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1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18 #include <linux/sched.h>
19 #include <linux/bio.h>
20 #include <linux/slab.h>
21 #include <linux/buffer_head.h>
22 #include <linux/blkdev.h>
23 #include <linux/random.h>
24 #include <linux/iocontext.h>
25 #include <linux/capability.h>
26 #include <asm/div64.h>
27 #include "compat.h"
28 #include "ctree.h"
29 #include "extent_map.h"
30 #include "disk-io.h"
31 #include "transaction.h"
32 #include "print-tree.h"
33 #include "volumes.h"
34 #include "async-thread.h"
35
36 static int init_first_rw_device(struct btrfs_trans_handle *trans,
37 struct btrfs_root *root,
38 struct btrfs_device *device);
39 static int btrfs_relocate_sys_chunks(struct btrfs_root *root);
40
41 #define map_lookup_size(n) (sizeof(struct map_lookup) + \
42 (sizeof(struct btrfs_bio_stripe) * (n)))
43
44 static DEFINE_MUTEX(uuid_mutex);
45 static LIST_HEAD(fs_uuids);
46
47 void btrfs_lock_volumes(void)
48 {
49 mutex_lock(&uuid_mutex);
50 }
51
52 void btrfs_unlock_volumes(void)
53 {
54 mutex_unlock(&uuid_mutex);
55 }
56
57 static void lock_chunks(struct btrfs_root *root)
58 {
59 mutex_lock(&root->fs_info->chunk_mutex);
60 }
61
62 static void unlock_chunks(struct btrfs_root *root)
63 {
64 mutex_unlock(&root->fs_info->chunk_mutex);
65 }
66
67 static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
68 {
69 struct btrfs_device *device;
70 WARN_ON(fs_devices->opened);
71 while (!list_empty(&fs_devices->devices)) {
72 device = list_entry(fs_devices->devices.next,
73 struct btrfs_device, dev_list);
74 list_del(&device->dev_list);
75 kfree(device->name);
76 kfree(device);
77 }
78 kfree(fs_devices);
79 }
80
81 int btrfs_cleanup_fs_uuids(void)
82 {
83 struct btrfs_fs_devices *fs_devices;
84
85 while (!list_empty(&fs_uuids)) {
86 fs_devices = list_entry(fs_uuids.next,
87 struct btrfs_fs_devices, list);
88 list_del(&fs_devices->list);
89 free_fs_devices(fs_devices);
90 }
91 return 0;
92 }
93
94 static noinline struct btrfs_device *__find_device(struct list_head *head,
95 u64 devid, u8 *uuid)
96 {
97 struct btrfs_device *dev;
98
99 list_for_each_entry(dev, head, dev_list) {
100 if (dev->devid == devid &&
101 (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
102 return dev;
103 }
104 }
105 return NULL;
106 }
107
108 static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
109 {
110 struct btrfs_fs_devices *fs_devices;
111
112 list_for_each_entry(fs_devices, &fs_uuids, list) {
113 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
114 return fs_devices;
115 }
116 return NULL;
117 }
118
119 static void requeue_list(struct btrfs_pending_bios *pending_bios,
120 struct bio *head, struct bio *tail)
121 {
122
123 struct bio *old_head;
124
125 old_head = pending_bios->head;
126 pending_bios->head = head;
127 if (pending_bios->tail)
128 tail->bi_next = old_head;
129 else
130 pending_bios->tail = tail;
131 }
132
133 /*
134 * we try to collect pending bios for a device so we don't get a large
135 * number of procs sending bios down to the same device. This greatly
136 * improves the schedulers ability to collect and merge the bios.
137 *
138 * But, it also turns into a long list of bios to process and that is sure
139 * to eventually make the worker thread block. The solution here is to
140 * make some progress and then put this work struct back at the end of
141 * the list if the block device is congested. This way, multiple devices
142 * can make progress from a single worker thread.
143 */
144 static noinline int run_scheduled_bios(struct btrfs_device *device)
145 {
146 struct bio *pending;
147 struct backing_dev_info *bdi;
148 struct btrfs_fs_info *fs_info;
149 struct btrfs_pending_bios *pending_bios;
150 struct bio *tail;
151 struct bio *cur;
152 int again = 0;
153 unsigned long num_run;
154 unsigned long batch_run = 0;
155 unsigned long limit;
156 unsigned long last_waited = 0;
157 int force_reg = 0;
158 struct blk_plug plug;
159
160 /*
161 * this function runs all the bios we've collected for
162 * a particular device. We don't want to wander off to
163 * another device without first sending all of these down.
164 * So, setup a plug here and finish it off before we return
165 */
166 blk_start_plug(&plug);
167
168 bdi = blk_get_backing_dev_info(device->bdev);
169 fs_info = device->dev_root->fs_info;
170 limit = btrfs_async_submit_limit(fs_info);
171 limit = limit * 2 / 3;
172
173 loop:
174 spin_lock(&device->io_lock);
175
176 loop_lock:
177 num_run = 0;
178
179 /* take all the bios off the list at once and process them
180 * later on (without the lock held). But, remember the
181 * tail and other pointers so the bios can be properly reinserted
182 * into the list if we hit congestion
183 */
184 if (!force_reg && device->pending_sync_bios.head) {
185 pending_bios = &device->pending_sync_bios;
186 force_reg = 1;
187 } else {
188 pending_bios = &device->pending_bios;
189 force_reg = 0;
190 }
191
192 pending = pending_bios->head;
193 tail = pending_bios->tail;
194 WARN_ON(pending && !tail);
195
196 /*
197 * if pending was null this time around, no bios need processing
198 * at all and we can stop. Otherwise it'll loop back up again
199 * and do an additional check so no bios are missed.
200 *
201 * device->running_pending is used to synchronize with the
202 * schedule_bio code.
203 */
204 if (device->pending_sync_bios.head == NULL &&
205 device->pending_bios.head == NULL) {
206 again = 0;
207 device->running_pending = 0;
208 } else {
209 again = 1;
210 device->running_pending = 1;
211 }
212
213 pending_bios->head = NULL;
214 pending_bios->tail = NULL;
215
216 spin_unlock(&device->io_lock);
217
218 while (pending) {
219
220 rmb();
221 /* we want to work on both lists, but do more bios on the
222 * sync list than the regular list
223 */
224 if ((num_run > 32 &&
225 pending_bios != &device->pending_sync_bios &&
226 device->pending_sync_bios.head) ||
227 (num_run > 64 && pending_bios == &device->pending_sync_bios &&
228 device->pending_bios.head)) {
229 spin_lock(&device->io_lock);
230 requeue_list(pending_bios, pending, tail);
231 goto loop_lock;
232 }
233
234 cur = pending;
235 pending = pending->bi_next;
236 cur->bi_next = NULL;
237 atomic_dec(&fs_info->nr_async_bios);
238
239 if (atomic_read(&fs_info->nr_async_bios) < limit &&
240 waitqueue_active(&fs_info->async_submit_wait))
241 wake_up(&fs_info->async_submit_wait);
242
243 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
244
245 submit_bio(cur->bi_rw, cur);
246 num_run++;
247 batch_run++;
248 if (need_resched())
249 cond_resched();
250
251 /*
252 * we made progress, there is more work to do and the bdi
253 * is now congested. Back off and let other work structs
254 * run instead
255 */
256 if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
257 fs_info->fs_devices->open_devices > 1) {
258 struct io_context *ioc;
259
260 ioc = current->io_context;
261
262 /*
263 * the main goal here is that we don't want to
264 * block if we're going to be able to submit
265 * more requests without blocking.
266 *
267 * This code does two great things, it pokes into
268 * the elevator code from a filesystem _and_
269 * it makes assumptions about how batching works.
270 */
271 if (ioc && ioc->nr_batch_requests > 0 &&
272 time_before(jiffies, ioc->last_waited + HZ/50UL) &&
273 (last_waited == 0 ||
274 ioc->last_waited == last_waited)) {
275 /*
276 * we want to go through our batch of
277 * requests and stop. So, we copy out
278 * the ioc->last_waited time and test
279 * against it before looping
280 */
281 last_waited = ioc->last_waited;
282 if (need_resched())
283 cond_resched();
284 continue;
285 }
286 spin_lock(&device->io_lock);
287 requeue_list(pending_bios, pending, tail);
288 device->running_pending = 1;
289
290 spin_unlock(&device->io_lock);
291 btrfs_requeue_work(&device->work);
292 goto done;
293 }
294 }
295
296 cond_resched();
297 if (again)
298 goto loop;
299
300 spin_lock(&device->io_lock);
301 if (device->pending_bios.head || device->pending_sync_bios.head)
302 goto loop_lock;
303 spin_unlock(&device->io_lock);
304
305 done:
306 blk_finish_plug(&plug);
307 return 0;
308 }
309
310 static void pending_bios_fn(struct btrfs_work *work)
311 {
312 struct btrfs_device *device;
313
314 device = container_of(work, struct btrfs_device, work);
315 run_scheduled_bios(device);
316 }
317
318 static noinline int device_list_add(const char *path,
319 struct btrfs_super_block *disk_super,
320 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
321 {
322 struct btrfs_device *device;
323 struct btrfs_fs_devices *fs_devices;
324 u64 found_transid = btrfs_super_generation(disk_super);
325 char *name;
326
327 fs_devices = find_fsid(disk_super->fsid);
328 if (!fs_devices) {
329 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
330 if (!fs_devices)
331 return -ENOMEM;
332 INIT_LIST_HEAD(&fs_devices->devices);
333 INIT_LIST_HEAD(&fs_devices->alloc_list);
334 list_add(&fs_devices->list, &fs_uuids);
335 memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
336 fs_devices->latest_devid = devid;
337 fs_devices->latest_trans = found_transid;
338 mutex_init(&fs_devices->device_list_mutex);
339 device = NULL;
340 } else {
341 device = __find_device(&fs_devices->devices, devid,
342 disk_super->dev_item.uuid);
343 }
344 if (!device) {
345 if (fs_devices->opened)
346 return -EBUSY;
347
348 device = kzalloc(sizeof(*device), GFP_NOFS);
349 if (!device) {
350 /* we can safely leave the fs_devices entry around */
351 return -ENOMEM;
352 }
353 device->devid = devid;
354 device->work.func = pending_bios_fn;
355 memcpy(device->uuid, disk_super->dev_item.uuid,
356 BTRFS_UUID_SIZE);
357 spin_lock_init(&device->io_lock);
358 device->name = kstrdup(path, GFP_NOFS);
359 if (!device->name) {
360 kfree(device);
361 return -ENOMEM;
362 }
363 INIT_LIST_HEAD(&device->dev_alloc_list);
364
365 mutex_lock(&fs_devices->device_list_mutex);
366 list_add(&device->dev_list, &fs_devices->devices);
367 mutex_unlock(&fs_devices->device_list_mutex);
368
369 device->fs_devices = fs_devices;
370 fs_devices->num_devices++;
371 } else if (!device->name || strcmp(device->name, path)) {
372 name = kstrdup(path, GFP_NOFS);
373 if (!name)
374 return -ENOMEM;
375 kfree(device->name);
376 device->name = name;
377 if (device->missing) {
378 fs_devices->missing_devices--;
379 device->missing = 0;
380 }
381 }
382
383 if (found_transid > fs_devices->latest_trans) {
384 fs_devices->latest_devid = devid;
385 fs_devices->latest_trans = found_transid;
386 }
387 *fs_devices_ret = fs_devices;
388 return 0;
389 }
390
391 static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
392 {
393 struct btrfs_fs_devices *fs_devices;
394 struct btrfs_device *device;
395 struct btrfs_device *orig_dev;
396
397 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
398 if (!fs_devices)
399 return ERR_PTR(-ENOMEM);
400
401 INIT_LIST_HEAD(&fs_devices->devices);
402 INIT_LIST_HEAD(&fs_devices->alloc_list);
403 INIT_LIST_HEAD(&fs_devices->list);
404 mutex_init(&fs_devices->device_list_mutex);
405 fs_devices->latest_devid = orig->latest_devid;
406 fs_devices->latest_trans = orig->latest_trans;
407 memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid));
408
409 /* We have held the volume lock, it is safe to get the devices. */
410 list_for_each_entry(orig_dev, &orig->devices, dev_list) {
411 device = kzalloc(sizeof(*device), GFP_NOFS);
412 if (!device)
413 goto error;
414
415 device->name = kstrdup(orig_dev->name, GFP_NOFS);
416 if (!device->name) {
417 kfree(device);
418 goto error;
419 }
420
421 device->devid = orig_dev->devid;
422 device->work.func = pending_bios_fn;
423 memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid));
424 spin_lock_init(&device->io_lock);
425 INIT_LIST_HEAD(&device->dev_list);
426 INIT_LIST_HEAD(&device->dev_alloc_list);
427
428 list_add(&device->dev_list, &fs_devices->devices);
429 device->fs_devices = fs_devices;
