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Merge branch 'for-2.6.38' of git://linux-nfs.org/~bfields/linux
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / btrfs / volumes.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18 #include <linux/sched.h>
19 #include <linux/bio.h>
20 #include <linux/slab.h>
21 #include <linux/buffer_head.h>
22 #include <linux/blkdev.h>
23 #include <linux/random.h>
24 #include <linux/iocontext.h>
25 #include <asm/div64.h>
26 #include "compat.h"
27 #include "ctree.h"
28 #include "extent_map.h"
29 #include "disk-io.h"
30 #include "transaction.h"
31 #include "print-tree.h"
32 #include "volumes.h"
33 #include "async-thread.h"
34
35 struct map_lookup {
36 u64 type;
37 int io_align;
38 int io_width;
39 int stripe_len;
40 int sector_size;
41 int num_stripes;
42 int sub_stripes;
43 struct btrfs_bio_stripe stripes[];
44 };
45
46 static int init_first_rw_device(struct btrfs_trans_handle *trans,
47 struct btrfs_root *root,
48 struct btrfs_device *device);
49 static int btrfs_relocate_sys_chunks(struct btrfs_root *root);
50
51 #define map_lookup_size(n) (sizeof(struct map_lookup) + \
52 (sizeof(struct btrfs_bio_stripe) * (n)))
53
54 static DEFINE_MUTEX(uuid_mutex);
55 static LIST_HEAD(fs_uuids);
56
57 void btrfs_lock_volumes(void)
58 {
59 mutex_lock(&uuid_mutex);
60 }
61
62 void btrfs_unlock_volumes(void)
63 {
64 mutex_unlock(&uuid_mutex);
65 }
66
67 static void lock_chunks(struct btrfs_root *root)
68 {
69 mutex_lock(&root->fs_info->chunk_mutex);
70 }
71
72 static void unlock_chunks(struct btrfs_root *root)
73 {
74 mutex_unlock(&root->fs_info->chunk_mutex);
75 }
76
77 static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
78 {
79 struct btrfs_device *device;
80 WARN_ON(fs_devices->opened);
81 while (!list_empty(&fs_devices->devices)) {
82 device = list_entry(fs_devices->devices.next,
83 struct btrfs_device, dev_list);
84 list_del(&device->dev_list);
85 kfree(device->name);
86 kfree(device);
87 }
88 kfree(fs_devices);
89 }
90
91 int btrfs_cleanup_fs_uuids(void)
92 {
93 struct btrfs_fs_devices *fs_devices;
94
95 while (!list_empty(&fs_uuids)) {
96 fs_devices = list_entry(fs_uuids.next,
97 struct btrfs_fs_devices, list);
98 list_del(&fs_devices->list);
99 free_fs_devices(fs_devices);
100 }
101 return 0;
102 }
103
104 static noinline struct btrfs_device *__find_device(struct list_head *head,
105 u64 devid, u8 *uuid)
106 {
107 struct btrfs_device *dev;
108
109 list_for_each_entry(dev, head, dev_list) {
110 if (dev->devid == devid &&
111 (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
112 return dev;
113 }
114 }
115 return NULL;
116 }
117
118 static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
119 {
120 struct btrfs_fs_devices *fs_devices;
121
122 list_for_each_entry(fs_devices, &fs_uuids, list) {
123 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
124 return fs_devices;
125 }
126 return NULL;
127 }
128
129 static void requeue_list(struct btrfs_pending_bios *pending_bios,
130 struct bio *head, struct bio *tail)
131 {
132
133 struct bio *old_head;
134
135 old_head = pending_bios->head;
136 pending_bios->head = head;
137 if (pending_bios->tail)
138 tail->bi_next = old_head;
139 else
140 pending_bios->tail = tail;
141 }
142
143 /*
144 * we try to collect pending bios for a device so we don't get a large
145 * number of procs sending bios down to the same device. This greatly
146 * improves the schedulers ability to collect and merge the bios.
147 *
148 * But, it also turns into a long list of bios to process and that is sure
149 * to eventually make the worker thread block. The solution here is to
150 * make some progress and then put this work struct back at the end of
151 * the list if the block device is congested. This way, multiple devices
152 * can make progress from a single worker thread.
153 */
154 static noinline int run_scheduled_bios(struct btrfs_device *device)
155 {
156 struct bio *pending;
157 struct backing_dev_info *bdi;
158 struct btrfs_fs_info *fs_info;
159 struct btrfs_pending_bios *pending_bios;
160 struct bio *tail;
161 struct bio *cur;
162 int again = 0;
163 unsigned long num_run;
164 unsigned long num_sync_run;
165 unsigned long batch_run = 0;
166 unsigned long limit;
167 unsigned long last_waited = 0;
168 int force_reg = 0;
169
170 bdi = blk_get_backing_dev_info(device->bdev);
171 fs_info = device->dev_root->fs_info;
172 limit = btrfs_async_submit_limit(fs_info);
173 limit = limit * 2 / 3;
174
175 /* we want to make sure that every time we switch from the sync
176 * list to the normal list, we unplug
177 */
178 num_sync_run = 0;
179
180 loop:
181 spin_lock(&device->io_lock);
182
183 loop_lock:
184 num_run = 0;
185
186 /* take all the bios off the list at once and process them
187 * later on (without the lock held). But, remember the
188 * tail and other pointers so the bios can be properly reinserted
189 * into the list if we hit congestion
190 */
191 if (!force_reg && device->pending_sync_bios.head) {
192 pending_bios = &device->pending_sync_bios;
193 force_reg = 1;
194 } else {
195 pending_bios = &device->pending_bios;
196 force_reg = 0;
197 }
198
199 pending = pending_bios->head;
200 tail = pending_bios->tail;
201 WARN_ON(pending && !tail);
202
203 /*
204 * if pending was null this time around, no bios need processing
205 * at all and we can stop. Otherwise it'll loop back up again
206 * and do an additional check so no bios are missed.
207 *
208 * device->running_pending is used to synchronize with the
209 * schedule_bio code.
210 */
211 if (device->pending_sync_bios.head == NULL &&
212 device->pending_bios.head == NULL) {
213 again = 0;
214 device->running_pending = 0;
215 } else {
216 again = 1;
217 device->running_pending = 1;
218 }
219
220 pending_bios->head = NULL;
221 pending_bios->tail = NULL;
222
223 spin_unlock(&device->io_lock);
224
225 /*
226 * if we're doing the regular priority list, make sure we unplug
227 * for any high prio bios we've sent down
228 */
229 if (pending_bios == &device->pending_bios && num_sync_run > 0) {
230 num_sync_run = 0;
231 blk_run_backing_dev(bdi, NULL);
232 }
233
234 while (pending) {
235
236 rmb();
237 /* we want to work on both lists, but do more bios on the
238 * sync list than the regular list
239 */
240 if ((num_run > 32 &&
241 pending_bios != &device->pending_sync_bios &&
242 device->pending_sync_bios.head) ||
243 (num_run > 64 && pending_bios == &device->pending_sync_bios &&
244 device->pending_bios.head)) {
245 spin_lock(&device->io_lock);
246 requeue_list(pending_bios, pending, tail);
247 goto loop_lock;
248 }
249
250 cur = pending;
251 pending = pending->bi_next;
252 cur->bi_next = NULL;
253 atomic_dec(&fs_info->nr_async_bios);
254
255 if (atomic_read(&fs_info->nr_async_bios) < limit &&
256 waitqueue_active(&fs_info->async_submit_wait))
257 wake_up(&fs_info->async_submit_wait);
258
259 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
260
261 if (cur->bi_rw & REQ_SYNC)
262 num_sync_run++;
263
264 submit_bio(cur->bi_rw, cur);
265 num_run++;
266 batch_run++;
267 if (need_resched()) {
268 if (num_sync_run) {
269 blk_run_backing_dev(bdi, NULL);
270 num_sync_run = 0;
271 }
272 cond_resched();
273 }
274
275 /*
276 * we made progress, there is more work to do and the bdi
277 * is now congested. Back off and let other work structs
278 * run instead
279 */
280 if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
281 fs_info->fs_devices->open_devices > 1) {
282 struct io_context *ioc;
283
284 ioc = current->io_context;
285
286 /*
287 * the main goal here is that we don't want to
288 * block if we're going to be able to submit
289 * more requests without blocking.
290 *
291 * This code does two great things, it pokes into
292 * the elevator code from a filesystem _and_
293 * it makes assumptions about how batching works.
294 */
295 if (ioc && ioc->nr_batch_requests > 0 &&
296 time_before(jiffies, ioc->last_waited + HZ/50UL) &&
297 (last_waited == 0 ||
298 ioc->last_waited == last_waited)) {
299 /*
300 * we want to go through our batch of
301 * requests and stop. So, we copy out
302 * the ioc->last_waited time and test
303 * against it before looping
304 */
305 last_waited = ioc->last_waited;
306 if (need_resched()) {
307 if (num_sync_run) {
308 blk_run_backing_dev(bdi, NULL);
309 num_sync_run = 0;
310 }
311 cond_resched();
312 }
313 continue;
314 }
315 spin_lock(&device->io_lock);
316 requeue_list(pending_bios, pending, tail);
317 device->running_pending = 1;
318
319 spin_unlock(&device->io_lock);
320 btrfs_requeue_work(&device->work);
321 goto done;
322 }
323 }
324
325 if (num_sync_run) {
326 num_sync_run = 0;
327 blk_run_backing_dev(bdi, NULL);
328 }
329 /*
330 * IO has already been through a long path to get here. Checksumming,
331 * async helper threads, perhaps compression. We've done a pretty
332 * good job of collecting a batch of IO and should just unplug
333 * the device right away.
334 *
335 * This will help anyone who is waiting on the IO, they might have
336 * already unplugged, but managed to do so before the bio they
337 * cared about found its way down here.
