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Btrfs: flush out and clean up any block device pages during mount
[deliverable/linux.git] / fs / btrfs / volumes.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18 #include <linux/sched.h>
19 #include <linux/bio.h>
20 #include <linux/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 void 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 }
81
82 static noinline struct btrfs_device *__find_device(struct list_head *head,
83 u64 devid, u8 *uuid)
84 {
85 struct btrfs_device *dev;
86
87 list_for_each_entry(dev, head, dev_list) {
88 if (dev->devid == devid &&
89 (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
90 return dev;
91 }
92 }
93 return NULL;
94 }
95
96 static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
97 {
98 struct btrfs_fs_devices *fs_devices;
99
100 list_for_each_entry(fs_devices, &fs_uuids, list) {
101 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
102 return fs_devices;
103 }
104 return NULL;
105 }
106
107 static void requeue_list(struct btrfs_pending_bios *pending_bios,
108 struct bio *head, struct bio *tail)
109 {
110
111 struct bio *old_head;
112
113 old_head = pending_bios->head;
114 pending_bios->head = head;
115 if (pending_bios->tail)
116 tail->bi_next = old_head;
117 else
118 pending_bios->tail = tail;
119 }
120
121 /*
122 * we try to collect pending bios for a device so we don't get a large
123 * number of procs sending bios down to the same device. This greatly
124 * improves the schedulers ability to collect and merge the bios.
125 *
126 * But, it also turns into a long list of bios to process and that is sure
127 * to eventually make the worker thread block. The solution here is to
128 * make some progress and then put this work struct back at the end of
129 * the list if the block device is congested. This way, multiple devices
130 * can make progress from a single worker thread.
131 */
132 static noinline void run_scheduled_bios(struct btrfs_device *device)
133 {
134 struct bio *pending;
135 struct backing_dev_info *bdi;
136 struct btrfs_fs_info *fs_info;
137 struct btrfs_pending_bios *pending_bios;
138 struct bio *tail;
139 struct bio *cur;
140 int again = 0;
141 unsigned long num_run;
142 unsigned long batch_run = 0;
143 unsigned long limit;
144 unsigned long last_waited = 0;
145 int force_reg = 0;
146 int sync_pending = 0;
147 struct blk_plug plug;
148
149 /*
150 * this function runs all the bios we've collected for
151 * a particular device. We don't want to wander off to
152 * another device without first sending all of these down.
153 * So, setup a plug here and finish it off before we return
154 */
155 blk_start_plug(&plug);
156
157 bdi = blk_get_backing_dev_info(device->bdev);
158 fs_info = device->dev_root->fs_info;
159 limit = btrfs_async_submit_limit(fs_info);
160 limit = limit * 2 / 3;
161
162 loop:
163 spin_lock(&device->io_lock);
164
165 loop_lock:
166 num_run = 0;
167
168 /* take all the bios off the list at once and process them
169 * later on (without the lock held). But, remember the
170 * tail and other pointers so the bios can be properly reinserted
171 * into the list if we hit congestion
172 */
173 if (!force_reg && device->pending_sync_bios.head) {
174 pending_bios = &device->pending_sync_bios;
175 force_reg = 1;
176 } else {
177 pending_bios = &device->pending_bios;
178 force_reg = 0;
179 }
180
181 pending = pending_bios->head;
182 tail = pending_bios->tail;
183 WARN_ON(pending && !tail);
184
185 /*
186 * if pending was null this time around, no bios need processing
187 * at all and we can stop. Otherwise it'll loop back up again
188 * and do an additional check so no bios are missed.
189 *
190 * device->running_pending is used to synchronize with the
191 * schedule_bio code.
192 */
193 if (device->pending_sync_bios.head == NULL &&
194 device->pending_bios.head == NULL) {
195 again = 0;
196 device->running_pending = 0;
197 } else {
198 again = 1;
199 device->running_pending = 1;
200 }
201
202 pending_bios->head = NULL;
203 pending_bios->tail = NULL;
204
205 spin_unlock(&device->io_lock);
206
207 while (pending) {
208
209 rmb();
210 /* we want to work on both lists, but do more bios on the
211 * sync list than the regular list
212 */
213 if ((num_run > 32 &&
214 pending_bios != &device->pending_sync_bios &&
215 device->pending_sync_bios.head) ||
216 (num_run > 64 && pending_bios == &device->pending_sync_bios &&
217 device->pending_bios.head)) {
218 spin_lock(&device->io_lock);
219 requeue_list(pending_bios, pending, tail);
220 goto loop_lock;
221 }
222
223 cur = pending;
224 pending = pending->bi_next;
225 cur->bi_next = NULL;
226 atomic_dec(&fs_info->nr_async_bios);
227
228 if (atomic_read(&fs_info->nr_async_bios) < limit &&
229 waitqueue_active(&fs_info->async_submit_wait))
230 wake_up(&fs_info->async_submit_wait);
231
232 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
233
234 /*
235 * if we're doing the sync list, record that our
236 * plug has some sync requests on it
237 *
238 * If we're doing the regular list and there are
239 * sync requests sitting around, unplug before
240 * we add more
241 */
242 if (pending_bios == &device->pending_sync_bios) {
243 sync_pending = 1;
244 } else if (sync_pending) {
245 blk_finish_plug(&plug);
246 blk_start_plug(&plug);
247 sync_pending = 0;
248 }
249
250 btrfsic_submit_bio(cur->bi_rw, cur);
251 num_run++;
252 batch_run++;
253 if (need_resched())
254 cond_resched();
255
256 /*
257 * we made progress, there is more work to do and the bdi
258 * is now congested. Back off and let other work structs
259 * run instead
260 */
261 if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
262 fs_info->fs_devices->open_devices > 1) {
263 struct io_context *ioc;
264
265 ioc = current->io_context;
266
267 /*
268 * the main goal here is that we don't want to
269 * block if we're going to be able to submit
270 * more requests without blocking.
271 *
272 * This code does two great things, it pokes into
273 * the elevator code from a filesystem _and_
274 * it makes assumptions about how batching works.
275 */
276 if (ioc && ioc->nr_batch_requests > 0 &&
277 time_before(jiffies, ioc->last_waited + HZ/50UL) &&
278 (last_waited == 0 ||
279 ioc->last_waited == last_waited)) {
280 /*
281 * we want to go through our batch of
282 * requests and stop. So, we copy out
283 * the ioc->last_waited time and test
284 * against it before looping
285 */
286 last_waited = ioc->last_waited;
287 if (need_resched())
288 cond_resched();
289 continue;
290 }
291 spin_lock(&device->io_lock);
292 requeue_list(pending_bios, pending, tail);
293 device->running_pending = 1;
294
295 spin_unlock(&device->io_lock);
296 btrfs_requeue_work(&device->work);
297 goto done;
298 }
299 /* unplug every 64 requests just for good measure */
300 if (batch_run % 64 == 0) {
301 blk_finish_plug(&plug);
302 blk_start_plug(&plug);
303 sync_pending = 0;
304 }
305 }
306
307 cond_resched();
308 if (again)
309 goto loop;
310
311 spin_lock(&device->io_lock);
312 if (device->pending_bios.head || device->pending_sync_bios.head)
313 goto loop_lock;
314 spin_unlock(&device->io_lock);
315
316 done:
317 blk_finish_plug(&plug);
318 }
319
320 static void pending_bios_fn(struct btrfs_work *work)
321 {
322 struct btrfs_device *device;
323
324 device = container_of(work, struct btrfs_device, work);
325 run_scheduled_bios(device);
326 }
327
328 static noinline int device_list_add(const char *path,
329 struct btrfs_super_block *disk_super,
330 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
331 {
332 struct btrfs_device *device;
333 struct btrfs_fs_devices *fs_devices;
334 u64 found_transid = btrfs_super_generation(disk_super);
335 char *name;
336
337 fs_devices = find_fsid(disk_super->fsid);
338 if (!fs_devices) {
339 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
340 if (!fs_devices)
341 return -ENOMEM;
342 INIT_LIST_HEAD(&fs_devices->devices);
343 INIT_LIST_HEAD(&fs_devices->alloc_list);
344 list_add(&fs_devices->list, &fs_uuids);
345 memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
346 fs_devices->latest_devid = devid;
347 fs_devices->latest_trans = found_transid;
348 mutex_init(&fs_devices->device_list_mutex);
349 device = NULL;
350 } else {
351 device = __find_device(&fs_devices->devices, devid,
352 disk_super->dev_item.uuid);
353 }
354 if (!device) {
355 if (fs_devices->opened)
356 return -EBUSY;
357
358 device = kzalloc(sizeof(*device), GFP_NOFS);
359 if (!device) {
360 /* we can safely leave the fs_devices entry around */
361 return -ENOMEM;
362 }
363 device->devid = devid;
364 device->work.func = pending_bios_fn;
365 memcpy(device->uuid, disk_super->dev_item.uuid,
366 BTRFS_UUID_SIZE);
367 spin_lock_init(&device->io_lock);
368 device->name = kstrdup(path, GFP_NOFS);
369 if (!device->name) {
370 kfree(device);
371 return -ENOMEM;
372 }
373 INIT_LIST_HEAD(&device->dev_alloc_list);
374
375 /* init readahead state */
376 spin_lock_init(&device->reada_lock);
377 device->reada_curr_zone = NULL;
378 atomic_set(&device->reada_in_flight, 0);
379 device->reada_next = 0;
380 INIT_RADIX_TREE(&device->reada_zones, GFP_NOFS & ~__GFP_WAIT);
381 INIT_RADIX_TREE(&device->reada_extents, GFP_NOFS & ~__GFP_WAIT);
382
383 mutex_lock(&fs_devices->device_list_mutex);
384 list_add_rcu(&device->dev_list, &fs_devices->devices);
385 mutex_unlock(&fs_devices->device_list_mutex);
386
387 device->fs_devices = fs_devices;
388 fs_devices->num_devices++;
389 } else if (!device->name || strcmp(device->name, path)) {
390 name = kstrdup(path, GFP_NOFS);
391 if (!name)
392 return -ENOMEM;
393 kfree(device->name);
394 device->name = name;
395 if (device->missing) {
396 fs_devices->missing_devices--;
397 device->missing = 0;
398 }
399 }
400
401 if (found_transid > fs_devices->latest_trans) {
402 fs_devices->latest_devid = devid;
403 fs_devices->latest_trans = found_transid;
404 }
405 *fs_devices_ret = fs_devices;
406 return 0;
407 }
408
409 static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
410 {
411 struct btrfs_fs_devices *fs_devices;
412 struct btrfs_device *device;
413 struct btrfs_device *orig_dev;
414
415 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
416 if (!fs_devices)
417 return ERR_PTR(-ENOMEM);
418
419 INIT_LIST_HEAD(&fs_devices->devices);
420 INIT_LIST_HEAD(&fs_devices->alloc_list);
421 INIT_LIST_HEAD(&fs_devices->list);
422 mutex_init(&fs_devices->device_list_mutex);
423 fs_devices->latest_devid = orig->latest_devid;
424 fs_devices->latest_trans = orig->latest_trans;
425 memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid));
426
427 /* We have held the volume lock, it is safe to get the devices. */
428 list_for_each_entry(orig_dev, &orig->devices, dev_list) {
429 device = kzalloc(sizeof(*device), GFP_NOFS);
430 if (!device)
431 goto error;
432
433 device->name = kstrdup(orig_dev->name, GFP_NOFS);
434 if (!device->name) {
435 kfree(device);
436 goto error;
437 }
438
439 device->devid = orig_dev->devid;
440 device->work.func = pending_bios_fn;
441 memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid));
442 spin_lock_init(&device->io_lock);
443 INIT_LIST_HEAD(&device->dev_list);
444 INIT_LIST_HEAD(&device->dev_alloc_list);
445
446 list_add(&device->dev_list, &fs_devices->devices);
447 device->fs_devices = fs_devices;
448 fs_devices->num_devices++;
449 }
450 return fs_devices;
451 error:
452 free_fs_devices(fs_devices);
453 return ERR_PTR(-ENOMEM);
454 }
455
456 void btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
457 {
458 struct btrfs_device *device, *next;
459
460 struct block_device *latest_bdev = NULL;
461 u64 latest_devid = 0;
462 u64 latest_transid = 0;
463
464 mutex_lock(&uuid_mutex);
465 again:
466 /* This is the initialized path, it is safe to release the devices. */
467 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
468 if (device->in_fs_metadata) {
469 if (!latest_transid ||
470 device->generation > latest_transid) {
471 latest_devid = device->devid;
472 latest_transid = device->generation;
473 latest_bdev = device->bdev;
474 }
475 continue;
476 }
477
478 if (device->bdev) {
479 blkdev_put(device->bdev, device->mode);
480 device->bdev = NULL;
481 fs_devices->open_devices--;
482 }
483 if (device->writeable) {
484 list_del_init(&device->dev_alloc_list);
485 device->writeable = 0;
486 fs_devices->rw_devices--;
487 }
488 list_del_init(&device->dev_list);
489 fs_devices->num_devices--;
490 kfree(device->name);
491 kfree(device);
492 }
493
494 if (fs_devices->seed) {
495 fs_devices = fs_devices->seed;
496 goto again;
497 }
498
499 fs_devices->latest_bdev = latest_bdev;
500 fs_devices->latest_devid = latest_devid;
501 fs_devices->latest_trans = latest_transid;
502
503 mutex_unlock(&uuid_mutex);
504 }
505
506 static void __free_device(struct work_struct *work)
507 {
508 struct btrfs_device *device;
509
510 device = container_of(work, struct btrfs_device, rcu_work);
511
512 if (device->bdev)
513 blkdev_put(device->bdev, device->mode);
514
515 kfree(device->name);
516 kfree(device);
517 }
518
519 static void free_device(struct rcu_head *head)
520 {
521 struct btrfs_device *device;
522
523 device = container_of(head, struct btrfs_device, rcu);
524
525 INIT_WORK(&device->rcu_work, __free_device);
526 schedule_work(&device->rcu_work);
527 }
528
529 static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
530 {
531 struct btrfs_device *device;
532
533 if (--fs_devices->opened > 0)
534 return 0;
535
536 mutex_lock(&fs_devices->device_list_mutex);
537 list_for_each_entry(device, &fs_devices->devices, dev_list) {
538 struct btrfs_device *new_device;
539
540 if (device->bdev)
541 fs_devices->open_devices--;
542
543 if (device->writeable) {
544 list_del_init(&device->dev_alloc_list);
545 fs_devices->rw_devices--;
546 }
547
548 if (device->can_discard)
549 fs_devices->num_can_discard--;
550
551 new_device = kmalloc(sizeof(*new_device), GFP_NOFS);
552 BUG_ON(!new_device); /* -ENOMEM */
553 memcpy(new_device, device, sizeof(*new_device));
554 new_device->name = kstrdup(device->name, GFP_NOFS);
555 BUG_ON(device->name && !new_device->name); /* -ENOMEM */
556 new_device->bdev = NULL;
557 new_device->writeable = 0;
558 new_device->in_fs_metadata = 0;
559 new_device->can_discard = 0;
560 list_replace_rcu(&device->dev_list, &new_device->dev_list);
561
562 call_rcu(&device->rcu, free_device);
563 }
564 mutex_unlock(&fs_devices->device_list_mutex);
565
566 WARN_ON(fs_devices->open_devices);
567 WARN_ON(fs_devices->rw_devices);
568 fs_devices->opened = 0;
569 fs_devices->seeding = 0;
570
571 return 0;
572 }
573
574 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
575 {
576 struct btrfs_fs_devices *seed_devices = NULL;
577 int ret;
578
579 mutex_lock(&uuid_mutex);
580 ret = __btrfs_close_devices(fs_devices);
581 if (!fs_devices->opened) {
582 seed_devices = fs_devices->seed;
583 fs_devices->seed = NULL;
584 }
585 mutex_unlock(&uuid_mutex);
586
587 while (seed_devices) {
588 fs_devices = seed_devices;
589 seed_devices = fs_devices->seed;
590 __btrfs_close_devices(fs_devices);
591 free_fs_devices(fs_devices);
592 }
593 return ret;
594 }
595
596 static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
597 fmode_t flags, void *holder)
598 {
599 struct request_queue *q;
600 struct block_device *bdev;
601 struct list_head *head = &fs_devices->devices;
602 struct btrfs_device *device;
603 struct block_device *latest_bdev = NULL;
604 struct buffer_head *bh;
605 struct btrfs_super_block *disk_super;
606 u64 latest_devid = 0;
607 u64 latest_transid = 0;
608 u64 devid;
609 int seeding = 1;
610 int ret = 0;
611
612 flags |= FMODE_EXCL;
613
614 list_for_each_entry(device, head, dev_list) {
615 if (device->bdev)
616 continue;
617 if (!device->name)
618 continue;
619
620 bdev = blkdev_get_by_path(device->name, flags, holder);
621 if (IS_ERR(bdev)) {
622 printk(KERN_INFO "open %s failed\n", device->name);
623 goto error;
624 }
625 filemap_write_and_wait(bdev->bd_inode->i_mapping);
626 invalidate_bdev(bdev);
627 set_blocksize(bdev, 4096);
628
629 bh = btrfs_read_dev_super(bdev);
630 if (!bh)
631 goto error_close;
632
633 disk_super = (struct btrfs_super_block *)bh->b_data;
634 devid = btrfs_stack_device_id(&disk_super->dev_item);
635 if (devid != device->devid)
636 goto error_brelse;
637
638 if (memcmp(device->uuid, disk_super->dev_item.uuid,
639 BTRFS_UUID_SIZE))
640 goto error_brelse;
641
642 device->generation = btrfs_super_generation(disk_super);
643 if (!latest_transid || device->generation > latest_transid) {
644 latest_devid = devid;
645 latest_transid = device->generation;
646 latest_bdev = bdev;
647 }
648
649 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
650 device->writeable = 0;
651 } else {
652 device->writeable = !bdev_read_only(bdev);
653 seeding = 0;
654 }
655
656 q = bdev_get_queue(bdev);
657 if (blk_queue_discard(q)) {
658 device->can_discard = 1;
659 fs_devices->num_can_discard++;
660 }
661
662 device->bdev = bdev;
663 device->in_fs_metadata = 0;
664 device->mode = flags;
665
666 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
667 fs_devices->rotating = 1;
668
669 fs_devices->open_devices++;
670 if (device->writeable) {
671 fs_devices->rw_devices++;
672 list_add(&device->dev_alloc_list,
673 &fs_devices->alloc_list);
674 }
675 brelse(bh);
676 continue;
677
678 error_brelse:
679 brelse(bh);
680 error_close:
681 blkdev_put(bdev, flags);
682 error:
683 continue;
684 }
685 if (fs_devices->open_devices == 0) {
686 ret = -EINVAL;
687 goto out;
688 }
689 fs_devices->seeding = seeding;