430 fs_devices->num_devices++;
431 }
432 return fs_devices;
433 error:
434 free_fs_devices(fs_devices);
435 return ERR_PTR(-ENOMEM);
436 }
437
438 int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
439 {
440 struct btrfs_device *device, *next;
441
442 mutex_lock(&uuid_mutex);
443 again:
444 /* This is the initialized path, it is safe to release the devices. */
445 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
446 if (device->in_fs_metadata)
447 continue;
448
449 if (device->bdev) {
450 blkdev_put(device->bdev, device->mode);
451 device->bdev = NULL;
452 fs_devices->open_devices--;
453 }
454 if (device->writeable) {
455 list_del_init(&device->dev_alloc_list);
456 device->writeable = 0;
457 fs_devices->rw_devices--;
458 }
459 list_del_init(&device->dev_list);
460 fs_devices->num_devices--;
461 kfree(device->name);
462 kfree(device);
463 }
464
465 if (fs_devices->seed) {
466 fs_devices = fs_devices->seed;
467 goto again;
468 }
469
470 mutex_unlock(&uuid_mutex);
471 return 0;
472 }
473
474 static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
475 {
476 struct btrfs_device *device;
477
478 if (--fs_devices->opened > 0)
479 return 0;
480
481 mutex_lock(&fs_devices->device_list_mutex);
482 list_for_each_entry(device, &fs_devices->devices, dev_list) {
483 if (device->bdev) {
484 blkdev_put(device->bdev, device->mode);
485 fs_devices->open_devices--;
486 }
487 if (device->writeable) {
488 list_del_init(&device->dev_alloc_list);
489 fs_devices->rw_devices--;
490 }
491
492 device->bdev = NULL;
493 device->writeable = 0;
494 device->in_fs_metadata = 0;
495 }
496 mutex_unlock(&fs_devices->device_list_mutex);
497
498 WARN_ON(fs_devices->open_devices);
499 WARN_ON(fs_devices->rw_devices);
500 fs_devices->opened = 0;
501 fs_devices->seeding = 0;
502
503 return 0;
504 }
505
506 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
507 {
508 struct btrfs_fs_devices *seed_devices = NULL;
509 int ret;
510
511 mutex_lock(&uuid_mutex);
512 ret = __btrfs_close_devices(fs_devices);
513 if (!fs_devices->opened) {
514 seed_devices = fs_devices->seed;
515 fs_devices->seed = NULL;
516 }
517 mutex_unlock(&uuid_mutex);
518
519 while (seed_devices) {
520 fs_devices = seed_devices;
521 seed_devices = fs_devices->seed;
522 __btrfs_close_devices(fs_devices);
523 free_fs_devices(fs_devices);
524 }
525 return ret;
526 }
527
528 static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
529 fmode_t flags, void *holder)
530 {
531 struct block_device *bdev;
532 struct list_head *head = &fs_devices->devices;
533 struct btrfs_device *device;
534 struct block_device *latest_bdev = NULL;
535 struct buffer_head *bh;
536 struct btrfs_super_block *disk_super;
537 u64 latest_devid = 0;
538 u64 latest_transid = 0;
539 u64 devid;
540 int seeding = 1;
541 int ret = 0;
542
543 flags |= FMODE_EXCL;
544
545 list_for_each_entry(device, head, dev_list) {
546 if (device->bdev)
547 continue;
548 if (!device->name)
549 continue;
550
551 bdev = blkdev_get_by_path(device->name, flags, holder);
552 if (IS_ERR(bdev)) {
553 printk(KERN_INFO "open %s failed\n", device->name);
554 goto error;
555 }
556 set_blocksize(bdev, 4096);
557
558 bh = btrfs_read_dev_super(bdev);
559 if (!bh) {
560 ret = -EINVAL;
561 goto error_close;
562 }
563
564 disk_super = (struct btrfs_super_block *)bh->b_data;
565 devid = btrfs_stack_device_id(&disk_super->dev_item);
566 if (devid != device->devid)
567 goto error_brelse;
568
569 if (memcmp(device->uuid, disk_super->dev_item.uuid,
570 BTRFS_UUID_SIZE))
571 goto error_brelse;
572
573 device->generation = btrfs_super_generation(disk_super);
574 if (!latest_transid || device->generation > latest_transid) {
575 latest_devid = devid;
576 latest_transid = device->generation;
577 latest_bdev = bdev;
578 }
579
580 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
581 device->writeable = 0;
582 } else {
583 device->writeable = !bdev_read_only(bdev);
584 seeding = 0;
585 }
586
587 device->bdev = bdev;
588 device->in_fs_metadata = 0;
589 device->mode = flags;
590
591 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
592 fs_devices->rotating = 1;
593
594 fs_devices->open_devices++;
595 if (device->writeable) {
596 fs_devices->rw_devices++;
597 list_add(&device->dev_alloc_list,
598 &fs_devices->alloc_list);
599 }
600 brelse(bh);
601 continue;
602
603 error_brelse:
604 brelse(bh);
605 error_close:
606 blkdev_put(bdev, flags);
607 error:
608 continue;
609 }
610 if (fs_devices->open_devices == 0) {
611 ret = -EIO;
612 goto out;
613 }
614 fs_devices->seeding = seeding;
615 fs_devices->opened = 1;
616 fs_devices->latest_bdev = latest_bdev;
617 fs_devices->latest_devid = latest_devid;
618 fs_devices->latest_trans = latest_transid;
619 fs_devices->total_rw_bytes = 0;
620 out:
621 return ret;
622 }
623
624 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
625 fmode_t flags, void *holder)
626 {
627 int ret;
628
629 mutex_lock(&uuid_mutex);
630 if (fs_devices->opened) {
631 fs_devices->opened++;
632 ret = 0;
633 } else {
634 ret = __btrfs_open_devices(fs_devices, flags, holder);
635 }
636 mutex_unlock(&uuid_mutex);
637 return ret;
638 }
639
640 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
641 struct btrfs_fs_devices **fs_devices_ret)
642 {
643 struct btrfs_super_block *disk_super;
644 struct block_device *bdev;
645 struct buffer_head *bh;
646 int ret;
647 u64 devid;
648 u64 transid;
649
650 mutex_lock(&uuid_mutex);
651
652 flags |= FMODE_EXCL;
653 bdev = blkdev_get_by_path(path, flags, holder);
654
655 if (IS_ERR(bdev)) {
656 ret = PTR_ERR(bdev);
657 goto error;
658 }
659
660 ret = set_blocksize(bdev, 4096);
661 if (ret)
662 goto error_close;
663 bh = btrfs_read_dev_super(bdev);
664 if (!bh) {
665 ret = -EINVAL;
666 goto error_close;
667 }
668 disk_super = (struct btrfs_super_block *)bh->b_data;
669 devid = btrfs_stack_device_id(&disk_super->dev_item);
670 transid = btrfs_super_generation(disk_super);
671 if (disk_super->label[0])
672 printk(KERN_INFO "device label %s ", disk_super->label);
673 else {
674 /* FIXME, make a readl uuid parser */
675 printk(KERN_INFO "device fsid %llx-%llx ",
676 *(unsigned long long *)disk_super->fsid,
677 *(unsigned long long *)(disk_super->fsid + 8));
678 }
679 printk(KERN_CONT "devid %llu transid %llu %s\n",
680 (unsigned long long)devid, (unsigned long long)transid, path);
681 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
682
683 brelse(bh);
684 error_close:
685 blkdev_put(bdev, flags);
686 error:
687 mutex_unlock(&uuid_mutex);
688 return ret;
689 }
690
691 /* helper to account the used device space in the range */
692 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
693 u64 end, u64 *length)
694 {
695 struct btrfs_key key;
696 struct btrfs_root *root = device->dev_root;
697 struct btrfs_dev_extent *dev_extent;
698 struct btrfs_path *path;
699 u64 extent_end;
700 int ret;
701 int slot;
702 struct extent_buffer *l;
703
704 *length = 0;
705
706 if (start >= device->total_bytes)
707 return 0;
708
709 path = btrfs_alloc_path();
710 if (!path)
711 return -ENOMEM;
712 path->reada = 2;
713
714 key.objectid = device->devid;
715 key.offset = start;
716 key.type = BTRFS_DEV_EXTENT_KEY;
717
718 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
719 if (ret < 0)
720 goto out;
721 if (ret > 0) {
722 ret = btrfs_previous_item(root, path, key.objectid, key.type);
723 if (ret < 0)
724 goto out;
725 }
726
727 while (1) {
728 l = path->nodes[0];
729 slot = path->slots[0];
730 if (slot >= btrfs_header_nritems(l)) {
731 ret = btrfs_next_leaf(root, path);
732 if (ret == 0)
733 continue;
734 if (ret < 0)
735 goto out;
736
737 break;
738 }
739 btrfs_item_key_to_cpu(l, &key, slot);
740
741 if (key.objectid < device->devid)
742 goto next;
743
744 if (key.objectid > device->devid)
745 break;
746
747 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
748 goto next;
749
750 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
751 extent_end = key.offset + btrfs_dev_extent_length(l,
752 dev_extent);
753 if (key.offset <= start && extent_end > end) {
754 *length = end - start + 1;
755 break;
756 } else if (key.offset <= start && extent_end > start)
757 *length += extent_end - start;
758 else if (key.offset > start && extent_end <= end)
759 *length += extent_end - key.offset;
760 else if (key.offset > start && key.offset <= end) {
761 *length += end - key.offset + 1;
762 break;
763 } else if (key.offset > end)
764 break;
765
766 next:
767 path->slots[0]++;
768 }
769 ret = 0;
770 out:
771 btrfs_free_path(path);
772 return ret;
773 }
774
775 /*
776 * find_free_dev_extent - find free space in the specified device
777 * @trans: transaction handler
778 * @device: the device which we search the free space in
779 * @num_bytes: the size of the free space that we need
780 * @start: store the start of the free space.
781 * @len: the size of the free space. that we find, or the size of the max
782 * free space if we don't find suitable free space
783 *
784 * this uses a pretty simple search, the expectation is that it is
785 * called very infrequently and that a given device has a small number
786 * of extents
787 *
788 * @start is used to store the start of the free space if we find. But if we
789 * don't find suitable free space, it will be used to store the start position
790 * of the max free space.
791 *
792 * @len is used to store the size of the free space that we find.
793 * But if we don't find suitable free space, it is used to store the size of
794 * the max free space.
795 */
796 int find_free_dev_extent(struct btrfs_trans_handle *trans,
797 struct btrfs_device *device, u64 num_bytes,
798 u64 *start, u64 *len)
799 {
800 struct btrfs_key key;
801 struct btrfs_root *root = device->dev_root;
802 struct btrfs_dev_extent *dev_extent;
803 struct btrfs_path *path;
804 u64 hole_size;
805 u64 max_hole_start;
806 u64 max_hole_size;
807 u64 extent_end;
808 u64 search_start;
809 u64 search_end = device->total_bytes;
810 int ret;
811 int slot;
812 struct extent_buffer *l;
813
814 /* FIXME use last free of some kind */
815
816 /* we don't want to overwrite the superblock on the drive,
817 * so we make sure to start at an offset of at least 1MB
818 */
819 search_start = 1024 * 1024;
820
821 if (root->fs_info->alloc_start + num_bytes <= search_end)
822 search_start = max(root->fs_info->alloc_start, search_start);
823
824 max_hole_start = search_start;
825 max_hole_size = 0;
826
827 if (search_start >= search_end) {
828 ret = -ENOSPC;
829 goto error;
830 }
831
832 path = btrfs_alloc_path();
833 if (!path) {
834 ret = -ENOMEM;
835 goto error;
836 }
837 path->reada = 2;
838
839 key.objectid = device->devid;
840 key.offset = search_start;
841 key.type = BTRFS_DEV_EXTENT_KEY;
842
843 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
844 if (ret < 0)
845 goto out;
846 if (ret > 0) {
847 ret = btrfs_previous_item(root, path, key.objectid, key.type);
848 if (ret < 0)
849 goto out;
850 }
851
852 while (1) {
853 l = path->nodes[0];
854 slot = path->slots[0];
855 if (slot >= btrfs_header_nritems(l)) {
856 ret = btrfs_next_leaf(root, path);
857 if (ret == 0)
858 continue;
859 if (ret < 0)
860 goto out;
861
862 break;
863 }
864 btrfs_item_key_to_cpu(l, &key, slot);
865
866 if (key.objectid < device->devid)
867 goto next;
868
869 if (key.objectid > device->devid)
870 break;
871
872 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
873 goto next;
874
875 if (key.offset > search_start) {
876 hole_size = key.offset - search_start;
877
878 if (hole_size > max_hole_size) {
879 max_hole_start = search_start;
880 max_hole_size = hole_size;
881 }
882
883 /*
884 * If this free space is greater than which we need,
885 * it must be the max free space that we have found
886 * until now, so max_hole_start must point to the start
887 * of this free space and the length of this free space
888 * is stored in max_hole_size. Thus, we return
889 * max_hole_start and max_hole_size and go back to the
890 * caller.