338 */
339 blk_run_backing_dev(bdi, NULL);
340
341 cond_resched();
342 if (again)
343 goto loop;
344
345 spin_lock(&device->io_lock);
346 if (device->pending_bios.head || device->pending_sync_bios.head)
347 goto loop_lock;
348 spin_unlock(&device->io_lock);
349
350 done:
351 return 0;
352 }
353
354 static void pending_bios_fn(struct btrfs_work *work)
355 {
356 struct btrfs_device *device;
357
358 device = container_of(work, struct btrfs_device, work);
359 run_scheduled_bios(device);
360 }
361
362 static noinline int device_list_add(const char *path,
363 struct btrfs_super_block *disk_super,
364 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
365 {
366 struct btrfs_device *device;
367 struct btrfs_fs_devices *fs_devices;
368 u64 found_transid = btrfs_super_generation(disk_super);
369 char *name;
370
371 fs_devices = find_fsid(disk_super->fsid);
372 if (!fs_devices) {
373 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
374 if (!fs_devices)
375 return -ENOMEM;
376 INIT_LIST_HEAD(&fs_devices->devices);
377 INIT_LIST_HEAD(&fs_devices->alloc_list);
378 list_add(&fs_devices->list, &fs_uuids);
379 memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
380 fs_devices->latest_devid = devid;
381 fs_devices->latest_trans = found_transid;
382 mutex_init(&fs_devices->device_list_mutex);
383 device = NULL;
384 } else {
385 device = __find_device(&fs_devices->devices, devid,
386 disk_super->dev_item.uuid);
387 }
388 if (!device) {
389 if (fs_devices->opened)
390 return -EBUSY;
391
392 device = kzalloc(sizeof(*device), GFP_NOFS);
393 if (!device) {
394 /* we can safely leave the fs_devices entry around */
395 return -ENOMEM;
396 }
397 device->devid = devid;
398 device->work.func = pending_bios_fn;
399 memcpy(device->uuid, disk_super->dev_item.uuid,
400 BTRFS_UUID_SIZE);
401 spin_lock_init(&device->io_lock);
402 device->name = kstrdup(path, GFP_NOFS);
403 if (!device->name) {
404 kfree(device);
405 return -ENOMEM;
406 }
407 INIT_LIST_HEAD(&device->dev_alloc_list);
408
409 mutex_lock(&fs_devices->device_list_mutex);
410 list_add(&device->dev_list, &fs_devices->devices);
411 mutex_unlock(&fs_devices->device_list_mutex);
412
413 device->fs_devices = fs_devices;
414 fs_devices->num_devices++;
415 } else if (!device->name || strcmp(device->name, path)) {
416 name = kstrdup(path, GFP_NOFS);
417 if (!name)
418 return -ENOMEM;
419 kfree(device->name);
420 device->name = name;
421 if (device->missing) {
422 fs_devices->missing_devices--;
423 device->missing = 0;
424 }
425 }
426
427 if (found_transid > fs_devices->latest_trans) {
428 fs_devices->latest_devid = devid;
429 fs_devices->latest_trans = found_transid;
430 }
431 *fs_devices_ret = fs_devices;
432 return 0;
433 }
434
435 static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
436 {
437 struct btrfs_fs_devices *fs_devices;
438 struct btrfs_device *device;
439 struct btrfs_device *orig_dev;
440
441 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
442 if (!fs_devices)
443 return ERR_PTR(-ENOMEM);
444
445 INIT_LIST_HEAD(&fs_devices->devices);
446 INIT_LIST_HEAD(&fs_devices->alloc_list);
447 INIT_LIST_HEAD(&fs_devices->list);
448 mutex_init(&fs_devices->device_list_mutex);
449 fs_devices->latest_devid = orig->latest_devid;
450 fs_devices->latest_trans = orig->latest_trans;
451 memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid));
452
453 mutex_lock(&orig->device_list_mutex);
454 list_for_each_entry(orig_dev, &orig->devices, dev_list) {
455 device = kzalloc(sizeof(*device), GFP_NOFS);
456 if (!device)
457 goto error;
458
459 device->name = kstrdup(orig_dev->name, GFP_NOFS);
460 if (!device->name) {
461 kfree(device);
462 goto error;
463 }
464
465 device->devid = orig_dev->devid;
466 device->work.func = pending_bios_fn;
467 memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid));
468 spin_lock_init(&device->io_lock);
469 INIT_LIST_HEAD(&device->dev_list);
470 INIT_LIST_HEAD(&device->dev_alloc_list);
471
472 list_add(&device->dev_list, &fs_devices->devices);
473 device->fs_devices = fs_devices;
474 fs_devices->num_devices++;
475 }
476 mutex_unlock(&orig->device_list_mutex);
477 return fs_devices;
478 error:
479 mutex_unlock(&orig->device_list_mutex);
480 free_fs_devices(fs_devices);
481 return ERR_PTR(-ENOMEM);
482 }
483
484 int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
485 {
486 struct btrfs_device *device, *next;
487
488 mutex_lock(&uuid_mutex);
489 again:
490 mutex_lock(&fs_devices->device_list_mutex);
491 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
492 if (device->in_fs_metadata)
493 continue;
494
495 if (device->bdev) {
496 blkdev_put(device->bdev, device->mode);
497 device->bdev = NULL;
498 fs_devices->open_devices--;
499 }
500 if (device->writeable) {
501 list_del_init(&device->dev_alloc_list);
502 device->writeable = 0;
503 fs_devices->rw_devices--;
504 }
505 list_del_init(&device->dev_list);
506 fs_devices->num_devices--;
507 kfree(device->name);
508 kfree(device);
509 }
510 mutex_unlock(&fs_devices->device_list_mutex);
511
512 if (fs_devices->seed) {
513 fs_devices = fs_devices->seed;
514 goto again;
515 }
516
517 mutex_unlock(&uuid_mutex);
518 return 0;
519 }
520
521 static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
522 {
523 struct btrfs_device *device;
524
525 if (--fs_devices->opened > 0)
526 return 0;
527
528 list_for_each_entry(device, &fs_devices->devices, dev_list) {
529 if (device->bdev) {
530 blkdev_put(device->bdev, device->mode);
531 fs_devices->open_devices--;
532 }
533 if (device->writeable) {
534 list_del_init(&device->dev_alloc_list);
535 fs_devices->rw_devices--;
536 }
537
538 device->bdev = NULL;
539 device->writeable = 0;
540 device->in_fs_metadata = 0;
541 }
542 WARN_ON(fs_devices->open_devices);
543 WARN_ON(fs_devices->rw_devices);
544 fs_devices->opened = 0;
545 fs_devices->seeding = 0;
546
547 return 0;
548 }
549
550 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
551 {
552 struct btrfs_fs_devices *seed_devices = NULL;
553 int ret;
554
555 mutex_lock(&uuid_mutex);
556 ret = __btrfs_close_devices(fs_devices);
557 if (!fs_devices->opened) {
558 seed_devices = fs_devices->seed;
559 fs_devices->seed = NULL;
560 }
561 mutex_unlock(&uuid_mutex);
562
563 while (seed_devices) {
564 fs_devices = seed_devices;
565 seed_devices = fs_devices->seed;
566 __btrfs_close_devices(fs_devices);
567 free_fs_devices(fs_devices);
568 }
569 return ret;
570 }
571
572 static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
573 fmode_t flags, void *holder)
574 {
575 struct block_device *bdev;
576 struct list_head *head = &fs_devices->devices;
577 struct btrfs_device *device;
578 struct block_device *latest_bdev = NULL;
579 struct buffer_head *bh;
580 struct btrfs_super_block *disk_super;
581 u64 latest_devid = 0;
582 u64 latest_transid = 0;
583 u64 devid;
584 int seeding = 1;
585 int ret = 0;
586
587 flags |= FMODE_EXCL;
588
589 list_for_each_entry(device, head, dev_list) {
590 if (device->bdev)
591 continue;
592 if (!device->name)
593 continue;
594
595 bdev = blkdev_get_by_path(device->name, flags, holder);
596 if (IS_ERR(bdev)) {
597 printk(KERN_INFO "open %s failed\n", device->name);
598 goto error;
599 }
600 set_blocksize(bdev, 4096);
601
602 bh = btrfs_read_dev_super(bdev);
603 if (!bh)
604 goto error_close;
605
606 disk_super = (struct btrfs_super_block *)bh->b_data;
607 devid = btrfs_stack_device_id(&disk_super->dev_item);
608 if (devid != device->devid)
609 goto error_brelse;
610
611 if (memcmp(device->uuid, disk_super->dev_item.uuid,
612 BTRFS_UUID_SIZE))
613 goto error_brelse;
614
615 device->generation = btrfs_super_generation(disk_super);
616 if (!latest_transid || device->generation > latest_transid) {
617 latest_devid = devid;
618 latest_transid = device->generation;
619 latest_bdev = bdev;
620 }
621
622 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
623 device->writeable = 0;
624 } else {
625 device->writeable = !bdev_read_only(bdev);
626 seeding = 0;
627 }
628
629 device->bdev = bdev;
630 device->in_fs_metadata = 0;
631 device->mode = flags;
632
633 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
634 fs_devices->rotating = 1;
635
636 fs_devices->open_devices++;
637 if (device->writeable) {
638 fs_devices->rw_devices++;
639 list_add(&device->dev_alloc_list,
640 &fs_devices->alloc_list);
641 }
642 continue;
643
644 error_brelse:
645 brelse(bh);
646 error_close:
647 blkdev_put(bdev, flags);
648 error:
649 continue;
650 }
651 if (fs_devices->open_devices == 0) {
652 ret = -EIO;
653 goto out;
654 }
655 fs_devices->seeding = seeding;
656 fs_devices->opened = 1;
657 fs_devices->latest_bdev = latest_bdev;
658 fs_devices->latest_devid = latest_devid;
659 fs_devices->latest_trans = latest_transid;
660 fs_devices->total_rw_bytes = 0;
661 out:
662 return ret;
663 }
664
665 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
666 fmode_t flags, void *holder)
667 {
668 int ret;
669
670 mutex_lock(&uuid_mutex);
671 if (fs_devices->opened) {
672 fs_devices->opened++;
673 ret = 0;
674 } else {
675 ret = __btrfs_open_devices(fs_devices, flags, holder);
676 }
677 mutex_unlock(&uuid_mutex);
678 return ret;
679 }
680
681 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
682 struct btrfs_fs_devices **fs_devices_ret)
683 {
684 struct btrfs_super_block *disk_super;
685 struct block_device *bdev;
686 struct buffer_head *bh;
687 int ret;
688 u64 devid;
689 u64 transid;
690
691 mutex_lock(&uuid_mutex);
692
693 flags |= FMODE_EXCL;
694 bdev = blkdev_get_by_path(path, flags, holder);
695
696 if (IS_ERR(bdev)) {
697 ret = PTR_ERR(bdev);
698 goto error;
699 }
700
701 ret = set_blocksize(bdev, 4096);
702 if (ret)
703 goto error_close;
704 bh = btrfs_read_dev_super(bdev);
705 if (!bh) {
706 ret = -EIO;
707 goto error_close;
708 }
709 disk_super = (struct btrfs_super_block *)bh->b_data;
710 devid = btrfs_stack_device_id(&disk_super->dev_item);
711 transid = btrfs_super_generation(disk_super);
712 if (disk_super->label[0])
713 printk(KERN_INFO "device label %s ", disk_super->label);
714 else {
715 /* FIXME, make a readl uuid parser */
716 printk(KERN_INFO "device fsid %llx-%llx ",
717 *(unsigned long long *)disk_super->fsid,
718 *(unsigned long long *)(disk_super->fsid + 8));
719 }
720 printk(KERN_CONT "devid %llu transid %llu %s\n",
721 (unsigned long long)devid, (unsigned long long)transid, path);
722 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
723
724 brelse(bh);
725 error_close:
726 blkdev_put(bdev, flags);
727 error:
728 mutex_unlock(&uuid_mutex);
729 return ret;
730 }
731
732 /*
733 * this uses a pretty simple search, the expectation is that it is
734 * called very infrequently and that a given device has a small number
735 * of extents
736 */
737 int find_free_dev_extent(struct btrfs_trans_handle *trans,
738 struct btrfs_device *device, u64 num_bytes,
739 u64 *start, u64 *max_avail)
740 {
741 struct btrfs_key key;
742 struct btrfs_root *root = device->dev_root;
743 struct btrfs_dev_extent *dev_extent = NULL;
744 struct btrfs_path *path;
745 u64 hole_size = 0;
746 u64 last_byte = 0;
747 u64 search_start = 0;
748 u64 search_end = device->total_bytes;
749 int ret;
750 int slot = 0;
751 int start_found;
752 struct extent_buffer *l;
753
754 path = btrfs_alloc_path();
755 if (!path)
756 return -ENOMEM;
757 path->reada = 2;
758 start_found = 0;
759
760 /* FIXME use last free of some kind */
761
762 /* we don't want to overwrite the superblock on the drive,
763 * so we make sure to start at an offset of at least 1MB
764 */
765 search_start = max((u64)1024 * 1024, search_start);
766
767 if (root->fs_info->alloc_start + num_bytes <= device->total_bytes)
768 search_start = max(root->fs_info->alloc_start, search_start);
769
770 key.objectid = device->devid;
771 key.offset = search_start;
772 key.type = BTRFS_DEV_EXTENT_KEY;
773 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
774 if (ret < 0)
775 goto error;
776 if (ret > 0) {
777 ret = btrfs_previous_item(root, path, key.objectid, key.type);
778 if (ret < 0)
779 goto error;
780 if (ret > 0)
781 start_found = 1;
782 }
783 l = path->nodes[0];
784 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
785 while (1) {
786 l = path->nodes[0];
787 slot = path->slots[0];
788 if (slot >= btrfs_header_nritems(l)) {
789 ret = btrfs_next_leaf(root, path);
790 if (ret == 0)
791 continue;
792 if (ret < 0)
793 goto error;
794 no_more_items:
795 if (!start_found) {
796 if (search_start >= search_end) {
797 ret = -ENOSPC;
798 goto error;
799 }
800 *start = search_start;
801 start_found = 1;
802 goto check_pending;
803 }
804 *start = last_byte > search_start ?
