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Linux 3.2.58
[linux/fpc-iii.git] / fs / btrfs / volumes.c
blob9899205bc430d716f1ab008b6839d63f2d481d5c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18 #include <linux/sched.h>
19 #include <linux/bio.h>
20 #include <linux/slab.h>
21 #include <linux/buffer_head.h>
22 #include <linux/blkdev.h>
23 #include <linux/random.h>
24 #include <linux/iocontext.h>
25 #include <linux/capability.h>
26 #include <asm/div64.h>
27 #include "compat.h"
28 #include "ctree.h"
29 #include "extent_map.h"
30 #include "disk-io.h"
31 #include "transaction.h"
32 #include "print-tree.h"
33 #include "volumes.h"
34 #include "async-thread.h"
35
36 static int init_first_rw_device(struct btrfs_trans_handle *trans,
37 struct btrfs_root *root,
38 struct btrfs_device *device);
39 static int btrfs_relocate_sys_chunks(struct btrfs_root *root);
40
41 static DEFINE_MUTEX(uuid_mutex);
42 static LIST_HEAD(fs_uuids);
43
44 static void lock_chunks(struct btrfs_root *root)
45 {
46 mutex_lock(&root->fs_info->chunk_mutex);
47 }
48
49 static void unlock_chunks(struct btrfs_root *root)
50 {
51 mutex_unlock(&root->fs_info->chunk_mutex);
52 }
53
54 static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
55 {
56 struct btrfs_device *device;
57 WARN_ON(fs_devices->opened);
58 while (!list_empty(&fs_devices->devices)) {
59 device = list_entry(fs_devices->devices.next,
60 struct btrfs_device, dev_list);
61 list_del(&device->dev_list);
62 kfree(device->name);
63 kfree(device);
64 }
65 kfree(fs_devices);
66 }
67
68 int btrfs_cleanup_fs_uuids(void)
69 {
70 struct btrfs_fs_devices *fs_devices;
71
72 while (!list_empty(&fs_uuids)) {
73 fs_devices = list_entry(fs_uuids.next,
74 struct btrfs_fs_devices, list);
75 list_del(&fs_devices->list);
76 free_fs_devices(fs_devices);
77 }
78 return 0;
79 }
80
81 static noinline struct btrfs_device *__find_device(struct list_head *head,
82 u64 devid, u8 *uuid)
83 {
84 struct btrfs_device *dev;
85
86 list_for_each_entry(dev, head, dev_list) {
87 if (dev->devid == devid &&
88 (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
89 return dev;
90 }
91 }
92 return NULL;
93 }
94
95 static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
96 {
97 struct btrfs_fs_devices *fs_devices;
98
99 list_for_each_entry(fs_devices, &fs_uuids, list) {
100 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
101 return fs_devices;
102 }
103 return NULL;
104 }
105
106 static void requeue_list(struct btrfs_pending_bios *pending_bios,
107 struct bio *head, struct bio *tail)
108 {
109
110 struct bio *old_head;
111
112 old_head = pending_bios->head;
113 pending_bios->head = head;
114 if (pending_bios->tail)
115 tail->bi_next = old_head;
116 else
117 pending_bios->tail = tail;
118 }
119
120 /*
121 * we try to collect pending bios for a device so we don't get a large
122 * number of procs sending bios down to the same device. This greatly
123 * improves the schedulers ability to collect and merge the bios.
124 *
125 * But, it also turns into a long list of bios to process and that is sure
126 * to eventually make the worker thread block. The solution here is to
127 * make some progress and then put this work struct back at the end of
128 * the list if the block device is congested. This way, multiple devices
129 * can make progress from a single worker thread.
130 */
131 static noinline int run_scheduled_bios(struct btrfs_device *device)
132 {
133 struct bio *pending;
134 struct backing_dev_info *bdi;
135 struct btrfs_fs_info *fs_info;
136 struct btrfs_pending_bios *pending_bios;
137 struct bio *tail;
138 struct bio *cur;
139 int again = 0;
140 unsigned long num_run;
141 unsigned long batch_run = 0;
142 unsigned long limit;
143 unsigned long last_waited = 0;
144 int force_reg = 0;
145 int sync_pending = 0;
146 struct blk_plug plug;
147
148 /*
149 * this function runs all the bios we've collected for
150 * a particular device. We don't want to wander off to
151 * another device without first sending all of these down.
152 * So, setup a plug here and finish it off before we return
153 */
154 blk_start_plug(&plug);
155
156 bdi = blk_get_backing_dev_info(device->bdev);
157 fs_info = device->dev_root->fs_info;
158 limit = btrfs_async_submit_limit(fs_info);
159 limit = limit * 2 / 3;
160
161 loop:
162 spin_lock(&device->io_lock);
163
164 loop_lock:
165 num_run = 0;
166
167 /* take all the bios off the list at once and process them
168 * later on (without the lock held). But, remember the
169 * tail and other pointers so the bios can be properly reinserted
170 * into the list if we hit congestion
171 */
172 if (!force_reg && device->pending_sync_bios.head) {
173 pending_bios = &device->pending_sync_bios;
174 force_reg = 1;
175 } else {
176 pending_bios = &device->pending_bios;
177 force_reg = 0;
178 }
179
180 pending = pending_bios->head;
181 tail = pending_bios->tail;
182 WARN_ON(pending && !tail);
183
184 /*
185 * if pending was null this time around, no bios need processing
186 * at all and we can stop. Otherwise it'll loop back up again
187 * and do an additional check so no bios are missed.
188 *
189 * device->running_pending is used to synchronize with the
190 * schedule_bio code.
191 */
192 if (device->pending_sync_bios.head == NULL &&
193 device->pending_bios.head == NULL) {
194 again = 0;
195 device->running_pending = 0;
196 } else {
197 again = 1;
198 device->running_pending = 1;
199 }
200
201 pending_bios->head = NULL;
202 pending_bios->tail = NULL;
203
204 spin_unlock(&device->io_lock);
205
206 while (pending) {
207
208 rmb();
209 /* we want to work on both lists, but do more bios on the
210 * sync list than the regular list
211 */
212 if ((num_run > 32 &&
213 pending_bios != &device->pending_sync_bios &&
214 device->pending_sync_bios.head) ||
215 (num_run > 64 && pending_bios == &device->pending_sync_bios &&
216 device->pending_bios.head)) {
217 spin_lock(&device->io_lock);
218 requeue_list(pending_bios, pending, tail);
219 goto loop_lock;
220 }
221
222 cur = pending;
223 pending = pending->bi_next;
224 cur->bi_next = NULL;
225 atomic_dec(&fs_info->nr_async_bios);
226
227 if (atomic_read(&fs_info->nr_async_bios) < limit &&
228 waitqueue_active(&fs_info->async_submit_wait))
229 wake_up(&fs_info->async_submit_wait);
230
231 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
232
233 /*
234 * if we're doing the sync list, record that our
235 * plug has some sync requests on it
236 *
237 * If we're doing the regular list and there are
238 * sync requests sitting around, unplug before
239 * we add more
240 */
241 if (pending_bios == &device->pending_sync_bios) {
242 sync_pending = 1;
243 } else if (sync_pending) {
244 blk_finish_plug(&plug);
245 blk_start_plug(&plug);
246 sync_pending = 0;
247 }
248
249 submit_bio(cur->bi_rw, cur);
250 num_run++;
251 batch_run++;
252 if (need_resched())
253 cond_resched();
254
255 /*
256 * we made progress, there is more work to do and the bdi
257 * is now congested. Back off and let other work structs
258 * run instead
259 */
260 if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
261 fs_info->fs_devices->open_devices > 1) {
262 struct io_context *ioc;
263
264 ioc = current->io_context;
265
266 /*
267 * the main goal here is that we don't want to
268 * block if we're going to be able to submit
269 * more requests without blocking.
270 *
271 * This code does two great things, it pokes into
272 * the elevator code from a filesystem _and_
273 * it makes assumptions about how batching works.
274 */
275 if (ioc && ioc->nr_batch_requests > 0 &&
276 time_before(jiffies, ioc->last_waited + HZ/50UL) &&
277 (last_waited == 0 ||
278 ioc->last_waited == last_waited)) {
279 /*
280 * we want to go through our batch of
281 * requests and stop. So, we copy out
282 * the ioc->last_waited time and test
283 * against it before looping
284 */
285 last_waited = ioc->last_waited;
286 if (need_resched())
287 cond_resched();
288 continue;
289 }
290 spin_lock(&device->io_lock);
291 requeue_list(pending_bios, pending, tail);
292 device->running_pending = 1;
293
294 spin_unlock(&device->io_lock);
295 btrfs_requeue_work(&device->work);
296 goto done;
297 }
298 /* unplug every 64 requests just for good measure */
299 if (batch_run % 64 == 0) {
300 blk_finish_plug(&plug);
301 blk_start_plug(&plug);
302 sync_pending = 0;
303 }
304 }
305
306 cond_resched();
307 if (again)
308 goto loop;
309
310 spin_lock(&device->io_lock);
311 if (device->pending_bios.head || device->pending_sync_bios.head)
312 goto loop_lock;
313 spin_unlock(&device->io_lock);
314
315 done:
316 blk_finish_plug(&plug);
317 return 0;
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 int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
457 {
458 struct btrfs_device *device, *next;
459
460 mutex_lock(&uuid_mutex);
461 again:
462 /* This is the initialized path, it is safe to release the devices. */
463 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
464 if (device->in_fs_metadata)
465 continue;
466
467 if (device->bdev) {
468 blkdev_put(device->bdev, device->mode);
469 device->bdev = NULL;
470 fs_devices->open_devices--;
471 }
472 if (device->writeable) {
473 list_del_init(&device->dev_alloc_list);
474 device->writeable = 0;
475 fs_devices->rw_devices--;
476 }
477 list_del_init(&device->dev_list);
478 fs_devices->num_devices--;
479 kfree(device->name);
480 kfree(device);
481 }
482
483 if (fs_devices->seed) {
484 fs_devices = fs_devices->seed;
485 goto again;
486 }
487
488 mutex_unlock(&uuid_mutex);
489 return 0;
490 }
491
492 static void __free_device(struct work_struct *work)
493 {
494 struct btrfs_device *device;
495
496 device = container_of(work, struct btrfs_device, rcu_work);
497
498 if (device->bdev)
499 blkdev_put(device->bdev, device->mode);
500
501 kfree(device->name);
502 kfree(device);
503 }
504
505 static void free_device(struct rcu_head *head)
506 {
507 struct btrfs_device *device;
508
509 device = container_of(head, struct btrfs_device, rcu);
510
511 INIT_WORK(&device->rcu_work, __free_device);
512 schedule_work(&device->rcu_work);
513 }
514
515 static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
516 {
517 struct btrfs_device *device;
518
519 if (--fs_devices->opened > 0)
520 return 0;
521
522 mutex_lock(&fs_devices->device_list_mutex);
523 list_for_each_entry(device, &fs_devices->devices, dev_list) {
524 struct btrfs_device *new_device;
525
526 if (device->bdev)
527 fs_devices->open_devices--;
528
529 if (device->writeable) {
530 list_del_init(&device->dev_alloc_list);
531 fs_devices->rw_devices--;
532 }
533
534 if (device->can_discard)
535 fs_devices->num_can_discard--;
536
537 new_device = kmalloc(sizeof(*new_device), GFP_NOFS);
538 BUG_ON(!new_device);
539 memcpy(new_device, device, sizeof(*new_device));
540 new_device->name = kstrdup(device->name, GFP_NOFS);
541 BUG_ON(device->name && !new_device->name);
542 new_device->bdev = NULL;
543 new_device->writeable = 0;
544 new_device->in_fs_metadata = 0;
545 new_device->can_discard = 0;
546 spin_lock_init(&new_device->io_lock);
547 list_replace_rcu(&device->dev_list, &new_device->dev_list);
548
549 call_rcu(&device->rcu, free_device);
550 }
551 mutex_unlock(&fs_devices->device_list_mutex);
552
553 WARN_ON(fs_devices->open_devices);
554 WARN_ON(fs_devices->rw_devices);
555 fs_devices->opened = 0;
556 fs_devices->seeding = 0;
557
558 return 0;
559 }
560
561 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
562 {
563 struct btrfs_fs_devices *seed_devices = NULL;
564 int ret;
565
566 mutex_lock(&uuid_mutex);
567 ret = __btrfs_close_devices(fs_devices);
568 if (!fs_devices->opened) {
569 seed_devices = fs_devices->seed;
570 fs_devices->seed = NULL;
571 }
572 mutex_unlock(&uuid_mutex);
573
574 while (seed_devices) {
575 fs_devices = seed_devices;
576 seed_devices = fs_devices->seed;
577 __btrfs_close_devices(fs_devices);
578 free_fs_devices(fs_devices);
579 }
580 /*
581 * Wait for rcu kworkers under __btrfs_close_devices
582 * to finish all blkdev_puts so device is really
583 * free when umount is done.