891 */
892 if (hole_size >= num_bytes) {
893 ret = 0;
894 goto out;
895 }
896 }
897
898 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
899 extent_end = key.offset + btrfs_dev_extent_length(l,
900 dev_extent);
901 if (extent_end > search_start)
902 search_start = extent_end;
903 next:
904 path->slots[0]++;
905 cond_resched();
906 }
907
908 hole_size = search_end- search_start;
909 if (hole_size > max_hole_size) {
910 max_hole_start = search_start;
911 max_hole_size = hole_size;
912 }
913
914 /* See above. */
915 if (hole_size < num_bytes)
916 ret = -ENOSPC;
917 else
918 ret = 0;
919
920 out:
921 btrfs_free_path(path);
922 error:
923 *start = max_hole_start;
924 if (len)
925 *len = max_hole_size;
926 return ret;
927 }
928
929 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
930 struct btrfs_device *device,
931 u64 start)
932 {
933 int ret;
934 struct btrfs_path *path;
935 struct btrfs_root *root = device->dev_root;
936 struct btrfs_key key;
937 struct btrfs_key found_key;
938 struct extent_buffer *leaf = NULL;
939 struct btrfs_dev_extent *extent = NULL;
940
941 path = btrfs_alloc_path();
942 if (!path)
943 return -ENOMEM;
944
945 key.objectid = device->devid;
946 key.offset = start;
947 key.type = BTRFS_DEV_EXTENT_KEY;
948
949 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
950 if (ret > 0) {
951 ret = btrfs_previous_item(root, path, key.objectid,
952 BTRFS_DEV_EXTENT_KEY);
953 if (ret)
954 goto out;
955 leaf = path->nodes[0];
956 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
957 extent = btrfs_item_ptr(leaf, path->slots[0],
958 struct btrfs_dev_extent);
959 BUG_ON(found_key.offset > start || found_key.offset +
960 btrfs_dev_extent_length(leaf, extent) < start);
961 } else if (ret == 0) {
962 leaf = path->nodes[0];
963 extent = btrfs_item_ptr(leaf, path->slots[0],
964 struct btrfs_dev_extent);
965 }
966 BUG_ON(ret);
967
968 if (device->bytes_used > 0)
969 device->bytes_used -= btrfs_dev_extent_length(leaf, extent);
970 ret = btrfs_del_item(trans, root, path);
971
972 out:
973 btrfs_free_path(path);
974 return ret;
975 }
976
977 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
978 struct btrfs_device *device,
979 u64 chunk_tree, u64 chunk_objectid,
980 u64 chunk_offset, u64 start, u64 num_bytes)
981 {
982 int ret;
983 struct btrfs_path *path;
984 struct btrfs_root *root = device->dev_root;
985 struct btrfs_dev_extent *extent;
986 struct extent_buffer *leaf;
987 struct btrfs_key key;
988
989 WARN_ON(!device->in_fs_metadata);
990 path = btrfs_alloc_path();
991 if (!path)
992 return -ENOMEM;
993
994 key.objectid = device->devid;
995 key.offset = start;
996 key.type = BTRFS_DEV_EXTENT_KEY;
997 ret = btrfs_insert_empty_item(trans, root, path, &key,
998 sizeof(*extent));
999 BUG_ON(ret);
1000
1001 leaf = path->nodes[0];
1002 extent = btrfs_item_ptr(leaf, path->slots[0],
1003 struct btrfs_dev_extent);
1004 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
1005 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
1006 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
1007
1008 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
1009 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
1010 BTRFS_UUID_SIZE);
1011
1012 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
1013 btrfs_mark_buffer_dirty(leaf);
1014 btrfs_free_path(path);
1015 return ret;
1016 }
1017
1018 static noinline int find_next_chunk(struct btrfs_root *root,
1019 u64 objectid, u64 *offset)
1020 {
1021 struct btrfs_path *path;
1022 int ret;
1023 struct btrfs_key key;
1024 struct btrfs_chunk *chunk;
1025 struct btrfs_key found_key;
1026
1027 path = btrfs_alloc_path();
1028 BUG_ON(!path);
1029
1030 key.objectid = objectid;
1031 key.offset = (u64)-1;
1032 key.type = BTRFS_CHUNK_ITEM_KEY;
1033
1034 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1035 if (ret < 0)
1036 goto error;
1037
1038 BUG_ON(ret == 0);
1039
1040 ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
1041 if (ret) {
1042 *offset = 0;
1043 } else {
1044 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1045 path->slots[0]);
1046 if (found_key.objectid != objectid)
1047 *offset = 0;
1048 else {
1049 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
1050 struct btrfs_chunk);
1051 *offset = found_key.offset +
1052 btrfs_chunk_length(path->nodes[0], chunk);
1053 }
1054 }
1055 ret = 0;
1056 error:
1057 btrfs_free_path(path);
1058 return ret;
1059 }
1060
1061 static noinline int find_next_devid(struct btrfs_root *root, u64 *objectid)
1062 {
1063 int ret;
1064 struct btrfs_key key;
1065 struct btrfs_key found_key;
1066 struct btrfs_path *path;
1067
1068 root = root->fs_info->chunk_root;
1069
1070 path = btrfs_alloc_path();
1071 if (!path)
1072 return -ENOMEM;
1073
1074 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1075 key.type = BTRFS_DEV_ITEM_KEY;
1076 key.offset = (u64)-1;
1077
1078 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1079 if (ret < 0)
1080 goto error;
1081
1082 BUG_ON(ret == 0);
1083
1084 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
1085 BTRFS_DEV_ITEM_KEY);
1086 if (ret) {
1087 *objectid = 1;
1088 } else {
1089 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1090 path->slots[0]);
1091 *objectid = found_key.offset + 1;
1092 }
1093 ret = 0;
1094 error:
1095 btrfs_free_path(path);
1096 return ret;
1097 }
1098
1099 /*
1100 * the device information is stored in the chunk root
1101 * the btrfs_device struct should be fully filled in
1102 */
1103 int btrfs_add_device(struct btrfs_trans_handle *trans,
1104 struct btrfs_root *root,
1105 struct btrfs_device *device)
1106 {
1107 int ret;
1108 struct btrfs_path *path;
1109 struct btrfs_dev_item *dev_item;
1110 struct extent_buffer *leaf;
1111 struct btrfs_key key;
1112 unsigned long ptr;
1113
1114 root = root->fs_info->chunk_root;
1115
1116 path = btrfs_alloc_path();
1117 if (!path)
1118 return -ENOMEM;
1119
1120 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1121 key.type = BTRFS_DEV_ITEM_KEY;
1122 key.offset = device->devid;
1123
1124 ret = btrfs_insert_empty_item(trans, root, path, &key,
1125 sizeof(*dev_item));
1126 if (ret)
1127 goto out;
1128
1129 leaf = path->nodes[0];
1130 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1131
1132 btrfs_set_device_id(leaf, dev_item, device->devid);
1133 btrfs_set_device_generation(leaf, dev_item, 0);
1134 btrfs_set_device_type(leaf, dev_item, device->type);
1135 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1136 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1137 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1138 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
1139 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1140 btrfs_set_device_group(leaf, dev_item, 0);
1141 btrfs_set_device_seek_speed(leaf, dev_item, 0);
1142 btrfs_set_device_bandwidth(leaf, dev_item, 0);
1143 btrfs_set_device_start_offset(leaf, dev_item, 0);
1144
1145 ptr = (unsigned long)btrfs_device_uuid(dev_item);
1146 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1147 ptr = (unsigned long)btrfs_device_fsid(dev_item);
1148 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
1149 btrfs_mark_buffer_dirty(leaf);
1150
1151 ret = 0;
1152 out:
1153 btrfs_free_path(path);
1154 return ret;
1155 }
1156
1157 static int btrfs_rm_dev_item(struct btrfs_root *root,
1158 struct btrfs_device *device)
1159 {
1160 int ret;
1161 struct btrfs_path *path;
1162 struct btrfs_key key;
1163 struct btrfs_trans_handle *trans;
1164
1165 root = root->fs_info->chunk_root;
1166
1167 path = btrfs_alloc_path();
1168 if (!path)
1169 return -ENOMEM;
1170
1171 trans = btrfs_start_transaction(root, 0);
1172 if (IS_ERR(trans)) {
1173 btrfs_free_path(path);
1174 return PTR_ERR(trans);
1175 }
1176 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1177 key.type = BTRFS_DEV_ITEM_KEY;
1178 key.offset = device->devid;
1179 lock_chunks(root);
1180
1181 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1182 if (ret < 0)
1183 goto out;
1184
1185 if (ret > 0) {
1186 ret = -ENOENT;
1187 goto out;
1188 }
1189
1190 ret = btrfs_del_item(trans, root, path);
1191 if (ret)
1192 goto out;
1193 out:
1194 btrfs_free_path(path);
1195 unlock_chunks(root);
1196 btrfs_commit_transaction(trans, root);
1197 return ret;
1198 }
1199
1200 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
1201 {
1202 struct btrfs_device *device;
1203 struct btrfs_device *next_device;
1204 struct block_device *bdev;
1205 struct buffer_head *bh = NULL;
1206 struct btrfs_super_block *disk_super;
1207 u64 all_avail;
1208 u64 devid;
1209 u64 num_devices;
1210 u8 *dev_uuid;
1211 int ret = 0;
1212
1213 mutex_lock(&uuid_mutex);
1214 mutex_lock(&root->fs_info->volume_mutex);
1215
1216 all_avail = root->fs_info->avail_data_alloc_bits |
1217 root->fs_info->avail_system_alloc_bits |
1218 root->fs_info->avail_metadata_alloc_bits;
1219
1220 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) &&
1221 root->fs_info->fs_devices->num_devices <= 4) {
1222 printk(KERN_ERR "btrfs: unable to go below four devices "
1223 "on raid10\n");
1224 ret = -EINVAL;
1225 goto out;
1226 }
1227
1228 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) &&
1229 root->fs_info->fs_devices->num_devices <= 2) {
1230 printk(KERN_ERR "btrfs: unable to go below two "
1231 "devices on raid1\n");
1232 ret = -EINVAL;
1233 goto out;
1234 }
1235
1236 if (strcmp(device_path, "missing") == 0) {
1237 struct list_head *devices;
1238 struct btrfs_device *tmp;
1239
1240 device = NULL;
1241 devices = &root->fs_info->fs_devices->devices;
1242 /*
1243 * It is safe to read the devices since the volume_mutex
1244 * is held.
1245 */
1246 list_for_each_entry(tmp, devices, dev_list) {
1247 if (tmp->in_fs_metadata && !tmp->bdev) {
1248 device = tmp;
1249 break;
1250 }
1251 }
1252 bdev = NULL;
1253 bh = NULL;
1254 disk_super = NULL;
1255 if (!device) {
1256 printk(KERN_ERR "btrfs: no missing devices found to "
1257 "remove\n");
1258 goto out;
1259 }
1260 } else {
1261 bdev = blkdev_get_by_path(device_path, FMODE_READ | FMODE_EXCL,
1262 root->fs_info->bdev_holder);
1263 if (IS_ERR(bdev)) {
1264 ret = PTR_ERR(bdev);
1265 goto out;
1266 }
1267
1268 set_blocksize(bdev, 4096);
1269 bh = btrfs_read_dev_super(bdev);
1270 if (!bh) {
1271 ret = -EINVAL;
1272 goto error_close;
1273 }
1274 disk_super = (struct btrfs_super_block *)bh->b_data;
1275 devid = btrfs_stack_device_id(&disk_super->dev_item);
1276 dev_uuid = disk_super->dev_item.uuid;
1277 device = btrfs_find_device(root, devid, dev_uuid,
1278 disk_super->fsid);
1279 if (!device) {
1280 ret = -ENOENT;
1281 goto error_brelse;
1282 }
1283 }
1284
1285 if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
1286 printk(KERN_ERR "btrfs: unable to remove the only writeable "
1287 "device\n");
1288 ret = -EINVAL;
1289 goto error_brelse;
1290 }
1291
1292 if (device->writeable) {
1293 lock_chunks(root);
1294 list_del_init(&device->dev_alloc_list);
1295 unlock_chunks(root);
1296 root->fs_info->fs_devices->rw_devices--;
1297 }
1298
1299 ret = btrfs_shrink_device(device, 0);
1300 if (ret)
1301 goto error_undo;
1302
1303 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1304 if (ret)
1305 goto error_undo;
1306
1307 device->in_fs_metadata = 0;
1308
1309 /*
1310 * the device list mutex makes sure that we don't change
1311 * the device list while someone else is writing out all
1312 * the device supers.
1313 */
1314 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1315 list_del_init(&device->dev_list);
1316 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1317
1318 device->fs_devices->num_devices--;
1319
1320 if (device->missing)
1321 root->fs_info->fs_devices->missing_devices--;
1322
1323 next_device = list_entry(root->fs_info->fs_devices->devices.next,
1324 struct btrfs_device, dev_list);
1325 if (device->bdev == root->fs_info->sb->s_bdev)
1326 root->fs_info->sb->s_bdev = next_device->bdev;
1327 if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1328 root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1329
1330 if (device->bdev) {
1331 blkdev_put(device->bdev, device->mode);
1332 device->bdev = NULL;
1333 device->fs_devices->open_devices--;
1334 }
1335
1336 num_devices = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
1337 btrfs_set_super_num_devices(&root->fs_info->super_copy, num_devices);
1338
1339 if (device->fs_devices->open_devices == 0) {
1340 struct btrfs_fs_devices *fs_devices;
1341 fs_devices = root->fs_info->fs_devices;
1342 while (fs_devices) {
1343 if (fs_devices->seed == device->fs_devices)
1344 break;
1345 fs_devices = fs_devices->seed;
1346 }
1347 fs_devices->seed = device->fs_devices->seed;
1348 device->fs_devices->seed = NULL;
1349 lock_chunks(root);
1350 __btrfs_close_devices(device->fs_devices);
1351 unlock_chunks(root);
1352 free_fs_devices(device->fs_devices);
1353 }
1354
1355 /*
1356 * at this point, the device is zero sized. We want to
1357 * remove it from the devices list and zero out the old super
1358 */
1359 if (device->writeable) {
1360 /* make sure this device isn't detected as part of
1361 * the FS anymore
1362 */
1363 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1364 set_buffer_dirty(bh);
1365 sync_dirty_buffer(bh);
1366 }
1367
1368 kfree(device->name);
1369 kfree(device);
1370 ret = 0;
1371
1372 error_brelse:
1373 brelse(bh);
1374 error_close:
1375 if (bdev)
1376 blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
1377 out:
1378 mutex_unlock(&root->fs_info->volume_mutex);
1379 mutex_unlock(&uuid_mutex);
1380 return ret;
1381 error_undo:
1382 if (device->writeable) {
1383 lock_chunks(root);
1384 list_add(&device->dev_alloc_list,
1385 &root->fs_info->fs_devices->alloc_list);
1386 unlock_chunks(root);
1387 root->fs_info->fs_devices->rw_devices++;
1388 }
1389 goto error_brelse;
1390 }
1391
1392 /*
1393 * does all the dirty work required for changing file system's UUID.
1394 */
1395 static int btrfs_prepare_sprout(struct btrfs_trans_handle *trans,
1396 struct btrfs_root *root)
1397 {
1398 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1399 struct btrfs_fs_devices *old_devices;
1400 struct btrfs_fs_devices *seed_devices;
1401 struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
1402 struct btrfs_device *device;
1403 u64 super_flags;
1404
1405 BUG_ON(!mutex_is_locked(&uuid_mutex));
1406 if (!fs_devices->seeding)
1407 return -EINVAL;
1408
1409 seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
1410 if (!seed_devices)
1411 return -ENOMEM;
1412
1413 old_devices = clone_fs_devices(fs_devices);
1414 if (IS_ERR(old_devices)) {
1415 kfree(seed_devices);
1416 return PTR_ERR(old_devices);
1417 }
1418
1419 list_add(&old_devices->list, &fs_uuids);
1420
1421 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1422 seed_devices->opened = 1;
1423 INIT_LIST_HEAD(&seed_devices->devices);
1424 INIT_LIST_HEAD(&seed_devices->alloc_list);
1425 mutex_init(&seed_devices->device_list_mutex);
1426
1427 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1428 list_splice_init(&fs_devices->devices, &seed_devices->devices);
1429 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1430
1431 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1432 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1433 device->fs_devices = seed_devices;
1434 }
1435
1436 fs_devices->seeding = 0;
1437 fs_devices->num_devices = 0;
1438 fs_devices->open_devices = 0;
1439 fs_devices->seed = seed_devices;
1440
1441 generate_random_uuid(fs_devices->fsid);
1442 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1443 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1444 super_flags = btrfs_super_flags(disk_super) &
1445 ~BTRFS_SUPER_FLAG_SEEDING;
1446 btrfs_set_super_flags(disk_super, super_flags);
1447
1448 return 0;
1449 }
1450
1451 /*
1452 * strore the expected generation for seed devices in device items.
1453 */
1454 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1455 struct btrfs_root *root)
1456 {
1457 struct btrfs_path *path;
1458 struct extent_buffer *leaf;
1459 struct btrfs_dev_item *dev_item;
1460 struct btrfs_device *device;
1461 struct btrfs_key key;
1462 u8 fs_uuid[BTRFS_UUID_SIZE];
1463 u8 dev_uuid[BTRFS_UUID_SIZE];
1464 u64 devid;
1465 int ret;
1466
1467 path = btrfs_alloc_path();
1468 if (!path)
1469 return -ENOMEM;
1470
1471 root = root->fs_info->chunk_root;
1472 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1473 key.offset = 0;
1474 key.type = BTRFS_DEV_ITEM_KEY;
1475
1476 while (1) {
1477 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1478 if (ret < 0)
1479 goto error;
1480
1481 leaf = path->nodes[0];
1482 next_slot:
1483 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1484 ret = btrfs_next_leaf(root, path);
1485 if (ret > 0)
1486 break;
1487 if (ret < 0)
1488 goto error;
1489 leaf = path->nodes[0];
1490 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1491 btrfs_release_path(root, path);
1492 continue;
1493 }
1494
1495 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1496 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1497 key.type != BTRFS_DEV_ITEM_KEY)
1498 break;
1499
1500 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1501 struct btrfs_dev_item);
1502 devid = btrfs_device_id(leaf, dev_item);
1503 read_extent_buffer(leaf, dev_uuid,
1504 (unsigned long)btrfs_device_uuid(dev_item),
1505 BTRFS_UUID_SIZE);
1506 read_extent_buffer(leaf, fs_uuid,
1507 (unsigned long)btrfs_device_fsid(dev_item),
1508 BTRFS_UUID_SIZE);
1509 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
1510 BUG_ON(!device);
1511
1512 if (device->fs_devices->seeding) {
1513 btrfs_set_device_generation(leaf, dev_item,
1514 device->generation);
1515 btrfs_mark_buffer_dirty(leaf);
1516 }
1517
1518 path->slots[0]++;
1519 goto next_slot;
1520 }
1521 ret = 0;
1522 error:
1523 btrfs_free_path(path);
1524 return ret;
1525 }
1526
1527 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1528 {
1529 struct btrfs_trans_handle *trans;
1530 struct btrfs_device *device;
1531 struct block_device *bdev;
1532 struct list_head *devices;
1533 struct super_block *sb = root->fs_info->sb;
1534 u64 total_bytes;
1535 int seeding_dev = 0;
1536 int ret = 0;
1537
1538 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1539 return -EINVAL;
1540
1541 bdev = blkdev_get_by_path(device_path, FMODE_EXCL,
1542 root->fs_info->bdev_holder);
1543 if (IS_ERR(bdev))
1544 return PTR_ERR(bdev);
1545
1546 if (root->fs_info->fs_devices->seeding) {
1547 seeding_dev = 1;
1548 down_write(&sb->s_umount);
1549 mutex_lock(&uuid_mutex);
1550 }
1551
1552 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1553 mutex_lock(&root->fs_info->volume_mutex);
1554
1555 devices = &root->fs_info->fs_devices->devices;
1556 /*
1557 * we have the volume lock, so we don't need the extra
1558 * device list mutex while reading the list here.