690 fs_devices->opened = 1;
691 fs_devices->latest_bdev = latest_bdev;
692 fs_devices->latest_devid = latest_devid;
693 fs_devices->latest_trans = latest_transid;
694 fs_devices->total_rw_bytes = 0;
695 out:
696 return ret;
697 }
698
699 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
700 fmode_t flags, void *holder)
701 {
702 int ret;
703
704 mutex_lock(&uuid_mutex);
705 if (fs_devices->opened) {
706 fs_devices->opened++;
707 ret = 0;
708 } else {
709 ret = __btrfs_open_devices(fs_devices, flags, holder);
710 }
711 mutex_unlock(&uuid_mutex);
712 return ret;
713 }
714
715 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
716 struct btrfs_fs_devices **fs_devices_ret)
717 {
718 struct btrfs_super_block *disk_super;
719 struct block_device *bdev;
720 struct buffer_head *bh;
721 int ret;
722 u64 devid;
723 u64 transid;
724
725 flags |= FMODE_EXCL;
726 bdev = blkdev_get_by_path(path, flags, holder);
727
728 if (IS_ERR(bdev)) {
729 ret = PTR_ERR(bdev);
730 goto error;
731 }
732
733 mutex_lock(&uuid_mutex);
734 ret = set_blocksize(bdev, 4096);
735 if (ret)
736 goto error_close;
737 bh = btrfs_read_dev_super(bdev);
738 if (!bh) {
739 ret = -EINVAL;
740 goto error_close;
741 }
742 disk_super = (struct btrfs_super_block *)bh->b_data;
743 devid = btrfs_stack_device_id(&disk_super->dev_item);
744 transid = btrfs_super_generation(disk_super);
745 if (disk_super->label[0])
746 printk(KERN_INFO "device label %s ", disk_super->label);
747 else
748 printk(KERN_INFO "device fsid %pU ", disk_super->fsid);
749 printk(KERN_CONT "devid %llu transid %llu %s\n",
750 (unsigned long long)devid, (unsigned long long)transid, path);
751 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
752
753 brelse(bh);
754 error_close:
755 mutex_unlock(&uuid_mutex);
756 blkdev_put(bdev, flags);
757 error:
758 return ret;
759 }
760
761 /* helper to account the used device space in the range */
762 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
763 u64 end, u64 *length)
764 {
765 struct btrfs_key key;
766 struct btrfs_root *root = device->dev_root;
767 struct btrfs_dev_extent *dev_extent;
768 struct btrfs_path *path;
769 u64 extent_end;
770 int ret;
771 int slot;
772 struct extent_buffer *l;
773
774 *length = 0;
775
776 if (start >= device->total_bytes)
777 return 0;
778
779 path = btrfs_alloc_path();
780 if (!path)
781 return -ENOMEM;
782 path->reada = 2;
783
784 key.objectid = device->devid;
785 key.offset = start;
786 key.type = BTRFS_DEV_EXTENT_KEY;
787
788 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
789 if (ret < 0)
790 goto out;
791 if (ret > 0) {
792 ret = btrfs_previous_item(root, path, key.objectid, key.type);
793 if (ret < 0)
794 goto out;
795 }
796
797 while (1) {
798 l = path->nodes[0];
799 slot = path->slots[0];
800 if (slot >= btrfs_header_nritems(l)) {
801 ret = btrfs_next_leaf(root, path);
802 if (ret == 0)
803 continue;
804 if (ret < 0)
805 goto out;
806
807 break;
808 }
809 btrfs_item_key_to_cpu(l, &key, slot);
810
811 if (key.objectid < device->devid)
812 goto next;
813
814 if (key.objectid > device->devid)
815 break;
816
817 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
818 goto next;
819
820 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
821 extent_end = key.offset + btrfs_dev_extent_length(l,
822 dev_extent);
823 if (key.offset <= start && extent_end > end) {
824 *length = end - start + 1;
825 break;
826 } else if (key.offset <= start && extent_end > start)
827 *length += extent_end - start;
828 else if (key.offset > start && extent_end <= end)
829 *length += extent_end - key.offset;
830 else if (key.offset > start && key.offset <= end) {
831 *length += end - key.offset + 1;
832 break;
833 } else if (key.offset > end)
834 break;
835
836 next:
837 path->slots[0]++;
838 }
839 ret = 0;
840 out:
841 btrfs_free_path(path);
842 return ret;
843 }
844
845 /*
846 * find_free_dev_extent - find free space in the specified device
847 * @device: the device which we search the free space in
848 * @num_bytes: the size of the free space that we need
849 * @start: store the start of the free space.
850 * @len: the size of the free space. that we find, or the size of the max
851 * free space if we don't find suitable free space
852 *
853 * this uses a pretty simple search, the expectation is that it is
854 * called very infrequently and that a given device has a small number
855 * of extents
856 *
857 * @start is used to store the start of the free space if we find. But if we
858 * don't find suitable free space, it will be used to store the start position
859 * of the max free space.
860 *
861 * @len is used to store the size of the free space that we find.
862 * But if we don't find suitable free space, it is used to store the size of
863 * the max free space.
864 */
865 int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes,
866 u64 *start, u64 *len)
867 {
868 struct btrfs_key key;
869 struct btrfs_root *root = device->dev_root;
870 struct btrfs_dev_extent *dev_extent;
871 struct btrfs_path *path;
872 u64 hole_size;
873 u64 max_hole_start;
874 u64 max_hole_size;
875 u64 extent_end;
876 u64 search_start;
877 u64 search_end = device->total_bytes;
878 int ret;
879 int slot;
880 struct extent_buffer *l;
881
882 /* FIXME use last free of some kind */
883
884 /* we don't want to overwrite the superblock on the drive,
885 * so we make sure to start at an offset of at least 1MB
886 */
887 search_start = max(root->fs_info->alloc_start, 1024ull * 1024);
888
889 max_hole_start = search_start;
890 max_hole_size = 0;
891 hole_size = 0;
892
893 if (search_start >= search_end) {
894 ret = -ENOSPC;
895 goto error;
896 }
897
898 path = btrfs_alloc_path();
899 if (!path) {
900 ret = -ENOMEM;
901 goto error;
902 }
903 path->reada = 2;
904
905 key.objectid = device->devid;
906 key.offset = search_start;
907 key.type = BTRFS_DEV_EXTENT_KEY;
908
909 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
910 if (ret < 0)
911 goto out;
912 if (ret > 0) {
913 ret = btrfs_previous_item(root, path, key.objectid, key.type);
914 if (ret < 0)
915 goto out;
916 }
917
918 while (1) {
919 l = path->nodes[0];
920 slot = path->slots[0];
921 if (slot >= btrfs_header_nritems(l)) {
922 ret = btrfs_next_leaf(root, path);
923 if (ret == 0)
924 continue;
925 if (ret < 0)
926 goto out;
927
928 break;
929 }
930 btrfs_item_key_to_cpu(l, &key, slot);
931
932 if (key.objectid < device->devid)
933 goto next;
934
935 if (key.objectid > device->devid)
936 break;
937
938 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
939 goto next;
940
941 if (key.offset > search_start) {
942 hole_size = key.offset - search_start;
943
944 if (hole_size > max_hole_size) {
945 max_hole_start = search_start;
946 max_hole_size = hole_size;
947 }
948
949 /*
950 * If this free space is greater than which we need,
951 * it must be the max free space that we have found
952 * until now, so max_hole_start must point to the start
953 * of this free space and the length of this free space
954 * is stored in max_hole_size. Thus, we return
955 * max_hole_start and max_hole_size and go back to the
956 * caller.
957 */
958 if (hole_size >= num_bytes) {
959 ret = 0;
960 goto out;
961 }
962 }
963
964 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
965 extent_end = key.offset + btrfs_dev_extent_length(l,
966 dev_extent);
967 if (extent_end > search_start)
968 search_start = extent_end;
969 next:
970 path->slots[0]++;
971 cond_resched();
972 }
973
974 /*
975 * At this point, search_start should be the end of
976 * allocated dev extents, and when shrinking the device,
977 * search_end may be smaller than search_start.
978 */
979 if (search_end > search_start)
980 hole_size = search_end - search_start;
981
982 if (hole_size > max_hole_size) {
983 max_hole_start = search_start;
984 max_hole_size = hole_size;
985 }
986
987 /* See above. */
988 if (hole_size < num_bytes)
989 ret = -ENOSPC;
990 else
991 ret = 0;
992
993 out:
994 btrfs_free_path(path);
995 error:
996 *start = max_hole_start;
997 if (len)
998 *len = max_hole_size;
999 return ret;
1000 }
1001
1002 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
1003 struct btrfs_device *device,
1004 u64 start)
1005 {
1006 int ret;
1007 struct btrfs_path *path;
1008 struct btrfs_root *root = device->dev_root;
1009 struct btrfs_key key;
1010 struct btrfs_key found_key;
1011 struct extent_buffer *leaf = NULL;
1012 struct btrfs_dev_extent *extent = NULL;
1013
1014 path = btrfs_alloc_path();
1015 if (!path)
1016 return -ENOMEM;
1017
1018 key.objectid = device->devid;
1019 key.offset = start;
1020 key.type = BTRFS_DEV_EXTENT_KEY;
1021 again:
1022 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1023 if (ret > 0) {
1024 ret = btrfs_previous_item(root, path, key.objectid,
1025 BTRFS_DEV_EXTENT_KEY);
1026 if (ret)
1027 goto out;
1028 leaf = path->nodes[0];
1029 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1030 extent = btrfs_item_ptr(leaf, path->slots[0],
1031 struct btrfs_dev_extent);
1032 BUG_ON(found_key.offset > start || found_key.offset +
1033 btrfs_dev_extent_length(leaf, extent) < start);
1034 key = found_key;
1035 btrfs_release_path(path);
1036 goto again;
1037 } else if (ret == 0) {
1038 leaf = path->nodes[0];
1039 extent = btrfs_item_ptr(leaf, path->slots[0],
1040 struct btrfs_dev_extent);
1041 } else {
1042 btrfs_error(root->fs_info, ret, "Slot search failed");
1043 goto out;
1044 }
1045
1046 if (device->bytes_used > 0) {
1047 u64 len = btrfs_dev_extent_length(leaf, extent);
1048 device->bytes_used -= len;
1049 spin_lock(&root->fs_info->free_chunk_lock);
1050 root->fs_info->free_chunk_space += len;
1051 spin_unlock(&root->fs_info->free_chunk_lock);
1052 }
1053 ret = btrfs_del_item(trans, root, path);
1054 if (ret) {
1055 btrfs_error(root->fs_info, ret,
1056 "Failed to remove dev extent item");
1057 }
1058 out:
1059 btrfs_free_path(path);
1060 return ret;
1061 }
1062
1063 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
1064 struct btrfs_device *device,
1065 u64 chunk_tree, u64 chunk_objectid,
1066 u64 chunk_offset, u64 start, u64 num_bytes)
1067 {
1068 int ret;
1069 struct btrfs_path *path;
1070 struct btrfs_root *root = device->dev_root;
1071 struct btrfs_dev_extent *extent;
1072 struct extent_buffer *leaf;
1073 struct btrfs_key key;
1074
1075 WARN_ON(!device->in_fs_metadata);
1076 path = btrfs_alloc_path();
1077 if (!path)
1078 return -ENOMEM;
1079
1080 key.objectid = device->devid;
1081 key.offset = start;
1082 key.type = BTRFS_DEV_EXTENT_KEY;
1083 ret = btrfs_insert_empty_item(trans, root, path, &key,
1084 sizeof(*extent));
1085 if (ret)
1086 goto out;
1087
1088 leaf = path->nodes[0];
1089 extent = btrfs_item_ptr(leaf, path->slots[0],
1090 struct btrfs_dev_extent);
1091 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
1092 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
1093 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
1094
1095 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
1096 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
1097 BTRFS_UUID_SIZE);
1098
1099 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
1100 btrfs_mark_buffer_dirty(leaf);
1101 out:
1102 btrfs_free_path(path);
1103 return ret;
1104 }
1105
1106 static noinline int find_next_chunk(struct btrfs_root *root,
1107 u64 objectid, u64 *offset)
1108 {
1109 struct btrfs_path *path;
1110 int ret;
1111 struct btrfs_key key;
1112 struct btrfs_chunk *chunk;
1113 struct btrfs_key found_key;
1114
1115 path = btrfs_alloc_path();
1116 if (!path)
1117 return -ENOMEM;
1118
1119 key.objectid = objectid;
1120 key.offset = (u64)-1;
1121 key.type = BTRFS_CHUNK_ITEM_KEY;
1122
1123 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1124 if (ret < 0)
1125 goto error;
1126
1127 BUG_ON(ret == 0); /* Corruption */
1128
1129 ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
1130 if (ret) {
1131 *offset = 0;
1132 } else {
1133 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1134 path->slots[0]);
1135 if (found_key.objectid != objectid)
1136 *offset = 0;
1137 else {
1138 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
1139 struct btrfs_chunk);
1140 *offset = found_key.offset +
1141 btrfs_chunk_length(path->nodes[0], chunk);
1142 }
1143 }
1144 ret = 0;
1145 error:
1146 btrfs_free_path(path);
1147 return ret;
1148 }
1149
1150 static noinline int find_next_devid(struct btrfs_root *root, u64 *objectid)
1151 {
1152 int ret;
1153 struct btrfs_key key;
1154 struct btrfs_key found_key;
1155 struct btrfs_path *path;
1156
1157 root = root->fs_info->chunk_root;
1158
1159 path = btrfs_alloc_path();
1160 if (!path)
1161 return -ENOMEM;
1162
1163 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1164 key.type = BTRFS_DEV_ITEM_KEY;
1165 key.offset = (u64)-1;
1166
1167 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1168 if (ret < 0)
1169 goto error;
1170
1171 BUG_ON(ret == 0); /* Corruption */
1172
1173 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
1174 BTRFS_DEV_ITEM_KEY);
1175 if (ret) {
1176 *objectid = 1;
1177 } else {
1178 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1179 path->slots[0]);
1180 *objectid = found_key.offset + 1;
1181 }
1182 ret = 0;
1183 error:
1184 btrfs_free_path(path);
1185 return ret;
1186 }
1187
1188 /*
1189 * the device information is stored in the chunk root
1190 * the btrfs_device struct should be fully filled in
1191 */
1192 int btrfs_add_device(struct btrfs_trans_handle *trans,
1193 struct btrfs_root *root,
1194 struct btrfs_device *device)
1195 {
1196 int ret;
1197 struct btrfs_path *path;
1198 struct btrfs_dev_item *dev_item;
1199 struct extent_buffer *leaf;
1200 struct btrfs_key key;
1201 unsigned long ptr;
1202
1203 root = root->fs_info->chunk_root;
1204
1205 path = btrfs_alloc_path();
1206 if (!path)
1207 return -ENOMEM;
1208
1209 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1210 key.type = BTRFS_DEV_ITEM_KEY;
1211 key.offset = device->devid;
1212
1213 ret = btrfs_insert_empty_item(trans, root, path, &key,
1214 sizeof(*dev_item));
1215 if (ret)
1216 goto out;
1217
1218 leaf = path->nodes[0];
1219 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1220
1221 btrfs_set_device_id(leaf, dev_item, device->devid);
1222 btrfs_set_device_generation(leaf, dev_item, 0);
1223 btrfs_set_device_type(leaf, dev_item, device->type);
1224 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1225 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1226 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1227 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
1228 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1229 btrfs_set_device_group(leaf, dev_item, 0);
1230 btrfs_set_device_seek_speed(leaf, dev_item, 0);
1231 btrfs_set_device_bandwidth(leaf, dev_item, 0);
1232 btrfs_set_device_start_offset(leaf, dev_item, 0);
1233
1234 ptr = (unsigned long)btrfs_device_uuid(dev_item);
1235 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1236 ptr = (unsigned long)btrfs_device_fsid(dev_item);
1237 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
1238 btrfs_mark_buffer_dirty(leaf);
1239
1240 ret = 0;
1241 out:
1242 btrfs_free_path(path);
1243 return ret;
1244 }
1245
1246 static int btrfs_rm_dev_item(struct btrfs_root *root,
1247 struct btrfs_device *device)
1248 {
1249 int ret;
1250 struct btrfs_path *path;
1251 struct btrfs_key key;
1252 struct btrfs_trans_handle *trans;
1253
1254 root = root->fs_info->chunk_root;
1255
1256 path = btrfs_alloc_path();
1257 if (!path)
1258 return -ENOMEM;
1259
1260 trans = btrfs_start_transaction(root, 0);
1261 if (IS_ERR(trans)) {
1262 btrfs_free_path(path);
1263 return PTR_ERR(trans);
1264 }
1265 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1266 key.type = BTRFS_DEV_ITEM_KEY;
1267 key.offset = device->devid;
1268 lock_chunks(root);
1269
1270 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1271 if (ret < 0)
1272 goto out;
1273
1274 if (ret > 0) {
1275 ret = -ENOENT;
1276 goto out;
1277 }
1278
1279 ret = btrfs_del_item(trans, root, path);
1280 if (ret)
1281 goto out;
1282 out:
1283 btrfs_free_path(path);
1284 unlock_chunks(root);
1285 btrfs_commit_transaction(trans, root);
1286 return ret;
1287 }
1288
1289 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
1290 {
1291 struct btrfs_device *device;
1292 struct btrfs_device *next_device;
1293 struct block_device *bdev;
1294 struct buffer_head *bh = NULL;
1295 struct btrfs_super_block *disk_super;
1296 struct btrfs_fs_devices *cur_devices;
1297 u64 all_avail;
1298 u64 devid;
1299 u64 num_devices;
1300 u8 *dev_uuid;
1301 int ret = 0;
1302 bool clear_super = false;
1303
1304 mutex_lock(&uuid_mutex);
1305
1306 all_avail = root->fs_info->avail_data_alloc_bits |
1307 root->fs_info->avail_system_alloc_bits |
1308 root->fs_info->avail_metadata_alloc_bits;
1309
1310 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) &&
1311 root->fs_info->fs_devices->num_devices <= 4) {
1312 printk(KERN_ERR "btrfs: unable to go below four devices "
1313 "on raid10\n");
1314 ret = -EINVAL;
1315 goto out;
1316 }
1317
1318 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) &&
1319 root->fs_info->fs_devices->num_devices <= 2) {
1320 printk(KERN_ERR "btrfs: unable to go below two "
1321 "devices on raid1\n");
1322 ret = -EINVAL;
1323 goto out;
1324 }
1325
1326 if (strcmp(device_path, "missing") == 0) {
1327 struct list_head *devices;
1328 struct btrfs_device *tmp;
1329
1330 device = NULL;
1331 devices = &root->fs_info->fs_devices->devices;
1332 /*
1333 * It is safe to read the devices since the volume_mutex
1334 * is held.
