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checkpatch: add a "prefer __aligned" check
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / btrfs / volumes.c
blob19450bc536327c77f7add37e723b668da410eedd
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 struct blk_plug plug;
146
147 /*
148 * this function runs all the bios we've collected for
149 * a particular device. We don't want to wander off to
150 * another device without first sending all of these down.
151 * So, setup a plug here and finish it off before we return
152 */
153 blk_start_plug(&plug);
154
155 bdi = blk_get_backing_dev_info(device->bdev);
156 fs_info = device->dev_root->fs_info;
157 limit = btrfs_async_submit_limit(fs_info);
158 limit = limit * 2 / 3;
159
160 loop:
161 spin_lock(&device->io_lock);
162
163 loop_lock:
164 num_run = 0;
165
166 /* take all the bios off the list at once and process them
167 * later on (without the lock held). But, remember the
168 * tail and other pointers so the bios can be properly reinserted
169 * into the list if we hit congestion
170 */
171 if (!force_reg && device->pending_sync_bios.head) {
172 pending_bios = &device->pending_sync_bios;
173 force_reg = 1;
174 } else {
175 pending_bios = &device->pending_bios;
176 force_reg = 0;
177 }
178
179 pending = pending_bios->head;
180 tail = pending_bios->tail;
181 WARN_ON(pending && !tail);
182
183 /*
184 * if pending was null this time around, no bios need processing
185 * at all and we can stop. Otherwise it'll loop back up again
186 * and do an additional check so no bios are missed.
187 *
188 * device->running_pending is used to synchronize with the
189 * schedule_bio code.
190 */
191 if (device->pending_sync_bios.head == NULL &&
192 device->pending_bios.head == NULL) {
193 again = 0;
194 device->running_pending = 0;
195 } else {
196 again = 1;
197 device->running_pending = 1;
198 }
199
200 pending_bios->head = NULL;
201 pending_bios->tail = NULL;
202
203 spin_unlock(&device->io_lock);
204
205 while (pending) {
206
207 rmb();
208 /* we want to work on both lists, but do more bios on the
209 * sync list than the regular list
210 */
211 if ((num_run > 32 &&
212 pending_bios != &device->pending_sync_bios &&
213 device->pending_sync_bios.head) ||
214 (num_run > 64 && pending_bios == &device->pending_sync_bios &&
215 device->pending_bios.head)) {
216 spin_lock(&device->io_lock);
217 requeue_list(pending_bios, pending, tail);
218 goto loop_lock;
219 }
220
221 cur = pending;
222 pending = pending->bi_next;
223 cur->bi_next = NULL;
224 atomic_dec(&fs_info->nr_async_bios);
225
226 if (atomic_read(&fs_info->nr_async_bios) < limit &&
227 waitqueue_active(&fs_info->async_submit_wait))
228 wake_up(&fs_info->async_submit_wait);
229
230 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
231
232 submit_bio(cur->bi_rw, cur);
233 num_run++;
234 batch_run++;
235 if (need_resched())
236 cond_resched();
237
238 /*
239 * we made progress, there is more work to do and the bdi
240 * is now congested. Back off and let other work structs
241 * run instead
242 */
243 if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
244 fs_info->fs_devices->open_devices > 1) {
245 struct io_context *ioc;
246
247 ioc = current->io_context;
248
249 /*
250 * the main goal here is that we don't want to
251 * block if we're going to be able to submit
252 * more requests without blocking.
253 *
254 * This code does two great things, it pokes into
255 * the elevator code from a filesystem _and_
256 * it makes assumptions about how batching works.
257 */
258 if (ioc && ioc->nr_batch_requests > 0 &&
259 time_before(jiffies, ioc->last_waited + HZ/50UL) &&
260 (last_waited == 0 ||
261 ioc->last_waited == last_waited)) {
262 /*
263 * we want to go through our batch of
264 * requests and stop. So, we copy out
265 * the ioc->last_waited time and test
266 * against it before looping
267 */
268 last_waited = ioc->last_waited;
269 if (need_resched())
270 cond_resched();
271 continue;
272 }
273 spin_lock(&device->io_lock);
274 requeue_list(pending_bios, pending, tail);
275 device->running_pending = 1;
276
277 spin_unlock(&device->io_lock);
278 btrfs_requeue_work(&device->work);
279 goto done;
280 }
281 }
282
283 cond_resched();
284 if (again)
285 goto loop;
286
287 spin_lock(&device->io_lock);
288 if (device->pending_bios.head || device->pending_sync_bios.head)
289 goto loop_lock;
290 spin_unlock(&device->io_lock);
291
292 done:
293 blk_finish_plug(&plug);
294 return 0;
295 }
296
297 static void pending_bios_fn(struct btrfs_work *work)
298 {
299 struct btrfs_device *device;
300
301 device = container_of(work, struct btrfs_device, work);
302 run_scheduled_bios(device);
303 }
304
305 static noinline int device_list_add(const char *path,
306 struct btrfs_super_block *disk_super,
307 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
308 {
309 struct btrfs_device *device;
310 struct btrfs_fs_devices *fs_devices;
311 u64 found_transid = btrfs_super_generation(disk_super);
312 char *name;
313
314 fs_devices = find_fsid(disk_super->fsid);
315 if (!fs_devices) {
316 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
317 if (!fs_devices)
318 return -ENOMEM;
319 INIT_LIST_HEAD(&fs_devices->devices);
320 INIT_LIST_HEAD(&fs_devices->alloc_list);
321 list_add(&fs_devices->list, &fs_uuids);
322 memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
323 fs_devices->latest_devid = devid;
324 fs_devices->latest_trans = found_transid;
325 mutex_init(&fs_devices->device_list_mutex);
326 device = NULL;
327 } else {
328 device = __find_device(&fs_devices->devices, devid,
329 disk_super->dev_item.uuid);
330 }
331 if (!device) {
332 if (fs_devices->opened)
333 return -EBUSY;
334
335 device = kzalloc(sizeof(*device), GFP_NOFS);
336 if (!device) {
337 /* we can safely leave the fs_devices entry around */
338 return -ENOMEM;
339 }
340 device->devid = devid;
341 device->work.func = pending_bios_fn;
342 memcpy(device->uuid, disk_super->dev_item.uuid,
343 BTRFS_UUID_SIZE);
344 spin_lock_init(&device->io_lock);
345 device->name = kstrdup(path, GFP_NOFS);
346 if (!device->name) {
347 kfree(device);
348 return -ENOMEM;
349 }
350 INIT_LIST_HEAD(&device->dev_alloc_list);
351
352 mutex_lock(&fs_devices->device_list_mutex);
353 list_add_rcu(&device->dev_list, &fs_devices->devices);
354 mutex_unlock(&fs_devices->device_list_mutex);
355
356 device->fs_devices = fs_devices;
357 fs_devices->num_devices++;
358 } else if (!device->name || strcmp(device->name, path)) {
359 name = kstrdup(path, GFP_NOFS);
360 if (!name)
361 return -ENOMEM;
362 kfree(device->name);
363 device->name = name;
364 if (device->missing) {
365 fs_devices->missing_devices--;
366 device->missing = 0;
367 }
368 }
369
370 if (found_transid > fs_devices->latest_trans) {
371 fs_devices->latest_devid = devid;
372 fs_devices->latest_trans = found_transid;
373 }
374 *fs_devices_ret = fs_devices;
375 return 0;
376 }
377
378 static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
379 {
380 struct btrfs_fs_devices *fs_devices;
381 struct btrfs_device *device;
382 struct btrfs_device *orig_dev;
383
384 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
385 if (!fs_devices)
386 return ERR_PTR(-ENOMEM);
387
388 INIT_LIST_HEAD(&fs_devices->devices);
389 INIT_LIST_HEAD(&fs_devices->alloc_list);
390 INIT_LIST_HEAD(&fs_devices->list);
391 mutex_init(&fs_devices->device_list_mutex);
392 fs_devices->latest_devid = orig->latest_devid;
393 fs_devices->latest_trans = orig->latest_trans;
394 memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid));
395
396 /* We have held the volume lock, it is safe to get the devices. */
397 list_for_each_entry(orig_dev, &orig->devices, dev_list) {
398 device = kzalloc(sizeof(*device), GFP_NOFS);
399 if (!device)
400 goto error;
401
402 device->name = kstrdup(orig_dev->name, GFP_NOFS);
403 if (!device->name) {
404 kfree(device);
405 goto error;
406 }
407
408 device->devid = orig_dev->devid;
409 device->work.func = pending_bios_fn;
410 memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid));
411 spin_lock_init(&device->io_lock);
412 INIT_LIST_HEAD(&device->dev_list);
413 INIT_LIST_HEAD(&device->dev_alloc_list);
414
415 list_add(&device->dev_list, &fs_devices->devices);
416 device->fs_devices = fs_devices;
417 fs_devices->num_devices++;
418 }
419 return fs_devices;
420 error:
421 free_fs_devices(fs_devices);
422 return ERR_PTR(-ENOMEM);
423 }
424
425 int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
426 {
427 struct btrfs_device *device, *next;
428
429 mutex_lock(&uuid_mutex);
430 again:
431 /* This is the initialized path, it is safe to release the devices. */
432 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
433 if (device->in_fs_metadata)
434 continue;
435
436 if (device->bdev) {
437 blkdev_put(device->bdev, device->mode);
438 device->bdev = NULL;
439 fs_devices->open_devices--;
440 }
441 if (device->writeable) {
442 list_del_init(&device->dev_alloc_list);
443 device->writeable = 0;
444 fs_devices->rw_devices--;
445 }
446 list_del_init(&device->dev_list);
447 fs_devices->num_devices--;
448 kfree(device->name);
449 kfree(device);
450 }
451
452 if (fs_devices->seed) {
453 fs_devices = fs_devices->seed;
454 goto again;
455 }
456
457 mutex_unlock(&uuid_mutex);
458 return 0;
459 }
460
461 static void __free_device(struct work_struct *work)
462 {
463 struct btrfs_device *device;
464
465 device = container_of(work, struct btrfs_device, rcu_work);
466
467 if (device->bdev)
468 blkdev_put(device->bdev, device->mode);
469
470 kfree(device->name);
471 kfree(device);
472 }
473
474 static void free_device(struct rcu_head *head)
475 {
476 struct btrfs_device *device;
477
478 device = container_of(head, struct btrfs_device, rcu);
479
480 INIT_WORK(&device->rcu_work, __free_device);
481 schedule_work(&device->rcu_work);
482 }
483
484 static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
485 {
486 struct btrfs_device *device;
487
488 if (--fs_devices->opened > 0)
489 return 0;
490
491 mutex_lock(&fs_devices->device_list_mutex);
492 list_for_each_entry(device, &fs_devices->devices, dev_list) {
493 struct btrfs_device *new_device;
494
495 if (device->bdev)
496 fs_devices->open_devices--;
497
498 if (device->writeable) {
499 list_del_init(&device->dev_alloc_list);
500 fs_devices->rw_devices--;
501 }
502
503 new_device = kmalloc(sizeof(*new_device), GFP_NOFS);
504 BUG_ON(!new_device);
505 memcpy(new_device, device, sizeof(*new_device));
506 new_device->name = kstrdup(device->name, GFP_NOFS);
507 BUG_ON(device->name && !new_device->name);
508 new_device->bdev = NULL;
509 new_device->writeable = 0;
510 new_device->in_fs_metadata = 0;
511 list_replace_rcu(&device->dev_list, &new_device->dev_list);
512
513 call_rcu(&device->rcu, free_device);
514 }
515 mutex_unlock(&fs_devices->device_list_mutex);
516
517 WARN_ON(fs_devices->open_devices);
518 WARN_ON(fs_devices->rw_devices);
519 fs_devices->opened = 0;
520 fs_devices->seeding = 0;
521
522 return 0;
523 }
524
525 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
526 {
527 struct btrfs_fs_devices *seed_devices = NULL;
528 int ret;
529
530 mutex_lock(&uuid_mutex);
531 ret = __btrfs_close_devices(fs_devices);
532 if (!fs_devices->opened) {
533 seed_devices = fs_devices->seed;
534 fs_devices->seed = NULL;
535 }
536 mutex_unlock(&uuid_mutex);
537
538 while (seed_devices) {
539 fs_devices = seed_devices;
540 seed_devices = fs_devices->seed;
541 __btrfs_close_devices(fs_devices);
542 free_fs_devices(fs_devices);
543 }
544 return ret;
545 }
546
547 static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
548 fmode_t flags, void *holder)
549 {
550 struct block_device *bdev;
551 struct list_head *head = &fs_devices->devices;
552 struct btrfs_device *device;
553 struct block_device *latest_bdev = NULL;
554 struct buffer_head *bh;
555 struct btrfs_super_block *disk_super;
556 u64 latest_devid = 0;
557 u64 latest_transid = 0;
558 u64 devid;
559 int seeding = 1;
560 int ret = 0;
561
562 flags |= FMODE_EXCL;
563
564 list_for_each_entry(device, head, dev_list) {
565 if (device->bdev)
566 continue;
567 if (!device->name)
568 continue;
569
570 bdev = blkdev_get_by_path(device->name, flags, holder);
571 if (IS_ERR(bdev)) {
572 printk(KERN_INFO "open %s failed\n", device->name);
573 goto error;
574 }
575 set_blocksize(bdev, 4096);
576
577 bh = btrfs_read_dev_super(bdev);
578 if (!bh) {
579 ret = -EINVAL;
580 goto error_close;
581 }
582
583 disk_super = (struct btrfs_super_block *)bh->b_data;
584 devid = btrfs_stack_device_id(&disk_super->dev_item);
585 if (devid != device->devid)
586 goto error_brelse;
587
588 if (memcmp(device->uuid, disk_super->dev_item.uuid,
589 BTRFS_UUID_SIZE))
590 goto error_brelse;
591
592 device->generation = btrfs_super_generation(disk_super);
593 if (!latest_transid || device->generation > latest_transid) {
594 latest_devid = devid;
595 latest_transid = device->generation;
596 latest_bdev = bdev;
597 }
598
599 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
600 device->writeable = 0;
601 } else {
602 device->writeable = !bdev_read_only(bdev);
603 seeding = 0;
604 }
605
606 device->bdev = bdev;
607 device->in_fs_metadata = 0;
608 device->mode = flags;
609
610 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
