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FRV: Use generic show_interrupts()
[cris-mirror.git] / fs / btrfs / volumes.c
blob9d554e8e6583e62a277eaa906ebd8dbe03d0f39f
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 struct map_lookup {
37 u64 type;
38 int io_align;
39 int io_width;
40 int stripe_len;
41 int sector_size;
42 int num_stripes;
43 int sub_stripes;
44 struct btrfs_bio_stripe stripes[];
45 };
46
47 static int init_first_rw_device(struct btrfs_trans_handle *trans,
48 struct btrfs_root *root,
49 struct btrfs_device *device);
50 static int btrfs_relocate_sys_chunks(struct btrfs_root *root);
51
52 #define map_lookup_size(n) (sizeof(struct map_lookup) + \
53 (sizeof(struct btrfs_bio_stripe) * (n)))
54
55 static DEFINE_MUTEX(uuid_mutex);
56 static LIST_HEAD(fs_uuids);
57
58 void btrfs_lock_volumes(void)
59 {
60 mutex_lock(&uuid_mutex);
61 }
62
63 void btrfs_unlock_volumes(void)
64 {
65 mutex_unlock(&uuid_mutex);
66 }
67
68 static void lock_chunks(struct btrfs_root *root)
69 {
70 mutex_lock(&root->fs_info->chunk_mutex);
71 }
72
73 static void unlock_chunks(struct btrfs_root *root)
74 {
75 mutex_unlock(&root->fs_info->chunk_mutex);
76 }
77
78 static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
79 {
80 struct btrfs_device *device;
81 WARN_ON(fs_devices->opened);
82 while (!list_empty(&fs_devices->devices)) {
83 device = list_entry(fs_devices->devices.next,
84 struct btrfs_device, dev_list);
85 list_del(&device->dev_list);
86 kfree(device->name);
87 kfree(device);
88 }
89 kfree(fs_devices);
90 }
91
92 int btrfs_cleanup_fs_uuids(void)
93 {
94 struct btrfs_fs_devices *fs_devices;
95
96 while (!list_empty(&fs_uuids)) {
97 fs_devices = list_entry(fs_uuids.next,
98 struct btrfs_fs_devices, list);
99 list_del(&fs_devices->list);
100 free_fs_devices(fs_devices);
101 }
102 return 0;
103 }
104
105 static noinline struct btrfs_device *__find_device(struct list_head *head,
106 u64 devid, u8 *uuid)
107 {
108 struct btrfs_device *dev;
109
110 list_for_each_entry(dev, head, dev_list) {
111 if (dev->devid == devid &&
112 (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
113 return dev;
114 }
115 }
116 return NULL;
117 }
118
119 static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
120 {
121 struct btrfs_fs_devices *fs_devices;
122
123 list_for_each_entry(fs_devices, &fs_uuids, list) {
124 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
125 return fs_devices;
126 }
127 return NULL;
128 }
129
130 static void requeue_list(struct btrfs_pending_bios *pending_bios,
131 struct bio *head, struct bio *tail)
132 {
133
134 struct bio *old_head;
135
136 old_head = pending_bios->head;
137 pending_bios->head = head;
138 if (pending_bios->tail)
139 tail->bi_next = old_head;
140 else
141 pending_bios->tail = tail;
142 }
143
144 /*
145 * we try to collect pending bios for a device so we don't get a large
146 * number of procs sending bios down to the same device. This greatly
147 * improves the schedulers ability to collect and merge the bios.
148 *
149 * But, it also turns into a long list of bios to process and that is sure
150 * to eventually make the worker thread block. The solution here is to
151 * make some progress and then put this work struct back at the end of
152 * the list if the block device is congested. This way, multiple devices
153 * can make progress from a single worker thread.
154 */
155 static noinline int run_scheduled_bios(struct btrfs_device *device)
156 {
157 struct bio *pending;
158 struct backing_dev_info *bdi;
159 struct btrfs_fs_info *fs_info;
160 struct btrfs_pending_bios *pending_bios;
161 struct bio *tail;
162 struct bio *cur;
163 int again = 0;
164 unsigned long num_run;
165 unsigned long batch_run = 0;
166 unsigned long limit;
167 unsigned long last_waited = 0;
168 int force_reg = 0;
169
170 bdi = blk_get_backing_dev_info(device->bdev);
171 fs_info = device->dev_root->fs_info;
172 limit = btrfs_async_submit_limit(fs_info);
173 limit = limit * 2 / 3;
174
175 loop:
176 spin_lock(&device->io_lock);
177
178 loop_lock:
179 num_run = 0;
180
181 /* take all the bios off the list at once and process them
182 * later on (without the lock held). But, remember the
183 * tail and other pointers so the bios can be properly reinserted
184 * into the list if we hit congestion
185 */
186 if (!force_reg && device->pending_sync_bios.head) {
187 pending_bios = &device->pending_sync_bios;
188 force_reg = 1;
189 } else {
190 pending_bios = &device->pending_bios;
191 force_reg = 0;
192 }
193
194 pending = pending_bios->head;
195 tail = pending_bios->tail;
196 WARN_ON(pending && !tail);
197
198 /*
199 * if pending was null this time around, no bios need processing
200 * at all and we can stop. Otherwise it'll loop back up again
201 * and do an additional check so no bios are missed.
202 *
203 * device->running_pending is used to synchronize with the
204 * schedule_bio code.
205 */
206 if (device->pending_sync_bios.head == NULL &&
207 device->pending_bios.head == NULL) {
208 again = 0;
209 device->running_pending = 0;
210 } else {
211 again = 1;
212 device->running_pending = 1;
213 }
214
215 pending_bios->head = NULL;
216 pending_bios->tail = NULL;
217
218 spin_unlock(&device->io_lock);
219
220 while (pending) {
221
222 rmb();
223 /* we want to work on both lists, but do more bios on the
224 * sync list than the regular list
225 */
226 if ((num_run > 32 &&
227 pending_bios != &device->pending_sync_bios &&
228 device->pending_sync_bios.head) ||
229 (num_run > 64 && pending_bios == &device->pending_sync_bios &&
230 device->pending_bios.head)) {
231 spin_lock(&device->io_lock);
232 requeue_list(pending_bios, pending, tail);
233 goto loop_lock;
234 }
235
236 cur = pending;
237 pending = pending->bi_next;
238 cur->bi_next = NULL;
239 atomic_dec(&fs_info->nr_async_bios);
240
241 if (atomic_read(&fs_info->nr_async_bios) < limit &&
242 waitqueue_active(&fs_info->async_submit_wait))
243 wake_up(&fs_info->async_submit_wait);
244
245 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
246
247 submit_bio(cur->bi_rw, cur);
248 num_run++;
249 batch_run++;
250 if (need_resched())
251 cond_resched();
252
253 /*
254 * we made progress, there is more work to do and the bdi
255 * is now congested. Back off and let other work structs
256 * run instead
257 */
258 if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
259 fs_info->fs_devices->open_devices > 1) {
260 struct io_context *ioc;
261
262 ioc = current->io_context;
263
264 /*
265 * the main goal here is that we don't want to
266 * block if we're going to be able to submit
267 * more requests without blocking.
268 *
269 * This code does two great things, it pokes into
270 * the elevator code from a filesystem _and_
271 * it makes assumptions about how batching works.
272 */
273 if (ioc && ioc->nr_batch_requests > 0 &&
274 time_before(jiffies, ioc->last_waited + HZ/50UL) &&
275 (last_waited == 0 ||
276 ioc->last_waited == last_waited)) {
277 /*
278 * we want to go through our batch of
279 * requests and stop. So, we copy out
280 * the ioc->last_waited time and test
281 * against it before looping
282 */
283 last_waited = ioc->last_waited;
284 if (need_resched())
285 cond_resched();
286 continue;
287 }
288 spin_lock(&device->io_lock);
289 requeue_list(pending_bios, pending, tail);
290 device->running_pending = 1;
291
292 spin_unlock(&device->io_lock);
293 btrfs_requeue_work(&device->work);
294 goto done;
295 }
296 }
297
298 cond_resched();
299 if (again)
300 goto loop;
301
302 spin_lock(&device->io_lock);
303 if (device->pending_bios.head || device->pending_sync_bios.head)
304 goto loop_lock;
305 spin_unlock(&device->io_lock);
306
307 done:
308 return 0;
309 }
310
311 static void pending_bios_fn(struct btrfs_work *work)
312 {
313 struct btrfs_device *device;
314
315 device = container_of(work, struct btrfs_device, work);
316 run_scheduled_bios(device);
317 }
318
319 static noinline int device_list_add(const char *path,
320 struct btrfs_super_block *disk_super,
321 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
322 {
323 struct btrfs_device *device;
324 struct btrfs_fs_devices *fs_devices;
325 u64 found_transid = btrfs_super_generation(disk_super);
326 char *name;
327
328 fs_devices = find_fsid(disk_super->fsid);
329 if (!fs_devices) {
330 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
331 if (!fs_devices)
332 return -ENOMEM;
333 INIT_LIST_HEAD(&fs_devices->devices);
334 INIT_LIST_HEAD(&fs_devices->alloc_list);
335 list_add(&fs_devices->list, &fs_uuids);
336 memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
337 fs_devices->latest_devid = devid;
338 fs_devices->latest_trans = found_transid;
339 mutex_init(&fs_devices->device_list_mutex);
340 device = NULL;
341 } else {
342 device = __find_device(&fs_devices->devices, devid,
343 disk_super->dev_item.uuid);
344 }
345 if (!device) {
346 if (fs_devices->opened)
347 return -EBUSY;
348
349 device = kzalloc(sizeof(*device), GFP_NOFS);
350 if (!device) {
351 /* we can safely leave the fs_devices entry around */
352 return -ENOMEM;
353 }
354 device->devid = devid;
355 device->work.func = pending_bios_fn;
356 memcpy(device->uuid, disk_super->dev_item.uuid,
357 BTRFS_UUID_SIZE);
358 spin_lock_init(&device->io_lock);
359 device->name = kstrdup(path, GFP_NOFS);
360 if (!device->name) {
361 kfree(device);
362 return -ENOMEM;
363 }
364 INIT_LIST_HEAD(&device->dev_alloc_list);
365
366 mutex_lock(&fs_devices->device_list_mutex);
367 list_add(&device->dev_list, &fs_devices->devices);
368 mutex_unlock(&fs_devices->device_list_mutex);
369
370 device->fs_devices = fs_devices;
371 fs_devices->num_devices++;
372 } else if (!device->name || strcmp(device->name, path)) {
373 name = kstrdup(path, GFP_NOFS);
374 if (!name)
375 return -ENOMEM;
376 kfree(device->name);
377 device->name = name;
378 if (device->missing) {
379 fs_devices->missing_devices--;
380 device->missing = 0;
381 }
382 }
383
384 if (found_transid > fs_devices->latest_trans) {
385 fs_devices->latest_devid = devid;
386 fs_devices->latest_trans = found_transid;
387 }
388 *fs_devices_ret = fs_devices;
389 return 0;
390 }
391
392 static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
393 {
394 struct btrfs_fs_devices *fs_devices;
395 struct btrfs_device *device;
396 struct btrfs_device *orig_dev;
397
398 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
399 if (!fs_devices)
400 return ERR_PTR(-ENOMEM);
401
402 INIT_LIST_HEAD(&fs_devices->devices);
403 INIT_LIST_HEAD(&fs_devices->alloc_list);
404 INIT_LIST_HEAD(&fs_devices->list);
405 mutex_init(&fs_devices->device_list_mutex);
406 fs_devices->latest_devid = orig->latest_devid;
407 fs_devices->latest_trans = orig->latest_trans;
408 memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid));
409
410 mutex_lock(&orig->device_list_mutex);
411 list_for_each_entry(orig_dev, &orig->devices, dev_list) {
412 device = kzalloc(sizeof(*device), GFP_NOFS);
413 if (!device)
414 goto error;
415
416 device->name = kstrdup(orig_dev->name, GFP_NOFS);
417 if (!device->name) {
418 kfree(device);
419 goto error;
420 }
421
422 device->devid = orig_dev->devid;