1335 */
1336 list_for_each_entry(tmp, devices, dev_list) {
1337 if (tmp->in_fs_metadata && !tmp->bdev) {
1338 device = tmp;
1339 break;
1340 }
1341 }
1342 bdev = NULL;
1343 bh = NULL;
1344 disk_super = NULL;
1345 if (!device) {
1346 printk(KERN_ERR "btrfs: no missing devices found to "
1347 "remove\n");
1348 goto out;
1349 }
1350 } else {
1351 bdev = blkdev_get_by_path(device_path, FMODE_READ | FMODE_EXCL,
1352 root->fs_info->bdev_holder);
1353 if (IS_ERR(bdev)) {
1354 ret = PTR_ERR(bdev);
1355 goto out;
1356 }
1357
1358 set_blocksize(bdev, 4096);
1359 invalidate_bdev(bdev);
1360 bh = btrfs_read_dev_super(bdev);
1361 if (!bh) {
1362 ret = -EINVAL;
1363 goto error_close;
1364 }
1365 disk_super = (struct btrfs_super_block *)bh->b_data;
1366 devid = btrfs_stack_device_id(&disk_super->dev_item);
1367 dev_uuid = disk_super->dev_item.uuid;
1368 device = btrfs_find_device(root, devid, dev_uuid,
1369 disk_super->fsid);
1370 if (!device) {
1371 ret = -ENOENT;
1372 goto error_brelse;
1373 }
1374 }
1375
1376 if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
1377 printk(KERN_ERR "btrfs: unable to remove the only writeable "
1378 "device\n");
1379 ret = -EINVAL;
1380 goto error_brelse;
1381 }
1382
1383 if (device->writeable) {
1384 lock_chunks(root);
1385 list_del_init(&device->dev_alloc_list);
1386 unlock_chunks(root);
1387 root->fs_info->fs_devices->rw_devices--;
1388 clear_super = true;
1389 }
1390
1391 ret = btrfs_shrink_device(device, 0);
1392 if (ret)
1393 goto error_undo;
1394
1395 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1396 if (ret)
1397 goto error_undo;
1398
1399 spin_lock(&root->fs_info->free_chunk_lock);
1400 root->fs_info->free_chunk_space = device->total_bytes -
1401 device->bytes_used;
1402 spin_unlock(&root->fs_info->free_chunk_lock);
1403
1404 device->in_fs_metadata = 0;
1405 btrfs_scrub_cancel_dev(root, device);
1406
1407 /*
1408 * the device list mutex makes sure that we don't change
1409 * the device list while someone else is writing out all
1410 * the device supers.
1411 */
1412
1413 cur_devices = device->fs_devices;
1414 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1415 list_del_rcu(&device->dev_list);
1416
1417 device->fs_devices->num_devices--;
1418
1419 if (device->missing)
1420 root->fs_info->fs_devices->missing_devices--;
1421
1422 next_device = list_entry(root->fs_info->fs_devices->devices.next,
1423 struct btrfs_device, dev_list);
1424 if (device->bdev == root->fs_info->sb->s_bdev)
1425 root->fs_info->sb->s_bdev = next_device->bdev;
1426 if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1427 root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1428
1429 if (device->bdev)
1430 device->fs_devices->open_devices--;
1431
1432 call_rcu(&device->rcu, free_device);
1433 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1434
1435 num_devices = btrfs_super_num_devices(root->fs_info->super_copy) - 1;
1436 btrfs_set_super_num_devices(root->fs_info->super_copy, num_devices);
1437
1438 if (cur_devices->open_devices == 0) {
1439 struct btrfs_fs_devices *fs_devices;
1440 fs_devices = root->fs_info->fs_devices;
1441 while (fs_devices) {
1442 if (fs_devices->seed == cur_devices)
1443 break;
1444 fs_devices = fs_devices->seed;
1445 }
1446 fs_devices->seed = cur_devices->seed;
1447 cur_devices->seed = NULL;
1448 lock_chunks(root);
1449 __btrfs_close_devices(cur_devices);
1450 unlock_chunks(root);
1451 free_fs_devices(cur_devices);
1452 }
1453
1454 /*
1455 * at this point, the device is zero sized. We want to
1456 * remove it from the devices list and zero out the old super
1457 */
1458 if (clear_super) {
1459 /* make sure this device isn't detected as part of
1460 * the FS anymore
1461 */
1462 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1463 set_buffer_dirty(bh);
1464 sync_dirty_buffer(bh);
1465 }
1466
1467 ret = 0;
1468
1469 error_brelse:
1470 brelse(bh);
1471 error_close:
1472 if (bdev)
1473 blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
1474 out:
1475 mutex_unlock(&uuid_mutex);
1476 return ret;
1477 error_undo:
1478 if (device->writeable) {
1479 lock_chunks(root);
1480 list_add(&device->dev_alloc_list,
1481 &root->fs_info->fs_devices->alloc_list);
1482 unlock_chunks(root);
1483 root->fs_info->fs_devices->rw_devices++;
1484 }
1485 goto error_brelse;
1486 }
1487
1488 /*
1489 * does all the dirty work required for changing file system's UUID.
1490 */
1491 static int btrfs_prepare_sprout(struct btrfs_root *root)
1492 {
1493 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1494 struct btrfs_fs_devices *old_devices;
1495 struct btrfs_fs_devices *seed_devices;
1496 struct btrfs_super_block *disk_super = root->fs_info->super_copy;
1497 struct btrfs_device *device;
1498 u64 super_flags;
1499
1500 BUG_ON(!mutex_is_locked(&uuid_mutex));
1501 if (!fs_devices->seeding)
1502 return -EINVAL;
1503
1504 seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
1505 if (!seed_devices)
1506 return -ENOMEM;
1507
1508 old_devices = clone_fs_devices(fs_devices);
1509 if (IS_ERR(old_devices)) {
1510 kfree(seed_devices);
1511 return PTR_ERR(old_devices);
1512 }
1513
1514 list_add(&old_devices->list, &fs_uuids);
1515
1516 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1517 seed_devices->opened = 1;
1518 INIT_LIST_HEAD(&seed_devices->devices);
1519 INIT_LIST_HEAD(&seed_devices->alloc_list);
1520 mutex_init(&seed_devices->device_list_mutex);
1521
1522 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1523 list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
1524 synchronize_rcu);
1525 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1526
1527 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1528 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1529 device->fs_devices = seed_devices;
1530 }
1531
1532 fs_devices->seeding = 0;
1533 fs_devices->num_devices = 0;
1534 fs_devices->open_devices = 0;
1535 fs_devices->seed = seed_devices;
1536
1537 generate_random_uuid(fs_devices->fsid);
1538 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1539 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1540 super_flags = btrfs_super_flags(disk_super) &
1541 ~BTRFS_SUPER_FLAG_SEEDING;
1542 btrfs_set_super_flags(disk_super, super_flags);
1543
1544 return 0;
1545 }
1546
1547 /*
1548 * strore the expected generation for seed devices in device items.
1549 */
1550 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1551 struct btrfs_root *root)
1552 {
1553 struct btrfs_path *path;
1554 struct extent_buffer *leaf;
1555 struct btrfs_dev_item *dev_item;
1556 struct btrfs_device *device;
1557 struct btrfs_key key;
1558 u8 fs_uuid[BTRFS_UUID_SIZE];
1559 u8 dev_uuid[BTRFS_UUID_SIZE];
1560 u64 devid;
1561 int ret;
1562
1563 path = btrfs_alloc_path();
1564 if (!path)
1565 return -ENOMEM;
1566
1567 root = root->fs_info->chunk_root;
1568 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1569 key.offset = 0;
1570 key.type = BTRFS_DEV_ITEM_KEY;
1571
1572 while (1) {
1573 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1574 if (ret < 0)
1575 goto error;
1576
1577 leaf = path->nodes[0];
1578 next_slot:
1579 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1580 ret = btrfs_next_leaf(root, path);
1581 if (ret > 0)
1582 break;
1583 if (ret < 0)
1584 goto error;
1585 leaf = path->nodes[0];
1586 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1587 btrfs_release_path(path);
1588 continue;
1589 }
1590
1591 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1592 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1593 key.type != BTRFS_DEV_ITEM_KEY)
1594 break;
1595
1596 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1597 struct btrfs_dev_item);
1598 devid = btrfs_device_id(leaf, dev_item);
1599 read_extent_buffer(leaf, dev_uuid,
1600 (unsigned long)btrfs_device_uuid(dev_item),
1601 BTRFS_UUID_SIZE);
1602 read_extent_buffer(leaf, fs_uuid,
1603 (unsigned long)btrfs_device_fsid(dev_item),
1604 BTRFS_UUID_SIZE);
1605 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
1606 BUG_ON(!device); /* Logic error */
1607
1608 if (device->fs_devices->seeding) {
1609 btrfs_set_device_generation(leaf, dev_item,
1610 device->generation);
1611 btrfs_mark_buffer_dirty(leaf);
1612 }
1613
1614 path->slots[0]++;
1615 goto next_slot;
1616 }
1617 ret = 0;
1618 error:
1619 btrfs_free_path(path);
1620 return ret;
1621 }
1622
1623 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1624 {
1625 struct request_queue *q;
1626 struct btrfs_trans_handle *trans;
1627 struct btrfs_device *device;
1628 struct block_device *bdev;
1629 struct list_head *devices;
1630 struct super_block *sb = root->fs_info->sb;
1631 u64 total_bytes;
1632 int seeding_dev = 0;
1633 int ret = 0;
1634
1635 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1636 return -EINVAL;
1637
1638 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
1639 root->fs_info->bdev_holder);
1640 if (IS_ERR(bdev))
1641 return PTR_ERR(bdev);
1642
1643 if (root->fs_info->fs_devices->seeding) {
1644 seeding_dev = 1;
1645 down_write(&sb->s_umount);
1646 mutex_lock(&uuid_mutex);
1647 }
1648
1649 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1650
1651 devices = &root->fs_info->fs_devices->devices;
1652 /*
1653 * we have the volume lock, so we don't need the extra
1654 * device list mutex while reading the list here.
1655 */
1656 list_for_each_entry(device, devices, dev_list) {
1657 if (device->bdev == bdev) {
1658 ret = -EEXIST;
1659 goto error;
1660 }
1661 }
1662
1663 device = kzalloc(sizeof(*device), GFP_NOFS);
1664 if (!device) {
1665 /* we can safely leave the fs_devices entry around */
1666 ret = -ENOMEM;
1667 goto error;
1668 }
1669
1670 device->name = kstrdup(device_path, GFP_NOFS);
1671 if (!device->name) {
1672 kfree(device);
1673 ret = -ENOMEM;
1674 goto error;
1675 }
1676
1677 ret = find_next_devid(root, &device->devid);
1678 if (ret) {
1679 kfree(device->name);
1680 kfree(device);
1681 goto error;
1682 }
1683
1684 trans = btrfs_start_transaction(root, 0);
1685 if (IS_ERR(trans)) {
1686 kfree(device->name);
1687 kfree(device);
1688 ret = PTR_ERR(trans);
1689 goto error;
1690 }
1691
1692 lock_chunks(root);
1693
1694 q = bdev_get_queue(bdev);
1695 if (blk_queue_discard(q))
1696 device->can_discard = 1;
1697 device->writeable = 1;
1698 device->work.func = pending_bios_fn;
1699 generate_random_uuid(device->uuid);
1700 spin_lock_init(&device->io_lock);
1701 device->generation = trans->transid;
1702 device->io_width = root->sectorsize;
1703 device->io_align = root->sectorsize;
1704 device->sector_size = root->sectorsize;
1705 device->total_bytes = i_size_read(bdev->bd_inode);
1706 device->disk_total_bytes = device->total_bytes;
1707 device->dev_root = root->fs_info->dev_root;
1708 device->bdev = bdev;
1709 device->in_fs_metadata = 1;
1710 device->mode = FMODE_EXCL;
1711 set_blocksize(device->bdev, 4096);
1712
1713 if (seeding_dev) {
1714 sb->s_flags &= ~MS_RDONLY;
1715 ret = btrfs_prepare_sprout(root);
1716 BUG_ON(ret); /* -ENOMEM */
1717 }
1718
1719 device->fs_devices = root->fs_info->fs_devices;
1720
1721 /*
1722 * we don't want write_supers to jump in here with our device
1723 * half setup
1724 */
1725 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1726 list_add_rcu(&device->dev_list, &root->fs_info->fs_devices->devices);
1727 list_add(&device->dev_alloc_list,
1728 &root->fs_info->fs_devices->alloc_list);
1729 root->fs_info->fs_devices->num_devices++;
1730 root->fs_info->fs_devices->open_devices++;
1731 root->fs_info->fs_devices->rw_devices++;
1732 if (device->can_discard)
1733 root->fs_info->fs_devices->num_can_discard++;
1734 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
1735
1736 spin_lock(&root->fs_info->free_chunk_lock);
1737 root->fs_info->free_chunk_space += device->total_bytes;
1738 spin_unlock(&root->fs_info->free_chunk_lock);
1739
1740 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
1741 root->fs_info->fs_devices->rotating = 1;
1742
1743 total_bytes = btrfs_super_total_bytes(root->fs_info->super_copy);
1744 btrfs_set_super_total_bytes(root->fs_info->super_copy,
1745 total_bytes + device->total_bytes);
1746
1747 total_bytes = btrfs_super_num_devices(root->fs_info->super_copy);
1748 btrfs_set_super_num_devices(root->fs_info->super_copy,
1749 total_bytes + 1);
1750 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1751
1752 if (seeding_dev) {
1753 ret = init_first_rw_device(trans, root, device);
1754 if (ret)
1755 goto error_trans;
1756 ret = btrfs_finish_sprout(trans, root);
1757 if (ret)
1758 goto error_trans;
1759 } else {
1760 ret = btrfs_add_device(trans, root, device);
1761 if (ret)
1762 goto error_trans;
1763 }
1764
1765 /*
1766 * we've got more storage, clear any full flags on the space
1767 * infos
1768 */
1769 btrfs_clear_space_info_full(root->fs_info);
1770
1771 unlock_chunks(root);
1772 ret = btrfs_commit_transaction(trans, root);
1773
1774 if (seeding_dev) {
1775 mutex_unlock(&uuid_mutex);
1776 up_write(&sb->s_umount);
1777
1778 if (ret) /* transaction commit */
1779 return ret;
1780
1781 ret = btrfs_relocate_sys_chunks(root);
1782 if (ret < 0)
1783 btrfs_error(root->fs_info, ret,
1784 "Failed to relocate sys chunks after "
1785 "device initialization. This can be fixed "
1786 "using the \"btrfs balance\" command.");
1787 }
1788
1789 return ret;
1790
1791 error_trans:
1792 unlock_chunks(root);
1793 btrfs_abort_transaction(trans, root, ret);
1794 btrfs_end_transaction(trans, root);
1795 kfree(device->name);
1796 kfree(device);
1797 error:
1798 blkdev_put(bdev, FMODE_EXCL);
1799 if (seeding_dev) {
1800 mutex_unlock(&uuid_mutex);
1801 up_write(&sb->s_umount);
