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Merge branch 'btrfs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
[mirror_ubuntu-zesty-kernel.git] / fs / btrfs / volumes.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18 #include <linux/sched.h>
19 #include <linux/bio.h>
20 #include <linux/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 <linux/kthread.h>
27 #include <asm/div64.h>
28 #include "compat.h"
29 #include "ctree.h"
30 #include "extent_map.h"
31 #include "disk-io.h"
32 #include "transaction.h"
33 #include "print-tree.h"
34 #include "volumes.h"
35 #include "async-thread.h"
36 #include "check-integrity.h"
37
38 static int init_first_rw_device(struct btrfs_trans_handle *trans,
39 struct btrfs_root *root,
40 struct btrfs_device *device);
41 static int btrfs_relocate_sys_chunks(struct btrfs_root *root);
42
43 static DEFINE_MUTEX(uuid_mutex);
44 static LIST_HEAD(fs_uuids);
45
46 static void lock_chunks(struct btrfs_root *root)
47 {
48 mutex_lock(&root->fs_info->chunk_mutex);
49 }
50
51 static void unlock_chunks(struct btrfs_root *root)
52 {
53 mutex_unlock(&root->fs_info->chunk_mutex);
54 }
55
56 static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
57 {
58 struct btrfs_device *device;
59 WARN_ON(fs_devices->opened);
60 while (!list_empty(&fs_devices->devices)) {
61 device = list_entry(fs_devices->devices.next,
62 struct btrfs_device, dev_list);
63 list_del(&device->dev_list);
64 kfree(device->name);
65 kfree(device);
66 }
67 kfree(fs_devices);
68 }
69
70 int btrfs_cleanup_fs_uuids(void)
71 {
72 struct btrfs_fs_devices *fs_devices;
73
74 while (!list_empty(&fs_uuids)) {
75 fs_devices = list_entry(fs_uuids.next,
76 struct btrfs_fs_devices, list);
77 list_del(&fs_devices->list);
78 free_fs_devices(fs_devices);
79 }
80 return 0;
81 }
82
83 static noinline struct btrfs_device *__find_device(struct list_head *head,
84 u64 devid, u8 *uuid)
85 {
86 struct btrfs_device *dev;
87
88 list_for_each_entry(dev, head, dev_list) {
89 if (dev->devid == devid &&
90 (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
91 return dev;
92 }
93 }
94 return NULL;
95 }
96
97 static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
98 {
99 struct btrfs_fs_devices *fs_devices;
100
101 list_for_each_entry(fs_devices, &fs_uuids, list) {
102 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
103 return fs_devices;
104 }
105 return NULL;
106 }
107
108 static void requeue_list(struct btrfs_pending_bios *pending_bios,
109 struct bio *head, struct bio *tail)
110 {
111
112 struct bio *old_head;
113
114 old_head = pending_bios->head;
115 pending_bios->head = head;
116 if (pending_bios->tail)
117 tail->bi_next = old_head;
118 else
119 pending_bios->tail = tail;
120 }
121
122 /*
123 * we try to collect pending bios for a device so we don't get a large
124 * number of procs sending bios down to the same device. This greatly
125 * improves the schedulers ability to collect and merge the bios.
126 *
127 * But, it also turns into a long list of bios to process and that is sure
128 * to eventually make the worker thread block. The solution here is to
129 * make some progress and then put this work struct back at the end of
130 * the list if the block device is congested. This way, multiple devices
131 * can make progress from a single worker thread.
132 */
133 static noinline int run_scheduled_bios(struct btrfs_device *device)
134 {
135 struct bio *pending;
136 struct backing_dev_info *bdi;
137 struct btrfs_fs_info *fs_info;
138 struct btrfs_pending_bios *pending_bios;
139 struct bio *tail;
140 struct bio *cur;
141 int again = 0;
142 unsigned long num_run;
143 unsigned long batch_run = 0;
144 unsigned long limit;
145 unsigned long last_waited = 0;
146 int force_reg = 0;
147 int sync_pending = 0;
148 struct blk_plug plug;
149
150 /*
151 * this function runs all the bios we've collected for
152 * a particular device. We don't want to wander off to
153 * another device without first sending all of these down.
154 * So, setup a plug here and finish it off before we return
155 */
156 blk_start_plug(&plug);
157
158 bdi = blk_get_backing_dev_info(device->bdev);
159 fs_info = device->dev_root->fs_info;
160 limit = btrfs_async_submit_limit(fs_info);
161 limit = limit * 2 / 3;
162
163 loop:
164 spin_lock(&device->io_lock);
165
166 loop_lock:
167 num_run = 0;
168
169 /* take all the bios off the list at once and process them
170 * later on (without the lock held). But, remember the
171 * tail and other pointers so the bios can be properly reinserted
172 * into the list if we hit congestion
173 */
174 if (!force_reg && device->pending_sync_bios.head) {
175 pending_bios = &device->pending_sync_bios;
176 force_reg = 1;
177 } else {
178 pending_bios = &device->pending_bios;
179 force_reg = 0;
180 }
181
182 pending = pending_bios->head;
183 tail = pending_bios->tail;
184 WARN_ON(pending && !tail);
185
186 /*
187 * if pending was null this time around, no bios need processing
188 * at all and we can stop. Otherwise it'll loop back up again
189 * and do an additional check so no bios are missed.
190 *
191 * device->running_pending is used to synchronize with the
192 * schedule_bio code.
193 */
194 if (device->pending_sync_bios.head == NULL &&
195 device->pending_bios.head == NULL) {
196 again = 0;
197 device->running_pending = 0;
198 } else {
199 again = 1;
200 device->running_pending = 1;
201 }
202
203 pending_bios->head = NULL;
204 pending_bios->tail = NULL;
205
206 spin_unlock(&device->io_lock);
207
208 while (pending) {
209
210 rmb();
211 /* we want to work on both lists, but do more bios on the
212 * sync list than the regular list
213 */
214 if ((num_run > 32 &&
215 pending_bios != &device->pending_sync_bios &&
216 device->pending_sync_bios.head) ||
217 (num_run > 64 && pending_bios == &device->pending_sync_bios &&
218 device->pending_bios.head)) {
219 spin_lock(&device->io_lock);
220 requeue_list(pending_bios, pending, tail);
221 goto loop_lock;
222 }
223
224 cur = pending;
225 pending = pending->bi_next;
226 cur->bi_next = NULL;
227 atomic_dec(&fs_info->nr_async_bios);
228
229 if (atomic_read(&fs_info->nr_async_bios) < limit &&
230 waitqueue_active(&fs_info->async_submit_wait))
231 wake_up(&fs_info->async_submit_wait);
232
233 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
234
235 /*
236 * if we're doing the sync list, record that our
237 * plug has some sync requests on it
238 *
239 * If we're doing the regular list and there are
240 * sync requests sitting around, unplug before
241 * we add more
242 */
243 if (pending_bios == &device->pending_sync_bios) {
244 sync_pending = 1;
245 } else if (sync_pending) {
246 blk_finish_plug(&plug);
247 blk_start_plug(&plug);
248 sync_pending = 0;
249 }
250
251 btrfsic_submit_bio(cur->bi_rw, cur);
252 num_run++;
253 batch_run++;
254 if (need_resched())
255 cond_resched();
256
257 /*
258 * we made progress, there is more work to do and the bdi
259 * is now congested. Back off and let other work structs
260 * run instead
261 */
262 if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
263 fs_info->fs_devices->open_devices > 1) {
264 struct io_context *ioc;
265
266 ioc = current->io_context;
267
268 /*
269 * the main goal here is that we don't want to
270 * block if we're going to be able to submit
271 * more requests without blocking.
272 *
273 * This code does two great things, it pokes into
274 * the elevator code from a filesystem _and_
275 * it makes assumptions about how batching works.
276 */
277 if (ioc && ioc->nr_batch_requests > 0 &&
278 time_before(jiffies, ioc->last_waited + HZ/50UL) &&
279 (last_waited == 0 ||
280 ioc->last_waited == last_waited)) {
281 /*
282 * we want to go through our batch of
283 * requests and stop. So, we copy out
284 * the ioc->last_waited time and test
285 * against it before looping
286 */
287 last_waited = ioc->last_waited;
288 if (need_resched())
289 cond_resched();
290 continue;
291 }
292 spin_lock(&device->io_lock);
293 requeue_list(pending_bios, pending, tail);
294 device->running_pending = 1;
295
296 spin_unlock(&device->io_lock);
297 btrfs_requeue_work(&device->work);
298 goto done;
299 }
300 /* unplug every 64 requests just for good measure */
301 if (batch_run % 64 == 0) {
302 blk_finish_plug(&plug);
303 blk_start_plug(&plug);
304 sync_pending = 0;
305 }
306 }
307
308 cond_resched();
309 if (again)
310 goto loop;
311
312 spin_lock(&device->io_lock);
313 if (device->pending_bios.head || device->pending_sync_bios.head)
314 goto loop_lock;
315 spin_unlock(&device->io_lock);
316
317 done:
318 blk_finish_plug(&plug);
319 return 0;
320 }
321
322 static void pending_bios_fn(struct btrfs_work *work)
323 {
324 struct btrfs_device *device;
325
326 device = container_of(work, struct btrfs_device, work);
327 run_scheduled_bios(device);
328 }
329
330 static noinline int device_list_add(const char *path,
331 struct btrfs_super_block *disk_super,
332 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
333 {
334 struct btrfs_device *device;
335 struct btrfs_fs_devices *fs_devices;
336 u64 found_transid = btrfs_super_generation(disk_super);
337 char *name;
338
339 fs_devices = find_fsid(disk_super->fsid);
340 if (!fs_devices) {
341 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
342 if (!fs_devices)
343 return -ENOMEM;
344 INIT_LIST_HEAD(&fs_devices->devices);
345 INIT_LIST_HEAD(&fs_devices->alloc_list);
346 list_add(&fs_devices->list, &fs_uuids);
347 memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
348 fs_devices->latest_devid = devid;
349 fs_devices->latest_trans = found_transid;
350 mutex_init(&fs_devices->device_list_mutex);
351 device = NULL;
352 } else {
353 device = __find_device(&fs_devices->devices, devid,
354 disk_super->dev_item.uuid);
355 }
356 if (!device) {
357 if (fs_devices->opened)
358 return -EBUSY;
359
360 device = kzalloc(sizeof(*device), GFP_NOFS);
361 if (!device) {
362 /* we can safely leave the fs_devices entry around */
363 return -ENOMEM;
364 }
365 device->devid = devid;
366 device->work.func = pending_bios_fn;
367 memcpy(device->uuid, disk_super->dev_item.uuid,
368 BTRFS_UUID_SIZE);
369 spin_lock_init(&device->io_lock);
370 device->name = kstrdup(path, GFP_NOFS);
371 if (!device->name) {
372 kfree(device);
373 return -ENOMEM;
374 }
375 INIT_LIST_HEAD(&device->dev_alloc_list);
376
377 /* init readahead state */
378 spin_lock_init(&device->reada_lock);
379 device->reada_curr_zone = NULL;
380 atomic_set(&device->reada_in_flight, 0);
381 device->reada_next = 0;
382 INIT_RADIX_TREE(&device->reada_zones, GFP_NOFS & ~__GFP_WAIT);
383 INIT_RADIX_TREE(&device->reada_extents, GFP_NOFS & ~__GFP_WAIT);
384
385 mutex_lock(&fs_devices->device_list_mutex);
386 list_add_rcu(&device->dev_list, &fs_devices->devices);
387 mutex_unlock(&fs_devices->device_list_mutex);
388
389 device->fs_devices = fs_devices;
390 fs_devices->num_devices++;
391 } else if (!device->name || strcmp(device->name, path)) {
392 name = kstrdup(path, GFP_NOFS);
393 if (!name)
394 return -ENOMEM;
395 kfree(device->name);
396 device->name = name;
397 if (device->missing) {
398 fs_devices->missing_devices--;
399 device->missing = 0;
400 }
401 }
402
403 if (found_transid > fs_devices->latest_trans) {
404 fs_devices->latest_devid = devid;
405 fs_devices->latest_trans = found_transid;
406 }
407 *fs_devices_ret = fs_devices;
408 return 0;
409 }
410
411 static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
412 {
413 struct btrfs_fs_devices *fs_devices;
414 struct btrfs_device *device;
415 struct btrfs_device *orig_dev;
416
417 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
418 if (!fs_devices)
419 return ERR_PTR(-ENOMEM);
420
421 INIT_LIST_HEAD(&fs_devices->devices);
422 INIT_LIST_HEAD(&fs_devices->alloc_list);
423 INIT_LIST_HEAD(&fs_devices->list);
424 mutex_init(&fs_devices->device_list_mutex);
425 fs_devices->latest_devid = orig->latest_devid;
426 fs_devices->latest_trans = orig->latest_trans;
427 memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid));
428
429 /* We have held the volume lock, it is safe to get the devices. */
430 list_for_each_entry(orig_dev, &orig->devices, dev_list) {
431 device = kzalloc(sizeof(*device), GFP_NOFS);
432 if (!device)
433 goto error;
434
435 device->name = kstrdup(orig_dev->name, GFP_NOFS);
436 if (!device->name) {
437 kfree(device);
438 goto error;
439 }
440
441 device->devid = orig_dev->devid;
442 device->work.func = pending_bios_fn;
443 memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid));
444 spin_lock_init(&device->io_lock);
445 INIT_LIST_HEAD(&device->dev_list);
446 INIT_LIST_HEAD(&device->dev_alloc_list);
447
448 list_add(&device->dev_list, &fs_devices->devices);
449 device->fs_devices = fs_devices;
450 fs_devices->num_devices++;
451 }
452 return fs_devices;
453 error:
454 free_fs_devices(fs_devices);
455 return ERR_PTR(-ENOMEM);
456 }
457
458 int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
459 {
460 struct btrfs_device *device, *next;
461
462 mutex_lock(&uuid_mutex);
463 again:
464 /* This is the initialized path, it is safe to release the devices. */
465 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
466 if (device->in_fs_metadata)
467 continue;
468
469 if (device->bdev) {
470 blkdev_put(device->bdev, device->mode);
471 device->bdev = NULL;
472 fs_devices->open_devices--;
473 }
474 if (device->writeable) {
475 list_del_init(&device->dev_alloc_list);
476 device->writeable = 0;
477 fs_devices->rw_devices--;
478 }
479 list_del_init(&device->dev_list);
480 fs_devices->num_devices--;
481 kfree(device->name);
482 kfree(device);
483 }
484
485 if (fs_devices->seed) {
486 fs_devices = fs_devices->seed;
487 goto again;
488 }
489
490 mutex_unlock(&uuid_mutex);
491 return 0;
492 }
493
494 static void __free_device(struct work_struct *work)
495 {
496 struct btrfs_device *device;
497
498 device = container_of(work, struct btrfs_device, rcu_work);
499
500 if (device->bdev)
501 blkdev_put(device->bdev, device->mode);
502
503 kfree(device->name);
504 kfree(device);
505 }
506
507 static void free_device(struct rcu_head *head)
508 {
509 struct btrfs_device *device;
510
511 device = container_of(head, struct btrfs_device, rcu);
512
513 INIT_WORK(&device->rcu_work, __free_device);
514 schedule_work(&device->rcu_work);
515 }
516
517 static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
518 {
519 struct btrfs_device *device;
520
521 if (--fs_devices->opened > 0)
522 return 0;
523
524 mutex_lock(&fs_devices->device_list_mutex);
525 list_for_each_entry(device, &fs_devices->devices, dev_list) {
526 struct btrfs_device *new_device;
527
528 if (device->bdev)
529 fs_devices->open_devices--;
530
531 if (device->writeable) {
532 list_del_init(&device->dev_alloc_list);
533 fs_devices->rw_devices--;
534 }
535
536 if (device->can_discard)
537 fs_devices->num_can_discard--;
538
539 new_device = kmalloc(sizeof(*new_device), GFP_NOFS);
540 BUG_ON(!new_device);
541 memcpy(new_device, device, sizeof(*new_device));
542 new_device->name = kstrdup(device->name, GFP_NOFS);
543 BUG_ON(device->name && !new_device->name);
544 new_device->bdev = NULL;
545 new_device->writeable = 0;
546 new_device->in_fs_metadata = 0;
547 new_device->can_discard = 0;
548 list_replace_rcu(&device->dev_list, &new_device->dev_list);
549
550 call_rcu(&device->rcu, free_device);
551 }
552 mutex_unlock(&fs_devices->device_list_mutex);
553
554 WARN_ON(fs_devices->open_devices);
555 WARN_ON(fs_devices->rw_devices);
556 fs_devices->opened = 0;
557 fs_devices->seeding = 0;
558
559 return 0;
560 }
561
562 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
563 {
564 struct btrfs_fs_devices *seed_devices = NULL;
565 int ret;
566
567 mutex_lock(&uuid_mutex);
568 ret = __btrfs_close_devices(fs_devices);
569 if (!fs_devices->opened) {
570 seed_devices = fs_devices->seed;
571 fs_devices->seed = NULL;
572 }
573 mutex_unlock(&uuid_mutex);
574
575 while (seed_devices) {
576 fs_devices = seed_devices;
577 seed_devices = fs_devices->seed;
578 __btrfs_close_devices(fs_devices);
579 free_fs_devices(fs_devices);
580 }
581 return ret;
582 }
583
584 static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
585 fmode_t flags, void *holder)
586 {
587 struct request_queue *q;
588 struct block_device *bdev;
589 struct list_head *head = &fs_devices->devices;
590 struct btrfs_device *device;
591 struct block_device *latest_bdev = NULL;
592 struct buffer_head *bh;
593 struct btrfs_super_block *disk_super;
594 u64 latest_devid = 0;
595 u64 latest_transid = 0;
596 u64 devid;
597 int seeding = 1;
598 int ret = 0;
599
600 flags |= FMODE_EXCL;
601
602 list_for_each_entry(device, head, dev_list) {
603 if (device->bdev)
604 continue;
605 if (!device->name)
606 continue;
607
608 bdev = blkdev_get_by_path(device->name, flags, holder);
609 if (IS_ERR(bdev)) {
610 printk(KERN_INFO "open %s failed\n", device->name);
611 goto error;
612 }
613 set_blocksize(bdev, 4096);
614
615 bh = btrfs_read_dev_super(bdev);
616 if (!bh)
617 goto error_close;
618
619 disk_super = (struct btrfs_super_block *)bh->b_data;
620 devid = btrfs_stack_device_id(&disk_super->dev_item);
621 if (devid != device->devid)
622 goto error_brelse;
623
624 if (memcmp(device->uuid, disk_super->dev_item.uuid,
625 BTRFS_UUID_SIZE))
626 goto error_brelse;
627
628 device->generation = btrfs_super_generation(disk_super);
629 if (!latest_transid || device->generation > latest_transid) {
630 latest_devid = devid;
631 latest_transid = device->generation;
632 latest_bdev = bdev;
633 }
634
635 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
636 device->writeable = 0;
637 } else {
638 device->writeable = !bdev_read_only(bdev);
639 seeding = 0;
640 }
641
642 q = bdev_get_queue(bdev);
643 if (blk_queue_discard(q)) {
644 device->can_discard = 1;
645 fs_devices->num_can_discard++;
646 }
647
648 device->bdev = bdev;
649 device->in_fs_metadata = 0;