611 fs_devices->rotating = 1;
612
613 fs_devices->open_devices++;
614 if (device->writeable) {
615 fs_devices->rw_devices++;
616 list_add(&device->dev_alloc_list,
617 &fs_devices->alloc_list);
618 }
619 brelse(bh);
620 continue;
621
622 error_brelse:
623 brelse(bh);
624 error_close:
625 blkdev_put(bdev, flags);
626 error:
627 continue;
628 }
629 if (fs_devices->open_devices == 0) {
630 ret = -EIO;
631 goto out;
632 }
633 fs_devices->seeding = seeding;
634 fs_devices->opened = 1;
635 fs_devices->latest_bdev = latest_bdev;
636 fs_devices->latest_devid = latest_devid;
637 fs_devices->latest_trans = latest_transid;
638 fs_devices->total_rw_bytes = 0;
639 out:
640 return ret;
641 }
642
643 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
644 fmode_t flags, void *holder)
645 {
646 int ret;
647
648 mutex_lock(&uuid_mutex);
649 if (fs_devices->opened) {
650 fs_devices->opened++;
651 ret = 0;
652 } else {
653 ret = __btrfs_open_devices(fs_devices, flags, holder);
654 }
655 mutex_unlock(&uuid_mutex);
656 return ret;
657 }
658
659 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
660 struct btrfs_fs_devices **fs_devices_ret)
661 {
662 struct btrfs_super_block *disk_super;
663 struct block_device *bdev;
664 struct buffer_head *bh;
665 int ret;
666 u64 devid;
667 u64 transid;
668
669 mutex_lock(&uuid_mutex);
670
671 flags |= FMODE_EXCL;
672 bdev = blkdev_get_by_path(path, flags, holder);
673
674 if (IS_ERR(bdev)) {
675 ret = PTR_ERR(bdev);
676 goto error;
677 }
678
679 ret = set_blocksize(bdev, 4096);
680 if (ret)
681 goto error_close;
682 bh = btrfs_read_dev_super(bdev);
683 if (!bh) {
684 ret = -EINVAL;
685 goto error_close;
686 }
687 disk_super = (struct btrfs_super_block *)bh->b_data;
688 devid = btrfs_stack_device_id(&disk_super->dev_item);
689 transid = btrfs_super_generation(disk_super);
690 if (disk_super->label[0])
691 printk(KERN_INFO "device label %s ", disk_super->label);
692 else
693 printk(KERN_INFO "device fsid %pU ", disk_super->fsid);
694 printk(KERN_CONT "devid %llu transid %llu %s\n",
695 (unsigned long long)devid, (unsigned long long)transid, path);
696 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
697
698 brelse(bh);
699 error_close:
700 blkdev_put(bdev, flags);
701 error:
702 mutex_unlock(&uuid_mutex);
703 return ret;
704 }
705
706 /* helper to account the used device space in the range */
707 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
708 u64 end, u64 *length)
709 {
710 struct btrfs_key key;
711 struct btrfs_root *root = device->dev_root;
712 struct btrfs_dev_extent *dev_extent;
713 struct btrfs_path *path;
714 u64 extent_end;
715 int ret;
716 int slot;
717 struct extent_buffer *l;
718
719 *length = 0;
720
721 if (start >= device->total_bytes)
722 return 0;
723
724 path = btrfs_alloc_path();
725 if (!path)
726 return -ENOMEM;
727 path->reada = 2;
728
729 key.objectid = device->devid;
730 key.offset = start;
731 key.type = BTRFS_DEV_EXTENT_KEY;
732
733 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
734 if (ret < 0)
735 goto out;
736 if (ret > 0) {
737 ret = btrfs_previous_item(root, path, key.objectid, key.type);
738 if (ret < 0)
739 goto out;
740 }
741
742 while (1) {
743 l = path->nodes[0];
744 slot = path->slots[0];
745 if (slot >= btrfs_header_nritems(l)) {
746 ret = btrfs_next_leaf(root, path);
747 if (ret == 0)
748 continue;
749 if (ret < 0)
750 goto out;
751
752 break;
753 }
754 btrfs_item_key_to_cpu(l, &key, slot);
755
756 if (key.objectid < device->devid)
757 goto next;
758
759 if (key.objectid > device->devid)
760 break;
761
762 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
763 goto next;
764
765 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
766 extent_end = key.offset + btrfs_dev_extent_length(l,
767 dev_extent);
768 if (key.offset <= start && extent_end > end) {
769 *length = end - start + 1;
770 break;
771 } else if (key.offset <= start && extent_end > start)
772 *length += extent_end - start;
773 else if (key.offset > start && extent_end <= end)
774 *length += extent_end - key.offset;
775 else if (key.offset > start && key.offset <= end) {
776 *length += end - key.offset + 1;
777 break;
778 } else if (key.offset > end)
779 break;
780
781 next:
782 path->slots[0]++;
783 }
784 ret = 0;
785 out:
786 btrfs_free_path(path);
787 return ret;
788 }
789
790 /*
791 * find_free_dev_extent - find free space in the specified device
792 * @trans: transaction handler
793 * @device: the device which we search the free space in
794 * @num_bytes: the size of the free space that we need
795 * @start: store the start of the free space.
796 * @len: the size of the free space. that we find, or the size of the max
797 * free space if we don't find suitable free space
798 *
799 * this uses a pretty simple search, the expectation is that it is
800 * called very infrequently and that a given device has a small number
801 * of extents
802 *
803 * @start is used to store the start of the free space if we find. But if we
804 * don't find suitable free space, it will be used to store the start position
805 * of the max free space.
806 *
807 * @len is used to store the size of the free space that we find.
808 * But if we don't find suitable free space, it is used to store the size of
809 * the max free space.
810 */
811 int find_free_dev_extent(struct btrfs_trans_handle *trans,
812 struct btrfs_device *device, u64 num_bytes,
813 u64 *start, u64 *len)
814 {
815 struct btrfs_key key;
816 struct btrfs_root *root = device->dev_root;
817 struct btrfs_dev_extent *dev_extent;
818 struct btrfs_path *path;
819 u64 hole_size;
820 u64 max_hole_start;
821 u64 max_hole_size;
822 u64 extent_end;
823 u64 search_start;
824 u64 search_end = device->total_bytes;
825 int ret;
826 int slot;
827 struct extent_buffer *l;
828
829 /* FIXME use last free of some kind */
830
831 /* we don't want to overwrite the superblock on the drive,
832 * so we make sure to start at an offset of at least 1MB
833 */
834 search_start = max(root->fs_info->alloc_start, 1024ull * 1024);
835
836 max_hole_start = search_start;
837 max_hole_size = 0;
838
839 if (search_start >= search_end) {
840 ret = -ENOSPC;
841 goto error;
842 }
843
844 path = btrfs_alloc_path();
845 if (!path) {
846 ret = -ENOMEM;
847 goto error;
848 }
849 path->reada = 2;
850
851 key.objectid = device->devid;
852 key.offset = search_start;
853 key.type = BTRFS_DEV_EXTENT_KEY;
854
855 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
856 if (ret < 0)
857 goto out;
858 if (ret > 0) {
859 ret = btrfs_previous_item(root, path, key.objectid, key.type);
860 if (ret < 0)
861 goto out;
862 }
863
864 while (1) {
865 l = path->nodes[0];
866 slot = path->slots[0];
867 if (slot >= btrfs_header_nritems(l)) {
868 ret = btrfs_next_leaf(root, path);
869 if (ret == 0)
870 continue;
871 if (ret < 0)
872 goto out;
873
874 break;
875 }
876 btrfs_item_key_to_cpu(l, &key, slot);
877
878 if (key.objectid < device->devid)
879 goto next;
880
881 if (key.objectid > device->devid)
882 break;
883
884 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
885 goto next;
886
887 if (key.offset > search_start) {
888 hole_size = key.offset - search_start;
889
890 if (hole_size > max_hole_size) {
891 max_hole_start = search_start;
892 max_hole_size = hole_size;
893 }
894
895 /*
896 * If this free space is greater than which we need,
897 * it must be the max free space that we have found
898 * until now, so max_hole_start must point to the start
899 * of this free space and the length of this free space
900 * is stored in max_hole_size. Thus, we return
901 * max_hole_start and max_hole_size and go back to the
902 * caller.
903 */
904 if (hole_size >= num_bytes) {
905 ret = 0;
906 goto out;
907 }
908 }
909
910 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
911 extent_end = key.offset + btrfs_dev_extent_length(l,
912 dev_extent);
913 if (extent_end > search_start)
914 search_start = extent_end;
915 next:
916 path->slots[0]++;
917 cond_resched();
918 }
919
920 hole_size = search_end- search_start;
921 if (hole_size > max_hole_size) {
922 max_hole_start = search_start;
923 max_hole_size = hole_size;
924 }
925
926 /* See above. */
927 if (hole_size < num_bytes)
928 ret = -ENOSPC;
929 else
930 ret = 0;
931
932 out:
933 btrfs_free_path(path);
934 error:
935 *start = max_hole_start;
936 if (len)
937 *len = max_hole_size;
938 return ret;
939 }
940
941 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
942 struct btrfs_device *device,
943 u64 start)
944 {
945 int ret;
946 struct btrfs_path *path;
947 struct btrfs_root *root = device->dev_root;
948 struct btrfs_key key;
949 struct btrfs_key found_key;
950 struct extent_buffer *leaf = NULL;
951 struct btrfs_dev_extent *extent = NULL;
952
953 path = btrfs_alloc_path();
954 if (!path)
955 return -ENOMEM;
956
957 key.objectid = device->devid;
958 key.offset = start;
959 key.type = BTRFS_DEV_EXTENT_KEY;
960
961 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
962 if (ret > 0) {
963 ret = btrfs_previous_item(root, path, key.objectid,
964 BTRFS_DEV_EXTENT_KEY);
965 if (ret)
966 goto out;
967 leaf = path->nodes[0];
968 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
969 extent = btrfs_item_ptr(leaf, path->slots[0],
970 struct btrfs_dev_extent);
971 BUG_ON(found_key.offset > start || found_key.offset +
972 btrfs_dev_extent_length(leaf, extent) < start);
973 } else if (ret == 0) {
974 leaf = path->nodes[0];
975 extent = btrfs_item_ptr(leaf, path->slots[0],
976 struct btrfs_dev_extent);
977 }
978 BUG_ON(ret);
979
980 if (device->bytes_used > 0)
981 device->bytes_used -= btrfs_dev_extent_length(leaf, extent);
982 ret = btrfs_del_item(trans, root, path);
983
984 out:
985 btrfs_free_path(path);
986 return ret;
987 }
988
989 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
990 struct btrfs_device *device,
991 u64 chunk_tree, u64 chunk_objectid,
992 u64 chunk_offset, u64 start, u64 num_bytes)
993 {
994 int ret;
995 struct btrfs_path *path;
996 struct btrfs_root *root = device->dev_root;
997 struct btrfs_dev_extent *extent;
998 struct extent_buffer *leaf;
999 struct btrfs_key key;
1000
1001 WARN_ON(!device->in_fs_metadata);
1002 path = btrfs_alloc_path();
1003 if (!path)
1004 return -ENOMEM;
1005
1006 key.objectid = device->devid;
1007 key.offset = start;
1008 key.type = BTRFS_DEV_EXTENT_KEY;
1009 ret = btrfs_insert_empty_item(trans, root, path, &key,
1010 sizeof(*extent));
1011 BUG_ON(ret);
1012
1013 leaf = path->nodes[0];
1014 extent = btrfs_item_ptr(leaf, path->slots[0],
1015 struct btrfs_dev_extent);
1016 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
1017 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
1018 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
1019
1020 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
1021 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
1022 BTRFS_UUID_SIZE);
1023
1024 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
1025 btrfs_mark_buffer_dirty(leaf);
1026 btrfs_free_path(path);
1027 return ret;
1028 }
1029
1030 static noinline int find_next_chunk(struct btrfs_root *root,
1031 u64 objectid, u64 *offset)
1032 {
1033 struct btrfs_path *path;
1034 int ret;
1035 struct btrfs_key key;
1036 struct btrfs_chunk *chunk;
1037 struct btrfs_key found_key;
1038
1039 path = btrfs_alloc_path();
1040 BUG_ON(!path);
1041
1042 key.objectid = objectid;
1043 key.offset = (u64)-1;
1044 key.type = BTRFS_CHUNK_ITEM_KEY;
1045
1046 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1047 if (ret < 0)
1048 goto error;
1049
1050 BUG_ON(ret == 0);
1051
1052 ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
1053 if (ret) {
1054 *offset = 0;
1055 } else {
1056 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1057 path->slots[0]);
1058 if (found_key.objectid != objectid)
1059 *offset = 0;
1060 else {
1061 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
1062 struct btrfs_chunk);
1063 *offset = found_key.offset +
1064 btrfs_chunk_length(path->nodes[0], chunk);
1065 }
1066 }
1067 ret = 0;
1068 error:
1069 btrfs_free_path(path);
1070 return ret;
1071 }
1072
1073 static noinline int find_next_devid(struct btrfs_root *root, u64 *objectid)
1074 {
1075 int ret;
1076 struct btrfs_key key;
1077 struct btrfs_key found_key;
1078 struct btrfs_path *path;
1079
1080 root = root->fs_info->chunk_root;
1081
1082 path = btrfs_alloc_path();
1083 if (!path)
1084 return -ENOMEM;
1085
1086 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1087 key.type = BTRFS_DEV_ITEM_KEY;
1088 key.offset = (u64)-1;
1089
1090 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1091 if (ret < 0)
1092 goto error;
1093
1094 BUG_ON(ret == 0);
1095
1096 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
1097 BTRFS_DEV_ITEM_KEY);
1098 if (ret) {
1099 *objectid = 1;
1100 } else {
1101 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1102 path->slots[0]);
1103 *objectid = found_key.offset + 1;
1104 }
1105 ret = 0;
1106 error:
1107 btrfs_free_path(path);
1108 return ret;
1109 }
1110
1111 /*
1112 * the device information is stored in the chunk root
1113 * the btrfs_device struct should be fully filled in
1114 */
1115 int btrfs_add_device(struct btrfs_trans_handle *trans,
1116 struct btrfs_root *root,
1117 struct btrfs_device *device)
1118 {