1802 }
1803 return ret;
1804 }
1805
1806 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
1807 struct btrfs_device *device)
1808 {
1809 int ret;
1810 struct btrfs_path *path;
1811 struct btrfs_root *root;
1812 struct btrfs_dev_item *dev_item;
1813 struct extent_buffer *leaf;
1814 struct btrfs_key key;
1815
1816 root = device->dev_root->fs_info->chunk_root;
1817
1818 path = btrfs_alloc_path();
1819 if (!path)
1820 return -ENOMEM;
1821
1822 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1823 key.type = BTRFS_DEV_ITEM_KEY;
1824 key.offset = device->devid;
1825
1826 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1827 if (ret < 0)
1828 goto out;
1829
1830 if (ret > 0) {
1831 ret = -ENOENT;
1832 goto out;
1833 }
1834
1835 leaf = path->nodes[0];
1836 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1837
1838 btrfs_set_device_id(leaf, dev_item, device->devid);
1839 btrfs_set_device_type(leaf, dev_item, device->type);
1840 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1841 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1842 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1843 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
1844 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1845 btrfs_mark_buffer_dirty(leaf);
1846
1847 out:
1848 btrfs_free_path(path);
1849 return ret;
1850 }
1851
1852 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
1853 struct btrfs_device *device, u64 new_size)
1854 {
1855 struct btrfs_super_block *super_copy =
1856 device->dev_root->fs_info->super_copy;
1857 u64 old_total = btrfs_super_total_bytes(super_copy);
1858 u64 diff = new_size - device->total_bytes;
1859
1860 if (!device->writeable)
1861 return -EACCES;
1862 if (new_size <= device->total_bytes)
1863 return -EINVAL;
1864
1865 btrfs_set_super_total_bytes(super_copy, old_total + diff);
1866 device->fs_devices->total_rw_bytes += diff;
1867
1868 device->total_bytes = new_size;
1869 device->disk_total_bytes = new_size;
1870 btrfs_clear_space_info_full(device->dev_root->fs_info);
1871
1872 return btrfs_update_device(trans, device);
1873 }
1874
1875 int btrfs_grow_device(struct btrfs_trans_handle *trans,
1876 struct btrfs_device *device, u64 new_size)
1877 {
1878 int ret;
1879 lock_chunks(device->dev_root);
1880 ret = __btrfs_grow_device(trans, device, new_size);
1881 unlock_chunks(device->dev_root);
1882 return ret;
1883 }
1884
1885 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
1886 struct btrfs_root *root,
1887 u64 chunk_tree, u64 chunk_objectid,
1888 u64 chunk_offset)
1889 {
1890 int ret;
1891 struct btrfs_path *path;
1892 struct btrfs_key key;
1893
1894 root = root->fs_info->chunk_root;
1895 path = btrfs_alloc_path();
1896 if (!path)
1897 return -ENOMEM;
1898
1899 key.objectid = chunk_objectid;
1900 key.offset = chunk_offset;
1901 key.type = BTRFS_CHUNK_ITEM_KEY;
1902
1903 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1904 if (ret < 0)
1905 goto out;
1906 else if (ret > 0) { /* Logic error or corruption */
1907 btrfs_error(root->fs_info, -ENOENT,
1908 "Failed lookup while freeing chunk.");
1909 ret = -ENOENT;
1910 goto out;
1911 }
1912
1913 ret = btrfs_del_item(trans, root, path);
1914 if (ret < 0)
1915 btrfs_error(root->fs_info, ret,
1916 "Failed to delete chunk item.");
1917 out:
1918 btrfs_free_path(path);
1919 return ret;
1920 }
1921
1922 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
1923 chunk_offset)
1924 {
1925 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
1926 struct btrfs_disk_key *disk_key;
1927 struct btrfs_chunk *chunk;
1928 u8 *ptr;
1929 int ret = 0;
1930 u32 num_stripes;
1931 u32 array_size;
1932 u32 len = 0;
1933 u32 cur;
1934 struct btrfs_key key;
1935
1936 array_size = btrfs_super_sys_array_size(super_copy);
1937
1938 ptr = super_copy->sys_chunk_array;
1939 cur = 0;
1940
1941 while (cur < array_size) {
1942 disk_key = (struct btrfs_disk_key *)ptr;
1943 btrfs_disk_key_to_cpu(&key, disk_key);
1944
1945 len = sizeof(*disk_key);
1946
1947 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
1948 chunk = (struct btrfs_chunk *)(ptr + len);
1949 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
1950 len += btrfs_chunk_item_size(num_stripes);
1951 } else {
1952 ret = -EIO;
1953 break;
1954 }
1955 if (key.objectid == chunk_objectid &&
1956 key.offset == chunk_offset) {
1957 memmove(ptr, ptr + len, array_size - (cur + len));
1958 array_size -= len;
1959 btrfs_set_super_sys_array_size(super_copy, array_size);
1960 } else {
1961 ptr += len;
1962 cur += len;
1963 }
1964 }
1965 return ret;
1966 }
1967
1968 static int btrfs_relocate_chunk(struct btrfs_root *root,
1969 u64 chunk_tree, u64 chunk_objectid,
1970 u64 chunk_offset)
1971 {
1972 struct extent_map_tree *em_tree;
1973 struct btrfs_root *extent_root;
1974 struct btrfs_trans_handle *trans;
1975 struct extent_map *em;
1976 struct map_lookup *map;
1977 int ret;
1978 int i;
1979
1980 root = root->fs_info->chunk_root;
1981 extent_root = root->fs_info->extent_root;
1982 em_tree = &root->fs_info->mapping_tree.map_tree;
1983
1984 ret = btrfs_can_relocate(extent_root, chunk_offset);
1985 if (ret)
1986 return -ENOSPC;
1987
1988 /* step one, relocate all the extents inside this chunk */
1989 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
1990 if (ret)
1991 return ret;
1992
1993 trans = btrfs_start_transaction(root, 0);
1994 BUG_ON(IS_ERR(trans));
1995
1996 lock_chunks(root);
1997
1998 /*
1999 * step two, delete the device extents and the
2000 * chunk tree entries
2001 */
2002 read_lock(&em_tree->lock);
2003 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
2004 read_unlock(&em_tree->lock);
2005
2006 BUG_ON(!em || em->start > chunk_offset ||
2007 em->start + em->len < chunk_offset);
2008 map = (struct map_lookup *)em->bdev;
2009
2010 for (i = 0; i < map->num_stripes; i++) {
2011 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
2012 map->stripes[i].physical);
2013 BUG_ON(ret);
2014
2015 if (map->stripes[i].dev) {
2016 ret = btrfs_update_device(trans, map->stripes[i].dev);
2017 BUG_ON(ret);
2018 }
2019 }
2020 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
2021 chunk_offset);
2022
2023 BUG_ON(ret);
2024
2025 trace_btrfs_chunk_free(root, map, chunk_offset, em->len);
2026
2027 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2028 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
2029 BUG_ON(ret);
2030 }
2031
2032 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
2033 BUG_ON(ret);
2034
2035 write_lock(&em_tree->lock);
2036 remove_extent_mapping(em_tree, em);
2037 write_unlock(&em_tree->lock);
2038
2039 kfree(map);
2040 em->bdev = NULL;
2041
2042 /* once for the tree */
2043 free_extent_map(em);
2044 /* once for us */
2045 free_extent_map(em);
2046
2047 unlock_chunks(root);
2048 btrfs_end_transaction(trans, root);
2049 return 0;
2050 }
2051
2052 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
2053 {
2054 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
2055 struct btrfs_path *path;
2056 struct extent_buffer *leaf;
2057 struct btrfs_chunk *chunk;
2058 struct btrfs_key key;
2059 struct btrfs_key found_key;
2060 u64 chunk_tree = chunk_root->root_key.objectid;
2061 u64 chunk_type;
2062 bool retried = false;
2063 int failed = 0;
2064 int ret;
2065
2066 path = btrfs_alloc_path();
2067 if (!path)
2068 return -ENOMEM;
2069
2070 again:
2071 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2072 key.offset = (u64)-1;
2073 key.type = BTRFS_CHUNK_ITEM_KEY;
2074
2075 while (1) {
2076 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2077 if (ret < 0)
2078 goto error;
2079 BUG_ON(ret == 0); /* Corruption */
2080
2081 ret = btrfs_previous_item(chunk_root, path, key.objectid,
2082 key.type);
2083 if (ret < 0)
2084 goto error;
2085 if (ret > 0)
2086 break;
2087
2088 leaf = path->nodes[0];
2089 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2090
2091 chunk = btrfs_item_ptr(leaf, path->slots[0],
2092 struct btrfs_chunk);
2093 chunk_type = btrfs_chunk_type(leaf, chunk);
2094 btrfs_release_path(path);
2095
2096 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
2097 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
2098 found_key.objectid,
2099 found_key.offset);
2100 if (ret == -ENOSPC)
2101 failed++;
2102 else if (ret)
2103 BUG();
2104 }
2105
2106 if (found_key.offset == 0)
2107 break;
2108 key.offset = found_key.offset - 1;
2109 }
2110 ret = 0;
2111 if (failed && !retried) {
2112 failed = 0;
2113 retried = true;
2114 goto again;
2115 } else if (failed && retried) {
2116 WARN_ON(1);
2117 ret = -ENOSPC;
2118 }
2119 error:
2120 btrfs_free_path(path);
2121 return ret;
2122 }
2123
2124 static int insert_balance_item(struct btrfs_root *root,
2125 struct btrfs_balance_control *bctl)
2126 {
2127 struct btrfs_trans_handle *trans;
2128 struct btrfs_balance_item *item;
2129 struct btrfs_disk_balance_args disk_bargs;
2130 struct btrfs_path *path;
2131 struct extent_buffer *leaf;
2132 struct btrfs_key key;
2133 int ret, err;
2134
2135 path = btrfs_alloc_path();
2136 if (!path)
2137 return -ENOMEM;
2138
2139 trans = btrfs_start_transaction(root, 0);
2140 if (IS_ERR(trans)) {
2141 btrfs_free_path(path);
2142 return PTR_ERR(trans);
2143 }
2144
2145 key.objectid = BTRFS_BALANCE_OBJECTID;
2146 key.type = BTRFS_BALANCE_ITEM_KEY;
2147 key.offset = 0;
2148
2149 ret = btrfs_insert_empty_item(trans, root, path, &key,
2150 sizeof(*item));
2151 if (ret)
2152 goto out;
2153
2154 leaf = path->nodes[0];
2155 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
2156
2157 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
2158
2159 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->data);
2160 btrfs_set_balance_data(leaf, item, &disk_bargs);
2161 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->meta);
2162 btrfs_set_balance_meta(leaf, item, &disk_bargs);
2163 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->sys);
2164 btrfs_set_balance_sys(leaf, item, &disk_bargs);
2165
2166 btrfs_set_balance_flags(leaf, item, bctl->flags);
2167
2168 btrfs_mark_buffer_dirty(leaf);
2169 out:
2170 btrfs_free_path(path);
2171 err = btrfs_commit_transaction(trans, root);
2172 if (err && !ret)
2173 ret = err;
2174 return ret;
2175 }
2176
2177 static int del_balance_item(struct btrfs_root *root)
2178 {
2179 struct btrfs_trans_handle *trans;
2180 struct btrfs_path *path;
2181 struct btrfs_key key;
2182 int ret, err;
2183
2184 path = btrfs_alloc_path();
2185 if (!path)
2186 return -ENOMEM;
2187
2188 trans = btrfs_start_transaction(root, 0);
2189 if (IS_ERR(trans)) {
2190 btrfs_free_path(path);
2191 return PTR_ERR(trans);
2192 }
2193
2194 key.objectid = BTRFS_BALANCE_OBJECTID;
2195 key.type = BTRFS_BALANCE_ITEM_KEY;
2196 key.offset = 0;
2197
2198 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2199 if (ret < 0)
2200 goto out;
2201 if (ret > 0) {
2202 ret = -ENOENT;
2203 goto out;
2204 }
2205
2206 ret = btrfs_del_item(trans, root, path);
2207 out:
2208 btrfs_free_path(path);
2209 err = btrfs_commit_transaction(trans, root);
2210 if (err && !ret)
2211 ret = err;
2212 return ret;
2213 }
2214
2215 /*
2216 * This is a heuristic used to reduce the number of chunks balanced on
2217 * resume after balance was interrupted.
2218 */
2219 static void update_balance_args(struct btrfs_balance_control *bctl)
2220 {
2221 /*
2222 * Turn on soft mode for chunk types that were being converted.
2223 */
2224 if (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)
2225 bctl->data.flags |= BTRFS_BALANCE_ARGS_SOFT;
2226 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)
2227 bctl->sys.flags |= BTRFS_BALANCE_ARGS_SOFT;
2228 if (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)
2229 bctl->meta.flags |= BTRFS_BALANCE_ARGS_SOFT;
2230
2231 /*
2232 * Turn on usage filter if is not already used. The idea is
2233 * that chunks that we have already balanced should be
2234 * reasonably full. Don't do it for chunks that are being
2235 * converted - that will keep us from relocating unconverted
2236 * (albeit full) chunks.
2237 */
2238 if (!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2239 !(bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2240 bctl->data.flags |= BTRFS_BALANCE_ARGS_USAGE;
2241 bctl->data.usage = 90;
2242 }
2243 if (!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2244 !(bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2245 bctl->sys.flags |= BTRFS_BALANCE_ARGS_USAGE;
2246 bctl->sys.usage = 90;
2247 }
2248 if (!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2249 !(bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2250 bctl->meta.flags |= BTRFS_BALANCE_ARGS_USAGE;
2251 bctl->meta.usage = 90;
2252 }
2253 }
2254
2255 /*
2256 * Should be called with both balance and volume mutexes held to
2257 * serialize other volume operations (add_dev/rm_dev/resize) with
2258 * restriper. Same goes for unset_balance_control.
2259 */
2260 static void set_balance_control(struct btrfs_balance_control *bctl)
2261 {
2262 struct btrfs_fs_info *fs_info = bctl->fs_info;
2263
2264 BUG_ON(fs_info->balance_ctl);
2265
2266 spin_lock(&fs_info->balance_lock);
2267 fs_info->balance_ctl = bctl;
2268 spin_unlock(&fs_info->balance_lock);
2269 }
2270
2271 static void unset_balance_control(struct btrfs_fs_info *fs_info)
2272 {
2273 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2274
2275 BUG_ON(!fs_info->balance_ctl);
2276
2277 spin_lock(&fs_info->balance_lock);
2278 fs_info->balance_ctl = NULL;
2279 spin_unlock(&fs_info->balance_lock);
2280
2281 kfree(bctl);
2282 }
2283
2284 /*
2285 * Balance filters. Return 1 if chunk should be filtered out
2286 * (should not be balanced).