650 device->mode = flags;
651
652 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
653 fs_devices->rotating = 1;
654
655 fs_devices->open_devices++;
656 if (device->writeable) {
657 fs_devices->rw_devices++;
658 list_add(&device->dev_alloc_list,
659 &fs_devices->alloc_list);
660 }
661 brelse(bh);
662 continue;
663
664 error_brelse:
665 brelse(bh);
666 error_close:
667 blkdev_put(bdev, flags);
668 error:
669 continue;
670 }
671 if (fs_devices->open_devices == 0) {
672 ret = -EINVAL;
673 goto out;
674 }
675 fs_devices->seeding = seeding;
676 fs_devices->opened = 1;
677 fs_devices->latest_bdev = latest_bdev;
678 fs_devices->latest_devid = latest_devid;
679 fs_devices->latest_trans = latest_transid;
680 fs_devices->total_rw_bytes = 0;
681 out:
682 return ret;
683 }
684
685 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
686 fmode_t flags, void *holder)
687 {
688 int ret;
689
690 mutex_lock(&uuid_mutex);
691 if (fs_devices->opened) {
692 fs_devices->opened++;
693 ret = 0;
694 } else {
695 ret = __btrfs_open_devices(fs_devices, flags, holder);
696 }
697 mutex_unlock(&uuid_mutex);
698 return ret;
699 }
700
701 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
702 struct btrfs_fs_devices **fs_devices_ret)
703 {
704 struct btrfs_super_block *disk_super;
705 struct block_device *bdev;
706 struct buffer_head *bh;
707 int ret;
708 u64 devid;
709 u64 transid;
710
711 flags |= FMODE_EXCL;
712 bdev = blkdev_get_by_path(path, flags, holder);
713
714 if (IS_ERR(bdev)) {
715 ret = PTR_ERR(bdev);
716 goto error;
717 }
718
719 mutex_lock(&uuid_mutex);
720 ret = set_blocksize(bdev, 4096);
721 if (ret)
722 goto error_close;
723 bh = btrfs_read_dev_super(bdev);
724 if (!bh) {
725 ret = -EINVAL;
726 goto error_close;
727 }
728 disk_super = (struct btrfs_super_block *)bh->b_data;
729 devid = btrfs_stack_device_id(&disk_super->dev_item);
730 transid = btrfs_super_generation(disk_super);
731 if (disk_super->label[0])
732 printk(KERN_INFO "device label %s ", disk_super->label);
733 else
734 printk(KERN_INFO "device fsid %pU ", disk_super->fsid);
735 printk(KERN_CONT "devid %llu transid %llu %s\n",
736 (unsigned long long)devid, (unsigned long long)transid, path);
737 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
738
739 brelse(bh);
740 error_close:
741 mutex_unlock(&uuid_mutex);
742 blkdev_put(bdev, flags);
743 error:
744 return ret;
745 }
746
747 /* helper to account the used device space in the range */
748 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
749 u64 end, u64 *length)
750 {
751 struct btrfs_key key;
752 struct btrfs_root *root = device->dev_root;
753 struct btrfs_dev_extent *dev_extent;
754 struct btrfs_path *path;
755 u64 extent_end;
756 int ret;
757 int slot;
758 struct extent_buffer *l;
759
760 *length = 0;
761
762 if (start >= device->total_bytes)
763 return 0;
764
765 path = btrfs_alloc_path();
766 if (!path)
767 return -ENOMEM;
768 path->reada = 2;
769
770 key.objectid = device->devid;
771 key.offset = start;
772 key.type = BTRFS_DEV_EXTENT_KEY;
773
774 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
775 if (ret < 0)
776 goto out;
777 if (ret > 0) {
778 ret = btrfs_previous_item(root, path, key.objectid, key.type);
779 if (ret < 0)
780 goto out;
781 }
782
783 while (1) {
784 l = path->nodes[0];
785 slot = path->slots[0];
786 if (slot >= btrfs_header_nritems(l)) {
787 ret = btrfs_next_leaf(root, path);
788 if (ret == 0)
789 continue;
790 if (ret < 0)
791 goto out;
792
793 break;
794 }
795 btrfs_item_key_to_cpu(l, &key, slot);
796
797 if (key.objectid < device->devid)
798 goto next;
799
800 if (key.objectid > device->devid)
801 break;
802
803 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
804 goto next;
805
806 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
807 extent_end = key.offset + btrfs_dev_extent_length(l,
808 dev_extent);
809 if (key.offset <= start && extent_end > end) {
810 *length = end - start + 1;
811 break;
812 } else if (key.offset <= start && extent_end > start)
813 *length += extent_end - start;
814 else if (key.offset > start && extent_end <= end)
815 *length += extent_end - key.offset;
816 else if (key.offset > start && key.offset <= end) {
817 *length += end - key.offset + 1;
818 break;
819 } else if (key.offset > end)
820 break;
821
822 next:
823 path->slots[0]++;
824 }
825 ret = 0;
826 out:
827 btrfs_free_path(path);
828 return ret;
829 }
830
831 /*
832 * find_free_dev_extent - find free space in the specified device
833 * @device: the device which we search the free space in
834 * @num_bytes: the size of the free space that we need
835 * @start: store the start of the free space.
836 * @len: the size of the free space. that we find, or the size of the max
837 * free space if we don't find suitable free space
838 *
839 * this uses a pretty simple search, the expectation is that it is
840 * called very infrequently and that a given device has a small number
841 * of extents
842 *
843 * @start is used to store the start of the free space if we find. But if we
844 * don't find suitable free space, it will be used to store the start position
845 * of the max free space.
846 *
847 * @len is used to store the size of the free space that we find.
848 * But if we don't find suitable free space, it is used to store the size of
849 * the max free space.
850 */
851 int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes,
852 u64 *start, u64 *len)
853 {
854 struct btrfs_key key;
855 struct btrfs_root *root = device->dev_root;
856 struct btrfs_dev_extent *dev_extent;
857 struct btrfs_path *path;
858 u64 hole_size;
859 u64 max_hole_start;
860 u64 max_hole_size;
861 u64 extent_end;
862 u64 search_start;
863 u64 search_end = device->total_bytes;
864 int ret;
865 int slot;
866 struct extent_buffer *l;
867
868 /* FIXME use last free of some kind */
869
870 /* we don't want to overwrite the superblock on the drive,
871 * so we make sure to start at an offset of at least 1MB
872 */
873 search_start = max(root->fs_info->alloc_start, 1024ull * 1024);
874
875 max_hole_start = search_start;
876 max_hole_size = 0;
877 hole_size = 0;
878
879 if (search_start >= search_end) {
880 ret = -ENOSPC;
881 goto error;
882 }
883
884 path = btrfs_alloc_path();
885 if (!path) {
886 ret = -ENOMEM;
887 goto error;
888 }
889 path->reada = 2;
890
891 key.objectid = device->devid;
892 key.offset = search_start;
893 key.type = BTRFS_DEV_EXTENT_KEY;
894
895 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
896 if (ret < 0)
897 goto out;
898 if (ret > 0) {
899 ret = btrfs_previous_item(root, path, key.objectid, key.type);
900 if (ret < 0)
901 goto out;
902 }
903
904 while (1) {
905 l = path->nodes[0];
906 slot = path->slots[0];
907 if (slot >= btrfs_header_nritems(l)) {
908 ret = btrfs_next_leaf(root, path);
909 if (ret == 0)
910 continue;
911 if (ret < 0)
912 goto out;
913
914 break;
915 }
916 btrfs_item_key_to_cpu(l, &key, slot);
917
918 if (key.objectid < device->devid)
919 goto next;
920
921 if (key.objectid > device->devid)
922 break;
923
924 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
925 goto next;
926
927 if (key.offset > search_start) {
928 hole_size = key.offset - search_start;
929
930 if (hole_size > max_hole_size) {
931 max_hole_start = search_start;
932 max_hole_size = hole_size;
933 }
934
935 /*
936 * If this free space is greater than which we need,
937 * it must be the max free space that we have found
938 * until now, so max_hole_start must point to the start
939 * of this free space and the length of this free space
940 * is stored in max_hole_size. Thus, we return
941 * max_hole_start and max_hole_size and go back to the
942 * caller.
943 */
944 if (hole_size >= num_bytes) {
945 ret = 0;
946 goto out;
947 }
948 }
949
950 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
951 extent_end = key.offset + btrfs_dev_extent_length(l,
952 dev_extent);
953 if (extent_end > search_start)
954 search_start = extent_end;
955 next:
956 path->slots[0]++;
957 cond_resched();
958 }
959
960 /*
961 * At this point, search_start should be the end of
962 * allocated dev extents, and when shrinking the device,
963 * search_end may be smaller than search_start.
964 */
965 if (search_end > search_start)
966 hole_size = search_end - search_start;
967
968 if (hole_size > max_hole_size) {
969 max_hole_start = search_start;
970 max_hole_size = hole_size;
971 }
972
973 /* See above. */
974 if (hole_size < num_bytes)
975 ret = -ENOSPC;
976 else
977 ret = 0;
978
979 out:
980 btrfs_free_path(path);
981 error:
982 *start = max_hole_start;
983 if (len)
984 *len = max_hole_size;
985 return ret;
986 }
987
988 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
989 struct btrfs_device *device,
990 u64 start)
991 {
992 int ret;
993 struct btrfs_path *path;
994 struct btrfs_root *root = device->dev_root;
995 struct btrfs_key key;
996 struct btrfs_key found_key;
997 struct extent_buffer *leaf = NULL;
998 struct btrfs_dev_extent *extent = NULL;
999
1000 path = btrfs_alloc_path();
1001 if (!path)
1002 return -ENOMEM;
1003
1004 key.objectid = device->devid;
1005 key.offset = start;
1006 key.type = BTRFS_DEV_EXTENT_KEY;
1007 again:
1008 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1009 if (ret > 0) {
1010 ret = btrfs_previous_item(root, path, key.objectid,
1011 BTRFS_DEV_EXTENT_KEY);
1012 if (ret)
1013 goto out;
1014 leaf = path->nodes[0];
1015 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1016 extent = btrfs_item_ptr(leaf, path->slots[0],
1017 struct btrfs_dev_extent);
1018 BUG_ON(found_key.offset > start || found_key.offset +
1019 btrfs_dev_extent_length(leaf, extent) < start);
1020 key = found_key;
1021 btrfs_release_path(path);
1022 goto again;
1023 } else if (ret == 0) {
1024 leaf = path->nodes[0];
1025 extent = btrfs_item_ptr(leaf, path->slots[0],
1026 struct btrfs_dev_extent);
1027 }
1028 BUG_ON(ret);
1029
1030 if (device->bytes_used > 0) {
1031 u64 len = btrfs_dev_extent_length(leaf, extent);
1032 device->bytes_used -= len;
1033 spin_lock(&root->fs_info->free_chunk_lock);
1034 root->fs_info->free_chunk_space += len;
1035 spin_unlock(&root->fs_info->free_chunk_lock);
1036 }
1037 ret = btrfs_del_item(trans, root, path);
1038
1039 out:
1040 btrfs_free_path(path);
1041 return ret;
1042 }
1043
1044 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
1045 struct btrfs_device *device,
1046 u64 chunk_tree, u64 chunk_objectid,
1047 u64 chunk_offset, u64 start, u64 num_bytes)
1048 {
1049 int ret;
1050 struct btrfs_path *path;
1051 struct btrfs_root *root = device->dev_root;
1052 struct btrfs_dev_extent *extent;
1053 struct extent_buffer *leaf;
1054 struct btrfs_key key;
1055
1056 WARN_ON(!device->in_fs_metadata);
1057 path = btrfs_alloc_path();
1058 if (!path)
1059 return -ENOMEM;
1060
1061 key.objectid = device->devid;
1062 key.offset = start;
1063 key.type = BTRFS_DEV_EXTENT_KEY;
1064 ret = btrfs_insert_empty_item(trans, root, path, &key,
1065 sizeof(*extent));
1066 BUG_ON(ret);
1067
1068 leaf = path->nodes[0];
1069 extent = btrfs_item_ptr(leaf, path->slots[0],
1070 struct btrfs_dev_extent);
1071 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
1072 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
1073 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
1074
1075 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
1076 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
1077 BTRFS_UUID_SIZE);
1078
1079 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
1080 btrfs_mark_buffer_dirty(leaf);
1081 btrfs_free_path(path);
1082 return ret;
1083 }
1084
1085 static noinline int find_next_chunk(struct btrfs_root *root,
1086 u64 objectid, u64 *offset)
1087 {
1088 struct btrfs_path *path;
1089 int ret;
1090 struct btrfs_key key;
1091 struct btrfs_chunk *chunk;
1092 struct btrfs_key found_key;
1093
1094 path = btrfs_alloc_path();
1095 if (!path)
1096 return -ENOMEM;
1097
1098 key.objectid = objectid;
1099 key.offset = (u64)-1;
1100 key.type = BTRFS_CHUNK_ITEM_KEY;
1101
1102 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1103 if (ret < 0)
1104 goto error;
1105
1106 BUG_ON(ret == 0);
1107
1108 ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
1109 if (ret) {
1110 *offset = 0;
1111 } else {
1112 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1113 path->slots[0]);
1114 if (found_key.objectid != objectid)
1115 *offset = 0;
1116 else {
1117 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
1118 struct btrfs_chunk);
1119 *offset = found_key.offset +
1120 btrfs_chunk_length(path->nodes[0], chunk);
1121 }
1122 }
1123 ret = 0;
1124 error:
1125 btrfs_free_path(path);
1126 return ret;
1127 }
1128
1129 static noinline int find_next_devid(struct btrfs_root *root, u64 *objectid)
1130 {
1131 int ret;
1132 struct btrfs_key key;
1133 struct btrfs_key found_key;
1134 struct btrfs_path *path;
1135
1136 root = root->fs_info->chunk_root;
1137
1138 path = btrfs_alloc_path();
1139 if (!path)
1140 return -ENOMEM;
1141
1142 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1143 key.type = BTRFS_DEV_ITEM_KEY;
1144 key.offset = (u64)-1;
1145
1146 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1147 if (ret < 0)
1148 goto error;
1149
1150 BUG_ON(ret == 0);
1151
1152 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
1153 BTRFS_DEV_ITEM_KEY);
1154 if (ret) {
1155 *objectid = 1;
1156 } else {
1157 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1158 path->slots[0]);
1159 *objectid = found_key.offset + 1;
1160 }
1161 ret = 0;
1162 error:
1163 btrfs_free_path(path);
1164 return ret;
1165 }
1166
1167 /*
1168 * the device information is stored in the chunk root
1169 * the btrfs_device struct should be fully filled in
1170 */
1171 int btrfs_add_device(struct btrfs_trans_handle *trans,
1172 struct btrfs_root *root,
1173 struct btrfs_device *device)
1174 {
1175 int ret;
1176 struct btrfs_path *path;
1177 struct btrfs_dev_item *dev_item;
1178 struct extent_buffer *leaf;
1179 struct btrfs_key key;
1180 unsigned long ptr;
1181
1182 root = root->fs_info->chunk_root;
1183
1184 path = btrfs_alloc_path();
1185 if (!path)
1186 return -ENOMEM;
1187
1188 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1189 key.type = BTRFS_DEV_ITEM_KEY;
1190 key.offset = device->devid;
1191
1192 ret = btrfs_insert_empty_item(trans, root, path, &key,
1193 sizeof(*dev_item));
1194 if (ret)
1195 goto out;
1196
1197 leaf = path->nodes[0];
1198 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1199
1200 btrfs_set_device_id(leaf, dev_item, device->devid);
1201 btrfs_set_device_generation(leaf, dev_item, 0);
1202 btrfs_set_device_type(leaf, dev_item, device->type);
1203 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1204 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1205 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1206 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
1207 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1208 btrfs_set_device_group(leaf, dev_item, 0);
1209 btrfs_set_device_seek_speed(leaf, dev_item, 0);
1210 btrfs_set_device_bandwidth(leaf, dev_item, 0);
1211 btrfs_set_device_start_offset(leaf, dev_item, 0);
1212
1213 ptr = (unsigned long)btrfs_device_uuid(dev_item);
1214 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1215 ptr = (unsigned long)btrfs_device_fsid(dev_item);
1216 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
1217 btrfs_mark_buffer_dirty(leaf);
1218
1219 ret = 0;
1220 out:
1221 btrfs_free_path(path);
1222 return ret;
1223 }
1224
1225 static int btrfs_rm_dev_item(struct btrfs_root *root,
1226 struct btrfs_device *device)
1227 {
1228 int ret;
1229 struct btrfs_path *path;
1230 struct btrfs_key key;
1231 struct btrfs_trans_handle *trans;
1232
1233 root = root->fs_info->chunk_root;
1234
1235 path = btrfs_alloc_path();
1236 if (!path)
1237 return -ENOMEM;
1238
1239 trans = btrfs_start_transaction(root, 0);
1240 if (IS_ERR(trans)) {
1241 btrfs_free_path(path);
1242 return PTR_ERR(trans);
1243 }
1244 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1245 key.type = BTRFS_DEV_ITEM_KEY;
1246 key.offset = device->devid;
1247 lock_chunks(root);
1248
1249 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1250 if (ret < 0)
1251 goto out;
1252
1253 if (ret > 0) {
1254 ret = -ENOENT;
1255 goto out;
1256 }
1257
1258 ret = btrfs_del_item(trans, root, path);
1259 if (ret)
1260 goto out;
1261 out:
1262 btrfs_free_path(path);
1263 unlock_chunks(root);
1264 btrfs_commit_transaction(trans, root);
1265 return ret;
1266 }
1267
1268 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
1269 {
1270 struct btrfs_device *device;
1271 struct btrfs_device *next_device;
1272 struct block_device *bdev;
1273 struct buffer_head *bh = NULL;
1274 struct btrfs_super_block *disk_super;
1275 struct btrfs_fs_devices *cur_devices;
1276 u64 all_avail;
1277 u64 devid;
1278 u64 num_devices;
1279 u8 *dev_uuid;
1280 int ret = 0;
1281 bool clear_super = false;
1282
1283 mutex_lock(&uuid_mutex);
1284
1285 all_avail = root->fs_info->avail_data_alloc_bits |
1286 root->fs_info->avail_system_alloc_bits |
1287 root->fs_info->avail_metadata_alloc_bits;
1288
1289 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) &&
1290 root->fs_info->fs_devices->num_devices <= 4) {
1291 printk(KERN_ERR "btrfs: unable to go below four devices "
1292 "on raid10\n");
1293 ret = -EINVAL;
1294 goto out;
1295 }
1296
1297 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) &&
1298 root->fs_info->fs_devices->num_devices <= 2) {
1299 printk(KERN_ERR "btrfs: unable to go below two "
1300 "devices on raid1\n");
1301 ret = -EINVAL;
1302 goto out;
1303 }
1304
1305 if (strcmp(device_path, "missing") == 0) {
1306 struct list_head *devices;
1307 struct btrfs_device *tmp;
1308
1309 device = NULL;
1310 devices = &root->fs_info->fs_devices->devices;
1311 /*
1312 * It is safe to read the devices since the volume_mutex
1313 * is held.