805 last_byte : search_start;
806 if (search_end <= *start) {
807 ret = -ENOSPC;
808 goto error;
809 }
810 goto check_pending;
811 }
812 btrfs_item_key_to_cpu(l, &key, slot);
813
814 if (key.objectid < device->devid)
815 goto next;
816
817 if (key.objectid > device->devid)
818 goto no_more_items;
819
820 if (key.offset >= search_start && key.offset > last_byte &&
821 start_found) {
822 if (last_byte < search_start)
823 last_byte = search_start;
824 hole_size = key.offset - last_byte;
825
826 if (hole_size > *max_avail)
827 *max_avail = hole_size;
828
829 if (key.offset > last_byte &&
830 hole_size >= num_bytes) {
831 *start = last_byte;
832 goto check_pending;
833 }
834 }
835 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
836 goto next;
837
838 start_found = 1;
839 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
840 last_byte = key.offset + btrfs_dev_extent_length(l, dev_extent);
841 next:
842 path->slots[0]++;
843 cond_resched();
844 }
845 check_pending:
846 /* we have to make sure we didn't find an extent that has already
847 * been allocated by the map tree or the original allocation
848 */
849 BUG_ON(*start < search_start);
850
851 if (*start + num_bytes > search_end) {
852 ret = -ENOSPC;
853 goto error;
854 }
855 /* check for pending inserts here */
856 ret = 0;
857
858 error:
859 btrfs_free_path(path);
860 return ret;
861 }
862
863 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
864 struct btrfs_device *device,
865 u64 start)
866 {
867 int ret;
868 struct btrfs_path *path;
869 struct btrfs_root *root = device->dev_root;
870 struct btrfs_key key;
871 struct btrfs_key found_key;
872 struct extent_buffer *leaf = NULL;
873 struct btrfs_dev_extent *extent = NULL;
874
875 path = btrfs_alloc_path();
876 if (!path)
877 return -ENOMEM;
878
879 key.objectid = device->devid;
880 key.offset = start;
881 key.type = BTRFS_DEV_EXTENT_KEY;
882
883 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
884 if (ret > 0) {
885 ret = btrfs_previous_item(root, path, key.objectid,
886 BTRFS_DEV_EXTENT_KEY);
887 BUG_ON(ret);
888 leaf = path->nodes[0];
889 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
890 extent = btrfs_item_ptr(leaf, path->slots[0],
891 struct btrfs_dev_extent);
892 BUG_ON(found_key.offset > start || found_key.offset +
893 btrfs_dev_extent_length(leaf, extent) < start);
894 ret = 0;
895 } else if (ret == 0) {
896 leaf = path->nodes[0];
897 extent = btrfs_item_ptr(leaf, path->slots[0],
898 struct btrfs_dev_extent);
899 }
900 BUG_ON(ret);
901
902 if (device->bytes_used > 0)
903 device->bytes_used -= btrfs_dev_extent_length(leaf, extent);
904 ret = btrfs_del_item(trans, root, path);
905 BUG_ON(ret);
906
907 btrfs_free_path(path);
908 return ret;
909 }
910
911 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
912 struct btrfs_device *device,
913 u64 chunk_tree, u64 chunk_objectid,
914 u64 chunk_offset, u64 start, u64 num_bytes)
915 {
916 int ret;
917 struct btrfs_path *path;
918 struct btrfs_root *root = device->dev_root;
919 struct btrfs_dev_extent *extent;
920 struct extent_buffer *leaf;
921 struct btrfs_key key;
922
923 WARN_ON(!device->in_fs_metadata);
924 path = btrfs_alloc_path();
925 if (!path)
926 return -ENOMEM;
927
928 key.objectid = device->devid;
929 key.offset = start;
930 key.type = BTRFS_DEV_EXTENT_KEY;
931 ret = btrfs_insert_empty_item(trans, root, path, &key,
932 sizeof(*extent));
933 BUG_ON(ret);
934
935 leaf = path->nodes[0];
936 extent = btrfs_item_ptr(leaf, path->slots[0],
937 struct btrfs_dev_extent);
938 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
939 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
940 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
941
942 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
943 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
944 BTRFS_UUID_SIZE);
945
946 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
947 btrfs_mark_buffer_dirty(leaf);
948 btrfs_free_path(path);
949 return ret;
950 }
951
952 static noinline int find_next_chunk(struct btrfs_root *root,
953 u64 objectid, u64 *offset)
954 {
955 struct btrfs_path *path;
956 int ret;
957 struct btrfs_key key;
958 struct btrfs_chunk *chunk;
959 struct btrfs_key found_key;
960
961 path = btrfs_alloc_path();
962 BUG_ON(!path);
963
964 key.objectid = objectid;
965 key.offset = (u64)-1;
966 key.type = BTRFS_CHUNK_ITEM_KEY;
967
968 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
969 if (ret < 0)
970 goto error;
971
972 BUG_ON(ret == 0);
973
974 ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
975 if (ret) {
976 *offset = 0;
977 } else {
978 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
979 path->slots[0]);
980 if (found_key.objectid != objectid)
981 *offset = 0;
982 else {
983 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
984 struct btrfs_chunk);
985 *offset = found_key.offset +
986 btrfs_chunk_length(path->nodes[0], chunk);
987 }
988 }
989 ret = 0;
990 error:
991 btrfs_free_path(path);
992 return ret;
993 }
994
995 static noinline int find_next_devid(struct btrfs_root *root, u64 *objectid)
996 {
997 int ret;
998 struct btrfs_key key;
999 struct btrfs_key found_key;
1000 struct btrfs_path *path;
1001
1002 root = root->fs_info->chunk_root;
1003
1004 path = btrfs_alloc_path();
1005 if (!path)
1006 return -ENOMEM;
1007
1008 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1009 key.type = BTRFS_DEV_ITEM_KEY;
1010 key.offset = (u64)-1;
1011
1012 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1013 if (ret < 0)
1014 goto error;
1015
1016 BUG_ON(ret == 0);
1017
1018 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
1019 BTRFS_DEV_ITEM_KEY);
1020 if (ret) {
1021 *objectid = 1;
1022 } else {
1023 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1024 path->slots[0]);
1025 *objectid = found_key.offset + 1;
1026 }
1027 ret = 0;
1028 error:
1029 btrfs_free_path(path);
1030 return ret;
1031 }
1032
1033 /*
1034 * the device information is stored in the chunk root
1035 * the btrfs_device struct should be fully filled in
1036 */
1037 int btrfs_add_device(struct btrfs_trans_handle *trans,
1038 struct btrfs_root *root,
1039 struct btrfs_device *device)
1040 {
1041 int ret;
1042 struct btrfs_path *path;
1043 struct btrfs_dev_item *dev_item;
1044 struct extent_buffer *leaf;
1045 struct btrfs_key key;
1046 unsigned long ptr;
1047
1048 root = root->fs_info->chunk_root;
1049
1050 path = btrfs_alloc_path();
1051 if (!path)
1052 return -ENOMEM;
1053
1054 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1055 key.type = BTRFS_DEV_ITEM_KEY;
1056 key.offset = device->devid;
1057
1058 ret = btrfs_insert_empty_item(trans, root, path, &key,
1059 sizeof(*dev_item));
1060 if (ret)
1061 goto out;
1062
1063 leaf = path->nodes[0];
1064 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1065
1066 btrfs_set_device_id(leaf, dev_item, device->devid);
1067 btrfs_set_device_generation(leaf, dev_item, 0);
1068 btrfs_set_device_type(leaf, dev_item, device->type);
1069 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1070 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1071 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1072 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
1073 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1074 btrfs_set_device_group(leaf, dev_item, 0);
1075 btrfs_set_device_seek_speed(leaf, dev_item, 0);
1076 btrfs_set_device_bandwidth(leaf, dev_item, 0);
1077 btrfs_set_device_start_offset(leaf, dev_item, 0);
1078
1079 ptr = (unsigned long)btrfs_device_uuid(dev_item);
1080 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1081 ptr = (unsigned long)btrfs_device_fsid(dev_item);
1082 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
1083 btrfs_mark_buffer_dirty(leaf);
1084
1085 ret = 0;
1086 out:
1087 btrfs_free_path(path);
1088 return ret;
1089 }
1090
1091 static int btrfs_rm_dev_item(struct btrfs_root *root,
1092 struct btrfs_device *device)
1093 {
1094 int ret;
1095 struct btrfs_path *path;
1096 struct btrfs_key key;
1097 struct btrfs_trans_handle *trans;
1098
1099 root = root->fs_info->chunk_root;
1100
1101 path = btrfs_alloc_path();
1102 if (!path)
1103 return -ENOMEM;
1104
1105 trans = btrfs_start_transaction(root, 0);
1106 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1107 key.type = BTRFS_DEV_ITEM_KEY;
1108 key.offset = device->devid;
1109 lock_chunks(root);
1110
1111 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1112 if (ret < 0)
1113 goto out;
1114
1115 if (ret > 0) {
1116 ret = -ENOENT;
1117 goto out;
1118 }
1119
1120 ret = btrfs_del_item(trans, root, path);
1121 if (ret)
1122 goto out;
1123 out:
1124 btrfs_free_path(path);
1125 unlock_chunks(root);
1126 btrfs_commit_transaction(trans, root);
1127 return ret;
1128 }
1129
1130 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
1131 {
1132 struct btrfs_device *device;
1133 struct btrfs_device *next_device;
1134 struct block_device *bdev;
1135 struct buffer_head *bh = NULL;
1136 struct btrfs_super_block *disk_super;
1137 u64 all_avail;
1138 u64 devid;
1139 u64 num_devices;
1140 u8 *dev_uuid;
1141 int ret = 0;
1142
1143 mutex_lock(&uuid_mutex);
1144 mutex_lock(&root->fs_info->volume_mutex);
1145
1146 all_avail = root->fs_info->avail_data_alloc_bits |
1147 root->fs_info->avail_system_alloc_bits |
1148 root->fs_info->avail_metadata_alloc_bits;
1149
1150 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) &&
1151 root->fs_info->fs_devices->num_devices <= 4) {
1152 printk(KERN_ERR "btrfs: unable to go below four devices "
1153 "on raid10\n");
1154 ret = -EINVAL;
1155 goto out;
1156 }
1157
1158 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) &&
1159 root->fs_info->fs_devices->num_devices <= 2) {
1160 printk(KERN_ERR "btrfs: unable to go below two "
1161 "devices on raid1\n");
1162 ret = -EINVAL;
1163 goto out;
1164 }
1165
1166 if (strcmp(device_path, "missing") == 0) {
1167 struct list_head *devices;
1168 struct btrfs_device *tmp;
1169
1170 device = NULL;
1171 devices = &root->fs_info->fs_devices->devices;
1172 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1173 list_for_each_entry(tmp, devices, dev_list) {
1174 if (tmp->in_fs_metadata && !tmp->bdev) {
1175 device = tmp;
1176 break;
1177 }
1178 }
1179 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1180 bdev = NULL;
1181 bh = NULL;
1182 disk_super = NULL;
1183 if (!device) {
1184 printk(KERN_ERR "btrfs: no missing devices found to "
1185 "remove\n");
1186 goto out;
1187 }
1188 } else {
1189 bdev = blkdev_get_by_path(device_path, FMODE_READ | FMODE_EXCL,
1190 root->fs_info->bdev_holder);
1191 if (IS_ERR(bdev)) {
1192 ret = PTR_ERR(bdev);
1193 goto out;
1194 }
1195
1196 set_blocksize(bdev, 4096);
1197 bh = btrfs_read_dev_super(bdev);
1198 if (!bh) {
1199 ret = -EIO;
1200 goto error_close;
1201 }
1202 disk_super = (struct btrfs_super_block *)bh->b_data;
1203 devid = btrfs_stack_device_id(&disk_super->dev_item);
1204 dev_uuid = disk_super->dev_item.uuid;
1205 device = btrfs_find_device(root, devid, dev_uuid,
1206 disk_super->fsid);
1207 if (!device) {
1208 ret = -ENOENT;
1209 goto error_brelse;
1210 }
1211 }
1212
1213 if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
1214 printk(KERN_ERR "btrfs: unable to remove the only writeable "
1215 "device\n");
1216 ret = -EINVAL;
1217 goto error_brelse;
1218 }
1219
1220 if (device->writeable) {
1221 list_del_init(&device->dev_alloc_list);
1222 root->fs_info->fs_devices->rw_devices--;
1223 }
1224
1225 ret = btrfs_shrink_device(device, 0);
1226 if (ret)
1227 goto error_brelse;
1228
1229 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1230 if (ret)
1231 goto error_brelse;
1232
1233 device->in_fs_metadata = 0;
1234
1235 /*
1236 * the device list mutex makes sure that we don't change
1237 * the device list while someone else is writing out all
1238 * the device supers.
1239 */
1240 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1241 list_del_init(&device->dev_list);
1242 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1243
1244 device->fs_devices->num_devices--;
1245
1246 if (device->missing)
1247 root->fs_info->fs_devices->missing_devices--;
1248
1249 next_device = list_entry(root->fs_info->fs_devices->devices.next,
1250 struct btrfs_device, dev_list);
1251 if (device->bdev == root->fs_info->sb->s_bdev)
1252 root->fs_info->sb->s_bdev = next_device->bdev;
1253 if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1254 root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1255
1256 if (device->bdev) {
1257 blkdev_put(device->bdev, device->mode);
1258 device->bdev = NULL;
1259 device->fs_devices->open_devices--;
1260 }
1261
1262 num_devices = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
1263 btrfs_set_super_num_devices(&root->fs_info->super_copy, num_devices);
1264
1265 if (device->fs_devices->open_devices == 0) {
1266 struct btrfs_fs_devices *fs_devices;
1267 fs_devices = root->fs_info->fs_devices;
1268 while (fs_devices) {
1269 if (fs_devices->seed == device->fs_devices)
1270 break;
1271 fs_devices = fs_devices->seed;
1272 }
1273 fs_devices->seed = device->fs_devices->seed;
1274 device->fs_devices->seed = NULL;
1275 __btrfs_close_devices(device->fs_devices);
1276 free_fs_devices(device->fs_devices);
1277 }
1278
1279 /*
1280 * at this point, the device is zero sized. We want to
1281 * remove it from the devices list and zero out the old super
1282 */
1283 if (device->writeable) {
1284 /* make sure this device isn't detected as part of
1285 * the FS anymore
1286 */
1287 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1288 set_buffer_dirty(bh);
1289 sync_dirty_buffer(bh);
1290 }
1291
1292 kfree(device->name);
1293 kfree(device);
1294 ret = 0;
1295
1296 error_brelse:
1297 brelse(bh);
1298 error_close:
1299 if (bdev)
1300 blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
1301 out:
1302 mutex_unlock(&root->fs_info->volume_mutex);
1303 mutex_unlock(&uuid_mutex);
1304 return ret;
1305 }
1306
1307 /*
1308 * does all the dirty work required for changing file system's UUID.
1309 */
1310 static int btrfs_prepare_sprout(struct btrfs_trans_handle *trans,
1311 struct btrfs_root *root)
1312 {
1313 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1314 struct btrfs_fs_devices *old_devices;
1315 struct btrfs_fs_devices *seed_devices;
1316 struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
1317 struct btrfs_device *device;
1318 u64 super_flags;
1319
1320 BUG_ON(!mutex_is_locked(&uuid_mutex));
1321 if (!fs_devices->seeding)
1322 return -EINVAL;
1323
1324 seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
1325 if (!seed_devices)
1326 return -ENOMEM;
1327
1328 old_devices = clone_fs_devices(fs_devices);
1329 if (IS_ERR(old_devices)) {
1330 kfree(seed_devices);
1331 return PTR_ERR(old_devices);
1332 }
1333
1334 list_add(&old_devices->list, &fs_uuids);
1335
1336 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1337 seed_devices->opened = 1;
1338 INIT_LIST_HEAD(&seed_devices->devices);
1339 INIT_LIST_HEAD(&seed_devices->alloc_list);
1340 mutex_init(&seed_devices->device_list_mutex);
1341 list_splice_init(&fs_devices->devices, &seed_devices->devices);
1342 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1343 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1344 device->fs_devices = seed_devices;
1345 }
1346
1347 fs_devices->seeding = 0;
1348 fs_devices->num_devices = 0;
1349 fs_devices->open_devices = 0;
1350 fs_devices->seed = seed_devices;
1351
1352 generate_random_uuid(fs_devices->fsid);
1353 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1354 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1355 super_flags = btrfs_super_flags(disk_super) &
1356 ~BTRFS_SUPER_FLAG_SEEDING;
1357 btrfs_set_super_flags(disk_super, super_flags);
1358
1359 return 0;
1360 }
1361
1362 /*
1363 * strore the expected generation for seed devices in device items.