2287 */
2288 static int chunk_profiles_filter(u64 chunk_type,
2289 struct btrfs_balance_args *bargs)
2290 {
2291 chunk_type = chunk_to_extended(chunk_type) &
2292 BTRFS_EXTENDED_PROFILE_MASK;
2293
2294 if (bargs->profiles & chunk_type)
2295 return 0;
2296
2297 return 1;
2298 }
2299
2300 static u64 div_factor_fine(u64 num, int factor)
2301 {
2302 if (factor <= 0)
2303 return 0;
2304 if (factor >= 100)
2305 return num;
2306
2307 num *= factor;
2308 do_div(num, 100);
2309 return num;
2310 }
2311
2312 static int chunk_usage_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset,
2313 struct btrfs_balance_args *bargs)
2314 {
2315 struct btrfs_block_group_cache *cache;
2316 u64 chunk_used, user_thresh;
2317 int ret = 1;
2318
2319 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
2320 chunk_used = btrfs_block_group_used(&cache->item);
2321
2322 user_thresh = div_factor_fine(cache->key.offset, bargs->usage);
2323 if (chunk_used < user_thresh)
2324 ret = 0;
2325
2326 btrfs_put_block_group(cache);
2327 return ret;
2328 }
2329
2330 static int chunk_devid_filter(struct extent_buffer *leaf,
2331 struct btrfs_chunk *chunk,
2332 struct btrfs_balance_args *bargs)
2333 {
2334 struct btrfs_stripe *stripe;
2335 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2336 int i;
2337
2338 for (i = 0; i < num_stripes; i++) {
2339 stripe = btrfs_stripe_nr(chunk, i);
2340 if (btrfs_stripe_devid(leaf, stripe) == bargs->devid)
2341 return 0;
2342 }
2343
2344 return 1;
2345 }
2346
2347 /* [pstart, pend) */
2348 static int chunk_drange_filter(struct extent_buffer *leaf,
2349 struct btrfs_chunk *chunk,
2350 u64 chunk_offset,
2351 struct btrfs_balance_args *bargs)
2352 {
2353 struct btrfs_stripe *stripe;
2354 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2355 u64 stripe_offset;
2356 u64 stripe_length;
2357 int factor;
2358 int i;
2359
2360 if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID))
2361 return 0;
2362
2363 if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP |
2364 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10))
2365 factor = 2;
2366 else
2367 factor = 1;
2368 factor = num_stripes / factor;
2369
2370 for (i = 0; i < num_stripes; i++) {
2371 stripe = btrfs_stripe_nr(chunk, i);
2372 if (btrfs_stripe_devid(leaf, stripe) != bargs->devid)
2373 continue;
2374
2375 stripe_offset = btrfs_stripe_offset(leaf, stripe);
2376 stripe_length = btrfs_chunk_length(leaf, chunk);
2377 do_div(stripe_length, factor);
2378
2379 if (stripe_offset < bargs->pend &&
2380 stripe_offset + stripe_length > bargs->pstart)
2381 return 0;
2382 }
2383
2384 return 1;
2385 }
2386
2387 /* [vstart, vend) */
2388 static int chunk_vrange_filter(struct extent_buffer *leaf,
2389 struct btrfs_chunk *chunk,
2390 u64 chunk_offset,
2391 struct btrfs_balance_args *bargs)
2392 {
2393 if (chunk_offset < bargs->vend &&
2394 chunk_offset + btrfs_chunk_length(leaf, chunk) > bargs->vstart)
2395 /* at least part of the chunk is inside this vrange */
2396 return 0;
2397
2398 return 1;
2399 }
2400
2401 static int chunk_soft_convert_filter(u64 chunk_type,
2402 struct btrfs_balance_args *bargs)
2403 {
2404 if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
2405 return 0;
2406
2407 chunk_type = chunk_to_extended(chunk_type) &
2408 BTRFS_EXTENDED_PROFILE_MASK;
2409
2410 if (bargs->target == chunk_type)
2411 return 1;
2412
2413 return 0;
2414 }
2415
2416 static int should_balance_chunk(struct btrfs_root *root,
2417 struct extent_buffer *leaf,
2418 struct btrfs_chunk *chunk, u64 chunk_offset)
2419 {
2420 struct btrfs_balance_control *bctl = root->fs_info->balance_ctl;
2421 struct btrfs_balance_args *bargs = NULL;
2422 u64 chunk_type = btrfs_chunk_type(leaf, chunk);
2423
2424 /* type filter */
2425 if (!((chunk_type & BTRFS_BLOCK_GROUP_TYPE_MASK) &
2426 (bctl->flags & BTRFS_BALANCE_TYPE_MASK))) {
2427 return 0;
2428 }
2429
2430 if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
2431 bargs = &bctl->data;
2432 else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
2433 bargs = &bctl->sys;
2434 else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
2435 bargs = &bctl->meta;
2436
2437 /* profiles filter */
2438 if ((bargs->flags & BTRFS_BALANCE_ARGS_PROFILES) &&
2439 chunk_profiles_filter(chunk_type, bargs)) {
2440 return 0;
2441 }
2442
2443 /* usage filter */
2444 if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) &&
2445 chunk_usage_filter(bctl->fs_info, chunk_offset, bargs)) {
2446 return 0;
2447 }
2448
2449 /* devid filter */
2450 if ((bargs->flags & BTRFS_BALANCE_ARGS_DEVID) &&
2451 chunk_devid_filter(leaf, chunk, bargs)) {
2452 return 0;
2453 }
2454
2455 /* drange filter, makes sense only with devid filter */
2456 if ((bargs->flags & BTRFS_BALANCE_ARGS_DRANGE) &&
2457 chunk_drange_filter(leaf, chunk, chunk_offset, bargs)) {
2458 return 0;
2459 }
2460
2461 /* vrange filter */
2462 if ((bargs->flags & BTRFS_BALANCE_ARGS_VRANGE) &&
2463 chunk_vrange_filter(leaf, chunk, chunk_offset, bargs)) {
2464 return 0;
2465 }
2466
2467 /* soft profile changing mode */
2468 if ((bargs->flags & BTRFS_BALANCE_ARGS_SOFT) &&
2469 chunk_soft_convert_filter(chunk_type, bargs)) {
2470 return 0;
2471 }
2472
2473 return 1;
2474 }
2475
2476 static u64 div_factor(u64 num, int factor)
2477 {
2478 if (factor == 10)
2479 return num;
2480 num *= factor;
2481 do_div(num, 10);
2482 return num;
2483 }
2484
2485 static int __btrfs_balance(struct btrfs_fs_info *fs_info)
2486 {
2487 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2488 struct btrfs_root *chunk_root = fs_info->chunk_root;
2489 struct btrfs_root *dev_root = fs_info->dev_root;
2490 struct list_head *devices;
2491 struct btrfs_device *device;
2492 u64 old_size;
2493 u64 size_to_free;
2494 struct btrfs_chunk *chunk;
2495 struct btrfs_path *path;
2496 struct btrfs_key key;
2497 struct btrfs_key found_key;
2498 struct btrfs_trans_handle *trans;
2499 struct extent_buffer *leaf;
2500 int slot;
2501 int ret;
2502 int enospc_errors = 0;
2503 bool counting = true;
2504
2505 /* step one make some room on all the devices */
2506 devices = &fs_info->fs_devices->devices;
2507 list_for_each_entry(device, devices, dev_list) {
2508 old_size = device->total_bytes;
2509 size_to_free = div_factor(old_size, 1);
2510 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
2511 if (!device->writeable ||
2512 device->total_bytes - device->bytes_used > size_to_free)
2513 continue;
2514
2515 ret = btrfs_shrink_device(device, old_size - size_to_free);
2516 if (ret == -ENOSPC)
2517 break;
2518 BUG_ON(ret);
2519
2520 trans = btrfs_start_transaction(dev_root, 0);
2521 BUG_ON(IS_ERR(trans));
2522
2523 ret = btrfs_grow_device(trans, device, old_size);
2524 BUG_ON(ret);
2525
2526 btrfs_end_transaction(trans, dev_root);
2527 }
2528
2529 /* step two, relocate all the chunks */
2530 path = btrfs_alloc_path();
2531 if (!path) {
2532 ret = -ENOMEM;
2533 goto error;
2534 }
2535
2536 /* zero out stat counters */
2537 spin_lock(&fs_info->balance_lock);
2538 memset(&bctl->stat, 0, sizeof(bctl->stat));
2539 spin_unlock(&fs_info->balance_lock);
2540 again:
2541 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2542 key.offset = (u64)-1;
2543 key.type = BTRFS_CHUNK_ITEM_KEY;
2544
2545 while (1) {
2546 if ((!counting && atomic_read(&fs_info->balance_pause_req)) ||
2547 atomic_read(&fs_info->balance_cancel_req)) {
2548 ret = -ECANCELED;
2549 goto error;
2550 }
2551
2552 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2553 if (ret < 0)
2554 goto error;
2555
2556 /*
2557 * this shouldn't happen, it means the last relocate
2558 * failed
2559 */
2560 if (ret == 0)
2561 BUG(); /* FIXME break ? */
2562
2563 ret = btrfs_previous_item(chunk_root, path, 0,
2564 BTRFS_CHUNK_ITEM_KEY);
2565 if (ret) {
2566 ret = 0;
2567 break;
2568 }
2569
2570 leaf = path->nodes[0];
2571 slot = path->slots[0];
2572 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2573
2574 if (found_key.objectid != key.objectid)
2575 break;
2576
2577 /* chunk zero is special */
2578 if (found_key.offset == 0)
2579 break;
2580
2581 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
2582
2583 if (!counting) {
2584 spin_lock(&fs_info->balance_lock);
2585 bctl->stat.considered++;
2586 spin_unlock(&fs_info->balance_lock);
2587 }
2588
2589 ret = should_balance_chunk(chunk_root, leaf, chunk,
2590 found_key.offset);
2591 btrfs_release_path(path);
2592 if (!ret)
2593 goto loop;
2594
2595 if (counting) {
2596 spin_lock(&fs_info->balance_lock);
2597 bctl->stat.expected++;
2598 spin_unlock(&fs_info->balance_lock);
2599 goto loop;
2600 }
2601
2602 ret = btrfs_relocate_chunk(chunk_root,
2603 chunk_root->root_key.objectid,
2604 found_key.objectid,
2605 found_key.offset);
2606 if (ret && ret != -ENOSPC)
2607 goto error;
2608 if (ret == -ENOSPC) {
2609 enospc_errors++;
2610 } else {
2611 spin_lock(&fs_info->balance_lock);
2612 bctl->stat.completed++;
2613 spin_unlock(&fs_info->balance_lock);
2614 }
2615 loop:
2616 key.offset = found_key.offset - 1;
2617 }
2618
2619 if (counting) {
2620 btrfs_release_path(path);
2621 counting = false;
2622 goto again;
2623 }
2624 error:
2625 btrfs_free_path(path);
2626 if (enospc_errors) {
2627 printk(KERN_INFO "btrfs: %d enospc errors during balance\n",
2628 enospc_errors);
2629 if (!ret)
2630 ret = -ENOSPC;
2631 }
2632
2633 return ret;
2634 }
2635
2636 /**
2637 * alloc_profile_is_valid - see if a given profile is valid and reduced
2638 * @flags: profile to validate
2639 * @extended: if true @flags is treated as an extended profile
2640 */
2641 static int alloc_profile_is_valid(u64 flags, int extended)
2642 {
2643 u64 mask = (extended ? BTRFS_EXTENDED_PROFILE_MASK :
2644 BTRFS_BLOCK_GROUP_PROFILE_MASK);
2645
2646 flags &= ~BTRFS_BLOCK_GROUP_TYPE_MASK;
2647
2648 /* 1) check that all other bits are zeroed */
2649 if (flags & ~mask)
2650 return 0;
2651
2652 /* 2) see if profile is reduced */
2653 if (flags == 0)
2654 return !extended; /* "0" is valid for usual profiles */
2655
2656 /* true if exactly one bit set */
2657 return (flags & (flags - 1)) == 0;
2658 }
2659
2660 static inline int balance_need_close(struct btrfs_fs_info *fs_info)
2661 {
2662 /* cancel requested || normal exit path */
2663 return atomic_read(&fs_info->balance_cancel_req) ||
2664 (atomic_read(&fs_info->balance_pause_req) == 0 &&
2665 atomic_read(&fs_info->balance_cancel_req) == 0);
2666 }
2667
2668 static void __cancel_balance(struct btrfs_fs_info *fs_info)
2669 {
2670 int ret;
2671
2672 unset_balance_control(fs_info);
2673 ret = del_balance_item(fs_info->tree_root);
2674 BUG_ON(ret);
2675 }
2676
2677 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
2678 struct btrfs_ioctl_balance_args *bargs);
2679
2680 /*
2681 * Should be called with both balance and volume mutexes held
2682 */
2683 int btrfs_balance(struct btrfs_balance_control *bctl,
2684 struct btrfs_ioctl_balance_args *bargs)
2685 {
2686 struct btrfs_fs_info *fs_info = bctl->fs_info;
2687 u64 allowed;
2688 int mixed = 0;
2689 int ret;
2690
2691 if (btrfs_fs_closing(fs_info) ||
2692 atomic_read(&fs_info->balance_pause_req) ||
2693 atomic_read(&fs_info->balance_cancel_req)) {
2694 ret = -EINVAL;
2695 goto out;
2696 }
2697
2698 allowed = btrfs_super_incompat_flags(fs_info->super_copy);
2699 if (allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
2700 mixed = 1;
2701
2702 /*
2703 * In case of mixed groups both data and meta should be picked,
2704 * and identical options should be given for both of them.
2705 */
2706 allowed = BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA;
2707 if (mixed && (bctl->flags & allowed)) {
2708 if (!(bctl->flags & BTRFS_BALANCE_DATA) ||
2709 !(bctl->flags & BTRFS_BALANCE_METADATA) ||
2710 memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) {
2711 printk(KERN_ERR "btrfs: with mixed groups data and "
2712 "metadata balance options must be the same\n");
2713 ret = -EINVAL;
2714 goto out;
2715 }
2716 }
2717
2718 allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
2719 if (fs_info->fs_devices->num_devices == 1)
2720 allowed |= BTRFS_BLOCK_GROUP_DUP;
2721 else if (fs_info->fs_devices->num_devices < 4)
2722 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
2723 else
2724 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
2725 BTRFS_BLOCK_GROUP_RAID10);
2726
2727 if ((bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2728 (!alloc_profile_is_valid(bctl->data.target, 1) ||
2729 (bctl->data.target & ~allowed))) {
2730 printk(KERN_ERR "btrfs: unable to start balance with target "
2731 "data profile %llu\n",
2732 (unsigned long long)bctl->data.target);
2733 ret = -EINVAL;
2734 goto out;
2735 }
2736 if ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2737 (!alloc_profile_is_valid(bctl->meta.target, 1) ||
2738 (bctl->meta.target & ~allowed))) {
2739 printk(KERN_ERR "btrfs: unable to start balance with target "
2740 "metadata profile %llu\n",
2741 (unsigned long long)bctl->meta.target);
2742 ret = -EINVAL;
2743 goto out;
2744 }
2745 if ((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2746 (!alloc_profile_is_valid(bctl->sys.target, 1) ||
2747 (bctl->sys.target & ~allowed))) {
2748 printk(KERN_ERR "btrfs: unable to start balance with target "
2749 "system profile %llu\n",
2750 (unsigned long long)bctl->sys.target);
2751 ret = -EINVAL;
2752 goto out;
2753 }
2754
2755 /* allow dup'ed data chunks only in mixed mode */
2756 if (!mixed && (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2757 (bctl->data.target & BTRFS_BLOCK_GROUP_DUP)) {
2758 printk(KERN_ERR "btrfs: dup for data is not allowed\n");
2759 ret = -EINVAL;
2760 goto out;
2761 }
2762
2763 /* allow to reduce meta or sys integrity only if force set */
2764 allowed = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
2765 BTRFS_BLOCK_GROUP_RAID10;
2766 if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2767 (fs_info->avail_system_alloc_bits & allowed) &&
2768 !(bctl->sys.target & allowed)) ||
2769 ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2770 (fs_info->avail_metadata_alloc_bits & allowed) &&
2771 !(bctl->meta.target & allowed))) {
2772 if (bctl->flags & BTRFS_BALANCE_FORCE) {
2773 printk(KERN_INFO "btrfs: force reducing metadata "
2774 "integrity\n");
2775 } else {
2776 printk(KERN_ERR "btrfs: balance will reduce metadata "
2777 "integrity, use force if you want this\n");
2778 ret = -EINVAL;
2779 goto out;
2780 }
2781 }
2782
2783 ret = insert_balance_item(fs_info->tree_root, bctl);
2784 if (ret && ret != -EEXIST)
2785 goto out;
2786
2787 if (!(bctl->flags & BTRFS_BALANCE_RESUME)) {
2788 BUG_ON(ret == -EEXIST);
2789 set_balance_control(bctl);
2790 } else {
2791 BUG_ON(ret != -EEXIST);
2792 spin_lock(&fs_info->balance_lock);
2793 update_balance_args(bctl);
2794 spin_unlock(&fs_info->balance_lock);
2795 }
2796
2797 atomic_inc(&fs_info->balance_running);
2798 mutex_unlock(&fs_info->balance_mutex);
2799
2800 ret = __btrfs_balance(fs_info);
2801
2802 mutex_lock(&fs_info->balance_mutex);
2803 atomic_dec(&fs_info->balance_running);
2804
2805 if (bargs) {
2806 memset(bargs, 0, sizeof(*bargs));
2807 update_ioctl_balance_args(fs_info, 0, bargs);
2808 }
2809
2810 if ((ret && ret != -ECANCELED && ret != -ENOSPC) ||
2811 balance_need_close(fs_info)) {
2812 __cancel_balance(fs_info);
2813 }
2814
2815 wake_up(&fs_info->balance_wait_q);
2816
2817 return ret;
2818 out:
2819 if (bctl->flags & BTRFS_BALANCE_RESUME)
2820 __cancel_balance(fs_info);
2821 else
2822 kfree(bctl);
2823 return ret;
2824 }
2825
2826 static int balance_kthread(void *data)
2827 {
2828 struct btrfs_balance_control *bctl =
2829 (struct btrfs_balance_control *)data;
2830 struct btrfs_fs_info *fs_info = bctl->fs_info;
2831 int ret = 0;
2832
2833 mutex_lock(&fs_info->volume_mutex);
2834 mutex_lock(&fs_info->balance_mutex);
2835
2836 set_balance_control(bctl);
2837
2838 if (btrfs_test_opt(fs_info->tree_root, SKIP_BALANCE)) {
2839 printk(KERN_INFO "btrfs: force skipping balance\n");
2840 } else {
2841 printk(KERN_INFO "btrfs: continuing balance\n");
2842 ret = btrfs_balance(bctl, NULL);
2843 }
2844
2845 mutex_unlock(&fs_info->balance_mutex);
2846 mutex_unlock(&fs_info->volume_mutex);
2847 return ret;
2848 }
2849
2850 int btrfs_recover_balance(struct btrfs_root *tree_root)
2851 {
2852 struct task_struct *tsk;
2853 struct btrfs_balance_control *bctl;
2854 struct btrfs_balance_item *item;
2855 struct btrfs_disk_balance_args disk_bargs;
2856 struct btrfs_path *path;
2857 struct extent_buffer *leaf;
2858 struct btrfs_key key;
2859 int ret;
2860
2861 path = btrfs_alloc_path();
2862 if (!path)
2863 return -ENOMEM;
2864
2865 bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
2866 if (!bctl) {
2867 ret = -ENOMEM;
2868 goto out;
2869 }
2870
2871 key.objectid = BTRFS_BALANCE_OBJECTID;
2872 key.type = BTRFS_BALANCE_ITEM_KEY;
2873 key.offset = 0;
2874
2875 ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
2876 if (ret < 0)
2877 goto out_bctl;
2878 if (ret > 0) { /* ret = -ENOENT; */
2879 ret = 0;
2880 goto out_bctl;
2881 }
2882
2883 leaf = path->nodes[0];
2884 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
2885
2886 bctl->fs_info = tree_root->fs_info;
2887 bctl->flags = btrfs_balance_flags(leaf, item) | BTRFS_BALANCE_RESUME;
2888
2889 btrfs_balance_data(leaf, item, &disk_bargs);
2890 btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);
2891 btrfs_balance_meta(leaf, item, &disk_bargs);
2892 btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs);
2893 btrfs_balance_sys(leaf, item, &disk_bargs);
2894 btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);
2895
2896 tsk = kthread_run(balance_kthread, bctl, "btrfs-balance");
2897 if (IS_ERR(tsk))
2898 ret = PTR_ERR(tsk);
2899 else
2900 goto out;
2901
2902 out_bctl:
2903 kfree(bctl);
2904 out:
2905 btrfs_free_path(path);
2906 return ret;
2907 }
2908
2909 int btrfs_pause_balance(struct btrfs_fs_info *fs_info)
2910 {
2911 int ret = 0;
2912
2913 mutex_lock(&fs_info->balance_mutex);
2914 if (!fs_info->balance_ctl) {
2915 mutex_unlock(&fs_info->balance_mutex);
2916 return -ENOTCONN;
2917 }
2918
2919 if (atomic_read(&fs_info->balance_running)) {
2920 atomic_inc(&fs_info->balance_pause_req);
2921 mutex_unlock(&fs_info->balance_mutex);
2922
2923 wait_event(fs_info->balance_wait_q,
2924 atomic_read(&fs_info->balance_running) == 0);
2925
2926 mutex_lock(&fs_info->balance_mutex);
2927 /* we are good with balance_ctl ripped off from under us */
2928 BUG_ON(atomic_read(&fs_info->balance_running));
2929 atomic_dec(&fs_info->balance_pause_req);
2930 } else {
2931 ret = -ENOTCONN;
2932 }
2933
2934 mutex_unlock(&fs_info->balance_mutex);
2935 return ret;
2936 }
2937
2938 int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
2939 {
2940 mutex_lock(&fs_info->balance_mutex);
2941 if (!fs_info->balance_ctl) {
2942 mutex_unlock(&fs_info->balance_mutex);
2943 return -ENOTCONN;
2944 }
2945
2946 atomic_inc(&fs_info->balance_cancel_req);
2947 /*
2948 * if we are running just wait and return, balance item is
2949 * deleted in btrfs_balance in this case
2950 */
2951 if (atomic_read(&fs_info->balance_running)) {
2952 mutex_unlock(&fs_info->balance_mutex);
2953 wait_event(fs_info->balance_wait_q,
2954 atomic_read(&fs_info->balance_running) == 0);
2955 mutex_lock(&fs_info->balance_mutex);
2956 } else {
2957 /* __cancel_balance needs volume_mutex */
2958 mutex_unlock(&fs_info->balance_mutex);
2959 mutex_lock(&fs_info->volume_mutex);
2960 mutex_lock(&fs_info->balance_mutex);
2961
2962 if (fs_info->balance_ctl)
2963 __cancel_balance(fs_info);
2964
2965 mutex_unlock(&fs_info->volume_mutex);
2966 }
2967
2968 BUG_ON(fs_info->balance_ctl || atomic_read(&fs_info->balance_running));
2969 atomic_dec(&fs_info->balance_cancel_req);
2970 mutex_unlock(&fs_info->balance_mutex);
2971 return 0;
2972 }
2973
2974 /*
2975 * shrinking a device means finding all of the device extents past
2976 * the new size, and then following the back refs to the chunks.