1314 */
1315 list_for_each_entry(tmp, devices, dev_list) {
1316 if (tmp->in_fs_metadata && !tmp->bdev) {
1317 device = tmp;
1318 break;
1319 }
1320 }
1321 bdev = NULL;
1322 bh = NULL;
1323 disk_super = NULL;
1324 if (!device) {
1325 printk(KERN_ERR "btrfs: no missing devices found to "
1326 "remove\n");
1327 goto out;
1328 }
1329 } else {
1330 bdev = blkdev_get_by_path(device_path, FMODE_READ | FMODE_EXCL,
1331 root->fs_info->bdev_holder);
1332 if (IS_ERR(bdev)) {
1333 ret = PTR_ERR(bdev);
1334 goto out;
1335 }
1336
1337 set_blocksize(bdev, 4096);
1338 bh = btrfs_read_dev_super(bdev);
1339 if (!bh) {
1340 ret = -EINVAL;
1341 goto error_close;
1342 }
1343 disk_super = (struct btrfs_super_block *)bh->b_data;
1344 devid = btrfs_stack_device_id(&disk_super->dev_item);
1345 dev_uuid = disk_super->dev_item.uuid;
1346 device = btrfs_find_device(root, devid, dev_uuid,
1347 disk_super->fsid);
1348 if (!device) {
1349 ret = -ENOENT;
1350 goto error_brelse;
1351 }
1352 }
1353
1354 if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
1355 printk(KERN_ERR "btrfs: unable to remove the only writeable "
1356 "device\n");
1357 ret = -EINVAL;
1358 goto error_brelse;
1359 }
1360
1361 if (device->writeable) {
1362 lock_chunks(root);
1363 list_del_init(&device->dev_alloc_list);
1364 unlock_chunks(root);
1365 root->fs_info->fs_devices->rw_devices--;
1366 clear_super = true;
1367 }
1368
1369 ret = btrfs_shrink_device(device, 0);
1370 if (ret)
1371 goto error_undo;
1372
1373 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1374 if (ret)
1375 goto error_undo;
1376
1377 spin_lock(&root->fs_info->free_chunk_lock);
1378 root->fs_info->free_chunk_space = device->total_bytes -
1379 device->bytes_used;
1380 spin_unlock(&root->fs_info->free_chunk_lock);
1381
1382 device->in_fs_metadata = 0;
1383 btrfs_scrub_cancel_dev(root, device);
1384
1385 /*
1386 * the device list mutex makes sure that we don't change
1387 * the device list while someone else is writing out all
1388 * the device supers.
1389 */
1390
1391 cur_devices = device->fs_devices;
1392 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1393 list_del_rcu(&device->dev_list);
1394
1395 device->fs_devices->num_devices--;
1396
1397 if (device->missing)
1398 root->fs_info->fs_devices->missing_devices--;
1399
1400 next_device = list_entry(root->fs_info->fs_devices->devices.next,
1401 struct btrfs_device, dev_list);
1402 if (device->bdev == root->fs_info->sb->s_bdev)
1403 root->fs_info->sb->s_bdev = next_device->bdev;
1404 if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1405 root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1406
1407 if (device->bdev)
1408 device->fs_devices->open_devices--;
1409
1410 call_rcu(&device->rcu, free_device);
1411 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1412
1413 num_devices = btrfs_super_num_devices(root->fs_info->super_copy) - 1;
1414 btrfs_set_super_num_devices(root->fs_info->super_copy, num_devices);
1415
1416 if (cur_devices->open_devices == 0) {
1417 struct btrfs_fs_devices *fs_devices;
1418 fs_devices = root->fs_info->fs_devices;
1419 while (fs_devices) {
1420 if (fs_devices->seed == cur_devices)
1421 break;
1422 fs_devices = fs_devices->seed;
1423 }
1424 fs_devices->seed = cur_devices->seed;
1425 cur_devices->seed = NULL;
1426 lock_chunks(root);
1427 __btrfs_close_devices(cur_devices);
1428 unlock_chunks(root);
1429 free_fs_devices(cur_devices);
1430 }
1431
1432 /*
1433 * at this point, the device is zero sized. We want to
1434 * remove it from the devices list and zero out the old super
1435 */
1436 if (clear_super) {
1437 /* make sure this device isn't detected as part of
1438 * the FS anymore
1439 */
1440 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1441 set_buffer_dirty(bh);
1442 sync_dirty_buffer(bh);
1443 }
1444
1445 ret = 0;
1446
1447 error_brelse:
1448 brelse(bh);
1449 error_close:
1450 if (bdev)
1451 blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
1452 out:
1453 mutex_unlock(&uuid_mutex);
1454 return ret;
1455 error_undo:
1456 if (device->writeable) {
1457 lock_chunks(root);
1458 list_add(&device->dev_alloc_list,
1459 &root->fs_info->fs_devices->alloc_list);
1460 unlock_chunks(root);
1461 root->fs_info->fs_devices->rw_devices++;
1462 }
1463 goto error_brelse;
1464 }
1465
1466 /*
1467 * does all the dirty work required for changing file system's UUID.
1468 */
1469 static int btrfs_prepare_sprout(struct btrfs_root *root)
1470 {
1471 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1472 struct btrfs_fs_devices *old_devices;
1473 struct btrfs_fs_devices *seed_devices;
1474 struct btrfs_super_block *disk_super = root->fs_info->super_copy;
1475 struct btrfs_device *device;
1476 u64 super_flags;
1477
1478 BUG_ON(!mutex_is_locked(&uuid_mutex));
1479 if (!fs_devices->seeding)
1480 return -EINVAL;
1481
1482 seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
1483 if (!seed_devices)
1484 return -ENOMEM;
1485
1486 old_devices = clone_fs_devices(fs_devices);
1487 if (IS_ERR(old_devices)) {
1488 kfree(seed_devices);
1489 return PTR_ERR(old_devices);
1490 }
1491
1492 list_add(&old_devices->list, &fs_uuids);
1493
1494 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1495 seed_devices->opened = 1;
1496 INIT_LIST_HEAD(&seed_devices->devices);
1497 INIT_LIST_HEAD(&seed_devices->alloc_list);
1498 mutex_init(&seed_devices->device_list_mutex);
1499
1500 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1501 list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
1502 synchronize_rcu);
1503 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1504
1505 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1506 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1507 device->fs_devices = seed_devices;
1508 }
1509
1510 fs_devices->seeding = 0;
1511 fs_devices->num_devices = 0;
1512 fs_devices->open_devices = 0;
1513 fs_devices->seed = seed_devices;
1514
1515 generate_random_uuid(fs_devices->fsid);
1516 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1517 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1518 super_flags = btrfs_super_flags(disk_super) &
1519 ~BTRFS_SUPER_FLAG_SEEDING;
1520 btrfs_set_super_flags(disk_super, super_flags);
1521
1522 return 0;
1523 }
1524
1525 /*
1526 * strore the expected generation for seed devices in device items.
1527 */
1528 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1529 struct btrfs_root *root)
1530 {
1531 struct btrfs_path *path;
1532 struct extent_buffer *leaf;
1533 struct btrfs_dev_item *dev_item;
1534 struct btrfs_device *device;
1535 struct btrfs_key key;
1536 u8 fs_uuid[BTRFS_UUID_SIZE];
1537 u8 dev_uuid[BTRFS_UUID_SIZE];
1538 u64 devid;
1539 int ret;
1540
1541 path = btrfs_alloc_path();
1542 if (!path)
1543 return -ENOMEM;
1544
1545 root = root->fs_info->chunk_root;
1546 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1547 key.offset = 0;
1548 key.type = BTRFS_DEV_ITEM_KEY;
1549
1550 while (1) {
1551 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1552 if (ret < 0)
1553 goto error;
1554
1555 leaf = path->nodes[0];
1556 next_slot:
1557 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1558 ret = btrfs_next_leaf(root, path);
1559 if (ret > 0)
1560 break;
1561 if (ret < 0)
1562 goto error;
1563 leaf = path->nodes[0];
1564 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1565 btrfs_release_path(path);
1566 continue;
1567 }
1568
1569 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1570 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1571 key.type != BTRFS_DEV_ITEM_KEY)
1572 break;
1573
1574 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1575 struct btrfs_dev_item);
1576 devid = btrfs_device_id(leaf, dev_item);
1577 read_extent_buffer(leaf, dev_uuid,
1578 (unsigned long)btrfs_device_uuid(dev_item),
1579 BTRFS_UUID_SIZE);
1580 read_extent_buffer(leaf, fs_uuid,
1581 (unsigned long)btrfs_device_fsid(dev_item),
1582 BTRFS_UUID_SIZE);
1583 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
1584 BUG_ON(!device);
1585
1586 if (device->fs_devices->seeding) {
1587 btrfs_set_device_generation(leaf, dev_item,
1588 device->generation);
1589 btrfs_mark_buffer_dirty(leaf);
1590 }
1591
1592 path->slots[0]++;
1593 goto next_slot;
1594 }
1595 ret = 0;
1596 error:
1597 btrfs_free_path(path);
1598 return ret;
1599 }
1600
1601 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1602 {
1603 struct request_queue *q;
1604 struct btrfs_trans_handle *trans;
1605 struct btrfs_device *device;
1606 struct block_device *bdev;
1607 struct list_head *devices;
1608 struct super_block *sb = root->fs_info->sb;
1609 u64 total_bytes;
1610 int seeding_dev = 0;
1611 int ret = 0;
1612
1613 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1614 return -EINVAL;
1615
1616 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
1617 root->fs_info->bdev_holder);
1618 if (IS_ERR(bdev))
1619 return PTR_ERR(bdev);
1620
1621 if (root->fs_info->fs_devices->seeding) {
1622 seeding_dev = 1;
1623 down_write(&sb->s_umount);
1624 mutex_lock(&uuid_mutex);
1625 }
1626
1627 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1628
1629 devices = &root->fs_info->fs_devices->devices;
1630 /*
1631 * we have the volume lock, so we don't need the extra
1632 * device list mutex while reading the list here.