1559 */
1560 list_for_each_entry(device, devices, dev_list) {
1561 if (device->bdev == bdev) {
1562 ret = -EEXIST;
1563 goto error;
1564 }
1565 }
1566
1567 device = kzalloc(sizeof(*device), GFP_NOFS);
1568 if (!device) {
1569 /* we can safely leave the fs_devices entry around */
1570 ret = -ENOMEM;
1571 goto error;
1572 }
1573
1574 device->name = kstrdup(device_path, GFP_NOFS);
1575 if (!device->name) {
1576 kfree(device);
1577 ret = -ENOMEM;
1578 goto error;
1579 }
1580
1581 ret = find_next_devid(root, &device->devid);
1582 if (ret) {
1583 kfree(device->name);
1584 kfree(device);
1585 goto error;
1586 }
1587
1588 trans = btrfs_start_transaction(root, 0);
1589 if (IS_ERR(trans)) {
1590 kfree(device->name);
1591 kfree(device);
1592 ret = PTR_ERR(trans);
1593 goto error;
1594 }
1595
1596 lock_chunks(root);
1597
1598 device->writeable = 1;
1599 device->work.func = pending_bios_fn;
1600 generate_random_uuid(device->uuid);
1601 spin_lock_init(&device->io_lock);
1602 device->generation = trans->transid;
1603 device->io_width = root->sectorsize;
1604 device->io_align = root->sectorsize;
1605 device->sector_size = root->sectorsize;
1606 device->total_bytes = i_size_read(bdev->bd_inode);
1607 device->disk_total_bytes = device->total_bytes;
1608 device->dev_root = root->fs_info->dev_root;
1609 device->bdev = bdev;
1610 device->in_fs_metadata = 1;
1611 device->mode = FMODE_EXCL;
1612 set_blocksize(device->bdev, 4096);
1613
1614 if (seeding_dev) {
1615 sb->s_flags &= ~MS_RDONLY;
1616 ret = btrfs_prepare_sprout(trans, root);
1617 BUG_ON(ret);
1618 }
1619
1620 device->fs_devices = root->fs_info->fs_devices;
1621
1622 /*
1623 * we don't want write_supers to jump in here with our device
1624 * half setup
1625 */
1626 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1627 list_add(&device->dev_list, &root->fs_info->fs_devices->devices);
1628 list_add(&device->dev_alloc_list,
1629 &root->fs_info->fs_devices->alloc_list);
1630 root->fs_info->fs_devices->num_devices++;
1631 root->fs_info->fs_devices->open_devices++;
1632 root->fs_info->fs_devices->rw_devices++;
1633 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
1634
1635 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
1636 root->fs_info->fs_devices->rotating = 1;
1637
1638 total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
1639 btrfs_set_super_total_bytes(&root->fs_info->super_copy,
1640 total_bytes + device->total_bytes);
1641
1642 total_bytes = btrfs_super_num_devices(&root->fs_info->super_copy);
1643 btrfs_set_super_num_devices(&root->fs_info->super_copy,
1644 total_bytes + 1);
1645 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1646
1647 if (seeding_dev) {
1648 ret = init_first_rw_device(trans, root, device);
1649 BUG_ON(ret);
1650 ret = btrfs_finish_sprout(trans, root);
1651 BUG_ON(ret);
1652 } else {
1653 ret = btrfs_add_device(trans, root, device);
1654 }
1655
1656 /*
1657 * we've got more storage, clear any full flags on the space
1658 * infos
1659 */
1660 btrfs_clear_space_info_full(root->fs_info);
1661
1662 unlock_chunks(root);
1663 btrfs_commit_transaction(trans, root);
1664
1665 if (seeding_dev) {
1666 mutex_unlock(&uuid_mutex);
1667 up_write(&sb->s_umount);
1668
1669 ret = btrfs_relocate_sys_chunks(root);
1670 BUG_ON(ret);
1671 }
1672 out:
1673 mutex_unlock(&root->fs_info->volume_mutex);
1674 return ret;
1675 error:
1676 blkdev_put(bdev, FMODE_EXCL);
1677 if (seeding_dev) {
1678 mutex_unlock(&uuid_mutex);
1679 up_write(&sb->s_umount);
1680 }
1681 goto out;
1682 }
1683
1684 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
1685 struct btrfs_device *device)
1686 {
1687 int ret;
1688 struct btrfs_path *path;
1689 struct btrfs_root *root;
1690 struct btrfs_dev_item *dev_item;
1691 struct extent_buffer *leaf;
1692 struct btrfs_key key;
1693
1694 root = device->dev_root->fs_info->chunk_root;
1695
1696 path = btrfs_alloc_path();
1697 if (!path)
1698 return -ENOMEM;
1699
1700 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1701 key.type = BTRFS_DEV_ITEM_KEY;
1702 key.offset = device->devid;
1703
1704 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1705 if (ret < 0)
1706 goto out;
1707
1708 if (ret > 0) {
1709 ret = -ENOENT;
1710 goto out;
1711 }
1712
1713 leaf = path->nodes[0];
1714 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1715
1716 btrfs_set_device_id(leaf, dev_item, device->devid);
1717 btrfs_set_device_type(leaf, dev_item, device->type);
1718 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1719 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1720 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1721 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
1722 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1723 btrfs_mark_buffer_dirty(leaf);
1724
1725 out:
1726 btrfs_free_path(path);
1727 return ret;
1728 }
1729
1730 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
1731 struct btrfs_device *device, u64 new_size)
1732 {
1733 struct btrfs_super_block *super_copy =
1734 &device->dev_root->fs_info->super_copy;
1735 u64 old_total = btrfs_super_total_bytes(super_copy);
1736 u64 diff = new_size - device->total_bytes;
1737
1738 if (!device->writeable)
1739 return -EACCES;
1740 if (new_size <= device->total_bytes)
1741 return -EINVAL;
1742
1743 btrfs_set_super_total_bytes(super_copy, old_total + diff);
1744 device->fs_devices->total_rw_bytes += diff;
1745
1746 device->total_bytes = new_size;
1747 device->disk_total_bytes = new_size;
1748 btrfs_clear_space_info_full(device->dev_root->fs_info);
1749
1750 return btrfs_update_device(trans, device);
1751 }
1752
1753 int btrfs_grow_device(struct btrfs_trans_handle *trans,
1754 struct btrfs_device *device, u64 new_size)
1755 {
1756 int ret;
1757 lock_chunks(device->dev_root);
1758 ret = __btrfs_grow_device(trans, device, new_size);
1759 unlock_chunks(device->dev_root);
1760 return ret;
1761 }
1762
1763 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
1764 struct btrfs_root *root,
1765 u64 chunk_tree, u64 chunk_objectid,
1766 u64 chunk_offset)
1767 {
1768 int ret;
1769 struct btrfs_path *path;
1770 struct btrfs_key key;
1771
1772 root = root->fs_info->chunk_root;
1773 path = btrfs_alloc_path();
1774 if (!path)
1775 return -ENOMEM;
1776
1777 key.objectid = chunk_objectid;
1778 key.offset = chunk_offset;
1779 key.type = BTRFS_CHUNK_ITEM_KEY;
1780
1781 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1782 BUG_ON(ret);
1783
1784 ret = btrfs_del_item(trans, root, path);
1785
1786 btrfs_free_path(path);
1787 return ret;
1788 }
1789
1790 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
1791 chunk_offset)
1792 {
1793 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
1794 struct btrfs_disk_key *disk_key;
1795 struct btrfs_chunk *chunk;
1796 u8 *ptr;
1797 int ret = 0;
1798 u32 num_stripes;
1799 u32 array_size;
1800 u32 len = 0;
1801 u32 cur;
1802 struct btrfs_key key;
1803
1804 array_size = btrfs_super_sys_array_size(super_copy);
1805
1806 ptr = super_copy->sys_chunk_array;
1807 cur = 0;
1808
1809 while (cur < array_size) {
1810 disk_key = (struct btrfs_disk_key *)ptr;
1811 btrfs_disk_key_to_cpu(&key, disk_key);
1812
1813 len = sizeof(*disk_key);
1814
1815 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
1816 chunk = (struct btrfs_chunk *)(ptr + len);
1817 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
1818 len += btrfs_chunk_item_size(num_stripes);
1819 } else {
1820 ret = -EIO;
1821 break;
1822 }
1823 if (key.objectid == chunk_objectid &&
1824 key.offset == chunk_offset) {
1825 memmove(ptr, ptr + len, array_size - (cur + len));
1826 array_size -= len;
1827 btrfs_set_super_sys_array_size(super_copy, array_size);
1828 } else {
1829 ptr += len;
1830 cur += len;
1831 }
1832 }
1833 return ret;
1834 }
1835
1836 static int btrfs_relocate_chunk(struct btrfs_root *root,
1837 u64 chunk_tree, u64 chunk_objectid,
1838 u64 chunk_offset)
1839 {
1840 struct extent_map_tree *em_tree;
1841 struct btrfs_root *extent_root;
1842 struct btrfs_trans_handle *trans;
1843 struct extent_map *em;
1844 struct map_lookup *map;
1845 int ret;
1846 int i;
1847
1848 root = root->fs_info->chunk_root;
1849 extent_root = root->fs_info->extent_root;
1850 em_tree = &root->fs_info->mapping_tree.map_tree;
1851
1852 ret = btrfs_can_relocate(extent_root, chunk_offset);
1853 if (ret)
1854 return -ENOSPC;
1855
1856 /* step one, relocate all the extents inside this chunk */
1857 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
1858 if (ret)
1859 return ret;
1860
1861 trans = btrfs_start_transaction(root, 0);
1862 BUG_ON(IS_ERR(trans));
1863
1864 lock_chunks(root);
1865
1866 /*
1867 * step two, delete the device extents and the
1868 * chunk tree entries
1869 */
1870 read_lock(&em_tree->lock);
1871 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
1872 read_unlock(&em_tree->lock);
1873
1874 BUG_ON(em->start > chunk_offset ||
1875 em->start + em->len < chunk_offset);
1876 map = (struct map_lookup *)em->bdev;
1877
1878 for (i = 0; i < map->num_stripes; i++) {
1879 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
1880 map->stripes[i].physical);
1881 BUG_ON(ret);
1882
1883 if (map->stripes[i].dev) {
1884 ret = btrfs_update_device(trans, map->stripes[i].dev);
1885 BUG_ON(ret);
1886 }
1887 }
1888 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
1889 chunk_offset);
1890
1891 BUG_ON(ret);
1892
1893 trace_btrfs_chunk_free(root, map, chunk_offset, em->len);
1894
1895 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
1896 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
1897 BUG_ON(ret);
1898 }
1899
1900 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
1901 BUG_ON(ret);
1902
1903 write_lock(&em_tree->lock);
1904 remove_extent_mapping(em_tree, em);
1905 write_unlock(&em_tree->lock);
1906
1907 kfree(map);
1908 em->bdev = NULL;
1909
1910 /* once for the tree */
1911 free_extent_map(em);
1912 /* once for us */
1913 free_extent_map(em);
1914
1915 unlock_chunks(root);
1916 btrfs_end_transaction(trans, root);
1917 return 0;
1918 }
1919
1920 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
1921 {
1922 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
1923 struct btrfs_path *path;
1924 struct extent_buffer *leaf;
1925 struct btrfs_chunk *chunk;
1926 struct btrfs_key key;
1927 struct btrfs_key found_key;
1928 u64 chunk_tree = chunk_root->root_key.objectid;
1929 u64 chunk_type;
1930 bool retried = false;
1931 int failed = 0;
1932 int ret;
1933
1934 path = btrfs_alloc_path();
1935 if (!path)
1936 return -ENOMEM;
1937
1938 again:
1939 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
1940 key.offset = (u64)-1;
1941 key.type = BTRFS_CHUNK_ITEM_KEY;
1942
1943 while (1) {
1944 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
1945 if (ret < 0)
1946 goto error;
1947 BUG_ON(ret == 0);
1948
1949 ret = btrfs_previous_item(chunk_root, path, key.objectid,
1950 key.type);
1951 if (ret < 0)
1952 goto error;
1953 if (ret > 0)
1954 break;
1955
1956 leaf = path->nodes[0];
1957 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1958
1959 chunk = btrfs_item_ptr(leaf, path->slots[0],
1960 struct btrfs_chunk);
1961 chunk_type = btrfs_chunk_type(leaf, chunk);
1962 btrfs_release_path(chunk_root, path);
1963
1964 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
1965 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
1966 found_key.objectid,
1967 found_key.offset);
1968 if (ret == -ENOSPC)
1969 failed++;
1970 else if (ret)
1971 BUG();
1972 }
1973
1974 if (found_key.offset == 0)
1975 break;
1976 key.offset = found_key.offset - 1;
1977 }
1978 ret = 0;
1979 if (failed && !retried) {
1980 failed = 0;
1981 retried = true;
1982 goto again;
1983 } else if (failed && retried) {
1984 WARN_ON(1);
1985 ret = -ENOSPC;
1986 }
1987 error:
1988 btrfs_free_path(path);
1989 return ret;
1990 }
1991
1992 static u64 div_factor(u64 num, int factor)
1993 {
1994 if (factor == 10)
1995 return num;
1996 num *= factor;
1997 do_div(num, 10);
1998 return num;
1999 }
2000
2001 int btrfs_balance(struct btrfs_root *dev_root)
2002 {
2003 int ret;
2004 struct list_head *devices = &dev_root->fs_info->fs_devices->devices;
2005 struct btrfs_device *device;
2006 u64 old_size;
2007 u64 size_to_free;
2008 struct btrfs_path *path;
2009 struct btrfs_key key;
2010 struct btrfs_root *chunk_root = dev_root->fs_info->chunk_root;
2011 struct btrfs_trans_handle *trans;
2012 struct btrfs_key found_key;
2013
2014 if (dev_root->fs_info->sb->s_flags & MS_RDONLY)
2015 return -EROFS;
2016
2017 if (!capable(CAP_SYS_ADMIN))
2018 return -EPERM;
2019
2020 mutex_lock(&dev_root->fs_info->volume_mutex);
2021 dev_root = dev_root->fs_info->dev_root;
2022
2023 /* step one make some room on all the devices */
2024 list_for_each_entry(device, devices, dev_list) {
2025 old_size = device->total_bytes;
2026 size_to_free = div_factor(old_size, 1);
2027 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
2028 if (!device->writeable ||
2029 device->total_bytes - device->bytes_used > size_to_free)
2030 continue;
2031
2032 ret = btrfs_shrink_device(device, old_size - size_to_free);
2033 if (ret == -ENOSPC)
2034 break;
2035 BUG_ON(ret);
2036
2037 trans = btrfs_start_transaction(dev_root, 0);
2038 BUG_ON(IS_ERR(trans));
2039
2040 ret = btrfs_grow_device(trans, device, old_size);
2041 BUG_ON(ret);
2042
2043 btrfs_end_transaction(trans, dev_root);
2044 }
2045
2046 /* step two, relocate all the chunks */
2047 path = btrfs_alloc_path();
2048 BUG_ON(!path);
2049
2050 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2051 key.offset = (u64)-1;
2052 key.type = BTRFS_CHUNK_ITEM_KEY;
2053
2054 while (1) {
2055 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2056 if (ret < 0)
2057 goto error;
2058
2059 /*
2060 * this shouldn't happen, it means the last relocate
2061 * failed
2062 */
2063 if (ret == 0)
2064 break;
2065
2066 ret = btrfs_previous_item(chunk_root, path, 0,
2067 BTRFS_CHUNK_ITEM_KEY);
2068 if (ret)
2069 break;
2070
2071 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2072 path->slots[0]);
2073 if (found_key.objectid != key.objectid)
2074 break;
2075
2076 /* chunk zero is special */
2077 if (found_key.offset == 0)
2078 break;
2079
2080 btrfs_release_path(chunk_root, path);
2081 ret = btrfs_relocate_chunk(chunk_root,
2082 chunk_root->root_key.objectid,
2083 found_key.objectid,
2084 found_key.offset);
2085 BUG_ON(ret && ret != -ENOSPC);
2086 key.offset = found_key.offset - 1;
2087 }
2088 ret = 0;
2089 error:
2090 btrfs_free_path(path);
2091 mutex_unlock(&dev_root->fs_info->volume_mutex);
2092 return ret;
2093 }
2094
2095 /*
2096 * shrinking a device means finding all of the device extents past
2097 * the new size, and then following the back refs to the chunks.