2977 * The chunk relocation code actually frees the device extent
2978 */
2979 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
2980 {
2981 struct btrfs_trans_handle *trans;
2982 struct btrfs_root *root = device->dev_root;
2983 struct btrfs_dev_extent *dev_extent = NULL;
2984 struct btrfs_path *path;
2985 u64 length;
2986 u64 chunk_tree;
2987 u64 chunk_objectid;
2988 u64 chunk_offset;
2989 int ret;
2990 int slot;
2991 int failed = 0;
2992 bool retried = false;
2993 struct extent_buffer *l;
2994 struct btrfs_key key;
2995 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
2996 u64 old_total = btrfs_super_total_bytes(super_copy);
2997 u64 old_size = device->total_bytes;
2998 u64 diff = device->total_bytes - new_size;
2999
3000 if (new_size >= device->total_bytes)
3001 return -EINVAL;
3002
3003 path = btrfs_alloc_path();
3004 if (!path)
3005 return -ENOMEM;
3006
3007 path->reada = 2;
3008
3009 lock_chunks(root);
3010
3011 device->total_bytes = new_size;
3012 if (device->writeable) {
3013 device->fs_devices->total_rw_bytes -= diff;
3014 spin_lock(&root->fs_info->free_chunk_lock);
3015 root->fs_info->free_chunk_space -= diff;
3016 spin_unlock(&root->fs_info->free_chunk_lock);
3017 }
3018 unlock_chunks(root);
3019
3020 again:
3021 key.objectid = device->devid;
3022 key.offset = (u64)-1;
3023 key.type = BTRFS_DEV_EXTENT_KEY;
3024
3025 do {
3026 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3027 if (ret < 0)
3028 goto done;
3029
3030 ret = btrfs_previous_item(root, path, 0, key.type);
3031 if (ret < 0)
3032 goto done;
3033 if (ret) {
3034 ret = 0;
3035 btrfs_release_path(path);
3036 break;
3037 }
3038
3039 l = path->nodes[0];
3040 slot = path->slots[0];
3041 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
3042
3043 if (key.objectid != device->devid) {
3044 btrfs_release_path(path);
3045 break;
3046 }
3047
3048 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
3049 length = btrfs_dev_extent_length(l, dev_extent);
3050
3051 if (key.offset + length <= new_size) {
3052 btrfs_release_path(path);
3053 break;
3054 }
3055
3056 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
3057 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
3058 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
3059 btrfs_release_path(path);
3060
3061 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
3062 chunk_offset);
3063 if (ret && ret != -ENOSPC)
3064 goto done;
3065 if (ret == -ENOSPC)
3066 failed++;
3067 } while (key.offset-- > 0);
3068
3069 if (failed && !retried) {
3070 failed = 0;
3071 retried = true;
3072 goto again;
3073 } else if (failed && retried) {
3074 ret = -ENOSPC;
3075 lock_chunks(root);
3076
3077 device->total_bytes = old_size;
3078 if (device->writeable)
3079 device->fs_devices->total_rw_bytes += diff;
3080 spin_lock(&root->fs_info->free_chunk_lock);
3081 root->fs_info->free_chunk_space += diff;
3082 spin_unlock(&root->fs_info->free_chunk_lock);
3083 unlock_chunks(root);
3084 goto done;
3085 }
3086
3087 /* Shrinking succeeded, else we would be at "done". */
3088 trans = btrfs_start_transaction(root, 0);
3089 if (IS_ERR(trans)) {
3090 ret = PTR_ERR(trans);
3091 goto done;
3092 }
3093
3094 lock_chunks(root);
3095
3096 device->disk_total_bytes = new_size;
3097 /* Now btrfs_update_device() will change the on-disk size. */
3098 ret = btrfs_update_device(trans, device);
3099 if (ret) {
3100 unlock_chunks(root);
3101 btrfs_end_transaction(trans, root);
3102 goto done;
3103 }
3104 WARN_ON(diff > old_total);
3105 btrfs_set_super_total_bytes(super_copy, old_total - diff);
3106 unlock_chunks(root);
3107 btrfs_end_transaction(trans, root);
3108 done:
3109 btrfs_free_path(path);
3110 return ret;
3111 }
3112
3113 static int btrfs_add_system_chunk(struct btrfs_root *root,
3114 struct btrfs_key *key,
3115 struct btrfs_chunk *chunk, int item_size)
3116 {
3117 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3118 struct btrfs_disk_key disk_key;
3119 u32 array_size;
3120 u8 *ptr;
3121
3122 array_size = btrfs_super_sys_array_size(super_copy);
3123 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
3124 return -EFBIG;
3125
3126 ptr = super_copy->sys_chunk_array + array_size;
3127 btrfs_cpu_key_to_disk(&disk_key, key);
3128 memcpy(ptr, &disk_key, sizeof(disk_key));
3129 ptr += sizeof(disk_key);
3130 memcpy(ptr, chunk, item_size);
3131 item_size += sizeof(disk_key);
3132 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
3133 return 0;
3134 }
3135
3136 /*
3137 * sort the devices in descending order by max_avail, total_avail
3138 */
3139 static int btrfs_cmp_device_info(const void *a, const void *b)
3140 {
3141 const struct btrfs_device_info *di_a = a;
3142 const struct btrfs_device_info *di_b = b;
3143
3144 if (di_a->max_avail > di_b->max_avail)
3145 return -1;
3146 if (di_a->max_avail < di_b->max_avail)
3147 return 1;
3148 if (di_a->total_avail > di_b->total_avail)
3149 return -1;
3150 if (di_a->total_avail < di_b->total_avail)
3151 return 1;
3152 return 0;
3153 }
3154
3155 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
3156 struct btrfs_root *extent_root,
3157 struct map_lookup **map_ret,
3158 u64 *num_bytes_out, u64 *stripe_size_out,
3159 u64 start, u64 type)
3160 {
3161 struct btrfs_fs_info *info = extent_root->fs_info;
3162 struct btrfs_fs_devices *fs_devices = info->fs_devices;
3163 struct list_head *cur;
3164 struct map_lookup *map = NULL;
3165 struct extent_map_tree *em_tree;
3166 struct extent_map *em;
3167 struct btrfs_device_info *devices_info = NULL;
3168 u64 total_avail;
3169 int num_stripes; /* total number of stripes to allocate */
3170 int sub_stripes; /* sub_stripes info for map */
3171 int dev_stripes; /* stripes per dev */
3172 int devs_max; /* max devs to use */
3173 int devs_min; /* min devs needed */
3174 int devs_increment; /* ndevs has to be a multiple of this */
3175 int ncopies; /* how many copies to data has */
3176 int ret;
3177 u64 max_stripe_size;
3178 u64 max_chunk_size;
3179 u64 stripe_size;
3180 u64 num_bytes;
3181 int ndevs;
3182 int i;
3183 int j;
3184
3185 BUG_ON(!alloc_profile_is_valid(type, 0));
3186
3187 if (list_empty(&fs_devices->alloc_list))
3188 return -ENOSPC;
3189
3190 sub_stripes = 1;
3191 dev_stripes = 1;
3192 devs_increment = 1;
3193 ncopies = 1;
3194 devs_max = 0; /* 0 == as many as possible */
3195 devs_min = 1;
3196
3197 /*
3198 * define the properties of each RAID type.
3199 * FIXME: move this to a global table and use it in all RAID
3200 * calculation code
3201 */
3202 if (type & (BTRFS_BLOCK_GROUP_DUP)) {
3203 dev_stripes = 2;
3204 ncopies = 2;
3205 devs_max = 1;
3206 } else if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
3207 devs_min = 2;
3208 } else if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
3209 devs_increment = 2;
3210 ncopies = 2;
3211 devs_max = 2;
3212 devs_min = 2;
3213 } else if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
3214 sub_stripes = 2;
3215 devs_increment = 2;
3216 ncopies = 2;
3217 devs_min = 4;
3218 } else {
3219 devs_max = 1;
3220 }
3221
3222 if (type & BTRFS_BLOCK_GROUP_DATA) {
3223 max_stripe_size = 1024 * 1024 * 1024;
3224 max_chunk_size = 10 * max_stripe_size;
3225 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
3226 /* for larger filesystems, use larger metadata chunks */
3227 if (fs_devices->total_rw_bytes > 50ULL * 1024 * 1024 * 1024)
3228 max_stripe_size = 1024 * 1024 * 1024;
3229 else
3230 max_stripe_size = 256 * 1024 * 1024;
3231 max_chunk_size = max_stripe_size;
3232 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
3233 max_stripe_size = 32 * 1024 * 1024;
3234 max_chunk_size = 2 * max_stripe_size;
3235 } else {
3236 printk(KERN_ERR "btrfs: invalid chunk type 0x%llx requested\n",
3237 type);
3238 BUG_ON(1);
3239 }
3240
3241 /* we don't want a chunk larger than 10% of writeable space */
3242 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
3243 max_chunk_size);
3244
3245 devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices,
3246 GFP_NOFS);
3247 if (!devices_info)
3248 return -ENOMEM;
3249
3250 cur = fs_devices->alloc_list.next;
3251
3252 /*
3253 * in the first pass through the devices list, we gather information
3254 * about the available holes on each device.
3255 */
3256 ndevs = 0;
3257 while (cur != &fs_devices->alloc_list) {
3258 struct btrfs_device *device;
3259 u64 max_avail;
3260 u64 dev_offset;
3261
3262 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
3263
3264 cur = cur->next;
3265
3266 if (!device->writeable) {
3267 printk(KERN_ERR
3268 "btrfs: read-only device in alloc_list\n");
3269 WARN_ON(1);
3270 continue;
3271 }
3272
3273 if (!device->in_fs_metadata)
3274 continue;
3275
3276 if (device->total_bytes > device->bytes_used)
3277 total_avail = device->total_bytes - device->bytes_used;
3278 else
3279 total_avail = 0;
3280
3281 /* If there is no space on this device, skip it. */
3282 if (total_avail == 0)
3283 continue;
3284
3285 ret = find_free_dev_extent(device,
3286 max_stripe_size * dev_stripes,
3287 &dev_offset, &max_avail);
3288 if (ret && ret != -ENOSPC)
3289 goto error;
3290
3291 if (ret == 0)
3292 max_avail = max_stripe_size * dev_stripes;
3293
3294 if (max_avail < BTRFS_STRIPE_LEN * dev_stripes)
3295 continue;
3296
3297 devices_info[ndevs].dev_offset = dev_offset;
3298 devices_info[ndevs].max_avail = max_avail;
3299 devices_info[ndevs].total_avail = total_avail;
3300 devices_info[ndevs].dev = device;
3301 ++ndevs;
3302 }
3303
3304 /*
3305 * now sort the devices by hole size / available space
3306 */
3307 sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
3308 btrfs_cmp_device_info, NULL);
3309
3310 /* round down to number of usable stripes */
3311 ndevs -= ndevs % devs_increment;
3312
3313 if (ndevs < devs_increment * sub_stripes || ndevs < devs_min) {
3314 ret = -ENOSPC;
3315 goto error;
3316 }
3317
3318 if (devs_max && ndevs > devs_max)
3319 ndevs = devs_max;
3320 /*
3321 * the primary goal is to maximize the number of stripes, so use as many
3322 * devices as possible, even if the stripes are not maximum sized.
3323 */
3324 stripe_size = devices_info[ndevs-1].max_avail;
3325 num_stripes = ndevs * dev_stripes;
3326
3327 if (stripe_size * num_stripes > max_chunk_size * ncopies) {
3328 stripe_size = max_chunk_size * ncopies;
3329 do_div(stripe_size, num_stripes);
3330 }
3331
3332 do_div(stripe_size, dev_stripes);
3333 do_div(stripe_size, BTRFS_STRIPE_LEN);
3334 stripe_size *= BTRFS_STRIPE_LEN;
3335
3336 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
3337 if (!map) {
3338 ret = -ENOMEM;
3339 goto error;
3340 }
3341 map->num_stripes = num_stripes;
3342
3343 for (i = 0; i < ndevs; ++i) {
3344 for (j = 0; j < dev_stripes; ++j) {
3345 int s = i * dev_stripes + j;
3346 map->stripes[s].dev = devices_info[i].dev;
3347 map->stripes[s].physical = devices_info[i].dev_offset +
3348 j * stripe_size;
3349 }
3350 }
3351 map->sector_size = extent_root->sectorsize;
3352 map->stripe_len = BTRFS_STRIPE_LEN;
3353 map->io_align = BTRFS_STRIPE_LEN;
3354 map->io_width = BTRFS_STRIPE_LEN;
3355 map->type = type;
3356 map->sub_stripes = sub_stripes;
3357
3358 *map_ret = map;
3359 num_bytes = stripe_size * (num_stripes / ncopies);
3360
3361 *stripe_size_out = stripe_size;
3362 *num_bytes_out = num_bytes;
3363
3364 trace_btrfs_chunk_alloc(info->chunk_root, map, start, num_bytes);
3365
3366 em = alloc_extent_map();
3367 if (!em) {
3368 ret = -ENOMEM;
3369 goto error;
3370 }
3371 em->bdev = (struct block_device *)map;
3372 em->start = start;
3373 em->len = num_bytes;
3374 em->block_start = 0;
3375 em->block_len = em->len;
3376
3377 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
3378 write_lock(&em_tree->lock);
3379 ret = add_extent_mapping(em_tree, em);
3380 write_unlock(&em_tree->lock);
3381 free_extent_map(em);
3382 if (ret)
3383 goto error;
3384
3385 ret = btrfs_make_block_group(trans, extent_root, 0, type,
3386 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3387 start, num_bytes);
3388 if (ret)
3389 goto error;
3390
3391 for (i = 0; i < map->num_stripes; ++i) {
3392 struct btrfs_device *device;
3393 u64 dev_offset;
3394
3395 device = map->stripes[i].dev;
3396 dev_offset = map->stripes[i].physical;
3397
3398 ret = btrfs_alloc_dev_extent(trans, device,
3399 info->chunk_root->root_key.objectid,
3400 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3401 start, dev_offset, stripe_size);
3402 if (ret) {
3403 btrfs_abort_transaction(trans, extent_root, ret);
3404 goto error;
3405 }
3406 }
3407
3408 kfree(devices_info);
3409 return 0;
3410
3411 error:
3412 kfree(map);
3413 kfree(devices_info);
3414 return ret;
3415 }
3416
3417 static int __finish_chunk_alloc(struct btrfs_trans_handle *trans,
3418 struct btrfs_root *extent_root,
3419 struct map_lookup *map, u64 chunk_offset,
3420 u64 chunk_size, u64 stripe_size)
3421 {
3422 u64 dev_offset;
3423 struct btrfs_key key;
3424 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
3425 struct btrfs_device *device;
3426 struct btrfs_chunk *chunk;
3427 struct btrfs_stripe *stripe;
3428 size_t item_size = btrfs_chunk_item_size(map->num_stripes);
3429 int index = 0;
3430 int ret;
3431
3432 chunk = kzalloc(item_size, GFP_NOFS);
3433 if (!chunk)
3434 return -ENOMEM;
3435
3436 index = 0;
3437 while (index < map->num_stripes) {
3438 device = map->stripes[index].dev;
3439 device->bytes_used += stripe_size;
3440 ret = btrfs_update_device(trans, device);
3441 if (ret)
3442 goto out_free;
3443 index++;
3444 }
3445
3446 spin_lock(&extent_root->fs_info->free_chunk_lock);
3447 extent_root->fs_info->free_chunk_space -= (stripe_size *
3448 map->num_stripes);
3449 spin_unlock(&extent_root->fs_info->free_chunk_lock);
3450
3451 index = 0;
3452 stripe = &chunk->stripe;
3453 while (index < map->num_stripes) {
3454 device = map->stripes[index].dev;
3455 dev_offset = map->stripes[index].physical;
3456
3457 btrfs_set_stack_stripe_devid(stripe, device->devid);
3458 btrfs_set_stack_stripe_offset(stripe, dev_offset);
3459 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
3460 stripe++;
3461 index++;
3462 }
3463
3464 btrfs_set_stack_chunk_length(chunk, chunk_size);
3465 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
3466 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
3467 btrfs_set_stack_chunk_type(chunk, map->type);
3468 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
3469 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
3470 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
3471 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
3472 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
3473
3474 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
3475 key.type = BTRFS_CHUNK_ITEM_KEY;
3476 key.offset = chunk_offset;
3477
3478 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
3479
3480 if (ret == 0 && map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
3481 /*
3482 * TODO: Cleanup of inserted chunk root in case of
3483 * failure.