423 device->work.func = pending_bios_fn;
424 memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid));
425 spin_lock_init(&device->io_lock);
426 INIT_LIST_HEAD(&device->dev_list);
427 INIT_LIST_HEAD(&device->dev_alloc_list);
428
429 list_add(&device->dev_list, &fs_devices->devices);
430 device->fs_devices = fs_devices;
431 fs_devices->num_devices++;
432 }
433 mutex_unlock(&orig->device_list_mutex);
434 return fs_devices;
435 error:
436 mutex_unlock(&orig->device_list_mutex);
437 free_fs_devices(fs_devices);
438 return ERR_PTR(-ENOMEM);
439 }
440
441 int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
442 {
443 struct btrfs_device *device, *next;
444
445 mutex_lock(&uuid_mutex);
446 again:
447 mutex_lock(&fs_devices->device_list_mutex);
448 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
449 if (device->in_fs_metadata)
450 continue;
451
452 if (device->bdev) {
453 blkdev_put(device->bdev, device->mode);
454 device->bdev = NULL;
455 fs_devices->open_devices--;
456 }
457 if (device->writeable) {
458 list_del_init(&device->dev_alloc_list);
459 device->writeable = 0;
460 fs_devices->rw_devices--;
461 }
462 list_del_init(&device->dev_list);
463 fs_devices->num_devices--;
464 kfree(device->name);
465 kfree(device);
466 }
467 mutex_unlock(&fs_devices->device_list_mutex);
468
469 if (fs_devices->seed) {
470 fs_devices = fs_devices->seed;
471 goto again;
472 }
473
474 mutex_unlock(&uuid_mutex);
475 return 0;
476 }
477
478 static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
479 {
480 struct btrfs_device *device;
481
482 if (--fs_devices->opened > 0)
483 return 0;
484
485 list_for_each_entry(device, &fs_devices->devices, dev_list) {
486 if (device->bdev) {
487 blkdev_put(device->bdev, device->mode);
488 fs_devices->open_devices--;
489 }
490 if (device->writeable) {
491 list_del_init(&device->dev_alloc_list);
492 fs_devices->rw_devices--;
493 }
494
495 device->bdev = NULL;
496 device->writeable = 0;
497 device->in_fs_metadata = 0;
498 }
499 WARN_ON(fs_devices->open_devices);
500 WARN_ON(fs_devices->rw_devices);
501 fs_devices->opened = 0;
502 fs_devices->seeding = 0;
503
504 return 0;
505 }
506
507 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
508 {
509 struct btrfs_fs_devices *seed_devices = NULL;
510 int ret;
511
512 mutex_lock(&uuid_mutex);
513 ret = __btrfs_close_devices(fs_devices);
514 if (!fs_devices->opened) {
515 seed_devices = fs_devices->seed;
516 fs_devices->seed = NULL;
517 }
518 mutex_unlock(&uuid_mutex);
519
520 while (seed_devices) {
521 fs_devices = seed_devices;
522 seed_devices = fs_devices->seed;
523 __btrfs_close_devices(fs_devices);
524 free_fs_devices(fs_devices);
525 }
526 return ret;
527 }
528
529 static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
530 fmode_t flags, void *holder)
531 {
532 struct block_device *bdev;
533 struct list_head *head = &fs_devices->devices;
534 struct btrfs_device *device;
535 struct block_device *latest_bdev = NULL;
536 struct buffer_head *bh;
537 struct btrfs_super_block *disk_super;
538 u64 latest_devid = 0;
539 u64 latest_transid = 0;
540 u64 devid;
541 int seeding = 1;
542 int ret = 0;
543
544 flags |= FMODE_EXCL;
545
546 list_for_each_entry(device, head, dev_list) {
547 if (device->bdev)
548 continue;
549 if (!device->name)
550 continue;
551
552 bdev = blkdev_get_by_path(device->name, flags, holder);
553 if (IS_ERR(bdev)) {
554 printk(KERN_INFO "open %s failed\n", device->name);
555 goto error;
556 }
557 set_blocksize(bdev, 4096);
558
559 bh = btrfs_read_dev_super(bdev);
560 if (!bh) {
561 ret = -EINVAL;
562 goto error_close;
563 }
564
565 disk_super = (struct btrfs_super_block *)bh->b_data;
566 devid = btrfs_stack_device_id(&disk_super->dev_item);
567 if (devid != device->devid)
568 goto error_brelse;
569
570 if (memcmp(device->uuid, disk_super->dev_item.uuid,
571 BTRFS_UUID_SIZE))
572 goto error_brelse;
573
574 device->generation = btrfs_super_generation(disk_super);
575 if (!latest_transid || device->generation > latest_transid) {
576 latest_devid = devid;
577 latest_transid = device->generation;
578 latest_bdev = bdev;
579 }
580
581 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
582 device->writeable = 0;
583 } else {
584 device->writeable = !bdev_read_only(bdev);
585 seeding = 0;
586 }
587
588 device->bdev = bdev;
589 device->in_fs_metadata = 0;
590 device->mode = flags;
591
592 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
593 fs_devices->rotating = 1;
594
595 fs_devices->open_devices++;
596 if (device->writeable) {
597 fs_devices->rw_devices++;
598 list_add(&device->dev_alloc_list,
599 &fs_devices->alloc_list);
600 }
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 BUG_ON(ret);
954 leaf = path->nodes[0];
955 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
956 extent = btrfs_item_ptr(leaf, path->slots[0],
957 struct btrfs_dev_extent);
958 BUG_ON(found_key.offset > start || found_key.offset +
959 btrfs_dev_extent_length(leaf, extent) < start);
960 ret = 0;
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 BUG_ON(ret);
972
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 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1243 list_for_each_entry(tmp, devices, dev_list) {
1244 if (tmp->in_fs_metadata && !tmp->bdev) {
1245 device = tmp;
1246 break;
1247 }
1248 }
1249 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1250 bdev = NULL;
1251 bh = NULL;
1252 disk_super = NULL;
1253 if (!device) {
1254 printk(KERN_ERR "btrfs: no missing devices found to "
1255 "remove\n");
1256 goto out;
1257 }
1258 } else {
1259 bdev = blkdev_get_by_path(device_path, FMODE_READ | FMODE_EXCL,
1260 root->fs_info->bdev_holder);
1261 if (IS_ERR(bdev)) {
1262 ret = PTR_ERR(bdev);
1263 goto out;
1264 }
1265
1266 set_blocksize(bdev, 4096);
1267 bh = btrfs_read_dev_super(bdev);
1268 if (!bh) {
1269 ret = -EINVAL;
1270 goto error_close;
1271 }
1272 disk_super = (struct btrfs_super_block *)bh->b_data;
1273 devid = btrfs_stack_device_id(&disk_super->dev_item);
1274 dev_uuid = disk_super->dev_item.uuid;
1275 device = btrfs_find_device(root, devid, dev_uuid,
1276 disk_super->fsid);
1277 if (!device) {
1278 ret = -ENOENT;
1279 goto error_brelse;
1280 }
1281 }
1282
1283 if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
1284 printk(KERN_ERR "btrfs: unable to remove the only writeable "
1285 "device\n");
1286 ret = -EINVAL;
1287 goto error_brelse;
1288 }
1289
1290 if (device->writeable) {
1291 list_del_init(&device->dev_alloc_list);
1292 root->fs_info->fs_devices->rw_devices--;
1293 }
1294
1295 ret = btrfs_shrink_device(device, 0);
1296 if (ret)
1297 goto error_undo;
1298
1299 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1300 if (ret)
1301 goto error_undo;
1302
1303 device->in_fs_metadata = 0;
1304
1305 /*
1306 * the device list mutex makes sure that we don't change
1307 * the device list while someone else is writing out all
1308 * the device supers.
1309 */
1310 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1311 list_del_init(&device->dev_list);
1312 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1313
1314 device->fs_devices->num_devices--;
1315
1316 if (device->missing)
1317 root->fs_info->fs_devices->missing_devices--;
1318
1319 next_device = list_entry(root->fs_info->fs_devices->devices.next,
1320 struct btrfs_device, dev_list);
1321 if (device->bdev == root->fs_info->sb->s_bdev)
1322 root->fs_info->sb->s_bdev = next_device->bdev;
1323 if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1324 root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1325
1326 if (device->bdev) {
1327 blkdev_put(device->bdev, device->mode);
1328 device->bdev = NULL;
1329 device->fs_devices->open_devices--;
1330 }
1331
1332 num_devices = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
1333 btrfs_set_super_num_devices(&root->fs_info->super_copy, num_devices);
1334
1335 if (device->fs_devices->open_devices == 0) {
1336 struct btrfs_fs_devices *fs_devices;
1337 fs_devices = root->fs_info->fs_devices;
1338 while (fs_devices) {
1339 if (fs_devices->seed == device->fs_devices)
1340 break;
1341 fs_devices = fs_devices->seed;
1342 }
1343 fs_devices->seed = device->fs_devices->seed;
1344 device->fs_devices->seed = NULL;
1345 __btrfs_close_devices(device->fs_devices);
1346 free_fs_devices(device->fs_devices);
1347 }
1348
1349 /*
1350 * at this point, the device is zero sized. We want to
1351 * remove it from the devices list and zero out the old super
1352 */
1353 if (device->writeable) {
1354 /* make sure this device isn't detected as part of
1355 * the FS anymore
1356 */
1357 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1358 set_buffer_dirty(bh);
1359 sync_dirty_buffer(bh);
1360 }
1361
1362 kfree(device->name);
1363 kfree(device);
1364 ret = 0;
1365
1366 error_brelse:
1367 brelse(bh);
1368 error_close:
1369 if (bdev)
1370 blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
1371 out:
1372 mutex_unlock(&root->fs_info->volume_mutex);
1373 mutex_unlock(&uuid_mutex);
1374 return ret;
1375 error_undo:
1376 if (device->writeable) {
1377 list_add(&device->dev_alloc_list,
1378 &root->fs_info->fs_devices->alloc_list);
1379 root->fs_info->fs_devices->rw_devices++;
1380 }
1381 goto error_brelse;
1382 }
1383
1384 /*
1385 * does all the dirty work required for changing file system's UUID.
1386 */
1387 static int btrfs_prepare_sprout(struct btrfs_trans_handle *trans,
1388 struct btrfs_root *root)
1389 {
1390 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1391 struct btrfs_fs_devices *old_devices;
1392 struct btrfs_fs_devices *seed_devices;
1393 struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
1394 struct btrfs_device *device;
1395 u64 super_flags;
1396
1397 BUG_ON(!mutex_is_locked(&uuid_mutex));
1398 if (!fs_devices->seeding)
1399 return -EINVAL;
1400
1401 seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
1402 if (!seed_devices)
1403 return -ENOMEM;
1404
1405 old_devices = clone_fs_devices(fs_devices);
1406 if (IS_ERR(old_devices)) {
1407 kfree(seed_devices);
1408 return PTR_ERR(old_devices);
1409 }
1410
1411 list_add(&old_devices->list, &fs_uuids);
1412
1413 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1414 seed_devices->opened = 1;
1415 INIT_LIST_HEAD(&seed_devices->devices);
1416 INIT_LIST_HEAD(&seed_devices->alloc_list);
1417 mutex_init(&seed_devices->device_list_mutex);
1418 list_splice_init(&fs_devices->devices, &seed_devices->devices);
1419 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1420 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1421 device->fs_devices = seed_devices;
1422 }
1423
1424 fs_devices->seeding = 0;
1425 fs_devices->num_devices = 0;
1426 fs_devices->open_devices = 0;
1427 fs_devices->seed = seed_devices;
1428
1429 generate_random_uuid(fs_devices->fsid);
1430 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1431 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1432 super_flags = btrfs_super_flags(disk_super) &
1433 ~BTRFS_SUPER_FLAG_SEEDING;
1434 btrfs_set_super_flags(disk_super, super_flags);
1435
1436 return 0;
1437 }
1438
1439 /*
1440 * strore the expected generation for seed devices in device items.