2098 * The chunk relocation code actually frees the device extent
2099 */
2100 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
2101 {
2102 struct btrfs_trans_handle *trans;
2103 struct btrfs_root *root = device->dev_root;
2104 struct btrfs_dev_extent *dev_extent = NULL;
2105 struct btrfs_path *path;
2106 u64 length;
2107 u64 chunk_tree;
2108 u64 chunk_objectid;
2109 u64 chunk_offset;
2110 int ret;
2111 int slot;
2112 int failed = 0;
2113 bool retried = false;
2114 struct extent_buffer *l;
2115 struct btrfs_key key;
2116 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
2117 u64 old_total = btrfs_super_total_bytes(super_copy);
2118 u64 old_size = device->total_bytes;
2119 u64 diff = device->total_bytes - new_size;
2120
2121 if (new_size >= device->total_bytes)
2122 return -EINVAL;
2123
2124 path = btrfs_alloc_path();
2125 if (!path)
2126 return -ENOMEM;
2127
2128 path->reada = 2;
2129
2130 lock_chunks(root);
2131
2132 device->total_bytes = new_size;
2133 if (device->writeable)
2134 device->fs_devices->total_rw_bytes -= diff;
2135 unlock_chunks(root);
2136
2137 again:
2138 key.objectid = device->devid;
2139 key.offset = (u64)-1;
2140 key.type = BTRFS_DEV_EXTENT_KEY;
2141
2142 while (1) {
2143 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2144 if (ret < 0)
2145 goto done;
2146
2147 ret = btrfs_previous_item(root, path, 0, key.type);
2148 if (ret < 0)
2149 goto done;
2150 if (ret) {
2151 ret = 0;
2152 btrfs_release_path(root, path);
2153 break;
2154 }
2155
2156 l = path->nodes[0];
2157 slot = path->slots[0];
2158 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
2159
2160 if (key.objectid != device->devid) {
2161 btrfs_release_path(root, path);
2162 break;
2163 }
2164
2165 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
2166 length = btrfs_dev_extent_length(l, dev_extent);
2167
2168 if (key.offset + length <= new_size) {
2169 btrfs_release_path(root, path);
2170 break;
2171 }
2172
2173 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
2174 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
2175 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
2176 btrfs_release_path(root, path);
2177
2178 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
2179 chunk_offset);
2180 if (ret && ret != -ENOSPC)
2181 goto done;
2182 if (ret == -ENOSPC)
2183 failed++;
2184 key.offset -= 1;
2185 }
2186
2187 if (failed && !retried) {
2188 failed = 0;
2189 retried = true;
2190 goto again;
2191 } else if (failed && retried) {
2192 ret = -ENOSPC;
2193 lock_chunks(root);
2194
2195 device->total_bytes = old_size;
2196 if (device->writeable)
2197 device->fs_devices->total_rw_bytes += diff;
2198 unlock_chunks(root);
2199 goto done;
2200 }
2201
2202 /* Shrinking succeeded, else we would be at "done". */
2203 trans = btrfs_start_transaction(root, 0);
2204 if (IS_ERR(trans)) {
2205 ret = PTR_ERR(trans);
2206 goto done;
2207 }
2208
2209 lock_chunks(root);
2210
2211 device->disk_total_bytes = new_size;
2212 /* Now btrfs_update_device() will change the on-disk size. */
2213 ret = btrfs_update_device(trans, device);
2214 if (ret) {
2215 unlock_chunks(root);
2216 btrfs_end_transaction(trans, root);
2217 goto done;
2218 }
2219 WARN_ON(diff > old_total);
2220 btrfs_set_super_total_bytes(super_copy, old_total - diff);
2221 unlock_chunks(root);
2222 btrfs_end_transaction(trans, root);
2223 done:
2224 btrfs_free_path(path);
2225 return ret;
2226 }
2227
2228 static int btrfs_add_system_chunk(struct btrfs_trans_handle *trans,
2229 struct btrfs_root *root,
2230 struct btrfs_key *key,
2231 struct btrfs_chunk *chunk, int item_size)
2232 {
2233 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
2234 struct btrfs_disk_key disk_key;
2235 u32 array_size;
2236 u8 *ptr;
2237
2238 array_size = btrfs_super_sys_array_size(super_copy);
2239 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
2240 return -EFBIG;
2241
2242 ptr = super_copy->sys_chunk_array + array_size;
2243 btrfs_cpu_key_to_disk(&disk_key, key);
2244 memcpy(ptr, &disk_key, sizeof(disk_key));
2245 ptr += sizeof(disk_key);
2246 memcpy(ptr, chunk, item_size);
2247 item_size += sizeof(disk_key);
2248 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
2249 return 0;
2250 }
2251
2252 static noinline u64 chunk_bytes_by_type(u64 type, u64 calc_size,
2253 int num_stripes, int sub_stripes)
2254 {
2255 if (type & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_DUP))
2256 return calc_size;
2257 else if (type & BTRFS_BLOCK_GROUP_RAID10)
2258 return calc_size * (num_stripes / sub_stripes);
2259 else
2260 return calc_size * num_stripes;
2261 }
2262
2263 /* Used to sort the devices by max_avail(descending sort) */
2264 int btrfs_cmp_device_free_bytes(const void *dev_info1, const void *dev_info2)
2265 {
2266 if (((struct btrfs_device_info *)dev_info1)->max_avail >
2267 ((struct btrfs_device_info *)dev_info2)->max_avail)
2268 return -1;
2269 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
2270 ((struct btrfs_device_info *)dev_info2)->max_avail)
2271 return 1;
2272 else
2273 return 0;
2274 }
2275
2276 static int __btrfs_calc_nstripes(struct btrfs_fs_devices *fs_devices, u64 type,
2277 int *num_stripes, int *min_stripes,
2278 int *sub_stripes)
2279 {
2280 *num_stripes = 1;
2281 *min_stripes = 1;
2282 *sub_stripes = 0;
2283
2284 if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
2285 *num_stripes = fs_devices->rw_devices;
2286 *min_stripes = 2;
2287 }
2288 if (type & (BTRFS_BLOCK_GROUP_DUP)) {
2289 *num_stripes = 2;
2290 *min_stripes = 2;
2291 }
2292 if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
2293 if (fs_devices->rw_devices < 2)
2294 return -ENOSPC;
2295 *num_stripes = 2;
2296 *min_stripes = 2;
2297 }
2298 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
2299 *num_stripes = fs_devices->rw_devices;
2300 if (*num_stripes < 4)
2301 return -ENOSPC;
2302 *num_stripes &= ~(u32)1;
2303 *sub_stripes = 2;
2304 *min_stripes = 4;
2305 }
2306
2307 return 0;
2308 }
2309
2310 static u64 __btrfs_calc_stripe_size(struct btrfs_fs_devices *fs_devices,
2311 u64 proposed_size, u64 type,
2312 int num_stripes, int small_stripe)
2313 {
2314 int min_stripe_size = 1 * 1024 * 1024;
2315 u64 calc_size = proposed_size;
2316 u64 max_chunk_size = calc_size;
2317 int ncopies = 1;
2318
2319 if (type & (BTRFS_BLOCK_GROUP_RAID1 |
2320 BTRFS_BLOCK_GROUP_DUP |
2321 BTRFS_BLOCK_GROUP_RAID10))
2322 ncopies = 2;
2323
2324 if (type & BTRFS_BLOCK_GROUP_DATA) {
2325 max_chunk_size = 10 * calc_size;
2326 min_stripe_size = 64 * 1024 * 1024;
2327 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
2328 max_chunk_size = 256 * 1024 * 1024;
2329 min_stripe_size = 32 * 1024 * 1024;
2330 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
2331 calc_size = 8 * 1024 * 1024;
2332 max_chunk_size = calc_size * 2;
2333 min_stripe_size = 1 * 1024 * 1024;
2334 }
2335
2336 /* we don't want a chunk larger than 10% of writeable space */
2337 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
2338 max_chunk_size);
2339
2340 if (calc_size * num_stripes > max_chunk_size * ncopies) {
2341 calc_size = max_chunk_size * ncopies;
2342 do_div(calc_size, num_stripes);
2343 do_div(calc_size, BTRFS_STRIPE_LEN);
2344 calc_size *= BTRFS_STRIPE_LEN;
2345 }
2346
2347 /* we don't want tiny stripes */
2348 if (!small_stripe)
2349 calc_size = max_t(u64, min_stripe_size, calc_size);
2350
2351 /*
2352 * we're about to do_div by the BTRFS_STRIPE_LEN so lets make sure
2353 * we end up with something bigger than a stripe
2354 */
2355 calc_size = max_t(u64, calc_size, BTRFS_STRIPE_LEN);
2356
2357 do_div(calc_size, BTRFS_STRIPE_LEN);
2358 calc_size *= BTRFS_STRIPE_LEN;
2359
2360 return calc_size;
2361 }
2362
2363 static struct map_lookup *__shrink_map_lookup_stripes(struct map_lookup *map,
2364 int num_stripes)
2365 {
2366 struct map_lookup *new;
2367 size_t len = map_lookup_size(num_stripes);
2368
2369 BUG_ON(map->num_stripes < num_stripes);
2370
2371 if (map->num_stripes == num_stripes)
2372 return map;
2373
2374 new = kmalloc(len, GFP_NOFS);
2375 if (!new) {
2376 /* just change map->num_stripes */
2377 map->num_stripes = num_stripes;
2378 return map;
2379 }
2380
2381 memcpy(new, map, len);
2382 new->num_stripes = num_stripes;
2383 kfree(map);
2384 return new;
2385 }
2386
2387 /*
2388 * helper to allocate device space from btrfs_device_info, in which we stored
2389 * max free space information of every device. It is used when we can not
2390 * allocate chunks by default size.
2391 *
2392 * By this helper, we can allocate a new chunk as larger as possible.
2393 */
2394 static int __btrfs_alloc_tiny_space(struct btrfs_trans_handle *trans,
2395 struct btrfs_fs_devices *fs_devices,
2396 struct btrfs_device_info *devices,
2397 int nr_device, u64 type,
2398 struct map_lookup **map_lookup,
2399 int min_stripes, u64 *stripe_size)
2400 {
2401 int i, index, sort_again = 0;
2402 int min_devices = min_stripes;
2403 u64 max_avail, min_free;
2404 struct map_lookup *map = *map_lookup;
2405 int ret;
2406
2407 if (nr_device < min_stripes)
2408 return -ENOSPC;
2409
2410 btrfs_descending_sort_devices(devices, nr_device);
2411
2412 max_avail = devices[0].max_avail;
2413 if (!max_avail)
2414 return -ENOSPC;
2415
2416 for (i = 0; i < nr_device; i++) {
2417 /*
2418 * if dev_offset = 0, it means the free space of this device
2419 * is less than what we need, and we didn't search max avail
2420 * extent on this device, so do it now.