1119 int ret;
1120 struct btrfs_path *path;
1121 struct btrfs_dev_item *dev_item;
1122 struct extent_buffer *leaf;
1123 struct btrfs_key key;
1124 unsigned long ptr;
1125
1126 root = root->fs_info->chunk_root;
1127
1128 path = btrfs_alloc_path();
1129 if (!path)
1130 return -ENOMEM;
1131
1132 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1133 key.type = BTRFS_DEV_ITEM_KEY;
1134 key.offset = device->devid;
1135
1136 ret = btrfs_insert_empty_item(trans, root, path, &key,
1137 sizeof(*dev_item));
1138 if (ret)
1139 goto out;
1140
1141 leaf = path->nodes[0];
1142 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1143
1144 btrfs_set_device_id(leaf, dev_item, device->devid);
1145 btrfs_set_device_generation(leaf, dev_item, 0);
1146 btrfs_set_device_type(leaf, dev_item, device->type);
1147 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1148 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1149 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1150 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
1151 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1152 btrfs_set_device_group(leaf, dev_item, 0);
1153 btrfs_set_device_seek_speed(leaf, dev_item, 0);
1154 btrfs_set_device_bandwidth(leaf, dev_item, 0);
1155 btrfs_set_device_start_offset(leaf, dev_item, 0);
1156
1157 ptr = (unsigned long)btrfs_device_uuid(dev_item);
1158 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1159 ptr = (unsigned long)btrfs_device_fsid(dev_item);
1160 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
1161 btrfs_mark_buffer_dirty(leaf);
1162
1163 ret = 0;
1164 out:
1165 btrfs_free_path(path);
1166 return ret;
1167 }
1168
1169 static int btrfs_rm_dev_item(struct btrfs_root *root,
1170 struct btrfs_device *device)
1171 {
1172 int ret;
1173 struct btrfs_path *path;
1174 struct btrfs_key key;
1175 struct btrfs_trans_handle *trans;
1176
1177 root = root->fs_info->chunk_root;
1178
1179 path = btrfs_alloc_path();
1180 if (!path)
1181 return -ENOMEM;
1182
1183 trans = btrfs_start_transaction(root, 0);
1184 if (IS_ERR(trans)) {
1185 btrfs_free_path(path);
1186 return PTR_ERR(trans);
1187 }
1188 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1189 key.type = BTRFS_DEV_ITEM_KEY;
1190 key.offset = device->devid;
1191 lock_chunks(root);
1192
1193 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1194 if (ret < 0)
1195 goto out;
1196
1197 if (ret > 0) {
1198 ret = -ENOENT;
1199 goto out;
1200 }
1201
1202 ret = btrfs_del_item(trans, root, path);
1203 if (ret)
1204 goto out;
1205 out:
1206 btrfs_free_path(path);
1207 unlock_chunks(root);
1208 btrfs_commit_transaction(trans, root);
1209 return ret;
1210 }
1211
1212 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
1213 {
1214 struct btrfs_device *device;
1215 struct btrfs_device *next_device;
1216 struct block_device *bdev;
1217 struct buffer_head *bh = NULL;
1218 struct btrfs_super_block *disk_super;
1219 struct btrfs_fs_devices *cur_devices;
1220 u64 all_avail;
1221 u64 devid;
1222 u64 num_devices;
1223 u8 *dev_uuid;
1224 int ret = 0;
1225 bool clear_super = false;
1226
1227 mutex_lock(&uuid_mutex);
1228 mutex_lock(&root->fs_info->volume_mutex);
1229
1230 all_avail = root->fs_info->avail_data_alloc_bits |
1231 root->fs_info->avail_system_alloc_bits |
1232 root->fs_info->avail_metadata_alloc_bits;
1233
1234 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) &&
1235 root->fs_info->fs_devices->num_devices <= 4) {
1236 printk(KERN_ERR "btrfs: unable to go below four devices "
1237 "on raid10\n");
1238 ret = -EINVAL;
1239 goto out;
1240 }
1241
1242 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) &&
1243 root->fs_info->fs_devices->num_devices <= 2) {
1244 printk(KERN_ERR "btrfs: unable to go below two "
1245 "devices on raid1\n");
1246 ret = -EINVAL;
1247 goto out;
1248 }
1249
1250 if (strcmp(device_path, "missing") == 0) {
1251 struct list_head *devices;
1252 struct btrfs_device *tmp;
1253
1254 device = NULL;
1255 devices = &root->fs_info->fs_devices->devices;
1256 /*
1257 * It is safe to read the devices since the volume_mutex
1258 * is held.
1259 */
1260 list_for_each_entry(tmp, devices, dev_list) {
1261 if (tmp->in_fs_metadata && !tmp->bdev) {
1262 device = tmp;
1263 break;
1264 }
1265 }
1266 bdev = NULL;
1267 bh = NULL;
1268 disk_super = NULL;
1269 if (!device) {
1270 printk(KERN_ERR "btrfs: no missing devices found to "
1271 "remove\n");
1272 goto out;
1273 }
1274 } else {
1275 bdev = blkdev_get_by_path(device_path, FMODE_READ | FMODE_EXCL,
1276 root->fs_info->bdev_holder);
1277 if (IS_ERR(bdev)) {
1278 ret = PTR_ERR(bdev);
1279 goto out;
1280 }
1281
1282 set_blocksize(bdev, 4096);
1283 bh = btrfs_read_dev_super(bdev);
1284 if (!bh) {
1285 ret = -EINVAL;
1286 goto error_close;
1287 }
1288 disk_super = (struct btrfs_super_block *)bh->b_data;
1289 devid = btrfs_stack_device_id(&disk_super->dev_item);
1290 dev_uuid = disk_super->dev_item.uuid;
1291 device = btrfs_find_device(root, devid, dev_uuid,
1292 disk_super->fsid);
1293 if (!device) {
1294 ret = -ENOENT;
1295 goto error_brelse;
1296 }
1297 }
1298
1299 if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
1300 printk(KERN_ERR "btrfs: unable to remove the only writeable "
1301 "device\n");
1302 ret = -EINVAL;
1303 goto error_brelse;
1304 }
1305
1306 if (device->writeable) {
1307 lock_chunks(root);
1308 list_del_init(&device->dev_alloc_list);
1309 unlock_chunks(root);
1310 root->fs_info->fs_devices->rw_devices--;
1311 clear_super = true;
1312 }
1313
1314 ret = btrfs_shrink_device(device, 0);
1315 if (ret)
1316 goto error_undo;
1317
1318 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1319 if (ret)
1320 goto error_undo;
1321
1322 device->in_fs_metadata = 0;
1323 btrfs_scrub_cancel_dev(root, device);
1324
1325 /*
1326 * the device list mutex makes sure that we don't change
1327 * the device list while someone else is writing out all
1328 * the device supers.
1329 */
1330
1331 cur_devices = device->fs_devices;
1332 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1333 list_del_rcu(&device->dev_list);
1334
1335 device->fs_devices->num_devices--;
1336
1337 if (device->missing)
1338 root->fs_info->fs_devices->missing_devices--;
1339
1340 next_device = list_entry(root->fs_info->fs_devices->devices.next,
1341 struct btrfs_device, dev_list);
1342 if (device->bdev == root->fs_info->sb->s_bdev)
1343 root->fs_info->sb->s_bdev = next_device->bdev;
1344 if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1345 root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1346
1347 if (device->bdev)
1348 device->fs_devices->open_devices--;
1349
1350 call_rcu(&device->rcu, free_device);
1351 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1352
1353 num_devices = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
1354 btrfs_set_super_num_devices(&root->fs_info->super_copy, num_devices);
1355
1356 if (cur_devices->open_devices == 0) {
1357 struct btrfs_fs_devices *fs_devices;
1358 fs_devices = root->fs_info->fs_devices;
1359 while (fs_devices) {
1360 if (fs_devices->seed == cur_devices)
1361 break;
1362 fs_devices = fs_devices->seed;
1363 }
1364 fs_devices->seed = cur_devices->seed;
1365 cur_devices->seed = NULL;
1366 lock_chunks(root);
1367 __btrfs_close_devices(cur_devices);
1368 unlock_chunks(root);
1369 free_fs_devices(cur_devices);
1370 }
1371
1372 /*
1373 * at this point, the device is zero sized. We want to
1374 * remove it from the devices list and zero out the old super
1375 */
1376 if (clear_super) {
1377 /* make sure this device isn't detected as part of
1378 * the FS anymore
1379 */
1380 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1381 set_buffer_dirty(bh);
1382 sync_dirty_buffer(bh);
1383 }
1384
1385 ret = 0;
1386
1387 error_brelse:
1388 brelse(bh);
1389 error_close:
1390 if (bdev)
1391 blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
1392 out:
1393 mutex_unlock(&root->fs_info->volume_mutex);
1394 mutex_unlock(&uuid_mutex);
1395 return ret;
1396 error_undo:
1397 if (device->writeable) {
1398 lock_chunks(root);
1399 list_add(&device->dev_alloc_list,
1400 &root->fs_info->fs_devices->alloc_list);
1401 unlock_chunks(root);
1402 root->fs_info->fs_devices->rw_devices++;
1403 }
1404 goto error_brelse;
1405 }
1406
1407 /*
1408 * does all the dirty work required for changing file system's UUID.
1409 */
1410 static int btrfs_prepare_sprout(struct btrfs_trans_handle *trans,
1411 struct btrfs_root *root)
1412 {
1413 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1414 struct btrfs_fs_devices *old_devices;
1415 struct btrfs_fs_devices *seed_devices;
1416 struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
1417 struct btrfs_device *device;
1418 u64 super_flags;
1419
1420 BUG_ON(!mutex_is_locked(&uuid_mutex));
1421 if (!fs_devices->seeding)
1422 return -EINVAL;
1423
1424 seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
1425 if (!seed_devices)
1426 return -ENOMEM;
1427
1428 old_devices = clone_fs_devices(fs_devices);
1429 if (IS_ERR(old_devices)) {
1430 kfree(seed_devices);
1431 return PTR_ERR(old_devices);
1432 }
1433
1434 list_add(&old_devices->list, &fs_uuids);
1435
1436 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1437 seed_devices->opened = 1;
1438 INIT_LIST_HEAD(&seed_devices->devices);
1439 INIT_LIST_HEAD(&seed_devices->alloc_list);
1440 mutex_init(&seed_devices->device_list_mutex);
1441
1442 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1443 list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
1444 synchronize_rcu);
1445 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1446
1447 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1448 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1449 device->fs_devices = seed_devices;
1450 }
1451
1452 fs_devices->seeding = 0;
1453 fs_devices->num_devices = 0;
1454 fs_devices->open_devices = 0;
1455 fs_devices->seed = seed_devices;
1456
1457 generate_random_uuid(fs_devices->fsid);
1458 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1459 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1460 super_flags = btrfs_super_flags(disk_super) &
1461 ~BTRFS_SUPER_FLAG_SEEDING;
1462 btrfs_set_super_flags(disk_super, super_flags);
1463
1464 return 0;
1465 }
1466
1467 /*
1468 * strore the expected generation for seed devices in device items.
1469 */
1470 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1471 struct btrfs_root *root)
1472 {
1473 struct btrfs_path *path;
1474 struct extent_buffer *leaf;
1475 struct btrfs_dev_item *dev_item;
1476 struct btrfs_device *device;
1477 struct btrfs_key key;
1478 u8 fs_uuid[BTRFS_UUID_SIZE];
1479 u8 dev_uuid[BTRFS_UUID_SIZE];
1480 u64 devid;
1481 int ret;
1482
1483 path = btrfs_alloc_path();
1484 if (!path)
1485 return -ENOMEM;
1486
1487 root = root->fs_info->chunk_root;
1488 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1489 key.offset = 0;
1490 key.type = BTRFS_DEV_ITEM_KEY;
1491
1492 while (1) {
1493 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1494 if (ret < 0)
1495 goto error;
1496
1497 leaf = path->nodes[0];
1498 next_slot:
1499 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1500 ret = btrfs_next_leaf(root, path);
1501 if (ret > 0)
1502 break;
1503 if (ret < 0)
1504 goto error;
1505 leaf = path->nodes[0];
1506 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1507 btrfs_release_path(path);
1508 continue;
1509 }
1510
1511 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1512 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1513 key.type != BTRFS_DEV_ITEM_KEY)
1514 break;
1515
1516 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1517 struct btrfs_dev_item);
1518 devid = btrfs_device_id(leaf, dev_item);
1519 read_extent_buffer(leaf, dev_uuid,
1520 (unsigned long)btrfs_device_uuid(dev_item),
1521 BTRFS_UUID_SIZE);
1522 read_extent_buffer(leaf, fs_uuid,
1523 (unsigned long)btrfs_device_fsid(dev_item),
1524 BTRFS_UUID_SIZE);
1525 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
1526 BUG_ON(!device);
1527
1528 if (device->fs_devices->seeding) {
1529 btrfs_set_device_generation(leaf, dev_item,
1530 device->generation);
1531 btrfs_mark_buffer_dirty(leaf);
1532 }
1533
1534 path->slots[0]++;
1535 goto next_slot;
1536 }
1537 ret = 0;
1538 error:
1539 btrfs_free_path(path);
1540 return ret;
1541 }
1542
1543 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1544 {
1545 struct btrfs_trans_handle *trans;
1546 struct btrfs_device *device;
1547 struct block_device *bdev;
1548 struct list_head *devices;
1549 struct super_block *sb = root->fs_info->sb;
1550 u64 total_bytes;
1551 int seeding_dev = 0;
1552 int ret = 0;
1553
1554 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1555 return -EINVAL;
1556
1557 bdev = blkdev_get_by_path(device_path, FMODE_EXCL,
1558 root->fs_info->bdev_holder);
1559 if (IS_ERR(bdev))
1560 return PTR_ERR(bdev);
1561
1562 if (root->fs_info->fs_devices->seeding) {
1563 seeding_dev = 1;
1564 down_write(&sb->s_umount);
1565 mutex_lock(&uuid_mutex);
1566 }
1567
1568 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1569 mutex_lock(&root->fs_info->volume_mutex);
1570
1571 devices = &root->fs_info->fs_devices->devices;
1572 /*
1573 * we have the volume lock, so we don't need the extra
1574 * device list mutex while reading the list here.
