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ACPI: pci_root: simplify list traversals
[linux-2.6/linux-acpi-2.6.git] / fs / btrfs / volumes.c
bloba6d35b0054ca7a0d8a83ed2708b3610cb10229d9
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/buffer_head.h>
21 #include <linux/blkdev.h>
22 #include <linux/random.h>
23 #include <linux/iocontext.h>
24 #include <asm/div64.h>
25 #include "compat.h"
26 #include "ctree.h"
27 #include "extent_map.h"
28 #include "disk-io.h"
29 #include "transaction.h"
30 #include "print-tree.h"
31 #include "volumes.h"
32 #include "async-thread.h"
33
34 struct map_lookup {
35 u64 type;
36 int io_align;
37 int io_width;
38 int stripe_len;
39 int sector_size;
40 int num_stripes;
41 int sub_stripes;
42 struct btrfs_bio_stripe stripes[];
43 };
44
45 static int init_first_rw_device(struct btrfs_trans_handle *trans,
46 struct btrfs_root *root,
47 struct btrfs_device *device);
48 static int btrfs_relocate_sys_chunks(struct btrfs_root *root);
49
50 #define map_lookup_size(n) (sizeof(struct map_lookup) + \
51 (sizeof(struct btrfs_bio_stripe) * (n)))
52
53 static DEFINE_MUTEX(uuid_mutex);
54 static LIST_HEAD(fs_uuids);
55
56 void btrfs_lock_volumes(void)
57 {
58 mutex_lock(&uuid_mutex);
59 }
60
61 void btrfs_unlock_volumes(void)
62 {
63 mutex_unlock(&uuid_mutex);
64 }
65
66 static void lock_chunks(struct btrfs_root *root)
67 {
68 mutex_lock(&root->fs_info->chunk_mutex);
69 }
70
71 static void unlock_chunks(struct btrfs_root *root)
72 {
73 mutex_unlock(&root->fs_info->chunk_mutex);
74 }
75
76 static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
77 {
78 struct btrfs_device *device;
79 WARN_ON(fs_devices->opened);
80 while (!list_empty(&fs_devices->devices)) {
81 device = list_entry(fs_devices->devices.next,
82 struct btrfs_device, dev_list);
83 list_del(&device->dev_list);
84 kfree(device->name);
85 kfree(device);
86 }
87 kfree(fs_devices);
88 }
89
90 int btrfs_cleanup_fs_uuids(void)
91 {
92 struct btrfs_fs_devices *fs_devices;
93
94 while (!list_empty(&fs_uuids)) {
95 fs_devices = list_entry(fs_uuids.next,
96 struct btrfs_fs_devices, list);
97 list_del(&fs_devices->list);
98 free_fs_devices(fs_devices);
99 }
100 return 0;
101 }
102
103 static noinline struct btrfs_device *__find_device(struct list_head *head,
104 u64 devid, u8 *uuid)
105 {
106 struct btrfs_device *dev;
107
108 list_for_each_entry(dev, head, dev_list) {
109 if (dev->devid == devid &&
110 (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
111 return dev;
112 }
113 }
114 return NULL;
115 }
116
117 static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
118 {
119 struct btrfs_fs_devices *fs_devices;
120
121 list_for_each_entry(fs_devices, &fs_uuids, list) {
122 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
123 return fs_devices;
124 }
125 return NULL;
126 }
127
128 static void requeue_list(struct btrfs_pending_bios *pending_bios,
129 struct bio *head, struct bio *tail)
130 {
131
132 struct bio *old_head;
133
134 old_head = pending_bios->head;
135 pending_bios->head = head;
136 if (pending_bios->tail)
137 tail->bi_next = old_head;
138 else
139 pending_bios->tail = tail;
140 }
141
142 /*
143 * we try to collect pending bios for a device so we don't get a large
144 * number of procs sending bios down to the same device. This greatly
145 * improves the schedulers ability to collect and merge the bios.
146 *
147 * But, it also turns into a long list of bios to process and that is sure
148 * to eventually make the worker thread block. The solution here is to
149 * make some progress and then put this work struct back at the end of
150 * the list if the block device is congested. This way, multiple devices
151 * can make progress from a single worker thread.
152 */
153 static noinline int run_scheduled_bios(struct btrfs_device *device)
154 {
155 struct bio *pending;
156 struct backing_dev_info *bdi;
157 struct btrfs_fs_info *fs_info;
158 struct btrfs_pending_bios *pending_bios;
159 struct bio *tail;
160 struct bio *cur;
161 int again = 0;
162 unsigned long num_run;
163 unsigned long num_sync_run;
164 unsigned long limit;
165 unsigned long last_waited = 0;
166
167 bdi = blk_get_backing_dev_info(device->bdev);
168 fs_info = device->dev_root->fs_info;
169 limit = btrfs_async_submit_limit(fs_info);
170 limit = limit * 2 / 3;
171
172 /* we want to make sure that every time we switch from the sync
173 * list to the normal list, we unplug
174 */
175 num_sync_run = 0;
176
177 loop:
178 spin_lock(&device->io_lock);
179 num_run = 0;
180
181 loop_lock:
182
183 /* take all the bios off the list at once and process them
184 * later on (without the lock held). But, remember the
185 * tail and other pointers so the bios can be properly reinserted
186 * into the list if we hit congestion
187 */
188 if (device->pending_sync_bios.head)
189 pending_bios = &device->pending_sync_bios;
190 else
191 pending_bios = &device->pending_bios;
192
193 pending = pending_bios->head;
194 tail = pending_bios->tail;
195 WARN_ON(pending && !tail);
196
197 /*
198 * if pending was null this time around, no bios need processing
199 * at all and we can stop. Otherwise it'll loop back up again
200 * and do an additional check so no bios are missed.
201 *
202 * device->running_pending is used to synchronize with the
203 * schedule_bio code.
204 */
205 if (device->pending_sync_bios.head == NULL &&
206 device->pending_bios.head == NULL) {
207 again = 0;
208 device->running_pending = 0;
209 } else {
210 again = 1;
211 device->running_pending = 1;
212 }
213
214 pending_bios->head = NULL;
215 pending_bios->tail = NULL;
216
217 spin_unlock(&device->io_lock);
218
219 /*
220 * if we're doing the regular priority list, make sure we unplug
221 * for any high prio bios we've sent down
222 */
223 if (pending_bios == &device->pending_bios && num_sync_run > 0) {
224 num_sync_run = 0;
225 blk_run_backing_dev(bdi, NULL);
226 }
227
228 while (pending) {
229
230 rmb();
231 if (pending_bios != &device->pending_sync_bios &&
232 device->pending_sync_bios.head &&
233 num_run > 16) {
234 cond_resched();
235 spin_lock(&device->io_lock);
236 requeue_list(pending_bios, pending, tail);
237 goto loop_lock;
238 }
239
240 cur = pending;
241 pending = pending->bi_next;
242 cur->bi_next = NULL;
243 atomic_dec(&fs_info->nr_async_bios);
244
245 if (atomic_read(&fs_info->nr_async_bios) < limit &&
246 waitqueue_active(&fs_info->async_submit_wait))
247 wake_up(&fs_info->async_submit_wait);
248
249 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
250 submit_bio(cur->bi_rw, cur);
251 num_run++;
252 if (bio_sync(cur))
253 num_sync_run++;
254
255 if (need_resched()) {
256 if (num_sync_run) {
257 blk_run_backing_dev(bdi, NULL);
258 num_sync_run = 0;
259 }
260 cond_resched();
261 }
262
263 /*
264 * we made progress, there is more work to do and the bdi
265 * is now congested. Back off and let other work structs
266 * run instead
267 */
268 if (pending && bdi_write_congested(bdi) && num_run > 16 &&
269 fs_info->fs_devices->open_devices > 1) {
270 struct io_context *ioc;
271
272 ioc = current->io_context;
273
274 /*
275 * the main goal here is that we don't want to
276 * block if we're going to be able to submit
277 * more requests without blocking.
278 *
279 * This code does two great things, it pokes into
280 * the elevator code from a filesystem _and_
281 * it makes assumptions about how batching works.
282 */
283 if (ioc && ioc->nr_batch_requests > 0 &&
284 time_before(jiffies, ioc->last_waited + HZ/50UL) &&
285 (last_waited == 0 ||
286 ioc->last_waited == last_waited)) {
287 /*
288 * we want to go through our batch of
289 * requests and stop. So, we copy out
290 * the ioc->last_waited time and test
291 * against it before looping
292 */
293 last_waited = ioc->last_waited;
294 if (need_resched()) {
295 if (num_sync_run) {
296 blk_run_backing_dev(bdi, NULL);
297 num_sync_run = 0;
298 }
299 cond_resched();
300 }
301 continue;
302 }
303 spin_lock(&device->io_lock);
304 requeue_list(pending_bios, pending, tail);
305 device->running_pending = 1;
306
307 spin_unlock(&device->io_lock);
308 btrfs_requeue_work(&device->work);
309 goto done;
310 }
311 }
312
313 if (num_sync_run) {
314 num_sync_run = 0;
315 blk_run_backing_dev(bdi, NULL);
316 }
317
318 cond_resched();
319 if (again)
320 goto loop;
321
322 spin_lock(&device->io_lock);
323 if (device->pending_bios.head || device->pending_sync_bios.head)
324 goto loop_lock;
325 spin_unlock(&device->io_lock);
326
327 /*
328 * IO has already been through a long path to get here. Checksumming,
329 * async helper threads, perhaps compression. We've done a pretty
330 * good job of collecting a batch of IO and should just unplug
331 * the device right away.
332 *
333 * This will help anyone who is waiting on the IO, they might have
334 * already unplugged, but managed to do so before the bio they
335 * cared about found its way down here.