1364 */
1365 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1366 struct btrfs_root *root)
1367 {
1368 struct btrfs_path *path;
1369 struct extent_buffer *leaf;
1370 struct btrfs_dev_item *dev_item;
1371 struct btrfs_device *device;
1372 struct btrfs_key key;
1373 u8 fs_uuid[BTRFS_UUID_SIZE];
1374 u8 dev_uuid[BTRFS_UUID_SIZE];
1375 u64 devid;
1376 int ret;
1377
1378 path = btrfs_alloc_path();
1379 if (!path)
1380 return -ENOMEM;
1381
1382 root = root->fs_info->chunk_root;
1383 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1384 key.offset = 0;
1385 key.type = BTRFS_DEV_ITEM_KEY;
1386
1387 while (1) {
1388 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1389 if (ret < 0)
1390 goto error;
1391
1392 leaf = path->nodes[0];
1393 next_slot:
1394 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1395 ret = btrfs_next_leaf(root, path);
1396 if (ret > 0)
1397 break;
1398 if (ret < 0)
1399 goto error;
1400 leaf = path->nodes[0];
1401 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1402 btrfs_release_path(root, path);
1403 continue;
1404 }
1405
1406 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1407 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1408 key.type != BTRFS_DEV_ITEM_KEY)
1409 break;
1410
1411 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1412 struct btrfs_dev_item);
1413 devid = btrfs_device_id(leaf, dev_item);
1414 read_extent_buffer(leaf, dev_uuid,
1415 (unsigned long)btrfs_device_uuid(dev_item),
1416 BTRFS_UUID_SIZE);
1417 read_extent_buffer(leaf, fs_uuid,
1418 (unsigned long)btrfs_device_fsid(dev_item),
1419 BTRFS_UUID_SIZE);
1420 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
1421 BUG_ON(!device);
1422
1423 if (device->fs_devices->seeding) {
1424 btrfs_set_device_generation(leaf, dev_item,
1425 device->generation);
1426 btrfs_mark_buffer_dirty(leaf);
1427 }
1428
1429 path->slots[0]++;
1430 goto next_slot;
1431 }
1432 ret = 0;
1433 error:
1434 btrfs_free_path(path);
1435 return ret;
1436 }
1437
1438 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1439 {
1440 struct btrfs_trans_handle *trans;
1441 struct btrfs_device *device;
1442 struct block_device *bdev;
1443 struct list_head *devices;
1444 struct super_block *sb = root->fs_info->sb;
1445 u64 total_bytes;
1446 int seeding_dev = 0;
1447 int ret = 0;
1448
1449 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1450 return -EINVAL;
1451
1452 bdev = blkdev_get_by_path(device_path, FMODE_EXCL,
1453 root->fs_info->bdev_holder);
1454 if (IS_ERR(bdev))
1455 return PTR_ERR(bdev);
1456
1457 if (root->fs_info->fs_devices->seeding) {
1458 seeding_dev = 1;
1459 down_write(&sb->s_umount);
1460 mutex_lock(&uuid_mutex);
1461 }
1462
1463 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1464 mutex_lock(&root->fs_info->volume_mutex);
1465
1466 devices = &root->fs_info->fs_devices->devices;
1467 /*
1468 * we have the volume lock, so we don't need the extra
1469 * device list mutex while reading the list here.
1470 */
1471 list_for_each_entry(device, devices, dev_list) {
1472 if (device->bdev == bdev) {
1473 ret = -EEXIST;
1474 goto error;
1475 }
1476 }
1477
1478 device = kzalloc(sizeof(*device), GFP_NOFS);
1479 if (!device) {
1480 /* we can safely leave the fs_devices entry around */
1481 ret = -ENOMEM;
1482 goto error;
1483 }
1484
1485 device->name = kstrdup(device_path, GFP_NOFS);
1486 if (!device->name) {
1487 kfree(device);
1488 ret = -ENOMEM;
1489 goto error;
1490 }
1491
1492 ret = find_next_devid(root, &device->devid);
1493 if (ret) {
1494 kfree(device);
1495 goto error;
1496 }
1497
1498 trans = btrfs_start_transaction(root, 0);
1499 lock_chunks(root);
1500
1501 device->writeable = 1;
1502 device->work.func = pending_bios_fn;
1503 generate_random_uuid(device->uuid);
1504 spin_lock_init(&device->io_lock);
1505 device->generation = trans->transid;
1506 device->io_width = root->sectorsize;
1507 device->io_align = root->sectorsize;
1508 device->sector_size = root->sectorsize;
1509 device->total_bytes = i_size_read(bdev->bd_inode);
1510 device->disk_total_bytes = device->total_bytes;
1511 device->dev_root = root->fs_info->dev_root;
1512 device->bdev = bdev;
1513 device->in_fs_metadata = 1;
1514 device->mode = 0;
1515 set_blocksize(device->bdev, 4096);
1516
1517 if (seeding_dev) {
1518 sb->s_flags &= ~MS_RDONLY;
1519 ret = btrfs_prepare_sprout(trans, root);
1520 BUG_ON(ret);
1521 }
1522
1523 device->fs_devices = root->fs_info->fs_devices;
1524
1525 /*
1526 * we don't want write_supers to jump in here with our device
1527 * half setup
1528 */
1529 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1530 list_add(&device->dev_list, &root->fs_info->fs_devices->devices);
1531 list_add(&device->dev_alloc_list,
1532 &root->fs_info->fs_devices->alloc_list);
1533 root->fs_info->fs_devices->num_devices++;
1534 root->fs_info->fs_devices->open_devices++;
1535 root->fs_info->fs_devices->rw_devices++;
1536 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
1537
1538 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
1539 root->fs_info->fs_devices->rotating = 1;
1540
1541 total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
1542 btrfs_set_super_total_bytes(&root->fs_info->super_copy,
1543 total_bytes + device->total_bytes);
1544
1545 total_bytes = btrfs_super_num_devices(&root->fs_info->super_copy);
1546 btrfs_set_super_num_devices(&root->fs_info->super_copy,
1547 total_bytes + 1);
1548 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1549
1550 if (seeding_dev) {
1551 ret = init_first_rw_device(trans, root, device);
1552 BUG_ON(ret);
1553 ret = btrfs_finish_sprout(trans, root);
1554 BUG_ON(ret);
1555 } else {
1556 ret = btrfs_add_device(trans, root, device);
1557 }
1558
1559 /*
1560 * we've got more storage, clear any full flags on the space
1561 * infos
1562 */
1563 btrfs_clear_space_info_full(root->fs_info);
1564
1565 unlock_chunks(root);
1566 btrfs_commit_transaction(trans, root);
1567
1568 if (seeding_dev) {
1569 mutex_unlock(&uuid_mutex);
1570 up_write(&sb->s_umount);
1571
1572 ret = btrfs_relocate_sys_chunks(root);
1573 BUG_ON(ret);
1574 }
1575 out:
1576 mutex_unlock(&root->fs_info->volume_mutex);
1577 return ret;
1578 error:
1579 blkdev_put(bdev, FMODE_EXCL);
1580 if (seeding_dev) {
1581 mutex_unlock(&uuid_mutex);
1582 up_write(&sb->s_umount);
1583 }
1584 goto out;
1585 }
1586
1587 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
1588 struct btrfs_device *device)
1589 {
1590 int ret;
1591 struct btrfs_path *path;
1592 struct btrfs_root *root;
1593 struct btrfs_dev_item *dev_item;
1594 struct extent_buffer *leaf;
1595 struct btrfs_key key;
1596
1597 root = device->dev_root->fs_info->chunk_root;
1598
1599 path = btrfs_alloc_path();
1600 if (!path)
1601 return -ENOMEM;
1602
1603 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1604 key.type = BTRFS_DEV_ITEM_KEY;
1605 key.offset = device->devid;
1606
1607 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1608 if (ret < 0)
1609 goto out;
1610
1611 if (ret > 0) {
1612 ret = -ENOENT;
1613 goto out;
1614 }
1615
1616 leaf = path->nodes[0];
1617 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1618
1619 btrfs_set_device_id(leaf, dev_item, device->devid);
1620 btrfs_set_device_type(leaf, dev_item, device->type);
1621 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1622 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1623 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1624 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
1625 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1626 btrfs_mark_buffer_dirty(leaf);
1627
1628 out:
1629 btrfs_free_path(path);
1630 return ret;
1631 }
1632
1633 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
1634 struct btrfs_device *device, u64 new_size)
1635 {
1636 struct btrfs_super_block *super_copy =
1637 &device->dev_root->fs_info->super_copy;
1638 u64 old_total = btrfs_super_total_bytes(super_copy);
1639 u64 diff = new_size - device->total_bytes;
1640
1641 if (!device->writeable)
1642 return -EACCES;
1643 if (new_size <= device->total_bytes)
1644 return -EINVAL;
1645
1646 btrfs_set_super_total_bytes(super_copy, old_total + diff);
1647 device->fs_devices->total_rw_bytes += diff;
1648
1649 device->total_bytes = new_size;
1650 device->disk_total_bytes = new_size;
1651 btrfs_clear_space_info_full(device->dev_root->fs_info);
1652
1653 return btrfs_update_device(trans, device);
1654 }
1655
1656 int btrfs_grow_device(struct btrfs_trans_handle *trans,
1657 struct btrfs_device *device, u64 new_size)
1658 {
1659 int ret;
1660 lock_chunks(device->dev_root);
1661 ret = __btrfs_grow_device(trans, device, new_size);
1662 unlock_chunks(device->dev_root);
1663 return ret;
1664 }
1665
1666 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
1667 struct btrfs_root *root,
1668 u64 chunk_tree, u64 chunk_objectid,
1669 u64 chunk_offset)
1670 {
1671 int ret;
1672 struct btrfs_path *path;
1673 struct btrfs_key key;
1674
1675 root = root->fs_info->chunk_root;
1676 path = btrfs_alloc_path();
1677 if (!path)
1678 return -ENOMEM;
1679
1680 key.objectid = chunk_objectid;
1681 key.offset = chunk_offset;
1682 key.type = BTRFS_CHUNK_ITEM_KEY;
1683
1684 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1685 BUG_ON(ret);
1686
1687 ret = btrfs_del_item(trans, root, path);
1688 BUG_ON(ret);
1689
1690 btrfs_free_path(path);
1691 return 0;
1692 }
1693
1694 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
1695 chunk_offset)
1696 {
1697 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
1698 struct btrfs_disk_key *disk_key;
1699 struct btrfs_chunk *chunk;
1700 u8 *ptr;
1701 int ret = 0;
1702 u32 num_stripes;
1703 u32 array_size;
1704 u32 len = 0;
1705 u32 cur;
1706 struct btrfs_key key;
1707
1708 array_size = btrfs_super_sys_array_size(super_copy);
1709
1710 ptr = super_copy->sys_chunk_array;
1711 cur = 0;
1712
1713 while (cur < array_size) {
1714 disk_key = (struct btrfs_disk_key *)ptr;
1715 btrfs_disk_key_to_cpu(&key, disk_key);
1716
1717 len = sizeof(*disk_key);
1718
1719 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
1720 chunk = (struct btrfs_chunk *)(ptr + len);
1721 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
1722 len += btrfs_chunk_item_size(num_stripes);
1723 } else {
1724 ret = -EIO;
1725 break;
1726 }
1727 if (key.objectid == chunk_objectid &&
1728 key.offset == chunk_offset) {
1729 memmove(ptr, ptr + len, array_size - (cur + len));
1730 array_size -= len;
1731 btrfs_set_super_sys_array_size(super_copy, array_size);
1732 } else {
1733 ptr += len;
1734 cur += len;
1735 }
1736 }
1737 return ret;
1738 }
1739
1740 static int btrfs_relocate_chunk(struct btrfs_root *root,
1741 u64 chunk_tree, u64 chunk_objectid,
1742 u64 chunk_offset)
1743 {
1744 struct extent_map_tree *em_tree;
1745 struct btrfs_root *extent_root;
1746 struct btrfs_trans_handle *trans;
1747 struct extent_map *em;
1748 struct map_lookup *map;
1749 int ret;
1750 int i;
1751
1752 root = root->fs_info->chunk_root;
1753 extent_root = root->fs_info->extent_root;
1754 em_tree = &root->fs_info->mapping_tree.map_tree;
1755
1756 ret = btrfs_can_relocate(extent_root, chunk_offset);