1575 */
1576 list_for_each_entry(device, devices, dev_list) {
1577 if (device->bdev == bdev) {
1578 ret = -EEXIST;
1579 goto error;
1580 }
1581 }
1582
1583 device = kzalloc(sizeof(*device), GFP_NOFS);
1584 if (!device) {
1585 /* we can safely leave the fs_devices entry around */
1586 ret = -ENOMEM;
1587 goto error;
1588 }
1589
1590 device->name = kstrdup(device_path, GFP_NOFS);
1591 if (!device->name) {
1592 kfree(device);
1593 ret = -ENOMEM;
1594 goto error;
1595 }
1596
1597 ret = find_next_devid(root, &device->devid);
1598 if (ret) {
1599 kfree(device->name);
1600 kfree(device);
1601 goto error;
1602 }
1603
1604 trans = btrfs_start_transaction(root, 0);
1605 if (IS_ERR(trans)) {
1606 kfree(device->name);
1607 kfree(device);
1608 ret = PTR_ERR(trans);
1609 goto error;
1610 }
1611
1612 lock_chunks(root);
1613
1614 device->writeable = 1;
1615 device->work.func = pending_bios_fn;
1616 generate_random_uuid(device->uuid);
1617 spin_lock_init(&device->io_lock);
1618 device->generation = trans->transid;
1619 device->io_width = root->sectorsize;
1620 device->io_align = root->sectorsize;
1621 device->sector_size = root->sectorsize;
1622 device->total_bytes = i_size_read(bdev->bd_inode);
1623 device->disk_total_bytes = device->total_bytes;
1624 device->dev_root = root->fs_info->dev_root;
1625 device->bdev = bdev;
1626 device->in_fs_metadata = 1;
1627 device->mode = FMODE_EXCL;
1628 set_blocksize(device->bdev, 4096);
1629
1630 if (seeding_dev) {
1631 sb->s_flags &= ~MS_RDONLY;
1632 ret = btrfs_prepare_sprout(trans, root);
1633 BUG_ON(ret);
1634 }
1635
1636 device->fs_devices = root->fs_info->fs_devices;
1637
1638 /*
1639 * we don't want write_supers to jump in here with our device
1640 * half setup
1641 */
1642 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1643 list_add_rcu(&device->dev_list, &root->fs_info->fs_devices->devices);
1644 list_add(&device->dev_alloc_list,
1645 &root->fs_info->fs_devices->alloc_list);
1646 root->fs_info->fs_devices->num_devices++;
1647 root->fs_info->fs_devices->open_devices++;
1648 root->fs_info->fs_devices->rw_devices++;
1649 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
1650
1651 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
1652 root->fs_info->fs_devices->rotating = 1;
1653
1654 total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
1655 btrfs_set_super_total_bytes(&root->fs_info->super_copy,
1656 total_bytes + device->total_bytes);
1657
1658 total_bytes = btrfs_super_num_devices(&root->fs_info->super_copy);
1659 btrfs_set_super_num_devices(&root->fs_info->super_copy,
1660 total_bytes + 1);
1661 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1662
1663 if (seeding_dev) {
1664 ret = init_first_rw_device(trans, root, device);
1665 BUG_ON(ret);
1666 ret = btrfs_finish_sprout(trans, root);
1667 BUG_ON(ret);
1668 } else {
1669 ret = btrfs_add_device(trans, root, device);
1670 }
1671
1672 /*
1673 * we've got more storage, clear any full flags on the space
1674 * infos
1675 */
1676 btrfs_clear_space_info_full(root->fs_info);
1677
1678 unlock_chunks(root);
1679 btrfs_commit_transaction(trans, root);
1680
1681 if (seeding_dev) {
1682 mutex_unlock(&uuid_mutex);
1683 up_write(&sb->s_umount);
1684
1685 ret = btrfs_relocate_sys_chunks(root);
1686 BUG_ON(ret);
1687 }
1688 out:
1689 mutex_unlock(&root->fs_info->volume_mutex);
1690 return ret;
1691 error:
1692 blkdev_put(bdev, FMODE_EXCL);
1693 if (seeding_dev) {
1694 mutex_unlock(&uuid_mutex);
1695 up_write(&sb->s_umount);
1696 }
1697 goto out;
1698 }
1699
1700 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
1701 struct btrfs_device *device)
1702 {
1703 int ret;
1704 struct btrfs_path *path;
1705 struct btrfs_root *root;
1706 struct btrfs_dev_item *dev_item;
1707 struct extent_buffer *leaf;
1708 struct btrfs_key key;
1709
1710 root = device->dev_root->fs_info->chunk_root;
1711
1712 path = btrfs_alloc_path();
1713 if (!path)
1714 return -ENOMEM;
1715
1716 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1717 key.type = BTRFS_DEV_ITEM_KEY;
1718 key.offset = device->devid;
1719
1720 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1721 if (ret < 0)
1722 goto out;
1723
1724 if (ret > 0) {
1725 ret = -ENOENT;
1726 goto out;
1727 }
1728
1729 leaf = path->nodes[0];
1730 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1731
1732 btrfs_set_device_id(leaf, dev_item, device->devid);
1733 btrfs_set_device_type(leaf, dev_item, device->type);
1734 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1735 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1736 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1737 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
1738 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1739 btrfs_mark_buffer_dirty(leaf);
1740
1741 out:
1742 btrfs_free_path(path);
1743 return ret;
1744 }
1745
1746 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
1747 struct btrfs_device *device, u64 new_size)
1748 {
1749 struct btrfs_super_block *super_copy =
1750 &device->dev_root->fs_info->super_copy;
1751 u64 old_total = btrfs_super_total_bytes(super_copy);
1752 u64 diff = new_size - device->total_bytes;
1753
1754 if (!device->writeable)
1755 return -EACCES;
1756 if (new_size <= device->total_bytes)
1757 return -EINVAL;
1758
1759 btrfs_set_super_total_bytes(super_copy, old_total + diff);
1760 device->fs_devices->total_rw_bytes += diff;
1761
1762 device->total_bytes = new_size;
1763 device->disk_total_bytes = new_size;
1764 btrfs_clear_space_info_full(device->dev_root->fs_info);
1765
1766 return btrfs_update_device(trans, device);
1767 }
1768
1769 int btrfs_grow_device(struct btrfs_trans_handle *trans,
1770 struct btrfs_device *device, u64 new_size)
1771 {
1772 int ret;
1773 lock_chunks(device->dev_root);
1774 ret = __btrfs_grow_device(trans, device, new_size);
1775 unlock_chunks(device->dev_root);
1776 return ret;
1777 }
1778
1779 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
1780 struct btrfs_root *root,
1781 u64 chunk_tree, u64 chunk_objectid,
1782 u64 chunk_offset)
1783 {
1784 int ret;
1785 struct btrfs_path *path;
1786 struct btrfs_key key;
1787
1788 root = root->fs_info->chunk_root;
1789 path = btrfs_alloc_path();
1790 if (!path)
1791 return -ENOMEM;
1792
1793 key.objectid = chunk_objectid;
1794 key.offset = chunk_offset;
1795 key.type = BTRFS_CHUNK_ITEM_KEY;
1796
1797 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1798 BUG_ON(ret);
1799
1800 ret = btrfs_del_item(trans, root, path);
1801
1802 btrfs_free_path(path);
1803 return ret;
1804 }
1805
1806 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
1807 chunk_offset)
1808 {
1809 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
1810 struct btrfs_disk_key *disk_key;
1811 struct btrfs_chunk *chunk;
1812 u8 *ptr;
1813 int ret = 0;
1814 u32 num_stripes;
1815 u32 array_size;
1816 u32 len = 0;
1817 u32 cur;
1818 struct btrfs_key key;
1819
1820 array_size = btrfs_super_sys_array_size(super_copy);
1821
1822 ptr = super_copy->sys_chunk_array;
1823 cur = 0;
1824
1825 while (cur < array_size) {
1826 disk_key = (struct btrfs_disk_key *)ptr;
1827 btrfs_disk_key_to_cpu(&key, disk_key);
1828
1829 len = sizeof(*disk_key);
1830
1831 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
1832 chunk = (struct btrfs_chunk *)(ptr + len);
1833 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
1834 len += btrfs_chunk_item_size(num_stripes);
1835 } else {
1836 ret = -EIO;
1837 break;
1838 }
1839 if (key.objectid == chunk_objectid &&
1840 key.offset == chunk_offset) {
1841 memmove(ptr, ptr + len, array_size - (cur + len));
1842 array_size -= len;
1843 btrfs_set_super_sys_array_size(super_copy, array_size);
1844 } else {
1845 ptr += len;
1846 cur += len;
1847 }
1848 }
1849 return ret;
1850 }
1851
1852 static int btrfs_relocate_chunk(struct btrfs_root *root,
1853 u64 chunk_tree, u64 chunk_objectid,
1854 u64 chunk_offset)
1855 {
1856 struct extent_map_tree *em_tree;
1857 struct btrfs_root *extent_root;
1858 struct btrfs_trans_handle *trans;
1859 struct extent_map *em;
1860 struct map_lookup *map;
1861 int ret;
1862 int i;
1863
1864 root = root->fs_info->chunk_root;
1865 extent_root = root->fs_info->extent_root;
1866 em_tree = &root->fs_info->mapping_tree.map_tree;
1867
1868 ret = btrfs_can_relocate(extent_root, chunk_offset);
1869 if (ret)
1870 return -ENOSPC;
1871
1872 /* step one, relocate all the extents inside this chunk */
1873 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
1874 if (ret)
1875 return ret;
1876
1877 trans = btrfs_start_transaction(root, 0);
1878 BUG_ON(IS_ERR(trans));
1879
1880 lock_chunks(root);
1881
1882 /*
1883 * step two, delete the device extents and the
1884 * chunk tree entries
1885 */
1886 read_lock(&em_tree->lock);
1887 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
1888 read_unlock(&em_tree->lock);
1889
1890 BUG_ON(em->start > chunk_offset ||
1891 em->start + em->len < chunk_offset);
1892 map = (struct map_lookup *)em->bdev;
1893
1894 for (i = 0; i < map->num_stripes; i++) {
1895 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
1896 map->stripes[i].physical);
1897 BUG_ON(ret);
1898
1899 if (map->stripes[i].dev) {
1900 ret = btrfs_update_device(trans, map->stripes[i].dev);
1901 BUG_ON(ret);
1902 }
1903 }
1904 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
1905 chunk_offset);
1906
1907 BUG_ON(ret);
1908
1909 trace_btrfs_chunk_free(root, map, chunk_offset, em->len);
1910
1911 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
1912 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
1913 BUG_ON(ret);
1914 }
1915
1916 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
1917 BUG_ON(ret);
1918
1919 write_lock(&em_tree->lock);
1920 remove_extent_mapping(em_tree, em);
1921 write_unlock(&em_tree->lock);
1922
1923 kfree(map);
1924 em->bdev = NULL;
1925
1926 /* once for the tree */
1927 free_extent_map(em);
1928 /* once for us */
1929 free_extent_map(em);
1930
1931 unlock_chunks(root);
1932 btrfs_end_transaction(trans, root);
1933 return 0;
1934 }
1935
1936 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
1937 {
1938 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
1939 struct btrfs_path *path;
1940 struct extent_buffer *leaf;
1941 struct btrfs_chunk *chunk;
1942 struct btrfs_key key;
1943 struct btrfs_key found_key;
1944 u64 chunk_tree = chunk_root->root_key.objectid;
1945 u64 chunk_type;
1946 bool retried = false;
1947 int failed = 0;
1948 int ret;
1949
1950 path = btrfs_alloc_path();
1951 if (!path)
1952 return -ENOMEM;
1953
1954 again:
1955 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
1956 key.offset = (u64)-1;
1957 key.type = BTRFS_CHUNK_ITEM_KEY;
1958
1959 while (1) {
1960 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
1961 if (ret < 0)
1962 goto error;
1963 BUG_ON(ret == 0);
1964
1965 ret = btrfs_previous_item(chunk_root, path, key.objectid,
1966 key.type);
1967 if (ret < 0)
1968 goto error;
1969 if (ret > 0)
1970 break;
1971
1972 leaf = path->nodes[0];
1973 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1974
1975 chunk = btrfs_item_ptr(leaf, path->slots[0],
1976 struct btrfs_chunk);
1977 chunk_type = btrfs_chunk_type(leaf, chunk);
1978 btrfs_release_path(path);
1979
1980 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
1981 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
1982 found_key.objectid,
1983 found_key.offset);
1984 if (ret == -ENOSPC)
1985 failed++;
1986 else if (ret)
1987 BUG();
1988 }
1989
1990 if (found_key.offset == 0)
1991 break;
1992 key.offset = found_key.offset - 1;
1993 }
1994 ret = 0;
1995 if (failed && !retried) {
1996 failed = 0;
1997 retried = true;
1998 goto again;
1999 } else if (failed && retried) {
2000 WARN_ON(1);
2001 ret = -ENOSPC;
2002 }
2003 error:
2004 btrfs_free_path(path);
2005 return ret;
2006 }
2007
2008 static u64 div_factor(u64 num, int factor)
2009 {
2010 if (factor == 10)
2011 return num;
2012 num *= factor;
2013 do_div(num, 10);
2014 return num;
2015 }
2016
2017 int btrfs_balance(struct btrfs_root *dev_root)
2018 {
2019 int ret;
2020 struct list_head *devices = &dev_root->fs_info->fs_devices->devices;
2021 struct btrfs_device *device;
2022 u64 old_size;
2023 u64 size_to_free;
2024 struct btrfs_path *path;
2025 struct btrfs_key key;
2026 struct btrfs_root *chunk_root = dev_root->fs_info->chunk_root;
2027 struct btrfs_trans_handle *trans;
2028 struct btrfs_key found_key;
2029
2030 if (dev_root->fs_info->sb->s_flags & MS_RDONLY)
2031 return -EROFS;
2032
2033 if (!capable(CAP_SYS_ADMIN))
2034 return -EPERM;
2035
2036 mutex_lock(&dev_root->fs_info->volume_mutex);
2037 dev_root = dev_root->fs_info->dev_root;
2038
2039 /* step one make some room on all the devices */
2040 list_for_each_entry(device, devices, dev_list) {
2041 old_size = device->total_bytes;
2042 size_to_free = div_factor(old_size, 1);
2043 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
2044 if (!device->writeable ||
2045 device->total_bytes - device->bytes_used > size_to_free)
2046 continue;
2047
2048 ret = btrfs_shrink_device(device, old_size - size_to_free);
2049 if (ret == -ENOSPC)
2050 break;
2051 BUG_ON(ret);
2052
2053 trans = btrfs_start_transaction(dev_root, 0);
2054 BUG_ON(IS_ERR(trans));
2055
2056 ret = btrfs_grow_device(trans, device, old_size);
2057 BUG_ON(ret);
2058
2059 btrfs_end_transaction(trans, dev_root);
2060 }
2061
2062 /* step two, relocate all the chunks */
2063 path = btrfs_alloc_path();
2064 BUG_ON(!path);
2065
2066 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2067 key.offset = (u64)-1;
2068 key.type = BTRFS_CHUNK_ITEM_KEY;
2069
2070 while (1) {
2071 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2072 if (ret < 0)
2073 goto error;
2074
2075 /*
2076 * this shouldn't happen, it means the last relocate
2077 * failed
2078 */
2079 if (ret == 0)
2080 break;
2081
2082 ret = btrfs_previous_item(chunk_root, path, 0,
2083 BTRFS_CHUNK_ITEM_KEY);
2084 if (ret)
2085 break;
2086
2087 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2088 path->slots[0]);
2089 if (found_key.objectid != key.objectid)
2090 break;
2091
2092 /* chunk zero is special */
2093 if (found_key.offset == 0)
2094 break;
2095
2096 btrfs_release_path(path);
2097 ret = btrfs_relocate_chunk(chunk_root,
2098 chunk_root->root_key.objectid,
2099 found_key.objectid,
2100 found_key.offset);
2101 if (ret && ret != -ENOSPC)
2102 goto error;
2103 key.offset = found_key.offset - 1;
2104 }
2105 ret = 0;
2106 error:
2107 btrfs_free_path(path);
2108 mutex_unlock(&dev_root->fs_info->volume_mutex);
2109 return ret;
2110 }
2111
2112 /*
2113 * shrinking a device means finding all of the device extents past
2114 * the new size, and then following the back refs to the chunks.