1441 */
1442 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1443 struct btrfs_root *root)
1444 {
1445 struct btrfs_path *path;
1446 struct extent_buffer *leaf;
1447 struct btrfs_dev_item *dev_item;
1448 struct btrfs_device *device;
1449 struct btrfs_key key;
1450 u8 fs_uuid[BTRFS_UUID_SIZE];
1451 u8 dev_uuid[BTRFS_UUID_SIZE];
1452 u64 devid;
1453 int ret;
1454
1455 path = btrfs_alloc_path();
1456 if (!path)
1457 return -ENOMEM;
1458
1459 root = root->fs_info->chunk_root;
1460 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1461 key.offset = 0;
1462 key.type = BTRFS_DEV_ITEM_KEY;
1463
1464 while (1) {
1465 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1466 if (ret < 0)
1467 goto error;
1468
1469 leaf = path->nodes[0];
1470 next_slot:
1471 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1472 ret = btrfs_next_leaf(root, path);
1473 if (ret > 0)
1474 break;
1475 if (ret < 0)
1476 goto error;
1477 leaf = path->nodes[0];
1478 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1479 btrfs_release_path(root, path);
1480 continue;
1481 }
1482
1483 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1484 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1485 key.type != BTRFS_DEV_ITEM_KEY)
1486 break;
1487
1488 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1489 struct btrfs_dev_item);
1490 devid = btrfs_device_id(leaf, dev_item);
1491 read_extent_buffer(leaf, dev_uuid,
1492 (unsigned long)btrfs_device_uuid(dev_item),
1493 BTRFS_UUID_SIZE);
1494 read_extent_buffer(leaf, fs_uuid,
1495 (unsigned long)btrfs_device_fsid(dev_item),
1496 BTRFS_UUID_SIZE);
1497 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
1498 BUG_ON(!device);
1499
1500 if (device->fs_devices->seeding) {
1501 btrfs_set_device_generation(leaf, dev_item,
1502 device->generation);
1503 btrfs_mark_buffer_dirty(leaf);
1504 }
1505
1506 path->slots[0]++;
1507 goto next_slot;
1508 }
1509 ret = 0;
1510 error:
1511 btrfs_free_path(path);
1512 return ret;
1513 }
1514
1515 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1516 {
1517 struct btrfs_trans_handle *trans;
1518 struct btrfs_device *device;
1519 struct block_device *bdev;
1520 struct list_head *devices;
1521 struct super_block *sb = root->fs_info->sb;
1522 u64 total_bytes;
1523 int seeding_dev = 0;
1524 int ret = 0;
1525
1526 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1527 return -EINVAL;
1528
1529 bdev = blkdev_get_by_path(device_path, FMODE_EXCL,
1530 root->fs_info->bdev_holder);
1531 if (IS_ERR(bdev))
1532 return PTR_ERR(bdev);
1533
1534 if (root->fs_info->fs_devices->seeding) {
1535 seeding_dev = 1;
1536 down_write(&sb->s_umount);
1537 mutex_lock(&uuid_mutex);
1538 }
1539
1540 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1541 mutex_lock(&root->fs_info->volume_mutex);
1542
1543 devices = &root->fs_info->fs_devices->devices;
1544 /*
1545 * we have the volume lock, so we don't need the extra
1546 * device list mutex while reading the list here.
1547 */
1548 list_for_each_entry(device, devices, dev_list) {
1549 if (device->bdev == bdev) {
1550 ret = -EEXIST;
1551 goto error;
1552 }
1553 }
1554
1555 device = kzalloc(sizeof(*device), GFP_NOFS);
1556 if (!device) {
1557 /* we can safely leave the fs_devices entry around */
1558 ret = -ENOMEM;
1559 goto error;
1560 }
1561
1562 device->name = kstrdup(device_path, GFP_NOFS);
1563 if (!device->name) {
1564 kfree(device);
1565 ret = -ENOMEM;
1566 goto error;
1567 }
1568
1569 ret = find_next_devid(root, &device->devid);
1570 if (ret) {
1571 kfree(device->name);
1572 kfree(device);
1573 goto error;
1574 }
1575
1576 trans = btrfs_start_transaction(root, 0);
1577 if (IS_ERR(trans)) {
1578 kfree(device->name);
1579 kfree(device);
1580 ret = PTR_ERR(trans);
1581 goto error;
1582 }
1583
1584 lock_chunks(root);
1585
1586 device->writeable = 1;
1587 device->work.func = pending_bios_fn;
1588 generate_random_uuid(device->uuid);
1589 spin_lock_init(&device->io_lock);
1590 device->generation = trans->transid;
1591 device->io_width = root->sectorsize;
1592 device->io_align = root->sectorsize;
1593 device->sector_size = root->sectorsize;
1594 device->total_bytes = i_size_read(bdev->bd_inode);
1595 device->disk_total_bytes = device->total_bytes;
1596 device->dev_root = root->fs_info->dev_root;
1597 device->bdev = bdev;
1598 device->in_fs_metadata = 1;
1599 device->mode = FMODE_EXCL;
1600 set_blocksize(device->bdev, 4096);
1601
1602 if (seeding_dev) {
1603 sb->s_flags &= ~MS_RDONLY;
1604 ret = btrfs_prepare_sprout(trans, root);
1605 BUG_ON(ret);
1606 }
1607
1608 device->fs_devices = root->fs_info->fs_devices;
1609
1610 /*
1611 * we don't want write_supers to jump in here with our device
1612 * half setup
1613 */
1614 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1615 list_add(&device->dev_list, &root->fs_info->fs_devices->devices);
1616 list_add(&device->dev_alloc_list,
1617 &root->fs_info->fs_devices->alloc_list);
1618 root->fs_info->fs_devices->num_devices++;
1619 root->fs_info->fs_devices->open_devices++;
1620 root->fs_info->fs_devices->rw_devices++;
1621 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
1622
1623 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
1624 root->fs_info->fs_devices->rotating = 1;
1625
1626 total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
1627 btrfs_set_super_total_bytes(&root->fs_info->super_copy,
1628 total_bytes + device->total_bytes);
1629
1630 total_bytes = btrfs_super_num_devices(&root->fs_info->super_copy);
1631 btrfs_set_super_num_devices(&root->fs_info->super_copy,
1632 total_bytes + 1);
1633 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1634
1635 if (seeding_dev) {
1636 ret = init_first_rw_device(trans, root, device);
1637 BUG_ON(ret);
1638 ret = btrfs_finish_sprout(trans, root);
1639 BUG_ON(ret);
1640 } else {
1641 ret = btrfs_add_device(trans, root, device);
1642 }
1643
1644 /*
1645 * we've got more storage, clear any full flags on the space
1646 * infos
1647 */
1648 btrfs_clear_space_info_full(root->fs_info);
1649
1650 unlock_chunks(root);
1651 btrfs_commit_transaction(trans, root);
1652
1653 if (seeding_dev) {
1654 mutex_unlock(&uuid_mutex);
1655 up_write(&sb->s_umount);
1656
1657 ret = btrfs_relocate_sys_chunks(root);
1658 BUG_ON(ret);
1659 }
1660 out:
1661 mutex_unlock(&root->fs_info->volume_mutex);
1662 return ret;
1663 error:
1664 blkdev_put(bdev, FMODE_EXCL);
1665 if (seeding_dev) {
1666 mutex_unlock(&uuid_mutex);
1667 up_write(&sb->s_umount);
1668 }
1669 goto out;
1670 }
1671
1672 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
1673 struct btrfs_device *device)
1674 {
1675 int ret;
1676 struct btrfs_path *path;
1677 struct btrfs_root *root;
1678 struct btrfs_dev_item *dev_item;
1679 struct extent_buffer *leaf;
1680 struct btrfs_key key;
1681
1682 root = device->dev_root->fs_info->chunk_root;
1683
1684 path = btrfs_alloc_path();
1685 if (!path)
1686 return -ENOMEM;
1687
1688 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1689 key.type = BTRFS_DEV_ITEM_KEY;
1690 key.offset = device->devid;
1691
1692 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1693 if (ret < 0)
1694 goto out;
1695
1696 if (ret > 0) {
1697 ret = -ENOENT;
1698 goto out;
1699 }
1700
1701 leaf = path->nodes[0];
1702 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1703
1704 btrfs_set_device_id(leaf, dev_item, device->devid);
1705 btrfs_set_device_type(leaf, dev_item, device->type);
1706 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1707 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1708 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1709 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
1710 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1711 btrfs_mark_buffer_dirty(leaf);
1712
1713 out:
1714 btrfs_free_path(path);
1715 return ret;
1716 }
1717
1718 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
1719 struct btrfs_device *device, u64 new_size)
1720 {
1721 struct btrfs_super_block *super_copy =
1722 &device->dev_root->fs_info->super_copy;
1723 u64 old_total = btrfs_super_total_bytes(super_copy);
1724 u64 diff = new_size - device->total_bytes;
1725
1726 if (!device->writeable)
1727 return -EACCES;
1728 if (new_size <= device->total_bytes)
1729 return -EINVAL;
1730
1731 btrfs_set_super_total_bytes(super_copy, old_total + diff);
1732 device->fs_devices->total_rw_bytes += diff;
1733
1734 device->total_bytes = new_size;
1735 device->disk_total_bytes = new_size;
1736 btrfs_clear_space_info_full(device->dev_root->fs_info);
1737
1738 return btrfs_update_device(trans, device);
1739 }
1740
1741 int btrfs_grow_device(struct btrfs_trans_handle *trans,
1742 struct btrfs_device *device, u64 new_size)
1743 {
1744 int ret;
1745 lock_chunks(device->dev_root);
1746 ret = __btrfs_grow_device(trans, device, new_size);
1747 unlock_chunks(device->dev_root);
1748 return ret;
1749 }
1750
1751 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
1752 struct btrfs_root *root,
1753 u64 chunk_tree, u64 chunk_objectid,
1754 u64 chunk_offset)
1755 {
1756 int ret;
1757 struct btrfs_path *path;
1758 struct btrfs_key key;
1759
1760 root = root->fs_info->chunk_root;
1761 path = btrfs_alloc_path();
1762 if (!path)
1763 return -ENOMEM;
1764
1765 key.objectid = chunk_objectid;
1766 key.offset = chunk_offset;
1767 key.type = BTRFS_CHUNK_ITEM_KEY;
1768
1769 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1770 BUG_ON(ret);
1771
1772 ret = btrfs_del_item(trans, root, path);
1773 BUG_ON(ret);
1774
1775 btrfs_free_path(path);
1776 return 0;
1777 }
1778
1779 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
1780 chunk_offset)
1781 {
1782 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
1783 struct btrfs_disk_key *disk_key;
1784 struct btrfs_chunk *chunk;
1785 u8 *ptr;
1786 int ret = 0;
1787 u32 num_stripes;
1788 u32 array_size;
1789 u32 len = 0;
1790 u32 cur;
1791 struct btrfs_key key;
1792
1793 array_size = btrfs_super_sys_array_size(super_copy);
1794
1795 ptr = super_copy->sys_chunk_array;
1796 cur = 0;
1797
1798 while (cur < array_size) {
1799 disk_key = (struct btrfs_disk_key *)ptr;
1800 btrfs_disk_key_to_cpu(&key, disk_key);
1801
1802 len = sizeof(*disk_key);
1803
1804 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
1805 chunk = (struct btrfs_chunk *)(ptr + len);
1806 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
1807 len += btrfs_chunk_item_size(num_stripes);
1808 } else {
1809 ret = -EIO;
1810 break;
1811 }
1812 if (key.objectid == chunk_objectid &&
1813 key.offset == chunk_offset) {
1814 memmove(ptr, ptr + len, array_size - (cur + len));
1815 array_size -= len;
1816 btrfs_set_super_sys_array_size(super_copy, array_size);
1817 } else {
1818 ptr += len;
1819 cur += len;
1820 }
1821 }