2421 */
2422 if (!devices[i].dev_offset) {
2423 ret = find_free_dev_extent(trans, devices[i].dev,
2424 max_avail,
2425 &devices[i].dev_offset,
2426 &devices[i].max_avail);
2427 if (ret != 0 && ret != -ENOSPC)
2428 return ret;
2429 sort_again = 1;
2430 }
2431 }
2432
2433 /* we update the max avail free extent of each devices, sort again */
2434 if (sort_again)
2435 btrfs_descending_sort_devices(devices, nr_device);
2436
2437 if (type & BTRFS_BLOCK_GROUP_DUP)
2438 min_devices = 1;
2439
2440 if (!devices[min_devices - 1].max_avail)
2441 return -ENOSPC;
2442
2443 max_avail = devices[min_devices - 1].max_avail;
2444 if (type & BTRFS_BLOCK_GROUP_DUP)
2445 do_div(max_avail, 2);
2446
2447 max_avail = __btrfs_calc_stripe_size(fs_devices, max_avail, type,
2448 min_stripes, 1);
2449 if (type & BTRFS_BLOCK_GROUP_DUP)
2450 min_free = max_avail * 2;
2451 else
2452 min_free = max_avail;
2453
2454 if (min_free > devices[min_devices - 1].max_avail)
2455 return -ENOSPC;
2456
2457 map = __shrink_map_lookup_stripes(map, min_stripes);
2458 *stripe_size = max_avail;
2459
2460 index = 0;
2461 for (i = 0; i < min_stripes; i++) {
2462 map->stripes[i].dev = devices[index].dev;
2463 map->stripes[i].physical = devices[index].dev_offset;
2464 if (type & BTRFS_BLOCK_GROUP_DUP) {
2465 i++;
2466 map->stripes[i].dev = devices[index].dev;
2467 map->stripes[i].physical = devices[index].dev_offset +
2468 max_avail;
2469 }
2470 index++;
2471 }
2472 *map_lookup = map;
2473
2474 return 0;
2475 }
2476
2477 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
2478 struct btrfs_root *extent_root,
2479 struct map_lookup **map_ret,
2480 u64 *num_bytes, u64 *stripe_size,
2481 u64 start, u64 type)
2482 {
2483 struct btrfs_fs_info *info = extent_root->fs_info;
2484 struct btrfs_device *device = NULL;
2485 struct btrfs_fs_devices *fs_devices = info->fs_devices;
2486 struct list_head *cur;
2487 struct map_lookup *map;
2488 struct extent_map_tree *em_tree;
2489 struct extent_map *em;
2490 struct btrfs_device_info *devices_info;
2491 struct list_head private_devs;
2492 u64 calc_size = 1024 * 1024 * 1024;
2493 u64 min_free;
2494 u64 avail;
2495 u64 dev_offset;
2496 int num_stripes;
2497 int min_stripes;
2498 int sub_stripes;
2499 int min_devices; /* the min number of devices we need */
2500 int i;
2501 int ret;
2502 int index;
2503
2504 if ((type & BTRFS_BLOCK_GROUP_RAID1) &&
2505 (type & BTRFS_BLOCK_GROUP_DUP)) {
2506 WARN_ON(1);
2507 type &= ~BTRFS_BLOCK_GROUP_DUP;
2508 }
2509 if (list_empty(&fs_devices->alloc_list))
2510 return -ENOSPC;
2511
2512 ret = __btrfs_calc_nstripes(fs_devices, type, &num_stripes,
2513 &min_stripes, &sub_stripes);
2514 if (ret)
2515 return ret;
2516
2517 devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices,
2518 GFP_NOFS);
2519 if (!devices_info)
2520 return -ENOMEM;
2521
2522 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
2523 if (!map) {
2524 ret = -ENOMEM;
2525 goto error;
2526 }
2527 map->num_stripes = num_stripes;
2528
2529 cur = fs_devices->alloc_list.next;
2530 index = 0;
2531 i = 0;
2532
2533 calc_size = __btrfs_calc_stripe_size(fs_devices, calc_size, type,
2534 num_stripes, 0);
2535
2536 if (type & BTRFS_BLOCK_GROUP_DUP) {
2537 min_free = calc_size * 2;
2538 min_devices = 1;
2539 } else {
2540 min_free = calc_size;
2541 min_devices = min_stripes;
2542 }
2543
2544 INIT_LIST_HEAD(&private_devs);
2545 while (index < num_stripes) {
2546 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
2547 BUG_ON(!device->writeable);
2548 if (device->total_bytes > device->bytes_used)
2549 avail = device->total_bytes - device->bytes_used;
2550 else
2551 avail = 0;
2552 cur = cur->next;
2553
2554 if (device->in_fs_metadata && avail >= min_free) {
2555 ret = find_free_dev_extent(trans, device, min_free,
2556 &devices_info[i].dev_offset,
2557 &devices_info[i].max_avail);
2558 if (ret == 0) {
2559 list_move_tail(&device->dev_alloc_list,
2560 &private_devs);
2561 map->stripes[index].dev = device;
2562 map->stripes[index].physical =
2563 devices_info[i].dev_offset;
2564 index++;
2565 if (type & BTRFS_BLOCK_GROUP_DUP) {
2566 map->stripes[index].dev = device;
2567 map->stripes[index].physical =
2568 devices_info[i].dev_offset +
2569 calc_size;
2570 index++;
2571 }
2572 } else if (ret != -ENOSPC)
2573 goto error;
2574
2575 devices_info[i].dev = device;
2576 i++;
2577 } else if (device->in_fs_metadata &&
2578 avail >= BTRFS_STRIPE_LEN) {
2579 devices_info[i].dev = device;
2580 devices_info[i].max_avail = avail;
2581 i++;
2582 }
2583
2584 if (cur == &fs_devices->alloc_list)
2585 break;
2586 }
2587
2588 list_splice(&private_devs, &fs_devices->alloc_list);
2589 if (index < num_stripes) {
2590 if (index >= min_stripes) {
2591 num_stripes = index;
2592 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
2593 num_stripes /= sub_stripes;
2594 num_stripes *= sub_stripes;
2595 }
2596
2597 map = __shrink_map_lookup_stripes(map, num_stripes);
2598 } else if (i >= min_devices) {
2599 ret = __btrfs_alloc_tiny_space(trans, fs_devices,
2600 devices_info, i, type,
2601 &map, min_stripes,
2602 &calc_size);
2603 if (ret)
2604 goto error;
2605 } else {
2606 ret = -ENOSPC;
2607 goto error;
2608 }
2609 }
2610 map->sector_size = extent_root->sectorsize;
2611 map->stripe_len = BTRFS_STRIPE_LEN;
2612 map->io_align = BTRFS_STRIPE_LEN;
2613 map->io_width = BTRFS_STRIPE_LEN;
2614 map->type = type;
2615 map->sub_stripes = sub_stripes;
2616
2617 *map_ret = map;
2618 *stripe_size = calc_size;
2619 *num_bytes = chunk_bytes_by_type(type, calc_size,
2620 map->num_stripes, sub_stripes);
2621
2622 trace_btrfs_chunk_alloc(info->chunk_root, map, start, *num_bytes);
2623
2624 em = alloc_extent_map(GFP_NOFS);
2625 if (!em) {
2626 ret = -ENOMEM;
2627 goto error;
2628 }
2629 em->bdev = (struct block_device *)map;
2630 em->start = start;
2631 em->len = *num_bytes;
2632 em->block_start = 0;
2633 em->block_len = em->len;
2634
2635 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
2636 write_lock(&em_tree->lock);
2637 ret = add_extent_mapping(em_tree, em);
2638 write_unlock(&em_tree->lock);
2639 BUG_ON(ret);
2640 free_extent_map(em);
2641
2642 ret = btrfs_make_block_group(trans, extent_root, 0, type,
2643 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2644 start, *num_bytes);
2645 BUG_ON(ret);
2646
2647 index = 0;
2648 while (index < map->num_stripes) {
2649 device = map->stripes[index].dev;
2650 dev_offset = map->stripes[index].physical;
2651
2652 ret = btrfs_alloc_dev_extent(trans, device,
2653 info->chunk_root->root_key.objectid,
2654 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2655 start, dev_offset, calc_size);
2656 BUG_ON(ret);
2657 index++;
2658 }
2659
2660 kfree(devices_info);
2661 return 0;
2662
2663 error:
2664 kfree(map);
2665 kfree(devices_info);
2666 return ret;
2667 }
2668
2669 static int __finish_chunk_alloc(struct btrfs_trans_handle *trans,
2670 struct btrfs_root *extent_root,
2671 struct map_lookup *map, u64 chunk_offset,
2672 u64 chunk_size, u64 stripe_size)
2673 {
2674 u64 dev_offset;
2675 struct btrfs_key key;
2676 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
2677 struct btrfs_device *device;
2678 struct btrfs_chunk *chunk;
2679 struct btrfs_stripe *stripe;
2680 size_t item_size = btrfs_chunk_item_size(map->num_stripes);
2681 int index = 0;
2682 int ret;
2683
2684 chunk = kzalloc(item_size, GFP_NOFS);
2685 if (!chunk)
2686 return -ENOMEM;
2687
2688 index = 0;
2689 while (index < map->num_stripes) {
2690 device = map->stripes[index].dev;
2691 device->bytes_used += stripe_size;
2692 ret = btrfs_update_device(trans, device);
2693 BUG_ON(ret);
2694 index++;
2695 }
2696
2697 index = 0;
2698 stripe = &chunk->stripe;
2699 while (index < map->num_stripes) {
2700 device = map->stripes[index].dev;
2701 dev_offset = map->stripes[index].physical;
2702
2703 btrfs_set_stack_stripe_devid(stripe, device->devid);
2704 btrfs_set_stack_stripe_offset(stripe, dev_offset);
2705 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
2706 stripe++;
2707 index++;
2708 }
2709
2710 btrfs_set_stack_chunk_length(chunk, chunk_size);
2711 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
2712 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
2713 btrfs_set_stack_chunk_type(chunk, map->type);
2714 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
2715 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
2716 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
2717 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
2718 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
2719
2720 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2721 key.type = BTRFS_CHUNK_ITEM_KEY;
2722 key.offset = chunk_offset;
2723
2724 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
2725 BUG_ON(ret);
2726
2727 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2728 ret = btrfs_add_system_chunk(trans, chunk_root, &key, chunk,
2729 item_size);
2730 BUG_ON(ret);
2731 }
2732
2733 kfree(chunk);
2734 return 0;
2735 }
2736
2737 /*
2738 * Chunk allocation falls into two parts. The first part does works
2739 * that make the new allocated chunk useable, but not do any operation
2740 * that modifies the chunk tree. The second part does the works that
2741 * require modifying the chunk tree. This division is important for the
2742 * bootstrap process of adding storage to a seed btrfs.
2743 */
2744 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
2745 struct btrfs_root *extent_root, u64 type)
2746 {
2747 u64 chunk_offset;
2748 u64 chunk_size;
2749 u64 stripe_size;
2750 struct map_lookup *map;
2751 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
2752 int ret;
2753
2754 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2755 &chunk_offset);
2756 if (ret)
2757 return ret;
2758
2759 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
2760 &stripe_size, chunk_offset, type);
2761 if (ret)
2762 return ret;
2763
2764 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
2765 chunk_size, stripe_size);
2766 BUG_ON(ret);
2767 return 0;
2768 }
2769
2770 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
2771 struct btrfs_root *root,
2772 struct btrfs_device *device)
2773 {
2774 u64 chunk_offset;
2775 u64 sys_chunk_offset;
2776 u64 chunk_size;
2777 u64 sys_chunk_size;
2778 u64 stripe_size;
2779 u64 sys_stripe_size;
2780 u64 alloc_profile;
2781 struct map_lookup *map;
2782 struct map_lookup *sys_map;
2783 struct btrfs_fs_info *fs_info = root->fs_info;
2784 struct btrfs_root *extent_root = fs_info->extent_root;
2785 int ret;
2786
2787 ret = find_next_chunk(fs_info->chunk_root,
2788 BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset);
2789 BUG_ON(ret);
2790
2791 alloc_profile = BTRFS_BLOCK_GROUP_METADATA |
2792 (fs_info->metadata_alloc_profile &
2793 fs_info->avail_metadata_alloc_bits);
2794 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
2795
2796 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
2797 &stripe_size, chunk_offset, alloc_profile);
2798 BUG_ON(ret);
2799
2800 sys_chunk_offset = chunk_offset + chunk_size;
2801
2802 alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM |
2803 (fs_info->system_alloc_profile &
2804 fs_info->avail_system_alloc_bits);
2805 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
2806
2807 ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,
2808 &sys_chunk_size, &sys_stripe_size,
2809 sys_chunk_offset, alloc_profile);
2810 BUG_ON(ret);
2811
2812 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
2813 BUG_ON(ret);
2814
2815 /*
2816 * Modifying chunk tree needs allocating new blocks from both
2817 * system block group and metadata block group. So we only can
2818 * do operations require modifying the chunk tree after both
2819 * block groups were created.