2115 * The chunk relocation code actually frees the device extent
2116 */
2117 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
2118 {
2119 struct btrfs_trans_handle *trans;
2120 struct btrfs_root *root = device->dev_root;
2121 struct btrfs_dev_extent *dev_extent = NULL;
2122 struct btrfs_path *path;
2123 u64 length;
2124 u64 chunk_tree;
2125 u64 chunk_objectid;
2126 u64 chunk_offset;
2127 int ret;
2128 int slot;
2129 int failed = 0;
2130 bool retried = false;
2131 struct extent_buffer *l;
2132 struct btrfs_key key;
2133 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
2134 u64 old_total = btrfs_super_total_bytes(super_copy);
2135 u64 old_size = device->total_bytes;
2136 u64 diff = device->total_bytes - new_size;
2137
2138 if (new_size >= device->total_bytes)
2139 return -EINVAL;
2140
2141 path = btrfs_alloc_path();
2142 if (!path)
2143 return -ENOMEM;
2144
2145 path->reada = 2;
2146
2147 lock_chunks(root);
2148
2149 device->total_bytes = new_size;
2150 if (device->writeable)
2151 device->fs_devices->total_rw_bytes -= diff;
2152 unlock_chunks(root);
2153
2154 again:
2155 key.objectid = device->devid;
2156 key.offset = (u64)-1;
2157 key.type = BTRFS_DEV_EXTENT_KEY;
2158
2159 while (1) {
2160 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2161 if (ret < 0)
2162 goto done;
2163
2164 ret = btrfs_previous_item(root, path, 0, key.type);
2165 if (ret < 0)
2166 goto done;
2167 if (ret) {
2168 ret = 0;
2169 btrfs_release_path(path);
2170 break;
2171 }
2172
2173 l = path->nodes[0];
2174 slot = path->slots[0];
2175 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
2176
2177 if (key.objectid != device->devid) {
2178 btrfs_release_path(path);
2179 break;
2180 }
2181
2182 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
2183 length = btrfs_dev_extent_length(l, dev_extent);
2184
2185 if (key.offset + length <= new_size) {
2186 btrfs_release_path(path);
2187 break;
2188 }
2189
2190 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
2191 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
2192 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
2193 btrfs_release_path(path);
2194
2195 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
2196 chunk_offset);
2197 if (ret && ret != -ENOSPC)
2198 goto done;
2199 if (ret == -ENOSPC)
2200 failed++;
2201 key.offset -= 1;
2202 }
2203
2204 if (failed && !retried) {
2205 failed = 0;
2206 retried = true;
2207 goto again;
2208 } else if (failed && retried) {
2209 ret = -ENOSPC;
2210 lock_chunks(root);
2211
2212 device->total_bytes = old_size;
2213 if (device->writeable)
2214 device->fs_devices->total_rw_bytes += diff;
2215 unlock_chunks(root);
2216 goto done;
2217 }
2218
2219 /* Shrinking succeeded, else we would be at "done". */
2220 trans = btrfs_start_transaction(root, 0);
2221 if (IS_ERR(trans)) {
2222 ret = PTR_ERR(trans);
2223 goto done;
2224 }
2225
2226 lock_chunks(root);
2227
2228 device->disk_total_bytes = new_size;
2229 /* Now btrfs_update_device() will change the on-disk size. */
2230 ret = btrfs_update_device(trans, device);
2231 if (ret) {
2232 unlock_chunks(root);
2233 btrfs_end_transaction(trans, root);
2234 goto done;
2235 }
2236 WARN_ON(diff > old_total);
2237 btrfs_set_super_total_bytes(super_copy, old_total - diff);
2238 unlock_chunks(root);
2239 btrfs_end_transaction(trans, root);
2240 done:
2241 btrfs_free_path(path);
2242 return ret;
2243 }
2244
2245 static int btrfs_add_system_chunk(struct btrfs_trans_handle *trans,
2246 struct btrfs_root *root,
2247 struct btrfs_key *key,
2248 struct btrfs_chunk *chunk, int item_size)
2249 {
2250 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
2251 struct btrfs_disk_key disk_key;
2252 u32 array_size;
2253 u8 *ptr;
2254
2255 array_size = btrfs_super_sys_array_size(super_copy);
2256 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
2257 return -EFBIG;
2258
2259 ptr = super_copy->sys_chunk_array + array_size;
2260 btrfs_cpu_key_to_disk(&disk_key, key);
2261 memcpy(ptr, &disk_key, sizeof(disk_key));
2262 ptr += sizeof(disk_key);
2263 memcpy(ptr, chunk, item_size);
2264 item_size += sizeof(disk_key);
2265 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
2266 return 0;
2267 }
2268
2269 /*
2270 * sort the devices in descending order by max_avail, total_avail
2271 */
2272 static int btrfs_cmp_device_info(const void *a, const void *b)
2273 {
2274 const struct btrfs_device_info *di_a = a;
2275 const struct btrfs_device_info *di_b = b;
2276
2277 if (di_a->max_avail > di_b->max_avail)
2278 return -1;
2279 if (di_a->max_avail < di_b->max_avail)
2280 return 1;
2281 if (di_a->total_avail > di_b->total_avail)
2282 return -1;
2283 if (di_a->total_avail < di_b->total_avail)
2284 return 1;
2285 return 0;
2286 }
2287
2288 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
2289 struct btrfs_root *extent_root,
2290 struct map_lookup **map_ret,
2291 u64 *num_bytes_out, u64 *stripe_size_out,
2292 u64 start, u64 type)
2293 {
2294 struct btrfs_fs_info *info = extent_root->fs_info;
2295 struct btrfs_fs_devices *fs_devices = info->fs_devices;
2296 struct list_head *cur;
2297 struct map_lookup *map = NULL;
2298 struct extent_map_tree *em_tree;
2299 struct extent_map *em;
2300 struct btrfs_device_info *devices_info = NULL;
2301 u64 total_avail;
2302 int num_stripes; /* total number of stripes to allocate */
2303 int sub_stripes; /* sub_stripes info for map */
2304 int dev_stripes; /* stripes per dev */
2305 int devs_max; /* max devs to use */
2306 int devs_min; /* min devs needed */
2307 int devs_increment; /* ndevs has to be a multiple of this */
2308 int ncopies; /* how many copies to data has */
2309 int ret;
2310 u64 max_stripe_size;
2311 u64 max_chunk_size;
2312 u64 stripe_size;
2313 u64 num_bytes;
2314 int ndevs;
2315 int i;
2316 int j;
2317
2318 if ((type & BTRFS_BLOCK_GROUP_RAID1) &&
2319 (type & BTRFS_BLOCK_GROUP_DUP)) {
2320 WARN_ON(1);
2321 type &= ~BTRFS_BLOCK_GROUP_DUP;
2322 }
2323
2324 if (list_empty(&fs_devices->alloc_list))
2325 return -ENOSPC;
2326
2327 sub_stripes = 1;
2328 dev_stripes = 1;
2329 devs_increment = 1;
2330 ncopies = 1;
2331 devs_max = 0; /* 0 == as many as possible */
2332 devs_min = 1;
2333
2334 /*
2335 * define the properties of each RAID type.
2336 * FIXME: move this to a global table and use it in all RAID
2337 * calculation code
2338 */
2339 if (type & (BTRFS_BLOCK_GROUP_DUP)) {
2340 dev_stripes = 2;
2341 ncopies = 2;
2342 devs_max = 1;
2343 } else if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
2344 devs_min = 2;
2345 } else if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
2346 devs_increment = 2;
2347 ncopies = 2;
2348 devs_max = 2;
2349 devs_min = 2;
2350 } else if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
2351 sub_stripes = 2;
2352 devs_increment = 2;
2353 ncopies = 2;
2354 devs_min = 4;
2355 } else {
2356 devs_max = 1;
2357 }
2358
2359 if (type & BTRFS_BLOCK_GROUP_DATA) {
2360 max_stripe_size = 1024 * 1024 * 1024;
2361 max_chunk_size = 10 * max_stripe_size;
2362 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
2363 max_stripe_size = 256 * 1024 * 1024;
2364 max_chunk_size = max_stripe_size;
2365 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
2366 max_stripe_size = 8 * 1024 * 1024;
2367 max_chunk_size = 2 * max_stripe_size;
2368 } else {
2369 printk(KERN_ERR "btrfs: invalid chunk type 0x%llx requested\n",
2370 type);
2371 BUG_ON(1);
2372 }
2373
2374 /* we don't want a chunk larger than 10% of writeable space */
2375 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
2376 max_chunk_size);
2377
2378 devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices,
2379 GFP_NOFS);
2380 if (!devices_info)
2381 return -ENOMEM;
2382
2383 cur = fs_devices->alloc_list.next;
2384
2385 /*
2386 * in the first pass through the devices list, we gather information
2387 * about the available holes on each device.
2388 */
2389 ndevs = 0;
2390 while (cur != &fs_devices->alloc_list) {
2391 struct btrfs_device *device;
2392 u64 max_avail;
2393 u64 dev_offset;
2394
2395 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
2396
2397 cur = cur->next;
2398
2399 if (!device->writeable) {
2400 printk(KERN_ERR
2401 "btrfs: read-only device in alloc_list\n");
2402 WARN_ON(1);
2403 continue;
2404 }
2405
2406 if (!device->in_fs_metadata)
2407 continue;
2408
2409 if (device->total_bytes > device->bytes_used)
2410 total_avail = device->total_bytes - device->bytes_used;
2411 else
2412 total_avail = 0;
2413 /* avail is off by max(alloc_start, 1MB), but that is the same
2414 * for all devices, so it doesn't hurt the sorting later on
2415 */
2416
2417 ret = find_free_dev_extent(trans, device,
2418 max_stripe_size * dev_stripes,
2419 &dev_offset, &max_avail);
2420 if (ret && ret != -ENOSPC)
2421 goto error;
2422
2423 if (ret == 0)
2424 max_avail = max_stripe_size * dev_stripes;
2425
2426 if (max_avail < BTRFS_STRIPE_LEN * dev_stripes)
2427 continue;
2428
2429 devices_info[ndevs].dev_offset = dev_offset;
2430 devices_info[ndevs].max_avail = max_avail;
2431 devices_info[ndevs].total_avail = total_avail;
2432 devices_info[ndevs].dev = device;
2433 ++ndevs;
2434 }
2435
2436 /*
2437 * now sort the devices by hole size / available space
2438 */
2439 sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
2440 btrfs_cmp_device_info, NULL);
2441
2442 /* round down to number of usable stripes */
2443 ndevs -= ndevs % devs_increment;
2444
2445 if (ndevs < devs_increment * sub_stripes || ndevs < devs_min) {
2446 ret = -ENOSPC;
2447 goto error;
2448 }
2449
2450 if (devs_max && ndevs > devs_max)
2451 ndevs = devs_max;
2452 /*
2453 * the primary goal is to maximize the number of stripes, so use as many
2454 * devices as possible, even if the stripes are not maximum sized.