584 */
585 rcu_barrier();
586 return ret;
587 }
588
589 static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
590 fmode_t flags, void *holder)
591 {
592 struct request_queue *q;
593 struct block_device *bdev;
594 struct list_head *head = &fs_devices->devices;
595 struct btrfs_device *device;
596 struct block_device *latest_bdev = NULL;
597 struct buffer_head *bh;
598 struct btrfs_super_block *disk_super;
599 u64 latest_devid = 0;
600 u64 latest_transid = 0;
601 u64 devid;
602 int seeding = 1;
603 int ret = 0;
604
605 flags |= FMODE_EXCL;
606
607 list_for_each_entry(device, head, dev_list) {
608 if (device->bdev)
609 continue;
610 if (!device->name)
611 continue;
612
613 bdev = blkdev_get_by_path(device->name, flags, holder);
614 if (IS_ERR(bdev)) {
615 printk(KERN_INFO "open %s failed\n", device->name);
616 goto error;
617 }
618 set_blocksize(bdev, 4096);
619
620 bh = btrfs_read_dev_super(bdev);
621 if (!bh)
622 goto error_close;
623
624 disk_super = (struct btrfs_super_block *)bh->b_data;
625 devid = btrfs_stack_device_id(&disk_super->dev_item);
626 if (devid != device->devid)
627 goto error_brelse;
628
629 if (memcmp(device->uuid, disk_super->dev_item.uuid,
630 BTRFS_UUID_SIZE))
631 goto error_brelse;
632
633 device->generation = btrfs_super_generation(disk_super);
634 if (!latest_transid || device->generation > latest_transid) {
635 latest_devid = devid;
636 latest_transid = device->generation;
637 latest_bdev = bdev;
638 }
639
640 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
641 device->writeable = 0;
642 } else {
643 device->writeable = !bdev_read_only(bdev);
644 seeding = 0;
645 }
646
647 q = bdev_get_queue(bdev);
648 if (blk_queue_discard(q)) {
649 device->can_discard = 1;
650 fs_devices->num_can_discard++;
651 }
652
653 device->bdev = bdev;
654 device->in_fs_metadata = 0;
655 device->mode = flags;
656
657 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
658 fs_devices->rotating = 1;
659
660 fs_devices->open_devices++;
661 if (device->writeable) {
662 fs_devices->rw_devices++;
663 list_add(&device->dev_alloc_list,
664 &fs_devices->alloc_list);
665 }
666 brelse(bh);
667 continue;
668
669 error_brelse:
670 brelse(bh);
671 error_close:
672 blkdev_put(bdev, flags);
673 error:
674 continue;
675 }
676 if (fs_devices->open_devices == 0) {
677 ret = -EINVAL;
678 goto out;
679 }
680 fs_devices->seeding = seeding;
681 fs_devices->opened = 1;
682 fs_devices->latest_bdev = latest_bdev;
683 fs_devices->latest_devid = latest_devid;
684 fs_devices->latest_trans = latest_transid;
685 fs_devices->total_rw_bytes = 0;
686 out:
687 return ret;
688 }
689
690 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
691 fmode_t flags, void *holder)
692 {
693 int ret;
694
695 mutex_lock(&uuid_mutex);
696 if (fs_devices->opened) {
697 fs_devices->opened++;
698 ret = 0;
699 } else {
700 ret = __btrfs_open_devices(fs_devices, flags, holder);
701 }
702 mutex_unlock(&uuid_mutex);
703 return ret;
704 }
705
706 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
707 struct btrfs_fs_devices **fs_devices_ret)
708 {
709 struct btrfs_super_block *disk_super;
710 struct block_device *bdev;
711 struct buffer_head *bh;
712 int ret;
713 u64 devid;
714 u64 transid;
715
716 mutex_lock(&uuid_mutex);
717
718 flags |= FMODE_EXCL;
719 bdev = blkdev_get_by_path(path, flags, holder);
720
721 if (IS_ERR(bdev)) {
722 ret = PTR_ERR(bdev);
723 goto error;
724 }
725
726 ret = set_blocksize(bdev, 4096);
727 if (ret)
728 goto error_close;
729 bh = btrfs_read_dev_super(bdev);
730 if (!bh) {
731 ret = -EINVAL;
732 goto error_close;
733 }
734 disk_super = (struct btrfs_super_block *)bh->b_data;
735 devid = btrfs_stack_device_id(&disk_super->dev_item);
736 transid = btrfs_super_generation(disk_super);
737 if (disk_super->label[0])
738 printk(KERN_INFO "device label %s ", disk_super->label);
739 else
740 printk(KERN_INFO "device fsid %pU ", disk_super->fsid);
741 printk(KERN_CONT "devid %llu transid %llu %s\n",
742 (unsigned long long)devid, (unsigned long long)transid, path);
743 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
744
745 brelse(bh);
746 error_close:
747 blkdev_put(bdev, flags);
748 error:
749 mutex_unlock(&uuid_mutex);
750 return ret;
751 }
752
753 /* helper to account the used device space in the range */
754 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
755 u64 end, u64 *length)
756 {
757 struct btrfs_key key;
758 struct btrfs_root *root = device->dev_root;
759 struct btrfs_dev_extent *dev_extent;
760 struct btrfs_path *path;
761 u64 extent_end;
762 int ret;
763 int slot;
764 struct extent_buffer *l;
765
766 *length = 0;
767
768 if (start >= device->total_bytes)
769 return 0;
770
771 path = btrfs_alloc_path();
772 if (!path)
773 return -ENOMEM;
774 path->reada = 2;
775
776 key.objectid = device->devid;
777 key.offset = start;
778 key.type = BTRFS_DEV_EXTENT_KEY;
779
780 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
781 if (ret < 0)
782 goto out;
783 if (ret > 0) {
784 ret = btrfs_previous_item(root, path, key.objectid, key.type);
785 if (ret < 0)
786 goto out;
787 }
788
789 while (1) {
790 l = path->nodes[0];
791 slot = path->slots[0];
792 if (slot >= btrfs_header_nritems(l)) {
793 ret = btrfs_next_leaf(root, path);
794 if (ret == 0)
795 continue;
796 if (ret < 0)
797 goto out;
798
799 break;
800 }
801 btrfs_item_key_to_cpu(l, &key, slot);
802
803 if (key.objectid < device->devid)
804 goto next;
805
806 if (key.objectid > device->devid)
807 break;
808
809 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
810 goto next;
811
812 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
813 extent_end = key.offset + btrfs_dev_extent_length(l,
814 dev_extent);
815 if (key.offset <= start && extent_end > end) {
816 *length = end - start + 1;
817 break;
818 } else if (key.offset <= start && extent_end > start)
819 *length += extent_end - start;
820 else if (key.offset > start && extent_end <= end)
821 *length += extent_end - key.offset;
822 else if (key.offset > start && key.offset <= end) {
823 *length += end - key.offset + 1;
824 break;
825 } else if (key.offset > end)
826 break;
827
828 next:
829 path->slots[0]++;
830 }
831 ret = 0;
832 out:
833 btrfs_free_path(path);
834 return ret;
835 }
836
837 /*
838 * find_free_dev_extent - find free space in the specified device
839 * @trans: transaction handler
840 * @device: the device which we search the free space in
841 * @num_bytes: the size of the free space that we need
842 * @start: store the start of the free space.
843 * @len: the size of the free space. that we find, or the size of the max
844 * free space if we don't find suitable free space
845 *
846 * this uses a pretty simple search, the expectation is that it is
847 * called very infrequently and that a given device has a small number
848 * of extents
849 *
850 * @start is used to store the start of the free space if we find. But if we
851 * don't find suitable free space, it will be used to store the start position
852 * of the max free space.
853 *
854 * @len is used to store the size of the free space that we find.
855 * But if we don't find suitable free space, it is used to store the size of
856 * the max free space.
857 */
858 int find_free_dev_extent(struct btrfs_trans_handle *trans,
859 struct btrfs_device *device, u64 num_bytes,
860 u64 *start, u64 *len)
861 {
862 struct btrfs_key key;
863 struct btrfs_root *root = device->dev_root;
864 struct btrfs_dev_extent *dev_extent;
865 struct btrfs_path *path;
866 u64 hole_size;
867 u64 max_hole_start;
868 u64 max_hole_size;
869 u64 extent_end;
870 u64 search_start;
871 u64 search_end = device->total_bytes;
872 int ret;
873 int slot;
874 struct extent_buffer *l;
875
876 /* FIXME use last free of some kind */
877
878 /* we don't want to overwrite the superblock on the drive,
879 * so we make sure to start at an offset of at least 1MB
880 */
881 search_start = max(root->fs_info->alloc_start, 1024ull * 1024);
882
883 max_hole_start = search_start;
884 max_hole_size = 0;
885 hole_size = 0;
886
887 if (search_start >= search_end) {
888 ret = -ENOSPC;
889 goto error;
890 }
891
892 path = btrfs_alloc_path();
893 if (!path) {
894 ret = -ENOMEM;
895 goto error;
896 }
897 path->reada = 2;
898
899 key.objectid = device->devid;
900 key.offset = search_start;
901 key.type = BTRFS_DEV_EXTENT_KEY;
902
903 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
904 if (ret < 0)
905 goto out;
906 if (ret > 0) {
907 ret = btrfs_previous_item(root, path, key.objectid, key.type);
908 if (ret < 0)
909 goto out;
910 }
911
912 while (1) {
913 l = path->nodes[0];
914 slot = path->slots[0];
915 if (slot >= btrfs_header_nritems(l)) {
916 ret = btrfs_next_leaf(root, path);
917 if (ret == 0)
918 continue;
919 if (ret < 0)
920 goto out;
921
922 break;
923 }
924 btrfs_item_key_to_cpu(l, &key, slot);
925
926 if (key.objectid < device->devid)
927 goto next;
928
929 if (key.objectid > device->devid)
930 break;
931
932 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
933 goto next;
934
935 if (key.offset > search_start) {
936 hole_size = key.offset - search_start;
937
938 if (hole_size > max_hole_size) {
939 max_hole_start = search_start;
940 max_hole_size = hole_size;
941 }
942
943 /*
944 * If this free space is greater than which we need,
945 * it must be the max free space that we have found
946 * until now, so max_hole_start must point to the start
947 * of this free space and the length of this free space
948 * is stored in max_hole_size. Thus, we return
949 * max_hole_start and max_hole_size and go back to the
950 * caller.
951 */
952 if (hole_size >= num_bytes) {
953 ret = 0;
954 goto out;
955 }
956 }
957
958 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
959 extent_end = key.offset + btrfs_dev_extent_length(l,
960 dev_extent);
961 if (extent_end > search_start)
962 search_start = extent_end;
963 next:
964 path->slots[0]++;
965 cond_resched();
966 }
967
968 /*
969 * At this point, search_start should be the end of
970 * allocated dev extents, and when shrinking the device,
971 * search_end may be smaller than search_start.
972 */
973 if (search_end > search_start)
974 hole_size = search_end - search_start;
975
976 if (hole_size > max_hole_size) {
977 max_hole_start = search_start;
978 max_hole_size = hole_size;
979 }
980
981 /* See above. */
982 if (hole_size < num_bytes)
983 ret = -ENOSPC;
984 else
985 ret = 0;
986
987 out:
988 btrfs_free_path(path);
989 error:
990 *start = max_hole_start;
991 if (len)
992 *len = max_hole_size;
993 return ret;
994 }
995
996 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
997 struct btrfs_device *device,
998 u64 start)
999 {
1000 int ret;
1001 struct btrfs_path *path;
1002 struct btrfs_root *root = device->dev_root;
1003 struct btrfs_key key;
1004 struct btrfs_key found_key;
1005 struct extent_buffer *leaf = NULL;
1006 struct btrfs_dev_extent *extent = NULL;
1007
1008 path = btrfs_alloc_path();
1009 if (!path)
1010 return -ENOMEM;
1011
1012 key.objectid = device->devid;
1013 key.offset = start;
1014 key.type = BTRFS_DEV_EXTENT_KEY;
1015 again:
1016 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1017 if (ret > 0) {
1018 ret = btrfs_previous_item(root, path, key.objectid,
1019 BTRFS_DEV_EXTENT_KEY);
1020 if (ret)
1021 goto out;
1022 leaf = path->nodes[0];
1023 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1024 extent = btrfs_item_ptr(leaf, path->slots[0],
1025 struct btrfs_dev_extent);
1026 BUG_ON(found_key.offset > start || found_key.offset +
1027 btrfs_dev_extent_length(leaf, extent) < start);
1028 key = found_key;
1029 btrfs_release_path(path);
1030 goto again;
1031 } else if (ret == 0) {
1032 leaf = path->nodes[0];
1033 extent = btrfs_item_ptr(leaf, path->slots[0],
1034 struct btrfs_dev_extent);
1035 }
1036 BUG_ON(ret);
1037
1038 if (device->bytes_used > 0) {
1039 u64 len = btrfs_dev_extent_length(leaf, extent);
1040 device->bytes_used -= len;
1041 spin_lock(&root->fs_info->free_chunk_lock);
1042 root->fs_info->free_chunk_space += len;
1043 spin_unlock(&root->fs_info->free_chunk_lock);
1044 }
1045 ret = btrfs_del_item(trans, root, path);
1046
1047 out:
1048 btrfs_free_path(path);
1049 return ret;
1050 }
1051
1052 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
1053 struct btrfs_device *device,
1054 u64 chunk_tree, u64 chunk_objectid,
1055 u64 chunk_offset, u64 start, u64 num_bytes)
1056 {
1057 int ret;
1058 struct btrfs_path *path;
1059 struct btrfs_root *root = device->dev_root;
1060 struct btrfs_dev_extent *extent;
1061 struct extent_buffer *leaf;
1062 struct btrfs_key key;
1063
1064 WARN_ON(!device->in_fs_metadata);
1065 path = btrfs_alloc_path();
1066 if (!path)
1067 return -ENOMEM;
1068
1069 key.objectid = device->devid;
1070 key.offset = start;
1071 key.type = BTRFS_DEV_EXTENT_KEY;
1072 ret = btrfs_insert_empty_item(trans, root, path, &key,
1073 sizeof(*extent));
1074 BUG_ON(ret);
1075
1076 leaf = path->nodes[0];
1077 extent = btrfs_item_ptr(leaf, path->slots[0],
1078 struct btrfs_dev_extent);
1079 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
1080 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
