cur_devices->seed;
3378 }
3379 return NULL;
3380 }
3381
3382 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
3383 u64 devid, u8 *dev_uuid)
3384 {
3385 struct btrfs_device *device;
3386 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
3387
3388 device = kzalloc(sizeof(*device), GFP_NOFS);
3389 if (!device)
3390 return NULL;
3391 list_add(&device->dev_list,
3392 &fs_devices->devices);
3393 device->dev_root = root->fs_info->dev_root;
3394 device->devid = devid;
3395 device->work.func = pending_bios_fn;
3396 device->fs_devices = fs_devices;
3397 device->missing = 1;
3398 fs_devices->num_devices++;
3399 fs_devices->missing_devices++;
3400 spin_lock_init(&device->io_lock);
3401 INIT_LIST_HEAD(&device->dev_alloc_list);
3402 memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
3403 return device;
3404 }
3405
3406 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
3407 struct extent_buffer *leaf,
3408 struct btrfs_chunk *chunk)
3409 {
3410 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
3411 struct map_lookup *map;
3412 struct extent_map *em;
3413 u64 logical;
3414 u64 length;
3415 u64 devid;
3416 u8 uuid[BTRFS_UUID_SIZE];
3417 int num_stripes;
3418 int ret;
3419 int i;
3420
3421 logical = key->offset;
3422 length = btrfs_chunk_length(leaf, chunk);
3423
3424 read_lock(&map_tree->map_tree.lock);
3425 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
3426 read_unlock(&map_tree->map_tree.lock);
3427
3428 /* already mapped? */
3429 if (em && em->start <= logical && em->start + em->len > logical) {
3430 free_extent_map(em);
3431 return 0;
3432 } else if (em) {
3433 free_extent_map(em);
3434 }
3435
3436 em = alloc_extent_map();
3437 if (!em)
3438 return -ENOMEM;
3439 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
3440 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
3441 if (!map) {
3442 free_extent_map(em);
3443 return -ENOMEM;
3444 }
3445
3446 em->bdev = (struct block_device *)map;
3447 em->start = logical;
3448 em->len = length;
3449 em->block_start = 0;
3450 em->block_len = em->len;
3451
3452 map->num_stripes = num_stripes;
3453 map->io_width = btrfs_chunk_io_width(leaf, chunk);
3454 map->io_align = btrfs_chunk_io_align(leaf, chunk);
3455 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
3456 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
3457 map->type = btrfs_chunk_type(leaf, chunk);
3458 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
3459 for (i = 0; i < num_stripes; i++) {
3460 map->stripes[i].physical =
3461 btrfs_stripe_offset_nr(leaf, chunk, i);
3462 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
3463 read_extent_buffer(leaf, uuid, (unsigned long)
3464 btrfs_stripe_dev_uuid_nr(chunk, i),
3465 BTRFS_UUID_SIZE);
3466 map->stripes[i].dev = btrfs_find_device(root, devid, uuid,
3467 NULL);
3468 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
3469 kfree(map);
3470 free_extent_map(em);
3471 return -EIO;
3472 }
3473 if (!map->stripes[i].dev) {
3474 map->stripes[i].dev =
3475 add_missing_dev(root, devid, uuid);
3476 if (!map->stripes[i].dev) {
3477 kfree(map);
3478 free_extent_map(em);
3479 return -EIO;
3480 }
3481 }
3482 map->stripes[i].dev->in_fs_metadata = 1;
3483 }
3484
3485 write_lock(&map_tree->map_tree.lock);
3486 ret = add_extent_mapping(&map_tree->map_tree, em);