336 */
337 blk_run_backing_dev(bdi, NULL);
338 done:
339 return 0;
340 }
341
342 static void pending_bios_fn(struct btrfs_work *work)
343 {
344 struct btrfs_device *device;
345
346 device = container_of(work, struct btrfs_device, work);
347 run_scheduled_bios(device);
348 }
349
350 static noinline int device_list_add(const char *path,
351 struct btrfs_super_block *disk_super,
352 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
353 {
354 struct btrfs_device *device;
355 struct btrfs_fs_devices *fs_devices;
356 u64 found_transid = btrfs_super_generation(disk_super);
357
358 fs_devices = find_fsid(disk_super->fsid);
359 if (!fs_devices) {
360 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
361 if (!fs_devices)
362 return -ENOMEM;
363 INIT_LIST_HEAD(&fs_devices->devices);
364 INIT_LIST_HEAD(&fs_devices->alloc_list);
365 list_add(&fs_devices->list, &fs_uuids);
366 memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
367 fs_devices->latest_devid = devid;
368 fs_devices->latest_trans = found_transid;
369 device = NULL;
370 } else {
371 device = __find_device(&fs_devices->devices, devid,
372 disk_super->dev_item.uuid);
373 }
374 if (!device) {
375 if (fs_devices->opened)
376 return -EBUSY;
377
378 device = kzalloc(sizeof(*device), GFP_NOFS);
379 if (!device) {
380 /* we can safely leave the fs_devices entry around */
381 return -ENOMEM;
382 }
383 device->devid = devid;
384 device->work.func = pending_bios_fn;
385 memcpy(device->uuid, disk_super->dev_item.uuid,
386 BTRFS_UUID_SIZE);
387 device->barriers = 1;
388 spin_lock_init(&device->io_lock);
389 device->name = kstrdup(path, GFP_NOFS);
390 if (!device->name) {
391 kfree(device);
392 return -ENOMEM;
393 }
394 INIT_LIST_HEAD(&device->dev_alloc_list);
395 list_add(&device->dev_list, &fs_devices->devices);
396 device->fs_devices = fs_devices;
397 fs_devices->num_devices++;
398 }
399
400 if (found_transid > fs_devices->latest_trans) {
401 fs_devices->latest_devid = devid;
402 fs_devices->latest_trans = found_transid;
403 }
404 *fs_devices_ret = fs_devices;
405 return 0;
406 }
407
408 static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
409 {
410 struct btrfs_fs_devices *fs_devices;
411 struct btrfs_device *device;
412 struct btrfs_device *orig_dev;
413
414 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
415 if (!fs_devices)
416 return ERR_PTR(-ENOMEM);
417
418 INIT_LIST_HEAD(&fs_devices->devices);
419 INIT_LIST_HEAD(&fs_devices->alloc_list);
420 INIT_LIST_HEAD(&fs_devices->list);
421 fs_devices->latest_devid = orig->latest_devid;
422 fs_devices->latest_trans = orig->latest_trans;
423 memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid));
424
425 list_for_each_entry(orig_dev, &orig->devices, dev_list) {
426 device = kzalloc(sizeof(*device), GFP_NOFS);
427 if (!device)
428 goto error;
429
430 device->name = kstrdup(orig_dev->name, GFP_NOFS);
431 if (!device->name)
432 goto error;
433
434 device->devid = orig_dev->devid;
435 device->work.func = pending_bios_fn;
436 memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid));
437 device->barriers = 1;
438 spin_lock_init(&device->io_lock);
439 INIT_LIST_HEAD(&device->dev_list);
440 INIT_LIST_HEAD(&device->dev_alloc_list);
441
442 list_add(&device->dev_list, &fs_devices->devices);
443 device->fs_devices = fs_devices;
444 fs_devices->num_devices++;
445 }
446 return fs_devices;
447 error:
448 free_fs_devices(fs_devices);
449 return ERR_PTR(-ENOMEM);
450 }
451
452 int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
453 {
454 struct btrfs_device *device, *next;
455
456 mutex_lock(&uuid_mutex);
457 again:
458 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
459 if (device->in_fs_metadata)
460 continue;
461
462 if (device->bdev) {
463 close_bdev_exclusive(device->bdev, device->mode);
464 device->bdev = NULL;
465 fs_devices->open_devices--;
466 }
467 if (device->writeable) {
468 list_del_init(&device->dev_alloc_list);
469 device->writeable = 0;
470 fs_devices->rw_devices--;
471 }
472 list_del_init(&device->dev_list);
473 fs_devices->num_devices--;
474 kfree(device->name);
475 kfree(device);
476 }
477
478 if (fs_devices->seed) {
479 fs_devices = fs_devices->seed;
480 goto again;
481 }
482
483 mutex_unlock(&uuid_mutex);
484 return 0;
485 }
486
487 static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
488 {
489 struct btrfs_device *device;
490
491 if (--fs_devices->opened > 0)
492 return 0;
493
494 list_for_each_entry(device, &fs_devices->devices, dev_list) {
495 if (device->bdev) {
496 close_bdev_exclusive(device->bdev, device->mode);
497 fs_devices->open_devices--;
498 }
499 if (device->writeable) {
500 list_del_init(&device->dev_alloc_list);
501 fs_devices->rw_devices--;
502 }
503
504 device->bdev = NULL;
505 device->writeable = 0;
506 device->in_fs_metadata = 0;
507 }
508 WARN_ON(fs_devices->open_devices);
509 WARN_ON(fs_devices->rw_devices);
510 fs_devices->opened = 0;
511 fs_devices->seeding = 0;
512
513 return 0;
514 }
515
516 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
517 {
518 struct btrfs_fs_devices *seed_devices = NULL;
519 int ret;
520
521 mutex_lock(&uuid_mutex);
522 ret = __btrfs_close_devices(fs_devices);
523 if (!fs_devices->opened) {
524 seed_devices = fs_devices->seed;
525 fs_devices->seed = NULL;
526 }
527 mutex_unlock(&uuid_mutex);
528
529 while (seed_devices) {
530 fs_devices = seed_devices;
531 seed_devices = fs_devices->seed;
532 __btrfs_close_devices(fs_devices);
533 free_fs_devices(fs_devices);
534 }
535 return ret;
536 }
537
538 static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
539 fmode_t flags, void *holder)
540 {
541 struct block_device *bdev;
542 struct list_head *head = &fs_devices->devices;
543 struct btrfs_device *device;
544 struct block_device *latest_bdev = NULL;
545 struct buffer_head *bh;
546 struct btrfs_super_block *disk_super;
547 u64 latest_devid = 0;
548 u64 latest_transid = 0;
549 u64 devid;
550 int seeding = 1;
551 int ret = 0;
552
553 list_for_each_entry(device, head, dev_list) {
554 if (device->bdev)
555 continue;
556 if (!device->name)
557 continue;
558
559 bdev = open_bdev_exclusive(device->name, flags, holder);
560 if (IS_ERR(bdev)) {
561 printk(KERN_INFO "open %s failed\n", device->name);
562 goto error;
563 }
564 set_blocksize(bdev, 4096);
565
566 bh = btrfs_read_dev_super(bdev);
567 if (!bh)
568 goto error_close;
569
570 disk_super = (struct btrfs_super_block *)bh->b_data;
571 devid = le64_to_cpu(disk_super->dev_item.devid);
572 if (devid != device->devid)
573 goto error_brelse;
574
575 if (memcmp(device->uuid, disk_super->dev_item.uuid,
576 BTRFS_UUID_SIZE))
577 goto error_brelse;
578
579 device->generation = btrfs_super_generation(disk_super);
580 if (!latest_transid || device->generation > latest_transid) {
581 latest_devid = devid;
582 latest_transid = device->generation;
583 latest_bdev = bdev;
584 }
585
586 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
587 device->writeable = 0;
588 } else {
589 device->writeable = !bdev_read_only(bdev);
590 seeding = 0;
591 }
592
593 device->bdev = bdev;
594 device->in_fs_metadata = 0;
595 device->mode = flags;
596
597 fs_devices->open_devices++;
598 if (device->writeable) {
599 fs_devices->rw_devices++;
600 list_add(&device->dev_alloc_list,
601 &fs_devices->alloc_list);
602 }
603 continue;
604
605 error_brelse:
606 brelse(bh);
607 error_close:
608 close_bdev_exclusive(bdev, FMODE_READ);
609 error:
610 continue;
611 }
612 if (fs_devices->open_devices == 0) {
613 ret = -EIO;
614 goto out;
615 }
616 fs_devices->seeding = seeding;
617 fs_devices->opened = 1;
618 fs_devices->latest_bdev = latest_bdev;
619 fs_devices->latest_devid = latest_devid;
620 fs_devices->latest_trans = latest_transid;
621 fs_devices->total_rw_bytes = 0;
622 out:
623 return ret;
624 }
625
626 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
627 fmode_t flags, void *holder)
628 {
629 int ret;
630
631 mutex_lock(&uuid_mutex);
632 if (fs_devices->opened) {
633 fs_devices->opened++;
634 ret = 0;
635 } else {
636 ret = __btrfs_open_devices(fs_devices, flags, holder);
637 }
638 mutex_unlock(&uuid_mutex);
639 return ret;
640 }
641
642 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
643 struct btrfs_fs_devices **fs_devices_ret)
644 {
645 struct btrfs_super_block *disk_super;
646 struct block_device *bdev;
647 struct buffer_head *bh;
648 int ret;
649 u64 devid;
650 u64 transid;
651
652 mutex_lock(&uuid_mutex);
653
654 bdev = open_bdev_exclusive(path, flags, holder);
655
656 if (IS_ERR(bdev)) {
657 ret = PTR_ERR(bdev);
658 goto error;
659 }
660
661 ret = set_blocksize(bdev, 4096);
662 if (ret)
663 goto error_close;
664 bh = btrfs_read_dev_super(bdev);
665 if (!bh) {
666 ret = -EIO;
667 goto error_close;
668 }
669 disk_super = (struct btrfs_super_block *)bh->b_data;
670 devid = le64_to_cpu(disk_super->dev_item.devid);
671 transid = btrfs_super_generation(disk_super);
672 if (disk_super->label[0])
673 printk(KERN_INFO "device label %s ", disk_super->label);
674 else {
675 /* FIXME, make a readl uuid parser */
676 printk(KERN_INFO "device fsid %llx-%llx ",
677 *(unsigned long long *)disk_super->fsid,
678 *(unsigned long long *)(disk_super->fsid + 8));
679 }
680 printk(KERN_CONT "devid %llu transid %llu %s\n",
681 (unsigned long long)devid, (unsigned long long)transid, path);
682 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
683
684 brelse(bh);
685 error_close:
686 close_bdev_exclusive(bdev, flags);
687 error:
688 mutex_unlock(&uuid_mutex);
689 return ret;
690 }
691
692 /*
693 * this uses a pretty simple search, the expectation is that it is
694 * called very infrequently and that a given device has a small number
695 * of extents
696 */
697 static noinline int find_free_dev_extent(struct btrfs_trans_handle *trans,
698 struct btrfs_device *device,
699 u64 num_bytes, u64 *start)
700 {
701 struct btrfs_key key;
702 struct btrfs_root *root = device->dev_root;
703 struct btrfs_dev_extent *dev_extent = NULL;
704 struct btrfs_path *path;
705 u64 hole_size = 0;
706 u64 last_byte = 0;
707 u64 search_start = 0;
708 u64 search_end = device->total_bytes;
709 int ret;
710 int slot = 0;
711 int start_found;
712 struct extent_buffer *l;
713
714 path = btrfs_alloc_path();
715 if (!path)
716 return -ENOMEM;
717 path->reada = 2;
718 start_found = 0;
719
720 /* FIXME use last free of some kind */
721
722 /* we don't want to overwrite the superblock on the drive,
723 * so we make sure to start at an offset of at least 1MB
724 */
725 search_start = max((u64)1024 * 1024, search_start);
726
727 if (root->fs_info->alloc_start + num_bytes <= device->total_bytes)
728 search_start = max(root->fs_info->alloc_start, search_start);
729
730 key.objectid = device->devid;
731 key.offset = search_start;
732 key.type = BTRFS_DEV_EXTENT_KEY;
733 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
734 if (ret < 0)
735 goto error;
736 ret = btrfs_previous_item(root, path, 0, key.type);
737 if (ret < 0)
738 goto error;
739 l = path->nodes[0];
740 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
741 while (1) {
742 l = path->nodes[0];
743 slot = path->slots[0];
744 if (slot >= btrfs_header_nritems(l)) {
745 ret = btrfs_next_leaf(root, path);
746 if (ret == 0)
747 continue;
748 if (ret < 0)
749 goto error;
750 no_more_items:
751 if (!start_found) {
752 if (search_start >= search_end) {
753 ret = -ENOSPC;
754 goto error;
755 }
756 *start = search_start;
757 start_found = 1;
758 goto check_pending;
759 }
760 *start = last_byte > search_start ?