1081 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
1082
1083 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
1084 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
1085 BTRFS_UUID_SIZE);
1086
1087 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
1088 btrfs_mark_buffer_dirty(leaf);
1089 btrfs_free_path(path);
1090 return ret;
1091 }
1092
1093 static noinline int find_next_chunk(struct btrfs_root *root,
1094 u64 objectid, u64 *offset)
1095 {
1096 struct btrfs_path *path;
1097 int ret;
1098 struct btrfs_key key;
1099 struct btrfs_chunk *chunk;
1100 struct btrfs_key found_key;
1101
1102 path = btrfs_alloc_path();
1103 if (!path)
1104 return -ENOMEM;
1105
1106 key.objectid = objectid;
1107 key.offset = (u64)-1;
1108 key.type = BTRFS_CHUNK_ITEM_KEY;
1109
1110 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1111 if (ret < 0)
1112 goto error;
1113
1114 BUG_ON(ret == 0);
1115
1116 ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
1117 if (ret) {
1118 *offset = 0;
1119 } else {
1120 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1121 path->slots[0]);
1122 if (found_key.objectid != objectid)
1123 *offset = 0;
1124 else {
1125 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
1126 struct btrfs_chunk);
1127 *offset = found_key.offset +
1128 btrfs_chunk_length(path->nodes[0], chunk);
1129 }
1130 }
1131 ret = 0;
1132 error:
1133 btrfs_free_path(path);
1134 return ret;
1135 }
1136
1137 static noinline int find_next_devid(struct btrfs_root *root, u64 *objectid)
1138 {
1139 int ret;
1140 struct btrfs_key key;
1141 struct btrfs_key found_key;
1142 struct btrfs_path *path;
1143
1144 root = root->fs_info->chunk_root;
1145
1146 path = btrfs_alloc_path();
1147 if (!path)
1148 return -ENOMEM;
1149
1150 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1151 key.type = BTRFS_DEV_ITEM_KEY;
1152 key.offset = (u64)-1;
1153
1154 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1155 if (ret < 0)
1156 goto error;
1157
1158 BUG_ON(ret == 0);
1159
1160 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
1161 BTRFS_DEV_ITEM_KEY);
1162 if (ret) {
1163 *objectid = 1;
1164 } else {
1165 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1166 path->slots[0]);
1167 *objectid = found_key.offset + 1;
1168 }
1169 ret = 0;
1170 error:
1171 btrfs_free_path(path);
1172 return ret;
1173 }
1174
1175 /*
1176 * the device information is stored in the chunk root
1177 * the btrfs_device struct should be fully filled in
1178 */
1179 int btrfs_add_device(struct btrfs_trans_handle *trans,
1180 struct btrfs_root *root,
1181 struct btrfs_device *device)
1182 {
1183 int ret;
1184 struct btrfs_path *path;
1185 struct btrfs_dev_item *dev_item;
1186 struct extent_buffer *leaf;
1187 struct btrfs_key key;
1188 unsigned long ptr;
1189
1190 root = root->fs_info->chunk_root;
1191
1192 path = btrfs_alloc_path();
1193 if (!path)
1194 return -ENOMEM;
1195
1196 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1197 key.type = BTRFS_DEV_ITEM_KEY;
1198 key.offset = device->devid;
1199
1200 ret = btrfs_insert_empty_item(trans, root, path, &key,
1201 sizeof(*dev_item));
1202 if (ret)
1203 goto out;
1204
1205 leaf = path->nodes[0];
1206 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1207
1208 btrfs_set_device_id(leaf, dev_item, device->devid);
1209 btrfs_set_device_generation(leaf, dev_item, 0);
1210 btrfs_set_device_type(leaf, dev_item, device->type);
1211 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1212 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1213 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1214 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
1215 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1216 btrfs_set_device_group(leaf, dev_item, 0);
1217 btrfs_set_device_seek_speed(leaf, dev_item, 0);
1218 btrfs_set_device_bandwidth(leaf, dev_item, 0);
1219 btrfs_set_device_start_offset(leaf, dev_item, 0);
1220
1221 ptr = (unsigned long)btrfs_device_uuid(dev_item);
1222 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1223 ptr = (unsigned long)btrfs_device_fsid(dev_item);
1224 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
1225 btrfs_mark_buffer_dirty(leaf);
1226
1227 ret = 0;
1228 out:
1229 btrfs_free_path(path);
1230 return ret;
1231 }
1232
1233 static int btrfs_rm_dev_item(struct btrfs_root *root,
1234 struct btrfs_device *device)
1235 {
1236 int ret;
1237 struct btrfs_path *path;
1238 struct btrfs_key key;
1239 struct btrfs_trans_handle *trans;
1240
1241 root = root->fs_info->chunk_root;
1242
1243 path = btrfs_alloc_path();
1244 if (!path)
1245 return -ENOMEM;
1246
1247 trans = btrfs_start_transaction(root, 0);
1248 if (IS_ERR(trans)) {
1249 btrfs_free_path(path);
1250 return PTR_ERR(trans);
1251 }
1252 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1253 key.type = BTRFS_DEV_ITEM_KEY;
1254 key.offset = device->devid;
1255 lock_chunks(root);
1256
1257 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1258 if (ret < 0)
1259 goto out;
1260
1261 if (ret > 0) {
1262 ret = -ENOENT;
1263 goto out;
1264 }
1265
1266 ret = btrfs_del_item(trans, root, path);
1267 if (ret)
1268 goto out;
1269 out:
1270 btrfs_free_path(path);
1271 unlock_chunks(root);
1272 btrfs_commit_transaction(trans, root);
1273 return ret;
1274 }
1275
1276 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
1277 {
1278 struct btrfs_device *device;
1279 struct btrfs_device *next_device;
1280 struct block_device *bdev;
1281 struct buffer_head *bh = NULL;
1282 struct btrfs_super_block *disk_super;
1283 struct btrfs_fs_devices *cur_devices;
1284 u64 all_avail;
1285 u64 devid;
1286 u64 num_devices;
1287 u8 *dev_uuid;
1288 int ret = 0;
1289 bool clear_super = false;
1290
1291 mutex_lock(&uuid_mutex);
1292 mutex_lock(&root->fs_info->volume_mutex);
1293
1294 all_avail = root->fs_info->avail_data_alloc_bits |
1295 root->fs_info->avail_system_alloc_bits |
1296 root->fs_info->avail_metadata_alloc_bits;
1297
1298 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) &&
1299 root->fs_info->fs_devices->num_devices <= 4) {
1300 printk(KERN_ERR "btrfs: unable to go below four devices "
1301 "on raid10\n");
1302 ret = -EINVAL;
1303 goto out;
1304 }
1305
1306 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) &&
1307 root->fs_info->fs_devices->num_devices <= 2) {
1308 printk(KERN_ERR "btrfs: unable to go below two "
1309 "devices on raid1\n");
1310 ret = -EINVAL;
1311 goto out;
1312 }
1313
1314 if (strcmp(device_path, "missing") == 0) {
1315 struct list_head *devices;
1316 struct btrfs_device *tmp;
1317
1318 device = NULL;
1319 devices = &root->fs_info->fs_devices->devices;
1320 /*
1321 * It is safe to read the devices since the volume_mutex
1322 * is held.
1323 */
1324 list_for_each_entry(tmp, devices, dev_list) {
1325 if (tmp->in_fs_metadata && !tmp->bdev) {
1326 device = tmp;
1327 break;
1328 }
1329 }
1330 bdev = NULL;
1331 bh = NULL;
1332 disk_super = NULL;
1333 if (!device) {
1334 printk(KERN_ERR "btrfs: no missing devices found to "
1335 "remove\n");
1336 goto out;
1337 }
1338 } else {
1339 bdev = blkdev_get_by_path(device_path, FMODE_READ | FMODE_EXCL,
1340 root->fs_info->bdev_holder);
1341 if (IS_ERR(bdev)) {
1342 ret = PTR_ERR(bdev);
1343 goto out;
1344 }
1345
1346 set_blocksize(bdev, 4096);
1347 bh = btrfs_read_dev_super(bdev);
1348 if (!bh) {
1349 ret = -EINVAL;
1350 goto error_close;
1351 }
1352 disk_super = (struct btrfs_super_block *)bh->b_data;
1353 devid = btrfs_stack_device_id(&disk_super->dev_item);
1354 dev_uuid = disk_super->dev_item.uuid;
1355 device = btrfs_find_device(root, devid, dev_uuid,
1356 disk_super->fsid);
1357 if (!device) {
1358 ret = -ENOENT;
1359 goto error_brelse;
1360 }
1361 }
1362
1363 if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
1364 printk(KERN_ERR "btrfs: unable to remove the only writeable "
1365 "device\n");
1366 ret = -EINVAL;
1367 goto error_brelse;
1368 }
1369
1370 if (device->writeable) {
1371 lock_chunks(root);
1372 list_del_init(&device->dev_alloc_list);
1373 unlock_chunks(root);
1374 root->fs_info->fs_devices->rw_devices--;
1375 clear_super = true;
1376 }
1377
1378 ret = btrfs_shrink_device(device, 0);
1379 if (ret)
1380 goto error_undo;
1381
1382 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1383 if (ret)
1384 goto error_undo;
1385
1386 spin_lock(&root->fs_info->free_chunk_lock);
1387 root->fs_info->free_chunk_space = device->total_bytes -
1388 device->bytes_used;
1389 spin_unlock(&root->fs_info->free_chunk_lock);
1390
1391 device->in_fs_metadata = 0;
1392 btrfs_scrub_cancel_dev(root, device);
1393
1394 /*
1395 * the device list mutex makes sure that we don't change
1396 * the device list while someone else is writing out all
1397 * the device supers.
1398 */
1399
1400 cur_devices = device->fs_devices;
1401 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1402 list_del_rcu(&device->dev_list);
1403
1404 device->fs_devices->num_devices--;
1405
1406 if (device->missing)
1407 root->fs_info->fs_devices->missing_devices--;
1408
1409 next_device = list_entry(root->fs_info->fs_devices->devices.next,
1410 struct btrfs_device, dev_list);
1411 if (device->bdev == root->fs_info->sb->s_bdev)
1412 root->fs_info->sb->s_bdev = next_device->bdev;
1413 if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1414 root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1415
1416 if (device->bdev)
1417 device->fs_devices->open_devices--;
1418
1419 call_rcu(&device->rcu, free_device);
1420 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1421
1422 num_devices = btrfs_super_num_devices(root->fs_info->super_copy) - 1;
1423 btrfs_set_super_num_devices(root->fs_info->super_copy, num_devices);
1424
1425 if (cur_devices->open_devices == 0) {
1426 struct btrfs_fs_devices *fs_devices;
1427 fs_devices = root->fs_info->fs_devices;
1428 while (fs_devices) {
1429 if (fs_devices->seed == cur_devices)
1430 break;
1431 fs_devices = fs_devices->seed;
1432 }
1433 fs_devices->seed = cur_devices->seed;
1434 cur_devices->seed = NULL;
1435 lock_chunks(root);
1436 __btrfs_close_devices(cur_devices);
1437 unlock_chunks(root);
1438 free_fs_devices(cur_devices);
1439 }
1440
1441 /*
1442 * at this point, the device is zero sized. We want to
1443 * remove it from the devices list and zero out the old super
1444 */
1445 if (clear_super) {
1446 /* make sure this device isn't detected as part of
1447 * the FS anymore
1448 */
1449 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1450 set_buffer_dirty(bh);
1451 sync_dirty_buffer(bh);
1452 }
1453
1454 ret = 0;
1455
1456 error_brelse:
1457 brelse(bh);
1458 error_close:
1459 if (bdev)
1460 blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
1461 out:
1462 mutex_unlock(&root->fs_info->volume_mutex);
1463 mutex_unlock(&uuid_mutex);
1464 return ret;
1465 error_undo:
1466 if (device->writeable) {
1467 lock_chunks(root);
1468 list_add(&device->dev_alloc_list,
1469 &root->fs_info->fs_devices->alloc_list);
1470 unlock_chunks(root);
1471 root->fs_info->fs_devices->rw_devices++;
1472 }
1473 goto error_brelse;
1474 }
1475
1476 /*
1477 * does all the dirty work required for changing file system's UUID.
1478 */
1479 static int btrfs_prepare_sprout(struct btrfs_trans_handle *trans,
1480 struct btrfs_root *root)
1481 {
1482 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1483 struct btrfs_fs_devices *old_devices;
1484 struct btrfs_fs_devices *seed_devices;
1485 struct btrfs_super_block *disk_super = root->fs_info->super_copy;
1486 struct btrfs_device *device;
1487 u64 super_flags;
1488
1489 BUG_ON(!mutex_is_locked(&uuid_mutex));
1490 if (!fs_devices->seeding)
1491 return -EINVAL;
1492
1493 seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
1494 if (!seed_devices)
1495 return -ENOMEM;
1496
1497 old_devices = clone_fs_devices(fs_devices);
1498 if (IS_ERR(old_devices)) {
1499 kfree(seed_devices);
1500 return PTR_ERR(old_devices);
1501 }
1502
1503 list_add(&old_devices->list, &fs_uuids);
1504
1505 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1506 seed_devices->opened = 1;
1507 INIT_LIST_HEAD(&seed_devices->devices);
1508 INIT_LIST_HEAD(&seed_devices->alloc_list);
1509 mutex_init(&seed_devices->device_list_mutex);
1510
1511 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1512 list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
1513 synchronize_rcu);
1514 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1515
1516 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1517 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1518 device->fs_devices = seed_devices;
1519 }
1520
1521 fs_devices->seeding = 0;
1522 fs_devices->num_devices = 0;
1523 fs_devices->open_devices = 0;
1524 fs_devices->seed = seed_devices;
1525
1526 generate_random_uuid(fs_devices->fsid);
1527 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1528 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1529 super_flags = btrfs_super_flags(disk_super) &
1530 ~BTRFS_SUPER_FLAG_SEEDING;
1531 btrfs_set_super_flags(disk_super, super_flags);
1532
1533 return 0;
1534 }
1535
1536 /*
1537 * strore the expected generation for seed devices in device items.