1633 */
1634 list_for_each_entry(device, devices, dev_list) {
1635 if (device->bdev == bdev) {
1636 ret = -EEXIST;
1637 goto error;
1638 }
1639 }
1640
1641 device = kzalloc(sizeof(*device), GFP_NOFS);
1642 if (!device) {
1643 /* we can safely leave the fs_devices entry around */
1644 ret = -ENOMEM;
1645 goto error;
1646 }
1647
1648 device->name = kstrdup(device_path, GFP_NOFS);
1649 if (!device->name) {
1650 kfree(device);
1651 ret = -ENOMEM;
1652 goto error;
1653 }
1654
1655 ret = find_next_devid(root, &device->devid);
1656 if (ret) {
1657 kfree(device->name);
1658 kfree(device);
1659 goto error;
1660 }
1661
1662 trans = btrfs_start_transaction(root, 0);
1663 if (IS_ERR(trans)) {
1664 kfree(device->name);
1665 kfree(device);
1666 ret = PTR_ERR(trans);
1667 goto error;
1668 }
1669
1670 lock_chunks(root);
1671
1672 q = bdev_get_queue(bdev);
1673 if (blk_queue_discard(q))
1674 device->can_discard = 1;
1675 device->writeable = 1;
1676 device->work.func = pending_bios_fn;
1677 generate_random_uuid(device->uuid);
1678 spin_lock_init(&device->io_lock);
1679 device->generation = trans->transid;
1680 device->io_width = root->sectorsize;
1681 device->io_align = root->sectorsize;
1682 device->sector_size = root->sectorsize;
1683 device->total_bytes = i_size_read(bdev->bd_inode);
1684 device->disk_total_bytes = device->total_bytes;
1685 device->dev_root = root->fs_info->dev_root;
1686 device->bdev = bdev;
1687 device->in_fs_metadata = 1;
1688 device->mode = FMODE_EXCL;
1689 set_blocksize(device->bdev, 4096);
1690
1691 if (seeding_dev) {
1692 sb->s_flags &= ~MS_RDONLY;
1693 ret = btrfs_prepare_sprout(root);
1694 BUG_ON(ret);
1695 }
1696
1697 device->fs_devices = root->fs_info->fs_devices;
1698
1699 /*
1700 * we don't want write_supers to jump in here with our device
1701 * half setup
1702 */
1703 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1704 list_add_rcu(&device->dev_list, &root->fs_info->fs_devices->devices);
1705 list_add(&device->dev_alloc_list,
1706 &root->fs_info->fs_devices->alloc_list);
1707 root->fs_info->fs_devices->num_devices++;
1708 root->fs_info->fs_devices->open_devices++;
1709 root->fs_info->fs_devices->rw_devices++;
1710 if (device->can_discard)
1711 root->fs_info->fs_devices->num_can_discard++;
1712 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
1713
1714 spin_lock(&root->fs_info->free_chunk_lock);
1715 root->fs_info->free_chunk_space += device->total_bytes;
1716 spin_unlock(&root->fs_info->free_chunk_lock);
1717
1718 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
1719 root->fs_info->fs_devices->rotating = 1;
1720
1721 total_bytes = btrfs_super_total_bytes(root->fs_info->super_copy);
1722 btrfs_set_super_total_bytes(root->fs_info->super_copy,
1723 total_bytes + device->total_bytes);
1724
1725 total_bytes = btrfs_super_num_devices(root->fs_info->super_copy);
1726 btrfs_set_super_num_devices(root->fs_info->super_copy,
1727 total_bytes + 1);
1728 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1729
1730 if (seeding_dev) {
1731 ret = init_first_rw_device(trans, root, device);
1732 BUG_ON(ret);
1733 ret = btrfs_finish_sprout(trans, root);
1734 BUG_ON(ret);
1735 } else {
1736 ret = btrfs_add_device(trans, root, device);
1737 }
1738
1739 /*
1740 * we've got more storage, clear any full flags on the space
1741 * infos
1742 */
1743 btrfs_clear_space_info_full(root->fs_info);
1744
1745 unlock_chunks(root);
1746 btrfs_commit_transaction(trans, root);
1747
1748 if (seeding_dev) {
1749 mutex_unlock(&uuid_mutex);
1750 up_write(&sb->s_umount);
1751
1752 ret = btrfs_relocate_sys_chunks(root);
1753 BUG_ON(ret);
1754 }
1755
1756 return ret;
1757 error:
1758 blkdev_put(bdev, FMODE_EXCL);
1759 if (seeding_dev) {
1760 mutex_unlock(&uuid_mutex);
1761 up_write(&sb->s_umount);
1762 }
1763 return ret;
1764 }
1765
1766 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
1767 struct btrfs_device *device)
1768 {
1769 int ret;
1770 struct btrfs_path *path;
1771 struct btrfs_root *root;
1772 struct btrfs_dev_item *dev_item;
1773 struct extent_buffer *leaf;
1774 struct btrfs_key key;
1775
1776 root = device->dev_root->fs_info->chunk_root;
1777
1778 path = btrfs_alloc_path();
1779 if (!path)
1780 return -ENOMEM;
1781
1782 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1783 key.type = BTRFS_DEV_ITEM_KEY;
1784 key.offset = device->devid;
1785
1786 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1787 if (ret < 0)
1788 goto out;
1789
1790 if (ret > 0) {
1791 ret = -ENOENT;
1792 goto out;
1793 }
1794
1795 leaf = path->nodes[0];
1796 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1797
1798 btrfs_set_device_id(leaf, dev_item, device->devid);
1799 btrfs_set_device_type(leaf, dev_item, device->type);
1800 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1801 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1802 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1803 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
1804 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1805 btrfs_mark_buffer_dirty(leaf);
1806
1807 out:
1808 btrfs_free_path(path);
1809 return ret;
1810 }
1811
1812 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
1813 struct btrfs_device *device, u64 new_size)
1814 {
1815 struct btrfs_super_block *super_copy =
1816 device->dev_root->fs_info->super_copy;
1817 u64 old_total = btrfs_super_total_bytes(super_copy);
1818 u64 diff = new_size - device->total_bytes;
1819
1820 if (!device->writeable)
1821 return -EACCES;
1822 if (new_size <= device->total_bytes)
1823 return -EINVAL;
1824
1825 btrfs_set_super_total_bytes(super_copy, old_total + diff);
1826 device->fs_devices->total_rw_bytes += diff;
1827
1828 device->total_bytes = new_size;
1829 device->disk_total_bytes = new_size;
1830 btrfs_clear_space_info_full(device->dev_root->fs_info);
1831
1832 return btrfs_update_device(trans, device);
1833 }
1834
1835 int btrfs_grow_device(struct btrfs_trans_handle *trans,
1836 struct btrfs_device *device, u64 new_size)
1837 {
1838 int ret;
1839 lock_chunks(device->dev_root);
1840 ret = __btrfs_grow_device(trans, device, new_size);
1841 unlock_chunks(device->dev_root);
1842 return ret;
1843 }
1844
1845 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
1846 struct btrfs_root *root,
1847 u64 chunk_tree, u64 chunk_objectid,
1848 u64 chunk_offset)
1849 {
1850 int ret;
1851 struct btrfs_path *path;
1852 struct btrfs_key key;
1853
1854 root = root->fs_info->chunk_root;
1855 path = btrfs_alloc_path();
1856 if (!path)
1857 return -ENOMEM;
1858
1859 key.objectid = chunk_objectid;
1860 key.offset = chunk_offset;
1861 key.type = BTRFS_CHUNK_ITEM_KEY;
1862
1863 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1864 BUG_ON(ret);
1865
1866 ret = btrfs_del_item(trans, root, path);
1867
1868 btrfs_free_path(path);
1869 return ret;
1870 }
1871
1872 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
1873 chunk_offset)
1874 {
1875 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
1876 struct btrfs_disk_key *disk_key;
1877 struct btrfs_chunk *chunk;
1878 u8 *ptr;
1879 int ret = 0;
1880 u32 num_stripes;
1881 u32 array_size;
1882 u32 len = 0;
1883 u32 cur;
1884 struct btrfs_key key;
1885
1886 array_size = btrfs_super_sys_array_size(super_copy);
1887
1888 ptr = super_copy->sys_chunk_array;
1889 cur = 0;
1890
1891 while (cur < array_size) {
1892 disk_key = (struct btrfs_disk_key *)ptr;
1893 btrfs_disk_key_to_cpu(&key, disk_key);
1894
1895 len = sizeof(*disk_key);
1896
1897 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
1898 chunk = (struct btrfs_chunk *)(ptr + len);
1899 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
1900 len += btrfs_chunk_item_size(num_stripes);
1901 } else {
1902 ret = -EIO;
1903 break;
1904 }
1905 if (key.objectid == chunk_objectid &&
1906 key.offset == chunk_offset) {
1907 memmove(ptr, ptr + len, array_size - (cur + len));
1908 array_size -= len;
1909 btrfs_set_super_sys_array_size(super_copy, array_size);
1910 } else {
1911 ptr += len;
1912 cur += len;
1913 }
1914 }
1915 return ret;
1916 }
1917
1918 static int btrfs_relocate_chunk(struct btrfs_root *root,
1919 u64 chunk_tree, u64 chunk_objectid,
1920 u64 chunk_offset)
1921 {
1922 struct extent_map_tree *em_tree;
1923 struct btrfs_root *extent_root;
1924 struct btrfs_trans_handle *trans;
1925 struct extent_map *em;
1926 struct map_lookup *map;
1927 int ret;
1928 int i;
1929
1930 root = root->fs_info->chunk_root;
1931 extent_root = root->fs_info->extent_root;
1932 em_tree = &root->fs_info->mapping_tree.map_tree;
1933
1934 ret = btrfs_can_relocate(extent_root, chunk_offset);
1935 if (ret)
1936 return -ENOSPC;
1937
1938 /* step one, relocate all the extents inside this chunk */
1939 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
1940 if (ret)
1941 return ret;
1942
1943 trans = btrfs_start_transaction(root, 0);
1944 BUG_ON(IS_ERR(trans));
1945
1946 lock_chunks(root);
1947
1948 /*
1949 * step two, delete the device extents and the
1950 * chunk tree entries
1951 */
1952 read_lock(&em_tree->lock);
1953 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
1954 read_unlock(&em_tree->lock);
1955
1956 BUG_ON(em->start > chunk_offset ||
1957 em->start + em->len < chunk_offset);
1958 map = (struct map_lookup *)em->bdev;
1959
1960 for (i = 0; i < map->num_stripes; i++) {
1961 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
1962 map->stripes[i].physical);
1963 BUG_ON(ret);
1964
1965 if (map->stripes[i].dev) {
1966 ret = btrfs_update_device(trans, map->stripes[i].dev);
1967 BUG_ON(ret);
1968 }
1969 }
1970 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
1971 chunk_offset);
1972
1973 BUG_ON(ret);
1974
1975 trace_btrfs_chunk_free(root, map, chunk_offset, em->len);
1976
1977 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
1978 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
1979 BUG_ON(ret);
1980 }
1981
1982 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
1983 BUG_ON(ret);
1984
1985 write_lock(&em_tree->lock);
1986 remove_extent_mapping(em_tree, em);
1987 write_unlock(&em_tree->lock);
1988
1989 kfree(map);
1990 em->bdev = NULL;
1991
1992 /* once for the tree */
1993 free_extent_map(em);
1994 /* once for us */
1995 free_extent_map(em);
1996
1997 unlock_chunks(root);
1998 btrfs_end_transaction(trans, root);
1999 return 0;
2000 }
2001
2002 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
2003 {
2004 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
2005 struct btrfs_path *path;
2006 struct extent_buffer *leaf;
2007 struct btrfs_chunk *chunk;
2008 struct btrfs_key key;
2009 struct btrfs_key found_key;
2010 u64 chunk_tree = chunk_root->root_key.objectid;
2011 u64 chunk_type;
2012 bool retried = false;
2013 int failed = 0;
2014 int ret;
2015
2016 path = btrfs_alloc_path();
2017 if (!path)
2018 return -ENOMEM;
2019
2020 again:
2021 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2022 key.offset = (u64)-1;
2023 key.type = BTRFS_CHUNK_ITEM_KEY;
2024
2025 while (1) {
2026 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2027 if (ret < 0)
2028 goto error;
2029 BUG_ON(ret == 0);
2030
2031 ret = btrfs_previous_item(chunk_root, path, key.objectid,
2032 key.type);
2033 if (ret < 0)
2034 goto error;
2035 if (ret > 0)
2036 break;
2037
2038 leaf = path->nodes[0];
2039 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2040
2041 chunk = btrfs_item_ptr(leaf, path->slots[0],
2042 struct btrfs_chunk);
2043 chunk_type = btrfs_chunk_type(leaf, chunk);
2044 btrfs_release_path(path);
2045
2046 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
2047 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
2048 found_key.objectid,
2049 found_key.offset);
2050 if (ret == -ENOSPC)
2051 failed++;
2052 else if (ret)
2053 BUG();
2054 }
2055
2056 if (found_key.offset == 0)
2057 break;
2058 key.offset = found_key.offset - 1;
2059 }
2060 ret = 0;
2061 if (failed && !retried) {
2062 failed = 0;
2063 retried = true;
2064 goto again;
2065 } else if (failed && retried) {
2066 WARN_ON(1);
2067 ret = -ENOSPC;
2068 }
2069 error:
2070 btrfs_free_path(path);
2071 return ret;
2072 }
2073
2074 static int insert_balance_item(struct btrfs_root *root,
2075 struct btrfs_balance_control *bctl)
2076 {
2077 struct btrfs_trans_handle *trans;
2078 struct btrfs_balance_item *item;
2079 struct btrfs_disk_balance_args disk_bargs;
2080 struct btrfs_path *path;
2081 struct extent_buffer *leaf;
2082 struct btrfs_key key;
2083 int ret, err;
2084
2085 path = btrfs_alloc_path();
2086 if (!path)
2087 return -ENOMEM;
2088
2089 trans = btrfs_start_transaction(root, 0);
2090 if (IS_ERR(trans)) {
2091 btrfs_free_path(path);
2092 return PTR_ERR(trans);
2093 }
2094
2095 key.objectid = BTRFS_BALANCE_OBJECTID;
2096 key.type = BTRFS_BALANCE_ITEM_KEY;
2097 key.offset = 0;
2098
2099 ret = btrfs_insert_empty_item(trans, root, path, &key,
2100 sizeof(*item));
2101 if (ret)
2102 goto out;
2103
2104 leaf = path->nodes[0];
2105 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
2106
2107 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
2108
2109 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->data);
2110 btrfs_set_balance_data(leaf, item, &disk_bargs);
2111 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->meta);
2112 btrfs_set_balance_meta(leaf, item, &disk_bargs);
2113 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->sys);
2114 btrfs_set_balance_sys(leaf, item, &disk_bargs);
2115
2116 btrfs_set_balance_flags(leaf, item, bctl->flags);
2117
2118 btrfs_mark_buffer_dirty(leaf);
2119 out:
2120 btrfs_free_path(path);
2121 err = btrfs_commit_transaction(trans, root);
2122 if (err && !ret)
2123 ret = err;
2124 return ret;
2125 }
2126
2127 static int del_balance_item(struct btrfs_root *root)
2128 {
2129 struct btrfs_trans_handle *trans;
2130 struct btrfs_path *path;
2131 struct btrfs_key key;
2132 int ret, err;
2133
2134 path = btrfs_alloc_path();
2135 if (!path)
2136 return -ENOMEM;
2137
2138 trans = btrfs_start_transaction(root, 0);
2139 if (IS_ERR(trans)) {
2140 btrfs_free_path(path);
2141 return PTR_ERR(trans);
2142 }
2143
2144 key.objectid = BTRFS_BALANCE_OBJECTID;
2145 key.type = BTRFS_BALANCE_ITEM_KEY;
2146 key.offset = 0;
2147
2148 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2149 if (ret < 0)
2150 goto out;
2151 if (ret > 0) {
2152 ret = -ENOENT;
2153 goto out;
2154 }
2155
2156 ret = btrfs_del_item(trans, root, path);
2157 out:
2158 btrfs_free_path(path);
2159 err = btrfs_commit_transaction(trans, root);
2160 if (err && !ret)
2161 ret = err;
2162 return ret;
2163 }
2164
2165 /*
2166 * This is a heuristic used to reduce the number of chunks balanced on
2167 * resume after balance was interrupted.
2168 */
2169 static void update_balance_args(struct btrfs_balance_control *bctl)
2170 {
2171 /*
2172 * Turn on soft mode for chunk types that were being converted.
2173 */
2174 if (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)
2175 bctl->data.flags |= BTRFS_BALANCE_ARGS_SOFT;
2176 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)
2177 bctl->sys.flags |= BTRFS_BALANCE_ARGS_SOFT;
2178 if (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)
2179 bctl->meta.flags |= BTRFS_BALANCE_ARGS_SOFT;
2180
2181 /*
2182 * Turn on usage filter if is not already used. The idea is
2183 * that chunks that we have already balanced should be
2184 * reasonably full. Don't do it for chunks that are being
2185 * converted - that will keep us from relocating unconverted
2186 * (albeit full) chunks.
2187 */
2188 if (!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2189 !(bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2190 bctl->data.flags |= BTRFS_BALANCE_ARGS_USAGE;
2191 bctl->data.usage = 90;
2192 }
2193 if (!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2194 !(bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2195 bctl->sys.flags |= BTRFS_BALANCE_ARGS_USAGE;
2196 bctl->sys.usage = 90;
2197 }
2198 if (!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2199 !(bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2200 bctl->meta.flags |= BTRFS_BALANCE_ARGS_USAGE;
2201 bctl->meta.usage = 90;
2202 }
2203 }
2204
2205 /*
2206 * Should be called with both balance and volume mutexes held to
2207 * serialize other volume operations (add_dev/rm_dev/resize) with
2208 * restriper. Same goes for unset_balance_control.
2209 */
2210 static void set_balance_control(struct btrfs_balance_control *bctl)
2211 {
2212 struct btrfs_fs_info *fs_info = bctl->fs_info;
2213
2214 BUG_ON(fs_info->balance_ctl);
2215
2216 spin_lock(&fs_info->balance_lock);
2217 fs_info->balance_ctl = bctl;
2218 spin_unlock(&fs_info->balance_lock);
2219 }
2220
2221 static void unset_balance_control(struct btrfs_fs_info *fs_info)
2222 {
2223 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2224
2225 BUG_ON(!fs_info->balance_ctl);
2226
2227 spin_lock(&fs_info->balance_lock);
2228 fs_info->balance_ctl = NULL;
2229 spin_unlock(&fs_info->balance_lock);
2230
2231 kfree(bctl);
2232 }
2233
2234 /*
2235 * Balance filters. Return 1 if chunk should be filtered out
2236 * (should not be balanced).