761 last_byte : search_start;
762 if (search_end <= *start) {
763 ret = -ENOSPC;
764 goto error;
765 }
766 goto check_pending;
767 }
768 btrfs_item_key_to_cpu(l, &key, slot);
769
770 if (key.objectid < device->devid)
771 goto next;
772
773 if (key.objectid > device->devid)
774 goto no_more_items;
775
776 if (key.offset >= search_start && key.offset > last_byte &&
777 start_found) {
778 if (last_byte < search_start)
779 last_byte = search_start;
780 hole_size = key.offset - last_byte;
781 if (key.offset > last_byte &&
782 hole_size >= num_bytes) {
783 *start = last_byte;
784 goto check_pending;
785 }
786 }
787 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
788 goto next;
789
790 start_found = 1;
791 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
792 last_byte = key.offset + btrfs_dev_extent_length(l, dev_extent);
793 next:
794 path->slots[0]++;
795 cond_resched();
796 }
797 check_pending:
798 /* we have to make sure we didn't find an extent that has already
799 * been allocated by the map tree or the original allocation
800 */
801 BUG_ON(*start < search_start);
802
803 if (*start + num_bytes > search_end) {
804 ret = -ENOSPC;
805 goto error;
806 }
807 /* check for pending inserts here */
808 ret = 0;
809
810 error:
811 btrfs_free_path(path);
812 return ret;
813 }
814
815 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
816 struct btrfs_device *device,
817 u64 start)
818 {
819 int ret;
820 struct btrfs_path *path;
821 struct btrfs_root *root = device->dev_root;
822 struct btrfs_key key;
823 struct btrfs_key found_key;
824 struct extent_buffer *leaf = NULL;
825 struct btrfs_dev_extent *extent = NULL;
826
827 path = btrfs_alloc_path();
828 if (!path)
829 return -ENOMEM;
830
831 key.objectid = device->devid;
832 key.offset = start;
833 key.type = BTRFS_DEV_EXTENT_KEY;
834
835 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
836 if (ret > 0) {
837 ret = btrfs_previous_item(root, path, key.objectid,
838 BTRFS_DEV_EXTENT_KEY);
839 BUG_ON(ret);
840 leaf = path->nodes[0];
841 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
842 extent = btrfs_item_ptr(leaf, path->slots[0],
843 struct btrfs_dev_extent);
844 BUG_ON(found_key.offset > start || found_key.offset +
845 btrfs_dev_extent_length(leaf, extent) < start);
846 ret = 0;
847 } else if (ret == 0) {
848 leaf = path->nodes[0];
849 extent = btrfs_item_ptr(leaf, path->slots[0],
850 struct btrfs_dev_extent);
851 }
852 BUG_ON(ret);
853
854 if (device->bytes_used > 0)
855 device->bytes_used -= btrfs_dev_extent_length(leaf, extent);
856 ret = btrfs_del_item(trans, root, path);
857 BUG_ON(ret);
858
859 btrfs_free_path(path);
860 return ret;
861 }
862
863 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
864 struct btrfs_device *device,
865 u64 chunk_tree, u64 chunk_objectid,
866 u64 chunk_offset, u64 start, u64 num_bytes)
867 {
868 int ret;
869 struct btrfs_path *path;
870 struct btrfs_root *root = device->dev_root;
871 struct btrfs_dev_extent *extent;
872 struct extent_buffer *leaf;
873 struct btrfs_key key;
874
875 WARN_ON(!device->in_fs_metadata);
876 path = btrfs_alloc_path();
877 if (!path)
878 return -ENOMEM;
879
880 key.objectid = device->devid;
881 key.offset = start;
882 key.type = BTRFS_DEV_EXTENT_KEY;
883 ret = btrfs_insert_empty_item(trans, root, path, &key,
884 sizeof(*extent));
885 BUG_ON(ret);
886
887 leaf = path->nodes[0];
888 extent = btrfs_item_ptr(leaf, path->slots[0],
889 struct btrfs_dev_extent);
890 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
891 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
892 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
893
894 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
895 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
896 BTRFS_UUID_SIZE);
897
898 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
899 btrfs_mark_buffer_dirty(leaf);
900 btrfs_free_path(path);
901 return ret;
902 }
903
904 static noinline int find_next_chunk(struct btrfs_root *root,
905 u64 objectid, u64 *offset)
906 {
907 struct btrfs_path *path;
908 int ret;
909 struct btrfs_key key;
910 struct btrfs_chunk *chunk;
911 struct btrfs_key found_key;
912
913 path = btrfs_alloc_path();
914 BUG_ON(!path);
915
916 key.objectid = objectid;
917 key.offset = (u64)-1;
918 key.type = BTRFS_CHUNK_ITEM_KEY;
919
920 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
921 if (ret < 0)
922 goto error;
923
924 BUG_ON(ret == 0);
925
926 ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
927 if (ret) {
928 *offset = 0;
929 } else {
930 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
931 path->slots[0]);
932 if (found_key.objectid != objectid)
933 *offset = 0;
934 else {
935 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
936 struct btrfs_chunk);
937 *offset = found_key.offset +
938 btrfs_chunk_length(path->nodes[0], chunk);
939 }
940 }
941 ret = 0;
942 error:
943 btrfs_free_path(path);
944 return ret;
945 }
946
947 static noinline int find_next_devid(struct btrfs_root *root, u64 *objectid)
948 {
949 int ret;
950 struct btrfs_key key;
951 struct btrfs_key found_key;
952 struct btrfs_path *path;
953
954 root = root->fs_info->chunk_root;
955
956 path = btrfs_alloc_path();
957 if (!path)
958 return -ENOMEM;
959
960 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
961 key.type = BTRFS_DEV_ITEM_KEY;
962 key.offset = (u64)-1;
963
964 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
965 if (ret < 0)
966 goto error;
967
968 BUG_ON(ret == 0);
969
970 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
971 BTRFS_DEV_ITEM_KEY);
972 if (ret) {
973 *objectid = 1;
974 } else {
975 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
976 path->slots[0]);
977 *objectid = found_key.offset + 1;
978 }
979 ret = 0;
980 error:
981 btrfs_free_path(path);
982 return ret;
983 }
984
985 /*
986 * the device information is stored in the chunk root
987 * the btrfs_device struct should be fully filled in
988 */
989 int btrfs_add_device(struct btrfs_trans_handle *trans,
990 struct btrfs_root *root,
991 struct btrfs_device *device)
992 {
993 int ret;
994 struct btrfs_path *path;
995 struct btrfs_dev_item *dev_item;
996 struct extent_buffer *leaf;
997 struct btrfs_key key;
998 unsigned long ptr;
999
1000 root = root->fs_info->chunk_root;
1001
1002 path = btrfs_alloc_path();
1003 if (!path)
1004 return -ENOMEM;
1005
1006 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1007 key.type = BTRFS_DEV_ITEM_KEY;
1008 key.offset = device->devid;
1009
1010 ret = btrfs_insert_empty_item(trans, root, path, &key,
1011 sizeof(*dev_item));
1012 if (ret)
1013 goto out;
1014
1015 leaf = path->nodes[0];
1016 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1017
1018 btrfs_set_device_id(leaf, dev_item, device->devid);
1019 btrfs_set_device_generation(leaf, dev_item, 0);
1020 btrfs_set_device_type(leaf, dev_item, device->type);
1021 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1022 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1023 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1024 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
1025 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1026 btrfs_set_device_group(leaf, dev_item, 0);
1027 btrfs_set_device_seek_speed(leaf, dev_item, 0);
1028 btrfs_set_device_bandwidth(leaf, dev_item, 0);
1029 btrfs_set_device_start_offset(leaf, dev_item, 0);
1030
1031 ptr = (unsigned long)btrfs_device_uuid(dev_item);
1032 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1033 ptr = (unsigned long)btrfs_device_fsid(dev_item);
1034 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
1035 btrfs_mark_buffer_dirty(leaf);
1036
1037 ret = 0;
1038 out:
1039 btrfs_free_path(path);
1040 return ret;
1041 }
1042
1043 static int btrfs_rm_dev_item(struct btrfs_root *root,
1044 struct btrfs_device *device)
1045 {
1046 int ret;
1047 struct btrfs_path *path;
1048 struct btrfs_key key;
1049 struct btrfs_trans_handle *trans;
1050
1051 root = root->fs_info->chunk_root;
1052
1053 path = btrfs_alloc_path();
1054 if (!path)
1055 return -ENOMEM;
1056
1057 trans = btrfs_start_transaction(root, 1);
1058 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1059 key.type = BTRFS_DEV_ITEM_KEY;
1060 key.offset = device->devid;
1061 lock_chunks(root);
1062
1063 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1064 if (ret < 0)
1065 goto out;
1066
1067 if (ret > 0) {
1068 ret = -ENOENT;
1069 goto out;
1070 }
1071
1072 ret = btrfs_del_item(trans, root, path);
1073 if (ret)
1074 goto out;
1075 out:
1076 btrfs_free_path(path);
1077 unlock_chunks(root);
1078 btrfs_commit_transaction(trans, root);
1079 return ret;
1080 }
1081
1082 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
1083 {
1084 struct btrfs_device *device;
1085 struct btrfs_device *next_device;
1086 struct block_device *bdev;
1087 struct buffer_head *bh = NULL;
1088 struct btrfs_super_block *disk_super;
1089 u64 all_avail;
1090 u64 devid;
1091 u64 num_devices;
1092 u8 *dev_uuid;
1093 int ret = 0;
1094
1095 mutex_lock(&uuid_mutex);
1096 mutex_lock(&root->fs_info->volume_mutex);
1097
1098 all_avail = root->fs_info->avail_data_alloc_bits |
1099 root->fs_info->avail_system_alloc_bits |
1100 root->fs_info->avail_metadata_alloc_bits;
1101
1102 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) &&
1103 root->fs_info->fs_devices->rw_devices <= 4) {
1104 printk(KERN_ERR "btrfs: unable to go below four devices "
1105 "on raid10\n");
1106 ret = -EINVAL;
1107 goto out;
1108 }
1109
1110 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) &&
1111 root->fs_info->fs_devices->rw_devices <= 2) {
1112 printk(KERN_ERR "btrfs: unable to go below two "
1113 "devices on raid1\n");
1114 ret = -EINVAL;
1115 goto out;
1116 }
1117
1118 if (strcmp(device_path, "missing") == 0) {
1119 struct list_head *devices;
1120 struct btrfs_device *tmp;
1121
1122 device = NULL;
1123 devices = &root->fs_info->fs_devices->devices;
1124 list_for_each_entry(tmp, devices, dev_list) {
1125 if (tmp->in_fs_metadata && !tmp->bdev) {
1126 device = tmp;
1127 break;
1128 }
1129 }
1130 bdev = NULL;
1131 bh = NULL;
1132 disk_super = NULL;
1133 if (!device) {
1134 printk(KERN_ERR "btrfs: no missing devices found to "
1135 "remove\n");
1136 goto out;
1137 }
1138 } else {
1139 bdev = open_bdev_exclusive(device_path, FMODE_READ,
1140 root->fs_info->bdev_holder);
1141 if (IS_ERR(bdev)) {
1142 ret = PTR_ERR(bdev);
1143 goto out;
1144 }
1145
1146 set_blocksize(bdev, 4096);
1147 bh = btrfs_read_dev_super(bdev);
1148 if (!bh) {
1149 ret = -EIO;
1150 goto error_close;
1151 }
1152 disk_super = (struct btrfs_super_block *)bh->b_data;
1153 devid = le64_to_cpu(disk_super->dev_item.devid);
1154 dev_uuid = disk_super->dev_item.uuid;
1155 device = btrfs_find_device(root, devid, dev_uuid,
1156 disk_super->fsid);
1157 if (!device) {
1158 ret = -ENOENT;
1159 goto error_brelse;
1160 }
1161 }
1162
1163 if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
1164 printk(KERN_ERR "btrfs: unable to remove the only writeable "
1165 "device\n");
1166 ret = -EINVAL;
1167 goto error_brelse;
1168 }
1169
1170 if (device->writeable) {
1171 list_del_init(&device->dev_alloc_list);
1172 root->fs_info->fs_devices->rw_devices--;
1173 }
1174
1175 ret = btrfs_shrink_device(device, 0);
1176 if (ret)
1177 goto error_brelse;
1178
1179 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1180 if (ret)
1181 goto error_brelse;
1182
1183 device->in_fs_metadata = 0;
1184 list_del_init(&device->dev_list);
1185 device->fs_devices->num_devices--;
1186
1187 next_device = list_entry(root->fs_info->fs_devices->devices.next,
1188 struct btrfs_device, dev_list);
1189 if (device->bdev == root->fs_info->sb->s_bdev)
1190 root->fs_info->sb->s_bdev = next_device->bdev;
1191 if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1192 root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1193
1194 if (device->bdev) {
1195 close_bdev_exclusive(device->bdev, device->mode);
1196 device->bdev = NULL;
1197 device->fs_devices->open_devices--;
1198 }
1199
1200 num_devices = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
1201 btrfs_set_super_num_devices(&root->fs_info->super_copy, num_devices);
1202
1203 if (device->fs_devices->open_devices == 0) {
1204 struct btrfs_fs_devices *fs_devices;
1205 fs_devices = root->fs_info->fs_devices;
1206 while (fs_devices) {
1207 if (fs_devices->seed == device->fs_devices)
1208 break;
1209 fs_devices = fs_devices->seed;
1210 }
1211 fs_devices->seed = device->fs_devices->seed;
1212 device->fs_devices->seed = NULL;
1213 __btrfs_close_devices(device->fs_devices);
1214 free_fs_devices(device->fs_devices);
1215 }
1216
1217 /*
1218 * at this point, the device is zero sized. We want to
1219 * remove it from the devices list and zero out the old super
1220 */
1221 if (device->writeable) {
1222 /* make sure this device isn't detected as part of
1223 * the FS anymore
1224 */
1225 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1226 set_buffer_dirty(bh);
1227 sync_dirty_buffer(bh);
1228 }
1229
1230 kfree(device->name);
1231 kfree(device);
1232 ret = 0;
1233
1234 error_brelse:
1235 brelse(bh);
1236 error_close:
1237 if (bdev)
1238 close_bdev_exclusive(bdev, FMODE_READ);
1239 out:
1240 mutex_unlock(&root->fs_info->volume_mutex);
1241 mutex_unlock(&uuid_mutex);
1242 return ret;
1243 }
1244
1245 /*
1246 * does all the dirty work required for changing file system's UUID.
1247 */
1248 static int btrfs_prepare_sprout(struct btrfs_trans_handle *trans,
1249 struct btrfs_root *root)
1250 {
1251 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1252 struct btrfs_fs_devices *old_devices;
1253 struct btrfs_fs_devices *seed_devices;
1254 struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
1255 struct btrfs_device *device;
1256 u64 super_flags;
1257
1258 BUG_ON(!mutex_is_locked(&uuid_mutex));
1259 if (!fs_devices->seeding)
1260 return -EINVAL;
1261
1262 seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
1263 if (!seed_devices)
1264 return -ENOMEM;
1265
1266 old_devices = clone_fs_devices(fs_devices);
1267 if (IS_ERR(old_devices)) {
1268 kfree(seed_devices);
1269 return PTR_ERR(old_devices);
1270 }
1271
1272 list_add(&old_devices->list, &fs_uuids);
1273
1274 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1275 seed_devices->opened = 1;
1276 INIT_LIST_HEAD(&seed_devices->devices);
1277 INIT_LIST_HEAD(&seed_devices->alloc_list);
1278 list_splice_init(&fs_devices->devices, &seed_devices->devices);
1279 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1280 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1281 device->fs_devices = seed_devices;
1282 }
1283
1284 fs_devices->seeding = 0;
1285 fs_devices->num_devices = 0;
1286 fs_devices->open_devices = 0;
1287 fs_devices->seed = seed_devices;
1288
1289 generate_random_uuid(fs_devices->fsid);
1290 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1291 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1292 super_flags = btrfs_super_flags(disk_super) &
1293 ~BTRFS_SUPER_FLAG_SEEDING;
1294 btrfs_set_super_flags(disk_super, super_flags);
1295
1296 return 0;
1297 }
1298
1299 /*
1300 * strore the expected generation for seed devices in device items.