1822 return ret;
1823 }
1824
1825 static int btrfs_relocate_chunk(struct btrfs_root *root,
1826 u64 chunk_tree, u64 chunk_objectid,
1827 u64 chunk_offset)
1828 {
1829 struct extent_map_tree *em_tree;
1830 struct btrfs_root *extent_root;
1831 struct btrfs_trans_handle *trans;
1832 struct extent_map *em;
1833 struct map_lookup *map;
1834 int ret;
1835 int i;
1836
1837 root = root->fs_info->chunk_root;
1838 extent_root = root->fs_info->extent_root;
1839 em_tree = &root->fs_info->mapping_tree.map_tree;
1840
1841 ret = btrfs_can_relocate(extent_root, chunk_offset);
1842 if (ret)
1843 return -ENOSPC;
1844
1845 /* step one, relocate all the extents inside this chunk */
1846 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
1847 if (ret)
1848 return ret;
1849
1850 trans = btrfs_start_transaction(root, 0);
1851 BUG_ON(IS_ERR(trans));
1852
1853 lock_chunks(root);
1854
1855 /*
1856 * step two, delete the device extents and the
1857 * chunk tree entries
1858 */
1859 read_lock(&em_tree->lock);
1860 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
1861 read_unlock(&em_tree->lock);
1862
1863 BUG_ON(em->start > chunk_offset ||
1864 em->start + em->len < chunk_offset);
1865 map = (struct map_lookup *)em->bdev;
1866
1867 for (i = 0; i < map->num_stripes; i++) {
1868 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
1869 map->stripes[i].physical);
1870 BUG_ON(ret);
1871
1872 if (map->stripes[i].dev) {
1873 ret = btrfs_update_device(trans, map->stripes[i].dev);
1874 BUG_ON(ret);
1875 }
1876 }
1877 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
1878 chunk_offset);
1879
1880 BUG_ON(ret);
1881
1882 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
1883 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
1884 BUG_ON(ret);
1885 }
1886
1887 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
1888 BUG_ON(ret);
1889
1890 write_lock(&em_tree->lock);
1891 remove_extent_mapping(em_tree, em);
1892 write_unlock(&em_tree->lock);
1893
1894 kfree(map);
1895 em->bdev = NULL;
1896
1897 /* once for the tree */
1898 free_extent_map(em);
1899 /* once for us */
1900 free_extent_map(em);
1901
1902 unlock_chunks(root);
1903 btrfs_end_transaction(trans, root);
1904 return 0;
1905 }
1906
1907 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
1908 {
1909 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
1910 struct btrfs_path *path;
1911 struct extent_buffer *leaf;
1912 struct btrfs_chunk *chunk;
1913 struct btrfs_key key;
1914 struct btrfs_key found_key;
1915 u64 chunk_tree = chunk_root->root_key.objectid;
1916 u64 chunk_type;
1917 bool retried = false;
1918 int failed = 0;
1919 int ret;
1920
1921 path = btrfs_alloc_path();
1922 if (!path)
1923 return -ENOMEM;
1924
1925 again:
1926 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
1927 key.offset = (u64)-1;
1928 key.type = BTRFS_CHUNK_ITEM_KEY;
1929
1930 while (1) {
1931 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
1932 if (ret < 0)
1933 goto error;
1934 BUG_ON(ret == 0);
1935
1936 ret = btrfs_previous_item(chunk_root, path, key.objectid,
1937 key.type);
1938 if (ret < 0)
1939 goto error;
1940 if (ret > 0)
1941 break;
1942
1943 leaf = path->nodes[0];
1944 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1945
1946 chunk = btrfs_item_ptr(leaf, path->slots[0],
1947 struct btrfs_chunk);
1948 chunk_type = btrfs_chunk_type(leaf, chunk);
1949 btrfs_release_path(chunk_root, path);
1950
1951 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
1952 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
1953 found_key.objectid,
1954 found_key.offset);
1955 if (ret == -ENOSPC)
1956 failed++;
1957 else if (ret)
1958 BUG();
1959 }
1960
1961 if (found_key.offset == 0)
1962 break;
1963 key.offset = found_key.offset - 1;
1964 }
1965 ret = 0;
1966 if (failed && !retried) {
1967 failed = 0;
1968 retried = true;
1969 goto again;
1970 } else if (failed && retried) {
1971 WARN_ON(1);
1972 ret = -ENOSPC;
1973 }
1974 error:
1975 btrfs_free_path(path);
1976 return ret;
1977 }
1978
1979 static u64 div_factor(u64 num, int factor)
1980 {
1981 if (factor == 10)
1982 return num;
1983 num *= factor;
1984 do_div(num, 10);
1985 return num;
1986 }
1987
1988 int btrfs_balance(struct btrfs_root *dev_root)
1989 {
1990 int ret;
1991 struct list_head *devices = &dev_root->fs_info->fs_devices->devices;
1992 struct btrfs_device *device;
1993 u64 old_size;
1994 u64 size_to_free;
1995 struct btrfs_path *path;
1996 struct btrfs_key key;
1997 struct btrfs_root *chunk_root = dev_root->fs_info->chunk_root;
1998 struct btrfs_trans_handle *trans;
1999 struct btrfs_key found_key;
2000
2001 if (dev_root->fs_info->sb->s_flags & MS_RDONLY)
2002 return -EROFS;
2003
2004 if (!capable(CAP_SYS_ADMIN))
2005 return -EPERM;
2006
2007 mutex_lock(&dev_root->fs_info->volume_mutex);
2008 dev_root = dev_root->fs_info->dev_root;
2009
2010 /* step one make some room on all the devices */
2011 list_for_each_entry(device, devices, dev_list) {
2012 old_size = device->total_bytes;
2013 size_to_free = div_factor(old_size, 1);
2014 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
2015 if (!device->writeable ||
2016 device->total_bytes - device->bytes_used > size_to_free)
2017 continue;
2018
2019 ret = btrfs_shrink_device(device, old_size - size_to_free);
2020 if (ret == -ENOSPC)
2021 break;
2022 BUG_ON(ret);
2023
2024 trans = btrfs_start_transaction(dev_root, 0);
2025 BUG_ON(IS_ERR(trans));
2026
2027 ret = btrfs_grow_device(trans, device, old_size);
2028 BUG_ON(ret);
2029
2030 btrfs_end_transaction(trans, dev_root);
2031 }
2032
2033 /* step two, relocate all the chunks */
2034 path = btrfs_alloc_path();
2035 BUG_ON(!path);
2036
2037 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2038 key.offset = (u64)-1;
2039 key.type = BTRFS_CHUNK_ITEM_KEY;
2040
2041 while (1) {
2042 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2043 if (ret < 0)
2044 goto error;
2045
2046 /*
2047 * this shouldn't happen, it means the last relocate
2048 * failed
2049 */
2050 if (ret == 0)
2051 break;
2052
2053 ret = btrfs_previous_item(chunk_root, path, 0,
2054 BTRFS_CHUNK_ITEM_KEY);
2055 if (ret)
2056 break;
2057
2058 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2059 path->slots[0]);
2060 if (found_key.objectid != key.objectid)
2061 break;
2062
2063 /* chunk zero is special */
2064 if (found_key.offset == 0)
2065 break;
2066
2067 btrfs_release_path(chunk_root, path);
2068 ret = btrfs_relocate_chunk(chunk_root,
2069 chunk_root->root_key.objectid,
2070 found_key.objectid,
2071 found_key.offset);
2072 BUG_ON(ret && ret != -ENOSPC);
2073 key.offset = found_key.offset - 1;
2074 }
2075 ret = 0;
2076 error:
2077 btrfs_free_path(path);
2078 mutex_unlock(&dev_root->fs_info->volume_mutex);
2079 return ret;
2080 }
2081
2082 /*
2083 * shrinking a device means finding all of the device extents past
2084 * the new size, and then following the back refs to the chunks.
2085 * The chunk relocation code actually frees the device extent
2086 */
2087 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
2088 {
2089 struct btrfs_trans_handle *trans;
2090 struct btrfs_root *root = device->dev_root;
2091 struct btrfs_dev_extent *dev_extent = NULL;
2092 struct btrfs_path *path;
2093 u64 length;
2094 u64 chunk_tree;
2095 u64 chunk_objectid;
2096 u64 chunk_offset;
2097 int ret;
2098 int slot;
2099 int failed = 0;
2100 bool retried = false;
2101 struct extent_buffer *l;
2102 struct btrfs_key key;
2103 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
2104 u64 old_total = btrfs_super_total_bytes(super_copy);
2105 u64 old_size = device->total_bytes;
2106 u64 diff = device->total_bytes - new_size;
2107
2108 if (new_size >= device->total_bytes)
2109 return -EINVAL;
2110
2111 path = btrfs_alloc_path();
2112 if (!path)
2113 return -ENOMEM;
2114
2115 path->reada = 2;
2116
2117 lock_chunks(root);
2118
2119 device->total_bytes = new_size;
2120 if (device->writeable)
2121 device->fs_devices->total_rw_bytes -= diff;
2122 unlock_chunks(root);
2123
2124 again:
2125 key.objectid = device->devid;
2126 key.offset = (u64)-1;
2127 key.type = BTRFS_DEV_EXTENT_KEY;
2128
2129 while (1) {
2130 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2131 if (ret < 0)
2132 goto done;
2133
2134 ret = btrfs_previous_item(root, path, 0, key.type);
2135 if (ret < 0)
2136 goto done;
2137 if (ret) {
2138 ret = 0;
2139 btrfs_release_path(root, path);
2140 break;
2141 }
2142
2143 l = path->nodes[0];
2144 slot = path->slots[0];
2145 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
2146
2147 if (key.objectid != device->devid) {
2148 btrfs_release_path(root, path);
2149 break;
2150 }
2151
2152 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
2153 length = btrfs_dev_extent_length(l, dev_extent);
2154
2155 if (key.offset + length <= new_size) {
2156 btrfs_release_path(root, path);
2157 break;
2158 }
2159
2160 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
2161 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
2162 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
2163 btrfs_release_path(root, path);
2164
2165 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
2166 chunk_offset);
2167 if (ret && ret != -ENOSPC)
2168 goto done;
2169 if (ret == -ENOSPC)
2170 failed++;
2171 key.offset -= 1;
2172 }
2173
2174 if (failed && !retried) {
2175 failed = 0;
2176 retried = true;
2177 goto again;
2178 } else if (failed && retried) {
2179 ret = -ENOSPC;
2180 lock_chunks(root);
2181
2182 device->total_bytes = old_size;
2183 if (device->writeable)
2184 device->fs_devices->total_rw_bytes += diff;
2185 unlock_chunks(root);
2186 goto done;
2187 }
2188
2189 /* Shrinking succeeded, else we would be at "done". */
2190 trans = btrfs_start_transaction(root, 0);
2191 if (IS_ERR(trans)) {
2192 ret = PTR_ERR(trans);
2193 goto done;
2194 }
2195
2196 lock_chunks(root);
2197
2198 device->disk_total_bytes = new_size;
2199 /* Now btrfs_update_device() will change the on-disk size. */
2200 ret = btrfs_update_device(trans, device);
2201 if (ret) {
2202 unlock_chunks(root);
2203 btrfs_end_transaction(trans, root);
2204 goto done;
2205 }
2206 WARN_ON(diff > old_total);
2207 btrfs_set_super_total_bytes(super_copy, old_total - diff);
2208 unlock_chunks(root);
2209 btrfs_end_transaction(trans, root);
2210 done:
2211 btrfs_free_path(path);
2212 return ret;
2213 }
2214
2215 static int btrfs_add_system_chunk(struct btrfs_trans_handle *trans,
2216 struct btrfs_root *root,
2217 struct btrfs_key *key,
2218 struct btrfs_chunk *chunk, int item_size)
2219 {
2220 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
2221 struct btrfs_disk_key disk_key;
2222 u32 array_size;
2223 u8 *ptr;
2224
2225 array_size = btrfs_super_sys_array_size(super_copy);