3484 */
3485 ret = btrfs_add_system_chunk(chunk_root, &key, chunk,
3486 item_size);
3487 }
3488
3489 out_free:
3490 kfree(chunk);
3491 return ret;
3492 }
3493
3494 /*
3495 * Chunk allocation falls into two parts. The first part does works
3496 * that make the new allocated chunk useable, but not do any operation
3497 * that modifies the chunk tree. The second part does the works that
3498 * require modifying the chunk tree. This division is important for the
3499 * bootstrap process of adding storage to a seed btrfs.
3500 */
3501 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
3502 struct btrfs_root *extent_root, u64 type)
3503 {
3504 u64 chunk_offset;
3505 u64 chunk_size;
3506 u64 stripe_size;
3507 struct map_lookup *map;
3508 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
3509 int ret;
3510
3511 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3512 &chunk_offset);
3513 if (ret)
3514 return ret;
3515
3516 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
3517 &stripe_size, chunk_offset, type);
3518 if (ret)
3519 return ret;
3520
3521 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
3522 chunk_size, stripe_size);
3523 if (ret)
3524 return ret;
3525 return 0;
3526 }
3527
3528 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
3529 struct btrfs_root *root,
3530 struct btrfs_device *device)
3531 {
3532 u64 chunk_offset;
3533 u64 sys_chunk_offset;
3534 u64 chunk_size;
3535 u64 sys_chunk_size;
3536 u64 stripe_size;
3537 u64 sys_stripe_size;
3538 u64 alloc_profile;
3539 struct map_lookup *map;
3540 struct map_lookup *sys_map;
3541 struct btrfs_fs_info *fs_info = root->fs_info;
3542 struct btrfs_root *extent_root = fs_info->extent_root;
3543 int ret;
3544
3545 ret = find_next_chunk(fs_info->chunk_root,
3546 BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset);
3547 if (ret)
3548 return ret;
3549
3550 alloc_profile = BTRFS_BLOCK_GROUP_METADATA |
3551 fs_info->avail_metadata_alloc_bits;
3552 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
3553
3554 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
3555 &stripe_size, chunk_offset, alloc_profile);
3556 if (ret)
3557 return ret;
3558
3559 sys_chunk_offset = chunk_offset + chunk_size;
3560
3561 alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM |
3562 fs_info->avail_system_alloc_bits;
3563 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
3564
3565 ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,
3566 &sys_chunk_size, &sys_stripe_size,
3567 sys_chunk_offset, alloc_profile);
3568 if (ret)
3569 goto abort;
3570
3571 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
3572 if (ret)
3573 goto abort;
3574
3575 /*
3576 * Modifying chunk tree needs allocating new blocks from both
3577 * system block group and metadata block group. So we only can
3578 * do operations require modifying the chunk tree after both
3579 * block groups were created.
3580 */
3581 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
3582 chunk_size, stripe_size);
3583 if (ret)
3584 goto abort;
3585
3586 ret = __finish_chunk_alloc(trans, extent_root, sys_map,
3587 sys_chunk_offset, sys_chunk_size,
3588 sys_stripe_size);
3589 if (ret)
3590 goto abort;
3591
3592 return 0;
3593
3594 abort:
3595 btrfs_abort_transaction(trans, root, ret);
3596 return ret;
3597 }
3598
3599 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
3600 {
3601 struct extent_map *em;
3602 struct map_lookup *map;
3603 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
3604 int readonly = 0;
3605 int i;
3606
3607 read_lock(&map_tree->map_tree.lock);
3608 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
3609 read_unlock(&map_tree->map_tree.lock);
3610 if (!em)
3611 return 1;
3612
3613 if (btrfs_test_opt(root, DEGRADED)) {
3614 free_extent_map(em);
3615 return 0;
3616 }
3617
3618 map = (struct map_lookup *)em->bdev;
3619 for (i = 0; i < map->num_stripes; i++) {
3620 if (!map->stripes[i].dev->writeable) {
3621 readonly = 1;
3622 break;
3623 }
3624 }
3625 free_extent_map(em);
3626 return readonly;
3627 }
3628
3629 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
3630 {
3631 extent_map_tree_init(&tree->map_tree);
3632 }
3633
3634 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
3635 {
3636 struct extent_map *em;
3637
3638 while (1) {
3639 write_lock(&tree->map_tree.lock);
3640 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
3641 if (em)
3642 remove_extent_mapping(&tree->map_tree, em);
3643 write_unlock(&tree->map_tree.lock);
3644 if (!em)
3645 break;
3646 kfree(em->bdev);
3647 /* once for us */
3648 free_extent_map(em);
3649 /* once for the tree */
3650 free_extent_map(em);
3651 }
3652 }
3653
3654 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
3655 {
3656 struct extent_map *em;
3657 struct map_lookup *map;
3658 struct extent_map_tree *em_tree = &map_tree->map_tree;
3659 int ret;
3660
3661 read_lock(&em_tree->lock);
3662 em = lookup_extent_mapping(em_tree, logical, len);
3663 read_unlock(&em_tree->lock);
3664 BUG_ON(!em);
3665
3666 BUG_ON(em->start > logical || em->start + em->len < logical);
3667 map = (struct map_lookup *)em->bdev;
3668 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
3669 ret = map->num_stripes;
3670 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
3671 ret = map->sub_stripes;
3672 else
3673 ret = 1;
3674 free_extent_map(em);
3675 return ret;
3676 }
3677
3678 static int find_live_mirror(struct map_lookup *map, int first, int num,
3679 int optimal)
3680 {
3681 int i;
3682 if (map->stripes[optimal].dev->bdev)
3683 return optimal;
3684 for (i = first; i < first + num; i++) {
3685 if (map->stripes[i].dev->bdev)
3686 return i;
3687 }
3688 /* we couldn't find one that doesn't fail. Just return something
3689 * and the io error handling code will clean up eventually
3690 */
3691 return optimal;
3692 }
3693
3694 static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
3695 u64 logical, u64 *length,
3696 struct btrfs_bio **bbio_ret,
3697 int mirror_num)
3698 {
3699 struct extent_map *em;
3700 struct map_lookup *map;
3701 struct extent_map_tree *em_tree = &map_tree->map_tree;
3702 u64 offset;
3703 u64 stripe_offset;
3704 u64 stripe_end_offset;
3705 u64 stripe_nr;
3706 u64 stripe_nr_orig;
3707 u64 stripe_nr_end;
3708 int stripe_index;
3709 int i;
3710 int ret = 0;
3711 int num_stripes;
3712 int max_errors = 0;
3713 struct btrfs_bio *bbio = NULL;
3714
3715 read_lock(&em_tree->lock);
3716 em = lookup_extent_mapping(em_tree, logical, *length);
3717 read_unlock(&em_tree->lock);
3718
3719 if (!em) {
3720 printk(KERN_CRIT "unable to find logical %llu len %llu\n",
3721 (unsigned long long)logical,
3722 (unsigned long long)*length);
3723 BUG();
3724 }
3725
3726 BUG_ON(em->start > logical || em->start + em->len < logical);
3727 map = (struct map_lookup *)em->bdev;
3728 offset = logical - em->start;
3729
3730 if (mirror_num > map->num_stripes)
3731 mirror_num = 0;
3732
3733 stripe_nr = offset;
3734 /*
3735 * stripe_nr counts the total number of stripes we have to stride
3736 * to get to this block
3737 */
3738 do_div(stripe_nr, map->stripe_len);
3739
3740 stripe_offset = stripe_nr * map->stripe_len;
3741 BUG_ON(offset < stripe_offset);
3742
3743 /* stripe_offset is the offset of this block in its stripe*/
3744 stripe_offset = offset - stripe_offset;
3745
3746 if (rw & REQ_DISCARD)
3747 *length = min_t(u64, em->len - offset, *length);
3748 else if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
3749 /* we limit the length of each bio to what fits in a stripe */
3750 *length = min_t(u64, em->len - offset,
3751 map->stripe_len - stripe_offset);
3752 } else {
3753 *length = em->len - offset;
3754 }
3755
3756 if (!bbio_ret)
3757 goto out;
3758
3759 num_stripes = 1;
3760 stripe_index = 0;
3761 stripe_nr_orig = stripe_nr;
3762 stripe_nr_end = (offset + *length + map->stripe_len - 1) &
3763 (~(map->stripe_len - 1));
3764 do_div(stripe_nr_end, map->stripe_len);
3765 stripe_end_offset = stripe_nr_end * map->stripe_len -
3766 (offset + *length);
3767 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3768 if (rw & REQ_DISCARD)
3769 num_stripes = min_t(u64, map->num_stripes,
3770 stripe_nr_end - stripe_nr_orig);
3771 stripe_index = do_div(stripe_nr, map->num_stripes);
3772 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
3773 if (rw & (REQ_WRITE | REQ_DISCARD))
3774 num_stripes = map->num_stripes;
3775 else if (mirror_num)
3776 stripe_index = mirror_num - 1;
3777 else {
3778 stripe_index = find_live_mirror(map, 0,
3779 map->num_stripes,
3780 current->pid % map->num_stripes);
3781 mirror_num = stripe_index + 1;
3782 }
3783
3784 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
3785 if (rw & (REQ_WRITE | REQ_DISCARD)) {
3786 num_stripes = map->num_stripes;
3787 } else if (mirror_num) {
3788 stripe_index = mirror_num - 1;
3789 } else {
3790 mirror_num = 1;
3791 }
3792
3793 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3794 int factor = map->num_stripes / map->sub_stripes;
3795
3796 stripe_index = do_div(stripe_nr, factor);
3797 stripe_index *= map->sub_stripes;
3798
3799 if (rw & REQ_WRITE)
3800 num_stripes = map->sub_stripes;
3801 else if (rw & REQ_DISCARD)
3802 num_stripes = min_t(u64, map->sub_stripes *
3803 (stripe_nr_end - stripe_nr_orig),
3804 map->num_stripes);
3805 else if (mirror_num)
3806 stripe_index += mirror_num - 1;
3807 else {
3808 stripe_index = find_live_mirror(map, stripe_index,
3809 map->sub_stripes, stripe_index +
3810 current->pid % map->sub_stripes);
3811 mirror_num = stripe_index + 1;
3812 }
3813 } else {
3814 /*
3815 * after this do_div call, stripe_nr is the number of stripes
3816 * on this device we have to walk to find the data, and
3817 * stripe_index is the number of our device in the stripe array
3818 */
3819 stripe_index = do_div(stripe_nr, map->num_stripes);
3820 mirror_num = stripe_index + 1;
3821 }
3822 BUG_ON(stripe_index >= map->num_stripes);
3823
3824 bbio = kzalloc(btrfs_bio_size(num_stripes), GFP_NOFS);
3825 if (!bbio) {
3826 ret = -ENOMEM;
3827 goto out;
3828 }
3829 atomic_set(&bbio->error, 0);
3830
3831 if (rw & REQ_DISCARD) {
3832 int factor = 0;
3833 int sub_stripes = 0;
3834 u64 stripes_per_dev = 0;
3835 u32 remaining_stripes = 0;
3836
3837 if (map->type &
3838 (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) {
3839 if (map->type & BTRFS_BLOCK_GROUP_RAID0)
3840 sub_stripes = 1;
3841 else
3842 sub_stripes = map->sub_stripes;
3843
3844 factor = map->num_stripes / sub_stripes;
3845 stripes_per_dev = div_u64_rem(stripe_nr_end -
3846 stripe_nr_orig,
3847 factor,
3848 &remaining_stripes);
3849 }
3850
3851 for (i = 0; i < num_stripes; i++) {
3852 bbio->stripes[i].physical =
3853 map->stripes[stripe_index].physical +
3854 stripe_offset + stripe_nr * map->stripe_len;
3855 bbio->stripes[i].dev = map->stripes[stripe_index].dev;
3856
3857 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
3858 BTRFS_BLOCK_GROUP_RAID10)) {
3859 bbio->stripes[i].length = stripes_per_dev *
3860 map->stripe_len;
3861 if (i / sub_stripes < remaining_stripes)
3862 bbio->stripes[i].length +=
3863 map->stripe_len;
3864 if (i < sub_stripes)
3865 bbio->stripes[i].length -=
3866 stripe_offset;
3867 if ((i / sub_stripes + 1) %
3868 sub_stripes == remaining_stripes)
3869 bbio->stripes[i].length -=
3870 stripe_end_offset;
3871 if (i == sub_stripes - 1)
3872 stripe_offset = 0;
3873 } else
3874 bbio->stripes[i].length = *length;
3875
3876 stripe_index++;
3877 if (stripe_index == map->num_stripes) {
3878 /* This could only happen for RAID0/10 */
3879 stripe_index = 0;
3880 stripe_nr++;
3881 }
3882 }
3883 } else {
3884 for (i = 0; i < num_stripes; i++) {
3885 bbio->stripes[i].physical =
3886 map->stripes[stripe_index].physical +
3887 stripe_offset +
3888 stripe_nr * map->stripe_len;
3889 bbio->stripes[i].dev =
3890 map->stripes[stripe_index].dev;
3891 stripe_index++;
3892 }
3893 }
3894
3895 if (rw & REQ_WRITE) {
3896 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
3897 BTRFS_BLOCK_GROUP_RAID10 |
3898 BTRFS_BLOCK_GROUP_DUP)) {
3899 max_errors = 1;
3900 }
3901 }
3902
3903 *bbio_ret = bbio;
3904 bbio->num_stripes = num_stripes;
3905 bbio->max_errors = max_errors;
3906 bbio->mirror_num = mirror_num;
3907 out:
3908 free_extent_map(em);
3909 return ret;
3910 }
3911
3912 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
3913 u64 logical, u64 *length,
3914 struct btrfs_bio **bbio_ret, int mirror_num)
3915 {
3916 return __btrfs_map_block(map_tree, rw, logical, length, bbio_ret,
3917 mirror_num);
3918 }
3919
3920 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
3921 u64 chunk_start, u64 physical, u64 devid,
3922 u64 **logical, int *naddrs, int *stripe_len)
3923 {
3924 struct extent_map_tree *em_tree = &map_tree->map_tree;
3925 struct extent_map *em;
3926 struct map_lookup *map;
3927 u64 *buf;
3928 u64 bytenr;
3929 u64 length;
3930 u64 stripe_nr;
3931 int i, j, nr = 0;
3932
3933 read_lock(&em_tree->lock);
3934 em = lookup_extent_mapping(em_tree, chunk_start, 1);
3935 read_unlock(&em_tree->lock);
3936
3937 BUG_ON(!em || em->start != chunk_start);
3938 map = (struct map_lookup *)em->bdev;
3939
3940 length = em->len;
3941 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
3942 do_div(length, map->num_stripes / map->sub_stripes);
3943 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
3944 do_div(length, map->num_stripes);
3945
3946 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
3947 BUG_ON(!buf); /* -ENOMEM */
3948
3949 for (i = 0; i < map->num_stripes; i++) {
3950 if (devid && map->stripes[i].dev->devid != devid)
3951 continue;
3952 if (map->stripes[i].physical > physical ||
3953 map->stripes[i].physical + length <= physical)
3954 continue;
3955
3956 stripe_nr = physical - map->stripes[i].physical;
3957 do_div(stripe_nr, map->stripe_len);
3958
3959 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3960 stripe_nr = stripe_nr * map->num_stripes + i;
3961 do_div(stripe_nr, map->sub_stripes);
3962 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3963 stripe_nr = stripe_nr * map->num_stripes + i;
3964 }
3965 bytenr = chunk_start + stripe_nr * map->stripe_len;
3966 WARN_ON(nr >= map->num_stripes);
3967 for (j = 0; j < nr; j++) {
3968 if (buf[j] == bytenr)
3969 break;
3970 }
3971 if (j == nr) {
3972 WARN_ON(nr >= map->num_stripes);
3973 buf[nr++] = bytenr;
3974 }
3975 }
3976
3977 *logical = buf;
3978 *naddrs = nr;
3979 *stripe_len = map->stripe_len;
3980
3981 free_extent_map(em);
3982 return 0;
3983 }
3984
3985 static void btrfs_end_bio(struct bio *bio, int err)
3986 {
3987 struct btrfs_bio *bbio = bio->bi_private;
3988 int is_orig_bio = 0;
3989
3990 if (err)
3991 atomic_inc(&bbio->error);
3992
3993 if (bio == bbio->orig_bio)
3994 is_orig_bio = 1;
3995
3996 if (atomic_dec_and_test(&bbio->stripes_pending)) {
3997 if (!is_orig_bio) {
3998 bio_put(bio);
3999 bio = bbio->orig_bio;
4000 }
4001 bio->bi_private = bbio->private;
4002 bio->bi_end_io = bbio->end_io;
4003 bio->bi_bdev = (struct block_device *)
4004 (unsigned long)bbio->mirror_num;
4005 /* only send an error to the higher layers if it is
4006 * beyond the tolerance of the multi-bio
4007 */
4008 if (atomic_read(&bbio->error) > bbio->max_errors) {
4009 err = -EIO;
4010 } else {
4011 /*
4012 * this bio is actually up to date, we didn't
4013 * go over the max number of errors
4014 */
4015 set_bit(BIO_UPTODATE, &bio->bi_flags);
4016 err = 0;
4017 }
4018 kfree(bbio);
4019
4020 bio_endio(bio, err);
4021 } else if (!is_orig_bio) {
4022 bio_put(bio);
4023 }
4024 }
4025
4026 struct async_sched {
4027 struct bio *bio;
4028 int rw;
4029 struct btrfs_fs_info *info;
4030 struct btrfs_work work;
4031 };
4032
4033 /*
4034 * see run_scheduled_bios for a description of why bios are collected for
4035 * async submit.