2237 */
2238 static int chunk_profiles_filter(u64 chunk_profile,
2239 struct btrfs_balance_args *bargs)
2240 {
2241 chunk_profile &= BTRFS_BLOCK_GROUP_PROFILE_MASK;
2242
2243 if (chunk_profile == 0)
2244 chunk_profile = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
2245
2246 if (bargs->profiles & chunk_profile)
2247 return 0;
2248
2249 return 1;
2250 }
2251
2252 static u64 div_factor_fine(u64 num, int factor)
2253 {
2254 if (factor <= 0)
2255 return 0;
2256 if (factor >= 100)
2257 return num;
2258
2259 num *= factor;
2260 do_div(num, 100);
2261 return num;
2262 }
2263
2264 static int chunk_usage_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset,
2265 struct btrfs_balance_args *bargs)
2266 {
2267 struct btrfs_block_group_cache *cache;
2268 u64 chunk_used, user_thresh;
2269 int ret = 1;
2270
2271 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
2272 chunk_used = btrfs_block_group_used(&cache->item);
2273
2274 user_thresh = div_factor_fine(cache->key.offset, bargs->usage);
2275 if (chunk_used < user_thresh)
2276 ret = 0;
2277
2278 btrfs_put_block_group(cache);
2279 return ret;
2280 }
2281
2282 static int chunk_devid_filter(struct extent_buffer *leaf,
2283 struct btrfs_chunk *chunk,
2284 struct btrfs_balance_args *bargs)
2285 {
2286 struct btrfs_stripe *stripe;
2287 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2288 int i;
2289
2290 for (i = 0; i < num_stripes; i++) {
2291 stripe = btrfs_stripe_nr(chunk, i);
2292 if (btrfs_stripe_devid(leaf, stripe) == bargs->devid)
2293 return 0;
2294 }
2295
2296 return 1;
2297 }
2298
2299 /* [pstart, pend) */
2300 static int chunk_drange_filter(struct extent_buffer *leaf,
2301 struct btrfs_chunk *chunk,
2302 u64 chunk_offset,
2303 struct btrfs_balance_args *bargs)
2304 {
2305 struct btrfs_stripe *stripe;
2306 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2307 u64 stripe_offset;
2308 u64 stripe_length;
2309 int factor;
2310 int i;
2311
2312 if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID))
2313 return 0;
2314
2315 if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP |
2316 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10))
2317 factor = 2;
2318 else
2319 factor = 1;
2320 factor = num_stripes / factor;
2321
2322 for (i = 0; i < num_stripes; i++) {
2323 stripe = btrfs_stripe_nr(chunk, i);
2324 if (btrfs_stripe_devid(leaf, stripe) != bargs->devid)
2325 continue;
2326
2327 stripe_offset = btrfs_stripe_offset(leaf, stripe);
2328 stripe_length = btrfs_chunk_length(leaf, chunk);
2329 do_div(stripe_length, factor);
2330
2331 if (stripe_offset < bargs->pend &&
2332 stripe_offset + stripe_length > bargs->pstart)
2333 return 0;
2334 }
2335
2336 return 1;
2337 }
2338
2339 /* [vstart, vend) */
2340 static int chunk_vrange_filter(struct extent_buffer *leaf,
2341 struct btrfs_chunk *chunk,
2342 u64 chunk_offset,
2343 struct btrfs_balance_args *bargs)
2344 {
2345 if (chunk_offset < bargs->vend &&
2346 chunk_offset + btrfs_chunk_length(leaf, chunk) > bargs->vstart)
2347 /* at least part of the chunk is inside this vrange */
2348 return 0;
2349
2350 return 1;
2351 }
2352
2353 static int chunk_soft_convert_filter(u64 chunk_profile,
2354 struct btrfs_balance_args *bargs)
2355 {
2356 if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
2357 return 0;
2358
2359 chunk_profile &= BTRFS_BLOCK_GROUP_PROFILE_MASK;
2360
2361 if (chunk_profile == 0)
2362 chunk_profile = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
2363
2364 if (bargs->target & chunk_profile)
2365 return 1;
2366
2367 return 0;
2368 }
2369
2370 static int should_balance_chunk(struct btrfs_root *root,
2371 struct extent_buffer *leaf,
2372 struct btrfs_chunk *chunk, u64 chunk_offset)
2373 {
2374 struct btrfs_balance_control *bctl = root->fs_info->balance_ctl;
2375 struct btrfs_balance_args *bargs = NULL;
2376 u64 chunk_type = btrfs_chunk_type(leaf, chunk);
2377
2378 /* type filter */
2379 if (!((chunk_type & BTRFS_BLOCK_GROUP_TYPE_MASK) &
2380 (bctl->flags & BTRFS_BALANCE_TYPE_MASK))) {
2381 return 0;
2382 }
2383
2384 if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
2385 bargs = &bctl->data;
2386 else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
2387 bargs = &bctl->sys;
2388 else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
2389 bargs = &bctl->meta;
2390
2391 /* profiles filter */
2392 if ((bargs->flags & BTRFS_BALANCE_ARGS_PROFILES) &&
2393 chunk_profiles_filter(chunk_type, bargs)) {
2394 return 0;
2395 }
2396
2397 /* usage filter */
2398 if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) &&
2399 chunk_usage_filter(bctl->fs_info, chunk_offset, bargs)) {
2400 return 0;
2401 }
2402
2403 /* devid filter */
2404 if ((bargs->flags & BTRFS_BALANCE_ARGS_DEVID) &&
2405 chunk_devid_filter(leaf, chunk, bargs)) {
2406 return 0;
2407 }
2408
2409 /* drange filter, makes sense only with devid filter */
2410 if ((bargs->flags & BTRFS_BALANCE_ARGS_DRANGE) &&
2411 chunk_drange_filter(leaf, chunk, chunk_offset, bargs)) {
2412 return 0;
2413 }
2414
2415 /* vrange filter */
2416 if ((bargs->flags & BTRFS_BALANCE_ARGS_VRANGE) &&
2417 chunk_vrange_filter(leaf, chunk, chunk_offset, bargs)) {
2418 return 0;
2419 }
2420
2421 /* soft profile changing mode */
2422 if ((bargs->flags & BTRFS_BALANCE_ARGS_SOFT) &&
2423 chunk_soft_convert_filter(chunk_type, bargs)) {
2424 return 0;
2425 }
2426
2427 return 1;
2428 }
2429
2430 static u64 div_factor(u64 num, int factor)
2431 {
2432 if (factor == 10)
2433 return num;
2434 num *= factor;
2435 do_div(num, 10);
2436 return num;
2437 }
2438
2439 static int __btrfs_balance(struct btrfs_fs_info *fs_info)
2440 {
2441 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2442 struct btrfs_root *chunk_root = fs_info->chunk_root;
2443 struct btrfs_root *dev_root = fs_info->dev_root;
2444 struct list_head *devices;
2445 struct btrfs_device *device;
2446 u64 old_size;
2447 u64 size_to_free;
2448 struct btrfs_chunk *chunk;
2449 struct btrfs_path *path;
2450 struct btrfs_key key;
2451 struct btrfs_key found_key;
2452 struct btrfs_trans_handle *trans;
2453 struct extent_buffer *leaf;
2454 int slot;
2455 int ret;
2456 int enospc_errors = 0;
2457 bool counting = true;
2458
2459 /* step one make some room on all the devices */
2460 devices = &fs_info->fs_devices->devices;
2461 list_for_each_entry(device, devices, dev_list) {
2462 old_size = device->total_bytes;
2463 size_to_free = div_factor(old_size, 1);
2464 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
2465 if (!device->writeable ||
2466 device->total_bytes - device->bytes_used > size_to_free)
2467 continue;
2468
2469 ret = btrfs_shrink_device(device, old_size - size_to_free);
2470 if (ret == -ENOSPC)
2471 break;
2472 BUG_ON(ret);
2473
2474 trans = btrfs_start_transaction(dev_root, 0);
2475 BUG_ON(IS_ERR(trans));
2476
2477 ret = btrfs_grow_device(trans, device, old_size);
2478 BUG_ON(ret);
2479
2480 btrfs_end_transaction(trans, dev_root);
2481 }
2482
2483 /* step two, relocate all the chunks */
2484 path = btrfs_alloc_path();
2485 if (!path) {
2486 ret = -ENOMEM;
2487 goto error;
2488 }
2489
2490 /* zero out stat counters */
2491 spin_lock(&fs_info->balance_lock);
2492 memset(&bctl->stat, 0, sizeof(bctl->stat));
2493 spin_unlock(&fs_info->balance_lock);
2494 again:
2495 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2496 key.offset = (u64)-1;
2497 key.type = BTRFS_CHUNK_ITEM_KEY;
2498
2499 while (1) {
2500 if ((!counting && atomic_read(&fs_info->balance_pause_req)) ||
2501 atomic_read(&fs_info->balance_cancel_req)) {
2502 ret = -ECANCELED;
2503 goto error;
2504 }
2505
2506 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2507 if (ret < 0)
2508 goto error;
2509
2510 /*
2511 * this shouldn't happen, it means the last relocate
2512 * failed
2513 */
2514 if (ret == 0)
2515 BUG(); /* FIXME break ? */
2516
2517 ret = btrfs_previous_item(chunk_root, path, 0,
2518 BTRFS_CHUNK_ITEM_KEY);
2519 if (ret) {
2520 ret = 0;
2521 break;
2522 }
2523
2524 leaf = path->nodes[0];
2525 slot = path->slots[0];
2526 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2527
2528 if (found_key.objectid != key.objectid)
2529 break;
2530
2531 /* chunk zero is special */
2532 if (found_key.offset == 0)
2533 break;
2534
2535 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
2536
2537 if (!counting) {
2538 spin_lock(&fs_info->balance_lock);
2539 bctl->stat.considered++;
2540 spin_unlock(&fs_info->balance_lock);
2541 }
2542
2543 ret = should_balance_chunk(chunk_root, leaf, chunk,
2544 found_key.offset);
2545 btrfs_release_path(path);
2546 if (!ret)
2547 goto loop;
2548
2549 if (counting) {
2550 spin_lock(&fs_info->balance_lock);
2551 bctl->stat.expected++;
2552 spin_unlock(&fs_info->balance_lock);
2553 goto loop;
2554 }
2555
2556 ret = btrfs_relocate_chunk(chunk_root,
2557 chunk_root->root_key.objectid,
2558 found_key.objectid,
2559 found_key.offset);
2560 if (ret && ret != -ENOSPC)
2561 goto error;
2562 if (ret == -ENOSPC) {
2563 enospc_errors++;
2564 } else {
2565 spin_lock(&fs_info->balance_lock);
2566 bctl->stat.completed++;
2567 spin_unlock(&fs_info->balance_lock);
2568 }
2569 loop:
2570 key.offset = found_key.offset - 1;
2571 }
2572
2573 if (counting) {
2574 btrfs_release_path(path);
2575 counting = false;
2576 goto again;
2577 }
2578 error:
2579 btrfs_free_path(path);
2580 if (enospc_errors) {
2581 printk(KERN_INFO "btrfs: %d enospc errors during balance\n",
2582 enospc_errors);
2583 if (!ret)
2584 ret = -ENOSPC;
2585 }
2586
2587 return ret;
2588 }
2589
2590 static inline int balance_need_close(struct btrfs_fs_info *fs_info)
2591 {
2592 /* cancel requested || normal exit path */
2593 return atomic_read(&fs_info->balance_cancel_req) ||
2594 (atomic_read(&fs_info->balance_pause_req) == 0 &&
2595 atomic_read(&fs_info->balance_cancel_req) == 0);
2596 }
2597
2598 static void __cancel_balance(struct btrfs_fs_info *fs_info)
2599 {
2600 int ret;
2601
2602 unset_balance_control(fs_info);
2603 ret = del_balance_item(fs_info->tree_root);
2604 BUG_ON(ret);
2605 }
2606
2607 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
2608 struct btrfs_ioctl_balance_args *bargs);
2609
2610 /*
2611 * Should be called with both balance and volume mutexes held
2612 */
2613 int btrfs_balance(struct btrfs_balance_control *bctl,
2614 struct btrfs_ioctl_balance_args *bargs)
2615 {
2616 struct btrfs_fs_info *fs_info = bctl->fs_info;
2617 u64 allowed;
2618 int ret;
2619
2620 if (btrfs_fs_closing(fs_info) ||
2621 atomic_read(&fs_info->balance_pause_req) ||
2622 atomic_read(&fs_info->balance_cancel_req)) {
2623 ret = -EINVAL;
2624 goto out;
2625 }
2626
2627 /*
2628 * In case of mixed groups both data and meta should be picked,
2629 * and identical options should be given for both of them.
2630 */
2631 allowed = btrfs_super_incompat_flags(fs_info->super_copy);
2632 if ((allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) &&
2633 (bctl->flags & (BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA))) {
2634 if (!(bctl->flags & BTRFS_BALANCE_DATA) ||
2635 !(bctl->flags & BTRFS_BALANCE_METADATA) ||
2636 memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) {
2637 printk(KERN_ERR "btrfs: with mixed groups data and "
2638 "metadata balance options must be the same\n");
2639 ret = -EINVAL;
2640 goto out;
2641 }
2642 }
2643
2644 /*
2645 * Profile changing sanity checks. Skip them if a simple
2646 * balance is requested.
2647 */
2648 if (!((bctl->data.flags | bctl->sys.flags | bctl->meta.flags) &
2649 BTRFS_BALANCE_ARGS_CONVERT))
2650 goto do_balance;
2651
2652 allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
2653 if (fs_info->fs_devices->num_devices == 1)
2654 allowed |= BTRFS_BLOCK_GROUP_DUP;
2655 else if (fs_info->fs_devices->num_devices < 4)
2656 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
2657 else
2658 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
2659 BTRFS_BLOCK_GROUP_RAID10);
2660
2661 if (!profile_is_valid(bctl->data.target, 1) ||
2662 bctl->data.target & ~allowed) {
2663 printk(KERN_ERR "btrfs: unable to start balance with target "
2664 "data profile %llu\n",
2665 (unsigned long long)bctl->data.target);
2666 ret = -EINVAL;
2667 goto out;
2668 }
2669 if (!profile_is_valid(bctl->meta.target, 1) ||
2670 bctl->meta.target & ~allowed) {
2671 printk(KERN_ERR "btrfs: unable to start balance with target "
2672 "metadata profile %llu\n",
2673 (unsigned long long)bctl->meta.target);
2674 ret = -EINVAL;
2675 goto out;
2676 }
2677 if (!profile_is_valid(bctl->sys.target, 1) ||
2678 bctl->sys.target & ~allowed) {
2679 printk(KERN_ERR "btrfs: unable to start balance with target "
2680 "system profile %llu\n",
2681 (unsigned long long)bctl->sys.target);
2682 ret = -EINVAL;
2683 goto out;
2684 }
2685
2686 if (bctl->data.target & BTRFS_BLOCK_GROUP_DUP) {
2687 printk(KERN_ERR "btrfs: dup for data is not allowed\n");
2688 ret = -EINVAL;
2689 goto out;
2690 }
2691
2692 /* allow to reduce meta or sys integrity only if force set */
2693 allowed = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
2694 BTRFS_BLOCK_GROUP_RAID10;
2695 if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2696 (fs_info->avail_system_alloc_bits & allowed) &&
2697 !(bctl->sys.target & allowed)) ||
2698 ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2699 (fs_info->avail_metadata_alloc_bits & allowed) &&
2700 !(bctl->meta.target & allowed))) {
2701 if (bctl->flags & BTRFS_BALANCE_FORCE) {
2702 printk(KERN_INFO "btrfs: force reducing metadata "
2703 "integrity\n");
2704 } else {
2705 printk(KERN_ERR "btrfs: balance will reduce metadata "
2706 "integrity, use force if you want this\n");
2707 ret = -EINVAL;
2708 goto out;
2709 }
2710 }
2711
2712 do_balance:
2713 ret = insert_balance_item(fs_info->tree_root, bctl);
2714 if (ret && ret != -EEXIST)
2715 goto out;
2716
2717 if (!(bctl->flags & BTRFS_BALANCE_RESUME)) {
2718 BUG_ON(ret == -EEXIST);
2719 set_balance_control(bctl);
2720 } else {
2721 BUG_ON(ret != -EEXIST);
2722 spin_lock(&fs_info->balance_lock);
2723 update_balance_args(bctl);
2724 spin_unlock(&fs_info->balance_lock);
2725 }
2726
2727 atomic_inc(&fs_info->balance_running);
2728 mutex_unlock(&fs_info->balance_mutex);
2729
2730 ret = __btrfs_balance(fs_info);
2731
2732 mutex_lock(&fs_info->balance_mutex);
2733 atomic_dec(&fs_info->balance_running);
2734
2735 if (bargs) {
2736 memset(bargs, 0, sizeof(*bargs));
2737 update_ioctl_balance_args(fs_info, 0, bargs);
2738 }
2739
2740 if ((ret && ret != -ECANCELED && ret != -ENOSPC) ||
2741 balance_need_close(fs_info)) {
2742 __cancel_balance(fs_info);
2743 }
2744
2745 wake_up(&fs_info->balance_wait_q);
2746
2747 return ret;
2748 out:
2749 if (bctl->flags & BTRFS_BALANCE_RESUME)
2750 __cancel_balance(fs_info);
2751 else
2752 kfree(bctl);
2753 return ret;
2754 }
2755
2756 static int balance_kthread(void *data)
2757 {
2758 struct btrfs_balance_control *bctl =
2759 (struct btrfs_balance_control *)data;
2760 struct btrfs_fs_info *fs_info = bctl->fs_info;
2761 int ret = 0;
2762
2763 mutex_lock(&fs_info->volume_mutex);
2764 mutex_lock(&fs_info->balance_mutex);
2765
2766 set_balance_control(bctl);
2767
2768 if (btrfs_test_opt(fs_info->tree_root, SKIP_BALANCE)) {
2769 printk(KERN_INFO "btrfs: force skipping balance\n");
2770 } else {
2771 printk(KERN_INFO "btrfs: continuing balance\n");
2772 ret = btrfs_balance(bctl, NULL);
2773 }
2774
2775 mutex_unlock(&fs_info->balance_mutex);
2776 mutex_unlock(&fs_info->volume_mutex);
2777 return ret;
2778 }
2779
2780 int btrfs_recover_balance(struct btrfs_root *tree_root)
2781 {
2782 struct task_struct *tsk;
2783 struct btrfs_balance_control *bctl;
2784 struct btrfs_balance_item *item;
2785 struct btrfs_disk_balance_args disk_bargs;
2786 struct btrfs_path *path;
2787 struct extent_buffer *leaf;
2788 struct btrfs_key key;
2789 int ret;
2790
2791 path = btrfs_alloc_path();
2792 if (!path)
2793 return -ENOMEM;
2794
2795 bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
2796 if (!bctl) {
2797 ret = -ENOMEM;
2798 goto out;
2799 }
2800
2801 key.objectid = BTRFS_BALANCE_OBJECTID;
2802 key.type = BTRFS_BALANCE_ITEM_KEY;
2803 key.offset = 0;
2804
2805 ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
2806 if (ret < 0)
2807 goto out_bctl;
2808 if (ret > 0) { /* ret = -ENOENT; */
2809 ret = 0;
2810 goto out_bctl;
2811 }
2812
2813 leaf = path->nodes[0];
2814 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
2815
2816 bctl->fs_info = tree_root->fs_info;
2817 bctl->flags = btrfs_balance_flags(leaf, item) | BTRFS_BALANCE_RESUME;
2818
2819 btrfs_balance_data(leaf, item, &disk_bargs);
2820 btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);
2821 btrfs_balance_meta(leaf, item, &disk_bargs);
2822 btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs);
2823 btrfs_balance_sys(leaf, item, &disk_bargs);
2824 btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);
2825
2826 tsk = kthread_run(balance_kthread, bctl, "btrfs-balance");
2827 if (IS_ERR(tsk))
2828 ret = PTR_ERR(tsk);
2829 else
2830 goto out;
2831
2832 out_bctl:
2833 kfree(bctl);
2834 out:
2835 btrfs_free_path(path);
2836 return ret;
2837 }
2838
2839 int btrfs_pause_balance(struct btrfs_fs_info *fs_info)
2840 {
2841 int ret = 0;
2842
2843 mutex_lock(&fs_info->balance_mutex);
2844 if (!fs_info->balance_ctl) {
2845 mutex_unlock(&fs_info->balance_mutex);
2846 return -ENOTCONN;
2847 }
2848
2849 if (atomic_read(&fs_info->balance_running)) {
2850 atomic_inc(&fs_info->balance_pause_req);
2851 mutex_unlock(&fs_info->balance_mutex);
2852
2853 wait_event(fs_info->balance_wait_q,
2854 atomic_read(&fs_info->balance_running) == 0);
2855
2856 mutex_lock(&fs_info->balance_mutex);
2857 /* we are good with balance_ctl ripped off from under us */
2858 BUG_ON(atomic_read(&fs_info->balance_running));
2859 atomic_dec(&fs_info->balance_pause_req);
2860 } else {
2861 ret = -ENOTCONN;
2862 }
2863
2864 mutex_unlock(&fs_info->balance_mutex);
2865 return ret;
2866 }
2867
2868 int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
2869 {
2870 mutex_lock(&fs_info->balance_mutex);
2871 if (!fs_info->balance_ctl) {
2872 mutex_unlock(&fs_info->balance_mutex);
2873 return -ENOTCONN;
2874 }
2875
2876 atomic_inc(&fs_info->balance_cancel_req);
2877 /*
2878 * if we are running just wait and return, balance item is
2879 * deleted in btrfs_balance in this case
2880 */
2881 if (atomic_read(&fs_info->balance_running)) {
2882 mutex_unlock(&fs_info->balance_mutex);
2883 wait_event(fs_info->balance_wait_q,
2884 atomic_read(&fs_info->balance_running) == 0);
2885 mutex_lock(&fs_info->balance_mutex);
2886 } else {
2887 /* __cancel_balance needs volume_mutex */
2888 mutex_unlock(&fs_info->balance_mutex);
2889 mutex_lock(&fs_info->volume_mutex);
2890 mutex_lock(&fs_info->balance_mutex);
2891
2892 if (fs_info->balance_ctl)
2893 __cancel_balance(fs_info);
2894
2895 mutex_unlock(&fs_info->volume_mutex);
2896 }
2897
2898 BUG_ON(fs_info->balance_ctl || atomic_read(&fs_info->balance_running));
2899 atomic_dec(&fs_info->balance_cancel_req);
2900 mutex_unlock(&fs_info->balance_mutex);
2901 return 0;
2902 }
2903
2904 /*
2905 * shrinking a device means finding all of the device extents past
2906 * the new size, and then following the back refs to the chunks.