2226 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
2227 return -EFBIG;
2228
2229 ptr = super_copy->sys_chunk_array + array_size;
2230 btrfs_cpu_key_to_disk(&disk_key, key);
2231 memcpy(ptr, &disk_key, sizeof(disk_key));
2232 ptr += sizeof(disk_key);
2233 memcpy(ptr, chunk, item_size);
2234 item_size += sizeof(disk_key);
2235 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
2236 return 0;
2237 }
2238
2239 static noinline u64 chunk_bytes_by_type(u64 type, u64 calc_size,
2240 int num_stripes, int sub_stripes)
2241 {
2242 if (type & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_DUP))
2243 return calc_size;
2244 else if (type & BTRFS_BLOCK_GROUP_RAID10)
2245 return calc_size * (num_stripes / sub_stripes);
2246 else
2247 return calc_size * num_stripes;
2248 }
2249
2250 /* Used to sort the devices by max_avail(descending sort) */
2251 int btrfs_cmp_device_free_bytes(const void *dev_info1, const void *dev_info2)
2252 {
2253 if (((struct btrfs_device_info *)dev_info1)->max_avail >
2254 ((struct btrfs_device_info *)dev_info2)->max_avail)
2255 return -1;
2256 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
2257 ((struct btrfs_device_info *)dev_info2)->max_avail)
2258 return 1;
2259 else
2260 return 0;
2261 }
2262
2263 static int __btrfs_calc_nstripes(struct btrfs_fs_devices *fs_devices, u64 type,
2264 int *num_stripes, int *min_stripes,
2265 int *sub_stripes)
2266 {
2267 *num_stripes = 1;
2268 *min_stripes = 1;
2269 *sub_stripes = 0;
2270
2271 if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
2272 *num_stripes = fs_devices->rw_devices;
2273 *min_stripes = 2;
2274 }
2275 if (type & (BTRFS_BLOCK_GROUP_DUP)) {
2276 *num_stripes = 2;
2277 *min_stripes = 2;
2278 }
2279 if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
2280 if (fs_devices->rw_devices < 2)
2281 return -ENOSPC;
2282 *num_stripes = 2;
2283 *min_stripes = 2;
2284 }
2285 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
2286 *num_stripes = fs_devices->rw_devices;
2287 if (*num_stripes < 4)
2288 return -ENOSPC;
2289 *num_stripes &= ~(u32)1;
2290 *sub_stripes = 2;
2291 *min_stripes = 4;
2292 }
2293
2294 return 0;
2295 }
2296
2297 static u64 __btrfs_calc_stripe_size(struct btrfs_fs_devices *fs_devices,
2298 u64 proposed_size, u64 type,
2299 int num_stripes, int small_stripe)
2300 {
2301 int min_stripe_size = 1 * 1024 * 1024;
2302 u64 calc_size = proposed_size;
2303 u64 max_chunk_size = calc_size;
2304 int ncopies = 1;
2305
2306 if (type & (BTRFS_BLOCK_GROUP_RAID1 |
2307 BTRFS_BLOCK_GROUP_DUP |
2308 BTRFS_BLOCK_GROUP_RAID10))
2309 ncopies = 2;
2310
2311 if (type & BTRFS_BLOCK_GROUP_DATA) {
2312 max_chunk_size = 10 * calc_size;
2313 min_stripe_size = 64 * 1024 * 1024;
2314 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
2315 max_chunk_size = 256 * 1024 * 1024;
2316 min_stripe_size = 32 * 1024 * 1024;
2317 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
2318 calc_size = 8 * 1024 * 1024;
2319 max_chunk_size = calc_size * 2;
2320 min_stripe_size = 1 * 1024 * 1024;
2321 }
2322
2323 /* we don't want a chunk larger than 10% of writeable space */
2324 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
2325 max_chunk_size);
2326
2327 if (calc_size * num_stripes > max_chunk_size * ncopies) {
2328 calc_size = max_chunk_size * ncopies;
2329 do_div(calc_size, num_stripes);
2330 do_div(calc_size, BTRFS_STRIPE_LEN);
2331 calc_size *= BTRFS_STRIPE_LEN;
2332 }
2333
2334 /* we don't want tiny stripes */
2335 if (!small_stripe)
2336 calc_size = max_t(u64, min_stripe_size, calc_size);
2337
2338 /*
2339 * we're about to do_div by the BTRFS_STRIPE_LEN so lets make sure
2340 * we end up with something bigger than a stripe
2341 */
2342 calc_size = max_t(u64, calc_size, BTRFS_STRIPE_LEN);
2343
2344 do_div(calc_size, BTRFS_STRIPE_LEN);
2345 calc_size *= BTRFS_STRIPE_LEN;
2346
2347 return calc_size;
2348 }
2349
2350 static struct map_lookup *__shrink_map_lookup_stripes(struct map_lookup *map,
2351 int num_stripes)
2352 {
2353 struct map_lookup *new;
2354 size_t len = map_lookup_size(num_stripes);
2355
2356 BUG_ON(map->num_stripes < num_stripes);
2357
2358 if (map->num_stripes == num_stripes)
2359 return map;
2360
2361 new = kmalloc(len, GFP_NOFS);
2362 if (!new) {
2363 /* just change map->num_stripes */
2364 map->num_stripes = num_stripes;
2365 return map;
2366 }
2367
2368 memcpy(new, map, len);
2369 new->num_stripes = num_stripes;
2370 kfree(map);
2371 return new;
2372 }
2373
2374 /*
2375 * helper to allocate device space from btrfs_device_info, in which we stored
2376 * max free space information of every device. It is used when we can not
2377 * allocate chunks by default size.
2378 *
2379 * By this helper, we can allocate a new chunk as larger as possible.
2380 */
2381 static int __btrfs_alloc_tiny_space(struct btrfs_trans_handle *trans,
2382 struct btrfs_fs_devices *fs_devices,
2383 struct btrfs_device_info *devices,
2384 int nr_device, u64 type,
2385 struct map_lookup **map_lookup,
2386 int min_stripes, u64 *stripe_size)
2387 {
2388 int i, index, sort_again = 0;
2389 int min_devices = min_stripes;
2390 u64 max_avail, min_free;
2391 struct map_lookup *map = *map_lookup;
2392 int ret;
2393
2394 if (nr_device < min_stripes)
2395 return -ENOSPC;
2396
2397 btrfs_descending_sort_devices(devices, nr_device);
2398
2399 max_avail = devices[0].max_avail;
2400 if (!max_avail)
2401 return -ENOSPC;
2402
2403 for (i = 0; i < nr_device; i++) {
2404 /*
2405 * if dev_offset = 0, it means the free space of this device
2406 * is less than what we need, and we didn't search max avail
2407 * extent on this device, so do it now.
2408 */
2409 if (!devices[i].dev_offset) {
2410 ret = find_free_dev_extent(trans, devices[i].dev,
2411 max_avail,
2412 &devices[i].dev_offset,
2413 &devices[i].max_avail);
2414 if (ret != 0 && ret != -ENOSPC)
2415 return ret;
2416 sort_again = 1;
2417 }
2418 }
2419
2420 /* we update the max avail free extent of each devices, sort again */
2421 if (sort_again)
2422 btrfs_descending_sort_devices(devices, nr_device);
2423
2424 if (type & BTRFS_BLOCK_GROUP_DUP)
2425 min_devices = 1;
2426
2427 if (!devices[min_devices - 1].max_avail)
2428 return -ENOSPC;
2429
2430 max_avail = devices[min_devices - 1].max_avail;
2431 if (type & BTRFS_BLOCK_GROUP_DUP)
2432 do_div(max_avail, 2);
2433
2434 max_avail = __btrfs_calc_stripe_size(fs_devices, max_avail, type,
2435 min_stripes, 1);
2436 if (type & BTRFS_BLOCK_GROUP_DUP)
2437 min_free = max_avail * 2;
2438 else
2439 min_free = max_avail;
2440
2441 if (min_free > devices[min_devices - 1].max_avail)
2442 return -ENOSPC;
2443
2444 map = __shrink_map_lookup_stripes(map, min_stripes);
2445 *stripe_size = max_avail;
2446
2447 index = 0;
2448 for (i = 0; i < min_stripes; i++) {
2449 map->stripes[i].dev = devices[index].dev;
2450 map->stripes[i].physical = devices[index].dev_offset;
2451 if (type & BTRFS_BLOCK_GROUP_DUP) {
2452 i++;
2453 map->stripes[i].dev = devices[index].dev;
2454 map->stripes[i].physical = devices[index].dev_offset +
2455 max_avail;
2456 }
2457 index++;
2458 }
2459 *map_lookup = map;
2460
2461 return 0;
2462 }
2463
2464 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
2465 struct btrfs_root *extent_root,
2466 struct map_lookup **map_ret,
2467 u64 *num_bytes, u64 *stripe_size,
2468 u64 start, u64 type)
2469 {
2470 struct btrfs_fs_info *info = extent_root->fs_info;
2471 struct btrfs_device *device = NULL;
2472 struct btrfs_fs_devices *fs_devices = info->fs_devices;
2473 struct list_head *cur;
2474 struct map_lookup *map;
2475 struct extent_map_tree *em_tree;
2476 struct extent_map *em;
2477 struct btrfs_device_info *devices_info;
2478 struct list_head private_devs;
2479 u64 calc_size = 1024 * 1024 * 1024;
2480 u64 min_free;
2481 u64 avail;
2482 u64 dev_offset;
2483 int num_stripes;
2484 int min_stripes;
2485 int sub_stripes;
2486 int min_devices; /* the min number of devices we need */
2487 int i;
2488 int ret;
2489 int index;
2490
2491 if ((type & BTRFS_BLOCK_GROUP_RAID1) &&
2492 (type & BTRFS_BLOCK_GROUP_DUP)) {
2493 WARN_ON(1);
2494 type &= ~BTRFS_BLOCK_GROUP_DUP;
2495 }
2496 if (list_empty(&fs_devices->alloc_list))
2497 return -ENOSPC;
2498
2499 ret = __btrfs_calc_nstripes(fs_devices, type, &num_stripes,
2500 &min_stripes, &sub_stripes);
2501 if (ret)
2502 return ret;
2503
2504 devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices,
2505 GFP_NOFS);
2506 if (!devices_info)
2507 return -ENOMEM;
2508
2509 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
2510 if (!map) {
2511 ret = -ENOMEM;
2512 goto error;
2513 }
2514 map->num_stripes = num_stripes;
2515
2516 cur = fs_devices->alloc_list.next;
2517 index = 0;
2518 i = 0;
2519
2520 calc_size = __btrfs_calc_stripe_size(fs_devices, calc_size, type,
2521 num_stripes, 0);
2522
2523 if (type & BTRFS_BLOCK_GROUP_DUP) {
2524 min_free = calc_size * 2;
2525 min_devices = 1;
2526 } else {
2527 min_free = calc_size;
2528 min_devices = min_stripes;
2529 }
2530
2531 INIT_LIST_HEAD(&private_devs);
2532 while (index < num_stripes) {
2533 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
2534 BUG_ON(!device->writeable);
2535 if (device->total_bytes > device->bytes_used)
2536 avail = device->total_bytes - device->bytes_used;
2537 else
2538 avail = 0;
2539 cur = cur->next;
2540
2541 if (device->in_fs_metadata && avail >= min_free) {
2542 ret = find_free_dev_extent(trans, device, min_free,
2543 &devices_info[i].dev_offset,
2544 &devices_info[i].max_avail);
2545 if (ret == 0) {
2546 list_move_tail(&device->dev_alloc_list,
2547 &private_devs);
2548 map->stripes[index].dev = device;
2549 map->stripes[index].physical =
2550 devices_info[i].dev_offset;
2551 index++;
2552 if (type & BTRFS_BLOCK_GROUP_DUP) {
2553 map->stripes[index].dev = device;
2554 map->stripes[index].physical =
2555 devices_info[i].dev_offset +
2556 calc_size;
2557 index++;
2558 }
2559 } else if (ret != -ENOSPC)
2560 goto error;
2561
2562 devices_info[i].dev = device;
2563 i++;
2564 } else if (device->in_fs_metadata &&
2565 avail >= BTRFS_STRIPE_LEN) {
2566 devices_info[i].dev = device;
2567 devices_info[i].max_avail = avail;
2568 i++;
2569 }
2570
2571 if (cur == &fs_devices->alloc_list)
2572 break;
2573 }
2574
2575 list_splice(&private_devs, &fs_devices->alloc_list);
2576 if (index < num_stripes) {
2577 if (index >= min_stripes) {
2578 num_stripes = index;
2579 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
2580 num_stripes /= sub_stripes;
2581 num_stripes *= sub_stripes;
2582 }
2583
2584 map = __shrink_map_lookup_stripes(map, num_stripes);
2585 } else if (i >= min_devices) {
2586 ret = __btrfs_alloc_tiny_space(trans, fs_devices,
2587 devices_info, i, type,
2588 &map, min_stripes,
2589 &calc_size);
2590 if (ret)
2591 goto error;
2592 } else {