1538 */
1539 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1540 struct btrfs_root *root)
1541 {
1542 struct btrfs_path *path;
1543 struct extent_buffer *leaf;
1544 struct btrfs_dev_item *dev_item;
1545 struct btrfs_device *device;
1546 struct btrfs_key key;
1547 u8 fs_uuid[BTRFS_UUID_SIZE];
1548 u8 dev_uuid[BTRFS_UUID_SIZE];
1549 u64 devid;
1550 int ret;
1551
1552 path = btrfs_alloc_path();
1553 if (!path)
1554 return -ENOMEM;
1555
1556 root = root->fs_info->chunk_root;
1557 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1558 key.offset = 0;
1559 key.type = BTRFS_DEV_ITEM_KEY;
1560
1561 while (1) {
1562 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1563 if (ret < 0)
1564 goto error;
1565
1566 leaf = path->nodes[0];
1567 next_slot:
1568 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1569 ret = btrfs_next_leaf(root, path);
1570 if (ret > 0)
1571 break;
1572 if (ret < 0)
1573 goto error;
1574 leaf = path->nodes[0];
1575 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1576 btrfs_release_path(path);
1577 continue;
1578 }
1579
1580 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1581 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1582 key.type != BTRFS_DEV_ITEM_KEY)
1583 break;
1584
1585 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1586 struct btrfs_dev_item);
1587 devid = btrfs_device_id(leaf, dev_item);
1588 read_extent_buffer(leaf, dev_uuid,
1589 (unsigned long)btrfs_device_uuid(dev_item),
1590 BTRFS_UUID_SIZE);
1591 read_extent_buffer(leaf, fs_uuid,
1592 (unsigned long)btrfs_device_fsid(dev_item),
1593 BTRFS_UUID_SIZE);
1594 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
1595 BUG_ON(!device);
1596
1597 if (device->fs_devices->seeding) {
1598 btrfs_set_device_generation(leaf, dev_item,
1599 device->generation);
1600 btrfs_mark_buffer_dirty(leaf);
1601 }
1602
1603 path->slots[0]++;
1604 goto next_slot;
1605 }
1606 ret = 0;
1607 error:
1608 btrfs_free_path(path);
1609 return ret;
1610 }
1611
1612 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1613 {
1614 struct request_queue *q;
1615 struct btrfs_trans_handle *trans;
1616 struct btrfs_device *device;
1617 struct block_device *bdev;
1618 struct list_head *devices;
1619 struct super_block *sb = root->fs_info->sb;
1620 u64 total_bytes;
1621 int seeding_dev = 0;
1622 int ret = 0;
1623
1624 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1625 return -EINVAL;
1626
1627 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
1628 root->fs_info->bdev_holder);
1629 if (IS_ERR(bdev))
1630 return PTR_ERR(bdev);
1631
1632 if (root->fs_info->fs_devices->seeding) {
1633 seeding_dev = 1;
1634 down_write(&sb->s_umount);
1635 mutex_lock(&uuid_mutex);
1636 }
1637
1638 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1639 mutex_lock(&root->fs_info->volume_mutex);
1640
1641 devices = &root->fs_info->fs_devices->devices;
1642 /*
1643 * we have the volume lock, so we don't need the extra
1644 * device list mutex while reading the list here.
1645 */
1646 list_for_each_entry(device, devices, dev_list) {
1647 if (device->bdev == bdev) {
1648 ret = -EEXIST;
1649 goto error;
1650 }
1651 }
1652
1653 device = kzalloc(sizeof(*device), GFP_NOFS);
1654 if (!device) {
1655 /* we can safely leave the fs_devices entry around */
1656 ret = -ENOMEM;
1657 goto error;
1658 }
1659
1660 device->name = kstrdup(device_path, GFP_NOFS);
1661 if (!device->name) {
1662 kfree(device);
1663 ret = -ENOMEM;
1664 goto error;
1665 }
1666
1667 ret = find_next_devid(root, &device->devid);
1668 if (ret) {
1669 kfree(device->name);
1670 kfree(device);
1671 goto error;
1672 }
1673
1674 trans = btrfs_start_transaction(root, 0);
1675 if (IS_ERR(trans)) {
1676 kfree(device->name);
1677 kfree(device);
1678 ret = PTR_ERR(trans);
1679 goto error;
1680 }
1681
1682 lock_chunks(root);
1683
1684 q = bdev_get_queue(bdev);
1685 if (blk_queue_discard(q))
1686 device->can_discard = 1;
1687 device->writeable = 1;
1688 device->work.func = pending_bios_fn;
1689 generate_random_uuid(device->uuid);
1690 spin_lock_init(&device->io_lock);
1691 device->generation = trans->transid;
1692 device->io_width = root->sectorsize;
1693 device->io_align = root->sectorsize;
1694 device->sector_size = root->sectorsize;
1695 device->total_bytes = i_size_read(bdev->bd_inode);
1696 device->disk_total_bytes = device->total_bytes;
1697 device->dev_root = root->fs_info->dev_root;
1698 device->bdev = bdev;
1699 device->in_fs_metadata = 1;
1700 device->mode = FMODE_EXCL;
1701 set_blocksize(device->bdev, 4096);
1702
1703 if (seeding_dev) {
1704 sb->s_flags &= ~MS_RDONLY;
1705 ret = btrfs_prepare_sprout(trans, root);
1706 BUG_ON(ret);
1707 }
1708
1709 device->fs_devices = root->fs_info->fs_devices;
1710
1711 /*
1712 * we don't want write_supers to jump in here with our device
1713 * half setup
1714 */
1715 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1716 list_add_rcu(&device->dev_list, &root->fs_info->fs_devices->devices);
1717 list_add(&device->dev_alloc_list,
1718 &root->fs_info->fs_devices->alloc_list);
1719 root->fs_info->fs_devices->num_devices++;
1720 root->fs_info->fs_devices->open_devices++;
1721 root->fs_info->fs_devices->rw_devices++;
1722 if (device->can_discard)
1723 root->fs_info->fs_devices->num_can_discard++;
1724 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
1725
1726 spin_lock(&root->fs_info->free_chunk_lock);
1727 root->fs_info->free_chunk_space += device->total_bytes;
1728 spin_unlock(&root->fs_info->free_chunk_lock);
1729
1730 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
1731 root->fs_info->fs_devices->rotating = 1;
1732
1733 total_bytes = btrfs_super_total_bytes(root->fs_info->super_copy);
1734 btrfs_set_super_total_bytes(root->fs_info->super_copy,
1735 total_bytes + device->total_bytes);
1736
1737 total_bytes = btrfs_super_num_devices(root->fs_info->super_copy);
1738 btrfs_set_super_num_devices(root->fs_info->super_copy,
1739 total_bytes + 1);
1740 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1741
1742 if (seeding_dev) {
1743 ret = init_first_rw_device(trans, root, device);
1744 BUG_ON(ret);
1745 ret = btrfs_finish_sprout(trans, root);
1746 BUG_ON(ret);
1747 } else {
1748 ret = btrfs_add_device(trans, root, device);
1749 }
1750
1751 /*
1752 * we've got more storage, clear any full flags on the space
1753 * infos
1754 */
1755 btrfs_clear_space_info_full(root->fs_info);
1756
1757 unlock_chunks(root);
1758 btrfs_commit_transaction(trans, root);
1759
1760 if (seeding_dev) {
1761 mutex_unlock(&uuid_mutex);
1762 up_write(&sb->s_umount);
1763
1764 ret = btrfs_relocate_sys_chunks(root);
1765 BUG_ON(ret);
1766 }
1767 out:
1768 mutex_unlock(&root->fs_info->volume_mutex);
1769 return ret;
1770 error:
1771 blkdev_put(bdev, FMODE_EXCL);
1772 if (seeding_dev) {
1773 mutex_unlock(&uuid_mutex);
1774 up_write(&sb->s_umount);
1775 }
1776 goto out;
1777 }
1778
1779 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
1780 struct btrfs_device *device)
1781 {
1782 int ret;
1783 struct btrfs_path *path;
1784 struct btrfs_root *root;
1785 struct btrfs_dev_item *dev_item;
1786 struct extent_buffer *leaf;
1787 struct btrfs_key key;
1788
1789 root = device->dev_root->fs_info->chunk_root;
1790
1791 path = btrfs_alloc_path();
1792 if (!path)
1793 return -ENOMEM;
1794
1795 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1796 key.type = BTRFS_DEV_ITEM_KEY;
1797 key.offset = device->devid;
1798
1799 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1800 if (ret < 0)
1801 goto out;
1802
1803 if (ret > 0) {
1804 ret = -ENOENT;
1805 goto out;
1806 }
1807
1808 leaf = path->nodes[0];
1809 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1810
1811 btrfs_set_device_id(leaf, dev_item, device->devid);
1812 btrfs_set_device_type(leaf, dev_item, device->type);
1813 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1814 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1815 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1816 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
1817 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1818 btrfs_mark_buffer_dirty(leaf);
1819
1820 out:
1821 btrfs_free_path(path);
1822 return ret;
1823 }
1824
1825 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
1826 struct btrfs_device *device, u64 new_size)
1827 {
1828 struct btrfs_super_block *super_copy =
1829 device->dev_root->fs_info->super_copy;
1830 u64 old_total = btrfs_super_total_bytes(super_copy);
1831 u64 diff = new_size - device->total_bytes;
1832
1833 if (!device->writeable)
1834 return -EACCES;
1835 if (new_size <= device->total_bytes)
1836 return -EINVAL;
1837
1838 btrfs_set_super_total_bytes(super_copy, old_total + diff);
1839 device->fs_devices->total_rw_bytes += diff;
1840
1841 device->total_bytes = new_size;
1842 device->disk_total_bytes = new_size;
1843 btrfs_clear_space_info_full(device->dev_root->fs_info);
1844
1845 return btrfs_update_device(trans, device);
1846 }
1847
1848 int btrfs_grow_device(struct btrfs_trans_handle *trans,
1849 struct btrfs_device *device, u64 new_size)
1850 {
1851 int ret;
1852 lock_chunks(device->dev_root);
1853 ret = __btrfs_grow_device(trans, device, new_size);
1854 unlock_chunks(device->dev_root);
1855 return ret;
1856 }
1857
1858 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
1859 struct btrfs_root *root,
1860 u64 chunk_tree, u64 chunk_objectid,
1861 u64 chunk_offset)
1862 {
1863 int ret;
1864 struct btrfs_path *path;
1865 struct btrfs_key key;
1866
1867 root = root->fs_info->chunk_root;
1868 path = btrfs_alloc_path();
1869 if (!path)
1870 return -ENOMEM;
1871
1872 key.objectid = chunk_objectid;
1873 key.offset = chunk_offset;
1874 key.type = BTRFS_CHUNK_ITEM_KEY;
1875
1876 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1877 BUG_ON(ret);
1878
1879 ret = btrfs_del_item(trans, root, path);
1880
1881 btrfs_free_path(path);
1882 return ret;
1883 }
1884
1885 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
1886 chunk_offset)
1887 {
1888 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
1889 struct btrfs_disk_key *disk_key;
1890 struct btrfs_chunk *chunk;
1891 u8 *ptr;
1892 int ret = 0;
1893 u32 num_stripes;
1894 u32 array_size;
1895 u32 len = 0;
1896 u32 cur;
1897 struct btrfs_key key;
1898
1899 array_size = btrfs_super_sys_array_size(super_copy);
1900
1901 ptr = super_copy->sys_chunk_array;
1902 cur = 0;
1903
1904 while (cur < array_size) {
1905 disk_key = (struct btrfs_disk_key *)ptr;
1906 btrfs_disk_key_to_cpu(&key, disk_key);
1907
1908 len = sizeof(*disk_key);
1909
1910 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
1911 chunk = (struct btrfs_chunk *)(ptr + len);
1912 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
1913 len += btrfs_chunk_item_size(num_stripes);
1914 } else {
1915 ret = -EIO;
1916 break;
1917 }
1918 if (key.objectid == chunk_objectid &&
1919 key.offset == chunk_offset) {
1920 memmove(ptr, ptr + len, array_size - (cur + len));
1921 array_size -= len;
1922 btrfs_set_super_sys_array_size(super_copy, array_size);
1923 } else {
1924 ptr += len;
1925 cur += len;
1926 }
1927 }
1928 return ret;
1929 }
1930
1931 static int btrfs_relocate_chunk(struct btrfs_root *root,
1932 u64 chunk_tree, u64 chunk_objectid,
1933 u64 chunk_offset)
1934 {
1935 struct extent_map_tree *em_tree;
1936 struct btrfs_root *extent_root;
1937 struct btrfs_trans_handle *trans;
1938 struct extent_map *em;
1939 struct map_lookup *map;
1940 int ret;
1941 int i;
1942
1943 root = root->fs_info->chunk_root;
1944 extent_root = root->fs_info->extent_root;
1945 em_tree = &root->fs_info->mapping_tree.map_tree;
1946
1947 ret = btrfs_can_relocate(extent_root, chunk_offset);
1948 if (ret)
1949 return -ENOSPC;
1950
1951 /* step one, relocate all the extents inside this chunk */
1952 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
1953 if (ret)
1954 return ret;
1955
1956 trans = btrfs_start_transaction(root, 0);
1957 BUG_ON(IS_ERR(trans));
1958
1959 lock_chunks(root);
1960
1961 /*
1962 * step two, delete the device extents and the
1963 * chunk tree entries
1964 */
1965 read_lock(&em_tree->lock);
1966 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
1967 read_unlock(&em_tree->lock);
1968
1969 BUG_ON(em->start > chunk_offset ||
1970 em->start + em->len < chunk_offset);
1971 map = (struct map_lookup *)em->bdev;
1972
1973 for (i = 0; i < map->num_stripes; i++) {
1974 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
1975 map->stripes[i].physical);
1976 BUG_ON(ret);
1977
1978 if (map->stripes[i].dev) {
1979 ret = btrfs_update_device(trans, map->stripes[i].dev);
1980 BUG_ON(ret);
1981 }
1982 }
1983 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
1984 chunk_offset);
1985
1986 BUG_ON(ret);
1987
1988 trace_btrfs_chunk_free(root, map, chunk_offset, em->len);
1989
1990 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
1991 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
1992 BUG_ON(ret);
1993 }
1994
1995 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
1996 BUG_ON(ret);
1997
1998 write_lock(&em_tree->lock);
1999 remove_extent_mapping(em_tree, em);
2000 write_unlock(&em_tree->lock);
2001