2907 * The chunk relocation code actually frees the device extent
2908 */
2909 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
2910 {
2911 struct btrfs_trans_handle *trans;
2912 struct btrfs_root *root = device->dev_root;
2913 struct btrfs_dev_extent *dev_extent = NULL;
2914 struct btrfs_path *path;
2915 u64 length;
2916 u64 chunk_tree;
2917 u64 chunk_objectid;
2918 u64 chunk_offset;
2919 int ret;
2920 int slot;
2921 int failed = 0;
2922 bool retried = false;
2923 struct extent_buffer *l;
2924 struct btrfs_key key;
2925 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
2926 u64 old_total = btrfs_super_total_bytes(super_copy);
2927 u64 old_size = device->total_bytes;
2928 u64 diff = device->total_bytes - new_size;
2929
2930 if (new_size >= device->total_bytes)
2931 return -EINVAL;
2932
2933 path = btrfs_alloc_path();
2934 if (!path)
2935 return -ENOMEM;
2936
2937 path->reada = 2;
2938
2939 lock_chunks(root);
2940
2941 device->total_bytes = new_size;
2942 if (device->writeable) {
2943 device->fs_devices->total_rw_bytes -= diff;
2944 spin_lock(&root->fs_info->free_chunk_lock);
2945 root->fs_info->free_chunk_space -= diff;
2946 spin_unlock(&root->fs_info->free_chunk_lock);
2947 }
2948 unlock_chunks(root);
2949
2950 again:
2951 key.objectid = device->devid;
2952 key.offset = (u64)-1;
2953 key.type = BTRFS_DEV_EXTENT_KEY;
2954
2955 while (1) {
2956 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2957 if (ret < 0)
2958 goto done;
2959
2960 ret = btrfs_previous_item(root, path, 0, key.type);
2961 if (ret < 0)
2962 goto done;
2963 if (ret) {
2964 ret = 0;
2965 btrfs_release_path(path);
2966 break;
2967 }
2968
2969 l = path->nodes[0];
2970 slot = path->slots[0];
2971 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
2972
2973 if (key.objectid != device->devid) {
2974 btrfs_release_path(path);
2975 break;
2976 }
2977
2978 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
2979 length = btrfs_dev_extent_length(l, dev_extent);
2980
2981 if (key.offset + length <= new_size) {
2982 btrfs_release_path(path);
2983 break;
2984 }
2985
2986 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
2987 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
2988 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
2989 btrfs_release_path(path);
2990
2991 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
2992 chunk_offset);
2993 if (ret && ret != -ENOSPC)
2994 goto done;
2995 if (ret == -ENOSPC)
2996 failed++;
2997 key.offset -= 1;
2998 }
2999
3000 if (failed && !retried) {
3001 failed = 0;
3002 retried = true;
3003 goto again;
3004 } else if (failed && retried) {
3005 ret = -ENOSPC;
3006 lock_chunks(root);
3007
3008 device->total_bytes = old_size;
3009 if (device->writeable)
3010 device->fs_devices->total_rw_bytes += diff;
3011 spin_lock(&root->fs_info->free_chunk_lock);
3012 root->fs_info->free_chunk_space += diff;
3013 spin_unlock(&root->fs_info->free_chunk_lock);
3014 unlock_chunks(root);
3015 goto done;
3016 }
3017
3018 /* Shrinking succeeded, else we would be at "done". */
3019 trans = btrfs_start_transaction(root, 0);
3020 if (IS_ERR(trans)) {
3021 ret = PTR_ERR(trans);
3022 goto done;
3023 }
3024
3025 lock_chunks(root);
3026
3027 device->disk_total_bytes = new_size;
3028 /* Now btrfs_update_device() will change the on-disk size. */
3029 ret = btrfs_update_device(trans, device);
3030 if (ret) {
3031 unlock_chunks(root);
3032 btrfs_end_transaction(trans, root);
3033 goto done;
3034 }
3035 WARN_ON(diff > old_total);
3036 btrfs_set_super_total_bytes(super_copy, old_total - diff);
3037 unlock_chunks(root);
3038 btrfs_end_transaction(trans, root);
3039 done:
3040 btrfs_free_path(path);
3041 return ret;
3042 }
3043
3044 static int btrfs_add_system_chunk(struct btrfs_root *root,
3045 struct btrfs_key *key,
3046 struct btrfs_chunk *chunk, int item_size)
3047 {
3048 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3049 struct btrfs_disk_key disk_key;
3050 u32 array_size;
3051 u8 *ptr;
3052
3053 array_size = btrfs_super_sys_array_size(super_copy);
3054 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
3055 return -EFBIG;
3056
3057 ptr = super_copy->sys_chunk_array + array_size;
3058 btrfs_cpu_key_to_disk(&disk_key, key);
3059 memcpy(ptr, &disk_key, sizeof(disk_key));
3060 ptr += sizeof(disk_key);
3061 memcpy(ptr, chunk, item_size);
3062 item_size += sizeof(disk_key);
3063 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
3064 return 0;
3065 }
3066
3067 /*
3068 * sort the devices in descending order by max_avail, total_avail
3069 */
3070 static int btrfs_cmp_device_info(const void *a, const void *b)
3071 {
3072 const struct btrfs_device_info *di_a = a;
3073 const struct btrfs_device_info *di_b = b;
3074
3075 if (di_a->max_avail > di_b->max_avail)
3076 return -1;
3077 if (di_a->max_avail < di_b->max_avail)
3078 return 1;
3079 if (di_a->total_avail > di_b->total_avail)
3080 return -1;
3081 if (di_a->total_avail < di_b->total_avail)
3082 return 1;
3083 return 0;
3084 }
3085
3086 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
3087 struct btrfs_root *extent_root,
3088 struct map_lookup **map_ret,
3089 u64 *num_bytes_out, u64 *stripe_size_out,
3090 u64 start, u64 type)
3091 {
3092 struct btrfs_fs_info *info = extent_root->fs_info;
3093 struct btrfs_fs_devices *fs_devices = info->fs_devices;
3094 struct list_head *cur;
3095 struct map_lookup *map = NULL;
3096 struct extent_map_tree *em_tree;
3097 struct extent_map *em;
3098 struct btrfs_device_info *devices_info = NULL;
3099 u64 total_avail;
3100 int num_stripes; /* total number of stripes to allocate */
3101 int sub_stripes; /* sub_stripes info for map */
3102 int dev_stripes; /* stripes per dev */
3103 int devs_max; /* max devs to use */
3104 int devs_min; /* min devs needed */
3105 int devs_increment; /* ndevs has to be a multiple of this */
3106 int ncopies; /* how many copies to data has */
3107 int ret;
3108 u64 max_stripe_size;
3109 u64 max_chunk_size;
3110 u64 stripe_size;
3111 u64 num_bytes;
3112 int ndevs;
3113 int i;
3114 int j;
3115
3116 if ((type & BTRFS_BLOCK_GROUP_RAID1) &&
3117 (type & BTRFS_BLOCK_GROUP_DUP)) {
3118 WARN_ON(1);
3119 type &= ~BTRFS_BLOCK_GROUP_DUP;
3120 }
3121
3122 if (list_empty(&fs_devices->alloc_list))
3123 return -ENOSPC;
3124
3125 sub_stripes = 1;
3126 dev_stripes = 1;
3127 devs_increment = 1;
3128 ncopies = 1;
3129 devs_max = 0; /* 0 == as many as possible */
3130 devs_min = 1;
3131
3132 /*
3133 * define the properties of each RAID type.
3134 * FIXME: move this to a global table and use it in all RAID
3135 * calculation code
3136 */
3137 if (type & (BTRFS_BLOCK_GROUP_DUP)) {
3138 dev_stripes = 2;
3139 ncopies = 2;
3140 devs_max = 1;
3141 } else if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
3142 devs_min = 2;
3143 } else if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
3144 devs_increment = 2;
3145 ncopies = 2;
3146 devs_max = 2;
3147 devs_min = 2;
3148 } else if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
3149 sub_stripes = 2;
3150 devs_increment = 2;
3151 ncopies = 2;
3152 devs_min = 4;
3153 } else {
3154 devs_max = 1;
3155 }
3156
3157 if (type & BTRFS_BLOCK_GROUP_DATA) {
3158 max_stripe_size = 1024 * 1024 * 1024;
3159 max_chunk_size = 10 * max_stripe_size;
3160 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
3161 /* for larger filesystems, use larger metadata chunks */
3162 if (fs_devices->total_rw_bytes > 50ULL * 1024 * 1024 * 1024)
3163 max_stripe_size = 1024 * 1024 * 1024;
3164 else
3165 max_stripe_size = 256 * 1024 * 1024;
3166 max_chunk_size = max_stripe_size;
3167 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
3168 max_stripe_size = 32 * 1024 * 1024;
3169 max_chunk_size = 2 * max_stripe_size;
3170 } else {
3171 printk(KERN_ERR "btrfs: invalid chunk type 0x%llx requested\n",
3172 type);
3173 BUG_ON(1);
3174 }
3175
3176 /* we don't want a chunk larger than 10% of writeable space */
3177 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
3178 max_chunk_size);
3179
3180 devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices,
3181 GFP_NOFS);
3182 if (!devices_info)
3183 return -ENOMEM;
3184
3185 cur = fs_devices->alloc_list.next;
3186
3187 /*
3188 * in the first pass through the devices list, we gather information
3189 * about the available holes on each device.
3190 */
3191 ndevs = 0;
3192 while (cur != &fs_devices->alloc_list) {
3193 struct btrfs_device *device;
3194 u64 max_avail;
3195 u64 dev_offset;
3196
3197 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
3198
3199 cur = cur->next;
3200
3201 if (!device->writeable) {
3202 printk(KERN_ERR
3203 "btrfs: read-only device in alloc_list\n");
3204 WARN_ON(1);
3205 continue;
3206 }
3207
3208 if (!device->in_fs_metadata)
3209 continue;
3210
3211 if (device->total_bytes > device->bytes_used)
3212 total_avail = device->total_bytes - device->bytes_used;
3213 else
3214 total_avail = 0;
3215
3216 /* If there is no space on this device, skip it. */
3217 if (total_avail == 0)
3218 continue;
3219
3220 ret = find_free_dev_extent(device,
3221 max_stripe_size * dev_stripes,
3222 &dev_offset, &max_avail);
3223 if (ret && ret != -ENOSPC)
3224 goto error;
3225
3226 if (ret == 0)
3227 max_avail = max_stripe_size * dev_stripes;
3228
3229 if (max_avail < BTRFS_STRIPE_LEN * dev_stripes)
3230 continue;
3231
3232 devices_info[ndevs].dev_offset = dev_offset;
3233 devices_info[ndevs].max_avail = max_avail;
3234 devices_info[ndevs].total_avail = total_avail;
3235 devices_info[ndevs].dev = device;
3236 ++ndevs;
3237 }
3238
3239 /*
3240 * now sort the devices by hole size / available space
3241 */
3242 sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
3243 btrfs_cmp_device_info, NULL);
3244
3245 /* round down to number of usable stripes */
3246 ndevs -= ndevs % devs_increment;
3247
3248 if (ndevs < devs_increment * sub_stripes || ndevs < devs_min) {
3249 ret = -ENOSPC;
3250 goto error;
3251 }
3252
3253 if (devs_max && ndevs > devs_max)
3254 ndevs = devs_max;
3255 /*
3256 * the primary goal is to maximize the number of stripes, so use as many
3257 * devices as possible, even if the stripes are not maximum sized.
3258 */
3259 stripe_size = devices_info[ndevs-1].max_avail;
3260 num_stripes = ndevs * dev_stripes;
3261
3262 if (stripe_size * num_stripes > max_chunk_size * ncopies) {
3263 stripe_size = max_chunk_size * ncopies;
3264 do_div(stripe_size, num_stripes);
3265 }
3266
3267 do_div(stripe_size, dev_stripes);
3268 do_div(stripe_size, BTRFS_STRIPE_LEN);
3269 stripe_size *= BTRFS_STRIPE_LEN;
3270
3271 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
3272 if (!map) {
3273 ret = -ENOMEM;
3274 goto error;
3275 }
3276 map->num_stripes = num_stripes;
3277
3278 for (i = 0; i < ndevs; ++i) {
3279 for (j = 0; j < dev_stripes; ++j) {
3280 int s = i * dev_stripes + j;
3281 map->stripes[s].dev = devices_info[i].dev;
3282 map->stripes[s].physical = devices_info[i].dev_offset +
3283 j * stripe_size;
3284 }
3285 }
3286 map->sector_size = extent_root->sectorsize;
3287 map->stripe_len = BTRFS_STRIPE_LEN;
3288 map->io_align = BTRFS_STRIPE_LEN;
3289 map->io_width = BTRFS_STRIPE_LEN;
3290 map->type = type;
3291 map->sub_stripes = sub_stripes;
3292
3293 *map_ret = map;
3294 num_bytes = stripe_size * (num_stripes / ncopies);
3295
3296 *stripe_size_out = stripe_size;
3297 *num_bytes_out = num_bytes;
3298
3299 trace_btrfs_chunk_alloc(info->chunk_root, map, start, num_bytes);
3300
3301 em = alloc_extent_map();
3302 if (!em) {
3303 ret = -ENOMEM;
3304 goto error;
3305 }
3306 em->bdev = (struct block_device *)map;
3307 em->start = start;
3308 em->len = num_bytes;
3309 em->block_start = 0;
3310 em->block_len = em->len;
3311
3312 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
3313 write_lock(&em_tree->lock);
3314 ret = add_extent_mapping(em_tree, em);
3315 write_unlock(&em_tree->lock);
3316 BUG_ON(ret);
3317 free_extent_map(em);
3318
3319 ret = btrfs_make_block_group(trans, extent_root, 0, type,
3320 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3321 start, num_bytes);
3322 BUG_ON(ret);
3323
3324 for (i = 0; i < map->num_stripes; ++i) {
3325 struct btrfs_device *device;
3326 u64 dev_offset;
3327
3328 device = map->stripes[i].dev;
3329 dev_offset = map->stripes[i].physical;
3330
3331 ret = btrfs_alloc_dev_extent(trans, device,
3332 info->chunk_root->root_key.objectid,
3333 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3334 start, dev_offset, stripe_size);
3335 BUG_ON(ret);
3336 }
3337
3338 kfree(devices_info);
3339 return 0;
3340
3341 error:
3342 kfree(map);
3343 kfree(devices_info);
3344 return ret;
3345 }
3346
3347 static int __finish_chunk_alloc(struct btrfs_trans_handle *trans,
3348 struct btrfs_root *extent_root,
3349 struct map_lookup *map, u64 chunk_offset,
3350 u64 chunk_size, u64 stripe_size)
3351 {
3352 u64 dev_offset;
3353 struct btrfs_key key;
3354 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
3355 struct btrfs_device *device;
3356 struct btrfs_chunk *chunk;
3357 struct btrfs_stripe *stripe;
3358 size_t item_size = btrfs_chunk_item_size(map->num_stripes);
3359 int index = 0;
3360 int ret;
3361
3362 chunk = kzalloc(item_size, GFP_NOFS);
3363 if (!chunk)
3364 return -ENOMEM;
3365
3366 index = 0;
3367 while (index < map->num_stripes) {
3368 device = map->stripes[index].dev;
3369 device->bytes_used += stripe_size;
3370 ret = btrfs_update_device(trans, device);
3371 BUG_ON(ret);
3372 index++;
3373 }
3374
3375 spin_lock(&extent_root->fs_info->free_chunk_lock);
3376 extent_root->fs_info->free_chunk_space -= (stripe_size *
3377 map->num_stripes);
3378 spin_unlock(&extent_root->fs_info->free_chunk_lock);
3379
3380 index = 0;
3381 stripe = &chunk->stripe;
3382 while (index < map->num_stripes) {
3383 device = map->stripes[index].dev;
3384 dev_offset = map->stripes[index].physical;
3385
3386 btrfs_set_stack_stripe_devid(stripe, device->devid);
3387 btrfs_set_stack_stripe_offset(stripe, dev_offset);
3388 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
3389 stripe++;
3390 index++;
3391 }
3392
3393 btrfs_set_stack_chunk_length(chunk, chunk_size);
3394 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
3395 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
3396 btrfs_set_stack_chunk_type(chunk, map->type);
3397 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
3398 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
3399 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
3400 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
3401 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
3402
3403 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
3404 key.type = BTRFS_CHUNK_ITEM_KEY;
3405 key.offset = chunk_offset;
3406
3407 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
3408 BUG_ON(ret);
3409
3410 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
3411 ret = btrfs_add_system_chunk(chunk_root, &key, chunk,
3412 item_size);
3413 BUG_ON(ret);
3414 }
3415
3416 kfree(chunk);
3417 return 0;
3418 }
3419
3420 /*
3421 * Chunk allocation falls into two parts. The first part does works
3422 * that make the new allocated chunk useable, but not do any operation
3423 * that modifies the chunk tree. The second part does the works that
3424 * require modifying the chunk tree. This division is important for the
3425 * bootstrap process of adding storage to a seed btrfs.