2455 */
2456 stripe_size = devices_info[ndevs-1].max_avail;
2457 num_stripes = ndevs * dev_stripes;
2458
2459 if (stripe_size * num_stripes > max_chunk_size * ncopies) {
2460 stripe_size = max_chunk_size * ncopies;
2461 do_div(stripe_size, num_stripes);
2462 }
2463
2464 do_div(stripe_size, dev_stripes);
2465 do_div(stripe_size, BTRFS_STRIPE_LEN);
2466 stripe_size *= BTRFS_STRIPE_LEN;
2467
2468 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
2469 if (!map) {
2470 ret = -ENOMEM;
2471 goto error;
2472 }
2473 map->num_stripes = num_stripes;
2474
2475 for (i = 0; i < ndevs; ++i) {
2476 for (j = 0; j < dev_stripes; ++j) {
2477 int s = i * dev_stripes + j;
2478 map->stripes[s].dev = devices_info[i].dev;
2479 map->stripes[s].physical = devices_info[i].dev_offset +
2480 j * stripe_size;
2481 }
2482 }
2483 map->sector_size = extent_root->sectorsize;
2484 map->stripe_len = BTRFS_STRIPE_LEN;
2485 map->io_align = BTRFS_STRIPE_LEN;
2486 map->io_width = BTRFS_STRIPE_LEN;
2487 map->type = type;
2488 map->sub_stripes = sub_stripes;
2489
2490 *map_ret = map;
2491 num_bytes = stripe_size * (num_stripes / ncopies);
2492
2493 *stripe_size_out = stripe_size;
2494 *num_bytes_out = num_bytes;
2495
2496 trace_btrfs_chunk_alloc(info->chunk_root, map, start, num_bytes);
2497
2498 em = alloc_extent_map();
2499 if (!em) {
2500 ret = -ENOMEM;
2501 goto error;
2502 }
2503 em->bdev = (struct block_device *)map;
2504 em->start = start;
2505 em->len = num_bytes;
2506 em->block_start = 0;
2507 em->block_len = em->len;
2508
2509 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
2510 write_lock(&em_tree->lock);
2511 ret = add_extent_mapping(em_tree, em);
2512 write_unlock(&em_tree->lock);
2513 BUG_ON(ret);
2514 free_extent_map(em);
2515
2516 ret = btrfs_make_block_group(trans, extent_root, 0, type,
2517 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2518 start, num_bytes);
2519 BUG_ON(ret);
2520
2521 for (i = 0; i < map->num_stripes; ++i) {
2522 struct btrfs_device *device;
2523 u64 dev_offset;
2524
2525 device = map->stripes[i].dev;
2526 dev_offset = map->stripes[i].physical;
2527
2528 ret = btrfs_alloc_dev_extent(trans, device,
2529 info->chunk_root->root_key.objectid,
2530 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2531 start, dev_offset, stripe_size);
2532 BUG_ON(ret);
2533 }
2534
2535 kfree(devices_info);
2536 return 0;
2537
2538 error:
2539 kfree(map);
2540 kfree(devices_info);
2541 return ret;
2542 }
2543
2544 static int __finish_chunk_alloc(struct btrfs_trans_handle *trans,
2545 struct btrfs_root *extent_root,
2546 struct map_lookup *map, u64 chunk_offset,
2547 u64 chunk_size, u64 stripe_size)
2548 {
2549 u64 dev_offset;
2550 struct btrfs_key key;
2551 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
2552 struct btrfs_device *device;
2553 struct btrfs_chunk *chunk;
2554 struct btrfs_stripe *stripe;
2555 size_t item_size = btrfs_chunk_item_size(map->num_stripes);
2556 int index = 0;
2557 int ret;
2558
2559 chunk = kzalloc(item_size, GFP_NOFS);
2560 if (!chunk)
2561 return -ENOMEM;
2562
2563 index = 0;
2564 while (index < map->num_stripes) {
2565 device = map->stripes[index].dev;
2566 device->bytes_used += stripe_size;
2567 ret = btrfs_update_device(trans, device);
2568 BUG_ON(ret);
2569 index++;
2570 }
2571
2572 index = 0;
2573 stripe = &chunk->stripe;
2574 while (index < map->num_stripes) {
2575 device = map->stripes[index].dev;
2576 dev_offset = map->stripes[index].physical;
2577
2578 btrfs_set_stack_stripe_devid(stripe, device->devid);
2579 btrfs_set_stack_stripe_offset(stripe, dev_offset);
2580 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
2581 stripe++;
2582 index++;
2583 }
2584
2585 btrfs_set_stack_chunk_length(chunk, chunk_size);
2586 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
2587 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
2588 btrfs_set_stack_chunk_type(chunk, map->type);
2589 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
2590 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
2591 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
2592 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
2593 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
2594
2595 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2596 key.type = BTRFS_CHUNK_ITEM_KEY;
2597 key.offset = chunk_offset;
2598
2599 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
2600 BUG_ON(ret);
2601
2602 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2603 ret = btrfs_add_system_chunk(trans, chunk_root, &key, chunk,
2604 item_size);
2605 BUG_ON(ret);
2606 }
2607
2608 kfree(chunk);
2609 return 0;
2610 }
2611
2612 /*
2613 * Chunk allocation falls into two parts. The first part does works
2614 * that make the new allocated chunk useable, but not do any operation
2615 * that modifies the chunk tree. The second part does the works that
2616 * require modifying the chunk tree. This division is important for the
2617 * bootstrap process of adding storage to a seed btrfs.
2618 */
2619 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
2620 struct btrfs_root *extent_root, u64 type)
2621 {
2622 u64 chunk_offset;
2623 u64 chunk_size;
2624 u64 stripe_size;
2625 struct map_lookup *map;
2626 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
2627 int ret;
2628
2629 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2630 &chunk_offset);
2631 if (ret)
2632 return ret;
2633
2634 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
2635 &stripe_size, chunk_offset, type);
2636 if (ret)
2637 return ret;
2638
2639 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
2640 chunk_size, stripe_size);
2641 BUG_ON(ret);
2642 return 0;
2643 }
2644
2645 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
2646 struct btrfs_root *root,
2647 struct btrfs_device *device)
2648 {
2649 u64 chunk_offset;
2650 u64 sys_chunk_offset;
2651 u64 chunk_size;
2652 u64 sys_chunk_size;
2653 u64 stripe_size;
2654 u64 sys_stripe_size;
2655 u64 alloc_profile;
2656 struct map_lookup *map;
2657 struct map_lookup *sys_map;
2658 struct btrfs_fs_info *fs_info = root->fs_info;
2659 struct btrfs_root *extent_root = fs_info->extent_root;
2660 int ret;
2661
2662 ret = find_next_chunk(fs_info->chunk_root,
2663 BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset);
2664 BUG_ON(ret);
2665
2666 alloc_profile = BTRFS_BLOCK_GROUP_METADATA |
2667 (fs_info->metadata_alloc_profile &
2668 fs_info->avail_metadata_alloc_bits);
2669 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
2670
2671 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
2672 &stripe_size, chunk_offset, alloc_profile);
2673 BUG_ON(ret);
2674
2675 sys_chunk_offset = chunk_offset + chunk_size;
2676
2677 alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM |
2678 (fs_info->system_alloc_profile &
2679 fs_info->avail_system_alloc_bits);
2680 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
2681
2682 ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,
2683 &sys_chunk_size, &sys_stripe_size,
2684 sys_chunk_offset, alloc_profile);
2685 BUG_ON(ret);
2686
2687 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
2688 BUG_ON(ret);
2689
2690 /*
2691 * Modifying chunk tree needs allocating new blocks from both
2692 * system block group and metadata block group. So we only can
2693 * do operations require modifying the chunk tree after both
2694 * block groups were created.
2695 */
2696 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
2697 chunk_size, stripe_size);
2698 BUG_ON(ret);
2699
2700 ret = __finish_chunk_alloc(trans, extent_root, sys_map,
2701 sys_chunk_offset, sys_chunk_size,
2702 sys_stripe_size);
2703 BUG_ON(ret);
2704 return 0;
2705 }
2706
2707 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
2708 {
2709 struct extent_map *em;
2710 struct map_lookup *map;
2711 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
2712 int readonly = 0;
2713 int i;
2714
2715 read_lock(&map_tree->map_tree.lock);
2716 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
2717 read_unlock(&map_tree->map_tree.lock);
2718 if (!em)
2719 return 1;
2720
2721 if (btrfs_test_opt(root, DEGRADED)) {
2722 free_extent_map(em);
2723 return 0;
2724 }
2725
2726 map = (struct map_lookup *)em->bdev;
2727 for (i = 0; i < map->num_stripes; i++) {
2728 if (!map->stripes[i].dev->writeable) {
2729 readonly = 1;
2730 break;
2731 }
2732 }
2733 free_extent_map(em);
2734 return readonly;
2735 }
2736
2737 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
2738 {
2739 extent_map_tree_init(&tree->map_tree);
2740 }
2741
2742 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
2743 {
2744 struct extent_map *em;
2745
2746 while (1) {
2747 write_lock(&tree->map_tree.lock);
2748 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
2749 if (em)
2750 remove_extent_mapping(&tree->map_tree, em);
2751 write_unlock(&tree->map_tree.lock);
2752 if (!em)
2753 break;
2754 kfree(em->bdev);
2755 /* once for us */
2756 free_extent_map(em);
2757 /* once for the tree */
2758 free_extent_map(em);
2759 }
2760 }
2761
2762 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
2763 {
2764 struct extent_map *em;
2765 struct map_lookup *map;
2766 struct extent_map_tree *em_tree = &map_tree->map_tree;
2767 int ret;
2768
2769 read_lock(&em_tree->lock);
2770 em = lookup_extent_mapping(em_tree, logical, len);
2771 read_unlock(&em_tree->lock);
2772 BUG_ON(!em);
2773
2774 BUG_ON(em->start > logical || em->start + em->len < logical);
2775 map = (struct map_lookup *)em->bdev;
2776 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
2777 ret = map->num_stripes;
2778 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
2779 ret = map->sub_stripes;
2780 else
2781 ret = 1;
2782 free_extent_map(em);
2783 return ret;
2784 }
2785
2786 static int find_live_mirror(struct map_lookup *map, int first, int num,
2787 int optimal)
2788 {
2789 int i;
2790 if (map->stripes[optimal].dev->bdev)
2791 return optimal;
2792 for (i = first; i < first + num; i++) {
2793 if (map->stripes[i].dev->bdev)
2794 return i;
2795 }
2796 /* we couldn't find one that doesn't fail. Just return something
2797 * and the io error handling code will clean up eventually
2798 */
2799 return optimal;
2800 }
2801
2802 static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
2803 u64 logical, u64 *length,
2804 struct btrfs_multi_bio **multi_ret,
2805 int mirror_num)
2806 {
2807 struct extent_map *em;
2808 struct map_lookup *map;
2809 struct extent_map_tree *em_tree = &map_tree->map_tree;
2810 u64 offset;
2811 u64 stripe_offset;
2812 u64 stripe_end_offset;
2813 u64 stripe_nr;
2814 u64 stripe_nr_orig;
2815 u64 stripe_nr_end;
2816 int stripes_allocated = 8;
2817 int stripes_required = 1;
2818 int stripe_index;
2819 int i;
2820 int num_stripes;
2821 int max_errors = 0;
2822 struct btrfs_multi_bio *multi = NULL;
2823