1301 */
1302 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1303 struct btrfs_root *root)
1304 {
1305 struct btrfs_path *path;
1306 struct extent_buffer *leaf;
1307 struct btrfs_dev_item *dev_item;
1308 struct btrfs_device *device;
1309 struct btrfs_key key;
1310 u8 fs_uuid[BTRFS_UUID_SIZE];
1311 u8 dev_uuid[BTRFS_UUID_SIZE];
1312 u64 devid;
1313 int ret;
1314
1315 path = btrfs_alloc_path();
1316 if (!path)
1317 return -ENOMEM;
1318
1319 root = root->fs_info->chunk_root;
1320 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1321 key.offset = 0;
1322 key.type = BTRFS_DEV_ITEM_KEY;
1323
1324 while (1) {
1325 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1326 if (ret < 0)
1327 goto error;
1328
1329 leaf = path->nodes[0];
1330 next_slot:
1331 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1332 ret = btrfs_next_leaf(root, path);
1333 if (ret > 0)
1334 break;
1335 if (ret < 0)
1336 goto error;
1337 leaf = path->nodes[0];
1338 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1339 btrfs_release_path(root, path);
1340 continue;
1341 }
1342
1343 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1344 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1345 key.type != BTRFS_DEV_ITEM_KEY)
1346 break;
1347
1348 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1349 struct btrfs_dev_item);
1350 devid = btrfs_device_id(leaf, dev_item);
1351 read_extent_buffer(leaf, dev_uuid,
1352 (unsigned long)btrfs_device_uuid(dev_item),
1353 BTRFS_UUID_SIZE);
1354 read_extent_buffer(leaf, fs_uuid,
1355 (unsigned long)btrfs_device_fsid(dev_item),
1356 BTRFS_UUID_SIZE);
1357 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
1358 BUG_ON(!device);
1359
1360 if (device->fs_devices->seeding) {
1361 btrfs_set_device_generation(leaf, dev_item,
1362 device->generation);
1363 btrfs_mark_buffer_dirty(leaf);
1364 }
1365
1366 path->slots[0]++;
1367 goto next_slot;
1368 }
1369 ret = 0;
1370 error:
1371 btrfs_free_path(path);
1372 return ret;
1373 }
1374
1375 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1376 {
1377 struct btrfs_trans_handle *trans;
1378 struct btrfs_device *device;
1379 struct block_device *bdev;
1380 struct list_head *devices;
1381 struct super_block *sb = root->fs_info->sb;
1382 u64 total_bytes;
1383 int seeding_dev = 0;
1384 int ret = 0;
1385
1386 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1387 return -EINVAL;
1388
1389 bdev = open_bdev_exclusive(device_path, 0, root->fs_info->bdev_holder);
1390 if (!bdev)
1391 return -EIO;
1392
1393 if (root->fs_info->fs_devices->seeding) {
1394 seeding_dev = 1;
1395 down_write(&sb->s_umount);
1396 mutex_lock(&uuid_mutex);
1397 }
1398
1399 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1400 mutex_lock(&root->fs_info->volume_mutex);
1401
1402 devices = &root->fs_info->fs_devices->devices;
1403 list_for_each_entry(device, devices, dev_list) {
1404 if (device->bdev == bdev) {
1405 ret = -EEXIST;
1406 goto error;
1407 }
1408 }
1409
1410 device = kzalloc(sizeof(*device), GFP_NOFS);
1411 if (!device) {
1412 /* we can safely leave the fs_devices entry around */
1413 ret = -ENOMEM;
1414 goto error;
1415 }
1416
1417 device->name = kstrdup(device_path, GFP_NOFS);
1418 if (!device->name) {
1419 kfree(device);
1420 ret = -ENOMEM;
1421 goto error;
1422 }
1423
1424 ret = find_next_devid(root, &device->devid);
1425 if (ret) {
1426 kfree(device);
1427 goto error;
1428 }
1429
1430 trans = btrfs_start_transaction(root, 1);
1431 lock_chunks(root);
1432
1433 device->barriers = 1;
1434 device->writeable = 1;
1435 device->work.func = pending_bios_fn;
1436 generate_random_uuid(device->uuid);
1437 spin_lock_init(&device->io_lock);
1438 device->generation = trans->transid;
1439 device->io_width = root->sectorsize;
1440 device->io_align = root->sectorsize;
1441 device->sector_size = root->sectorsize;
1442 device->total_bytes = i_size_read(bdev->bd_inode);
1443 device->disk_total_bytes = device->total_bytes;
1444 device->dev_root = root->fs_info->dev_root;
1445 device->bdev = bdev;
1446 device->in_fs_metadata = 1;
1447 device->mode = 0;
1448 set_blocksize(device->bdev, 4096);
1449
1450 if (seeding_dev) {
1451 sb->s_flags &= ~MS_RDONLY;
1452 ret = btrfs_prepare_sprout(trans, root);
1453 BUG_ON(ret);
1454 }
1455
1456 device->fs_devices = root->fs_info->fs_devices;
1457 list_add(&device->dev_list, &root->fs_info->fs_devices->devices);
1458 list_add(&device->dev_alloc_list,
1459 &root->fs_info->fs_devices->alloc_list);
1460 root->fs_info->fs_devices->num_devices++;
1461 root->fs_info->fs_devices->open_devices++;
1462 root->fs_info->fs_devices->rw_devices++;
1463 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
1464
1465 total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
1466 btrfs_set_super_total_bytes(&root->fs_info->super_copy,
1467 total_bytes + device->total_bytes);
1468
1469 total_bytes = btrfs_super_num_devices(&root->fs_info->super_copy);
1470 btrfs_set_super_num_devices(&root->fs_info->super_copy,
1471 total_bytes + 1);
1472
1473 if (seeding_dev) {
1474 ret = init_first_rw_device(trans, root, device);
1475 BUG_ON(ret);
1476 ret = btrfs_finish_sprout(trans, root);
1477 BUG_ON(ret);
1478 } else {
1479 ret = btrfs_add_device(trans, root, device);
1480 }
1481
1482 /*
1483 * we've got more storage, clear any full flags on the space
1484 * infos
1485 */
1486 btrfs_clear_space_info_full(root->fs_info);
1487
1488 unlock_chunks(root);
1489 btrfs_commit_transaction(trans, root);
1490
1491 if (seeding_dev) {
1492 mutex_unlock(&uuid_mutex);
1493 up_write(&sb->s_umount);
1494
1495 ret = btrfs_relocate_sys_chunks(root);
1496 BUG_ON(ret);
1497 }
1498 out:
1499 mutex_unlock(&root->fs_info->volume_mutex);
1500 return ret;
1501 error:
1502 close_bdev_exclusive(bdev, 0);
1503 if (seeding_dev) {
1504 mutex_unlock(&uuid_mutex);
1505 up_write(&sb->s_umount);
1506 }
1507 goto out;
1508 }
1509
1510 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
1511 struct btrfs_device *device)
1512 {
1513 int ret;
1514 struct btrfs_path *path;
1515 struct btrfs_root *root;
1516 struct btrfs_dev_item *dev_item;
1517 struct extent_buffer *leaf;
1518 struct btrfs_key key;
1519
1520 root = device->dev_root->fs_info->chunk_root;
1521
1522 path = btrfs_alloc_path();
1523 if (!path)
1524 return -ENOMEM;
1525
1526 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1527 key.type = BTRFS_DEV_ITEM_KEY;
1528 key.offset = device->devid;
1529
1530 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1531 if (ret < 0)
1532 goto out;
1533
1534 if (ret > 0) {
1535 ret = -ENOENT;
1536 goto out;
1537 }
1538
1539 leaf = path->nodes[0];
1540 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1541
1542 btrfs_set_device_id(leaf, dev_item, device->devid);
1543 btrfs_set_device_type(leaf, dev_item, device->type);
1544 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1545 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1546 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1547 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
1548 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1549 btrfs_mark_buffer_dirty(leaf);
1550
1551 out:
1552 btrfs_free_path(path);
1553 return ret;
1554 }
1555
1556 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
1557 struct btrfs_device *device, u64 new_size)
1558 {
1559 struct btrfs_super_block *super_copy =
1560 &device->dev_root->fs_info->super_copy;
1561 u64 old_total = btrfs_super_total_bytes(super_copy);
1562 u64 diff = new_size - device->total_bytes;
1563
1564 if (!device->writeable)
1565 return -EACCES;
1566 if (new_size <= device->total_bytes)
1567 return -EINVAL;
1568
1569 btrfs_set_super_total_bytes(super_copy, old_total + diff);
1570 device->fs_devices->total_rw_bytes += diff;
1571
1572 device->total_bytes = new_size;
1573 btrfs_clear_space_info_full(device->dev_root->fs_info);
1574
1575 return btrfs_update_device(trans, device);
1576 }
1577
1578 int btrfs_grow_device(struct btrfs_trans_handle *trans,
1579 struct btrfs_device *device, u64 new_size)
1580 {
1581 int ret;
1582 lock_chunks(device->dev_root);
1583 ret = __btrfs_grow_device(trans, device, new_size);
1584 unlock_chunks(device->dev_root);
1585 return ret;
1586 }
1587
1588 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
1589 struct btrfs_root *root,
1590 u64 chunk_tree, u64 chunk_objectid,
1591 u64 chunk_offset)
1592 {
1593 int ret;
1594 struct btrfs_path *path;
1595 struct btrfs_key key;
1596
1597 root = root->fs_info->chunk_root;
1598 path = btrfs_alloc_path();
1599 if (!path)
1600 return -ENOMEM;
1601
1602 key.objectid = chunk_objectid;
1603 key.offset = chunk_offset;
1604 key.type = BTRFS_CHUNK_ITEM_KEY;
1605
1606 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1607 BUG_ON(ret);
1608
1609 ret = btrfs_del_item(trans, root, path);
1610 BUG_ON(ret);
1611
1612 btrfs_free_path(path);
1613 return 0;
1614 }
1615
1616 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
1617 chunk_offset)
1618 {
1619 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
1620 struct btrfs_disk_key *disk_key;
1621 struct btrfs_chunk *chunk;
1622 u8 *ptr;
1623 int ret = 0;
1624 u32 num_stripes;
1625 u32 array_size;
1626 u32 len = 0;
1627 u32 cur;
1628 struct btrfs_key key;
1629
1630 array_size = btrfs_super_sys_array_size(super_copy);
1631
1632 ptr = super_copy->sys_chunk_array;
1633 cur = 0;
1634
1635 while (cur < array_size) {
1636 disk_key = (struct btrfs_disk_key *)ptr;
1637 btrfs_disk_key_to_cpu(&key, disk_key);
1638
1639 len = sizeof(*disk_key);
1640
1641 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
1642 chunk = (struct btrfs_chunk *)(ptr + len);
1643 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
1644 len += btrfs_chunk_item_size(num_stripes);
1645 } else {
1646 ret = -EIO;
1647 break;
1648 }
1649 if (key.objectid == chunk_objectid &&
1650 key.offset == chunk_offset) {
1651 memmove(ptr, ptr + len, array_size - (cur + len));
1652 array_size -= len;
1653 btrfs_set_super_sys_array_size(super_copy, array_size);
1654 } else {
1655 ptr += len;
1656 cur += len;
1657 }
1658 }
1659 return ret;
1660 }
1661
1662 static int btrfs_relocate_chunk(struct btrfs_root *root,
1663 u64 chunk_tree, u64 chunk_objectid,
1664 u64 chunk_offset)
1665 {
1666 struct extent_map_tree *em_tree;
1667 struct btrfs_root *extent_root;
1668 struct btrfs_trans_handle *trans;
1669 struct extent_map *em;
1670 struct map_lookup *map;
1671 int ret;
1672 int i;
1673
1674 printk(KERN_INFO "btrfs relocating chunk %llu\n",
1675 (unsigned long long)chunk_offset);
1676 root = root->fs_info->chunk_root;
1677 extent_root = root->fs_info->extent_root;
1678 em_tree = &root->fs_info->mapping_tree.map_tree;
1679
1680 /* step one, relocate all the extents inside this chunk */
1681 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
1682 BUG_ON(ret);
1683
1684 trans = btrfs_start_transaction(root, 1);
1685 BUG_ON(!trans);
1686
1687 lock_chunks(root);
1688
1689 /*
1690 * step two, delete the device extents and the
1691 * chunk tree entries