3426 */
3427 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
3428 struct btrfs_root *extent_root, u64 type)
3429 {
3430 u64 chunk_offset;
3431 u64 chunk_size;
3432 u64 stripe_size;
3433 struct map_lookup *map;
3434 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
3435 int ret;
3436
3437 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3438 &chunk_offset);
3439 if (ret)
3440 return ret;
3441
3442 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
3443 &stripe_size, chunk_offset, type);
3444 if (ret)
3445 return ret;
3446
3447 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
3448 chunk_size, stripe_size);
3449 BUG_ON(ret);
3450 return 0;
3451 }
3452
3453 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
3454 struct btrfs_root *root,
3455 struct btrfs_device *device)
3456 {
3457 u64 chunk_offset;
3458 u64 sys_chunk_offset;
3459 u64 chunk_size;
3460 u64 sys_chunk_size;
3461 u64 stripe_size;
3462 u64 sys_stripe_size;
3463 u64 alloc_profile;
3464 struct map_lookup *map;
3465 struct map_lookup *sys_map;
3466 struct btrfs_fs_info *fs_info = root->fs_info;
3467 struct btrfs_root *extent_root = fs_info->extent_root;
3468 int ret;
3469
3470 ret = find_next_chunk(fs_info->chunk_root,
3471 BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset);
3472 if (ret)
3473 return ret;
3474
3475 alloc_profile = BTRFS_BLOCK_GROUP_METADATA |
3476 fs_info->avail_metadata_alloc_bits;
3477 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
3478
3479 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
3480 &stripe_size, chunk_offset, alloc_profile);
3481 BUG_ON(ret);
3482
3483 sys_chunk_offset = chunk_offset + chunk_size;
3484
3485 alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM |
3486 fs_info->avail_system_alloc_bits;
3487 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
3488
3489 ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,
3490 &sys_chunk_size, &sys_stripe_size,
3491 sys_chunk_offset, alloc_profile);
3492 BUG_ON(ret);
3493
3494 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
3495 BUG_ON(ret);
3496
3497 /*
3498 * Modifying chunk tree needs allocating new blocks from both
3499 * system block group and metadata block group. So we only can
3500 * do operations require modifying the chunk tree after both
3501 * block groups were created.
3502 */
3503 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
3504 chunk_size, stripe_size);
3505 BUG_ON(ret);
3506
3507 ret = __finish_chunk_alloc(trans, extent_root, sys_map,
3508 sys_chunk_offset, sys_chunk_size,
3509 sys_stripe_size);
3510 BUG_ON(ret);
3511 return 0;
3512 }
3513
3514 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
3515 {
3516 struct extent_map *em;
3517 struct map_lookup *map;
3518 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
3519 int readonly = 0;
3520 int i;
3521
3522 read_lock(&map_tree->map_tree.lock);
3523 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
3524 read_unlock(&map_tree->map_tree.lock);
3525 if (!em)
3526 return 1;
3527
3528 if (btrfs_test_opt(root, DEGRADED)) {
3529 free_extent_map(em);
3530 return 0;
3531 }
3532
3533 map = (struct map_lookup *)em->bdev;
3534 for (i = 0; i < map->num_stripes; i++) {
3535 if (!map->stripes[i].dev->writeable) {
3536 readonly = 1;
3537 break;
3538 }
3539 }
3540 free_extent_map(em);
3541 return readonly;
3542 }
3543
3544 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
3545 {
3546 extent_map_tree_init(&tree->map_tree);
3547 }
3548
3549 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
3550 {
3551 struct extent_map *em;
3552
3553 while (1) {
3554 write_lock(&tree->map_tree.lock);
3555 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
3556 if (em)
3557 remove_extent_mapping(&tree->map_tree, em);
3558 write_unlock(&tree->map_tree.lock);
3559 if (!em)
3560 break;
3561 kfree(em->bdev);
3562 /* once for us */
3563 free_extent_map(em);
3564 /* once for the tree */
3565 free_extent_map(em);
3566 }
3567 }
3568
3569 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
3570 {
3571 struct extent_map *em;
3572 struct map_lookup *map;
3573 struct extent_map_tree *em_tree = &map_tree->map_tree;
3574 int ret;
3575
3576 read_lock(&em_tree->lock);
3577 em = lookup_extent_mapping(em_tree, logical, len);
3578 read_unlock(&em_tree->lock);
3579 BUG_ON(!em);
3580
3581 BUG_ON(em->start > logical || em->start + em->len < logical);
3582 map = (struct map_lookup *)em->bdev;
3583 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
3584 ret = map->num_stripes;
3585 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
3586 ret = map->sub_stripes;
3587 else
3588 ret = 1;
3589 free_extent_map(em);
3590 return ret;
3591 }
3592
3593 static int find_live_mirror(struct map_lookup *map, int first, int num,
3594 int optimal)
3595 {
3596 int i;
3597 if (map->stripes[optimal].dev->bdev)
3598 return optimal;
3599 for (i = first; i < first + num; i++) {
3600 if (map->stripes[i].dev->bdev)
3601 return i;
3602 }
3603 /* we couldn't find one that doesn't fail. Just return something
3604 * and the io error handling code will clean up eventually
3605 */
3606 return optimal;
3607 }
3608
3609 static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
3610 u64 logical, u64 *length,
3611 struct btrfs_bio **bbio_ret,
3612 int mirror_num)
3613 {
3614 struct extent_map *em;
3615 struct map_lookup *map;
3616 struct extent_map_tree *em_tree = &map_tree->map_tree;
3617 u64 offset;
3618 u64 stripe_offset;
3619 u64 stripe_end_offset;
3620 u64 stripe_nr;
3621 u64 stripe_nr_orig;
3622 u64 stripe_nr_end;
3623 int stripe_index;
3624 int i;
3625 int ret = 0;
3626 int num_stripes;
3627 int max_errors = 0;
3628 struct btrfs_bio *bbio = NULL;
3629
3630 read_lock(&em_tree->lock);
3631 em = lookup_extent_mapping(em_tree, logical, *length);
3632 read_unlock(&em_tree->lock);
3633
3634 if (!em) {
3635 printk(KERN_CRIT "unable to find logical %llu len %llu\n",
3636 (unsigned long long)logical,
3637 (unsigned long long)*length);
3638 BUG();
3639 }
3640
3641 BUG_ON(em->start > logical || em->start + em->len < logical);
3642 map = (struct map_lookup *)em->bdev;
3643 offset = logical - em->start;
3644
3645 if (mirror_num > map->num_stripes)
3646 mirror_num = 0;
3647
3648 stripe_nr = offset;
3649 /*
3650 * stripe_nr counts the total number of stripes we have to stride
3651 * to get to this block
3652 */
3653 do_div(stripe_nr, map->stripe_len);
3654
3655 stripe_offset = stripe_nr * map->stripe_len;
3656 BUG_ON(offset < stripe_offset);
3657
3658 /* stripe_offset is the offset of this block in its stripe*/
3659 stripe_offset = offset - stripe_offset;
3660
3661 if (rw & REQ_DISCARD)
3662 *length = min_t(u64, em->len - offset, *length);
3663 else if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
3664 /* we limit the length of each bio to what fits in a stripe */
3665 *length = min_t(u64, em->len - offset,
3666 map->stripe_len - stripe_offset);
3667 } else {
3668 *length = em->len - offset;
3669 }
3670
3671 if (!bbio_ret)
3672 goto out;
3673
3674 num_stripes = 1;
3675 stripe_index = 0;
3676 stripe_nr_orig = stripe_nr;
3677 stripe_nr_end = (offset + *length + map->stripe_len - 1) &
3678 (~(map->stripe_len - 1));
3679 do_div(stripe_nr_end, map->stripe_len);
3680 stripe_end_offset = stripe_nr_end * map->stripe_len -
3681 (offset + *length);
3682 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3683 if (rw & REQ_DISCARD)
3684 num_stripes = min_t(u64, map->num_stripes,
3685 stripe_nr_end - stripe_nr_orig);
3686 stripe_index = do_div(stripe_nr, map->num_stripes);
3687 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
3688 if (rw & (REQ_WRITE | REQ_DISCARD))
3689 num_stripes = map->num_stripes;
3690 else if (mirror_num)
3691 stripe_index = mirror_num - 1;
3692 else {
3693 stripe_index = find_live_mirror(map, 0,
3694 map->num_stripes,
3695 current->pid % map->num_stripes);
3696 mirror_num = stripe_index + 1;
3697 }
3698
3699 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
3700 if (rw & (REQ_WRITE | REQ_DISCARD)) {
3701 num_stripes = map->num_stripes;
3702 } else if (mirror_num) {
3703 stripe_index = mirror_num - 1;
3704 } else {
3705 mirror_num = 1;
3706 }
3707
3708 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3709 int factor = map->num_stripes / map->sub_stripes;
3710
3711 stripe_index = do_div(stripe_nr, factor);
3712 stripe_index *= map->sub_stripes;
3713
3714 if (rw & REQ_WRITE)
3715 num_stripes = map->sub_stripes;
3716 else if (rw & REQ_DISCARD)
3717 num_stripes = min_t(u64, map->sub_stripes *
3718 (stripe_nr_end - stripe_nr_orig),
3719 map->num_stripes);
3720 else if (mirror_num)
3721 stripe_index += mirror_num - 1;
3722 else {
3723 stripe_index = find_live_mirror(map, stripe_index,
3724 map->sub_stripes, stripe_index +
3725 current->pid % map->sub_stripes);
3726 mirror_num = stripe_index + 1;
3727 }
3728 } else {
3729 /*
3730 * after this do_div call, stripe_nr is the number of stripes
3731 * on this device we have to walk to find the data, and
3732 * stripe_index is the number of our device in the stripe array
3733 */
3734 stripe_index = do_div(stripe_nr, map->num_stripes);
3735 mirror_num = stripe_index + 1;
3736 }
3737 BUG_ON(stripe_index >= map->num_stripes);
3738
3739 bbio = kzalloc(btrfs_bio_size(num_stripes), GFP_NOFS);
3740 if (!bbio) {
3741 ret = -ENOMEM;
3742 goto out;
3743 }
3744 atomic_set(&bbio->error, 0);
3745
3746 if (rw & REQ_DISCARD) {
3747 int factor = 0;
3748 int sub_stripes = 0;
3749 u64 stripes_per_dev = 0;
3750 u32 remaining_stripes = 0;
3751
3752 if (map->type &
3753 (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) {
3754 if (map->type & BTRFS_BLOCK_GROUP_RAID0)
3755 sub_stripes = 1;
3756 else
3757 sub_stripes = map->sub_stripes;
3758
3759 factor = map->num_stripes / sub_stripes;
3760 stripes_per_dev = div_u64_rem(stripe_nr_end -
3761 stripe_nr_orig,
3762 factor,
3763 &remaining_stripes);
3764 }
3765
3766 for (i = 0; i < num_stripes; i++) {
3767 bbio->stripes[i].physical =
3768 map->stripes[stripe_index].physical +
3769 stripe_offset + stripe_nr * map->stripe_len;
3770 bbio->stripes[i].dev = map->stripes[stripe_index].dev;
3771
3772 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
3773 BTRFS_BLOCK_GROUP_RAID10)) {
3774 bbio->stripes[i].length = stripes_per_dev *
3775 map->stripe_len;
3776 if (i / sub_stripes < remaining_stripes)
3777 bbio->stripes[i].length +=
3778 map->stripe_len;
3779 if (i < sub_stripes)
3780 bbio->stripes[i].length -=
3781 stripe_offset;
3782 if ((i / sub_stripes + 1) %
3783 sub_stripes == remaining_stripes)
3784 bbio->stripes[i].length -=
3785 stripe_end_offset;
3786 if (i == sub_stripes - 1)
3787 stripe_offset = 0;
3788 } else
3789 bbio->stripes[i].length = *length;
3790
3791 stripe_index++;
3792 if (stripe_index == map->num_stripes) {
3793 /* This could only happen for RAID0/10 */
3794 stripe_index = 0;
3795 stripe_nr++;
3796 }
3797 }
3798 } else {
3799 for (i = 0; i < num_stripes; i++) {
3800 bbio->stripes[i].physical =
3801 map->stripes[stripe_index].physical +
3802 stripe_offset +
3803 stripe_nr * map->stripe_len;
3804 bbio->stripes[i].dev =
3805 map->stripes[stripe_index].dev;
3806 stripe_index++;
3807 }
3808 }
3809
3810 if (rw & REQ_WRITE) {
3811 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
3812 BTRFS_BLOCK_GROUP_RAID10 |
3813 BTRFS_BLOCK_GROUP_DUP)) {
3814 max_errors = 1;
3815 }
3816 }
3817
3818 *bbio_ret = bbio;
3819 bbio->num_stripes = num_stripes;
3820 bbio->max_errors = max_errors;
3821 bbio->mirror_num = mirror_num;
3822 out:
3823 free_extent_map(em);
3824 return ret;
3825 }
3826
3827 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
3828 u64 logical, u64 *length,
3829 struct btrfs_bio **bbio_ret, int mirror_num)
3830 {
3831 return __btrfs_map_block(map_tree, rw, logical, length, bbio_ret,
3832 mirror_num);
3833 }
3834
3835 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
3836 u64 chunk_start, u64 physical, u64 devid,
3837 u64 **logical, int *naddrs, int *stripe_len)
3838 {
3839 struct extent_map_tree *em_tree = &map_tree->map_tree;
3840 struct extent_map *em;
3841 struct map_lookup *map;
3842 u64 *buf;
3843 u64 bytenr;
3844 u64 length;
3845 u64 stripe_nr;
3846 int i, j, nr = 0;
3847
3848 read_lock(&em_tree->lock);
3849 em = lookup_extent_mapping(em_tree, chunk_start, 1);
3850 read_unlock(&em_tree->lock);
3851
3852 BUG_ON(!em || em->start != chunk_start);
3853 map = (struct map_lookup *)em->bdev;
3854
3855 length = em->len;
3856 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
3857 do_div(length, map->num_stripes / map->sub_stripes);
3858 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
3859 do_div(length, map->num_stripes);
3860
3861 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
3862 BUG_ON(!buf);
3863
3864 for (i = 0; i < map->num_stripes; i++) {
3865 if (devid && map->stripes[i].dev->devid != devid)
3866 continue;
3867 if (map->stripes[i].physical > physical ||
3868 map->stripes[i].physical + length <= physical)
3869 continue;
3870
3871 stripe_nr = physical - map->stripes[i].physical;
3872 do_div(stripe_nr, map->stripe_len);
3873
3874 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3875 stripe_nr = stripe_nr * map->num_stripes + i;
3876 do_div(stripe_nr, map->sub_stripes);
3877 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3878 stripe_nr = stripe_nr * map->num_stripes + i;
3879 }
3880 bytenr = chunk_start + stripe_nr * map->stripe_len;
3881 WARN_ON(nr >= map->num_stripes);
3882 for (j = 0; j < nr; j++) {
3883 if (buf[j] == bytenr)
3884 break;
3885 }
3886 if (j == nr) {
3887 WARN_ON(nr >= map->num_stripes);
3888 buf[nr++] = bytenr;
3889 }
3890 }
3891
3892 *logical = buf;
3893 *naddrs = nr;
3894 *stripe_len = map->stripe_len;
3895
3896 free_extent_map(em);
3897 return 0;
3898 }
3899
3900 static void btrfs_end_bio(struct bio *bio, int err)
3901 {
3902 struct btrfs_bio *bbio = bio->bi_private;
3903 int is_orig_bio = 0;
3904
3905 if (err)
3906 atomic_inc(&bbio->error);
3907
3908 if (bio == bbio->orig_bio)
3909 is_orig_bio = 1;
3910
3911 if (atomic_dec_and_test(&bbio->stripes_pending)) {
3912 if (!is_orig_bio) {
3913 bio_put(bio);
3914 bio = bbio->orig_bio;
3915 }
3916 bio->bi_private = bbio->private;
3917 bio->bi_end_io = bbio->end_io;
3918 bio->bi_bdev = (struct block_device *)
3919 (unsigned long)bbio->mirror_num;
3920 /* only send an error to the higher layers if it is
3921 * beyond the tolerance of the multi-bio
3922 */
3923 if (atomic_read(&bbio->error) > bbio->max_errors) {
3924 err = -EIO;
3925 } else {
3926 /*
3927 * this bio is actually up to date, we didn't
3928 * go over the max number of errors
3929 */
3930 set_bit(BIO_UPTODATE, &bio->bi_flags);
3931 err = 0;
3932 }
3933 kfree(bbio);
3934
3935 bio_endio(bio, err);
3936 } else if (!is_orig_bio) {
3937 bio_put(bio);
3938 }
3939 }
3940
3941 struct async_sched {
3942 struct bio *bio;
3943 int rw;
3944 struct btrfs_fs_info *info;
3945 struct btrfs_work work;
3946 };
3947
3948 /*
3949 * see run_scheduled_bios for a description of why bios are collected for
3950 * async submit.