3487 write_unlock(&map_tree->map_tree.lock);
3488 BUG_ON(ret);
3489 free_extent_map(em);
3490
3491 return 0;
3492 }
3493
3494 static int fill_device_from_item(struct extent_buffer *leaf,
3495 struct btrfs_dev_item *dev_item,
3496 struct btrfs_device *device)
3497 {
3498 unsigned long ptr;
3499
3500 device->devid = btrfs_device_id(leaf, dev_item);
3501 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
3502 device->total_bytes = device->disk_total_bytes;
3503 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
3504 device->type = btrfs_device_type(leaf, dev_item);
3505 device->io_align = btrfs_device_io_align(leaf, dev_item);
3506 device->io_width = btrfs_device_io_width(leaf, dev_item);
3507 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
3508
3509 ptr = (unsigned long)btrfs_device_uuid(dev_item);
3510 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
3511
3512 return 0;
3513 }
3514
3515 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
3516 {
3517 struct btrfs_fs_devices *fs_devices;
3518 int ret;
3519
3520 mutex_lock(&uuid_mutex);
3521
3522 fs_devices = root->fs_info->fs_devices->seed;
3523 while (fs_devices) {
3524 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
3525 ret = 0;
3526 goto out;
3527 }
3528 fs_devices = fs_devices->seed;
3529 }
3530
3531 fs_devices = find_fsid(fsid);
3532 if (!fs_devices) {
3533 ret = -ENOENT;
3534 goto out;
3535 }
3536
3537 fs_devices = clone_fs_devices(fs_devices);
3538 if (IS_ERR(fs_devices)) {
3539 ret = PTR_ERR(fs_devices);
3540 goto out;
3541 }
3542
3543 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
3544 root->fs_info->bdev_holder);
3545 if (ret)
3546 goto out;
3547
3548 if (!fs_devices->seeding) {
3549 __btrfs_close_devices(fs_devices);
3550 free_fs_devices(fs_devices);
3551 ret = -EINVAL;
3552 goto out;
3553 }
3554
3555 fs_devices->seed = root->fs_info->fs_devices->seed;
3556 root->fs_info->fs_devices->seed = fs_devices;
3557 out:
3558 mutex_unlock(&uuid_mutex);
3559 return ret;
3560 }
3561
3562 static int read_one_dev(struct btrfs_root *root,
3563 struct extent_buffer *leaf,
3564 struct btrfs_dev_item *dev_item)
3565 {
3566 struct btrfs_device *device;
3567 u64 devid;
3568 int ret;
3569 u8 fs_uuid[BTRFS_UUID_SIZE];
3570 u8 dev_uuid[BTRFS_UUID_SIZE];
3571
3572 devid = btrfs_device_id(leaf, dev_item);
3573 read_extent_buffer(leaf, dev_uuid,
3574 (unsigned long)btrfs_device_uuid(dev_item),
3575 BTRFS_UUID_SIZE);
3576 read_extent_buffer(leaf, fs_uuid,
3577 (unsigned long)btrfs_device_fsid(dev_item),
3578 BTRFS_UUID_SIZE);
3579
3580 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
3581 ret = open_seed_devices(root, fs_uuid);
3582 if (ret && !btrfs_test_opt(root, DEGRADED))
3583 return ret;
3584 }
3585
3586 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
3587 if (!device || !device->bdev) {
3588 if (!btrfs_test_opt(root, DEGRADED))
3589 return -EIO;
3590
3591 if (!device) {
3592 printk(KERN_WARNING "warning devid %llu missing\n",
3593 (unsigned long long)devid);
3594 device = add_missing_dev(root, devid, dev_uuid);
3595 if (!device)
3596 return -ENOMEM;
3597 } else if (!device->missing) {
3598 /*
3599 * this happens when a device that was properly setup
3600 * in the device info lists suddenly goes bad.