2593 ret = -ENOSPC;
2594 goto error;
2595 }
2596 }
2597 map->sector_size = extent_root->sectorsize;
2598 map->stripe_len = BTRFS_STRIPE_LEN;
2599 map->io_align = BTRFS_STRIPE_LEN;
2600 map->io_width = BTRFS_STRIPE_LEN;
2601 map->type = type;
2602 map->sub_stripes = sub_stripes;
2603
2604 *map_ret = map;
2605 *stripe_size = calc_size;
2606 *num_bytes = chunk_bytes_by_type(type, calc_size,
2607 map->num_stripes, sub_stripes);
2608
2609 em = alloc_extent_map(GFP_NOFS);
2610 if (!em) {
2611 ret = -ENOMEM;
2612 goto error;
2613 }
2614 em->bdev = (struct block_device *)map;
2615 em->start = start;
2616 em->len = *num_bytes;
2617 em->block_start = 0;
2618 em->block_len = em->len;
2619
2620 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
2621 write_lock(&em_tree->lock);
2622 ret = add_extent_mapping(em_tree, em);
2623 write_unlock(&em_tree->lock);
2624 BUG_ON(ret);
2625 free_extent_map(em);
2626
2627 ret = btrfs_make_block_group(trans, extent_root, 0, type,
2628 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2629 start, *num_bytes);
2630 BUG_ON(ret);
2631
2632 index = 0;
2633 while (index < map->num_stripes) {
2634 device = map->stripes[index].dev;
2635 dev_offset = map->stripes[index].physical;
2636
2637 ret = btrfs_alloc_dev_extent(trans, device,
2638 info->chunk_root->root_key.objectid,
2639 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2640 start, dev_offset, calc_size);
2641 BUG_ON(ret);
2642 index++;
2643 }
2644
2645 kfree(devices_info);
2646 return 0;
2647
2648 error:
2649 kfree(map);
2650 kfree(devices_info);
2651 return ret;
2652 }
2653
2654 static int __finish_chunk_alloc(struct btrfs_trans_handle *trans,
2655 struct btrfs_root *extent_root,
2656 struct map_lookup *map, u64 chunk_offset,
2657 u64 chunk_size, u64 stripe_size)
2658 {
2659 u64 dev_offset;
2660 struct btrfs_key key;
2661 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
2662 struct btrfs_device *device;
2663 struct btrfs_chunk *chunk;
2664 struct btrfs_stripe *stripe;
2665 size_t item_size = btrfs_chunk_item_size(map->num_stripes);
2666 int index = 0;
2667 int ret;
2668
2669 chunk = kzalloc(item_size, GFP_NOFS);
2670 if (!chunk)
2671 return -ENOMEM;
2672
2673 index = 0;
2674 while (index < map->num_stripes) {
2675 device = map->stripes[index].dev;
2676 device->bytes_used += stripe_size;
2677 ret = btrfs_update_device(trans, device);
2678 BUG_ON(ret);
2679 index++;
2680 }
2681
2682 index = 0;
2683 stripe = &chunk->stripe;
2684 while (index < map->num_stripes) {
2685 device = map->stripes[index].dev;
2686 dev_offset = map->stripes[index].physical;
2687
2688 btrfs_set_stack_stripe_devid(stripe, device->devid);
2689 btrfs_set_stack_stripe_offset(stripe, dev_offset);
2690 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
2691 stripe++;
2692 index++;
2693 }
2694
2695 btrfs_set_stack_chunk_length(chunk, chunk_size);
2696 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
2697 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
2698 btrfs_set_stack_chunk_type(chunk, map->type);
2699 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
2700 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
2701 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
2702 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
2703 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
2704
2705 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2706 key.type = BTRFS_CHUNK_ITEM_KEY;
2707 key.offset = chunk_offset;
2708
2709 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
2710 BUG_ON(ret);
2711
2712 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2713 ret = btrfs_add_system_chunk(trans, chunk_root, &key, chunk,
2714 item_size);
2715 BUG_ON(ret);
2716 }
2717 kfree(chunk);
2718 return 0;
2719 }
2720
2721 /*
2722 * Chunk allocation falls into two parts. The first part does works
2723 * that make the new allocated chunk useable, but not do any operation
2724 * that modifies the chunk tree. The second part does the works that
2725 * require modifying the chunk tree. This division is important for the
2726 * bootstrap process of adding storage to a seed btrfs.
2727 */
2728 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
2729 struct btrfs_root *extent_root, u64 type)
2730 {
2731 u64 chunk_offset;
2732 u64 chunk_size;
2733 u64 stripe_size;
2734 struct map_lookup *map;
2735 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
2736 int ret;
2737
2738 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2739 &chunk_offset);
2740 if (ret)
2741 return ret;
2742
2743 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
2744 &stripe_size, chunk_offset, type);
2745 if (ret)
2746 return ret;
2747
2748 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
2749 chunk_size, stripe_size);
2750 BUG_ON(ret);
2751 return 0;
2752 }
2753
2754 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
2755 struct btrfs_root *root,
2756 struct btrfs_device *device)
2757 {
2758 u64 chunk_offset;
2759 u64 sys_chunk_offset;
2760 u64 chunk_size;
2761 u64 sys_chunk_size;
2762 u64 stripe_size;
2763 u64 sys_stripe_size;
2764 u64 alloc_profile;
2765 struct map_lookup *map;
2766 struct map_lookup *sys_map;
2767 struct btrfs_fs_info *fs_info = root->fs_info;
2768 struct btrfs_root *extent_root = fs_info->extent_root;
2769 int ret;
2770
2771 ret = find_next_chunk(fs_info->chunk_root,
2772 BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset);
2773 BUG_ON(ret);
2774
2775 alloc_profile = BTRFS_BLOCK_GROUP_METADATA |
2776 (fs_info->metadata_alloc_profile &
2777 fs_info->avail_metadata_alloc_bits);
2778 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
2779
2780 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
2781 &stripe_size, chunk_offset, alloc_profile);
2782 BUG_ON(ret);
2783
2784 sys_chunk_offset = chunk_offset + chunk_size;
2785
2786 alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM |
2787 (fs_info->system_alloc_profile &
2788 fs_info->avail_system_alloc_bits);
2789 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
2790
2791 ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,
2792 &sys_chunk_size, &sys_stripe_size,
2793 sys_chunk_offset, alloc_profile);
2794 BUG_ON(ret);
2795
2796 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
2797 BUG_ON(ret);
2798
2799 /*
2800 * Modifying chunk tree needs allocating new blocks from both
2801 * system block group and metadata block group. So we only can
2802 * do operations require modifying the chunk tree after both
2803 * block groups were created.
2804 */
2805 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
2806 chunk_size, stripe_size);
2807 BUG_ON(ret);
2808
2809 ret = __finish_chunk_alloc(trans, extent_root, sys_map,
2810 sys_chunk_offset, sys_chunk_size,
2811 sys_stripe_size);
2812 BUG_ON(ret);
2813 return 0;
2814 }
2815
2816 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
2817 {
2818 struct extent_map *em;
2819 struct map_lookup *map;
2820 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
2821 int readonly = 0;
2822 int i;
2823
2824 read_lock(&map_tree->map_tree.lock);
2825 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
2826 read_unlock(&map_tree->map_tree.lock);
2827 if (!em)
2828 return 1;
2829
2830 if (btrfs_test_opt(root, DEGRADED)) {
2831 free_extent_map(em);
2832 return 0;
2833 }
2834
2835 map = (struct map_lookup *)em->bdev;
2836 for (i = 0; i < map->num_stripes; i++) {
2837 if (!map->stripes[i].dev->writeable) {
2838 readonly = 1;
2839 break;
2840 }
2841 }
2842 free_extent_map(em);
2843 return readonly;
2844 }
2845
2846 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
2847 {
2848 extent_map_tree_init(&tree->map_tree, GFP_NOFS);
2849 }
2850
2851 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
2852 {
2853 struct extent_map *em;
2854
2855 while (1) {
2856 write_lock(&tree->map_tree.lock);
2857 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
2858 if (em)
2859 remove_extent_mapping(&tree->map_tree, em);
2860 write_unlock(&tree->map_tree.lock);
2861 if (!em)
2862 break;
2863 kfree(em->bdev);
2864 /* once for us */
2865 free_extent_map(em);
2866 /* once for the tree */
2867 free_extent_map(em);
2868 }
2869 }
2870
2871 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
2872 {
2873 struct extent_map *em;
2874 struct map_lookup *map;
2875 struct extent_map_tree *em_tree = &map_tree->map_tree;
2876 int ret;
2877
2878 read_lock(&em_tree->lock);
2879 em = lookup_extent_mapping(em_tree, logical, len);
2880 read_unlock(&em_tree->lock);
2881 BUG_ON(!em);
2882
2883 BUG_ON(em->start > logical || em->start + em->len < logical);
2884 map = (struct map_lookup *)em->bdev;
2885 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
2886 ret = map->num_stripes;
2887 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
2888 ret = map->sub_stripes;
2889 else
2890 ret = 1;
2891 free_extent_map(em);
2892 return ret;
2893 }
2894
2895 static int find_live_mirror(struct map_lookup *map, int first, int num,
2896 int optimal)
2897 {
2898 int i;
2899 if (map->stripes[optimal].dev->bdev)
2900 return optimal;
2901 for (i = first; i < first + num; i++) {
2902 if (map->stripes[i].dev->bdev)
2903 return i;
2904 }
2905 /* we couldn't find one that doesn't fail. Just return something
2906 * and the io error handling code will clean up eventually
2907 */
2908 return optimal;
2909 }
2910
2911 static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
2912 u64 logical, u64 *length,
2913 struct btrfs_multi_bio **multi_ret,
2914 int mirror_num)
2915 {
2916 struct extent_map *em;
2917 struct map_lookup *map;
2918 struct extent_map_tree *em_tree = &map_tree->map_tree;
2919 u64 offset;
2920 u64 stripe_offset;
2921 u64 stripe_nr;
2922 int stripes_allocated = 8;
2923 int stripes_required = 1;
2924 int stripe_index;
2925 int i;
2926 int num_stripes;
2927 int max_errors = 0;
2928 struct btrfs_multi_bio *multi = NULL;
2929
2930 if (multi_ret && !(rw & REQ_WRITE))
2931 stripes_allocated = 1;
2932 again:
2933 if (multi_ret) {
2934 multi = kzalloc(btrfs_multi_bio_size(stripes_allocated),
2935 GFP_NOFS);
2936 if (!multi)
2937 return -ENOMEM;
2938
2939 atomic_set(&multi->error, 0);
2940 }
2941
2942 read_lock(&em_tree->lock);
2943 em = lookup_extent_mapping(em_tree, logical, *length);
2944 read_unlock(&em_tree->lock);
2945
2946 if (!em) {
2947 printk(KERN_CRIT "unable to find logical %llu len %llu\n",
2948 (unsigned long long)logical,
2949 (unsigned long long)*length);
2950 BUG();
2951 }
2952
2953 BUG_ON(em->start > logical || em->start + em->len < logical);
2954 map = (struct map_lookup *)em->bdev;
2955 offset = logical - em->start;
2956
2957 if (mirror_num > map->num_stripes)
2958 mirror_num = 0;
2959
2960 /* if our multi bio struct is too small, back off and try again */