4036 *
4037 * This will add one bio to the pending list for a device and make sure
4038 * the work struct is scheduled.
4039 */
4040 static noinline void schedule_bio(struct btrfs_root *root,
4041 struct btrfs_device *device,
4042 int rw, struct bio *bio)
4043 {
4044 int should_queue = 1;
4045 struct btrfs_pending_bios *pending_bios;
4046
4047 /* don't bother with additional async steps for reads, right now */
4048 if (!(rw & REQ_WRITE)) {
4049 bio_get(bio);
4050 btrfsic_submit_bio(rw, bio);
4051 bio_put(bio);
4052 return;
4053 }
4054
4055 /*
4056 * nr_async_bios allows us to reliably return congestion to the
4057 * higher layers. Otherwise, the async bio makes it appear we have
4058 * made progress against dirty pages when we've really just put it
4059 * on a queue for later
4060 */
4061 atomic_inc(&root->fs_info->nr_async_bios);
4062 WARN_ON(bio->bi_next);
4063 bio->bi_next = NULL;
4064 bio->bi_rw |= rw;
4065
4066 spin_lock(&device->io_lock);
4067 if (bio->bi_rw & REQ_SYNC)
4068 pending_bios = &device->pending_sync_bios;
4069 else
4070 pending_bios = &device->pending_bios;
4071
4072 if (pending_bios->tail)
4073 pending_bios->tail->bi_next = bio;
4074
4075 pending_bios->tail = bio;
4076 if (!pending_bios->head)
4077 pending_bios->head = bio;
4078 if (device->running_pending)
4079 should_queue = 0;
4080
4081 spin_unlock(&device->io_lock);
4082
4083 if (should_queue)
4084 btrfs_queue_worker(&root->fs_info->submit_workers,
4085 &device->work);
4086 }
4087
4088 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
4089 int mirror_num, int async_submit)
4090 {
4091 struct btrfs_mapping_tree *map_tree;
4092 struct btrfs_device *dev;
4093 struct bio *first_bio = bio;
4094 u64 logical = (u64)bio->bi_sector << 9;
4095 u64 length = 0;
4096 u64 map_length;
4097 int ret;
4098 int dev_nr = 0;
4099 int total_devs = 1;
4100 struct btrfs_bio *bbio = NULL;
4101
4102 length = bio->bi_size;
4103 map_tree = &root->fs_info->mapping_tree;
4104 map_length = length;
4105
4106 ret = btrfs_map_block(map_tree, rw, logical, &map_length, &bbio,
4107 mirror_num);
4108 if (ret) /* -ENOMEM */
4109 return ret;
4110
4111 total_devs = bbio->num_stripes;
4112 if (map_length < length) {
4113 printk(KERN_CRIT "mapping failed logical %llu bio len %llu "
4114 "len %llu\n", (unsigned long long)logical,
4115 (unsigned long long)length,
4116 (unsigned long long)map_length);
4117 BUG();
4118 }
4119
4120 bbio->orig_bio = first_bio;
4121 bbio->private = first_bio->bi_private;
4122 bbio->end_io = first_bio->bi_end_io;
4123 atomic_set(&bbio->stripes_pending, bbio->num_stripes);
4124
4125 while (dev_nr < total_devs) {
4126 if (dev_nr < total_devs - 1) {
4127 bio = bio_clone(first_bio, GFP_NOFS);
4128 BUG_ON(!bio); /* -ENOMEM */
4129 } else {
4130 bio = first_bio;
4131 }
4132 bio->bi_private = bbio;
4133 bio->bi_end_io = btrfs_end_bio;
4134 bio->bi_sector = bbio->stripes[dev_nr].physical >> 9;
4135 dev = bbio->stripes[dev_nr].dev;
4136 if (dev && dev->bdev && (rw != WRITE || dev->writeable)) {
4137 pr_debug("btrfs_map_bio: rw %d, secor=%llu, dev=%lu "
4138 "(%s id %llu), size=%u\n", rw,
4139 (u64)bio->bi_sector, (u_long)dev->bdev->bd_dev,
4140 dev->name, dev->devid, bio->bi_size);
4141 bio->bi_bdev = dev->bdev;
4142 if (async_submit)
4143 schedule_bio(root, dev, rw, bio);
4144 else
4145 btrfsic_submit_bio(rw, bio);
4146 } else {
4147 bio->bi_bdev = root->fs_info->fs_devices->latest_bdev;
4148 bio->bi_sector = logical >> 9;
4149 bio_endio(bio, -EIO);
4150 }
4151 dev_nr++;
4152 }
4153 return 0;
4154 }
4155
4156 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
4157 u8 *uuid, u8 *fsid)
4158 {
4159 struct btrfs_device *device;
4160 struct btrfs_fs_devices *cur_devices;
4161
4162 cur_devices = root->fs_info->fs_devices;
4163 while (cur_devices) {
4164 if (!fsid ||
4165 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
4166 device = __find_device(&cur_devices->devices,
4167 devid, uuid);
4168 if (device)
4169 return device;
4170 }
4171 cur_devices = cur_devices->seed;
4172 }
4173 return NULL;
4174 }
4175
4176 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
4177 u64 devid, u8 *dev_uuid)
4178 {
4179 struct btrfs_device *device;
4180 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
4181
4182 device = kzalloc(sizeof(*device), GFP_NOFS);
4183 if (!device)
4184 return NULL;
4185 list_add(&device->dev_list,
4186 &fs_devices->devices);
4187 device->dev_root = root->fs_info->dev_root;
4188 device->devid = devid;
4189 device->work.func = pending_bios_fn;
4190 device->fs_devices = fs_devices;
4191 device->missing = 1;
4192 fs_devices->num_devices++;
4193 fs_devices->missing_devices++;
4194 spin_lock_init(&device->io_lock);
4195 INIT_LIST_HEAD(&device->dev_alloc_list);
4196 memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
4197 return device;
4198 }
4199
4200 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
4201 struct extent_buffer *leaf,
4202 struct btrfs_chunk *chunk)
4203 {
4204 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
4205 struct map_lookup *map;
4206 struct extent_map *em;
4207 u64 logical;
4208 u64 length;
4209 u64 devid;
4210 u8 uuid[BTRFS_UUID_SIZE];
4211 int num_stripes;
4212 int ret;
4213 int i;
4214
4215 logical = key->offset;
4216 length = btrfs_chunk_length(leaf, chunk);
4217
4218 read_lock(&map_tree->map_tree.lock);
4219 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
4220 read_unlock(&map_tree->map_tree.lock);
4221
4222 /* already mapped? */
4223 if (em && em->start <= logical && em->start + em->len > logical) {
4224 free_extent_map(em);
4225 return 0;
4226 } else if (em) {
4227 free_extent_map(em);
4228 }
4229
4230 em = alloc_extent_map();
4231 if (!em)
4232 return -ENOMEM;
4233 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
4234 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
4235 if (!map) {
4236 free_extent_map(em);
4237 return -ENOMEM;
4238 }
4239
4240 em->bdev = (struct block_device *)map;
4241 em->start = logical;
4242 em->len = length;
4243 em->block_start = 0;
4244 em->block_len = em->len;
4245
4246 map->num_stripes = num_stripes;
4247 map->io_width = btrfs_chunk_io_width(leaf, chunk);
4248 map->io_align = btrfs_chunk_io_align(leaf, chunk);
4249 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
4250 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
4251 map->type = btrfs_chunk_type(leaf, chunk);
4252 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
4253 for (i = 0; i < num_stripes; i++) {
4254 map->stripes[i].physical =
4255 btrfs_stripe_offset_nr(leaf, chunk, i);
4256 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
4257 read_extent_buffer(leaf, uuid, (unsigned long)
4258 btrfs_stripe_dev_uuid_nr(chunk, i),
4259 BTRFS_UUID_SIZE);
4260 map->stripes[i].dev = btrfs_find_device(root, devid, uuid,
4261 NULL);
4262 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
4263 kfree(map);
4264 free_extent_map(em);
4265 return -EIO;
4266 }
4267 if (!map->stripes[i].dev) {
4268 map->stripes[i].dev =
4269 add_missing_dev(root, devid, uuid);
4270 if (!map->stripes[i].dev) {
4271 kfree(map);
4272 free_extent_map(em);
4273 return -EIO;
4274 }
4275 }
4276 map->stripes[i].dev->in_fs_metadata = 1;
4277 }
4278
4279 write_lock(&map_tree->map_tree.lock);
4280 ret = add_extent_mapping(&map_tree->map_tree, em);
4281 write_unlock(&map_tree->map_tree.lock);
4282 BUG_ON(ret); /* Tree corruption */
4283 free_extent_map(em);
4284
4285 return 0;
4286 }
4287
4288 static void fill_device_from_item(struct extent_buffer *leaf,
4289 struct btrfs_dev_item *dev_item,
4290 struct btrfs_device *device)
4291 {
4292 unsigned long ptr;
4293
4294 device->devid = btrfs_device_id(leaf, dev_item);
4295 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
4296 device->total_bytes = device->disk_total_bytes;
4297 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
4298 device->type = btrfs_device_type(leaf, dev_item);
4299 device->io_align = btrfs_device_io_align(leaf, dev_item);
4300 device->io_width = btrfs_device_io_width(leaf, dev_item);
4301 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
4302
4303 ptr = (unsigned long)btrfs_device_uuid(dev_item);
4304 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
4305 }
4306
4307 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
4308 {
4309 struct btrfs_fs_devices *fs_devices;
4310 int ret;
4311
4312 BUG_ON(!mutex_is_locked(&uuid_mutex));
4313
4314 fs_devices = root->fs_info->fs_devices->seed;
4315 while (fs_devices) {
4316 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
4317 ret = 0;
4318 goto out;
4319 }
4320 fs_devices = fs_devices->seed;
4321 }
4322
4323 fs_devices = find_fsid(fsid);
4324 if (!fs_devices) {
4325 ret = -ENOENT;
4326 goto out;
4327 }
4328
4329 fs_devices = clone_fs_devices(fs_devices);
4330 if (IS_ERR(fs_devices)) {
4331 ret = PTR_ERR(fs_devices);
4332 goto out;
4333 }
4334
4335 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
4336 root->fs_info->bdev_holder);
4337 if (ret)
4338 goto out;
4339
4340 if (!fs_devices->seeding) {
4341 __btrfs_close_devices(fs_devices);
4342 free_fs_devices(fs_devices);
4343 ret = -EINVAL;
4344 goto out;
4345 }
4346
4347 fs_devices->seed = root->fs_info->fs_devices->seed;
4348 root->fs_info->fs_devices->seed = fs_devices;
4349 out:
4350 return ret;
4351 }
4352
4353 static int read_one_dev(struct btrfs_root *root,
4354 struct extent_buffer *leaf,
4355 struct btrfs_dev_item *dev_item)
4356 {
4357 struct btrfs_device *device;
4358 u64 devid;
4359 int ret;
4360 u8 fs_uuid[BTRFS_UUID_SIZE];
4361 u8 dev_uuid[BTRFS_UUID_SIZE];
4362
4363 devid = btrfs_device_id(leaf, dev_item);
4364 read_extent_buffer(leaf, dev_uuid,
4365 (unsigned long)btrfs_device_uuid(dev_item),
4366 BTRFS_UUID_SIZE);
4367 read_extent_buffer(leaf, fs_uuid,
4368 (unsigned long)btrfs_device_fsid(dev_item),
4369 BTRFS_UUID_SIZE);
4370
4371 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
4372 ret = open_seed_devices(root, fs_uuid);
4373 if (ret && !btrfs_test_opt(root, DEGRADED))
4374 return ret;
4375 }
4376
4377 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
4378 if (!device || !device->bdev) {
4379 if (!btrfs_test_opt(root, DEGRADED))
4380 return -EIO;
4381
4382 if (!device) {
4383 printk(KERN_WARNING "warning devid %llu missing\n",
4384 (unsigned long long)devid);
4385 device = add_missing_dev(root, devid, dev_uuid);
4386 if (!device)
4387 return -ENOMEM;
4388 } else if (!device->missing) {
4389 /*
4390 * this happens when a device that was properly setup
4391 * in the device info lists suddenly goes bad.
4392 * device->bdev is NULL, and so we have to set
4393 * device->missing to one here
4394 */
4395 root->fs_info->fs_devices->missing_devices++;
4396 device->missing = 1;
4397 }
4398 }
4399
4400 if (device->fs_devices != root->fs_info->fs_devices) {
4401 BUG_ON(device->writeable);
4402 if (device->generation !=
4403 btrfs_device_generation(leaf, dev_item))
4404 return -EINVAL;
4405 }
4406
4407 fill_device_from_item(leaf, dev_item, device);
4408 device->dev_root = root->fs_info->dev_root;
4409 device->in_fs_metadata = 1;
4410 if (device->writeable) {
4411 device->fs_devices->total_rw_bytes += device->total_bytes;
4412 spin_lock(&root->fs_info->free_chunk_lock);
4413 root->fs_info->free_chunk_space += device->total_bytes -
4414 device->bytes_used;
4415 spin_unlock(&root->fs_info->free_chunk_lock);
4416 }
4417 ret = 0;
4418 return ret;
4419 }
4420
4421 int btrfs_read_sys_array(struct btrfs_root *root)
4422 {
4423 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
4424 struct extent_buffer *sb;
4425 struct btrfs_disk_key *disk_key;
4426 struct btrfs_chunk *chunk;
4427 u8 *ptr;
4428 unsigned long sb_ptr;
4429 int ret = 0;
4430 u32 num_stripes;
4431 u32 array_size;
4432 u32 len = 0;
4433 u32 cur;
4434 struct btrfs_key key;
4435
4436 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
4437 BTRFS_SUPER_INFO_SIZE);
4438 if (!sb)
4439 return -ENOMEM;
4440 btrfs_set_buffer_uptodate(sb);
4441 btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0);
4442 /*
4443 * The sb extent buffer is artifical and just used to read the system array.
4444 * btrfs_set_buffer_uptodate() call does not properly mark all it's
4445 * pages up-to-date when the page is larger: extent does not cover the
4446 * whole page and consequently check_page_uptodate does not find all
4447 * the page's extents up-to-date (the hole beyond sb),
4448 * write_extent_buffer then triggers a WARN_ON.
4449 *
4450 * Regular short extents go through mark_extent_buffer_dirty/writeback cycle,
4451 * but sb spans only this function. Add an explicit SetPageUptodate call
4452 * to silence the warning eg. on PowerPC 64.
4453 */
4454 if (PAGE_CACHE_SIZE > BTRFS_SUPER_INFO_SIZE)
4455 SetPageUptodate(sb->pages[0]);
4456
4457 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
4458 array_size = btrfs_super_sys_array_size(super_copy);
4459
4460 ptr = super_copy->sys_chunk_array;
4461 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
4462 cur = 0;
4463
4464 while (cur < array_size) {
4465 disk_key = (struct btrfs_disk_key *)ptr;
4466 btrfs_disk_key_to_cpu(&key, disk_key);
4467
4468 len = sizeof(*disk_key); ptr += len;
4469 sb_ptr += len;
4470 cur += len;
4471
4472 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
4473 chunk = (struct btrfs_chunk *)sb_ptr;
4474 ret = read_one_chunk(root, &key, sb, chunk);
4475 if (ret)
4476 break;
4477 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
4478 len = btrfs_chunk_item_size(num_stripes);
4479 } else {
4480 ret = -EIO;
4481 break;
4482 }
4483 ptr += len;
4484 sb_ptr += len;
4485 cur += len;
4486 }
4487 free_extent_buffer(sb);
4488 return ret;
4489 }
4490
4491 int btrfs_read_chunk_tree(struct btrfs_root *root)
4492 {
4493 struct btrfs_path *path;
4494 struct extent_buffer *leaf;
4495 struct btrfs_key key;
4496 struct btrfs_key found_key;
4497 int ret;
4498 int slot;
4499
4500 root = root->fs_info->chunk_root;
4501
4502 path = btrfs_alloc_path();
4503 if (!path)
4504 return -ENOMEM;
4505
4506 mutex_lock(&uuid_mutex);
4507 lock_chunks(root);
4508
4509 /* first we search for all of the device items, and then we
4510 * read in all of the chunk items. This way we can create chunk
4511 * mappings that reference all of the devices that are afound
4512 */
4513 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
4514 key.offset = 0;
4515 key.type = 0;
4516 again:
4517 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4518 if (ret < 0)
4519 goto error;
4520 while (1) {
4521 leaf = path->nodes[0];
4522 slot = path->slots[0];
4523 if (slot >= btrfs_header_nritems(leaf)) {
4524 ret = btrfs_next_leaf(root, path);
4525 if (ret == 0)
4526 continue;
4527 if (ret < 0)
4528 goto error;
4529 break;
4530 }
4531 btrfs_item_key_to_cpu(leaf, &found_key, slot);
4532 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
4533 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
4534 break;
4535 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
4536 struct btrfs_dev_item *dev_item;
4537 dev_item = btrfs_item_ptr(leaf, slot,
4538 struct btrfs_dev_item);
4539 ret = read_one_dev(root, leaf, dev_item);
4540 if (ret)
4541 goto error;
4542 }
4543 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
4544 struct btrfs_chunk *chunk;
4545 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
4546 ret = read_one_chunk(root, &found_key, leaf, chunk);
4547 if (ret)
4548 goto error;
4549 }
4550 path->slots[0]++;
4551 }
4552 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
4553 key.objectid = 0;
4554 btrfs_release_path(path);
4555 goto again;
4556 }
4557 ret = 0;
4558 error:
4559 unlock_chunks(root);
4560 mutex_unlock(&uuid_mutex);
4561
4562 btrfs_free_path(path);
4563 return ret;
4564 }
Linux kernel - Deliverables
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