3601 * device->bdev is NULL, and so we have to set
3602 * device->missing to one here
3603 */
3604 root->fs_info->fs_devices->missing_devices++;
3605 device->missing = 1;
3606 }
3607 }
3608
3609 if (device->fs_devices != root->fs_info->fs_devices) {
3610 BUG_ON(device->writeable);
3611 if (device->generation !=
3612 btrfs_device_generation(leaf, dev_item))
3613 return -EINVAL;
3614 }
3615
3616 fill_device_from_item(leaf, dev_item, device);
3617 device->dev_root = root->fs_info->dev_root;
3618 device->in_fs_metadata = 1;
3619 if (device->writeable)
3620 device->fs_devices->total_rw_bytes += device->total_bytes;
3621 ret = 0;
3622 return ret;
3623 }
3624
3625 int btrfs_read_sys_array(struct btrfs_root *root)
3626 {
3627 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
3628 struct extent_buffer *sb;
3629 struct btrfs_disk_key *disk_key;
3630 struct btrfs_chunk *chunk;
3631 u8 *ptr;
3632 unsigned long sb_ptr;
3633 int ret = 0;
3634 u32 num_stripes;
3635 u32 array_size;
3636 u32 len = 0;
3637 u32 cur;
3638 struct btrfs_key key;
3639
3640 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
3641 BTRFS_SUPER_INFO_SIZE);
3642 if (!sb)
3643 return -ENOMEM;
3644 btrfs_set_buffer_uptodate(sb);
3645 btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0);
3646
3647 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
3648 array_size = btrfs_super_sys_array_size(super_copy);
3649
3650 ptr = super_copy->sys_chunk_array;
3651 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
3652 cur = 0;
3653
3654 while (cur < array_size) {
3655 disk_key = (struct btrfs_disk_key *)ptr;
3656 btrfs_disk_key_to_cpu(&key, disk_key);
3657
3658 len = sizeof(*disk_key); ptr += len;
3659 sb_ptr += len;
3660 cur += len;
3661
3662 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
3663 chunk = (struct btrfs_chunk *)sb_ptr;
3664 ret = read_one_chunk(root, &key, sb, chunk);
3665 if (ret)
3666 break;
3667 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
3668 len = btrfs_chunk_item_size(num_stripes);
3669 } else {
3670 ret = -EIO;
3671 break;
3672 }
3673 ptr += len;
3674 sb_ptr += len;
3675 cur += len;
3676 }
3677 free_extent_buffer(sb);
3678 return ret;
3679 }
3680
3681 int btrfs_read_chunk_tree(struct btrfs_root *root)
3682 {
3683 struct btrfs_path *path;
3684 struct extent_buffer *leaf;
3685 struct btrfs_key key;
3686 struct btrfs_key found_key;
3687 int ret;
3688 int slot;
3689
3690 root = root->fs_info->chunk_root;
3691
3692 path = btrfs_alloc_path();
3693 if (!path)
3694 return -ENOMEM;
3695
3696 /* first we search for all of the device items, and then we
3697 * read in all of the chunk items. This way we can create chunk
3698 * mappings that reference all of the devices that are afound
3699 */
3700 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
3701 key.offset = 0;
3702 key.type = 0;
3703 again:
3704 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3705 if (ret < 0)
3706 goto error;
3707 while (1) {
3708 leaf = path->nodes[0];
3709 slot = path->slots[0];
3710 if (slot >= btrfs_header_nritems(leaf)) {
3711 ret = btrfs_next_leaf(root, path);
3712 if (ret == 0)
3713 continue;
3714 if (ret < 0)
3715 goto error;
3716 break;
3717 }
3718 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3719 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
3720 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
3721 break;
3722 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
3723 struct btrfs_dev_item *dev_item;
3724 dev_item = btrfs_item_ptr(leaf, slot,
3725 struct btrfs_dev_item);
3726 ret = read_one_dev(root, leaf, dev_item);
3727 if (ret)
3728 goto error;
3729 }
3730 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
3731 struct btrfs_chunk *chunk;
3732 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
3733 ret = read_one_chunk(root, &found_key, leaf, chunk);
3734 if (ret)
3735 goto error;
3736 }
3737 path->slots[0]++;
3738 }
3739 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
3740 key.objectid = 0;
3741 btrfs_release_path(path);
3742 goto again;
3743 }
3744 ret = 0;
3745 error:
3746 btrfs_free_path(path);
3747 return ret;
3748 }
Linux Btrfs Development