2961 if (rw & REQ_WRITE) {
2962 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
2963 BTRFS_BLOCK_GROUP_DUP)) {
2964 stripes_required = map->num_stripes;
2965 max_errors = 1;
2966 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2967 stripes_required = map->sub_stripes;
2968 max_errors = 1;
2969 }
2970 }
2971 if (multi_ret && (rw & REQ_WRITE) &&
2972 stripes_allocated < stripes_required) {
2973 stripes_allocated = map->num_stripes;
2974 free_extent_map(em);
2975 kfree(multi);
2976 goto again;
2977 }
2978 stripe_nr = offset;
2979 /*
2980 * stripe_nr counts the total number of stripes we have to stride
2981 * to get to this block
2982 */
2983 do_div(stripe_nr, map->stripe_len);
2984
2985 stripe_offset = stripe_nr * map->stripe_len;
2986 BUG_ON(offset < stripe_offset);
2987
2988 /* stripe_offset is the offset of this block in its stripe*/
2989 stripe_offset = offset - stripe_offset;
2990
2991 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
2992 BTRFS_BLOCK_GROUP_RAID10 |
2993 BTRFS_BLOCK_GROUP_DUP)) {
2994 /* we limit the length of each bio to what fits in a stripe */
2995 *length = min_t(u64, em->len - offset,
2996 map->stripe_len - stripe_offset);
2997 } else {
2998 *length = em->len - offset;
2999 }
3000
3001 if (!multi_ret)
3002 goto out;
3003
3004 num_stripes = 1;
3005 stripe_index = 0;
3006 if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
3007 if (rw & REQ_WRITE)
3008 num_stripes = map->num_stripes;
3009 else if (mirror_num)
3010 stripe_index = mirror_num - 1;
3011 else {
3012 stripe_index = find_live_mirror(map, 0,
3013 map->num_stripes,
3014 current->pid % map->num_stripes);
3015 }
3016
3017 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
3018 if (rw & REQ_WRITE)
3019 num_stripes = map->num_stripes;
3020 else if (mirror_num)
3021 stripe_index = mirror_num - 1;
3022
3023 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3024 int factor = map->num_stripes / map->sub_stripes;
3025
3026 stripe_index = do_div(stripe_nr, factor);
3027 stripe_index *= map->sub_stripes;
3028
3029 if (rw & REQ_WRITE)
3030 num_stripes = map->sub_stripes;
3031 else if (mirror_num)
3032 stripe_index += mirror_num - 1;
3033 else {
3034 stripe_index = find_live_mirror(map, stripe_index,
3035 map->sub_stripes, stripe_index +
3036 current->pid % map->sub_stripes);
3037 }
3038 } else {
3039 /*
3040 * after this do_div call, stripe_nr is the number of stripes
3041 * on this device we have to walk to find the data, and
3042 * stripe_index is the number of our device in the stripe array
3043 */
3044 stripe_index = do_div(stripe_nr, map->num_stripes);
3045 }
3046 BUG_ON(stripe_index >= map->num_stripes);
3047
3048 for (i = 0; i < num_stripes; i++) {
3049 multi->stripes[i].physical =
3050 map->stripes[stripe_index].physical +
3051 stripe_offset + stripe_nr * map->stripe_len;
3052 multi->stripes[i].dev = map->stripes[stripe_index].dev;
3053 stripe_index++;
3054 }
3055 if (multi_ret) {
3056 *multi_ret = multi;
3057 multi->num_stripes = num_stripes;
3058 multi->max_errors = max_errors;
3059 }
3060 out:
3061 free_extent_map(em);
3062 return 0;
3063 }
3064
3065 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
3066 u64 logical, u64 *length,
3067 struct btrfs_multi_bio **multi_ret, int mirror_num)
3068 {
3069 return __btrfs_map_block(map_tree, rw, logical, length, multi_ret,
3070 mirror_num);
3071 }
3072
3073 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
3074 u64 chunk_start, u64 physical, u64 devid,
3075 u64 **logical, int *naddrs, int *stripe_len)
3076 {
3077 struct extent_map_tree *em_tree = &map_tree->map_tree;
3078 struct extent_map *em;
3079 struct map_lookup *map;
3080 u64 *buf;
3081 u64 bytenr;
3082 u64 length;
3083 u64 stripe_nr;
3084 int i, j, nr = 0;
3085
3086 read_lock(&em_tree->lock);
3087 em = lookup_extent_mapping(em_tree, chunk_start, 1);
3088 read_unlock(&em_tree->lock);
3089
3090 BUG_ON(!em || em->start != chunk_start);
3091 map = (struct map_lookup *)em->bdev;
3092
3093 length = em->len;
3094 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
3095 do_div(length, map->num_stripes / map->sub_stripes);
3096 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
3097 do_div(length, map->num_stripes);
3098
3099 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
3100 BUG_ON(!buf);
3101
3102 for (i = 0; i < map->num_stripes; i++) {
3103 if (devid && map->stripes[i].dev->devid != devid)
3104 continue;
3105 if (map->stripes[i].physical > physical ||
3106 map->stripes[i].physical + length <= physical)
3107 continue;
3108
3109 stripe_nr = physical - map->stripes[i].physical;
3110 do_div(stripe_nr, map->stripe_len);
3111
3112 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3113 stripe_nr = stripe_nr * map->num_stripes + i;
3114 do_div(stripe_nr, map->sub_stripes);
3115 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3116 stripe_nr = stripe_nr * map->num_stripes + i;
3117 }
3118 bytenr = chunk_start + stripe_nr * map->stripe_len;
3119 WARN_ON(nr >= map->num_stripes);
3120 for (j = 0; j < nr; j++) {
3121 if (buf[j] == bytenr)
3122 break;
3123 }
3124 if (j == nr) {
3125 WARN_ON(nr >= map->num_stripes);
3126 buf[nr++] = bytenr;
3127 }
3128 }
3129
3130 *logical = buf;
3131 *naddrs = nr;
3132 *stripe_len = map->stripe_len;
3133
3134 free_extent_map(em);
3135 return 0;
3136 }
3137
3138 static void end_bio_multi_stripe(struct bio *bio, int err)
3139 {
3140 struct btrfs_multi_bio *multi = bio->bi_private;
3141 int is_orig_bio = 0;
3142
3143 if (err)
3144 atomic_inc(&multi->error);
3145
3146 if (bio == multi->orig_bio)
3147 is_orig_bio = 1;
3148
3149 if (atomic_dec_and_test(&multi->stripes_pending)) {
3150 if (!is_orig_bio) {
3151 bio_put(bio);
3152 bio = multi->orig_bio;
3153 }
3154 bio->bi_private = multi->private;
3155 bio->bi_end_io = multi->end_io;
3156 /* only send an error to the higher layers if it is
3157 * beyond the tolerance of the multi-bio
3158 */
3159 if (atomic_read(&multi->error) > multi->max_errors) {
3160 err = -EIO;
3161 } else if (err) {
3162 /*
3163 * this bio is actually up to date, we didn't
3164 * go over the max number of errors
3165 */
3166 set_bit(BIO_UPTODATE, &bio->bi_flags);
3167 err = 0;
3168 }
3169 kfree(multi);
3170
3171 bio_endio(bio, err);
3172 } else if (!is_orig_bio) {
3173 bio_put(bio);
3174 }
3175 }
3176
3177 struct async_sched {
3178 struct bio *bio;
3179 int rw;
3180 struct btrfs_fs_info *info;
3181 struct btrfs_work work;
3182 };
3183
3184 /*
3185 * see run_scheduled_bios for a description of why bios are collected for
3186 * async submit.
3187 *
3188 * This will add one bio to the pending list for a device and make sure
3189 * the work struct is scheduled.
3190 */
3191 static noinline int schedule_bio(struct btrfs_root *root,
3192 struct btrfs_device *device,
3193 int rw, struct bio *bio)
3194 {
3195 int should_queue = 1;
3196 struct btrfs_pending_bios *pending_bios;
3197
3198 /* don't bother with additional async steps for reads, right now */
3199 if (!(rw & REQ_WRITE)) {
3200 bio_get(bio);
3201 submit_bio(rw, bio);
3202 bio_put(bio);
3203 return 0;
3204 }
3205
3206 /*
3207 * nr_async_bios allows us to reliably return congestion to the
3208 * higher layers. Otherwise, the async bio makes it appear we have
3209 * made progress against dirty pages when we've really just put it
3210 * on a queue for later
3211 */
3212 atomic_inc(&root->fs_info->nr_async_bios);
3213 WARN_ON(bio->bi_next);
3214 bio->bi_next = NULL;
3215 bio->bi_rw |= rw;
3216
3217 spin_lock(&device->io_lock);
3218 if (bio->bi_rw & REQ_SYNC)
3219 pending_bios = &device->pending_sync_bios;
3220 else
3221 pending_bios = &device->pending_bios;
3222
3223 if (pending_bios->tail)
3224 pending_bios->tail->bi_next = bio;
3225
3226 pending_bios->tail = bio;
3227 if (!pending_bios->head)
3228 pending_bios->head = bio;
3229 if (device->running_pending)
3230 should_queue = 0;
3231
3232 spin_unlock(&device->io_lock);
3233
3234 if (should_queue)
3235 btrfs_queue_worker(&root->fs_info->submit_workers,
3236 &device->work);
3237 return 0;
3238 }
3239
3240 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
3241 int mirror_num, int async_submit)
3242 {
3243 struct btrfs_mapping_tree *map_tree;
3244 struct btrfs_device *dev;
3245 struct bio *first_bio = bio;
3246 u64 logical = (u64)bio->bi_sector << 9;
3247 u64 length = 0;
3248 u64 map_length;
3249 struct btrfs_multi_bio *multi = NULL;
3250 int ret;
3251 int dev_nr = 0;
3252 int total_devs = 1;
3253
3254 length = bio->bi_size;
3255 map_tree = &root->fs_info->mapping_tree;
3256 map_length = length;
3257
3258 ret = btrfs_map_block(map_tree, rw, logical, &map_length, &multi,
3259 mirror_num);
3260 BUG_ON(ret);
3261
3262 total_devs = multi->num_stripes;
3263 if (map_length < length) {
3264 printk(KERN_CRIT "mapping failed logical %llu bio len %llu "
3265 "len %llu\n", (unsigned long long)logical,
3266 (unsigned long long)length,
3267 (unsigned long long)map_length);
3268 BUG();
3269 }
3270 multi->end_io = first_bio->bi_end_io;
3271 multi->private = first_bio->bi_private;
3272 multi->orig_bio = first_bio;
3273 atomic_set(&multi->stripes_pending, multi->num_stripes);
3274
3275 while (dev_nr < total_devs) {
3276 if (total_devs > 1) {
3277 if (dev_nr < total_devs - 1) {
3278 bio = bio_clone(first_bio, GFP_NOFS);
3279 BUG_ON(!bio);
3280 } else {
3281 bio = first_bio;
3282 }
3283 bio->bi_private = multi;
3284 bio->bi_end_io = end_bio_multi_stripe;
3285 }
3286 bio->bi_sector = multi->stripes[dev_nr].physical >> 9;
3287 dev = multi->stripes[dev_nr].dev;
3288 if (dev && dev->bdev && (rw != WRITE || dev->writeable)) {
3289 bio->bi_bdev = dev->bdev;
3290 if (async_submit)
3291 schedule_bio(root, dev, rw, bio);
3292 else
3293 submit_bio(rw, bio);
3294 } else {
3295 bio->bi_bdev = root->fs_info->fs_devices->latest_bdev;
3296 bio->bi_sector = logical >> 9;
3297 bio_endio(bio, -EIO);
3298 }
3299 dev_nr++;
3300 }
3301 if (total_devs == 1)
3302 kfree(multi);
3303 return 0;
3304 }
3305
3306 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
3307 u8 *uuid, u8 *fsid)
3308 {
3309 struct btrfs_device *device;
3310 struct btrfs_fs_devices *cur_devices;
3311
3312 cur_devices = root->fs_info->fs_devices;
3313 while (cur_devices) {
3314 if (!fsid ||
3315 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
3316 device = __find_device(&cur_devices->devices,
3317 devid, uuid);
3318 if (device)
3319 return device;
3320 }
3321 cur_devices = cur_devices->seed;
3322 }
3323 return NULL;
3324 }
3325
3326 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
3327 u64 devid, u8 *dev_uuid)
3328 {
3329 struct btrfs_device *device;
3330 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
3331