2002 kfree(map);
2003 em->bdev = NULL;
2004
2005 /* once for the tree */
2006 free_extent_map(em);
2007 /* once for us */
2008 free_extent_map(em);
2009
2010 unlock_chunks(root);
2011 btrfs_end_transaction(trans, root);
2012 return 0;
2013 }
2014
2015 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
2016 {
2017 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
2018 struct btrfs_path *path;
2019 struct extent_buffer *leaf;
2020 struct btrfs_chunk *chunk;
2021 struct btrfs_key key;
2022 struct btrfs_key found_key;
2023 u64 chunk_tree = chunk_root->root_key.objectid;
2024 u64 chunk_type;
2025 bool retried = false;
2026 int failed = 0;
2027 int ret;
2028
2029 path = btrfs_alloc_path();
2030 if (!path)
2031 return -ENOMEM;
2032
2033 again:
2034 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2035 key.offset = (u64)-1;
2036 key.type = BTRFS_CHUNK_ITEM_KEY;
2037
2038 while (1) {
2039 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2040 if (ret < 0)
2041 goto error;
2042 BUG_ON(ret == 0);
2043
2044 ret = btrfs_previous_item(chunk_root, path, key.objectid,
2045 key.type);
2046 if (ret < 0)
2047 goto error;
2048 if (ret > 0)
2049 break;
2050
2051 leaf = path->nodes[0];
2052 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2053
2054 chunk = btrfs_item_ptr(leaf, path->slots[0],
2055 struct btrfs_chunk);
2056 chunk_type = btrfs_chunk_type(leaf, chunk);
2057 btrfs_release_path(path);
2058
2059 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
2060 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
2061 found_key.objectid,
2062 found_key.offset);
2063 if (ret == -ENOSPC)
2064 failed++;
2065 else if (ret)
2066 BUG();
2067 }
2068
2069 if (found_key.offset == 0)
2070 break;
2071 key.offset = found_key.offset - 1;
2072 }
2073 ret = 0;
2074 if (failed && !retried) {
2075 failed = 0;
2076 retried = true;
2077 goto again;
2078 } else if (failed && retried) {
2079 WARN_ON(1);
2080 ret = -ENOSPC;
2081 }
2082 error:
2083 btrfs_free_path(path);
2084 return ret;
2085 }
2086
2087 static u64 div_factor(u64 num, int factor)
2088 {
2089 if (factor == 10)
2090 return num;
2091 num *= factor;
2092 do_div(num, 10);
2093 return num;
2094 }
2095
2096 int btrfs_balance(struct btrfs_root *dev_root)
2097 {
2098 int ret;
2099 struct list_head *devices = &dev_root->fs_info->fs_devices->devices;
2100 struct btrfs_device *device;
2101 u64 old_size;
2102 u64 size_to_free;
2103 struct btrfs_path *path;
2104 struct btrfs_key key;
2105 struct btrfs_root *chunk_root = dev_root->fs_info->chunk_root;
2106 struct btrfs_trans_handle *trans;
2107 struct btrfs_key found_key;
2108
2109 if (dev_root->fs_info->sb->s_flags & MS_RDONLY)
2110 return -EROFS;
2111
2112 if (!capable(CAP_SYS_ADMIN))
2113 return -EPERM;
2114
2115 mutex_lock(&dev_root->fs_info->volume_mutex);
2116 dev_root = dev_root->fs_info->dev_root;
2117
2118 /* step one make some room on all the devices */
2119 list_for_each_entry(device, devices, dev_list) {
2120 old_size = device->total_bytes;
2121 size_to_free = div_factor(old_size, 1);
2122 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
2123 if (!device->writeable ||
2124 device->total_bytes - device->bytes_used > size_to_free)
2125 continue;
2126
2127 ret = btrfs_shrink_device(device, old_size - size_to_free);
2128 if (ret == -ENOSPC)
2129 break;
2130 BUG_ON(ret);
2131
2132 trans = btrfs_start_transaction(dev_root, 0);
2133 BUG_ON(IS_ERR(trans));
2134
2135 ret = btrfs_grow_device(trans, device, old_size);
2136 BUG_ON(ret);
2137
2138 btrfs_end_transaction(trans, dev_root);
2139 }
2140
2141 /* step two, relocate all the chunks */
2142 path = btrfs_alloc_path();
2143 if (!path) {
2144 ret = -ENOMEM;
2145 goto error;
2146 }
2147 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2148 key.offset = (u64)-1;
2149 key.type = BTRFS_CHUNK_ITEM_KEY;
2150
2151 while (1) {
2152 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2153 if (ret < 0)
2154 goto error;
2155
2156 /*
2157 * this shouldn't happen, it means the last relocate
2158 * failed
2159 */
2160 if (ret == 0)
2161 break;
2162
2163 ret = btrfs_previous_item(chunk_root, path, 0,
2164 BTRFS_CHUNK_ITEM_KEY);
2165 if (ret)
2166 break;
2167
2168 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2169 path->slots[0]);
2170 if (found_key.objectid != key.objectid)
2171 break;
2172
2173 /* chunk zero is special */
2174 if (found_key.offset == 0)
2175 break;
2176
2177 btrfs_release_path(path);
2178 ret = btrfs_relocate_chunk(chunk_root,
2179 chunk_root->root_key.objectid,
2180 found_key.objectid,
2181 found_key.offset);
2182 if (ret && ret != -ENOSPC)
2183 goto error;
2184 key.offset = found_key.offset - 1;
2185 }
2186 ret = 0;
2187 error:
2188 btrfs_free_path(path);
2189 mutex_unlock(&dev_root->fs_info->volume_mutex);
2190 return ret;
2191 }
2192
2193 /*
2194 * shrinking a device means finding all of the device extents past
2195 * the new size, and then following the back refs to the chunks.
2196 * The chunk relocation code actually frees the device extent
2197 */
2198 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
2199 {
2200 struct btrfs_trans_handle *trans;
2201 struct btrfs_root *root = device->dev_root;
2202 struct btrfs_dev_extent *dev_extent = NULL;
2203 struct btrfs_path *path;
2204 u64 length;
2205 u64 chunk_tree;
2206 u64 chunk_objectid;
2207 u64 chunk_offset;
2208 int ret;
2209 int slot;
2210 int failed = 0;
2211 bool retried = false;
2212 struct extent_buffer *l;
2213 struct btrfs_key key;
2214 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
2215 u64 old_total = btrfs_super_total_bytes(super_copy);
2216 u64 old_size = device->total_bytes;
2217 u64 diff = device->total_bytes - new_size;
2218
2219 if (new_size >= device->total_bytes)
2220 return -EINVAL;
2221
2222 path = btrfs_alloc_path();
2223 if (!path)
2224 return -ENOMEM;
2225
2226 path->reada = 2;
2227
2228 lock_chunks(root);
2229
2230 device->total_bytes = new_size;
2231 if (device->writeable) {
2232 device->fs_devices->total_rw_bytes -= diff;
2233 spin_lock(&root->fs_info->free_chunk_lock);
2234 root->fs_info->free_chunk_space -= diff;
2235 spin_unlock(&root->fs_info->free_chunk_lock);
2236 }
2237 unlock_chunks(root);
2238
2239 again:
2240 key.objectid = device->devid;
2241 key.offset = (u64)-1;
2242 key.type = BTRFS_DEV_EXTENT_KEY;
2243
2244 while (1) {
2245 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2246 if (ret < 0)
2247 goto done;
2248
2249 ret = btrfs_previous_item(root, path, 0, key.type);
2250 if (ret < 0)
2251 goto done;
2252 if (ret) {
2253 ret = 0;
2254 btrfs_release_path(path);
2255 break;
2256 }
2257
2258 l = path->nodes[0];
2259 slot = path->slots[0];
2260 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
2261
2262 if (key.objectid != device->devid) {
2263 btrfs_release_path(path);
2264 break;
2265 }
2266
2267 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
2268 length = btrfs_dev_extent_length(l, dev_extent);
2269
2270 if (key.offset + length <= new_size) {
2271 btrfs_release_path(path);
2272 break;
2273 }
2274
2275 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
2276 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
2277 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
2278 btrfs_release_path(path);
2279
2280 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
2281 chunk_offset);
2282 if (ret && ret != -ENOSPC)
2283 goto done;
2284 if (ret == -ENOSPC)
2285 failed++;
2286 key.offset -= 1;
2287 }
2288
2289 if (failed && !retried) {
2290 failed = 0;
2291 retried = true;
2292 goto again;
2293 } else if (failed && retried) {
2294 ret = -ENOSPC;
2295 lock_chunks(root);
2296
2297 device->total_bytes = old_size;
2298 if (device->writeable)
2299 device->fs_devices->total_rw_bytes += diff;
2300 spin_lock(&root->fs_info->free_chunk_lock);
2301 root->fs_info->free_chunk_space += diff;
2302 spin_unlock(&root->fs_info->free_chunk_lock);
2303 unlock_chunks(root);
2304 goto done;
2305 }
2306
2307 /* Shrinking succeeded, else we would be at "done". */
2308 trans = btrfs_start_transaction(root, 0);
2309 if (IS_ERR(trans)) {
2310 ret = PTR_ERR(trans);
2311 goto done;
2312 }
2313
2314 lock_chunks(root);
2315
2316 device->disk_total_bytes = new_size;
2317 /* Now btrfs_update_device() will change the on-disk size. */
2318 ret = btrfs_update_device(trans, device);
2319 if (ret) {
2320 unlock_chunks(root);
2321 btrfs_end_transaction(trans, root);
2322 goto done;
2323 }
2324 WARN_ON(diff > old_total);
2325 btrfs_set_super_total_bytes(super_copy, old_total - diff);
2326 unlock_chunks(root);
2327 btrfs_end_transaction(trans, root);
2328 done:
2329 btrfs_free_path(path);
2330 return ret;
2331 }
2332
2333 static int btrfs_add_system_chunk(struct btrfs_trans_handle *trans,
2334 struct btrfs_root *root,
2335 struct btrfs_key *key,
2336 struct btrfs_chunk *chunk, int item_size)
2337 {
2338 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
2339 struct btrfs_disk_key disk_key;
2340 u32 array_size;
2341 u8 *ptr;
2342
2343 array_size = btrfs_super_sys_array_size(super_copy);
2344 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
2345 return -EFBIG;
2346
2347 ptr = super_copy->sys_chunk_array + array_size;
2348 btrfs_cpu_key_to_disk(&disk_key, key);
2349 memcpy(ptr, &disk_key, sizeof(disk_key));
2350 ptr += sizeof(disk_key);
2351 memcpy(ptr, chunk, item_size);
2352 item_size += sizeof(disk_key);
2353 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
2354 return 0;
2355 }
2356
2357 /*
2358 * sort the devices in descending order by max_avail, total_avail
2359 */
2360 static int btrfs_cmp_device_info(const void *a, const void *b)
2361 {
2362 const struct btrfs_device_info *di_a = a;
2363 const struct btrfs_device_info *di_b = b;
2364
2365 if (di_a->max_avail > di_b->max_avail)
2366 return -1;
2367 if (di_a->max_avail < di_b->max_avail)
2368 return 1;
2369 if (di_a->total_avail > di_b->total_avail)
2370 return -1;
2371 if (di_a->total_avail < di_b->total_avail)
2372 return 1;
2373 return 0;
2374 }
2375
2376 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
2377 struct btrfs_root *extent_root,
2378 struct map_lookup **map_ret,
2379 u64 *num_bytes_out, u64 *stripe_size_out,
2380 u64 start, u64 type)
2381 {
2382 struct btrfs_fs_info *info = extent_root->fs_info;
2383 struct btrfs_fs_devices *fs_devices = info->fs_devices;
2384 struct list_head *cur;
2385 struct map_lookup *map = NULL;
2386 struct extent_map_tree *em_tree;
2387 struct extent_map *em;
2388 struct btrfs_device_info *devices_info = NULL;
2389 u64 total_avail;
2390 int num_stripes; /* total number of stripes to allocate */
2391 int sub_stripes; /* sub_stripes info for map */
2392 int dev_stripes; /* stripes per dev */
2393 int devs_max; /* max devs to use */
2394 int devs_min; /* min devs needed */
2395 int devs_increment; /* ndevs has to be a multiple of this */
2396 int ncopies; /* how many copies to data has */
2397 int ret;
2398 u64 max_stripe_size;
2399 u64 max_chunk_size;
2400 u64 stripe_size;
2401 u64 num_bytes;
2402 int ndevs;
2403 int i;
2404 int j;
2405
2406 if ((type & BTRFS_BLOCK_GROUP_RAID1) &&
2407 (type & BTRFS_BLOCK_GROUP_DUP)) {
2408 WARN_ON(1);
2409 type &= ~BTRFS_BLOCK_GROUP_DUP;
2410 }
2411
2412 if (list_empty(&fs_devices->alloc_list))
2413 return -ENOSPC;
2414
2415 sub_stripes = 1;
2416 dev_stripes = 1;
2417 devs_increment = 1;
2418 ncopies = 1;
2419 devs_max = 0; /* 0 == as many as possible */
2420 devs_min = 1;
2421
2422 /*
2423 * define the properties of each RAID type.
2424 * FIXME: move this to a global table and use it in all RAID
2425 * calculation code
2426 */
2427 if (type & (BTRFS_BLOCK_GROUP_DUP)) {
2428 dev_stripes = 2;
2429 ncopies = 2;
2430 devs_max = 1;
2431 } else if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
2432 devs_min = 2;
2433 } else if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
2434 devs_increment = 2;
2435 ncopies = 2;
2436 devs_max = 2;
2437 devs_min = 2;
2438 } else if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
2439 sub_stripes = 2;
2440 devs_increment = 2;
2441 ncopies = 2;
2442 devs_min = 4;
2443 } else {
2444 devs_max = 1;
2445 }
2446
2447 if (type & BTRFS_BLOCK_GROUP_DATA) {
2448 max_stripe_size = 1024 * 1024 * 1024;
2449 max_chunk_size = 10 * max_stripe_size;
2450 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
2451 max_stripe_size = 256 * 1024 * 1024;
2452 max_chunk_size = max_stripe_size;
2453 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
2454 max_stripe_size = 8 * 1024 * 1024;
2455 max_chunk_size = 2 * max_stripe_size;
2456 } else {
2457 printk(KERN_ERR "btrfs: invalid chunk type 0x%llx requested\n",
2458 type);
2459 BUG_ON(1);
2460 }
2461
2462 /* we don't want a chunk larger than 10% of writeable space */
2463 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
2464 max_chunk_size);
2465
2466 devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices,
2467 GFP_NOFS);
2468 if (!devices_info)
2469 return -ENOMEM;
2470
2471 cur = fs_devices->alloc_list.next;
2472
2473 /*
2474 * in the first pass through the devices list, we gather information
2475 * about the available holes on each device.