3951 *
3952 * This will add one bio to the pending list for a device and make sure
3953 * the work struct is scheduled.
3954 */
3955 static noinline int schedule_bio(struct btrfs_root *root,
3956 struct btrfs_device *device,
3957 int rw, struct bio *bio)
3958 {
3959 int should_queue = 1;
3960 struct btrfs_pending_bios *pending_bios;
3961
3962 /* don't bother with additional async steps for reads, right now */
3963 if (!(rw & REQ_WRITE)) {
3964 bio_get(bio);
3965 btrfsic_submit_bio(rw, bio);
3966 bio_put(bio);
3967 return 0;
3968 }
3969
3970 /*
3971 * nr_async_bios allows us to reliably return congestion to the
3972 * higher layers. Otherwise, the async bio makes it appear we have
3973 * made progress against dirty pages when we've really just put it
3974 * on a queue for later
3975 */
3976 atomic_inc(&root->fs_info->nr_async_bios);
3977 WARN_ON(bio->bi_next);
3978 bio->bi_next = NULL;
3979 bio->bi_rw |= rw;
3980
3981 spin_lock(&device->io_lock);
3982 if (bio->bi_rw & REQ_SYNC)
3983 pending_bios = &device->pending_sync_bios;
3984 else
3985 pending_bios = &device->pending_bios;
3986
3987 if (pending_bios->tail)
3988 pending_bios->tail->bi_next = bio;
3989
3990 pending_bios->tail = bio;
3991 if (!pending_bios->head)
3992 pending_bios->head = bio;
3993 if (device->running_pending)
3994 should_queue = 0;
3995
3996 spin_unlock(&device->io_lock);
3997
3998 if (should_queue)
3999 btrfs_queue_worker(&root->fs_info->submit_workers,
4000 &device->work);
4001 return 0;
4002 }
4003
4004 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
4005 int mirror_num, int async_submit)
4006 {
4007 struct btrfs_mapping_tree *map_tree;
4008 struct btrfs_device *dev;
4009 struct bio *first_bio = bio;
4010 u64 logical = (u64)bio->bi_sector << 9;
4011 u64 length = 0;
4012 u64 map_length;
4013 int ret;
4014 int dev_nr = 0;
4015 int total_devs = 1;
4016 struct btrfs_bio *bbio = NULL;
4017
4018 length = bio->bi_size;
4019 map_tree = &root->fs_info->mapping_tree;
4020 map_length = length;
4021
4022 ret = btrfs_map_block(map_tree, rw, logical, &map_length, &bbio,
4023 mirror_num);
4024 BUG_ON(ret);
4025
4026 total_devs = bbio->num_stripes;
4027 if (map_length < length) {
4028 printk(KERN_CRIT "mapping failed logical %llu bio len %llu "
4029 "len %llu\n", (unsigned long long)logical,
4030 (unsigned long long)length,
4031 (unsigned long long)map_length);
4032 BUG();
4033 }
4034
4035 bbio->orig_bio = first_bio;
4036 bbio->private = first_bio->bi_private;
4037 bbio->end_io = first_bio->bi_end_io;
4038 atomic_set(&bbio->stripes_pending, bbio->num_stripes);
4039
4040 while (dev_nr < total_devs) {
4041 if (dev_nr < total_devs - 1) {
4042 bio = bio_clone(first_bio, GFP_NOFS);
4043 BUG_ON(!bio);
4044 } else {
4045 bio = first_bio;
4046 }
4047 bio->bi_private = bbio;
4048 bio->bi_end_io = btrfs_end_bio;
4049 bio->bi_sector = bbio->stripes[dev_nr].physical >> 9;
4050 dev = bbio->stripes[dev_nr].dev;
4051 if (dev && dev->bdev && (rw != WRITE || dev->writeable)) {
4052 pr_debug("btrfs_map_bio: rw %d, secor=%llu, dev=%lu "
4053 "(%s id %llu), size=%u\n", rw,
4054 (u64)bio->bi_sector, (u_long)dev->bdev->bd_dev,
4055 dev->name, dev->devid, bio->bi_size);
4056 bio->bi_bdev = dev->bdev;
4057 if (async_submit)
4058 schedule_bio(root, dev, rw, bio);
4059 else
4060 btrfsic_submit_bio(rw, bio);
4061 } else {
4062 bio->bi_bdev = root->fs_info->fs_devices->latest_bdev;
4063 bio->bi_sector = logical >> 9;
4064 bio_endio(bio, -EIO);
4065 }
4066 dev_nr++;
4067 }
4068 return 0;
4069 }
4070
4071 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
4072 u8 *uuid, u8 *fsid)
4073 {
4074 struct btrfs_device *device;
4075 struct btrfs_fs_devices *cur_devices;
4076
4077 cur_devices = root->fs_info->fs_devices;
4078 while (cur_devices) {
4079 if (!fsid ||
4080 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
4081 device = __find_device(&cur_devices->devices,
4082 devid, uuid);
4083 if (device)
4084 return device;
4085 }
4086 cur_devices = cur_devices->seed;
4087 }
4088 return NULL;
4089 }
4090
4091 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
4092 u64 devid, u8 *dev_uuid)
4093 {
4094 struct btrfs_device *device;
4095 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
4096
4097 device = kzalloc(sizeof(*device), GFP_NOFS);
4098 if (!device)
4099 return NULL;
4100 list_add(&device->dev_list,
4101 &fs_devices->devices);
4102 device->dev_root = root->fs_info->dev_root;
4103 device->devid = devid;
4104 device->work.func = pending_bios_fn;
4105 device->fs_devices = fs_devices;
4106 device->missing = 1;
4107 fs_devices->num_devices++;
4108 fs_devices->missing_devices++;
4109 spin_lock_init(&device->io_lock);
4110 INIT_LIST_HEAD(&device->dev_alloc_list);
4111 memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
4112 return device;
4113 }
4114
4115 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
4116 struct extent_buffer *leaf,
4117 struct btrfs_chunk *chunk)
4118 {
4119 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
4120 struct map_lookup *map;
4121 struct extent_map *em;
4122 u64 logical;
4123 u64 length;
4124 u64 devid;
4125 u8 uuid[BTRFS_UUID_SIZE];
4126 int num_stripes;
4127 int ret;
4128 int i;
4129
4130 logical = key->offset;
4131 length = btrfs_chunk_length(leaf, chunk);
4132
4133 read_lock(&map_tree->map_tree.lock);
4134 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
4135 read_unlock(&map_tree->map_tree.lock);
4136
4137 /* already mapped? */
4138 if (em && em->start <= logical && em->start + em->len > logical) {
4139 free_extent_map(em);
4140 return 0;
4141 } else if (em) {
4142 free_extent_map(em);
4143 }
4144
4145 em = alloc_extent_map();
4146 if (!em)
4147 return -ENOMEM;
4148 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
4149 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
4150 if (!map) {
4151 free_extent_map(em);
4152 return -ENOMEM;
4153 }
4154
4155 em->bdev = (struct block_device *)map;
4156 em->start = logical;
4157 em->len = length;
4158 em->block_start = 0;
4159 em->block_len = em->len;
4160
4161 map->num_stripes = num_stripes;
4162 map->io_width = btrfs_chunk_io_width(leaf, chunk);
4163 map->io_align = btrfs_chunk_io_align(leaf, chunk);
4164 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
4165 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
4166 map->type = btrfs_chunk_type(leaf, chunk);
4167 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
4168 for (i = 0; i < num_stripes; i++) {
4169 map->stripes[i].physical =
4170 btrfs_stripe_offset_nr(leaf, chunk, i);
4171 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
4172 read_extent_buffer(leaf, uuid, (unsigned long)
4173 btrfs_stripe_dev_uuid_nr(chunk, i),
4174 BTRFS_UUID_SIZE);
4175 map->stripes[i].dev = btrfs_find_device(root, devid, uuid,
4176 NULL);
4177 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
4178 kfree(map);
4179 free_extent_map(em);
4180 return -EIO;
4181 }
4182 if (!map->stripes[i].dev) {
4183 map->stripes[i].dev =
4184 add_missing_dev(root, devid, uuid);
4185 if (!map->stripes[i].dev) {
4186 kfree(map);
4187 free_extent_map(em);
4188 return -EIO;
4189 }
4190 }
4191 map->stripes[i].dev->in_fs_metadata = 1;
4192 }
4193
4194 write_lock(&map_tree->map_tree.lock);
4195 ret = add_extent_mapping(&map_tree->map_tree, em);
4196 write_unlock(&map_tree->map_tree.lock);
4197 BUG_ON(ret);
4198 free_extent_map(em);
4199
4200 return 0;
4201 }
4202
4203 static int fill_device_from_item(struct extent_buffer *leaf,
4204 struct btrfs_dev_item *dev_item,
4205 struct btrfs_device *device)
4206 {
4207 unsigned long ptr;
4208
4209 device->devid = btrfs_device_id(leaf, dev_item);
4210 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
4211 device->total_bytes = device->disk_total_bytes;
4212 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
4213 device->type = btrfs_device_type(leaf, dev_item);
4214 device->io_align = btrfs_device_io_align(leaf, dev_item);
4215 device->io_width = btrfs_device_io_width(leaf, dev_item);
4216 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
4217
4218 ptr = (unsigned long)btrfs_device_uuid(dev_item);
4219 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
4220
4221 return 0;
4222 }
4223
4224 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
4225 {
4226 struct btrfs_fs_devices *fs_devices;
4227 int ret;
4228
4229 BUG_ON(!mutex_is_locked(&uuid_mutex));
4230
4231 fs_devices = root->fs_info->fs_devices->seed;
4232 while (fs_devices) {
4233 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
4234 ret = 0;
4235 goto out;
4236 }
4237 fs_devices = fs_devices->seed;
4238 }
4239
4240 fs_devices = find_fsid(fsid);
4241 if (!fs_devices) {
4242 ret = -ENOENT;
4243 goto out;
4244 }
4245
4246 fs_devices = clone_fs_devices(fs_devices);
4247 if (IS_ERR(fs_devices)) {
4248 ret = PTR_ERR(fs_devices);
4249 goto out;
4250 }
4251
4252 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
4253 root->fs_info->bdev_holder);
4254 if (ret)
4255 goto out;
4256
4257 if (!fs_devices->seeding) {
4258 __btrfs_close_devices(fs_devices);
4259 free_fs_devices(fs_devices);
4260 ret = -EINVAL;
4261 goto out;
4262 }
4263
4264 fs_devices->seed = root->fs_info->fs_devices->seed;
4265 root->fs_info->fs_devices->seed = fs_devices;
4266 out:
4267 return ret;
4268 }
4269
4270 static int read_one_dev(struct btrfs_root *root,
4271 struct extent_buffer *leaf,
4272 struct btrfs_dev_item *dev_item)
4273 {
4274 struct btrfs_device *device;
4275 u64 devid;
4276 int ret;
4277 u8 fs_uuid[BTRFS_UUID_SIZE];
4278 u8 dev_uuid[BTRFS_UUID_SIZE];
4279
4280 devid = btrfs_device_id(leaf, dev_item);
4281 read_extent_buffer(leaf, dev_uuid,
4282 (unsigned long)btrfs_device_uuid(dev_item),
4283 BTRFS_UUID_SIZE);
4284 read_extent_buffer(leaf, fs_uuid,
4285 (unsigned long)btrfs_device_fsid(dev_item),
4286 BTRFS_UUID_SIZE);
4287
4288 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
4289 ret = open_seed_devices(root, fs_uuid);
4290 if (ret && !btrfs_test_opt(root, DEGRADED))
4291 return ret;
4292 }
4293
4294 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
4295 if (!device || !device->bdev) {
4296 if (!btrfs_test_opt(root, DEGRADED))
4297 return -EIO;
4298
4299 if (!device) {
4300 printk(KERN_WARNING "warning devid %llu missing\n",
4301 (unsigned long long)devid);
4302 device = add_missing_dev(root, devid, dev_uuid);
4303 if (!device)
4304 return -ENOMEM;
4305 } else if (!device->missing) {
4306 /*
4307 * this happens when a device that was properly setup
4308 * in the device info lists suddenly goes bad.
4309 * device->bdev is NULL, and so we have to set
4310 * device->missing to one here
4311 */
4312 root->fs_info->fs_devices->missing_devices++;
4313 device->missing = 1;
4314 }
4315 }
4316
4317 if (device->fs_devices != root->fs_info->fs_devices) {
4318 BUG_ON(device->writeable);
4319 if (device->generation !=
4320 btrfs_device_generation(leaf, dev_item))
4321 return -EINVAL;
4322 }
4323
4324 fill_device_from_item(leaf, dev_item, device);
4325 device->dev_root = root->fs_info->dev_root;
4326 device->in_fs_metadata = 1;
4327 if (device->writeable) {
4328 device->fs_devices->total_rw_bytes += device->total_bytes;
4329 spin_lock(&root->fs_info->free_chunk_lock);
4330 root->fs_info->free_chunk_space += device->total_bytes -
4331 device->bytes_used;
4332 spin_unlock(&root->fs_info->free_chunk_lock);
4333 }
4334 ret = 0;
4335 return ret;
4336 }
4337
4338 int btrfs_read_sys_array(struct btrfs_root *root)
4339 {
4340 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
4341 struct extent_buffer *sb;
4342 struct btrfs_disk_key *disk_key;
4343 struct btrfs_chunk *chunk;
4344 u8 *ptr;
4345 unsigned long sb_ptr;
4346 int ret = 0;
4347 u32 num_stripes;
4348 u32 array_size;
4349 u32 len = 0;
4350 u32 cur;
4351 struct btrfs_key key;
4352
4353 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
4354 BTRFS_SUPER_INFO_SIZE);
4355 if (!sb)
4356 return -ENOMEM;
4357 btrfs_set_buffer_uptodate(sb);
4358 btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0);
4359
4360 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
4361 array_size = btrfs_super_sys_array_size(super_copy);
4362
4363 ptr = super_copy->sys_chunk_array;
4364 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
4365 cur = 0;
4366
4367 while (cur < array_size) {
4368 disk_key = (struct btrfs_disk_key *)ptr;
4369 btrfs_disk_key_to_cpu(&key, disk_key);
4370
4371 len = sizeof(*disk_key); ptr += len;
4372 sb_ptr += len;
4373 cur += len;
4374
4375 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
4376 chunk = (struct btrfs_chunk *)sb_ptr;
4377 ret = read_one_chunk(root, &key, sb, chunk);
4378 if (ret)
4379 break;
4380 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
4381 len = btrfs_chunk_item_size(num_stripes);
4382 } else {
4383 ret = -EIO;
4384 break;
4385 }
4386 ptr += len;
4387 sb_ptr += len;
4388 cur += len;
4389 }
4390 free_extent_buffer(sb);
4391 return ret;
4392 }
4393
4394 int btrfs_read_chunk_tree(struct btrfs_root *root)
4395 {
4396 struct btrfs_path *path;
4397 struct extent_buffer *leaf;
4398 struct btrfs_key key;
4399 struct btrfs_key found_key;
4400 int ret;
4401 int slot;
4402
4403 root = root->fs_info->chunk_root;
4404
4405 path = btrfs_alloc_path();
4406 if (!path)
4407 return -ENOMEM;
4408
4409 mutex_lock(&uuid_mutex);
4410 lock_chunks(root);
4411
4412 /* first we search for all of the device items, and then we
4413 * read in all of the chunk items. This way we can create chunk
4414 * mappings that reference all of the devices that are afound
4415 */
4416 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
4417 key.offset = 0;
4418 key.type = 0;
4419 again:
4420 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4421 if (ret < 0)
4422 goto error;
4423 while (1) {
4424 leaf = path->nodes[0];
4425 slot = path->slots[0];
4426 if (slot >= btrfs_header_nritems(leaf)) {
4427 ret = btrfs_next_leaf(root, path);
4428 if (ret == 0)
4429 continue;
4430 if (ret < 0)
4431 goto error;
4432 break;
4433 }
4434 btrfs_item_key_to_cpu(leaf, &found_key, slot);
4435 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
4436 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
4437 break;
4438 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
4439 struct btrfs_dev_item *dev_item;
4440 dev_item = btrfs_item_ptr(leaf, slot,
4441 struct btrfs_dev_item);
4442 ret = read_one_dev(root, leaf, dev_item);
4443 if (ret)
4444 goto error;
4445 }
4446 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
4447 struct btrfs_chunk *chunk;
4448 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
4449 ret = read_one_chunk(root, &found_key, leaf, chunk);
4450 if (ret)
4451 goto error;
4452 }
4453 path->slots[0]++;
4454 }
4455 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
4456 key.objectid = 0;
4457 btrfs_release_path(path);
4458 goto again;
4459 }
4460 ret = 0;
4461 error:
4462 unlock_chunks(root);
4463 mutex_unlock(&uuid_mutex);
4464
4465 btrfs_free_path(path);
4466 return ret;
4467 }
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