3332 device = kzalloc(sizeof(*device), GFP_NOFS);
3333 if (!device)
3334 return NULL;
3335 list_add(&device->dev_list,
3336 &fs_devices->devices);
3337 device->dev_root = root->fs_info->dev_root;
3338 device->devid = devid;
3339 device->work.func = pending_bios_fn;
3340 device->fs_devices = fs_devices;
3341 device->missing = 1;
3342 fs_devices->num_devices++;
3343 fs_devices->missing_devices++;
3344 spin_lock_init(&device->io_lock);
3345 INIT_LIST_HEAD(&device->dev_alloc_list);
3346 memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
3347 return device;
3348 }
3349
3350 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
3351 struct extent_buffer *leaf,
3352 struct btrfs_chunk *chunk)
3353 {
3354 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
3355 struct map_lookup *map;
3356 struct extent_map *em;
3357 u64 logical;
3358 u64 length;
3359 u64 devid;
3360 u8 uuid[BTRFS_UUID_SIZE];
3361 int num_stripes;
3362 int ret;
3363 int i;
3364
3365 logical = key->offset;
3366 length = btrfs_chunk_length(leaf, chunk);
3367
3368 read_lock(&map_tree->map_tree.lock);
3369 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
3370 read_unlock(&map_tree->map_tree.lock);
3371
3372 /* already mapped? */
3373 if (em && em->start <= logical && em->start + em->len > logical) {
3374 free_extent_map(em);
3375 return 0;
3376 } else if (em) {
3377 free_extent_map(em);
3378 }
3379
3380 em = alloc_extent_map(GFP_NOFS);
3381 if (!em)
3382 return -ENOMEM;
3383 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
3384 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
3385 if (!map) {
3386 free_extent_map(em);
3387 return -ENOMEM;
3388 }
3389
3390 em->bdev = (struct block_device *)map;
3391 em->start = logical;
3392 em->len = length;
3393 em->block_start = 0;
3394 em->block_len = em->len;
3395
3396 map->num_stripes = num_stripes;
3397 map->io_width = btrfs_chunk_io_width(leaf, chunk);
3398 map->io_align = btrfs_chunk_io_align(leaf, chunk);
3399 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
3400 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
3401 map->type = btrfs_chunk_type(leaf, chunk);
3402 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
3403 for (i = 0; i < num_stripes; i++) {
3404 map->stripes[i].physical =
3405 btrfs_stripe_offset_nr(leaf, chunk, i);
3406 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
3407 read_extent_buffer(leaf, uuid, (unsigned long)
3408 btrfs_stripe_dev_uuid_nr(chunk, i),
3409 BTRFS_UUID_SIZE);
3410 map->stripes[i].dev = btrfs_find_device(root, devid, uuid,
3411 NULL);
3412 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
3413 kfree(map);
3414 free_extent_map(em);
3415 return -EIO;
3416 }
3417 if (!map->stripes[i].dev) {
3418 map->stripes[i].dev =
3419 add_missing_dev(root, devid, uuid);
3420 if (!map->stripes[i].dev) {
3421 kfree(map);
3422 free_extent_map(em);
3423 return -EIO;
3424 }
3425 }
3426 map->stripes[i].dev->in_fs_metadata = 1;
3427 }
3428
3429 write_lock(&map_tree->map_tree.lock);
3430 ret = add_extent_mapping(&map_tree->map_tree, em);
3431 write_unlock(&map_tree->map_tree.lock);
3432 BUG_ON(ret);
3433 free_extent_map(em);
3434
3435 return 0;
3436 }
3437
3438 static int fill_device_from_item(struct extent_buffer *leaf,
3439 struct btrfs_dev_item *dev_item,
3440 struct btrfs_device *device)
3441 {
3442 unsigned long ptr;
3443
3444 device->devid = btrfs_device_id(leaf, dev_item);
3445 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
3446 device->total_bytes = device->disk_total_bytes;
3447 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
3448 device->type = btrfs_device_type(leaf, dev_item);
3449 device->io_align = btrfs_device_io_align(leaf, dev_item);
3450 device->io_width = btrfs_device_io_width(leaf, dev_item);
3451 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
3452
3453 ptr = (unsigned long)btrfs_device_uuid(dev_item);
3454 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
3455
3456 return 0;
3457 }
3458
3459 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
3460 {
3461 struct btrfs_fs_devices *fs_devices;
3462 int ret;
3463
3464 mutex_lock(&uuid_mutex);
3465
3466 fs_devices = root->fs_info->fs_devices->seed;
3467 while (fs_devices) {
3468 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
3469 ret = 0;
3470 goto out;
3471 }
3472 fs_devices = fs_devices->seed;
3473 }
3474
3475 fs_devices = find_fsid(fsid);
3476 if (!fs_devices) {
3477 ret = -ENOENT;
3478 goto out;
3479 }
3480
3481 fs_devices = clone_fs_devices(fs_devices);
3482 if (IS_ERR(fs_devices)) {
3483 ret = PTR_ERR(fs_devices);
3484 goto out;
3485 }
3486
3487 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
3488 root->fs_info->bdev_holder);
3489 if (ret)
3490 goto out;
3491
3492 if (!fs_devices->seeding) {
3493 __btrfs_close_devices(fs_devices);
3494 free_fs_devices(fs_devices);
3495 ret = -EINVAL;
3496 goto out;
3497 }
3498
3499 fs_devices->seed = root->fs_info->fs_devices->seed;
3500 root->fs_info->fs_devices->seed = fs_devices;
3501 out:
3502 mutex_unlock(&uuid_mutex);
3503 return ret;
3504 }
3505
3506 static int read_one_dev(struct btrfs_root *root,
3507 struct extent_buffer *leaf,
3508 struct btrfs_dev_item *dev_item)
3509 {
3510 struct btrfs_device *device;
3511 u64 devid;
3512 int ret;
3513 u8 fs_uuid[BTRFS_UUID_SIZE];
3514 u8 dev_uuid[BTRFS_UUID_SIZE];
3515
3516 devid = btrfs_device_id(leaf, dev_item);
3517 read_extent_buffer(leaf, dev_uuid,
3518 (unsigned long)btrfs_device_uuid(dev_item),
3519 BTRFS_UUID_SIZE);
3520 read_extent_buffer(leaf, fs_uuid,
3521 (unsigned long)btrfs_device_fsid(dev_item),
3522 BTRFS_UUID_SIZE);
3523
3524 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
3525 ret = open_seed_devices(root, fs_uuid);
3526 if (ret && !btrfs_test_opt(root, DEGRADED))
3527 return ret;
3528 }
3529
3530 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
3531 if (!device || !device->bdev) {
3532 if (!btrfs_test_opt(root, DEGRADED))
3533 return -EIO;
3534
3535 if (!device) {
3536 printk(KERN_WARNING "warning devid %llu missing\n",
3537 (unsigned long long)devid);
3538 device = add_missing_dev(root, devid, dev_uuid);
3539 if (!device)
3540 return -ENOMEM;
3541 } else if (!device->missing) {
3542 /*
3543 * this happens when a device that was properly setup
3544 * in the device info lists suddenly goes bad.
3545 * device->bdev is NULL, and so we have to set
3546 * device->missing to one here
3547 */
3548 root->fs_info->fs_devices->missing_devices++;
3549 device->missing = 1;
3550 }
3551 }
3552
3553 if (device->fs_devices != root->fs_info->fs_devices) {
3554 BUG_ON(device->writeable);
3555 if (device->generation !=
3556 btrfs_device_generation(leaf, dev_item))
3557 return -EINVAL;
3558 }
3559
3560 fill_device_from_item(leaf, dev_item, device);
3561 device->dev_root = root->fs_info->dev_root;
3562 device->in_fs_metadata = 1;
3563 if (device->writeable)
3564 device->fs_devices->total_rw_bytes += device->total_bytes;
3565 ret = 0;
3566 return ret;
3567 }
3568
3569 int btrfs_read_super_device(struct btrfs_root *root, struct extent_buffer *buf)
3570 {
3571 struct btrfs_dev_item *dev_item;
3572
3573 dev_item = (struct btrfs_dev_item *)offsetof(struct btrfs_super_block,
3574 dev_item);
3575 return read_one_dev(root, buf, dev_item);
3576 }
3577
3578 int btrfs_read_sys_array(struct btrfs_root *root)
3579 {
3580 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
3581 struct extent_buffer *sb;
3582 struct btrfs_disk_key *disk_key;
3583 struct btrfs_chunk *chunk;
3584 u8 *ptr;
3585 unsigned long sb_ptr;
3586 int ret = 0;
3587 u32 num_stripes;
3588 u32 array_size;
3589 u32 len = 0;
3590 u32 cur;
3591 struct btrfs_key key;
3592
3593 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
3594 BTRFS_SUPER_INFO_SIZE);
3595 if (!sb)
3596 return -ENOMEM;
3597 btrfs_set_buffer_uptodate(sb);
3598 btrfs_set_buffer_lockdep_class(sb, 0);
3599
3600 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
3601 array_size = btrfs_super_sys_array_size(super_copy);
3602
3603 ptr = super_copy->sys_chunk_array;
3604 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
3605 cur = 0;
3606
3607 while (cur < array_size) {
3608 disk_key = (struct btrfs_disk_key *)ptr;
3609 btrfs_disk_key_to_cpu(&key, disk_key);
3610
3611 len = sizeof(*disk_key); ptr += len;
3612 sb_ptr += len;
3613 cur += len;
3614
3615 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
3616 chunk = (struct btrfs_chunk *)sb_ptr;
3617 ret = read_one_chunk(root, &key, sb, chunk);
3618 if (ret)
3619 break;
3620 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
3621 len = btrfs_chunk_item_size(num_stripes);
3622 } else {
3623 ret = -EIO;
3624 break;
3625 }
3626 ptr += len;
3627 sb_ptr += len;
3628 cur += len;
3629 }
3630 free_extent_buffer(sb);
3631 return ret;
3632 }
3633
3634 int btrfs_read_chunk_tree(struct btrfs_root *root)
3635 {
3636 struct btrfs_path *path;
3637 struct extent_buffer *leaf;
3638 struct btrfs_key key;
3639 struct btrfs_key found_key;
3640 int ret;
3641 int slot;
3642
3643 root = root->fs_info->chunk_root;
3644
3645 path = btrfs_alloc_path();
3646 if (!path)
3647 return -ENOMEM;
3648
3649 /* first we search for all of the device items, and then we
3650 * read in all of the chunk items. This way we can create chunk
3651 * mappings that reference all of the devices that are afound
3652 */
3653 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
3654 key.offset = 0;
3655 key.type = 0;
3656 again:
3657 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3658 if (ret < 0)
3659 goto error;
3660 while (1) {
3661 leaf = path->nodes[0];
3662 slot = path->slots[0];
3663 if (slot >= btrfs_header_nritems(leaf)) {
3664 ret = btrfs_next_leaf(root, path);
3665 if (ret == 0)
3666 continue;
3667 if (ret < 0)
3668 goto error;
3669 break;
3670 }
3671 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3672 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
3673 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
3674 break;
3675 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
3676 struct btrfs_dev_item *dev_item;
3677 dev_item = btrfs_item_ptr(leaf, slot,
3678 struct btrfs_dev_item);
3679 ret = read_one_dev(root, leaf, dev_item);
3680 if (ret)
3681 goto error;
3682 }
3683 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
3684 struct btrfs_chunk *chunk;
3685 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
3686 ret = read_one_chunk(root, &found_key, leaf, chunk);
3687 if (ret)
3688 goto error;
3689 }
3690 path->slots[0]++;
3691 }
3692 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
3693 key.objectid = 0;
3694 btrfs_release_path(root, path);
3695 goto again;
3696 }
3697 ret = 0;
3698 error:
3699 btrfs_free_path(path);
3700 return ret;
3701 }
CRIS linux kernel tree