1692 */
1693 spin_lock(&em_tree->lock);
1694 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
1695 spin_unlock(&em_tree->lock);
1696
1697 BUG_ON(em->start > chunk_offset ||
1698 em->start + em->len < chunk_offset);
1699 map = (struct map_lookup *)em->bdev;
1700
1701 for (i = 0; i < map->num_stripes; i++) {
1702 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
1703 map->stripes[i].physical);
1704 BUG_ON(ret);
1705
1706 if (map->stripes[i].dev) {
1707 ret = btrfs_update_device(trans, map->stripes[i].dev);
1708 BUG_ON(ret);
1709 }
1710 }
1711 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
1712 chunk_offset);
1713
1714 BUG_ON(ret);
1715
1716 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
1717 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
1718 BUG_ON(ret);
1719 }
1720
1721 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
1722 BUG_ON(ret);
1723
1724 spin_lock(&em_tree->lock);
1725 remove_extent_mapping(em_tree, em);
1726 spin_unlock(&em_tree->lock);
1727
1728 kfree(map);
1729 em->bdev = NULL;
1730
1731 /* once for the tree */
1732 free_extent_map(em);
1733 /* once for us */
1734 free_extent_map(em);
1735
1736 unlock_chunks(root);
1737 btrfs_end_transaction(trans, root);
1738 return 0;
1739 }
1740
1741 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
1742 {
1743 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
1744 struct btrfs_path *path;
1745 struct extent_buffer *leaf;
1746 struct btrfs_chunk *chunk;
1747 struct btrfs_key key;
1748 struct btrfs_key found_key;
1749 u64 chunk_tree = chunk_root->root_key.objectid;
1750 u64 chunk_type;
1751 int ret;
1752
1753 path = btrfs_alloc_path();
1754 if (!path)
1755 return -ENOMEM;
1756
1757 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
1758 key.offset = (u64)-1;
1759 key.type = BTRFS_CHUNK_ITEM_KEY;
1760
1761 while (1) {
1762 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
1763 if (ret < 0)
1764 goto error;
1765 BUG_ON(ret == 0);
1766
1767 ret = btrfs_previous_item(chunk_root, path, key.objectid,
1768 key.type);
1769 if (ret < 0)
1770 goto error;
1771 if (ret > 0)
1772 break;
1773
1774 leaf = path->nodes[0];
1775 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1776
1777 chunk = btrfs_item_ptr(leaf, path->slots[0],
1778 struct btrfs_chunk);
1779 chunk_type = btrfs_chunk_type(leaf, chunk);
1780 btrfs_release_path(chunk_root, path);
1781
1782 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
1783 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
1784 found_key.objectid,
1785 found_key.offset);
1786 BUG_ON(ret);
1787 }
1788
1789 if (found_key.offset == 0)
1790 break;
1791 key.offset = found_key.offset - 1;
1792 }
1793 ret = 0;
1794 error:
1795 btrfs_free_path(path);
1796 return ret;
1797 }
1798
1799 static u64 div_factor(u64 num, int factor)
1800 {
1801 if (factor == 10)
1802 return num;
1803 num *= factor;
1804 do_div(num, 10);
1805 return num;
1806 }
1807
1808 int btrfs_balance(struct btrfs_root *dev_root)
1809 {
1810 int ret;
1811 struct list_head *devices = &dev_root->fs_info->fs_devices->devices;
1812 struct btrfs_device *device;
1813 u64 old_size;
1814 u64 size_to_free;
1815 struct btrfs_path *path;
1816 struct btrfs_key key;
1817 struct btrfs_chunk *chunk;
1818 struct btrfs_root *chunk_root = dev_root->fs_info->chunk_root;
1819 struct btrfs_trans_handle *trans;
1820 struct btrfs_key found_key;
1821
1822 if (dev_root->fs_info->sb->s_flags & MS_RDONLY)
1823 return -EROFS;
1824
1825 mutex_lock(&dev_root->fs_info->volume_mutex);
1826 dev_root = dev_root->fs_info->dev_root;
1827
1828 /* step one make some room on all the devices */
1829 list_for_each_entry(device, devices, dev_list) {
1830 old_size = device->total_bytes;
1831 size_to_free = div_factor(old_size, 1);
1832 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
1833 if (!device->writeable ||
1834 device->total_bytes - device->bytes_used > size_to_free)
1835 continue;
1836
1837 ret = btrfs_shrink_device(device, old_size - size_to_free);
1838 BUG_ON(ret);
1839
1840 trans = btrfs_start_transaction(dev_root, 1);
1841 BUG_ON(!trans);
1842
1843 ret = btrfs_grow_device(trans, device, old_size);
1844 BUG_ON(ret);
1845
1846 btrfs_end_transaction(trans, dev_root);
1847 }
1848
1849 /* step two, relocate all the chunks */
1850 path = btrfs_alloc_path();
1851 BUG_ON(!path);
1852
1853 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
1854 key.offset = (u64)-1;
1855 key.type = BTRFS_CHUNK_ITEM_KEY;
1856
1857 while (1) {
1858 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
1859 if (ret < 0)
1860 goto error;
1861
1862 /*
1863 * this shouldn't happen, it means the last relocate
1864 * failed
1865 */
1866 if (ret == 0)
1867 break;
1868
1869 ret = btrfs_previous_item(chunk_root, path, 0,
1870 BTRFS_CHUNK_ITEM_KEY);
1871 if (ret)
1872 break;
1873
1874 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1875 path->slots[0]);
1876 if (found_key.objectid != key.objectid)
1877 break;
1878
1879 chunk = btrfs_item_ptr(path->nodes[0],
1880 path->slots[0],
1881 struct btrfs_chunk);
1882 key.offset = found_key.offset;
1883 /* chunk zero is special */
1884 if (key.offset == 0)
1885 break;
1886
1887 btrfs_release_path(chunk_root, path);
1888 ret = btrfs_relocate_chunk(chunk_root,
1889 chunk_root->root_key.objectid,
1890 found_key.objectid,
1891 found_key.offset);
1892 BUG_ON(ret);
1893 }
1894 ret = 0;
1895 error:
1896 btrfs_free_path(path);
1897 mutex_unlock(&dev_root->fs_info->volume_mutex);
1898 return ret;
1899 }
1900
1901 /*
1902 * shrinking a device means finding all of the device extents past
1903 * the new size, and then following the back refs to the chunks.
1904 * The chunk relocation code actually frees the device extent
1905 */
1906 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
1907 {
1908 struct btrfs_trans_handle *trans;
1909 struct btrfs_root *root = device->dev_root;
1910 struct btrfs_dev_extent *dev_extent = NULL;
1911 struct btrfs_path *path;
1912 u64 length;
1913 u64 chunk_tree;
1914 u64 chunk_objectid;
1915 u64 chunk_offset;
1916 int ret;
1917 int slot;
1918 struct extent_buffer *l;
1919 struct btrfs_key key;
1920 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
1921 u64 old_total = btrfs_super_total_bytes(super_copy);
1922 u64 diff = device->total_bytes - new_size;
1923
1924 if (new_size >= device->total_bytes)
1925 return -EINVAL;
1926
1927 path = btrfs_alloc_path();
1928 if (!path)
1929 return -ENOMEM;
1930
1931 trans = btrfs_start_transaction(root, 1);
1932 if (!trans) {
1933 ret = -ENOMEM;
1934 goto done;
1935 }
1936
1937 path->reada = 2;
1938
1939 lock_chunks(root);
1940
1941 device->total_bytes = new_size;
1942 if (device->writeable)
1943 device->fs_devices->total_rw_bytes -= diff;
1944 unlock_chunks(root);
1945 btrfs_end_transaction(trans, root);
1946
1947 key.objectid = device->devid;
1948 key.offset = (u64)-1;
1949 key.type = BTRFS_DEV_EXTENT_KEY;
1950
1951 while (1) {
1952 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1953 if (ret < 0)
1954 goto done;
1955
1956 ret = btrfs_previous_item(root, path, 0, key.type);
1957 if (ret < 0)
1958 goto done;
1959 if (ret) {
1960 ret = 0;
1961 goto done;
1962 }
1963
1964 l = path->nodes[0];
1965 slot = path->slots[0];
1966 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
1967
1968 if (key.objectid != device->devid)
1969 goto done;
1970
1971 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
1972 length = btrfs_dev_extent_length(l, dev_extent);
1973
1974 if (key.offset + length <= new_size)
1975 break;
1976
1977 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
1978 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
1979 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
1980 btrfs_release_path(root, path);
1981
1982 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
1983 chunk_offset);
1984 if (ret)
1985 goto done;
1986 }
1987
1988 /* Shrinking succeeded, else we would be at "done". */
1989 trans = btrfs_start_transaction(root, 1);
1990 if (!trans) {
1991 ret = -ENOMEM;
1992 goto done;
1993 }
1994 lock_chunks(root);
1995
1996 device->disk_total_bytes = new_size;
1997 /* Now btrfs_update_device() will change the on-disk size. */
1998 ret = btrfs_update_device(trans, device);
1999 if (ret) {
2000 unlock_chunks(root);
2001 btrfs_end_transaction(trans, root);
2002 goto done;
2003 }
2004 WARN_ON(diff > old_total);
2005 btrfs_set_super_total_bytes(super_copy, old_total - diff);
2006 unlock_chunks(root);
2007 btrfs_end_transaction(trans, root);
2008 done:
2009 btrfs_free_path(path);
2010 return ret;
2011 }
2012
2013 static int btrfs_add_system_chunk(struct btrfs_trans_handle *trans,
2014 struct btrfs_root *root,
2015 struct btrfs_key *key,
2016 struct btrfs_chunk *chunk, int item_size)
2017 {
2018 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
2019 struct btrfs_disk_key disk_key;
2020 u32 array_size;
2021 u8 *ptr;
2022
2023 array_size = btrfs_super_sys_array_size(super_copy);
2024 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
2025 return -EFBIG;
2026
2027 ptr = super_copy->sys_chunk_array + array_size;
2028 btrfs_cpu_key_to_disk(&disk_key, key);
2029 memcpy(ptr, &disk_key, sizeof(disk_key));
2030 ptr += sizeof(disk_key);
2031 memcpy(ptr, chunk, item_size);
2032 item_size += sizeof(disk_key);
2033 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
2034 return 0;
2035 }
2036
2037 static noinline u64 chunk_bytes_by_type(u64 type, u64 calc_size,
2038 int num_stripes, int sub_stripes)
2039 {
2040 if (type & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_DUP))
2041 return calc_size;
2042 else if (type & BTRFS_BLOCK_GROUP_RAID10)
2043 return calc_size * (num_stripes / sub_stripes);
2044 else
2045 return calc_size * num_stripes;
2046 }
2047
2048 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
2049 struct btrfs_root *extent_root,
2050 struct map_lookup **map_ret,
2051 u64 *num_bytes, u64 *stripe_size,
2052 u64 start, u64 type)
2053 {
2054 struct btrfs_fs_info *info = extent_root->fs_info;
2055 struct btrfs_device *device = NULL;
2056 struct btrfs_fs_devices *fs_devices = info->fs_devices;
2057 struct list_head *cur;
2058 struct map_lookup *map = NULL;
2059 struct extent_map_tree *em_tree;
2060 struct extent_map *em;
2061 struct list_head private_devs;
2062 int min_stripe_size = 1 * 1024 * 1024;
2063 u64 calc_size = 1024 * 1024 * 1024;
2064 u64 max_chunk_size = calc_size;
2065 u64 min_free;
2066 u64 avail;
2067 u64 max_avail = 0;
2068 u64 dev_offset;
2069 int num_stripes = 1;
2070 int min_stripes = 1;
2071 int sub_stripes = 0;
2072 int looped = 0;
2073 int ret;
2074 int index;
2075 int stripe_len = 64 * 1024;
2076
2077 if ((type & BTRFS_BLOCK_GROUP_RAID1) &&
2078 (type & BTRFS_BLOCK_GROUP_DUP)) {
2079 WARN_ON(1);
2080 type &= ~BTRFS_BLOCK_GROUP_DUP;
2081 }
2082 if (list_empty(&fs_devices->alloc_list))
2083 return -ENOSPC;
2084
2085 if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
2086 num_stripes = fs_devices->rw_devices;
2087 min_stripes = 2;
2088 }