2476 */
2477 ndevs = 0;
2478 while (cur != &fs_devices->alloc_list) {
2479 struct btrfs_device *device;
2480 u64 max_avail;
2481 u64 dev_offset;
2482
2483 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
2484
2485 cur = cur->next;
2486
2487 if (!device->writeable) {
2488 printk(KERN_ERR
2489 "btrfs: read-only device in alloc_list\n");
2490 WARN_ON(1);
2491 continue;
2492 }
2493
2494 if (!device->in_fs_metadata)
2495 continue;
2496
2497 if (device->total_bytes > device->bytes_used)
2498 total_avail = device->total_bytes - device->bytes_used;
2499 else
2500 total_avail = 0;
2501
2502 /* If there is no space on this device, skip it. */
2503 if (total_avail == 0)
2504 continue;
2505
2506 ret = find_free_dev_extent(trans, device,
2507 max_stripe_size * dev_stripes,
2508 &dev_offset, &max_avail);
2509 if (ret && ret != -ENOSPC)
2510 goto error;
2511
2512 if (ret == 0)
2513 max_avail = max_stripe_size * dev_stripes;
2514
2515 if (max_avail < BTRFS_STRIPE_LEN * dev_stripes)
2516 continue;
2517
2518 devices_info[ndevs].dev_offset = dev_offset;
2519 devices_info[ndevs].max_avail = max_avail;
2520 devices_info[ndevs].total_avail = total_avail;
2521 devices_info[ndevs].dev = device;
2522 ++ndevs;
2523 }
2524
2525 /*
2526 * now sort the devices by hole size / available space
2527 */
2528 sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
2529 btrfs_cmp_device_info, NULL);
2530
2531 /* round down to number of usable stripes */
2532 ndevs -= ndevs % devs_increment;
2533
2534 if (ndevs < devs_increment * sub_stripes || ndevs < devs_min) {
2535 ret = -ENOSPC;
2536 goto error;
2537 }
2538
2539 if (devs_max && ndevs > devs_max)
2540 ndevs = devs_max;
2541 /*
2542 * the primary goal is to maximize the number of stripes, so use as many
2543 * devices as possible, even if the stripes are not maximum sized.
2544 */
2545 stripe_size = devices_info[ndevs-1].max_avail;
2546 num_stripes = ndevs * dev_stripes;
2547
2548 if (stripe_size * num_stripes > max_chunk_size * ncopies) {
2549 stripe_size = max_chunk_size * ncopies;
2550 do_div(stripe_size, num_stripes);
2551 }
2552
2553 do_div(stripe_size, dev_stripes);
2554 do_div(stripe_size, BTRFS_STRIPE_LEN);
2555 stripe_size *= BTRFS_STRIPE_LEN;
2556
2557 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
2558 if (!map) {
2559 ret = -ENOMEM;
2560 goto error;
2561 }
2562 map->num_stripes = num_stripes;
2563
2564 for (i = 0; i < ndevs; ++i) {
2565 for (j = 0; j < dev_stripes; ++j) {
2566 int s = i * dev_stripes + j;
2567 map->stripes[s].dev = devices_info[i].dev;
2568 map->stripes[s].physical = devices_info[i].dev_offset +
2569 j * stripe_size;
2570 }
2571 }
2572 map->sector_size = extent_root->sectorsize;
2573 map->stripe_len = BTRFS_STRIPE_LEN;
2574 map->io_align = BTRFS_STRIPE_LEN;
2575 map->io_width = BTRFS_STRIPE_LEN;
2576 map->type = type;
2577 map->sub_stripes = sub_stripes;
2578
2579 *map_ret = map;
2580 num_bytes = stripe_size * (num_stripes / ncopies);
2581
2582 *stripe_size_out = stripe_size;
2583 *num_bytes_out = num_bytes;
2584
2585 trace_btrfs_chunk_alloc(info->chunk_root, map, start, num_bytes);
2586
2587 em = alloc_extent_map();
2588 if (!em) {
2589 ret = -ENOMEM;
2590 goto error;
2591 }
2592 em->bdev = (struct block_device *)map;
2593 em->start = start;
2594 em->len = num_bytes;
2595 em->block_start = 0;
2596 em->block_len = em->len;
2597
2598 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
2599 write_lock(&em_tree->lock);
2600 ret = add_extent_mapping(em_tree, em);
2601 write_unlock(&em_tree->lock);
2602 BUG_ON(ret);
2603 free_extent_map(em);
2604
2605 ret = btrfs_make_block_group(trans, extent_root, 0, type,
2606 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2607 start, num_bytes);
2608 BUG_ON(ret);
2609
2610 for (i = 0; i < map->num_stripes; ++i) {
2611 struct btrfs_device *device;
2612 u64 dev_offset;
2613
2614 device = map->stripes[i].dev;
2615 dev_offset = map->stripes[i].physical;
2616
2617 ret = btrfs_alloc_dev_extent(trans, device,
2618 info->chunk_root->root_key.objectid,
2619 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2620 start, dev_offset, stripe_size);
2621 BUG_ON(ret);
2622 }
2623
2624 kfree(devices_info);
2625 return 0;
2626
2627 error:
2628 kfree(map);
2629 kfree(devices_info);
2630 return ret;
2631 }
2632
2633 static int __finish_chunk_alloc(struct btrfs_trans_handle *trans,
2634 struct btrfs_root *extent_root,
2635 struct map_lookup *map, u64 chunk_offset,
2636 u64 chunk_size, u64 stripe_size)
2637 {
2638 u64 dev_offset;
2639 struct btrfs_key key;
2640 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
2641 struct btrfs_device *device;
2642 struct btrfs_chunk *chunk;
2643 struct btrfs_stripe *stripe;
2644 size_t item_size = btrfs_chunk_item_size(map->num_stripes);
2645 int index = 0;
2646 int ret;
2647
2648 chunk = kzalloc(item_size, GFP_NOFS);
2649 if (!chunk)
2650 return -ENOMEM;
2651
2652 index = 0;
2653 while (index < map->num_stripes) {
2654 device = map->stripes[index].dev;
2655 device->bytes_used += stripe_size;
2656 ret = btrfs_update_device(trans, device);
2657 BUG_ON(ret);
2658 index++;
2659 }
2660
2661 spin_lock(&extent_root->fs_info->free_chunk_lock);
2662 extent_root->fs_info->free_chunk_space -= (stripe_size *
2663 map->num_stripes);
2664 spin_unlock(&extent_root->fs_info->free_chunk_lock);
2665
2666 index = 0;
2667 stripe = &chunk->stripe;
2668 while (index < map->num_stripes) {
2669 device = map->stripes[index].dev;
2670 dev_offset = map->stripes[index].physical;
2671
2672 btrfs_set_stack_stripe_devid(stripe, device->devid);
2673 btrfs_set_stack_stripe_offset(stripe, dev_offset);
2674 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
2675 stripe++;
2676 index++;
2677 }
2678
2679 btrfs_set_stack_chunk_length(chunk, chunk_size);
2680 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
2681 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
2682 btrfs_set_stack_chunk_type(chunk, map->type);
2683 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
2684 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
2685 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
2686 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
2687 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
2688
2689 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2690 key.type = BTRFS_CHUNK_ITEM_KEY;
2691 key.offset = chunk_offset;
2692
2693 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
2694 BUG_ON(ret);
2695
2696 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2697 ret = btrfs_add_system_chunk(trans, chunk_root, &key, chunk,
2698 item_size);
2699 BUG_ON(ret);
2700 }
2701
2702 kfree(chunk);
2703 return 0;
2704 }
2705
2706 /*
2707 * Chunk allocation falls into two parts. The first part does works
2708 * that make the new allocated chunk useable, but not do any operation
2709 * that modifies the chunk tree. The second part does the works that
2710 * require modifying the chunk tree. This division is important for the
2711 * bootstrap process of adding storage to a seed btrfs.
2712 */
2713 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
2714 struct btrfs_root *extent_root, u64 type)
2715 {
2716 u64 chunk_offset;
2717 u64 chunk_size;
2718 u64 stripe_size;
2719 struct map_lookup *map;
2720 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
2721 int ret;
2722
2723 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2724 &chunk_offset);
2725 if (ret)
2726 return ret;
2727
2728 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
2729 &stripe_size, chunk_offset, type);
2730 if (ret)
2731 return ret;
2732
2733 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
2734 chunk_size, stripe_size);
2735 BUG_ON(ret);
2736 return 0;
2737 }
2738
2739 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
2740 struct btrfs_root *root,
2741 struct btrfs_device *device)
2742 {
2743 u64 chunk_offset;
2744 u64 sys_chunk_offset;
2745 u64 chunk_size;
2746 u64 sys_chunk_size;
2747 u64 stripe_size;
2748 u64 sys_stripe_size;
2749 u64 alloc_profile;
2750 struct map_lookup *map;
2751 struct map_lookup *sys_map;
2752 struct btrfs_fs_info *fs_info = root->fs_info;
2753 struct btrfs_root *extent_root = fs_info->extent_root;
2754 int ret;
2755
2756 ret = find_next_chunk(fs_info->chunk_root,
2757 BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset);
2758 if (ret)
2759 return ret;
2760
2761 alloc_profile = BTRFS_BLOCK_GROUP_METADATA |
2762 (fs_info->metadata_alloc_profile &
2763 fs_info->avail_metadata_alloc_bits);
2764 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
2765
2766 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
2767 &stripe_size, chunk_offset, alloc_profile);
2768 BUG_ON(ret);
2769
2770 sys_chunk_offset = chunk_offset + chunk_size;
2771
2772 alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM |
2773 (fs_info->system_alloc_profile &
2774 fs_info->avail_system_alloc_bits);
2775 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
2776
2777 ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,
2778 &sys_chunk_size, &sys_stripe_size,
2779 sys_chunk_offset, alloc_profile);
2780 BUG_ON(ret);
2781
2782 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
2783 BUG_ON(ret);
2784
2785 /*
2786 * Modifying chunk tree needs allocating new blocks from both
2787 * system block group and metadata block group. So we only can
2788 * do operations require modifying the chunk tree after both
2789 * block groups were created.
2790 */
2791 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
2792 chunk_size, stripe_size);
2793 BUG_ON(ret);
2794
2795 ret = __finish_chunk_alloc(trans, extent_root, sys_map,
2796 sys_chunk_offset, sys_chunk_size,
2797 sys_stripe_size);
2798 BUG_ON(ret);
2799 return 0;
2800 }
2801
2802 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
2803 {
2804 struct extent_map *em;
2805 struct map_lookup *map;
2806 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
2807 int readonly = 0;
2808 int i;
2809
2810 read_lock(&map_tree->map_tree.lock);
2811 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
2812 read_unlock(&map_tree->map_tree.lock);
2813 if (!em)
2814 return 1;
2815
2816 if (btrfs_test_opt(root, DEGRADED)) {
2817 free_extent_map(em);
2818 return 0;
2819 }
2820
2821 map = (struct map_lookup *)em->bdev;
2822 for (i = 0; i < map->num_stripes; i++) {
2823 if (!map->stripes[i].dev->writeable) {
2824 readonly = 1;
2825 break;
2826 }
2827 }
2828 free_extent_map(em);
2829 return readonly;
2830 }
2831
2832 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
2833 {
2834 extent_map_tree_init(&tree->map_tree);
2835 }
2836
2837 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
2838 {
2839 struct extent_map *em;
2840
2841 while (1) {
2842 write_lock(&tree->map_tree.lock);
2843 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
2844 if (em)
2845 remove_extent_mapping(&tree->map_tree, em);
2846 write_unlock(&tree->map_tree.lock);
2847 if (!em)
2848 break;
2849 kfree(em->bdev);
2850 /* once for us */
2851 free_extent_map(em);
2852 /* once for the tree */
2853 free_extent_map(em);
2854 }
2855 }
2856
2857 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
2858 {
2859 struct extent_map *em;
2860 struct map_lookup *map;
2861 struct extent_map_tree *em_tree = &map_tree->map_tree;
2862 int ret;
2863
2864 read_lock(&em_tree->lock);
2865 em = lookup_extent_mapping(em_tree, logical, len);
2866 read_unlock(&em_tree->lock);
2867 BUG_ON(!em);
2868
2869 BUG_ON(em->start > logical || em->start + em->len < logical);
2870 map = (struct map_lookup *)em->bdev;
2871 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
2872 ret = map->num_stripes;
2873 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
2874 ret = map->sub_stripes;
2875 else
2876 ret = 1;
2877 free_extent_map(em);
2878 return ret;
2879 }
2880
2881 static int find_live_mirror(struct map_lookup *map, int first, int num,
2882 int optimal)
2883 {
2884 int i;
2885 if (map->stripes[optimal].dev->bdev)