2820 */
2821 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
2822 chunk_size, stripe_size);
2823 BUG_ON(ret);
2824
2825 ret = __finish_chunk_alloc(trans, extent_root, sys_map,
2826 sys_chunk_offset, sys_chunk_size,
2827 sys_stripe_size);
2828 BUG_ON(ret);
2829 return 0;
2830 }
2831
2832 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
2833 {
2834 struct extent_map *em;
2835 struct map_lookup *map;
2836 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
2837 int readonly = 0;
2838 int i;
2839
2840 read_lock(&map_tree->map_tree.lock);
2841 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
2842 read_unlock(&map_tree->map_tree.lock);
2843 if (!em)
2844 return 1;
2845
2846 if (btrfs_test_opt(root, DEGRADED)) {
2847 free_extent_map(em);
2848 return 0;
2849 }
2850
2851 map = (struct map_lookup *)em->bdev;
2852 for (i = 0; i < map->num_stripes; i++) {
2853 if (!map->stripes[i].dev->writeable) {
2854 readonly = 1;
2855 break;
2856 }
2857 }
2858 free_extent_map(em);
2859 return readonly;
2860 }
2861
2862 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
2863 {
2864 extent_map_tree_init(&tree->map_tree, GFP_NOFS);
2865 }
2866
2867 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
2868 {
2869 struct extent_map *em;
2870
2871 while (1) {
2872 write_lock(&tree->map_tree.lock);
2873 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
2874 if (em)
2875 remove_extent_mapping(&tree->map_tree, em);
2876 write_unlock(&tree->map_tree.lock);
2877 if (!em)
2878 break;
2879 kfree(em->bdev);
2880 /* once for us */
2881 free_extent_map(em);
2882 /* once for the tree */
2883 free_extent_map(em);
2884 }
2885 }
2886
2887 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
2888 {
2889 struct extent_map *em;
2890 struct map_lookup *map;
2891 struct extent_map_tree *em_tree = &map_tree->map_tree;
2892 int ret;
2893
2894 read_lock(&em_tree->lock);
2895 em = lookup_extent_mapping(em_tree, logical, len);
2896 read_unlock(&em_tree->lock);
2897 BUG_ON(!em);
2898
2899 BUG_ON(em->start > logical || em->start + em->len < logical);
2900 map = (struct map_lookup *)em->bdev;
2901 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
2902 ret = map->num_stripes;
2903 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
2904 ret = map->sub_stripes;
2905 else
2906 ret = 1;
2907 free_extent_map(em);
2908 return ret;
2909 }
2910
2911 static int find_live_mirror(struct map_lookup *map, int first, int num,
2912 int optimal)
2913 {
2914 int i;
2915 if (map->stripes[optimal].dev->bdev)
2916 return optimal;
2917 for (i = first; i < first + num; i++) {
2918 if (map->stripes[i].dev->bdev)
2919 return i;
2920 }
2921 /* we couldn't find one that doesn't fail. Just return something
2922 * and the io error handling code will clean up eventually
2923 */
2924 return optimal;
2925 }
2926
2927 static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
2928 u64 logical, u64 *length,
2929 struct btrfs_multi_bio **multi_ret,
2930 int mirror_num)
2931 {
2932 struct extent_map *em;
2933 struct map_lookup *map;
2934 struct extent_map_tree *em_tree = &map_tree->map_tree;
2935 u64 offset;
2936 u64 stripe_offset;
2937 u64 stripe_end_offset;
2938 u64 stripe_nr;
2939 u64 stripe_nr_orig;
2940 u64 stripe_nr_end;
2941 int stripes_allocated = 8;
2942 int stripes_required = 1;
2943 int stripe_index;
2944 int i;
2945 int num_stripes;
2946 int max_errors = 0;
2947 struct btrfs_multi_bio *multi = NULL;
2948
2949 if (multi_ret && !(rw & (REQ_WRITE | REQ_DISCARD)))
2950 stripes_allocated = 1;
2951 again:
2952 if (multi_ret) {
2953 multi = kzalloc(btrfs_multi_bio_size(stripes_allocated),
2954 GFP_NOFS);
2955 if (!multi)
2956 return -ENOMEM;
2957
2958 atomic_set(&multi->error, 0);
2959 }
2960
2961 read_lock(&em_tree->lock);
2962 em = lookup_extent_mapping(em_tree, logical, *length);
2963 read_unlock(&em_tree->lock);
2964
2965 if (!em) {
2966 printk(KERN_CRIT "unable to find logical %llu len %llu\n",
2967 (unsigned long long)logical,
2968 (unsigned long long)*length);
2969 BUG();
2970 }
2971
2972 BUG_ON(em->start > logical || em->start + em->len < logical);
2973 map = (struct map_lookup *)em->bdev;
2974 offset = logical - em->start;
2975
2976 if (mirror_num > map->num_stripes)
2977 mirror_num = 0;
2978
2979 /* if our multi bio struct is too small, back off and try again */
2980 if (rw & REQ_WRITE) {
2981 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
2982 BTRFS_BLOCK_GROUP_DUP)) {
2983 stripes_required = map->num_stripes;
2984 max_errors = 1;
2985 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2986 stripes_required = map->sub_stripes;
2987 max_errors = 1;
2988 }
2989 }
2990 if (rw & REQ_DISCARD) {
2991 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
2992 BTRFS_BLOCK_GROUP_RAID1 |
2993 BTRFS_BLOCK_GROUP_DUP |
2994 BTRFS_BLOCK_GROUP_RAID10)) {
2995 stripes_required = map->num_stripes;
2996 }
2997 }
2998 if (multi_ret && (rw & (REQ_WRITE | REQ_DISCARD)) &&
2999 stripes_allocated < stripes_required) {
3000 stripes_allocated = map->num_stripes;
3001 free_extent_map(em);
3002 kfree(multi);
3003 goto again;
3004 }
3005 stripe_nr = offset;
3006 /*
3007 * stripe_nr counts the total number of stripes we have to stride
3008 * to get to this block
3009 */
3010 do_div(stripe_nr, map->stripe_len);
3011
3012 stripe_offset = stripe_nr * map->stripe_len;
3013 BUG_ON(offset < stripe_offset);
3014
3015 /* stripe_offset is the offset of this block in its stripe*/
3016 stripe_offset = offset - stripe_offset;
3017
3018 if (rw & REQ_DISCARD)
3019 *length = min_t(u64, em->len - offset, *length);
3020 else if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
3021 BTRFS_BLOCK_GROUP_RAID1 |
3022 BTRFS_BLOCK_GROUP_RAID10 |
3023 BTRFS_BLOCK_GROUP_DUP)) {
3024 /* we limit the length of each bio to what fits in a stripe */
3025 *length = min_t(u64, em->len - offset,
3026 map->stripe_len - stripe_offset);
3027 } else {
3028 *length = em->len - offset;
3029 }
3030
3031 if (!multi_ret)
3032 goto out;
3033
3034 num_stripes = 1;
3035 stripe_index = 0;
3036 stripe_nr_orig = stripe_nr;
3037 stripe_nr_end = (offset + *length + map->stripe_len - 1) &
3038 (~(map->stripe_len - 1));
3039 do_div(stripe_nr_end, map->stripe_len);
3040 stripe_end_offset = stripe_nr_end * map->stripe_len -
3041 (offset + *length);
3042 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3043 if (rw & REQ_DISCARD)
3044 num_stripes = min_t(u64, map->num_stripes,
3045 stripe_nr_end - stripe_nr_orig);
3046 stripe_index = do_div(stripe_nr, map->num_stripes);
3047 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
3048 if (rw & (REQ_WRITE | REQ_DISCARD))
3049 num_stripes = map->num_stripes;
3050 else if (mirror_num)
3051 stripe_index = mirror_num - 1;
3052 else {
3053 stripe_index = find_live_mirror(map, 0,
3054 map->num_stripes,
3055 current->pid % map->num_stripes);
3056 }
3057
3058 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
3059 if (rw & (REQ_WRITE | REQ_DISCARD))
3060 num_stripes = map->num_stripes;
3061 else if (mirror_num)
3062 stripe_index = mirror_num - 1;
3063
3064 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3065 int factor = map->num_stripes / map->sub_stripes;
3066
3067 stripe_index = do_div(stripe_nr, factor);
3068 stripe_index *= map->sub_stripes;
3069
3070 if (rw & REQ_WRITE)
3071 num_stripes = map->sub_stripes;
3072 else if (rw & REQ_DISCARD)
3073 num_stripes = min_t(u64, map->sub_stripes *
3074 (stripe_nr_end - stripe_nr_orig),
3075 map->num_stripes);
3076 else if (mirror_num)
3077 stripe_index += mirror_num - 1;
3078 else {
3079 stripe_index = find_live_mirror(map, stripe_index,
3080 map->sub_stripes, stripe_index +
3081 current->pid % map->sub_stripes);
3082 }
3083 } else {
3084 /*
3085 * after this do_div call, stripe_nr is the number of stripes
3086 * on this device we have to walk to find the data, and
3087 * stripe_index is the number of our device in the stripe array
3088 */
3089 stripe_index = do_div(stripe_nr, map->num_stripes);
3090 }
3091 BUG_ON(stripe_index >= map->num_stripes);
3092
3093 if (rw & REQ_DISCARD) {
3094 for (i = 0; i < num_stripes; i++) {
3095 multi->stripes[i].physical =
3096 map->stripes[stripe_index].physical +
3097 stripe_offset + stripe_nr * map->stripe_len;
3098 multi->stripes[i].dev = map->stripes[stripe_index].dev;
3099
3100 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3101 u64 stripes;
3102 u32 last_stripe = 0;
3103 int j;
3104
3105 div_u64_rem(stripe_nr_end - 1,
3106 map->num_stripes,
3107 &last_stripe);
3108
3109 for (j = 0; j < map->num_stripes; j++) {
3110 u32 test;
3111
3112 div_u64_rem(stripe_nr_end - 1 - j,
3113 map->num_stripes, &test);
3114 if (test == stripe_index)
3115 break;
3116 }
3117 stripes = stripe_nr_end - 1 - j;
3118 do_div(stripes, map->num_stripes);
3119 multi->stripes[i].length = map->stripe_len *
3120 (stripes - stripe_nr + 1);
3121
3122 if (i == 0) {
3123 multi->stripes[i].length -=
3124 stripe_offset;
3125 stripe_offset = 0;
3126 }
3127 if (stripe_index == last_stripe)
3128 multi->stripes[i].length -=
3129 stripe_end_offset;
3130 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3131 u64 stripes;
3132 int j;
3133 int factor = map->num_stripes /
3134 map->sub_stripes;
3135 u32 last_stripe = 0;
3136
3137 div_u64_rem(stripe_nr_end - 1,
3138 factor, &last_stripe);
3139 last_stripe *= map->sub_stripes;
3140
3141 for (j = 0; j < factor; j++) {
3142 u32 test;
3143
3144 div_u64_rem(stripe_nr_end - 1 - j,
3145 factor, &test);
3146
3147 if (test ==
3148 stripe_index / map->sub_stripes)
3149 break;
3150 }
3151 stripes = stripe_nr_end - 1 - j;
3152 do_div(stripes, factor);
3153 multi->stripes[i].length = map->stripe_len *
3154 (stripes - stripe_nr + 1);
3155
3156 if (i < map->sub_stripes) {
3157 multi->stripes[i].length -=
3158 stripe_offset;
3159 if (i == map->sub_stripes - 1)
3160 stripe_offset = 0;
3161 }
3162 if (stripe_index >= last_stripe &&
3163 stripe_index <= (last_stripe +
3164 map->sub_stripes - 1)) {
3165 multi->stripes[i].length -=
3166 stripe_end_offset;
3167 }
3168 } else
3169 multi->stripes[i].length = *length;
3170
3171 stripe_index++;
3172 if (stripe_index == map->num_stripes) {
3173 /* This could only happen for RAID0/10 */
3174 stripe_index = 0;
3175 stripe_nr++;
3176 }
3177 }
3178 } else {
3179 for (i = 0; i < num_stripes; i++) {
3180 multi->stripes[i].physical =
3181 map->stripes[stripe_index].physical +
3182 stripe_offset +
3183 stripe_nr * map->stripe_len;
3184 multi->stripes[i].dev =
3185 map->stripes[stripe_index].dev;
3186 stripe_index++;
3187 }
3188 }
3189 if (multi_ret) {
3190 *multi_ret = multi;
3191 multi->num_stripes = num_stripes;
3192 multi->max_errors = max_errors;
3193 }
3194 out:
3195 free_extent_map(em);
3196 return 0;
3197 }
3198
3199 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
3200 u64 logical, u64 *length,
3201 struct btrfs_multi_bio **multi_ret, int mirror_num)
3202 {
3203 return __btrfs_map_block(map_tree, rw, logical, length, multi_ret,
3204 mirror_num);
3205 }
3206
3207 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
3208 u64 chunk_start, u64 physical, u64 devid,
3209 u64 **logical, int *naddrs, int *stripe_len)
3210 {
3211 struct extent_map_tree *em_tree = &map_tree->map_tree;
3212 struct extent_map *em;
3213 struct map_lookup *map;
3214 u64 *buf;
3215 u64 bytenr;
3216 u64 length;
3217 u64 stripe_nr;
3218 int i, j, nr = 0;
3219
3220 read_lock(&em_tree->lock);
3221 em = lookup_extent_mapping(em_tree, chunk_start, 1);
3222 read_unlock(&em_tree->lock);
3223
3224 BUG_ON(!em || em->start != chunk_start);
3225 map = (struct map_lookup *)em->bdev;
3226
3227 length = em->len;
3228 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
3229 do_div(length, map->num_stripes / map->sub_stripes);
3230 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
3231 do_div(length, map->num_stripes);
3232
3233 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
3234 BUG_ON(!buf);
3235
3236 for (i = 0; i < map->num_stripes; i++) {
3237 if (devid && map->stripes[i].dev->devid != devid)
3238 continue;
3239 if (map->stripes[i].physical > physical ||
3240 map->stripes[i].physical + length <= physical)
3241 continue;
3242
3243 stripe_nr = physical - map->stripes[i].physical;
3244 do_div(stripe_nr, map->stripe_len);
3245
3246 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3247 stripe_nr = stripe_nr * map->num_stripes + i;
3248 do_div(stripe_nr, map->sub_stripes);
3249 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3250 stripe_nr = stripe_nr * map->num_stripes + i;
3251 }
3252 bytenr = chunk_start + stripe_nr * map->stripe_len;
3253 WARN_ON(nr >= map->num_stripes);
3254 for (j = 0; j < nr; j++) {
3255 if (buf[j] == bytenr)
3256 break;
3257 }
3258 if (j == nr) {
3259 WARN_ON(nr >= map->num_stripes);
3260 buf[nr++] = bytenr;
3261 }
3262 }
3263
3264 *logical = buf;
3265 *naddrs = nr;
3266 *stripe_len = map->stripe_len;
3267
3268 free_extent_map(em);
3269 return 0;
3270 }
3271
3272 static void end_bio_multi_stripe(struct bio *bio, int err)
3273 {
3274 struct btrfs_multi_bio *multi = bio->bi_private;
3275 int is_orig_bio = 0;
3276
3277 if (err)
3278 atomic_inc(&multi->error);
3279
3280 if (bio == multi->orig_bio)
3281 is_orig_bio = 1;
3282
3283 if (atomic_dec_and_test(&multi->stripes_pending)) {
3284 if (!is_orig_bio) {
3285 bio_put(bio);
3286 bio = multi->orig_bio;
3287 }
3288 bio->bi_private = multi->private;
3289 bio->bi_end_io = multi->end_io;
3290 /* only send an error to the higher layers if it is
3291 * beyond the tolerance of the multi-bio
3292 */
3293 if (atomic_read(&multi->error) > multi->max_errors) {
3294 err = -EIO;
3295 } else if (err) {
3296 /*
3297 * this bio is actually up to date, we didn't
3298 * go over the max number of errors
3299 */
3300 set_bit(BIO_UPTODATE, &bio->bi_flags);
3301 err = 0;
3302 }
3303 kfree(multi);
3304
3305 bio_endio(bio, err);
3306 } else if (!is_orig_bio) {
3307 bio_put(bio);
3308 }
3309 }
3310
3311 struct async_sched {
3312 struct bio *bio;
3313 int rw;
3314 struct btrfs_fs_info *info;
3315 struct btrfs_work work;
3316 };
3317
3318 /*
3319 * see run_scheduled_bios for a description of why bios are collected for
3320 * async submit.
3321 *
3322 * This will add one bio to the pending list for a device and make sure
3323 * the work struct is scheduled.