2089 if (type & (BTRFS_BLOCK_GROUP_DUP)) {
2090 num_stripes = 2;
2091 min_stripes = 2;
2092 }
2093 if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
2094 num_stripes = min_t(u64, 2, fs_devices->rw_devices);
2095 if (num_stripes < 2)
2096 return -ENOSPC;
2097 min_stripes = 2;
2098 }
2099 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
2100 num_stripes = fs_devices->rw_devices;
2101 if (num_stripes < 4)
2102 return -ENOSPC;
2103 num_stripes &= ~(u32)1;
2104 sub_stripes = 2;
2105 min_stripes = 4;
2106 }
2107
2108 if (type & BTRFS_BLOCK_GROUP_DATA) {
2109 max_chunk_size = 10 * calc_size;
2110 min_stripe_size = 64 * 1024 * 1024;
2111 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
2112 max_chunk_size = 4 * calc_size;
2113 min_stripe_size = 32 * 1024 * 1024;
2114 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
2115 calc_size = 8 * 1024 * 1024;
2116 max_chunk_size = calc_size * 2;
2117 min_stripe_size = 1 * 1024 * 1024;
2118 }
2119
2120 /* we don't want a chunk larger than 10% of writeable space */
2121 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
2122 max_chunk_size);
2123
2124 again:
2125 if (!map || map->num_stripes != num_stripes) {
2126 kfree(map);
2127 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
2128 if (!map)
2129 return -ENOMEM;
2130 map->num_stripes = num_stripes;
2131 }
2132
2133 if (calc_size * num_stripes > max_chunk_size) {
2134 calc_size = max_chunk_size;
2135 do_div(calc_size, num_stripes);
2136 do_div(calc_size, stripe_len);
2137 calc_size *= stripe_len;
2138 }
2139 /* we don't want tiny stripes */
2140 calc_size = max_t(u64, min_stripe_size, calc_size);
2141
2142 do_div(calc_size, stripe_len);
2143 calc_size *= stripe_len;
2144
2145 cur = fs_devices->alloc_list.next;
2146 index = 0;
2147
2148 if (type & BTRFS_BLOCK_GROUP_DUP)
2149 min_free = calc_size * 2;
2150 else
2151 min_free = calc_size;
2152
2153 /*
2154 * we add 1MB because we never use the first 1MB of the device, unless
2155 * we've looped, then we are likely allocating the maximum amount of
2156 * space left already
2157 */
2158 if (!looped)
2159 min_free += 1024 * 1024;
2160
2161 INIT_LIST_HEAD(&private_devs);
2162 while (index < num_stripes) {
2163 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
2164 BUG_ON(!device->writeable);
2165 if (device->total_bytes > device->bytes_used)
2166 avail = device->total_bytes - device->bytes_used;
2167 else
2168 avail = 0;
2169 cur = cur->next;
2170
2171 if (device->in_fs_metadata && avail >= min_free) {
2172 ret = find_free_dev_extent(trans, device,
2173 min_free, &dev_offset);
2174 if (ret == 0) {
2175 list_move_tail(&device->dev_alloc_list,
2176 &private_devs);
2177 map->stripes[index].dev = device;
2178 map->stripes[index].physical = dev_offset;
2179 index++;
2180 if (type & BTRFS_BLOCK_GROUP_DUP) {
2181 map->stripes[index].dev = device;
2182 map->stripes[index].physical =
2183 dev_offset + calc_size;
2184 index++;
2185 }
2186 }
2187 } else if (device->in_fs_metadata && avail > max_avail)
2188 max_avail = avail;
2189 if (cur == &fs_devices->alloc_list)
2190 break;
2191 }
2192 list_splice(&private_devs, &fs_devices->alloc_list);
2193 if (index < num_stripes) {
2194 if (index >= min_stripes) {
2195 num_stripes = index;
2196 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
2197 num_stripes /= sub_stripes;
2198 num_stripes *= sub_stripes;
2199 }
2200 looped = 1;
2201 goto again;
2202 }
2203 if (!looped && max_avail > 0) {
2204 looped = 1;
2205 calc_size = max_avail;
2206 goto again;
2207 }
2208 kfree(map);
2209 return -ENOSPC;
2210 }
2211 map->sector_size = extent_root->sectorsize;
2212 map->stripe_len = stripe_len;
2213 map->io_align = stripe_len;
2214 map->io_width = stripe_len;
2215 map->type = type;
2216 map->num_stripes = num_stripes;
2217 map->sub_stripes = sub_stripes;
2218
2219 *map_ret = map;
2220 *stripe_size = calc_size;
2221 *num_bytes = chunk_bytes_by_type(type, calc_size,
2222 num_stripes, sub_stripes);
2223
2224 em = alloc_extent_map(GFP_NOFS);
2225 if (!em) {
2226 kfree(map);
2227 return -ENOMEM;
2228 }
2229 em->bdev = (struct block_device *)map;
2230 em->start = start;
2231 em->len = *num_bytes;
2232 em->block_start = 0;
2233 em->block_len = em->len;
2234
2235 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
2236 spin_lock(&em_tree->lock);
2237 ret = add_extent_mapping(em_tree, em);
2238 spin_unlock(&em_tree->lock);
2239 BUG_ON(ret);
2240 free_extent_map(em);
2241
2242 ret = btrfs_make_block_group(trans, extent_root, 0, type,
2243 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2244 start, *num_bytes);
2245 BUG_ON(ret);
2246
2247 index = 0;
2248 while (index < map->num_stripes) {
2249 device = map->stripes[index].dev;
2250 dev_offset = map->stripes[index].physical;
2251
2252 ret = btrfs_alloc_dev_extent(trans, device,
2253 info->chunk_root->root_key.objectid,
2254 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2255 start, dev_offset, calc_size);
2256 BUG_ON(ret);
2257 index++;
2258 }
2259
2260 return 0;
2261 }
2262
2263 static int __finish_chunk_alloc(struct btrfs_trans_handle *trans,
2264 struct btrfs_root *extent_root,
2265 struct map_lookup *map, u64 chunk_offset,
2266 u64 chunk_size, u64 stripe_size)
2267 {
2268 u64 dev_offset;
2269 struct btrfs_key key;
2270 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
2271 struct btrfs_device *device;
2272 struct btrfs_chunk *chunk;
2273 struct btrfs_stripe *stripe;
2274 size_t item_size = btrfs_chunk_item_size(map->num_stripes);
2275 int index = 0;
2276 int ret;
2277
2278 chunk = kzalloc(item_size, GFP_NOFS);
2279 if (!chunk)
2280 return -ENOMEM;
2281
2282 index = 0;
2283 while (index < map->num_stripes) {
2284 device = map->stripes[index].dev;
2285 device->bytes_used += stripe_size;
2286 ret = btrfs_update_device(trans, device);
2287 BUG_ON(ret);
2288 index++;
2289 }
2290
2291 index = 0;
2292 stripe = &chunk->stripe;
2293 while (index < map->num_stripes) {
2294 device = map->stripes[index].dev;
2295 dev_offset = map->stripes[index].physical;
2296
2297 btrfs_set_stack_stripe_devid(stripe, device->devid);
2298 btrfs_set_stack_stripe_offset(stripe, dev_offset);
2299 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
2300 stripe++;
2301 index++;
2302 }
2303
2304 btrfs_set_stack_chunk_length(chunk, chunk_size);
2305 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
2306 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
2307 btrfs_set_stack_chunk_type(chunk, map->type);
2308 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
2309 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
2310 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
2311 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
2312 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
2313
2314 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2315 key.type = BTRFS_CHUNK_ITEM_KEY;
2316 key.offset = chunk_offset;
2317
2318 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
2319 BUG_ON(ret);
2320
2321 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2322 ret = btrfs_add_system_chunk(trans, chunk_root, &key, chunk,
2323 item_size);
2324 BUG_ON(ret);
2325 }
2326 kfree(chunk);
2327 return 0;
2328 }
2329
2330 /*
2331 * Chunk allocation falls into two parts. The first part does works
2332 * that make the new allocated chunk useable, but not do any operation
2333 * that modifies the chunk tree. The second part does the works that
2334 * require modifying the chunk tree. This division is important for the
2335 * bootstrap process of adding storage to a seed btrfs.
2336 */
2337 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
2338 struct btrfs_root *extent_root, u64 type)
2339 {
2340 u64 chunk_offset;
2341 u64 chunk_size;
2342 u64 stripe_size;
2343 struct map_lookup *map;
2344 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
2345 int ret;
2346
2347 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2348 &chunk_offset);
2349 if (ret)
2350 return ret;
2351
2352 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
2353 &stripe_size, chunk_offset, type);
2354 if (ret)
2355 return ret;
2356
2357 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
2358 chunk_size, stripe_size);
2359 BUG_ON(ret);
2360 return 0;
2361 }
2362
2363 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
2364 struct btrfs_root *root,
2365 struct btrfs_device *device)
2366 {
2367 u64 chunk_offset;
2368 u64 sys_chunk_offset;
2369 u64 chunk_size;
2370 u64 sys_chunk_size;
2371 u64 stripe_size;
2372 u64 sys_stripe_size;
2373 u64 alloc_profile;
2374 struct map_lookup *map;
2375 struct map_lookup *sys_map;
2376 struct btrfs_fs_info *fs_info = root->fs_info;
2377 struct btrfs_root *extent_root = fs_info->extent_root;
2378 int ret;
2379
2380 ret = find_next_chunk(fs_info->chunk_root,
2381 BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset);
2382 BUG_ON(ret);
2383
2384 alloc_profile = BTRFS_BLOCK_GROUP_METADATA |
2385 (fs_info->metadata_alloc_profile &
2386 fs_info->avail_metadata_alloc_bits);
2387 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
2388
2389 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
2390 &stripe_size, chunk_offset, alloc_profile);
2391 BUG_ON(ret);
2392
2393 sys_chunk_offset = chunk_offset + chunk_size;
2394
2395 alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM |
2396 (fs_info->system_alloc_profile &
2397 fs_info->avail_system_alloc_bits);
2398 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
2399
2400 ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,
2401 &sys_chunk_size, &sys_stripe_size,
2402 sys_chunk_offset, alloc_profile);
2403 BUG_ON(ret);
2404
2405 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
2406 BUG_ON(ret);
2407
2408 /*
2409 * Modifying chunk tree needs allocating new blocks from both
2410 * system block group and metadata block group. So we only can
2411 * do operations require modifying the chunk tree after both
2412 * block groups were created.
2413 */
2414 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
2415 chunk_size, stripe_size);
2416 BUG_ON(ret);
2417
2418 ret = __finish_chunk_alloc(trans, extent_root, sys_map,
2419 sys_chunk_offset, sys_chunk_size,
2420 sys_stripe_size);
2421 BUG_ON(ret);
2422 return 0;
2423 }
2424
2425 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
2426 {
2427 struct extent_map *em;
2428 struct map_lookup *map;
2429 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
2430 int readonly = 0;
2431 int i;
2432
2433 spin_lock(&map_tree->map_tree.lock);
2434 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
2435 spin_unlock(&map_tree->map_tree.lock);
2436 if (!em)
2437 return 1;
2438
2439 map = (struct map_lookup *)em->bdev;
2440 for (i = 0; i < map->num_stripes; i++) {
2441 if (!map->stripes[i].dev->writeable) {
2442 readonly = 1;
2443 break;
2444 }
2445 }
2446 free_extent_map(em);
2447 return readonly;
2448 }
2449
2450 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
2451 {
2452 extent_map_tree_init(&tree->map_tree, GFP_NOFS);