2824 if (multi_ret && !(rw & (REQ_WRITE | REQ_DISCARD)))
2825 stripes_allocated = 1;
2826 again:
2827 if (multi_ret) {
2828 multi = kzalloc(btrfs_multi_bio_size(stripes_allocated),
2829 GFP_NOFS);
2830 if (!multi)
2831 return -ENOMEM;
2832
2833 atomic_set(&multi->error, 0);
2834 }
2835
2836 read_lock(&em_tree->lock);
2837 em = lookup_extent_mapping(em_tree, logical, *length);
2838 read_unlock(&em_tree->lock);
2839
2840 if (!em) {
2841 printk(KERN_CRIT "unable to find logical %llu len %llu\n",
2842 (unsigned long long)logical,
2843 (unsigned long long)*length);
2844 BUG();
2845 }
2846
2847 BUG_ON(em->start > logical || em->start + em->len < logical);
2848 map = (struct map_lookup *)em->bdev;
2849 offset = logical - em->start;
2850
2851 if (mirror_num > map->num_stripes)
2852 mirror_num = 0;
2853
2854 /* if our multi bio struct is too small, back off and try again */
2855 if (rw & REQ_WRITE) {
2856 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
2857 BTRFS_BLOCK_GROUP_DUP)) {
2858 stripes_required = map->num_stripes;
2859 max_errors = 1;
2860 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2861 stripes_required = map->sub_stripes;
2862 max_errors = 1;
2863 }
2864 }
2865 if (rw & REQ_DISCARD) {
2866 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
2867 BTRFS_BLOCK_GROUP_RAID1 |
2868 BTRFS_BLOCK_GROUP_DUP |
2869 BTRFS_BLOCK_GROUP_RAID10)) {
2870 stripes_required = map->num_stripes;
2871 }
2872 }
2873 if (multi_ret && (rw & (REQ_WRITE | REQ_DISCARD)) &&
2874 stripes_allocated < stripes_required) {
2875 stripes_allocated = map->num_stripes;
2876 free_extent_map(em);
2877 kfree(multi);
2878 goto again;
2879 }
2880 stripe_nr = offset;
2881 /*
2882 * stripe_nr counts the total number of stripes we have to stride
2883 * to get to this block
2884 */
2885 do_div(stripe_nr, map->stripe_len);
2886
2887 stripe_offset = stripe_nr * map->stripe_len;
2888 BUG_ON(offset < stripe_offset);
2889
2890 /* stripe_offset is the offset of this block in its stripe*/
2891 stripe_offset = offset - stripe_offset;
2892
2893 if (rw & REQ_DISCARD)
2894 *length = min_t(u64, em->len - offset, *length);
2895 else if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
2896 BTRFS_BLOCK_GROUP_RAID1 |
2897 BTRFS_BLOCK_GROUP_RAID10 |
2898 BTRFS_BLOCK_GROUP_DUP)) {
2899 /* we limit the length of each bio to what fits in a stripe */
2900 *length = min_t(u64, em->len - offset,
2901 map->stripe_len - stripe_offset);
2902 } else {
2903 *length = em->len - offset;
2904 }
2905
2906 if (!multi_ret)
2907 goto out;
2908
2909 num_stripes = 1;
2910 stripe_index = 0;
2911 stripe_nr_orig = stripe_nr;
2912 stripe_nr_end = (offset + *length + map->stripe_len - 1) &
2913 (~(map->stripe_len - 1));
2914 do_div(stripe_nr_end, map->stripe_len);
2915 stripe_end_offset = stripe_nr_end * map->stripe_len -
2916 (offset + *length);
2917 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
2918 if (rw & REQ_DISCARD)
2919 num_stripes = min_t(u64, map->num_stripes,
2920 stripe_nr_end - stripe_nr_orig);
2921 stripe_index = do_div(stripe_nr, map->num_stripes);
2922 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
2923 if (rw & (REQ_WRITE | REQ_DISCARD))
2924 num_stripes = map->num_stripes;
2925 else if (mirror_num)
2926 stripe_index = mirror_num - 1;
2927 else {
2928 stripe_index = find_live_mirror(map, 0,
2929 map->num_stripes,
2930 current->pid % map->num_stripes);
2931 }
2932
2933 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
2934 if (rw & (REQ_WRITE | REQ_DISCARD))
2935 num_stripes = map->num_stripes;
2936 else if (mirror_num)
2937 stripe_index = mirror_num - 1;
2938
2939 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2940 int factor = map->num_stripes / map->sub_stripes;
2941
2942 stripe_index = do_div(stripe_nr, factor);
2943 stripe_index *= map->sub_stripes;
2944
2945 if (rw & REQ_WRITE)
2946 num_stripes = map->sub_stripes;
2947 else if (rw & REQ_DISCARD)
2948 num_stripes = min_t(u64, map->sub_stripes *
2949 (stripe_nr_end - stripe_nr_orig),
2950 map->num_stripes);
2951 else if (mirror_num)
2952 stripe_index += mirror_num - 1;
2953 else {
2954 stripe_index = find_live_mirror(map, stripe_index,
2955 map->sub_stripes, stripe_index +
2956 current->pid % map->sub_stripes);
2957 }
2958 } else {
2959 /*
2960 * after this do_div call, stripe_nr is the number of stripes
2961 * on this device we have to walk to find the data, and
2962 * stripe_index is the number of our device in the stripe array
2963 */
2964 stripe_index = do_div(stripe_nr, map->num_stripes);
2965 }
2966 BUG_ON(stripe_index >= map->num_stripes);
2967
2968 if (rw & REQ_DISCARD) {
2969 for (i = 0; i < num_stripes; i++) {
2970 multi->stripes[i].physical =
2971 map->stripes[stripe_index].physical +
2972 stripe_offset + stripe_nr * map->stripe_len;
2973 multi->stripes[i].dev = map->stripes[stripe_index].dev;
2974
2975 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
2976 u64 stripes;
2977 u32 last_stripe = 0;
2978 int j;
2979
2980 div_u64_rem(stripe_nr_end - 1,
2981 map->num_stripes,
2982 &last_stripe);
2983
2984 for (j = 0; j < map->num_stripes; j++) {
2985 u32 test;
2986
2987 div_u64_rem(stripe_nr_end - 1 - j,
2988 map->num_stripes, &test);
2989 if (test == stripe_index)
2990 break;
2991 }
2992 stripes = stripe_nr_end - 1 - j;
2993 do_div(stripes, map->num_stripes);
2994 multi->stripes[i].length = map->stripe_len *
2995 (stripes - stripe_nr + 1);
2996
2997 if (i == 0) {
2998 multi->stripes[i].length -=
2999 stripe_offset;
3000 stripe_offset = 0;
3001 }
3002 if (stripe_index == last_stripe)
3003 multi->stripes[i].length -=
3004 stripe_end_offset;
3005 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3006 u64 stripes;
3007 int j;
3008 int factor = map->num_stripes /
3009 map->sub_stripes;
3010 u32 last_stripe = 0;
3011
3012 div_u64_rem(stripe_nr_end - 1,
3013 factor, &last_stripe);
3014 last_stripe *= map->sub_stripes;
3015
3016 for (j = 0; j < factor; j++) {
3017 u32 test;
3018
3019 div_u64_rem(stripe_nr_end - 1 - j,
3020 factor, &test);
3021
3022 if (test ==
3023 stripe_index / map->sub_stripes)
3024 break;
3025 }
3026 stripes = stripe_nr_end - 1 - j;
3027 do_div(stripes, factor);
3028 multi->stripes[i].length = map->stripe_len *
3029 (stripes - stripe_nr + 1);
3030
3031 if (i < map->sub_stripes) {
3032 multi->stripes[i].length -=
3033 stripe_offset;
3034 if (i == map->sub_stripes - 1)
3035 stripe_offset = 0;
3036 }
3037 if (stripe_index >= last_stripe &&
3038 stripe_index <= (last_stripe +
3039 map->sub_stripes - 1)) {
3040 multi->stripes[i].length -=
3041 stripe_end_offset;
3042 }
3043 } else
3044 multi->stripes[i].length = *length;
3045
3046 stripe_index++;
3047 if (stripe_index == map->num_stripes) {
3048 /* This could only happen for RAID0/10 */
3049 stripe_index = 0;
3050 stripe_nr++;
3051 }
3052 }
3053 } else {
3054 for (i = 0; i < num_stripes; i++) {
3055 multi->stripes[i].physical =
3056 map->stripes[stripe_index].physical +
3057 stripe_offset +
3058 stripe_nr * map->stripe_len;
3059 multi->stripes[i].dev =
3060 map->stripes[stripe_index].dev;
3061 stripe_index++;
3062 }
3063 }
3064 if (multi_ret) {
3065 *multi_ret = multi;
3066 multi->num_stripes = num_stripes;
3067 multi->max_errors = max_errors;
3068 }
3069 out:
3070 free_extent_map(em);
3071 return 0;
3072 }
3073
3074 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
3075 u64 logical, u64 *length,
3076 struct btrfs_multi_bio **multi_ret, int mirror_num)
3077 {
3078 return __btrfs_map_block(map_tree, rw, logical, length, multi_ret,
3079 mirror_num);
3080 }
3081
3082 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
3083 u64 chunk_start, u64 physical, u64 devid,
3084 u64 **logical, int *naddrs, int *stripe_len)
3085 {
3086 struct extent_map_tree *em_tree = &map_tree->map_tree;
3087 struct extent_map *em;
3088 struct map_lookup *map;
3089 u64 *buf;
3090 u64 bytenr;
3091 u64 length;
3092 u64 stripe_nr;
3093 int i, j, nr = 0;
3094
3095 read_lock(&em_tree->lock);
3096 em = lookup_extent_mapping(em_tree, chunk_start, 1);
3097 read_unlock(&em_tree->lock);
3098
3099 BUG_ON(!em || em->start != chunk_start);
3100 map = (struct map_lookup *)em->bdev;
3101
3102 length = em->len;
3103 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
3104 do_div(length, map->num_stripes / map->sub_stripes);
3105 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
3106 do_div(length, map->num_stripes);
3107
3108 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
3109 BUG_ON(!buf);
3110
3111 for (i = 0; i < map->num_stripes; i++) {
3112 if (devid && map->stripes[i].dev->devid != devid)
3113 continue;
3114 if (map->stripes[i].physical > physical ||
3115 map->stripes[i].physical + length <= physical)
3116 continue;
3117
3118 stripe_nr = physical - map->stripes[i].physical;
3119 do_div(stripe_nr, map->stripe_len);
3120
3121 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3122 stripe_nr = stripe_nr * map->num_stripes + i;
3123 do_div(stripe_nr, map->sub_stripes);
3124 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3125 stripe_nr = stripe_nr * map->num_stripes + i;
3126 }
3127 bytenr = chunk_start + stripe_nr * map->stripe_len;
3128 WARN_ON(nr >= map->num_stripes);
3129 for (j = 0; j < nr; j++) {
3130 if (buf[j] == bytenr)
3131 break;
3132 }
3133 if (j == nr) {
3134 WARN_ON(nr >= map->num_stripes);
3135 buf[nr++] = bytenr;
3136 }
3137 }
3138
3139 *logical = buf;
3140 *naddrs = nr;
3141 *stripe_len = map->stripe_len;
3142
3143 free_extent_map(em);
3144 return 0;
3145 }
3146
3147 static void end_bio_multi_stripe(struct bio *bio, int err)
3148 {
3149 struct btrfs_multi_bio *multi = bio->bi_private;
3150 int is_orig_bio = 0;
3151
3152 if (err)
3153 atomic_inc(&multi->error);
3154
3155 if (bio == multi->orig_bio)
3156 is_orig_bio = 1;
3157
3158 if (atomic_dec_and_test(&multi->stripes_pending)) {
3159 if (!is_orig_bio) {
3160 bio_put(bio);
3161 bio = multi->orig_bio;
3162 }
3163 bio->bi_private = multi->private;
3164 bio->bi_end_io = multi->end_io;
3165 /* only send an error to the higher layers if it is
3166 * beyond the tolerance of the multi-bio
3167 */
3168 if (atomic_read(&multi->error) > multi->max_errors) {
3169 err = -EIO;
3170 } else if (err) {
3171 /*
3172 * this bio is actually up to date, we didn't
3173 * go over the max number of errors
3174 */
3175 set_bit(BIO_UPTODATE, &bio->bi_flags);
3176 err = 0;
3177 }
3178 kfree(multi);
3179
3180 bio_endio(bio, err);
3181 } else if (!is_orig_bio) {
3182 bio_put(bio);
3183 }
3184 }
3185
3186 struct async_sched {
3187 struct bio *bio;
3188 int rw;
3189 struct btrfs_fs_info *info;
3190 struct btrfs_work work;
3191 };
3192
3193 /*
3194 * see run_scheduled_bios for a description of why bios are collected for
3195 * async submit.
3196 *
3197 * This will add one bio to the pending list for a device and make sure
3198 * the work struct is scheduled.