1757 if (ret)
1758 return -ENOSPC;
1759
1760 /* step one, relocate all the extents inside this chunk */
1761 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
1762 if (ret)
1763 return ret;
1764
1765 trans = btrfs_start_transaction(root, 0);
1766 BUG_ON(!trans);
1767
1768 lock_chunks(root);
1769
1770 /*
1771 * step two, delete the device extents and the
1772 * chunk tree entries
1773 */
1774 read_lock(&em_tree->lock);
1775 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
1776 read_unlock(&em_tree->lock);
1777
1778 BUG_ON(em->start > chunk_offset ||
1779 em->start + em->len < chunk_offset);
1780 map = (struct map_lookup *)em->bdev;
1781
1782 for (i = 0; i < map->num_stripes; i++) {
1783 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
1784 map->stripes[i].physical);
1785 BUG_ON(ret);
1786
1787 if (map->stripes[i].dev) {
1788 ret = btrfs_update_device(trans, map->stripes[i].dev);
1789 BUG_ON(ret);
1790 }
1791 }
1792 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
1793 chunk_offset);
1794
1795 BUG_ON(ret);
1796
1797 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
1798 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
1799 BUG_ON(ret);
1800 }
1801
1802 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
1803 BUG_ON(ret);
1804
1805 write_lock(&em_tree->lock);
1806 remove_extent_mapping(em_tree, em);
1807 write_unlock(&em_tree->lock);
1808
1809 kfree(map);
1810 em->bdev = NULL;
1811
1812 /* once for the tree */
1813 free_extent_map(em);
1814 /* once for us */
1815 free_extent_map(em);
1816
1817 unlock_chunks(root);
1818 btrfs_end_transaction(trans, root);
1819 return 0;
1820 }
1821
1822 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
1823 {
1824 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
1825 struct btrfs_path *path;
1826 struct extent_buffer *leaf;
1827 struct btrfs_chunk *chunk;
1828 struct btrfs_key key;
1829 struct btrfs_key found_key;
1830 u64 chunk_tree = chunk_root->root_key.objectid;
1831 u64 chunk_type;
1832 bool retried = false;
1833 int failed = 0;
1834 int ret;
1835
1836 path = btrfs_alloc_path();
1837 if (!path)
1838 return -ENOMEM;
1839
1840 again:
1841 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
1842 key.offset = (u64)-1;
1843 key.type = BTRFS_CHUNK_ITEM_KEY;
1844
1845 while (1) {
1846 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
1847 if (ret < 0)
1848 goto error;
1849 BUG_ON(ret == 0);
1850
1851 ret = btrfs_previous_item(chunk_root, path, key.objectid,
1852 key.type);
1853 if (ret < 0)
1854 goto error;
1855 if (ret > 0)
1856 break;
1857
1858 leaf = path->nodes[0];
1859 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1860
1861 chunk = btrfs_item_ptr(leaf, path->slots[0],
1862 struct btrfs_chunk);
1863 chunk_type = btrfs_chunk_type(leaf, chunk);
1864 btrfs_release_path(chunk_root, path);
1865
1866 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
1867 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
1868 found_key.objectid,
1869 found_key.offset);
1870 if (ret == -ENOSPC)
1871 failed++;
1872 else if (ret)
1873 BUG();
1874 }
1875
1876 if (found_key.offset == 0)
1877 break;
1878 key.offset = found_key.offset - 1;
1879 }
1880 ret = 0;
1881 if (failed && !retried) {
1882 failed = 0;
1883 retried = true;
1884 goto again;
1885 } else if (failed && retried) {
1886 WARN_ON(1);
1887 ret = -ENOSPC;
1888 }
1889 error:
1890 btrfs_free_path(path);
1891 return ret;
1892 }
1893
1894 static u64 div_factor(u64 num, int factor)
1895 {
1896 if (factor == 10)
1897 return num;
1898 num *= factor;
1899 do_div(num, 10);
1900 return num;
1901 }
1902
1903 int btrfs_balance(struct btrfs_root *dev_root)
1904 {
1905 int ret;
1906 struct list_head *devices = &dev_root->fs_info->fs_devices->devices;
1907 struct btrfs_device *device;
1908 u64 old_size;
1909 u64 size_to_free;
1910 struct btrfs_path *path;
1911 struct btrfs_key key;
1912 struct btrfs_root *chunk_root = dev_root->fs_info->chunk_root;
1913 struct btrfs_trans_handle *trans;
1914 struct btrfs_key found_key;
1915
1916 if (dev_root->fs_info->sb->s_flags & MS_RDONLY)
1917 return -EROFS;
1918
1919 mutex_lock(&dev_root->fs_info->volume_mutex);
1920 dev_root = dev_root->fs_info->dev_root;
1921
1922 /* step one make some room on all the devices */
1923 list_for_each_entry(device, devices, dev_list) {
1924 old_size = device->total_bytes;
1925 size_to_free = div_factor(old_size, 1);
1926 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
1927 if (!device->writeable ||
1928 device->total_bytes - device->bytes_used > size_to_free)
1929 continue;
1930
1931 ret = btrfs_shrink_device(device, old_size - size_to_free);
1932 if (ret == -ENOSPC)
1933 break;
1934 BUG_ON(ret);
1935
1936 trans = btrfs_start_transaction(dev_root, 0);
1937 BUG_ON(!trans);
1938
1939 ret = btrfs_grow_device(trans, device, old_size);
1940 BUG_ON(ret);
1941
1942 btrfs_end_transaction(trans, dev_root);
1943 }
1944
1945 /* step two, relocate all the chunks */
1946 path = btrfs_alloc_path();
1947 BUG_ON(!path);
1948
1949 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
1950 key.offset = (u64)-1;
1951 key.type = BTRFS_CHUNK_ITEM_KEY;
1952
1953 while (1) {
1954 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
1955 if (ret < 0)
1956 goto error;
1957
1958 /*
1959 * this shouldn't happen, it means the last relocate
1960 * failed
1961 */
1962 if (ret == 0)
1963 break;
1964
1965 ret = btrfs_previous_item(chunk_root, path, 0,
1966 BTRFS_CHUNK_ITEM_KEY);
1967 if (ret)
1968 break;
1969
1970 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1971 path->slots[0]);
1972 if (found_key.objectid != key.objectid)
1973 break;
1974
1975 /* chunk zero is special */
1976 if (found_key.offset == 0)
1977 break;
1978
1979 btrfs_release_path(chunk_root, path);
1980 ret = btrfs_relocate_chunk(chunk_root,
1981 chunk_root->root_key.objectid,
1982 found_key.objectid,
1983 found_key.offset);
1984 BUG_ON(ret && ret != -ENOSPC);
1985 key.offset = found_key.offset - 1;
1986 }
1987 ret = 0;
1988 error:
1989 btrfs_free_path(path);
1990 mutex_unlock(&dev_root->fs_info->volume_mutex);
1991 return ret;
1992 }
1993
1994 /*
1995 * shrinking a device means finding all of the device extents past
1996 * the new size, and then following the back refs to the chunks.
1997 * The chunk relocation code actually frees the device extent
1998 */
1999 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
2000 {
2001 struct btrfs_trans_handle *trans;
2002 struct btrfs_root *root = device->dev_root;
2003 struct btrfs_dev_extent *dev_extent = NULL;
2004 struct btrfs_path *path;
2005 u64 length;
2006 u64 chunk_tree;
2007 u64 chunk_objectid;
2008 u64 chunk_offset;
2009 int ret;
2010 int slot;
2011 int failed = 0;
2012 bool retried = false;
2013 struct extent_buffer *l;
2014 struct btrfs_key key;
2015 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
2016 u64 old_total = btrfs_super_total_bytes(super_copy);
2017 u64 old_size = device->total_bytes;
2018 u64 diff = device->total_bytes - new_size;
2019
2020 if (new_size >= device->total_bytes)
2021 return -EINVAL;
2022
2023 path = btrfs_alloc_path();
2024 if (!path)
2025 return -ENOMEM;
2026
2027 path->reada = 2;
2028
2029 lock_chunks(root);
2030
2031 device->total_bytes = new_size;
2032 if (device->writeable)
2033 device->fs_devices->total_rw_bytes -= diff;
2034 unlock_chunks(root);
2035
2036 again:
2037 key.objectid = device->devid;
2038 key.offset = (u64)-1;
2039 key.type = BTRFS_DEV_EXTENT_KEY;
2040
2041 while (1) {
2042 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2043 if (ret < 0)
2044 goto done;
2045
2046 ret = btrfs_previous_item(root, path, 0, key.type);
2047 if (ret < 0)
2048 goto done;
2049 if (ret) {
2050 ret = 0;
2051 btrfs_release_path(root, path);
2052 break;
2053 }
2054
2055 l = path->nodes[0];
2056 slot = path->slots[0];
2057 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
2058
2059 if (key.objectid != device->devid) {
2060 btrfs_release_path(root, path);
2061 break;
2062 }
2063
2064 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
2065 length = btrfs_dev_extent_length(l, dev_extent);
2066
2067 if (key.offset + length <= new_size) {
2068 btrfs_release_path(root, path);
2069 break;
2070 }
2071
2072 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
2073 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
2074 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
2075 btrfs_release_path(root, path);
2076
2077 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
2078 chunk_offset);
2079 if (ret && ret != -ENOSPC)
2080 goto done;
2081 if (ret == -ENOSPC)
2082 failed++;
2083 key.offset -= 1;
2084 }
2085
2086 if (failed && !retried) {
2087 failed = 0;
2088 retried = true;
2089 goto again;
2090 } else if (failed && retried) {
2091 ret = -ENOSPC;
2092 lock_chunks(root);
2093
2094 device->total_bytes = old_size;
2095 if (device->writeable)
2096 device->fs_devices->total_rw_bytes += diff;
2097 unlock_chunks(root);
2098 goto done;
2099 }
2100
2101 /* Shrinking succeeded, else we would be at "done". */
2102 trans = btrfs_start_transaction(root, 0);
2103 lock_chunks(root);
2104
2105 device->disk_total_bytes = new_size;
2106 /* Now btrfs_update_device() will change the on-disk size. */
2107 ret = btrfs_update_device(trans, device);
2108 if (ret) {
2109 unlock_chunks(root);
2110 btrfs_end_transaction(trans, root);
2111 goto done;
2112 }
2113 WARN_ON(diff > old_total);
2114 btrfs_set_super_total_bytes(super_copy, old_total - diff);
2115 unlock_chunks(root);
2116 btrfs_end_transaction(trans, root);
2117 done:
2118 btrfs_free_path(path);
2119 return ret;
2120 }
2121
2122 static int btrfs_add_system_chunk(struct btrfs_trans_handle *trans,
2123 struct btrfs_root *root,
2124 struct btrfs_key *key,
2125 struct btrfs_chunk *chunk, int item_size)
2126 {
2127 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
2128 struct btrfs_disk_key disk_key;
2129 u32 array_size;
2130 u8 *ptr;
2131
2132 array_size = btrfs_super_sys_array_size(super_copy);
2133 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
2134 return -EFBIG;
2135
2136 ptr = super_copy->sys_chunk_array + array_size;
2137 btrfs_cpu_key_to_disk(&disk_key, key);
2138 memcpy(ptr, &disk_key, sizeof(disk_key));
2139 ptr += sizeof(disk_key);
2140 memcpy(ptr, chunk, item_size);
2141 item_size += sizeof(disk_key);
2142 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
2143 return 0;
2144 }
2145
2146 static noinline u64 chunk_bytes_by_type(u64 type, u64 calc_size,
2147 int num_stripes, int sub_stripes)
2148 {
2149 if (type & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_DUP))
2150 return calc_size;
2151 else if (type & BTRFS_BLOCK_GROUP_RAID10)
2152 return calc_size * (num_stripes / sub_stripes);
2153 else
2154 return calc_size * num_stripes;
2155 }
2156
2157 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
2158 struct btrfs_root *extent_root,
2159 struct map_lookup **map_ret,
2160 u64 *num_bytes, u64 *stripe_size,
2161 u64 start, u64 type)
2162 {
2163 struct btrfs_fs_info *info = extent_root->fs_info;
2164 struct btrfs_device *device = NULL;
2165 struct btrfs_fs_devices *fs_devices = info->fs_devices;
2166 struct list_head *cur;
2167 struct map_lookup *map = NULL;
2168 struct extent_map_tree *em_tree;
2169 struct extent_map *em;
2170 struct list_head private_devs;
2171 int min_stripe_size = 1 * 1024 * 1024;
2172 u64 calc_size = 1024 * 1024 * 1024;
2173 u64 max_chunk_size = calc_size;
2174 u64 min_free;
2175 u64 avail;
2176 u64 max_avail = 0;
2177 u64 dev_offset;
2178 int num_stripes = 1;
2179 int min_stripes = 1;
2180 int sub_stripes = 0;
2181 int looped = 0;
2182 int ret;
2183 int index;
2184 int stripe_len = 64 * 1024;
2185
2186 if ((type & BTRFS_BLOCK_GROUP_RAID1) &&
2187 (type & BTRFS_BLOCK_GROUP_DUP)) {
2188 WARN_ON(1);
2189 type &= ~BTRFS_BLOCK_GROUP_DUP;
2190 }
2191 if (list_empty(&fs_devices->alloc_list))
2192 return -ENOSPC;
2193
2194 if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
2195 num_stripes = fs_devices->rw_devices;
2196 min_stripes = 2;
2197 }
2198 if (type & (BTRFS_BLOCK_GROUP_DUP)) {
2199 num_stripes = 2;
2200 min_stripes = 2;
2201 }
2202 if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
2203 if (fs_devices->rw_devices < 2)
2204 return -ENOSPC;
2205 num_stripes = 2;
2206 min_stripes = 2;
2207 }
2208 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
2209 num_stripes = fs_devices->rw_devices;
2210 if (num_stripes < 4)
2211 return -ENOSPC;
2212 num_stripes &= ~(u32)1;
2213 sub_stripes = 2;
2214 min_stripes = 4;
2215 }
2216
2217 if (type & BTRFS_BLOCK_GROUP_DATA) {
2218 max_chunk_size = 10 * calc_size;
2219 min_stripe_size = 64 * 1024 * 1024;
2220 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
2221 max_chunk_size = 256 * 1024 * 1024;
2222 min_stripe_size = 32 * 1024 * 1024;
2223 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
2224 calc_size = 8 * 1024 * 1024;
2225 max_chunk_size = calc_size * 2;
2226 min_stripe_size = 1 * 1024 * 1024;
2227 }
2228
2229 /* we don't want a chunk larger than 10% of writeable space */
2230 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
2231 max_chunk_size);
2232
2233 again:
2234 max_avail = 0;
2235 if (!map || map->num_stripes != num_stripes) {
2236 kfree(map);
2237 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
2238 if (!map)
2239 return -ENOMEM;
2240 map->num_stripes = num_stripes;
2241 }
2242
2243 if (calc_size * num_stripes > max_chunk_size) {
2244 calc_size = max_chunk_size;
2245 do_div(calc_size, num_stripes);
2246 do_div(calc_size, stripe_len);
2247 calc_size *= stripe_len;
2248 }
2249
2250 /* we don't want tiny stripes */
2251 if (!looped)
2252 calc_size = max_t(u64, min_stripe_size, calc_size);
2253
2254 /*
2255 * we're about to do_div by the stripe_len so lets make sure
2256 * we end up with something bigger than a stripe
2257 */
2258 calc_size = max_t(u64, calc_size, stripe_len * 4);
2259
2260 do_div(calc_size, stripe_len);
2261 calc_size *= stripe_len;
2262
2263 cur = fs_devices->alloc_list.next;
2264 index = 0;
2265
2266 if (type & BTRFS_BLOCK_GROUP_DUP)
2267 min_free = calc_size * 2;
2268 else
2269 min_free = calc_size;
2270
2271 /*
2272 * we add 1MB because we never use the first 1MB of the device, unless
2273 * we've looped, then we are likely allocating the maximum amount of
2274 * space left already
2275 */
2276 if (!looped)
2277 min_free += 1024 * 1024;
2278
2279 INIT_LIST_HEAD(&private_devs);
2280 while (index < num_stripes) {
2281 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
2282 BUG_ON(!device->writeable);
2283 if (device->total_bytes > device->bytes_used)
2284 avail = device->total_bytes - device->bytes_used;
2285 else
2286 avail = 0;
2287 cur = cur->next;
2288
2289 if (device->in_fs_metadata && avail >= min_free) {
2290 ret = find_free_dev_extent(trans, device,
2291 min_free, &dev_offset,
2292 &max_avail);
2293 if (ret == 0) {
2294 list_move_tail(&device->dev_alloc_list,
2295 &private_devs);
2296 map->stripes[index].dev = device;
2297 map->stripes[index].physical = dev_offset;
2298 index++;
2299 if (type & BTRFS_BLOCK_GROUP_DUP) {
2300 map->stripes[index].dev = device;
2301 map->stripes[index].physical =
2302 dev_offset + calc_size;
2303 index++;
2304 }
2305 }
2306 } else if (device->in_fs_metadata && avail > max_avail)
2307 max_avail = avail;
2308 if (cur == &fs_devices->alloc_list)
2309 break;
2310 }
2311 list_splice(&private_devs, &fs_devices->alloc_list);
2312 if (index < num_stripes) {
2313 if (index >= min_stripes) {
2314 num_stripes = index;
2315 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
2316 num_stripes /= sub_stripes;
2317 num_stripes *= sub_stripes;
2318 }
2319 looped = 1;
2320 goto again;
2321 }
2322 if (!looped && max_avail > 0) {
2323 looped = 1;
2324 calc_size = max_avail;
2325 goto again;
2326 }
2327 kfree(map);
2328 return -ENOSPC;
2329 }
2330 map->sector_size = extent_root->sectorsize;
2331 map->stripe_len = stripe_len;
2332 map->io_align = stripe_len;
2333 map->io_width = stripe_len;
2334 map->type = type;
2335 map->num_stripes = num_stripes;
2336 map->sub_stripes = sub_stripes;
2337
2338 *map_ret = map;
2339 *stripe_size = calc_size;
2340 *num_bytes = chunk_bytes_by_type(type, calc_size,
2341 num_stripes, sub_stripes);
2342
2343 em = alloc_extent_map(GFP_NOFS);
2344 if (!em) {
2345 kfree(map);
2346 return -ENOMEM;
2347 }
2348 em->bdev = (struct block_device *)map;
2349 em->start = start;
2350 em->len = *num_bytes;
2351 em->block_start = 0;
2352 em->block_len = em->len;
2353
2354 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
2355 write_lock(&em_tree->lock);
2356 ret = add_extent_mapping(em_tree, em);
2357 write_unlock(&em_tree->lock);
2358 BUG_ON(ret);
2359 free_extent_map(em);
2360
2361 ret = btrfs_make_block_group(trans, extent_root, 0, type,
2362 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2363 start, *num_bytes);
2364 BUG_ON(ret);
2365
2366 index = 0;
2367 while (index < map->num_stripes) {
2368 device = map->stripes[index].dev;
2369 dev_offset = map->stripes[index].physical;
2370
2371 ret = btrfs_alloc_dev_extent(trans, device,
2372 info->chunk_root->root_key.objectid,
2373 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2374 start, dev_offset, calc_size);
2375 BUG_ON(ret);
2376 index++;
2377 }
2378
2379 return 0;
2380 }
2381
2382 static int __finish_chunk_alloc(struct btrfs_trans_handle *trans,
2383 struct btrfs_root *extent_root,
2384 struct map_lookup *map, u64 chunk_offset,
2385 u64 chunk_size, u64 stripe_size)
2386 {
2387 u64 dev_offset;
2388 struct btrfs_key key;
2389 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
2390 struct btrfs_device *device;
2391 struct btrfs_chunk *chunk;
2392 struct btrfs_stripe *stripe;
2393 size_t item_size = btrfs_chunk_item_size(map->num_stripes);
2394 int index = 0;
2395 int ret;
2396
2397 chunk = kzalloc(item_size, GFP_NOFS);
2398 if (!chunk)
2399 return -ENOMEM;
2400
2401 index = 0;
2402 while (index < map->num_stripes) {
2403 device = map->stripes[index].dev;
2404 device->bytes_used += stripe_size;
2405 ret = btrfs_update_device(trans, device);
2406 BUG_ON(ret);
2407 index++;
2408 }
2409
2410 index = 0;
2411 stripe = &chunk->stripe;
2412 while (index < map->num_stripes) {
2413 device = map->stripes[index].dev;
2414 dev_offset = map->stripes[index].physical;
2415
2416 btrfs_set_stack_stripe_devid(stripe, device->devid);
2417 btrfs_set_stack_stripe_offset(stripe, dev_offset);
2418 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
2419 stripe++;
2420 index++;
2421 }
2422
2423 btrfs_set_stack_chunk_length(chunk, chunk_size);
2424 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
2425 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
2426 btrfs_set_stack_chunk_type(chunk, map->type);
2427 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
2428 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
2429 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
2430 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
2431 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
2432
2433 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2434 key.type = BTRFS_CHUNK_ITEM_KEY;
2435 key.offset = chunk_offset;
2436
2437 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
2438 BUG_ON(ret);
2439
2440 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2441 ret = btrfs_add_system_chunk(trans, chunk_root, &key, chunk,
2442 item_size);
2443 BUG_ON(ret);
2444 }
2445 kfree(chunk);
2446 return 0;
2447 }
2448
2449 /*
2450 * Chunk allocation falls into two parts. The first part does works
2451 * that make the new allocated chunk useable, but not do any operation
2452 * that modifies the chunk tree. The second part does the works that
2453 * require modifying the chunk tree. This division is important for the
2454 * bootstrap process of adding storage to a seed btrfs.
2455 */
2456 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
2457 struct btrfs_root *extent_root, u64 type)
2458 {
2459 u64 chunk_offset;
2460 u64 chunk_size;
2461 u64 stripe_size;
2462 struct map_lookup *map;
2463 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
2464 int ret;
2465
2466 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2467 &chunk_offset);
2468 if (ret)
2469 return ret;
2470
2471 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
2472 &stripe_size, chunk_offset, type);
2473 if (ret)
2474 return ret;
2475
2476 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
2477 chunk_size, stripe_size);
2478 BUG_ON(ret);
2479 return 0;
2480 }
2481
2482 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
2483 struct btrfs_root *root,
2484 struct btrfs_device *device)
2485 {
2486 u64 chunk_offset;
2487 u64 sys_chunk_offset;
2488 u64 chunk_size;
2489 u64 sys_chunk_size;
2490 u64 stripe_size;
2491 u64 sys_stripe_size;
2492 u64 alloc_profile;
2493 struct map_lookup *map;
2494 struct map_lookup *sys_map;
2495 struct btrfs_fs_info *fs_info = root->fs_info;
2496 struct btrfs_root *extent_root = fs_info->extent_root;
2497 int ret;
2498
2499 ret = find_next_chunk(fs_info->chunk_root,
2500 BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset);
2501 BUG_ON(ret);
2502
2503 alloc_profile = BTRFS_BLOCK_GROUP_METADATA |
2504 (fs_info->metadata_alloc_profile &
2505 fs_info->avail_metadata_alloc_bits);
2506 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
2507
2508 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
2509 &stripe_size, chunk_offset, alloc_profile);
2510 BUG_ON(ret);
2511
2512 sys_chunk_offset = chunk_offset + chunk_size;
2513
2514 alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM |
2515 (fs_info->system_alloc_profile &
2516 fs_info->avail_system_alloc_bits);
2517 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
2518
2519 ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,
2520 &sys_chunk_size, &sys_stripe_size,
2521 sys_chunk_offset, alloc_profile);
2522 BUG_ON(ret);
2523
2524 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
2525 BUG_ON(ret);
2526
2527 /*
2528 * Modifying chunk tree needs allocating new blocks from both
2529 * system block group and metadata block group. So we only can
2530 * do operations require modifying the chunk tree after both
2531 * block groups were created.
2532 */
2533 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
2534 chunk_size, stripe_size);
2535 BUG_ON(ret);
2536
2537 ret = __finish_chunk_alloc(trans, extent_root, sys_map,
2538 sys_chunk_offset, sys_chunk_size,
2539 sys_stripe_size);
2540 BUG_ON(ret);
2541 return 0;
2542 }
2543
2544 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
2545 {
2546 struct extent_map *em;
2547 struct map_lookup *map;
2548 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
2549 int readonly = 0;
2550 int i;
2551
2552 read_lock(&map_tree->map_tree.lock);
2553 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
2554 read_unlock(&map_tree->map_tree.lock);
2555 if (!em)
2556 return 1;
2557
2558 if (btrfs_test_opt(root, DEGRADED)) {
2559 free_extent_map(em);
2560 return 0;
2561 }
2562
2563 map = (struct map_lookup *)em->bdev;
2564 for (i = 0; i < map->num_stripes; i++) {
2565 if (!map->stripes[i].dev->writeable) {
2566 readonly = 1;
2567 break;
2568 }
2569 }
2570 free_extent_map(em);
2571 return readonly;
2572 }
2573
2574 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
2575 {
2576 extent_map_tree_init(&tree->map_tree, GFP_NOFS);
2577 }
2578
2579 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
2580 {
2581 struct extent_map *em;
2582
2583 while (1) {
2584 write_lock(&tree->map_tree.lock);
2585 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
2586 if (em)
2587 remove_extent_mapping(&tree->map_tree, em);
2588 write_unlock(&tree->map_tree.lock);
2589 if (!em)
2590 break;
2591 kfree(em->bdev);
2592 /* once for us */
2593 free_extent_map(em);
2594 /* once for the tree */
2595 free_extent_map(em);
2596 }
2597 }
2598
2599 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
2600 {
2601 struct extent_map *em;
2602 struct map_lookup *map;
2603 struct extent_map_tree *em_tree = &map_tree->map_tree;
2604 int ret;
2605
2606 read_lock(&em_tree->lock);
2607 em = lookup_extent_mapping(em_tree, logical, len);
2608 read_unlock(&em_tree->lock);
2609 BUG_ON(!em);
2610
2611 BUG_ON(em->start > logical || em->start + em->len < logical);
2612 map = (struct map_lookup *)em->bdev;
2613 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
2614 ret = map->num_stripes;
2615 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
2616 ret = map->sub_stripes;
2617 else
2618 ret = 1;
2619 free_extent_map(em);
2620 return ret;
2621 }
2622
2623 static int find_live_mirror(struct map_lookup *map, int first, int num,
2624 int optimal)
2625 {
2626 int i;
2627 if (map->stripes[optimal].dev->bdev)
2628 return optimal;
2629 for (i = first; i < first + num; i++) {
2630 if (map->stripes[i].dev->bdev)
2631 return i;
2632 }
2633 /* we couldn't find one that doesn't fail. Just return something
2634 * and the io error handling code will clean up eventually
2635 */
2636 return optimal;
2637 }
2638
2639 static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
2640 u64 logical, u64 *length,
2641 struct btrfs_multi_bio **multi_ret,
2642 int mirror_num, struct page *unplug_page)
2643 {
2644 struct extent_map *em;
2645 struct map_lookup *map;
2646 struct extent_map_tree *em_tree = &map_tree->map_tree;
2647 u64 offset;
2648 u64 stripe_offset;
2649 u64 stripe_nr;
2650 int stripes_allocated = 8;
2651 int stripes_required = 1;
2652 int stripe_index;
2653 int i;
2654 int num_stripes;
2655 int max_errors = 0;
2656 struct btrfs_multi_bio *multi = NULL;
2657
2658 if (multi_ret && !(rw & REQ_WRITE))
2659 stripes_allocated = 1;
2660 again:
2661 if (multi_ret) {
2662 multi = kzalloc(btrfs_multi_bio_size(stripes_allocated),
2663 GFP_NOFS);
2664 if (!multi)
2665 return -ENOMEM;
2666
2667 atomic_set(&multi->error, 0);
2668 }
2669
2670 read_lock(&em_tree->lock);
2671 em = lookup_extent_mapping(em_tree, logical, *length);
2672 read_unlock(&em_tree->lock);
2673
2674 if (!em && unplug_page) {
2675 kfree(multi);
2676 return 0;
2677 }
2678
2679 if (!em) {
2680 printk(KERN_CRIT "unable to find logical %llu len %llu\n",
2681 (unsigned long long)logical,
2682 (unsigned long long)*length);
2683 BUG();
2684 }
2685
2686 BUG_ON(em->start > logical || em->start + em->len < logical);
2687 map = (struct map_lookup *)em->bdev;
2688 offset = logical - em->start;
2689
2690 if (mirror_num > map->num_stripes)
2691 mirror_num = 0;
2692
2693 /* if our multi bio struct is too small, back off and try again */
2694 if (rw & REQ_WRITE) {
2695 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
2696 BTRFS_BLOCK_GROUP_DUP)) {
2697 stripes_required = map->num_stripes;
2698 max_errors = 1;
2699 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2700 stripes_required = map->sub_stripes;
2701 max_errors = 1;
2702 }
2703 }
2704 if (multi_ret && (rw & REQ_WRITE) &&
2705 stripes_allocated < stripes_required) {
2706 stripes_allocated = map->num_stripes;
2707 free_extent_map(em);
2708 kfree(multi);
2709 goto again;
2710 }
2711 stripe_nr = offset;
2712 /*
2713 * stripe_nr counts the total number of stripes we have to stride
2714 * to get to this block
2715 */
2716 do_div(stripe_nr, map->stripe_len);
2717
2718 stripe_offset = stripe_nr * map->stripe_len;
2719 BUG_ON(offset < stripe_offset);
2720
2721 /* stripe_offset is the offset of this block in its stripe*/
2722 stripe_offset = offset - stripe_offset;
2723
2724 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
2725 BTRFS_BLOCK_GROUP_RAID10 |
2726 BTRFS_BLOCK_GROUP_DUP)) {
2727 /* we limit the length of each bio to what fits in a stripe */
2728 *length = min_t(u64, em->len - offset,
2729 map->stripe_len - stripe_offset);
2730 } else {
2731 *length = em->len - offset;
2732 }
2733
2734 if (!multi_ret && !unplug_page)
2735 goto out;
2736
2737 num_stripes = 1;
2738 stripe_index = 0;
2739 if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
2740 if (unplug_page || (rw & REQ_WRITE))
2741 num_stripes = map->num_stripes;
2742 else if (mirror_num)
2743 stripe_index = mirror_num - 1;
2744 else {
2745 stripe_index = find_live_mirror(map, 0,
2746 map->num_stripes,
2747 current->pid % map->num_stripes);
2748 }
2749
2750 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
2751 if (rw & REQ_WRITE)
2752 num_stripes = map->num_stripes;
2753 else if (mirror_num)
2754 stripe_index = mirror_num - 1;
2755
2756 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2757 int factor = map->num_stripes / map->sub_stripes;
2758
2759 stripe_index = do_div(stripe_nr, factor);
2760 stripe_index *= map->sub_stripes;
2761
2762 if (unplug_page || (rw & REQ_WRITE))
2763 num_stripes = map->sub_stripes;
2764 else if (mirror_num)
2765 stripe_index += mirror_num - 1;
2766 else {
2767 stripe_index = find_live_mirror(map, stripe_index,
2768 map->sub_stripes, stripe_index +
2769 current->pid % map->sub_stripes);
2770 }
2771 } else {
2772 /*
2773 * after this do_div call, stripe_nr is the number of stripes
2774 * on this device we have to walk to find the data, and
2775 * stripe_index is the number of our device in the stripe array
2776 */
2777 stripe_index = do_div(stripe_nr, map->num_stripes);
2778 }
2779 BUG_ON(stripe_index >= map->num_stripes);
2780
2781 for (i = 0; i < num_stripes; i++) {
2782 if (unplug_page) {
2783 struct btrfs_device *device;
2784 struct backing_dev_info *bdi;
2785
2786 device = map->stripes[stripe_index].dev;
2787 if (device->bdev) {
2788 bdi = blk_get_backing_dev_info(device->bdev);
2789 if (bdi->unplug_io_fn)
2790 bdi->unplug_io_fn(bdi, unplug_page);
2791 }
2792 } else {
2793 multi->stripes[i].physical =
2794 map->stripes[stripe_index].physical +
2795 stripe_offset + stripe_nr * map->stripe_len;
2796 multi->stripes[i].dev = map->stripes[stripe_index].dev;
2797 }
2798 stripe_index++;
2799 }
2800 if (multi_ret) {
2801 *multi_ret = multi;
2802 multi->num_stripes = num_stripes;
2803 multi->max_errors = max_errors;
2804 }
2805 out:
2806 free_extent_map(em);
2807 return 0;
2808 }
2809
2810 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
2811 u64 logical, u64 *length,
2812 struct btrfs_multi_bio **multi_ret, int mirror_num)
2813 {
2814 return __btrfs_map_block(map_tree, rw, logical, length, multi_ret,
2815 mirror_num, NULL);
2816 }
2817
2818 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
2819 u64 chunk_start, u64 physical, u64 devid,
2820 u64 **logical, int *naddrs, int *stripe_len)
2821 {
2822 struct extent_map_tree *em_tree = &map_tree->map_tree;
2823 struct extent_map *em;
2824 struct map_lookup *map;
2825 u64 *buf;
2826 u64 bytenr;
2827 u64 length;
2828 u64 stripe_nr;
2829 int i, j, nr = 0;
2830
2831 read_lock(&em_tree->lock);
2832 em = lookup_extent_mapping(em_tree, chunk_start, 1);
2833 read_unlock(&em_tree->lock);
2834
2835 BUG_ON(!em || em->start != chunk_start);
2836 map = (struct map_lookup *)em->bdev;
2837
2838 length = em->len;
2839 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
2840 do_div(length, map->num_stripes / map->sub_stripes);
2841 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
2842 do_div(length, map->num_stripes);
2843
2844 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
2845 BUG_ON(!buf);
2846
2847 for (i = 0; i < map->num_stripes; i++) {
2848 if (devid && map->stripes[i].dev->devid != devid)
2849 continue;
2850 if (map->stripes[i].physical > physical ||
2851 map->stripes[i].physical + length <= physical)
2852 continue;
2853
2854 stripe_nr = physical - map->stripes[i].physical;
2855 do_div(stripe_nr, map->stripe_len);
2856
2857 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2858 stripe_nr = stripe_nr * map->num_stripes + i;
2859 do_div(stripe_nr, map->sub_stripes);
2860 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
2861 stripe_nr = stripe_nr * map->num_stripes + i;
2862 }
2863 bytenr = chunk_start + stripe_nr * map->stripe_len;
2864 WARN_ON(nr >= map->num_stripes);
2865 for (j = 0; j < nr; j++) {
2866 if (buf[j] == bytenr)
2867 break;
2868 }
2869 if (j == nr) {
2870 WARN_ON(nr >= map->num_stripes);
2871 buf[nr++] = bytenr;
2872 }
2873 }
2874
2875 *logical = buf;
2876 *naddrs = nr;
2877 *stripe_len = map->stripe_len;
2878
2879 free_extent_map(em);
2880 return 0;
2881 }
2882
2883 int btrfs_unplug_page(struct btrfs_mapping_tree *map_tree,
2884 u64 logical, struct page *page)
2885 {
2886 u64 length = PAGE_CACHE_SIZE;
2887 return __btrfs_map_block(map_tree, READ, logical, &length,
2888 NULL, 0, page);
2889 }
2890
2891 static void end_bio_multi_stripe(struct bio *bio, int err)
2892 {
2893 struct btrfs_multi_bio *multi = bio->bi_private;
2894 int is_orig_bio = 0;
2895
2896 if (err)
2897 atomic_inc(&multi->error);
2898
2899 if (bio == multi->orig_bio)
2900 is_orig_bio = 1;
2901
2902 if (atomic_dec_and_test(&multi->stripes_pending)) {
2903 if (!is_orig_bio) {
2904 bio_put(bio);
2905 bio = multi->orig_bio;
2906 }
2907 bio->bi_private = multi->private;
2908 bio->bi_end_io = multi->end_io;
2909 /* only send an error to the higher layers if it is
2910 * beyond the tolerance of the multi-bio
2911 */
2912 if (atomic_read(&multi->error) > multi->max_errors) {
2913 err = -EIO;
2914 } else if (err) {
2915 /*
2916 * this bio is actually up to date, we didn't
2917 * go over the max number of errors
2918 */
2919 set_bit(BIO_UPTODATE, &bio->bi_flags);
2920 err = 0;
2921 }
2922 kfree(multi);
2923
2924 bio_endio(bio, err);
2925 } else if (!is_orig_bio) {
2926 bio_put(bio);
2927 }
2928 }
2929
2930 struct async_sched {
2931 struct bio *bio;
2932 int rw;
2933 struct btrfs_fs_info *info;
2934 struct btrfs_work work;
2935 };
2936
2937 /*
2938 * see run_scheduled_bios for a description of why bios are collected for
2939 * async submit.
2940 *
2941 * This will add one bio to the pending list for a device and make sure
2942 * the work struct is scheduled.
2943 */
2944 static noinline int schedule_bio(struct btrfs_root *root,
2945 struct btrfs_device *device,
2946 int rw, struct bio *bio)
2947 {
2948 int should_queue = 1;
2949 struct btrfs_pending_bios *pending_bios;
2950
2951 /* don't bother with additional async steps for reads, right now */
2952 if (!(rw & REQ_WRITE)) {
2953 bio_get(bio);
2954 submit_bio(rw, bio);
2955 bio_put(bio);
2956 return 0;
2957 }
2958
2959 /*
2960 * nr_async_bios allows us to reliably return congestion to the
2961 * higher layers. Otherwise, the async bio makes it appear we have
2962 * made progress against dirty pages when we've really just put it
2963 * on a queue for later
2964 */
2965 atomic_inc(&root->fs_info->nr_async_bios);
2966 WARN_ON(bio->bi_next);
2967 bio->bi_next = NULL;
2968 bio->bi_rw |= rw;
2969
2970 spin_lock(&device->io_lock);
2971 if (bio->bi_rw & REQ_SYNC)
2972 pending_bios = &device->pending_sync_bios;
2973 else
2974 pending_bios = &device->pending_bios;
2975
2976 if (pending_bios->tail)
2977 pending_bios->tail->bi_next = bio;
2978
2979 pending_bios->tail = bio;
2980 if (!pending_bios->head)
2981 pending_bios->head = bio;
2982 if (device->running_pending)
2983 should_queue = 0;
2984
2985 spin_unlock(&device->io_lock);
2986
2987 if (should_queue)
2988 btrfs_queue_worker(&root->fs_info->submit_workers,
2989 &device->work);
2990 return 0;
2991 }
2992
2993 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
2994 int mirror_num, int async_submit)
2995 {
2996 struct btrfs_mapping_tree *map_tree;
2997 struct btrfs_device *dev;
2998 struct bio *first_bio = bio;
2999 u64 logical = (u64)bio->bi_sector << 9;
3000 u64 length = 0;
3001 u64 map_length;
3002 struct btrfs_multi_bio *multi = NULL;
3003 int ret;
3004 int dev_nr = 0;
3005 int total_devs = 1;
3006
3007 length = bio->bi_size;
3008 map_tree = &root->fs_info->mapping_tree;
3009 map_length = length;
3010
3011 ret = btrfs_map_block(map_tree, rw, logical, &map_length, &multi,
3012 mirror_num);
3013 BUG_ON(ret);
3014
3015 total_devs = multi->num_stripes;
3016 if (map_length < length) {
3017 printk(KERN_CRIT "mapping failed logical %llu bio len %llu "
3018 "len %llu\n", (unsigned long long)logical,
3019 (unsigned long long)length,
3020 (unsigned long long)map_length);
3021 BUG();
3022 }
3023 multi->end_io = first_bio->bi_end_io;
3024 multi->private = first_bio->bi_private;
3025 multi->orig_bio = first_bio;
3026 atomic_set(&multi->stripes_pending, multi->num_stripes);
3027
3028 while (dev_nr < total_devs) {
3029 if (total_devs > 1) {
3030 if (dev_nr < total_devs - 1) {
3031 bio = bio_clone(first_bio, GFP_NOFS);
3032 BUG_ON(!bio);
3033 } else {
3034 bio = first_bio;
3035 }
3036 bio->bi_private = multi;
3037 bio->bi_end_io = end_bio_multi_stripe;
3038 }
3039 bio->bi_sector = multi->stripes[dev_nr].physical >> 9;
3040 dev = multi->stripes[dev_nr].dev;
3041 if (dev && dev->bdev && (rw != WRITE || dev->writeable)) {
3042 bio->bi_bdev = dev->bdev;
3043 if (async_submit)
3044 schedule_bio(root, dev, rw, bio);
3045 else
3046 submit_bio(rw, bio);
3047 } else {
3048 bio->bi_bdev = root->fs_info->fs_devices->latest_bdev;
3049 bio->bi_sector = logical >> 9;
3050 bio_endio(bio, -EIO);
3051 }
3052 dev_nr++;
3053 }
3054 if (total_devs == 1)
3055 kfree(multi);
3056 return 0;
3057 }
3058
3059 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
3060 u8 *uuid, u8 *fsid)
3061 {
3062 struct btrfs_device *device;
3063 struct btrfs_fs_devices *cur_devices;
3064
3065 cur_devices = root->fs_info->fs_devices;
3066 while (cur_devices) {
3067 if (!fsid ||
3068 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
3069 device = __find_device(&cur_devices->devices,
3070 devid, uuid);
3071 if (device)
3072 return device;
3073 }
3074 cur_devices = cur_devices->seed;
3075 }
3076 return NULL;
3077 }
3078
3079 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
3080 u64 devid, u8 *dev_uuid)
3081 {
3082 struct btrfs_device *device;
3083 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
3084
3085 device = kzalloc(sizeof(*device), GFP_NOFS);
3086 if (!device)
3087 return NULL;
3088 list_add(&device->dev_list,
3089 &fs_devices->devices);
3090 device->dev_root = root->fs_info->dev_root;
3091 device->devid = devid;
3092 device->work.func = pending_bios_fn;
3093 device->fs_devices = fs_devices;
3094 device->missing = 1;
3095 fs_devices->num_devices++;
3096 fs_devices->missing_devices++;
3097 spin_lock_init(&device->io_lock);
3098 INIT_LIST_HEAD(&device->dev_alloc_list);
3099 memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
3100 return device;
3101 }
3102
3103 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
3104 struct extent_buffer *leaf,
3105 struct btrfs_chunk *chunk)
3106 {
3107 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
3108 struct map_lookup *map;
3109 struct extent_map *em;
3110 u64 logical;
3111 u64 length;
3112 u64 devid;
3113 u8 uuid[BTRFS_UUID_SIZE];
3114 int num_stripes;
3115 int ret;
3116 int i;
3117
3118 logical = key->offset;
3119 length = btrfs_chunk_length(leaf, chunk);
3120
3121 read_lock(&map_tree->map_tree.lock);
3122 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
3123 read_unlock(&map_tree->map_tree.lock);
3124
3125 /* already mapped? */
3126 if (em && em->start <= logical && em->start + em->len > logical) {
3127 free_extent_map(em);
3128 return 0;
3129 } else if (em) {
3130 free_extent_map(em);
3131 }
3132
3133 em = alloc_extent_map(GFP_NOFS);
3134 if (!em)
3135 return -ENOMEM;
3136 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
3137 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
3138 if (!map) {
3139 free_extent_map(em);
3140 return -ENOMEM;
3141 }
3142
3143 em->bdev = (struct block_device *)map;
3144 em->start = logical;
3145 em->len = length;
3146 em->block_start = 0;
3147 em->block_len = em->len;
3148
3149 map->num_stripes = num_stripes;
3150 map->io_width = btrfs_chunk_io_width(leaf, chunk);
3151 map->io_align = btrfs_chunk_io_align(leaf, chunk);
3152 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
3153 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
3154 map->type = btrfs_chunk_type(leaf, chunk);
3155 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
3156 for (i = 0; i < num_stripes; i++) {
3157 map->stripes[i].physical =
3158 btrfs_stripe_offset_nr(leaf, chunk, i);
3159 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
3160 read_extent_buffer(leaf, uuid, (unsigned long)
3161 btrfs_stripe_dev_uuid_nr(chunk, i),
3162 BTRFS_UUID_SIZE);
3163 map->stripes[i].dev = btrfs_find_device(root, devid, uuid,
3164 NULL);
3165 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
3166 kfree(map);
3167 free_extent_map(em);
3168 return -EIO;
3169 }
3170 if (!map->stripes[i].dev) {
3171 map->stripes[i].dev =
3172 add_missing_dev(root, devid, uuid);
3173 if (!map->stripes[i].dev) {
3174 kfree(map);
3175 free_extent_map(em);
3176 return -EIO;
3177 }
3178 }
3179 map->stripes[i].dev->in_fs_metadata = 1;
3180 }
3181
3182 write_lock(&map_tree->map_tree.lock);
3183 ret = add_extent_mapping(&map_tree->map_tree, em);
3184 write_unlock(&map_tree->map_tree.lock);
3185 BUG_ON(ret);
3186 free_extent_map(em);
3187
3188 return 0;
3189 }
3190
3191 static int fill_device_from_item(struct extent_buffer *leaf,
3192 struct btrfs_dev_item *dev_item,
3193 struct btrfs_device *device)
3194 {
3195 unsigned long ptr;
3196
3197 device->devid = btrfs_device_id(leaf, dev_item);
3198 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
3199 device->total_bytes = device->disk_total_bytes;
3200 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
3201 device->type = btrfs_device_type(leaf, dev_item);
3202 device->io_align = btrfs_device_io_align(leaf, dev_item);
3203 device->io_width = btrfs_device_io_width(leaf, dev_item);
3204 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
3205
3206 ptr = (unsigned long)btrfs_device_uuid(dev_item);
3207 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
3208
3209 return 0;
3210 }
3211
3212 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
3213 {
3214 struct btrfs_fs_devices *fs_devices;
3215 int ret;
3216
3217 mutex_lock(&uuid_mutex);
3218
3219 fs_devices = root->fs_info->fs_devices->seed;
3220 while (fs_devices) {
3221 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
3222 ret = 0;
3223 goto out;
3224 }
3225 fs_devices = fs_devices->seed;
3226 }
3227
3228 fs_devices = find_fsid(fsid);
3229 if (!fs_devices) {
3230 ret = -ENOENT;
3231 goto out;
3232 }
3233
3234 fs_devices = clone_fs_devices(fs_devices);
3235 if (IS_ERR(fs_devices)) {
3236 ret = PTR_ERR(fs_devices);
3237 goto out;
3238 }
3239
3240 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
3241 root->fs_info->bdev_holder);
3242 if (ret)
3243 goto out;
3244
3245 if (!fs_devices->seeding) {
3246 __btrfs_close_devices(fs_devices);
3247 free_fs_devices(fs_devices);
3248 ret = -EINVAL;
3249 goto out;
3250 }
3251
3252 fs_devices->seed = root->fs_info->fs_devices->seed;
3253 root->fs_info->fs_devices->seed = fs_devices;
3254 out:
3255 mutex_unlock(&uuid_mutex);
3256 return ret;
3257 }
3258
3259 static int read_one_dev(struct btrfs_root *root,
3260 struct extent_buffer *leaf,
3261 struct btrfs_dev_item *dev_item)
3262 {
3263 struct btrfs_device *device;
3264 u64 devid;
3265 int ret;
3266 u8 fs_uuid[BTRFS_UUID_SIZE];
3267 u8 dev_uuid[BTRFS_UUID_SIZE];
3268
3269 devid = btrfs_device_id(leaf, dev_item);
3270 read_extent_buffer(leaf, dev_uuid,
3271 (unsigned long)btrfs_device_uuid(dev_item),
3272 BTRFS_UUID_SIZE);
3273 read_extent_buffer(leaf, fs_uuid,
3274 (unsigned long)btrfs_device_fsid(dev_item),
3275 BTRFS_UUID_SIZE);
3276
3277 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
3278 ret = open_seed_devices(root, fs_uuid);
3279 if (ret && !btrfs_test_opt(root, DEGRADED))
3280 return ret;
3281 }
3282
3283 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
3284 if (!device || !device->bdev) {
3285 if (!btrfs_test_opt(root, DEGRADED))
3286 return -EIO;
3287
3288 if (!device) {
3289 printk(KERN_WARNING "warning devid %llu missing\n",
3290 (unsigned long long)devid);
3291 device = add_missing_dev(root, devid, dev_uuid);
3292 if (!device)
3293 return -ENOMEM;
3294 } else if (!device->missing) {
3295 /*
3296 * this happens when a device that was properly setup
3297 * in the device info lists suddenly goes bad.
3298 * device->bdev is NULL, and so we have to set
3299 * device->missing to one here
3300 */
3301 root->fs_info->fs_devices->missing_devices++;
3302 device->missing = 1;
3303 }
3304 }
3305
3306 if (device->fs_devices != root->fs_info->fs_devices) {
3307 BUG_ON(device->writeable);
3308 if (device->generation !=
3309 btrfs_device_generation(leaf, dev_item))
3310 return -EINVAL;
3311 }
3312
3313 fill_device_from_item(leaf, dev_item, device);
3314 device->dev_root = root->fs_info->dev_root;
3315 device->in_fs_metadata = 1;
3316 if (device->writeable)
3317 device->fs_devices->total_rw_bytes += device->total_bytes;
3318 ret = 0;
3319 return ret;
3320 }
3321
3322 int btrfs_read_super_device(struct btrfs_root *root, struct extent_buffer *buf)
3323 {
3324 struct btrfs_dev_item *dev_item;
3325
3326 dev_item = (struct btrfs_dev_item *)offsetof(struct btrfs_super_block,
3327 dev_item);
3328 return read_one_dev(root, buf, dev_item);
3329 }
3330
3331 int btrfs_read_sys_array(struct btrfs_root *root)
3332 {
3333 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
3334 struct extent_buffer *sb;
3335 struct btrfs_disk_key *disk_key;
3336 struct btrfs_chunk *chunk;
3337 u8 *ptr;
3338 unsigned long sb_ptr;
3339 int ret = 0;
3340 u32 num_stripes;
3341 u32 array_size;
3342 u32 len = 0;
3343 u32 cur;
3344 struct btrfs_key key;
3345
3346 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
3347 BTRFS_SUPER_INFO_SIZE);
3348 if (!sb)
3349 return -ENOMEM;
3350 btrfs_set_buffer_uptodate(sb);
3351 btrfs_set_buffer_lockdep_class(sb, 0);
3352
3353 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
3354 array_size = btrfs_super_sys_array_size(super_copy);
3355
3356 ptr = super_copy->sys_chunk_array;
3357 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
3358 cur = 0;
3359
3360 while (cur < array_size) {
3361 disk_key = (struct btrfs_disk_key *)ptr;
3362 btrfs_disk_key_to_cpu(&key, disk_key);
3363
3364 len = sizeof(*disk_key); ptr += len;
3365 sb_ptr += len;
3366 cur += len;
3367
3368 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
3369 chunk = (struct btrfs_chunk *)sb_ptr;
3370 ret = read_one_chunk(root, &key, sb, chunk);
3371 if (ret)
3372 break;
3373 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
3374 len = btrfs_chunk_item_size(num_stripes);
3375 } else {
3376 ret = -EIO;
3377 break;
3378 }
3379 ptr += len;
3380 sb_ptr += len;
3381 cur += len;
3382 }
3383 free_extent_buffer(sb);
3384 return ret;
3385 }
3386
3387 int btrfs_read_chunk_tree(struct btrfs_root *root)
3388 {
3389 struct btrfs_path *path;
3390 struct extent_buffer *leaf;
3391 struct btrfs_key key;
3392 struct btrfs_key found_key;
3393 int ret;
3394 int slot;
3395
3396 root = root->fs_info->chunk_root;
3397
3398 path = btrfs_alloc_path();
3399 if (!path)
3400 return -ENOMEM;
3401
3402 /* first we search for all of the device items, and then we
3403 * read in all of the chunk items. This way we can create chunk
3404 * mappings that reference all of the devices that are afound
3405 */
3406 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
3407 key.offset = 0;
3408 key.type = 0;
3409 again:
3410 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3411 if (ret < 0)
3412 goto error;
3413 while (1) {
3414 leaf = path->nodes[0];
3415 slot = path->slots[0];
3416 if (slot >= btrfs_header_nritems(leaf)) {
3417 ret = btrfs_next_leaf(root, path);
3418 if (ret == 0)
3419 continue;
3420 if (ret < 0)
3421 goto error;
3422 break;
3423 }
3424 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3425 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
3426 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
3427 break;
3428 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
3429 struct btrfs_dev_item *dev_item;
3430 dev_item = btrfs_item_ptr(leaf, slot,
3431 struct btrfs_dev_item);
3432 ret = read_one_dev(root, leaf, dev_item);
3433 if (ret)
3434 goto error;
3435 }
3436 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
3437 struct btrfs_chunk *chunk;
3438 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
3439 ret = read_one_chunk(root, &found_key, leaf, chunk);
3440 if (ret)
3441 goto error;
3442 }
3443 path->slots[0]++;
3444 }
3445 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
3446 key.objectid = 0;
3447 btrfs_release_path(root, path);
3448 goto again;
3449 }
3450 ret = 0;
3451 error:
3452 btrfs_free_path(path);
3453 return ret;
3454 }
kernel source for telekom puls (alcatel/mediatek)