2453 }
2454
2455 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
2456 {
2457 struct extent_map *em;
2458
2459 while (1) {
2460 spin_lock(&tree->map_tree.lock);
2461 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
2462 if (em)
2463 remove_extent_mapping(&tree->map_tree, em);
2464 spin_unlock(&tree->map_tree.lock);
2465 if (!em)
2466 break;
2467 kfree(em->bdev);
2468 /* once for us */
2469 free_extent_map(em);
2470 /* once for the tree */
2471 free_extent_map(em);
2472 }
2473 }
2474
2475 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
2476 {
2477 struct extent_map *em;
2478 struct map_lookup *map;
2479 struct extent_map_tree *em_tree = &map_tree->map_tree;
2480 int ret;
2481
2482 spin_lock(&em_tree->lock);
2483 em = lookup_extent_mapping(em_tree, logical, len);
2484 spin_unlock(&em_tree->lock);
2485 BUG_ON(!em);
2486
2487 BUG_ON(em->start > logical || em->start + em->len < logical);
2488 map = (struct map_lookup *)em->bdev;
2489 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
2490 ret = map->num_stripes;
2491 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
2492 ret = map->sub_stripes;
2493 else
2494 ret = 1;
2495 free_extent_map(em);
2496 return ret;
2497 }
2498
2499 static int find_live_mirror(struct map_lookup *map, int first, int num,
2500 int optimal)
2501 {
2502 int i;
2503 if (map->stripes[optimal].dev->bdev)
2504 return optimal;
2505 for (i = first; i < first + num; i++) {
2506 if (map->stripes[i].dev->bdev)
2507 return i;
2508 }
2509 /* we couldn't find one that doesn't fail. Just return something
2510 * and the io error handling code will clean up eventually
2511 */
2512 return optimal;
2513 }
2514
2515 static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
2516 u64 logical, u64 *length,
2517 struct btrfs_multi_bio **multi_ret,
2518 int mirror_num, struct page *unplug_page)
2519 {
2520 struct extent_map *em;
2521 struct map_lookup *map;
2522 struct extent_map_tree *em_tree = &map_tree->map_tree;
2523 u64 offset;
2524 u64 stripe_offset;
2525 u64 stripe_nr;
2526 int stripes_allocated = 8;
2527 int stripes_required = 1;
2528 int stripe_index;
2529 int i;
2530 int num_stripes;
2531 int max_errors = 0;
2532 struct btrfs_multi_bio *multi = NULL;
2533
2534 if (multi_ret && !(rw & (1 << BIO_RW)))
2535 stripes_allocated = 1;
2536 again:
2537 if (multi_ret) {
2538 multi = kzalloc(btrfs_multi_bio_size(stripes_allocated),
2539 GFP_NOFS);
2540 if (!multi)
2541 return -ENOMEM;
2542
2543 atomic_set(&multi->error, 0);
2544 }
2545
2546 spin_lock(&em_tree->lock);
2547 em = lookup_extent_mapping(em_tree, logical, *length);
2548 spin_unlock(&em_tree->lock);
2549
2550 if (!em && unplug_page)
2551 return 0;
2552
2553 if (!em) {
2554 printk(KERN_CRIT "unable to find logical %llu len %llu\n",
2555 (unsigned long long)logical,
2556 (unsigned long long)*length);
2557 BUG();
2558 }
2559
2560 BUG_ON(em->start > logical || em->start + em->len < logical);
2561 map = (struct map_lookup *)em->bdev;
2562 offset = logical - em->start;
2563
2564 if (mirror_num > map->num_stripes)
2565 mirror_num = 0;
2566
2567 /* if our multi bio struct is too small, back off and try again */
2568 if (rw & (1 << BIO_RW)) {
2569 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
2570 BTRFS_BLOCK_GROUP_DUP)) {
2571 stripes_required = map->num_stripes;
2572 max_errors = 1;
2573 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2574 stripes_required = map->sub_stripes;
2575 max_errors = 1;
2576 }
2577 }
2578 if (multi_ret && (rw & (1 << BIO_RW)) &&
2579 stripes_allocated < stripes_required) {
2580 stripes_allocated = map->num_stripes;
2581 free_extent_map(em);
2582 kfree(multi);
2583 goto again;
2584 }
2585 stripe_nr = offset;
2586 /*
2587 * stripe_nr counts the total number of stripes we have to stride
2588 * to get to this block
2589 */
2590 do_div(stripe_nr, map->stripe_len);
2591
2592 stripe_offset = stripe_nr * map->stripe_len;
2593 BUG_ON(offset < stripe_offset);
2594
2595 /* stripe_offset is the offset of this block in its stripe*/
2596 stripe_offset = offset - stripe_offset;
2597
2598 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
2599 BTRFS_BLOCK_GROUP_RAID10 |
2600 BTRFS_BLOCK_GROUP_DUP)) {
2601 /* we limit the length of each bio to what fits in a stripe */
2602 *length = min_t(u64, em->len - offset,
2603 map->stripe_len - stripe_offset);
2604 } else {
2605 *length = em->len - offset;
2606 }
2607
2608 if (!multi_ret && !unplug_page)
2609 goto out;
2610
2611 num_stripes = 1;
2612 stripe_index = 0;
2613 if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
2614 if (unplug_page || (rw & (1 << BIO_RW)))
2615 num_stripes = map->num_stripes;
2616 else if (mirror_num)
2617 stripe_index = mirror_num - 1;
2618 else {
2619 stripe_index = find_live_mirror(map, 0,
2620 map->num_stripes,
2621 current->pid % map->num_stripes);
2622 }
2623
2624 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
2625 if (rw & (1 << BIO_RW))
2626 num_stripes = map->num_stripes;
2627 else if (mirror_num)
2628 stripe_index = mirror_num - 1;
2629
2630 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2631 int factor = map->num_stripes / map->sub_stripes;
2632
2633 stripe_index = do_div(stripe_nr, factor);
2634 stripe_index *= map->sub_stripes;
2635
2636 if (unplug_page || (rw & (1 << BIO_RW)))
2637 num_stripes = map->sub_stripes;
2638 else if (mirror_num)
2639 stripe_index += mirror_num - 1;
2640 else {
2641 stripe_index = find_live_mirror(map, stripe_index,
2642 map->sub_stripes, stripe_index +
2643 current->pid % map->sub_stripes);
2644 }
2645 } else {
2646 /*
2647 * after this do_div call, stripe_nr is the number of stripes
2648 * on this device we have to walk to find the data, and
2649 * stripe_index is the number of our device in the stripe array
2650 */
2651 stripe_index = do_div(stripe_nr, map->num_stripes);
2652 }
2653 BUG_ON(stripe_index >= map->num_stripes);
2654
2655 for (i = 0; i < num_stripes; i++) {
2656 if (unplug_page) {
2657 struct btrfs_device *device;
2658 struct backing_dev_info *bdi;
2659
2660 device = map->stripes[stripe_index].dev;
2661 if (device->bdev) {
2662 bdi = blk_get_backing_dev_info(device->bdev);
2663 if (bdi->unplug_io_fn)
2664 bdi->unplug_io_fn(bdi, unplug_page);
2665 }
2666 } else {
2667 multi->stripes[i].physical =
2668 map->stripes[stripe_index].physical +
2669 stripe_offset + stripe_nr * map->stripe_len;
2670 multi->stripes[i].dev = map->stripes[stripe_index].dev;
2671 }
2672 stripe_index++;
2673 }
2674 if (multi_ret) {
2675 *multi_ret = multi;
2676 multi->num_stripes = num_stripes;
2677 multi->max_errors = max_errors;
2678 }
2679 out:
2680 free_extent_map(em);
2681 return 0;
2682 }
2683
2684 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
2685 u64 logical, u64 *length,
2686 struct btrfs_multi_bio **multi_ret, int mirror_num)
2687 {
2688 return __btrfs_map_block(map_tree, rw, logical, length, multi_ret,
2689 mirror_num, NULL);
2690 }
2691
2692 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
2693 u64 chunk_start, u64 physical, u64 devid,
2694 u64 **logical, int *naddrs, int *stripe_len)
2695 {
2696 struct extent_map_tree *em_tree = &map_tree->map_tree;
2697 struct extent_map *em;
2698 struct map_lookup *map;
2699 u64 *buf;
2700 u64 bytenr;
2701 u64 length;
2702 u64 stripe_nr;
2703 int i, j, nr = 0;
2704
2705 spin_lock(&em_tree->lock);
2706 em = lookup_extent_mapping(em_tree, chunk_start, 1);
2707 spin_unlock(&em_tree->lock);
2708
2709 BUG_ON(!em || em->start != chunk_start);
2710 map = (struct map_lookup *)em->bdev;
2711
2712 length = em->len;
2713 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
2714 do_div(length, map->num_stripes / map->sub_stripes);
2715 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
2716 do_div(length, map->num_stripes);
2717
2718 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
2719 BUG_ON(!buf);
2720
2721 for (i = 0; i < map->num_stripes; i++) {
2722 if (devid && map->stripes[i].dev->devid != devid)
2723 continue;
2724 if (map->stripes[i].physical > physical ||
2725 map->stripes[i].physical + length <= physical)
2726 continue;
2727
2728 stripe_nr = physical - map->stripes[i].physical;
2729 do_div(stripe_nr, map->stripe_len);
2730
2731 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2732 stripe_nr = stripe_nr * map->num_stripes + i;
2733 do_div(stripe_nr, map->sub_stripes);
2734 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
2735 stripe_nr = stripe_nr * map->num_stripes + i;
2736 }
2737 bytenr = chunk_start + stripe_nr * map->stripe_len;
2738 WARN_ON(nr >= map->num_stripes);
2739 for (j = 0; j < nr; j++) {
2740 if (buf[j] == bytenr)
2741 break;
2742 }
2743 if (j == nr) {
2744 WARN_ON(nr >= map->num_stripes);
2745 buf[nr++] = bytenr;
2746 }
2747 }
2748
2749 for (i = 0; i > nr; i++) {
2750 struct btrfs_multi_bio *multi;
2751 struct btrfs_bio_stripe *stripe;
2752 int ret;
2753
2754 length = 1;
2755 ret = btrfs_map_block(map_tree, WRITE, buf[i],
2756 &length, &multi, 0);
2757 BUG_ON(ret);
2758
2759 stripe = multi->stripes;
2760 for (j = 0; j < multi->num_stripes; j++) {
2761 if (stripe->physical >= physical &&
2762 physical < stripe->physical + length)
2763 break;
2764 }
2765 BUG_ON(j >= multi->num_stripes);
2766 kfree(multi);
2767 }
2768
2769 *logical = buf;
2770 *naddrs = nr;
2771 *stripe_len = map->stripe_len;
2772
2773 free_extent_map(em);
2774 return 0;
2775 }
2776
2777 int btrfs_unplug_page(struct btrfs_mapping_tree *map_tree,
2778 u64 logical, struct page *page)
2779 {
2780 u64 length = PAGE_CACHE_SIZE;
2781 return __btrfs_map_block(map_tree, READ, logical, &length,
2782 NULL, 0, page);
2783 }
2784
2785 static void end_bio_multi_stripe(struct bio *bio, int err)
2786 {
2787 struct btrfs_multi_bio *multi = bio->bi_private;
2788 int is_orig_bio = 0;
2789
2790 if (err)
2791 atomic_inc(&multi->error);
2792
2793 if (bio == multi->orig_bio)
2794 is_orig_bio = 1;
2795
2796 if (atomic_dec_and_test(&multi->stripes_pending)) {
2797 if (!is_orig_bio) {
2798 bio_put(bio);
2799 bio = multi->orig_bio;
2800 }
2801 bio->bi_private = multi->private;
2802 bio->bi_end_io = multi->end_io;
2803 /* only send an error to the higher layers if it is
2804 * beyond the tolerance of the multi-bio
2805 */
2806 if (atomic_read(&multi->error) > multi->max_errors) {
2807 err = -EIO;
2808 } else if (err) {
2809 /*
2810 * this bio is actually up to date, we didn't
2811 * go over the max number of errors
2812 */
2813 set_bit(BIO_UPTODATE, &bio->bi_flags);
2814 err = 0;
2815 }
2816 kfree(multi);
2817
2818 bio_endio(bio, err);
2819 } else if (!is_orig_bio) {
2820 bio_put(bio);
2821 }
2822 }
2823
2824 struct async_sched {
2825 struct bio *bio;
2826 int rw;
2827 struct btrfs_fs_info *info;
2828 struct btrfs_work work;
2829 };
2830
2831 /*
2832 * see run_scheduled_bios for a description of why bios are collected for
2833 * async submit.
2834 *
2835 * This will add one bio to the pending list for a device and make sure
2836 * the work struct is scheduled.