3324 */
3325 static noinline int schedule_bio(struct btrfs_root *root,
3326 struct btrfs_device *device,
3327 int rw, struct bio *bio)
3328 {
3329 int should_queue = 1;
3330 struct btrfs_pending_bios *pending_bios;
3331
3332 /* don't bother with additional async steps for reads, right now */
3333 if (!(rw & REQ_WRITE)) {
3334 bio_get(bio);
3335 submit_bio(rw, bio);
3336 bio_put(bio);
3337 return 0;
3338 }
3339
3340 /*
3341 * nr_async_bios allows us to reliably return congestion to the
3342 * higher layers. Otherwise, the async bio makes it appear we have
3343 * made progress against dirty pages when we've really just put it
3344 * on a queue for later
3345 */
3346 atomic_inc(&root->fs_info->nr_async_bios);
3347 WARN_ON(bio->bi_next);
3348 bio->bi_next = NULL;
3349 bio->bi_rw |= rw;
3350
3351 spin_lock(&device->io_lock);
3352 if (bio->bi_rw & REQ_SYNC)
3353 pending_bios = &device->pending_sync_bios;
3354 else
3355 pending_bios = &device->pending_bios;
3356
3357 if (pending_bios->tail)
3358 pending_bios->tail->bi_next = bio;
3359
3360 pending_bios->tail = bio;
3361 if (!pending_bios->head)
3362 pending_bios->head = bio;
3363 if (device->running_pending)
3364 should_queue = 0;
3365
3366 spin_unlock(&device->io_lock);
3367
3368 if (should_queue)
3369 btrfs_queue_worker(&root->fs_info->submit_workers,
3370 &device->work);
3371 return 0;
3372 }
3373
3374 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
3375 int mirror_num, int async_submit)
3376 {
3377 struct btrfs_mapping_tree *map_tree;
3378 struct btrfs_device *dev;
3379 struct bio *first_bio = bio;
3380 u64 logical = (u64)bio->bi_sector << 9;
3381 u64 length = 0;
3382 u64 map_length;
3383 struct btrfs_multi_bio *multi = NULL;
3384 int ret;
3385 int dev_nr = 0;
3386 int total_devs = 1;
3387
3388 length = bio->bi_size;
3389 map_tree = &root->fs_info->mapping_tree;
3390 map_length = length;
3391
3392 ret = btrfs_map_block(map_tree, rw, logical, &map_length, &multi,
3393 mirror_num);
3394 BUG_ON(ret);
3395
3396 total_devs = multi->num_stripes;
3397 if (map_length < length) {
3398 printk(KERN_CRIT "mapping failed logical %llu bio len %llu "
3399 "len %llu\n", (unsigned long long)logical,
3400 (unsigned long long)length,
3401 (unsigned long long)map_length);
3402 BUG();
3403 }
3404 multi->end_io = first_bio->bi_end_io;
3405 multi->private = first_bio->bi_private;
3406 multi->orig_bio = first_bio;
3407 atomic_set(&multi->stripes_pending, multi->num_stripes);
3408
3409 while (dev_nr < total_devs) {
3410 if (total_devs > 1) {
3411 if (dev_nr < total_devs - 1) {
3412 bio = bio_clone(first_bio, GFP_NOFS);
3413 BUG_ON(!bio);
3414 } else {
3415 bio = first_bio;
3416 }
3417 bio->bi_private = multi;
3418 bio->bi_end_io = end_bio_multi_stripe;
3419 }
3420 bio->bi_sector = multi->stripes[dev_nr].physical >> 9;
3421 dev = multi->stripes[dev_nr].dev;
3422 if (dev && dev->bdev && (rw != WRITE || dev->writeable)) {
3423 bio->bi_bdev = dev->bdev;
3424 if (async_submit)
3425 schedule_bio(root, dev, rw, bio);
3426 else
3427 submit_bio(rw, bio);
3428 } else {
3429 bio->bi_bdev = root->fs_info->fs_devices->latest_bdev;
3430 bio->bi_sector = logical >> 9;
3431 bio_endio(bio, -EIO);
3432 }
3433 dev_nr++;
3434 }
3435 if (total_devs == 1)
3436 kfree(multi);
3437 return 0;
3438 }
3439
3440 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
3441 u8 *uuid, u8 *fsid)
3442 {
3443 struct btrfs_device *device;
3444 struct btrfs_fs_devices *cur_devices;
3445
3446 cur_devices = root->fs_info->fs_devices;
3447 while (cur_devices) {
3448 if (!fsid ||
3449 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
3450 device = __find_device(&cur_devices->devices,
3451 devid, uuid);
3452 if (device)
3453 return device;
3454 }
3455 cur_devices = cur_devices->seed;
3456 }
3457 return NULL;
3458 }
3459
3460 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
3461 u64 devid, u8 *dev_uuid)
3462 {
3463 struct btrfs_device *device;
3464 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
3465
3466 device = kzalloc(sizeof(*device), GFP_NOFS);
3467 if (!device)
3468 return NULL;
3469 list_add(&device->dev_list,
3470 &fs_devices->devices);
3471 device->dev_root = root->fs_info->dev_root;
3472 device->devid = devid;
3473 device->work.func = pending_bios_fn;
3474 device->fs_devices = fs_devices;
3475 device->missing = 1;
3476 fs_devices->num_devices++;
3477 fs_devices->missing_devices++;
3478 spin_lock_init(&device->io_lock);
3479 INIT_LIST_HEAD(&device->dev_alloc_list);
3480 memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
3481 return device;
3482 }
3483
3484 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
3485 struct extent_buffer *leaf,
3486 struct btrfs_chunk *chunk)
3487 {
3488 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
3489 struct map_lookup *map;
3490 struct extent_map *em;
3491 u64 logical;
3492 u64 length;
3493 u64 devid;
3494 u8 uuid[BTRFS_UUID_SIZE];
3495 int num_stripes;
3496 int ret;
3497 int i;
3498
3499 logical = key->offset;
3500 length = btrfs_chunk_length(leaf, chunk);
3501
3502 read_lock(&map_tree->map_tree.lock);
3503 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
3504 read_unlock(&map_tree->map_tree.lock);
3505
3506 /* already mapped? */
3507 if (em && em->start <= logical && em->start + em->len > logical) {
3508 free_extent_map(em);
3509 return 0;
3510 } else if (em) {
3511 free_extent_map(em);
3512 }
3513
3514 em = alloc_extent_map(GFP_NOFS);
3515 if (!em)
3516 return -ENOMEM;
3517 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
3518 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
3519 if (!map) {
3520 free_extent_map(em);
3521 return -ENOMEM;
3522 }
3523
3524 em->bdev = (struct block_device *)map;
3525 em->start = logical;
3526 em->len = length;
3527 em->block_start = 0;
3528 em->block_len = em->len;
3529
3530 map->num_stripes = num_stripes;
3531 map->io_width = btrfs_chunk_io_width(leaf, chunk);
3532 map->io_align = btrfs_chunk_io_align(leaf, chunk);
3533 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
3534 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
3535 map->type = btrfs_chunk_type(leaf, chunk);
3536 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
3537 for (i = 0; i < num_stripes; i++) {
3538 map->stripes[i].physical =
3539 btrfs_stripe_offset_nr(leaf, chunk, i);
3540 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
3541 read_extent_buffer(leaf, uuid, (unsigned long)
3542 btrfs_stripe_dev_uuid_nr(chunk, i),
3543 BTRFS_UUID_SIZE);
3544 map->stripes[i].dev = btrfs_find_device(root, devid, uuid,
3545 NULL);
3546 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
3547 kfree(map);
3548 free_extent_map(em);
3549 return -EIO;
3550 }
3551 if (!map->stripes[i].dev) {
3552 map->stripes[i].dev =
3553 add_missing_dev(root, devid, uuid);
3554 if (!map->stripes[i].dev) {
3555 kfree(map);
3556 free_extent_map(em);
3557 return -EIO;
3558 }
3559 }
3560 map->stripes[i].dev->in_fs_metadata = 1;
3561 }
3562
3563 write_lock(&map_tree->map_tree.lock);
3564 ret = add_extent_mapping(&map_tree->map_tree, em);
3565 write_unlock(&map_tree->map_tree.lock);
3566 BUG_ON(ret);
3567 free_extent_map(em);
3568
3569 return 0;
3570 }
3571
3572 static int fill_device_from_item(struct extent_buffer *leaf,
3573 struct btrfs_dev_item *dev_item,
3574 struct btrfs_device *device)
3575 {
3576 unsigned long ptr;
3577
3578 device->devid = btrfs_device_id(leaf, dev_item);
3579 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
3580 device->total_bytes = device->disk_total_bytes;
3581 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
3582 device->type = btrfs_device_type(leaf, dev_item);
3583 device->io_align = btrfs_device_io_align(leaf, dev_item);
3584 device->io_width = btrfs_device_io_width(leaf, dev_item);
3585 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
3586
3587 ptr = (unsigned long)btrfs_device_uuid(dev_item);
3588 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
3589
3590 return 0;
3591 }
3592
3593 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
3594 {
3595 struct btrfs_fs_devices *fs_devices;
3596 int ret;
3597
3598 mutex_lock(&uuid_mutex);
3599
3600 fs_devices = root->fs_info->fs_devices->seed;
3601 while (fs_devices) {
3602 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
3603 ret = 0;
3604 goto out;
3605 }
3606 fs_devices = fs_devices->seed;
3607 }
3608
3609 fs_devices = find_fsid(fsid);
3610 if (!fs_devices) {
3611 ret = -ENOENT;
3612 goto out;
3613 }
3614
3615 fs_devices = clone_fs_devices(fs_devices);
3616 if (IS_ERR(fs_devices)) {
3617 ret = PTR_ERR(fs_devices);
3618 goto out;
3619 }
3620
3621 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
3622 root->fs_info->bdev_holder);
3623 if (ret)
3624 goto out;
3625
3626 if (!fs_devices->seeding) {
3627 __btrfs_close_devices(fs_devices);
3628 free_fs_devices(fs_devices);
3629 ret = -EINVAL;
3630 goto out;
3631 }
3632
3633 fs_devices->seed = root->fs_info->fs_devices->seed;
3634 root->fs_info->fs_devices->seed = fs_devices;
3635 out:
3636 mutex_unlock(&uuid_mutex);
3637 return ret;
3638 }
3639
3640 static int read_one_dev(struct btrfs_root *root,
3641 struct extent_buffer *leaf,
3642 struct btrfs_dev_item *dev_item)
3643 {
3644 struct btrfs_device *device;
3645 u64 devid;
3646 int ret;
3647 u8 fs_uuid[BTRFS_UUID_SIZE];
3648 u8 dev_uuid[BTRFS_UUID_SIZE];
3649
3650 devid = btrfs_device_id(leaf, dev_item);
3651 read_extent_buffer(leaf, dev_uuid,
3652 (unsigned long)btrfs_device_uuid(dev_item),
3653 BTRFS_UUID_SIZE);
3654 read_extent_buffer(leaf, fs_uuid,
3655 (unsigned long)btrfs_device_fsid(dev_item),
3656 BTRFS_UUID_SIZE);
3657
3658 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
3659 ret = open_seed_devices(root, fs_uuid);
3660 if (ret && !btrfs_test_opt(root, DEGRADED))
3661 return ret;
3662 }
3663
3664 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
3665 if (!device || !device->bdev) {
3666 if (!btrfs_test_opt(root, DEGRADED))
3667 return -EIO;
3668
3669 if (!device) {
3670 printk(KERN_WARNING "warning devid %llu missing\n",
3671 (unsigned long long)devid);
3672 device = add_missing_dev(root, devid, dev_uuid);
3673 if (!device)
3674 return -ENOMEM;
3675 } else if (!device->missing) {
3676 /*
3677 * this happens when a device that was properly setup
3678 * in the device info lists suddenly goes bad.
3679 * device->bdev is NULL, and so we have to set
3680 * device->missing to one here
3681 */
3682 root->fs_info->fs_devices->missing_devices++;
3683 device->missing = 1;
3684 }
3685 }
3686
3687 if (device->fs_devices != root->fs_info->fs_devices) {
3688 BUG_ON(device->writeable);
3689 if (device->generation !=
3690 btrfs_device_generation(leaf, dev_item))
3691 return -EINVAL;
3692 }
3693
3694 fill_device_from_item(leaf, dev_item, device);
3695 device->dev_root = root->fs_info->dev_root;
3696 device->in_fs_metadata = 1;
3697 if (device->writeable)
3698 device->fs_devices->total_rw_bytes += device->total_bytes;
3699 ret = 0;
3700 return ret;
3701 }
3702
3703 int btrfs_read_super_device(struct btrfs_root *root, struct extent_buffer *buf)
3704 {
3705 struct btrfs_dev_item *dev_item;
3706
3707 dev_item = (struct btrfs_dev_item *)offsetof(struct btrfs_super_block,
3708 dev_item);
3709 return read_one_dev(root, buf, dev_item);
3710 }
3711
3712 int btrfs_read_sys_array(struct btrfs_root *root)
3713 {
3714 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
3715 struct extent_buffer *sb;
3716 struct btrfs_disk_key *disk_key;
3717 struct btrfs_chunk *chunk;
3718 u8 *ptr;
3719 unsigned long sb_ptr;
3720 int ret = 0;
3721 u32 num_stripes;
3722 u32 array_size;
3723 u32 len = 0;
3724 u32 cur;
3725 struct btrfs_key key;
3726
3727 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
3728 BTRFS_SUPER_INFO_SIZE);
3729 if (!sb)
3730 return -ENOMEM;
3731 btrfs_set_buffer_uptodate(sb);
3732 btrfs_set_buffer_lockdep_class(sb, 0);
3733
3734 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
3735 array_size = btrfs_super_sys_array_size(super_copy);
3736
3737 ptr = super_copy->sys_chunk_array;
3738 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
3739 cur = 0;
3740
3741 while (cur < array_size) {
3742 disk_key = (struct btrfs_disk_key *)ptr;
3743 btrfs_disk_key_to_cpu(&key, disk_key);
3744
3745 len = sizeof(*disk_key); ptr += len;
3746 sb_ptr += len;
3747 cur += len;
3748
3749 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
3750 chunk = (struct btrfs_chunk *)sb_ptr;
3751 ret = read_one_chunk(root, &key, sb, chunk);
3752 if (ret)
3753 break;
3754 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
3755 len = btrfs_chunk_item_size(num_stripes);
3756 } else {
3757 ret = -EIO;
3758 break;
3759 }
3760 ptr += len;
3761 sb_ptr += len;
3762 cur += len;
3763 }
3764 free_extent_buffer(sb);
3765 return ret;
3766 }
3767
3768 int btrfs_read_chunk_tree(struct btrfs_root *root)
3769 {
3770 struct btrfs_path *path;
3771 struct extent_buffer *leaf;
3772 struct btrfs_key key;
3773 struct btrfs_key found_key;
3774 int ret;
3775 int slot;
3776
3777 root = root->fs_info->chunk_root;
3778
3779 path = btrfs_alloc_path();
3780 if (!path)
3781 return -ENOMEM;
3782
3783 /* first we search for all of the device items, and then we
3784 * read in all of the chunk items. This way we can create chunk
3785 * mappings that reference all of the devices that are afound
3786 */
3787 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
3788 key.offset = 0;
3789 key.type = 0;
3790 again:
3791 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3792 if (ret < 0)
3793 goto error;
3794 while (1) {
3795 leaf = path->nodes[0];
3796 slot = path->slots[0];
3797 if (slot >= btrfs_header_nritems(leaf)) {
3798 ret = btrfs_next_leaf(root, path);
3799 if (ret == 0)
3800 continue;
3801 if (ret < 0)
3802 goto error;
3803 break;
3804 }
3805 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3806 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
3807 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
3808 break;
3809 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
3810 struct btrfs_dev_item *dev_item;
3811 dev_item = btrfs_item_ptr(leaf, slot,
3812 struct btrfs_dev_item);
3813 ret = read_one_dev(root, leaf, dev_item);
3814 if (ret)
3815 goto error;
3816 }
3817 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
3818 struct btrfs_chunk *chunk;
3819 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
3820 ret = read_one_chunk(root, &found_key, leaf, chunk);
3821 if (ret)
3822 goto error;
3823 }
3824 path->slots[0]++;
3825 }
3826 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
3827 key.objectid = 0;
3828 btrfs_release_path(root, path);
3829 goto again;
3830 }
3831 ret = 0;
3832 error:
3833 btrfs_free_path(path);
3834 return ret;
3835 }
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