2886 return optimal;
2887 for (i = first; i < first + num; i++) {
2888 if (map->stripes[i].dev->bdev)
2889 return i;
2890 }
2891 /* we couldn't find one that doesn't fail. Just return something
2892 * and the io error handling code will clean up eventually
2893 */
2894 return optimal;
2895 }
2896
2897 static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
2898 u64 logical, u64 *length,
2899 struct btrfs_bio **bbio_ret,
2900 int mirror_num)
2901 {
2902 struct extent_map *em;
2903 struct map_lookup *map;
2904 struct extent_map_tree *em_tree = &map_tree->map_tree;
2905 u64 offset;
2906 u64 stripe_offset;
2907 u64 stripe_end_offset;
2908 u64 stripe_nr;
2909 u64 stripe_nr_orig;
2910 u64 stripe_nr_end;
2911 int stripes_allocated = 8;
2912 int stripes_required = 1;
2913 int stripe_index;
2914 int i;
2915 int num_stripes;
2916 int max_errors = 0;
2917 struct btrfs_bio *bbio = NULL;
2918
2919 if (bbio_ret && !(rw & (REQ_WRITE | REQ_DISCARD)))
2920 stripes_allocated = 1;
2921 again:
2922 if (bbio_ret) {
2923 bbio = kzalloc(btrfs_bio_size(stripes_allocated),
2924 GFP_NOFS);
2925 if (!bbio)
2926 return -ENOMEM;
2927
2928 atomic_set(&bbio->error, 0);
2929 }
2930
2931 read_lock(&em_tree->lock);
2932 em = lookup_extent_mapping(em_tree, logical, *length);
2933 read_unlock(&em_tree->lock);
2934
2935 if (!em) {
2936 printk(KERN_CRIT "unable to find logical %llu len %llu\n",
2937 (unsigned long long)logical,
2938 (unsigned long long)*length);
2939 BUG();
2940 }
2941
2942 BUG_ON(em->start > logical || em->start + em->len < logical);
2943 map = (struct map_lookup *)em->bdev;
2944 offset = logical - em->start;
2945
2946 if (mirror_num > map->num_stripes)
2947 mirror_num = 0;
2948
2949 /* if our btrfs_bio struct is too small, back off and try again */
2950 if (rw & REQ_WRITE) {
2951 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
2952 BTRFS_BLOCK_GROUP_DUP)) {
2953 stripes_required = map->num_stripes;
2954 max_errors = 1;
2955 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2956 stripes_required = map->sub_stripes;
2957 max_errors = 1;
2958 }
2959 }
2960 if (rw & REQ_DISCARD) {
2961 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
2962 BTRFS_BLOCK_GROUP_RAID1 |
2963 BTRFS_BLOCK_GROUP_DUP |
2964 BTRFS_BLOCK_GROUP_RAID10)) {
2965 stripes_required = map->num_stripes;
2966 }
2967 }
2968 if (bbio_ret && (rw & (REQ_WRITE | REQ_DISCARD)) &&
2969 stripes_allocated < stripes_required) {
2970 stripes_allocated = map->num_stripes;
2971 free_extent_map(em);
2972 kfree(bbio);
2973 goto again;
2974 }
2975 stripe_nr = offset;
2976 /*
2977 * stripe_nr counts the total number of stripes we have to stride
2978 * to get to this block
2979 */
2980 do_div(stripe_nr, map->stripe_len);
2981
2982 stripe_offset = stripe_nr * map->stripe_len;
2983 BUG_ON(offset < stripe_offset);
2984
2985 /* stripe_offset is the offset of this block in its stripe*/
2986 stripe_offset = offset - stripe_offset;
2987
2988 if (rw & REQ_DISCARD)
2989 *length = min_t(u64, em->len - offset, *length);
2990 else if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
2991 BTRFS_BLOCK_GROUP_RAID1 |
2992 BTRFS_BLOCK_GROUP_RAID10 |
2993 BTRFS_BLOCK_GROUP_DUP)) {
2994 /* we limit the length of each bio to what fits in a stripe */
2995 *length = min_t(u64, em->len - offset,
2996 map->stripe_len - stripe_offset);
2997 } else {
2998 *length = em->len - offset;
2999 }
3000
3001 if (!bbio_ret)
3002 goto out;
3003
3004 num_stripes = 1;
3005 stripe_index = 0;
3006 stripe_nr_orig = stripe_nr;
3007 stripe_nr_end = (offset + *length + map->stripe_len - 1) &
3008 (~(map->stripe_len - 1));
3009 do_div(stripe_nr_end, map->stripe_len);
3010 stripe_end_offset = stripe_nr_end * map->stripe_len -
3011 (offset + *length);
3012 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3013 if (rw & REQ_DISCARD)
3014 num_stripes = min_t(u64, map->num_stripes,
3015 stripe_nr_end - stripe_nr_orig);
3016 stripe_index = do_div(stripe_nr, map->num_stripes);
3017 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
3018 if (rw & (REQ_WRITE | REQ_DISCARD))
3019 num_stripes = map->num_stripes;
3020 else if (mirror_num)
3021 stripe_index = mirror_num - 1;
3022 else {
3023 stripe_index = find_live_mirror(map, 0,
3024 map->num_stripes,
3025 current->pid % map->num_stripes);
3026 mirror_num = stripe_index + 1;
3027 }
3028
3029 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
3030 if (rw & (REQ_WRITE | REQ_DISCARD)) {
3031 num_stripes = map->num_stripes;
3032 } else if (mirror_num) {
3033 stripe_index = mirror_num - 1;
3034 } else {
3035 mirror_num = 1;
3036 }
3037
3038 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3039 int factor = map->num_stripes / map->sub_stripes;
3040
3041 stripe_index = do_div(stripe_nr, factor);
3042 stripe_index *= map->sub_stripes;
3043
3044 if (rw & REQ_WRITE)
3045 num_stripes = map->sub_stripes;
3046 else if (rw & REQ_DISCARD)
3047 num_stripes = min_t(u64, map->sub_stripes *
3048 (stripe_nr_end - stripe_nr_orig),
3049 map->num_stripes);
3050 else if (mirror_num)
3051 stripe_index += mirror_num - 1;
3052 else {
3053 stripe_index = find_live_mirror(map, stripe_index,
3054 map->sub_stripes, stripe_index +
3055 current->pid % map->sub_stripes);
3056 mirror_num = stripe_index + 1;
3057 }
3058 } else {
3059 /*
3060 * after this do_div call, stripe_nr is the number of stripes
3061 * on this device we have to walk to find the data, and
3062 * stripe_index is the number of our device in the stripe array
3063 */
3064 stripe_index = do_div(stripe_nr, map->num_stripes);
3065 mirror_num = stripe_index + 1;
3066 }
3067 BUG_ON(stripe_index >= map->num_stripes);
3068
3069 if (rw & REQ_DISCARD) {
3070 for (i = 0; i < num_stripes; i++) {
3071 bbio->stripes[i].physical =
3072 map->stripes[stripe_index].physical +
3073 stripe_offset + stripe_nr * map->stripe_len;
3074 bbio->stripes[i].dev = map->stripes[stripe_index].dev;
3075
3076 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3077 u64 stripes;
3078 u32 last_stripe = 0;
3079 int j;
3080
3081 div_u64_rem(stripe_nr_end - 1,
3082 map->num_stripes,
3083 &last_stripe);
3084
3085 for (j = 0; j < map->num_stripes; j++) {
3086 u32 test;
3087
3088 div_u64_rem(stripe_nr_end - 1 - j,
3089 map->num_stripes, &test);
3090 if (test == stripe_index)
3091 break;
3092 }
3093 stripes = stripe_nr_end - 1 - j;
3094 do_div(stripes, map->num_stripes);
3095 bbio->stripes[i].length = map->stripe_len *
3096 (stripes - stripe_nr + 1);
3097
3098 if (i == 0) {
3099 bbio->stripes[i].length -=
3100 stripe_offset;
3101 stripe_offset = 0;
3102 }
3103 if (stripe_index == last_stripe)
3104 bbio->stripes[i].length -=
3105 stripe_end_offset;
3106 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3107 u64 stripes;
3108 int j;
3109 int factor = map->num_stripes /
3110 map->sub_stripes;
3111 u32 last_stripe = 0;
3112
3113 div_u64_rem(stripe_nr_end - 1,
3114 factor, &last_stripe);
3115 last_stripe *= map->sub_stripes;
3116
3117 for (j = 0; j < factor; j++) {
3118 u32 test;
3119
3120 div_u64_rem(stripe_nr_end - 1 - j,
3121 factor, &test);
3122
3123 if (test ==
3124 stripe_index / map->sub_stripes)
3125 break;
3126 }
3127 stripes = stripe_nr_end - 1 - j;
3128 do_div(stripes, factor);
3129 bbio->stripes[i].length = map->stripe_len *
3130 (stripes - stripe_nr + 1);
3131
3132 if (i < map->sub_stripes) {
3133 bbio->stripes[i].length -=
3134 stripe_offset;
3135 if (i == map->sub_stripes - 1)
3136 stripe_offset = 0;
3137 }
3138 if (stripe_index >= last_stripe &&
3139 stripe_index <= (last_stripe +
3140 map->sub_stripes - 1)) {
3141 bbio->stripes[i].length -=
3142 stripe_end_offset;
3143 }
3144 } else
3145 bbio->stripes[i].length = *length;
3146
3147 stripe_index++;
3148 if (stripe_index == map->num_stripes) {
3149 /* This could only happen for RAID0/10 */
3150 stripe_index = 0;
3151 stripe_nr++;
3152 }
3153 }
3154 } else {
3155 for (i = 0; i < num_stripes; i++) {
3156 bbio->stripes[i].physical =
3157 map->stripes[stripe_index].physical +
3158 stripe_offset +
3159 stripe_nr * map->stripe_len;
3160 bbio->stripes[i].dev =
3161 map->stripes[stripe_index].dev;
3162 stripe_index++;
3163 }
3164 }
3165 if (bbio_ret) {
3166 *bbio_ret = bbio;
3167 bbio->num_stripes = num_stripes;
3168 bbio->max_errors = max_errors;
3169 bbio->mirror_num = mirror_num;
3170 }
3171 out:
3172 free_extent_map(em);
3173 return 0;
3174 }
3175
3176 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
3177 u64 logical, u64 *length,
3178 struct btrfs_bio **bbio_ret, int mirror_num)
3179 {
3180 return __btrfs_map_block(map_tree, rw, logical, length, bbio_ret,
3181 mirror_num);
3182 }
3183
3184 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
3185 u64 chunk_start, u64 physical, u64 devid,
3186 u64 **logical, int *naddrs, int *stripe_len)
3187 {
3188 struct extent_map_tree *em_tree = &map_tree->map_tree;
3189 struct extent_map *em;
3190 struct map_lookup *map;
3191 u64 *buf;
3192 u64 bytenr;
3193 u64 length;
3194 u64 stripe_nr;
3195 int i, j, nr = 0;
3196
3197 read_lock(&em_tree->lock);
3198 em = lookup_extent_mapping(em_tree, chunk_start, 1);
3199 read_unlock(&em_tree->lock);
3200
3201 BUG_ON(!em || em->start != chunk_start);
3202 map = (struct map_lookup *)em->bdev;
3203
3204 length = em->len;
3205 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
3206 do_div(length, map->num_stripes / map->sub_stripes);
3207 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
3208 do_div(length, map->num_stripes);
3209
3210 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
3211 BUG_ON(!buf);
3212
3213 for (i = 0; i < map->num_stripes; i++) {
3214 if (devid && map->stripes[i].dev->devid != devid)
3215 continue;
3216 if (map->stripes[i].physical > physical ||
3217 map->stripes[i].physical + length <= physical)
3218 continue;
3219
3220 stripe_nr = physical - map->stripes[i].physical;
3221 do_div(stripe_nr, map->stripe_len);
3222
3223 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3224 stripe_nr = stripe_nr * map->num_stripes + i;
3225 do_div(stripe_nr, map->sub_stripes);
3226 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3227 stripe_nr = stripe_nr * map->num_stripes + i;
3228 }
3229 bytenr = chunk_start + stripe_nr * map->stripe_len;
3230 WARN_ON(nr >= map->num_stripes);
3231 for (j = 0; j < nr; j++) {
3232 if (buf[j] == bytenr)
3233 break;
3234 }
3235 if (j == nr) {
3236 WARN_ON(nr >= map->num_stripes);
3237 buf[nr++] = bytenr;
3238 }
3239 }
3240
3241 *logical = buf;
3242 *naddrs = nr;
3243 *stripe_len = map->stripe_len;
3244
3245 free_extent_map(em);
3246 return 0;
3247 }
3248
3249 static void btrfs_end_bio(struct bio *bio, int err)
3250 {
3251 struct btrfs_bio *bbio = bio->bi_private;
3252 int is_orig_bio = 0;
3253
3254 if (err)
3255 atomic_inc(&bbio->error);
3256
3257 if (bio == bbio->orig_bio)
3258 is_orig_bio = 1;
3259
3260 if (atomic_dec_and_test(&bbio->stripes_pending)) {
3261 if (!is_orig_bio) {
3262 bio_put(bio);
3263 bio = bbio->orig_bio;
3264 }
3265 bio->bi_private = bbio->private;
3266 bio->bi_end_io = bbio->end_io;
3267 bio->bi_bdev = (struct block_device *)
3268 (unsigned long)bbio->mirror_num;
3269 /* only send an error to the higher layers if it is
3270 * beyond the tolerance of the multi-bio
3271 */
3272 if (atomic_read(&bbio->error) > bbio->max_errors) {
3273 err = -EIO;
3274 } else {
3275 /*
3276 * this bio is actually up to date, we didn't
3277 * go over the max number of errors
3278 */
3279 set_bit(BIO_UPTODATE, &bio->bi_flags);
3280 err = 0;
3281 }
3282 kfree(bbio);
3283
3284 bio_endio(bio, err);
3285 } else if (!is_orig_bio) {
3286 bio_put(bio);
3287 }
3288 }
3289
3290 struct async_sched {
3291 struct bio *bio;
3292 int rw;
3293 struct btrfs_fs_info *info;
3294 struct btrfs_work work;
3295 };
3296
3297 /*
3298 * see run_scheduled_bios for a description of why bios are collected for
3299 * async submit.
3300 *
3301 * This will add one bio to the pending list for a device and make sure
3302 * the work struct is scheduled.
3303 */
3304 static noinline int schedule_bio(struct btrfs_root *root,
3305 struct btrfs_device *device,
3306 int rw, struct bio *bio)
3307 {
3308 int should_queue = 1;
3309 struct btrfs_pending_bios *pending_bios;
3310
3311 /* don't bother with additional async steps for reads, right now */
3312 if (!(rw & REQ_WRITE)) {
3313 bio_get(bio);
3314 submit_bio(rw, bio);
3315 bio_put(bio);
3316 return 0;
3317 }
3318
3319 /*
3320 * nr_async_bios allows us to reliably return congestion to the
3321 * higher layers. Otherwise, the async bio makes it appear we have
3322 * made progress against dirty pages when we've really just put it
3323 * on a queue for later
3324 */
3325 atomic_inc(&root->fs_info->nr_async_bios);
3326 WARN_ON(bio->bi_next);
3327 bio->bi_next = NULL;
3328 bio->bi_rw |= rw;
3329
3330 spin_lock(&device->io_lock);
3331 if (bio->bi_rw & REQ_SYNC)
3332 pending_bios = &device->pending_sync_bios;
3333 else
3334 pending_bios = &device->pending_bios;
3335
3336 if (pending_bios->tail)
3337 pending_bios->tail->bi_next = bio;
3338
3339 pending_bios->tail = bio;
3340 if (!pending_bios->head)
3341 pending_bios->head = bio;
3342 if (device->running_pending)
3343 should_queue = 0;
3344
3345 spin_unlock(&device->io_lock);
3346
3347 if (should_queue)
3348 btrfs_queue_worker(&root->fs_info->submit_workers,
3349 &device->work);
3350 return 0;
3351 }
3352
3353 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
3354 int mirror_num, int async_submit)
3355 {
3356 struct btrfs_mapping_tree *map_tree;
3357 struct btrfs_device *dev;
3358 struct bio *first_bio = bio;
3359 u64 logical = (u64)bio->bi_sector << 9;
3360 u64 length = 0;
3361 u64 map_length;
3362 int ret;
3363 int dev_nr = 0;
3364 int total_devs = 1;
3365 struct btrfs_bio *bbio = NULL;
3366
3367 length = bio->bi_size;
3368 map_tree = &root->fs_info->mapping_tree;
3369 map_length = length;
3370
3371 ret = btrfs_map_block(map_tree, rw, logical, &map_length, &bbio,
3372 mirror_num);
3373 BUG_ON(ret);
3374
3375 total_devs = bbio->num_stripes;
3376 if (map_length < length) {
3377 printk(KERN_CRIT "mapping failed logical %llu bio len %llu "
3378 "len %llu\n", (unsigned long long)logical,
3379 (unsigned long long)length,
3380 (unsigned long long)map_length);
3381 BUG();
3382 }
3383
3384 bbio->orig_bio = first_bio;
3385 bbio->private = first_bio->bi_private;
3386 bbio->end_io = first_bio->bi_end_io;
3387 atomic_set(&bbio->stripes_pending, bbio->num_stripes);
3388
3389 while (dev_nr < total_devs) {
3390 if (dev_nr < total_devs - 1) {
3391 bio = bio_clone(first_bio, GFP_NOFS);
3392 BUG_ON(!bio);
3393 } else {
3394 bio = first_bio;
3395 }
3396 bio->bi_private = bbio;
3397 bio->bi_end_io = btrfs_end_bio;
3398 bio->bi_sector = bbio->stripes[dev_nr].physical >> 9;
3399 dev = bbio->stripes[dev_nr].dev;
3400 if (dev && dev->bdev && (rw != WRITE || dev->writeable)) {
3401 pr_debug("btrfs_map_bio: rw %d, secor=%llu, dev=%lu "
3402 "(%s id %llu), size=%u\n", rw,
3403 (u64)bio->bi_sector, (u_long)dev->bdev->bd_dev,
3404 dev->name, dev->devid, bio->bi_size);
3405 bio->bi_bdev = dev->bdev;
3406 if (async_submit)
3407 schedule_bio(root, dev, rw, bio);
3408 else
3409 submit_bio(rw, bio);
3410 } else {
3411 bio->bi_bdev = root->fs_info->fs_devices->latest_bdev;
3412 bio->bi_sector = logical >> 9;
3413 bio_endio(bio, -EIO);
3414 }
3415 dev_nr++;
3416 }
3417 return 0;
3418 }
3419
3420 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
3421 u8 *uuid, u8 *fsid)
3422 {
3423 struct btrfs_device *device;
3424 struct btrfs_fs_devices *cur_devices;
3425
3426 cur_devices = root->fs_info->fs_devices;
3427 while (cur_devices) {
3428 if (!fsid ||
3429 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
3430 device = __find_device(&cur_devices->devices,
3431 devid, uuid);
3432 if (device)
3433 return device;
3434 }
3435 cur_devices = cur_devices->seed;
3436 }
3437 return NULL;
3438 }
3439
3440 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
3441 u64 devid, u8 *dev_uuid)
3442 {
3443 struct btrfs_device *device;
3444 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
3445
3446 device = kzalloc(sizeof(*device), GFP_NOFS);
3447 if (!device)
3448 return NULL;
3449 list_add(&device->dev_list,
3450 &fs_devices->devices);
3451 device->dev_root = root->fs_info->dev_root;
3452 device->devid = devid;
3453 device->work.func = pending_bios_fn;
3454 device->fs_devices = fs_devices;
3455 device->missing = 1;
3456 fs_devices->num_devices++;
3457 fs_devices->missing_devices++;
3458 spin_lock_init(&device->io_lock);
3459 INIT_LIST_HEAD(&device->dev_alloc_list);
3460 memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
3461 return device;
3462 }
3463
3464 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
3465 struct extent_buffer *leaf,
3466 struct btrfs_chunk *chunk)
3467 {
3468 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
3469 struct map_lookup *map;
3470 struct extent_map *em;
3471 u64 logical;
3472 u64 length;
3473 u64 devid;
3474 u8 uuid[BTRFS_UUID_SIZE];
3475 int num_stripes;
3476 int ret;
3477 int i;
3478
3479 logical = key->offset;
3480 length = btrfs_chunk_length(leaf, chunk);
3481
3482 read_lock(&map_tree->map_tree.lock);
3483 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
3484 read_unlock(&map_tree->map_tree.lock);
3485
3486 /* already mapped? */
3487 if (em && em->start <= logical && em->start + em->len > logical) {
3488 free_extent_map(em);
3489 return 0;
3490 } else if (em) {
3491 free_extent_map(em);
3492 }
3493
3494 em = alloc_extent_map();
3495 if (!em)
3496 return -ENOMEM;
3497 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
3498 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
3499 if (!map) {
3500 free_extent_map(em);
3501 return -ENOMEM;
3502 }
3503
3504 em->bdev = (struct block_device *)map;
3505 em->start = logical;
3506 em->len = length;
3507 em->block_start = 0;
3508 em->block_len = em->len;
3509
3510 map->num_stripes = num_stripes;
3511 map->io_width = btrfs_chunk_io_width(leaf, chunk);
3512 map->io_align = btrfs_chunk_io_align(leaf, chunk);
3513 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
3514 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
3515 map->type = btrfs_chunk_type(leaf, chunk);
3516 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
3517 for (i = 0; i < num_stripes; i++) {
3518 map->stripes[i].physical =
3519 btrfs_stripe_offset_nr(leaf, chunk, i);
3520 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
3521 read_extent_buffer(leaf, uuid, (unsigned long)
3522 btrfs_stripe_dev_uuid_nr(chunk, i),
3523 BTRFS_UUID_SIZE);
3524 map->stripes[i].dev = btrfs_find_device(root, devid, uuid,
3525 NULL);
3526 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
3527 kfree(map);
3528 free_extent_map(em);
3529 return -EIO;
3530 }
3531 if (!map->stripes[i].dev) {
3532 map->stripes[i].dev =
3533 add_missing_dev(root, devid, uuid);
3534 if (!map->stripes[i].dev) {
3535 kfree(map);
3536 free_extent_map(em);
3537 return -EIO;
3538 }
3539 }
3540 map->stripes[i].dev->in_fs_metadata = 1;
3541 }
3542
3543 write_lock(&map_tree->map_tree.lock);
3544 ret = add_extent_mapping(&map_tree->map_tree, em);
3545 write_unlock(&map_tree->map_tree.lock);
3546 BUG_ON(ret);
3547 free_extent_map(em);
3548
3549 return 0;
3550 }
3551
3552 static int fill_device_from_item(struct extent_buffer *leaf,
3553 struct btrfs_dev_item *dev_item,
3554 struct btrfs_device *device)
3555 {
3556 unsigned long ptr;
3557
3558 device->devid = btrfs_device_id(leaf, dev_item);
3559 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
3560 device->total_bytes = device->disk_total_bytes;
3561 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
3562 device->type = btrfs_device_type(leaf, dev_item);
3563 device->io_align = btrfs_device_io_align(leaf, dev_item);
3564 device->io_width = btrfs_device_io_width(leaf, dev_item);
3565 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
3566
3567 ptr = (unsigned long)btrfs_device_uuid(dev_item);
3568 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
3569
3570 return 0;
3571 }
3572
3573 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
3574 {
3575 struct btrfs_fs_devices *fs_devices;
3576 int ret;
3577
3578 mutex_lock(&uuid_mutex);
3579
3580 fs_devices = root->fs_info->fs_devices->seed;
3581 while (fs_devices) {
3582 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
3583 ret = 0;
3584 goto out;
3585 }
3586 fs_devices = fs_devices->seed;
3587 }
3588
3589 fs_devices = find_fsid(fsid);
3590 if (!fs_devices) {
3591 ret = -ENOENT;
3592 goto out;
3593 }
3594
3595 fs_devices = clone_fs_devices(fs_devices);
3596 if (IS_ERR(fs_devices)) {
3597 ret = PTR_ERR(fs_devices);
3598 goto out;
3599 }
3600
3601 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
3602 root->fs_info->bdev_holder);
3603 if (ret)
3604 goto out;
3605
3606 if (!fs_devices->seeding) {
3607 __btrfs_close_devices(fs_devices);
3608 free_fs_devices(fs_devices);
3609 ret = -EINVAL;
3610 goto out;
3611 }
3612
3613 fs_devices->seed = root->fs_info->fs_devices->seed;
3614 root->fs_info->fs_devices->seed = fs_devices;
3615 out:
3616 mutex_unlock(&uuid_mutex);
3617 return ret;
3618 }
3619
3620 static int read_one_dev(struct btrfs_root *root,
3621 struct extent_buffer *leaf,
3622 struct btrfs_dev_item *dev_item)
3623 {
3624 struct btrfs_device *device;
3625 u64 devid;
3626 int ret;
3627 u8 fs_uuid[BTRFS_UUID_SIZE];
3628 u8 dev_uuid[BTRFS_UUID_SIZE];
3629
3630 devid = btrfs_device_id(leaf, dev_item);
3631 read_extent_buffer(leaf, dev_uuid,
3632 (unsigned long)btrfs_device_uuid(dev_item),
3633 BTRFS_UUID_SIZE);
3634 read_extent_buffer(leaf, fs_uuid,
3635 (unsigned long)btrfs_device_fsid(dev_item),
3636 BTRFS_UUID_SIZE);
3637
3638 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
3639 ret = open_seed_devices(root, fs_uuid);
3640 if (ret && !btrfs_test_opt(root, DEGRADED))
3641 return ret;
3642 }
3643
3644 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
3645 if (!device || !device->bdev) {
3646 if (!btrfs_test_opt(root, DEGRADED))
3647 return -EIO;
3648
3649 if (!device) {
3650 printk(KERN_WARNING "warning devid %llu missing\n",
3651 (unsigned long long)devid);
3652 device = add_missing_dev(root, devid, dev_uuid);
3653 if (!device)
3654 return -ENOMEM;
3655 } else if (!device->missing) {
3656 /*
3657 * this happens when a device that was properly setup
3658 * in the device info lists suddenly goes bad.
3659 * device->bdev is NULL, and so we have to set
3660 * device->missing to one here
3661 */
3662 root->fs_info->fs_devices->missing_devices++;
3663 device->missing = 1;
3664 }
3665 }
3666
3667 if (device->fs_devices != root->fs_info->fs_devices) {
3668 BUG_ON(device->writeable);
3669 if (device->generation !=
3670 btrfs_device_generation(leaf, dev_item))
3671 return -EINVAL;
3672 }
3673
3674 fill_device_from_item(leaf, dev_item, device);
3675 device->dev_root = root->fs_info->dev_root;
3676 device->in_fs_metadata = 1;
3677 if (device->writeable) {
3678 device->fs_devices->total_rw_bytes += device->total_bytes;
3679 spin_lock(&root->fs_info->free_chunk_lock);
3680 root->fs_info->free_chunk_space += device->total_bytes -
3681 device->bytes_used;
3682 spin_unlock(&root->fs_info->free_chunk_lock);
3683 }
3684 ret = 0;
3685 return ret;
3686 }
3687
3688 int btrfs_read_sys_array(struct btrfs_root *root)
3689 {
3690 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3691 struct extent_buffer *sb;
3692 struct btrfs_disk_key *disk_key;
3693 struct btrfs_chunk *chunk;
3694 u8 *ptr;
3695 unsigned long sb_ptr;
3696 int ret = 0;
3697 u32 num_stripes;
3698 u32 array_size;
3699 u32 len = 0;
3700 u32 cur;
3701 struct btrfs_key key;
3702
3703 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
3704 BTRFS_SUPER_INFO_SIZE);
3705 if (!sb)
3706 return -ENOMEM;
3707 btrfs_set_buffer_uptodate(sb);
3708 btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0);
3709
3710 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
3711 array_size = btrfs_super_sys_array_size(super_copy);
3712
3713 ptr = super_copy->sys_chunk_array;
3714 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
3715 cur = 0;
3716
3717 while (cur < array_size) {
3718 disk_key = (struct btrfs_disk_key *)ptr;
3719 btrfs_disk_key_to_cpu(&key, disk_key);
3720
3721 len = sizeof(*disk_key); ptr += len;
3722 sb_ptr += len;
3723 cur += len;
3724
3725 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
3726 chunk = (struct btrfs_chunk *)sb_ptr;
3727 ret = read_one_chunk(root, &key, sb, chunk);
3728 if (ret)
3729 break;
3730 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
3731 len = btrfs_chunk_item_size(num_stripes);
3732 } else {
3733 ret = -EIO;
3734 break;
3735 }
3736 ptr += len;
3737 sb_ptr += len;
3738 cur += len;
3739 }
3740 free_extent_buffer(sb);
3741 return ret;
3742 }
3743
3744 int btrfs_read_chunk_tree(struct btrfs_root *root)
3745 {
3746 struct btrfs_path *path;
3747 struct extent_buffer *leaf;
3748 struct btrfs_key key;
3749 struct btrfs_key found_key;
3750 int ret;
3751 int slot;
3752
3753 root = root->fs_info->chunk_root;
3754
3755 path = btrfs_alloc_path();
3756 if (!path)
3757 return -ENOMEM;
3758
3759 /* first we search for all of the device items, and then we
3760 * read in all of the chunk items. This way we can create chunk
3761 * mappings that reference all of the devices that are afound
3762 */
3763 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
3764 key.offset = 0;
3765 key.type = 0;
3766 again:
3767 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3768 if (ret < 0)
3769 goto error;
3770 while (1) {
3771 leaf = path->nodes[0];
3772 slot = path->slots[0];
3773 if (slot >= btrfs_header_nritems(leaf)) {
3774 ret = btrfs_next_leaf(root, path);
3775 if (ret == 0)
3776 continue;
3777 if (ret < 0)
3778 goto error;
3779 break;
3780 }
3781 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3782 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
3783 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
3784 break;
3785 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
3786 struct btrfs_dev_item *dev_item;
3787 dev_item = btrfs_item_ptr(leaf, slot,
3788 struct btrfs_dev_item);
3789 ret = read_one_dev(root, leaf, dev_item);
3790 if (ret)
3791 goto error;
3792 }
3793 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
3794 struct btrfs_chunk *chunk;
3795 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
3796 ret = read_one_chunk(root, &found_key, leaf, chunk);
3797 if (ret)
3798 goto error;
3799 }
3800 path->slots[0]++;
3801 }
3802 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
3803 key.objectid = 0;
3804 btrfs_release_path(path);
3805 goto again;
3806 }
3807 ret = 0;
3808 error:
3809 btrfs_free_path(path);
3810 return ret;
3811 }
Linux with added FPC-III support