2837 */
2838 static noinline int schedule_bio(struct btrfs_root *root,
2839 struct btrfs_device *device,
2840 int rw, struct bio *bio)
2841 {
2842 int should_queue = 1;
2843 struct btrfs_pending_bios *pending_bios;
2844
2845 /* don't bother with additional async steps for reads, right now */
2846 if (!(rw & (1 << BIO_RW))) {
2847 bio_get(bio);
2848 submit_bio(rw, bio);
2849 bio_put(bio);
2850 return 0;
2851 }
2852
2853 /*
2854 * nr_async_bios allows us to reliably return congestion to the
2855 * higher layers. Otherwise, the async bio makes it appear we have
2856 * made progress against dirty pages when we've really just put it
2857 * on a queue for later
2858 */
2859 atomic_inc(&root->fs_info->nr_async_bios);
2860 WARN_ON(bio->bi_next);
2861 bio->bi_next = NULL;
2862 bio->bi_rw |= rw;
2863
2864 spin_lock(&device->io_lock);
2865 if (bio_sync(bio))
2866 pending_bios = &device->pending_sync_bios;
2867 else
2868 pending_bios = &device->pending_bios;
2869
2870 if (pending_bios->tail)
2871 pending_bios->tail->bi_next = bio;
2872
2873 pending_bios->tail = bio;
2874 if (!pending_bios->head)
2875 pending_bios->head = bio;
2876 if (device->running_pending)
2877 should_queue = 0;
2878
2879 spin_unlock(&device->io_lock);
2880
2881 if (should_queue)
2882 btrfs_queue_worker(&root->fs_info->submit_workers,
2883 &device->work);
2884 return 0;
2885 }
2886
2887 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
2888 int mirror_num, int async_submit)
2889 {
2890 struct btrfs_mapping_tree *map_tree;
2891 struct btrfs_device *dev;
2892 struct bio *first_bio = bio;
2893 u64 logical = (u64)bio->bi_sector << 9;
2894 u64 length = 0;
2895 u64 map_length;
2896 struct btrfs_multi_bio *multi = NULL;
2897 int ret;
2898 int dev_nr = 0;
2899 int total_devs = 1;
2900
2901 length = bio->bi_size;
2902 map_tree = &root->fs_info->mapping_tree;
2903 map_length = length;
2904
2905 ret = btrfs_map_block(map_tree, rw, logical, &map_length, &multi,
2906 mirror_num);
2907 BUG_ON(ret);
2908
2909 total_devs = multi->num_stripes;
2910 if (map_length < length) {
2911 printk(KERN_CRIT "mapping failed logical %llu bio len %llu "
2912 "len %llu\n", (unsigned long long)logical,
2913 (unsigned long long)length,
2914 (unsigned long long)map_length);
2915 BUG();
2916 }
2917 multi->end_io = first_bio->bi_end_io;
2918 multi->private = first_bio->bi_private;
2919 multi->orig_bio = first_bio;
2920 atomic_set(&multi->stripes_pending, multi->num_stripes);
2921
2922 while (dev_nr < total_devs) {
2923 if (total_devs > 1) {
2924 if (dev_nr < total_devs - 1) {
2925 bio = bio_clone(first_bio, GFP_NOFS);
2926 BUG_ON(!bio);
2927 } else {
2928 bio = first_bio;
2929 }
2930 bio->bi_private = multi;
2931 bio->bi_end_io = end_bio_multi_stripe;
2932 }
2933 bio->bi_sector = multi->stripes[dev_nr].physical >> 9;
2934 dev = multi->stripes[dev_nr].dev;
2935 BUG_ON(rw == WRITE && !dev->writeable);
2936 if (dev && dev->bdev) {
2937 bio->bi_bdev = dev->bdev;
2938 if (async_submit)
2939 schedule_bio(root, dev, rw, bio);
2940 else
2941 submit_bio(rw, bio);
2942 } else {
2943 bio->bi_bdev = root->fs_info->fs_devices->latest_bdev;
2944 bio->bi_sector = logical >> 9;
2945 bio_endio(bio, -EIO);
2946 }
2947 dev_nr++;
2948 }
2949 if (total_devs == 1)
2950 kfree(multi);
2951 return 0;
2952 }
2953
2954 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
2955 u8 *uuid, u8 *fsid)
2956 {
2957 struct btrfs_device *device;
2958 struct btrfs_fs_devices *cur_devices;
2959
2960 cur_devices = root->fs_info->fs_devices;
2961 while (cur_devices) {
2962 if (!fsid ||
2963 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
2964 device = __find_device(&cur_devices->devices,
2965 devid, uuid);
2966 if (device)
2967 return device;
2968 }
2969 cur_devices = cur_devices->seed;
2970 }
2971 return NULL;
2972 }
2973
2974 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
2975 u64 devid, u8 *dev_uuid)
2976 {
2977 struct btrfs_device *device;
2978 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2979
2980 device = kzalloc(sizeof(*device), GFP_NOFS);
2981 if (!device)
2982 return NULL;
2983 list_add(&device->dev_list,
2984 &fs_devices->devices);
2985 device->barriers = 1;
2986 device->dev_root = root->fs_info->dev_root;
2987 device->devid = devid;
2988 device->work.func = pending_bios_fn;
2989 device->fs_devices = fs_devices;
2990 fs_devices->num_devices++;
2991 spin_lock_init(&device->io_lock);
2992 INIT_LIST_HEAD(&device->dev_alloc_list);
2993 memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
2994 return device;
2995 }
2996
2997 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
2998 struct extent_buffer *leaf,
2999 struct btrfs_chunk *chunk)
3000 {
3001 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
3002 struct map_lookup *map;
3003 struct extent_map *em;
3004 u64 logical;
3005 u64 length;
3006 u64 devid;
3007 u8 uuid[BTRFS_UUID_SIZE];
3008 int num_stripes;
3009 int ret;
3010 int i;
3011
3012 logical = key->offset;
3013 length = btrfs_chunk_length(leaf, chunk);
3014
3015 spin_lock(&map_tree->map_tree.lock);
3016 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
3017 spin_unlock(&map_tree->map_tree.lock);
3018
3019 /* already mapped? */
3020 if (em && em->start <= logical && em->start + em->len > logical) {
3021 free_extent_map(em);
3022 return 0;
3023 } else if (em) {
3024 free_extent_map(em);
3025 }
3026
3027 em = alloc_extent_map(GFP_NOFS);
3028 if (!em)
3029 return -ENOMEM;
3030 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
3031 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
3032 if (!map) {
3033 free_extent_map(em);
3034 return -ENOMEM;
3035 }
3036
3037 em->bdev = (struct block_device *)map;
3038 em->start = logical;
3039 em->len = length;
3040 em->block_start = 0;
3041 em->block_len = em->len;
3042
3043 map->num_stripes = num_stripes;
3044 map->io_width = btrfs_chunk_io_width(leaf, chunk);
3045 map->io_align = btrfs_chunk_io_align(leaf, chunk);
3046 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
3047 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
3048 map->type = btrfs_chunk_type(leaf, chunk);
3049 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
3050 for (i = 0; i < num_stripes; i++) {
3051 map->stripes[i].physical =
3052 btrfs_stripe_offset_nr(leaf, chunk, i);
3053 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
3054 read_extent_buffer(leaf, uuid, (unsigned long)
3055 btrfs_stripe_dev_uuid_nr(chunk, i),
3056 BTRFS_UUID_SIZE);
3057 map->stripes[i].dev = btrfs_find_device(root, devid, uuid,
3058 NULL);
3059 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
3060 kfree(map);
3061 free_extent_map(em);
3062 return -EIO;
3063 }
3064 if (!map->stripes[i].dev) {
3065 map->stripes[i].dev =
3066 add_missing_dev(root, devid, uuid);
3067 if (!map->stripes[i].dev) {
3068 kfree(map);
3069 free_extent_map(em);
3070 return -EIO;
3071 }
3072 }
3073 map->stripes[i].dev->in_fs_metadata = 1;
3074 }
3075
3076 spin_lock(&map_tree->map_tree.lock);
3077 ret = add_extent_mapping(&map_tree->map_tree, em);
3078 spin_unlock(&map_tree->map_tree.lock);
3079 BUG_ON(ret);
3080 free_extent_map(em);
3081
3082 return 0;
3083 }
3084
3085 static int fill_device_from_item(struct extent_buffer *leaf,
3086 struct btrfs_dev_item *dev_item,
3087 struct btrfs_device *device)
3088 {
3089 unsigned long ptr;
3090
3091 device->devid = btrfs_device_id(leaf, dev_item);
3092 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
3093 device->total_bytes = device->disk_total_bytes;
3094 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
3095 device->type = btrfs_device_type(leaf, dev_item);
3096 device->io_align = btrfs_device_io_align(leaf, dev_item);
3097 device->io_width = btrfs_device_io_width(leaf, dev_item);
3098 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
3099
3100 ptr = (unsigned long)btrfs_device_uuid(dev_item);
3101 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
3102
3103 return 0;
3104 }
3105
3106 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
3107 {
3108 struct btrfs_fs_devices *fs_devices;
3109 int ret;
3110
3111 mutex_lock(&uuid_mutex);
3112
3113 fs_devices = root->fs_info->fs_devices->seed;
3114 while (fs_devices) {
3115 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
3116 ret = 0;
3117 goto out;
3118 }
3119 fs_devices = fs_devices->seed;
3120 }
3121
3122 fs_devices = find_fsid(fsid);
3123 if (!fs_devices) {
3124 ret = -ENOENT;
3125 goto out;
3126 }
3127
3128 fs_devices = clone_fs_devices(fs_devices);
3129 if (IS_ERR(fs_devices)) {
3130 ret = PTR_ERR(fs_devices);
3131 goto out;
3132 }
3133
3134 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
3135 root->fs_info->bdev_holder);
3136 if (ret)
3137 goto out;
3138
3139 if (!fs_devices->seeding) {
3140 __btrfs_close_devices(fs_devices);
3141 free_fs_devices(fs_devices);
3142 ret = -EINVAL;
3143 goto out;
3144 }
3145
3146 fs_devices->seed = root->fs_info->fs_devices->seed;
3147 root->fs_info->fs_devices->seed = fs_devices;
3148 out:
3149 mutex_unlock(&uuid_mutex);
3150 return ret;
3151 }
3152
3153 static int read_one_dev(struct btrfs_root *root,
3154 struct extent_buffer *leaf,
3155 struct btrfs_dev_item *dev_item)
3156 {
3157 struct btrfs_device *device;
3158 u64 devid;
3159 int ret;
3160 u8 fs_uuid[BTRFS_UUID_SIZE];
3161 u8 dev_uuid[BTRFS_UUID_SIZE];
3162
3163 devid = btrfs_device_id(leaf, dev_item);
3164 read_extent_buffer(leaf, dev_uuid,
3165 (unsigned long)btrfs_device_uuid(dev_item),
3166 BTRFS_UUID_SIZE);
3167 read_extent_buffer(leaf, fs_uuid,
3168 (unsigned long)btrfs_device_fsid(dev_item),
3169 BTRFS_UUID_SIZE);
3170
3171 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
3172 ret = open_seed_devices(root, fs_uuid);
3173 if (ret && !btrfs_test_opt(root, DEGRADED))
3174 return ret;
3175 }
3176
3177 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
3178 if (!device || !device->bdev) {
3179 if (!btrfs_test_opt(root, DEGRADED))
3180 return -EIO;
3181
3182 if (!device) {
3183 printk(KERN_WARNING "warning devid %llu missing\n",
3184 (unsigned long long)devid);
3185 device = add_missing_dev(root, devid, dev_uuid);
3186 if (!device)
3187 return -ENOMEM;
3188 }
3189 }
3190
3191 if (device->fs_devices != root->fs_info->fs_devices) {
3192 BUG_ON(device->writeable);
3193 if (device->generation !=
3194 btrfs_device_generation(leaf, dev_item))
3195 return -EINVAL;
3196 }
3197
3198 fill_device_from_item(leaf, dev_item, device);
3199 device->dev_root = root->fs_info->dev_root;
3200 device->in_fs_metadata = 1;
3201 if (device->writeable)
3202 device->fs_devices->total_rw_bytes += device->total_bytes;
3203 ret = 0;
3204 return ret;
3205 }
3206
3207 int btrfs_read_super_device(struct btrfs_root *root, struct extent_buffer *buf)
3208 {
3209 struct btrfs_dev_item *dev_item;
3210
3211 dev_item = (struct btrfs_dev_item *)offsetof(struct btrfs_super_block,
3212 dev_item);
3213 return read_one_dev(root, buf, dev_item);
3214 }
3215
3216 int btrfs_read_sys_array(struct btrfs_root *root)
3217 {
3218 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
3219 struct extent_buffer *sb;
3220 struct btrfs_disk_key *disk_key;
3221 struct btrfs_chunk *chunk;
3222 u8 *ptr;
3223 unsigned long sb_ptr;
3224 int ret = 0;
3225 u32 num_stripes;
3226 u32 array_size;
3227 u32 len = 0;
3228 u32 cur;
3229 struct btrfs_key key;
3230
3231 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
3232 BTRFS_SUPER_INFO_SIZE);
3233 if (!sb)
3234 return -ENOMEM;
3235 btrfs_set_buffer_uptodate(sb);
3236 btrfs_set_buffer_lockdep_class(sb, 0);
3237
3238 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
3239 array_size = btrfs_super_sys_array_size(super_copy);
3240
3241 ptr = super_copy->sys_chunk_array;
3242 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
3243 cur = 0;
3244
3245 while (cur < array_size) {
3246 disk_key = (struct btrfs_disk_key *)ptr;
3247 btrfs_disk_key_to_cpu(&key, disk_key);
3248
3249 len = sizeof(*disk_key); ptr += len;
3250 sb_ptr += len;
3251 cur += len;
3252
3253 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
3254 chunk = (struct btrfs_chunk *)sb_ptr;
3255 ret = read_one_chunk(root, &key, sb, chunk);
3256 if (ret)
3257 break;
3258 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
3259 len = btrfs_chunk_item_size(num_stripes);
3260 } else {
3261 ret = -EIO;
3262 break;
3263 }
3264 ptr += len;
3265 sb_ptr += len;
3266 cur += len;
3267 }
3268 free_extent_buffer(sb);
3269 return ret;
3270 }
3271
3272 int btrfs_read_chunk_tree(struct btrfs_root *root)
3273 {
3274 struct btrfs_path *path;
3275 struct extent_buffer *leaf;
3276 struct btrfs_key key;
3277 struct btrfs_key found_key;
3278 int ret;
3279 int slot;
3280
3281 root = root->fs_info->chunk_root;
3282
3283 path = btrfs_alloc_path();
3284 if (!path)
3285 return -ENOMEM;
3286
3287 /* first we search for all of the device items, and then we
3288 * read in all of the chunk items. This way we can create chunk
3289 * mappings that reference all of the devices that are afound
3290 */
3291 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
3292 key.offset = 0;
3293 key.type = 0;
3294 again:
3295 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3296 while (1) {
3297 leaf = path->nodes[0];
3298 slot = path->slots[0];
3299 if (slot >= btrfs_header_nritems(leaf)) {
3300 ret = btrfs_next_leaf(root, path);
3301 if (ret == 0)
3302 continue;
3303 if (ret < 0)
3304 goto error;
3305 break;
3306 }
3307 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3308 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
3309 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
3310 break;
3311 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
3312 struct btrfs_dev_item *dev_item;
3313 dev_item = btrfs_item_ptr(leaf, slot,
3314 struct btrfs_dev_item);
3315 ret = read_one_dev(root, leaf, dev_item);
3316 if (ret)
3317 goto error;
3318 }
3319 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
3320 struct btrfs_chunk *chunk;
3321 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
3322 ret = read_one_chunk(root, &found_key, leaf, chunk);
3323 if (ret)
3324 goto error;
3325 }
3326 path->slots[0]++;
3327 }
3328 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
3329 key.objectid = 0;
3330 btrfs_release_path(root, path);
3331 goto again;
3332 }
3333 ret = 0;
3334 error:
3335 btrfs_free_path(path);
3336 return ret;
3337 }
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