3199 */
3200 static noinline int schedule_bio(struct btrfs_root *root,
3201 struct btrfs_device *device,
3202 int rw, struct bio *bio)
3203 {
3204 int should_queue = 1;
3205 struct btrfs_pending_bios *pending_bios;
3206
3207 /* don't bother with additional async steps for reads, right now */
3208 if (!(rw & REQ_WRITE)) {
3209 bio_get(bio);
3210 submit_bio(rw, bio);
3211 bio_put(bio);
3212 return 0;
3213 }
3214
3215 /*
3216 * nr_async_bios allows us to reliably return congestion to the
3217 * higher layers. Otherwise, the async bio makes it appear we have
3218 * made progress against dirty pages when we've really just put it
3219 * on a queue for later
3220 */
3221 atomic_inc(&root->fs_info->nr_async_bios);
3222 WARN_ON(bio->bi_next);
3223 bio->bi_next = NULL;
3224 bio->bi_rw |= rw;
3225
3226 spin_lock(&device->io_lock);
3227 if (bio->bi_rw & REQ_SYNC)
3228 pending_bios = &device->pending_sync_bios;
3229 else
3230 pending_bios = &device->pending_bios;
3231
3232 if (pending_bios->tail)
3233 pending_bios->tail->bi_next = bio;
3234
3235 pending_bios->tail = bio;
3236 if (!pending_bios->head)
3237 pending_bios->head = bio;
3238 if (device->running_pending)
3239 should_queue = 0;
3240
3241 spin_unlock(&device->io_lock);
3242
3243 if (should_queue)
3244 btrfs_queue_worker(&root->fs_info->submit_workers,
3245 &device->work);
3246 return 0;
3247 }
3248
3249 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
3250 int mirror_num, int async_submit)
3251 {
3252 struct btrfs_mapping_tree *map_tree;
3253 struct btrfs_device *dev;
3254 struct bio *first_bio = bio;
3255 u64 logical = (u64)bio->bi_sector << 9;
3256 u64 length = 0;
3257 u64 map_length;
3258 struct btrfs_multi_bio *multi = NULL;
3259 int ret;
3260 int dev_nr = 0;
3261 int total_devs = 1;
3262
3263 length = bio->bi_size;
3264 map_tree = &root->fs_info->mapping_tree;
3265 map_length = length;
3266
3267 ret = btrfs_map_block(map_tree, rw, logical, &map_length, &multi,
3268 mirror_num);
3269 BUG_ON(ret);
3270
3271 total_devs = multi->num_stripes;
3272 if (map_length < length) {
3273 printk(KERN_CRIT "mapping failed logical %llu bio len %llu "
3274 "len %llu\n", (unsigned long long)logical,
3275 (unsigned long long)length,
3276 (unsigned long long)map_length);
3277 BUG();
3278 }
3279 multi->end_io = first_bio->bi_end_io;
3280 multi->private = first_bio->bi_private;
3281 multi->orig_bio = first_bio;
3282 atomic_set(&multi->stripes_pending, multi->num_stripes);
3283
3284 while (dev_nr < total_devs) {
3285 if (total_devs > 1) {
3286 if (dev_nr < total_devs - 1) {
3287 bio = bio_clone(first_bio, GFP_NOFS);
3288 BUG_ON(!bio);
3289 } else {
3290 bio = first_bio;
3291 }
3292 bio->bi_private = multi;
3293 bio->bi_end_io = end_bio_multi_stripe;
3294 }
3295 bio->bi_sector = multi->stripes[dev_nr].physical >> 9;
3296 dev = multi->stripes[dev_nr].dev;
3297 if (dev && dev->bdev && (rw != WRITE || dev->writeable)) {
3298 bio->bi_bdev = dev->bdev;
3299 if (async_submit)
3300 schedule_bio(root, dev, rw, bio);
3301 else
3302 submit_bio(rw, bio);
3303 } else {
3304 bio->bi_bdev = root->fs_info->fs_devices->latest_bdev;
3305 bio->bi_sector = logical >> 9;
3306 bio_endio(bio, -EIO);
3307 }
3308 dev_nr++;
3309 }
3310 if (total_devs == 1)
3311 kfree(multi);
3312 return 0;
3313 }
3314
3315 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
3316 u8 *uuid, u8 *fsid)
3317 {
3318 struct btrfs_device *device;
3319 struct btrfs_fs_devices *cur_devices;
3320
3321 cur_devices = root->fs_info->fs_devices;
3322 while (cur_devices) {
3323 if (!fsid ||
3324 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
3325 device = __find_device(&cur_devices->devices,
3326 devid, uuid);
3327 if (device)
3328 return device;
3329 }
3330 cur_devices = cur_devices->seed;
3331 }
3332 return NULL;
3333 }
3334
3335 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
3336 u64 devid, u8 *dev_uuid)
3337 {
3338 struct btrfs_device *device;
3339 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
3340
3341 device = kzalloc(sizeof(*device), GFP_NOFS);
3342 if (!device)
3343 return NULL;
3344 list_add(&device->dev_list,
3345 &fs_devices->devices);
3346 device->dev_root = root->fs_info->dev_root;
3347 device->devid = devid;
3348 device->work.func = pending_bios_fn;
3349 device->fs_devices = fs_devices;
3350 device->missing = 1;
3351 fs_devices->num_devices++;
3352 fs_devices->missing_devices++;
3353 spin_lock_init(&device->io_lock);
3354 INIT_LIST_HEAD(&device->dev_alloc_list);
3355 memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
3356 return device;
3357 }
3358
3359 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
3360 struct extent_buffer *leaf,
3361 struct btrfs_chunk *chunk)
3362 {
3363 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
3364 struct map_lookup *map;
3365 struct extent_map *em;
3366 u64 logical;
3367 u64 length;
3368 u64 devid;
3369 u8 uuid[BTRFS_UUID_SIZE];
3370 int num_stripes;
3371 int ret;
3372 int i;
3373
3374 logical = key->offset;
3375 length = btrfs_chunk_length(leaf, chunk);
3376
3377 read_lock(&map_tree->map_tree.lock);
3378 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
3379 read_unlock(&map_tree->map_tree.lock);
3380
3381 /* already mapped? */
3382 if (em && em->start <= logical && em->start + em->len > logical) {
3383 free_extent_map(em);
3384 return 0;
3385 } else if (em) {
3386 free_extent_map(em);
3387 }
3388
3389 em = alloc_extent_map();
3390 if (!em)
3391 return -ENOMEM;
3392 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
3393 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
3394 if (!map) {
3395 free_extent_map(em);
3396 return -ENOMEM;
3397 }
3398
3399 em->bdev = (struct block_device *)map;
3400 em->start = logical;
3401 em->len = length;
3402 em->block_start = 0;
3403 em->block_len = em->len;
3404
3405 map->num_stripes = num_stripes;
3406 map->io_width = btrfs_chunk_io_width(leaf, chunk);
3407 map->io_align = btrfs_chunk_io_align(leaf, chunk);
3408 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
3409 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
3410 map->type = btrfs_chunk_type(leaf, chunk);
3411 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
3412 for (i = 0; i < num_stripes; i++) {
3413 map->stripes[i].physical =
3414 btrfs_stripe_offset_nr(leaf, chunk, i);
3415 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
3416 read_extent_buffer(leaf, uuid, (unsigned long)
3417 btrfs_stripe_dev_uuid_nr(chunk, i),
3418 BTRFS_UUID_SIZE);
3419 map->stripes[i].dev = btrfs_find_device(root, devid, uuid,
3420 NULL);
3421 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
3422 kfree(map);
3423 free_extent_map(em);
3424 return -EIO;
3425 }
3426 if (!map->stripes[i].dev) {
3427 map->stripes[i].dev =
3428 add_missing_dev(root, devid, uuid);
3429 if (!map->stripes[i].dev) {
3430 kfree(map);
3431 free_extent_map(em);
3432 return -EIO;
3433 }
3434 }
3435 map->stripes[i].dev->in_fs_metadata = 1;
3436 }
3437
3438 write_lock(&map_tree->map_tree.lock);
3439 ret = add_extent_mapping(&map_tree->map_tree, em);
3440 write_unlock(&map_tree->map_tree.lock);
3441 BUG_ON(ret);
3442 free_extent_map(em);
3443
3444 return 0;
3445 }
3446
3447 static int fill_device_from_item(struct extent_buffer *leaf,
3448 struct btrfs_dev_item *dev_item,
3449 struct btrfs_device *device)
3450 {
3451 unsigned long ptr;
3452
3453 device->devid = btrfs_device_id(leaf, dev_item);
3454 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
3455 device->total_bytes = device->disk_total_bytes;
3456 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
3457 device->type = btrfs_device_type(leaf, dev_item);
3458 device->io_align = btrfs_device_io_align(leaf, dev_item);
3459 device->io_width = btrfs_device_io_width(leaf, dev_item);
3460 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
3461
3462 ptr = (unsigned long)btrfs_device_uuid(dev_item);
3463 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
3464
3465 return 0;
3466 }
3467
3468 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
3469 {
3470 struct btrfs_fs_devices *fs_devices;
3471 int ret;
3472
3473 mutex_lock(&uuid_mutex);
3474
3475 fs_devices = root->fs_info->fs_devices->seed;
3476 while (fs_devices) {
3477 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
3478 ret = 0;
3479 goto out;
3480 }
3481 fs_devices = fs_devices->seed;
3482 }
3483
3484 fs_devices = find_fsid(fsid);
3485 if (!fs_devices) {
3486 ret = -ENOENT;
3487 goto out;
3488 }
3489
3490 fs_devices = clone_fs_devices(fs_devices);
3491 if (IS_ERR(fs_devices)) {
3492 ret = PTR_ERR(fs_devices);
3493 goto out;
3494 }
3495
3496 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
3497 root->fs_info->bdev_holder);
3498 if (ret)
3499 goto out;
3500
3501 if (!fs_devices->seeding) {
3502 __btrfs_close_devices(fs_devices);
3503 free_fs_devices(fs_devices);
3504 ret = -EINVAL;
3505 goto out;
3506 }
3507
3508 fs_devices->seed = root->fs_info->fs_devices->seed;
3509 root->fs_info->fs_devices->seed = fs_devices;
3510 out:
3511 mutex_unlock(&uuid_mutex);
3512 return ret;
3513 }
3514
3515 static int read_one_dev(struct btrfs_root *root,
3516 struct extent_buffer *leaf,
3517 struct btrfs_dev_item *dev_item)
3518 {
3519 struct btrfs_device *device;
3520 u64 devid;
3521 int ret;
3522 u8 fs_uuid[BTRFS_UUID_SIZE];
3523 u8 dev_uuid[BTRFS_UUID_SIZE];
3524
3525 devid = btrfs_device_id(leaf, dev_item);
3526 read_extent_buffer(leaf, dev_uuid,
3527 (unsigned long)btrfs_device_uuid(dev_item),
3528 BTRFS_UUID_SIZE);
3529 read_extent_buffer(leaf, fs_uuid,
3530 (unsigned long)btrfs_device_fsid(dev_item),
3531 BTRFS_UUID_SIZE);
3532
3533 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
3534 ret = open_seed_devices(root, fs_uuid);
3535 if (ret && !btrfs_test_opt(root, DEGRADED))
3536 return ret;
3537 }
3538
3539 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
3540 if (!device || !device->bdev) {
3541 if (!btrfs_test_opt(root, DEGRADED))
3542 return -EIO;
3543
3544 if (!device) {
3545 printk(KERN_WARNING "warning devid %llu missing\n",
3546 (unsigned long long)devid);
3547 device = add_missing_dev(root, devid, dev_uuid);
3548 if (!device)
3549 return -ENOMEM;
3550 } else if (!device->missing) {
3551 /*
3552 * this happens when a device that was properly setup
3553 * in the device info lists suddenly goes bad.
3554 * device->bdev is NULL, and so we have to set
3555 * device->missing to one here
3556 */
3557 root->fs_info->fs_devices->missing_devices++;
3558 device->missing = 1;
3559 }
3560 }
3561
3562 if (device->fs_devices != root->fs_info->fs_devices) {
3563 BUG_ON(device->writeable);
3564 if (device->generation !=
3565 btrfs_device_generation(leaf, dev_item))
3566 return -EINVAL;
3567 }
3568
3569 fill_device_from_item(leaf, dev_item, device);
3570 device->dev_root = root->fs_info->dev_root;
3571 device->in_fs_metadata = 1;
3572 if (device->writeable)
3573 device->fs_devices->total_rw_bytes += device->total_bytes;
3574 ret = 0;
3575 return ret;
3576 }
3577
3578 int btrfs_read_sys_array(struct btrfs_root *root)
3579 {
3580 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
3581 struct extent_buffer *sb;
3582 struct btrfs_disk_key *disk_key;
3583 struct btrfs_chunk *chunk;
3584 u8 *ptr;
3585 unsigned long sb_ptr;
3586 int ret = 0;
3587 u32 num_stripes;
3588 u32 array_size;
3589 u32 len = 0;
3590 u32 cur;
3591 struct btrfs_key key;
3592
3593 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
3594 BTRFS_SUPER_INFO_SIZE);
3595 if (!sb)
3596 return -ENOMEM;
3597 btrfs_set_buffer_uptodate(sb);
3598 btrfs_set_buffer_lockdep_class(sb, 0);
3599
3600 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
3601 array_size = btrfs_super_sys_array_size(super_copy);
3602
3603 ptr = super_copy->sys_chunk_array;
3604 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
3605 cur = 0;
3606
3607 while (cur < array_size) {
3608 disk_key = (struct btrfs_disk_key *)ptr;
3609 btrfs_disk_key_to_cpu(&key, disk_key);
3610
3611 len = sizeof(*disk_key); ptr += len;
3612 sb_ptr += len;
3613 cur += len;
3614
3615 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
3616 chunk = (struct btrfs_chunk *)sb_ptr;
3617 ret = read_one_chunk(root, &key, sb, chunk);
3618 if (ret)
3619 break;
3620 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
3621 len = btrfs_chunk_item_size(num_stripes);
3622 } else {
3623 ret = -EIO;
3624 break;
3625 }
3626 ptr += len;
3627 sb_ptr += len;
3628 cur += len;
3629 }
3630 free_extent_buffer(sb);
3631 return ret;
3632 }
3633
3634 int btrfs_read_chunk_tree(struct btrfs_root *root)
3635 {
3636 struct btrfs_path *path;
3637 struct extent_buffer *leaf;
3638 struct btrfs_key key;
3639 struct btrfs_key found_key;
3640 int ret;
3641 int slot;
3642
3643 root = root->fs_info->chunk_root;
3644
3645 path = btrfs_alloc_path();
3646 if (!path)
3647 return -ENOMEM;
3648
3649 /* first we search for all of the device items, and then we
3650 * read in all of the chunk items. This way we can create chunk
3651 * mappings that reference all of the devices that are afound
3652 */
3653 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
3654 key.offset = 0;
3655 key.type = 0;
3656 again:
3657 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3658 if (ret < 0)
3659 goto error;
3660 while (1) {
3661 leaf = path->nodes[0];
3662 slot = path->slots[0];
3663 if (slot >= btrfs_header_nritems(leaf)) {
3664 ret = btrfs_next_leaf(root, path);
3665 if (ret == 0)
3666 continue;
3667 if (ret < 0)
3668 goto error;
3669 break;
3670 }
3671 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3672 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
3673 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
3674 break;
3675 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
3676 struct btrfs_dev_item *dev_item;
3677 dev_item = btrfs_item_ptr(leaf, slot,
3678 struct btrfs_dev_item);
3679 ret = read_one_dev(root, leaf, dev_item);
3680 if (ret)
3681 goto error;
3682 }
3683 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
3684 struct btrfs_chunk *chunk;
3685 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
3686 ret = read_one_chunk(root, &found_key, leaf, chunk);
3687 if (ret)
3688 goto error;
3689 }
3690 path->slots[0]++;
3691 }
3692 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
3693 key.objectid = 0;
3694 btrfs_release_path(path);
3695 goto again;
3696 }
3697 ret = 0;
3698 error:
3699 btrfs_free_path(path);
3700 return ret;
3701 }
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree